THE CAHLE SHIP OX REPAIRS. 



207 



by limiting the thickness of rock which a toe can hook. This 

 obviates the necessity of providing for the replacement of 

 prongs, which is all the less necessary because the construction 

 lends itself to very low cost of manufacture. 



These advantages have been amply proved during many 

 years of use on rocky bottoms. For boat work the lighter types 

 have been found to be of great service. 



Another grapnel designed to protect the prongs from break- 

 age was brought out by Mr. W. J. E. Hill in 1903 (Fig. 119). 

 This is made with a shank of square section containing, as in 

 the form A, four prongs, one on each face and in succession to 



Murphy's Grapnel in action. 



each other. The prongs are hinged loosely on bolts passing 

 through the shank, and, therefore, the prong on the iinder- 

 neath face is free to swing open by gravity and hook cable, 

 while the others remain within recesses in the shank. Should 

 the working prong encounter a rock, it will be pushed back 

 into its recess, out of harm's way, until the obstacle is passed, 

 when it will drop out again ready for work. The flukes, when 

 home, have so little projection from the shank that the grapnel 

 can pass through a rocky crevice with little chance of damaging 

 them. It can also pass inboard over the sheaves of the ship. 

 Another good point is the wide and rounded seating for the 

 caWe in the prong, thus preventing it bending too sharply on 

 the bight. 



In the form B there are four or more small grapnels coupled 



