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Swing bridge
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 | This article needs additional citations for verification. (August 2008) |
 | |
| Ancestor | Truss bridge, cantilever bridge |
|---|---|
| Related | Other moving types: Bascule bridge, drawbridge, jetway, vertical-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 (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
[edit]
- 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
[edit]
- 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
[edit]
Albania
[edit]- Buna river Bridge, in Shkodra, Albania.
Argentina
[edit]- Puente de la Mujer, an asymmetrical cable-stayed span.
Australia
[edit]- 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
[edit]- 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.[1]
- 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
[edit]- Belize City Swing Bridge, Belize City, Belize. Oldest such bridge in Central America and one of the few manually operated swing bridge in world still in operation. (Restored in the 2000s)
Canada
[edit]| Bridge Name | Waterway | Co-ordinates | Status | Comments |
|---|---|---|---|---|
| Cambie Street Bridge Connaught Bridge | False Creek, Vancouver, British Columbia | 49°16′19″N 123°6′54″W / 49.27194°N 123.11500°W | 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 | 45°38′50″N 61°24′45″W / 45.64722°N 61.41250°W | 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 | 49°11′50″N 122°55′24″W / 49.19722°N 122.92333°W | Still swings, Rail Traffic | Between Queensborough in New Westminster, British Columbia and the mainland |
| Derwent Way Bridge | Fraser River, British Columbia | 49°11′09″N 122°55′55″W / 49.18583°N 122.93194°W | 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 | 45°57′25″N 66°37′43″W / 45.95694°N 66.62861°W | 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 | 45°57′35.75″N 60°48′1.03″W / 45.9599306°N 60.8002861°W | Was last opened for marine traffic on December 30, 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 | 45°22′11″N 75°41′54″W / 45.36972°N 75.69833°W | 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 | 43°08′15″N 79°10′38″W / 43.13750°N 79.17722°W | No longer swings, Rail Traffic | Carrying the CNR Grimsby Subdivision over the third Welland Canal. |
| Kaministiquia River Swing Bridge | Kaministiquia River, Thunder Bay, Ontario | 48°21′31″N 89°17′15″W / 48.35861°N 89.28750°W | No longer swings. Road and rail traffic only. Currently closed due to 29 October 2013 fire[2] | Built in 1908 by Grand Trunk Railway; currently owned by the CNR |
| Little Current Swing Bridge | North Channel, Little Current, Ontario | 45°58′48″N 81°54′50″W / 45.98000°N 81.91389°W | Still swings, Vehicle Traffic (formerly rail) | Built by Algoma Eastern Railway, 1913 |
| Montrose Swing Bridge | Welland River, Niagara Falls, Ontario | 43°02′45″N 79°07′11″W / 43.04583°N 79.11972°W | No longer swings, Rail Traffic | Formerly Canada Southern Railway, now CPR |
| Moray Bridge | Middle Arm of the Fraser River, Richmond, British Columbia | 49°11′30″N 123°08′13″W / 49.19167°N 123.13694°W | 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 | 49°12′29″N 122°53′38″W / 49.20806°N 122.89389°W | Still swings, Rail Traffic, formerly had 2nd deck for vehicles | Between New Westminster and Surrey. |
| Pitt River Bridge | Pitt River, British Columbia | 49°14′52″N 122°43′44″W / 49.24778°N 122.72889°W | 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 | 49°14′42″N 122°44′01″W / 49.24500°N 122.73361°W | Still swings – Rail Traffic | (Please Contribute) |
| Wasauksing (Rose Point) Swing Bridge | South Channel, Georgian Bay, near Parry Sound, Ontario | 45°18′54″N 80°2′40″W / 45.31500°N 80.04444°W | 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 | 42°58′37″N 79°15′21″W / 42.97694°N 79.25583°W | No longer swings, Rail Traffic | Built by Canada Southern Railway, c. 1910. Now operated by Trillium Railway |
| Welland Canal, Bridge 20 Approach Span | 2nd and 3rd Welland Canal, Port Colborne, Ontario | 42°53′14″N 79°14′58″W / 42.88722°N 79.24944°W | No longer swings, Abandoned (formerly rail) | Abandoned 1998 when adjacent Vertical-lift bridge was dismantled. |
| Bergen Cut-off Bridge | Red River, Winnipeg, Manitoba | 49°56′49″N 97°5′53″W / 49.94694°N 97.09806°W | Centre span permanently in open position, allowing unrestricted river traffic | Decommissioned CPR railway bridge (last used in 1946) Superstructure built by Dominion Bridge Co. 1913–1914 |
| Pont CN-Du port | Lachine Canal, Montreal, Quebec | 45°29′24.9″N 73°33′26.1″W / 45.490250°N 73.557250°W | No 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.[3] The pivot system and the cockpit are still in place, but the bridge has not been operational since the late 1960s.[4] |
China
[edit]- Jintang Bridge (Tianjin), across Hai River in Tianjin
Denmark
[edit]- Lille Langebro Pedestrian double swing bridge crossing the inner harbour at Copenhagen.[5]
- Naestved Svingbro, Horizontal clearance 42.0m. Carries a 14m-wide trunk road over the Naestved Canal.[6]
- Odin's Bridge, a double swing bridge crossing Odense Canal, with a horizontal span of almost 200 meters.[7]
Egypt
[edit]
- The longest swing bridge span is 340 metres, by the El Ferdan Railway Bridge across the Suez Canal.
