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RCgothic
01-10-2009, 15:31
I was thinking the other evening about how big a fleet would need to be in terms of volume in order to move a planetary invasion force, and wondered if the military minded amongst warseer could help.

Imagine an invasion of a planet of similar military resources to modern day Earth. According to wikipedia, the planet has at its disposal in the region of:


20M active troops
35M reserve troops
30M paramilitary troops
90k tanks
30k military aircraft
1.3k military surface vessels.


Let's assume that these forces are of similar to Imperial technology and you can't simply bombard them from orbit. My questions are:


What size of force would be required to defeat an enemy such as that detailed above?
What additional logistical support would such a force require (such as drop ships, field hospitals, supply and distribution)?
What volume of cargo space would all of the above take up?
Finally, how many starships would be required for transport?


If we approach the questions one by one I'm sure we can get a reasonable ballpark figure. To start with, I'm sure that a successful invasion requires more forces than the defenders have. Is 150-200% reasonable?

Condottiere
01-10-2009, 15:42
To establish a beach head, you only need overwhelming local superiority, and there plenty of remote places on thi planet where you could do that.

The problem isn't in conquering a single planet - the Imperium could shovel enough resources in that direction to make it a certainty, it's if they have to garrison it, assuming they can't just kill the entire population.

Justicar Cullen
01-10-2009, 15:47
You'd also have to take in consideration the infrastructure and what system it is part of, points of interests and key resources. You could always drop some virus toxins while in orbit and wait a few weeks for it to clear up.

RCgothic
01-10-2009, 15:49
Ok, so assuming that the invading forces can achieve overwhelming local superiority at initial planetfall, thanks to their dropships, they wouldn't need massively more troops in the initial stages.

That does leave the fact that they'd still be trying to claim defended territory for the rest of the planetary campaign, and I'd think you'd need more numbers for that, to defeat the enemy in land battles, force them back to their citadels and then take those as well.

To provide air cover, you'd need in the region of 30k aircraft, more for air superiority over enemy territory.

x-esiv-4c
01-10-2009, 16:22
This is always a tricky area.
What defines an "invasion"? If you are looking to conquer and subvert the local populous then you have quite an arduous task ahead of you regardless of your own military strength. Superior firepower / air superiority isn't enough to fully squash resistance.

Clearly by using weight of numbers and surprise it would be fairly easy to establish a beach-head as already mentioned but depending on your goals of an invasion, it can become a very long and costly campaign.

Good thread.

Sai-Lauren
01-10-2009, 16:29
Hmm, interesting question, although I've a vague feeling we've had it, or something fairly like it before.

But, let's start from the basics - why are you invading?
Do you need to invade, or can you drop some troops, use them to clear a region of orbital defences and then drop genocidal ordanance?
If you just take out the leadership, will the planet fall to you without a fight?
Can you take the planet through diplomatic means?

Let's set some parameters - it's a formerly imperial world, that's been invaded by Orks, and the planetary defence grid is fully operational, along with a Cruiser-led battlegroup and some system defence boats based in system.

Firstly, you'd need to attain orbital superiority - you're looking at sending in enough warships to drive off their ships and be able to defend a convoy route. We'll also assume that you've got a company of marines who can be used to take orbital defence platforms and outlying installations in the system in the initial phases.

Secondly, your transports would arrive. The old Space Fleet galaxy transport could carry the equivalent of four guard regiments, but most transports supposedly can only carry one. However, you wouldn't send all the regiments at once - you'd send enough for your planned initial assault(s), plus some contingency, and then have the rest arriving throughout the campaign - the biggest overhead is that they'll be consuming supplies whilst they're waiting for deployment.

One of the transports is likely to be a command and control vessel - something that can sit in orbit and allow the general staff to run the campaign. And we'll also assume there's a titan battlegroup in transit, a Warlord, a Reaver and say three pairs of Warhounds.

What will probably happen is each regular transport will drop off it's troops, then head out of system to pick up the next regiment to bring in, whilst the Marine's and the Titan vessels will remain in orbit to pick up their charges as need be.

Supplies - you're probably looking at one supply transport per 1-2 troop transports, carrying everything from food to fuel to ammunition to clothing to the officers tea.

Then you've got to get all that down - I would imagine that the Marines would be the first to force a beachhead, supported quickly by Drop Troops and Stormtroopers from the guard, then regular guardsmen to hold the beachhead whilst the Drop Troops and Stormtroopers recover, and the Marines either recover, or get their heavy equipment dropped to go and attack their own choice of targets.

If you've attacked a space port, then you've got cargo handling gear ready and waiting - but it's likely to be heavily defended. If you've attacked elsewhere, it's likely to be more lightly defended, but dealing with the supplies coming down is going to be more difficult.
This is why the allies built the Mulberry harbours for D-Day - and the Imperium could well do something similar, although they'll almost certainly look to take a spaceport if the cost in lives is acceptable, and they'd certainly try and take one as soon as possible to give their aircraft a dirtside base.

After the beach head's secure, you're probably looking at one shuttle of supplies per shuttle of military units, and borrowing the D-Day technology again, the Imperium might have something similar in principle to the DUKW, a cargo shuttle that can land, drive to a store area, unload, then drive back to the landing field and take off again. Meantime, there'd be wounded from MASH facilities going the other way in the cargo shuttles once they've unloaded, certainly up until the time that a medical facility has been captured, and for the most seriously wounded, probably up until the end of the campaign.

For numbers, you're probably looking at equal numbers of equal strength forces, although there'd probably be additional landings and Officio Sabatorum/ Special Forces missions into enemy territory to prevent enemy forces massing on the one beachhead and keep them honest, to disable defences and allow air and or-tillery and to assassinate local leaders.

Tarian
01-10-2009, 16:40
I believe that conventional military wisdom places a 3-1 for a "successful" (i.e. acceptable losses) attack against a fortified defensive position. (Could be wrong though, been a while since I've looked at this.)

Argastes
01-10-2009, 16:49
A good military rule-of-thumb is that when you're attacking a defended position, the attacking force strength should be three to four times that of the defender; i.e. if you are attacking a dug-in platoon, the attacking force should be company-strength at least. Of course this is on a small-unit scale and doesn't hold so true at a strategic scale, but the point should be well-taken; defending forces have numerous advantages and the attacker should have superior force strength to counteract them.

So yeah, to thoroughly conquer a planet like Earth, the IG would need at least several tens of millions of troops, and probably well over a hundred million to be on the safe side, with correspondingly large numbers of armored vehicles and aircraft, as well as incredibly huge quantity of materiel and the incredibly huge logistical machine to distribute it. And in order to effectively keep order, the follow-on occupation forces would have to be similar in number.

Let's go with 150 million troops; even more would be better, but let's say 150 million for now. Fortunately, this number does include logistics/supply personnel as well as all other support and service personnel--medical, signals, intelligence, maintenance, and so forth--because it was dreamed up based on the number of military personnel on Earth you gave, and those figures also include such personnel (i.e., 20 million active duty doesn't mean 20 million combat personnel).

Projecting the actual logistical needs of a fighting unit is quite difficult. It depends on the type of unit (armored/mechanized obviously consume a lot more than leg infantry), what sort of combat they are engaged in (if any), how much artillery they include and how much they use it (artillery ammunition is heavy and, for instance, accounted for a large portion of the weight of supplies consumed by Allied units in France in WW2), and lots of other things. An EXTREMELY coarse estimate might be 100 tons per division per day, but this could swing drastically in either direction depending on circumstances. This also assumes a force that is predominantly leg infantry, mechanised/armored divisions can consume thousands of tons per day as they guzzle down fuel, and aircraft are fuel hogs too. Plus remember that, depending on how far units are operating from their logistical supply heads (in this case the landing zones/airbases where supplies are shuttled down from ships in orbit), a substantial additional tonnage of motor fuel will be required to haul those supplies to the fighting units. Around the time of the Ardennes forest offensive, it was estimated that Allied forces were burning as much gas in transportation as they were on the front (i.e. if you wanted to carry a gallon of fuel to a tank on the front, it would take another gallon of fuel for the transport truck to carry it there). This was bringing it from Cherbourg, a couple hundred miles away.

Assuming a division is 15,000 men, and sticking with the 100 tons/division/day estimate, this means our 150 million man invasion force is going to churn through a million tons of supplies per day. And this number will rise, probably quite substantially, if the invasion force includes lots of armored vehicles and aircraft. Under the (very optimistic) assumption that this force could take Earth in 6 months, you are looking at, bare minimum, a couple hundred million tons of supplies. It could easily spiral up into the billions of tons if we assume more mechanized/armored/aviation units, and/or a longer campaign.

As for how many ships would be required to transport this stuff.... I have no idea. Making that estimate would require information such as: The size of Imperial troop transports and cargo ships, their troop/cargo capacity in terms of numbers of people or mass/volume of cargo, the mean density of all the material being transported (if volume constraints matter more than mass constraints when it comes to cargo capacity), and so forth. Don't forget all the fuel and consumables that will be used by the ships themselves, and by all those heavy-lift cargo shuttles as they constantly ferry supplies down to the surface. Even if each Imperial troop transport carries a million soldiers and the supplies needed to support them for several months, though, that means a fleet of 150 vessels at a minimum. And I don't think Imperial troop transports are that huge. So we are definitely looking at a fleet of hundreds or thousands of ships. If each transport can only hold a few regiments, then we are looking at a fleet of tens of thousands of ships.

Bottom line, you can see how ridiculous it is when GW talks about planetary invasion forces in terms of IG regiments.

RCgothic
01-10-2009, 17:14
Ok, good start to the thread, particularly Argastes and Sai-Loren.

Refining the parameters:

The Imperials have absolute space control. We'll assume it has already been established, and are not threatened by anti-orbit weapons.
The world is crucial to the crusade, and cannot be bombarded from orbit.
It is a hive world, similar to Verghast, eg mostly open terrain and small settlements, with 15-20 hive cities similar to vervunhive.
These hives have curtain walls, void shields, wall defences, sprawling habs beyond the walls, and the spaceports are protected within the primary defences.
The Crusade staging area is 6 weeks warp travel away (similar to the assault on Gereon).

The Orkish strengths are:
85M orks/gretchin
90k armour units (not counting transports, eg battlewagons, looted tanks, etc)
30k combat aircraft
130 stompas/gargants (substitued for the naval vessels at a 10-1 ratio).

Let's not worry about the size of the navy transports for now, we can have a go at that later. Argastes and Tarian suppose a 3-1 advantage is required in terms of military force brought to bear to prevent unacceptable losses. That means we're looking somewhere in the region of:

250M guardsmen/support personel
270k armour units/heavy artillery pieces
90k Imperial Navy units
390 titans

Argastes
01-10-2009, 17:19
Thanks for defining your scenario clearly, lots of people can't seem to do that when asking "what if" 40K military questions. Now, what numbers are you looking for exactly? Sounds like you have already settled on the Imperial force strength... what else do you need? Logistical requirements in weight terms? The number of ships needed to transport this force (note that estimating this will require hard info about Imperial transport/cargo ship capacity)?

Also, how long do you estimate this campaign will last? That obviously makes a big difference in terms of logistical requirements.

Makiaveli
01-10-2009, 17:29
One thing to keep in mind is local vs global. For example you wouldn't need over 30K aircraft to establish air superiority in a given location as that number of planes represents the whole planet's resources in that area. I don't they can amass all of them in one spot, and even if they tried, the capability to refuel, provide maintenance etc wouldn't be available. Also if they did try that, it would leave the rest of the planet relatively undefended.


EDIT: Another thing. I think the 3-1 ratio is for attacking a defended position. So if you attacked the above world which had say 130 gargants, you would only need 3 times the number where you are attacking. Say 7 continents, so you have roughly 18-20 on a given continent. So bring 60 titans and you are covered in that area. Granted one area might have 50 and another, more sparsely populated, might only have 10, but the point holds I think.

RCgothic
01-10-2009, 17:36
I'm primarily interested in the size of fleet, and I realise this will require consensus on the size of imperial transport vessels, but it can be put off until we've decided how much cargo we need to cram into them. I'm of course interested in every stage of the campaign as well.

The length of campaign will be determined by how quickly we think the Imperial forces we've so far determined will be able to exterminate the orks defending the terrain, and I think this is what we should think about next, as it determines the number of supplies required. I think the ground war would have 3 stages, planetfall, driving back the orks, overthrowing the hives.

I imagine the navy can secure a landing site by bombarding the open terrain, as the hives are the important points. So planetfall can be achieved by dropping into this secure zone. You then need to get as many drop ships down as quickly as possible, and establish a defensive perimeter whilst setting up a marshalling ground. I can see this happening at 2-3 locations simultaneously.

Argastes
01-10-2009, 17:39
EDIT: Another thing. I think the 3-1 ratio is for attacking a defended position. So if you attacked the above world which had say 130 gargants, you would only need 3 times the number where you are attacking. Say 7 continents, so you have roughly 18-20 on a given continent. So bring 60 titans and you are covered in that area. Granted one area might have 50 and another, more sparsely populated, might only have 10, but the point holds I think.

This assumes that you can move forces to concentrate them while the enemy can't, which may not be the case. It also assumes your Titans will suffer no, or very little, losses as they go from continent to continent knocking out those 20-strong Gargant mobs, which is also probably not going to be the case. By the time your titan force gets to the last continent, it will probably not have it's full 60 titans anymore, and thus won't be able to bring the desired 3-to-1 superiority to bear.

But I do agree that you wouldn't necessarily need a 3-to-1 numerical superiority for the entire invasion force. As I said in my long post, the 3-to-1/4-to-1 rule is for small unit engagements, it doesn't hold as true on the strategic scale.

EDIT:


I imagine the navy can secure a landing site by bombarding the open terrain, as the hives are the important points. So planetfall can be achieved by dropping into this secure zone. You then need to get as many drop ships down as quickly as possible, and establish a defensive perimeter whilst setting up a marshalling ground. I can see this happening at 2-3 locations simultaneously.

Bear in mind that if this is a planet-wide campaign, you will need to continue to establish more and more landing zones as the front expands, to avoid developing excessively long logistical trains. Fighting units should always be, at most, within a couple hundred miles of their supply head. You don't want your log weenies having to convoy across thousands of miles to get supplies to the front. Expect to need to establish dozens, or probably hundreds, of landing zones for supply shuttles as the campaign carries on. The engineers will be busy, that's for sure.

As for the logistical requirements in weight terms, I'll try to address that in a bit more detail later, and expand on my earlier rough estimate of 100 tons per division (15,000 men) per day. I have to warn you, though, the number is probably only going to increase with all those titans and tanks and aircraft! As I said, 100 tons/division/day is for a force that's almost entirely leg infantry. Your total force is also substantially larger than the 150 million men I initially estimated. Expect your total force to consuming at least several million tons per day.

Ivan Stupidor
01-10-2009, 17:54
Don't forget that "complete orbital supremacy" means that you have artillery that cannot be neutralized, and Imperial orbital strikes can be called down with an accuracy of a few metres and can be set anywhere from "wreck that building" to "wreck that continent". Don't underestimate its value as a force multiplier - a single squad of Storm Troopers with an orbital uplink could destroy an entire enemy army, and a single destroyer tasked with scan and destroy could make every Gargant in a hemisphere a crater in short order.

Col. Tartleton
01-10-2009, 18:16
I had a very long opinion written but thanks to my internet connection (laptops are stupid stupid stupid things) it no longer exists.

As a result here is my rough estimate.

There are 800 million humans at point of invasion.
The orks kill or scatter half of them.
400 million humans are in labor camps.
10 million orks are tied up in overseeing the labor.
10 million orks died in the initial fight against the PDF.
The 20 hives are being pulled down by orks and slaves to build starships.

Due to the orkish mentality success can only be found in a genocide against them.

Unmolested every very few years the number of orks will multiply by a factor of ten.

Thus we must destroy them now.

We have to decide on how effective an ork is compared to a human fighter and scale the needs of the operation from there. An ork is not a human, so 1:1 assumptions are not necessarily true.

RCgothic
01-10-2009, 19:50
Sounds like what the orks would be doing. I'd expect that as they pulled down the hives they'd keep the defences relatively intact. They'd still have curtain walls and void shields. The starship construction sites would be protected by the orkish equivalent.

I think we should also assume that the orks have a particularly cunning warboss, who won't just march all his boyz into superior numbers and firepower, and will strategise in effictive (if also orky) ways.

Urath
01-10-2009, 19:57
Perhaps organise a strike force of Space Marines to spearhead a beach head assault, followed up by landing Imperial Guard and Mechanicus support to fortofy the area and expand from there, with attached Astartes acting as a strike force.

Sorry, a bit vague and not particularly descriptive, but my internet has been dangerously weak tonight so I don't want to suffer "a Tartleton".

Sekhmet
01-10-2009, 20:41
I was thinking the other evening about how big a fleet would need to be in terms of volume in order to move a planetary invasion force, and wondered if the military minded amongst warseer could help.

Imagine an invasion of a planet of similar military resources to modern day Earth. According to wikipedia, the planet has at its disposal in the region of:


20M active troops
35M reserve troops
30M paramilitary troops
90k tanks
30k military aircraft
1.3k military surface vessels.


Let's assume that these forces are of similar to Imperial technology and you can't simply bombard them from orbit. My questions are:


What size of force would be required to defeat an enemy such as that detailed above?
What additional logistical support would such a force require (such as drop ships, field hospitals, supply and distribution)?
What volume of cargo space would all of the above take up?
Finally, how many starships would be required for transport?


If we approach the questions one by one I'm sure we can get a reasonable ballpark figure. To start with, I'm sure that a successful invasion requires more forces than the defenders have. Is 150-200% reasonable?
I'm just curious as to why you can't bomb them from orbit? That's really the best option... In the fluff, orbital strikes provide strategic attack capabilities without any consequences if the target planet doesn't have extremely hardened anti-high-orbit weapons. If there's no anti-ship defenses whatsoever and you have complete aerospace superiority, large formations in open ground are suicidal for the defender. Thus all fighting will take place in close quarters around strategic locations deemed vital to at least the attacker.

If the location is vital and disallows ordnance to be used against it, that would remove the possibility of orbital strikes, air strikes, and even artillery.

But what kind of strategic locations are we talking about? An entire hive is not vital to your mission. You do not care about every single little apartment or courtyard or even city block (or whatever they're called in a hive).



So from my limited experience as an air force officer and avid reader of 40k fluff, here's what I would do, assuming rough generalizations like they have a void shield around the hive similar to Hoth's in ESB, portions of the hive contain vital components to the war effort such as grain stores, factories, weapons and ammunition caches, maybe a few religious locations that are irreplaceable, and even just the people of the hive. Oh, and the enemy is Orks.

First objective is to remove the void shield. Depending on the shield and its location/dependencies, it can be done in different ways. A sustained bombardment might take it down in some cases. You may be able to disrupt/disable/remove the power source of the shield, or the emitters, or controls, or just wait until they fail due to lack of maintenance. In any case, you'd need marines or storm troopers to do this. Why? Because you want to do it quickly and without much attention, you want to avoid a large battle of attrition against the Orks if possible, because you'll probably lose.

After the void shield is down, it's game over really. Virus bomb the local area to preserve your materiel. If you really need the food, you'll probably have problems, since you're wasting a lot of food just to sustain your forces for a siege or protracted engagement against an enemy that essentially photosynthesizes its nutrition. But assuming you want the human captives/resistance alive too for some un-Imperial reason, you still need the shield down, but you have a problem now.

Going back to the original scenario but assuming the above and against an intelligent rather than stupid (orky) opponent, they'll probably do what the VC and NVA did: fight a guerilla campaign by using dense cover to stay near your troops without them knowing to prevent your effective utilization of aerospace assets, or staying near your vital objectives if they know what they are. Imagine if you had to fight off a planet-wide insurgency utilizing guerilla tactics rather than conventional ones. If the insurgents are highly motivated, such as many people are when their homes are invaded, and if the invaders are somehow militarily hindered from using their advantages (for example, Iraq), it may take decades or even centuries before the planet is remotely close to being considered safe for non-military personnel.

Basically if we remove orbital bombardment from the situation and you establish a beachhead, it's not like all the world's armies are going to meet up and engage your forces at the insertion point. Even if they were under a single government rather than a multitude of governments, some of the most successful campaigns were waged when the enemy was allowed into the defender's territory. For example, see anything involving Russians.

And finally, we're talking about a three dimensional battlefield. Conventional warfare pre-WW2 was all about ground forces, maneuvering in a 2-dimensional plane and establishing logistics in that same 2-dimensional plane. Post-WW2, many battlefields no longer have what you'd call "battle lines". Aircraft can pass over lines with ease and provide support, intel, and resupply. The idea of establishing a beachhead from orbit is necessary, but at the same time, ridiculous. Your resupply has to come from space until you can move out far enough to live off the land. That generally means a slower resupply rate and an extremely vulnerable one too. Unless we're assuming no anti-aircraft capabilities.

tl;dr:
- No orbital support is silly
- Assuming no orbital support, a guerilla campaign would make it almost impossible to take the planet, or at least draw it out so long that the crusade commander decides the planet is taking up more resources than it's worth and withdraws forces
- See Russians for ridiculous tactics, such as burning their own farms and abandoning their cities to beat Napoleon
- See the NVA and VC vs the USA for guerilla tactics and strategies, and how a tiny army with every disadvantage beat a superpower
- Remember logistics
- Remember that you've essentially flanked yourself if you drop in ground forces

Conclusion: If I didn't have aerospace support, I'd be extremely hesitant to invade a planet considering the sheer scale of it. You would have to weigh your losses of men, material and time vs what you gain if you are successful. And if you invade every planet like this, your crusade of 600 million men will be ground down by a defending force of 100 million. There would have to be an extremely good reason to set down forces on the planet, almost to the point of ridiculousness. A better strategy is to isolate them and move on with the crusade, as done in Gulf War 2. If you encounter heavy resistance, isolate the area with minimum forces and move on, then come back later after they're worn out to finish the job.

This is all theoretical of course and I don't have much/any experience beyond theory in ground warfare.

Argastes
01-10-2009, 21:18
Okay I'll try to do some very rough estimating of logistical requirements. Starting from this:


250M guardsmen/support personel
270k armour units/heavy artillery pieces
90k Imperial Navy units
390 titans

I'll be calculating using the division as the basic unit, even though the IG doesn't really seem to use divisions in the same way modern militaries do. So in personnel terms, we basically have the rough equivalent of about 16,000 infantry divisions (I realize that in practice, an infantry division can range from under 10,000 to over 20,000, but we'll use 15,000 as a representative figure). Again, based on historical precedent (mostly from WW2), an infantry division is going to eat up anywhere from 50 to 100 tons of supplies per day, perhaps going as high as 200 tons per day if they're seeing a lot of action. This is food, ammunition, replacement equipment, medical supplies, fuel and spare parts for such transport vehicles as they may have (even an infantry division has a good number of trucks, etc. in the CSS elements), and assorted other sundries. Again, let's use 100 tons per day as our figure, since it seems like a good mean. In modern terms, this is about ten HEMTT loads per day. So our 250,000,000 personnel are going to need 1.6 million tons of supplies per day. I realize that a large portion of these personnel are going to be non-combat support and service personnel, and thus won't require ammunition and other combat equipment, but at the same time the support/service units will require a lot of materiel that doesn't go to combat units, so I think it works out okay. Again, bear in mind that these are very rough estimates and could be varied a lot while still staying within the bounds of reason.

Next, 270,000 tanks and heavy artillery pieces. Yikes. This is going to add up to a lot. Whereas an infantry division might consume at most a few hundred tons of supplies per day of operations, a modern armored division can easily consume thousands (note that WW2 era tank divisions consumed far less per day; the logistical demands of mechanized warfare have increased drastically over the past 60 years). I have a book about Desert Storm which states that a US mechanized infantry division ca. 1991 consumed about 2700 tons of supplies per day when on the offensive. A true armored division will have more tanks and will thus consume even more; I have seen estimates as high as 11,000 tons per day! This would be a division equipped with Abrams tanks though, which are admittedly more fuel-hungry than similarly sized tanks with conventional engines. I'll go with a middle-of-the-road estimate of 5,000 tons per division per day when on the offensive, but obviously it would be silly to base our figures on the assumption that every unit is engaged in offensive operations every day for the duration of the campaign, so let's go with a mean figure of, say, 1,000 tons per day over the course of the campaign (an armored division's consumption can drop to a couple hundred tons per day or even less when it's not on the move). By the way, a "division" here means about 500 vehicles, similar to what's present in a modern US heavy division, because that's the formation that I'm using to base these supply requirement estimates on. I realize I'm guilty of lumping artillery in with tanks here, but while tanks require more fuel, artillery generally requires more ammo in terms of tonnage, so again, hopefully it will work out. This means the tanks and artillery of the invasion force will require, on average over the course of the campaign, another 540,000 tons of supplies per day. This brings us to a total of a bit over 2.1 million tons per day.

I'm not sure what you mean by "Imperial Navy units" (aviation?), so I'll leave that alone for now, but if you explain what you mean I can add them in later.

That brings us to Titans. In terms of it's logistical requirements, I'm going to tentatively estimate that a Titan is, ON AVERAGE, equivalent to a modern tank battalion (~20 vehicles). Obviously different classes of titans will have different individual requirements (a Warhound probably requires no more than a couple tanks would while an Imperator might suck up as much supplies as a whole armored regiment), but let's use 1 titan = 20 tanks as an average. This means our 390 titans equal roughly another fifteen divisions of armor/arty and such down another 15,000 tons per day... again, averaged over the duration of the campaign. This is pretty insignificant in comparison to the 250 million men and 270,000 tanks/guns of the invasion force, so our total is about 2.15 million tons per day for the entire invasion force.

Again, this number could be adjusted up or down a good deal without becoming unreasonable. You could go as low as a million tons per day or as high as several million tons per day, depending on all sorts of variables. But I think about two million tons per day is a good estimate based on the force composition you have given.

RCgothic
01-10-2009, 21:53
By Imperial Navy units I mean:

Squadrons of Lightnings and Thunderbolts attempting to gain air superiority.
Squadrons of Marauder Bombers on both tactical bombing runs and strategic carpet bombing.
Squadrons of Vulture, Valkyrie and Destrier providing close air support and supply runs.
Call it maybe a 2:1:1 split respectively.

The reason I'm trying to eliminate orbital support from the orks is that I'm not currently concerned about how much of the IN would need to be warships. I'm also not allowing orbital bombardments because I'm interested in the ground campaign.

Say that the IN has established an orbital exclusion zone, but is totally occupied with maintaining the security of the transports in orbit against ongoing counter attack, and have no ships to spare for bombardment duty.

Col. Tartleton
01-10-2009, 23:23
We have to remember that orks by their nature are going to outsmart us all of the time. We can catch them off guard, but they'll quickly counter most of our attempts thanks to their inherent orkish mentality.

If we attack them from the air they'll build anti aircraft weapons, then they'll shoot down our planes reverse engineer them and build fighta bomba squadrons to shoot down our planes. There's a lot of countermeasures the orks will place on us. Orks are smarter then humans, (yes, really) so we'd be screwed unless we have overwhelming force constistently. We have to remember that orks are designed to fight, so we can't just invent a strategy and run with it, they'll counter it. We're going to need several strategies and use them simultaneously.

BTW I don't know how much longer I'll be able to post on Warseer. Apparently T Tauri is probably about to ban me... which is almost my own fault but still. Just thought I'd share that if I fall off the grid it's probably the reason. Forum rules are unconstitutional. :rolleyes:)

Argastes
02-10-2009, 00:15
BTW I don't know how much longer I'll be able to post on Warseer. Apparently T Tauri is probably about to ban me... which is almost my own fault but still. Just thought I'd share that if I fall off the grid it's probably the reason. Forum rules are unconstitutional. :rolleyes:)

:confused: Have you been making a bunch of really crappy posts in parts of the forums that I don't read or something? I've never seen anything problematic with your posting...

HK-47
02-10-2009, 00:28
This is a lot of info to go through, but going by what I read I say that if you ca get away with destroying enemy strongholds and large population centers from orbit then the Navy would most certainly do it. I'm not talking about Exterminatus, but things like the fire bombing of Dresden, and the Atomic bombings of Hiroshima and Nagasaki. Local release of WMDs to disable the enemy infrastructure and soften up targets for land assault.

I'm not that good at numbers but generally I say that any large offensives, the kind designed to take whole continents, should be no smaller then the Nazi invasion of the Soviet Union. Which should be about 3 million strong. Remember I'm not that good at number so I my be overestimating.

Col. Tartleton
02-10-2009, 01:39
:confused: Have you been making a bunch of really crappy posts in parts of the forums that I don't read or something? I've never seen anything problematic with your posting...

No, my last warning was for calling out a subtle pedophile joke about the dark angels and then compared them to illuminati free masons. Apparently pointing out something innapropriate is innapropriate. Apparently religion and politics are off limits in a forum for a game about totalitarian governments, military oppression, conspiracy, and fanatically corrupt religions...

This is worse than getting like fifteen warning points for using a slang word for German on a British person who was being a bit of a smart alec about the proper usage of British vs. English. (It's the second half of Sauerkraut) Somehow it's a racial slur (didn't know that). I also jokingly advocated IP theft in that series of posts, but that wasn't mentioned as being a problem...

This 25 point system is silly. This is a forum. 90% of the posts are trolling or spam. We need to accept that. We can't ban people for sharing our opinions. It's a forum, a market place for ideas...

I'm at 17 and I can honestly say only 2 of those warning make any sense. This is like the time I got a warning on Bolter and Chainsword for bad language (I think I used in universe curses like "Feth" and "Frakk" to edit my dismay. The Mod in that case had a log called "Legion of the Darned", so I felt like he may be biased in terms of language. I chewed him out for it though.

I feel like I may get in trouble for discussing this stuff (just because the game's about dictatorships and killing insubordinate people doesn't mean you should in real life) though, so it's in spoilers.

So... On topic, how many guardsmen would it take to kill ten defending orks in built up terrain like a city?

Makiaveli
02-10-2009, 03:17
This assumes that you can move forces to concentrate them while the enemy can't, which may not be the case. It also assumes your Titans will suffer no, or very little, losses as they go from continent to continent knocking out those 20-strong Gargant mobs, which is also probably not going to be the case. By the time your titan force gets to the last continent, it will probably not have it's full 60 titans anymore, and thus won't be able to bring the desired 3-to-1 superiority to bear.

