-12- 



affect the directional stability. With the single cable attach- 

 ment the boat-type and the TMB-design targets have a tendency 

 to be self-righting when capsized. 



3. At full-scale speeds up to 35 knots, the boat-type 

 and the TMB-design targets have towing and resistance charac- 

 teristics superior to the sled- type targets. At full-scale 

 speeds above 35 knots, the two boat-type targets have better 

 resistance characteristics than the TMB design but they are 

 susceptible to porpoising. The porpoising is of sufficient 

 severity to make it inadvisable to operate the boat- type tar- 

 gets at these speeds. The TMB design does not porpoise at any 

 speed, even when violently disturbed. 



4. The estimated full-scale horizontal drag with simu- 

 lated cable load is less for the two boat-type and the TMB- 

 design targets than for the sled- type targets. With the excep- 

 tion of the revised G-60 sled-type target, all of the targets 

 have, at high speeds with long cable lengths and at both displace • 

 ments, practically equal horizontal cable tension. Similarly, 

 with the exception of the revised G-60 sled-type target, for 

 60,000 pounds horizontal cable tension and a given length of 

 cable, within the limits of the tests, the estimated maximum 

 speed attainable with either displacement is practically the 



same for all of the targets. This leads to the conclusion 

 that the fundamental factors involved in the design of a tar- 

 get with improved towing characteristics are not the conditions 



