260 SUBMARINE CABLE LAYING AND EEPAIRING. 



Consequently, to slide the driving pinion out of engagement 

 with the drum, it has to pass through a hole in the frame, and 

 a bearing cannot be provided in the usual way on the frame 

 itself. An inner and outer bearing is therefore arranged by 

 means of a cast bracket bolted to the frame giving the necessary 

 stiffness to this shaft and effecting a much-needed improve- 

 ment over the old style of overhung pinion. 



The brakes are fitted with steel bands lined with elm blocks, 

 closed in on the ring in the usual way by a right and left- 

 handed screw, but with the addition of worm gear to the 

 operating hand-wheel. This gives a very gradual regulation 

 and a powerful retaining hold on the brake. 



The double-screw spindle is connected to the operating rod 

 by a universal joint, so that where head-room is limited the 

 spindles need not be exactly in line. The back of each brake 

 band is fitted with a water-service pipe with nozzles at 

 intervals, which direct jets of water between the joints of the 

 brake blocks inwards, on the surface of the drum. A small 

 steam-pump is used to supply the water service. The lower 

 parts of the bands have large cast-iron eyes attached to them, 

 and these are kept in position by means of a shaft, 8^in. 

 diameter, which passes through both frames. When the brake 

 is applied the pull is transmitted to the machine frames 

 through the eyes and shaft, and thus to the deck of the vessel. 

 The brake handles, engine-starting valves, reversing levers, 

 change-speed hand-wheels, drain-cock handles and hauling-off 

 gears are fixed in convenient positions on the spar deck 

 {see Fig. 154). The hauling-off gear on either side is arranged 

 so that it can be traversed in a direction parallel to the 

 drum shaft to suit an outside or inside lead of cable. It 

 Is driven by pitch chain from a shaft carrying a pinion 

 which can be made to slide into engagement with the internal 

 gearing on one of the main drums. Besides the usual 

 friction brake, there is a " free-wheel " arrangement by means 

 of which the hauling-off gear can be instantly converted 

 {on reversing the direction of rotation of the drum) to " hold- 

 ing-back " action, on the application of the brake. Therefore 

 when it is necessary on a picking-up job to reverse and pay out 

 a little slack, the gear acts automatically without the necessity 

 of putting the driving pinion out of gear. 



