2½-ton 6x6 truck
The 2 1⁄2-ton 6x6 truck was a class of medium trucks designed for the US Armed Forces. The basic cargo versions were designed to transport a 5,000 lb (2,300 kg) cargo load over all terrain in all weather. Widely used in World War II, the "deuce and a half" continued to be the US standard medium duty truck class after the war. Five different designs were standardized by the U.S., two were also standardized by Canada. One was built primarily for Lend-Lease export during World War II, and many others have been exported to smaller militaries. The US began replacing 6x6 trucks with the 4x4 Light Medium Tactical Vehicle (LMTV) in 1991.
In 1939-1940 the US Army Ordnance Corps was developing a 2 1⁄2-ton (2,268 kg) load-rated 6×6 tactical cargo truck that could operate off-road in all weather. This size truck could carry a full infantry squad, tow light artillery, and yet be built in large numbers on moving assembly lines. Dump, semi-tractor, tanker, and other bodies were also planned.
Yellow Coach (a GM company), Studebaker, International Harvester, and REO submitted designs, all except REO's were accepted and in production by 1941. Yellow’s CCKW became the Army standard, International’s M-5-6 became Navy and Marine Corps standard, and Studebaker’s US6 was built for export to allied countries. Reo built the Studebaker design.
In the late 1940s the military needed a new standard truck. Chrysler, GMC, REO, and Studebaker submitted designs. The REO design was standardized for all services as the M35, and continued standard until 1990. The GMC was classed as substitute standard M135 in the US but became standard in Canada.
As the standard US Army design during World War II, over 560,000 were built, more than any other US vehicle except the "Jeep". By 1947 there were over 20 standardized bodies, and many more special modifications.
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