1126 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1957 



Natural fibers, notably jute, have been degraded extensively by borers 

 and microorganisms. There is considerable evidence of fiuigus attack. 



Under fouling and in the sediment area, rods of polyvinvl chloride 

 plastics containing basic lead stabilizers have been blackened as the re- 

 sult of hydrogen sulfide produced by sulfate-reducing bacteria reacting 

 with the lead salts to give black lead sulfide. This sulfiding has caused 

 no apparent degradation of the physical properties of the plastics. 



4. The examination of cable samples from service has indicated that 

 the impregnated outer jute serves an important function in limiting cor- 

 rosion of armor wires. Generally, when corrosion is present the outer jute 

 has been lost. 



Two unusual cases of extensive corrosion have been reported • — one 

 in a cable 12 years old, the other in a cable which was in service 36 years. 

 In both cases, corrosion occurred in pockets between adjacent armor 

 wires rather than on the outside surfaces (water side) of the wires. 



The performance of the inner jute in samples from service has been 

 generally good for as long as 30 or 40 years in deep water. In samples 

 from relatively shallow water in the Caribbean, inner jute bedding was 

 l)adly deteriorated in as short a time as five years. 



ACKNOWLEDGMENTS 



The data which have been acquired in this program are the result of 

 teamwork by many different members of the Laboratories. Special 

 thanks are due to Priscilla Leach for obtaining much of the data in the 

 BOD test, and her general assistance on many phases of the program. 

 Madeline L. Cook is responsible for the majority of the electrical meas- 

 urements in the conductor tests. T. D. Kegelman, formerly of the 

 Laboratories, and W. C. Gibson gave considerable assistance in setting 

 up the equipment and establishing the procedures for measurement of 

 capacitance and conductance. Many members of the Chemical Research 

 Department cooperated in furnishing the materials which have been 

 tested. J. B. DeCoste has been particularly helpful in assembling the 

 recjuired information on the materials. From outside the Laboratories, 

 Professor Claude E. ZoBell of the Scripps Institute of Oceanography has 

 made many helpful suggestions and comments with regard to the labora- 

 tory portion of the program, and provided supplementary enrichment 

 cultures and samples of sediment. The marine borer test program has 

 been executed with the cooperation of A. P. Richards, William F. Clapp 

 Laboratories, Inc., who has furnished nuich valuable information in 

 many discussions of the tests. The cooperation of C. S. Lawton, Western 

 Union Telegraph Company, and the personnel of C. S. Lord Kelvin in 



