'The Conway Tubular Bridge on the Chester and Holyhead Railway', 1851.
© Science Museum / Science & Society Picture Library
Engraving by A Ashley. The Conwy (formerly known as Conway) Tubular Bridge, which was built in 1849, was designed by Robert Stephenson (1803-1859) as part of the Chester to Holyhead Railway. The main span of the bridge is 125 metres.