The M-123 Truck, Tractor, 10-Ton, 6x6 is part of the G-792 series of vehicles which includes the M-125 Truck, Cargo, 10-ton, 6x6. The M123 is a tractor for hauling semi-trailer loads such as heavy vehicles (tanks, bulldozers) or ammunition or other supplies. Its gearing restricts it use to off-road field activity, not line haul.
This huge tractor was manufactured by Mack from 1955 to 1957 (the M123 series) and 1965 to 1969 (M123A1C), the successor to the M26 'Dragon Wagon' tractor. One or two winches, depending on the variant, were mounted behind the cab, used to draw loads onto a trailer or a trailer onto the fifth wheel. Variant differences included the engine, fifth wheel height, and details like a warning beacon, clearance and turn signal lights, and access steps. Tires were 14.00x24 inch.
Today in WW II: 15 Oct 1940 In the heaviest attacks of the Blitz so far, Birmingham and Bristol suffer while 400 bombers hit London for six hours. Exhausted RAF puts up only 41 fighters, shooting down only one bomber. More↓
The C variants had a single rear winch and low mounted fifth wheel. The M123D was the same as the M123C, but with dual rear winches. Later M123 variants were assembled by Consolidated Diesel Electric Company (CONDEC) from Mack components. After total production of approximately 4,000 vehicles, the M123 10-ton tractor was superseded by the heavier and more powerful Oshkosh M911 C-HET tractor.
For transport, the overall height can be reduced to 93.0 inches (2.36 m) by lowering the windshield and by removing the floodlight, spare wheel, spare wheel davit, trolley tracks, level wind trolleys, hydraulic control handle, and operator's cab cover.
To assist with operations during conditions of limited visibility, the M123 is equipped with a swivel-mounted floodlight on a stanchion at the left rear of the cab.
M-123 Truck, Tractor, 10-Ton, 6x6 Manuals and Documentation
Some of the manuals for the M-123 Truck, Tractor, 10-Ton, 6x6 are:
ORD 7 SNL G792 (31 January 1958) Section I, LeRoi engine parts.
TM 9-8002 (1 November 1955)
TM 9-8003-1 (25 June 1956) Ordnance Maintenance for Engine, Engine Accessories and Clutch
TM 9-2815-213-34 Cummins V8-300 Maintenance
TM 9-2320-206-10 (29 April 1977) Operator's Manual
TM 9-2320-206-10 (8 December 1978) HR Hand Receipt
TM 9-2320-206-12 (4 February 1960) Supersedes TM 9-8002 & ORD 7 SNL G792
TM 9-2320-206-20 (22 October 1971) Organizational Maintenance
TM 9-2320-206-20P Parts
TM 9-2320-206-34 Direct & General Support Maintenance
TM 9-2320-206-34P (6 March 1972) Direct & General Support Maintenance Repair Parts & Special Tools List
LO 9-2320-206-12 Lube Order
Thanks to Corjan de Wit of Middelburg, the Netherlands, you will find TM 9-2320-206-12 (M123 and M125) at the linked page.