A long lay will tend to increase the flexibility up to a point where, 

 if too great a load is placed on the core of a cable , its strength 

 will be reduced. 



The flexibility of a wire rope of fixed diameter also in- 

 creases with the number of wires or strands used in its con- 

 struction, with the size of the individual strands decreasing 

 proportionately. 



o I ' 



HAZARDS TO CABLE IN 

 OCEANOGRAPHIC OPERATIONS 



Cable used in oceanographic operations must meet rigorous 

 demands, imposed both by the ocean environment itself and by the 

 nature of the work in which the cable is used. The principal haz- 

 ards to the cable are as noted briefly here. 



Corrosion 



Constant exposure to sea water has a corrosive effect upon 

 cable, first appearing as microscopic pitting which cannot be de- 

 tected without powerful magnification. The pits act like little 

 keys; as they develop they restrict the action of the cable ele- 

 ments, creating stress concentration points, rapidly diminishing 

 the flexibility of the cable, and reducing its ability to withstand 

 impact loads and shock. Corroded rope creates a serious hazard 

 not only to the equipment being handled but to the persons using it. 

 Frequent inspection and regular lubrication are imperative, as by 

 the time the corrosive effect becomes visible it is too late to take 

 preventive action. 



Generally, corrosion attacks wire rope on the exposed sur- 

 face of the wire first and, when this is the case, it is readily ap- 

 parent. However, it is possible for corrosion to develop inside 



