238 



SUBMABINE CABLE LAYING AND REPAIRING. 



sea-bottom. Before lowering the buoy the cable-end is stoppered 

 to a 50-fathom length of 3 x 3 buoy rope, the other end of which 

 is shackled to the buoy mooring chain. A short length of manilla 

 is attached to the 50-fathom length about 15 fathoms from the 

 end next chain, and this is eased away through stoppers on 

 board while cable and buoy are lowered so as to prevent the 

 weight of cable coming too suddenly on the moorings. The 

 manilla is then cut and the buoy floats free with cable suspended. 



Picking Up. — The ship now starts picking up cable towards 

 the fault, the main engines being kept moving easy ahead in 



w y/M 



Fig. 134. — Rotometer Gear. 



order to keep the ship's head to the cable and relieve the strain 

 on the cable. The cable comes in at the rate of about one or 

 two miles an hour in deep water, a six-foot winding-drum being 

 slowly driven at about 10 revolutions per minute. The steam 

 engine used for driving the picking-up gear runs at about 150 

 revolutions per minute, the power being transmitted from the 

 engine to the drum shaft through speed-reducing gear on two 

 or more intermediate shafts. The length of cable hauled in- 

 board can be ascertained at any moment from the indications of 

 a revolution counter or rotometer (Fig. 134), which records the 



