Transatlantic Telegraph Cable - Transatlantic

Transatlantic

With Charles Tilston Bright as chief engineer, Field then directed the transoceanic cable effort. A survey was made of the proposed route and showed that the cable was feasible. Funds were raised from both American and British sources by selling shares in the Atlantic Telegraph Company. Field himself supplied a quarter of the needed capital.

The cable consisted of seven copper wires, each weighing 26 kg/km (107 pounds per nautical mile), covered with three coats of gutta-percha, weighing 64 kg/km (261 pounds per nautical mile), and wound with tarred hemp, over which a sheath of 18 strands, each of seven iron wires, was laid in a close spiral. It weighed nearly 550 kg/km (1.1 tons per nautical mile), was relatively flexible and was able to withstand a pull of several tens of kilonewtons (several tons). It was made jointly by two English firms – Glass, Elliot & Co., of Greenwich, and R. S. Newall & Co., of Birkenhead. Late in manufacturing it was discovered that the respective sections had been made with strands twisted in opposite directions. While the two sections proved a simple matter to join, this mistake subsequently became magnified in the public mind.

The British government gave Field a subsidy of £1,400 a year and loaned the ships needed. Field solicited aid from the United States Congress. The vote was very close, with a number of anglophobe senators opposing any grant, but the Bill was passed by a single vote. In the House of Representatives it encountered a similar hostility, but was ultimately signed by President Franklin Pierce.

The first attempt, in 1857, was a failure. The cable-laying vessels were the converted warships HMS Agamemnon and USS Niagara. The cable was started at the white strand near Ballycarbery Castle County Kerry, the southwest coast of Ireland, on August 5, 1857. The cable broke on the first day, but was grappled and repaired; it broke again over the 'telegraph plateau,' nearly 3,200 m (2 statute miles) deep, and the operation was abandoned for the year.

The following summer the Agamemnon and Niagara, after experiments in the Bay of Biscay, tried again. The vessels were to meet in the middle of the Atlantic, where the two halves of the cable were to be spliced together, and while the Agamemnon paid out eastwards to Valentia Island the Niagara was to pay out westward to Newfoundland. On June 26, the middle splice was made and the cable was dropped. Again the cable broke, the first time after less than 5.5 km (three nautical miles), again after some 100 km (54 nautical miles) and for a third time when about 370 km (200 nautical miles) of cable had run out of each vessel.

The expedition returned to Queenstown and set out again on July 17 with little enthusiasm among the crews. The middle splice was finished on July 29, 1858. The cable ran easily this time. The Niagara arrived in Trinity Bay, Newfoundland on August 4 and the next morning the shore end was landed. The Agamemnon made an equally successful run. On August 5, she arrived at Valentia Island, and the shore end was landed at Knightstown and then laid to the nearby cable house.