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The Guy
01-09-2008, 08:02
I was just wondering how a flamer actually kills a space marine [one wearing a helmet]. He's covered head to foot in tank armour. Does the heat burst their ammo or power plant on their back making them explode?

Koryphaus
01-09-2008, 08:54
In Dark Apostle, there is a Terminator wearing really old style armour, and the air conduits or something on the outside melt and burn, which then burns into his lungs and kills him.

I guess it could melt through the joints at the knees, or the eyepieces or something.

ChrisMurray
01-09-2008, 09:00
In IA 4 one of the terminators (if I recall correctly) gets hit by a flamer and the seals around his joints melts. So I assume it's not really a case of the flamer needing to do anything to the armour, just all the joints and meterials holding the arour in place, it'll then just drop to the floor and the marine singed alive.

Clockwork-Knight
01-09-2008, 09:02
Keep in mind that the future flame-throwers of the Wh40k-verse uses "promethium", which could mean anything, starting from normal average oil given fancy name, to really weird substances that have super-heating properties. Also, there might be special acidic stuff applied to the flame, so that it actually melts the armour.

Mr Kibbles
01-09-2008, 09:58
Whats IA mean?

Tonberry
01-09-2008, 10:06
Whats IA mean?

Imperial Armour, a series of campaign books from Forge World.

ashc
01-09-2008, 10:10
Imperial Armour, a series of campaign books from Forge World.

Perhaps that one should be a warseer dictionary term, you would think it would be one. (although I do know that sometimes it gets used for Index Astartes as well.....)

Ash

Mr Kibbles
01-09-2008, 10:17
I just thought it would be a bit strange for there to be a story in the IA books, cause i have the 1st one and it doesn't have any.

Clockwork-Knight
01-09-2008, 10:24
It starts having one with Imperial Armoury Volume 3: The Taros Campaign.

Master Stark
01-09-2008, 10:34
Well, I figure that a S4 flame pretty much represents a normal strength flame. Very likely to ruin your day if it hits you. Super hot burny flame would probably be S6 or something.

To be honest, I imagine power armour would be almost totally immune to normal flamers. The restraints of game balance mean that they will suffer wounds from them in the game, but speaking strictly about the fluff I think even the joints of power armour would be largely heat and flame resistant.

Firaxin
01-09-2008, 11:53
It doesn't have to melt the armor or the joints or whatever. Exposed long enough, the marine inside will die from heat-exhaustion or something to that effect, boiled away within his own armor. The heat will bleed through the armor itself, turning the inside into a furnace. DAoT tech, like air conditioning and the like, helps delay this though, and thats why we read about armor joints and stuff melting, because dying from heat-exhaustion would simply take too long in battlefield terms.

dreameater
01-09-2008, 12:09
I would imagine it to be like deep frying an shelled egg to long and the armour erupts due to the buid up of gases.

Koryphaus
01-09-2008, 12:58
It doesn't have to melt the armor or the joints or whatever. Exposed long enough, the marine inside will die from heat-exhaustion or something to that effect, boiled away within his own armor. The heat will bleed through the armor itself, turning the inside into a furnace. DAoT tech, like air conditioning and the like, helps delay this though, and thats why we read about armor joints and stuff melting, because dying from heat-exhaustion would simply take too long in battlefield terms.

That is commented on in Dark Apostle. The Terminators turn off their suits to avoid auspex detection, and when they do that, they don't have the cooling systems, and they nearly roast in their suits.

Master Stark
01-09-2008, 13:09
It doesn't have to melt the armor or the joints or whatever. Exposed long enough, the marine inside will die from heat-exhaustion or something to that effect, boiled away within his own armor. The heat will bleed through the armor itself, turning the inside into a furnace. DAoT tech, like air conditioning and the like, helps delay this though, and thats why we read about armor joints and stuff melting, because dying from heat-exhaustion would simply take too long in battlefield terms.

Power armour is rated for vacuum space operations though, isn't it? If it can take the heat of a sun without an atmosphere to mitigate it, I imagine it can handle the heat of a flamer. You'd have to bake the Marine for several hours, IMO, before you started baking the dude inside the armour.

Koryphaus
01-09-2008, 13:39
Bake for 2 hours at 1000*C, turning once. Then lower the temperature and bake for a further 30 min at 500*C, or until the top is golden brown and flakey.

Master Stark
01-09-2008, 14:09
So having spent a few minutes reading up on it:

Most flamethrowers use petrol (or gasoline) as their base fuel, which burns at around 500 celsius. The suits used for fire entry by firemen today withstand around 540, but only for about five minutes before the wearer starts to suffer the effects of the heat.

So, assuming the weakest parts of a marines armour only offer the same heat protection as a modern firemans suit, and that the thicker parts (chest, thighs, etc) offer better protection, and that 40K flamers operate at about the same intensity as modern flamers, and that a Marine can stand a bit more pain and injury than a fireman, then you'd need to hit a Marine with a continuous blast of flamer fire for around ten minutes before he'd start to become injured. Possibly fifteen or twenty minutes if you wanted to take him out of action.

olmsted
01-09-2008, 16:01
which is why the joints are the favorite part to hit. in the first grey knights novel. a mob of civvies kill 1-2 grey knights and a crew of the thunderbird by stapping the joints.

joints kill.


also in my 2nd to last game i fired 2 flamers and hit 10 marines (5 each) in a squad of 8. 5 failed their tests including the powerfist vet sgt.

PondaNagura
01-09-2008, 16:17
well i'd imagine it deosn't kill them outright, since not every casualty in 40k is necessarily a death. it could be the armors rebreather didn't stop all the heat and incinerated the lungs, or the joints melted, the optics burst blinding the marine...also marine armor is probably pretty effective against the heat wash of the inferno, due to ceramite.
it could be they are render incapacitated momentarily, temporarily engulfed in flames and need to extinguish themselves.
crap now i want to make a conversion of marine striding through combat while on fire.

Burnthem
01-09-2008, 18:43
IMHO in the fluff Space Marines would be nearly invulnerable to 'normal' flame weapons, it's only due to that magic phrase 'game balance' that they are affected in-game. Power Armour is designed to operate in pretty harsh extremes of both environment and temperature.

Remember that Tactical Dreadnought (terminator) armour was based upon suits invented to work inside Plasma Reactors, so IMO a piddly little flamethrower will offer no danger whatsoever.

olmsted
01-09-2008, 19:17
ITT people who dont understand flame throwers.

Brother Siccarius
01-09-2008, 19:49
Well, I figure that a S4 flame pretty much represents a normal strength flame. Very likely to ruin your day if it hits you. Super hot burny flame would probably be S6 or something.

To be honest, I imagine power armour would be almost totally immune to normal flamers. The restraints of game balance mean that they will suffer wounds from them in the game, but speaking strictly about the fluff I think even the joints of power armour would be largely heat and flame resistant.

Take a pressurized suit or system, expose it to open flame for any amount of time, watch the pressure seals burst and see the suit go *pop!*. GURPS future system had a special rule for that one I believe.

Da Black Gobbo
01-09-2008, 20:02
it's pretty simple, maybe the promethium when burns, it turns really hot say 1000šC for example, with just a little "bath" from it some parts of the armour can perfectly get melted, maybe the liquid promethium in flames penetrate the breathing system of the armour before it can be closed making the marine to swallow a big "tequila sunrise" shot.

Lothlanathorian
01-09-2008, 20:22
Not all template weapons fire...fire. Some shoot acid, some shoot weird alien stuff. Also, a kill in-game is only a casualty and a casualty isn't always a KIA. It may just disable the armor or adversly affect the Marine enough that he is out of the action. Also, game balance. That really matters. A lot. In =][=, a fully sealed suit of SM power armour can take at least one hit from a melta weapon. Also, Power Armor is made from several composites with lots of ceramics/steel alloys and such. That would drastically reduce heat damage. Remember, they are wearing spaceshuttletank suits.

downundercadet07
01-09-2008, 21:12
It might cook off his ammo, and hand grenades as well. Having ten mags of mass reactive armor piercing rockets detonate next to you, as well as a couple of four pound fragmentation grenades makes even the most leet space suit go frowny face.

Additionally, promethium might well be massively radioactive, as it is currently. I understand that in many imperial applications it is not, but that doesn't mean they don't weaponize it for use in flamers. Plus, if you damage the heat sink of the armor, the little bowl guys on the backpack, the dude inside is going too cook. Sort of like in The Forever War, by Haldeman.

carl
01-09-2008, 21:46
In the SW books A Flamer, (well Heavy Flamer really), can seriouslly threaten a power armoured SM.

I'd guess the tempreture is just much higher, sort of low temp plasma. Add that to the fact that a suit of power armour surrounded in flame has nowehere to dump it's heat and thus it's easy to cook the armour real quick, not to mention it's supposedly able to cause power armour to crack and blister and flake. Plus on top it seems to pack sinificant physical force too, so i'd guess where dealing with a liquid explosive that gets it's oxegyn from the air raher than somthing in it's chemical construction, fired at very high velocity so it goes a fair way before it all ignites.

Lothlanathorian
01-09-2008, 23:22
It might cook off his ammo, and hand grenades as well. Having ten mags of mass reactive armor piercing rockets detonate next to you, as well as a couple of four pound fragmentation grenades makes even the most leet space suit go frowny face.


I lolled. I lolled hard. That is basically how I see it. I prefer to think of Marines as 'Movie Marines', so I think that the armor would hold out longer than the ammo and such.

Malevon
01-09-2008, 23:26
It doesn't have to break the armour, does it? Wouldn't extreme temperatures applied to the outside of the armour cause it to become unbearably hot inside? It doesn't really matter if the armour survives if the wearer is burnt to a crisp.

Lothlanathorian
01-09-2008, 23:51
Don't forget that it is made of ceramics. It doesn't get real hot very easy.

Hellebore
02-09-2008, 01:19
I lolled. I lolled hard. That is basically how I see it. I prefer to think of Marines as 'Movie Marines', so I think that the armor would hold out longer than the ammo and such.

You think that marines are as strong and tough as 20 foot hive tyrants or Lords of Change?

Hellebore

Brother Siccarius
02-09-2008, 01:43
I lolled. I lolled hard. That is basically how I see it. I prefer to think of Marines as 'Movie Marines', so I think that the armor would hold out longer than the ammo and such.

Actually considering the armor that they're wearing (both shape and what it can withstand, and that any cooked off round isn't going to be as well guided as one shot from a bolter), they would have a much higher chance of surviving....if their ammo wasn't held right next to a weak spot in their armor....and pointed directly at another weak spot in their armor (almost either way the shot goesonce cooked off, up or down, it's going to hit a weak spot, either the arm pit or the leg joint). If, say, they had it across their chest (rambo style) they'd be better off, because the bullet is going to be less likely to hit a weak spot (being across the strongest part of the armor).

A grenade would be less likely to do major damage when worn across power armor, most of the energy of the blast escaping away from the armor and into the open air.

(another gurps-ism that led to the least successful suicide bombings in recorded history, and with an engineer GM backing up the physics behind it.)

sabre4190
02-09-2008, 02:17
The flame throwers are much more powerful than we think of, easily capable of burning down just about everything. So while power armor can withstand extreme temperatures, i think "extraodinarily powerful flames" arn't very common, even in the 40k universe. I mean, we don't expect marines to jump into lava and survive right....? Oh god what a scary image.....

Master Stark
02-09-2008, 08:24
Take a pressurized suit or system, expose it to open flame for any amount of time, watch the pressure seals burst and see the suit go *pop!*. GURPS future system had a special rule for that one I believe.

Yes and no. Obviously a suit of astartes armour is going to have all sorts of survival systems. Internal air supplies, cooling systems, heating systems, and no doubt some form of pressure control.

If a guy in a modern day firemans suit can stand inside a 540 celsius fire for a few minutes without dieing, and we assume that the joints of a marines armour (the areas with the least protection) offer at least the same amount of protection as a firemans suit, then the only way you're going to kill a marine with a flamer is if you tie him up first so you can cook him for quarter of an hour. Anything less is probably only going to scorch the skin around his knees and elbows, and maybe his armpits. And thats just going to make him mad...

Tonberry
02-09-2008, 09:03
The =][= book says that ceramite is 'made to absorb and reflect heat', and in the rules it provides +d6 protection against flamers.

Lothlanathorian
02-09-2008, 19:11
No, I don't think that Marines are as strong as Hive Tyrants. I think that they would also be much larger and more powerful than their tabletop counterpart. I am not just a Marine-fapping fanboy.

I do, however, expect that superbadassfuturearmor + helmetofawesomewin, when donned properly, would keep our super awesome warriors of the future safe while walking through a fire. I think that a single Hive Tyrant would chew through many, many Movie Marines and a swarm of Tyranids would bog them down and eat them, but fire is for sissies.

Brother_Chaplian Raimo
02-09-2008, 23:36
...least successful suicide bombings in recorded history,...

I love anecdotes like this. I can has elaboration, please?

Actually contributing to the disscussion, I think, when dealing with Astartes, flamers are more an incapacitating/disabling weapon, overloading cooling systems (and thus powerplants), respiration equipment, and the occasional delicate internal system (say, servomotors exposed by prior damage). To actually wound the Marine inside the armor, considerable time and effort would be required.

Adra
03-09-2008, 00:53
Flamers are very very hot. Q.E.D.

Burnthem
03-09-2008, 09:57
Yes and no. Obviously a suit of astartes armour is going to have all sorts of survival systems. Internal air supplies, cooling systems, heating systems, and no doubt some form of pressure control.

If a guy in a modern day firemans suit can stand inside a 540 celsius fire for a few minutes without dieing, and we assume that the joints of a marines armour (the areas with the least protection) offer at least the same amount of protection as a firemans suit, then the only way you're going to kill a marine with a flamer is if you tie him up first so you can cook him for quarter of an hour. Anything less is probably only going to scorch the skin around his knees and elbows, and maybe his armpits. And thats just going to make him mad...

QFT. A few flames aren't going to hurt a Marine, especially considering that anybody close enough to a Marine to use a Flamer is only a few seconds from death anyway it brings the chances of a successful flaming to almost nil. (A bit like these forums ;) )

Lothlanathorian
03-09-2008, 18:56
I love anecdotes like this. I can has elaboration, please?

Actually contributing to the disscussion, I think, when dealing with Astartes, flamers are more an incapacitating/disabling weapon, overloading cooling systems (and thus powerplants), respiration equipment, and the occasional delicate internal system (say, servomotors exposed by prior damage). To actually wound the Marine inside the armor, considerable time and effort would be required.

This man is making sense. On my internet. Stop with that.

Brother Siccarius
03-09-2008, 19:41
Yes and no. Obviously a suit of astartes armour is going to have all sorts of survival systems. Internal air supplies, cooling systems, heating systems, and no doubt some form of pressure control.

If a guy in a modern day firemans suit can stand inside a 540 celsius fire for a few minutes without dieing, and we assume that the joints of a marines armour (the areas with the least protection) offer at least the same amount of protection as a firemans suit, then the only way you're going to kill a marine with a flamer is if you tie him up first so you can cook him for quarter of an hour. Anything less is probably only going to scorch the skin around his knees and elbows, and maybe his armpits. And thats just going to make him mad...

Modern Day Fireman suits aren't stiff, armored, or inflexible like a suit of power armor, nor are they pressurized.
A pressure control would involve having some way of releasing heated or expanding gases, which just means more ways for a flammable liquid to get in there.

Brother_Chaplian Raimo
03-09-2008, 20:13
This man is making sense. On my internet. Stop with that.

Don't worry- I make up for any sense I make with daily overdoses of pure random. Always dignified random, though.

imperial_scholar
04-09-2008, 00:41
In my opinion. A flamer probably wouldn't hurt a power armoured marine easily. However, may I suggest that maybe the armour is weakened (not compromised) by the heat, but maybe a secondary source of small arms (battle shrapnel, lasgun/pistol, bolter/pistol) combined together might have more of an effect; abet unintentional on the firers part. (I find it hard to believe that a gun would go from a single shot to full automatic only offering double a firing rate).

