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.
5-513: The Longboat Pass Bridge (also known as Longboat Key Bridge ) is a single-leaf bascule bridge that crosses the Longboat Pass, connecting Longboat Key and Bradenton Beach , Florida . The bridge carries State Road 789 , which is known as Gulf Drive on Anna Maria Island, and Gulf of Mexico Drive on Longboat Key. The Longboat Pass Bridge was built in 1957. It was built at the site of a former bridge that had been built in 1926. In 1932,
10-640: The 1965 Legislature of Florida. This article about a bridge in Florida is a stub . You can help Misplaced Pages by expanding it . 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
15-404: 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
20-457: 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
25-405: The original Longboat Pass Bridge was washed away by a hurricane, severing the connection between Longboat Key and Anna Maria Island. Remains of the structure were found by Jewfish Key which were reused for a new bridge to Snead Island . The connection between the two islands would not be restored until 1957, when the current Longboat Pass Bridge opened. The Longboat Pass Bridge is designated by
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