But I do agree that you wouldn't necessarily need a 3-to-1 numerical superiority for the entire invasion force. As I said in my long post, the 3-to-1/4-to-1 rule is for small unit engagements, it doesn't hold as true on the strategic scale.



Granted, I thought about losses after I posted. And we are on the same page now :)

Marshal2Crusaders
02-10-2009, 05:02
I was thinking the other evening about how big a fleet would need to be in terms of volume in order to move a planetary invasion force, and wondered if the military minded amongst warseer could help.

Imagine an invasion of a planet of similar military resources to modern day Earth. According to wikipedia, the planet has at its disposal in the region of:


20M active troops
35M reserve troops
30M paramilitary troops
90k tanks
30k military aircraft
1.3k military surface vessels.


Let's assume that these forces are of similar to Imperial technology and you can't simply bombard them from orbit. My questions are:


What size of force would be required to defeat an enemy such as that detailed above?
What additional logistical support would such a force require (such as drop ships, field hospitals, supply and distribution)?
What volume of cargo space would all of the above take up?
Finally, how many starships would be required for transport?


If we approach the questions one by one I'm sure we can get a reasonable ballpark figure. To start with, I'm sure that a successful invasion requires more forces than the defenders have. Is 150-200% reasonable?

All you need is one company of Space Marines. Don't ask, just accept it.

Firaxin
02-10-2009, 05:31
Ok, I can see some serious flaws in the numbers being thrown around here.


The Orkish strengths are:
85M orks/gretchin
90k armour units (not counting transports, eg battlewagons, looted tanks, etc)
30k combat aircraft
130 stompas/gargants (substitued for the naval vessels at a 10-1 ratio).

Let's not worry about the size of the navy transports for now, we can have a go at that later. Argastes and Tarian suppose a 3-1 advantage is required in terms of military force brought to bear to prevent unacceptable losses. That means we're looking somewhere in the region of:

250M guardsmen/support personel
270k armour units/heavy artillery pieces
90k Imperial Navy units
390 titans
First of all, the 3:1 ratio assumes all else is equal. You wouldn't require 3,000 men with automatic weapons and grenades to capture a medieval fortress defended by medieval peasants with swords and halberds.

So how do the Imperial units compare?
--When it comes to Main Battle Tanks, Guard have the Orks truly beat. I'd guess 12 Ork tanks for every 1 Russ would be an even match.
--1 Imperial Titan can match 2 Ork Gargants.
--Navy aircraft are more maneuverable, faster, carry stronger weaponry, and are more accurate. 3 Ork fighta-bombas for every Navy plane, at least.

Infantry? That's harder. Going on resilience alone, you'd probably need a lot more guardsmen than Orks. It'll take a fair few lasgun shots to put an ork down, but the huge bolts Orks fire will take a human out pretty reliably in one shot. Likewise, if Orks get into CC, they'll simply own. The only thing the Guard have going for them is their accuracy at longer ranged firefights. In an infantry war, expect to need 3-4x as many Guardsmen on an even playing field, or as many as 10x Guardsmen as Orks if the Orks are defending. Orks also present the problem of reproducing asexually and then growing to adulthood within a few years--not only does this provide the Orks with extra warriors but also with food/slaves/etc.

It's only when you add in armor, air superiority, etc, that the Guard have a chance.

Therefore, I'd estimate the following numbers (numbers which assume the Orks will be able to rebuild their losses and the Imperials will have to rely on what they bring with them):

300-400M Guardsmen/Support Personnel
20k Armored Units/Heavy Artillery
15k Aircraft
40 Titans


Again, based on historical precedent (mostly from WW2)
<snip>
2.15 million tons per day for the entire invasion force.
Second, you can't really compare 40k logistics to anything modern, let alone WW2.

--100 Tons for an Infantry division? Crates of lightweight rechargeable laspacks (each clip containing as many as 300 shots, if I recall my Uplifting Primer correctly) are far far more compact and lighter than shipping the same amount of modern 5.56 or 7.62NATO ammunition, let alone the same amount of (American) WW2's standard .30cal for the M1 Garand (even if we use the more common/conservative estimates of 60 shots/laspack).

Then you have MRE's, which again are far more lightweight and compact than WW2's canned rations.

--Armored/Artillery regiments...
Titans? Yes, there will be a lot of weight in ammunition--depending on the vehicle and its armaments. The sci-fantasy reactor of a Titan's can probably go as long without refueling as a marine's power armor or a modern nuclear-powered aircraft carrier; and in addition its energy weapons will be plugged directly into the reactor, meaning it won't require a logistical chain for its ammunition. This is one of the reasons Warhound Titans are effective at being lone wolves/scouts.

Tanks? Well, again, vehicles with energy weapons such as the LR Annihilator, Executioner, and the Destroyer Tank Hunter (not to mention the hull-mounted lascannon on other Russ variants) are plugged directly into the vehicle's engine, eliminating the need to carry ammunition for those. With regards to fuel... the Leman Russ is supposed to be able to run on grass clippings if it needs to. Petroleum/whatever 40k uses (which could easily be more efficient than modern fuel) would be the most efficient, obviously, but the Russ can run on anything combustible, from coal to wood to carcasses to feces.

On top of these logistical advantages, it's fun to note that the AdMech (who, being there with the titans, will largely cover most of the logistics) can and will recycle corpses to create everything from servitors (including combat servitors) to food.


@ Tartleton: That sucks, good luck man.

Argastes
02-10-2009, 06:38
Ok, I can see some serious flaws in the numbers being thrown around here.

Therefore, I'd estimate the following numbers (numbers which assume the Orks will be able to rebuild their losses and the Imperials will have to rely on what they bring with them):

300-400M Guardsmen/Support Personnel
20k Armored Units/Heavy Artillery

You know that this means less than one tank--one single solitary tank--per infantry division, right? Actually it means less than one tank OR one artillery piece per division, not both. The troops landing on this planet will be told: "Right lads, for every 20,000 of you, you'll get one tank or one Basilisk, but not one of each--don't be greedy!" That's pretty absurd. At that point, frankly you might as well not bring any tanks or artillery at all. In comparison to the scale of the campaign, the armor/artillery assets you propose are insignificant.

Tanks are for more than just dueling enemy tanks, you know. They are versatile machines. Even if the enemy has no tanks at all, there will be plenty for your own tanks to do. Raiding, reconnaissance, breakthrough exploitation, direct fire support for the infantry against targets such as enemy infantry, strongpoints, etc., the list goes on. And as for artillery, I have absolutely no idea why you use the inferiority of Ork vehicles an excuse to slash the invasion force's artillery assets to such meager levels--killing tanks isn't even one of artillery's main jobs. Every division should have at the very least an organic artillery battalion, which means a bare minimum of about 150,000 guns for the 300-400 million man force you call for. And more--a lot more--would really be better (modern US heavy divisions have three organic M109 battalions and one organic MLRS battalion, plus there are arty assets at the corps and higher level as well). I find it hard to understand why anyone wouldn't want artillery when fighting orks....


Second, you can't really compare 40k logistics to anything modern, let alone WW2.

--100 Tons for an Infantry division? Crates of lightweight rechargeable laspacks (each clip containing as many as 300 shots, if I recall my Uplifting Primer correctly) are far far more compact and lighter than shipping the same amount of modern 5.56 or 7.62NATO ammunition, let alone the same amount of (American) WW2's standard .30cal for the M1 Garand (even if we use the more common/conservative estimates of 60 shots/laspack).

Then you have MRE's, which again are far more lightweight and compact than WW2's canned rations.

I don't know why you say "let alone WW2", because logistical requirements have only grown since then; if I had based my estimates off of a modern infantry division, the figure probably would have been higher.

But as I said my numbers are rough estimates and I have already stated that you can get away with varying them a lot. If you feel that many Imperial items are substantially lighter than their modern equivalents, that's fine, adjust the number downwards--say only 50 tons a day, or whatever. I have a book that states that a Japanese infantry division (16,000 men) in Manchuria in 1944 consumed about 60 tons per day, and bear in mind that this was on what amounted to fairly peaceful garrison duty, so they wouldn't have been using up much ammunition at all, nor would they have been receiving a lot of canned rations (mostly bulk stuff like big bags of rice). So I wouldn't go much below about 50 tons/day; for a division engaging in combat, that's probably lowballing it even with lighter ammo and rations.


Titans? Yes, there will be a lot of weight in ammunition--depending on the vehicle and its armaments. The sci-fantasy reactor of a Titan's can probably go as long without refueling as a marine's power armor or a modern nuclear-powered aircraft carrier; and in addition its energy weapons will be plugged directly into the reactor, meaning it won't require a logistical chain for its ammunition. This is one of the reasons Warhound Titans are effective at being lone wolves/scouts.

Thats fine, we can cut out Titans from my estimate, they added an insignificant amount of logistical demand anyhow.


Tanks? Well, again, vehicles with energy weapons such as the LR Annihilator, Executioner, and the Destroyer Tank Hunter (not to mention the hull-mounted lascannon on other Russ variants) are plugged directly into the vehicle's engine, eliminating the need to carry ammunition for those. With regards to fuel... the Leman Russ is supposed to be able to run on grass clippings if it needs to. Petroleum/whatever 40k uses (which could easily be more efficient than modern fuel) would be the most efficient, obviously, but the Russ can run on anything combustible, from coal to wood to carcasses to feces.

Aren't Annihilators, Executioners, Destroyer Tank Hunters, etc., all quite rare? Seems to that the overwhelming majority of the tanks used are going to be vanilla Russes, with their big ol' shell-firing battlecannons.

As for fuel, they may be theoretically capable of running on that stuff, but good luck keeping thousands upon thousands of tanks running through the course of a campaign with grass clippings, wood, coal, carcasses, and feces. They will need a reliable fuel source--which means fuel delivered through the supply chain, and lots of it--or they aren't going to be much use to anyone. I can't imagine what a nightmare it would be to try to coordinate combined arms action when your tanks are dependent on the ability of their crews to constantly scrounge up large quantities of biodegradable refuse to use as fuel. And even if they are consistently able to do so, how much of their time is it going to take up? For every day your tanks are able to fight, they'll have to spend two days sitting idle while their crews gather up big heaps of sticks and leaves and **** like that. I can hear the armored division commander now: "My tanks aren't ready yet sir, but they should be within the next couple days; the men only need to gather up another two thousand tons of grass clippings and dead bodies to get the division fully refueled!" Kind of makes resupply a hassle in the desert, too.

On the other hand, the possibility that Imperial motor fuel is more energetic than modern diesel/gasoline, and thus that the tanks get better mileage, is a reasonable one; so again, since my numbers are only rough estimates that could easily be adjusted up or down by quite a bit if anyone is so inclined, you could certainly assume a lower average supply consumption rate than the one I gave for armored units. Although frankly, since my estimate was 1,000 tons per division per day, when a modern US Army mechanized division can go through more than 10,000 tons per day when advancing, I think I was already being pretty lenient.


On top of these logistical advantages, it's fun to note that the AdMech (who, being there with the titans, will largely cover most of the logistics) can and will recycle corpses to create everything from servitors (including combat servitors) to food.

Why would they cover the Guard's logistics? I'm sure they'd handle the logistical needs of their own units (the titans and so forth), but what makes you think they'd take over the Guard's CSS elements? I've never seen anything in the fluff to suggest that they do this. Guard units seem to have their own log/supply/transport assets. If anything, having an entirely different service (or whatever you want to call it...) handling the logistical support of Guard units would complicate things no end.

EDIT: Just to clarify how silly it is to expect to actually be able to use wood, plant matter, etc. as fuel for large numbers of Leman Russ tanks: Modern MBTs usually have fuel tanks that hold 400-500 gallons of fuel, and a gallon of diesel weighs a bit over 7 pounds, so a full fuel load for a modern tank is usually going to weigh somewhere between 1.5 and 2 tons. This usually gives an operational range of anywhere between 250-400 miles, depending on what kind of mileage the tank in question gets. And petroleum fuels like gasoline and diesel are FAR more energetic on a per-weight basis than the other stuff that Leman Russ engines can supposedly burn; gasoline has an energy density of 46 megajoules per kilogram and diesel is similar, but coal ranges from 15-30 MJ/kg, dung and peat are around 12-15, and wood is a measly six. Grass clippings and leaf litter would presumably be in the same region as wood or peat. Imagine a four-man tank crew having to gather up a two-ton pile of wood, grass, etc. for every 50 miles their tank travels. Tanks are going to be nearly useless under that sort of operational constraint. By contrast, if they use normal liquid motor fuel, they just have to pull up next to a tanker truck, hook up the refueling hoses, wait ten minutes, and they're gassed up with enough fuel to travel a few hundred miles. So again, if tanks are to be used with any kind of effectiveness, the logistical system will have to supply them with fuel in the same way it supplies them with ammo, spare parts, and so forth. So the logistical demands of IG tank units are going to be heavy for the same reasons that the logistical demands of modern tank units are heavy: Tanks need lots of fuel.

Sai-Lauren
02-10-2009, 08:50
Ok, good start to the thread, particularly Argastes and Sai-Loren.

Sai-Lauren :D

Thanks though.



But I do agree that you wouldn't necessarily need a 3-to-1 numerical superiority for the entire invasion force. As I said in my long post, the 3-to-1/4-to-1 rule is for small unit engagements, it doesn't hold as true on the strategic scale.

Agree here, it could even be an advantage to set a fortified area and "allow" the orks to attack it, making them waste their strength there and freeing up troops to attack into weaker areas.

There's also the possibility of resistance cells, SF types could be sent deep into enemy territory to support, train or even set them up, destroying or delaying supplies and reinforcements and diverting troops from the front lines to try and protect them. And if you can kill the Warlord, you might be able to get them fighting amongst themselves, and take advantage of the confusion.

Plus any local PDFs or militias that could be formed from the civilian population would be pressed into service, if only for their local knowledge.



Bear in mind that if this is a planet-wide campaign, you will need to continue to establish more and more landing zones as the front expands, to avoid developing excessively long logistical trains. Fighting units should always be, at most, within a couple hundred miles of their supply head. You don't want your log weenies having to convoy across thousands of miles to get supplies to the front. Expect to need to establish dozens, or probably hundreds, of landing zones for supply shuttles as the campaign carries on. The engineers will be busy, that's for sure.

Agreed, agreed, agreed and agreed :)

The Italy, Normandy and Southern France campaigns are a good reference - the landings themselves were on beaches, but a high priority in the immediate aftermath was to push on and take a port. The Mulberry piers in Normandy were really a stop gap until then, and if they'd been attacked, the whole campaign would have eventually ground to a halt - which it virtually did late in 1944 anyway, mainly because the supply lines had become too long.

You can also look at the Ardennes campaign and what turned into the Dunkirk evacuation, where the ports were the main target (successfully in the latter) to deny supplies and evacuation. Plus the attacks on the supply convoys by fighter-bombers, and fighters who'd escorted bombers to targets and were basically told not to come home with any ammuniton.

I think I mentioned that in my first post though, that they would be looking to take space port facilities as they go, and they'll be taking some supplies from the planet where they can - the longer the campaign goes, the more chance they've got of being able to set up production facilities in their territory and reducing their dependance on the convoys to the system.



As for the logistical requirements in weight terms, I'll try to address that in a bit more detail later, and expand on my earlier rough estimate of 100 tons per division (15,000 men) per day. I have to warn you, though, the number is probably only going to increase with all those titans and tanks and aircraft! As I said, 100 tons/division/day is for a force that's almost entirely leg infantry. Your total force is also substantially larger than the 150 million men I initially estimated. Expect your total force to consuming at least several million tons per day.
I'd say Titans would consume less - they've no real fuel demands (fusion plant), crew supplies are minimal (although they've probably got a massive technical support crew that needs feeding :)), and their main consumables will be ammunition and repairs.

But we can probably use the Normandy supply figures as a starting point, divide the weight per day by the number of troops (and aricraft, tanks, naval fire support vessels etc) in theatre, add a factor for things like refugee relief and go from there.

The real question then becomes "how many pairs of boots do you have on the ground?" Do you try and take the whole planet at once, or do you accept the campaign will take years (like Vraks) and start off by taking a part of it, establishing supply bases and production facilities and taking the rest of the planet from there?

Longer term, it might even reach the stage where the local PDFs have reformed enough and can take the brunt of the fighting (with Guard levels of training, equipment and tactics - and they'll probably be taken for the Guard once the campaign's done ;)), meaning non-native forces (Marines, Titans, Guard, Sororitas if involved) can be scaled back to a lower level, although they'd probably still be needed for the really hard targets.

Random Integer
02-10-2009, 10:16
Isn't it the case that Imperial forces often bring production facilities with them on a campaign? Im sure there are some references to such things (though I'll be damned if I can recall the details) and it would certainly make sense given the IGs focus on minimizing logistical overhead.

RCgothic
02-10-2009, 10:25
On the case of titans, many of their weapons do use solid ammunition. The Quake Cannon fires solid rounds almost the size of battle tanks, while the Inferno Gun, Megabolter and Gatling Cannon all get through a stupendous number of rounds. Then you've got ground crews who can turn around serious battle damage in just a week or two, along with the supplies to effect those repairs. In Titanicus, several titans are mentioned as being desperately low on power at the end of their walk (of about 8 days). The orbital lift infrastructure for titans is going to dwarf that required for armoured and infantry regiments as well. In fact, probably the easiest supplies to get planetside are the aircraft of the IN, almost all of which have orbital capability and can get up or down under their own power.

Sai-Lauren
02-10-2009, 10:42
Random Integer - Maybe, but they're going to be tertiary phase deployments at best, once the Imperial lines have pushed out far enough that they're not going to be under constant threat.

Tanks rolling off the production lines and going directly into combat sounds cool, but in reality, the workers would have been dead through diliberate or accidental enemy action or have run away a long time before.

Besides which, it's not like an RTS game, you'd still need to fuel them, load the munitions and train the crew, they won't come off the production line as well.

RCgothic - Titan support infrastructure's a whole other topic (like how do you get ammunition to the carapace mounts in the field? ;))

But aircraft don't have it easy either - if they need to get back to a carrier in orbit, they need to maintain fuel levels to break out of the atmosphere and if the cockpit's damaged (even just cracked glass), the pilot may not be able to survive the trip, even if the rest of the airframe is still servicable - ideally they need ground bases (presuming the Imperium doesn't have the Valiant from Dr Who or Skybase from Captain Scarlet).

RCgothic
02-10-2009, 11:44
Of course a ground base is better, and I'm sure construction is high on the list of priorities. My point was that unlike every other unit they don't need a drop ship (and by extension crews and logistical chain for the drop ship) to get to the surface.

Ikkaan
02-10-2009, 12:34
Well, if the idea is that there is a planet equivalent of earth to be brought under imperial control, with the given numbers of defenders, the imperium wouldnīt invade.

The advantage of having such a large world, with an intact industry, government structures, infrastructure, culture, large population, standing military is....having it. You donīt need to wait ages to produce all this. It is there.

So, tactically you are not going to invade them and destroy a large part of the cake. You want most of the cake intact. This does not apply if the planet is corrupted to the core, in that case virus bombing and recolonization is in order.

So, if you want all these goodies so badly, you send cloaked dropships, chock full of Ordo Sabinus Sisters, Clerics, trained Acolytes of the Inquisition and a few assassins. Those people undermine the governments, assassinate leaders, bribe, seduce, rally, corrupt and generally undermine the existing structures until the moment comes when the population is rife to welcome their new overlords from space.

RCgothic
02-10-2009, 12:37
It is frequently mentioned in fluff that planets too vital to be bombarded are claimed by full scale invasion. The Ordo Inquisition units you mentioned are not even capable of wresting control of the planet from the Archenemy, let alone from orks.

Random Integer
02-10-2009, 14:52
Random Integer - Maybe, but they're going to be tertiary phase deployments at best, once the Imperial lines have pushed out far enough that they're not going to be under constant threat.

Tanks rolling off the production lines and going directly into combat sounds cool, but in reality, the workers would have been dead through diliberate or accidental enemy action or have run away a long time before.

Besides which, it's not like an RTS game, you'd still need to fuel them, load the munitions and train the crew, they won't come off the production line as well.


Actually I wasn't thinking of planet based installations. More like Ad Mech factory ships capable of harvesting in-system resources (such as metal rich asteroids) in order to produce staples (such as ammunition and fuel) for the invasion force.

Assuming orbital supremacy such ships would be quite safe and much more reliable a source of supply than bulk shipping over light years through a medium as inherently unreliable as the warp.

Firaxin
02-10-2009, 18:39
You know that this means less than one tank--one single solitary tank--per infantry division, right? Actually it means less than one tank OR one artillery piece per division, not both. The troops landing on this planet will be told: "Right lads, for every 20,000 of you, you'll get one tank or one Basilisk, but not one of each--don't be greedy!" That's pretty absurd. At that point, frankly you might as well not bring any tanks or artillery at all. In comparison to the scale of the campaign, the armor/artillery assets you propose are insignificant.
The vast majority of my infantry estimation will not be at the front line. Most will remain in orbit as reserves to replace combat losses, or will remain behind to defend the landing sites and supply chains between the landing sites and the front. You could get away with only 2 million combat troops at the fore, which would mean there'd be 1 tank per infantry platoon (50 guys).

Tanks/aircraft/etc, unlike infantry, can be repaired/constructed from scratch by the admech.


Tanks are for more than just dueling enemy tanks, you know. They are versatile machines. Even if the enemy has no tanks at all, there will be plenty for your own tanks to do. Raiding, reconnaissance, breakthrough exploitation, direct fire support for the infantry against targets such as enemy infantry, strongpoints, etc., the list goes on.
Which is why I estimated 20k rather than the 7.5k that my 12:1 ratio would suggest.


And as for artillery,
Somehow I totally forgot artillery, even though I wrote it in there. Double the number then:

300M Infantry
40k Tanks/Artillery
15k Aircraft
40 Titans


I don't know why you say "let alone WW2"
Referring to ammunition requirements, mainly.


Aren't Annihilators, Executioners, Destroyer Tank Hunters, etc., all quite rare? Seems to that the overwhelming majority of the tanks used are going to be vanilla Russes, with their big ol' shell-firing battlecannons.
True, but plasma cannon/multi-melta sponsons and lascannon hull weapons are not rare.

And when you have huge numbers of tanks (like 20,000), suddenly the "rare" ones that compose only 30-15% of the force become a significant number.


As for fuel, they may be theoretically capable of running on that stuff, but good luck keeping thousands upon thousands of tanks running through the course of a campaign
Obviously they wouldn't rely on grass clippings/etc, I was simply pointing out that since Russes have been known to go into combat on the stuff, their engines are somehow extremely efficient and would make very good use of very limited shipments of normal fuel.


Why would they cover the Guard's logistics?
I dunno, that's what they did in Dark Apostle. Wouldn't another service, the Imperial Navy, be doing it for them even if the AdMech weren't?

Col. Tartleton
02-10-2009, 19:55
We can't forget that we're fighting orks...

We can't wage a successful war of attrition against orks on a hive world that they've taken control of. They control the high ground, number in the millions, and worst of all will have enough supplies to last for a few years just sitting around in warehouses and stores. 80 million orks is several million per hive city. They have human slave labor working in proximity which isn't a huge deal, because we're the Imperium, but theoretically we don't want to waste human resources via friendly fire.

Now, being a planet with less than a billion people it's not particularly vital in the scheme of things (Armageddon for example was about 100 billion people if I recall.) So we can't count on more than a single marine chapter or so and a Sororitas Order taking to the field.

We can probably get 1,000 astartes and 10,000 sorors max.

Those thousand marines will be of great value, perhaps killing a hundred thousand orks if they carry out missions constantly each month. However at such a rate they'd probably lose a large amount of their forces and "burn out" and no longer have military value as a fighting force. With limited action we can preserve our marine's better, which is very important because they're more expensive then they are worth.

Sorors would likely be able to inflict 20-40,000 casualties before suffering severe losses and being unavailable.

So between those two forces we're going to be able to inflict about 140,000 orkish deaths for a month. The question is when to put them into play. Do you use them for a few days at insertion and kill 20,000 orks and then put them back into reserve in case the orks manage to cobble together a counter attack or do we give them full reign and let them burn themselves out in that month.

Regardless, these "special operations" units have a limited duration due to their style of operations (Space-heads and kill team operations) and in the scale of the campaign will have little impact against the orks. Killing the leadership will be difficult, and it will only be effective if we can severely cripple orkish strength before they can reform. Each phase of "total decapitation" will only buy us a few weeks if that. By the time we muster forces to begin with Orks will only be a year or so away from the first generation to be mature due to the time of mustering even local troops. If we're delayed for whatever reason it may be several years before we can launch our operation. By then the number or orks will be in the hundreds of millions and not only will we have trouble dealing with it, we will have a major crisis forming because they'll have a space fleet ready and be months away from spreading the waaagh.

If the orks control all twenty hives (which is quite possible) we'll have no friendly harbor for our assets and we'll have to build a staging ground in a plain region. We'll need secondary staging areas in the vicinity of each hive. We'll need tertiary staging areas near the hives where we begin our "frontline operations"

Each hive theoretically will have the following defending it:

4 million orkish infantry-
4500 armored vehicles-
1500 aircraft-
6-7 gargants-

With orks in a heavily built up urban jungle, they have a lot of advantages strategically. I'd say that the Imperium could easily lose five-ten men for each ork if the orks are on the defensive in an urban environment. Orks are very cunning and acting as guerillas it would take a large number of Imperial infantry to drive them from their holdings.

So we'd probably need the following to drive them out:
40 million infantry assets (20 million mechanized troops may be substituted)
9000 armored vehicles
2000 aircraft
10 titans

I'd say that number of troops could guarantee a victory which is necessary because the orks will only further work to make things harder.

So we'd need about 800 million infantry
180,000 armored vehicles
40,000 aircraft
200 titans

We have to apply this amount of force to guarantee a speedy victory. Marines and Sororitas will hasten this, but not stand alone as troops.

Sekhmet
02-10-2009, 20:12
We can't forget that we're fighting orks...

We can't wage a successful war of attrition against orks on a hive world that they've taken control of. They control the high ground, number in the millions, and worst of all will have enough supplies to last for a few years just sitting around in warehouses and stores. 80 million orks is several million per hive city. They have human slave labor working in proximity which isn't a huge deal, because we're the Imperium, but theoretically we don't want to waste human resources via friendly fire.

Now, being a planet with less than a billion people it's not particularly vital in the scheme of things (Armageddon for example was about 100 billion people if I recall.) So we can't count on more than a single marine chapter or so and a Sororitas Order taking to the field.

We can probably get 1,000 astartes and 10,000 sorors max.

Those thousand marines will be of great value, perhaps killing a hundred thousand orks if they carry out missions constantly each month. However at such a rate they'd probably lose a large amount of their forces and "burn out" and no longer have military value as a fighting force. With limited action we can preserve our marine's better, which is very important because they're more expensive then they are worth.

Sorors would likely be able to inflict 20-40,000 casualties before suffering severe losses and being unavailable.

So between those two forces we're going to be able to inflict about 140,000 orkish deaths for a month. The question is when to put them into play. Do you use them for a few days at insertion and kill 20,000 orks and then put them back into reserve in case the orks manage to cobble together a counter attack or do we give them full reign and let them burn themselves out in that month.

Regardless, these "special operations" units have a limited duration due to their style of operations (Space-heads and kill team operations) and in the scale of the campaign will have little impact against the orks. Killing the leadership will be difficult, and it will only be effective if we can severely cripple orkish strength before they can reform. Each phase of "total decapitation" will only buy us a few weeks if that. By the time we muster forces to begin with Orks will only be a year or so away from the first generation to be mature due to the time of mustering even local troops. If we're delayed for whatever reason it may be several years before we can launch our operation. By then the number or orks will be in the hundreds of millions and not only will we have trouble dealing with it, we will have a major crisis forming because they'll have a space fleet ready and be months away from spreading the waaagh.

If the orks control all twenty hives (which is quite possible) we'll have no friendly harbor for our assets and we'll have to build a staging ground in a plain region. We'll need secondary staging areas in the vicinity of each hive. We'll need tertiary staging areas near the hives where we begin our "frontline operations"

Each hive theoretically will have the following defending it:

4 million orkish infantry-
4500 armored vehicles-
1500 aircraft-
6-7 gargants-

With orks in a heavily built up urban jungle, they have a lot of advantages strategically. I'd say that the Imperium could easily lose five-ten men for each ork if the orks are on the defensive in an urban environment. Orks are very cunning and acting as guerillas it would take a large number of Imperial infantry to drive them from their holdings.

So we'd probably need the following to drive them out:
40 million infantry assets (20 million mechanized troops may be substituted)
9000 armored vehicles
2000 aircraft
10 titans

I'd say that number of troops could guarantee a victory which is necessary because the orks will only further work to make things harder.

So we'd need about 800 million infantry
180,000 armored vehicles
40,000 aircraft
200 titans

We have to apply this amount of force to guarantee a speedy victory. Marines and Sororitas will hasten this, but not stand alone as troops.

Are you taking into account the reproduction rate of orks?

If you only kill 140,000 orks a month, they may actually have a net gain of orks in the long run.

Argastes
02-10-2009, 20:22
The vast majority of my infantry estimation will not be at the front line. Most will remain in orbit as reserves to replace combat losses, or will remain behind to defend the landing sites and supply chains between the landing sites and the front. You could get away with only 2 million combat troops at the fore, which would mean there'd be 1 tank per infantry platoon (50 guys).

Of course the majority of the personnel will not be on the front line; historically, it has always taken several CSS personnel to keep every combat infantryman in the fight. And obviously losses will need to be replaced. But less than 1% of the total manpower on the actual front at any given time? That seems absurdly small. If you are content to only put 2 million men on the line, then you should be bringing 20 million total, not 300-400 million.


True, but plasma cannon/multi-melta sponsons and lascannon hull weapons are not rare.

