History of the Atlantic Cable & Undersea Communications
from the first submarine cable of 1850 to the worldwide fiber optic network
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History of the Atlantic Cable & Undersea Communications |
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Cable Stamps - Repeaters and Branching Unit |
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to Bill Glover for providing the stamp images and text for this page. All material on this page is copyright © 2005 Bill Glover |
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| ENGLAND - FRANCE TELEPHONE CABLE 1891 Comoro Islands 1976 25f The first commercial submarine telephone cable was laid between England and France in 1891. It could only carry one telephone call at a time. Siemens Brothers manufactured the cable which was laid by CS Monarch (2). Later developments were to include more conductors in the cable to enable more calls to be made at the same time. But until the development of the submerged repeater, equipment that could receive, amplify and retransmit signals, such cables could only be used over relatively short distances. |
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SUBMARINE CABLE REPEATERS
The GPO had concentrated its research on developing a repeater for use in shallow waters and on 24 June 1943, using HMCS Iris (2), inserted the first commercial one way repeater into the Anglesey - Isle of Man telephone cable, doubling the number of circuits. It failed after five months but the replacement worked for seven years. Further research brought about the development of the two-way rigid repeater and in 1950 CS Alert (3) inserted four two-way repeaters into the Aldeburgh, England - Domberg, Holland, No 4 cable. In the following year the same number were inserted into the No 5 cable. These rigid repeaters were difficult to lay, the cable ship having to stop while they were inserted into the cable. In America, AT&T worked on a deep water system using one way rigid repeaters. When TAT 1 was laid the AT&T system was used between Oban, Scotland and Clarenville, Newfoundland using two cables, one for each direction, each with one way repeaters. The GPO system, one cable with two way repeaters, was used from Clarenville to Sydney Mines, Nova Scotia. Similar arrangements were made for TAT 2. TAT 3 however used two way rigid repeaters, eliminating the need for two cables. The development of a two way flexible repeater made laying cables much easier. The benefits to submarine telegraphy of this device were enormous. Early versions enabled each telephone circuit to carry a minimum of twenty telegraph circuits. See also David Watson's article on splicing repeaters into the cable on board ship. |
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BRANCHING UNIT Vietnam S. R. 1993 2500d A device which allows pairs of fibres in a fibre optic cable to be separated and routed to different landing points. |
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Many additional stamps are shown on the pages linked from the Stamps Index page
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Last revised: 18 May, 2010 |
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