Estonia
[edit]- 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
[edit]- 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
[edit]- Kaiser-Wilhelm-Brücke in Wilhelmshaven, built in 1907, with a length of 159m, it was once Europe's biggest swing bridge.
India
[edit]
- Garden Reach Road Swing Bridge, for Calcutta Port, Kidderpore, Kolkata[citation needed]
- Poira-Corjuem Bridge, for GSIDC, Corjuem, Goa by Rajdeep Buildcon Pvt. Ltd.[citation needed]
Ireland
[edit]- Samuel Beckett Bridge, Dublin
- Seán O'Casey Bridge, Dublin
- Michael Davitt Bridge, County Mayo
- Portumna bridge, between County Galway and County Tipperary
Italy
[edit]
- 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.[8][9]
Latvia
[edit]Lithuania
[edit]
- 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
[edit]
- The "Abtsewoudsebrug" in Delft, close to the Technische Universiteit Delft, is a bridge of this type. 52°0′5.71″N 4°21′50.10″E / 52.0015861°N 4.3639167°E
- 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.[10]
- There is another one on the channel between Ghent (Belgium) and Terneuzen (The Netherlands) at Sas Van Gent.[11]
Many inner cities have swing bridges, since these require less street space than other types of bridges.
New Zealand
[edit]- Kopu Bridge, Waihou River, near Thames, New Zealand
- Tamaki River Swing Bridge (also known as 1st Panmure Bridge), Tāmaki River, near Panmure, New Zealand
(A "swing bridge" in New Zealand refers to a flexible walking track bridge which "swings" as you walk across.)[12]
Panama
[edit]- 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
[edit]- 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
[edit]
- The Clocktower Bridge is a pedestrian swing bridge at the Victoria and Alfred Waterfront in Cape Town.
Taiwan
[edit].jpg)
- Great Harbor Bridge in Kaohsiung is the longest cross-port rotating bridge in Asia.[13]
Ukraine
[edit]- Varvarivskyi Bridge over the Southern Bug in Mykolaiv, with Europe's longest span (134 m)[14]
United Kingdom
[edit]
In the UK, there is a legal definition in current statute as to what is, or is not a 'swing bridge'[15]
- Acton swing bridge – road
- Barmouth Bridge – rail
- Beccles swing bridge – rail
- Bell's Bridge, Glasgow – pedestrian
- Bethells Swing Bridge
- Boothferry swing bridge at Boothferry, Yorkshire
- Caernarfon swing bridge
- 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.
- Cross Keys Bridge in Sutton Bridge – carries the A17 road over the River Nene in Lincolnshire
- Folkestone Harbour railway station – railway bridge on the branch line.
- Foxton Swingbridge - road bridge over the Harborough arm of the Grand Union Canal in the village of Foxton.
- Goole railway swing bridge
- Glasson Dock swing bridge
- Govan–Partick Bridge, Glasgow – pedestrian
- Hawarden Railway Bridge – rail (now deactivated).[16]
- Hull, England docks branch bridge – rail
- Kennet and Avon Canal at Tyle Mill Lock, Sulhamstead, Berkshire
- Kincardine Bridge – crossing the Firth of Forth from Falkirk council area to Kincardine-on-Forth, Fife (now deactivated).