Plasma cannons are supposed to be rare too.... Anyhow, I realize IG tanks have various energy weapons, but as long as the main gun is a huge shell-firing cannon, they are going to need to be supplied with lots of ammo for that cannon, and their logistical requirements (in terms of weight of supplies consumed) are thus going to be large (again, fuel is the main reason, but ammo contributes too). Each individual battlecannon shell is probably a good bit heavier than the individual rounds used by modern tank guns (APFSDS rounds are lighter than other shell types of the same caliber), which will help offset the fact that the Russes sometimes fire their hull lascannon instead of the battlecannon.


And when you have huge numbers of tanks (like 20,000), suddenly the "rare" ones that compose only 30-15% of the force become a significant number.

I think that 15-30% is too high an estimate; but even if it wasn't, it's the percentage of vehicles that don't need ammunition--not the actual number--that matters when estimating the logistical needs of armored units. No matter how large or small the number of vehicles, if 15% don't need ammo and 85% do, it affects the logistical needs in the same way (i.e. it decreases the weight of ammo consumed by each armored unit by 15%).


Obviously they wouldn't rely on grass clippings/etc, I was simply pointing out that since Russes have been known to go into combat on the stuff, their engines are somehow extremely efficient and would make very good use of very limited shipments of normal fuel.

That doesn't necessarily follow. The ability to run on grass clippings, etc., proves that their engines are extremely versatile, not extremely efficient. It doesn't tell us anything about their fuel efficiency. Multi-fuel capability is not the same as high fuel efficiency.


I dunno, that's what they did in Dark Apostle. Wouldn't another service, the Imperial Navy, be doing it for them even if the AdMech weren't?

Uhhhh no... why would any other service, whether it's the Navy or the Admech or anyone else, be handling their logistics?? I mean obviously the Navy will use it's ships to carry the stuff into the system, and use their shuttles to carry it down to the planetary surface, but from that point onwards I would think that every step in the logistical chain would be handled by IG log/supply/transport units. Do you think Navy personnel are administering the supply head dumps, organizing convoys, loading up trucks, driving them to the divisional areas, dropping the stuff off, loading it onto the divisional log tracks, and running it up to frontline units? Again, I've always though the fluff implied that IG units had their own logistical elements as part of their CSS elements. All real-life armies certainly do.

RCgothic
02-10-2009, 21:33
The Munitorum is the logistical arm of the guard, and I believe it's the largest branch of the Imperium bar none. Unless it's actually a mechanicus world, the bulk of the logistics is going to be handled through the munitorum.

Thinking about the number wikipedia initially gave for the number of vehicles, it seems incredibly low. I think that this number must mean MBTs only, and that Artillery, Mechanised and Motorised units must be included under the infantry figure.

Going back and recalculating the initial forces arrayed against us, Earth has 85M troops, and perhaps only 1/4 to 1/3 of that is actual front line grunt.

That's an equivalent fighting strength of 20-30M orks. We can assume the rest are gretchin. Supported by 100k armour units, that's 1 tank per 200 troopers, which seems more reasonable.

Justicar Cullen
02-10-2009, 22:26
Exterminatus

Argastes
02-10-2009, 22:29
I could of sworn I've seen this topic before...

I'm sure you have, it's not like each topic only ever gets discussed once and then never comes up on Warseer again. There are plenty of recurring topics that pop up every few months or so.

Firaxin
02-10-2009, 22:49
If you are content to only put 2 million men on the line, then you should be bringing 20 million total, not 300-400 million.
I expect high daily casualty rates and a multi-year campaign.

As Tartleton pointed out... you're attacking Orks in a dense, urban, jungle.


Each individual battlecannon shell is probably a good bit heavier than the individual rounds used by modern tank guns
I guess I can agree with that, especially since Russ shells are so much more massive in caliber.


I think that 15-30% is too high an estimate;
In Gunheads (one of the leading BL sources on Armored Companies, and particularly pertinent because they were invading an Ork-held world), only about 50-40% of the force were standard Russes.
50-60% of the overall force were alternate variants, but a significant number of these were solid projectile based (ie; Vanquishers, Conquerors, Exterminators, Demolishers, Punishers, etc).

There were Destroyers, Annihilators, and Executioners present, though. Maybe not 30%, but quite a few; at least 1 per Armored Company of 10, sometimes more.

Thus: 20% Energy Russes, 40% Alternate Solid-munition Russes, and 40% Standard Russes.

I don't know how ammunition weight would vary between a standard russ and say an Exterminator, but it's probably negligible.


That doesn't necessarily follow. The ability to run on grass clippings, etc., proves that their engines are extremely versatile, not extremely efficient. It doesn't tell us anything about their fuel efficiency. Multi-fuel capability is not the same as high fuel efficiency.
If they weren't more efficient, they shouldn't be combat-capable while running on those other combustibles, yet they are.


Uhhhh no... why would any other service, whether it's the Navy or the Admech or anyone else, be handling their logistics??
Because the AdMech advances with the Guard and produces everything from food to ammunition for them, in the field, through whatever mobile forge-units they've brought with them.


I've always though the fluff implied that IG units had their own logistical elements as part of their CSS elements. All real-life armies certainly do.
Of course they do, because Guard are able to operate alone if they need to. But it's easier for the Navy to stick crates of laspacks/food/etc in a drop pod and send it down a hundred meters behind the front lines than to fly the stuff down to the original landing site and drive it to the frontline from there.

It's not like the advancing AdMech units would physically carry their produce to the front lines; Guard units rotating out from the front will come back to the AdMech in order to resupply before going back in. Take the movie Black Hawk Down... there was no supply chain from the base to the combat. Troops came back to base for more ammo/water/etc.

Argastes
02-10-2009, 23:52
I expect high daily casualty rates and a multi-year campaign.

As Tartleton pointed out... you're attacking Orks in a dense, urban, jungle.

Well, I guess there is no accounting for differing casualty rate estimates... I still think a 300-400 million man invasion force that puts 2 million men on the line at once is ridiculous though. I think most people ITT would agree with me (including RCGothic, which is what matters I suppose).


If they weren't more efficient, they shouldn't be combat-capable while running on those other combustibles, yet they are.

What do you mean by "combat capable"? As I said earlier: A Russ with a fuel capacity and operational range equivalent to that of a modern MBT (~1.5 tons and 250-350 miles, respectively), assuming that it's normal fuel is as energetic as diesel and that it can burn plant matter with the same efficiency it burns it's normal fuel, could still make it about 50 miles on a fuel tank full of wood or peat. This is certainly enough to get it into, and through, a battle. Obviously it wouldn't be practical to keep the tanks fueled in this way for a long period or in large numbers or on the advance, but it would be sufficient to make the tank "combat capable" in an emergency. I'd imagine that if the logistical situation is so dire that fuel is unavailable and tank crews are stuffing leaf litter into their fuel tanks, a major advance is out of the question anyhow and the situation is probably defensive (in which tanks require much less fuel per day).


Because the AdMech advances with the Guard and produces everything from food to ammunition for them, in the field, through whatever mobile forge-units they've brought with them.

I've never heard this in the fluff, and it's laughably impractical anyhow.


Of course they do, because Guard are able to operate alone if they need to. But it's easier for the Navy to stick crates of laspacks/food/etc in a drop pod and send it down a hundred meters behind the front lines than to fly the stuff down to the original landing site and drive it to the frontline from there.

Any fluff support for the idea that the Navy is capable of doing this sort of resupply via precision-guided drop pods, especially over the long term and for millions of men? Again, bearing in mind that an infantry division is going to consume at the very least dozens of tons of supplies per day, and an armored division will consume thousands of tons per day when on the offensive? For a multi-year campaign with hundreds of millions of men, the Navy is going to need literally billions of these disposable, precision-guided supply-delivering reentry pods. Again, laughably impractical.


It's not like the advancing AdMech units would physically carry their produce to the front lines; Guard units rotating out from the front will come back to the AdMech in order to resupply before going back in. Take the movie Black Hawk Down... there was no supply chain from the base to the combat. Troops came back to base for more ammo/water/etc.

:eyebrows: Blackhawk Down deals with a small group of special operations personnel in a comparatively quite small area of operations. Let's not pretend it can be extrapolated to represent large-scale conventional, linear warfare. Realistically, it's absurd to expect a large unit to rotate out from the front every time it needs to be resupplied, because it is going to need resupply constantly. As in, every day. They will need constant delivery of supplies to the fighting elements. Units, especially mechanized/armored/artillery units, will become totally unable to keep fighting within 24 to 48 hours if they are cut off from their logistical lifeline. Do some research into the logistical realities of mass warfare. It's a lot more complicated than you make it out to be.

Makiaveli
02-10-2009, 23:55
[SPOILER]


LOL the comment about the Legion cracked me up. That really sounds like someone who needs to read a book that is a gaming one. People forget the meaning of the word. I especially love people who argue that the proper term for a female dog is a "curse" word. Umm.... so is the food you mentioned also a curse word?

That said, it is Warseer's forum and so they can run it anyway they see fit. And we can vote with our posts.

Also, so the spoiler thing is just the tag as above? Some how it never occurred to me that it was just a tag.... :rolleyes:

Makiaveli
03-10-2009, 00:02
I've never heard this in the fluff, and it's laughably impractical anyhow.



Any fluff support for the idea that the Navy is capable of doing this sort of resupply via precision-guided drop pods, especially over the long term and for millions of men? Again, bearing in mind that an infantry division is going to consume at the very least dozens of tons of supplies per day, and an armored division will consume thousands of tons per day? For a multi-year campaign with hundreds of millions of men, the Navy is going to need literally billions of these disposable, precision-guided supply-delivering reentry pods. Again, laughably impractical.




First I have read something like that before. At least the part about them recycling parts and mobile forge units. Will try to remember where.

Second, the navy is the one who will be bringing it to the world right? Or does the IG have a transport only fleet? So I think it's logical they would find a way to unload it as quickly as possible.

And I thought drop pods were recovered and reused? Also why not special cargo model drop pods? Less armor, no weapons, and designed to carry cargo not people. Could even be larger the same way military cargo planes are larger than your typical bomber. And I would imagine the supplies would be brought down in a multitude of ways. DPs would be used to resupply in the field and in emergencies. "Shuttles" could be used to deliver to bases etc.


**EDIT** Oops...meant to add that to my above post and not double post.

Argastes
03-10-2009, 00:11
Second, the navy is the one who will be bringing it to the world right? Or does the IG have a transport only fleet? So I think it's logical they would find a way to unload it as quickly as possible.

Yes, the Navy is the one operating the cargo ships that bring supplies into the system. But delivering it "quickly" isn't the issue. The most important factor is efficiency and practicality. Once the supply chain is set up and in motion, speed doesn't matter much, assuming it operates on a "push" mentality like modern military logistics (i.e., send the units what they will be needing, rather than waiting for them to put in a supply request detailing what they need). With the system set up and in motion, units will be receiving a constant stream of needed supplies no matter how long it takes a given individual crate to get from cargo ship to front line.


And I thought drop pods were recovered and reused? Also why not special cargo model drop pods? Less armor, no weapons, and designed to carry cargo not people. Could even be larger the same way military cargo planes are larger than your typical bomber. And I would imagine the supplies would be brought down in a multitude of ways. DPs would be used to resupply in the field and in emergencies. "Shuttles" could be used to deliver to bases etc.

I'm questioning whether the Navy has this capability period, even if the drop pods are reusable (and if they are reusable, now you are talking about hundreds of thousands, or possibly millions, of shuttle flights per day to recover them, as well as all the effort that will be required on the ground to round them up from front-line areas all over the planet). Do we have any fluff support for this type of resupply being used for large forces over long periods?

I'm not sure I understand the point of these drop pods. Again, they're just utterly impractical. There's a reason the real-life US military doesn't use CDS drops from cargo planes to resupply large forces; it's stupid, wasteful, and pointless.

RCgothic
03-10-2009, 00:26
I'd always thought that drop pods were recoverable, but to be honest they're pretty impractible compared to bulk-carrier dropships.

Argastes
03-10-2009, 00:31
I know SM drop pods are recoverable, but what I'm saying is that I'm dubious about whether the Imperial Navy has huge stockpiles of their own drop pods to be used for resupply of large IG ground forces.

Firaxin
03-10-2009, 00:50
Well, I guess there is no accounting for differing casualty rate estimates... I still think a 300-400 million man invasion force that puts 2 million men on the line at once is ridiculous though. I think most people ITT would agree with me (including RCGothic, which is what matters I suppose).
There's no reason they couldn't have more than one front. One front is Hive City A, with 2 million men on the immediate front line 24/7. One front is Hive City B, 200 miles to the east, with 2 million men on the immediate front line 24/7. Then you've got others to defend the vast supply/reinforcement lines between the two fronts and between the fronts and the original landing site/etc.


I've never heard this in the fluff, and it's laughably impractical anyhow.
Again; Dark Apostle, where the AdMech advances with the Guard with their mobile forges (forget the term used for them) producing ammunition, food, etc.


Any fluff support for the idea that the Navy is capable of doing this sort of resupply via precision-guided drop pods, especially over the long term and for millions of men?
They do it for the Elysians. They even have models for the crates of supplies that they drop in for them. You'd just have to scale the number of supply ships so they can do the same for a 2M Guard force.


Realistically, it's absurd to expect a large unit to rotate out from the front every time it needs to be resupplied, because it is going to need resupply constantly. As in, every day.
With 300M men and only 2M in the combat zone at any time, you could rotate in/out quite a few divisions worth of men a day and still not worry about having to resupply anyone with ammunition immediately.


shuttle flights per day to recover them,
You wouldn't even have to recover them, the AdMech navy present could mine in system asteroids/produce new ones, etc.


I'm not sure I understand the point of these drop pods. Again, they're just utterly impractical.
There isn't a point, because the AdMech is present. They'd be more of a point if the AdMech wasn't present.

Drop Pods used by the Guard are huge. They're not like the 10-man Space Marine drop pods; each IG pod can fit whole companies of Guardsmen. That's a lot of supplies per drop.


There's a reason the real-life US military doesn't use CDS drops from cargo planes to resupply large forces; it's stupid, wasteful, and pointless.
The reason real-life military units don't drop resources straight down from orbit (which wouldn't even require fuel) is mainly because the resources are already on the ground, and thus would require more resources to send into space than to ship to the front in trucks. :eyebrows:

Argastes
03-10-2009, 01:34
There's no reason they couldn't have more than one front. One front is Hive City A, with 2 million men on the immediate front line 24/7. One front is Hive City B, 200 miles to the east, with 2 million men on the immediate front line 24/7. Then you've got others to defend the vast supply/reinforcement lines between the two fronts and between the fronts and the original landing site/etc.

Okay, I thought that when you said "the front", you were referring to all fighting units on the planet. If you actually meant ~2 million mean at EACH front, then it's a bit more reasonable. Although if that's what you meant, why did you say that 20,000 tanks for the entire invasion force would be sufficient to provide a tank per platoon of 50 men?


Again; Dark Apostle, where the AdMech advances with the Guard with their mobile forges (forget the term used for them) producing ammunition, food, etc.

Well, like I said: Laughably impractical. Where do the millions of tons of raw materials come from? In a war zone? Why does this work better than producing ammo/parts/vehicles on forge worlds, and food on agri-worlds, and shipping it to the contested planet? Forge worlds and agri-worlds already have established economies that are already geared toward the production of this stuff; what's the point of trying to ship in huge mobile factories and use them to set up a whole new economy, basically from scratch, on the contested planet?


They do it for the Elysians. They even have models for the crates of supplies that they drop in for them. You'd just have to scale the number of supply ships so they can do the same for a 2M Guard force.

In real-life, they also do CDS drops for Ranger and SF units... but they aren't going to "just scale it up" to supply the US 3rd Army on the offensive, for a variety of very good reasons. And Elysian supply crates are dropped from aircraft, not from orbit.


With 300M men and only 2M in the combat zone at any time, you could rotate in/out quite a few divisions worth of men a day and still not worry about having to resupply anyone with ammunition immediately.

It's not manpower shortages that make rotating divisions in and out of the FEBA constantly problematic. It's the utter impracticality of having an arrangement where a division fights for a day, then spends a day or two leaving it's positions and getting relieved and going back to a rear-echelon area, then spends a day resupplying, then spends another day moving back to the FEBA and relieving some other division, then gets to fight for another day (or MAYBE two) before having to repeat the whole pointless musical-chairs act again. Why? What's the point? It's going to ruin the operational tempo, prohibit aggressive manuever, prohibit fast advances, and just be incredibly disruptive, overly complicated, inefficient, and wasteful. All to avoid what--having a supply chain leading from the rear areas to the FEBA? Especially when you already admit that Guard units have organic log/supply/transport CSS elements? Why? It's just a terrible, pointless idea.

Again: Your view of how the logistical side of warfare works is extremely simplistic. I recommend doing some research on this stuff before you try to make up these wild theories about rotating entire divisions through the rear area every time they need resupply (i.e. nearly every day). There are extremely good reasons that armies don't operate like that in real life. There are extremely good reasons that they bring the supplies to the fighting units instead of vice-versa.


You wouldn't even have to recover them, the AdMech navy present could mine in system asteroids/produce new ones, etc.

There isn't a point, because the AdMech is present. They'd be more of a point if the AdMech wasn't present.

So when the Admech isn't present, what's the point of drop pod resupply scheme? What advantage does it offer?


Drop Pods used by the Guard are huge. They're not like the 10-man Space Marine drop pods; each IG pod can fit whole companies of Guardsmen. That's a lot of supplies per drop.

I know about IG drop ships, i.e. large surface-to-orbit landing craft. Where are these multi-company IG drop pods coming from? And whether you use lots of small drop pods, or a smaller number of larger drop pods, the problems with the concept of a large-scale logistical system based on drop pods remain.


The reason real-life military units don't drop resources straight down from orbit (which wouldn't even require fuel) is mainly because the resources are already on the ground, and thus would require more resources to send into space than to ship to the front in trucks. :eyebrows:

Uhhh CDS drops don't come from space, they come from cargo planes (which are probably going to be used anyhow to move supplies in from out-of-theater--by your logic, instead of landing it in the theater rear areas and trucking the stuff to the front lines, why not just fly them right over the line battalions and push the pallets out the tail ramp!). :eyebrows: Did you really think I was talking about why real-life military units don't get resupplied from space???

Also, dropping objects from orbit DOES require fuel, you need fuel for a separation and de-orbit burn... if you just release an object from a ship in orbit, it will remain in the same orbit as the ship that released it. It's sad how many people think that ships in orbit are like bombers and can just "drop" things.

Obviously when the IG invades a planet, their supplies are in orbit to begin with and have to get down to the surface. That's not in question. The question is what's the best way to get them down there: Shuttling them down to supply heads from whence they will be transported via ground vehicles/aircraft to the FEBA, or dropping them directly into the FEBA via drop pods of some sort? I'm saying that the former option is more practical and efficient, and should therefore be the basis of a large force's logistical system.

Yodhrin
03-10-2009, 02:46
Hello, just popped in to throw another small spanner in the works RE Titans.

The likelyhood of a single crusade army being able to bring 200+ titans to bear on a single world is quite small. A Legio typically numbers between 16 and 50 Engines, combined with the fact that each Forgeworld typically only supports a single Legio this means you would need anywhere between four and twelve full Legios to reach those numbers. Outside of galaxy-changing engagements like Armageddon or the 1th Black Crusade, you probably won't see more than a single Legio numbering between 16 and 50 engines.

Nevermind the logistics of invading the planet, it would take years just to gather that much Titan strength in a single location.

In addition, do your troop numbers take into account Skitarii? A Titan Legio is a self-contained unit in-theatre, bringing all of it's own support elements(Knight walkers, Skitarii Centuries, landers, transports etc), so if we ignore the likelyhood of finding such a large force of Titans on one world, you would need to add/factor in approx 100,000 additional infantry(assuming a conservative number of 500 Skitarii per-Titan, I would put it at double that myself), 5-10,000 additional armoured vehicles, 10-20 Knights and all their attendant personnel and materiel.

Argastes
03-10-2009, 02:56
I think a big part of this thread is about how GW makes military units unrealistically small in comparison to the job they're supposed to do, or the scale of the wars they are supposed to be the "building block" elements in, or the economic base that's supposed to support them, or whatever. Titan Legions are as subject to this as SM chapters or IG armies. A single Forge World should be able to support hundreds or thousands of Titans, not 15 to 60.

Firaxin
03-10-2009, 05:50
why did you say that 20,000 tanks for the entire invasion force would be sufficient to provide a tank per platoon of 50 men?
Because I enjoy overexaggeration and deliberately misleading statements. :angel:


Well, like I said: Laughably impractical. Where do the millions of tons of raw materials come from? In a war zone?
I don't know, ask GW, or the author of Dark Apostle. Food is easy--they recycle dead and critically wounded soldiers/skitarri. Laspacks have a liquid metal core... of what, we don't know--maybe they can get the raw materials they need by smelting down vehicles/body armor ruined beyond practical repair (which could also be used to build more tanks/body armor/shells). Enemy vehicles/body armor/etc is all fair game, too.


It's the utter impracticality of having an arrangement where a division fights for a day, then spends a day or two leaving it's positions and getting relieved and going back to a rear-echelon area, then spends a day resupplying, then spends another day moving back to the FEBA and relieving some other division, then gets to fight for another day (or MAYBE two) before having to repeat the whole pointless musical-chairs act again. Why? What's the point? It's going to ruin the operational tempo, prohibit aggressive manuever, prohibit fast advances, and just be incredibly disruptive, overly complicated, inefficient, and wasteful.
Wonderful! That sounds exactly like something the Guard would do if they could.


Again: Your view of how the logistical side of warfare works is extremely simplistic. I recommend doing some research on this stuff before you try to make up these wild theories about rotating entire divisions through the rear area every time they need resupply (i.e. nearly every day). There are extremely good reasons that armies don't operate like that in real life. There are extremely good reasons that they bring the supplies to the fighting units instead of vice-versa.
I know they're unrealistic. 40k isn't realistic anyways. I'm trying to rationalize ways to reduce the quota of men/ships required so that the campaign for this one planet isn't larger than all the known campaigns in Imperial history combined (which as it stands, it is).


So when the Admech isn't present, what's the point of drop pod resupply scheme? What advantage does it offer?
*shrug* Uses ceramite resources instead of fuel resources... ceramite being easier to get.


I know about IG drop ships, i.e. large surface-to-orbit landing craft. Where are these multi-company IG drop pods coming from? And whether you use lots of small drop pods, or a smaller number of larger drop pods, the problems with the concept of a large-scale logistical system based on drop pods remain.
Yes, drop pods. One of the Last Chancer short stories at the beginning of the omnibus, before they're whittled down to Kill Team size. They land in company-sized drop pods. Several dudes near Kage are killed by the impact. They were fighting Eldar, IIRC.

Drop ships on the other hand, are regiment sized or larger (like the ones in the artwork unloading whole armies, or the one in Titanticus which unloads a whole Legio).


Uhhh CDS drops don't come from space, they come from cargo planes
Exactly, I was pointing out why it's less feasible than dropping stuff from space. Planes need fuel, can get intercepted, etc...


Also, dropping objects from orbit DOES require fuel, you need fuel for a separation and de-orbit burn... if you just release an object from a ship in orbit, it will remain in the same orbit as the ship that released it. It's sad how many people think that ships in orbit are like bombers and can just "drop" things.
:eyebrows: Or they can just accelerate it down a ramp, magnetically, like they do with space marine drop pods, nova cannon shells, and a slew of different weapons battery systems...

And unlike living soldiers, the nutrient-paste rations Guardsmen are supplied with don't need retro-jets to slow their decent.


The question is what's the best way to get them down there
If we really stretch it, they can just be teleported down, though that wouldn't be the most accurate or reliable form of delivery, it would be okay if you had supplies coming from out of system constantly (via the 'push' technique) and could consequently send down a percentage more than what the troops actually require.



The likelyhood of a single crusade army being able to bring 200+ titans to bear on a single world is quite small. A Legio typically numbers between 16 and 50 Engines
Making my 40 Titan estimate the most reasonable suggestion so far. A single Gargant really isn't a match for an Imperial Titan, and it's not like they're going to engage all the enemy Gargants at once.

Argastes
03-10-2009, 07:39
I don't know, ask GW, or the author of Dark Apostle. Food is easy--they recycle dead and critically wounded soldiers/skitarri. Laspacks have a liquid metal core... of what, we don't know--maybe they can get the raw materials they need by smelting down vehicles/body armor ruined beyond practical repair (which could also be used to build more tanks/body armor/shells). Enemy vehicles/body armor/etc is all fair game, too.

This is all very silly. 350 million soldiers need ~500,000 tons of food per day (350 million times three pounds per person); assuming 100% efficiency in the conversion process (which is absurd in it's own right), and assuming the average person weighs 160 pounds, this means that you would have to shovel more than SIX MILLION dead bodies (or severely wounded soldiers) into the recyclers EVERY SINGLE DAY to keep the invasion force fed. The problems are just going to escalate when you start looking at manufactured goods like ammunition, and my god, did you seriously just propose whole tanks?!

I'm sure the "mobile forge units" sounded very cool in Dark Apostle or whatever, but they just aren't workable. If RCGothic cares in the slightest about having a sensible logistical framework for this invasion he's writing his fluff about (and the fact that he started this thread suggests that he does indeed care about that), he will leave this "mobile forge" nonsense alone and have his supplies shipped in from the actual forgeworlds and agri-worlds, which exist to produce this stuff in the first place.


Wonderful! That sounds exactly like something the Guard would do if they could.

I guess I don't really hold with the idea of the Guard deliberately doing every single thing in the most retarded way possible as a matter of principle. I know some people like to think they do; I know some people like to assign every army a "shtick", and inefficiency and stupidity are what they give to they give to the IG. I know the Guard way of warfare is resource-intensive and doesn't place a high value on the lives of individual soldiers (i.e. is willing to tolerate high losses, because there's more where they came from), but it's quite a jump from there to believing that they would purposefully do everything in the most ass-backwards way imaginable just because "that's how they are". These guys ARE supposed to be able to actually win a war from time to time, you know.


I know they're unrealistic. 40k isn't realistic anyways. I'm trying to rationalize ways to reduce the quota of men/ships required so that the campaign for this one planet isn't larger than all the known campaigns in Imperial history combined (which as it stands, it is).

Firstly, don't be ridiculous; a few hundred million men and a few thousand ships is nowhere NEAR "larger than all the known campaigns in Imperial history".

Secondly, if this invasion force is disproportionately large in comparison to the "typical" force in GW fluff, then the problem is with GW fluff--not with this invasion force. We all know how incapable GW is of coming up with realistic manpower numbers for the wars/campaigns/battles they describe.... why are you trying to "rationalize" this force to match forces that are themselves irrationally small? RCGothic started this thread because he wanted the background he's writing to make sense; you're not making a helpful contribution when you come in and say "It shouldn't make sense because GW's own background doesn't make sense".


*shrug* Uses ceramite resources instead of fuel resources... ceramite being easier to get.

Is it? Sounds like you're just making that up to support your drop pod resupply scheme... Where in the fluff does it say that? If anything, I'd think that shuttle fuel (surely one of the most fundamental and important military consumables through the Imperium, just as jet fuel is today) would be easier to manufacture than what is apparently a quite sophisticated composite armor material.


Exactly, I was pointing out why it's less feasible than dropping stuff from space. Planes need fuel, can get intercepted, etc...

But the problem with this drop pod resupply scheme isn't the risk of interception or the amount of fuel it would consume. So those points of comparison are irrelevant.


:eyebrows: Or they can just accelerate it down a ramp, magnetically, like they do with space marine drop pods, nova cannon shells, and a slew of different weapons battery systems...

Ultimately, this is still going to require fuel. Ships that fire out drop pods (or nova cannon shells or reentry bombs or whatever) via this method are creating thrust, as surely as if they fired their engines. And that thrust will be nudging them into slightly different orbits. Push a drop pod in one direction, the ship goes in the other direction. It's Newtons laws, and it's how mass driver engines for spacecraft work. Obviously the ship's delta-V from firing a single drop pod will be negligible, because the ship is so much more massive than the drop pod (e.g., firing out a one-ton drop pod at 1000 m/s is only going to yield a delta-V of 0.001 m/s for a million-ton ship), but it will add up as they launch large numbers of them, and eventually the ship will have to burn rocket fuel to correct it's orbit. And if you run the numbers, you will find that--unsurprisingly--the amount of fuel the ship has to burn to correct it's orbit after magnetically launching a lot of drop pods is the same amount of fuel that would have been used if those pods had been deorbited by their own onboard rocket motors instead (assuming equal exhaust velocities for the ship engines and the pods' de-orbit motors, of course, which admittedly may not be the case). Conservation of momentum, you know.

Even if it was somehow possible to de-orbit a drop pod without burning any fuel, the fuel issue isn't the main constraint on resupply via drop pod. It's the pods themselves.

And of course, if the pods aren't disposable, you also have to burn shuttle fuel ferrying them back up to orbit. And per pound of payload, those shuttles will be burning more fuel than they would if they were being used to shuttle supplies down to the surface, because they're adding weight on the wrong leg of the trip--for obvious reasons, you burn more fuel going from the surface up to orbit than from orbit down to the surface, which is great for shuttles carrying supplies down to the surface, because they are heavier when coming down than they are when going back up. But a shuttle ferrying drop pods back up to orbit is on the wrong side of the equation; it's lighter when it's coming down, then picks up weight on the ground and is heavier when it has to climb back into orbit. Not good.


And unlike living soldiers, the nutrient-paste rations Guardsmen are supplied with don't need retro-jets to slow their decent.

Well it's going to need SOMETHING to slow it's descent; if you think that it can just hit the ground at reentry velocity and be fine because it's contents are already paste, you're in for a disappointing surprise. Objects that reenter the atmosphere from orbit and hit the ground without braking tend to leave large, smoldering craters and very small chunks of debris scattered over a wide area. Hitting the ground at those velocities (which can be as high as several miles per second) doesn't just mash the contents, it explosively vaporizes the impacting object. Parachutes might work, although for these huge drop pods you are saying the IG have, probably not; retrorockets will be needed. Otherwise those drop pods are going to make mushroom clouds when they hit the ground.


If we really stretch it, they can just be teleported down, though that wouldn't be the most accurate or reliable form of delivery, it would be okay if you had supplies coming from out of system constantly (via the 'push' technique) and could consequently send down a percentage more than what the troops actually require.

