Perhaps the best comparable figure would be Necromunda. Hive Primus is 10 miles high and 5 miles wide, whereas your average cruiser is, say, 5 miles long and 1 mile wide. If my maths is good, that makes a cruiser about a 20th the size of Hive Primus.
I don't think exact populations were given for Hive Primus (old confrontation fluff had thousands of billions of people per hive world, though there hives were bigger and there were more of them) but I'm assuming many billions, all feed by recycling and imports. A 20th of many billions is a very high number, though obviously cruisers need room for weapon systems and engines that Hive Primus lacks.
Last edited by One Man Assault; 06-03-2012 at 11:22.
A Hive World has upwards of 100 billion citizens, according to the 3rd Edition rulebook. Assuming that there are only two hives on Necromunda (Primus and Secundus) that's a minimum of 50 billion citizens in each Hive.
However, Necromunda, being in Segmentum Solar, is a very old world with a very large population; it is not unreasonable to assume that there are many more citizens in each hive and many more hives than two in turn!
EDIT: It was 22 billion:
and that was with hives covering "70% of its surface"
Imperial Armour: Siege of Badab gives Badab Primaris as about 6 billion.
And the FFG books have some low-population hiveworlds as well.
But 100 billion is more usual as a minimum.
Last edited by Iron_Lord; 06-03-2012 at 12:10.
Assume a hive could hold 1 billion, a very low estimate. Divide that by 20 given that a hive is about 20 times the volume of a cruiser and you get 50 million. Assume that a cruiser could spare a 100th of its volume to house troops, a very low estimate, and each cruiser could transport half a million troops.
This means you'd need 6 cruisers to transports the Wehrmacht at the start of operation barbarossa. Actually, I think the German army in 1941 was about 5 million, had they conquered Russia they'd have, say, conquered a third of the industrialised world? 10 cruisers to capture a third of a planet sounds not too far off the victory requirements of the planetary assault mission.
Last edited by One Man Assault; 06-03-2012 at 12:47.
Ichar IV - 500 billion
Minea - 154 billion
these are just a few hive worlds where they have populations above 100 billion
yes, take the initial 10,621,434,879 mentioned earlier and now multiply it by a factor of 7, bringing the total Guard count to 74,350,044,153 as of the 9th year into the crusade (current standing date)It is a bit odd for so small a proportion of Guardsmen in the crusade (20%) to be deployed- but that's possibly to do with the need to keep a strong reserve to reinforce them.
Now while you could in theory pack in an extra few thousand bodies you are not just transporting bodies, but gear and supplies as well and those you just loaded up on your ship are sleeping in the halls, the extra compartments and eating into your ship stores at an alarming rate.It is like anything not made to carry extra people. You can do it , but its not easy and may be a really bad idea.
Now if you look at Rogue trader barracks you can hold more then one upon a ship. Cargo ships with the massive space would be the best pick to be troop carriers. I am not sure how big the Barracks are they only say "thousands" So most likely a regiment or two. Now Barracks are not just beds, but also a place to store gear, train and includes the items you need such as extra ship stores for the extra bodies and most likely larger bays to fit extra small craft.
A dedicated transport would be built for just that, you can't just place them on any old ship.
The sizes given for imperial battleships are usually in the 6+ kilometer range for length. Putting them at roughly a kilometer high and about a quarter to half that wide. Twenty times the length, and likely more than that high and wide. And somewhere between 1.5 and 3 square kilometers of space.
Greater London is about 1.5. And has a population of 7+ million.
So yeah. A battleship having a crew of about 3 million is within the realms of possibility (it'd be hugely cramped of course, but it's not like greater london is wide open spaces). The main issue would be keeping them fed but, like super carriers, I doubt battleships go off alone very often.
Some of the things we've seen for imperial troopships are way bigger than battleships (take those cathederal things from that blood angels comic, or whatever would be carrying those carrier sized landing craft on the front of the guard codex). So a ship that can carry 5 million plus people, if it's entire purpose is transporting massive amounts of people, isn't exactly far fetch for 40k.
They'll likely be fairly rare and valuable and of course would make massive massive targets and would lack the kind of anti-ship guns that would be needed to defend themselves against anything but strike craft due to space issues. But it's well within acceptable fluff limits.
Victorus Aut Mortis.
For The Bridge.
Remember that a ship has crew to perform functions. It doesn't try to fill the volume with crew just because it can. In 40K, the STC based machinery of the Adeptus Mechanicus requires maintenance far less often than any comparable modern machinery. In the 40K universe, we hear of weapons and tanks being mothballed for centuries and being in working order. That means that the maintenance requirements of a 40K ship is likely far less than a comparable scaled up modern ship.
In A Thousand Sons, we find it normally takes a mass conveyor 4 days to reach the jump point, from Prospero, but with a good angle of launch they can make it in 3.
