Big Red here with a question from "Gny. Sgt Hartman"...
So, TAKE FIVE!
“Big Red, if the Army knew a helmet had a defect, why did they allow them to be issued?”
Fantastic question Gny. Sgt. Hartman
During its development, the M-1 helmet experienced a multitude of defects and performance issues ranging from the quality of steel to production practices. The Army Ordnance Department promoted an environment of continuous improvement by applying knowledge gained from the results of a multitude of experimental tests they ordered on variations of both steel making and fabrication techniques.
Among these results were quality issues that were determined to be “negligible defects”. A couple of the “negligible defects” you will come across while collecting the M-1 helmet are “age cracks” and “pin holes”.
Age cracks formed in the zones of the helmet which contained the highest residual stresses making them the most susceptible. Body cracks were triggered by weak spots in poor quality steel and normally formed in the vertical portion at the rear of the helmet body.
Edge cracks were triggered by notches left on the edge of the helmet by damaged trimming dies and normally formed in the visor area.
In 1943, firing tests were conducted in the Labs at Watertown Arsenal against helmets with stress cracks. Rounds were fired around both body and edge cracks as well as directly on cracks. It was determined that ballistic resistance was only lowered when a missile struck directly on a crack and that the reduction in ballistic resistance was only minimal.
Pin holes were the result of the application of the chin strap loop welds either by the manufacturer or at the time of repair or replacement. Firing tests were conducted to have rounds impact directly upon pin holes. The results of these tests concluded that the presence of a pin hole had little or no influence upon the helmets ballistic resistance. It was also discovered however, that the spot welds themselves lowered the resistance to ballistic impact to a slight degree regardless of the presence of a pin hole.
As the average age crack or the presence of pin holes were determined to have, at best, only minor influence on the helmet’s ballistic resistance, these defects were determined to be negligible. The Ordnance Department understood that from a morale point of view that the presence of either of these defects was undesirable however, because the Army was in desperate need of helmets and these helmets, cosmetic defects aside, met the standards of ballistic protection they were allowed to be issued into service.
Big Red Says!
FIVE'S OVER - MOVE OUT!