The computations were made for speeds from 1 to 6 knots and cable 

 lengths up to 2^0 feet. The resulting predictions are presented in 

 Figure B-k as depth of detector as a function of cable length in the 

 water for speeds of 1 to 6 knots and in Figure B-5 as tension at the 

 ship as a function of cable length in the water. 



Figure B-k may be used as a guide to determine the minimum amount of 

 cable that must be used to reach a desired depth for a particular survey- 

 speed. Figure B-5 may be used as a guide to determine the strength of 

 cable required for a particular survey speed. 



CONCLUSIONS AND RECOMMENDATIONS 



Based on the results of the towing tests, the following are concluded: 



1. The detector vehicle has good tracking characteristics for 

 all speeds up to 6 knots . 



2. The detector housing will not rotate unless in contact 

 with the bottom. 



3. At the design survey speed of k knots and a cable scope of 

 200 feet, the detector will maintain bottom contact in water 

 depths down to 80 feet. At an increased speed of 6 knots, 

 contact is maintained at depths down to 55 feet. 



k. The addition of approximately 100 pounds of weight will 



neither effectively increase the bottom contact capability 

 nor impair the tracking characterisitcs of the vehicle. 



In using the CERC towcable during survey operations, one obvious 

 modification is recommended. The present towcable, consisting of a 

 lA-inch wire rope and two plastic tubes containing the electrical leads, 

 should be replaced by an electro-mechanical towcable. This modified cable 

 might be constructed of two reverse lays of steel wire wrapped around a 

 core containing the necessary electrical conductors. This arrangement 

 should simplify handling, reduce the drag on the towcable, increase the 

 depth capability for a shorter length of cable, and make the electrical 

 bundles less susceptible to wear. 



B-8 



