-3- 



high-speed towing target for the War Department Coast Artillery. 

 A 25-foot by 12-foot rectangular timber sled was the result of 

 this investigation,. 



Subsequently^, the demand for larger target screens 

 and higher target speeds led to further investigations and the 

 ultimate development of 30-., 40-, and 60-foot sleds (2)„ The 

 present 60-foot sled is reported to perform the best of the 

 series, however, it is not entirely satisfactory,, Because of 

 the high resistance of the target, the relative instability 

 when under tow, and the limited strength of the towing cable, 

 failures have occurred in service 



In order to reduce the cable tension and develop an 

 improved planing-type target, the Bureau of Ships prepared plans 

 for three new designs of targets and requested (3) that the 

 Taylor Model Basin conduct tests on models of the new designs 

 and on a model of the revised 60-foot sled-type target to ob- 

 tain quantitative data. 



In addition to the four models constructed from the 

 Bureau of Ships plans, a fifth model was developed at the 

 Taylor Model Basin,, '^he Bureau of Ships subsequently requested 

 (4) that maneuvering tests of the models be conducted in the 

 Potomac River to observe the effect of varying the fore and 

 aft position of the towpointo 



DESCRIPTION OF MODELS 



The TMB model numbers and the corresponding full- 

 scale design designations are given below; 



