Big Red here with a question from "Barney Fife"...
So, TAKE FIVE!
"Big Red, How did they finally get all the M-1 production breakage problems under control?"
Great hearing from you Barn,
First, for those who haven’t followed our breakage discussion, I will provide an abbreviated history on how we arrived at this question…
When American helmet production resumed in preparation for the war in Europe, steel making and helmet fabrication proceeded under the assumption that doing so would be just like any other commercial venture. The specifications for helmets called for the use of Hadfield manganese steel because it is tough, hard and well suited for personal armor. It is difficult to make and even more difficult to draw into shape on a press.
When the design of the M-1 was presented to private industry, most professionals, including metal working experts, feared it could not be done. That shaping a piece of Hadfield steel into such a helmet in a single press operation would prove impossible.
Much of the steel used in the early stages of helmet work, though entirely satisfactory for other armament work, proved this fear real as it was too brittle to stand the severe cold working necessary to form the 7-inch draw in a single pressing. The need for the new helmet was deemed desperate enough to forego any initial evaluation to determine the factors necessary to successfully mass produce the helmet which resulted in experimentation, innovation and manufacturing to occur simultaneously.
The McCord and Carnegie team, more through trial and error and less through scientific evaluation, managed to produce the helmet at a sustainable level until the introduction of Sharon’s helmet steel. The addition of this helmet steel to both fabricators tipped the scale away from predictable losses plunging the helmet program into its darkest hour as breakage and “service cracking” almost made continuing the M-1 helmet, as it was, prohibitive.
Now ya see Red, that’s what I’ve been tryin to say. You gotta situation like this here helmet problem of yours, you don’t wait around. You attack it straight on and….
I hear ya Barn, I hear ya.
Army Ordnance needed to find a way to stabilize the situation long enough to formulate a plan to reduce or eliminate the breakage problem. They did this by contracting McCord to double their current production. The initial helmet contract, which had included liner assembly, had just concluded so McCord accepted the contract, utilized the warehouse space previously set aside for liner assembly and duplicated their helmet production operations. The new line went into production in late February 1943 and achieved sustained output of approximately 750,000 helmets per month by March.
This action alone seems to have allowed Army Ordnance to keep “heads above water”, as the saying goes, while they evaluated the situation. By late 1942 early 1943, as breakage losses reached fever pitch, many persons involved in the M-1 program had begun to believe that continuing the M-1 helmet, in its current form, was untenable.
Metallurgists at both the steel suppliers and fabricators were at a loss regarding the breakage problem and approached Army Ordnance with a request for outside help. At this juncture, Army Ordnance contacted the Watertown Arsenal Laboratories and requested metallurgical assistance and in April of 1943 they got it.
Abraham Hurlich or “A. Hurlich”, as he is identified on countless Arsenal reports, quickly began collecting and assessing information regarding the current helmet problem. He and the Watertown Arsenal Lab team hypothesized that there had to be a correlation between production breakage and service cracking later verified in association with the discovery of steel defects and poor fabrication techniques. Correspondence on the issues noted that the conditions discovered should never have been allowed to exist.
Under Hurlich’s expert guidance, all the necessary investigative and experimental development that should have taken place prior to the mass production of the helmet, had the urgent necessity of the war not warranted bypassing these steps, were conducted at this time in order to overcome the failings of the helmet’s design in combination with imposed criteria and limitations.
It was quickly assessed that there were no specifications or process controls over steel quality and manufacturing to the extent necessary to successfully fabricate the M-1 without breakage. It was discovered that there were no standardized rules for inspection of steel, that the existing tests were woefully lacking and that the .45 caliber ammunition used to test helmets and helmet steel were attained from stocks of service rounds which resulted in anomalous ballistic limits. Further it was determined that the highly stressed nature of the helmet, even with steel and fabrication techniques that were flawless, was in itself enough to cause breakage.
Therefore, steel quality and helmet fabrication factors were scrutinized through experimental runs of both steel and helmets. Steel was made under various circumstances of heat treatment in the forming of the initial ingot and sheet rolling phases as well as from differing formulas until the most consistent result was identified. Fabrication techniques were analyzed resulting in the best selection of tooling steel as well as the implementation of preventative maintenance programs to ensure tooling health. Residual stress was addressed with an edge-annealing process and minor changes in helmet design to better accommodate the necessary spot welding operations in assembly.
By the conclusion of their analysis, Abe and the Watertown Arsenal Lab team knew where high levels of stress existed within the finished helmet. They determined what conditions within the steel would yield a good, average or poor finished helmet and they understood the fabrication process clearly enough to know what practices needed to be changed to reduce breakage and cracking. They developed appropriate specifications for determining steel quality, standardized ballistic testing and established best practices in regard to both steel making and fabricating.
Carnegie-Illinois, at their own expense, purchased an electric-arc furnace to better control steel making while Sharon Steel altered their manufacturing conditions to better form their ingot while both companies adopted best practices in their rolling operations effectively eliminating the occurrence of body cracks.
McCord and Schlueter updated die material to a high-carbon high chromium air-hardening steel. Asserted a high level of quality control over the alignment, cleanliness, lubrication and general health of their tooling dies and implemented changes in spot welding technique along with the addition of an edge-annealing process which effectively minimized service cracking.
In short, the work performed by Abe Hurlich and the team of engineers and metallurgists at Watertown Arsenal Laboratories in cooperation with both steel makers and helmet fabricators raised performance through the combination of proper tools, techniques and steel quality to a level that rejects due to breakage and service cracking was reduced to only a few percent.
Big Red Says!
FIVE'S OVER - MOVE OUT!
Nice blog! But you should of Put Andy in it ;)
-farewell form Jack.
Leave a comment