Of powered armor, mechs and feasibility.

[Night_stalker]

G1 PA will be doubtlessly a rough design, comparable to MJOLNIR's early versions from the Halo universe. They will be tough, but not really usable outside of a lab, due to power issues. If it has a battery, then it really isn't too useful for field ops in areas without ready access to friendly forces.

[Gunhead]

Wait a minute here, I'd like to see some hard evidence on Dragon skin surviving a contact detonation of 184g of HE. More specifically would the person wearing the vest survive the blast. While 184g doesn't produce a large area blast, at contact it would still produce one helluva kick to the wearer.
Concussive blast generated by grenades 81mm and below is not that great, they cause casualties primarily through shrapnel, against which we've had protective vests since the Korean war. Artillery shells are a whole different beast, they can be pretty much guaranteed to kill any living thing within 20 meters of the point of detonation through sheer overpressure. They also produce heavy fast moving shrapnel, which is why they have greater casualty radius even against protected infantry.

I could be wrong about the lethal blast radius, I'm really just going from memory and using more conservative estimates. Anyway, against standard HE shell, PA should give significant protection against shrapnel, the real killer would the blast.

-Gunhead

[Simon_Jester]

I'm not doubting modern artillery can KILL a man in any reasonably realistic power armour. I'm asking how likely it is for him to be HIT by it as he or she is bound to be a LOT smaller than an armoured vehicle.

If we follow that line of reasoning, then infantry should be invulnerable to artillery, since they're so small compared to an AFV, how can artillery ever hope to hit 'em?

Fragmentation rounds don't do point damage, they do area damage.

Fragmentation is exactly what power armor is supposed to be used against, and to force the enemy to achieve direct hits instead of proximity soft kills. No one will ever design power armor that can shrug off a 155mm shell to the kisser, and I'd bet long odds that no one will ever design power armor that can shrug off a direct hit from a single submunition from one either. But putting the soldiers in better armor reduces the lethal footprint of an artillery strike from "everything in the hectare dies" to "everything within a few meters of these fifty dots dies." That's a significant improvement.

Well, a dragonskin vest can stop fragmentation from a frag grenade lying on top of it. I think that a zero distance frag grenade explosion is a good example of AP effects.

What? We're talking about artillery here! A M67 grenade has 184 grams of explosive. A M795 dumb 155mm fragmentation shell has 11 Kilos.

Yes. And I don't think anyone proposes to make it survivable to have an M795 go off on the user's chest. But the AP effect of a bursting M67 to the chest is many times more than lethal damage; armor that can survive that would greatly reduce the lethal radius due to fragmentation for the M795, too.

I could be wrong about the lethal blast radius, I'm really just going from memory and using more conservative estimates. Anyway, against standard HE shell, PA should give significant protection against shrapnel, the real killer would the blast.

True. Blast is shorter-ranged than shrapnel, but is definitely going to be a critical factor for power armor. Nobody's designing an overpressure-proof power suit any time soon, either.

Then again, people are also comparing the power armor's performance against DPICM, which doesn't drop a single massive shell at all and instead throws out a rain of anti-tank grenades. Those grenades won't have much blast, and rely mainly on shrapnel for AP effects, just like normal-sized ones.

[Sea Skimmer]

A lot people are missing the point that powered armor combines the protective advantage of a light armored vehicles with the ability to exploit cover and easily dig in without heavy machinery that an infantryman has. Combined that and artillery is only going to be effective with intensive barrages, which will kill anything but also burn up a whole lot of ammo and just as importantly, time. The more time taken by artillery to fire to achieve the desired effect on target, the more time friendly counter battery has to shoot back.

Typical dispersion of submuntions is about one per twenty square meters. The odds of a guy in powered armor being directly hit by DPICM is lower then the odds of a tank being hit and disabled on the engine deck, a hatch or the suspension. How horrible! APERS bomblets meanwhile just wont be effective, they use very small preformed fragments which are basically razor blades. This assumes you aren't in a forest or in buildings either, both of which make submuntions almost completely ineffective by detonating them before they reach the ground.

The idea that the enemy will kill powered armor one guy at a time with GPS guided artillery is kind of laughable. Sure that might happen, but for the same amount of money the enemy could have fired 100 conventional shells and wiped out a whole regular infantry platoon. Using GPS weapons is also dependent on being able to pin down the exact location of the target, easier said then done with the target is one man who you can you know... move.

[CBG]

Wait a minute here, I'd like to see some hard evidence on Dragon skin surviving a contact detonation of 184g of HE. More specifically would the person wearing the vest survive the blast. While 184g doesn't produce a large area blast, at contact it would still produce one helluva kick to the wearer.

http://www.youtube.com/watch?v=u_HRQNd84ZA
Also, the sheer mass of a power armor would make the "kick" a lot smaller.

