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Allis-Chalmers M-7 Snow Tractor (G194)

M-7 Snow Tractor, 1944 Allis-Chalmers. Photo: Courtesy of Dave Klink
M-7 Snow Tractor, 1944 Allis-Chalmers. Photo: Courtesy of Dave Klink.

The M-7 Snow Tractor, manufactured by Allis-Chalmers, is a small half-track, intended for operations in show covered terrain. The tractor was motivated by the US Army Air Forces need for rescue capability in northern areas where reaching a downed crew might entail cross-country travel in snow. The M7 may be used for either highway or snow travel as the front axle can be equipped with either wheels or skis. Because of its relatively low center of gravity, the M7 tractor can easily climb steep slopes, depending on the traction available, and the load being pulled.

Power is supplied by a 4-cylinder, liquid-cooled, 4-cycle, L-head, gasoline engine from the Willys Model MB jeep with a maximum rated horsepower of 63 at 3900 rpm. The synchromesh transmission is also common to the Willys MB, but there are two modifications which must be made to a standard Willys MB transmission for use in the Snow Tractor M7 because of the oiling system and accessibility of shifting lever when installed in the M7 tractor.

The body is divided into two compartments, with seating room for the driver in the front compartment and for one passenger in the rear compartment. White seat cushions and back cushions with padded springs, are provided.

In development, the tractor was known as the T26. The T26E4 version of the Snow Tractor was standardized as the M7 in August 1943.

Find additional photos and hi-res versions of the M-7 Snow Tractor at the Olive-Drab Military Mashup.

Characteristics of the M-7 Snow Tractor

Manufacturer Allis-Chalmers
Seating Driver plus one passenger
Engine Willys Model MB, 4-cylinder, liquid-cooled, 4-cycle, L-head, gasoline
Transmission 3 fwd speeds, 1 rev, synchromesh 2nd/3rd, mated to two speed auxiliary transmission/transfer case
Wheelbase (with wheels) 81 in
Length, over-all (with skis) 13 ft 7 1/2 in
Length, over-all (with wheels) 10 ft 11 in
Width, over-all (with skis) 5 ft 3 in
Width, over-all (with wheels) 5 ft 3 in
Height, over-all (with skis) 5 ft 3 1/2 in
Height, over-all (with wheels) 5 ft 4 in
Wheel size 4:00x15 in
Weight of vehicle, empty 2,620 lb
Weight of vehicle, with personnel 3,120 lb
Ground clearance (with skis) 12 3/4 in
Ground clearance (with wheels) 13 3/4 in
Pintle height 15 3/4 in
Approach angle (with skis) 40 degrees
Approach angle (with wheels) 60 degrees
Departure angle (with wheels or skis) 60 degrees
Max speed 3rd gear, high range 41 mph
Minimum turning radius 15 ft
Fording depth 30 in
Maximum drawbar pull 1,000 lb
Maximum grade ascending ability 75 per cent
Miles per gallon (at 20 mph without load) 15 mpg
Cruising range (at 20 mph without load) 160 miles

Table data from TM 9-774. 31 January 1944.

The M7 Snow Tractor was paired with the specially designed M19 one ton snow trailer. Use the link to download the datasheet for the M19 trailer.

Manuals for the M-7 Snow Tractor include:

  • TM 9-774 Snow Tractor M7 and 1-Ton Snow Trailer M19 (January 31, 1944)
  • TM 9-1774 Ordnance Maintenance: Snow Tractor M7 and 1-ton Snow Trailer M19 (April 17, 1944)

M-7 Snow Tractor Photo Gallery

M7 Snow Tractors parked at Camp Hale, CO, the training headquarters of the Tenth Mountain Division, circa 1943-1944
M7 Snow Tractors parked at Camp Hale, CO, the training headquarters of the Tenth Mountain Division, circa 1943-1944.