Do Imperial ships have the teleporter capabilities to be beaming down hundreds of thousands (or probably millions) of tons of stuff every single day for years on end? I don't think so. This is even sillier than the drop pods and the "mobile forges".



EDIT: You know, if your objective with all of this is to reduce the size of the invasion force because you feel it's too big in comparison to invasion forces from GW fluff, you should probably start by trying to figure out ways to reduce the actual number of soldiers involved. Your own estimate, 300-400 million, is like twice as high as the other manpower estimates that have been put forth in this thread. Reducing the number of soldiers will reduce the invasion force's logistical needs far more effectively than any of this fabulist nonsense about mobile forges, and drop pods, and teleportation, and units rotating into the rear area every time they need to be resupplied, and so forth. None of these logistical schemes you've dreamed up are going to address the fact that the force proposed in this thread is much bigger than most of the forces in GW fluff (although I don't understand why, if this fact bothers you, you yourself are the source of the highest manpower estimate).

Firaxin
03-10-2009, 10:58
This is all very silly. 350 million soldiers need ~500,000 tons of food per day (350 million times three pounds per person); assuming 100% efficiency in the conversion process (which is absurd in it's own right), and assuming the average person weighs 160 pounds, this means that you would have to shovel more than SIX MILLION dead bodies (or severely wounded soldiers) into the recyclers EVERY SINGLE DAY to keep the invasion force fed.
They use the enemy dead, too. Obviously it wouldn't be the only source of food, it would just drastically reduce the amount you need to ship in/the troops need to scavenge.


These guys ARE supposed to be able to actually win a war from time to time, you know.
I totally agree. They're my most favorite army.


Firstly, don't be ridiculous; a few hundred million men and a few thousand ships is nowhere NEAR "larger than all the known campaigns in Imperial history".
...If it isn't, it's damned close (assuming of course that the Crusade doesn't count, since that way the Army). Note that the largest concentration of ships assembled for battle ever recorded post Heresy is the 300 or so at Macragge, an entire Segmentum's fleet. And you're suggesting thousands of ships.

Armageddon? I thought the number of Guardsmen casualties there was a laughing stock. The Macharian Crusade, most successful since the Heresy, only had 22 IG regiments, which is only ~0.1 million men assuming each regiment has an average of 5,000 men. Etc.


why are you trying to "rationalize" this force to match forces that are themselves irrationally small?
Because if the Imperium is falling all over itself to organize crusades/wars even a tiny fraction of this size, I don't think it's possible for them to logistically support this thing. If they could, the Tau would have been steam-rolled a long time ago. In the context of the greater universe it just isn't possible unless they have a really good reason for taking the planet really fast... Like a Primarch('s body) has been positively identified on the surface.


Is it? Sounds like you're just making that up to support your drop pod resupply scheme... Where in the fluff does it say that? If anything, I'd think that shuttle fuel (surely one of the most fundamental and important military consumables through the Imperium, just as jet fuel is today) would be easier to manufacture than what is apparently a quite sophisticated composite armor material.
*shrug* Look at the billions of metric tons of ceramite that go into space ship hulls, aircraft, carapace armor, bunkers, tanks, etc, compared to the relatively few things that actually use fuel: certain ground vehicles and atmospheric aircraft... while the majority of transportation in the Imperium (ie, space ships) use huge plasma/nuclear/warp/sci-fantasy reactors and only need refueling once every few generations.


Ultimately, this is still going to require fuel.
As I pointed out, space ships don't really use promethium for fuel...


Well it's going to need SOMETHING to slow it's descent;
Perhaps they cheat and manipulate gravity then. They're certainly big enough to house a generator; and the Imperium is really good at manipulating gravity on large scales.


This is even sillier than
You don't need to froth at the mouth. I admitted it's silly when I said "if we really wanted to stretch it." I'm standing back, looking at this objectively and trying to prevent RCgothic from making the same kind of background mistake as saying "my regiment is the most faithful in the imperium" or "my chapter master is so good he got to meet the emperor" etc. Forces this large just don't happen. If he can acknowledge that and still wants to orchestrate a campaign this size than fine, I'm not going to/can't stop him. I understand the allure of making one's background 'cooler' than the norm.


You know, if your objective with all of this is to reduce the size of the invasion force because you feel it's too big in comparison to invasion forces from GW fluff, you should probably start by trying to figure out ways to reduce the actual number of soldiers involved. Your own estimate, 300-400 million, is like twice as high as the other manpower estimates that have been put forth in this thread.
300M is only 17% larger than the 250M number everyone else was using.

Conversely, I cut the required tanks/artillery pieces to 15% of the number everyone else was using, I cut the required aircraft to 33% the number everyone else was using, and I cut the number of titans needed to 10% of what everyone else was using (and down to a number I actually agree would be feasible, being within the limits of a single Legio).

Considering the daily tonnage consumed (that we agreed on) by an infantry division is 50-100, while the daily tonnage consumed by an armored division is 1,000-10,000, I think the net result is I've vastly reduced this campaign's implausibility.

The BEST way to reduce the number of troops needed to take this planet is to reduce the number of defending Orks (there are never more than a dozen million or so per world in the fluff... this can actually be rationalized; Orks alone on a planet they control are going to be fighting themselves constantly, so Ork populations must have a density limit because they're constantly killing each other).

If you're basing it on Earth, with only 20M active duty personnel, I don't know how we arrived at 85M Orks... Yeah, we got 30M Paramilitary, but that includes coast guards, police forces, totally ill-equipped and trained terrorist organizations, the Pope's Swiss bodyguards, etc...

Besides, are we going for numeric comparisons or effectiveness comparisons? You wouldn't need 20M Orks to match all of Earth's armed forces in capability.

Sekhmet
03-10-2009, 10:59
I just want to point out that using anything but some sort of grav-chute to drop cargo from orbit on a daily basis is a HUGE waste of resources. Sure you waste the grav-chutes, but those are cheap. What you don't waste is the massive amount of fuel it takes to use a cargo ship to land on the planet then achieve escape velocity again.

Random Integer
03-10-2009, 11:22
...If it isn't, it's damned close (assuming of course that the Crusade doesn't count, since that way the Army). Note that the largest concentration of ships assembled for battle ever recorded post Heresy is the 300 or so at Macragge, an entire Segmentum's fleet. And you're suggesting thousands of ships.


The Sabbat Worlds Crusade consisted of 1 billion Guardsmen and theres no indication that its considered unique in Imperial history.

Also those 300 ships were 300 warships. Given that the average sector battlefleet is 50-75 warships that not unreasonable as an atypically large concentration. However a sector battlefleet also has an unspecified number of support vessels and there are the ships of a sectors civilian fleet to account for. A crusade fleet numbering in the thousands isn't unfeasible, it would just represent the greater part of a single sectors shipping capacity and consist almost entirely of lightly armed or unarmed vessels.

RCgothic
03-10-2009, 11:52
The Sabbat Worlds Crusade consisted of 1 billion Guardsmen and theres no indication that its considered unique in Imperial history.

A crusade fleet numbering in the thousands isn't unfeasible, it would just represent the greater part of a single sectors shipping capacity and consist almost entirely of lightly armed or unarmed vessels.

+1. The Sabbat crusade doesn't even strike me as a particularly large crusade.

I think that I'm going to have to step in at this point and put us back on track. I don't want to limit avenues of discussion, but I think the general consensus is:

Resupply happens by drop ship, first at the initial landings, and then at secondary landing sites and eventually captured starports. A chain of dispersal points is set up, and the goods are shipped to the front. It more practical to move convoys of supplies to the front than to move around convoys of guardsmen AND supplies. Front line units will be put back into reserve, but only when they've seen enough action to warrant it.

If the Mechanicus is involved it is only as tech-priests embedded in units and repair grounds, the crews of the Navy ships, and as the skitarii and support units of the Titans. Mobile forges are not typical of what can be expected in a battlezone. Similarly large amounts of mining/manufacturing will not be going on in orbit whilst the orks try and reclaim their orbital supremacy.

This theatre is completely supplied by The Munitorum, from a staging ground 6 weeks warp transit away.

Iracundus
03-10-2009, 11:54
This is all very silly. 350 million soldiers need ~500,000 tons of food per day (350 million times three pounds per person); assuming 100% efficiency in the conversion process (which is absurd in it's own right), and assuming the average person weighs 160 pounds, this means that you would have to shovel more than SIX MILLION dead bodies (or severely wounded soldiers) into the recyclers EVERY SINGLE DAY to keep the invasion force fed. The problems are just going to escalate when you start looking at manufactured goods like ammunition, and my god, did you seriously just propose whole tanks?!

I'm sure the "mobile forge units" sounded very cool in Dark Apostle or whatever, but they just aren't workable. If RCGothic cares in the slightest about having a sensible logistical framework for this invasion he's writing his fluff about (and the fact that he started this thread suggests that he does indeed care about that), he will leave this "mobile forge" nonsense alone and have his supplies shipped in from the actual forgeworlds and agri-worlds, which exist to produce this stuff in the first place.


Nonetheless these "mobile factories" are described as part of the logistics train of an AdMech army so cannot be entirely dismissed out of hand into thin air. However, in Dark Apostle, they aren't a real replacement for offworld supplies. They are at best the equivalent of a mobile salvage base, recycling dead flesh and weapons, supplementing the main supply lines rather than being truly an independent manufacturing base.

Makiaveli
03-10-2009, 15:35
Yes, the Navy is the one operating the cargo ships that bring supplies into the system. But delivering it "quickly" isn't the issue. The most important factor is efficiency and practicality. Once the supply chain is set up and in motion, speed doesn't matter much, assuming it operates on a "push" mentality like modern military logistics (i.e., send the units what they will be needing, rather than waiting for them to put in a supply request detailing what they need). With the system set up and in motion, units will be receiving a constant stream of needed supplies no matter how long it takes a given individual crate to get from cargo ship to front line.

I said quickly when I should have said efficiently. You're right there. I think we agree on this part.




I'm questioning whether the Navy has this capability period, even if the drop pods are reusable (and if they are reusable, now you are talking about hundreds of thousands, or possibly millions, of shuttle flights per day to recover them, as well as all the effort that will be required on the ground to round them up from front-line areas all over the planet). Do we have any fluff support for this type of resupply being used for large forces over long periods?

I'm not sure I understand the point of these drop pods. Again, they're just utterly impractical. There's a reason the real-life US military doesn't use CDS drops from cargo planes to resupply large forces; it's stupid, wasteful, and pointless.

I can't say if they do or not, just that it would be one way. And the Imperium often does things because that is they way they do things. If it was feasible 23K years ago, then they might still do it.

And if they use shuttles to deliver supplies, then carry drop pods back that could increase efficiency.

And I see your point on the US military, but that is a bit off point as they don't have to bring the supplies down from orbit. The Navy does have the option of delivering them straight from orbit.


And lastly, we have to remember this is Sci-Fi. They can do it because the authors said they could. And fluff-wise, as I said before, the Imperium isn't known for creative and original thinking.

Argastes
03-10-2009, 15:43
I just want to point out that using anything but some sort of grav-chute to drop cargo from orbit on a daily basis is a HUGE waste of resources. Sure you waste the grav-chutes, but those are cheap. What you don't waste is the massive amount of fuel it takes to use a cargo ship to land on the planet then achieve escape velocity again.

It's not this simple, since as I pointed out, the drop pods themselves either have to be shuttled back up to orbit (which also burns massive amounts of shuttle fuel; more per pound of payload, in fact, because the shuttles are adding weight on the wrong leg of their flight), or are considered disposable, in which case they represent a massive daily waste of resources in their own right.

Argastes
03-10-2009, 16:17
They use the enemy dead, too. Obviously it wouldn't be the only source of food, it would just drastically reduce the amount you need to ship in/the troops need to scavenge.

The reduction in food requirements isn't going to be "drastic" by any stretch. It will be slight at best. Even to achieve a 10% reduction in the force's food supply requirements, you'd need to recycle 50,000 tons of bodies per day (again assuming 100% recycling efficiency, which isn't actually going to happen); that's hundreds of thousands of dead bodies per day. Every day. For a campaign that you say will last years. Even with tens of millions of combat troops on each side, and even assuming a casualty rate far in excess of anything the real world has ever seen, that's simply ridiculous.


...If it isn't, it's damned close (assuming of course that the Crusade doesn't count, since that way the Army). Note that the largest concentration of ships assembled for battle ever recorded post Heresy is the 300 or so at Macragge, an entire Segmentum's fleet. And you're suggesting thousands of ships.

No, this simply isn't true. As has been pointed out, the Sabbat Worlds crusade alone had 1 billion troops, and thus would have required many thousands of ships.


Because if the Imperium is falling all over itself to organize crusades/wars even a tiny fraction of this size, I don't think it's possible for them to logistically support this thing. If they could, the Tau would have been steam-rolled a long time ago. In the context of the greater universe it just isn't possible unless they have a really good reason for taking the planet really fast... Like a Primarch('s body) has been positively identified on the surface.

I think you missed my point. My point is, the idea of the Imperium struggling to organize much smaller crusades is silly and absurd, and if RCGothic wants his own fluff to make some sense, he shouldn't let himself be confined by GW's inability to come up with reasonable numbers. He should just assume, as many on Warseer do, that the numbers the fluff provides are often untenable, and would actually be much higher than GW states.


*shrug* Look at the billions of metric tons of ceramite that go into space ship hulls, aircraft, carapace armor, bunkers, tanks, etc, compared to the relatively few things that actually use fuel: certain ground vehicles and atmospheric aircraft... while the majority of transportation in the Imperium (ie, space ships) use huge plasma/nuclear/warp/sci-fantasy reactors and only need refueling once every few generations.

I don't think you are thinking this through. Everything that's produced on a planet (i.e., everything the Imperium makes, not just all that ceramite but everything else too) requires fuel to get it up into orbit to be put onto ships. It's absurd to say that the "majority" of the transportation in the Imperium is via spaceship. That might be true in terms of distance, but any planet that isn't a feral/medieval world is going to be moving a LOT of stuff around on the surface, and between the surface and orbit. To suggest that a single militarily useful material is more widely produced and used than the basic necessity of surface and surface-to-space transportation is ridiculous.


As I pointed out, space ships don't really use promethium for fuel...

:confused: Neither would chemical rockets used to de-orbit drop pods... But as I said, it's likely that starship engines have a higher exhaust velocity/Isp (the "fuel efficiency" of spacecraft) than drop pod chemical rockets, which is what you are getting at even if you don't realize it.


Perhaps they cheat and manipulate gravity then. They're certainly big enough to house a generator; and the Imperium is really good at manipulating gravity on large scales.

If this is so, then I'm not sure why supply shuttles couldn't use the same methods (as in fact we already know that dropships do); so again, what's the advantage of these drop pods?


You don't need to froth at the mouth. I admitted it's silly when I said "if we really wanted to stretch it." I'm standing back, looking at this objectively and trying to prevent RCgothic from making the same kind of background mistake as saying "my regiment is the most faithful in the imperium" or "my chapter master is so good he got to meet the emperor" etc. Forces this large just don't happen. If he can acknowledge that and still wants to orchestrate a campaign this size than fine, I'm not going to/can't stop him. I understand the allure of making one's background 'cooler' than the norm.

:eyebrows: I don't think that's at all what he's trying to do. He's trying to make it make sense. He's trying to make it less stupid than the norm, not "cooler". That's not a mistake at all. The fact that "forces this large just don't happen" is a serious problem with GW's fluff, and one that is irksome to people with any understanding of military history. So, again, I think it's perfectly reasonable to simply recognize that GW's numbers are poorly thought out, and would realistically have to be much larger.

Or, conversely, you could look at things like the 1-billion-man Sabbat Worlds crusade, and say that GW's numbers aren't always so bad; in which case RCGothic's proposed force isn't even unreasonably large by GW standards. Either way, I think your attempt to prevent RCGothic from "making a mistake" with his background is sorely misguided.


300M is only 17% larger than the 250M number everyone else was using.

Sai-Lauren and I both suggested 100-150 million.


Conversely, I cut the required tanks/artillery pieces to 15% of the number everyone else was using, I cut the required aircraft to 33% the number everyone else was using, and I cut the number of titans needed to 10% of what everyone else was using (and down to a number I actually agree would be feasible, being within the limits of a single Legio).

Considering the daily tonnage consumed (that we agreed on) by an infantry division is 50-100, while the daily tonnage consumed by an armored division is 1,000-10,000, I think the net result is I've vastly reduced this campaign's implausibility.

No, in fact you have not. You should really run the numbers on this stuff before you make your claims. Earlier, as you will recall, I estimated 2.15 million tons per day based on RCGothic's 250 million man force, with it's large numbers of tanks/artillery and titans. By the same math, a 300-400 million man force without any tanks or artillery at all would need 2 to 2.6 million tons per day. Remember that in my 2.15 million tons/day estimate for RCGothic's proposed force, the majority of the tonnage was accounted for by the personnel, not the tanks and big guns. Slashing a few hundred thousand tanks and artillery pieces while adding 50-150 million more troops does not in any way "vastly reduce" the campaign's implausibility.

Iracundus
03-10-2009, 17:16
The reduction in food requirements isn't going to be "drastic" by any stretch. It will be slight at best. Even to achieve a 10% reduction in the force's food supply requirements, you'd need to recycle 50,000 tons of bodies per day (again assuming 100% recycling efficiency, which isn't actually going to happen); that's hundreds of thousands of dead bodies per day. Every day. For a campaign that you say will last years. Even with tens of millions of combat troops on each side, and even assuming a casualty rate far in excess of anything the real world has ever seen, that's simply ridiculous.


Given the AdMech's theological dogma towards the machine, I'd probably say the recycling and repair of any broken machinery and servitor parts is more important to them. The production of nutrition paste from organic parts is probably a secondary (albeit sometimes useful) function.

In Dark Apostle, the world was mostly barren and dead and the only source of organic parts was the dead. It is unknown whether it has to be human parts that can be rendered down, or whether it can take other sorts of organic matter.

In the book, it was also used to create new Skitarii combat servitors by getting bodies from other sources. The book had criminals from other Guard forces being handed over to the AdMech for conversion. If there were civilian population areas, the AdMech could conceivably snatch more bodies to create replacements for combat losses, although unless they're converting whole settlements, it'll still likely be only a trickle resupply.

Ultimately, the AdMech's reasons for using such machinery is likely bound up with theological doctrine as much as actual military concerns.

massey
03-10-2009, 17:16
I think people are overlooking some important things.

First, mobile forges make sense. They aren't there to simply churn out regular supplies, though. The concept of a mobile forge is being explored right now, in real life. The reason you have something like this is to replace specific individual parts. Leman Russ have a damaged thingamabob? Just use the mobile forge to create a new one instead of having to wait 6 months for an order to go in and a replacement to get here. You'd still have to bring in raw materials, and you'd want to bring in normal stuff like replacement tracks, fuel, food, ammo, and common spare parts. But if some rare widget broke, you wouldn't be out of commission very long because you could just make the part right there.

Second, we're invading an Imperial world, so one of our big priorities will be to get to the food and ammunition storage areas. You'll probably bring along enough fuel and supplies to keep your initial invasion force going for like three months. By the end of that time, you expect you'll have seized resources that are already on planet. It's much easier to seize a prometheum refinery on the southern continent than it is to ship fuel in from halfway across the galaxy.

RCgothic
03-10-2009, 17:50
I'm standing back, looking at this objectively and trying to prevent RCgothic from making the same kind of background mistake as saying "my regiment is the most faithful in the imperium" or "my chapter master is so good he got to meet the emperor" etc. Forces this large just don't happen. If he can acknowledge that and still wants to orchestrate a campaign this size than fine, I'm not going to/can't stop him. I understand the allure of making one's background 'cooler' than the norm.

Firstly:

There are planets in the 41st millenium with far greater populations than that of modern day earth.
Society is much more militarised. (grim darkness, far future, only war etc.)
Therefore there must be planets which can field as much military power as we can, without any outside aid.


Secondly:

There are fortress worlds, where the forces of many such earth-like words are concentrated.
The Imperium can overthrow such worlds (Morlond, Cadia, Jago all examples of overthrown or nearly overthrown fortress worlds).
Therefore the Imperium must be in posession of the forces required.


Purely and simply, the Imperium could not exist without the ability to overthrow planets much, much stronger than current day earth. This is not about cool, this is about things making sense.

For the purposes of the hypothetical crusade in this thread, the Imperium has enough resources.

Argastes
03-10-2009, 18:06
First, mobile forges make sense. They aren't there to simply churn out regular supplies, though. The concept of a mobile forge is being explored right now, in real life. The reason you have something like this is to replace specific individual parts. Leman Russ have a damaged thingamabob? Just use the mobile forge to create a new one instead of having to wait 6 months for an order to go in and a replacement to get here. You'd still have to bring in raw materials, and you'd want to bring in normal stuff like replacement tracks, fuel, food, ammo, and common spare parts. But if some rare widget broke, you wouldn't be out of commission very long because you could just make the part right there.

This is fine; sophisticated 3d printers (or whatever) to fabricate the occasional spare part is very different from mobile forges used to supply the invasion force. Although I should point out that there should really be no such thing as a rare widget that takes 6 months to replace. In real-life armored units, most spare parts will be available at the divisional level; practically everything will be in stock at the corps or higher level. You should be able to get almost any spare part needed within a couple weeks at most. Plus there will always be plenty of wrecked vehicles to cannabilize parts from. The idea of a vehicle being out of action for months because a single component broke doesn't make much sense. But that said, again, having the capability to fabricate replacement parts as needed is helpful, because it helps reduce the quantity of spares that have to be kept on hand.


Second, we're invading an Imperial world, so one of our big priorities will be to get to the food and ammunition storage areas. You'll probably bring along enough fuel and supplies to keep your initial invasion force going for like three months. By the end of that time, you expect you'll have seized resources that are already on planet. It's much easier to seize a prometheum refinery on the southern continent than it is to ship fuel in from halfway across the galaxy.

Being able to seize such resources would be nice, but shouldn't be counted on. If it looks like the Imperial forces are going to capture something, the enemy is likely to destroy it before hand. I'm sure Orks would have no reluctance to do so. A massive promethium refinery, for instance, would be a prime candidate for this sort of treatment.

Iracundus
03-10-2009, 18:09
This is fine; sophisticated 3d printers (or whatever) to fabricate the occasional spare part is very different from mobile forges used to supply the invasion force. Although I should point out that there should really be no such thing as a rare widget that takes 6 months to replace. In real-life armored units, most spare parts will be available at the divisional level; practically everything will be in stock at the corps or higher level. You should be able to get almost any spare part needed within a couple weeks at most. Plus there will always be plenty of wrecked vehicles to cannabilize parts from. The idea of a vehicle being out of action for months because a single component broke doesn't make much sense. But that said, again, having the capability to fabricate replacement parts as needed is helpful, because it helps reduce the quantity of spares that have to be kept on hand.

For the AdMech, the human flesh in their servitor creations are just another type of "spare parts", to be replaced when they wear out or are destroyed.

Argastes
03-10-2009, 18:15
Okay, I have no problems with them taking dead/wounded soldiers, or criminals, and turning them into combat servitors or whatever. Makes perfect sense to me. What's ridiculous is the idea of using the dead/wounded as a food source by recycling their biomass. Because again, given the number of people involved in this invasion, you'd need hundreds of thousands of bodies per day just to supply a small fraction of the invasion force's food requirements.

massey
03-10-2009, 18:20
This is fine; sophisticated 3d printers (or whatever) to fabricate the occasional spare part is very different from mobile forges used to supply the invasion force. Although I should point out that there should really be no such thing as a rare widget that takes 6 months to replace. In real-life armored units, most spare parts will be available at the divisional level; practically everything will be in stock at the corps or higher level. You should be able to get almost any spare part needed within a couple weeks at most. Plus there will always be plenty of wrecked vehicles to cannabilize parts from. The idea of a vehicle being out of action for months because a single component broke doesn't make much sense. But that said, again, having the capability to fabricate replacement parts as needed is helpful, because it helps reduce the quantity of spares that have to be kept on hand.


Well, in real life, you might have things out of action for only a few weeks, but imagine if you're waiting for resupply from some place a thousand light years away? With the Imperium's notorious bureaucracy, I could see long delays because someone somewhere had a paperwork mix-up.



Being able to seize such resources would be nice, but shouldn't be counted on. If it looks like the Imperial forces are going to capture something, the enemy is likely to destroy it before hand. I'm sure Orks would have no reluctance to do so. A massive promethium refinery, for instance, would be a prime candidate for this sort of treatment.

Except the orks need the stuff, too. Their tanks and planes don't just run on fairy dust, you know. You'd want to move in quickly, eliminate the defenders, and then push them far back enough so that you could hold it and protect it.

Argastes
03-10-2009, 18:27
Well, in real life, you might have things out of action for only a few weeks, but imagine if you're waiting for resupply from some place a thousand light years away? With the Imperium's notorious bureaucracy, I could see long delays because someone somewhere had a paperwork mix-up.

You missed my point: What I'm saying is that even the rarest spare parts should be present on the planet, in the stocks of the higher-level CSS elements (especially in such a huge force). Just as they are usually present in-theater in real life. And again, there's always the option of taking them from KO'ed tanks. This is how real-life armored units get a lot of spare parts during campaigns. It's not like there will be any shortage.


Except the orks need the stuff, too. Their tanks and planes don't just run on fairy dust, you know. You'd want to move in quickly, eliminate the defenders, and then push them far back enough so that you could hold it and protect it.

It isn't realistic to expect to be able to capture large infrastructural targets so quickly and unexpectedly that the enemy doesn't have time to destroy them. And then push the enemy back out of artillery range (which can be 30 miles or more) before they can shell the target. That sort of offensive would usually take days even if executed with incredible speed and success. If an Ork commander realized the refinery was in danger of being captured, he could destroy the facility in hours or less. You simply aren't going to be able to amass overwhelming force, advance on the target from the offensive's staging area, attack it and defeat the defenders, and push them back 20-30 miles, all before they can send around a bunch of guys with satchel charges.

The US Army's expulsion of the Iraqis from Kuwait in 1991 was one of the swiftest and most one-sided offensives in history, yet the Iraqis still managed to blow up a huge number of Kuwaiti oil wells as they retreated.

And of course the Orks need the stuff too, but if they can see it's about to be captured, then obviously they will realize that it's not going to be useful to them even if they leave it intact. "We need fuel too so we'll let the enemy capture our fuel stocks intact"? Come on, Orks aren't that stupid.

massey
03-10-2009, 18:40
Look at what Saddam Hussein did in Iraq in 1991. He tried to set his own oil fields on fire, but couldn't get them all in time. On Earth, refineries are massive structures, and they tend to be grouped together (like, in the same city or region). On a hive world, they'd be even bigger. I don't think the orks could damage them all beyond repair. Besides, those are things you fight over. You don't place bombs all over the place unless you know you have no hope of holding it.

Argastes
03-10-2009, 18:49
Look at what Saddam Hussein did in Iraq in 1991. He tried to set his own oil fields on fire, but couldn't get them all in time. On Earth, refineries are massive structures, and they tend to be grouped together (like, in the same city or region). On a hive world, they'd be even bigger. I don't think the orks could damage them all beyond repair. Besides, those are things you fight over. You don't place bombs all over the place unless you know you have no hope of holding it.

It was the Kuwaiti oil fields he set on fire, not his own. Why would he do it to his own? Anyhow, it's true he didn't get all of them, but he did massive damage to the Kuwaiti oil industry. It took years to repair.

Refineries are actually far easier to destroy than oil wells spread over a wide area, precisely BECAUSE they are massive structures grouped together. And the flow of oil through their pipes is usually controlled from a central location, which makes it even easier. A small group of men (Orks?) with demolitions equipment could very easily destroy a massive refinery in a short period of time, if they knew what they were doing. The resultant fires would last for weeks or months, and be impossible to extinguish.

I know they are things you fight over, and I know you don't destroy them until it becomes obvious that the enemy is going to capture them. That's what I'm saying: As it becomes obvious that the enemy is going to capture the refinery, it's quite easy to destroy it quickly.

EDIT: I know it's not exactly academically proper to cite a work of fiction, but look at the beginning of Red Storm Rising to see a technically accurate description of how quickly and easily a refinery can be destroyed. The book is fiction but the refinery attack is well-researched. If the right valves are opened and the right pumps are on when the charges go off, millions of gallons of oil will continue to pour out of the ruptured pipelines and feed the fire. This is why refinery attacks are such a huge anti-terrorism concern; they are comparatively easy, and if they are pulled off, the damage is incredible.

And this doesn't even begin to examine the possibilities of simply bombing/shelling it (which could be done even if the attackers have pushed the defending ground forces out of the facility without it being destroyed as they retreat).

Another edit: I'm not saying it is absolutely impossible to capture an oil refinery, or some similar target, intact. I'm saying that while it's possible, it's far from a sure thing, because there is a quite real possibility that the enemy could manage to destroy it first. So the invasion force probably shouldn't plan their logistics around the assumption that they will be able to capture such targets. If they are lucky enough to do so, great, good for them--it will certainly be helpful. But if they only brought 3 months worth of fuel because they assumed they'd capture more, and then their gamble fails and they don't manage to do so, then they're in pretty deep trouble.

RCgothic
03-10-2009, 19:56
The most likely reason not to destroy an asset you're about to lose is that you think you may be able to recapture it.

Argastes
03-10-2009, 22:30
Yeah, that's a possibility, but you'd have to be pretty confident of your ability to recapture it if you are willing to take that gamble. The more potentially useful the asset in question is, the truer this holds. Assets/territory changing hands multiple times like that is far from likely, if real history is any indication. You'd also have to be confident that when (or rather, if) you did manage to recapture it, the enemy wouldn't do what you refrained from doing and destroy it himself.

Again, not saying it's impossible to capture supplies in-theater, but it's not something you should rely on, or assume will happen, when planning your own logistics. Doing so would be a foolish gamble.

RCgothic
03-10-2009, 23:28
Ok, so going back, we've got:

Combat Theatre:

Hive World.
19 Fortress hives similar to vervunhive (void shielded, curtain walls, sprawling suburbs).
Terrain similar to Earth of M3.
Produces Crusade-critical munitions, vehicles and supplies.
Orbital space is secure only thanks to constant efforts of the IN.
Supplied entirely from crusade HQ 6 weeks warp travel away.
Supplies are delivered by bulk lander to primary dispersal sites and then trucked to secondary and tertiary dispersal.


