Power Armour - Practical or otherwise?

[Nitrophage]

I was recently doing some research into modern body armour, out of curiosity more than anything else, when I found this http://http://www.engardebodyarmor.com/hardarmor.htm. The last entry caught my attention as I knew Level IV body armour was incredibly strong (rated against 30-06 Armour Piercing rounds at basically point blank range) but I had always thought it would be too heavy for all over protection, even in a powered suit. However the web page gives the insert as having a weight of 3.2 Kg and an area of 0.075M^2. Scaling up to the surface area of an average adult (1.75-2 m^2) gives a weight of roughly 80kg for full body protection. For full effectiveness it will also need a soft body armour underlay but that shouldn't weigh nearly as much, and I think the whole suit could be kept within the weight limits of something like the HULC or any of the other prototype powered exoskeletons.
All put together this sort of PA could be very useful in the sort of fighting you see today in Afghanistan, strong enough to protect against even fairly prolonged AK fire and the odd sniper shot, and providing excellent shrapnel protection whilst remaining small enough to move through all but the worst made and smallest houses, and to be near-impossible to get a direct RPG hit on. Battery life would be less of a concern for mechanised troops who do only a few hours of foot patrol a day, and while maybe less personal from a hearts and minds campaign than a regular soldier (Transparent visors = highly recommended) it would certainly be better than just driving by in vehicles.

Here's the inevitable "However".

However, I am no engineer and I have a very cursory understanding of the mechanical challenges involved in making something like this work reliably, with decent range etc. I really couldn't say whether this sort of thing would become practical in the near future, more distantly, or never. Feedback as to the practicalities of such a suit would be greatly appreciated.

[Sea Skimmer]

Keep in mind anybody testing vs .30-06 is normally using the M2 AP round, which is a steel nosed bullet from the Second World War, modern .30-06 AP ammo does not exist that I've ever heard of as it would be illegal for civilian sale and unwanted for military use since the 1950s, and the standard NIJ armor tests call for M2. Current 7.62x51 and 7.62x54R tungsten cored ammo is a considerably greater threat, and tungsten ammo in the later caliber is fairly common thanks to the USSR making vast piles of it for the SVD. As I recall even the M995 tungsten ammo for 5.56mm exceeds the armor piercing capabilities of M2 AP, at least at very close ranges. In tests it could shoot through the 6-8mm armor sides of a BRDM-2, and 10mm thick mild steel plate. So armor weight may need to be higher then you project, depending on what you want to expect out of the armor, if the goal is to resist medium caliber sniper rifles. Maybe not by a lot, but higher empty armor weight compounds the weight of everything else.

Also the bulk of the power armor itself and whatever power pack it uses will push up the area you need to armor incrementally in turn.

Powering with batteries seems unlikely to work, but they can be useful as buffers for a combustion based power supply. With any present design power densities are just not anywhere close to what is required. Some ideas for carbon nanotube based batteries might change this, some fairly insane stuff has been claimed, but nobody is even remotely close to being able to manufacture such devices and indeed it may never be possible. Weight would also remain pretty high. Ultra high power batteries also start to introduce really damn serious safety problems that could easily exceed those of the soliders own ammunition or fuel for combustion engines. Look how well lithium batteries already burn, what happens if we have a battery with ten times as much energy in it? Fuel cells, or a gas turbine, or very plausibly both with a battery as a buffer while the turbine fires up in spurts and the fuel cell runs all the time might work. A turbine gives issues with noise, and the shear amount of heat that will be thrown out by any power supply, but that's the highest power sort of engine we can build today and they scale in size easily. They also don't mind shock as much as a piston engine even if the latter may be able to reach higher thermal efficiency. That might also change, I forget the name but some wired rotary piston engine is being worked on at the moment.

