PRINCIPLES OF NAVAL ENGINEERING 



AUTOMATIC BYPASS 

 VALVE 



STBD. 

 CniNDER. 



STEERING WHEEL 



ON AFTER DECK HOUSE . 



TRANSMIHER UNIT, 



STEERING WHEEL 

 ON BRIDGE 



||_ ELECTRIC CONTROlI 

 SL SYSTEM 



CRANK FOR HAND OPERATION 

 OF PORT PUMP 



PORT 



SYSTEM 



TRANSMIHER UNIT 



RUNNING ELEC. MOTOR 

 WORM WHEEL 



RECEIVING UNIT 



t>«f>mi!mfl>. 



TRANSFER SWITCH TRANSMITS 

 CURRENT THROUGH EITHER 

 CABLE OR EITHER TRANSMIHER 

 TO RECEIVER AS SELEOED 

 f*' TRICK WHEEL FOR 

 HAND CONTROL 



IDLE ELEaRIC 

 MOTOR 



WORM 

 WHEEL 



STARBOARD 



suppLy 



RETURN 



^ 

 ^ 



WORM 



SPIRAL GEARS 

 H-H 



AUTOMATIC BYPASS VALVE 



27.83X 



Figure 21-6.— Single-ram electrohydraulic steering gear. 



steering gear, an additional switch is provided 

 in the steering room for selecting the proper 

 receiver. 



HYDRAULIC TELEMOTOR SYSTEM. -Atele- 

 motor is a hydraulic device by means of which 

 the motion of the steering gear is controlled 

 from the pilot house. In general, telemotor 

 systems are employed for remote steering 

 control where it is impractical to provide an 

 electrical synchronous transmission system 

 and where the length of runs of shafting or 

 wire rope and the paths for such shafting or 

 ropes would make the use of these types of 

 mechanical controls impracticable. 



The hydraulic telemotor system consists of 

 one or more transmitters located at remote 

 steering stations connected by piping to a 

 receiver or receivers located in the steering 

 engineroom. Each transmitter unit is either a 



a pair of cylinders or a fixed-delivery piston- 

 type pump connected so that movement of the 

 steering wheel causes fluid to flow through the 

 system, resulting in a corresponding movement 

 of the plungers in the receiver unit. The 

 receiver unit is connected by suitable means to 

 the pump control or valve operating mechanism 

 of the steering engine. The principal components 

 of a hydraulic telemotor control system are 

 shown schematically in figure 21-7. 



WIRE ROPE SYSTEM.-This type of remote 

 control is found in some small ships. The 

 steering engine control mechanism is connected 

 to the wheel by wire ropes. The system has the 

 disadvantages of requiring long leads involving 

 large friction loads; of the ropes being vulnerable 

 to gunfire above decks; of impairing watertight 

 integrity by passage of the cables through 

 bulkheads and decks; and of requiring a 



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