Swing bridge
From Wikipedia, the free encyclopedia
| Swing bridge | |
|---|---|
 |
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| Ancestor | Truss bridge, cantilever bridge |
| Related | Other moving types: Bascule bridge, drawbridge, jetway, lift bridge, tilt bridge |
| Descendant | Gate-swing bridge - see Puente de la Mujer |
| Carries | Automobile, truck, light rail, heavy rail |
| Span range | Short |
| Material | Steel |
| Movable | Yes |
| Design effort | Medium |
| Falsework required | No |
A swing bridge is a bridge that has as its primary structural support a vertical locating pin and support ring at or near to its center, about which it can then pivot horizontally as shown in the animated illustration below. Small swing bridges as found over canals may be pivoted only at one end, opening as would a gate, but require substantial underground structure to support the pivot.
In its closed position, a swing bridge carrying a road over a river or canal, for example, allows road traffic to cross. When a water vessel needs to pass the bridge, road traffic is stopped (usually by traffic signals and barriers), and then motors rotate the bridge approximately 90 degrees horizontally about its pivot point.
Contents |
[edit] Advantages
- As this type requires no counterweights the complete weight is significantly reduced as compared to other moveable bridges.
- Where sufficient channel is available to have individual traffic directions on each side the likelihood of vessel-to-vessel collisions is reduced.
- The central support is often mounted upon a berm along the axis of the watercourse, intended to protect the bridge from watercraft collisions when it is opened. This artificial island forms an excellent construction area for building the movable span as the construction will not impede channel traffic.
[edit] Disadvantages
- The central pier forms a hazard to navigation.
- Where a wide channel is not available a large portion of the bridge may be over an area that would be easily spanned by other means.
- A wide channel will be reduced by the center pivot and foundation.
- When open, the bridge will have to maintain its own weight as a balanced double cantilever, while when closed and in use for traffic the live loads will be distributed as in a pair of conventional truss bridges, which may require additional stiffness in some members whose loading will be alternately in compression or tension.
- If struck from the water near the edge of the span, it may rotate enough to cause safety problems (cf. Big Bayou Conot train disaster).
[edit] Examples
[edit] Argentina
- Puente de la Mujer, a uniquely beautiful and dramatic asymmetrical cable-stayed span.
[edit] Australia
- Pyrmont Bridge, Sydney, Australia. (opened 1902. Closed to traffic, 1988. Still in use as pedestrian and monorail bridge.)
- Glebe Island Bridge, Sydney, Australia. (Opened 1901. Closed to traffic, 1995; supplanted by Anzac Bridge. Still in existence.)
[edit] Canada
- Little Current Swing Bridge, crossing the North Channel in Little Current, Ontario.
- A swing bridge crosses the Kaministiquia River in Thunder Bay, Ontario.
- A swing bridge crosses the Canso Canal in Nova Scotia.
- The Derwent Way Bridge crosses the Annacis Channel of the Fraser River between Queensborough in New Westminster, British Columbia and Annacis Island in Delta, British Columbia.
- The Fraser River Swing Bridge is a rail bridge that crosses the Fraser River between New Westminster and Surrey in British Columbia.
- The Hog's Back bridge over the Rideau Canal at Hog's Back Road in Ottawa, Ontario. This bridge swings from one end. There is an ajacent fixed bridge over Hog's Back Falls
- The Moray Bridge that connects between Richmond, British Columbia to Vancouver International Airport.
- Bridge 15 (Welland South Railway Bridge) on the Welland Recreational Waterway, a former channel of the Welland Canal in Welland, Ontario. This bridge formerly carried the Penn Central Railway and the Toronto, Hamilton and Buffalo Railway across the channel. The presence of this old swing bridge (built in the 1910s) was one of the factors which eventually led to the construction of the Welland By-Pass east of the urban section of Welland between 1967-1973.
[edit] Egypt
- The longest swing bridge span is 340 metres, by the El Ferdan Railway Bridge across the Suez Canal.