Thermal efficiency leads into to another problem with enclosed power armor vs a exoskeleton for load transporting which is much closer to being usable, cooling the poor user. Even assuming we put a special uniform over the power armor to keep it cooler in the sun, the user is going to roast alive and need active air conditioning in even mild weather. That in its own right will take a considerable amount of complexity and size and power, indeed US Army attempts to build a stand alone air conditioned vest for AFV gunners basically failed and the thing was already the size of a backpack, though with much greater weight. Its a serious thermodynamics problem that we can only make the refrigerated coolant get so cold, and so you can only scale down the compressor system and radiator area so much as your effectiveness is governed by the temperature difference between the coolant and the outside air multipled by radiator area.

A lot of work is going into breathable NBC warfare gear and breathable body armor fabrics, the former exists to some extent, but in hot desert weather I would question that this will be able to do anything more then keep the user from not actually dying of heatstroke should his AC unit fail. All the more so since the suit itself is making a lot of extra heat to move around. Perhaps though in the future we will be able to make immensely effective materials for this purpose. Removing a requirement for power armor to be NBC protected would certainly help matters as it could be more breathable and still resist flash-explosive gas hazards.

Fault tolerance in general is a huge problem for powered armor. For the moment we'd have to use hydraulics, and packing in redundant hydraulics would become very bulky quickly, while even a non redundant system is still very complex because of how high of precision you need to mimic human movements at high speeds while standing up to heavy shocks like the guy diving on the ground. this problem we just cannot solve right now. With an skeletal system bailing out of a failed unit should be fairly quick, if your actually inside powered armor I dunno on getting out fast, or when wounded and with the suit damaged, so this is a big problem. What we really need is artificial muscle, which ought to be very fault tolerant, but boy is that a long way off.

I think you are on the right track that even very limited powered armor might be accepted, precisely for situations like Afghanistan in which avoiding deaths is a goal in and of itself, but even a limited armored system is still a very long ways off and more or less dependent on specific materials breakthroughs becoming usable on an industrial scale. I'd be great if we could make an artificial muscle that is breathable (one way, this can be done, so water vapor goes out, nerve gas cant come in) strong enough to be armor, rugged enough to resist abrasion from rocks and trees and webgear, offers little resistance to the users movements when unpowered other then the inertia of its own mass, and a few other things, but I doubt anything that awesome will ever happen. Its more or less how the suits in Crysis seemed to be imagined, only with added implausible gimmicks.

[someone_else]

Main issues, inertia, traction and weight.

Even with a powered exoskeleton you won't be able to do very tight turns or run horribly fast. That's because the thing has a hefty weight, that will be hard to counterbalance.

Traction is likewise an issue as trying to move this weight with a human footprint will result in the soldier escavating the ground if it isn't hard rock. In sand or mud (or loose rocks) it will be especially funny. So it will need larger footprints, think of snowshoes. Maybe not so big, but definitely bigger than human feet.

Weight is another major issue for infantry. They have to be able to get inside buildings, and given that they do carry significant weight already (80ish kg of equipment on top of their won weight I think, but maybe more), there is the risk of collapsing the floor/roof and ending in the basement if you have a soldier that weights 200+ kg. And armor or not, that is one soldier with serious fractures if not dead.

[Formless]

Traction is likewise an issue as trying to move this weight with a human footprint will result in the soldier escavating the ground if it isn't hard rock. In sand or mud (or loose rocks) it will be especially funny. So it will need larger footprints, think of snowshoes. Maybe not so big, but definitely bigger than human feet.

On Earth, this might be a problem. What if you are fighting on the moon or Mars? Since power armor is mostly a sci-fi thing, a terrestrial battlefield isn't necessarily where its advantages are most pronounced. In space you are already required to wear a (heavy) sealed environmental suit anyway, why not add extra capabilities to it?

[Dr. Trainwreck]

I'd be great if we could make an artificial muscle that is breathable (one way, this can be done, so water vapor goes out, nerve gas cant come in) strong enough to be armor, rugged enough to resist abrasion from rocks and trees and webgear, offers little resistance to the users movements when unpowered other then the inertia of its own mass, and a few other things, but I doubt anything that awesome will ever happen. Its more or less how the suits in Crysis seemed to be imagined, only with added implausible gimmicks.

