Bow Thruster Water Set System

TM 55-1915-200-10

shaft turns the drive flange assembly of the bow thruster

anchor chain. Auxiliary clutches transfer power to

and compensates for the offset between the gear box

outboard gypsies providing pulling power during mooring

and bow thruster. The marine drive changes direction

and for operating the port and starboard bow ramp

via hydraulically controlled clutches. The marine drive

winch drums in the event of bow ramp winch failure.

clutches and bow thruster shaft brakes are

The bow anchor windlass receives hydraulic power from

pneumatically actuated via controls located on the PHC

the bow anchor windlass hydraulic piping system.

and ERC. The shaft brake, when actuated, prevents the

propeller and marine drive from turning when not in use.

1-10.12.2. Bow Ramp Winch. The port and starboard

bow ramp winch assemblies raise and lower the bow

1-10.11. Bow Thruster Water Set System. The bow

ramp. They are operated by a single control valve, at

thruster water set system delivers athwartships thrust at

the port winch assembly. The control valve controls

the bow for close quarter maneuvering. The bow

direction and rotation speed of both port and starboard

thruster functions as an onboard maneuvering system to

ramp winch drums, which in turn haul in or pay out port

provide immediate maneuvers without the aid of

and starboard wire ropes connected to each side of the

supporting vessels. The bow thruster can be used when

bow ramp. As the wire ropes are hauled in, the ramp

docking, in an emergency situation, such as impending

raises. When they are payed out, the ramp lowers.

collision, or in station keeping. The system is installed

Auxiliary clutches on the port and starboard bow anchor

in the bow thruster tunnel with the bow thruster propeller

windlasses can be engaged to drive the bow ramp winch

forcing water through the tunnel in either direction to

drums, providing a backup source of power for operating

provide the required thrust. Direction of thrust is

the bow ramp, in case of bow ramp hydraulic failure.

determined by the rotational direction of the propeller.

The bow ramp winch receives hydraulic power from the

The bow thruster water set system receives drive torque

bow ramp hydraulic piping system.

from the articulated shaft which is part of the bow

thruster power generation system.

1-10.12.3. Bow Ramp. The bow ramp, when lowered,

forms a bridge into the vessel allowing vehicle and

1-10.12. Bow Anchor Windlass and Bow Ramp Winch

cargo loading and unloading. The ramp's outermost

section is hinged, allowing the ramp to adjust to beach

System. The bow anchor windlass and bow ramp winch

or dock, thus providing smooth vehicle passage. When

system raises and lowers the bow anchors and the bow

fully closed, the bow ramp contacts a gasket system

ramp. The system consists of the bow anchor windlass,

along the vessel's bottom and sides forming a watertight

bow ramp winch, and the bow ramp. The bow anchor

seal. It is secured in its upright closed position by two

windlass and bow ramp winch systems are hydraulically

manually operated upper locking bars and four manually

powered.

operated ratchet dogs. Port and starboard chains

support the ramp in its lowered position.

1-10.12.1. Bow Anchor Windlass.

The port and

starboard bow anchor windlass assemblies raise and

1-10.13. Stern Anchor and Stern Ramp Winch System.

lower the bow anchor. They are operated by individual

port and starboard control valves at each assembly.

The stern anchor and stern ramp winch system raises

The control valves control direction and rotation speed

and lowers the stern anchor and the stern

of chain-hauling wildcats, which in turn haul in or pay out

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