I think this is one of those times where the fluff isn't fulled synced with the game. But if you were to play a game and someone's unit was 100% immune to your weapon just because of the armour they wear.. it'd be upsetting (2nd edition).

However, most flamers are not AP3. So it still represents the off chance that a marine could be wounded by a flamer.

In addition you could turn the question around and ask how wearing an Imperial Guardsman in Carapace Armour gets a 50% chance of surviving a wash of flames over their head. Visually (artwise) the armour offers very little. This might be chalked up to superior materials design in the 41st Millennium.

kylsnik ironhead
04-09-2008, 02:47
In the old Ork Codex it says Ork flamers double as cutting torches that they use to take apart Spaceships so that would hurt.

Brother Siccarius
04-09-2008, 06:10
I love anecdotes like this. I can has elaboration, please?

Well, since it's somewhat relevant, and could help explain my point a bit more, here goes:

Alright, the slightly over-used metaphor for this is a firecracker in your hand. If you keep your hand open, it only singes and burns you a little (unless you're stupid enough to hold a really huge one), if you close it, it blows the F out of your hand.

Here's my take on it (and the explanation to my anecdote).

A GURPS campaign with a friend as our GM who happens to be an engineer and an interesting guy to talk to about physics in game systems (you need an engineer to get through the GURPS system rules ;) ). So the question came up rather forcefully, of: When stuck in an ammo dump trying to avoid a bloodletter that's just been summoned and the cultists backing it, what do you do to save yourself and your group.
The answer, somewhat mock heroically, is:
Take a handful of frag grenades, a few shaped charges pointing outwards, and strap them to the outside of the chest piece of a set of Carpace armor (which is pretty solid, even though the entire suit leaves a number of weak spots). Now, run towards a group of seven cultists and a bloodletter (yes, it's nuts already) and blow the grenades.

Now, the shaped charges you don't have to worry about, they're designed to blow in one direction. The frag grenades however, are against a solid chest piece on one side, and a thin piece of webbing and nothing but air on the other. When they explode, the majority of the force from the explosion goes outwards, away from the chest piece, taking the path of least resistance (it's not just for electricity and pacifists you know) the rest is redirected along the chest piece. Ironically, If the grenade had been, say, a few inches away from the chest piece instead of strapped to it, the grenade's full effect would probably be enough to make the armor mean little, but strapped against it, the energy and force of the blast escapes the easiest way possible.

In the end, it ended up blowing up the bloodletter, the cultists, their ammo (which only intensified the blast) and a section of a wall, as well as injuring me, the slightly suicidal escaped pit slave. It only avoided blowing the whole ammo dump by a few feet.



In addition you could turn the question around and ask how wearing an Imperial Guardsman in Carapace Armour gets a 50% chance of surviving a wash of flames over their head. Visually (artwise) the armour offers very little. This might be chalked up to superior materials design in the 41st Millennium.

Actually, that one's quite simple in it's own way. The armor itself is quite strong and resistant to quite a bit, but it's so sparse over the person that it doesn't protect very much of them.

Also I think "Wearing an Imperial Guardsman in Carapace armor" should give more than a 50% chance for you to survive, I wouldn't bet on the chances of the guardsman surviving.;)

Master Stark
04-09-2008, 08:31
Modern Day Fireman suits aren't stiff, armored, or inflexible like a suit of power armor

Indeed. If they were also covered in thick, heat absorbing/reflective ceramite, I imagine their protective abilities would be much greater.


nor are they pressurized.
A pressure control would involve having some way of releasing heated or expanding gases,

Or it could involve some way of rapidly compressing air inside the suit. Obviously emergency blow-off valves would also be incorporated, but given that the suit is vacuum rated I imagine there would be all kinds of airlock mechanisms to prevent uncontrolled travel of gasses through said valves.

Poseidal
04-09-2008, 10:11
No, I don't think that Marines are as strong as Hive Tyrants. I think that they would also be much larger and more powerful than their tabletop counterpart.
Consider how strong Jaws of Life are or other tools like that compared to a man and you see how monstrously strong S6 really is.

If you scale it appropriately, marines are overrepresented in the rules. If they are only 'twice / four / ten times' I would say that that's not enough to justify being above S3; the only way would be that they are augmented by their power armour.

Also, a flamer is not 'just a fire'. In general house fires, it's the smoke that kills people, not the flames. A military flame thrower (like one they used in WW2) are much more potent and their main purpose was to kill the occupants of Bunkers. If anything, Marines should be weaker against Flamers than a guardsmen in the open as the flames would easily get into the ventilation parts of the armour cooking the occupant from the inside.

Burnthem
04-09-2008, 10:57
If anything, Marines should be weaker against Flamers than a guardsmen in the open as the flames would easily get into the ventilation parts of the armour cooking the occupant from the inside.


Power Armour is sealed against everything from hard vacuum to biological warfare weapons, a piddly bit of flame isn't going to bother a suit of power armour in the slightest. Escpecially (as i pointed out earlier) anyone close enough to fire a flamer at a Marine hasn't got very long left to live anyway.

Poseidal
04-09-2008, 11:01
Power Armour is sealed against everything from hard vacuum to biological warfare weapons, a piddly bit of flame isn't going to bother a suit of power armour in the slightest. Escpecially (as i pointed out earlier) anyone close enough to fire a flamer at a Marine hasn't got very long left to live anyway.
Flamers are not a 'piddly bit of flame' and a very different kettle of fish to a house fire. Marine armour clearly has vents and holes in it, regardless of whether or not this reaches the breathable air the temperature and burning fuel will still cause all sorts of havoc in it. A Gas mask protects you from gas attacks, but won't save you from a flamer.

Also, if this 'anyone' happens to be a Wraithlord, Chaos Lord or Terminator, I dispute that they would have a shorter lifespan than the marine.

Master Stark
04-09-2008, 11:29
Flamers are not a 'piddly bit of flame' and a very different kettle of fish to a house fire.

Indeed. They shoot a jet of fuel that burns at around 500 celcius at you.


Marine armour clearly has vents and holes in it, regardless of whether or not this reaches the breathable air the temperature and burning fuel will still cause all sorts of havoc in it. A Gas mask protects you from gas attacks, but won't save you from a flamer.

We don't know the exact specs of the armour, so this is speculation.\

If the armour is designed to protect the wearer, I think anything as simple as 'putting stuff* in the vents' would have been covered by the, what, eighth incarnation?

If it was that simple, you'd just spray Marines with glue, covering the vents and intakes, and wait to see how long they could hold their breath.

* - Stuff in this context having the meaning of fire, or chemical weapons.

Poseidal
04-09-2008, 11:52
If it was that simple, you'd just spray Marines with glue, covering the vents and intakes, and wait to see how long they could hold their breath.

* - Stuff in this context having the meaning of fire, or chemical weapons.
The difference here though is that Fire would have very different properties. Gas, Disease and (most) Chemicals would not have any effect on the mechanical and physical armour - a barrier exists here.

However, heat (energy) would be highly localised in these small spaces and do cause damage to materials and whatever is inside, even more so than an even spread over the entire marine.

This is another reason why MkVI is vastly superior to MkVII. No huge vent in front of the marine's face.

(the comment about Guardsman was an exaggeration though, it's likely the material would be heat resistant so while it provides protection, it does not mean invulnerability; exactly as the rules represent)

Burnthem
04-09-2008, 12:13
Power Armour is very resistant to Lasgun shots, which concentrate far higher temperatures onto far smaller spaces than a Flamer could ever do, therefore if a Lasgun struggles to wound a Marine (both in the fluff and in game) than surely a Flamer, which is a 'piddly little flame' by comparison would do hardly any damage at all.


Also, if this 'anyone' happens to be a Wraithlord, Chaos Lord or Terminator, I dispute that they would have a shorter lifespan than the marine.

True, but remember that the vast majority of enemies fought by the Imperium are simple rebels and not hulking Chaos monstrosities. If a Wraithlord or Chaos Dread' was bearing down on you i'm sure the fact that you were on fire would be the last of a Marines worries so your point is moot.

Poseidal
04-09-2008, 12:19
Power Armour is very resistant to Lasgun shots, which concentrate far higher temperatures onto far smaller spaces than a Flamer could ever do, therefore if a Lasgun struggles to wound a Marine (both in the Fluff and in game) than surely a Flamer, which is a 'piddly little flame' by comparison would do hardly any damage at all.

A Lasgun can't get into air vents, cracks, joints etc... ;)

Brother Siccarius
04-09-2008, 14:48
Power Armour is very resistant to Lasgun shots, which concentrate far higher temperatures onto far smaller spaces than a Flamer could ever do, therefore if a Lasgun struggles to wound a Marine (both in the fluff and in game) than surely a Flamer, which is a 'piddly little flame' by comparison would do hardly any damage at all.
Resistant but not immune, which I think is the argument here; as to what power armor is immune to. We have plenty of information, from just the novels that marines appear in, that lasgun shots can hurt them. Power armor is also resistant to flamers, but why are we assuming that they're immune? Because we attribute different abilities to the armor that isn't stated elsewhere?

Burnthem
04-09-2008, 16:37
Ok, so there is very little a suit of Power Armour is immune to, for example a person with a pencil could kill a Marine in his armour if he was given enough time. And that's my main point, in order to do any damage to a Marine with fire would require a prolonged exposure, but anyone close enough to a Marine to use a flamer isn't exactly going to be given the chance.

I agree that it could work, a lucky hit, the armours vents being open, the Marine not having a helmet on etc etc, but in the majority of cases, IMO, a Marine wouldn't be too worried about getting briefly set on fire.

Lothlanathorian
04-09-2008, 18:00
The flamer isn't on the Marine for the time neccessary to facilitate such failures as a vent melting or the suit over heating and causing death/injury. By the time he is close enough to get shot by a flamer, he is also close enough for you to show up on his sensors and shoot you with whatever gun he happens to be carrying or charge in and pull you in two with his hands.


And as far as Marines being stregth for goes, don't forget that the game uses a graduate scale. Strength 3 covers everything from you average soldier today to Arnold frikkin Governator. A Marine is capable of crushing your head with one hand unarmored and crushing rocks with his armor on. In the game, while wearing his armor, he is strength 4. That's one helluva big gap right there from Arnold to CRUSHING ROCKS WITH YOUR HANDS.

Also, I don't get your point at all in talking about strength 6 as I was speaking in favor of the Hive Tyrant.


@Brother Siccarius: Awesome way to fail at suicidal heroism :p

Helsing
05-09-2008, 05:03
Good luck, if they're not in cover, the squad with the flamer is screwed. Screwed. Screwed.

Helsing.

TheOverlord
05-09-2008, 05:05
Flames were an absurdly good weapon against tanks, so I don't see the reference.

Dribble Joy
05-09-2008, 06:04
Indeed. They shoot a jet of fuel that burns at around 500 celcius at you.

And the rest. Plus a real/40K flamer doesn't shoot a liquid, it's more of a gel that sticks to stuff and burns untill it's all gone and won't go out even if you jump into water (phosphorous is nasty ****).

Power armour is depicted variably, but in general, anything that isn't a lasgun/autogun shot hurts and will cause serious damage to the armour.
In the SW books this is found repeatedly. A boltgun hit tears a chunk out and gives the wearer a massive blow. Ragnar takes a heavy bolter shell to the chest, which puts a massive hole in the chest plate, knocks him back and shafts his vision for a good while.

More importantly when dodging the hellhound blast, he can feel the prometium melting his armour just being a few inches from it and causing him considerable pain.

Flamers are nasty, unless you're a terminator or a meganob (with a helmet), you are pretty screwed.

Burnthem
05-09-2008, 14:57
The trouble is that in one book Power armour is paper-weak, and in others it's the best thing since sliced bread, it all depends on your source.

as for Flamers against tanks, they were only effective against old tanks that weren't airtight and had weakpoints that the flames could get into. Attack a modern battle tank with a flamethrower and you'd be wasting your time. Which is my point about PA, it's sealed and proof against high temperatures, which is all you need.

carl
05-09-2008, 15:35
it's sealed and proof against high temperatures, which is all you need.

Except several sources have Flamers causing PA to blister and crack and tottally overload it's coolant systems, Flamer in 40K are nothing like what we have, why do you think everything upto and including the rear armour of MBT's is vulnrable to one vershion or another of these things.

x-esiv-4c
05-09-2008, 16:56
It's funny that someone mentioned the origin of terminator armour. Originally designed so people could work on plasma reactors yet a plasma gun cuts right throught termie armour :)

Mag-El
05-09-2008, 16:58
Indeed. They shoot a jet of fuel that burns at around 500 celcius at you.


A typical housefire is about 800°C, 500°C is in fact pretty low for a flamer I believe. heck even a cigarette reach temperatures higher than 500°C.

//Magnus

McPherson
05-09-2008, 17:21
It's funny that someone mentioned the origin of terminator armour. Originally designed so people could work on plasma reactors yet a plasma gun cuts right throught termie armour :)

Plasma guns contain the power of the blast in a localised area capable of burning through Terminator armor.

Plasma reactor cores while full of plasma i'm guessing its not as concentrated or focused thus the terminator armor can survive in this diffuse energy environment for a while.

Now regarding flamers, honestly I see it more like overloading the suits cooling systems, not neccerssarily for the space marine but for the nuclear backpack they're packing. Perhaps the flamer causes the coolant system to 'scram the powersupply' and shuts the whole thing down - or on the odd occasion causes it to explode killing the marine.

All I know is whenever my marines get his by flamers I refer to my armor save as a Airconditioning save.

- McPherson

Argastes
05-09-2008, 19:17
ITT people who dont understand flame throwers.

QFT. Here we go....


as for Flamers against tanks, they were only effective against old tanks that weren't airtight and had weakpoints that the flames could get into. Attack a modern battle tank with a flamethrower and you'd be wasting your time. Which is my point about PA, it's sealed and proof against high temperatures, which is all you need.

No, it's not true that modern tanks are immune to flamethrowers. Their crew spaces might be sealed, but engine compartments cannot be (they must have vents, louvres, etc.), and if burning fuel enters the engine compartment through these openings, the vehicle will become a mobility kill. In Iraq several years ago, there was an incident where an M1A2 Abrams was mobility killed by a 12.7mm machine gun round that penetrated the APU unit on the rear of the turret, causing burning APU fuel to dribble down and enter the engine compartment via the louvres on the engine deck, which disabled the engine. A flamethrower, or anything else that used burning liquid/gel as it's mechanism of attack, would have a similar effect.


And the rest. Plus a real/40K flamer doesn't shoot a liquid, it's more of a gel that sticks to stuff and burns untill it's all gone and won't go out even if you jump into water (phosphorous is nasty ****).

Phosphorus is not used in modern flamethrowers, and there is no indication that it is used in 40K flamers either. Modern flamethrowers have historically used various petroleum fuels, thickened in various ways, but none have used phosphorus. Phosphorus is also not a gel; it's a solid, and when used in phosphorus-containing bombs, rockets, shells, grenades, etc., it is scattered by the weapon's explosive bursting charge in the form of small flakes or particles of burning material that stick to whatever they land on.


Marine armour clearly has vents and holes in it, regardless of whether or not this reaches the breathable air the temperature and burning fuel will still cause all sorts of havoc in it.


However, heat (energy) would be highly localised in these small spaces and do cause damage to materials and whatever is inside, even more so than an even spread over the entire marine.

This is another reason why MkVI is vastly superior to MkVII. No huge vent in front of the marine's face.

Without knowing the design specifics and material properties of the interiors of the vents, intakes, and other small spaces, you cannot say whether or not a coating of burning liquid would damage them. Perhaps they are capable of withstanding such treatment, or perhaps the marine could continue to function with at least some of them blocked or damaged. Master Stark is correct when he says that without knowing the specs of the armor, this is all groundless speculation. Also, has it ever been established that the triangular vent-like thing on the faceplate of a Mk.7 helmet is necessarily an actual vent? I seem to recall it once being referred to as a "vocalizer grill" somewhere. It could also be several other things besides an intake for breathing air. It could be the air intake for the "chemical sniffers" of the auto-senses, for instance.