- Leeds and Liverpool Canal Has a large number of swing bridges, especially between Bingley and Skipton and Burscough and Liverpool. Many are manually operated, carrying only farm tracks, but a significant number carry road traffic and are mechanised for boater operation.
- 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 Road Swing Bridge is adjacent to the Barton Swing Aqueduct – a 234-foot, 800-ton trough holding some 800 tons 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.
- Myton Swing Bridge - road bridge in Kingston upon Hull
- Oulton Broad swing bridge – rail
- Reedham Swing Bridge (52°33′32″N 1°34′21″E / 52.55887°N 1.57237°E) – rail
- Renfrew Bridge, Glasgow - road[17]
- Ross Bridge, Penzance
- Sandwich Toll Bridge (rebuilt 1892)[18]
- Selby swing bridge – rail
- Somerleyton swing bridge
- Trowse Bridge at Norwich. Carries the electrified Great Eastern Main Line over the River Yare. It is the only overhead electrified swing bridge in the country.
- Tyne swing bridge at Newcastle Upon Tyne, which 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.
- Whitby Swing Bridge over the River Esk at Whitby, North Yorkshire, with two swing leaves (though only one is usually opened).
- Yar Swing Bridge, Yarmouth, Isle of Wight
- Operation of the Sulhamstead Tyle Mill swing bridge on the Kennet & Avon Canal
-
Bridge with road traffic -
Bridge opening -
Bridge with canal traffic
United States
[edit]
The largest double swing-span bridge in the United States is the 3,250 feet (990 m) long, 450 feet (140 m) navigable span, 60 feet (18 m) clearance George P. Coleman Memorial Bridge.[19]
- CSXT Blackwater River bridge in Milton, Florida.
- Alanson Swing Bridge, billed as America's shortest swing bridge, crossing the Crooked River in Alanson, Michigan.[20] The world's shortest are located in the United Kingdom over some of the narrowest canals in the world, for example on the Stroudwater Navigation,[21] or, see Yar Swing Bridge above.
- Ben Sawyer Bridge, connecting the city of Mount Pleasant, South Carolina, with Sullivan's Island
- Berkley–Dighton Bridge (1896), connecting the towns of Berkley and Dighton, Massachusetts, crossing the Taunton River; removed in 2010. The replacement bridge is not a swing structure.
- Black Point Bridge carrying Northwestern Pacific Railroad over the Petaluma River at Black Point-Green Point, California
- Blackburn Point Road Bridge, over the Intracoastal Waterway in Osprey, Florida
- Bridge No. 4455, Central Avenue over Lewis Gut, Bridgeport, Connecticut (1924 steel swing bridge)
- Boca Grande Causeway, Built in 1958, this bridge is used for passage between Placida, FL to the island of Boca Grande. The original swing bridge was replaced by the current swing bridge in late 2015.[22]
- Bridgeport Swing Bridge, Bridgeport, Alabama (demolished in the late 1970s, replaced with new span)
- Burlington Northern Railroad Bridge 9.6 (or BNSF Railway Bridge 9.6), crossing the Columbia River, from Portland, Oregon, to Vancouver, Washington, built in 1908.[23]
- Center Street Bridge, Cleveland, Ohio (1901)[24]
- Chef Menteur Bridge, near Slidell, Louisiana
- Chincoteague Channel Swing Bridge, Chincoteague, Virginia (demolished)
- Choptank River, modest swing bridge carrying former Baltimore & Eastern Railroad (PRR subsidiary) at Denton, Maryland (disused and isolated)
- Clinton Railroad Bridge crossing the Mississippi River, Clinton, Iowa[25][26]
- Columbus Drive Bridge, Tampa, Florida, a bobtail swing bridge over the Hillsborough River
- CSX Rail Bridge, Indiantown, Florida[27]
- Curtis Creek Rail Bridge, Baltimore, Maryland[28]
- Deweyville Swing Bridge, crossing the Sabine River east of Deweyville, Texas
- Dubuque Rail Bridge, crossing the Mississippi River and connecting Dubuque, Iowa with East Dubuque, Illinois
- Dumbarton Rail Bridge, crossing San Francisco Bay in California (1910); since being decommissioned, the swing portion of the bridge has been welded open.
