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TheBearminator
05-02-2014, 12:26
What kind of fuel does the Imperium use in the 41st century? Unobtainium? Endurium? Smurf berries? I can't find any fuel ports on my Imperial vehicles but all of them seem to have some kind of exhaust system.

Apologist
05-02-2014, 12:57
Typically promethium, but the great advantage of the standard template construct (that forms the basis of all common Imperial vehicles) is that it would design things that used locally-available resources. There are references to Leman Russ battle tanks being powered by everything from wood to fusion, for example.

Tomxj
05-02-2014, 14:53
They Burn Heretics.

TheBearminator
05-02-2014, 15:11
They Burn Heretics.

Hahaha! :D

DoomedToRepeatIt
05-02-2014, 16:42
I remember a quote from somewhere about how all Imperial vehicles run on skulls, eagles, and screaming bald men....

Ramius4
05-02-2014, 17:42
screaming bald men....

Oh no! They're using Space Marine Sergeants? :p

TheBearminator
05-02-2014, 17:56
Oh no! They're using Space Marine Sergeants? :p

It is funny, because it's true. :) As the Mexican guy said in Family guy.

Lord Damocles
05-02-2014, 19:22
The third edition Rulebook (seven pages from the back) notes that the type XV Phaethon pattern Russ uses a solar powered crystal battery unit for ancillary power generation (which probably accounts for why Imperial Armour books note that Russ Lascannons have unlimited ammunition).

This is also the source for the Russ being able to run on 'vegetative-substances and foodstuffs as fuel' in it's 'Adaptable Thermic Combustor engine'.

Pellefantman
14-12-2014, 12:03
Maybe Ratlings! they've become so rare so where did they go..? :)

quantumcollider
14-12-2014, 16:53
In once source (I think it was a White Dwarf some years ago) it was mentioned that Space Marine vehicles use 'clean fusion power', but this seem to contradict an old cut-out drawing of a Land Raider, that had a fossile fuel engine with atomic powered secondary drive.

I prefer to think that Imperial vehicles are rather modular. Als long as a it fits in the enigne compartment, a power plant can power the vehicle, no matter the actual technology used.

ADF
15-12-2014, 21:52
Several kinds of fuel are mentionend.

Combustion engine-analogues run on promethium, which seems to be similar to petrol, but much more volatile. Detailled descriptions of promethium and its method of extraction can be found in "Caves of Ice", a Ciaphas Cain story set on a petroleum-exporting ice world. Promethium is therein described as a malodorous, flammable and even explosive liquid - it's really just sci-fi oil.

Many larger or particularly sophisticated imperial vehicles use onboard fusion or plasma reactors (land raiders and most superheavies vehicles use those), while others run either on energy cells or on various local fuels. Imperial fuel cells seem to be Hydrogen cells or their sci-fi analogue, as they are quite prone to exploding (the old 2nd edition datafaxes had critical hit tables for vehicles; almos every vehicle had a "energy cells explode" result that led to spectacular destruction of the vehicle).

Keep
15-12-2014, 23:30
The third edition Rulebook (seven pages from the back) notes that the type XV Phaethon pattern Russ uses a solar powered crystal battery unit for ancillary power generation (which probably accounts for why Imperial Armour books note that Russ Lascannons have unlimited ammunition).
You could create electrical energy with every power source therefore thats no indication of solar powered battery units... Forgeworld internal scheme has a combustion engine coupled to an electrical generator (you need one anyway for the various board electronics). And i haven't seen any solar panels or huge "thermal collectors" that safe the heat of sun light on leman russes yet... I dont think the author(s) who wrote "solar powered crystal battery" thought this thing through, (t)he(y) just wanted to make it sound cool.

Besides, the tank kits all had and have exhausts. Also, what's more fitting to a dark grim setting? Where everything runs on silent electric motors with green energy, or where almost everything spits out huge black plumes of exhaust gasses while the engine is roaring?

