Section 56 



SEATTLE, WASHUHGTON — U. S. HAYAL STATIOT 



A56. 01 Location of the Teat Station and Test Boards 



Teat "boards of the panel type were installed June I5, 19^+^, at 

 different locations at the U. S. Naval Station at Seattle, Washington. 

 One of these hoards, designated hy the symbol USNS-1, was installed at 

 the southwest comer of Pier No. 90. The other, designated "by the 

 symbol USNS-2, was Installed at the southwest comer of Pier No. 91. 

 Both piers are located in ELllott Bay, Puget Sound. The operation of 

 these test hoards is being continued. The results of these tests have 

 "been summarized to the end of 1947. 



On Septeniber 15, 19hk, the Naval Station advised that the test 

 hoard at Pier No. 9I liad been destroyed. A new one was installed on 

 October 15. On August 20, 19it-5, the Naval Station advised that the 

 test board at this pier had a^ln been destroyed and had been replaced 

 by a new one on August 18. On February 15, 19k^, the Naval Station ad- 

 vised that the test board at Pier No. 90 had been destroyed. This 

 board was replaced by a new one on March 15 . On November 29, 19^5^ hews 

 came from the Naval Station that the test board at this pier had again 

 been destroyed. This board was replaced by a new one on February 8, 

 19h6. 



It was found by pulling and testing piling from different areas 

 of the piers at this station that the piles. had been damaged by marine 

 borers so extensively as to lose their structural value. These piles 

 had been in place 11 months when they were pulled for tests. Figure 9 

 shows sections of an untreated pile, removed from Pier No. 91, which 

 was almost completely destroyed by marine borers, 



A56.02, Hyarographlc Data 



The depths of water where the test boards were Installed were 

 50 ft at Pier No. 90 and 53.5 ft at Pier No. 9I. The tidal range was 

 19.5 ft (from -4.5 to /l4.8 ft). The velocity of the current was tidal 

 flow only, but on October 15, 19^6, it was stated to be 600 ft per hour 

 measured by the U, S, Coast and Geodetic Survey Office. The measure- 

 ments were taken one hour before and two hours after low water. The 

 direction of the water current one hour before low water was 108° j 

 after low water, 560° or due north. The tengjerature of the water at the 

 time of installation was 52° F at Pier No. 90 and 56° F at Pier No. 91. 

 The degree of polluticm was given as 10,000 Bacillus coll per 100 'cc. 

 By request of the Public Works Department of the Naval Station, analyses 

 were made at the Sanitary Engineering Laboratory on four san^jles of water 

 collected from Elliott Bay off Pier No. 91, following the completion of 



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