It also gives a ballpark size for a mass conveyor:
So- you're looking at a vessel between 60 and 80 km long (since the viewing dome is in the "rear quarter").Set high on the rear quarter of the Cypria Selene, the dome provided a commanding view over the vast superstructure of the mass conveyor. Its hull stretched away from them for sixty kilometres, ending in a blunt wedge of a snout. For a vessel intended to carry vast quantities of war materiel, troops and bulk items of warfare and compliance, it was handsomely appointed.
Last edited by Iron_Lord; 07-04-2012 at 09:31.
Armour plate and shield generators, internal bracing, shuttle bays, life pods, weapons, magazines and shell hoists/power feeds, life support, manuevering thrusters...Originally Posted by Palvinore
And top it off with a level of redundancy so that the vessel can complete it's mission.
I'd say some people might well be sleeping in the accessways - anything to grab a few extra cubic inches of space.Look at the BFG ship models. A good third or so of the rear of the ship is taken up with engines and reactors. A fuel tank or reactor chamber is not going have any people in it, and people are not going to be sleeping on the access walkways.
Originally Posted by Bestaltan
Other than that you have to garrison newly conquered worlds in case they rise up against you (look at the way the Great Crusade handled things, alot of resentment and upset over being forced back into the Imperium. I doubt things would be much different in that respect 10K years later.) although you could probably overlap those two duties with rotations. But also internal security and guarding vital facilities (stockpiles, shipyards, training centers, vital areas of communication, command and control, etc.) are not trivial problems either.
Don't forget that the Imperium is highly political (infighting and the like - one of the problems of the Achilus Crusade, point of fact) and that's going to use up resources as well (think Ebongrave as one such example, but infighting amongst specific generals, admirals, etc.) There's always the fact that aliens (like the Eldar and Tau) as well as Ork and Chaos pirates/raiders like to engage in wolf pack and raiding tactics (or just general piracy) and you may need to defend against those problems.
I'll also not ethe Achilus Crusade numbers are probably quite conservative - for one thing the Achilus crusade hit a snag when they ended up in a multi-front war against the Tyranids, Chaos, and the tau (as well as general problems from teh Eldar and I think Necrons, and I'm pretty sure the Orks are around somewhere, not to mention assorted rebels, aliens, and whatnot.) and they face supply problems within the sector (They don't hold enough productive territory to help supplement what they get through the gate, basically, and there's threat that the sectors supplying them might cut them off.) so they're actually sort of stretched thin with all their commitments and other complications (again politics and infighting, ineptitude, insanity - again Ebongrave - adn other factors.) Hell they probably could stand to be tapping from more sectors (They're only drawing from Ixianad, Scarus and Calixis, and none of those are particularily major or notable sectors.)
As a comparative example, in Dark Creed they mention 5 billion guardsmen on one planet (Boros gate) to defend a vital facility, and that wasnt as well defended as (say) CAdia IIRC. And that number was closer to 10K I believe with PDF and militia forces (The Boros troops had a structure quite similar to Cadia, in which much of the population could be drafted in times of emergency.)
And it can also depend on the length of the journey or what things you're dealing with - troops having to spend weeks or months in transit may get bored or fractious (think First and Only, or For the Emperor.) so you need to keep them busy training (Last Chancers Omnibus, uplifting primer, earlier fluff) onboard ship, which you need space for.
You might be able to fudge alot of details if you assume some sort of stasis or cryogenic suspension (something various sources have mentioend - at leats for Space Marines) but I dont know exactly how widespread that technology is.
One ting we've never had addressed in 40K is issues like fuel and propellant requirements and how much intenral volume THAT takes. They use reaction engines, and often are depicted as thrusting for days or weeks, so its quite likely that both fuel and propellant, and that can quite possibly be a BIG issue in some starships.
The atomic rockets website has some details on life support (and starship design in general) that may or may not help. I wouldn't take it as 100% gospel and some things might not fit in with 40K's ideas perfectly, but it can help with ideas in that regard.
The fairly hard-SF Star Cruiser rule set (a companion/ spin off of Traveller 2300AD) had some ship construction rules - IIRC, life support was 0.02 cubic meters per person per day.Originally Posted by Connor MacLeod
Assuming the Cadian 8th (10,000 soldiers) for a four month trip, with an additional 50% safety margin for warp travel variance, thats 36,000 cubic meters just to keep them alive - and not including the crew of the vessel that they're actually on.
Originally Posted by Bestaltan
Plus officers, advisors, drivers, cooks, medicae, armourers, quarter masters...Originally Posted by Aun'aart'al
Originally Posted by Bestaltan
The Guard codex family picture is actually listed as nearly half of the Cadian 8th, which admittedly could put it at anywhere between 6 and 10,000. But 10k's a nice round number.
Originally Posted by Bestaltan