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)

(p)    Other type tires, if required (see 3.4.10.1).

(q)    Spare wheel or rim, if required (see 3.4.10.3). (r)     Spare tire assembly, if required (see 3.4.10.4). (s)     Air brakes, if required (see 3.4.11.2).

(t)     Trailer brake control system, if required (see 3.4.11.3).

(u)    Brake controls for use from a towing vehicle, if required (see 3.4.11.4). (v)    Tilting hood and fender assembly, if required (see 3.4.12).

(w)   Tilt cab, if required (see 3.4.12).

(x)    Air ride driver's seat, if required (see 3.4.12).

(y)    Tilt cab windshield cleaning step and grab handle, if required (see 3.4.12). (z)     Tools, if required (see 3.4.16.1).

(aa)   Air operated horn, in addition, if required (see 3.4.21).

6.3  Performance prediction.  SAE Truck Ability Prediction Procedure computations and computations for low speed and maximum geared speed will be required by the contract.  The SAE Work Sheet Item 1 should include vehicle model number, engine model number, and vehicle type.  Unless other conditions are cited in the contract, computations should be made for normal atmospheric pressure, normal ambient air temperature, and still dry air.  The factors to be used in predicting truck ability (see 3.3.1.1) are established as follows for the corresponding

SAE Truck Ability Prediction Procedure Table:

Table 1    -   Tire Factor.  This factor must relate to the size of tires furnished by the contractor in accordance with this specification.

Table 2    -   Altitude Factor.  1.00

Table 3    -   Rolling Factor.  1.613

Table 4    -   Area Factor.  0.173

Table 5      -  Velocity Factor.  250.0

Table 6      -  Altitude Factor.  1.00

Table 7      -  Chassis Friction Horsepower.  Use applicable power unit GVW (to nearest,

higher, 1,000 pounds) and the engine rpm (to nearest l00 revolutions) which is required for 50 mph geared speed.  For GVW and engine speed beyond the range of this table, factors shall be extrapolated.

Table 8      -  Grade Factor.  0.75

Table 8A   -  Correction Factor.  Not required

Table 9      -  Road Factor.  0.0

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