[edit] Germany
- Kaiser Wilhelm Brücke in Wilhelmshaven, built in 1908, with the length of 159m, it was once Europe's biggest swing bridge
[edit] Great Britain
- Connaught Crossing in London Docklands, built as a low-rising swing bridge to allow marine traffic in the Royal Docks to pass at a place when the proximity of London City Airport meant a higher fixed bridge was not practicable.
- Manchester Ship Canal at Latchford, Stockton Heath and Lower Walton in Warrington, and also slightly further west at Moore. Near the eastern end of the canal in Salford, the Barton swing bridge is adjacent to the Barton Swing Aqueduct - a 234-foot, 800-tonne trough holding some 800 tonnes of water (retained by gates at either end) swings so that it is at right angles to the Bridgewater Canal to allow ships to pass up the Ship Canal.
- Swing Bridge, River Tyne at Newcastle Upon Tyne. The Tyne swing bridge has an 85.7 metre cantilevered span with a central axis of rotation able to move through 90° to allow vessels to pass on either side of it.
- Trowse swing bridge at Norwich. Carries the electrified Great Eastern Mainline over the River Yare. It is the only overhead electrified swing bridge in the world.
- Beccles swing bridge - rail
- Bethells Swing Bridge
- Goole swing bridge - rail
- Kennet and Avon Canal at Sulhamstead, Berkshire
- Oulton Broad swing bridge - rail
- Reedham swing bridge - rail
- Selby swing bridge - rail
- Somerleyton swing bridge
- Sutton Bridge swing bridge
- Caernarfon swing bridge
[edit] Ireland
- Michael Davitt Bridge, Co. Mayo, Ireland
[edit] United States
- Air Line Railway Bridge, Middletown, Connecticut
- Bridgeport Swing Bridge, Bridgeport, Alabama (demolished in late 1970s, replaced with new span)
- Bridge No. 1397, Route 156 over the Niantic River, East Lyme, Connecticut-Waterford, Connecticut (1921 steel swing bridge)
- Bridge No. 4455, Central Avenue over Lewis Gut, Bridgeport, Connecticut (1924 steel swing bridge)
- Burlington Northern Santa Fe Railroad Bridge crossing the Columbia River, Portland, OR
- Center Street Bridge, Cleveland, Ohio (1901)
- East Haddam Swing Bridge, Route 82 over the Connecticut River, East Haddam, Connecticut (1913)
- Fort Madison Toll Bridge
- Figure Eight Island Bridge, North of Wilmington, NC
- Grosse Ile Toll Bridge, Grosse Ile, Michigan
- I Street Bridge, Sacramento, California
- Livingston Avenue Bridge, Albany, New York
- Mathers Bridge, Connecting Merritt Island, Florida to Indian Harbour Beach, Florida across the Banana River
- New Richmond Swing Bridge, near Fennville, Michigan
- Norfolk Southern Railway (former Conrail) Bridge crossing the Maumee River, Toledo, Ohio
- North Fork New River Bridge, Fort Lauderdale, Florida
- Northern Avenue Bridge over Fort Point Channel in Boston, Massachusetts (1908 steel truss)
- Omaha Road Bridge Number 15, an asymmetrical single track railroad bridge over the Mississippi River between Saint Paul, Minnesota and Lilydale, Minnesota (1916)
- Pennsylvania Railroad's Shellpot Branch over Christina River in Wilmington, Delaware (original two-track bridge replaced with a single track bridge in 2003)
- Pennsylvania Railroad's South Philadelphia Branch over Schyulkill River
- Saugatuck River Bridge (Bridge No. 1349), Route 136 over the Saugatuck River, Westport, Connecticut (1884 iron-truss swing bridge)
- Spokane Street Bridge over the Duwamish Waterway in Seattle, Washington (1991 reinforced concrete double swing span)
- St. Joseph Swing Bridge over the St. Joseph River, St. Joseph, Michigan (1904)
- Surf City Bridge Surf City, NC
- Union Pacific Railroad (former CNW) Bridge crossing the Mississippi River, Clinton, Iowa
- Willis Avenue Bridge, New York City
[edit] See also
- Movable bridge for a list of other movable bridge types
