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 Section k6 



BALBOA, CAHAL ZOHE ^- U. S. MVAL STATION 



Ai)-6. 01 Location of the Test Station and Test Boards 



Tvro test toardfl of the panel type were Installed June 15* 19^^ » 

 at the U. S. Naval Station at Ballioa, Canal Zone. This Station Is 

 located at the western end of the Panama Canal on the Pacific Ocean 

 side of the Isthmus of Panama. The test hoards were Installed near 

 the San Juan rump on the west hank of the Canal at the north end of 

 Balljoa Barhor, Just across from Balhoa. Two kinds of wood were used for 

 panels, namely Southern yellow pine and Douigslas fir, as hoth kinds are 

 used in waterfront structures at this Station. These test "boards were 

 designated hy the symbols USMCZ-l and USMCZ-2, the first hoard having 

 panels of Southern yellow pine and the second, panels of Douglas fir. 

 The test hoards were suspended from an untreated wooden dock and were 

 covered at all times hy salt water at the Pacific end of the Canal. 

 They were Installed approximately 3 ft from an untreated pine pile. 



On Novemher 20, 19^5, a new series of panels was installed on 

 Test Board No. 1, for which the period of suhmergence was reduced from 

 8 to Jf months on accoimt of the destructiveness of the Teredinldae . 

 The operation of the second test hoard was discontinued at this time, as 

 it gave essentially the same results with respect to marine horers 

 as did the first hoard. 



In January 19'4-6, the near collapse of the untreated pile structure, 

 from which Test Board No. 1 was still suspended, necessitated the relocation 

 of that hoard; it was Installed on a pile cluster (treated piling) 

 50 ft south of its original location. The operation of this test hoard 

 is heing 6ontlnued, and the results of these tests have heen summarized 

 to the end of 19^7. 



Ak6.02 Hydrographic Data 



1. The mean depth of water at the location where the test hoards 

 were Installed was 22 ft. The maximum range of tide was 22 ft, and the 

 normal range was 12 ft. The velocity of the cvirrent was approximately 

 5 knots. The temperature of the water was given as 75° F to 

 80° F, though whether this is the range for the year is not clear. 

 It was reported that a slight dilution of the salt water may occur at 

 this location hecause of fresh water discharged from the ca n al locks 

 located approximately l^- miles upstream from the test hoards. To 

 determine the degree of pollution of the water at this location, samples 

 were taken from the end of the wooden pier nesif the salvage yard on 

 three successive days at high, mean, eind low water. Tests made on these 



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