Biotech, man!

I think this is too far on the advancement vs practicality curve. It won't be practical until the tech is seriously advanced, and no one will bother to advance the tech if it will be so late to become practical. Shame.

[someone_else]

Mh, a pressure spacesuit will turn even Rambo in a goofy pacifist with stiffness and worthless gauntlets alone. Adding armor on top is useless as you are a sitting duck anyway.

If we are talking of mechanical pressure suits, like this, it could be different.
Planet-side versions do need some pretty hefty protection in airless worlds due to how fucking pointy is anything. And how fucking abrasive is dust (if moon dust is any indication).

Depends from the battlefield though. I somehow don't see soldiers playing hide and seek with guns on the Moon to capture a flag.

I suspect that bulk of the fights in airless environments will happen close-ish to the entrance of a pressurized environment, so they are likely well-defended places and will have something to prevent the use of vehicles (otherwise it's just a "drive something with armor and drop troops in front of the door" affair). A miniature D-day.

Theoretically having some additional armor while you charge the door / drop from a low "flying" lander with the main engine backward would be useful, but given the kind of engagement you don't need more than a shield-like device you then easily discard when getting into the airlock/hatch.
I keep thinking about using jetpacks.

[Sea Skimmer]

Weight is another major issue for infantry. They have to be able to get inside buildings, and given that they do carry significant weight already (80ish kg of equipment on top of their won weight I think, but maybe more), there is the risk of collapsing the floor/roof and ending in the basement if you have a soldier that weights 200+ kg. And armor or not, that is one soldier with serious fractures if not dead.

Only mortar crews carry up to 80kg loads, 50kg is more normalish for overburndened western troops and in combat or near combat your going to dump most of your gear like tents and sleeping bags out of hand. Some weight is also being folded into this powered suit, like your body armor and NBC gear. The extra equipment wont be carried at all in a situation like Afghanistan were missions are short, and resupply relatively assured. Floors in typical houses can support 200kg loads, remember people even more fat then that are walking around the planet and 150kg people are no longer uncommon at least in the US but I've never heard of one falling through a floor from it. Roofs vary a lot.

Its when you end up with power armored guys who are more like half a ton that you'll have some really serious problems with floor strength and sinking into the mud like crazy. The later problem may require power armor snowshoes be carried. Maybe a personal batwinch too; though more realistically I think we just aren't going such suits in say, the jungle.

[MrDakka]

Maybe a personal batwinch too; though more realistically I think we just aren't going such suits in say, the jungle.

Obviously you've never played Metal Gear Solid 4. They do exactly that.



These guys serve more as mobile weapons emplacements than anything else. I also don't know why design leaves the torso open when the legs are covered, but a fun game regardless.

More on topic IMHO I agree with skimmer in that the power density issue is the biggest roadblock for IRL power armor.

[Nitrophage]

Thanks for the feedback, guys, very helpful. One slight nitpick though, the page that gave me the initial information on the armour claims that they do actually proof against 7.62x54 API (whether that penetrates better, worse or the same than regular AP in that calibre I don't know) so that should already be included in the weight estimate.

One thing that still eludes me though is data on the power requirements of the exoskeleton prototypes that are in the works. It would be a big factor in the practicality of this sort of thing.

[Arthur_Tuxedo]

How many 14.5mm Soviet anti-material rifles would start showing up in insurgent hands if the West actually started using these things? Given that a force could only afford to outfit a small fraction of its soldiers with powered armor, I would guess that wearing PA would come to be regarded as donning a giant bullseye. I suppose it would be nice to have for house-to-house fighting where any weapon with enough punch to make a dent would be wildly impractical in close quarters (except maybe a short spear haft rigged with a motor that drives a heavy duty drill-bit).

[MrDakka]

One thing that still eludes me though is data on the power requirements of the exoskeleton prototypes that are in the works. It would be a big factor in the practicality of this sort of thing.