True. Blast is shorter-ranged than shrapnel, but is definitely going to be a critical factor for power armor. Nobody's designing an overpressure-proof power suit any time soon, either.

That's where the remote controlled suit comes in. I think that without a human inside, it could survive a lot of overpressure even without any extra protection against it.

Typical dispersion of submuntions is about one per twenty square meters. The odds of a guy in powered armor being directly hit by DPICM is lower then the odds of a tank being hit and disabled on the engine deck, a hatch or the suspension. How horrible! APERS bomblets meanwhile just wont be effective, they use very small preformed fragments which are basically razor blades. This assumes you aren't in a forest or in buildings either, both of which make submuntions almost completely ineffective by detonating them before they reach the ground.

I gave a figure for the above profile of an average IFV before. It's 16 square meters. With 1 per twenty meters the odds of scoring a hit are pretty good. A PA would be 0,5-1 square meter. M1 Abrams is 29 square meters.

[Gunhead]

Btw. Skimmer do you have more accurate numbers at hand about blast area of different artillery rounds? You're right about submunitions being unlikely to hit a guy dead on, and shrapnel would be rendered almost useless by available cover and digging in. So that leaves just bigger bombs or more bombs or more bigger bombs. But there's a limit how much explosive power you stick into a 155mm shell, even if something more powerful than TNT is used. Even then raising the lethal blast radius is pretty inefficient.
Going to bigger rounds means bigger guns and those are not as plentiful and are usually under higher echelon command, and not really available for on the spot fire support.
So I'm thinking about how much can we increase the blast area of a 155mm arty munition or a 120mm mortar ammunition.


-Gunhead

[Gunhead]

Wait a minute here, I'd like to see some hard evidence on Dragon skin surviving a contact detonation of 184g of HE. More specifically would the person wearing the vest survive the blast. While 184g doesn't produce a large area blast, at contact it would still produce one helluva kick to the wearer.

http://www.youtube.com/watch?v=u_HRQNd84ZA
Also, the sheer mass of a power armor would make the "kick" a lot smaller.

That hardly proves the guy wearing the vest would have survived. The plate parts did stay in one piece as could have been predicted and shrapnel was also stopped, but concussion transfer still happens and that is the real killer here. That chest plate is moving upwards quite fast. Fast enough to sling the dummy upwards and the extra weight on it's back clear off. Now I'm not sure how much energy was involved, but I'm a long way from convinced the wearer would have lived.

Even if the chest plate of a supposed power armor weights enough it won't press against the wearer when hit by a blast wave, it will still have trouble with the impact itself which will transmit through the armor. Trauma liners etc. might mitigate this to some extent. All of this is extremely dependent on the exact circumstances. AFV's for this very reason have systems that isolate the crew from contact with the hull.

-Gunhead

[Sea Skimmer]

Btw. Skimmer do you have more accurate numbers at hand about blast area of different artillery rounds?

Not handy at the moment but Ill look into it. Its hard finding details of the blast effects of artillery because they are so slight in smaller calibers. Artillery is really all about fragmentation until you get to shell around 8in and up. So the main way of comparing artillery shell effectiveness is the 100% lethal radius. The radius in which not only are the fragments lethal, but you are guaranteed to a hit a person with one. The further you get from the burst point of course, the more spread out the shells are until you are no longer certain to hit a person.

You're right about submunitions being unlikely to hit a guy dead on, and shrapnel would be rendered almost useless by available cover and digging in. So that leaves just bigger bombs or more bombs or more bigger bombs. But there's a limit how much explosive power you stick into a 155mm shell, even if something more powerful than TNT is used. Even then raising the lethal blast radius is pretty inefficient.
Going to bigger rounds means bigger guns and those are not as plentiful and are usually under higher echelon command, and not really available for on the spot fire support.
So I'm thinking about how much can we increase the blast area of a 155mm arty munition or a 120mm mortar ammunition.

Trying to kill someone protected by semi rigid armor with the blast effects of such small projectiles is a loosing proposition . The only way to make the blast effect significantly larger then it already is would be to adapt a fuel air explosive, and those have endless relability issues which is why they are not used in artillery currently. With convetional bulk HE you aren't going to be able to make shells explode much better then they already do because we already fill shells with the best high explosives around. You could only make them more powerful by making them purer... but we normally blend down high explosives slightly to increase safety.
Instead the more likely countermeasure would be to change the way the shell fragments, so it produces fewer but larger fragments. This would be done by prescoring the inside of the shell walls, literally they cut grooves and the shell breaks along the groove lines. We used to use ammo like that against personal in Nam (called COFRAM for controlled fragmentation, though it was meant to produce a hail of very small fragments in that case), but cluster shells replaced it. Even if the powered armor guy has all around Level III or IV protection large enough fragments will go through it. However that means you have a lower chance of hitting the guy, and the shell is less effective against other kinds of targets.

