Ancestor | Drawbridge, Plate girder bridge, cantilever bridge |
---|---|
Related | Lift bridge, swing bridge |
Descendant | None |
Carries | Pedestrian, bicycle, automobile, truck, light rail, heavy rail |
Span range | Short |
Material | Steel |
Movable | Yes |
Design effort | Medium |
Falsework required | Site and prefabrication specific |
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.
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 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 [1] 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 the location where it is widely used, and is a refinement by Joseph Strauss of the fixed-trunnion. [2]
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. [3]
The rarer Rall type combines rolling lift with longitudinal motion on trunnions when opening. [4] It was patented (1901) by Theodor Rall. [2] [4] [5] One of the few surviving examples is the Broadway Bridge (1913), in Portland, Oregon. [4] [6]
Joseph Baermann Strauss was an American structural engineer who revolutionized the design of bascule bridges. He was the chief engineer of the Golden Gate Bridge in San Francisco, California.
A drawbridge or draw-bridge is a type of moveable bridge typically at the entrance to a castle or tower surrounded by a moat. In some forms of English, including American English, the word drawbridge commonly refers to all types of moveable bridges, such as bascule bridges, vertical-lift bridges and swing bridges, but this article concerns the narrower historical definition of the term where the bridge is used in a defensive structure.
The Broadway Bridge is a Rall-type bascule bridge spanning the Willamette River in Portland, Oregon, United States, built in 1913. It was Portland's first bascule bridge, and it continues to hold the distinction of being the longest span of its bascule design type in the world. It was added to the National Register of Historic Places in November 2012.
A vertical-lift bridge or just lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck.
A moveable bridge, or movable bridge, is a bridge that moves to allow passage for boats or barges. In American English, the term is synonymous with drawbridge, and the latter is the common term, but drawbridge can be limited to the narrower, historical definition used in some other forms of English, in which drawbridge refers to only a specific type of moveable bridge often found in castles.
The Newark Bay Bridge of the Central Railroad of New Jersey (CNJ) was a railroad bridge in New Jersey that connected Elizabethport and Bayonne at the southern end of Newark Bay. Its third and final incarnation was a four-track vertical-lift design that opened in 1926, replacing a bascule bridge from 1904 which superseded the original swing bridge from 1887. The bridge served the main line of the CNJ, carrying daily interstate trains as well as commuter trains.
The North Avenue Bridge can refer to one of three bridges that has carried North Avenue over the North Branch of the Chicago River on the north side of Chicago, Illinois. A center-pier swing bridge built in 1877 was replaced in 1907 by a bascule bridge, allowing river traffic more room for maneuvering in and out of the North Canal, just north of Goose Island.
The Glimmer Glass Bridge is a county owned bridge in Monmouth County, New Jersey, United States. It carries traffic from Brielle Road over the Glimmer Glass, a navigable tidal inlet of the Manasquan River, between Manasquan and Brielle. It has also been on the National Register of Historic Places, since 2008. Due to its age, Commercial vehicles cannot be driven over it. It also allows Bicycles and pedestrians to walk on the wooden sidewalk.
The Skansen Bridge is a 52-meter span bascule railway bridge located at Skansen in Trondheim, Norway.
The Cortland Street Drawbridge over the Chicago River is the original Chicago-style fixed-trunnion bascule bridge, designed by John Ericson and Edward Wilmann. When it opened in 1902, on Chicago's north side, it was the first such bridge built in the United States. The bridge was a major advance in American movable bridge engineering, and was the prototype for over 50 additional bridges in Chicago alone. The bridge was designated as an ASCE Civil Engineering Landmark in 1981, and a Chicago Landmark in 1991.
Amtrak's Thames River Bridge spans the Thames River between New London and Groton, Connecticut.
The St. Charles Air Line Bridge is a Strauss Trunnion bascule bridge which spans the Chicago River in Chicago, Illinois.
The Tomlinson Lift Bridge is a crossing of the Quinnipiac River in New Haven, Connecticut. The bridge forms a segment of U.S. Route 1. The Tomlinson Vertical Lift Bridge carries four lanes of traffic across New Haven Harbor and a single-track freight line owned by the Providence & Worcester Railroad that connects the waterfront with the Northeast Corridor line of Metro North and CSX. A sidewalk is present along the southern edge of the bridge.
Niantic River Bridge, also known as Amtrak Bascule Bridge No. 116.74, is a railroad bridge carrying Amtrak's Northeast Corridor line across the Niantic River between East Lyme and Waterford, Connecticut. It is a drawbridge with a bascule-type draw span. A new bridge was constructed in 2012 to replace the former span built in 1907. It opened on September 8, 2012. Related construction work finished in June 2013.
The Grand Street Bridge was a double-leaf deck-girder bascule bridge in Bridgeport, Connecticut, United States, that spanned the Pequonnock River and connected Grand Street and Artic Street. It was one of three movable bridges planned by the City of Bridgeport in 1916 at the request of the War Department during World War I. Construction was completed in 1919, but the delays surrounding the construction went to the Connecticut Supreme Court in case of Edward DeV. Tompkins, Inc. vs. City of Bridgeport, Connecticut. The court ruled in favor of Tompkins and awarded damages equal to the contract. In 1936, the bridge had excessive settling and required the replacement of its southeast pier. As part of the repairs, a new floor and electrical system were installed. In 1965, the floor was replaced with a steel grate on I-beam floor. In 1984, the eastern approach span was replaced and the northwest trunnion post was reconstructed. The bridge was closed in the 1990s and dismantled in 1999.
Eighth Street Bridge is a road bridge over the Passaic River in northeastern New Jersey, United States. It connects the City of Passaic in Passaic County with the Borough of Wallington in Bergen County and is jointly owned by both counties. The bridge connects Eighth Street in Passaic with County Route 507 in Wallington.
William Donald Scherzer was an American engineer and inventor who invented the rolling lift bridge.
Market Street Bridge, also known as the Second Street Bridge, is a vehicular bridge over the Passaic River crossing the Passaic-Bergen county line in Passaic and Wallington in northeastern New Jersey. The double-leaf bascule bridge was built in 1930 and fixed in the closed position in 1977. It was reconstructed in 2002. It carries a two-lane street and sidewalks in a late-19th and early-20th century industrial area along the river. An earlier structure built at the crossing in 1894 was damaged during the Passaic floods of 1902 and 1903 but survived.
A double-beam drawbridge, seesaw or folding bridge is a movable bridge. It opens by rotation about a horizontal axis parallel to the water. Historically, the double-beam drawbridge has emerged from the drawbridge. Unlike a drawbridge, a double-beam drawbridge has counterweights, so that opening requires much less energy.