196 



SUBMARINE CABLE LAYING AND REPAIRING. 



Grapnel Trailers and Ropes. — Trailers (as iu Fig. 109) are 

 used sometimes with the grapnels, being dragged either after 

 or before the grapnel, to keep it from jumping, and at the same 

 time offer a better chance of hooking the cable. There is 

 generally also a trailing or steering chain attached to the end 

 of the grapnel. This is a fathom or two in length, and has at 

 one end a large link, so as to allow the other end to be reeved 



Fig. 106. — Centipede Grapnel. 



through it after being reeved through the end link of the grap- 

 nel. The noose is then hauled tight, and the chain follows the 

 grapnel and keeps it moving in a straight line. 



The leading chain, the duty of which is to keep the front 

 end of the grapnel low as it is dragged along, is fin. and about 

 15 fathoms in length. The grapnel rope is shackled on to this 

 chain. 



What is known as three-by- three-by-four compound grapnel 

 rope is generally used for the entire length. This consists of 



Fig. 107. 



12 hemp-yarn ropes laid up in four strands, each strand con- 

 sisting of three ropes, and each rope containing a heart of three 

 steel wires. The wires are of one ton breaking strain each, so 

 that the whole rope will stand up to 36 tons. Sometimes it is 

 more convenient to use a stout manilla rope, 6^in. circumference, 

 with a breaking strain of about 11 tons. The leading chain is 

 supposed to take all chafe, but when tjianilla rope is used, a few 