- East Haddam Bridge, Route 82 over the Connecticut River, East Haddam, Connecticut (1913)
- Fort Madison Toll Bridge, crossing the Mississippi River and connecting Fort Madison, Iowa with Niota, Illinois
- Fort Pike Bridge, near Slidell and New Orleans, Louisiana
- Fort Denaud Bridge, near LaBelle and Alva, Florida[29]
- Figure Eight Island Bridge, north of Wilmington, North Carolina
- Frederick Douglass Memorial Bridge, Washington, D.C.
- George P. Coleman Memorial Bridge, over the York River between Yorktown and Gloucester Point, Virginia
- Gianella Bridge, near Hamilton City California, connecting Glenn and Butte Counties over the Sacramento River, It was built in 1937 and demolished in 1987.
- Government Bridge on the Mississippi River between Davenport, Iowa and Rock Island, Illinois (1896)
- Grand Haven GTW RR Swing Bridge, connecting Grand Haven and Ferrysburg, Michigan[30]
- Grand Rapids Swing Bridge, Grand Rapids, Michigan
- Grosse Ile Toll Bridge and nearby Wayne County Bridge, Grosse Ile, Michigan
- Hannibal Bridge (1869, demolished) and Second Hannibal Bridge (1917), Kansas City, Missouri, crossing the Missouri River
- Harlem River bridges in New York City, including from south to north:
- Harmar Railroad Bridge, Marietta, Ohio
- Hodgdon Island Bridge, Boothbay, Maine. This is one of two manual swing bridges in Maine (see Songo Locks in Naples, Maine)
- I Street Bridge, Sacramento, California
- India Point Railroad Bridge, Providence, Rhode Island crossing the Seekonk River
- International Railway Bridge connecting Buffalo, New York and Fort Erie, Ontario, Canada[31]
- La Crosse Rail Bridge, crossing the Mississippi River between La Crescent, Minnesota, and La Crosse, Wisconsin
- Livingston Avenue Bridge, Albany, New York
- Mathers Bridge, connecting Merritt Island to Indian Harbour Beach, Florida across the Banana River
- Middle Branch of Patapsco River Rail Bridge, near Camden Yards, Baltimore, Maryland[32]
- Mystic River Railroad Bridge, Mystic, Connecticut, carries Amtrak's Northeast Corridor tracks over the Mystic River.[33]
- Nature Coast State Trail, over the Suwannee River between Wilcox, Florida and Old Town, Florida
- New Bedford-Fairhaven Bridge, connecting New Bedford and Fairhaven, Massachusetts
- New Richmond Swing Bridge, near Fennville, Michigan
- Norfolk Southern Railway Bridge crossing the Maumee River, Toledo, Ohio[34][35]
- Norfolk Southern Railway Bridge crossing the Ocmulgee River in Lumber City, Georgia (2,800 feet (850 m) long; built 1916) (electrical swing components removed)[36]
- Northern Avenue Bridge over Fort Point Channel in Boston, Massachusetts (1908 steel truss)
- North Landing Bridge, built in the 1950s, on the Atlantic Intracoastal Waterway where it forms part of the border between Chesapeake and Virginia Beach, Virginia,[37]
- Omaha Road Bridge Number 15, an asymmetrical single-track railroad bridge over the Mississippi River between Saint Paul and Lilydale, Minnesota (1916)
- Oregon Slough Railroad Bridge (1908), Portland, Oregon
- Padanaram Bridge on the causeway protecting Apponagansett Bay in Dartmouth, Massachusetts[38]
- Passaic River in Newark, New Jersey
- Pennsylvania Railroad's Shellpot Branch over the Christina River in Wilmington, Delaware (original two-track bridge replaced with a single-track bridge in 2003)
- Pennsylvania Railroad's South Philadelphia Branch Bridge over the Schuylkill River, Philadelphia, Pennsylvania
- Point Street Bridge, Providence, Rhode Island crossing the Providence River
- Portal Bridge, carrying the Northeast Corridor over the Hackensack River between Kearny and Secaucus, New Jersey
- Providence & Worcester railroad bridge, Middletown, Connecticut
