ANALYSIS OF THE CONDITION OF ECHO TOWER, AZORES FIXED ACOUSTIC RANGE, 

 AFTER ONE YEAR AT 1500 FEET OF DEPTH 



Technical Note N-1284 



52-021 



by 



James F. Jenkins 



ABSTRACT 



The condition of ECHO tower after a one year exposure to seawater at 

 a depth of 1500 feet was analyzed immediately after recovery, after five 

 days exposure near the surface and after removal from the sea. The only 

 areas of critical corrosion were several pits found on the antennas. 

 These pits were recoated but failure of the repair coatings could result 

 in tube penetration in as little as one year of additional exposure. 

 Recommendations for modification of existing towers to increase their 

 useful life, as well as that of future designs, are given. 



Approved for public release; 

 distribution unlimited. 



