The telegraphic life : maintenance of the system 1850-1914 /John Trelawny Brooks Moyle

"Htherto, historians have assumed that one a submarine telegraph cable had been laid, it would provide 50 to 70 years of reliable service. As one who has practical experience of engineering in a professional capacity, I found this order of reliability difficult to believe. I therefore set out to try and determine how reliable or otherwise this technology actually was and how it was maintained. These questions had not been asked before and proved more difficult to answer than might have been predicted because much of the information was concealed, deliberately or otherwise, by the cable operating companies. However there were key clues such as the number of cable repair ships afloat and multiple textbooks on cable maintenance. Having unearthed useful data from the archives of the Eastern Telegraph Company (ETC) and of the Telegraph Construction and Maintenance Company, I conclude that the submarine telegraph cables during the period from the first experimental attempts in 1850 up until the Great War were not as reliable as previously assumed. On average, a voyage to repair these cables was required once per annum per 500 nautical miles of cable and this rate remained constant from 1873, when the ETC was formed, up until 1914, the end of my period of research. During this period the system which was composed of a submarine cable connecting two telegraph stations appeared increasingly reliable and efficient because of improvements in the technology at the cable stations and the duplication of many cables which allowed rerouting of communications when malfunctions occurred. I also conclude that data was concealed by operating companies for commercial reasons. If this concealment had been less, then the genesis of the discipline of reliability engineering in the 9140s might have been developed 50 years earlier"--Provided by the author.