The defenders are:

30M Orks
55M Gretchin
100k Armoured units (Battlefortresses, looted Imperial Armour etc)
30k Air units (fightas, fighta-bommerz, blasta-bommerz etc)
120 Stompas, Super Stompas and Gargants


The attacking force should be at least:

90M front line guardsmen (skitarii inclusive).
A few companies of marines.
180M reserve and logistical personnel
300k Armoured units/Heavy Artillery pieces
90k air units
60 Titans


I figure that Imperial Titans can probably take down gargants at a 2-1 disadvantage, particularly with titan-hunter shadowsword groups amongst the armoured units, and the idea that unlike the Legios where the Battle Titans dominate, gargant mobs are likely to be mostly composed of stompas, whilst unit for unit the orks are probably outclassed at this scale.

That way we only have to imagine 1 titan legio being involved.

Sekhmet
03-10-2009, 23:41
The US Army's expulsion of the Iraqis from Kuwait in 1991 was one of the swiftest and most one-sided offensives in history, yet the Iraqis still managed to blow up a huge number of Kuwaiti oil wells as they retreated.


US Army? It was a coalition of many nations, and it wasn't just ground forces, but all service branches that took part.

Argastes
03-10-2009, 23:41
Okay. So do you still want estimates of logistical requirements for this force?


US Army? It was a coalition of many nations, and it wasn't just ground forces, but all service branches that took part.

Yes, excuse me. You're quite right. That was unfair of me. "US Army" was what slipped out of my mouth (uh, typin' fingers) because they provided the bulk of the ground forces that actually expelled the Iraqis from Kuwait. But yes, it involved a lot more than just the US Army.

RCgothic
04-10-2009, 00:31
Okay. So do you still want estimates of logistical requirements for this force?


An estimation of the length of the campaign, and therefore total logistical requirements, following up with an estimation of the volume/weight of those supplies.

We can then expand onto troop rotations, number of drop ships/landers and transports, and perhaps the number of round trips the transports would have to make through the warp (I'm guessing not all the supplies or troops would arrive with the first wave.).

Argastes
04-10-2009, 01:24
Well, I think that estimating the length of the campaign is going to have to be up to you. How long do you want it to be? It could potentially be anywhere from several months to many years or even decades, depending on the acumen of the commanders on both sides, as well countless other factors. Weather, terrain, and sheer luck will play a large role. If you want a short campaign, decide that the Imperial commanders are far more cunning and perceptive (or just luckier) than the Ork commanders, and are able to lure the Orks into huge cauldron battles where massive numbers of Orks are encircled and destroyed relatively soon after the campaign begins (or vice versa; say that the Ork commanders are far brighter than the Imperials, and are able to inflict unsustainable losses on the invasion force within a short time after landfall). If you want a long campaign, there are plenty of ways to rationalize that too. Any one of us could give you a timeframe, but all the variables mean that whatever we give you will be no or less correct than any other estimate. I could lay out an intricate argument for why the campaign might take, say, five years; but it would necessarily assume a huge number of things about the circumstances under which the campaign is fought, and someone else could make a different set of assumptions about the circumstances and arrive at a totally different, and equally valid, time estimate.

Anyhow, once you have decided for yourself how long this campaign will last, I would recommend the following rules of thumb for estimating logistical consumption:

1. Every ~15,000 men worth of leg infantry will consume 50 to 200 tons of material per day, with lower figures being more likely for low-intensity operations, garrison duty, etc., and higher figures being more likely when engaged in serious combat. This will rise somewhat if the CSS elements of infantry units are heavily motorised; maybe as high as 300-400 tons per day of fighting or advancing. The same number of mechanised infantry will use roughly similar amounts of supplies when sitting still, but as much as several thousand tons per day when advancing, especially if there's enemy forces in the way of that advance.

2. Every ~15,000 men worth of non-combat personnel will consume 30 to 80 tons of material per day; lower figures in this range will tend to suggest that they are not receiving many supplies other than bare-bones rations. Note that this does NOT include the supplies that will be consumed by engineering units, etc. engaged in activities like construction. Such activities may consume a substantial additional amount of material.

3. Every ~500 tanks/SPGs will consume anywhere from several hundred to 10,000 tons per day; if they are sitting around doing very little, that's when their daily consumption will drop to a couple hundred tons, but if they are moving around (or doing a lot of firing, for artillery), that's when it will rise into the thousands of tons per day. Fighting defensive battle will consume a lot less than fighting an offensive battle; a tank division defending a position might consume under a thousand tons per day, but when the battle is offensive, that's when you get figures approaching the 10,000 tons/day mark.

4. Every ~100 aircraft (rough USAF wing equivalent) will consume anywhere from 10 to a few thousand tons of material per day, depending on how much they are flying. If they sit on the ground all day, the unit's consumption of supplies will basically be limited to the food and sundries consumed by it's personnel, plus some maintenance-related stuff. But if they are flying sorties, it could rise into the thousands of tons per day. Exactly how much will really depend on the distance/duration of the sorties, how much ordnance is used, the type of aircraft used, and of course how many sorties are actually flown. In order for ~100 fighter-type aircraft to use up 1000+ tons of supplies in a day, you'd have to have basically all of them flying at least one sortie per day, and burning through good bit of fuel/munitions as they do so, but it's certainly not impossible in a warzone. Some modern fighter/attack jets can come back to base ten tons (or more) lighter than they were when they took off.

Titans and Space Marines can, I think, be safely ignored because the logistical demand that they add will be very small in comparison to that of tens of millions of troops and hundreds of thousands of tanks/guns.

As for volume of this stuff, personally I'd ignore that and just worry about the weight; estimating the volume is frankly impossible without a bunch of information that we don't have. You'd have to figure out what percentage of the total tonnage is composed of motor fuel, what percentage is composed of food, what percentage is composed of ammunition of various sorts, what percentage is composed of sundries like uniforms and spare parts and tools and construction materials, etc., and then estimate densities for all that stuff, taking into account how it's packaged and so forth. Sounds like more trouble than it's worth to me.

As for how many dropships/landers/shuttles would be needed, that depends entirely on the cargo capacity of such vehicles--anyone have any specifics about various classes of Imperial shuttles, and how much weight they can carry? Oh yeah, and don't forget fuel for all those shuttles. After we figure out the total tonnage of supplies that had to be delivered to the surface per day, and the number of shuttle flights per day that will require, we also have to figure out how much fuel each shuttle consumes per flight, then multiply it by the number of shuttles in order get the weight of the daily shuttle fuel requirements. I frankly doubt we have the info needed to make anything more than blind guesses at some of this stuff...

Iracundus
04-10-2009, 04:30
I figure that Imperial Titans can probably take down gargants at a 2-1 disadvantage, particularly with titan-hunter shadowsword groups amongst the armoured units, and the idea that unlike the Legios where the Battle Titans dominate, gargant mobs are likely to be mostly composed of stompas, whilst unit for unit the orks are probably outclassed at this scale.


That assumption is probably incorrect as Gargant mobs, from Epic, funnily enough are composed of Gargants which are Battle Titan equivalents. Stompas are equivalent to light Titans. It is also debateable whether Imperial Titans can do 2 vs 1 odds, as Imperial Titans are only slightly faster and more maneuverable, while Gargants are more durable overall (again going by 2nd ed. Epic). Gargants had no critical parts, and had to to have their banks of power fields worn down and then the structure set on fire and parts blown away. Imperial Titans by contrast, have a plasma reactor that can go critical (which the Gargant lacks), and they have fewer shields per unit, as they have void shields which recharge, unlike Gargant power fields which don't.

What this means is an Imperial Titan group might win if they used maneuver and hit and run tactics, but in straight slugging matches with a fresh Gargant mob with full shields, I'd put my bets on the Gargants.

As for the Ork numbers, is that assuming front line troops or is that total planetary population? If it's the latter, 30M is rather low. Remember that although Orks like fighting, and have probably a higher proportion of their total population under arms, they are still ultimately a technological civilization and require non-combatants still performing their roles in order to keep things running. Ammunition and fuel still needs to be produced as does a steady supply of food (fungus + squigs for Orks). If it's a recently Ork conquered world, then there would be also be a significant slave population of humans, and these likely need overseeing to make sure they keep working and don't revolt.

A hive world is unlikely to have Earth like terrain because of the ecological pressures of supporting so many people, particularly if they are engaged in heavy manufacturing spewing out toxic air pollution and water pollution as the Imperium is so fond of doing. Well established hive worlds like Armageddon and Necromunda just have toxic wastes, toxic seas, and fierce out of control weather. Armageddon had some equatorial jungle but that was probably the last and most hardy of the remaining plant and wild life.

ProfessorCurly
04-10-2009, 05:43
As far as the number of Orks and logistics is concerned, Orks don't actually do any of their own logistical support. It's pretty much all delegated to the swarms of Gretchin and Snotlings that run rampant. They're the ones that forage/cook food, fetch ammunition/fixy-bits/hurty-bits, and when the need arises they themselves become the food for the Orks.

Basically it can safely be assumed that, by special dispensation due to the peculiar nature of Orkish biology and the way they reproduce, that any number of Orks will have the appropriate numbers of gretchin, snotlings, and squigs to logistically support them.

What does need to be addressed in this particular mental exercise is the type of Orks that are being dealt with. The predominant clan would determine much on how the campaign would go.

Dealing with Death Skulls or Evil Sunz might not be so bad, but in these conditions trying to deal with say the Blood Axes would be a bloody nightmare.

Iracundus
04-10-2009, 05:54
As far as the number of Orks and logistics is concerned, Orks don't actually do any of their own logistical support. It's pretty much all delegated to the swarms of Gretchin and Snotlings that run rampant. They're the ones that forage/cook food, fetch ammunition/fixy-bits/hurty-bits, and when the need arises they themselves become the food for the Orks.

That's not entirely accurate. There are still Orks required to oversee the Gretchin, whether it be in daily tasks or mechanically oriented ones. Gretchin and Snotlings are unskilled labor and certainly wouldn't be able to be trusted to take the initiative or have the intelligence to organize and manage logistical tasks on their own. Hence Oddboyz such as Mekboyz and Runtherdz and Painboyz will not all be able to join the frontlines.

Also ultimately to be competitive there will be large scale logistical efforts needed, such as factories pumping out vehicles, parts, or ammunition. Although Orks are good salvagers, that is workshop or craftsmanship scale, not the kind of mass production that is necessary when dealing with a planetary war front.

RCgothic
04-10-2009, 12:11
That assumption is probably incorrect as Gargant mobs, from Epic, funnily enough are composed of Gargants which are Battle Titan equivalents. Stompas are equivalent to light Titans. It is also debateable whether Imperial Titans can do 2 vs 1 odds, as Imperial Titans are only slightly faster and more maneuverable, while Gargants are more durable overall (again going by 2nd ed. Epic).

I'm assuming stompas predominate, with fewer heavier machines, perhaps 30 gargants and 90 stompas, it just seems to be how orks tend to organise themselves, with things getting rarer as they get bigger. The Legio on the other hand, would probably have 50 battle titans and 10 warhounds, backed up by superheavy titan hunters. I consider that force enough combined with orbital intel.

Anyway, the marines and titans can probably be ignored for now(until it comes to thinking about transporting them).

I think 18 months is probably a good length of campaign, and attached is how I think this campaign will play out in terms of infantry casualties:

The landing doesn't go well at all, but after the orks are driven from open terrain the first two hives are captured easily in month 4.
In months 7 and 8 there is heavy fighting for the eight northern hives.
Months 11-13 see sustained and bloody battles for the 7 western hives, and are the bloodiest months of the campaign since the landing.
The ork warlord has gathered his forces in the two eastern hives, the largest and best defended on the planet, and these are the bloodiest individual battlegrounds in months 15 and 16, with forces being withdrawn in months 17 and 18. The war ends with 30% casualties amongst the fighting guardsmen.

I'll think up something similar for the aircraft/armour. No point supplying dead/destroyed forces! The troops who aren't active or dead are in reserve. Injured troops are considered to have been rotated into the reserve.

Iracundus
04-10-2009, 12:56
I'm assuming stompas predominate, with fewer heavier machines, perhaps 30 gargants and 90 stompas, it just seems to be how orks tend to organise themselves, with things getting rarer as they get bigger. The Legio on the other hand, would probably have 50 battle titans and 10 warhounds, backed up by superheavy titan hunters. I consider that force enough combined with orbital intel.


That assumption of Imperial Battle Titans making up most of the numbers isn't correct though. I cite Imperial Armour 6, Vraks part 2, where a battlegroup from Legio Astorum is deployed. It consisted of 10 Reavers and 12 Warhounds. That's almost equal numbers of main Titans and scout Titans, with the scout Titans having a slight edge in numbers. So the overall numbers of a Titan Legion wouldn't be as skewed towards heavy Titans as you are assuming. If the numbers are approximately equal, then it runs into the differences in technology and endurance as described previously, with Ork Gargants actually being more durable in a fresh battle due to their more numerous power shields and lack of any volatile reactors for the humans to inflict quick kills.

Argastes
04-10-2009, 14:36
Okay. With regards to armor/artillery/aircraft: Should we assume that the invasion force's full armor/air/arty assets are committed to the front lines, or that some portion of them are held in reserve as you're doing with the infantry? If it's the latter, should we assume that the percentage of armor/air/arty assets committed at any given time are equivalent to the percentage of the infantry that are active at that time? And as for losses, should we assume that losses of armor/air/arty assets are proportionate to losses among the infantry, e.g. if 10% of the active personnel are killed in a given month, should we assume that 10% of the committed armor/air/artillery assets are lost as well?

Oh yeah, and should we assume that there are no (significant) casualties among the non-combat elements, and that the full 180 million non-combat support personnel are present for the duration of the campaign?

Also, what percentage of the combat troops are mechanized vs. straightleg infantry?

Dexter099
04-10-2009, 15:04
This is where GW messes up; the numbers.

There's no way that 200 Space Marines can subdue planets like this. Maybe saying each Chapter has about 5000 Marines might make more sense.

Argastes
04-10-2009, 15:08
This is where GW messes up; the numbers.

There's no way that 200 Space Marines can subdue planets like this. Maybe saying each Chapter has about 5000 Marines might make more sense.

True, but this thread is about using hundreds of millions of Guardsmen to subdue this planet, not 200 Space Marines. Come to think of it, in fact, I don't think I've ever seen even GW claim that 200 Space Marines could subdue a planet infested with tens of millions of Orks. I do still agree that their numbers are usually silly though.

massey
04-10-2009, 15:22
Most planets in the Imperium would appear to be relatively lightly populated, and relatively lightly defended. It makes sense -- anything beyond the bare minimum force required to keep the peace would be pulled off and sent to a battle. So it would be sort of like RISK, where you've got control of North America, and you've got 43 armies in Greenland, 27 armies in Alaska, 31 armies in Mexico, and the rest of the continent is stripped bare, with maybe one army in each territory at most. The heavily defended planets are the ones in a warzone, the rest have only minor garrisons because they're considered "safe". So that's how a small force of marines can quell a rebellion -- because there aren't many soldiers there in the first place.

Argastes
04-10-2009, 15:54
That's not really the whole picture of how military forces are distributed in the Imperium, though; it's true that threatened/contested planets will have large IG forces present on them while "safe" planets won't, but the presence/absence of IG forces isn't the only thing determining how well-defended a planet is. Remember that every planetary governor has the obligation (and usually the desire as well) to maintain Planetary Defense Forces, the size of which will be proportionate to the planet's population. It's from these forces that IG regiments are drawn when the planet pays it's tithe of military manpower, once every decade or whatever. An Earth-like "civilized world" will have millions of soldiers in it's PDF, while a hive world could have hundreds of millions or even billions. PDF troops, not IG troops, actually make up the majority of the armed forces present within the Imperium; they just aren't available for use in campaigns. They are obviously available for use in the defense of their planet, though.

EDIT: But, that point aside, I do agree that it's somewhat plausible for small forces of Space Marines to suppress a planetary rebellion, at least temporarily, with "decapitation" strikes from orbit. But Dexter said "there's no way that 200 Space Marines can subdue planets like this", which I assume is in reference to the planet being discussed in the thread, i.e. an Ork-held hive world. Which again, is of course true, but I don't think I've ever seen GW actually say that they could.

Firaxin
04-10-2009, 20:36
It's not this simple, since as I pointed out, the drop pods themselves either have to be shuttled back up to orbit (which also burns massive amounts of shuttle fuel; more per pound of payload, in fact, because the shuttles are adding weight on the wrong leg of their flight), or are considered disposable, in which case they represent a massive daily waste of resources in their own right.
Actually, Mass Lifters use a combination of anti-gravity and the same sci-fantasy reactors that battleships use. ie, fuel isn't really an issue for them.


Remember that every planetary governor has the obligation (and usually the desire as well) to maintain Planetary Defense Forces, the size of which will be proportionate to the planet's population. It's from these forces that IG regiments are drawn when the planet pays it's tithe of military manpower, once every decade or whatever. An Earth-like "civilized world" will have millions of soldiers in it's PDF, while a hive world could have hundreds of millions or even billions.
This doesn't necessarily follow. You can never underestimate the arrogance of politicians. As with our own world, I can see the planetary governor stripping military funding/recruitment so he has more money to spend on frivolous things, like his personal pleasure yachts/gardens/etc.

I cite the 5th ed main rulebook, where the example Hive World--population 154 billion--only has a PDF of 2 million.

Dexter099
04-10-2009, 20:38
True, but this thread is about using hundreds of millions of Guardsmen to subdue this planet, not 200 Space Marines. Come to think of it, in fact, I don't think I've ever seen even GW claim that 200 Space Marines could subdue a planet infested with tens of millions of Orks. I do still agree that their numbers are usually silly though.

200 Black Templars supposedly cleanse a world, in the vinculus crusade, as well as in a few others (there are a few realistic ones, such as taking over a space station or an Ork Rok. I can believe that). It's really hard to believe.

It's also hard to believe that 50 Space Marines on each pole of Macragge could fend off everything that Behemoth landed.

Who here thinks that GW should change the number of SM's in each chapter to be 5000? The IG have way higher numbers, I think that would make more sense.

RCgothic
04-10-2009, 20:41
Which is a ridiculously low number for such a large hive. That's 1 in 75,000 people in the military, as opposed to 1 in 80 on modern day earth.

That hive has a military at least a thousand times smaller than it should be.

Dexter099
04-10-2009, 20:55
Just pretend that there are 5x as many marines as GW says there are.

MontytheMighty
04-10-2009, 20:55
I think GW is really bad at offering plausible figures

the logistics for the SM is ridiculous, a million space marines for the entire galaxy? Even as the elite of the elite last line of defenders this number is way too low to be effective

200 marines conquering a world is totally absurd,
200 marines wouldn't even be enough to take out a large, well-fortified city IMO, there's simply not enough of them to spread out

Random Integer
04-10-2009, 21:11
I cite the 5th ed main rulebook, where the example Hive World--population 154 billion--only has a PDF of 2 million.

I do not have the rule book at hand but I am almost entirely certain that the 2 million figure was for the planets IG garrison not the PDF. Those are rather different things.

Argastes
04-10-2009, 21:31
I tend to think that GW should leave each Space Marine chapter at 1000 men, and just start giving them tasks/capabilities in line with that number. But that's getting off topic. This thread is about IG logistics, people. Dexter, I hear you and I can tell that you are enthusiastic about these 5000-man chapters, but if you want to talk about them, start a thread about them. And Monty, we know that GW's numbers suck--people have been saying that since page 1 of the thread--but again, let's not try to divert this thread into a discussion of what Space Marines are capable of. It's not about that.


This doesn't necessarily follow. You can never underestimate the arrogance of politicians. As with our own world, I can see the planetary governor stripping military funding/recruitment so he has more money to spend on frivolous things, like his personal pleasure yachts/gardens/etc.

I cite the 5th ed main rulebook, where the example Hive World--population 154 billion--only has a PDF of 2 million.

As RCGothic says, that sounds like another example of GW's awful numbers, and in fact that figure isn't even internally consistent with what we know about how tithe obligations work. Again, planetary governors have to pay a periodic tithe of manpower from their PDF to supply the IG with soldiers, and the number of men required in that tithe will be determined by the Administratum based on the planet's population. So that governor will be in quite a pickle when the Imperium shows up to collect what's due and he doesn't have enough men.

There MUST be more PDF troopers in the Imperium than their are IG troopers. It is not up for debate. It is a necessary truth. Because the IG's manpower comes from periodic "skimming" of personnel of the PDFs of Imperial planets. It is literally impossible for PDF troops to not outnumber IG troops.


Actually, Mass Lifters use a combination of anti-gravity and the same sci-fantasy reactors that battleships use. ie, fuel isn't really an issue for them.

Then heavy-lift cargo shuttles, such as would be employed to shuttle down supplies to the central logistical dispersal points of the ground forces, can employ the same technology--which blows away your argument that drop pod resupply is desirable because it "uses ceramite resources instead of fuel resources". You still haven't explained the merits of this drop pod resupply scheme and frankly, I don't think you can. RCGothic has thankfully decided that his campaign will use a reasonable method of resupply anyhow (i.e., shuttles, not drop-pods or "mobile forges" or teleportation), and so frankly I think we should drop this topic of discussion along with the topic of how many Marines should be in a chapter and whether GW numbers suck.


RCGothic: Given any thought to the questions I asked earlier, about the proportion of air/armor/artillery assets that are committed at any given point, and how much of the infantry is mechanized? Using your graphs, I've got a month-by-month breakdown of the number of combat personnel that are on the line and in reserves each month, but I need more info before I can come up with an estimate of the overall logistical needs of the invasion force.

RCgothic
04-10-2009, 21:57
I do not have the rule book at hand but I am almost entirely certain that the 2 million figure was for the planets IG garrison not the PDF. Those are rather different things.

Found it. Imperial Garrison Force: 2M.
Annual Planetary Tithe: 1.25M

If they're shipping 1.25M guardsmen offworld each year, I some how think that the PDF must be substantially larger than 2M.

Anyway, I've got casualty figures for the aircraft and armour done. The armour didn't have such a bad landing, as they didn't get down as quickly (Some regimental commanders complain the lack of armour support was the reason for the bad start.), but then take heavier casualties as they spearhead driving the orks from open terrain in the early months. The aircraft take heavy casualties until they destroy the enemy airforce, and then take only light casualties for the remainder of the campaign.

I've done some research, and WWII strategic/tactical bombers in the Marauder's payload range can drop 15k Kg in one sortie. I'd expect maybe 3 sorties per day in the initial stages of the campaign where air superiority is disputed, reducing to 2 as the focus terns to strike missions, for active squadrons.

Firaxin
04-10-2009, 22:04
As RCGothic says, that sounds like another example of GW's awful numbers, and in fact that figure isn't even internally consistent with what we know about how tithe obligations work.
Totally agree.


Again, planetary governors have to pay a periodic tithe of manpower from their PDF to supply the IG with soldiers, and the number of men required in that tithe will be determined by the Administratum based on the planet's population. So that governor will be in quite a pickle when the Imperium shows up to collect what's due and he doesn't have enough men.
The annual tithe was 1.25 million men. Which is just another reason to not invest too heavily in a force if it's getting cut down to just the green recruits every year.


There MUST be more PDF troopers in the Imperium than their are IG troopers.
I agree, again. But there are trillions upon trillions of people in the Imperium. Not every planet has to have the same Population:PDF ratio. Perhaps the example hive world made up the difference in munitions or something.


Then heavy-lift cargo shuttles, such as would be employed to shuttle down supplies to the central logistical dispersal points of the ground forces, can employ the same technology--which blows away your argument that drop pod resupply is desirable because it "uses ceramite resources instead of fuel resources".
My argument still applies. Look at this:
A______________________________________B_C

Where A is the central drop site, B is where the drop pods would be landing, and C is where front lines are. It's saving fuel by cutting out all the ground transportation between A and B. You're coming from space. You can land anywhere, supply lines may as well be obsolete, the real expenditure will simply be patrolling between A and B.

It doesn't even have to be drop pods, that was just an off the cuff suggestion I made on the assumption that the Orks have AA assets capable of reaching far past the front lines. If the air is safe, the Mass Lifters could come down at B, too.


RCGothic has thankfully decided that his campaign will use a reasonable method of resupply anyhow (i.e., shuttles, not drop-pods or "mobile forges" or teleportation), and so frankly I think we should drop this topic of discussion along with the topic of how many Marines should be in a chapter and whether GW numbers suck.
Fair enough.

Argastes
04-10-2009, 22:30
My argument still applies. Look at this:
A______________________________________B_C

Where A is the central drop site, B is where the drop pods would be landing, and C is where front lines are. It's saving fuel by cutting out all the ground transportation between A and B. You're coming from space. You can land anywhere, supply lines may as well be obsolete, the real expenditure will simply be patrolling between A and B.

No, you still are not thinking this through. The empty drop pods--thousands, or tens of thousands, or even hundreds of thousands of them every day--then have to be gathered up, loaded onto huge numbers of trucks, and carried to the shuttle LZs where they will be loaded onto shuttles (or "mass lifters" or whatever) to be carried back into orbit. And those LZs will be the same distance from the front, be it 20 miles or 1000 miles, that they would be if you were using the shuttles to carry supplies down instead of carrying used drop pods up. If you are assuming that shuttles have to land at point A on your diagram, then the empty drop pods will have to be transported overland from Point B back to point A so that they can be taken back up to the ships. You can't try to cheat by assuming that the shuttles which retrieve spent drop pods get to land closer to the front than the shuttles which deliver supplies.

Supply lines aren't going to become obsolete even when you can shuttle stuff down from orbit, because supplies are necessarily going to be delivered to a limited number of points on the planetary surface, and have to be distributed overland from there. Every platoon's daily allotment of supplies can't be shuttled down right to the platoon's metaphorical doorstep. The larger each individual supply shuttle is, and the more engineering work is required to prepare a large LZ, and the more cargo-handling gear is needed at the supply heads, the truer this is. There is also the fact that the LZs and associated supply dumps have to be far enough behind the front lines to be out of enemy artillery range. Obviously the ability to shuttle down supplies from orbit implies that supply lines can be much shorter than they would be if the supplies were coming from static sources on the planetary surface (cities or industrial centers or whatever), because you can keep moving the LZs so that they are always relatively near the front, but there will still be supply lines connecting the LZs to the front.

EDIT: I know I said we should drop this, but... I found myself compelled to respond.

Firaxin
04-10-2009, 22:59
No, you still are not thinking this through. The empty drop pods--thousands, or tens of thousands, or even hundreds of thousands of them every day--then have to be gathered up, loaded onto huge numbers of trucks, and carried to the shuttle LZs where they will be loaded onto shuttles (or "mass lifters" or whatever) to be carried back into orbit.
You're the only one suggesting the drop pods would be brought back into orbit. I think the AdMech would use their mobile-forges to smelt the used drop pods into more tanks. ;)

Argastes
04-10-2009, 23:34
I thought you said that IG drop pods were huge craft, much bigger than SM drop pods, with antigrav motors to slow their descent? Now you're saying they're disposable vehicles that will get shoved into a furnace after one use? And no, I'm not at all the "only one" suggesting that the drop pods would be reusable. In fact, when you first proposed the idea, my assumption was that they'd be disposable, and I said so, which you'll see if you go back and read over the thread again. But other posters suggested otherwise... as did your own description of IG drop pods, taken from the Last Chancers story you mentioned, as gigantic antigrav-powered things. Stop trying to squirm about here.

You just keep going around and around with one ridiculous statement after another. It's a waste of time. It's obvious that you are totally fixated on these silly drop pod/mobile forge schemes, and it's equally obvious that you haven't thought them through beyond the point of "it sounds cool", and it's also obvious that you are just going to keep on making whatever claims are needed--no matter how fabulist--to justify/rationalize them. Which you really should be ashamed of yourself for doing in a thread where the OP is trying to get actual, reasonable, makes-sense information about the logistical needs of a large military force. Again, thankfully, RCGothic hasn't bought into your nonsense. I'm done with it too.

randian
05-10-2009, 02:07
How about another scenario? The Imperium discovers Earth, and wants to make us part of their empire, whether we want to or not. Our technology is good enough that, assuming the Imperium wants to preserve Earth's people and infrastructure (a quite reasonable assumption for a first-class planet I think), I don't think the Imperium could win unless it puts crusade-level resources into accomplishing it. If they try a years-long war of attrition instead, it just gets worse for them, because unlike the Mechanicum we don't have stupid religious hangups about technology. The amusing thing is that keeping its citizens pig-ignorant about everything paradoxically helps the Imperium, because we couldn't capture enemy soldiers and interrogate them about how all their stuff works, we have to go the slower route and reverse-engineer them from first principles.

Argastes
05-10-2009, 04:16
How about another scenario? The Imperium discovers Earth, and...

Interesting idea. I recommend you start a new thread about it, since this thread has it's own topic, which we are in the middle of hashing out.

Marshal2Crusaders
05-10-2009, 09:23
Ok, for the Space Marines not being able to subdue a planet argument, I have some comparisons.


First, lets establish an example so that everyone can understand my comparisons.
1 Space Marines= Master Chief on Normal, without the super acrobatics. I will also add that you are more vulnerable due to your enemies having access to more lethal weapons, artillery, and so on. But...

Before you cry halo noob, or that the universes arn't compatible, just think about how you chew threw the enemy, now add 8 buddies and one badass veteran. That would be a fair comparison for a squad of Space Marines. Now multiply your ability by a BC size strength. Yes, you would be quite capable of subduing a city. In the Halo's you frequently dominate and plow through a city with little to no trouble, running through gunfire. Now, the Master Chief doesn't hold cities, that isn't what he is for, but he does ravage them and leave them ghost towns. That is why Space Marines are so effective, they erase your enemy from your city.*

A Chapter of Space Marines, is in this specific scenario, with abilities about on the level I have described, very able to take a planet, because well, there wont be many people left. The White Flag has no significance, things like winning the hearts and minds of those not killed in the crossfire is for the IG. Scenarios of insurgency and terrorism are Guard exclusive (unless it happens on an SM homeworld, or a contested world), things like kids with soda bombs grenades wouldn't happen because they would just kill the kid anyway.

