TELEPHONE LINE WIRE SPACING PROBLEMS 



221 



pair of wires with equal sags, the appHcability of the accelerated 

 method is not limited to this case. It was also used where the sags 

 in the two wires of a pair were unequal and, as referred to later, for 

 determining the most promising design of insulating disc (described 

 below) for use in natural wind tests as a means of mitigating the 

 contacting on pairs with the wires spaced, 3, 4 and 6 inches. 



Anti-Contacting Insulators 



As stated above it was found that wires spaced 3 or 4 inches con- 

 tacted in wind velocities rather commonly experienced. Some 



Fig. 14 — Insulating disc. 



contacting was also recorded on pairs with wires spaced 6 inches. 

 In giving consideration to means of increasing the natural wind 

 threshold velocities of such circuits to those occurring less frequently, 

 two types of anti-contacting insulators were developed. One type, 

 Fig. 14, was a perforated disc of insulating material. When this type 

 was installed on one wire of a pair it was not in contact with the other 

 wire of the pair except when forced there by the action of the wires 

 in wind. The other type, Fig. 15, was a rod-shaped insulating spacer. 

 This spacer bridged the two wires of a pair in the span. 



The insulating discs used were 3 and 4 inches in diameter. The 

 arrangements of these discs tested in natural winds comprised one, 

 two or three discs per span per pair of wires. When one disc was 

 used, it was placed at the approximate center of the span on the wire 



