Barton Swing Aqueduct

"The Barton Swing Aqueduct (grid reference SJ76679766) is a moveable aqueduct located at Barton upon Irwell in north-west England, it carries the Bridgewater Canal over the Manchester Ship Canal. It is considered a feat of late Victorian civil engineering. The aqueduct is a Grade II* listed building. The swing aqueduct replaced an earlier stone bridge over the River Irwell. The original bridge was designed by James Brindley and dated to 1761; it was described as "one of the seven wonders of the canal age". It was replaced with the current swing aqueduct when the Manchester Ship Canal was constructed because some sailing ships were unable to pass beyond the bridge. It is a form of swing bridge. In its closed position, it allows canal traffic to pass along the Bridgewater Canal. However, when large vessels need to pass along the Ship Canal, the massive iron trough ? 330 feet (100 m) long with a gross weight of 1450 tonnes ? can be swung through 90 degrees via a pivot mounted on a small, purpose-built island in the Ship Canal to allow them to pass. Gates at either end of the trough retain around 800 tonnes of water within the trough; further gates on either bank retain water in their adjacent stretches of canal. The aqueduct originally had a suspended towpath along its length. This has been removed in recent years on safety grounds. The island in the ship canal is also the pivot point and control centre for the swing road bridge so when boats pass on the ship canal, both are lined up along the island. The swing aqueduct was designed by Sir Edward Leader Williams, engineer to the Manchester Ship Canal Company, and built by Andrew Handyside of Derby. It became operational in 1893 with the first barge crossing it on 21 August (Williams was also involved with the design of the region's other major 'moving canal' feat: the Anderton Boat Lift in Cheshire). The aqueduct was commercially opened on 1st January 1894." -Wikipedia