Swing bridge


A swing bridge is a movable bridge that can be rotated horizontally around a vertical axis. It has as its primary structural support a vertical locating pin and support ring, usually at or near to its center of gravity, about which the swing span can then pivot horizontally as shown in the animated illustration to the right.
In its closed position, a swing bridge carrying a road or railway over a river or canal, for example, allows traffic to cross. When a water vessel needs to pass the bridge, road traffic is stopped, and then motors rotate the bridge horizontally about its pivot point. The typical swing bridge will rotate approximately 90 degrees, or one-quarter turn; however, a bridge which intersects the navigation channel at an oblique angle may be built to rotate only 45 degrees, or one-eighth turn, in order to clear the channel. Small swing bridges as found over narrow canals may be pivoted only at one end, opening as would a gate, but require substantial underground structure to support the pivot.

Advantages

  • As this type requires no counterweights, the complete weight is significantly reduced as compared to other moveable bridges.
  • Where the channel is wide enough for separate 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 moveable span, as the construction will not impede traffic.

Disadvantages

  • In a symmetrical bridge, the central pier forms a hazard to navigation. Asymmetrical bridges may place the pivot near one side of the channel.
  • 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 and tension.
  • If struck from the water near the edge of the span, it may rotate enough to cause safety problems.

Examples

Albania

Argentina

Australia

  • Gladesville Bridge, Sydney. Opened 1881, closed 1964 and demolished; had a small swing span on the southern end.
  • Pyrmont Bridge, Sydney. Opened 1902. Closed to traffic 1988. Still in use as a pedestrian bridge.
  • Glebe Island Bridge, Sydney. Opened 1903. Tramway defunct. Closed to traffic, 1995; supplanted by Anzac Bridge. Still in existence.
  • Hay Bridge, Hay, New South Wales. Opened 1873, demolished 1973. Replaced by a fixed concrete bridge.
  • Victoria Bridge, Townsville, Queensland. Opened 1889, closed to traffic 1975. Still in use as a foot bridge.
  • Sale Swing Bridge, Sale, Victoria. Opened 1883. Closed to traffic in 2002. Restored to full working order in 2006.
  • Dunalley Bridge, Dunalley, Tasmania. Still in use.

Belgium

Belize

China

Denmark

  • Lille Langebro Pedestrian double swing bridge crossing the inner harbour at Copenhagen.
  • Naestved Svingbro, Horizontal clearance 42.0m. Carries a 14m-wide trunk road over the Naestved Canal.
  • Odin's Bridge, a double swing bridge crossing Odense Canal, with a horizontal span of almost 200 meters.

Egypt

Estonia

  • The Admiral Bridge is a pedestrian bridge in Tallinn, Estonia, connecting two parts of the Old City Harbour. It allows access to the Admiralty Pool for yachts. It became the first swing bridge in Estonia in 2021.

France

  • Le pont tournant rue Dieu, across the Canal Saint-Martin in Paris, is a distinctive location in the 1938 film Hôtel du Nord, and is featured in the opening shot of the film.

Germany

India

Ireland

Italy

  • Ponte Girevole, Taranto – a very unusual type, with two spans that separate at the bridge's center and pivot sideways from the bridge's outer ends.

Latvia

  • Kalpaka Tilts, Liepāja, connecting the city with the former Russian/Soviet port Karosta.

Lithuania

  • Chain Bridge, Klaipeda. Built in 1855 and still working today, this is the only swing bridge in Lithuania. When the bridge is turned, boats and yachts can enter the Castle port. Rotation of the bridge is manual; two people can rotate the bridge.

The Netherlands

Many inner cities have swing bridges, since these require less street space than other types of bridges.

New Zealand

Panama

Poland

  • A swing bridge at the Giżycko is one of four bridges that cross over the Luczanski Channel. It is one of ten swing bridges in Poland.
  • A swing bridge in Ustka, which crosses the Słupia River, and is walkable every 20 minutes.
  • A swing bridge in Wolin, which crosses the Dziwna River.

South Africa

Taiwan

Ukraine

United Kingdom

In the UK, there is a legal definition in current statute as to what is or is not a 'swing bridge'.
File:Crosskeys Bridge Sutton Bridge Lincolnshire.JPG|thumb|Cross Keys Bridge in Sutton Bridge, which carries the A17 over the River Nene in Lincolnshire close to the border with Norfolk

United States

The largest double swing-span bridge in the United States is the long, navigable span, clearance George P. Coleman Memorial Bridge.
File:I Street Bridge Sacramento.jpg|thumb|right|The swing span of the double-deck I Street Bridge, in Sacramento, open for a ship
Omaha NE Turn Style Bridge is now a historical landmark. Located 86H674H5+98 Used for rail transport. Connecting Council Bluffs, Iowa to downtown Omaha, Nebraska

Uruguay

Vietnam

  • Han River Bridge in downtown Da Nang was designed and built by Vietnamese engineers and workers, and opened on 29 March 2000. Featuring a symmetrical cable-stayed steel swing span with a total length of 122.7m rotating on a rim-bearing circular central pier, it is the only swing bridge operating in Vietnam as of 2025.