World War II Database

Contributor: Alan Chanter

ww2dbaseThese 45-ton tank transporters were a truck-trailer combination. They were originally built to fill a British order under the Lend-Lease scheme, and the design was later adopted for service with the US Army, standardised in 1942 as the M19 truck-trailer. In British service, however, they were known merely as the Diamond T, from the name of the company that made the trucks.

ww2dbaseThe trucks were Model 980 12-ton hard-cab 6x4 trucks built by the Diamond T Company of Chicago, Illinois, United States. The US Army designated the trucks "M20", while the British designated them "Diamond T Tractor 6x4 for 40 ton Trailer". In broad terms, these trucks were more useful as supply vehicles, rather than as recovery units, since their cross-country ability was limited. Nevertheless, they served admirably in taking tanks from railheads to forward units, back to repair facilities, and in similar tasks. Each of the 6x4 tractors had a small cargo bed located above the rear axles which was usually filled with concrete slabs to give more weight and grip. The crews of the vehicles frequently used the beds area as sleeping and storage areas, each covered by a canvas tilt.

ww2dbaseThose in US Army service used M9 trailers built by Fruehauf Trailer Corporation, Pointer Williamette Co., Winter-Weis Co., and Rodgers Brothers Corporation. Those in British Army service used "40 ton Trailer British Mk. I (Crane)" trailers built by Cranes Limited of Dereham or "40 ton Trailer British Mk. II (Dyson)" trailers built by R. A. Dyson and Company of Liverpool. All of these trialers were provided with ramps for loading at the rear end and with fail-safe air brakes. Loading of tanks could be done either by the tank's own power or by a rear-mounted winch on the truck. The trailers had a maximum payload of 90,000 pounds (40,823 kilograms).

ww2dbaseBetween 1941 and 1945, 6,554 trucks were built by Diamond T, and 5,871 truck-trailer combinations were put into service. About 1,000 of the truck-trailer combinations were in British Army service, while the remainder served with the Americans.

ww2dbaseUltimately the M19 tank transporters' poor cross-country ability led the US Army to press for the development of a more specialised vehicle with improved mobility and better recovery equipment. Development undertaken by the Knuckey Truck Company resulted in the M25 transporter being standardised for front line service in June 1943, though M19s would remain in service in rear areas through the end of the war. British Army continued to operate Diamond T truck-trailers until superseded by the Thornycroft Antar tractors in early 1950. Many of them would remain in both military use with other nations until well after the war.

SPECIFICATIONS

M20 Truck

Machinery	Hercules DFXE 14,700cc 6-cyl inline diesel engine rated at 185hp
Suspension	Beam axles on leaf springs
Crew	2
Length	7.11 m
Width	2.59 m
Height	2.57 m
Weight	12.0 t
Speed	37 km/h
Range	482 km

M9 Trailer

Suspension	Front: trailing beams; Rear: center pivot beams
Length	9.04 m
Width	2.90 m
Height	1.45 m
Weight	9.9 t

Photographs