| Tweet |
Custom Search
|
|
|
||
 TM 55-1905-223-24-6
Section II. EQUIPMENT DESCRIPTION AND DATA
1-6. General. The bowthruster system installed aboard the LCU 2000Class watercraft is a Schottel Model SPJ-55
steerable waterjet powered by a 300 horsepower Cummins Model NT855M diesel engine. Operation of this jet applies
directionally controlled thrust near the bow to help maneuver the vessel in close quarters.
1-7. Characteristics, Capabilities, and Features. A very broad view of the bowthruster waterjet is as follows:
a. Characteristics.
(1) Both a propulsion and steering system.
(2) High volume jet pump provides propulsion.
(3) Used with ship's twin propellers and rudders.
b. Capabilities and Features.
(1) Ejects seawater through a steerable nozzle.
(2) Bowthruster engine is also auxiliary fire pump.
(3) Controls are at ship control console in pilothouse and in bowthruster room.
1-8. Location and Description of Major Components. (FIGURES 1-2 and 1-3). The bowthruster waterjet is a high
displacement centrifugal water pump. System machinery includes drive shafting to the pump plus steering machinery for the
nozzle. This machinery is integrated into a compact unit installed in the bowthruster room. The well cover is the watertight
closure and the structural support for both the external and internal components.
a. Hull Interface. The waterjet is installed over a cylindrical well (FIGURE 1-2) in the ship's bottom. This protects
external components from grounding damage. A grid over the intake throat protects the impeller from trash ingestion. An
upper flange forms the foundation for the waterjet.
b. Bowthruster Engine Interface. The bowthruster engine is installed between the bowthruster waterjet (forward) and fire
pump No. 1 (aft) (FIGURE 1-3). Power takeoff couplings and independently operated clutches allow the same engine to
power either the waterjet or the fire pump. Engine controls and primary waterjet controls are remoted to the ship control
console in the pilothouse.
c. Drive Shaft. (FIGURE 1-4). A drive shaft transfers engine torque to the waterjet upper gear assembly. This steel
tube has a U-joint at each end. One bolts to a flexible coupling on the engine power takeoff shaft (FIGURE 1-5). The
other incorporates a flange which mates with the drive flange of the upper gear assembly. One end of the tube also
includes a spline. Grease fittings are provided at each U-joint and at the spine.
|
||
|
||
