THE CABLE SHIP ON REPAIBS. 267 



test is used continuously during paying out to show that the 

 cable remains perfect, and to detect, should such an untoward 

 event happen, the paying out of a faulty length. The same 

 connections apply when measuring the insulation by fall of 

 charge or seeing what amount of capacity there is in the length 

 of eiable from ship to shore. From the deflection test con- 

 nections 16 will be seen that it is only a matter of a few seconds 

 to change over on to the bridge connections by the plugs. 

 The bridge is used for all fault localisation tests, and, with the 

 exception of the Mance and Schaefer tests, balance is obtained to 

 false zero. 



With a single fault making partial earth it generally happens 

 that when tested from the ship at close quarters it can be opened 

 out more with the zinc current and its resistance reduced, so 

 obtaining a more reliable localisation than from shore. Suppose, 

 for instance, that after trying a number of different tests from 

 the moment the ship starts picking up, the fault is estimated 

 to be 1| miles off. The cable would be cut at 2 miles, and when 

 the rotometer showed this length hauled in, the cut would be 

 made in tank, and the new end connected up to the testing- 

 room. Tests now may show the fault to be still further away 

 and picking up would be continued. Tests are applied again, 

 and this time it is estimated that another half-mile will bring 

 in the fault, Tiie cable is accordingly cut again after this 

 length is picked up, and the new end connected to the testing- 

 room, when, if successful, the electrician has the satisfaction to 

 find that his low readings have disappeared, and the cable now 

 hanging to the ship is electrically perfect. The fault is, there- 

 fore, contained somewhere in the last piece coiled in tank, which 

 is labelled, and shortly afterwards treated by loop test, spotted, 

 examined, and reported on. Each time the cable is cut the 

 drum is heavily braked and the engine stopped. 



When picking up to the fault, the Gott fault-searcher has 

 been found extremely useful when the sheathing wires are not 

 covered with insulating material and the resistance of the fault 

 is not very high. This apparatus is described in the J our naloi the 

 Society of Telegraph Engineers and Electricians, Vol. XV., p. 345. 

 It consists of a large number of turns of insulated wire wound 

 round a frame, made of any durable material, of semicircular 

 form. This coil is usually fixed permanently on board in a 