I think solar power is pretty much out of question for logical reasons. You just cant run a tank on solar energy effectively. The star of the system only delivers so much energy per surfacearea. ~1370W per squaremeter at the most favorable condition on earth (high noon, at equator, 100% efficiency). The Engine of a WW2 Tiger Tank, Maybach HL 230, had ~500kW Power Output. The Name of the Engine for the Leman Russ that FW gave it is "HL230" ... best case: Leman Russ takes only as much Energy as much as a Tiger Tank. If it produces more instead, it means the tank requires more energy, therefore it would need even more solar power input. To produce 500kW you need 364mē surfacearea in the most optimal conditions on earth you can have and only if you can achieve efficiency of 100% (impossible). And that requires the sun to shine 24/7 for the tank to be operable 24/7. If you want to do it with less then that, the sun has to be more powerfull in which case it might be that walking/living on the planet isn't possible (not sure what would be endurable for a human)

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Boris_Quarta_Jaw
16-12-2014, 19:57
I believe he said the solar powered batteries ran the ancillary systems. I know how much the IG love their big guns, but even on a Russ I think the engine would count as a main system. That said if you can recharge a lasgun in a fire I'm sure you can kit out Russ with some solar panels to recharge the Lascannons. I just don't see them making it through a fire fight which would lead to believe that it would a recharge kit for when you were in the rear or just plain out of battery packs and you were gonna die anyway.

Keep
18-12-2014, 17:24
As long as the combustion engine is running you can generate energy with it if you couple an electric generator to it (and the engine has a lot more power then just solar energy). The tank needs electricity , so the generator has to be there anyway, with lascannons or without.
Also, just think of how much energy a lasercannon shot uses... regaining that via solar energy that you could collect from Leman-Russ-mountable-sized Panels could be a matter of days/weeks. Lasgun magazines, i can get behind that they might be rechargable with some solar tech or fires in the field... but Tankhunter weapons that eat through hundreds of millimeters of armor?

Foulacy
18-12-2014, 17:36
They have several squats in the hull running around a hamster wheel.

Snake Tortoise
18-12-2014, 17:49
As far as solar powered lascannons go we probably have to assume 30-40k solar panels are far more effective than they are in 2k. Science breaking levels of effectiveness.

Tastyfish
18-12-2014, 23:34
The solar powered Russ doesn't mention powering the lascannon, just that the tank can never really run out of fuel. You could probably run the tank off the capacitors for the lascannnon should you take a critical fuel tank hit and be ina position to use the tanks innate solar power but not the other way around.

They wouldn't have given them battlecannons if that was the case.

The Black Shield
18-12-2014, 23:50
So that's what happened to the Squats.

Boris_Quarta_Jaw
19-12-2014, 00:56
I don't thinks it too far flung to think with better tech you could have solar powered lascannons. Increase how effective battery storage can be, as well as solar power and I think it's possible to have banks of solar panels recharging lascannon batteries ready to re-supply the front line. As to the tanks alternator I think most of that power would be used to supply the comms and other sensory equipment. However assuming solar power got better in the future we can also presume that a smaller generator can produce the power to supply the entire tank.

ManOfRust
19-12-2014, 08:02
I recall from the STC discussions when the MkIIc Rhino came out there was a big technical poster in WD that outlined the main systems. The distinction was between the motors, that ran the drive train and the track linkages, the fuel cells that stored electrical energy for the motors and systems and the four engines that convert combustible fuel into electrical energy and charge the fuel cells.

Converting combustible fuel>heat energy>electrical energy>rotational motion is much more efficient (sum waste processes) than converting combustible fuel>expanding gas>lateral motion>rotational motion. Once you solve the engineering challenges of storing the electrical energy in high density format and flexible combustion of a wide range of fuels it becomes a good system for locomotion.

The fuel cells are the main STC marvel, closely followed by the high-power electrical motors and the any-fuel engines. But if you have the fuel cells then you can exchange the motors for locally available equivalents or the fuel engines for something a little more dedicated to a particularly abundant local fuel source and the layout will still work.

If you run out of fuel for the engines (or you're operating in a non-oxygen atmosphere), the fuel cells can keep the motors and systems running for a short while but will probably drain quite quickly if they need to run drives, weapons and comms, similarly if you need to run silent you can do so without running an exhaust generating combustion cycle.