Don't forget that it is made of ceramics. It doesn't get real hot very easy.

That's not really accurate. There are several advantages to (certain) ceramics in high-temp. applications, but one of them is not that they are more difficult to get hot. They may perform better at high temp. than an alloy would, or have unusual thermal properties such as very poor thermal conductivity (which is the case with the silica HRSI tiles on the space shuttle orbiter), but they are not "harder" to get hot than other materials.


Take a pressurized suit or system, expose it to open flame for any amount of time, watch the pressure seals burst and see the suit go *pop!*. GURPS future system had a special rule for that one I believe.

By the time the air in the suit was so hot that it was expanding enough to blow the suit's seals, the Marine would be pretty well roasted in his armor. There is also very little air to expand inside a suit of power armor, other than that inside the Marine's lungs (the suit interior fits snugly around the operator's body). And if the air in the poor guy's LUNGS is so hot that it's expanding enough to blow the suit open, then he's REALLY going to be black and crispy!


A pressure control would involve having some way of releasing heated or expanding gases, which just means more ways for a flammable liquid to get in there.

Although this is a non-issue for the reason above, a pressure reduction system for the suit interior would not necessarily have to release gas through a valve to the outside atmosphere through which flaming liquid could enter; it could draw air in the suit off into an internal pressure vessel, for instance. Additionally, if the system did release pressure directly to the outside environment, it would incredibly easy to simply use a check valve of some type, that allows gas from inside the suit to escape, but precluded the entry of outside fluids (even burning fuel, or the resultant flames).


EDIT: Regarding the general idea that a flamer could incapacitate a Marine by damaging his breathing system/intakes/vents and thus cutting off his air supply... Several people have expressed support for that idea in this thread, but I don't think this is true. Let's set aside the question of whether burning Promethium would be able to damage the breathing system if it entered vents and intakes; even if it could damage the breathing system, a suit of power armor probably includes a self-contained air supply of limited duration, like a scuba diver's air tank (or a closed-cycle rebreather that recycles exhaled CO2 into oxygen), which could be used to supply the Marine with breathable air even when his breathing system is unable to extract oxygen from the outside air. Otherwise, how would Space Marines operate in airless environments, or atmospheres which didn't contain oxygen? And besides, aren't space marines capable of surviving exposure to hard vacuum, and remaining conscious, for a limited time? This certainly suggests that even if their suit was no longer capable of supplying them with breathable air extracted from the outside atmosphere, they would not be incapacitated, at least not immediately.

Lothlanathorian
05-09-2008, 19:40
Well, assuming that Marines use a rebreather is acceptable. That only makes sense.

As to ceramics getting hot and your response to my comment, I wasn't talking about the outside of the armor as that is completely irrelevant to me. I was referring to the inside of the armor and the Marine himself getting too hot. The ceramite would do what ceramics do and keep the guy inside from getting too damn hot.

Argastes
05-09-2008, 20:39
As to ceramics getting hot and your response to my comment, I wasn't talking about the outside of the armor as that is completely irrelevant to me. I was referring to the inside of the armor and the Marine himself getting too hot. The ceramite would do what ceramics do and keep the guy inside from getting too damn hot.

...Except that's not what ceramics, at least the ceramics used in armor, do. Ceramics don't necessarily make better thermal insulation than other materials; just because the armor is made of ceramics will not necessarily stop heat from reaching the interior of the armor via conduction through the plates. Unfortunately, the types of ceramic that do make good insulators, by virtue of low thermal conductivity, do not make good armor materials because their low thermal conductivity depends on low density (in fact, they are often mostly air). The ceramics used in the SSO heat shield, for instance, have about the consistency of rigid fiberglass, and a child's pellet gun could put a dent in them. Ceramics that insulate against heat well make crappy armor, and vice-versa. In ceramics, good thermal properties are usually in inverse relation to good mechanical properties.

It's a fallacy to assume that because Ceramite is a ceramic, it is automatically a good enough heat insulator to do what you're claiming. Your chain of logic seems to be that Ceramite is a ceramic, and stopping heat is "what ceramics do", and therefore power armor simply must be immune to such-and-such levels of heat, because that's just "what ceramics do". That just doesn't follow. The word "ceramic" does not automatically equate to a level of thermal insulation that can automatically be safely assumed to protect a person against high temperatures (especially when we don't know the actual temperature, the exposure time, or the thickness of the plate, in addition to not knowing the plate's thermal conductivity!) Yes, some ceramics are good thermal insulators; and yes, most ceramics are better thermal insulators than metals. But that in no way justifies your assumption, and in fact there is good reason to guess that Ceramite is not a particularly great thermal insulator in comparison to most other ceramics.

Burnthem
05-09-2008, 20:44
Well thats game balance for you, and this is the background forums, which, for my aforementioned reasons, is why IMO PA would be proof against flamers.

But no amount of reasons are going to change peoples minds so lets just agree to disagree :)

Master Stark
06-09-2008, 03:00
A typical housefire is about 800°C, 500°C is in fact pretty low for a flamer I believe. heck even a cigarette reach temperatures higher than 500°C.

//Magnus

http://en.wikipedia.org/wiki/Flamethrower

"The flamethrower is in two elements: back pack and gun. The backpack element usually consists of two or three cylinders. One cylinder holds compressed, inert propellant gas (usually nitrogen), and the other two hold flammable liquid - typically petrol with some form of fuel thickener added to it"

http://www.tcforensic.com.au/docs/article10.html

"temperature of flame from burning petrol is 471-560"

madd0ct0r
06-09-2008, 03:52
hmmm. lets try a different idea.

Spray a marine with a thick, sticky, fiercely burning gel. His suit seals itself off, the rebreather kicks in and while he's getting warm the suit is still insulating him from the worst of it (environmental system not 'ceramic' insulation).

The marine is still covered in a a thick, sticky, fiercely burning gel. If he can safely hold his bolter (without the ammo cooking off) he'd only be able to aim it by remote.
The thick burning jelly would block out the section of EM from visual to the end of infra-red (and possibly microwaves too depending on radiation)
By patching through to his sergeant's helmet camera he might be able to guess where he should be aiming but at the moment his best chance is to catch the enemy in a big burny bear hug.
Of course, moving about generates lots of heat within the suit and it might not be worth the risk of overloading the environmental system. He ain't dead, once the gel burns out the suit'll be fully operational again and you'll have one angry marine. In the meantime, he's only really useful for lighting up a dark room.

Koryphaus
06-09-2008, 04:07
The marine is still covered in a a thick, sticky, fiercely burning gel. If he can safely hold his bolter (without the ammo cooking off) he'd only be able to aim it by remote.
The thick burning jelly would block out the section of EM from visual to the end of infra-red (and possibly microwaves too depending on radiation)
By patching through to his sergeant's helmet camera he might be able to guess where he should be aiming but at the moment his best chance is to catch the enemy in a big burny bear hug.

Couldn't wipe his visor? Actually, it wouldn't surprise me at all if there were visor cleaning apparatus built into the suit (kinda like in Republic Commando, when you get stuff on your visor it wipes it clean).

Argastes
06-09-2008, 05:33
A typical housefire is about 800°C, 500°C is in fact pretty low for a flamer I believe. heck even a cigarette reach temperatures higher than 500°C.

//Magnus

But it sounds here like you are assuming that the temperature of a house fire is some kind of baseline or minimum threshold for the temperature of fires, and that the flame generated by military incendiary weapons should be hotter than the flame generated by a "mundane" fire like a house fire. In fact, house fires are an unusually hot type of fire, due to their unique conditions (closed spaces with lots of flammables creates a furnace-like situation). It is perfectly reasonable for a house fire, or other structure fire, to run hotter than petroleum fuel burning in a non-enclosed space. Remember that "only" 500 degrees Centrigrade is hot enough to soften some steels.

Master Stark
06-09-2008, 05:35
Couldn't wipe his visor? Actually, it wouldn't surprise me at all if there were visor cleaning apparatus built into the suit (kinda like in Republic Commando, when you get stuff on your visor it wipes it clean).

I imagine they would have to have something like that. After all, when you are wearing rounded metal gloves, and can only see via glass lenses, then getting something as simple as mud on those lenses would be a massive hindrance.

Argastes
06-09-2008, 05:48
Couldn't wipe his visor? Actually, it wouldn't surprise me at all if there were visor cleaning apparatus built into the suit (kinda like in Republic Commando, when you get stuff on your visor it wipes it clean).

Not really, no. Even with armored fingers, it would certainly be impossible be clear the faceplate of the helmet so thoroughly that flames aren't obstructing the optics. You can't completely wipe away sticky gel by rubbing at it with articulated metal rods (which is basically what a Marine's fingers are when he's suited up). To wipe a substance away, you need absorbency and/or an object that can be pressed properly flush against the surface being wiped, like a squeegee or a towel; that means pliancy or flexibility. A Marine could smear around fuel on his faceplate, and maybe remove some excess if it was really gooped on there, but otherwise, no. Plus, bear in mind that even if he gets the actual lenses of the optics clear, flame from burning fuel on his chest, and the rest of his face, would probably still obstruct his vision.

Of course, we don't know exactly what kind of instruments are included in the sensor systems of a suit of power armor. If the armor's sensors include an ultrasonic or millimeter-wave radar system with imaging capability, he could use such sensors to see right through the flames as if they weren't there. The fundamental problem in this thread is that we simply do not have enough technical information about SM power armor.

EDIT: A system for automatically cleaning the optics if they got stuff on them would definitely be useful for mud, rainwater, etc., but in the particular case of flaming fuel, probably wouldn't help much, for the reason I mentioned above: When you are drenched in flaming fuel, clearing the fuel from the eyepieces of your helmet is not going to prevent flames from blinding optical and infrared sensors, because it does nothing to remove the fuel coating your face, chest, and so forth. Out of all that fuel-covered area, clearing two small patches (the eyepieces) is not going to do anything to reduce the amount of flames engulfing you. But if such a system were present, it might resemble the nictitating membranes on various animals; I know that at least some animals do use such membranes to clear debris from their eyes. Interesting thought.

azimaith
06-09-2008, 06:20
It's funny that someone mentioned the origin of terminator armour. Originally designed so people could work on plasma reactors yet a plasma gun cuts right throught termie armour :)
I could wear armor working in a bullet factory but still be killed by a bullet actually being shot at me though bullets exploding with direction or force would be or relatively little concern.

Kildash
06-09-2008, 06:21
Well, assuming that Marines use a rebreather is acceptable. That only makes sense.

Sorry mate, but marines do not use rebreathers. Their body can withstand any poison or filth in the air and simply destroy it before it can do anything. Read the horus heresy novels...

Master Stark
06-09-2008, 07:17
Sorry mate, but marines do not use rebreathers. Their body can withstand any poison or filth in the air and simply destroy it before it can do anything. Read the horus heresy novels...

That would make the best weapon against a marine a flamethrower filled with hot glue. Cover up the faceplate, and watch the marine suffocate.

Koryphaus
06-09-2008, 08:42
But surely their armour has a rebreather in it, otherwise they'd have a lot of trouble operating in environments like spacehulks where there is no guarantee of atmospheric pressure.

Mag-El
06-09-2008, 09:14
But it sounds here like you are assuming that the temperature of a house fire is some kind of baseline or minimum threshold for the temperature of fires, and that the flame generated by military incendiary weapons should be hotter than the flame generated by a "mundane" fire like a house fire. In fact, house fires are an unusually hot type of fire, due to their unique conditions (closed spaces with lots of flammables creates a furnace-like situation). It is perfectly reasonable for a house fire, or other structure fire, to run hotter than petroleum fuel burning in a non-enclosed space. Remember that "only" 500 degrees Centrigrade is hot enough to soften some steels.

I donīt assume nothing, I have been in buildings on fire at roughly 800°C and I have seen my protective gear starting to get in the first phase of creating a flame. I have got my protective boots so hot that they started to melt. I know how hot is it because have have experienced it several times.

I donīt know much about flamethrowers, thats why I did not throw out a number on how hot they get, but I know for a fact that a lot of fuels can create a lot higher temperatures than 500°C. On the top of my head I donīt remember the high end of the scale regarding fuel temperature(like airplane fuel, rocket fuel). But we are talking a couple of thousands of degrees.

Remember that most Steels we use today(in buildings and stuff) can sustain more than 500°C.

As I said before I donīt know much about Flamethrowers and todays requirements for fuel to them(availability, length of flame and such) but I have in person watch my Fire captain create an roughly 7-8 meters long flame that was above 1000°C just for the fun of it, and we are no exactly scientists=).
7-8 meters is a bit short for military use and we used gas when flamethrowers(what I know of) use liquid.

//Magnus

Burnthem
06-09-2008, 09:33
Another point, Marines spend 90% of thier lives training for every possibility imaginable, so i expect its fair to assume that at one point or another somebody has said 'hey, lets figure out what to do when we're on fire'. I mean if the British Army can do it then i'm sure super trained genetically engineered uber-eunachs can manage it to.

For example, even if the Marine is blinded by the flames, the aforementioned networked helmet cams' could work, as could the marines photographic memory (as he could simply remember where the enemy was to a fairly accurate degree, the Armours/Bolter autotargetters would probably do most of the work anyway etc etc. As for panicking, a Space Marine would be the LAST person in the galaxy to start to panic and get flustered simply because there's a few flames stuck to the outside of his armour.

IMO ;)

Master Stark
06-09-2008, 11:17
Some housefire temperatures:

Hot gas layer 600°-1000°

Floor temperature >180°

Glowing smoldering combustion to 600°

Flashover >600°

Glowing coals to 1300°


As I said before I donīt know much about Flamethrowers

Neither did I before I started reading up on them. But when you think about it, you shouldn't need to generate a temeperature that high for a military flamethrower. 500C is more than enough to seriously ruin just about anyones day!

According to wikipedia, flamethrowers generally use petrol as their main fuel. According to the intarwebs, petrol burns at around 500C.

Argastes
06-09-2008, 11:21
Sorry mate, but marines do not use rebreathers. Their body can withstand any poison or filth in the air and simply destroy it before it can do anything. Read the horus heresy novels...

So you are saying that Marines cannot operate in a vacuum, or on a planet where the atmosphere contains no oxygen? Power armor must include, or at least have the option to attach, either a rebreather-type system or pressurized air tanks for situations where there is no available oxygen in the atmosphere. And it's utterly untrue that the Space Marine's body can withstand "any" poison or filth in the air... they can handle many toxins that would kill a normal person, but they aren't immune to every toxin the entire galaxy. There are things that would still affect them. And no, I'm not going to read the HH novels.


I donīt assume nothing, I have been in buildings on fire at roughly 800°C and I have seen my protective gear starting to get in the first phase of creating a flame. I have got my protective boots so hot that they started to melt. I know how hot is it because have have experienced it several times.

I donīt know much about flamethrowers, thats why I did not throw out a number on how hot they get, but I know for a fact that a lot of fuels can create a lot higher temperatures than 500°C. On the top of my head I donīt remember the high end of the scale regarding fuel temperature(like airplane fuel, rocket fuel). But we are talking a couple of thousands of degrees.

Remember that most Steels we use today(in buildings and stuff) can sustain more than 500°C.

As I said before I donīt know much about Flamethrowers and todays requirements for fuel to them(availability, length of flame and such) but I have in person watch my Fire captain create an roughly 7-8 meters long flame that was above 1000°C just for the fun of it, and we are no exactly scientists=).
7-8 meters is a bit short for military use and we used gas when flamethrowers(what I know of) use liquid.

Glad to hear I misunderstood you. Jet fuel (kerosene) burns at about 1000 degrees C in open air. As for "rocket fuel", the temperature is going to depend wildly upon the specific fuel. Kerosene, liquid hydrogen, potassium nitrate, powdered aluminum, various rubbers, nitric acid, and a range of other materials are all rocket fuels. Obviously they burn a bunch of different temperatures, ranging from very hot to comparatively quite cool, in open air. And IIRC, the thickened diesel used in many real-life flamethrowers does indeed burn at about 500 degrees C, as Master Stark said.

