Chapter 6 



DESCRIPTION AND OPERATIONAL PROCEDURES 

 OF THE USRL TEST STATIONS 



By Erhard Hartmann and Earle C. Gregg, Jr. 



6.1 DESCRIPTION OF MOUNTAIN LAKES 

 TEST STATION 



611 Site of Station 



The mountain lakes test station is located on Crys- 

 tal Lake in the township of Mountain Lakes, New 

 Jersey. This lake is about 650 yards long and 230 

 yards wide, and has a small island approximately at 

 the center. 



The depth of the lake is fairly uniform, averaging 

 about 15 feet. The bottom is a thick stratum of mud, 



which has good sound-absorbing properties, espe- 

 cially at supersonic frequencies. The mud, however, 

 contains some decomposing organic material which 

 produces gas bubbles. Since these are good reflectors 

 of sound, the top layer of the mud which contains the 

 decomposing material has been removed from the 

 bottom of the test areas by dredging. The depth of the 

 water in these areas has been accordingly increased 

 to about 18 feet. In addition, the lake has been 

 treated frequently with copper sulphate to retard 

 decomposition and the growth of algae. 



TERM BOXES 

 REC BOOTH 



POWER ROOM 

 -PAINT STORAGE 



Fira'RE 1. Plan view of Mountain Lakes laboratory and grounds. 



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