2 ton, multi-fuel engine driven, six-wheel six-wheel drive, military design truck chassis, trucks, and truck tractors.

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MIL-T-46780D(AT)

3.3.11.2 Boring machine. The earth boring machine equipment shall be capable of boring holes to a diameter of 30 inches and to a depth of 10 feet vertically. The auger shaft shall be driven through a power divider, which allows independent operation of the body winch, or boring machine. CAUTION (see 3.7.3). The transer shift lever of truck transfer must be in neutral position during all boring, to avoid movement of truck. The operation of the truck transmission gear shift shall control the truck engine speed to the auger shaft. Levelers shall permit boring vertical holes regardless of truck position and anchor holes to an angle of

45 degrees. A leveling bubble indicator shall be provided to show when auger is properly

vertically oriented. The powered vertical leveler shall permit stowage of the integral pole derrick in a near level travel position. The auger bar control levers shall remain in a neutral position

until pressure is applied to the levers by the operator.

3.3.11.3 Mounting. The earth boring machine shall be designed to be readily removable, or replaceable. Provision shall be made for towing a trailer behind the truck with boring

machine removed.

3.3.11.4 Outrigger. A left band and a right hand hydraulic outrigger shall be provided integral with the boring machine support structure, to relieve the loads imposed on the truck springs; and to provide truck stability during boring, or winching, operations. The outrigger shall operate under a maximum hydraulic system pressure of 1500 psi and shall perform safely within the load limitations of the winch and derrick. Mechanical locks are provided to prevent drifting of the cylinders during vehicle travel. CAUTION (see 3.7.3). The truck is not to be moved while a weight is suspended from the derrick assembly.

3.3.11.5 Pole derrick. The pole derrick shall be a tripod frame of steel tubing supported from the truck aft body, with an adjustable center leg, with head sheave. The tripod support legs shall be straight, round, steel tubing and shall be free of any kinks, flats, dents or other mechanical defects. When used in conjunction with the body winch, it shall be capable of supporting posted weights at different derrick positions, with a maximum weight of

9,000 pounds, plus 25 percent safety factor. The pole derrick with associated winch and

equipment shall be able to remove, install and straighten poles 45 feet in length. The pulling load limit with universal sheave block, shall be 5,000 pounds from any direction. The derrick shall be stowable on truck body, when not in use, in such a manner that it will not prevent the opening of the cab doors.

3.3.11.6 Derrick support jack. The pole derrick supports of 15 ton capacity each shall be provided for truck stability during winch and derrick operation. The adjustable support jack

shall be mounted on truck body aft frame and be removable for stowage in truck body for travel.

CAUTION (see 3.7.3). The truck is not to be moved while a weight is suspended from the pole derrick.

3.3.11.7 Wheel chocks. Metal triangular wheel chocks shall be provided to adequately restrict vehicular movement when operating the truck body winch and pole derrick.