THE CABLE SHIP OX REPAIRS. ^ 209 



10 inches long by 1 inch or so in thickness, while the prongs 

 are about the same width across as the link. The lower part 

 of the flukes is slotted as shown at A, and the link is also 

 slotted at B. The flukes are passed through the large hole in 

 the link, and the slotted base is fitted into the slot in the link 

 and bolted up. This gives a very strong, rigid connection, and 

 at the same time one that can readily be detached for renewal 

 when required. The experience with this grapnel up to the 

 present is that cable is always hooked when an indication of 

 strain appears, thus showing that its special form of construction 

 prevents it getting hooked or jammed by rock. 



The illustration (Pig. 121) is from a photograph taken on 

 board the "Electra" while grappling, and shows the efi"ect of a 

 heavy strain on the dynamometer, the sheave of which is seen 

 to be raised so that the rope passes almost in a horizontal line 



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Fig. 120. — Eennie Chain Grapnel. 



•underneath it. The strain in lifting a bight of cable is due more 

 to the pulling of the cable from both sides towards the bight than 

 to the weight of cable alone. A certain percentage of slack, 

 varying according to the depth, is paid out at the time of laying 

 for the purpose of facilitating lifting during repairs ; but even 

 with a liberal allowance, spread as it is uniformly along the 

 route, there is a good deal of shifting of cable on both sides 

 towards the ship when she lifts a bight. Say the ship raises a 

 bight of type D in 1,500 fathoms laid with 10 per cent, 

 slack. To raise this to the surface, cable must be lifted off 

 the ground or pulled towards the ship from a distance on each 

 side of bight equal at least to double the depth, or a total 

 lifting or moving of about six knots of cable. This adds to 

 vthe strain about as much again as the weight of cable alone. 



