TWO TRACTORS proved their worth pulling petroleum tankers during the Iraq war. One is a Freightliner conventional and the other a cabover from Stewart & Stevenson.
Based on the FLD-120, Freightliner's tractor is designated the M915A3 by the US military and is intended primarily for on-road use. It has a daycab constructed of aluminum and sheet-molded-compound material. Cab features include Bostrom seats, air-conditioning, and an adjustable steering wheel.
The M915A3 is powered by a Series 60 Detroit Diesel engine rated at 430 horsepower. Also part of the drivetrain is an Allison six-speed automatic transmission and Meritor drive tandem. The Freightliner TufTrac suspension has a 40,000-lb capacity.
In addition to MeritorWABCO's antilock braking, the M915A3 was specified with the Eaton VORAD Collision Warning System. Other components include a Holland two-way oscillating fifthwheel, 100-gallon fuel tank (providing a 600-mile range), Accuride wheels, and Michelin 11R22.5 tires.
A relatively new player in the truck manufacturing sector, Stewart & Stevenson holds the contract for the FMTV (Family of Medium Tactical Vehicles) line of cabover trucks, which includes the five-ton M1088A1 tractor.
Designed with off-road capabilities, the tractor has full-time four-wheel-drive, Eaton's Central Tire Inflation System, and MeritorWABCO antilock braking. Michelin 395/85R20 XML all-terrain tires contribute to good tracking off road.
Power comes from a Caterpillar 3126 diesel engine rated for 330-hp at 2400 rpm. Among other drivetrain components are a seven-speed Allison automatic transmission and ArvinMeritor axles.