Aqueducts & Viaducts The Crymlyn Viaduct under construction, Wales, c 1850s

Aqueducts & Viaducts The Crymlyn Viaduct under construction, Wales, c 1850s. Crumlin (or Crymlyn in Welsh), which opened in 1857, was the most famous of all the early Warren truss bridges and with it this structural form reached maturity. The Warren truss deck girders at Crumlin were made entirely of wrought iron and carried on innovative and dramatic tall trestle piers made up of hexagonal clusters of cast-iron tubes. Built to carry the Taff Vale extension of the Newport, Abergavenny & Hereford railway over Ebbw Vale, it remained the highest railway viaduct in Britain until its closure in 1964. It was the first of hundreds of such bridges exported to British-built railways all over the world throughout the 1850s and 1860s, for the component parts could be pre-fabricated, shipped out and fitted together on site. ©SSPL/NMeM/Royal Photographic Society