Thats the frustrating part. There are no official numbers because I'm assuming they're all classified. Instead we get stuff like range on level terrain, speed, etc. at least with the LockMart HULC : http://www.lockheedmartin.com/content/d ... -pc-01.pdf.

The Raytheon/Sarcos XOS is still tethered to a generator last I heard.

So in short its a crapshoot with no official data on battery capacity, average/peak power consumption, etc. although one can make a few estimates with the featured range, speed, workload, operating time, etc.

Given that a force could only afford to outfit a small fraction of its soldiers with powered armor, I would guess that wearing PA would come to be regarded as donning a giant bullseye.

Current/near future powered exoskeletons are pretty damn skeletal and don't add too much to a soldier's silhouette and they're designed for increasing a soldier's endurance and decreasing fatigue and/or cargo handling.

[Lord of the Abyss]

How many 14.5mm Soviet anti-material rifles would start showing up in insurgent hands if the West actually started using these things? Given that a force could only afford to outfit a small fraction of its soldiers with powered armor, I would guess that wearing PA would come to be regarded as donning a giant bullseye. I suppose it would be nice to have for house-to-house fighting where any weapon with enough punch to make a dent would be wildly impractical in close quarters (except maybe a short spear haft rigged with a motor that drives a heavy duty drill-bit).

I've heard it said in the past that the benefit isn't making it as impossibly invulnerable as sci-fi armor; it's that such powered armor would be resistant to the low-energy shrapnel and more-or-less unaimed fire that wounds and kills lots of soldiers. Sure, an anti-material rifle or RPG would still kill them, but there's a lot fewer of those than there are of things that kill un-powered armor troops.

And logically, house-to-house and other fights in constrained areas are exactly where you would use powered armor. If you're out in the open, why not just use a tank? Powered armor would be primarily for places where armored vehicles don't fit.

[Nitrophage]

How many 14.5mm Soviet anti-material rifles would start showing up in insurgent hands if the West actually started using these things? Given that a force could only afford to outfit a small fraction of its soldiers with powered armor, I would guess that wearing PA would come to be regarded as donning a giant bullseye. I suppose it would be nice to have for house-to-house fighting where any weapon with enough punch to make a dent would be wildly impractical in close quarters (except maybe a short spear haft rigged with a motor that drives a heavy duty drill-bit).

I've heard it said in the past that the benefit isn't making it as impossibly invulnerable as sci-fi armor; it's that such powered armor would be resistant to the low-energy shrapnel and more-or-less unaimed fire that wounds and kills lots of soldiers. Sure, an anti-material rifle or RPG would still kill them, but there's a lot fewer of those than there are of things that kill un-powered armor troops.

And logically, house-to-house and other fights in constrained areas are exactly where you would use powered armor. If you're out in the open, why not just use a tank? Powered armor would be primarily for places where armored vehicles don't fit.

Exactly my point - nothing is indestructible, but if you force your enemies to rely on giant, loud, slow firing rifles to kill you, you have just greatly reduced his effective firepower (There were reasons people dropped battle rifles for assault rifles, and all the problems with the former would be massively exaserbated in an AM rifle). Of course even a small shaped charge would cut through it like a semi-moltern copper knife through butter, but that would require a direct hit on a man sized target under battlefield conditions. Good luck with that.

[Nitrophage]

Mr Dakka- thanks for the link. Pity all the juicy stuff is classified, though at least that shows they see enough potential in it to bother hiding the details. Although, that picture of the soldier using the HULC along with all his standard gear gets me thinking - If Power armour ever does come into use it may well be through gradual evolution of much simpler systems. Hmmm, food for thought.

[Admiral Valdemar]

Exactly my point - nothing is indestructible, but if you force your enemies to rely on giant, loud, slow firing rifles to kill you, you have just greatly reduced his effective firepower (There were reasons people dropped battle rifles for assault rifles, and all the problems with the former would be massively exaserbated in an AM rifle). Of course even a small shaped charge would cut through it like a semi-moltern copper knife through butter, but that would require a direct hit on a man sized target under battlefield conditions. Good luck with that.

