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.
4-680: The Ray Nitschke Memorial Bridge is a twin-leaf bascule bridge over the Fox River on Main Street ( US 141 ) in Green Bay, Wisconsin . It is named in honor of the former Green Bay Packer linebacker Ray Nitschke . The bridge was designed by Parsons Brinckerhoff in 1995. It was built in 1998 replacing the old Main Street Bridge that was built in 1923. In September 2012, the bridge was closed for repairs because of rust problems. The bridge
8-404: 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 a "Chicago" bascule) rotates around a large axle that raises the span(s). The Chicago bascule name derives from
12-457: 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
16-542: Was reopened in November 2012. 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 the possibility for unlimited vertical clearance for marine traffic. Bascule bridges have been in use since ancient times, but until
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