IRON AND COPPER
This year; 2016, saw a number of engineering anniversaries impacting on Wales, most of which concerned bridges, the 200th anniversary of Chepstow Wye Bridge was celebrated on 24th July with a number of events including a re-enactment of the 1816 opening ceremony. Designed and built by John Urpeth Rastrick FRS (1780-1856) it was opened on the 24th July 1816. A bridge with five spans, 372ft (113m) long, it was the third longest cast-iron arch road bridge in the world when built and it is now the largest survivor from the first fifty years of iron bridge construction. A civil and mechanical engineer Rastrick is remembered today as a railway pioneer. He built the first steam engine to run in the USA, chaired the Rainhill Trials for the Liverpool & Manchester Railway in 1829, and built numerous railways in Great Britain. The iron arches were cast at the foundry of John Hazeldine at Bridgnorth in Shropshire where Rastrick was the engineer. On the 24th July 2016 a procession was led over the bridge headed by engineers, as it was in 1816, with the President of the Institution of Civil Engineers; Sir John Armitt, leading the way. Until 1989 it carried the normal road traffic through Chepstow and across the Wye into England and still carries road traffic, subject to a 7.5T weight restriction, today.
Not quite as old, the Severn Bridge also celebrated a 50th birthday this year, on 8th September 2016. The 5,240ft (1,597m) long bridge was world’s first major suspension bridge to be built with an aerodynamic road deck it was also the lightest, and set the standard for future long span bridges, such as the Humber Bridge. Many people remember using the car ferries; Severn King and Severn Queen, to cross the Severn before the bridge opened. The Second Severn Crossing also celebrated a milestone this year, being opened on the 5th June 1996 – 20 years ago. At 5,134m long it is not a suspension bridge but a cable stayed bridge similar to the Wye (M48) Bridge – which also opened in 1966.
Another form of communications impacted on Wales 150 years ago with the successful completion of the laying of the Atlantic telegraph cable in 1866. On 27 July 1866 the quite Pembrokeshire bay of Abermawr became part of a trans-Atlantic
communications network with the laying of the fifth, and ultimately successful, telegraph cable between Valentia in Ireland and Trinity Bay in Newfoundland by Brunel’s Great Eastern steamship – the only ship big enough to take all the almost 2,000 nautical miles of telegraph cable required. Messages could now be transmitted from New York to Newfoundland and through the Atlantic cable to Ireland and across to Abermawr, being taken on to London via the SWR and GWR’s telegraph wires. Copper refined in Llanelli and Swansea provided the conductive core of the cable through which messages would be transmitted.
The former telegraph hut at Abermawr, now a holiday cottage, actually predates the successful laying of the Atlantic Telegraph Cable by some four years and if we go back some fifteen years before that to 1847 we find that Isambard Kingdom Brunel had chosen Abermawr as the western terminus and port for the South Wales Railway. This was never carried out but the rural setting of the beach made it an ideal landing point for an underwater telegraph cable from Wexford, Ireland in 1862. Fear of German sabotage of the cable during the first world war saw soldiers being stationed on guard duty at Abermawr.
In 1866 the transmission speed of the transatlantic telegraph system was eight words per minute, by 1900 transmission rates of 120 words per minute were being sent reliably between continents. It was a system for business and governments, for example a ten word transatlantic message from the USA to Great Britain cost $100 or about £76 (today’s values about $2,600 or £1,980). The speed of cable borne news can be gauged with the assassination of Abraham Lincoln in April 1865, then the news took 12 days to reach British newspapers, When President James Garfield was shot in 1881, and it was reported within hours. Some 25 telegraph cables would be laid across the Atlantic by 1922 – the year that the Great Storm washed away the shore ends of the cable at Abermawr and the telegraph station closed.
Stephen K. Jones 6