Menai Bridge

The Menai Strait was created by glacial erosion along a line of weakness associated with the Menai Strait fault system. During a series of Pleistocene glaciations (that lasted from about 2,580,000 to 11,700 years ago), a succession of ice-sheets moved from northeast to southwest across Anglesey and neighbouring Gwynedd, scouring the underlying rock and creating a series of linear bedrock hollows. The deepest of these channels eventually became flooded by the sea as the ice sheets receded, forming the Menai Strait. As Anglesey has been an island throughout recorded human history, the only way to reach it was by crossing the strait. However, this has always been a dangerous endeavour because…

Construction of the bridge, to Telford's design, began in 1819 with the towers on either side of the strait. These were constructed from Penmon limestone and were hollow with internal cross-walls. Then came the sixteen huge chain cables to support the 176 m span, each consisting of five parallel bars of wrought iron links, for a total of 80 iron bars and 935 links per cable. The chains were carried over the piers on cast iron saddles with rollers, allowing for movement caused by temperature changes. On both sides of the strait the chains were conveyed through three tunnels into a chamber cut into the rock, where they were held in place by 9 ft bolts resting in cast iron sockets. Workmen…