the full-size torpedoes. The next step was to work out funda- 

 mental theory which would bring the basic concepts of small- 

 scale modeling into a more serviceable relationship with full- 

 scale performance. This investigation was in progress when 

 the war ended. It forms part of the continuing program of 

 research which y along with the Morris Dam Laboratory and the 

 model tank, is being carried on by the underwater ordnance 

 section of the Naval Ordnance Test Station, Inyokernj, California, 



Torpedo Launc hi rig Station, 



In the fall of 1942 the Bureau of Ordnance requested NDRC 

 to undertake the development of a new aircraft torpedo which 

 would give satisfactory performance when dropped from high- 

 speed planes at higher altitudes. Such a development was a 

 major enterprise. Within NDRC, Division 6 was given respon- 

 sibility for the design work and Division 3 for furnishing 

 basic information for the design. The Morris Dam Laboratory 

 set up a torpedo launching station, where California Institute 

 of Technology groups under contracts with both Divisions worked 

 together under the supervision of P, C, Lindvall, The Division 

 3 part of the work (under contract OEMsr-418) Involved full- 

 scale studies of the fundamental hydromechanical phenomena 

 associated with high speed water entry of torpedoes. 



The general problems which were set for the CIT torpedo 

 launching range were ; 



(1) General hydrodynamic effects at entry, 



(2) The effect of dynamic characteristics of the torpedo, 



(3) The effect of nose and tail structures on entry 

 and underwater trs jectories , 



(4) The determination of underwater trajectories, 



(5) The measurement of deceleration forces and the 

 effects on structure and mechanisms of the con- 

 sequent impact loadings „ 



(6) The general structural aspects of the entry problem. 



In particular, dynamic loading data were sought which 

 could serve as a basis for future torpedo design. Furthermore, 

 as a general problem, the Mark 13 torpedo was to be studied 

 under controlled entry conditions for clues to improvements 

 in both dynamic and structural behavior. 



Functionally the work divided Itself into engineering 

 design and structural analysis of torpedo bodies and components, 



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