- Richard V. Woods Memorial Bridge over the Beaufort River/Intracoastal Waterway in Beaufort, South Carolina
Navigation Locks Bridge, Bonneville Dam - Riverside-Delanco Bridge over Rancocas Creek in New Jersey
- Rock Island Swing Bridge over the Mississippi River between Inver Grove Heights and St. Paul Park, Minnesota
- "S" Swing Bridge over the Perquimans River, Hertford, North Carolina.[39]
- Sakonnet River rail bridge, crossing the Sakonnet River between Tiverton and Portsmouth, Rhode Island
- Saugatuck River Bridge (Bridge No. 1349), Route 136 over the Saugatuck River, Westport, Connecticut (1884 iron-truss swing bridge)
- Shaw Cove Railroad Bridge, New London, Connecticut, carrying Amtrak's Northeast Corridor tracks over the entrance to Shaw Cove in New London[33]
- Snow-Reed Swing Bridge, Fort Lauderdale, Florida, crossing the New River and connecting the Sailboat Bend neighborhood with the Riverside Park neighborhood
- Songo Lock Bridge, Naples, Maine; carries Songo Lock Road over the Songo River just upstream of the lock. Powered by human operator turning gears using a removable crank. Not to be confused with a former swing bridge about two miles upstream which carried US 302 until replaced with a fixed span in May 2012.
- South Bristol, Maine Asymmetric swing bridge connecting Rutherford Island to the mainland.
- Southport, ME connects Southport Island to Boothbay Harbor on Route 27.
- Spokane Street Bridge over the Duwamish Waterway in Seattle, Washington, built 1991. Features two reinforced concrete, serial swing spans, each rotating 45 degrees[40]
- St. Joseph Swing Bridge over the Missouri River, St. Joseph, Missouri (1904)[41]
- Topsail Island Swing Bridge, Surf City, North Carolina (Constructed in the 1950s, the swing bridge was demolished after being replaced by a fixed-span high rise bridge in 2018).
- Trail Creek Swing Bridge in Michigan City, Indiana, carrying the Michigan Central Railroad (now operated by Amtrak)
- Torry Island Swing Bridge, Torry Island, Florida
- Umpqua River Bridge near Reedsport, Oregon on US-101
- Victory Bridge, crossing the Raritan River in Perth Amboy, New Jersey (taken down in 2003)
- Walt Disney World Railroad (former Florida East Coast Railway) swing bridge, Bay Lake, Florida[42]
- Woods Memorial Bridge over the Beaufort River in Beaufort, South Carolina[43]
- Yancopin Bridge, Arkansas River, southeastern Arkansas. Former Missouri Pacific railroad bridge with separate vertical-lift and swing trusses now part of rail-trail; swing span now manually operated
- State Hwy 87 northbound bridge the eastern boundary of Bridge City, Texas
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
[edit]
- Carmelo Bridge. Built in 1912 in Carmelo, it is the oldest swing bridge in all of Latin America.
- Barra del Santa Lucia Bridge. Built in 1925 as a railway bridge, today is used only by pedestrians.
Vietnam
[edit]
- 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.[44]
See also
[edit]
- Movable bridges for a list of other movable bridge types
References
[edit]- ^ "Gloednieuwe brug in Zeebrugge feestelijk geopend: "Het is de langste beweegbare draaibrug van Europa" | VRT NWS: Nieuws". 22 May 2022.
- ^ "Burned bridge fate in CN's hands, officials say". Canadian Broadcasting Corporation. 31 October 2013. Archived from the original on 3 November 2013. Retrieved 31 October 2013.
- ^ "Connection". login.ville.montreal.qc.ca.
- ^ "Lieu historique national du Canal-de-Lachine" (PDF) (in French). Archived from the original (PDF) on 12 August 2021.
- ^ Williams, Fran (14 August 2019). "WilkinsonEyre creates £9m cycle and pedestrian bridge for Copenhagen harbour". Architects Journal. Retrieved 10 January 2022.
- ^ "Næstved Svingbro". www.vejdirektoratet.dk. Retrieved 14 August 2025.
