i 



1098 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1957 



for the laboratory microbiological portion of the program, as well as a 

 means of evaluating the relative performance of materials in the physical 

 and chemical conditions of the ocean. 



The integrated program, shown in Fig. 1, involves a series of three 

 laboratory tests on the one hand, and actual marine exposure on the 

 other. Eventually, more than fifty different materials including plastics, 

 elastomers, natural and synthetic fibers, as well as sections of cable will 

 be tested. The present paper is in the nature of a progress report in which 

 only a portion of the data to be acquired are presented. The results of the 

 program to date will be examined beginning with the laboratory experi- 

 ments. 



III. LABORATORY TESTS 



3.1 Biochemical Oxygen Demand Type Test 



The BOD (biochemical oxygen demand) type of test as applied in this 

 study is really composed of two separate bioassay procedures. In one 

 case, the oxygen consumed by aerobic bacteria is determined, and in the 

 other a metabolic by-product resulting from anaerobic activity is meas- 

 ured. With a few changes, both methods follow those which have been 

 employed by ZoBelP^ in tests of elastomers and various natural organic 

 materials. 



There is one point which should be emphasized regarding both the 

 aerobic and anaerobic procedures used in this accelerated sea water test. 

 It is considered primarily a screening test which provides basic data on 



BIOLOGICAL TEST PROGRAM 



LABORATORY TESTS 



CONDUCTOR TEST 



MEASURE 

 BREAKDOWN 

 OF DIELECTRIC 

 (MONTHS OR YEARS) 



SOIL BURIAL 



ELECTRICAL 

 OR PHYSICAL 

 MEASUREMENTS 

 (MONTHS OR YEARS] 



MARINE EXPOSURE 



I 



MARINE BORER TESTS 



WRIGHTSVILLE 

 BEACH, N.C. 



DAYTONA 

 BEACH, FLA 



ANALYSIS OF 



CABLE 



SAMPLES 



FROM SERVICE 



Fig. 1 — Outline of marine biological test program. 



