Western Star Trucks has designed a 40-ton dump truck that it says is a lower-cost alternative to traditional haul trucks. The extra-heavy-duty vehicle is based on a 6900XD with a commercial-style cab, and an off-road chassis with a standardized power train and an integrated dump box that cost less to buy, operate and maintain.
Aimed at quarry and dirt-haul operations with well-maintained haul roads, the three-axle 6900XD 40-ton dump can haul the same loads as 35- to 40-ton articulated and rigid dump trucks but uses about 35 percent less fuel. Fuel consumption of 7.13 gallons per hour has been recorded on hauls of more than 12 miles, the company said. The truck's top speed is 43 mph.
The vehicle costs "considerably less" than a traditional haul truck because it is an uprated on/off-highway truck instead of a downsized "yellow iron" machine normally used in this payload range, a Western Star spokesman said. The 6900XD's engine, transmission, axles, wheels and tires are long-lasting and efficient, but replacement parts are less costly and easier to obtain. For example, its high-pressure 14R25 earthmoving tires are priced about 40 percent less than larger specialty tires needed by haul trucks.
The 6900XD's 14-liter 475-horsepower Detroit Diesel Series 60 runs through a 6-speed Allison 4500 RDS automatic transmission. The Axletech tandem rear axles have planetary-gear reduction and are combined with a high-articulating Chalmers 800 mechanical suspension for a capacity of 110,000 pounds. A 28,000-pound non-driving front axle needs no drop boxes and transfer case, and its flat-leaf springs are simple and easy to maintain. Brakes are a simple and low-cost dry drum design that are effective but easier and cheaper to maintain than the wet discs used by haul trucks. A Jacobs Engine Brake is standard.
The severe-duty galvanized steel cab is air suspended and comes with a multi-adjustable air-ride seat, tilt-telescoping steering column, premium insulation, roomy dimensions, and other features to make the driver comfortable and productive. Complete gauges and waterproof marine-grade rocker switches are included. An exterior sun visor limits glare through the large two-piece windshield; the two-piece design limits the cost of replacing broken glass.
The dump box is made by J&J Truck Bodies & Trailers expressly for this truck model. J&J constructs it of Hardox 400 and 450 steel, with 5/16-inch sides and a 5/8-inch floor and 5/8-inch liner strips. Capacity is 24 cubic yards struck and 30 yards heaped; rated payload is 77,100 pounds, for a total laden vehicle weight of 138,000 pounds. The hoist mechanism includes a four-stage hydraulic cylinder that can tip the body in 25 seconds at 1,000 rpm and lower it in 18 seconds at the same engine speed.
A heated dump body is one of the features of an optional cold weather package, which also includes a block heater and ether starting system, -60F coolant, and a heated fuel-water separator. Other options range from an automatic chassis greasing system to carbon filters for the cab's heating and air conditioning system.