Logistically, SM's are their own deal. They are designed for lightning raids and heavy hits, so they carry what they need with them, but like paratroopers they arn't meant for slugfests(bad comparison, but work with me) and actually would suffer worse than a GEQ if caught in such an engagement. See IA:3, where the Avenging Sons got caught on the ground against the Tau, who spanked them. So, fighting on their own, they would resupply themselves. Fighting at somewhere like Armageddon, they would rearm until the run out of supplies on the BBs, then they need Mechanicus Support. It also depends on the Chapter, the Templars can just park a Crusade Fleet in orbit and as long as they have raw materials, they just make what they need on the forge ships. The Ultras are not so lucky, as they have to resupply from Ultramar, hence why they stick to the Eastern Fringe. Chapters like the Dark Angels and Imperial Fists are even luckier, because if a Crusade Fleet is self sustaining, then a warship built like a planet is way better.




*Based on unaltered human level comparisons. Xenos throw a wrench into the equations so just take what I have said at the low trained, guard equivalents that make up most cult forces and rebels.

Sai-Lauren
05-10-2009, 11:24
A weekend full of stuff to comment on - so, sorry for the length of post, but here we go.



Because the AdMech advances with the Guard and produces everything from food to ammunition for them, in the field, through whatever mobile forge-units they've brought with them.


I've never heard this in the fluff, and it's laughably impractical anyhow.


I'd say that most of the stuff that the guard uses is produced by bodies such as corporations (such as the industrial houses on hove worlds), or is taken from planets as part of the tithe.

The AM does not, cannot, and almost certainly will not produce every single boot, mess tin or bandage that the guard need. They don't even make every single armoured vehicle (for example, Armageddon produces Chimeras, likely under license from the AM).



Any fluff support for the idea that the Navy is capable of doing this sort of resupply via precision-guided drop pods, especially over the long term and for millions of men? Again, bearing in mind that an infantry division is going to consume at the very least dozens of tons of supplies per day, and an armored division will consume thousands of tons per day when on the offensive? For a multi-year campaign with hundreds of millions of men, the Navy is going to need literally billions of these disposable, precision-guided supply-delivering reentry pods. Again, laughably impractical.

Agreed, Marines possibly could for a limited time away from base (they'll eventually need to get back for maintenance if nothing else), as could SFs and the like, who can potentially live off the land and get supplies from sympathisers, but not the Guard as we are talking about them here.



Realistically, it's absurd to expect a large unit to rotate out from the front every time it needs to be resupplied, because it is going to need resupply constantly. As in, every day. They will need constant delivery of supplies to the fighting elements. Units, especially mechanized/armored/artillery units, will become totally unable to keep fighting within 24 to 48 hours if they are cut off from their logistical lifeline. Do some research into the logistical realities of mass warfare. It's a lot more complicated than you make it out to be.

Bastogne.

During the Ardennes campaign it was effectively cut off (one supply air drop worked, a previous one only supplied the German forces encircling them and the weather prevented any more IIRC), and held out.



Again; Dark Apostle, where the AdMech advances with the Guard with their mobile forges (forget the term used for them) producing ammunition, food, etc.

Written by? And was it a rejected C&C universe novel - because all you need is a mobile construction vehicle and mining for resources, and you'd be about there! ;)



They do it for the Elysians. They even have models for the crates of supplies that they drop in for them. You'd just have to scale the number of supply ships so they can do the same for a 2M Guard force.

Are those crates dropped along with the Elysians? If so, then chances are they're the intial supply reserves so that they can hold a beachhead whilst the rest of the guard get dropped conventionally.



You wouldn't even have to recover them, the AdMech navy present could mine in system asteroids/produce new ones, etc.

:eek:

As I've said before, the Imperium is rich, but not infinitely so. What you're proposing is outrageously expensive, plus you'd need to have a fleet permenantly on hand to protect it, supply it resources etc.

There's also the question of time - you've got to mine out the ores, smelt them down to produce the metals, mix them to make alloys or ceramic precursors, make the pods, transport them from the factory ship to the planet, then load them and drop them. And after the campaign, you've suddenly got a load of old drop pods that need to either be dragged up to orbit and taken to the next campaign, or scrapped.



Also, dropping objects from orbit DOES require fuel, you need fuel for a separation and de-orbit burn... if you just release an object from a ship in orbit, it will remain in the same orbit as the ship that released it. It's sad how many people think that ships in orbit are like bombers and can just "drop" things.

Fuel, or maybe just a big spring (which IIRC, is effectively what the Space Shuttle uses to launch satellites from its' cargo bay :D).

But yes, you will need to expend fuel to drop something from orbit, either on the item that's coming down, or on the dropping craft to orientate it. And then fuel on the way through the atmosphere to counter wind shifts and turbulence and make sure it gets to it's intended spot.

And the drop pod can't lift casualties back to orbit for major surgery that planet based medical facilities cannot deal with.



Obviously when the IG invades a planet, their supplies are in orbit to begin with and have to get down to the surface. That's not in question. The question is what's the best way to get them down there: Shuttling them down to supply heads from whence they will be transported via ground vehicles/aircraft to the FEBA, or dropping them directly into the FEBA via drop pods of some sort? I'm saying that the former option is more practical and efficient, and should therefore be the basis of a large force's logistical system.

Agreed.

Although I would say there would be some front-line drops of supplies, but mostly as emergency relief drops etc, not as regular supplies.



The Sabbat Worlds Crusade consisted of 1 billion Guardsmen and theres no indication that its considered unique in Imperial history.

Also those 300 ships were 300 warships. Given that the average sector battlefleet is 50-75 warships that not unreasonable as an atypically large concentration. However a sector battlefleet also has an unspecified number of support vessels and there are the ships of a sectors civilian fleet to account for. A crusade fleet numbering in the thousands isn't unfeasible, it would just represent the greater part of a single sectors shipping capacity and consist almost entirely of lightly armed or unarmed vessels.

The Sabbat Worlds crusade was for a sector, not a single system.

We're talking about a single world in a single system.



Leman Russ have a damaged thingamabob? Just use the mobile forge to create a new one instead of having to wait 6 months for an order to go in and a replacement to get here. You'd still have to bring in raw materials, and you'd want to bring in normal stuff like replacement tracks, fuel, food, ammo, and common spare parts. But if some rare widget broke, you wouldn't be out of commission very long because you could just make the part right there.

Hmm, and I thought the Imperium didn't have STC systems anymore. Because that's effectively what you've just given them.

Armoured, mechanised and other regiments with vehicles (which includes the Regimental level transport pool for infantry regiments) would have spares available, plus a machine shop organic to at the very least regimental level (and more likely company level) to make or repair things, and there's always battlefield casualties to cannibalise.



Second, we're invading an Imperial world, so one of our big priorities will be to get to the food and ammunition storage areas. You'll probably bring along enough fuel and supplies to keep your initial invasion force going for like three months. By the end of that time, you expect you'll have seized resources that are already on planet. It's much easier to seize a prometheum refinery on the southern continent than it is to ship fuel in from halfway across the galaxy.

True, but until you get there (and presuming it's not already destroyed/consumed or you don't damage it in the fighting), you're going to need to ferry supplies in. You'll probably still need to ferry some supplies in until the end of the campaign.

Fuel supplies, food production, on planet weapons/ammunition manufacture, even locally supplied troops - they're all a long way down the line.



My argument still applies. Look at this:
A______________________________________B_C

Where A is the central drop site, B is where the drop pods would be landing, and C is where front lines are. It's saving fuel by cutting out all the ground transportation between A and B. You're coming from space. You can land anywhere, supply lines may as well be obsolete, the real expenditure will simply be patrolling between A and B.

If A to C is three miles, then it's not worth having B at all.

If A to C is three hundred miles, you'd also get D, E, F and G (if not somewhere up to Q) along the way - settlements, supply depots and landing fields set up or captured during the advance. "A" will probably be the major heavy item handling site (Titans, Super Heavies etc), as it's the oldest and best set up, but the others will still be able to handle the supply shuttles coming in. You also get the redundancy of multiple supply depots, so that if one gets taken, all your forces don't starve, shuttles can land where there's good weather, rather than risk a landing in poor weather and so on.

And the front lines aren't the only thing you need to supply, there's the general staff, the pilots and mechanics/ground crew at airfields, maritime forces if there's any bodies of water, Military Police, regimental support staff, any garrisons you leave behind to defend installations, the transport network and so on from guerillas or fifth columnists, supply convoy drivers, mechanics, warehousemen and cargo handlers, engineers to maintain the transport network, field hospitals and so on.

And that's assuming you don't need to supply relief to the civilian population, if you do, then it's extra food, clothing, blankets, medicine, construction supplies to house them, troops/MPs to prevent looting and act as a police force until a proper one can be set up, and so on.

As I've implied before, and am now stating catagorically, we've got a historical example to work from - the second world war from D-Day on.

Finally, we had an Imperium vs 21st Century Earth thread a couple of weeks ago.

Let's not have another one just yet, please?

RCgothic
05-10-2009, 11:42
Working from the casualty figures I've determined, and using an average month length of 30.4 days, this invasion uses:


19.6 billion man-days for active guard units.
22 billion man-days for reserve guard units
93 billion man-days for munitorum units

57.5 million-tank days for active armour/artillery units
74 million-tank days for reserve armour/artillery units

21.3 million aircraft-days for active squadrons
22.5 million aircraft-days for reserve squadrons


Approximating argastes advice,:
Active guard units consume 200T per day per 15k troopers (assuming totally motorised, and substantial mech).
Reserve guard units consume 50T per day per 15k troopers
Munitorum units consume 80T per day (taking into account engineering/construction work) per 15k troopers

Active artillery/tanks consume 10,000T per day per 100 vehicles
Reserve artillery/tanks consume 100T per day per 100 vehicles

Aircraft squadrons composed 2/3rds fighters/transports/gunships and 1/3rd tactical/strategic bombers:
Active bomber squadrons: 40,000T per day per 100 aircraft
Reserve Bomber squadrons: 150T per day per 100 aircraft
Active other squadrons: 4000T per day per 100 aircraft
Reserve other squadrons: 100T per day per 100 aircraft

This gives a total supply requirement (just for planetside forces) of:
10 billion tons.

That approximates to almost 40 cubic kilometres of supplies, assuming a density half way between petroleum and Iron. Stacked 10 metres high that requires a depot that takes up 4000 square kilometres.

EDIT:


The Sabbat Worlds crusade was for a sector, not a single system.
100 worlds IIRC, and perhaps 6-10 of those were heavily contested at any one time (3 on each crusade front). That gives 100M guardsmen per theatre of operations, and combined with the reduction in forces required for the softer targets (such as only a couple of regiments required for worlds such as Heridor, Haigia and Phantine) and you easily get up to the 270M required for this planet. Dan Abnett at least knows what he's talking about.

Sai-Lauren
05-10-2009, 12:40
EDIT:

100 worlds IIRC, and perhaps 6-10 of those were heavily contested at any one time (3 on each crusade front). That gives 100M guardsmen per theatre of operations, and combined with the reduction in forces required for the softer targets (such as only a couple of regiments required for worlds such as Heridor, Haigia and Phantine) and you easily get up to the 270M required for this planet.

It's not going to be a case of take and move on, it's going to be more like assault, take, hold, defend, reinforce, rebuild, move to next system where the navy's established dominance at worst, with the assault forces designed to make a beachhead going first.

Some of those guardsmen will be in the rear, on R&R, on training for specific missions on the next world, combining with other regiments, or even simply being used to garrison recovered worlds, hunting down fifth columnists and helping to rebuild their infrastructure (from building houses to training the new PDF).

Others will be in transit to the target system, their journey time planned so that they arrive at the appropriate time to be deployed, meaning they're not consuming supplies whilst sat around in orbit twiddling their thumbs waiting to go, or at risk if the naval control is lost.

And even the "softer worlds" may need a considerable sized reserve force in place, as a defence force if the system is attacked (the warp links are the quickest and safest routes to travel, but they're not the only routes that can be travelled, so a world that's behind the lines and "safe" could be attacked very easily), and as a dispersal point to be sent to the front lines, rather than all being assigned to specific theatres and then having to travel again from an easily conquered world to a more difficult one.

There's probably also advance units, that will go into a "soft" enemy held system and either infiltrate to aid local resistance groups, lie low to support the attack directly when it comes, or attack certain installations now to take them or deny them to the enemy if the assault force left just after them.

Not saying they wouldn't get those numbers that they need to retake the world, just saying that they wouldn't necessarily get them all in one go. ;) If they need 270 million guardsmen, then it might be planned as a 10 year campaign, with an initial 50 million and then 20 million a year average for five years and 8 million a year average for the remaining time, with the assumption being that local forces and supplies will become available for use over time.

If the numbers don't match up to projections a few years down the line, then the general in charge would be able to appeal to the Munitorium for more troops, but they would have to justify them being sent - and the justification might be his poor planning and the price his head.



Dan Abnett at least knows what he's talking about.
Think that's the first time I've ever heard that said on Warseer... :D

Argastes
05-10-2009, 13:03
Glad you're using my numbers, but a few quibbles:

200 tons/day is bit low for "substantially" mechanized infantry. The 50-200 tons/day figure was for straight-leg infantry. A mechanized infantry division will consume a lot more than that when on the move. I'd decide what percentage of the infantry is mechanized and what percentage isn't, and use 200 tons/day/15K for the non-mech forces and maybe 2000 tons/day/15K for the mech forces.

Conversely, 10,000 tons/day for every 100 tanks/SPGs is too high. I suggested 10,000 tons/day for every 500 such vehicles, based on the consumption of a modern US heavy division which has about 500 vehicles in a roughly even mix of Abrams and Bradleys. And even then, 10,000 tons/day is a maximum; that's how much they would consume in a day of rapid advance with hard fighting, they surely wouldn't be consuming that much every day of the campaign. I would use a figure of maybe 3000 tons/day per 500 vehicles, to represent their mean consumption averaged out over some days of going on the offensive, and other days of not moving/shooting much.

The numbers for aircraft may also be a bit high. 40,000 tons per day per 100 bombers suggests that each bomber and associated ground crew, support vehicles, etc. is consuming 400 tons per day, which is quite high even if they are flying a sortie every single day of the campaign. A modern B-52 holds, at the absolute maximum, about 140 tons of fuel and bombs (and will usually carry less). I would drop that number to somewhere around 5000 tons per day per 100 bombers, which indicates a daily per-bomber consumption of 50 tons (again, representing their mean consumption averaged out over some days of flying two sorties a day, other days flying one, and other days flying none). Similarly, with each 100 fighters consuming 4000 tons per day, you're looking at a per-aircraft daily consumption of 40 tons, which is quite high for fighters or attack craft; a fully laden F-15 (which are BIG planes) carries only 18 tons of consumables, and will usually carry less. I would suggest maybe 1500-2000 tons per day per 100 fighters/attack craft, again representing average consumption for planes that fly sometimes one, sometimes two, and sometimes no sorties in a day.

Anyhow, if you take these figures into consideration, they will of course change your ten billion tons figure, but just looking at that figure for the sake of discussion, it's not unreasonable in terms of shipping requirements. If the "average" cargo ship has 0.0625 cubic km of hold space (equivalent to a hold one kilometer long and 250 meters wide by 250 meters high, although of course this space will probably be divided into multiple separate holds instead of being one huge hold), which I don't think is unreasonable in a universe where warships are several kilometers long, it would take roughly 640 such cargo ships to carry the entire 10 billion tons that will be needed by the invasion force for the duration of it's campaign. Each ship would have about 15 million tons of cargo on board.

Sai-Lauren
05-10-2009, 14:34
Argastes, just one thing I would ask - does that x thousand tonnes/unit/time include the packing crates, boxes, drums etc that the supplies would come in, or just the supplies themselves?

But if we work on 640 cargo ships and assume a 10 year campaign, that's only just a little more than 1 a week on average (and you'd probably get 1-2 months worth arriving at a time in a convoy, along with the next load of troops to send down).

Unloading those size ships is going to be the next problem though, you'd almost certainly need some kind of orbital facility in place for the freighters to dock to, rather than them making planetfall. Even if they do, probably only the main space ports will be able to handle them, so you're stuck until you either take one intact enough to use or construct your own.

MontytheMighty
05-10-2009, 14:37
against less advanced opponents, maybe terror tactics would be more efficient

instead of launching a planetary ground assault, the Imperium could destroy a few of the largest cities from orbit and then "request" that the native government and military submit (sort of like what the Allies did to Japan), just let your enemy know they're outclassed (if that indeed is the case)

if the planet has heavy space-based defenses on par with the Imperium's technology, then of course this probably wouldn't work

Argastes
05-10-2009, 14:52
Argastes, just one thing I would ask - does that x thousand tonnes/unit/time include the packing crates, boxes, drums etc that the supplies would come in, or just the supplies themselves?

You know, that's a good question. I based my estimates on real-world figures from various military history texts I have on my shelf, but none of them actually mention whether their numbers include packing materials. I would suspect that they do, because these numbers are what commanders used to plan the logistical side of their campaigns (and so they would need to know the total transport capacity they'd need to deliver stuff to their troops), but I can't say for sure because the reference books I'm using don't clarify.


But if we work on 640 cargo ships and assume a 10 year campaign, that's only just a little more than 1 a week on average (and you'd probably get 1-2 months worth arriving at a time in a convoy, along with the next load of troops to send down).

Ah, unfortunately, if we assume a ten year campaign, the amount of supplies will increase several times over.... the 10-billion-ton figure that RCGothic provided, and thus the 640 ships that I estimated, was based on a campaign lasting only 18 months. So that's a bit over one ship per day--in practice, maybe a convoy of 8 or 9 ships arriving once per week. Of course we could also assume bigger ships if we wanted. In real life, huge cargo vessels like ULCCs and Emma Maersk-type container ships are substantially larger than even the biggest warships (Nimitz-class CVNs). So it might not be unreasonable for huge Imperial cargo vessels to be even bigger than Emperor-class battleships, in which case they could have much larger hold capacties than the 0.0625 cubic kilometers (1000 x 250 x 250 meters) I estimated. How big are Imperial battleships? My understanding is that they're several thousand meters long at least...


Unloading those size ships is going to be the next problem though, you'd almost certainly need some kind of orbital facility in place for the freighters to dock to, rather than them making planetfall. Even if they do, probably only the main space ports will be able to handle them, so you're stuck until you either take one intact enough to use or construct your own.

I'm assuming that the actual interstellar cargo ships would be flat-out incapable of making planetfall even at a huge spaceport; the supplies would be ferried down to the surface by heavy-lift cargo shuttles similar to the big landing craft that are used to put IG troops/tanks (or titans) onto planetary surfaces. I don't think an orbital facility or space station would be necessary or desirable; seems like it would just complicate the cargo-handling process. I see the shuttles docking directly with the cargo ships; each hold would have a suitably large docking lock for this purpose, and automated cargo-handling gear to move containers from the hold into the shuttle's cargo compartment(s). The shuttle would then decouple, de-orbit, descend to the planetary surface, land, unload, lift off, return to orbit, and dock with a cargo ship again to take on another load. Of course these shuttles are huge in their own right and will also have to be quite numerous, so the invasion fleet will have to include "carriers" for them in addition to the actual cargo ships (though fortunately, it would be possible to have some supplies, probably whatever mix of stuff is projected to be needed by the initial landing forces, pre-loaded into the landers when the invasion fleet sets out--this would reduce the number of normal cargo ships required, and prevent the lander carriers from wasting capacity by carrying landers that are full of empty space).


against less advanced opponents, maybe terror tactics would be more efficient

instead of launching a planetary ground assault, the Imperium could destroy a few of the largest cities from orbit and then "request" that the native government and military submit (sort of like what the Allies did to Japan), just let your enemy know they're outclassed (if that indeed is the case)

if the planet has heavy space-based defenses on par with the Imperium's technology, then of course this probably wouldn't work

Monty, this thread is about what sort of logistical support would be required for an IG invasion force trying to reclaim a planet from Orks. The OP has devised a specific scenario and wants to know what quantity of supplies it would involve. It's not a thread about how the Imperium might conquer/defeat planets in general.

RCgothic
05-10-2009, 15:01
200 tons/day is bit low for "substantially" mechanized infantry.
With 20% mech, the total figure for both mech and motorised adjusts to 560T per 1500 per day.


Conversely, 10,000 tons/day for every 100 tanks/SPGs is too high. I suggested 10,000 tons/day for every 500 such vehicles, based on the consumption of a modern US heavy division which has about 500 vehicles in a roughly even mix of Abrams and Bradleys.
I consider AFVs like the Bradley or Chimera to be included under mech. What I'm considering here is MBTs like the Leman Russ, Superheavies such as the baneblade/shadowsword, and Heavy Artillery pieces such as the basilisk, collosus and bombard laying down a constant barrage. Given these considerations I've reconsidered to 3000T per 100 per day. I consider units not actively involved in fighting to be in reserve.



The numbers for aircraft may also be a bit high. 40,000 tons per day per 100 bombers suggests that each bomber and associated ground crew, support vehicles, etc. is consuming 400 tons per day, which is quite high even if they are flying a sortie every single day of the campaign. A modern B-52 holds, at the absolute maximum, about 140 tons of fuel and bombs (and will usually carry less). I would drop that number to somewhere around 5000 tons per day per 100 bombers, which indicates a daily per-bomber consumption of 50 tons (again, representing their mean consumption averaged out over some days of flying two sorties a day, other days flying one, and other days flying none). Similarly, with each 100 fighters consuming 4000 tons per day, you're looking at a per-aircraft daily consumption of 40 tons, which is quite high for fighters or attack craft; a fully laden F-15 (which are BIG planes) carries only 18 tons of consumables, and will usually carry less. I would suggest maybe 1500-2000 tons per day per 100 fighters/attack craft, again representing average consumption for planes that fly sometimes one, sometimes two, and sometimes no sorties in a day.
I did base my numbers on modern aircraft, but I can't for the life of me remember how I arrived at my figures.

Bombers adjusted down to 10,000T per day, fighters to 2,000T per day.


That adjusts the figure down to 4 billion tons, but I've just remembered that deploying and retrieving the forces takes 3 months. 3 months on reserve adds another 0.13 billion tons, for:

4.14 billion tons, 16.5 cubic kilometers, 264 tranport runs with transports with hold capacity 250m x 250m x 1km.

Taking into account the 3 month supply run, and then assuming half a month to load/unload, you can get 3 round trips in max. That reduces the number of transports needed to 88, which sounds reassuringly in the right ballpark, considering perhaps a fleet of perhaps 30 warships as escort.

Now we need to factor in transports required for moving the troops themselves around. How much space do 270M guardsmen and 400k fighting vehicles take up?

Argastes
05-10-2009, 15:57
With 20% mech, the total figure for both mech and motorised adjusts to 560T per 1500 per day.

:eek: Per 15,000 I hope you mean! Assuming so, that sounds reasonable.


Now we need to factor in transports required for moving the troops themselves around. How much space do 270M guardsmen and 400k fighting vehicles take up?

Well, the vehicles are fairly easy. According to Imperial Armor, an LRBT measures ~7 meter long, ~4.8 meters wide, and ~4.4 meters high. So it's going to occupy a 'box' of ~147 cubic meters. But obviously they can't actually be stacked in a hold with no space between them. I would estimate maybe 250 cubic meters of hold space required per vehicle (and even that's assuming quite efficient use of space, but it should be possible on a starship where the holds can be left in zero-G and the vehicles stored in stacked layers using some sort of palletised system). This means that our cargo ships with 1000 x 250 x 250 meters of hold space should be able to each carry 250,000 LRBTs or equivalently sized vehicles (Chimera-based self propelled artillery, etc.), so you'd only need two such ships to carry all the tanks/SPGs of the invasion force--maybe three if a significant portion of the armored vehicles are larger than LRBTs.

The Chimeras for the mechanized infantry, though, will take up a lot more space. You said that 20% of the invasion force's infantry are mechanized, which means 18 million mech. infantry, which means ~1.8 million Chimeras. Imperial Armor says a Chimera is ~7 meters long, ~5.6 meters wide, and ~3.7 meters high, meaning that it coincidentally also takes up a 'box' of ~147 cubic meters. Again, let's assume 250 cubic meters of hold space per vehicle, thus 250,000 vehicles per ship if we stick with our 1000 x 250 x 250 meter holds, thus the Chimeras will need another seven or eight such ships.

Okay, that brings us to personnel: 270 million of them. How much living space is required per berth in a troop transport? Obviously they are pretty cramped, but we need an actual cubic meters figure... apparently, modern nuclear submarines tend to have about 10-12 cubic meters of living space per crewman. Going with 10 cubic meters per man, this means about 6.25 million men per ship if each troopship has the same volume of berthing space than the cargo ships have of hold space. So your 270 million personnel would require another ~45 ships to transport them. Of course bear in mind that this doesn't mean that each Guardsmen has a ten-cubic-meter cabin; in terms of personal space, he probably only has a narrow bunk in a berthroom with hundreds of other guys. But there are the galleys, mess halls, storage rooms for gear, all sorts of corridors and companionways, and so forth to consider. Plus the life support equipment that will be needed to keep 6 million people alive for three months, but frankly, that's too much trouble to calculate, so let's just assume that a troopship with 0.0625 cubic km of berthing space is larger (by an unspecified amount) than a cargo ship with the same volume of hold space, due to the life support plant and associated consumables.

EDIT: Oh yeah, aircraft... they would probably take up another 1-2 cargo ships. There are obviously fewer aircraft than their are tanks/SPGs, but X tons of tank obviously takes up less space than X tons of airplane.

RCgothic
05-10-2009, 16:20
So we're looking at in the region of 264 supply runs Staging-->Theatre and 57 return trips for all the troops involved. We're probably looking at in the region of 145 transports until someone thinks up a supply scheme that doesn't leave 57 troop transports sitting in orbit for the duration of the campaign leaving all the supply work to the other transports.

Then there's the supplies each transport requires. To load/disembark 6.25 million troops in half a month would require each transport to have ten 2500 man drop ships each making 16 flights per day. You'd need enough fuel for all those flights, for the warp transitions, food for the crew, etc.

massey
05-10-2009, 16:47
Ok, for the Space Marines not being able to subdue a planet argument, I have some comparisons.


First, lets establish an example so that everyone can understand my comparisons.
1 Space Marines= Master Chief on Normal, without the super acrobatics. I will also add that you are more vulnerable due to your enemies having access to more lethal weapons, artillery, and so on. But...

Before you cry halo noob, or that the universes arn't compatible, just think about how you chew threw the enemy, now add 8 buddies and one badass veteran. That would be a fair comparison for a squad of Space Marines. Now multiply your ability by a BC size strength. Yes, you would be quite capable of subduing a city. In the Halo's you frequently dominate and plow through a city with little to no trouble, running through gunfire. Now, the Master Chief doesn't hold cities, that isn't what he is for, but he does ravage them and leave them ghost towns. That is why Space Marines are so effective, they erase your enemy from your city.*

A Chapter of Space Marines, is in this specific scenario, with abilities about on the level I have described, very able to take a planet, because well, there wont be many people left. The White Flag has no significance, things like winning the hearts and minds of those not killed in the crossfire is for the IG. Scenarios of insurgency and terrorism are Guard exclusive (unless it happens on an SM homeworld, or a contested world), things like kids with soda bombs grenades wouldn't happen because they would just kill the kid anyway.

Logistically, SM's are their own deal. They are designed for lightning raids and heavy hits, so they carry what they need with them, but like paratroopers they arn't meant for slugfests(bad comparison, but work with me) and actually would suffer worse than a GEQ if caught in such an engagement. See IA:3, where the Avenging Sons got caught on the ground against the Tau, who spanked them. So, fighting on their own, they would resupply themselves. Fighting at somewhere like Armageddon, they would rearm until the run out of supplies on the BBs, then they need Mechanicus Support. It also depends on the Chapter, the Templars can just park a Crusade Fleet in orbit and as long as they have raw materials, they just make what they need on the forge ships. The Ultras are not so lucky, as they have to resupply from Ultramar, hence why they stick to the Eastern Fringe. Chapters like the Dark Angels and Imperial Fists are even luckier, because if a Crusade Fleet is self sustaining, then a warship built like a planet is way better.




*Based on unaltered human level comparisons. Xenos throw a wrench into the equations so just take what I have said at the low trained, guard equivalents that make up most cult forces and rebels.

No offense, Halo noob, (:)) but Space Marines aren't going to be able to pull that off. There's a world of difference between an action video game and planning an invasion. I mean, forget the Master Chief, just send in those two guys from Contra. They should be able to stop a nid invasion all by themselves.

Let's say you're going to send a squad of marines rampaging through, oh, Dallas. Either they stay together or they split up. If they stay together, they're going to have a hell of a time covering the entire city. Dallas is about a thousand square kilometers (or 385 square miles). So it's big. To big for a squad of marines to cover. They can't carry enough ammo to kill Dallas' 6 million inhabitants. And that's 6 million Texans, many of whom are armed with guns (and some of those guns are actually shaped like the state of Texas). There's simply no way for the marine to cover ground effectively. Watch as he spends 6 hours walking down the freeway, trying to get from one end of the city to the other.

MontytheMighty
05-10-2009, 17:09
There's simply no way for the marine to cover ground effectively. Watch as he spends 6 hours walking down the freeway, trying to get from one end of the city to the other.

point being you have to have enough marines to allow you to split your forces

Argastes
05-10-2009, 17:20
Ahhhhh!! Stop it, all of you! Go start a new thread if you want to argue about Master Chief and how many Marines could take over a city! This thread is not about that! It's about IG logistics and the problems of supplying a large force over interstellar distances! It has absolutely nothing to do with Space Marines! How is it that no matter how little a thread has to do with Marines, someone ALWAYS manages to derail it into a Marine discussion?

MontytheMighty
05-10-2009, 17:34
Monty, this thread is about what sort of logistical support would be required for an IG invasion force trying to reclaim a planet from Orks. The OP has devised a specific scenario and wants to know what quantity of supplies it would involve. It's not a thread about how the Imperium might conquer/defeat planets in general.

fair enough, he did explicitly say:


I was thinking the other evening about how big a fleet would need to be in terms of volume in order to move a planetary invasion force, and wondered if the military minded amongst warseer could help.

