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Poldhu Wireless Telegraphy Station
Poldhu Point, Mullion, Cornwall, UK
associated engineer
Guglielmo Marconi
date  1900
era  Victorian  |  category  Telecommmunications  |  reference  SW663195
Poldhu Wireless Telegraphy Station is sited on the cliffs at Poldhu Point, north west of Mullion, and was built by the Marconi Company of London to a design by John Ambrose Fleming. The first transatlantic wireless signals were sent from here to Newfoundland in 1901.
Guglielmo Marconi convinced sceptical investors to put 50,000 into his project to try to transmit messages across the Atlantic Ocean. Marconi had already sent and received messages over 300km, from his test station 10km away at his Lizard Wireless Telgraphy Station, proving that 'over the horizon' communications were possible. Now he sought to extend the distance much further and set up a commercial transatlantic wireless telegraphy service.
The station at Poldhu therefore contained much more powerful equipment than the apparatus at the Lizard. For example, the transmitter was powered by a 25W motor-driven generator. The aerial system was supported on a ring of 20 masts, each 61m tall and arranged in a circle of 61m diameter. Severe gales in September 1901 destroyed the aerial, which was replaced by one only 48m tall supported on two masts.
A receiving station of similar design was set up originally at Cape Cod in America, 5000km away. However, gales in November 1901 demolished the aerial, and the receiving station was moved to St John's, Newfoundland, which was only 3400km away. The new aerial consisted of some 150m of wire kept aloft by a kite.
Marconi travelled to Newfoundland to listen for the agreed signal an S in Morse code and on 12th December 1901 he heard it faintly in his earphones, but the signal was too weak to trigger the printer. In February 1902, Marconi set out from England on board the SS Philadelphia, recording messages from Poldhu as he travelled across the Atlantic. He received printed messages out to 1100km by day and 2500km by night, and aural signals out to 3400km at night. This convinced people that a transatlantic wireless communication system actually was possible.
Disputes with the undersea cable companies, with whom Marconi was competing for a share of the commercial telegraphy business, prevented the station in Newfoundland becoming permanent. Instead Marconi established one at Grace Bay, Nova Scotia, Canada, 4000km from Poldhu and its first signals were heard in Cornwall in November and December 1902.
However, by 1905 the Poldhu station was not suitable for a reliable transatlantic service, and a new station was built at Clifden, Ireland. At the time the trend was towards using lower frequencies and longer wavelengths for signals, which in turn required larger aerials.
In 1909, Marconi was awarded the Nobel Prize for Physics, jointly with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy".
Poldhu operated commercially with European stations and with shipping in the Atlantic until 1922, and as a wireless research station until 1934, although some buildings were demolished in 1933. A stone column with plaques commemorating Marconi's achievements was erected some 90m south west of the station. The Poldhu Wireless Telegraphy Station land was given to the National Trust in 1937, with most of the footings of the buildings and plinths of the mast anchor points remaining.
A new wooden building was constructed close by as a museum to honour the centenary of the first transatlantic wireless signal. Work began on 9th April 2001 and the new Marconi Centre was opened on 12th December 2001. It is likely that Marconi's grandson also named Guglielmo Marconi visited the station on that day, as he also visited the Lizard station.
The centre commemorates Marconi's work and achievements, houses transmitting equipment and exhibits, and acts as an operating base for amateur radio. The project was a joint venture between The National Trust, Marconi plc and Poldhu Amateur Radio Club, with funding from Objective One Partnership for Cornwall and Scilly, Marconi plc and the National Trust's Enterprise Neptune Fund.
Research: ECPK
bibliography
"Marconi at The Lizard The story of communication systems at Housel Bay"
by Courtney Rowe, Trevithick Society, 2000
www.bbc.co.uk
www.hamradio.piatt.com
www.lizardwireless.org
www.nationaltrust.org.uk
www.nobelprizes.com
Location

Poldhu Wireless Telegraphy Station