132 SUBMARINE CABLE LAYING AND KEPAIEING. 



cables) a steam locomotive was used, the landing place being 

 opposite a railroad. 



Laying Main Cable. — The shore-ends having been laid 

 and buoyed, we have next to follow the work on board ship 

 during the laying of the intermediate and deep-sea portions of 

 the main cable. In this work the staff of electricians and 

 engineers are kept continuously busy, proper watches being 

 arranged for day and night work. It is the most important 

 and critical work of the expedition. All portions of the work- 

 ing machinery are well illuminated by electric light at night. 

 Half-hourly records are kept of dynamometer strains, weights on 

 the brake, length of cable payed out, revolutions of ship's engines, 

 revolutions of cable drum, and readings of patent log. Note is 

 also made of the times and positions when course changed, 

 times of changing over to the different tanks, ship's positions.- 

 percentage slack, soundings, type of cable going out and 

 from what tank, &c. At the same time, continuous watch 

 is kept on the spot of light in the ship's testing room, by which 

 any flaw in the insulation of the cable payed out would be at 

 once detected. In addition, the continuity of the cable is 

 proved at intervals by signals exchanged with the cable-house 

 on shore. 



Ships specially built for the laying of long cables are of 

 considerable tonnage for carrying large quantities of cable 

 at a time, and there is a considerable deck area, allowing 

 of the most convenient arrangement of machinery for 

 the requirements of laying cable. The after portion of the 

 vessel is fitted with well-adapted machinery for paying-out, 

 capable of dealing with any emergency that may arise during 

 this operation. 



The cable passes up from the tank over leading pulleys 

 to the friction table, where a retarding strain can be instantly 

 applied should any accident in tank or elsewhere call for 

 immediate stoppage of the ship and of the cable running out. 

 From the friction table the cable passes to the paying-out 

 drum, round which three or four turns are taken, and thence 

 to dynamometer and over stern sheave into the sea. The drum 

 is provided with brake wheels, the friction on which can 

 be adjusted by means of weights on the ends of levers, in 

 accordance with the conditions of depth, type of cable and speed 



