Diamond T 980 The Diamond T 980 was a heavy tank transporter developed early in World War II by the Diamond T Company . History . Designed as a heavy prime mover for tank transporting , the 980 was the product of the Diamond T Company in Chicago . In 1940 the British Purchasing Commission , looking to equip the British Army with a vehicle capable of transporting larger and heavier tanks , approached a number of American truck manufacturers to assess their models . The Diamond T Company had a long history of building rugged , military vehicles for the U . S . Army Quartermaster Corps and had recently produced a prototype heavy vehicle for the US Army which , with a few slight modifications met British requirements and an initial order for 200 was very quickly filled . The result was the 980 , a 12 - ton hard - cab 6x4 vehicle which proved to be one of the most successful and memorable in its class . Powered by a Hercules DXFE OHV inline six diesel engine developing with Bosch fuel injection , or the Hall - Scott 440 OHV inline - six gasoline engine ( the largest gasoline engine in any WW2 military truck ) of , and geared very low , it could pull a trailer load of up to , and proved capable of the task of moving the heaviest tanks then in service . With a single dry - plate clutch , It had a four - speed manual constant - mesh transmission plus a similar three - speed auxiliary gearbox , for a total of twelve forward and three reverse speeds , driving through Timken double - reduction differential s . Airbrake s were standard . The electrics were 24 - volt . Top speed was , and with fuel , maximum range was . Wheelbase was , length , track , and height . Steering was manual , with no power assist . The weight was , with GVW of A winch of capacity , chain drive n off the top of the auxiliary transmission and intended mainly for hauling damaged tanks aboard trailers , was mounted behind the cab . The 981 was the same chassis with open cab ( no top ) and cargo box . Both the 980 and 981 used a cab design similar to the 4 - ton truck . Service . Production began in 1941 . The first batch of the vehicles was received in Britain in 1942 and very quickly demonstrated their rugged reliability in the British campaign in North Africa . Battle - damaged tanks needed to be quickly recovered , often under hostile fire , and returned to workshops for repair . The Diamond T , with its well trained Royal Army Service Corps crew and powerful engine and winch , could accomplish this , even in the harshest desert conditions . 5 , 871 were built by 1945 and were used by virtually every Allied army in every theatre of WWII . The British Army took delivery of around 1 , 000 during the war years . It suffered from " very limited off - road performance " as a result of only the two rear axles being driven . Today many of the 60 year - old Diamond T ' s can still be found in private ownership in Britain and frequently appear at historic vehicle shows . U . S . nomenclature . This combination unit is referred to as the M19 tank transporter , consisting of the M20 tractor and M9 24 - wheel trailer . In the nomenclature system used by the U . S Army Ordnance Corps Supply Catalog this vehicle is referred as the G159 . It was superseded by the M26 , which would use the same Hall Scott 440 engine . After the introduction of the M26 , the U . S . relegated M20s to ammunition hauling , for which they proved " tremendous " .