Re: Low-Tech Forces in DSII

Adrian spake thusly upon matters weighty: 

> >They'll punch through Kevlar like butter. So will stilletos, sharp 
> >spears, ice picks, teflon bullets, and a few other things. Kevlar 
> >weave is exceptionally permeable to sharp objects which force 
> >themselves between the fibers. Teflon is even better still because it

> >is slippery too. A bullet proof vest means you won't even feel a hit 
> >with a club or mace, but a stilleto will puncture you like a stuck 
> >pig (unless you have steel or plastic/ceramic inserts).
> 
> 
> Correct me if I'm wrong here, but people die from blunt trauma damage
> wearing "bullet proof" jackets (ie Kevlar vest) - the vest stops the
bullet
> from penetrating but not the kinetic energy applied to a small spot...
> which can break ribs, cause all kinds of nasty soft tissue damage, etc
etc.
>  That's why they put trauma plates into kevlar battle armour - to stop
> blunt trauma damage.
> 
> I imagine that someone wearing a kevlar vest would be plenty hurt if
you
> whacked him in the chest with a mace.  Hard enough, and you'll still
break
> ribs at least...

Yes and no. The point of the Kevlar vest is distribution. Whereas you 
might not be able to take the impact of a bullet on an area about .38 
of an inch in diameter, you may well take that same force applied 
across an area 2' in diameter (your sternum). The weave distributes 
the force over the area. Do you still get hit with the force? Well, 
one of the laws of conservation of energy says "yeah, mostly." but 
a bruise with a chance of a broken rib is better than a bullet wound. 
I imagine (was it in one of the lethal weapon movies that Mel Gibson 
took a shot in the chest and it looked like it hurt and burned a bit) 
that getting whacked with a shotgun would hurt. I've worn a Vietnam 
era vest and taken a crack in the ribs from a 4 battery mag light and 
it stung but didn't break ribs. Swung harder, it might have, but I 
doubt it. The area the force is distributed over was enough to hurt, 
but with the vest, that is about it. Now, put points on your Mace and 
I'm singing another tune. 

I was under the impression the trauma plating was added to stop the 
rounds too hot for the Kevlar alone - assault rifle rounds, some SMG 
rounds (not all 9mms come from short barrells), and (if you have the 
heaviest armour) heavier things. Note that shotguns hurt but that is 
about it. Small pistols hurt, large pistols may give you a bruised or 
broken rib. I imagine an assault rifle round would hurt a lot. But a 
darn site better than being perforated. Especially with a round 
tumbling about (once, as they tend to) inside your body. 

I recall a Grenada story about a US Marine taking a 5.45 or 7.62 mm 
Soviet slug from an AK series weapon IN THE FOREHEAD. He had his 
Kevlar helmet on. It gave him wicked whiplash (so he was 'casualtied' 
for weeks) but he survived without injury otherwise. And he still has 
the bullet. (Or maybe this is urban myth...)

I have an excellent book by osprey entirely on body armour which I 
will reference if I can find it to anyone who mails me. Also, several 
RPGs (Cyberpunk and the later edition of Traveller (TNE)) have done 
some excellent research in ballistics, bullet damage, and the nature 
of firefights. 

Tom.  
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Thomas Barclay		     
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