MATERIAL HANDLING CRANE (MHC). -726250075

TM 9-2320-364-34-1

1-17. MATERIAL HANDLING CRANE (MHC).

Figure 1-20. Material Handling Crane (MHC)

The truck Material Handling Crane (MHC) (Figure 1-20) is a fully hydraulic load-moment sensing crane (1) powered

by the truck hydraulic system. The crane is mounted behind the cab, bolt-attached to the truck frame and is capable of

lifting a 3,900 lb (1770 kg) pallet from any location on the FR. The crane can load/unload pallets to either side of the

truck. Truck stability and leveling is accomplished with left- and right-side hydraulically operated stabilizers (2) that

are fabricated as a part of the crane substructure. These stabilizers/outrigger jacks can be controlled from either side

of the truck by individual hydraulic controls. The jacks can level the truck when it is inclined up to 7 degree side slope.

Check valves are used to hold the outriggers position. Safety switches are installed in the outrigger jacks to prevent

crane operation unless the outriggers are in place. The outrigger pads (3) are attached to the outrigger jacks by means

of quick pins (4) and are stowed on the crane base. The pads swivel 360 degrees when installed on the jacks.

a. Hydraulic System. The hydraulic filters and strainers are located to provide direct access and to allow removal

without causing damage to the truck. Bypasses are furnished, where necessary, to protect filters during cold

temperature operation. All cylinder rods exposed during operations have a hard chromium plating. Integral mounted

or cartridge-type holding valves prevent sudden cylinder collapse in the event of hose burst or major hydraulic failure.

If a hydraulic system failure occurs, a hydraulic hand pump (5) located at the operator station permits the operator to

lower any load to the ground and stow the crane. The MHC is operated by two hydraulic valve banks (6), located

approximately 60 inches (152 cm) above ground on the passenger side of the truck. Four electro-proportional control

valves with manual handles connected to spools are used to control crane proper function. Three additional

proportional manual control valves are used for erection and outrigger control. The outrigger manual control valves

are also duplicated on the driver's side of the truck.