Specific: Delivered with open and closed
cab (44 kb)
as part of the MDAP 1951/55.
Historical: Design and development began in
1939. Diamond T´s model, based on a 4 ton chassis,
became most successful and was adopted in 1940.
Developed for issue to all arms and services of the US
forces as a recovery unit for automotive vehicles and as
a general mobile hoist.
Like most US Army load capacities, the 4 ton rating was
an underestimate of the vehicle's capability. This was
intended to ensure that the designated load could be
carried on rough ground. The strength of the vehicle's
construction allowed it to carry twice this load on good
roads but the US rating remained part of the vehicle's
The recovery vehicle was sometimes assessed as an
equivalent to the British and Canadian light recovery
vehicles. In practice it was in an intermediate class. It
was capable of recovering trucks heavier than those a 3
ton gantry lorry might handle but not as heavy as the
loads recovered by Scammell, the US Mack or Ward LaFrance.
The Diamond T carried a heavy duty set of Holmes W45 Twin
Boom Wrecker gear. This gear was designed in the
inter-war period for civilian breakdown trucks, like the
similar Gar Wood system. One boom could be used to lift a
disabled vehicle out of a ditch on one side of the
recovery vehicle while, if necessary, the boom on the
other side could be swung out and anchored to a
convenient solid object to act as a stabiliser. Either
boom could operate as a normal crane but together the
booms provided a greater lifting capacity at the rear of
the vehicle for suspended tows.
As with most of the military wreckers', the Diamond
T was fitted with stabiliser legs on each side to keep
the vehicle upright while the boom was being used for
side lift. This also saved the necessity of using the
opposite boom as an anchor and overstraining the
structure and supporting cables. The Holmes gear booms
were tubular with reinforcing trusses made from steel
The lifting winches were power operated and were rated at
5 US tons each (10,000 lbs.). Linked together, a lift of
10 US tons was possible, but to suspend a towed load of
this weight would exceed the truck's chassis loading. The
US Army system of recovery was to use the boom jibs for
recovery tasks which with British equipment would be
carried out using the chassis winch. The Diamond T 4
tonner carried a front mounted Gar Wood winch rated at
15,000 lbs. (7½ US tons), i.e. less than the combined
rating of the two jib winches.
More than 6.000 wreckers produced as closed cab from 1940
until late 1942, and as open cab from late 1942 until
Approx. 25 % of the vehicles were mounted with ring mount
M32 (closed cab) or M36 (open cab) for anti-aircraft
Length: 7.42 m (289 inches).
Width: 2.50 m (97 inches).
Height: 3.06 m (119 inches).
Weight: 11.875 kg (26.118 lb.).
Engine: Hercules RXC 6-cylinder, 8.668 cm3 (529 cubic
inches) displacement, liquid cooled.
Horsepower: 106 at 2.300 rpm.
Transmission: 5-speed (OD top) gearbox.
Transfer case: 2 speed.
Electrical system: 6 volt, starter 12 volt,
Brakes: Air (Bendix-Westinghouse).
Tyres: 9.00 - 20.
without preparation: 0.6 m (24 inches).
with deep water fording kit: N/A.
Fuel type: Petrol.
Fuel capacity: 225 liter (50 gallons).
Range: 215 km (134 miles).
Crew: 1 + 1.
Additional: 7.5 ton front winch
capacity, Gar Wood type 3-U-615. Unlike the later M
series wreckers, which used their air brake system as an
air source for tyre inflation etc., the Diamond T 969
left the factory with a self-contained air compressor
mounted between the booms.