PRINCIPLES OF NAVAL ENGINEERING 



PUSH BUTTON MASTER 

 (RESET a 

 EMERGENCY RUN 

 START 

 STOP) 



BRAKE BRAKE 



APPLIED RELEASED 



EMERGENCY 

 DRUM BRAKE 



147.128 



Figure 21-2.— Electrohydraulic transmission. 



The steering motor control may be either of 

 the follow-up or the nonfolloiw-up type. In the 

 nonfollow-up type, the motor is controlled by a 

 master controller at the steering station. When 

 the master controller is brought to neutral, 

 dynamic braking action takes place to slow down 

 the motor; the motor is finally brought to rest 

 and held by a magnetic brake. 



In the follow-up type of control, the follow- 

 up feature is incorporated in a contact ring 

 assembly in the steering stand. The rings make 

 contact with rollers which control the circuits to 

 contractors on the control panel. Movement of the 

 steering wheel rotates the contact rollers in the 

 proper direction to start the motor. Motion of the 

 steering motor is transmitted through shafting to 

 the contact ring assembly, which follows up the 

 motion of the rollers. By this action the rudder is 



moved an amount proportional to the rotation of 

 of the steering wheel. 



Most wire rope and drum type steering 

 gears utilize a follow-up control arrangement. 

 The follow-up motion is transmitted from the 

 steering gear to the steering stand by means 

 of shafting, bevel gears, and flexible couplings. 



In most electromechanical installations, the 

 shafting connecting the steering engine to the 

 wheel is utilized not only to provide follow-up 

 control to the steering stand but also to provide 

 a means for steering by hand from the pilot 

 house if power is lost. 



ELECTROHYDRAULIC STEERING GEAR 



Steering gear 

 naval ships are 



installations on most modern 

 of the electrohydraulic type. 



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