Big Red here with another question from "John Connor"...
So, TAKE FIVE!
John asks,
"Big Red, I got a two part question for ya on ballistics.”
All right, let's take 'em one at a time,
“Sweet…
First, if a thicker helmet means higher ballistics and McCord had to make a thinner helmet to stay at the maximum weight, how did the helmet meet the ballistics test?"
Short answer John, it didn’t…
The original "ideal" criteria for the M-1 ballistic test required helmet bodies to "resist penetration" from .45 caliber ball ammunition impacting at 800 fps (feet per second). After adjustments were made to keep the helmet assembly at a maximum weight of 3-pounds, the Army Ordnance Department altered the requirement of the ballistics test to match the resistance of the thinner helmet.
The new standard for ballistic testing would require a helmet body to "resist penetration" from .45 caliber ball ammunition designed to travel at 725 fps with a maximum indention of 1 ¼ inches.
“Wow, that seems sorta…”
Before you come down too harshly on the Army here John, they did consider the men that would be wearing these helmets before they made their final decision.
Understanding that limits upon weight and ballistic properties are self-contradictory, the Army conducted tests on helmets of various final thicknesses at Watertown Arsenal Laboratories.
What the Engineers at Watertown learned was reducing the steel disc from 0.046 to 0.044 inches thick also reduced the helmet thickness from 0.037 to 0.035 inches, on average, making the helmet lighter. They also determined that helmets thicker than 0.037 inches did not perform significantly better than a thinner one.
Basically, they found a middle ground between weight and ballistic resistance. Furthermore, McCord and the Army Ordnance Department agreed to allow helmets to be a tad overweight in the interest of higher ballistic resistance.
“Okay that’s cool.
So, do you know how they did the test, like what the testing looked like? "
You betcha, take a look at this……………
and John,
Big Red Says!
FIVE'S OVER - MOVE OUT!
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