MIL-T-62246 Truck, Dump, Street Maintenance, Diesel And Gasoline Engine Driven, 21,000 Pounds Gvw, 4X2, CommericalThis specification covers diesel and gasoline engine driven, four-wheel, two-rear-wheel drive dump trucks equipped with a material sprayer, an auxiliary engine driven air compressor, and a vibrating roller for use in street maintenance. Vehicles shall have a minimum gross vehicle weight GVW of 21,000 pounds for normal operating conditions. Vehicles procured under this specification are commercial items which shall be warranted by the manufacturer as specified in acquisition documents.

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MIL-T-62246B(AT)

3.2.5 Gross vehicle weight. Gross vehicle weight (GVW) shall consist of curb weight, operator weight (computed at 175 pounds), and a payload to provide not less than the specified GVW.

3.2.6 Weight distribution. The distribution of GVW for the purpose of establishing suspension, axle and tire capacities shall be determined with the payload uniformly distributed over the load area.

3.2.7 Ratings. Vehicle ratings shall be the manufacturer's published ratings. Component and vehicular ratings shall not be raised to meet the requirements of this specification. When published ratings are not available, verification of ratings shall be available to the engineering office of the procuring activity. Minimum GVW rating shall be 21,000 pounds.

* 3.2.8 Overall width. The overall width of the vehicle, exclusive of mirrors, lights, reflectors and tires, shall be not more than 96 inches. The width over the tires shall be not more than

100 inches.

* 3.2.9 Accessibility. The design of the vehicle and optional equipment shall permit access for routine servicing and shall permit access for replacement and adjustment of component parts and accessories with minimal disturbance of other components and systems.

3.3 Performance.

3.3.1 Speeds. High and low speed requirements shall be met with the truck loaded to specified GVW.

3.3.1.1 High speed gradeability. The vehicle shall ascend a continuous grade of 1.5 percent at 50 miles per hour (mph). Gradeability requirements shall be met with the main transmission in direct drive, and when a multispeed axle is furnished with the axle in high speed range. Gradeability shall be verified with calculations in accordance with SAE J688 (see 6.3).

3.3.1.2 Low speed. Low speed for vehicles with a manual transmission shall be calculated with the engine operating at not less than 35 percent of the recommended governed speed, and shall provide a vehicle speed of not more than 3 mph.

* 3.3.1.3 Maximum geared speed. Maximum geared speed at engine governed speed shall be not less than 58 mph. Conformance to geared speed specified shall be determined by calculating in accordance with the following formula:

Maximum geared speed (mph)= Governed speed (rpm)

Total gear reduction x tire factor (see 6.3).