A swing bridge (or swing span 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 (turning 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 (usually by traffic signals and barriers), 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 (see Big Bayou Canot rail accident).
Examples
Albania Buna river Bridge, in Shkodra, Albania.
Argentina Puente de la Mujer, an asymmetrical cable-stayed span.
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 Verbindingsbrug, Zeebrugge. Opened in May 2022. With a length of 130 metres and a passage width of 55 metres, it is the longest swing bridge in Europe. Wiedauwkaaibrug (nl), Ghent. It allows railway lines 58 and 55 (nl) to cross the Ghent–Terneuzen Canal. The current iteration of the bridge was built in 2008.
Belize Belize City Swing Bridge, Belize City, Belize. Oldest such bridge in Central America and one of the few manually operated swing bridges in the world still in operation. (Restored in the 2000s)
Canada Bridge Name Waterway Co-ordinates Status Comments Cambie Street Bridge Connaught Bridge False Creek, Vancouver, British Columbia Demolished/replaced (1985), formerly vehicle, pedestrian & streetcar traffic Short documentary "Swingspan" tells the history of the bridge and its demolition. Canso Canal Bridge Canso Canal, Nova Scotia Still swings, Vehicle/Rail Traffic Links Nova Scotia mainland with Cape Breton Island with 2 traffic lanes of Highway 104 (the Trans-Canada Highway) as well as a single track railway line operated by the Cape Breton and Central Nova Scotia Railway (CBNS). CNR Bridge Fraser River, British Columbia Still swings, Rail Traffic Between Queensborough in New Westminster, British Columbia and the mainland Derwent Way Bridge Fraser River, British Columbia Still swings, Vehicle/Rail Traffic Between Queensborough in New Westminster, British Columbia and Annacis Island in Delta, British Columbia Fredericton Railway Bridge Fredericton, New Brunswick No longer swings, pedestrian traffic. Constructed in 1887 and opened 1889. Last train on the bridge was in 1996. Grand Narrows Bridge Barra Strait, Bras d'Or Lake, Nova Scotia Was last opened for marine traffic on 30 December 2014 remaining open for marine traffic since that date, no longer swings, Rail Traffic cannot cross. Carrying the Cape Breton and Central Nova Scotia Railway (CBNS). Hog's Back Bridge Rideau Canal, Ottawa, Ontario Still swings, Vehicle Traffic This bridge swings from one end. There is an adjacent fixed bridge over Hog's Back Falls Iron Bridge Third Welland Canal, Thorold, Ontario No longer swings, Rail Traffic Carrying the CNR Grimsby Subdivision over the third Welland Canal. Kaministiquia River Swing Bridge Kaministiquia River, Thunder Bay, Ontario No longer swings. Road and rail traffic only. Currently closed due to 29 October 2013 fire Built in 1908 by Grand Trunk Railway; currently owned by the CNR Little Current Swing Bridge North Channel, Little Current, Ontario Still swings, Vehicle Traffic (formerly rail) Built by Algoma Eastern Railway, 1913 Montrose Swing Bridge Welland River, Niagara Falls, Ontario No longer swings, Rail Traffic Formerly Canada Southern Railway, now CPR Moray Bridge Middle Arm of the Fraser River, Richmond, British Columbia Still swings; Eastbound Vehicle Traffic Connects Sea Island, Richmond, BC (location of Vancouver International Airport) to Lulu Island, Richmond, BC New Westminster Bridge Fraser River, British Columbia Still swings, Rail Traffic, formerly had 2nd deck for vehicles Between New Westminster and Surrey. Pitt River Bridge Pitt River, British Columbia No longer swings, Vehicle Traffic Twin side-by-side bridges connecting Port Coquitlam, British Columbia to Pitt Meadows, British Columbia Pitt River Railway Bridge Pitt River, British Columbia Still swings – Rail Traffic (Please Contribute) Wasauksing (Rose Point) Swing Bridge South Channel, Georgian Bay, near Parry Sound, Ontario Still swings, Vehicle Traffic (formerly rail) Links Wasauksing First Nation (Parry Island) to the mainland at Rose Point Welland Canal, Bridge 15 Welland Recreational Waterway, Welland, Ontario No longer swings, Rail Traffic Built by Canada Southern Railway, . Now operated by Trillium Railway Welland Canal, Bridge 20 Approach Span 2nd and 3rd Welland Canal, Port Colborne, Ontario No longer swings, Abandoned (formerly rail) Abandoned 1998 when adjacent Vertical-lift bridge was dismantled. Bergen Cut-off Bridge Red River, Winnipeg, Manitoba Centre span permanently in open position, allowing unrestricted river traffic Decommissioned CPR railway bridge (last used in 1946)Superstructure built by Dominion Bridge Co. 1913–1914Pont CN-Du portLachine Canal, Montreal, QuebecNo longer swings.Abandoned CN railway swing bridge in the middle of Lachine Canal. Constructed in 1912 by the Dominion Bridge Company for the Grand Trunk Railway company. The pivot system and the cockpit are still in place, but the bridge has not been operational since the late 1960s.
