country and in Great Britain, whose cooperative effort resulted 

 in the defeat of the U-boat „ Notable among these were the two 

 great U„ So Navy laboratories -- the Naval Research Laboratory 

 of the Bureau of Ships and the Naval Ordnance Laboratory of 

 the Bureau of Ordnance , and in Great Britain the Ant i- Submarine 

 Experimental Establishment of the Admiralty„ The part played 

 by our industrial research laboratories cannot be overemphasized; 

 not only did they originate many new ideas „ but they made the 

 important contribution of reducing to manufacturable form the 

 laboratory developments initiated by others „ Other divisions 

 of NDRC also contributed to the success of the anti-U-boat cara- 

 paign Most notable perhaps were the developments of Division 3 

 in rocket ordnance and of Division 14 in microwave radar If, 

 therefore j, the present volume appears to lack balance in terms 

 of the total Allied effort p it is because it is intended to be 

 the story of but one aspect of that efforto 



This volume is a record of achievement „ Yet s lest this 

 achievement lead to undue optimism, this introduction must end 

 on a note of warning. It must be remembered that the U-boat 

 at the end of World War II was not defeated,, It had been 

 driven to the defensive, but not from the seas German sub- 

 marines with their Schnorchel equipment were able to operate 

 as true undersea craft rather than as submersible torpedo 

 boatSo Japanese submarines were preparing to attempt opera- 

 tions as submersible aircraft carriers. New types of Nazi 

 U-boats capable of submerged speeds which might have made 

 current Allied anti-submarine gear and tactics obsolete s were 

 on the point of entering active service when the war ended. 

 Had the Nazis been able to advance by even six months the op- 

 erational use of these new-type submarines, the victory might 

 well have been materially delayed and made far more costly 



- 3 



