Everyone knows about Brunel's Suspension Bridge which was opened to the public in 1864 but few know about Brunel's Swivel Bridge which was in operation 15 years before that in 1849.
The Swivel Bridge was Brunel's first large wrought iron opening bridge and a key part of the creation of the Floating Harbour.
The bridge was designed by staff in Brunel's Westminster office to carry traffic over the new South Entrance Lock to the Floating Harbour in the Cumberland Basin, which was under construction at the time. Brunel himself was closely involved in both its design and its construction. In 1872-1873 the bridge was shortened and relocated to its present position over the North Entrance Lock ('Howard's Lock'). The bridge was decommissioned in 1968 after the construction of the Plimsoll Bridge
The bridge rotates on four fixed wheels in contact with a solid ring under the bridge. It was turned by a hydraulic mechanism of twin rams located in pits that are connected to a turning ring under the bridge via wire cable. The original turning mechanism prior to conversion to hydraulic machinery was a hand turned crank similar to that used on old train turntables. The pistons and chains are still in position. The original hydraulic system ran on fresh water supplied from a pressurised water system sited in Underfall Yard.