China , across Hai River in Tianjin
Denmark Lille Langebro, a cycling and pedestrian double swing bridge crossing the inner harbour at Copenhagen. Cirkelbroen ('The Circle Bridge'), a cycling and pedestrian bridge spanning the southern mouth of Christianshavn Canal in the Christianshavn area of central 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
The longest swing bridge span is 340 metres, by the El Ferdan Railway Bridge across the Suez Canal.
Estonia The Admiral Bridge (Admiralisild) is a pedestrian bridge in Tallinn, Estonia, connecting two parts of the Old City Harbour. It allows access to the Admiralty Pool (Admiraliteedi bassein) 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 Kaiser-Wilhelm-Brücke in Wilhelmshaven, built in 1907, with a length of 159m, it was once Europe's biggest swing bridge.
India
Garden Reach Road Swing Bridge, for Calcutta Port, Kidderpore, Kolkata Poira-Corjuem Bridge, for GSIDC, Corjuem, Goa by Rajdeep Buildcon Pvt. Ltd.
Ireland Samuel Beckett Bridge, Dublin Seán O'Casey Bridge, Dublin Michael Davitt Bridge, County Mayo Portumna bridge, between County Galway and County Tipperary
Italy
Ponte Girevole, Taranto (built in 1958, after an 1887 one of similar design but using different materials) – 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
The "Abtsewoudsebrug" in Delft, close to the Technische Universiteit Delft, is a bridge of this type. There are four bridges of this type in use on the Afsluitdijk (Enclosure dam). They span the waterways that link the shipping lock complexes to the Wadden Sea. There is another one on the channel between Ghent (Belgium) and Terneuzen (The Netherlands) at Sas Van Gent.
Many inner cities have swing bridges, since these require less street space than other types of bridges.
New Zealand Kopu Bridge, Waihou River, near Thames, New Zealand Tamaki River Swing Bridge (also known as 1st Panmure Bridge), Tāmaki River, near Panmure, New Zealand Kotuitui Whitinga Bridge (pedestrian bridge), Waiarohia Stream, Whangārei, New Zealand (A "swing bridge" in New Zealand refers to a flexible walking track bridge which "swings" as one walks across.)Walkway swingbridge manual / prepared and finalised by S. Chiet ... [et al.] Published by : New Zealand Forest Service, Wellington [N.Z.] : 1986.
Panama A swing bridge at the Gatun Locks provides the only road passage over the Atlantic side of the Panama Canal. This is a small bridge that swings out from each side. Another larger swing bridge at the Miraflores Locks is on the Pacific side but is rarely used, having been supplanted by the Bridge of the Americas and the Centennial Bridge.
Poland A swing bridge at the Giżycko is one of four bridges that cross over the Luczanski Channel. It is one of ten (four still in operation) 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
The Clocktower Bridge is a pedestrian swing bridge at the Victoria and Alfred Waterfront in Cape Town.
Taiwan
Great Harbor Bridge in Kaohsiung is the longest cross-port rotating bridge in Asia.
Ukraine