ELECTRIC AUXILIARIES ON MERCHANT SHIPS. 159 



hydraulic speed reducing- gear is fitted between motor and drum. The latter class seems, to 

 have found considerable favor abroad, where certain well-known manufacturers have de- 

 veloped winches, usinj;^ either the Williams-Jenney or Hele-Shaw hydraulic power transmis- 

 sion. Electric hydraulic power transmission is particularly well adapted for steering gear 

 work and has been developed in this country. For general winch service the hydraulic pump 

 and motor are excessively costly. A brief comparison of winclies developed abroad and in 

 this country would indicate as follows : 



(a) That the speeds for given load are somewhat lower for the foreign-made winch. 

 A drum speed of approximately 175 feet per minute for 5,000 pounds and 250 feet per min- 

 ute for 2,000 pounds would seem to be good practice. 



(b) Certain manufacturers abroad have developed very neat worm-driven winches. 

 These, if properly built, should be very quiet and, from the descriptions, appear to be quite 

 compact. The writer does not know of any winches of this type developed in this country. 

 One particular merit of such a winch is that the gear is readily encased, lubricated and 

 protected from the action of the weather. 



(c) From several descriptions there appears to be a tendency abroad to operate the 

 motors by contactors. While this arrangement has much merit, it tal<es up additional space 

 and costs more to install. In one description it is stated that the contactor controller is be- 

 low deck. This, of course, is possible only in certain cases. Where the winches are located 

 over the cargo holds, special space must be provided on deck for the control panels, and 

 this space, of course, must be properly enclosed. 



(d) There would seem to be a tendency on the part of the foreign winch manufacturers 

 to considerably complicate the motor and control by the addition of special safety devices. 

 In the writer's opinion this will be found undesirable. One manufacturer in this country who 

 has fitted about two hundred electric winches on ships during the past five or six years 

 claims that special safety devices are not only unnecessary but are actually undesirable. For 

 the reason that they must be kept in perfect operating condition at all times so as to function 

 properly when called upon at infrequent intervals, it will be recognized that apparatus for 

 such service is the most difficult of all to maintain. It must be remembered that winches 

 are operated in various parts of the world by longshoremen at the ports and not by the per- 

 sonnel of the ship. Experience indicates that properly designed and substantial equipment is 

 entirely suitable for the service and does not require complicated safety-guarding features. 



(e) With the majority of foreign-built winches it would appear that a handwheel is 

 used for operation. This necessitates a tiring and urmatural movement on the part of the 

 winch man. The natural motion, and therefore one which can be carried on for hours at a 

 stretch without unduly tiring the operator, is similar to working a pump handle — that is, to 

 control by means of a lever, raised to raise the load and depressed to lower the load. 



For gear winches the series motor or compoimd-wound with very small amount of 

 shunt winding is the most desirable. Plate 28 shows how the natural characteristics of the 

 series motor make it most suitable for winch service. It is found necessary to throttle the 

 steam winch at light loads to reduce the speed. In practice, therefore, it approaches more 

 nearly the speed of the electric winch. Many winches are fitted with winch heads. When 

 handling cargo with these instead of the drum the revolutions per minute will run up some- 

 what. However, the winch head being of smaller diameter than the drum, it is generally 

 found that the rope speed on the winch head will be about right. 



For all service using hydraulic gear, constant-speed motors are used, either alternating- 

 current or direct-current. 