Lord Zarkov
06-09-2008, 11:28
Sorry mate, but marines do not use rebreathers. Their body can withstand any poison or filth in the air and simply destroy it before it can do anything. Read the horus heresy novels...

Except according to Inquisitor their helmet does incorporate a rebreather.

The Horus Heresy Novels also have a number of occasions where the marines keep their helmets and rely on the suit's systems, especially when their not sure there's any breathable air at all.

While they can filter out pollutants they can't breath without any oxygen at all so the re-breather is still useful (especially as with it marines can even survive for a good while in hard vacuum when suited up). Also there's no point straining the marines system when you don't need to as even it has limits.

StarshipBOb
06-09-2008, 15:45
According to wikipedia, flamethrowers generally use petrol as their main fuel. According to the intarwebs, petrol burns at around 500C.

Flamethrowers don't use raw petrol, even before the invention of napalm they used thickners to increase the burn time and temperature. Current napalm can burn up to 10 minutes at 1200C; one can assume that futuristic flamethrowers burn hotter and longer.

madd0ct0r
06-09-2008, 16:12
From what master Stark said, I'm thinking that military flamethower's @only' reach 500 degrees because we don't need them hotter yet.

This (http://publications.drdo.gov.in/gsdl/collect/defences/index/assoc/HASH0148/a9d31b07.dir/doc.pdf) is a a paper from 1995 looking at different additives to solidified incendiary weapons. Temperatures of 2000 degrees were standard.


The original Napalm burnt about 675degrees c
Napalm B (the version developed for burning vietnamese villages) burnt hotter, at about 1000 degrees.

EDIT: Whoops. Bob beat me to it.

Lothlanathorian
07-09-2008, 09:32
...Except that's not what ceramics,...Ceramite is not a particularly great thermal insulator in comparison to most other ceramics.

Well, I have been educated. I did not know all of that. I will admit that I figured that since ceramic is used as armor and as an insulator, it could be both at the same time. I didn't know that it was based on the density of the ceramics. I stand correct and better because of it.


Sorry mate, but marines do not use rebreathers. Their body can withstand any poison or filth in the air and simply destroy it before it can do anything. Read the horus heresy novels...


So, since when does Mkii or Mkiii PA matter? Let's jump ahead 10,000 years to something I like to call 'relevant'. Also, the HH books are crap on a stick so I try not to read them if it can be avoided, though I will acknowledge that they count as canon.

And everyone else already put forth the arguments that make my assumption that there is a rebreather safe, such as the fact that they have them in the =][= game. And the Death Guard models with the rebreathers, we'll just ignore them for now, I guess.

Argastes
07-09-2008, 13:58
Flamethrowers don't use raw petrol, even before the invention of napalm they used thickners to increase the burn time and temperature. Current napalm can burn up to 10 minutes at 1200C; one can assume that futuristic flamethrowers burn hotter and longer.

Right, no-one ever said that flamethrowers use unadulterated petrol; I think it is fairly common knowledge that the fuel is usually thickened. But the main purpose of the thickener is to maximize the weapon's range, and the amount of fuel it can put on-target, by making the fuel stream hold together better. With unthickened fuel, the stream rapidly diffuses into a broad unfocused spray, which doesn't travel very far, because the fuel doesn't stick to itself as well. Whereas with thickened fuel, the fuel has better cohesion, the stream remains tight and doesn't break up into a spray, and the weapon has better range and can put more fuel on the target point per second of firing (particularly useful when you are using the weapon against a bunker or pillbox, which of course is what it's meant for). Whether the thickener also increases temperature or burn time depends on the particular agent used. Initially, the thickeners used were natural rubber, various soaps, or compounds like aluminum stearate, magnesium palmitrate, and so forth, which do not really increase the burn temperature or burn time by that much. Some increase it moderately, but as madd0ct0r points out, even the original napalm only burnt at 600-something degrees Centigrade (and only for about 30 seconds), and it was thickened with aluminum compounds. Clearly the thickeners did not significantly increase it's burn time, or temperature, over that of unthickened gasoline. It wasn't until we started using polymeric thickeners (polystyrene, in fact, the same stuff plastic minis are made of) and benzene that we got modern napalm, that burns at 1000+ degrees for 10 minutes.

Bottom line, not all thickeners improve temperature or burn time. Often their main benefit is to give the fuel a more useful consistency, rather than any improved effects. Many thickened flamethrower fuels don't burn much hotter, or much longer, than unthickened fuel of the same type. That said, I could accept that the "Promethium" fuel used in 40K flamers burns at least as hot as modern napalm, possibly a good bit hotter. There is a limit on how hot we can assume Prothemium burns, however. Fluff and artwork seem to indicate that the flames produced by burning promethium bear a good bit of resemblence to "normal" fires, i.e. they incandesce yellow-orange. If they burned into the multi-thousand-degree range, their flames would be blindingly bright (anyone who has ever seen thermite or magnesium burning knows what I mean), and that doesn't seem to be the case. The flames produced by 40K flamers seem to be "normal" flames, not dazzlingly brilliant white-hot flames, so they are probably in the temperature range of modern petrochemical fuels. Very high burn temperatures for Promethium would also preclude a cohesive liquid fuel stream, essentially destroying the weapon's range and effectiveness. Based on this, I would estimate a maximum burn temp. of not much more than about 1500 degrees Centigrade for Promethium.

EDIT: I remember once having a book that contained a side-by-side picture comparison of a flamethrower firing thickened fuel, and a flamethrower firing unthickened fuel. The one firing thickened fuel was shooting out a long, narrow, jet of flaming fuel that held together all the way to the target. Something like this (http://vietnamresearch.com/flame/info/flamethrower-boat.jpg) picture of a Vietnam-era gunboat-mounted flamethrower; you can actually see the fuel stream as a dark line wreathed in flames. The one firing unthickened fuel was shooting out a broad, billowing gout of fire that didn't get much further than about 5 to 10 meters. I think the pic might have actually been in a 1950s-era US Army field manual, to demonstrate why it's essential for flamethrower operators to make sure their fuel is properly thickened. I'll try to find a similar comparison picture online and post it here.


Well, I have been educated. I did not know all of that. I will admit that I figured that since ceramic is used as armor and as an insulator, it could be both at the same time. I didn't know that it was based on the density of the ceramics. I stand correct and better because of it.

I am glad to have been informative :).

madd0ct0r
07-09-2008, 19:57
I'm not sure we should be calculating the temperature of a flamer from the light spectra in the artwork.
I doubt the artists checked.

I was considering a gellified thermite, possibly even suspended nano particles of Promethium (the RL metal). That's more like the melta weaponry though.

Lothlanathorian
07-09-2008, 20:11
Well, whatever the IoM uses, I would think it would be cost effective and plentiful. Although, at the same time, with 'a million worlds...blah...' you never really know what they'll be using. Some of them may be what you just described, Madd0ctor, while others aren't nearly hot enough to bother an armored Marine, but will cling to the armor or whoever is shot and burn for a long time. Prometheum isn't so much a fuel as it is the word 'fuel'. So, imho, it is anything that burns and is used in a capacity as fuel.

Argastes
08-09-2008, 00:44
I'm not sure we should be calculating the temperature of a flamer from the light spectra in the artwork.
I doubt the artists checked.

I doubt they did too, and I agree that the apparent emission spectra of flamer flames in the artwork is not, in and of itself, grounds to reach a solid conclusion about the fuel's burn temperature. What I'm saying is that based on a wide variety of evidence in the fluff, artwork, etc. (the color of the flames in the artwork being just one example of such evidence), flamers seem to fire something that is at least somewhat similar to modern petrochemical fuels, rather than some super-high-temperature fuel.


I was considering a gellified thermite, possibly even suspended nano particles of Promethium (the RL metal). That's more like the melta weaponry though.

But a thermite-like composition does not correspond at all with the described effects of flame weapons in 40K, which was my point above. I don't know much about the combustion properties of RL promethium, but I suspect that like most flammable metals, it burns very hot, so the same objection would apply (along with several others). And the destructive mechanism used by melta weaponry is a little fuzzy ("sub-atomic thermal agitation?"), but it doesn't seem to expel a burning fuel--even a very high-temperature fuel--so a flamer using the fuels you propose wouldn't really bear much of a resemblance to melta weapons either.

Neknoh
08-09-2008, 11:49
What we perhaps should take into consideration is the use of Hellhounds as well, at least when thinking of the fuels used.

Simply because Hellhounds are able to send their flames over very long distances, this has, of course, to do with preassure and available ammount of fuel, however, the fuel still needs to be consistant, burning, cohesive and sticky when reaching it's target a couple of hundred metres away.

As such, we might be able to guestimate the makeup of the fuel used in a Hellhound. A normal flamer however might be slightly weaker due to the distance put between the flame and the viechle.

Eidre
08-09-2008, 17:24
Yes and no. Obviously a suit of astartes armour is going to have all sorts of survival systems. Internal air supplies, cooling systems, heating systems, and no doubt some form of pressure control.

If a guy in a modern day firemans suit can stand inside a 540 celsius fire for a few minutes without dieing, and we assume that the joints of a marines armour (the areas with the least protection) offer at least the same amount of protection as a firemans suit, then the only way you're going to kill a marine with a flamer is if you tie him up first so you can cook him for quarter of an hour. Anything less is probably only going to scorch the skin around his knees and elbows, and maybe his armpits. And thats just going to make him mad...

Having gone through naval firefighting training, I can assure you that being in 500+ degree air is not even remotely similar to having something burning in physical contact with you...air, even very hot air, is a terrible conductor of heat, and the rate of heat transfer is proportional to the temperature and the amount of conductivity between the hot side and the cooler side. There is no good way to protect yourself from being entirely covered in burning fuel; the ceramics will absorb more heat than metal or plastic, meaning it'll take longer for the heat to conduct through to the inside of the suit, but that is largely irrelevant because the suit's generators and so forth are making more than enough heat to cook the space marine anyway (go hug a running 10 hp diesel generator some time and you'll see what I mean). No matter how good or efficient the cooling system is, you still have to have some place cooler to push the heat; when you're totally engulfed in burning, sticky fluid, the heat has nowhere to go.

In game terms, I would see ones that survive getting hit by a flamer as not being totally engulfed, ducking and rolling, getting the flames beaten out by their buddies, and so forth.

Last note: modern day analogy, of tanks getting taken out by molotov cocktails (pick your civil disturbance or revolution, I'm sure you can find an example). No matter how much armor you have, burning fluids just suck.

Lothlanathorian
08-09-2008, 18:52
No matter how much armor you have, burning fluids just suck.

/Thread.





Man just ended our whole thread right there.

Argastes
08-09-2008, 20:10
...but that is largely irrelevant because the suit's generators and so forth are making more than enough heat to cook the space marine anyway (go hug a running 10 hp diesel generator some time and you'll see what I mean). No matter how good or efficient the cooling system is, you still have to have some place cooler to push the heat; when you're totally engulfed in burning, sticky fluid, the heat has nowhere to go.

I agree that this would be a flame weapon's most likely casualty-producing mechanism against space marines. I think earlier in this thread someone mentioned Joe Haldemann's The Forever War, in which a trainee in powered armor has a similar problem because his suit's radiator gets damaged. Incidentally, the cooling issue is also why it is somewhat ridiculous that the fluff says power armor can operate in a vacuum, when it clearly lacks any kind of serious radiators.

But anyhow, for what it's worth, I should point out that the following factors all play a role in determining whether a coating of flaming fuel would take down a Marine by preventing his suit's cooling system from dumping the suit's waste heat:
How long does the fuel burn? (I.e., for how long is the suit going to be unable to dispose of it's waste heat; thirty seconds? Ten minutes?)
How much waste heat is actually generated by the suit's powerplant, musculature, and other systems?
How much does the combined Marine-and-suit combo mass?
How easily does heat conduct from the parts of the suit where it is generated, into the Marine's body? (although the Marine's own body heat, and it's buildup in the absence of active cooling, is also a major issue).
How high a temperature can a Marine tolerate inside his suit, and for how long?
Does his suit incorporate an internal heat sink for just this sort of situation? (I wouldn't think so, but it's a possibility). If so, how much waste heat can it handle?

All of these factors, and more, would determine what a flamer would actually do to a Marine in terms of inhibiting his suit's cooling system and causing a dangerous buildup of waste heat. If the flamer fuel only burns for a comparatively short time and his suit systems generate a comparatively small amount of waste heat, the Marine could be okay, because his suit's cooling system might not be inhibited long enough for waste heat to build up to dangerous levels. If the flamer fuel burns for a comparatively long time, or his suit generates a comparatively large amount of waste heat (or both), he may be cooked. It will all depend.

g0ddy
08-09-2008, 20:57
We have composite materials today that can withstand a blowtorch to one side of say 1/2" of said material while remaining cool to the touch on the other side (I want to say.. Boron Carbide? and related materials - think shuttle heat shield). I would be under the assumption that 'ceramite' is a similar type material and would have a similar/significant/superior insulation type qualities as part of its "works well against heat/melta weapons" mantra. Does anyone know off the top of there head what the backpack power unit ona space marine is supposed to be? some sort of miniaturized cold fusion reactor? It does have 4 noticeable vents on the bottom portion of it aswell.

Ive heard of battle type scenarios described where... marines normally prefer to go helmet-less, however if the enemy is known to make use of snipers... they would opt to wear there helmets. You could have a similar situation where the enemy theyre facing is known to make heavy use of flame type weapons... and as such the marines are going to opt to work in 'vacume mode' for lack of a better term.

Another thought, assuming their powerplant is some sort of fission/fusion reactor and is already generating buckets of heat... Assuming is was not designed to handle minuscule fluctuations in the heat generated by said reactor. Would a few hundred/thousand extra degrees from some promethium really make a difference? I would also assume that the suit has some sort of monitoring system to know if the reactor starts to overheat.. and some system to remedy the issue and or "jettison it". As I understand it the suit itself has backup power reserves that can power the suit for a number of hours after the backpack has been lost (for whatever reason).

~ zilla

Argastes
08-09-2008, 22:13
We have composite materials today that can withstand a blowtorch to one side of say 1/2" of said material while remaining cool to the touch on the other side (I want to say.. Boron Carbide? and related materials - think shuttle heat shield). I would be under the assumption that 'ceramite' is a similar type material and would have a similar/significant/superior insulation type qualities as part of its "works well against heat/melta weapons" mantra.

An appealing theory, but one that doesn't really hold water, for reasons mentioned earlier in this thread. You're thinking of the silica fiber HSRI materials used in the shuttle TPS, which don't really have much in common with the described properties of ceramite. See, those materials are able to protect the shuttle from reentry heat (and to be touched with bare hands even when hot enough to glow) because of their extremely poor thermal conductivity, which they have largely because of their very low density. the tiles are actually 90% air by volume. They are weak and brittle, with very poor mechanical properties (this is the reason that everyone is always worrying about the possibility of heat shield damage on shuttle missions; the fragility of the tiles makes it a quite real possibility). Ceramite is, by every indication, NOT one of these light, brittle, low-density, low-thermal-conductivity ceramics (it wouldn't be very good armor if it was), which means that it is going to have thermal properties that are very different from the stuff used on the shuttle's heat shield. Just because something is ceramic doesn't mean it will necessarily be a good insulator. Only certain ceramics with certain physical properties are good insulators, and the physical properties that allow a ceramic to be a good insulator are usually incompatible with the physical properties that allow a ceramic to be a good armor material.

Regarding boron carbide: Boron carbide is a ceramic that's notable for it's extreme hardness, not it's thermal properties. It is useful as an armor material, and probably represents a real-life ceramic that is much more similar to Ceramite than, say, the materials used in the HSRI tiles. It's about as dense as elemental boron and is a mediocre heat conductor; while a better insulator than most metals, it is still way more thermally conductive than something like the HSRI tiles, and you could certainly burn the hell out of yourself if you tried to touch one side of a 1/2" thickness of it while the other had been heated with a blowtorch.


Does anyone know off the top of there head what the backpack power unit ona space marine is supposed to be? some sort of miniaturized cold fusion reactor? It does have 4 noticeable vents on the bottom portion of it aswell.

