M5 Combat Mask

For more than a year thereafter the Army s standard service masks— both the M3 lightweight mask standardized earlier and its shortlived successor, the M5 combat mask—were made of neoprene. As in the case of any major change in specifications, there was an occasional hitch on the production lines. Some of these hitches were caused by the fact that batches of neoprene compound were not always uniform. A more critical problem arose when one contractor attempted to produce faceblanks for the complicated optical gas mask from neoprene. The neoprene stock refused to take molding acceptably, and nearly all the first batch of one thousand faceblanks failed to pass inspection. The contract had to be terminated. But with these exceptions, production of neoprene masks proceeded smoothly enough. 

Fig. 2-37. The M5 Combat Service Mask, the first U.S. mask with the canister placed directly on the cheek. The M5 mask was part of the personal equipment of the troops who landed at Normandy on 6 June 1944. Postwar tests indicated that it might have protected against respiratory exposure to the nerve agent tabun if the Germans had chosen to use it against the invasion armada. Photograph Chemical and Biological Defense Command Historical Research and Response Team, Aberdeen Proving Ground, Md.

The cutback coincided with the start of production on a new service mask, the M5-11-7 combat (or assault) mask. The CWS meant to ultimately replace this new item, a hoseless mask with a cheek mounted axial-flow canister and a new waterproof carrier, but at the outset scheduled only limited production with a single assembler. Firestone of Fall River. The principal production difficulties were in the assembly of components. New seaming and filling machines had to be installed for the Mil canister, an item radically different from the radial-flow canisters that had preceded it. The filters took the form of elaborately pleated shells of specially treated absorbent paper. Although a comparatively simple shell pattern was available, the CWS had also developed a pattern involving concentric pleats and wanted comparative field reports on the two types. Consequently, both types were produced. The concentric filter was considerably more troublesome to assemble. The M7 carrier, a complex item made of butyl coated duck, was a source of trouble from the start. The specifications, especially those for the waterproof closure, were such as to make for an inherently awkward assembly job. ... 

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