Assuming such a weapon could even be brought to bear. We have dazzler lasers now on rifles to disorient and temporarily blind combatants, it's not all that hard to have a system that is on a turret and detects any prying eyes and runs interference. It need only target those with weapons capable of causing severe damage to the suit as a priority. Plus, a guy with such a rifle will be a huge target himself, only with the chief advantage being surprise only.

[Sea Skimmer]

Exactly my point - nothing is indestructible, but if you force your enemies to rely on giant, loud, slow firing rifles to kill you, you have just greatly reduced his effective firepower (There were reasons people dropped battle rifles for assault rifles, and all the problems with the former would be massively exaserbated in an AM rifle). Of course even a small shaped charge would cut through it like a semi-moltern copper knife through butter, but that would require a direct hit on a man sized target under battlefield conditions. Good luck with that.

Even more significant would be just how resistant you'd become to artillery fire and bomb explosions. Blast injury would be dramatically less significant (depends on how rigid the armor is), flash and lung burns near eliminated and the vast bulk of fragmentation would be stopped too. It might be possible to actually physically charge through a barrage of artillery airbursts and not take serious losses doing it, while a bouncing betty style land mine that would have killed a whole squad before now might not kill a single person. Not that you'd really want to try any of this anyway, but it should be possible. This would be extra useful as various nations begin fielding weapons like the XM25 grenade launcher, which is simply incapable of producing high power fragments, so you might be talking total immunity to such airbursts at least until the armor is degraded by multiple hits.

I think though, 7.62mm rifles with discarding sabot ammunition are going to be a threat without dramatically more armor. The Sweds have now made this technology work in a 6.25mm submachine gun, and it pierced the side of an MT-LB (7mm angled steel) at 50m. From a freaking submachine gun. Accuracy of small caliber discarding sabot will always suck though at longer ranges, as they lack fin stabilization, but it'd be a problem close quarters.

[Admiral Valdemar]

For sabots, the armour could utilise the kind of hybrid armour system inspired by deep-sea snails, that is, a hard outer casing of nanoparticulates wrapped around a synthetic solidus like matrix that absorbs energy. The evolved purpose was to stop penetration by crabs and the like by deflecting their pincer claws, or if that failed, absorbing the energy of the impact and any shrapnel with the secondary layer. I know the British Army is looking into D3O filled body armour for deployment, and the same dilatant is used in my phone case, which you can throw at a brick wall and it won't faze it at all.

It's probably more complex and expensive than just normal plate armour like the Class IV stuff you'd get on a powered EOD suit, but it has the benefits of being harder to shatter or penetrate as easily with sabots. You're never going to be invulnerable, so the best you can do is have armour that absorbs as much energy as possible without letting it reach the pilot.

Course, you can always try and not be hit first.

[Sea Skimmer]

Your more or less describing how boron carbide based body armor works anyway, its very very hard armor which breaks into many tiny pieces to absorb energy, while also forcing more mass into the projectiles path in the process via that very absorbed energy. In fact its one of the hardest materials mankind can make right now other then artificial diamonds and one or two other things. It used to be we glued on layers of of aramid type fibers for spall protection and to help resist cracking, now polyethylene based stuff like spectra is used for the best plates.

As for the D3O armor, only being worked on for helmets that I've ever heard of, as the volume of the helmet isn't a serious concern, while is a very real concern for torso or limb armor. Allowing volume always allows for more effective armor solutions, and more use of reactive armor technologies, but as long as the armor has to go on a human form you'll have problems. If we could allow a small gap between two body armor plates, just enough for the projectile to yaw, we could make body armor that stops much more powerful threats for much less weight. Problem is you'd then have a guy with a foot thick armor package on his chest. Its also in any case by no means clear D30 will actually work out to be effective for the weight, nor was the goal to resist rifle fire that I'm aware of. Most military helmets are only tested against fragmentation and in some cases handguns, the latter mainly as fragment simulators.