I believe it's been described as a "stacked atomic power cell". I don't think GW has ever given us any other information about it, certainly no detailed technical information or explanation of it's mechanism, and the term doesn't correspond very well with any existing devices. Is it an actual nuclear reactor? A radioisotope thermoelectric generator? We don't know. Whatever it may be, the use of the term "atomic" suggests that a fission reaction, not a fusion reaction, are the source of it's energy. This assumption is reinforced by the face that GW does make mention of various forms of fusion reactors elsewhere in the fluff, referring to them explicitly as such, but have never used the term "fusion" to describe a space marine's backpack power supply (to the best of my knowledge). If it was a fusion device, it seems they would have called it that. And there is certainly no evidence anywhere (again, to the best of my knowledge) that the Imperium has COLD fusion technology, so we can probably rule that out.


Another thought, assuming their powerplant is some sort of fission/fusion reactor and is already generating buckets of heat... Assuming is was not designed to handle minuscule fluctuations in the heat generated by said reactor. Would a few hundred/thousand extra degrees from some promethium really make a difference?

Absolutely, for the reason that Eidre discussed above. If the Marine's powerplant is already generating bucketloads of heat, then the suit must have a cooling system to dump that heat into the outside environment in order to prevent it from cooking the Marine inside his armor. A coating of burning fuel would almost certainly interfere with the operation of this cooling system. Cooling systems depend on a heat gradient, remember. They work by providing a pathway for heat to flow from areas of high heat (those parts of the suit that generate heat) to areas of low heat (the outside environment). This differential is called a heat gradient. The sharper the heat gradient, the better the cooling system will work; this means that the hotter the outside environment is, the less effectively the cooling system will get rid of the suit's waste heat (this is sort of an oversimplification, and there are other factors at work too, but just bear with me). So the cooling system would work less and less well as the outside environment's temperature rises. Arctic snowstorm? It'll work well. Scorching desert at high noon? It'll work less well, but presumably still well enough, since the armor is surely designed to function in a wide range of environments. But if the outside environment is a 1200-degree inferno of burning Promethium, the cooling system isn't going to work very well at all. Waste heat from the suit's systems will not build up in the suit, since it cannot be transferred to the outside environment very well (if at all). If this goes on too long, the Marine cooks in his armor, not from the heat of the actual burning flamer fuel, but from the waste heat that his own suit is generating but can't dispose of due to the burning flamer fuel.

So it is a fallacy to assume that because the suit can deal with the heat generated by the backpack power supply, it can therefore also deal with the heat generated by the burning flamer fuel. The suit deals with the heat from the powerplant only by dumping that heat into the outside environment; and the burning flamer fuel would significantly inhibit that from happening. I hope that's clearer now.

madd0ct0r
08-09-2008, 23:37
Actually, the suit could loose thermal energy in a vacumn quite easily - bleed off a fluid. This might be why they can only operate in vacumn for a little while.



But a thermite-like composition does not correspond at all with the described effects of flame weapons in 40K, which was my point above. I don't know much about the combustion properties of RL promethium, but I suspect that like most flammable metals, it burns very hot, so the same objection would apply (along with several others).


I was thinking of powdered metal / thermite held in suspension in a petroleum gel (Vaseline for example, but probably based on a much longer hydrocarbon and sticky with it).
The yellow flames and oily smoke is the gel burning off. Although I can't get around it, the flames would be pretty damn bright.


The gel stabilises the powdered metal by keeping it airtight and fairly spark proof. The flamer unit fires a long cone shape with either air or oxygen mix being sprayed into the center of the cone. Some very high powered flame, (acetlyne?) is used to spark the outside of the cone.

Probable firing order goes:

Start narrow cone spray of gunk and suspended metal particles.
Keep spraying
half a second later spray oxygen mix within the interior of cone for 0.5 seconds.
Once oxygen spray ceased, immediately ignite exterior of cone and cease spraying.
Look for next target.

The idea is the victim gets hit by the start of the cone which douses him in sticky gel. The oxygen mix gets entrained as bubbles as the cone continues to hit the target. Then the end of the cone (already burning) arrives.

The times of course would be variant on distance and this method would get less effective when targeting a large squad instead of a single person.



The melta should probably be left for another thread. Suffice to say I've always thought it fired a small cylinder of highly radioactive waste.

Argastes
09-09-2008, 02:21
Actually, the suit could loose thermal energy in a vacumn quite easily - bleed off a fluid. This might be why they can only operate in vacumn for a little while.

Well yeah, that is an obvious option if you only want a short operating time. But I had always gotten the impression that a suit of power armor enabled it's wearer to operate in vacuum for a prolonged period, and that it was an unarmored Space Marine who could "only" survive hard vacuum for a limited period. If this is correct (and I may be wrong, but I think it is the case), the suit would need a cooling system that doesn't rely on an expendable, i.e. a sizable radiator. It's a shame GW never considered this, because I'm picturing Marine models wearing special backpack units for vacuum operations, with radiators and air bottles and RCS nozzles for freefall maneuvering, and they look really neat in my mind. Of course this is 40K and real science goes out the window, so we might as well say that their existing backpack units are capable of disposing of all their waste heat in a vacuum despite the lack of radiators. Or that the laws of thermodynamics don't apply to marines, for that matter.


I was thinking of powdered metal / thermite held in suspension in a petroleum gel (Vaseline for example, but probably based on a much longer hydrocarbon and sticky with it).
The yellow flames and oily smoke is the gel burning off. Although I can't get around it, the flames would be pretty damn bright.

The gel stabilises the powdered metal by keeping it airtight and fairly spark proof. The flamer unit fires a long cone shape with either air or oxygen mix being sprayed into the center of the cone. Some very high powered flame, (acetlyne?) is used to spark the outside of the cone.

Probable firing order goes:

Start narrow cone spray of gunk and suspended metal particles.
Keep spraying
half a second later spray oxygen mix within the interior of cone for 0.5 seconds.
Once oxygen spray ceased, immediately ignite exterior of cone and cease spraying.
Look for next target.

The idea is the victim gets hit by the start of the cone which douses him in sticky gel. The oxygen mix gets entrained as bubbles as the cone continues to hit the target. Then the end of the cone (already burning) arrives.

The times of course would be variant on distance and this method would get less effective when targeting a large squad instead of a single person.

This is an interesting idea. I'm not sure I understand the point of oxygenating the fuel spray as it leaves the nozzle, though. Thermite is a self-oxidizing composition that doesn't need atmospheric oxygen to burn. It is a mix of iron oxide and aluminum, with the aluminum serving as the oxidizer. This is why it still burns underwater or when smothered with dirt/sand. You might also have a problem with the thermite component of the mix rapidly vaporizing the gel component (thermite burns at 2500 degrees Centigrade), which of course would prevent the weapon from working properly. This is what I mentioned earlier as one of the limitations on the burn temp. of flamer fuel; the fuel burn temp. needs to be low enough that the fuel remains liquid as it travels to and hits the target. Although I suppose this could be mitigated the ignition timing you describe, so that the fuel stream isn't ignited until the target is already doused. Also, acetylene is not nearly hot enough to ignite thermite; you can get thermite glowing red-hot and it still will not ignite. Although some other method could be substituted, and perhaps thermite nanoparticles would behave quite differently.

Okay, I'm rambling, because your idea here has intrigued me.. but ultimately, what is the point of this? To provide a rationale for why 40K flamer fuel might burn much hotter than modern-day fuels? At a certain point, an incendiary weapon with such high burn temp. is going to become a useful anti-armor weapon (well, useful except for the very short range), at which point it would--once again--no longer really match up with descriptions of the 40K flamer's capabilities and effects. A good hosing down from the weapon you describe, if it did indeed use a thermite-like composition, would be crippling to even a very well-protected AFV. Which doesn't seem to be what 40K flamers are all about. And, as you say, there is the issue of the blindingly bright silvery-white flames that such a weapon would produce--again, not how 40K flamers seem to behave.

Why are we trying to argue for flamer fuel that burns super-hot? It isn't necessary to explain the weapon's effects, and in fact it would seem not to correspond with the described effects.

g0ddy
09-09-2008, 16:55
Okay - Interesting. It would seem I was confusing the 'super-hard' compound used in armour plates.. (vest inserts etc..) with the tiles.

What do we know about Ceramite? I was just drawing the comparison of "we have such materials today" therefore presumably they could have something similar in the future...

Is it safe to assume Ceramite is itself a ceramic? Or is the name simply derived from its usefulness combating the effects of heat. You often hear the term "ceramite shielding" this would seem to imply a compound that is extremely resistant to being melted. Is it a single compound that is layered into other composite armours? or is it in itself a composite material that gets used in layered armours (which may get around the issue of creating a 'magical' hard and low heat conductive compound)? How this could be effectively incorporated into armour is unknown to me.

I have a basic understanding of how CHOBAM (sp?) type armours work against shaped projectiles (molten metals burning through the armour in some way - possibly similar to a melta weapon - the effect at least, not the means by which it created). The gist of it is, different compounds are layered into the armour in such a way that it is not one layer that is "impossible to melt" but that as the "bolt" of molten metal passes through the layers its energy/direction gets disrupted therefore increases the relative thickness of what it has to go through. Blunting the head so to speak...

~ zilla

madd0ct0r
09-09-2008, 19:44
See http://www.ceram.com/ceramics/ceramic-armour.htm

"Ceramic armour is a composite system incorporating fibre reinforced polymer composites as well as hard ceramic plates to defeat the ballistic projectile. Most of the energy of the projectile is absorbed in fracturing the ceramic tile. The remaining energy is absorbed by the composite backing which contains the remnants of the projectile and the ceramic debris.

The keys to high performance ceramic armour include good ceramic properties such as hardness and stiffness coupled with the ability to work harden under extreme stress. These properties combine to increase the impact duration allowing the ceramic to progressively damage the projectile and absorb its kinetic energy.
"
Nothing to do with temperature at all.

@Argastes - you know, I'm not sure why i was arguing for a 2000degree burn on a flamer either? One of those ideas that drags you along. I think i was just trying to demonstrate the 500degrees is not necessarily an absolute limit.

g0ddy
09-09-2008, 20:54
Im not sure how that is relevant....

Now if it was... http://www.ceram.com/ceramite/ceramite-armour.htm

Wait a moment.. I should check to make sure this link doesnt actually go somewhere!

~zilla

Argastes
09-09-2008, 21:47
Okay - Interesting. It would seem I was confusing the 'super-hard' compound used in armour plates.. (vest inserts etc..) with the tiles.

What do we know about Ceramite? I was just drawing the comparison of "we have such materials today" therefore presumably they could have something similar in the future...

Certainly we could have such materials (ceramics that insulate very effectively due to very poor thermal conductivity) in the future; in fact, since the Imperium of course possesses transatmospheric aircraft, they MUST have materials with similar properties, or else such craft would be unable to survive atmospheric entry. But what I'm saying is that such materials wouldn't make very good armor, and since Ceramite is apparently pretty damn good armor, Ceramite probably is not in the same class of materials and can't be assumed to have similar thermal properties.


Is it safe to assume Ceramite is itself a ceramic? Or is the name simply derived from its usefulness combating the effects of heat. You often hear the term "ceramite shielding" this would seem to imply a compound that is extremely resistant to being melted.

Well, generally speaking, ceramics don't melt, so yeah :D. Yes, I think we can safely assume Ceramite is a ceramic. It doesn't make any sense that they would use a name derived from the word "ceramic" to indicate good heat resistance, when--as I pointed out all earlier--not all ceramics have such properties. And remember that resistance to being melted is not necessarily what makes something effective for shielding against heat. It is poor thermal conductivity, not a high melting point, that makes a good insulator. For instance, tungsten is incredibly resistant to being melted (melting point around 3400 K) but would still make a crappy insulator because it also has a high thermal conductivity (because it's so dense... see how this all ties together?). So when we talk about "protecting against heat", there are several different things that might be meant, depending on the circumstances in question, and the ability of a given material to "protect against heat" is going to be quite different depending on what sort of protection we are talking about. Unfortunately, most people don't seem to appreciate this, and GW's meaningless pseudo-science nonsense about how Ceramite is "good against heat" doesn't help matters.


Is it a single compound that is layered into other composite armours? or is it in itself a composite material that gets used in layered armours (which may get around the issue of creating a 'magical' hard and low heat conductive compound)? How this could be effectively incorporated into armour is unknown to me.

My understanding is that the armor elements in a suit of power armor are composed of a "main" layer of Ceramite ("main" in that it appears to be the thickest layer, and to provide most of the suit's protective properties), with a couple of thinner outer layers that have largely non-protective roles (a cladding layer that bears the suit's coloration, for instance), and a few inner layers associated with life-support, ergonomic, etc. functions. I honestly don't know whether or not it could properly be called a composite armor; I would lean towards describing the actual armor as basically being a homogeneous ceramic, but I can't say for sure. But yes, if it did incorporate a layer of highly effective insulation beneath the armor elements, that would partially solve the problem of how to get the armor to effectively protect the operator against both projectiles (or laser beams, etc.) and high temperatures. I say "partially" because the insulation layer of course adds thickness that otherwise either wouldn't be there, or could be put towards additional armor instead; so in order to protect against high temperatures you would be sacrificing either range of motion and agility and such, or a degree of ballistic protection. Of course, it might well be a worthwhile tradeoff, depending on the combat environment and the expected opposition.


I have a basic understanding of how CHOBAM (sp?) type armours work against shaped projectiles (molten metals burning through the armour in some way - possibly similar to a melta weapon - the effect at least, not the means by which it created).

This is actually a common misconception about how shaped charge anti-tank weapons work. The metal penetrator formed by a shaped-charge warhead is able to penetrate armor not because it is super-hot and burns it's way through with thermal energy, but because it is a chunk of metal moving at several thousand meters per second and is able to punch through the armor like a bullet, using it's great kinetic energy. At the incredible velocities at which the penetrator jet hits the armor, it doesn't really matter that the jet is made of molten copper; the jet's velocity means steel is pushed out of the way as if it were modeling putty. And ceramic composite armors of the type we call "chobham" (ultra-hard, dense ceramic tiles held in a matrix) defeat shaped-charge penetrator jets by simple virtue of being hard enough that when the jet hits the tile, it cannot punch through as it would against much softer steel armor. Obviously the dynamics are a bit more complicated than that, but that's basically what's up.

EDIT: I think this is what mad0ct0r was getting at with his description of ceramic armor and his comment that it has nothing to do with temperature; he was correcting your statement that shaped charges burn through armor, and pointing out that ceramic tank armor defends against a mechanical, not thermal, penetration mechanism.

g0ddy
09-09-2008, 22:25
Sorry - that was not my intent. Poor choice of words with "burning"... The fact the 'penetrator' portion of a shaped charge warhead is 'molten' is by virtue of the high energy/stresses involved - whether or not this is advantageous.. I dont know.

What I was trying to explain with my analogy to Chobham, was that a "comparable" modern day ceramic based layered armour system does not work by simply deflecting/stopping projectiles by virtue of its 'hardness' but there were more forces (thermodynamics?) at work. Most notably the disruption effect it has as the 'penetrator' passes through it as being the primary basis for its effectiveness. Now this is contrary to what youve just posted, but it is how it was explained to me... and if I recall correctly - also the explanation given on wikipedia (which is of course potentially incorrect).

Now this whole anolgy/arguement/assumption thing was based on my belief that power armour contained a Ceramite element as one of the many layers in its armour system, but perhaps this is not the case as you pointed out you believe the "protective" portion of power armour is almost entirely made up of Ceramite.

If we want to agree/assume that power armour is largely just a slab of molded ceramite stuck on the outside of lifesupport/movement/ergonomical systems then we can move on and leave this talk behind us - as it doesnt really make any sense :p


Hopefully this atleast explains it slightly better...

~ zilla

bojan
09-09-2008, 23:03
...it doesn't really matter that the jet is made of molten copper...