In the field of cluster bombs, the logical counter would be to scale down the shaped charge equipped DPICM bomblets to be the size of fragmentation based APERS bomblets. That way you can have a lot more bomblets per shell or bomb/rocket, increasing the chances of hitting the guy with a shaped charge. But once more, you are reducing effectiveness against other kinds of targets. The tiny DPICM shaped charges wont work well against armored vehicles, and it wont produce more then a few fragments to kill normal infantry.

Since an artillery battalion only has so many supply trucks full of ammo it can move around with itself, and the storage of ammunition ready to fire on a specific self propellent gun or on the prime mover of a towed gun is even more limited (30-60 rounds), its obvious that forcing the enemy to use specialist ammo is a major advantage. The enemy can either only have a very limited supply on hand, limiting its utility in the first place, or else he must sacrifice his ability to quickly attack other kinds of targets. Artillery already needs to stock a half dozen kinds of ammo or more, so this is a serious issue to add yet another one. Multiple rocket launchers would be even more limited in ammo choices, since they can take 10-20 minutes to reload.

That hardly proves the guy wearing the vest would have survived. The plate parts did stay in one piece as could have been predicted and shrapnel was also stopped, but concussion transfer still happens and that is the real killer here. That chest plate is moving upwards quite fast. Fast enough to sling the dummy upwards and the extra weight on it's back clear off. Now I'm not sure how much energy was involved, but I'm a long way from convinced the wearer would have lived.

Yeah odds are the vibrations would have killed the user in that test since Dragon skin is all soft, with small pieces of hard plate sewed together. However a British solider did recently survive throwing himself ontop of a grenade because his backpack was also in the way. So its pretty easy to see how rigid powered armor, which would deflect the blast more then absorb it, could protect the user from a direct contact with a grenade. The joints are always going to be vulnerable, but that still beats being limited to a helmet and a flak jacket which aren't even certain to save your life, let alone avoid all injury, from a grenade that exploded 5 meters away.

[CBG]

The difference would be 300kg power armor vs 80 kg soldier. Acceleration is force divided by mass, so the wearer would feel around 3 times less acceleration than a soldier in dragonskin. Also, the situation in the video is pretty extreme - the grenade is positioned between ground and armor, making it seem more like a mine explosion than a normal hit.
You can see that dummy didn't get deformed. The blast has slinged the dummy and the weight, but notice how high. It was less than a meter. I think that the guy would have lived, maybye with a few broken ribs, but alive.
And a titanium chest plate would not be flexible, like the dragonskin. If properly designed, it would uniformly distribute the impact over user's chest in a longer time.
Aircraft ejection seats can give up-down accelerations (worse for human body than front-back accelerations) of even 20g. Frontal explosion would be an "eyeballs-out" kind of peak acceleration, the kind of acceleration a human can survive most of. About 30-40 g's after reduction by armor and any of it's anti trauma elements. The mine\IFV situation is much worse, as the acceleration is paralell to the spine.
Still, remote controlled suits would resist that way better.

And with artilery effectivness, don't forget about cover, which would pre detonate small shaped charges and significantly slow down fragments large enough to harm the PA.

[Iosef Cross]

You'll just see shells that dispense guided bomblets be developed and deployed to counter the power armour. Such things already exist to kill AFV's in any number of forms.

And yet, light infantry still hasn't replaced AFV's.

[Iosef Cross]

That depends on the cost. But considering that if a power armor costs the price of a car (around 20 grand), them it would be feasible to have an fully equipped army with power armor. Of course, if a PA costs 200 grand, them only a few specialized soldiers would use them, if a PA costs 2 million, them it wouldn't be of military use because you could get a tank for this price.

I disagree there because the cost, while important is not the true bottle neck for the issue.
The true issue with PA is maintenance. There are going to be costs involved with keeping that soldier in the field and with PA these costs will multiply many fold. Think fuel and maintenance for a start. Because of this, there will always be missions where it is more cost effective to deploy light infantry who, in the worst case can live off the land and only need to be supplied with ammunition. Furthermore, deploying PA infantry on missions like policing (like in Iraq today) could even prove counterproductive since the local population will feel detached from the land mobile tanks surrounding them. (unless you can make some sort of powered armor that looks like a normal uniform ) Hence Heavy Powered Armor will newer replace light infantry.

Well, all that depends on conjectures on how the technology will evolve.

If it is possible to make PA for the price of car and make it function for months without maintenance. Then it will tend to equip light infantry.

[Purple]

On a side note. If we abstract the technical problems of actually making power armor and keeping it in the field. What kind of equipment would be best used for it?

I am talking about optics, aiming assistance and things like that.