Armor

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Harold Weiss by way of Terry Fritz <teslalist-at-qwest-dot-net>" <hweiss-at-new.rr-dot-com>

Hi All,

With all the talk about Kevlar and protective panels for the prop gap, as a 
former wearer of body armor, I know a little about their construction.

For soft armor, such as flak jackets, they use either polyethelene, Kevlar, 
or nylon.  The military flak jacket is constructed of multiple layers of 
ballistic nylon.  The layers of nylon are about 1/2" thick when sewn 
together. Polyethelene panels about 1/16" thick are tack sewn to the fabric 
to help prevent bunching of the fabric.  Bunched fabric loses it's 
protective properties.  My tests on a flak jacket stopped a .22LR, but 
failed to stop a 9mm 115gr FMJ at point blank ranges.  Kevlar and Spectrum 
(polyethelene) are used in higher threat vests.  In SWAT team vests 48 
layers are used along with titanium or ceramic plates.

In the military, I had to wear the kevlar/ceramic vests that could stop 
7.62mm.  In the OH-58 helicopter, we had problems with the torque meter 
gear exploding in the accessory gearbox on the engine. This gear was 
spinning at about 32-36,000 RPM, and when it went, it blew scrapnel thru 
the back seat area of the aircraft.  We had to keep the ceramic armor 
panels on the front seats at all times.  If we had passengers, they rode in 
the front seat, while I as crew chief, had to put on the armor vest and 
helmet to ride in the back.  It's fun when your aircraft is built by the 
deepest pocket/lowest bidder.

For something like the prop gap, I think 1/4" HDPE cutting board would do 
fine in catching the electrode chunks.  For a large ASRG, I would consider 
anything that could stop a 30-06 or better.

David E Weiss