Corection - jet is not molten actually - it is in the state known as "super-plastic". However, jet interaction with armor can be best represented by reaction between two liquids (something like strong stream from hose hitting the water in the pool).
Main defeat mechanism of composite armor is jet erosion (ceramics) and jet breaking (ERA, spaced armors). There is also effect of shanging density of armor that damages HEAT jet, so often composite armor is in many different thin layers (eh steel/rubber/Al/air gap/Al/rubber/steel or steel/rubber/Al/ceramics/Al/rubber/steel).

Argastes
10-09-2008, 00:19
Sorry - that was not my intent. Poor choice of words with "burning"... The fact the 'penetrator' portion of a shaped charge warhead is 'molten' is by virtue of the high energy/stresses involved - whether or not this is advantageous.. I dont know.

AFAIK, the temperature of the jet doesn't have much of an effect; it's penetration mechanism is overwhelmingly mechanical. Someone with more knowledge in the area could probably resolve this point for us, though.


What I was trying to explain with my analogy to Chobham, was that a "comparable" modern day ceramic based layered armour system does not work by simply deflecting/stopping projectiles by virtue of its 'hardness' but there were more forces (thermodynamics?) at work. Most notably the disruption effect it has as the 'penetrator' passes through it as being the primary basis for its effectiveness. Now this is contrary to what youve just posted, but it is how it was explained to me... and if I recall correctly - also the explanation given on wikipedia (which is of course potentially incorrect).

Well, the problem with this is that "disruption" is not a technical term, nor is it a particularly descriptive one. So I'm not entirely sure what that is supposed to mean. On the other hand, reading back over it, my previous post was unclear; it looks like I suggested that the ceramic component of the armor remains intact as it stops the jet, whereas the fact is that the ceramic shatters upon being penetrated (and must be replaced). But no, to the best of my knowledge, the hardness of the ceramics (and associated properties, such as abrasiveness) are what account for the effectiveness of ceramic armor against penetration by HEAT jets. There are certainly not significant thermodynamic effects at work (again, to the best of my knowledge). As bojan correctly points out, the actual, specific process by which ceramic armors defeat HEAT penetrator jets is erosion of the jet, which is an effect that occurs because of the hardness, and related properties, of the ceramics used. The jet geometry is spoiled as it penetrates the ceramic tile, as opposed to the way in which the jet holds together as it goes through much softer and more ductile steel. I suppose you could call this disruption, but in any event, it is largely a direct result of the hardness of the tiles. Less hard materials would not have the same effect.

Of course, I do not know how the function of ceramic armor was explained to you, or by whom. If it was explained to you by a materials engineer from TACOM or GDLS, then ignore me and listen to them! But if you heard it from a less authoritative source, just be aware that there is an awful lot of misunderstanding and vague/misleading/inaccurate descriptions out there of how AT weapons, and the armors designed to defeat them, actually work. For this reason, I wouldn't trust Wikipedia too far either; although some Wikipedia pages are looked after by very knowledgeable professionals, many others are updated by more or less ignorant people, using information they may have picked up on a Discovery Channel program (which are a prime source of misleading information about military equipment, by the way). What is the specific Wikipedia article that you referred to?


Now this whole anolgy/arguement/assumption thing was based on my belief that power armour contained a Ceramite element as one of the many layers in its armour system, but perhaps this is not the case as you pointed out you believe the "protective" portion of power armour is almost entirely made up of Ceramite.

If we want to agree/assume that power armour is largely just a slab of molded ceramite stuck on the outside of lifesupport/movement/ergonomical systems then we can move on and leave this talk behind us - as it doesnt really make any sense :p

Well, like I said, I honestly can't say one way or the other. I have (rather vague) memories of once seeing a cross-sectional diagram of a thickness of power armor with the various layers labelled, but I cannot recall exactly where; it might have been in White Dwarf, a rulebook, or somewhere else entirely. I (rather vaguely) recall that a single thick layer of Ceramite made up most of the thickness, but I'm not positive and I don't know where to find that diagram again, which is why I can't do any better than to "lean towards" saying that it's a homogeneous ceramic armor. Until someone can chime in with a conclusive fluff reference, looks like we are stuck on this one.

Also, bojan: Thanks for the correction regarding superplasticity. I had no idea that pertained to HEAT penetrators.

g0ddy
10-09-2008, 15:48
Both of those sound like far more detailed and correct explanations... :p
EDIT : Poking around Wikipedia a bit.. I am unable to find anything closely resembling what I was thinking of... so its probably a conglomeration of thoughts based on a number less qualified sources than your own ;).

So where were we.... we were trying to decide if there would be enough heat transmitted through the Ceramite armour to effect the survivability of a space marine when doused with a flamer thrower?

Im still leaning towards it providing very good insulation properties. The term "Ceramite Shielding" is used by GW as a 'in-game' name for the 'heat-shielding' in thunderhawk gunships and transports as the means that they withstand orbital/atmospheric reentry (various forgeworld books). It was also available as an upgrade to landraiders of the Salamanders Chapter - in both cases, in game terms, it negated the additional armour penetration dice granted by melta weapons at short range.

I guess perhaps whether or not this "Ceramite Shielding" is indeed similar to the normal application of Ceramite in space marine power armour is still unknown.

~zilla

Lothlanathorian
10-09-2008, 19:34
Maybe they have, at some point in the next 38,000 years, found a way to make dense armor that also manages to shield against heat?

Argastes
10-09-2008, 20:13
So where were we.... we were trying to decide if there would be enough heat transmitted through the Ceramite armour to effect the survivability of a space marine when doused with a flamer thrower?

Im still leaning towards it providing very good insulation properties. The term "Ceramite Shielding" is used by GW as a 'in-game' name for the 'heat-shielding' in thunderhawk gunships and transports as the means that they withstand orbital/atmospheric reentry (various forgeworld books). It was also available as an upgrade to landraiders of the Salamanders Chapter - in both cases, in game terms, it negated the additional armour penetration dice granted by melta weapons at short range.

I guess perhaps whether or not this "Ceramite Shielding" is indeed similar to the normal application of Ceramite in space marine power armour is still unknown.

Hmm, good points. It could be that in the 41st millennium, "Ceramite" is a generic term for a group of ceramic materials with varying properties, rather than a single specific ceramic. Even if "Ceramite" is one specific composition, different structural properties or manufacturing techniques in different applications of "Ceramite" might also account for varying thermal properties; for instance, a foamed ceramic composition (meaning a composition containing small bubbles or airspaces distributed through it) might have better insulating properties, as some foamed materials do in real life (real-life foamed alloys are also lighter while retaining strength, incidentally). For that matter, the Ceramite heat shielding used on 40K transatmospheric aircraft might use a "wool blanket" design similar to the space shuttle HRSI tiles, being a composite of Ceramite fibers (instead of silica fibers) and air spaces, with the air spaces predominating by volume even though the material (under it's outer coating) looks like a mass of fibers compressed together.

I think that the real answer is that the GW guys don't know much about science and have never grasped the difference between armor ceramics and insulating ceramics, but I suppose we do have to work with what the fluff says if we're not going to just dismiss the whole question on the grounds that the writers didn't know what they were talking about.


Maybe they have, at some point in the next 38,000 years, found a way to make dense armor that also manages to shield against heat?

Maybe. But as I pointed out earlier, density and high thermal conductivity tend to go hand in hand, and this is as a result of the basic laws of physics that govern the universe. Beyond a certain point, it's not something that improved material science can circumvent; materials that have lots of mass packed into a small volume tend to conduct heat better, due to the way in which heat conducts through matter from atom to atom. On the other hand, 40K already violates the laws of physics in a number of ways, so perhaps this isn't such a big deal. On the other other hand, I've always thought that it was a bad argument to say "this sci-fi setting breaks the laws in physics in such-and-such a way, so why not just assume that it also breaks the laws of physics in any other ways that we need it to?" That is a slippery slope that rapidly degrades the setting to the level of pure fantasy and absurdity. On the other other OTHER hand, one might make the argument that 40K has already plunged headlong down that slippery slope and is absolutely wallowing in pure fantasy and absurdity, with all the scientific realism of a Space Ghost cartoon, to the point that even calling it "science fiction" is an insult to real science fiction.

I dunno. If you want to believe that 40K Imperial technology can make a dense ceramic armor that is also somehow a poor enough thermal conductor to be used in heat shields for atmospheric entry, it will certainly not be the most ludicrous thing in a setting with warp space, magic, daemons, psykers, alien gods, anti-gravity, stasis fields, and so on and so forth.

g0ddy
10-09-2008, 21:09
The most logical answer might be that 'Ceramite' is a armour system which may or may nothave insulation built into it depending on the desired usage?

Going along with the "Ceramite Shielding" example a bit more... I think we can all agree that almost every type of space marine related armour (tanks/power power/space ships etc) when given semi-detailed information from GW, it is stated that atleast some portion of it is made up of ceramite... Again using a landraider as the example, it has Ceramite in it normally - but not in the same amounts as a specially upgraded Salamanders 'Melta-resistant' landraider. However I also feel that this is likely a combination of that - and GW's lack of foresight into 'real' armour systems - that we hold any such issues of practicality/usage/reusage (other impacts damaging the 'special armour') within the realm of suspended disbelief.

So perhaps it is not a safe assumption that power armour's ceramite is insulated in the same way as "Ceramite Heat Shielding".

Actually - here is another thought, can anyone think of any background information regarding Assault Marines being 'dropped of' via thunderhawk at a significant altitude to warrant significant heat generation from their own descent through the remaining atmosphere? Perhaps that would be evidence to the contrary.

~zilla

The Song of Spears
10-09-2008, 21:23
My thoughts are along the lines of the armour saves.

a 3+ save means that unless the weapon is AP3 or lower the marine armour will shrug off ANY super tech hit of ANY kind 2/3 of the time. Thus since a average flamer is ap5 and str 4 it has a 50/50 chance to even hurt the marine, and there is a 2/3 chance the armour will shrug off the effects of a good hit.

So it doesn't really matter what they call it, promethium or methane/petrol or whatever, its strong enough to hurt a marine 50% of the time and kill him after the 30% of the time.

How it accomplishes this is likely a myriad of ways: joints, internal heat, melting the armour its self, ruining weapons/mobile/power/comms systems etc.

I also take into consideration ork with their burnas. In flamer mode they are normal flamers, but in CC mode they are power weapons, so that kinda also gives me a idea of just how powerful/hot they are.

madd0ct0r
10-09-2008, 21:33
Well, in game turns removing a model isn't quite the same as that person actually dying; just whatever has happened to them means they won't be much use for the next 6 turns (15min?)
Dead, dying, wounded, unconscious, very very happy (blame slaneesh), on fire but not hurt, Stuck in the mud, playing dead, hiding or otherwise useless.

One d6 dosen't really give you detail.

bojan
10-09-2008, 21:52
...But no, to the best of my knowledge, the hardness of the ceramics (and associated properties, such as abrasiveness) are what account for the effectiveness of ceramic armor against penetration by HEAT jets...

To be picky - hardness of the small granules in the ceramics (ceramics used in tank armors are usually sintered Al-oxide or various carbides (Boron, Si) and prevention of their movement out of the jet path.
Sand (actually pure SiO2) works reasonably well, as long it is held by something (water-glass in honeycomb like structures on T-72M1, resins on early experimental US composite armor etc) and confined by steel.


Anyway, back to the flamer vs marines - if you consider modern tanks again they are almost immune to Molotovs/flamers/incendiaries, but still some will be burned if burning liquid gets in the engine compartment (by the design it is easiest to set engine compartment on flame as it has most openings). At that point fire extinguisher activates - but fire extinguishers on tanks are really made just to enable crew to get out, so if fire is not smothered by 2-3 shots of the built in fire extinguisher tank will most probably burn out. Exactly what happened to the M1A1 named "Cojone Eh" in 2003. during one of the attacks on Baghdad - RPG hit spilled burning fuel in the engine compartment, it led to more fuel spills as fuel supply hoses were damaged, fire extinguisher could not smother the flames (fuel/fumes reignited with a contact with hot engine) and tank was abandoned.

Guess something like that could happen to Space Marine when doused with liberal amounts of the flamethrower fuel. :)

g0ddy
10-09-2008, 22:27
Go-go-Gaget Power armour! I can picture it now... Little tiny fire extinguishers would pop out of carefully concealed openings on voice command! :D

~ zilla

madd0ct0r
10-09-2008, 22:34
just out of interest - does a fire extinguisher going off inside the engine not cock the engine up a for a bit?
Going on my distraction/incapacitation theory...

g0ddy
10-09-2008, 23:41
The fire would be on the outside of the engine itself.

The Abrams in particular.... used to have the option of (in addition to its normal smoke launchers) spraying some diesel fuel onto the engine manifold to generate a smoke screen. However when they made the switch to JP-9 (or is it 6?) in the 90's they had to disable the system as it was prone to catching fire as opposed to just generating smoke.

~ zilla

Argastes
11-09-2008, 01:36
Exactly what happened to the M1A1 named "Cojone Eh" in 2003. during one of the attacks on Baghdad - RPG hit spilled burning fuel in the engine compartment, it led to more fuel spills as fuel supply hoses were damaged, fire extinguisher could not smother the flames (fuel/fumes reignited with a contact with hot engine) and tank was abandoned.

There was another incident like this in Iraq a few years ago (I think it may have actually been mentioned earlier in this thread) where a 12.7mm MG round penetrated the APU on the turret bustle of an Abrams and ignited the APU fuel, causing burning fuel to run down onto the engine deck and enter the engine compartment via the louvres. An Abrams MKed by a single HMG round--embarrassing!


Guess something like that could happen to Space Marine when doused with liberal amounts of the flamethrower fuel.

Since the suit's backpack power supply is non-air-breathing (in fact, it's apparently atomic) and presumably a good bit less exposed to the outside environment than a tank's engine, it would probably be at least somewhat less vulnerable to this. But as mentioned earlier in the thread, the cooling system might well be vulnerable in a similar way.


just out of interest - does a fire extinguisher going off inside the engine not cock the engine up a for a bit?
Going on my distraction/incapacitation theory...

Yes, it does, since it floods the engine compartment with an inert gas (Halon in the Abrams). And a tank with an engine fire is typically going to be a mobility kill even if the extinguishers go off. As bojan points out, the main purpose of the extinguishers is to increase the chances of the crew successfully bailing out, not to keep the tank running.


However when they made the switch to JP-9 (or is it 6?)

JP-8, actually.

madd0ct0r
11-09-2008, 17:46
I wonder how long it'd take to get a tank hot enough for things to start to cook off.

Probably far too long - multiple tons of metal tends to have a good heat capacity.

A space marine on the other hand...

Lothlanathorian
11-09-2008, 19:14
Maybe. But as I pointed out earlier...even calling it "science fiction" is an insult to real science fiction.

I dunno. If you want to believe...so on and so forth.


I, clearly, don't know as much as a lot of the others in here do on the topic at hand. I am, however, very VERY interested. Not only I am learning a lot of real world facts, but we are breaking down and solving this 'ceramite/heat shielding' issue. I agree with the slippery slope of assuming they have technology that can do anything. My goal when I post in here (since I can't add to the science) is to try to stimulate thoughts and play Devil's Idiot (Devil's Advocate's retarded nephew) when I can.


If the Ceramite were some form of layered composite, could we make it work? Like something hard and sense over something less dense over something more dense, if you get my meaning?

Argastes
11-09-2008, 20:08
I, clearly, don't know as much as a lot of the others in here do on the topic at hand. I am, however, very VERY interested. Not only I am learning a lot of real world facts, but we are breaking down and solving this 'ceramite/heat shielding' issue. I agree with the slippery slope of assuming they have technology that can do anything. My goal when I post in here (since I can't add to the science) is to try to stimulate thoughts and play Devil's Idiot (Devil's Advocate's retarded nephew) when I can.

I am quite happy to have you in the conversation. It's a welcome change to see a fan of 40K/sci-fi/whatever take an interest in a technical discussion even though they might not recognize every technical term right off the bat. All too often, a lot of fans just lose interest when someone starts talking about the technical aspects or realism of the sci-fi setting in question. And I'm glad that you're picking up new knowledge. Cheers!


