A bascule bridge (also referred to as a drawbridge or a lifting bridge ) is a moveable bridge with a counterweight that continuously balances a span , or leaf, throughout its upward swing to provide clearance for boat traffic. It may be single- or double-leafed.
4-824: The Mary MacKillop Bridge is a bascule bridge in Adelaide , Australia that carries the Dry Creek-Port Adelaide railway line over the Port River . In July 2005, Abigroup was awarded a contract to build a railway bridge and the adjoining Tom 'Diver' Derrick Bridge to carry the Port River Expressway over the Port River. The bridge was built as part of a project to divert the Dry Creek-Port Adelaide line away from
8-571: A "Chicago" bascule) rotates around a large axle that raises the span(s). The Chicago bascule name derives from the location where it is widely used, and is a refinement by Joseph Strauss of the fixed-trunnion. The rolling lift trunnion (sometimes a "Scherzer" rolling lift), raises the span by rolling on a track resembling a rocking-chair base. The "Scherzer" rolling lift is a refinement patented in 1893 by American engineer William Donald Scherzer . The rarer Rall type combines rolling lift with longitudinal motion on trunnions when opening. It
12-572: The Rosewater loop and bypass the suburban network . It was opened on 1 August 2008 by Premier Mike Rann . [REDACTED] Media related to Mary MacKillop Bridge at Wikimedia Commons Bascule bridge The name comes from the French term for balance scale , which employs the same principle. Bascule bridges are the most common type of movable span because they open quickly and require relatively little energy to operate, while providing
16-425: The possibility for unlimited vertical clearance for marine traffic. Bascule bridges have been in use since ancient times, but until the adoption of steam power in the 1850s, very long, heavy spans could not be moved quickly enough for practical application. There are three types of bascule bridge and the counterweights to the span may be located above or below the bridge deck. The fixed- trunnion (sometimes
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