View of Porthcurno beach from the coastal path

Porthcurno's submarine telegraph system

Beneath the sands of Porthcurno, Cornwall, lie the remains of a submarine telegraph system that helped pave the way for modern communications technology.

In the far west of Cornwall, beyond Penzance and just three miles east of Land's End, lies one of the most beautiful beaches in Britain. Porthcurno, the name is reputedly a derivation of 'bay of rocks' in old Cornish, is an idyllic cove, sheltered between towering granite cliffs, with a beach of pale soft sand sloping into the turquoise sea. It takes a bit of getting to, but on a summer's day the other-worldly beauty of the place is a veritable magnet for tourists.

But Porthcurno is much more than a 'hot' beach. In the last decades of the 19th Century, and the opening decades of the 20th Century, this isolated Cornish valley was home to the world's largest and most important telegraph cable station. This was the heyday of the British Empire, and it was through cables passing under Porthcurno's inviting sands, reaching out to the farthermost ends of the earth, that Britain was able to exercise sway over more than 450 million people and a quarter of the world's land area.

A safe haven

The British government was an early convert to the benefits of long-distance telegraphy. In 1857, during the Indian Mutiny, an emergency request for troops had taken 40 days to reach London from Lucknow. The following year, with the Mutiny effectively over, the government managed to get a message through the short-lived 1858 transatlantic cable, cancelling an embarkation order to troops in Canada and saving an estimated £50,000.

The first London-to-India telegraph link was opened in 1864. This ran overland through Europe to the Musandam Peninsula at the top of the Persian Gulf, then on to India via undersea cable. Unfortunately, problems with the overland section – it was prone to attacks by the locals – limited its usefulness, forcing the government to invest in a new link between Britain and India. This was all undersea, apart from a relatively short length across Egypt.

London to India via Porthcurno

The last section of this new cable, laid by the Falmouth, Gibraltar and Malta Telegraph Company, was brought ashore at Porthcurno on 8 June 1870. As the name suggests, the original intention was to bring the cable ashore at Falmouth, but late in the planning stage it was decided that the risk from ships' anchors in that area was too great, prompting the switch to Porthcurno.

Watching the landing of this cable was the one-time Manchester cotton merchant John Pender, who had been a director of the Atlantic Telegraph Company, responsible for the 1858 transatlantic cable. Four separate companies had been involved in laying the 1870 London-India cable, and in 1872, under Pender's chairmanship, they were all merged to form the Eastern Telegraph Company.

This company went on to develop a worldwide telegraph network – aptly called the 'Victorian Internet' – with Porthcurno as its principal station. When Pender died in 1896, he was the undisputed leader of the worldwide cable business, with the well-earned soubriquet 'The Cable King'.

At its height, 14 separate telegraph cables were landed at Porthcurno, necessitating the employment of a sizeable workforce. Teams of operators were required to read and re-key cable traffic – automatic signal regenerating equipment wasn't introduced until the mid 1920s – and the station also acted as a training centre for operators destined to work in overseas cable stations.

At the turn of the 20th Century, some 150 staff and trainees were based at Porthcurno. They must have been a rugged, independent lot, with the nearest sizeable settlement, Penzance, seven miles way along a potholed road. With intended irony, the Porthcurno staff social club was called 'The Exiles'.

Technology is ever changing, and by the 1920s, Marconi's radio telegraph was beginning to undermine the profitability of cable telegraphy. In 1928 the Imperial Wireless and Cable Conference, held in London, led to the merger of cable and wireless networks, to form Imperial and International Communications Limited – changed to Cable & Wireless in 1934.

Broadband communications

In the end, it was the submarine telephone cable that finally ended telegraphy's long reign. In 1952, Cable & Wireless's last major telegraph cable was laid from Porthcurno to Harbour Grace, Newfoundland. Four years later, TAT-1, the first submarine transatlantic telephony cable system began operating between Scotland and Newfoundland, initially carrying 36 telephone channels.

In 1983, TAT-7 was brought ashore at Porthcurno from New Jersey. With an initial capacity of 4,000 telephone circuits, it was one of the last transatlantic coaxial cables to be laid. Five years later, the fibre-optic TAT-8 came into service – the era of international broadband communications had arrived and telegraphy was fading into history.

The last telegraph circuit at Porthcurno was closed in 1970, but this didn't mean the end of the valley's link with international communications. After World War Two, Porthcurno's training function expanded with the opening of the Cable & Wireless Telegraph Engineering College. The college remained at Porthcurno until 1993, when it moved to Coventry. Four years later, on 28 March, 1997, the college buildings were re-opened as the Cable & Wireless Museum of Submarine Telegraphy, under the auspices of the PK Trust, an independent educational charity set up by Cable & Wireless. 'PK' had been Porthcurno's telegraphic code.

Telegraphy was the first major application of electricity, and the technical and commercial challenges faced by the pioneers of submarine cable systems were the inspiration for one of the great stories of human endeavour. In the communications age, it's good to remember how we got to where we are, and the engineers and scientists who made our journey possible. The Porthcurno museum does all that, and more. You can't miss it – it's the large white building just up from the beach. 

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