You could use secondary electrical power to charge the cells instead of the engines, solar or plug it into an energy grid. But solar energy on it's own isn't going to be able to run a moving battletank, there just isn't enough energy in sunlight to do it. I'm not sure if someone mentioned it earlier but direct sunlight only provides about 1000 watts per square meter at ground level - that's total energy, before you convert it to something you can use, which will include efficiency losses. To put that in perspective a kettle or a toaster uses about 1100 watts. Even if you had 100% efficient energy conversion sunlight>electricity that means you would need 500 square meters of solar collection to run the Tiger tank in Keep's example, not practical and a huge target.

However, very efficient, high capacity fuel cells might allow you to deploy a more manageably sized, believably efficient solar collector array and charge the fuel cells when you're out of combat, saving you non-recoverable combustibles and letting you stay active in the field for longer. For the Imperial G..., I mean Astra Militarum, I'm sure warfare still involves more waiting around than actual combat so anything that makes that easier would be beneficial.

tneva82
19-12-2014, 08:49
And i haven't seen any solar panels or huge "thermal collectors" that safe the heat of sun light on leman russes yet...

Besides, the tank kits all had and have exhausts. Also, what's more fitting to a dark grim setting? Where everything runs on silent electric motors with green energy, or where almost everything spits out huge black plumes of exhaust gasses while the engine is roaring?

Are the leman russ models XV Phaethon patterns though? Different patterns, different workings. Hell even different PLANET with same pattern could easily produce different looking russes due to the nature of STC's.

GW doesn't produce kit for every kind of leman russ in 40k. Would take big warehouse to house 1 box of each if they did :D

Keep
19-12-2014, 16:13
Phaeton pattern is the Leman Russ from 2nd/3rd edition. The current ("new") Leman Russ has a different turret, so is likely a different pattern (but its nowhere mentioned). At least i would like to think that it's a new pattern.
And while yes the Leman Russ has many patterns, the main hull still looks very similar for every version, otherwise it would just be a new tank type.


As far as solar powered lascannons go we probably have to assume 30-40k solar panels are far more effective than they are in 2k. Science breaking levels of effectiveness.
No not science, but physical law breaking... So unless they are solar cells made with warp technology... in which case they would propably be more worth then the entire tank.


Converting combustible fuel>heat energy>electrical energy>rotational motion is much more efficient (sum waste processes) than converting combustible fuel>expanding gas>lateral motion>rotational motion. Once you solve the engineering challenges of storing the electrical energy in high density format and flexible combustion of a wide range of fuels it becomes a good system for locomotion.
Heat is the least efficient form of energy, that's why every mobile machine that uses electrical motors (some big dumptrucks in mining pits for example) uses a regular piston-engine and an electrical generator, to power the electrical motor, instead of converting to heat and use a turbine to generate rotational motion. Using a turbine wouldnt be not only more inefficient but also more costly.

Lord Zarkov
19-12-2014, 19:30
Phaeton pattern is the Leman Russ from 2nd/3rd edition. The current ("new") Leman Russ has a different turret, so is likely a different pattern (but its nowhere mentioned). At least i would like to think that it's a new pattern.
And while yes the Leman Russ has many patterns, the main hull still looks very similar for every version, otherwise it would just be a new tank type.


No not science, but physical law breaking... So unless they are solar cells made with warp technology... in which case they would propably be more worth then the entire tank.


Heat is the least efficient form of energy, that's why every mobile machine that uses electrical motors (some big dumptrucks in mining pits for example) uses a regular piston-engine and an electrical generator, to power the electrical motor, instead of converting to heat and use a turbine to generate rotational motion. Using a turbine wouldnt be not only more inefficient but also more costly.

To back this up heat is generally considered 'wasted' energy as using it for a anything requires more energy to be put in, and generating it means that the energy has not gone into a more useful purpose - it is effectively a 'waste product' of any process involving energy transfer.

Most processes that use 'hot things' to do work (be it motion, generation of electricity, etc) work by expanding a fluid and using that expansion to drive the moving parts - whether this be driving a piston in an internal combustion engine, spinning a turbine to generate electricity, propelling an aircraft as a jet, etc.

