The crane body is a steel casting with the upper part being a closed welded box design through which hydraulic hoses
are routed to inner and outer boom actuating cylinders. Inner and outer boom assemblies are positioned, as required, by
extending or retracting hydraulic actuators. A winch assembly is mounted on top of the primary element of the boom for
retrieving loads of 10,000 pounds or less. To winch loads greater than 10,000 pounds, the sheave block must be
installed on the end of the outer boom.
Operator controls for the crane are on the forward side of the deckhouse top. They include five control levers for
controlling crane movement, a START/STOP control switch, and a key lock for the anti-2-block control system. The
START/STOP control switch, and a key lock for the anti-2-block control system. The START/STOP control switch and
anti-2-block key lock are in a watertight storage box aft of the crane control levers. Another START/STOP control switch,
primarily for emergency use, is on the weatherdeck forward bulkhead.
Hydraulic pressure for the bow crane is supplied by a hydraulic power unit in void 1 port. A 30 Hp electric motor drives
the pump to produce 3600 psi of hydraulic pressure. A motor controller in void 1 (Figure 3-4), starts and stops the local
unit and supplies power to the two remote START/STOP control switches. The motor controller requires 440 Vac, 3
phase, 60 Hz power.
13-3.3 Void 4 Trolley Hoist. Void 4 trolley hoist (Figure 13-3) in void 4 starboard is a low-headroom, manually operated
hoist. Major components include an "I" beam suspended from the void 4 overhead structure, a manual hoist assembly,
load chains, a block hook, and a brake mechanism. The trolley hoist has a net weight of 230 pounds and a standard lift
height of 8 feet. The load chains measure approximately 9 feet 6 inches and require 41 pounds of pull to lift a full load.
The hook assembly has a diameter of 1 3/7 inches. The "Ul beam measures approximately 6 inches in width.