Scale mail in the modern age

[green slime]

Some people are already arguing that the RPG is the primary weapon of insurgents, and assault rifles are merely support weapons, so I think heavily armored infantry would quickly go up in smoke -- if they didn't overheat before they even got into combat.

Mobility and perception are very, very important in modern warfare.

Except that RPG's are not that easily carried around either, nor are their rounds. And they aren't rapidly reloadable.

The armoured infantryman isn't about to go up in a puff of smoke any time soon.

 

[Umbran]

So a gunshot should be able to knock someone over about as well as a javelin, if we're generous. The real difference is that the small, fast bullet has much more kinetic energy than slower weapons, so it has more destructive power.

Your typical 9mm round has a mass of about 8 grams. From a modern weapon, it may have a muzzle velocity of, oh, 1000 meters per second. That makes for a total momentum of 8 kgm/s. The arquebus round you mentioned would have roughly 1.5 times as much momentum, and the crossbow bolt about 60% as much momentum as the bullet.

Your average man has a mass of about 70 kilograms. If all the bullet's momentum is transferred to the body, that body will end up moving at roughly 0.11 meters per second. That is about 4 inches per second.

Note that the energy goes like the velocity squared. So, while it is lighter, the bullet has about twice the kinetic energy of the arquebus round, and thirty times the energy of the crossbow bolt.

 

[mmadsen]

Except that RPG's are not that easily carried around either, nor are their rounds.

Please read the article or the Wikipedia entry. An RPG-7 launcher weighs 15 lbs, and fragmentation rounds weigh 4 lbs. (HEAT rounds weigh 6 lbs.)

A Dragonskin vest, on the other hand, weighs 20 lbs more than the 28-lb Interceptor body armor currently issued -- or 48 lbs, roughly as much as an RPG launcher with six frag rounds. A full suit of Dragonskin armor would be prohibitively heavy and still would not offer any meaningful protection against RPGs.

Edit: Those weight numbers came from this article, which appears to be in error. Another article noted that the Dragonskin was only a few pounds heavier. Of course, a full suit of either would be much, much heavier -- and hotter -- than a vest.

 

[Schmoe]

A Dragonskin vest, on the other hand, weighs 20 lbs more than the 28-lb Interceptor body armor currently issued -- or 48 lbs, roughly as much as an RPG launcher with six frag rounds. A full suit of Dragonskin armor would be prohibitively heavy and still would not offer any meaningful protection against RPGs.

Edit: Those weight numbers came from this article, which appears to be in error. Another article noted that the Dragonskin was only a few pounds heavier. Of course, a full suit of either would be much, much heavier -- and hotter -- than a vest.

From the Pinnacle Armor website, the strongest suit of Dragon Skin armor weighs only 17 lbs in a normal configuration (front and back protection), so I'm not sure where all the conflicting information is coming from.

Also, from what I've been able to read, it seems that one of the primary flaws the Army has found deals with long-term environmental effects on the armor. That's just a hunch, but based on the Army's desire to test only several weeks after unpackaging the armor, and Pinnacle's desire to test immediately, as well as several mentions of heat-treating the armor prior to testing.

No armor will ever provide 100% protection against 100% of enemy ordnance (tactical nukes, anyone?), but I sure would feel safer with some of the modern armor available!

Great information in this thread, everyone.

 

[mmadsen]

As long as we're discussing high-tech, full-body armor, I suppose we should all (re-)watch Troy Hurtubis discuss his Trojan body armor, which he designed to be lighter than his infamous grizzly suit.

Addendum: If you enjoyed that first video, you should enjoy this second video too. I suppose he seems craziest in the Trojan Stealth video.

 

[Andor]

And next year... Mechs!

 

[mmadsen]

Watching the two shows together made me think that armor really has come full-circle. It took a while for the technology to catch up with the ability to stop armor-piercing rounds. But now it seems that the technology is accessible once again.

Looking forward, at least for the short term, it should be far, far easier to increase the power of firearms than to increase the protection afforded by armor. After all, we're using much less powerful rifles than 60 or 100 years ago.

The difference today is the sociology of modern armies. Whereas in medieval times it was acceptable to have heavily armored, socially priveleged knights with heavy armor, yet have masses of troops that were poorly equipped, in modern day armies of democratic nations such a division of privelege is less palatable. That makes the economics of protecting troops a more difficult issue.

We have some of our warriors in multi-million-dollar fighter jets. The real difference is that those warriors aren't making the decision to equip themselves at the expense of other warriors; there's an entire political process for allocating those resources.

 

[Phlebas]

Watch footage of people being shot. They do not recoil backwards as in hollywood movies. They crumple.

thats because the bullet goes straight through...

If it hit a bone or something it would break it - thats a LOT of force required and you WOULD move backwards if the armour stopped it and transferred the force

 

[Schmoe]

thats because the bullet goes straight through...

If it hit a bone or something it would break it - thats a LOT of force required and you WOULD move backwards if the armour stopped it and transferred the force

I think you're also discounting the effect of the armor in dissipating and absorbing the energy from the bullet. I've seen footage of a man in armor being hit by a sniper rifle. Basically, he reeled back sideways and fell in place. He certainly wasn't blown backward by the shot.

 

[mmadsen]

thats because the bullet goes straight through...

While you're right that a bullet that penetrates confers less momentum than one that is stopped (by armor or flesh), you've ignored the physics presented earlier.

A bullet hits with as much momentum as the recoil felt by the shooter. That is not a lot of momentum, and it is certainly not enough to knock someone around.

If it hit a bone or something it would break it - thats a LOT of force required and you WOULD move backwards if the armour stopped it and transferred the force

High kinetic energy and high momentum are two different, but related, things. A musket ball capable of shattering a man's femur can have less momentum than a thrown spear, which can have less momentum than an NFL linebacker.