If the Ceramite were some form of layered composite, could we make it work? Like something hard and sense over something less dense over something more dense, if you get my meaning?

Yes, the armor would offer much better protection against high temperatures if there was a layer of a highly effective insulating material (i.e., a material with very poor thermal conductivity) underneath the armor layer(s). However, as I pointed out above, this would degrade the suit's performance in one way or another; on the other hand, that performance loss may well be worthwhile if exposure to high temperature is a serious risk.

IMO, however, the problem with this theory is that although it accounts for all the material properties of Ceramite, it doesn't really make much sense from a terminological standpoint. Granted, "Ceramite" is a fictitious word and it's exact meaning has never been clarified by GW, but to my ears, "Ceramite" sounds like a word that refers to a specific material, not a layer of armor material backed up by a layer of an entirely different insulating material. I certainly don't rule out the possibility that power armor incorporates an insulating layer under the armor layer (in fact, it makes good sense), but what I would have trouble accepting is that these two layers, taken in combination, are collectively called "Ceramite". I can easily accept that the armor layer is made of a fictitious super-ceramic called "Ceramite" while the insulating layer is made of something else (maybe even a different ceramic), but calling the whole armor+insulation affair "Ceramite" doesn't really make sense to me. Composite armor materials are (sometimes) given names that collectively refer to all their layers, but those still have a single function and are physically unitary. I realize this probably sounds like a rather flimsy objection, but to me, the idea that "ceramite" means "ceramic armor backed up by a layer of low-density insulation" just doesn't sound right. Anyone else is free to disagree of course; this is pure opinion on my part.

Treadhead_1st
12-09-2008, 02:16
Couple of things, first a serious pondering and second a light-hearted note about universal domination.

1) How do we know what a 40K flamer fires? They make reference to "promethium" and other sources mention it as a liquid fuel, drilled and pumped through wells etc - but conditions vary from world to world. Maybe it's a rare liquid form of the radioactive metal promethium (unlikely, but maybe), or maybe it's a combination of chemicals akin to napalm (with chemical mixes giving different properties, allowng it to be a weaponised fuel or a motor fuel and so forth - sort of how cracking oil creates petrol, gas and bitumen - but in this case either by blending [as you would to refine petrol into something that goes into your car] or cracking a thicker base-fuel to get a highly volatile, maybe even gaseous, fuel). Or small particals of radioactive metal in a petrol-like stream. Can't say, the chemical compound is never given

2) The imperium is short-sighted in equiping it's Marines. I would doubt a visor would have auto-clean (not that wipers would help against burning chemicals) - the Mariens wage war on so many planets against so many foes, that there wouldn't be one catch-all cleaner (imagine a mild acid cleaner meeting concentrated alkaline Nid blood [small explosion/volatile reaction in the eyes] - ouch).


To wipe a substance away, you need absorbency and/or an object that can be pressed properly flush against the surface being wiped, like a squeegee or a towel; that means pliancy or flexibility.

Geoff the renengade Guardsman was fed up of carrying the flamer. It was heavy, smelly and marked him out to snipers - but he knew what a potent weapon it was. Bobus the Blue Marine strode down the road, blasting away Geoff's buddies. Geoff jumped out of cover, and gave the metal behemoth a good blasting from the flamer. The nightmarish liquid coated the Marines body, his efforts to scrape the sticky, burning gel off futile. Seeing the blinded monster's fumblings and watching the paint bubble away, Geoff thought he'd defeated the so-called "Emperor's Finest". But the Marine opened a slot in his leg armour, and pulled out a strange, white implement with which he proceeded to deftly clean the gunge out of his eyes.

Dismayed, Geoff let out a final howl, before Bobus' bolter blew his torso apart: "Run - he's got a towel!"

bojan
12-09-2008, 12:04
...Yes, the armor would offer much better protection against high temperatures if there was a layer of a highly effective insulating material (i.e., a material with very poor thermal conductivity) underneath the armor layer(s). However, as I pointed out above, this would degrade the suit's performance in one way or another; on the other hand, that performance loss may well be worthwhile if exposure to high temperature is a serious risk.


Good insulation material does not have to be ineffective vs ballistic weapons - prime example is glass/asbestos based textolite - it has very high effectiveness as insulation material (it was used as insulation material for ICBM warheads) and also very good mass effectiveness (1.5-1.8 compared to steel) vs ballistic impacts, especially if sandwiched between two steel layers. This composition was used as early T-64/72/80 composite armor and was also used on early M1 and Leopard 2 tanks.

And for Ceramite - it could really be something simple as epoxy bonded Al oxide/Si carbide/DU ceramics. It would have both good insulation vs heat and very high ballistic resistance.

BTW, does any fluff source notes a weight of the Marine power armor?



1) How do we know what a 40K flamer fires?

We do not, but as was noted even more-less ordinary diesel/JP-8 fires can seriously threaten some very well armored tanks, so being possible to kill Marine with one is not really out of question - note that Marines still get their save and there is a chance they would not get wounded - basically only 1/6 marines well doused in flamethrower fuel will be killed - IMO excellent results.

Brucopeloso
12-09-2008, 13:16
Heath shock?
If you pump enough fire at a tank the crew will dies from the heat even if the flames do not penetrate the armour.
Also there is a fair chance that the ammo that the marine is carrying will go off with pretty nasty results.

On the subject of tanks, remeber that tanks were and still are vulnerable to a well placed molotov cocktail (a glass bottle with gasoline and a burning rag).

Argastes
12-09-2008, 13:32
Also there is a fair chance that the ammo that the marine is carrying will go off with pretty nasty results.

Actually, boltgun ammunition cooking off will almost certainly not harm a power-armored Marine. When a round of ammunition cooks off outside of the chamber of it's weapon, it achieves very little velocity (and with such a short distance between the cooked-off round and whatever part of the Marine's body it might hit, the rocket assistance would be a non-issue as well). Fragmentation grenades would probably not be fatal either, given the described mass and thickness of a suit of power armor.


On the subject of tanks, remeber that tanks were and still are vulnerable to a well placed molotov cocktail (a glass bottle with gasoline and a burning rag).

Well yes, but with modern tanks, the vulnerability mainly stems from the risk of engine fires, which are a risk because even the best-armored modern tank has an air-breathing engine which must be exposed to the outside environment via louvres, exhausts, and so on. It also uses flammable fuel, meaning that if some burning liquid gets into the engine compartment, the fire can rapidly grow if fuel-carrying engine parts (hoses, etc.) are damaged. A Space Marine's backpack power supply is not air-breathing and doesn't use flammable fuel, and is presumably "sealed away" to a greater degree than a tank's engine, meaning he would be less vulnerable to flames in this regard than a modern tank. Of course, as mentioned earlier in the thread, his suit's cooling system might be quite vulnerable.

Argastes
12-09-2008, 14:17
Good insulation material does not have to be ineffective vs ballistic weapons - prime example is glass/asbestos based textolite - it has very high effectiveness as insulation material (it was used as insulation material for ICBM warheads)...

Unfortunately, I can't speak to this because I am unable to find any useful technical information about the thermal properties of textolite; seems like most of the information out there is in Russian. If you have some information about this in English, I'd be quite interested in seeing it.


...and also very good mass effectiveness (1.5-1.8 compared to steel) vs ballistic impacts, especially if sandwiched between two steel layers. This composition was used as early T-64/72/80 composite armor and was also used on early M1 and Leopard 2 tanks.

But that is actually quite poor performance when compared to the effectiveness of modern ceramic composite armors, which can easily be ten times more effective than an equivalent weight of RHA. This is why, for instance, the frontal turret armor of the M1A2 is ~1500mm RHAe even though the physical thickness of the armor is well under 300mm and weighs a small fraction of what 1500mm thick steel would weigh. An armor material that is only 1.5 or 1.8 times more effective than RHA is, frankly, obsolete crap. And this is by the standards of modern technology, which seems to be less sophisticated than the materials technology that goes into SM power armor.

As you may know, the plastic composite armor used by the T-72 and the -64 series (T-64, T-80, etc.) didn't work very well at all, and was replaced by ceramic compositions using boron carbide, which work much better as armor (but could never be used as heat shielding on reentry vehicles). In fact, the inadequacy of high-modulus plastic composites as armor (and the problems with Soviet ceramic production) are what led the Russians to be such prolific users and developers of ERA, active protection systems, infrared jammers, and so forth, which are technologies that the West never explored as much because our ceramic armor technology made them less necessary.

Bottom line, textolite may be a better armor than RHA but it still isn't very good even the standards of the 1980s, let alone today, let alone 40K.


And for Ceramite - it could really be something simple as epoxy bonded Al oxide/Si carbide/DU ceramics. It would have both good insulation vs heat and very high ballistic resistance.

By DU, do you mean depleted uranium? If so, the phrase "DU ceramics" is contradictory; DU mesh is used along with ceramics in some tank armors, but a metallic material cannot be a ceramic by definition. But at any rate, certainly I agree that such a composite would offer good ballistic protection, but I question how great an insulator it would really be. Certainly it would be better than most metals, but that's not necessarily saying much. Whether it would be a poor enough thermal conductor to, say, protect the Space Marine from a coat of burning napalm is not at all a given, to my mind. We would need at least a ballpark estimate of this material's thermal conductivity, in watts/(m*K), to hazard a guess.


BTW, does any fluff source notes a weight of the Marine power armor?

2nd Edition Angels of Death codex says 250 lbs. (about 113 kg), but to my mind, that is ludicrously light. I would think that 500 kg would be a minimum reasonable value, maybe as much as a 1000 kg.

BLZBOB
12-09-2008, 14:31
Dismayed, Geoff let out a final howl, before Bobus' bolter blew his torso apart: "Run - he's got a towel!"

Just goes to show you're never in trouble as long as you've packed your towel.

On a more serious note I have always assumed, and yes I am well aware of the dangers of assumption that any suit of powered armour that goes to the extent of having an atomic reactor (I favour the 'lensman' style atomic reactor it seems to fit the sizes/power/fuel capacity) strapped on for power would have several features to keep the wearer alive.

As has been mentioned in game terms a model removed from play does not necessarily indicate a fatality, I am sure some of us remember the Burn tests that were a part of second edition and how team members could help beat out the flames. So we must consider that a hit from a flamer may not be fatal but is incapacitating, being on fire can do that to you.

Now back to the armour a single element armour construction makes no sense given the background, even guardsmen had composite armour, after all a bulletproof vest with inserts is still a composite. The armour itself need not consist of a thin layer of mechnically resistant material all over a core of insulation. In fact the bulk of the armour by mass may well be this hard armour but within you already have data cables and synthetic musculature, so why not a heat dispersion layer? Even today heat pumps can transfer excess heat. Applying this technology it is not beyond the realms of credability that excess heat will be shunted around the armour and removed. After all in that enclosed suit a marine is likely to cook himself just by dint of contained body heat. Therefore we can deduce that a heat dissipation mechanism exists and that it is capable of operating in a wide variety of environments, including a vacuum so it is not entirely dependent upon close association with a cooler environment.

So given that by simple deduction of background data we can safely assume a suit of power armour contains a heat dissipation web and that it is capable of dissipating any normal heat generated through use without recourse to a 'thermal dump' we are left trying to marry the evidence to the game-play mechanic.

Its unlikely that a flamer strike would slag down the armour, it is possible that it would kill a marine outright by burning a seal through or secondary damage due to explosives cooking off. Its not likely though to kill immediately as even covered in burning fuel the thermal transfer to the marine will take time. More likely in the games mechanics is that the marine is incapacitated if you are on fire you are going to be combat inneffective. If any of you have tried paintballing shots to the visor whilst not damaging render you unable to return fire. Flames would have a detrimental effect upon autosenses and even a highly trained astartes would be at least mildly alarmed to find themselves alight.

With regards to background there is plenty of justification for calling them a casualty as they are unable to fight. We could even say that the marine is a combat ineffective as the suit is attempting to dissipate the increased thermal load but has to reduce suit power output (and associated thermal build up) to compensate.

Sadly in a game ruled by the D6 we don't have a lot of flexibility one needs only have recourse to the necromunda rules for a more detailed 'damage' table. Getting ones finger blown off is quite vexing.

Argastes
12-09-2008, 15:15
Now back to the armour a single element armour construction makes no sense given the background, even guardsmen had composite armour, after all a bulletproof vest with inserts is still a composite.

It may be strange that SM power armor uses a homogeneous material for ballistic protection, but I don't think we can go so far as to say it "makes no sense". The fluff does seem to suggest it, strange as it may seem.


The armour itself need not consist of a thin layer of mechnically resistant material all over a core of insulation. In fact the bulk of the armour by mass may well be this hard armour but within you already have data cables and synthetic musculature, so why not a heat dispersion layer? Even today heat pumps can transfer excess heat. Applying this technology it is not beyond the realms of credability that excess heat will be shunted around the armour and removed. After all in that enclosed suit a marine is likely to cook himself just by dint of contained body heat.

Yes, it has already been mentioned, in this thread, that power armor must have an active cooling system to deal with the Marine's body heat, among other things. However, the problem that a flamer would cause--and this has also already been brought up in this thread--is that the active cooling system needs to be able to get rid of that waste heat once it draws it off; obviously, otherwise you are just shuffling the heat around inside the suit, which does no good at all. That means it needs to have a way to get that waste heat into the outside environment. And a coating of flaming, thousand-degree fuel would severely inhibit that from being done by practically any conceivable mechanism.

Also, an active cooling layer inside the armor doesn't necessarily make insulation unnecessary if you are trying to protect against very high temperatures (such as those that would be created by a coat of burning napalm). Both insulation and an active cooling layer would be needed for such protection, because there are performance parameters that limit the effectiveness of a cooling system to a certain range of thermal load. Outside that range, the system doesn't work well. An active cooling system that can effectively handle the heat from the Marine's body and normal suit operation is, generally speaking, not going to be able to also effectively handle a greatly increased heat load, such as would be experienced if the suit was coated in burning napalm. And vice versa; an active cooling system that can handle the heat from a coat of burning napalm is going to be wildly inappropriate for normal use. That, and the fact that the active cooling system would be unable to effectively get rid of that heat under such circumstances anyhow, for the reason given above (and I'll talk more about this below). So insulation would probably still be needed. I'm not saying that Marine's armor would be a "thin" layer of ballistic protection over a core of insulation, but there would have to be some sort of insulating layer if high temperatures are a concern. And since the most effective insulators are low-density, it could still easily be the case that the bulk of the armor, by mass, is ballistic protection; an insulation layer does not preclude that.


Therefore we can deduce that a heat dissipation mechanism exists and that it is capable of operating in a wide variety of environments, including a vacuum so it is not entirely dependent upon close association with a cooler environment.

Whoa. Now I am afraid you have gone completely wrong. As you probably know, there are three methods of transferring heat: Radiation, conduction, and convection. The first one only works if you have a substantial radiator area, the second two only work if your outside environment is cooler. SM armor clearly does not have a serious radiator, so it must be dependent on the outside atmosphere to get rid of it's waste heat via a conductive or convective heat exchanger (incidentally, this means it shouldn't be able to function in a vacuum, since conduction and convection don't work there... but we'll ignore that for now). And that means that a very hot outside environment, such as a coat of burning flamer fuel, WILL significantly inhibit the cooling system's performance unless the operating temperatures of the heat exchanger are higher still, which would be unimaginable in a case like this. There is no way around it. Your deduction was interesting, but unfortunately it sidestepped the laws of thermodynamics and the facts of thermal engineering.


So given that by simple deduction of background data we can safely assume a suit of power armour contains a heat dissipation web and that it is capable of dissipating any normal heat generated through use without recourse to a 'thermal dump'

Not sure what you mean by "thermal dump" (are you talking about a heat sink?), but the crux of the issue--and the reason that your deduction is unfortunately wrong--is that:

A). The "heat generated by normal use" is vastly different from the heat generated by a 1200-degree environment, especially when the suit has no insulation layer, as you have proposed.

B). Dissipation of heat by an active cooling system depends on a heat exchanger (radiator, etc.) that moves that heat into the outside environment, and heat exchangers of all types DO require a cooler outside environment (except radiators in a vacuum, which is a totally different issue).

