Big Red here with a question from "Eugene Tackleberry"...
So, TAKE FIVE!
“Big Red, other than the T-21 series helmet and the depth of draw analysis performed by the Ordnance Department, were there any other experimental designs that explored increased ballistics?
Good to hear from you Tack,
Yes, there was one other noteworthy experimental option explored by the Ordnance Department in 1945.
At the same time Ordnance was exploring altering the curvature of the helmet, which eventually became known as the T-21 experimental helmet, they had discovered from ballistic testing that the high pressure liners contributed nothing whatsoever to the ballistic efficiency of the helmet assembly.
Upon learning this information, the Detroit Ordnance District hypothesized what the M-1 would look like if the liner was eliminated and the suspension was attached directly to the helmet body.
Mr. E. F. Baldwin out of the Detroit Ordnance District Office developed a removable fabric suspension system like that used in the M-3 flak helmet.
The general idea being that a two-piece metal headband would be welded inside the helmet body and the suspension cradle and neck strap would then be attached by clips.
The helmet bodies were then altered based on the idea of replacing the weight of the liner body, approximately 9 ½ ounces, with the equivalent weight in steel. Experimentation showed that the helmet thickness could be increased by 25% or approximately 0.008-inch throughout and, when fitted with Mr. Baldwin’s suspension system, still not exceed the 3-pound weight limit for the helmet assembly.
Helmets of this design would have had superior ballistic resistance over that of the production version of the M-1 however, other than a few physical examples, there isn’t any readily attainable information on them. It would be interesting to see how the welded headband performed under ballistic attack as well as what the intended suspension system looked like. Perhaps sometime in the future documentation or a fully assembled helmet will be discovered.