Also changing from one energy type to another wastes energy. Going Chemical => Thermal (=> Kinetic) => Electrical => Kinetic is much less efficient than just going Chemical => Thermal => Kinetic


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MrKeef
23-12-2014, 02:34
Promethium is a very common fuel of the vehicles of the Imperium and has been described as a petrol/oil/napalm like liquid depending on the source. Another energy source that is used in the 40th millennium is plasma generators, which commonly used in starships.

I remember reading somewhere that Leman Russes had different engines depending on where they were built, probably according to what technology was available at the location and popular STC patterns. I distinctly remember the two examples given were a wood or coal burning engine being contrasted against an atomic or plasma drive, although I can find no evidence to back this up. All GW and FW models have exhaust pipes though, so we can safely assume that something is being burned by the engines of at least 1 type of LR.

The Black Shield
23-12-2014, 03:34
They could be cooling stacks like on a nuclear reactor.

Hakar
24-12-2014, 15:49
They Burn Heretics.

But what do they burn apart from heretics?

Keep
25-12-2014, 20:03
They could be cooling stacks like on a nuclear reactor.
They would need a very big water tank then, because cooling is done by using an external cold water source (in case of a power plant via river water, in case of subs and carriers... the ocean).


But what do they burn apart from heretics?
alleged heretics

The Black Shield
28-12-2014, 21:05
Sometime before the Heresy they must have burned up all of the Squats that is why they have resorted to using Prometheum.

Night Bearer
02-01-2015, 17:42
Besides, the tank kits all had and have exhausts. Also, what's more fitting to a dark grim setting? Where everything runs on silent electric motors with green energy, or where almost everything spits out huge black plumes of exhaust gasses while the engine is roaring?
Option 3: turning green energy into industrial exhaust for religious purposes.

"Brother Meineke, we have smoke - habemus vroomum! Let us anoint our faces with the sacred #2 combo at Burgerus Rex!"
"Blessed is the sacred drive-thru - ALL HAIL THE OMNISSIAH!"

Griefbringer
03-01-2015, 13:25
I would think that in the Imperium, green energy refers to burning orks to power their engines. Besides being naturally green, they are an abundant and renewable natural resource on many places (like Armageddon jungles).

The main problem with burning xenos or heretics for fuel is the high water content in the bodies, which can not be burned, thus reducing energy density. Thus, it would be more efficient to first dry them (though this also requires energy), and then to chop them into suitably small pieces in order to conveniently feed them into the fuel container.

Alternatively, one could always save fuel by harnessing the heretics (presuming that they are still alive) in front of the vehicle, and having them pull it to the desired location.

mightymconeshot
03-01-2015, 14:31
I would think that in the Imperium, green energy refers to burning orks to power their engines. Besides being naturally green, they are an abundant and renewable natural resource on many places (like Armageddon jungles).

The main problem with burning xenos or heretics for fuel is the high water content in the bodies, which can not be burned, thus reducing energy density. Thus, it would be more efficient to first dry them (though this also requires energy), and then to chop them into suitably small pieces in order to conveniently feed them into the fuel container.

Alternatively, one could always save fuel by harnessing the heretics (presuming that they are still alive) in front of the vehicle, and having them pull it to the desired location.

I can see it now, giant drying beds where thousands of ork bodies are set out under giant magnifying lens to dry and some old man shouting out in front of a little shed "Quality ork fuel, nothing burns better than an ork. Get your orks right here. Burn some xenos and power your things at the same time"

Lord General Armstrong
04-01-2015, 05:25
Alleged heretics

If this site had a like button...

Griefbringer
04-01-2015, 17:29
and some old man shouting out in front of a little shed "Quality ork fuel, nothing burns better than an ork. Get your orks right here. Burn some xenos and power your things at the same time"

Remember that it is a high orctane fuel!

In practice, it would probably be easier to use whatever plant matter is locally available. But if you happen to live in some pretty barren place, like Tallarn or Valhalla, then it might be necessary to make good use of any organic material that is available.