BLZBOB
12-09-2008, 15:56
Well yes I do realise I am jumping into a heated debate (pun fully intended) and although some background indicates a homogenous armour simple logic would rule against it. Yes I am painfully aware that logic and 40k should never meet.

With regards to being unable to vent heat by radiation, convection or conduction the only problem we have is that space hulk exists an entire piece of backstory that does involve fighting in a vaccuum. Radiation would still work even without a large radiator. Conduction & Convection are of limited use where particle density of the atmosphere is low or null.

One way around this it to be venting additional heat to a thermal fluid in insulated tanks, somewhat similar to a coolant. I am aware that there are several leaps here and don't wish to rely to much on hand wavium technology but still find it difficult to believe that when power armour was begin designed safety against flame based weapons was ignored.

I do feel that I am onto a lose situation anyway simply because we are comapring the results as a digital event the marine is either alive or dead, in game terms this is adequate attempting to reconcile this with 'real' life and background is where the problems begin.

I fully concur that a thermal dump system would be compromised by being set alight and thats why the design must take into account that it may happen, after all there is the armour save.

By no means is the armour impervious to all attacks and its entirely possible that a flame attack could destroy armour and troop due to previous damage to the armour layer providing an option for burn through.

In a nutshell power armour is good but not indestructible and seems to have been designed to counter most threats.

g0ddy
12-09-2008, 16:14
...
By DU, do you mean depleted uranium? If so, the phrase "DU ceramics" is contradictory; DU mesh is used along with ceramics in some tank armors, but a metallic material cannot be a ceramic by definition

....

2nd Edition Angels of Death codex says 250 lbs. (about 113 kg), but to my mind, that is ludicrously light. I would think that 500 kg would be a minimum reasonable value, maybe as much as a 1000 kg.

I thought the DU-mesh used in (american) abrams was largely a spalling liner?

250lbs for the armour? wow.. thats astronomically low :p the marine himself is going to be at least 300-400 pounds.... I would concur with the assumption the armour itself weighs 500kg ~ 1100 lb + maybe all told... the marine in his armour is running 1500lbs. However this by no means makes it cumbersome ;)

~ zilla

Argastes
12-09-2008, 18:57
I thought the DU-mesh used in (american) abrams was largely a spalling liner?

No, it is intended to protect against long-rod kinetic penetrators such as APFSDS projectiles. It's a good armor because of it's extreme density; it blunts or breaks impacting penetrators. As I understand it, the mesh design (with steel cast around interwoven DU "threads") is lighter than a layer of solid DU would be, but still provides the same protective qualities. There would be no real point to using an exotic material like DU in the spall liner, which only has to catch steel fragments. These fragments are really no different from the fragments produced by an exploding fragmentation grenade or shell, and they can be stopped by fairly light armor. The spall liners in an Abrams are made of Kevlar and aluminum, IIRC.




Well yes I do realise I am jumping into a heated debate (pun fully intended) and although some background indicates a
homogenous armour simple logic would rule against it. Yes I am painfully aware that logic and 40k should never meet.

I sympathize with this point, but the design of most 40K technology is so crack-headed already (power armor included... cool as it may be, power armor's design is really laughable) that I don't think we can make assumptions about the composition of the armor elements, especially when those assumptions contradict what the fluff suggests.


With regards to being unable to vent heat by radiation, convection or conduction the only problem we have is that space hulk exists an entire piece of backstory that does involve fighting in a vaccuum. Radiation would still work even without a large radiator.

Depends on what you mean by "large", but I assure you that to get rid of the waste heat generated by a piece of equipment like a suit of powered armor, you would need a radiator of a size that would definitely be a prominent design feature of the armor. We can do the math if you want; I have the equations on hand. And such a radiator simply does not appear on space marine armor. Yes, I know there are numerous instances where the background describes Marines operating in a vacuum; the space hulk backstory is only one of many examples. I am not saying "power armor cannot operate in a vacuum", because according to the fluff, it can; I am saying "power armor should not realistically be able to operate in a vacuum". Since the fluff says it can do so anyway, this is just one of the many scientific flaws in the 40K setting.


Conduction & Convection are of limited use where particle density of the atmosphere is low or null.

...Yes, that's what I said.


One way around this it to be venting additional heat to a thermal fluid in insulated tanks, somewhat similar to a coolant. I am aware that there are several leaps here and don't wish to rely to much on hand wavium technology but still find it difficult to believe that when power armour was begin designed safety against flame based weapons was ignored.

Umm, that's not handwavium technology at all, and it doesn't rely on any leaps. That's called a heat sink, and they exist today. Earlier in this thread, I already pointed out that SM power armor might include a heat sink of this type. The limitation on it's effectiveness would be size, among other factors. We can get more into the math of this as well, if you like.


I do feel that I am onto a lose situation anyway simply because we are comapring the results as a digital event the marine is either alive or dead, in game terms this is adequate attempting to reconcile this with 'real' life and background is where the problems begin.

Actually, I think it has already been pointed out in this thread that a space marine who is "killed" in game terms may well actually be alive but incapacitated in one of several ways. And the discussion so far has generally taken this into account. Who is comparing results only in terms of an alive/dead dichotomy? I know I'm not.


I fully concur that a thermal dump system would be compromised by being set alight and thats why the design must take into account that it may happen, after all there is the armour save.

Again, I don't know what exactly you mean by "thermal dump"; in this context it sounds like you mean the heat exchanger? Assuming so, what I'm saying is that once the heat exchanger is nonfunctional, it is quite difficult to "take that into account" and somehow find a way to still keep the Marine cool. Heat sinks are a possibility, but a strongly limited one due to size constraints. Other than that, I can't really think of anything. This is why I was saying earlier that insulation is necessary even with an active cooling system.




Bottom line, the heat load on a flamed Marine is going to be very severe, and his suit's ability to keep him cool is going to be sharply limited because it can't effectively transfer that heat to the outside environment due to the fact that the outside environment is creating the heat in the first place. Insulation will reduce the heat load on the Marine, and a heat sink will provide LIMITED protection, but if the flamer fuel burns too hot and/or too long, that Marine may just be KIA. Ultimately, in order to reconcile this with the "in-game" fact that Marines do indeed have a good chance of surviving a flamer hit, we may have to conclude that flamer fuel just doesn't burn that hot and/or that long.

bojan
13-09-2008, 13:16
...If you have some information about this in English, I'd be quite interested in seeing it...

Unfortunately I don't have any amount of info in English - but basically asbestos textolite, as long it is not directly exposed to flames (ie. between two metal layers) is excellent thermal insulator, with 10cm preventing rise of interior temperature for more then 10degC vs 500degC for about half hour. It is however heavy, making other insulation materials better for most roles except when good structural integrity is required.



But that is actually quite poor performance when compared to the effectiveness of modern ceramic composite armors, which can easily be ten times more effective than an equivalent weight of RHA.

Yes, I know that, but it is still popular on anything other then MBTs - eg. British add-on side armor for Challenger2 and Warrior has it.
Anyway Soviets replaced it in the glacis in mid-80s, US with IPM1 and Germans with Leopard 2A4.



This is why, for instance, the frontal turret armor of the M1A2 is ~1500mm RHAe even though the physical thickness of the armor is well under 300mm and weighs a small fraction of what 1500mm thick steel would weigh.

Physical thickness of M1A2 turret armor from the front straight on is ~750mm. It gives M1A2 ~800-900mm resistance vs KE and ~1400-1500mm resistance vs HEAT.
M1A2 hull is ~450mm thickness and probably gives some 600-700mm KE resistance and ~900-1000mm HEAT resistance.
Which is more then plenty vs most AT weapons used today.



An armor material that is only 1.5 or 1.8 times more effective than RHA is, frankly, obsolete crap. And this is by the standards of modern technology, which seems to be less sophisticated than the materials technology that goes into SM power armor.


Textolite is still used in lesser armored vehicles - lot of today IFVs use it. Point with textolite is that it is very universal:
You want spall liner - use aramide fibers.
You want heat resistance - use azbestos fibers.
You want anti-neutron liner - impregnate it with boron.
All of the above can be actually combined, and was.



As you may know, the plastic composite armor used by the T-72 and the -64 series (T-64, T-80, etc.) didn't work very well at all

Relatively. In the mid-70s when T-64/72 entered service in mass it's glacis was very resistant to all western KE ammo, with only exception being Chieftain's 120mm APDS that could penetrate glacis at less then 1000m.
Glacis was ~350mm vs KE, 450-500mm vs HEAT.

Turrets never had textolite except as a spall/anti-neutron liner, using Corundum based ceramics in T-64A, starting from 1971 (earlier versions went through several different combinations for turret armor, including multiple steel/Al layers).
T-64B/T-80B used ceramics/epoxy/Al combo.
Initial T-72 did not have composite turret, later models of base T-72 had Corundum based ceramics, but as that was expensive for a 2nd-rate tank it got changed to waterglass/SiO2 on T-72A. T-72B has steel/rubber/Al plates.



, and was replaced by ceramic compositions using boron carbide, which work much better as armor (but could never be used as heat shielding on reentry vehicles).


Depends on the generation of tank - T-64A (1971) already had ceramics in turret, as did T-64B and T-80B. T-64B/80B still had textolite in glacis but had altered structure of glacis (7 layers instead of 5 previously used).
Textolite was replaced with 7 layers high-hardness steel/rubber/Al sandwich on T-72B (1984) and later with 9 layers variation on T-80U (1986) and T-72B model 1989. (1988). Same idea with steel/rubber/Al structure is used on eg. Leopard 2A5/2A6 add-on armor.



In fact, the inadequacy of high-modulus plastic composites as armor (and the problems with Soviet ceramic production) are what led the Russians to be such prolific users and developers of ERA, active protection systems, infrared jammers, and so forth, which are technologies that the West never explored as much because our ceramic armor technology made them less necessary.


Not really, they just chose different approach - note that they had plenty of projects that used same routes as a "west" school of tank design - they just had different priorities.



By DU, do you mean depleted uranium? If so, the phrase "DU ceramics" is contradictory; DU mesh is used along with ceramics in some tank armors, but a metallic material cannot be a ceramic by definition.


DU is used in two versions - one is metallic form, other is form of Uranium Carbide (Carbides are considered ceramics). Both are used in the tank armor, where Uranium Carbide is extremely effective as a erosion medium, while metallic DU resists shocks of impact excellently.

Anyway, if you are interested in armor properties, use and how the tanks work - Tanknet is The Forum:
http://63.99.108.76/forums/index.php?



2nd Edition Angels of Death codex says 250 lbs. (about 113 kg), but to my mind, that is ludicrously light. I would think that 500 kg would be a minimum reasonable value, maybe as much as a 1000 kg.

250lb, if using rigid armor is stretching it, but with 500+kg you could make equivalent of SM armor even today.

Argastes
13-09-2008, 20:19
Unfortunately I don't have any amount of info in English - but basically asbestos textolite, as long it is not directly exposed to flames (ie. between two metal layers) is excellent thermal insulator, with 10cm preventing rise of interior temperature for more then 10degC vs 500degC for about half hour. It is however heavy, making other insulation materials better for most roles except when good structural integrity is required.

Hmm. This is interesting. We can't actually calculate a value for thermal conductivity from that, but it sounds reasonably good.


Physical thickness of M1A2 turret armor from the front straight on is ~750mm. It gives M1A2 ~800-900mm resistance vs KE and ~1400-1500mm resistance vs HEAT.
M1A2 hull is ~450mm thickness and probably gives some 600-700mm KE resistance and ~900-1000mm HEAT resistance.
Which is more then plenty vs most AT weapons used today.

I think we must have conflicting sources here; it is my understanding that the M1A2's frontal turret armor is definitely less than 750mm thick.

At any rate, textolite is still significantly inferior to modern ceramic armor. Based on what you said earlier, it does sound like a pretty good thermal insulator, but without more information, I cannot conclude that the example of textolite proves the possibility of materials that are both good thermal insulators and good ballistic armor. At best, it proves the possibility of materials that are good thermal insulators, and can also be used, along with other materials, to create composite armor that is better than homogeneous steel but still semi-obsolete by 21st century standards.


Textolite is still used in lesser armored vehicles - lot of today IFVs use it. Point with textolite is that it is very universal:
You want spall liner - use aramide fibers.
You want heat resistance - use azbestos fibers.
You want anti-neutron liner - impregnate it with boron.
All of the above can be actually combined, and was.

Not that I disbelieve you, but if textolite really is so widely used in AFV armor--including Western AFV armor--I find it really strange that I am unable to find any substantive information about it's use. Is textolite perhaps a trade name or generic name for this material? Do you know of any other terms that might be used to refer to it? Perhaps the Russians/Eastern Europeans refer to it as "textolite" but a different term is used in the West? There seems to be very little info out there about textolite in AFV armor.


Relatively. In the mid-70s when T-64/72 entered service in mass it's glacis was very resistant to all western KE ammo, with only exception being Chieftain's 120mm APDS that could penetrate glacis at less then 1000m.
Glacis was ~350mm vs KE, 450-500mm vs HEAT.

Okay, but here we are comparing the armor's performance to the main guns of Western tanks with designs basically dating to the 1960s or earlier. This is before the advent of modern KE ammunition I have no problem accepting that when the 1970s-era T-tanks first hit the field, the fiberglass composite armors were acceptable. But developments in main gun and ammunition technology rapidly overtook them. When I say they didn't work very well, I mean that their obsolescence against modern AT weapons has been established, not necessarily that they were obsolete at the time of introduction.


Depends on the generation of tank - T-64A (1971) already had ceramics in turret, as did T-64B and T-80B. T-64B/80B still had textolite in glacis but had altered structure of glacis (7 layers instead of 5 previously used).
Textolite was replaced with 7 layers high-hardness steel/rubber/Al sandwich on T-72B (1984) and later with 9 layers variation on T-80U (1986) and T-72B model 1989. (1988). Same idea with steel/rubber/Al structure is used on eg. Leopard 2A5/2A6 add-on armor.

That's all fine; the point is not that no Soviet tanks had ceramic armor before textolite stopped being used in tank armor, but that when the textolite was replaced, it was replaced with composites incorporating ceramics in at least some cases (I wasn’t aware that rubber-metal sandwich composites were so widely used, though).


Not really, they just chose different approach - note that they had plenty of projects that used same routes as a "west" school of tank design - they just had different priorities.

Again, we seem to have differing sources. Most of what I’ve read about Soviet tank design history indicates that the interest in ERA, ADS, etc. was partially a result of the fact that Soviet ceramic armor never measured up to that of the US/UK (not necessarily as a result of inferior technology; there are cost and production issues at work there as well). Of course, NATO was always more concerned about the HEAT threat as well.


DU is used in two versions - one is metallic form, other is form of Uranium Carbide (Carbides are considered ceramics). Both are used in the tank armor, where Uranium Carbide is extremely effective as a erosion medium, while metallic DU resists shocks of impact excellently.

Okay, I think I know what you mean now. I’ve just never heard of uranium carbide referred to as “DU”, although admittedly I am not too familiar with it’s use in tank armor (I’m mainly familiar with it as a nuclear fuel, and of course it’s enriched, not depleted, for such use).


Anyway, if you are interested in armor properties, use and how the tanks work - Tanknet is The Forum:

Ahh, tanknet! I actually lurk there quite a bit. If you don't mind me asking, what is your username there? If you post there much, I have actually probably picked up a lot of information from you.


EDIT:

250lb, if using rigid armor is stretching it, but with 500+kg you could make equivalent of SM armor even today.

Yes, probably so. The 500-1000 kg estimate is quite rough, and is based on the (approximately) known physical dimensions of a space marine, the AOD codex's statement that the main armor elements of SM power armor are about an inch thick, and a loose guesstimate of Ceramite's density. Of course much of the variation comes from the unknown weight of the suit's musculature and other internal systems. But yeah, if we could encase a soldier in several hundred kilograms of modern composite-based composite armor, he would easily have the same level of ballistic protection as an SM (definitely 12.7mm SLAP resistance at a minimum).