This is a section of the shore end of a submarine telegraph cable.
The shore-ends of a telegraph cable could extend several miles from land on either coast. Shore-end cable was manufactured separately from the main deep-sea cable, and was constructed to be of greater strength than the main cable to withstand the more severe conditions close to shore. The shore-end section of the cable could weigh up to or more than twenty tons to the mile, and measured more than an inch or two in diameter at the shore end. The diameter would diminish gradually, in its last few hundred yards, to the ordinary size of the main deep-sea cable, with which it was joined. The shore end cable and the main length cable had the same core, but the core was wrapped differently and covered outside by a winding of several thick strands of galvanised iron wires.
Shore-end cables usually have two layers of armouring wire. A display label for this object, dating from 1915 or 1916, describes it as a "Cross section of the shore end of a light cable." Theis may explain why only one layer of armouring wire is present.
The cable was donated by S.W. Silver & Co of London, England. There is no indication as to where the cable of which this is a sample was actually used.
The cable has a stranded central conductor made up of 7 wires, each with a diameter of about 1 mm. The conductor is surrounded by insulating material, probably gutta percha, to a diameter of about 8 mm. A wrapping of fabric, possibly jute or hemp, takes the diameter to about 12 mm. Finally, the cable is armoured with 12 wires with a left-hand lay, each wire having a diameter of about 4 mm.
Donation from S.W. Silver & Co
Type of item
68 mm (Length)