Imagine an invasion of a planet of similar military resources to modern day Earth. According to wikipedia, the planet has at its disposal in the region of:


20M active troops
35M reserve troops
30M paramilitary troops
90k tanks
30k military aircraft
1.3k military surface vessels.


Let's assume that these forces are of similar to Imperial technology and you can't simply bombard them from orbit. My questions are:


What size of force would be required to defeat an enemy such as that detailed above?
What additional logistical support would such a force require (such as drop ships, field hospitals, supply and distribution)?
What volume of cargo space would all of the above take up?
Finally, how many starships would be required for transport?


If we approach the questions one by one I'm sure we can get a reasonable ballpark figure. To start with, I'm sure that a successful invasion requires more forces than the defenders have. Is 150-200% reasonable?

however I didn't read anything about orks in the original post...of course, if orks are the enemy and reclaiming is the goal then none of what I've said would be effective

I don't want to derail this thread but let's say the planet in question is occupied by non-Imperium humans or what could be termed a "reasonable" race. If such were the case, I think a planetary ground assault would be the last option a commander would want to employ or at least way down the list.

I guess you guys are assuming a scenario in which a full-scale ground+air invasion is somehow the best option, but I feel that what I said above isn't totally irrelevant as the original post only really mentions the subjugation of a planet with orbital defenses. I think the main objective should be disabling the orbital defenses.

Taking out orbital defenses and then letting the defenders know that their cities could be bombed at will (and giving them just a taste of the potential destruction) would seem to be a cheaper alternative in many cases.

Argastes
05-10-2009, 17:35
I didn't read anything about orks in the original post though...of course, if orks are the enemy and reclaiming is the goal then none of what I've said would be effective

This is why you should read the whole thread before responding, not just the OP. The thread is about IG invading an Ork-held hive world. RCGothic made that clear just a few posts down on the first page of the thread.


I don't want to derail this thread but let's say the planet in question is occupied by non-Imperium humans or a race prone to fear. I think a planetary ground assault should be the last option a commander would want to employ or at least way down the list unless of course we're talking about a valuable planet infested by orks and tyranids.

I agree, that is a fair point; against a rebellious Imperial planet, or some other planet held by forces that might be 'persuaded' to surrender by space-to-ground bombardment, forcing surrender in this way would be far more desirable than launching a surface campaign. But in the case that the OP has laid out for us here, that option isn't viable.

MontytheMighty
05-10-2009, 17:38
This is why you should read the whole thread before responding, not just the OP. The thread is about IG invading an Ork-held hive world. RCGothic made that clear just a few posts down on the first page of the thread.
I agree, that is a fair point; against a rebellious Imperial planet, or some other planet held by forces that might be 'persuaded' to surrender by space-to-ground bombardment, forcing surrender in this way would be far more desirable than launching a surface campaign. But in the case that the OP has laid out for us here, that option isn't viable.

OK sorry about that :P

Argastes
05-10-2009, 17:41
Sorry, I didn't mean to sound like a jerk. It's just that this thread topic is quite interesting, and it's nice to see 40K warfare examined from a realistic military-science standpoint for a change, and I don't want to see it derailed into areas that have nothing to do with the OP's topic. Again, sorry if I sounded harsh.

Firaxin
05-10-2009, 19:53
I thought you said that IG drop pods were huge craft, much bigger than SM drop pods, with antigrav motors to slow their descent? Now you're saying they're disposable vehicles that will get shoved into a furnace after one use?
Yes. Anti-grav/grav chute technology isn't exactly rare in the Imperium. Deep striking guardsmen use disposable grav chutes all the time.


you really should be ashamed of yourself... Again, thankfully, RCGothic hasn't bought into your nonsense. I'm done with it too.
I admit that we have belabored a somewhat off-topic point for longer than was necessary, but at least I kept my cool the whole time. You've been hostile since your first response, and arrogant. Neither of which is needed to get your argument across; Sai-Lauren's gentle reminder that you have to feed all the mechanics/general staff/convoy drivers/surgeons/etc between points A B has convinced me of your point.


Written by? And was it a rejected C&C universe novel - because all you need is a mobile construction vehicle and mining for resources, and you'd be about there! ;)
Anthony Reynolds. And they weren't dinky things, they were veritable mobile forges, as large or larger than Capitol Imperialis super heavies, kilometer+ long constructs.


So it might not be unreasonable for huge Imperial cargo vessels to be even bigger than Emperor-class battleships, in which case they could have much larger hold capacties than the 0.0625 cubic kilometers (1000 x 250 x 250 meters) I estimated. How big are Imperial battleships? My understanding is that they're several thousand meters long at least...
BFG: Armada has rules for Heavy Tranports equivalent in mass to a Cruiser. This would make them ~ 4000m x 500m x 500m.


aircraft... they would probably take up another 1-2 cargo ships. There are obviously fewer aircraft than their are tanks/SPGs, but X tons of tank obviously takes up less space than X tons of airplane.
Outside of abnormal situations, the navy carries atmospheric aircraft wings in the fighter bays of their warships, not transports.

Marshal2Crusaders
05-10-2009, 22:24
For a deployment if this size you would need one of the imperiums force multipliers. Like titans or space marines.

Phytrion
05-10-2009, 23:05
Working from the casualty figures I've determined, and using an average month length of 30.4 days, this invasion uses:


19.6 billion man-days for active guard units.
22 billion man-days for reserve guard units
93 billion man-days for munitorum units

57.5 million-tank days for active armour/artillery units
74 million-tank days for reserve armour/artillery units

21.3 million aircraft-days for active squadrons
22.5 million aircraft-days for reserve squadrons


Approximating argastes advice,:
Active guard units consume 200T per day per 15k troopers (assuming totally motorised, and substantial mech).
Reserve guard units consume 50T per day per 15k troopers
Munitorum units consume 80T per day (taking into account engineering/construction work) per 15k troopers

Active artillery/tanks consume 10,000T per day per 100 vehicles
Reserve artillery/tanks consume 100T per day per 100 vehicles

Aircraft squadrons composed 2/3rds fighters/transports/gunships and 1/3rd tactical/strategic bombers:
Active bomber squadrons: 40,000T per day per 100 aircraft
Reserve Bomber squadrons: 150T per day per 100 aircraft
Active other squadrons: 4000T per day per 100 aircraft
Reserve other squadrons: 100T per day per 100 aircraft

This gives a total supply requirement (just for planetside forces) of:
10 billion tons.

That approximates to almost 40 cubic kilometres of supplies, assuming a density half way between petroleum and Iron. Stacked 10 metres high that requires a depot that takes up 4000 square kilometres.

Jumping in this thread here - LOVE this topic, and I had a few things come to mind, especially looking at the logistics of planetfall and keeping it supplied.

10 billion tons would equate out to 18 million tons per day (you said 18 month campaign if I remember right). I wanted to figure out how many vehicles would be required for that - and I'm talking traditional shuttle/cargo landings per your earlier posts.

I thought about the Berlin Airlift for some food for thought:

At its most efficient numbers, the airlift was doing 8,893 tons per day using 635 flights per day. The C-54 had a 14 ton capacity.

If the same number of flights took place each shuttle would need to have a 28,000 ton capacity. To give you a modern perspective - a C-5 globetrotter has a 135 ton capacity.

But that's on the supply level, what about the fleet for this army?

For that - let's look @ Normandy.

6,939 vessels, and of those 4,126 were transport vessels - just in the initial landing. So about 60% of the fleet is transport purposes, which I thought was low actually. So how would this translate for an invasion force of this magnitude? What are the capacity/logistics of the transport fleet?

According to wikipedia (and I need to verify with another source), there were 7 battleships, 5 heavy cruisers, 17 light cruisers, 135 destroyers for the landing. Obviously, carrier oriented vehicles aren't in consideration - but based on that what should a naval fleet look like for a guard landing?

Just tossing some more present/near present #s out there for comparison.

Argastes
05-10-2009, 23:11
For a deployment if this size you would need one of the imperiums force multipliers. Like titans or space marines.

Wha? The point of a force multiplier is to enable a smaller force to act as effectively as a larger force; to "punch above it's weight". Force multipliers are most essential when you DON'T have a large force, not when you DO have a large force. Large forces need force multipliers less than smaller forces need them. Why do you think that the fact that the deployment is large necessitates force multipliers? Just the opposite is true.


Yes. Anti-grav/grav chute technology isn't exactly rare in the Imperium. Deep striking guardsmen use disposable grav chutes all the time.

But is grav-chute technology the same thing as the anti-grav technology that's used in large aerospace vehicles (such as these huge IG drop pods you talked about)? I don't think so, based on the fact that the Imperium doesn't seem to have any common/cheap/disposable anti-grav systems that are much larger than grav chutes. In fact, when it comes to anything other than grav-chutes, anti-grav technology is very explicitly described as precious due to the difficulty of it's manufacture. This suggests that the technology used in grav-chutes is not the same as the technology used in larger anti-grav vehicles, and while grav-chute technology may be cheap/common and thus disposable, the same doesn't hold true for the form of anti-grav technology used in larger vehicles.

RCgothic
05-10-2009, 23:16
To disembark the 57 troop transports, each holding 6.25 million troops, would take 16 flights per day from 10 landers per transport each capable of carrying 2500 troops. That's 570 landers making a total of 9120 flights per day.

Argastes
05-10-2009, 23:20
16 flights per day is a bit of a stretch IMO; I'd lower that number, and either increase the number of landers per troopship, or increase the capacity of the landers (based on some of the art for these things, they are capable of carrying many thousands of troops), or accept that the total invasion force will take longer to shuttle down.

Marshal2Crusaders
05-10-2009, 23:46
Wha? The point of a force multiplier is to enable a smaller force to act as effectively as a larger force; to "punch above it's weight". Force multipliers are most essential when you DON'T have a large force, not when you DO have a large force. Large forces need force multipliers less than smaller forces need them. Why do you think that the fact that the deployment is large necessitates force multipliers? Just the opposite is true.


Sure, if this Imperial Army was invading Europe or Asia, but this is a planetary subjugation(unless I am mistaken?). So if the planet has close to the inhabited land mass of earth AND has Hive Cities, your rather large task force of several million fighting men is actually a small force. I am aware of what force multipliers do. So say for instance that the less inhabited, but still densly populated, eastern continent with less strategic value still needs subjugating, you will need force multipliers to help subdue it. It is still a continent. I knowmy grammar makes this less credoblebut I am writing from a phone during lecture so cut me some slack, planetary subjugations are my thing.

Argastes
06-10-2009, 00:09
Sure, if this Imperial Army was invading Europe or Asia, but this is a planetary subjugation(unless I am mistaken?). So if the planet has close to the inhabited land mass of earth AND has Hive Cities, your rather large task force of several million fighting men is actually a small force. I am aware of what force multipliers do. So say for instance that the less inhabited, but still densly populated, eastern continent with less strategic value still needs subjugating, you will need force multipliers to help subdue it. It is still a continent. I knowmy grammar makes this less credoblebut I am writing from a phone during lecture so cut me some slack, planetary subjugations are my thing.

I think the problem here is that you have somehow gotten the idea that the invasion force consists of "several" million men fighting men. It actually consists of nearly 100 million fighting men, as RCGothic stipulated back on page 4 or 5. They are up against about 30 million Orks and 55 million Grots. I think that they will have the manpower needed to prevail without any significant force multipliers. Obviously force multipliers are always nice--a force is never so big that it doesn't help to have it's fighting strength increased still more--but I think that in the scenario defined in this thread, the IG have what's needed to win even if there is parity (on everything except numbers, obviously) between them and the Orks.

EDIT: "Planetary subjugations are your thing"? Aren't you the guy who tried to argue that one thousand Space Marines could subjugate a planet based on the combat performance of a character in a non-40K first person shooter video game?

Marshal2Crusaders
06-10-2009, 00:33
EDIT: "Planetary subjugations are your thing"? Aren't you the guy who tried to argue that one thousand Space Marines could subjugate a planet based on the combat performance of a character in a non-40K first person shooter video game?


Ooh, now that hurt.

Said fictional character is, in fact, also made in a way similar to space marines, giving him super-human characteristics needed to provide the example of combat ability. Its called a visual/training aid/what have you, normally you give them to let the people you're talking to a better idea of what you mean.


So, real quick, lets go through a little check list that helps illustrate why I choose the Master Chief, a nearly universal figure to the video game generation. Given your extensive knowledge of logistics, you must have a military background, and frankly you know it so well, your rank must have been/is high enough to attend staff colleges and schools where this stuff is the bread and butter of warfare, but it would also put you out of touch with younger players who do indeed enjoy some thumb-smashing now and then. So...

Enhanced Physique-Check
Powerful Battle Armor-Check
Training from early age-Check
Enhanced Biological/Neural Systems-Check
Access to powerful weapons systems-Check

I could go on, but I think it is fairly clear that a duck is a duck, no matter which universe you put it in. So, since it was you who asked this time. Yes, 1000 of these super-humans could indeed subjugate a planet, using their already extensive logistical capacity, as well as there mobility. Do you want to know how they would subjugate this planet? By killing most everyone. War is alot easier when everyone is a target. When every building is a fortress to be flattened and every forest a hiding place to be burned down. Given the warriors already extensive battle capabilities, it would only be in situations these soldiers are not prepared for or adequately equipped for, like trench warfare(not trench fighting, warfare) that they could be killed.

So while I'm sure your barb was just meant to continue to prove you are indeed an expert of the logistical side of warfare, which you no doubt are, you felt that by putting me down you would raise yourself to an even higher level of awesome. Well, it would have worked if we were arguing against each other, but we are not. The title is the logistics of planetary invasion, his conditions came latter. It is completely on topic to discuss marines and how they affect invasions. So while on the world of RCGothic, you are right, for the other planets that involve Marine forces, I'm am trying to explain what they do and how they would indeed affect it. Are we on the same page yet? Or is your hatred for power armor so strong I can't discuss it...

Argastes
06-10-2009, 01:26
Whoa, cool your jets. It was semi-joking comment, not a "barb" or an attempt to elevate me to "higher levels of awesome" (whatever that means). I was just expressing a bit of amused skepticism, not trying to cut you down. I disagree with your analysis--it's overly simplistic in many ways--but that's beside the point and I don't want to get into in this thread. Despite your claim to the contrary, I don't think that the question of what Space Marines can do is relevant to a thread about RCGothic's interest in the logistical requirements of large IG forces. You can start a new thread if you want to argue that point, and if you do, I'll gladly post in it and explain my objections to your analysis.

For the record, I have never attended a staff college or service academy of any type (my degree is from a state university, and is in a non-military field), nor have I ever held a commissioned officer's rank. I'm also in my 20s and thus a member of the "video game generation" (I grew up with a Sega Genesis and then a Playstation in the house, plus of course a PC), and I engage in plenty of button-smashing myself, and of course I've played Halo and it's sequels, so no, I'm don't think I'm "out of touch with the younger players". As for whether my "hatred of power armor is so strong that you can't discuss it"--I'm a Marine player, so probably not!

Basically, you seem to have made a whole slew of totally false assumptions about me simply because I know something about logistics and because I raised my eyebrow at you for saying "Master Chief is badass so 1000 Marines can subjugate a planet." Just because someone raises their eyebrow at this statement doesn't mean they are an elderly staff college alumnus who's out of touch with young people (I really don't know where you even all got that from).

Marshal2Crusaders
06-10-2009, 02:23
You have a firm grasp of logistics. I know many Officers with far worse understanding of how things work than you do, therefore your knowledge thoroughly impressed me to the point where I thought you where much older with military experience. Apparently, I'm not the only one who misses semi-joking comments ;) . Also, as I have said, I am in class, well not now, but I am still away from my PC and relevant data, so unfortunately that thread will have to wait until I am home, and not typing this on my tiny screen.


For the record: the Master Chief is a badass.

Argastes
06-10-2009, 02:36
You have a firm grasp of logistics. I know many Officers with far worse understanding of how things work than you do, therefore your knowledge thoroughly impressed me to the point where I thought you where much older with military experience.

I never said I don't have military experience, I said I never held an officer's commission ;). I'm flattered at any rate. I look forward to your thread when you get a chance to make it. I will say this much in this thread: My problems with your analysis aren't with your comparison of SMs to Halo Spartans (that comparison seems fairly reasonable to me), but with the idea that any 1000 soldiers, no matter how tough and well-equipped, could "subjugate a planet". And in fact, with the idea that "a planet", simple and unqualified, is even something about which these statements can be meaningfully made. In order to say whether or not ANY number of ANY type of troops are capable of doing something to a planet, you would first need a laundry list of information about the particular planet in question. Generalized statements to the effect of "X troops could do Y to a planet" are therefore fundamentally useless and meaningless.

MontytheMighty
06-10-2009, 04:30
Yes. Anti-grav/grav chute technology isn't exactly rare in the Imperium. Deep striking guardsmen use disposable grav chutes all the time.

wouldn't traditional parachutes be even cheaper, and possibly just as effective (depending on how powerful the anti-grav effect is)?

afghanistan supply drop

image: http://www.bestpicturegallery.com/Afghanistan-Supply-drop-Bahgran-Valley-lakerae-best-picture-gallery.jpg

Argastes
06-10-2009, 04:49
wouldn't traditional parachutes be even cheaper, and possibly just as effective (depending on how powerful the anti-grav effect is)?

This would be true if the drop pods were fairly small, but according to Firaxin, they would be huge (I initially assumed that he was talking about pods similar in size to those used by the SMs, but he said back on page 3 that IG drop pods are massive things). There is a limit to how large/heavy an object you can effectively slow with parachutes, imposed by the good old square-cube law; mass of the object scales up with the cube of it's size, but the a parachute canopy can only scale up with the square of the object's size. It was when I pointed this out that he came up with the anti-grav thing.

Firaxin
06-10-2009, 07:54
But is grav-chute technology the same thing as the anti-grav technology that's used in large aerospace vehicles (such as these huge IG drop pods you talked about)?
Pretty much. It's not like we have an intimate understanding about how anti-grav technology works in 40k, but grav-chutes appear to simply be an anti-grav device with a limited (short-lived) power source. As with a skimmer, the grav-chute repels the operator in the opposite direction of the nearest gravity well (in terms of physics, and as with any force that is slowing down in one direction, by creating a positive acceleration in the opposite direction that the operator is moving. That means if the grav-chute was activated while the user was stationary, he'd actually fly up into the air). Either through an inbuilt sensor, timer, (or most simply the anti-grav's "burn" is calibrated to a very specific length of time), a grav chute simply stops short of bringing the drop trooper/pod to a complete halt in mid-air (which would be, obviously, bad).


the Imperium doesn't seem to have any common/cheap/disposable anti-grav systems that are much larger than grav chutes.
Cheap and disposable? No (in fact, grav-chutes are one of the rarest forms of anti-grav, after land speeders and jetbikes. They're undoubtedly expensive and complicated, too, or else we'd see a lot more mobile airborne Guard regiments instead of the cumbrous sledgehammer stereotype. In the Guard, however, even 'rare' items have billions of models in service. And as an author with creative liberties may decide, RCgothic can have as many or as few of these rarer resources as the plot demands. Which is one of the beauties of having a million-world sandbox).

But common? Yes. Ground vehicles for prosperous Imperial citizens; most fighter craft and bombers (in fact the VTOL-capable Valkyrie [and variants] are one of the few exceptions. The Arvus Lighter, Aquila Lander, the Lightning, the Marauder variants, the Starfury Interceptor, the Starhawk Bomber, etc have all demonstrated the ability to take off and land vertically without the ability to rotate their engines downwards); surface to orbit transport ships larger than Valkyries (including everything from Thunderhawks to the city-sized Mass Lifters... and, of course, certain larger types of drop pod); the smaller Imperial Navy frigates and cruisers capable of descending into the atmosphere of a planet.

If you accept things from Rogue Trader, there was even an anti-grav Imperial Hover (skate) Board that granted users a 40" move (back when there was a movement stat and almost no one moved 6"/turn).

It would appear the real reasons why anti-grav is rare in the Guard/etc is because of:

a) the expense. Is one land speeder worth a company of russes?
b) the reliability. Unlike most Imperial tech (which has a penchant for being extremely reliable and hardly ever breaking down/etc) anti-grav requires a LOT of maintenance. Thus, why chaos legions don't have landspeeders anymore. Not only is this the antithesis of Imperial design ethos, but it also poses the problem of requiring you to train, supply, and protect more technicians qualified to deal with it.
c) lack of STCs. The Imperium is very slow to innovate, and when they do they only take very small steps (such as trading out weapons/etc). Even if they have a full understanding of how anti-gravity works, and they see it functioning on a governor's limo or a marine's land speeder, the idea that the same technology might be applied to a leman russ will probably never cross their minds. Imperials just don't think that way. The vast vast majority of them are subjected to dogmatism starting at birth that limits creativity/etc.

And a possible reason for revering anti-grav vehicles is that most things with anti-grav capabilities (ranging from thunderhawks up through IN frigates) would have a pretty sophisticated machine spirit/AI.

Anyways, I'm not sure why we're still discussing this, since I admitted over half a page ago that it would just make more sense to shuttle everything down to the various multiple landing zones spread across friendly territory.

Neither do I understand why my more relevant observation about Armada's heavy transports--which would, if I did my maths right (and feel free to correct me if I didn't), mean that with their 1km^3 holds you would only require 40 transport ships instead of 640--was ignored. A much, much, much more reasonable number, as far as I'm concerned.

Sai-Lauren
06-10-2009, 10:43
You know, that's a good question.

I do come up with them occasionally. :D



I based my estimates on real-world figures from various military history texts I have on my shelf, but none of them actually mention whether their numbers include packing materials. I would suspect that they do, because these numbers are what commanders used to plan the logistical side of their campaigns (and so they would need to know the total transport capacity they'd need to deliver stuff to their troops), but I can't say for sure because the reference books I'm using don't clarify.

Probably doesn't matter too much, although I guess the munitorium would like most of the packaging back for reuse (ammo crates, fuel and water drums etc). So, shall we say that once the campaign's going, they ship maybe 10% of the weight back to orbit to go out to be refilled and returned?



Ah, unfortunately, if we assume a ten year campaign, the amount of supplies will increase several times over.... the 10-billion-ton figure that RCGothic provided, and thus the 640 ships that I estimated, was based on a campaign lasting only 18 months.

Ok, but if we assume that after about two years or so, the reconquered part of the planet will have recovered enough to start producing materiel for the war effort (I'd hope that in two years they've taken something like a continent), we can begin to figure that in to the maths as well. Plus there would be certain things that could be recycled from casualties (be they a single dead soldier or a regiment that's been rendered combat incapable, and demobilised or rolled into another - although most of the recycled gear would probably go to the reborn PDF/founded guard regiments from the planet), which would again reduce the amount of space needed for spares.



So that's a bit over one ship per day--in practice, maybe a convoy of 8 or 9 ships arriving once per week. Of course we could also assume bigger ships if we wanted. In real life, huge cargo vessels like ULCCs and Emma Maersk-type container ships are substantially larger than even the biggest warships (Nimitz-class CVNs). So it might not be unreasonable for huge Imperial cargo vessels to be even bigger than Emperor-class battleships, in which case they could have much larger hold capacties than the 0.0625 cubic kilometers (1000 x 250 x 250 meters) I estimated. How big are Imperial battleships? My understanding is that they're several thousand meters long at least...

In reverse order:
Sizes are generally reckoned at 1, 5 and 8km for Escorts, Cruisers and Battleships if I remember correctly, but I agree there would be super-freighters, in the 10s of km scales. There'd also be smaller freighters, designed for carrying small quantities of goods, pretty much a warp engine, a hot-rack crew compartment, and somewhere to stow cargo containers, but the ones you mentioned are probably a decent average to work from (the super-freighters would be expensive and comparatively rare, whilst the small ones would be cheaper and much more common, possibly even "privately" owned, and pressed into service - if you ever played Elite, I'm talking things about the sizes of Pythons being run like you ran your Cobra :)).

Troop transports could also carry some supplies for their troops as well, which would ease the burden to a small extent (maybe 2-3 weeks worth say, after which they have to draw from the campaigns supply chain, but it gives their RQMs time to mesh themselves into it and get the supplies flowing towards the troops).



I'm assuming that the actual interstellar cargo ships would be flat-out incapable of making planetfall even at a huge spaceport;

The super-freighter, yes - although I posited on another thread that they may have detachable cargo bays (effectively container containers) that they can detach and leave to be unloaded, whilst they pick up empty ones to take back to be reloaded.

The average ones might just about be able to land at the primary port for the planet, and the smaller ones will be able to land anywhere there's a landing pad that can support them, possibly even in the field (effectively designed as blockade runners, to get supplies and infiltrators in and out of enemy held worlds).



the supplies would be ferried down to the surface by heavy-lift cargo shuttles similar to the big landing craft that are used to put IG troops/tanks (or titans) onto planetary surfaces. I don't think an orbital facility or space station would be necessary or desirable; seems like it would just complicate the cargo-handling process. I see the shuttles docking directly with the cargo ships; each hold would have a suitably large docking lock for this purpose, and automated cargo-handling gear to move containers from the hold into the shuttle's cargo compartment(s). The shuttle would then decouple, de-orbit, descend to the planetary surface, land, unload, lift off, return to orbit, and dock with a cargo ship again to take on another load. Of course these shuttles are huge in their own right and will also have to be quite numerous, so the invasion fleet will have to include "carriers" for them in addition to the actual cargo ships (though fortunately, it would be possible to have some supplies, probably whatever mix of stuff is projected to be needed by the initial landing forces, pre-loaded into the landers when the invasion fleet sets out--this would reduce the number of normal cargo ships required, and prevent the lander carriers from wasting capacity by carrying landers that are full of empty space).

The longer the freighter stays in orbit, the more freighters you'll need to maintain the supply lines, which raises the cost (in money and supplies for them). Hence the super-freighter with detachable bays, it might take a month to unload everything, so if you can just drop them off as someone elses problem, you can do more trips (the basic idea behind containerisation of transported goods in the first place).

If you have an orbital facility, then you can use it as a primary distribution centre - freighters dock, unload in bulk, then leave with things to go back, the empty ammo crates and fuel drums I mentioned earlier, whilst the general staff quartermasters on board break it down into smaller packages which the shuttles pick up for the planetside depots, where the field quartermasters split it again for transport to the units in their sector - basically a military version of supermarket supply chains ;).

There's also the ability to use it as a command centre, or-tillery platform, hospital for the most badly injured and so on.



We're probably looking at in the region of 145 transports until someone thinks up a supply scheme that doesn't leave 57 troop transports sitting in orbit for the duration of the campaign leaving all the supply work to the other transports.

They wouldn't, they'd go back and pick up new regiments. Don't forget that in most cases, the guard leaves their units in the field until they're physically incapable of fighting any more, then either demobilises them (where they go then and how they get there is the ex-guardsman's problem), or combines them in with other regiments until they're too badly mauled to continue, rinse and repeat.

End of campaign, the Munitorium would review what regiments are still standing, look at what's needed elsewhere, take the regiments that are required now, and then take the rest off over the next however long - either direct to a new warzone as required or back to a dispersal planet for a little R&R, whilst in the meantime, those who stay on world will help with the relief effort, rebuilding the planets infrastructure, training the PDFs and so on.



How is it that no matter how little a thread has to do with Marines, someone ALWAYS manages to derail it into a Marine discussion?

GW's obsessive devotion to, and ceaseless marketing of, marines? :angel:



The thread is about IG invading an Ork-held hive world. RCGothic made that clear just a few posts down on the first page of the thread.

Kind of my doing (sorry everyone), I suggested it as an example (mainly to try and stop the Imperium vs 21st Century Earth posts), RCGothic chose to go with it.



Anthony Reynolds. And they weren't dinky things, they were veritable mobile forges, as large or larger than Capitol Imperialis super heavies, kilometer+ long constructs.

Ah, the good old "this sounds cool, so let's make it REALLY REALLY BIG to emphasise how cool it is".

How many of those do you think the AM have? If they are approaching double figures across the whole imperium, I'd be surprised. It's also somethat would simply wouldn't be deplolyed in the field until its' safety could be guaranteed, which is probably months if not years down the line - it's too valuable to lose, and you still need to feed it with raw materials to produce things.



But that's on the supply level, what about the fleet for this army?

For that - let's look @ Normandy.

6,939 vessels, and of those 4,126 were transport vessels - just in the initial landing. So about 60% of the fleet is transport purposes, which I thought was low actually. So how would this translate for an invasion force of this magnitude? What are the capacity/logistics of the transport fleet?

According to wikipedia (and I need to verify with another source), there were 7 battleships, 5 heavy cruisers, 17 light cruisers, 135 destroyers for the landing. Obviously, carrier oriented vehicles aren't in consideration - but based on that what should a naval fleet look like for a guard landing?

They were there for landing craft escort (mainly anti-submarine/MTB) and coastal/inland bombardment duties (HMS Belfast was one of the cruisers, and there's some stuff on her role on board ;)).

Carrier's weren't really needed, although I think virtually every single aircraft in Britain was used at some point in the pre-invasion bombing raids, para-drops etc.

For our landing, there would be everything flying, fighters and escort ships in low orbit to intercept anything trying to go after the dropships and their carrier, more fighters in the atmosphere to try and obtain air dominance if not superiority, bombers and or-tillery fire to clear the landing area and knock out defences, heavy concentrations of the enemy, plus maybe two or three fake landing sites to keep the enemy guessing as to where you're coming, and then the dropships themselves, carrying the troops to both the beachhead and to vital locations that need securing or denying to the enemy to protect the landing (bridges, transport infrastructure nodes etc).

RCgothic
06-10-2009, 12:33
There was an Ad Mech bulk conveyer in the first Gaunt's Ghosts Novel. It was a 16km Behemoth. I don't think the current campaign has any of those.

I agree that having heavy transports reduced the total number required, but it makes unloading more difficult. If there was an operational space port (such as in the recent ghosts novel Blood Pact), then they'd certainly be a good choice.

