400 



SUBMABINE CABLE LAYING AND REPAIRING. 



Table I. — Co-efficients for Kennelly Two-current Test. 



The following are actual figures obtained on localising a 

 break by this method : — 



Balances. —The balance B with the high current is taken 

 first. 



B -with — -— m/amps to line 



A -with 



11 



6,790 6,830 6,800 6,800 

 6,860 6,890 6,840 6,900 



%=. 



43-5 

 11 ' 



:3-95, 



A-B = 

 xP 



70 

 2-01 



60 

 2-01 



40 

 2-01 



100 

 2-01 



P=2-01 (by Table) 



141 121 80 201 



x= 6,719 6,769 6,760 6,699 

 Mean of four readings, 6,737 ohms. 

 Actual distance of break, 6,744 „ 



The readings on the milammeter (150 range) are entered as 

 divided by 2 because the instrument was used in the battery 

 circuit, and the currents to line are half the readings. This 

 shows that the larger current was 21-75 milliamperes to line. 



In Fig. 236 the several resistances taken account of in this 

 test are shown in the form of plain divided lines. The upper 

 line represents the resistance of the line x up to the break 

 and that of the break/ as tested with the lower current. The 



