The Armored-Vehicle Protective-Mask 3 History - development of gas mask for use by military-tank personnel

CML Army Chemical Review, July, 2000 by Robert D. Walk

Masks for the Collective Protector

The M14 protective mask has a gray, 85 percent natural-rubber faceblank with a large plastic, flexible lens designed so that air enters the chin and deflects over the lens to prevent fogging. An air deflector was used and not a true nosecup. The inner surface is stippled (rough) to allow a better grip on the face and, thus, a better seal. A 2-foot hose supplied air to an M10A2 filter. The M10A2 filter was an M10A1 filter with an M1 canister coupling. The M1 canister coupling was an adapter that attached the filter to the M6 or M7 hose. The only reference to the M10A2 is the early 1950s; thereafter, it was the M10A1 canister with M1 canister coupling.

An M51/UR microphone mounted in front of the mouth inside the mask enabled communications. A wire passed from the microphone through the facepiece to a connector to plug into the intercom system. The M1 antidim kit was included to reduce fogging in the mask. The operator carried the mask in the M13 tank mask carrier. For long-term storage, the M6 faceform was used to prevent distortion of the mask.

Tests found the M14 mask was acceptable, but not as good as the standard M9A1 protective mask. Other deficiencies noted in the mask included the following:

* A soldier could not wear glasses with the mask.

* The outlet airflow was bad.

* The eye lens scratched easily.

* The eye lens had a distracting glare.

* The mask had a tendency to fog up.

The Chemical Corps worked to correct the problems.

The M14A1 (E56R2) (1960) mask included a nosecup capability; was constructed of black rubber (for low-temperature flexibility); and had smooth inner surfaces, better eye-lens adhesion, and improved eye-lens design. In 1961, atomic, biological, and chemical (ABC) protection was added to the nomenclature to make it ABC-M14A1.

The M14A2 (E56R4), adopted in 1961, improved the mask by adding a permanent C11 nosecup, eyeglass capability, M9 harness, and the E34 hood. This mask was retained until the AN/ARC-44-series radio sets were deleted from the inventory. This mask was standardized with Canada and Australia in 1967. To modify this mask for the new radio sets, the M51/R microphone was replaced with the M116G microphone and the mask became the M25.

The initial M25 was only a remicrophoned M14A2 for use with the ANIVRC-12-series radios. The M25A1 (E56R5) (1963) was an improved M25 by adding an eye-lens outsert for arctic use and improving the fit. The M25A1 mask took the U.S. Army into the 1990s. This mask was effectively an M24 with a different microphone, simplifying logistics and procurement. Problems with lens scratching from use with a tank's sighting systems never went away; therefore, research for a better mask continued.

Continuing Research

Other work in the 1960s involved adding an overpressure system for the MBT-70. The idea of overpressure, rejected during World War II, resurfaced in the 1960s. In an overpressure environment, soldiers working in the tank can be in relative comfort while operating the tank in a contaminated area. Every time the tank is fired, though, the overpressure can be lost when reloading the cannon, and overpressure doesn't help the soldier when rapid egress is required in a contaminated environment.