CONFIDENTIAL REPORT 2G-21
S17
     
 
FORMER GERMAN SUBMARINE TYPE XXI
 
 
 
 
TOWERS, MASTS, SPARS, CRANES AND DERRICKS
 
 
 
 
SUMMARY
 
     
          No towers, cranes, derricks, masts or spars are provided, except as noted under radar, radio and torpedo handling discussions.  The one fixed pipe mast for the after end of the after antenna does not appear on any available plan, and is apparently a concession to the limitations of the radio installation in the vessel.  Photographs of other vessels indicate that the mast was not always provided, and that a low tripod assembly was frequently employed.  From a standpoint of resistance to motion through the water, the light, low tripod is superior to the heavier, larger pipe mast, although probably inferior from an electronic standpoint.  
          Other than the foregoing, no comment is warranted, and no further exploitation is recommended.  
     
     
     
     
     
 
March, 1946
 
 
 
 
PORTSMOUTH NAVAL SHIPYARD, PORTSMOUTH, N. H.