84 SUBMAEINE CABLE LAYING AND KEPAERING. 



passes through the closing machine at the rate of lOin. for each 

 revolution of the frame of coils. For a given lay there is a 

 ■definite ratio between the speed at which the cable is drawn 

 through the closing machine and the speed of rotation of the 

 irames of coils. The intermediate and shore-end sizes require 

 a shorter lay and the speed of rotation of the frame of coils is 

 reduced to the proper extent to effect this, but not so much as 

 to make the angle of lay the same for all sizes. In other words^ 

 the angle between the direction of the spiral and the cable is 

 made greater in the larger sizes so that more wire is laid on in 



Fig, 41. — Irish Shore End. 



ti'given length. This provision, together with the use of larger 

 wires, is made for protection against the greater wear and tear 

 to which shallow-water cables are subject. 



The lay is a variable function of the diameter or circumference 

 of pitch circle of sheathing wires in section, becoming greater 

 as the diameter increases. In deep-sea types the pitch circum- 

 ference would be about Ifin., in intermediate types 2jin., and 

 in shore-end types 4in. to S^in. The lay in each case would be 

 approximately lOin., ll|in., and 16in. to 18in. respectively. 

 In special cases the lay of shore-end sheathing is made very 

 much less than this, namely, about 6 in. A cross section through 

 the cable then shows the sheathing wires cut obliquely, pre- 



