Section 9 

 BROOKLYN, HEW YORK — U. S. MVAL MAGAZIHE AT FORT LAFAIETTE 



A9.01 Location of the Teat Station and Test Board 



A test "board of the panel type was operated at the U. S. Naval 

 Magazine at Fort Lafayette, Brooklyn, New York, from May Jl, 19l^l^, to 

 October 2, 19^6. No further panels have "been received since the latter 

 date, and no reason has "been given for the discontinuance of this test 

 hoard. The Fort is located on the east side of The Narrows where upper 

 Hew York Bay connects with the Atlantic Ocean. The test "board was 

 suspended xinder the dock at the northwest comer of the Fort and was 

 exposed to the free movement of water under the dock. 



A9.02 Hydrographlc Data 



The depth of water where the test "board was installed was approxi- 

 mately 15 ft at low tide and 20 ft at high tide. The lower end of the 

 "board was a'bout 7 ft from the "bottom. The mean range of tide at Fort 

 Hamilton was given as U.7 ft and the spring range as 5.6 ft. The standard 

 current ta^blea give the average velocity of the current ais one knot, 

 with a spring velocity of 1.2 knots. Local o'baervations have indicated 

 a maximum speed of e"b"blng tide as U.5 knots and a maximum of rising tide 

 as 3.5 knots. It was noted, however, that the standard tahles for The 

 Narrows to the west of the Island indicate a maximum velocity of flood 

 tide of 2.6 knots, with a maximum e"b"b of 2.7 knots. The temperature of 

 the water at the time of installation was 62° F. The standard of salinity 

 of sea water, taken 200 miles east of Hew York Harhor and averaged from 

 191^ to 19^5* vas 52.5 parts of the salt per 1,000. In The Narrows, in 

 the vicinity of Fort Lafayette during this same period, salinity varied 

 from 21.5 to 26.5 parts of salt per 1,000. Three sewers were reported 

 to empty into The Narrows within a radius of one mile of Fort Lafayette. 



A9.O5 Marine Borers 



1. Teredlnidae . Ho evidence whatever of Teredinida^ was recorded 

 during the test. 



2. Llmnoria . No evidence of Limnoria was recorded in any of the 

 control panels, and only from 2 to 20 tunnels were recorded in 5 test 

 panels removed on August 1, Octoher 1, and Novem'ber 1, 191^5, after having 

 "been su"bmerged for 8 months. While only the "bfitrest trace of Llmnoria was 

 recorded during the test, damage "by this crustacean "borer led to the 

 removal of a conalderahie numher of piling at this location in 195^, as 

 evidenced "by a series of photographs on file. 



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