Cable Fairing 



Considerable effort has been expended, during the past 

 ten years, on the development of a satisfactory design for 

 cable fairing. The most outstanding development of this 

 period was the David Taylor Model Basin enclosed fairing 

 design (DTMB No. 7). This fairing, of molded rubber in a 

 streamline cross section, completely encloses the cable. 

 The fairing was used in continuous lengths for such applications 

 as the air-towed and ship-towed sonar. Success was tempered by 

 serious problems in handling and storing, as fairing of the 

 enclosed design did not lend itself to running oyer drums 

 and sheaves under load. Canadian researchers partially 

 solved the handling problem when they modified the DTMB design 

 and clipped the fairing to the cable. Certain improvements 

 in this modification were introduced at DTMB as a result of 

 model studies. It was found that the fineness ratio (the 

 ratio of the chord length of cable-plus-fairing to the cable 

 diameter) could be reduced to 4:1. It was also found that 

 the ideal fairing thickness was about eight-tenths the diameter 

 of the cable. A clip-type fairing for a three-quarter-inch 

 ccible designed according to these specifications, is shown in 

 Figure 9. 



The tendency of fairing to stretch more than cable under 

 load constitutes a serious design problem. Even with fiber 

 reinforcing strands molded into the leading edge, long sections 

 of fairing tend to stretch along the cable and bunch up at 



37 ' 