The Landers on the cover of Codex:IG are by my estimation about 500m long. That sounds to me like very small independantly warp capable transports rather than drop ships that hitch a ride with another vessel, unless that vessel happened to be the aformentioned ad mech bulk conveyer.

Phytrion
06-10-2009, 12:36
They were there for landing craft escort (mainly anti-submarine/MTB) and coastal/inland bombardment duties (HMS Belfast was one of the cruisers, and there's some stuff on her role on board ).

Carrier's weren't really needed, although I think virtually every single aircraft in Britain was used at some point in the pre-invasion bombing raids, para-drops etc.

For our landing, there would be everything flying, fighters and escort ships in low orbit to intercept anything trying to go after the dropships and their carrier, more fighters in the atmosphere to try and obtain air dominance if not superiority, bombers and or-tillery fire to clear the landing area and knock out defences, heavy concentrations of the enemy, plus maybe two or three fake landing sites to keep the enemy guessing as to where you're coming, and then the dropships themselves, carrying the troops to both the beachhead and to vital locations that need securing or denying to the enemy to protect the landing (bridges, transport infrastructure nodes etc).

Well, I figure for this fleet, although there's no anti-submarine needs, there would be a need for carriers that would make up for those numbers.

I also imagine the interstellar transports would be similar to the amphibious assault ships, with a giant hangar for the atmospheric craft similar to the well deck, but instead of 1600 troops per vehicle I'd imagine there'd be more like 2 million to a vessel, making it like 50 or so big troop transports.

Sai-Lauren
06-10-2009, 12:55
Well, I figure for this fleet, although there's no anti-submarine needs, there would be a need for carriers that would make up for those numbers.

Anti-sub, no. Anti-interdictor craft, mines, concealed defence batteries and so on, yes. Still need to protect the transports and landing craft. ;)



I also imagine the interstellar transports would be similar to the amphibious assault ships, with a giant hangar for the atmospheric craft similar to the well deck, but instead of 1600 troops per vehicle I'd imagine there'd be more like 2 million to a vessel, making it like 50 or so big troop transports.

Problem there is that the fluff says that transports are designed to carry a single regiment (or that regiments are designed to fill the transport capacity of a troop transport and no more).

I'd go further, and say there's things like the old Space Fleet Galaxy transport around, but at most you're going to get 4-6 regiments on such a vessel, and maybe only one deployable at a time.

Which is another reason for the orbital command centre, it could be an assault base in the early stages of the campaign, and then a supply base once the beachhead's secure.

And I also think there'd be various sizes of dropship - from 30 man recon platoon carriers to ones capable of carrying super-heavies (I'll work some sample stat lines out so you can see what I'm thinking of), most would be in the infantry platoon (plus support) and infantry company/armoured squadron capacity range though, otherwise you're risking too much being lost due to a single accident or enemy action.

Phytrion
06-10-2009, 14:11
See, the fluff is not very consistent then, because it also says regiments vary wildly in size - from over one hundred thousand men to maybe a thousand or so because it's a mechanized regiment. I just figure bigger is better for the interstellar transports because it would save on maintenance, supplies, etc.

The important landing forces would be in smaller craft sure, the regiments designed to be the shock troops would be in the more amphibious assault ships - whereas the follow up units I imagine would be in the gigantic transports.

Just some thoughts I guess, since we've outlined numbers on the ground I'd just like to outline the #s in space. One of my goals is to build a BFG planetary invasion fleet - I'd love to have one a massive scale that would take years to assemble.

RCgothic
06-10-2009, 14:19
Problem there is that the fluff says that transports are designed to carry a single regiment (or that regiments are designed to fill the transport capacity of a troop transport and no more).


Frankly ludicrous fluff. Assuming an average regiment of 10,000 men, you're looking at 27,000 transports.

Argastes
06-10-2009, 14:22
Yeah, the one regiment per transport thing is, IMO, just another example of GW's terrible grasp on numbers. Even if troop transports are only the size of a Navy destroyer, they should be capable of carrying a lot more than that.


Neither do I understand why my more relevant observation about Armada's heavy transports--which would, if I did my maths right (and feel free to correct me if I didn't), mean that with their 1km^3 holds you would only require 40 transport ships instead of 640--was ignored. A much, much, much more reasonable number, as far as I'm concerned.

You'd have to ask RCGothic why he ran with 640 ships (1000 x 250 x 250 meter holds) instead of 40 (4000 x 500 x 500 meter holds). I didn't ignore your statement about the 4000 x 500 x 500 meter heavy freighters, I found it quite interesting. It was a good answer to my question.

However, I don't see why 40 ships is necessarily more reasonable than 640 ships; yeah, it's only one-sixteenth as many ships, but each ship is sixteen times bigger. So they represent the same commitment of shipping resources, and the same total investment of shipbuilding expense/time/effort. Maybe even more, since bigger ships may be disproportionately more expensive/difficult to build than smaller ships. Anyhow, I'm not necessarily opposed to the idea of the invasion fleet using a smaller number of larger ships instead of a larger number of smaller ships, but I don't see what makes it "much, much, much" more reasonable.


It would appear the real reasons why anti-grav is rare in the Guard/etc is because of:

a) the expense. Is one land speeder worth a company of russes?

Right, this is exactly why I think it would make no sense for the drop pods to be treated as disposable and melted down in mobile forges after one use: If they incorporate anti-grav technology, they must be fairly valuable, and would be treated as reusable rather than expendable. And I do realize you are no longer espousing the drop pod resupply scheme.

Sai-Lauren
06-10-2009, 16:25
Frankly ludicrous fluff. Assuming an average regiment of 10,000 men, you're looking at 27,000 transports.

Yep, but there you go. :)

Although, if we assume a minimum of 25 cubic metres of space per person (borrowed shamelessly from Star Cruiser, the starship construction and combat rules for Traveller 2300AD as the absolute minimum living space you could have :)), we still need a quarter of a million cubic meters per regiment or a space about 250m long by 100 m wide by 10m high.

And I'd say you'd need more than that (maybe double?), to make sure that they arrive in a fit state to fight (training rooms, gyms, shooting ranges etc). I can't really see hot-racking working, ideally you'll need to keep them eating, sleeping and training as a unit, not in duty-shifts.

And if you're thinking of sticking them into one of the freighters, you'll need to consider adding extra life support for them.

Plus you'll need security to keep them in line, medical facilities to patch them up after training accidents and so on.

RCgothic
06-10-2009, 16:27
The Medicae and Commissariat troops are assumed to be part of the 180M logistical guardsmen. ;)

Argastes
06-10-2009, 16:52
Yep, but there you go. :)

Although, if we assume a minimum of 25 cubic metres of space per person (borrowed shamelessly from Star Cruiser, the starship construction and combat rules for Traveller 2300AD as the absolute minimum living space you could have :)), we still need a quarter of a million cubic meters per regiment or a space about 250m long by 100 m wide by 10m high.

As I mentioned earlier, submarine crewmen get away with considerably less than 25 cubic meters per person.... It sounds to me like the guys who wrote Star Cruiser didn't do their research. Attached to the bottom of this post are a couple of pics I have knocking around on my hard drive, scanned from NASA reports on spacecraft habitability (I'm even more of a hard sci-fi dork then I am a 40K dork). Note that NASA considers 8-10 cubic meters per person acceptable for military space habitats where the crew will be aboard for several months, and apparently considers a mere 5 cubic meters per person the tolerable minimum for an indefinite period.


And I'd say you'd need more than that (maybe double?), to make sure that they arrive in a fit state to fight (training rooms, gyms, shooting ranges etc).

This is a fair point, but the additional space needed for this stuff should be tacked onto maybe 10 cubic meters per person, instead of onto 25 per person (although note that on US nuclear subs, the 10-12 cubic meters per person DOES include a shipboard mini-gym... of course combat infantrymen will need more training/gym facilities than sub crews, but I think that clever design could achieve useful training/gym facilities that take up less volume than we might initially think).


I can't really see hot-racking working, ideally you'll need to keep them eating, sleeping and training as a unit, not in duty-shifts.

It should work fine. Yes, you want the soldiers sleeping/eating/training as a unit, but that can be accommodated within a hot-rack system; it's just that the units in which they train/eat/sleep will necessarily be smaller than the total number of troops assigned to a given set of berths. say you have an infantry regiment with three line battalions, berthed in a compartment that only has racks for one battalion's worth of men to sleep in. Each battalion spends 8 hours per day sleeping in those racks, and 16 hours per day eating, training, etc. as a unit. A battalion-sized unit is more than big enough to train, eat, etc. separately from other units without causing any problems with unit cohesion, camaraderie, and so forth.... you were in the military, how often did you see a unit bigger than a company messing in one place? Or doing PT together?

massey
06-10-2009, 17:05
See, I figured you'd land the bulk of your forces in a secured landing zone with super-massive transport craft.

Our local college football stadium holds 85,000 people. It's a stadium, so area wise, there's a huge chunk of space there that is simply open air. I'm thinking a stadium sized transport could reasonably be built that could hold a million+ troops. Simply cram them in on benches, row upon row, with just enough space underneath each man's seat for his own equipment. Floor after floor could be stacked on top of each other. Remember, these guys don't have to ride in this sucker the whole time, just for a few hours as they prepare for transport to the surface. The rest of the time they can live in those city sized space ships that seem to be made up of mostly empty space.

Yes, such a ship wouldn't carry tanks or artillery, but I'm thinking a variant could. A massive lander like that would take only an hour or so to unload, so you could concentrate your defenses around it fairly easily. Besides, it seems thematically appropriate for the Imperium to do it that way, as the ship would be cramped, dark, uncomfortable, etc. :)

RCgothic
06-10-2009, 17:57
I think that's the sort of supermassive lander we see on the cover of codex IG. I wonder how those landers dock and are loaded whilst in orbit however.

I think, that whilst a hot-berthing system could be functional, I'd feel more comfortable with each trooper having his own berth.
Perhaps 6.5m^3 per trooper is acceptable for barrack room accomodation. (2.25m x 80cm x 1m bed, 80cm x 50cm x 2.25m tall locker, 3.5m x 2m x 2.25m shared changing area)

Then you have corridors, mess room, ablutions block, armoury, target range, medicae centre, commissariat, gym and multipurpose training room (for exercises such as building clearance, fire and manouevre, drop training etc) at the very least.

DoombringerATT
06-10-2009, 18:27
Just a little tidbit of colorful text to add food for thought;


920.M41 - Eldar pirates attack the troopship Emperor's Faithful as it exits Warp space in the Thanas system. The ship is boarded and then disappears, taking with it a complement of 5,000,000 Imperial Guardsmen and 200,000 men of the Imperial Navy.

Big ships exist. Maybe not as efficient as multiple smaller vessels, since the loss of one can have such devastating results, but troopships that carry more than a single regiment are out there in the black.

---

Thoroughly enjoying this thread. Have been tempted at multiple junctures to participate and lend another hand (with military enlisted experience and some logistics "schooling"), but it seems like all the finer points are being hit here, and I've been rather busy lately preparing for deployment. :)

Phytrion
06-10-2009, 18:30
I figure the vehicles actually making initial landfall wouldn't be that big, simply because that's a ripe target - 80,000 people is nearly an entire modern army corp, and trying to deploy in that central of a location makes them an easy fire target.

Here's what I thought about:

The latest America class amphibious assault ship transports a marine expedition battalion, has 8 helicopters with the capacity to transport a small platoon (30 people), and has 12 Ospreys with similar transport capacity along with a few fighters.

Magnify that to Imperial Guard standards, and I'd imagine you have something like this:

Bellum Class Planetary Assault Ship
Vehicle is primarily used for deployment of troops through smaller vehicles. Can supply and maintain a Corp of troops (80,000) after they transfer off interplanetary transporters.

Capacity: 80,000 infantry, or up to [need to figure this out] tanks

Contains 40 Combat Landing Craft variants, carrying anywhere from 2,000 infantry to 18 tanks and support staff for atmospheric entry into combat zone.

Maybe 2 squadrons of fighters?

Thoughts?

Col. Tartleton
06-10-2009, 20:39
I'm starting to think this is an impossible discussion for the same reason every 40k background discussion is doomed to fail (there's always interesting debate and a lot of good ideas generated) we'll never all be able to agree on something because 40k is different for all of us.

I can write a story about a billion guardsmen assaulting a hive world with a half trillion people on it and getting mauled.

A billion soldiers getting mauled.

I can also write about a chapter of marines doing the same thing and getting mauled within a few seconds. Or I can write those marines fighting smart and have a terminator company destroy a planet in a month.

It's my universe. Not ours. It's mine, it's yours, but it can never be all of ours.

Iracundus
06-10-2009, 20:46
Big ships exist. Maybe not as efficient as multiple smaller vessels, since the loss of one can have such devastating results, but troopships that carry more than a single regiment are out there in the black.


Its mention in the main book suggests that the loss of such a ship was actually noteworthy and remarkable. This implies that large ships capable of such capacities are either not common or not commonly lost. It at the least certainly puts it in a class different from the standard BFG transports, which seem capable of about 1 regiment, or even just a fraction of a regiment, according to their listed cargoes when they appear in Imperial Armour. Therefore although such super heavy ships might exist, I would not necessarily operate under the assumption that a planetary invasion force would have significant numbers of these as part of their force.

Lord_Crull
06-10-2009, 21:19
Its mention in the main book suggests that the loss of such a ship was actually noteworthy and remarkable. This implies that large ships capable of such capacities are either not common or not commonly lost. It at the least certainly puts it in a class different from the standard BFG transports, which seem capable of about 1 regiment, or even just a fraction of a regiment, according to their listed cargoes when they appear in Imperial Armour. Therefore although such super heavy ships might exist, I would not necessarily operate under the assumption that a planetary invasion force would have significant numbers of these as part of their force.


Ghostmaker and First and Only had a ship that could transport roughly about 5,000 men at least. It had the Roane, Jantine (then Volpone) and Ghost regiments.

Iracundus
06-10-2009, 21:27
Ghostmaker and First and Only had a ship that could transport roughly about 5,000 men at least. It had the Roane, Jantine (then Volpone) and Ghost regiments.

There is a thousand fold difference between 5,000 and the aforementioned 5,000,000 capacity transport.

The regiments in Imperial Armour were from offhand recall larger than 5,000 each, and they were transported either in 1 or several standard BFG transports. That 5,000 capacity transport therefore doesn't come off as particularly unusual or remarkable. If 3 regiments are transported on it, what it instead shows is that those regiments are quite small in comparison to some other regiments elsewhere.

Lord_Crull
06-10-2009, 21:38
The regiments in Imperial Armour were from offhand recall larger than 5,000 each, and they were transported either in 1 or several standard BFG transports. That 5,000 capacity transport therefore doesn't come off as particularly unusual or remarkable. If 3 regiments are transported on it, what it instead shows is that those regiments are quite small in comparison to some other regiments elsewhere.

The Volpone regiment was stated to be 50,000 men at least once in Ghostmaker.

And the regiments at Taros where not that big. The Tallarn had around 10,000men and the Cadian armored regiment was half that. From what I can recall.

I am not saying that the 5,000,000 man troop transport is the norm. Far from it./ It just seems to me that their are no ''set'' size transport or standard ship class.

Argastes
06-10-2009, 23:14
I think that's the sort of supermassive lander we see on the cover of codex IG. I wonder how those landers dock and are loaded whilst in orbit however.

Docking and loading in orbit is the easy part. They'd dock the way any other two spacecraft would dock: Carefully maneuvering up to each other, and bringing together their docking gear (docking collar, docking ring, docking lock, whatever you want to call it). Hatchways in the docking gear would mate and then open, so that personnel could walk from the troopship into the lander via a boarding tube/corridor. The fact that they are huge doesn't change the basic procedure.


Its mention in the main book suggests that the loss of such a ship was actually noteworthy and remarkable. This implies that large ships capable of such capacities are either not common or not commonly lost. It at the least certainly puts it in a class different from the standard BFG transports, which seem capable of about 1 regiment, or even just a fraction of a regiment, according to their listed cargoes when they appear in Imperial Armour. Therefore although such super heavy ships might exist, I would not necessarily operate under the assumption that a planetary invasion force would have significant numbers of these as part of their force.

Isn't this rather bizarre, though? If the "standard" troopship is only capable of carrying a single regiment (or even less!), they will be tiny next to even small Naval warships. That's like the US military having a fleet of carriers and cruisers and destroyers, but carrying troops across the Atlantic in a vast fleet of ten-man motorboats. How big were the BFG transport models? If they only hold a single regiment, they should be much smaller even than the escort-type warship models.

EDIT: And if troop transports can only carry a regiment or a fraction of a regiment, it might take multiple troopships to fill a single landing craft. That also seems weird. It implies that landing craft (of the large types we see in the art) couldn't be carried by the troopships themselves, but would need their own dedicated carriers, which would in turn be vastly larger than the troopships (and more on the scale of the Navy's warships).

Phytrion
07-10-2009, 00:33
Although for the most park 40k keeps with traditional military organization to a decent degree; they break with the regiment - the current book even says that there are some regiments that number in the hundreds of thousands. Regiment just signifies the troops raised from that particular planet for that role, at least that's how I've interpreted it. I don't think they view the regiment as a few thousand/several battalions like you'd see in a modern military.

MontytheMighty
07-10-2009, 00:55
This would be true if the drop pods were fairly small, but according to Firaxin, they would be huge (I initially assumed that he was talking about pods similar in size to those used by the SMs, but he said back on page 3 that IG drop pods are massive things).

why can't the imperial guard drop their stuff in smaller pods? what's not going to fit...

what would be the advantages of these gigantic drop pods that would outweigh their disadvantages?

just some semi-rhetorical questions :P

Argastes
07-10-2009, 01:24
why can't the imperial guard drop their stuff in smaller pods? what's not going to fit...

what would be the advantages of these gigantic drop pods that would outweigh their disadvantages?

just some semi-rhetorical questions :P

I dunno; as I said to Firaxin when he first stated that the IG pods would be huge, the whole idea of resupplying large forces via drop pod is equally silly whether the pods are big or small.

Daver X
07-10-2009, 01:56
I have noticed that after a dropship/troop transport has dropped its cargo it waits until the end of the campaign before moving again.

There doesn't actually have to be a 1:1 ratio or a 1:15 ratio of soliders/supplies to ships because you can't have all those men on the ground in the same place at the same time. meaning that you can have 1 dropship within a day or so, accounting that A-A fire is almost non existant transport over ten regiments that are around 1 load each, with the transport it would carry more men but over a longer period of time. The estimate on the dropship is probably pretty conservative considering a drop in most black libary books only takes a few minutes to get down plus perhaps an hour or so loading time. Then say you have 1000 landers....

Ships could do this as well but with the unreliability of warp travel this would be a lot more difficult

Col. Tartleton
07-10-2009, 02:00
You could also land a battleship on the ground and use it as a vast fortress, but why would you want to...

Raellos
07-10-2009, 08:43
I tend to dislike number crunching when it comes to mathhammer, but I can't help but find this sort of stuff engrossing.

I just thought I'd add that, in my campaign background, the sector reserve fleet's carriers are used as aircraft transports, carrying fighters and marauders to assist in the initial invasion before air bases are established on the ground. I'm not all that sure how Starhawks and whatever the big fighters are would cope in atmosphere, and wasn't sure how the Imperium got it's aircraft to places.

Iracundus
07-10-2009, 09:10
The BFG rulebook for fighting in low orbit says only escorts and transports can land. Capital ships, which is cruiser size and larger, cannot land. The reason isn't specifically given but I would assume it would be structural integrity issues from their sheer size.

Sai-Lauren
07-10-2009, 11:08
Argastes, I always assumed the 25cubic metres per person also included the other facilities such as latrines/showers, mess etc, plus the corridors that connect everything up.



Ghostmaker and First and Only had a ship that could transport roughly about 5,000 men at least. It had the Roane, Jantine (then Volpone) and Ghost regiments.

The one in F&O was an Adeptus Mechanicus vessel, which was supplied to the crusade fleet as a thank you for reclaiming the world at the start of the book (forgotten it's name) - it had 6 regiments on it.

The only vessel in Ghostmaker was the Frigate that carried the Tanith around for a while, Corbec called down a lance strike from it on a greater daemon.



Docking and loading in orbit is the easy part. They'd dock the way any other two spacecraft would dock: Carefully maneuvering up to each other, and bringing together their docking gear (docking collar, docking ring, docking lock, whatever you want to call it). Hatchways in the docking gear would mate and then open, so that personnel could walk from the troopship into the lander via a boarding tube/corridor. The fact that they are huge doesn't change the basic procedure.

Or they have dropship hangers, whether they're a Star Trek shuttle bay, a BSG style through deck, Starship troopers style with rails out of the side above an airlock, or an Aliens style pit.

Personally, I'd go with a ST shuttle bay - fly in, land, close the outer hatch, pump atmosphere in, load the troops, pump the atmosphere back out again, open the outer hatch and take off.



Although for the most park 40k keeps with traditional military organization to a decent degree; they break with the regiment - the current book even says that there are some regiments that number in the hundreds of thousands. Regiment just signifies the troops raised from that particular planet for that role, at least that's how I've interpreted it. I don't think they view the regiment as a few thousand/several battalions like you'd see in a modern military.

Unfortunatly, the munitorium then have nervous breakdowns because they have to keep track of what size the regiment is. :)

I've always felt that regiments are sized based on their role - recon/scout types like the Tanith would be about 3,000 strong (and the smallest), and have a fairly flat command structure, Mechanised and Stormtroopers at maybe 5,000, line infantry would be 10,000, siege infantry up to about 25,000. The munitorium then use those designations to transport, supply, barrack them on world and so on.



The BFG rulebook for fighting in low orbit says only escorts and transports can land. Capital ships, which is cruiser size and larger, cannot land. The reason isn't specifically given but I would assume it would be structural integrity issues from their sheer size.

Finding somewhere they can land without crushing something is probably an issue as well. :D

Anyway, the drop shuttles I mentioned in my last post - some suggested in-game statlines for everyone to pick over (no points though, I'm not that daft :D ).

Gawaine Class Insertion Landing Craft
Crew: 1 Pilot, 1 Crew Chief
Armour: 13/13/13
Weapons: Heavy Bolter
Transport: 10 infantry

Notes:
Dropship
Same rules vs Melta Weapons as Thunderhawk.
Stealth - all shots fired at craft are affected by night-fighting rules.
+++++

Galahad Class Landing Craft
Crew: 1 Pilot, 1 Crew Chief, 1 Gunner
Armour: 14/13/13
Weapons: 2x Heavy Bolter, 1x Twinlinked Missile Launcher
Transport: 30 Infantry.

Notes:
Dropship
Same rules vs Melta Weapons as Thunderhawk.
Any number of units may be embarked, up to the transport capacity.
+++++

Lancelot Class Assault Landing craft
Crew: 1 Pilot, 1 Crew Chief, 2 Gunners
Armour: 14/13/13, Power Field
Weapons: 2x Twinlinked Heavy Bolter, 1 Dorsal Whirlwind Multi-Launcher (single shot)
Transport: 100 Infantry or 3 Chimera or Leman Russ chassis or combination (30 Infantry = 1 Armoured Vehicle).

Notes:
Dropship
Same rules vs Melta Weapons as Thunderhawk.
Any number of units may be embarked, up to the transport capacity. Up to 50 infantry models or all vehicles may disembark in one turn.
Vehicles may carry up to their normal allowance of infantry without penalty.
May only fire Multi-Launcher whilst airborne, not whilst landed.
+++++

Bors Class Heavy Landing Craft
Crew: 1 Pilot, 2 Crew Chiefs, 6 Gunners
Armour: 14/14/13, 3 Structure Points, Power Field
Weapons: 4x Long Barrelled Twin Linked Heavy Bolters, 1 Dorsal Whirlwind Multi Launcher, 2x Long Barrelled Battlecannon
Transport: 350 Infantry, 10 Chimera/Leman Russ Chassis or 2 Super Heavy Tanks or combination (150 Infantry = 5 Armoured Vehicles = 1 Super Heavy).

Notes:
Dropship
Same rules vs Melta Weapons as Thunderhawk.
Up to 150 infantry or five tanks/one super heavy may disembark in one turn.
Vehicles may carry up to their normal allowance of infantry without penalty.
Stable platform - May fire ordanance weapons in flight as though it were not moving.
+++++

The Bors is about as large as it should get IMO - we're already way beyond Tau Manta territory. Most of the craft will be Galahad's and Lancelot's - with an unarmed, power field less cargo version of the Lancelot doing most of the supply runs. The Gawaine's to get SFs and Infiltration units down, pick up people who need extraction from behind enemy lines (downed pilots for example) and to get supplies to resistance units.

If you want to land Titans or Praetorians (Leviathans etc), you'll be into landing their transport vessel.

I certainly don't see Titan sized drop pods.

Argastes
07-10-2009, 15:30
Argastes, I always assumed the 25cubic metres per person also included the other facilities such as latrines/showers, mess etc, plus the corridors that connect everything up.

Those NASA figures are based on total habitable volume of the spacecraft/ship/habitat in question, not just living space, so their figures do include such facilities. I.e., on a nuclear submarine, there is a total of ~12 cubic meters of habitable space per man INCLUDING the mess hall, latrines/showers, corridors, etc., not ~12 cubic meters of personal living space per man.


Or they have dropship hangers, whether they're a Star Trek shuttle bay, a BSG style through deck, Starship troopers style with rails out of the side above an airlock, or an Aliens style pit.

Personally, I'd go with a ST shuttle bay - fly in, land, close the outer hatch, pump atmosphere in, load the troops, pump the atmosphere back out again, open the outer hatch and take off.

Internal hangars/docking bays/"well decks" are a common feature in sci-fi movies and TV shows but I don't think they make a lot of sense. They mean the larger ship has to include large empty compartments, large hangar/bay doors, the equipment needed to pump out and store the air, and so forth. They also increase the chances for an accident to occur during docking/loading. Direct "mating"-type docking, where the two craft float up next to each other and connect via external docking gear, makes much more sense. It's mechanically simpler, has less things to go wrong, would be easier and quicker, and doesn't require the larger of the two ships to waste internal space with big hangars. I think the hangar/docking bay method as seen in TV shows and movies stems from the fact that it's more visually interesting for the audience--you get to see the landing craft in a huge hangar with infantry walking out of their ready rooms and climbing up the ramps, then the dramatic sequence of the landing craft being dropped/launched. Like most cases in which various aspects of spaceflight and space warfare are extrapolated from real-life naval ships or aviation, it might look cool but it doesn't make much sense (though GW is certainly already guilty of treating spaceships as "naval warships in spaaace!", so it wouldn't be too out-of-place to use the hangar/docking bay model in 40K if you really wanted to).

RCgothic
07-10-2009, 15:37
I think that there are enough mentions of launch bays and embarkation decks to assume that the hanger is a common feature of 40k ships. Patching up the holes the enemy has inevitably shot in your fighter craft/drop ships is much easier if your deck crew doesn't have to operate in zero-G vacuum conditions.

Phytrion
07-10-2009, 16:05
Plus you have to consider interstellar travel - small landing craft with 200 troops isn't going to travel through the warp, and I imagine that having a bunch of ships attached externally would pose problems with the geller field.

Argastes
07-10-2009, 16:07
Plus you have to consider interstellar travel - small landing craft with 200 troops isn't going to travel through the warp, and I imagine that having a bunch of ships attached externally would pose problems with the geller field.

I don't imagine it would, they'd just be part of the structure of the "mother" ship for the purposes of being encapsulated by the Geller field.

Felwether
07-10-2009, 19:20
As RCgothic said I think there are enough references in the background to assume that large Imperial vessels have landing bays/hangars.

Plus when you consider the sheer size of a cruiser/battleship the fact that a landing bay is a large empty compartment and all the equipment required isn't that much of a problem. Although I can't really see the sense in said landing bays being able to cater for much more than fighters, bombers and smaller landing craft.

EDIT: Also, doesn't the Imperium make use of warp capable 'bulk landers' to ferry particularly large war machines and numbers of troops to a planet's surface? Not sure where I read that, could be wrong.

Phytrion
07-10-2009, 19:51
I wouldn't doubt it if they did, but I imagine the smaller landers that have 1-2 tanks or a few hundred troops aren't going to be warp capable.

Some food for thought - what would the size of the mega transports (1-2 million men) be? Are we going with 12 m3 space per person? If so, for 2 million men per transport you'd need 24 million cubic meters of space, correct?

I imagine these transports being at least destroyer size, which are about 1500 m long. I'm not sure about height or width of the destroyers, but I imagine the transport sprues they have that are destroyer size for BFG would represent the big bulk transports for troops between systems. Am I off base on that one?

Wolflord Havoc
07-10-2009, 19:51
I tend to dislike number crunching when it comes to mathhammer, but I can't help but find this sort of stuff engrossing.

I just thought I'd add that, in my campaign background, the sector reserve fleet's carriers are used as aircraft transports, carrying fighters and marauders to assist in the initial invasion before air bases are established on the ground. I'm not all that sure how Starhawks and whatever the big fighters are would cope in atmosphere, and wasn't sure how the Imperium got it's aircraft to places.

Hello Raellos,

In Double Eagle, I seem to recall that the T-bolts of the XX Phantine where Transported to the world as cargo in much the same way that smaller AC in WW2 would have been tansported from the UK/USA to other theaters beyond range of the given aircraft type.

However according to the AI rule book the T-bolt, Lightning and Marauder designs all have rocket boosters in addition to atmospheric engines in order to allow them to return to orbit. So this would suggest that these aircraft types are 'man enough' to survive re-entry into an atmosphere in the first place - so its not inconcievable that IN Carriers (or even converted escort freighters) would carry extra fighter and bomber wings intended to opperate from captured airfields or forward airstrips.

Perhaps once these carriers have delivered their load they will be withdrawn possibly from that campaign altogether - while the lighter frieghter 'escort carriers' are used as a relay to return to the supply worlds in order to pick up new squadrons (or replacements) of fighters/bombers etc and also to act as orbiting workshops until sufficient ground facilities are available.

My Tuppence worth

Thornz
07-10-2009, 20:23
Love this discussion.

In "15 Hours" in the first quarter of the book they make a drop onto enemy teritory. I can't remember the exact specification of the ship but it told you exact seating numbers & number of decks.

If someone could look that up it might shead some light on the transport capacity of an "assault lander"