The First Transatlantic Telegraph Cable Was a Bold, Beautiful Failure

By Allison Marsh

On 16 August 1858, Queen Victoria and U.S. President James Buchanan exchanged telegraphic pleasantries, inaugurating the first transatlantic cable connecting British North America to Ireland. It wasn’t exactly instant messaging: The queen’s 98-word greeting of goodwill took almost 16 hours to send through the 3,200-kilometer cable. Still, compared to packet steamships, which could take 10 days to cross the Atlantic, the cable promised a tremendous improvement in speed for urgent communications.

This milestone in telegraphy had been a long time coming. Samuel Morse first suggested linking the two continents in 1840, and various attempts were made over the ensuing years. Progress on the project took off in the mid-1850s when U.S. entrepreneur Cyrus W. Field began investing heavily in telegraphy.

Field had made his fortune in the paper industry by the age of 34. The first telegraph project he invested in was a link from St. Johns, Newfoundland, to New York City, as envisioned by Canadian engineer Frederic Newton Gisborne. The venture never secured enough funding, but Field’s enthusiasm for telegraphy was undiminished. Over the next decade, he invested his own money and rallied other inventors and investors to form several telegraph companies.

The most audacious of these was the Atlantic Telegraph Company (ATC). Field and the English engineers John Watkins Brett and Charles Tilston Bright, both specialists in submarine telegraphy, formed the company in 1856, with the goal of laying a transatlantic cable. The British and U.S. governments both agreed to subsidize the project.

Terrestrial telegraphy was by then well established, and several shorter submarine cables had been deployed in Europe and the United States. Still, the transatlantic cable’s great length posed some unique challenges, especially because transmission theory and cable design were still very much under debate.

Morse and British physicist Michael Faraday believed that the conducting wire of a submarine cable should be as narrow as possible, to limit retardation of the signal. And the wider the wire, the more electricity would be needed to charge it. Edward Orange Wildman Whitehouse, an electrician for the Atlantic Telegraph Company, subscribed to this view.

The other school of thought was represented by William Thomson (later Lord Kelvin). He argued that the amount of retardation was inversely proportional to the square of the cable’s length. Thomson suggested using a large-diameter core made with the purest copper available in order to reduce the resistance. Bright, the project’s chief engineer, shared Thomson’s view. This design was significantly heavier and more costly than the one proposed by the Morse-Faraday school, and the ATC did not adopt it.

The Gutta Percha Co. manufactured the cable’s core and insulation. The core consisted of seven strands of copper wire twisted together to make a wire 0.083 inch in diameter. The finished core weighed 107 pounds per nautical mile, which was significantly lighter than the 392 pounds per nautical mile that Thomson and Bright had proposed. The copper core was wrapped in three layers of gutta-percha, a latex that comes from trees of the same name. The insulated core was then covered in tarred hemp and wrapped with iron wire. The finished cable was about five-eighths of an inch in diameter.

At the time, no ship could carry all of the submarine cable needed, so the cargo was split between two naval ships, the HMS Agamemnon and the USSF Niagara, both of which were refitted to carry the load. It took three weeks to load the cable. Many spectators gathered to watch, while local officials and visiting dignitaries treated the naval officers to countless dinners and celebrations, much of which was recorded and amplified by the press.

Of course, two ships meant that the cables would have to be spliced together at some point. Once again, there was disagreement about how to proceed.

Bright argued for splicing the cable in midocean and then having each ship head in opposite directions, paying out its cable as it went. Whitehouse and the other electricians preferred to begin laying the cable in Ireland and splicing in the second half once the first half had been laid. This plan would allow continuous contact with the shore and ongoing testing of the cable’s signal. Bright’s plan had the advantage of having the time to lay the cable, thus lessening the chance of encountering foul weather.

The directors initially chose Whitehouse’s plan. Niagara and Agamemnon met at Queenstown, Ireland, to test the cable with a temporary splice. After a successful transmission, the ships headed to Valentia Bay to begin their mission, escorted by the USS Susquehanna and the HMS Leopard. Also joining the fleet were the support ships HMS Advice, HMS Willing Mind, and HMS Cyclops.

On 5 August 1857, the expedition got underway. The first portion of the cable to be laid was known as the shore cable: heavily reinforced line to guard against strains of waves, currents, rocks, and anchors. But less than 5 miles out, the shore cable got caught in the machinery and broke. The fleet returned to port.

Go to IEEE The Institute to read the complete article.