[Lord of the Abyss]

If we could allow a small gap between two body armor plates, just enough for the projectile to yaw, we could make body armor that stops much more powerful threats for much less weight. Problem is you'd then have a guy with a foot thick armor package on his chest.

OK, possibly stupid idea, but would a shield help then? Something like a tougher version of a riot shield like the cops have. Someone in power armor could presumably carry a pretty heavily armored shield without tiring, and it gives you that gap, at least against an enemy from the direction the shield is covering. And unlike that foot thick chest armor, the user can just drop the shield if it gets too awkward.

[Simon_Jester]

The big problem with that is that power armor is most advantageous in relatively close quarters... which is exactly where you're most likely to get shot from unexpected directions. And exactly where having this big honking kite shield is likely to trip you or your buddy up.

In more open environments where this is less of an issue (say, fighting your way up a hill in Afghanistan to get at the guerillas on top), the enemy will counter the shield with larger, heavier weapons- just as they'd counter the armor itself.

A shield also means the guy with the shield does NOT have both hands free to use a rifle-type weapon. That limits the applications pretty drastically.

[Formless]

This guy doesn't seem to have a problem using a rifle with a shield. Turns out AR-15's have pistol grips for a reason?

(and notice that the forend can be rested on the shield's cutouts. That's what they are there for, in fact.)

And moving with shields just means you have to learn to coordinate with your buddies and move in formation. Actually, once you have the movement down, it seems only one or two people really need to carry a shield, and the rest take cover behind them. Police use these things in real life, so there is no need to speculate on how they can be used or how to overcome their disadvantages. Just go out and look.

[Admiral Valdemar]

The shield could also have ERA on it, much like Sundowner's shields in Metal Gear Rising.

http://metalgearsolid.nl/wp-content/upl ... reen-4.jpg

[Zaune]

A shield's going to do sod-all to protect you from the sides or rear, or from overpressure. How hard would it be for some ragged-arsed insurgent group to get hold of a few old 60mm mortars, or if that failed kludge some together out of scrap metal?

[Simon_Jester]

This guy doesn't seem to have a problem using a rifle with a shield. Turns out AR-15's have pistol grips for a reason?

(and notice that the forend can be rested on the shield's cutouts. That's what they are there for, in fact.)

And moving with shields just means you have to learn to coordinate with your buddies and move in formation. Actually, once you have the movement down, it seems only one or two people really need to carry a shield, and the rest take cover behind them. Police use these things in real life, so there is no need to speculate on how they can be used or how to overcome their disadvantages. Just go out and look.

Police use them under almost ideal conditions by the standards of combat.

Sure, they work for certain SWAT teams when staging drug raids against house-sized buildings occupied by only a few enemies. Would they be a good choice of weapon in the battle of Fallujah? Because that's the kind of environment the army thinks of when they hear the words "urban warfare;" tools and tactics that break down when the combat is that intense probably aren't going to be acceptable to them.

[Formless]

A shield's going to do sod-all to protect you from the sides or rear, or from overpressure. How hard would it be for some ragged-arsed insurgent group to get hold of a few old 60mm mortars, or if that failed kludge some together out of scrap metal?

We were talking about room to room indoor fighting, where (contrary to Simmo's data-less claims) you would least expect to be attacked from behind due to the linear nature of most modern architecture. Or even ancient architecture. Certainly mortars are irrelevant, because there is a ceiling above the defender's heads they don't want to collapse. From what I have heard, basically military room clearing tactics and SWAT operate under similar methodologies, main difference being the level of force they face and use. Its easy to call what SWAT does "ideal" combat conditions when you have no experience to base it on. After all, they can't (officially) just burn a house down or frag grenade it if things get too difficult.

The thing is, the military does use ballistic shields (their own designs, even). Fucking Wikipedia has the pictures to prove it. There are even pictures of shields that are so heavy they are put on wheels and look like the front door of my house (so they can be used while disarming explosives). I'd post a link, but fuck it. I'm not doing basic Google searches for people who should know better than to ask me loaded questions.