the fairing and modules. In addition, an attempt was made 

 to establish quantitative values of the tractive force with 

 faired and unfaired cable for various conditions of service 

 and for various values of the ratio of the maximum thick- 

 ness of the fairing to the cable diameter. For convenience, 

 wire rope was used for these tests. The results, presented 

 in (3) , are summarized in Table 1, below. 



TftBLE 1 

 CC*IPUTED VALUES OF STATIC COEFFICIENT OF FRICTION^ u- 



In the table, m- is defined as the ratio of the tension 

 in the rope to the normal force exerted on the rope by the 

 track treads. As is more fully explained in (3) „ the normal 

 force was deduced from measurement of the air pressure in the 



This seemingly anomalous result would indicate that wetting 

 increases the tractive coefficient of friction; the true 

 explanation would appear to be that at the higher tread 

 pressures the water has a negligible effect^, the discrepancy 

 in the results being attributable to inexactitude in deter- 

 mination of the inception of slipping or lifting. 



22 



