DESCRIPTION OF EXPERIMENTAL EQUIPMENT 

 The experimental equipment consisted of a towed depressor body and the 

 experimental ribbon towcable. The towed body is shown in Figure 1; its dimen- 

 sions are given in Figure 2. This depressor weighs 1609 pounds (7204 N) in water 

 and has a variable incidence mid-wing. For this experiment, the wing incidence 

 angle was set at -5 (leading edge down) . The hydrodynamic performance of the 

 body as measured in the towing basin is shown in Figure 3. 



The ribbon towcable consisted of a 1450-ft (442-m) length of 0.78-inch 

 (1.98 cm) diameter, double-^armored, electrical-mechanical cable with ribbons 

 attached, as shown in Figure 4. The cable consisted of two layers, reverse lay, 

 of galvanized steel armor strands surrounding a 10-conductor electrical core. 

 The cable weighed 0.688 pounds per foot (1.02 kg/m) in sea water and had a 

 breaking strength of approximately 50,000 pounds (223,880 N) . The ribbons were 

 polyurethane strips threaded under the outer layers of armor. Ribbon geometry 

 is given in Table 1. 



TABLE 1 - CABLE AND RIBBON GEOMETRY 



Cable diameter 



0.78 in. 



(1.98 cm) 



Cable length 



1450 ft. 



(442 m) 



Ribbon loop length 



9.36 in. 



(23.77 cm) 



Ribbon length-to-cable- 







diameter ratio 



6 





Ribbon width 



0.78 in. 



(1.98 cm) 



Material thickness 



0.015 in 



. (.038 cm) 



Spacing (centers) 



0.78 in. 



(1.98 cm) 



Ribbon coverage 



100% 





The towcable was marked at 100-ft (30.5-m) intervals to permit estimation 

 of cable scope in the water to about +5 ft (+ 1.5 m). 