ManOfRust
14-01-2015, 10:34
To back this up heat is generally considered 'wasted' energy as using it for a anything requires more energy to be put in, and generating it means that the energy has not gone into a more useful purpose - it is effectively a 'waste product' of any process involving energy transfer.

Most processes that use 'hot things' to do work (be it motion, generation of electricity, etc) work by expanding a fluid and using that expansion to drive the moving parts - whether this be driving a piston in an internal combustion engine, spinning a turbine to generate electricity, propelling an aircraft as a jet, etc.

Also changing from one energy type to another wastes energy. Going Chemical => Thermal (=> Kinetic) => Electrical => Kinetic is much less efficient than just going Chemical => Thermal => Kinetic



Heat is the least efficient form of energy, that's why every mobile machine that uses electrical motors (some big dumptrucks in mining pits for example) uses a regular piston-engine and an electrical generator, to power the electrical motor, instead of converting to heat and use a turbine to generate rotational motion. Using a turbine wouldnt be not only more inefficient but also more costly.

Sorry to raise this thread from the dead but I have been offline over the winterval :)

You guys are right in that heat is conventionally seen as waste energy, it is very easy to make heat but very hard to make it do useful work - secondary effects of increasing temperature (increased pressure, expansion, preferential chemical/ionic reactions) are much more easily harnessed. Which is of course where efficiency comes in. Pressure can be contained and directed, expansion can be concentrated and harnessed against resistance. Losses are in mechanical resistance(Friction/heat) and failure to convert your heat into useful pressure/expansion. Heat can't be directed easily, heat energy radiates according to the rules of heat transfer in thermodynamics, entropy dictates that high temperature material loses energy to low temperature material without concern for where you might want it to go. It's not useful so it's waste.

Thermoelectric generation is direct conversion of heat to electricity. It has the advantage of no moving parts, correctly insulated the efficiency loss through non-process heat loss is minimal and the thermocouple systems that are already in use don't much care what the source of the heat is. The jupiter probes used radioisotope thermoelectrics once they passed beyond useful solar range and are still going.

However, conventional thermocouples are NOT viable for large scale electricity generation as they are only 1-5% efficient (compared to a relatively efficient diesel cycle at 45-50%), meaning that less than 5% of the heat energy created is converted to electricity - the rest stays as heat and the increased temp actually makes the thermocouple drop in efficiency further! But as the Rhino follows 15,000 years of materials development I can hope that this efficiency has increased somewhat.

If heat is your goal rather than waste, the advantage of being able to generate electricity from literally anything that burns is huge!

Of course, being able to surround a combustion engine in equally efficient thermo-electric generators makes heat loss for these systems suddenly disappear as well, although combustion engine cycles must be designed into the engine - meaning that you are committed to just one fuel source (although it is possible to convert a gasoline engine to use ammonia for example, but it requires significant structural change to the cylinders).

AndrewGPaul
14-01-2015, 10:58
I think part of the vaunted adaptability of Imperial vehicles is having engines that can run on a wide variety of fuels (for a current example, running your diesel on old chip fat), but also having the vehicle itself being able to accept a wide variety of power systems. For example, if the "standard" Rhino uses a petrol engine to power an electrical drive, then you can swap that engine out for a diesel, a gas turbine, a nuclear or fusion reactor, a steam engine burning coal, oil or wood, etc, etc ...

ManOfRust
14-01-2015, 11:07
Very true, but thinking even more scifi - having an STC combustion engine that can change it's internal dimensions and expansion cycle to suit any combustible fluid based on a simple burn analysis would be very cool indeed.

AndrewGPaul
14-01-2015, 13:46
That's what meant by saying "engines that can run on a wide variety of fuels", but it's been stated that the vehicles can run on anything from a wood stove to a nuclear reactor; there's no way that one engine is going to do all that. :)

Nazguire
15-01-2015, 04:22
That's what meant by saying "engines that can run on a wide variety of fuels", but it's been stated that the vehicles can run on anything from a wood stove to a nuclear reactor; there's no way that one engine is going to do all that. :)


Killjoy. Buzzkill. Fun Police. Party Pooper.

There's a magical motor in the Imperium that can run off anything, and you'll damn well like it.