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big-red-says

M-1 Helmet Production Breakage IX – Necessity and Limitations

Big Red

Big Red here with a question from "Jerry Casale"...

    So, TAKE FIVE!

    Jerry asks,

    "Big Red, Woooah!, you can’t drop a bomb like that and not explain!

    Just how bad did things get? and What would have happened if the M1 design had failed?"

    Great to hear from you Jerry.

    Let’s start with how bad it got….

    You may recall I mentioned that the M-1 helmet was a product of experimentation, innovation and manufacturing happening simultaneously. As you read through the available documentation on the development of the M-1 helmet it becomes clear that necessity and limitations started the U.S. Army, and their chosen partners in industry, down a road littered with mine fields of the unknown.

    This road began with the manufacture of the M1917 “trench” style helmet body in February of 1941. The new M-1 “pot” design was adopted that summer and went into production September of the same year. The M-1 design was not studied or evaluated in any way as to the feasibility of economical mass production. It began as a Frankenstein pot pieced together from the best attributes of other helmets, which was then successfully formed from a single sheet of aluminum in the Armory of the Metropolitan Museum of Art. This aluminum shell was combined with a handmade liner and suspension that telescope fit inside completing the desired helmet. This proposed helmet was shown to the production engineers at McCord Radiator & Manufacturing Company following which Ordnance entered into discussion as to the feasibility of manufacturing the helmet in place of the M1917 currently in production.

    McCord accepted a contract for experimental dies they used to produce 200 sample helmets and shortly thereafter accepted a contract to mass-produce the helmet. In a letter dated August, 1945 McCord uses hindsight to declare that if they had known the magnitude of the helmet program at the onset that they would have insisted upon better facility to produce better steel. Perhaps the production run of the 200 sample helmets resulted in a false sense of confidence by all concerned because the reality of the time was that the M1917 helmet body, currently in production, was experiencing upwards of 25% loss to production breakage due to poor quality steel and poor manufacturing techniques.

    Notwithstanding the experience of McCord and Carnegie-Illinois, the Ordnance Department limitation of the deep straight sided pot shape of the design, the limitation that only Hadfield manganese steel be used, and the limitation on steel thickness in order to meet a finished weight limit, all contributed to the serious manufacturing problems that plagued the M-1. The loss due to production breakage during the initial M-1 contract was upward of 30%. This number increased when the weight limit was enforced and only became manageable as a result of trial and error experience gained by McCord and Carnegie, along with some metallurgical help from the Watertown Arsenal Laboratories regarding steel quality. McCord and the Ordnance Department came to a temporary agreement for a 30% breakage allowance, which afforded a tenuous hold on predictable levels of breakage. This predictability was lost when Sharon Steel and Schlueter Manufacturing entered the program with their own unique issues.

    The Metallurgists at the Watertown Arsenal Laboratories, who were not fully engaged until the problems were close to being out of hand, evaluated the situation and in rather short order noted the highly stressed nature of the design, coupled with multiple steel quality issues and poor fabrication techniques that were all contributing to the breakage problem.

    They also noted that there were no regulations specific to helmet steel quality which meant there wasn't a means for fabricators to evaluate quality of incoming steel and therefore no grounds to reject bad steel. Furthermore, there were no acceptable standardized test procedures for either determining steel quality or verifying ballistic resistance of a finished helmet.

    Arsenal records indicate that production breakage was at times as high as 35% and that in August 1942, intending to improve ballistic properties, Carnegie altered the steel formula resulting in a 7% increase in breakage. It was at this time the term “service cracking” was added to the helmet lexicon when 6,062 of 245,000 helmets that passed quality inspections prior to May 1943 were reported as unserviceable, after issue, due to cracking. Taken in total, at the best of times Ordnance was losing around 3 out of every 10 helmets they procured and at the worst of times they were losing 4 to 5 out of every ten.

    Now, what would have happened if the M-1 design had failed?

    It is entirely feasible that the M1917A-1 could have been resurrected in some capacity, although there seems to have been a general acknowledgement of the M-1 liner and therefore multiple investigations into ways in which the shape of the helmet body might be altered in a way that the level of residual stress could be reduced while still allowing for the use of the existing liner design.

    An example of this direction of thought was the T21 helmet project. The Master Armorer at the Metropolitan Museum of Art, Leonard Heinrich, fabricated versions of the T21 out of both non-ballistic and ballistic steels.

    The idea was to use anthropomorphic studies of the contour of the human head to reshape and minimize the size of the helmet in order to reduce residual stress and increase ballistic resistance while retaining the ability to accept the current production liner assembly.

     

    And Jerry,
    if your friends want to know how you gained your intel, tell em

     

    Big Red Says!

    FIVE'S OVER  -  MOVE OUT!


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