- ^ "Odin's Bridge (Odins Bro) new landmark". Odense Havn. Retrieved 14 August 2025.
- ^ "Photograph of the Ponte Girevole (Taranto, Italy) while fully open" (JPG). Cityofart.net. Retrieved 9 February 2013.
- ^ "Apertura Ponte Girevole Taranto". 16 April 2008. Archived from the original on 3 June 2016. Retrieved 17 February 2016 – via YouTube.
- ^ "A7 Afsluitdijk Kornwerderzand: werkzaamheden Lorentzsluizencomplex 9–26 april 2018". 3 April 2018.
- ^ "Draaibrug over het kanaal Gent-Terneuzen bij Sas van Gent". Beeldbank Zeeland Seaports. 1 August 1977. Archived from the original on 17 February 2016. Retrieved 17 February 2016.
- ^ Walkway swingbridge manual / prepared and finalised by S. Chiet ... [et al.] Published by : New Zealand Forest Service, Wellington [N.Z.] : 1986.
- ^ "Great Harbor Bridge". Kaohsiung Travel. Retrieved 12 November 2024.
- ^ "History". Kyivdiprotrans Institute. Archived from the original on 30 December 2013. Retrieved 19 August 2013.
- ^ Highways Act 1980. London: HMSO. 1980.
- ^ "Shotton Steelworks – general scenes". Archived from the original on 11 January 2011. Retrieved 1 February 2008.
- ^ "£117M twin-leaf opening road bridge across River Clyde opens to traffic". 9 May 2025. Retrieved 23 May 2025.
- ^ Historic England. "The Toll Bridge (1343735)". National Heritage List for England. Retrieved 10 February 2020.
- ^ "BUILDING BIG: Databank: George P. Coleman Bridge". Pbs.org. 13 May 1995. Archived from the original on 4 March 2016. Retrieved 17 February 2016.
- ^ "Alanson Swing Bridge". fairbairnrealtyblog.com. Northern Michigan lifestyle, history & real estate blog. 26 August 2021. Retrieved 30 May 2024.
- ^ "Moveable Bridges". Stroud Valleys Canal Company. Retrieved 12 April 2023.
- ^ "About Us". Gasparilla Island Bridge Authority. 11 March 2022. Retrieved 30 April 2024.
- ^ Wood Wortman, Sharon; Wortman, Ed (2006). The Portland Bridge Book (3rd ed.). Urban Adventure Press. pp. 119–120. ISBN 0-9787365-1-6.
- ^ "Google Maps". Google Maps. Retrieved 17 February 2016.
- ^ "Photo: UP 8007 Union Pacific EMD SD9043MAC at Clinton, Iowa by Eric Salter". Railpictures.net. Archived from the original on 3 March 2016. Retrieved 17 February 2016.
- ^ "Photo: UP 3806 Union Pacific EMD SD70M at Clinton, Iowa by Eric Salter". Railpictures.net. Archived from the original on 3 March 2016. Retrieved 17 February 2016.
- ^ "Google Maps". Google Maps. Retrieved 17 February 2016.
- ^ "Google Maps". Google Maps. Retrieved 17 February 2016.
- ^ "Historic Fort Denaud Swing Span Bridge, History of the Fort Denaud Bridge The Fort Denaud Bride is a vital link between residents and agricultural operations on both sides of the Caloosahatchee River". hendryfla.net. Archived from the original on 16 January 2018. Retrieved 7 May 2018.
- ^ "Bridge: GTW Grand Haven Swing Bridge". Michiganrailroads.com. Archived from the original on 3 March 2016. Retrieved 17 February 2016.
- ^ "International Railroad Bridge". Buffaloah.com. Archived from the original on 3 March 2016. Retrieved 17 February 2016.
- ^ "Google Maps". Google Maps. Retrieved 17 February 2016.
- ^ a b Amtrak Moveable Bridge Smart Card
- ^ "Google Maps". Google Maps. Retrieved 17 February 2016.
- ^ "Photo: NS 9869 Norfolk Southern GE C40-9W (Dash 9-40CW) at Toledo, Ohio by Matt Smith". Railpictures.net. Archived from the original on 3 March 2016. Retrieved 17 February 2016.
- ^ "Google Maps". Google Maps. Retrieved 17 February 2016.
- ^ "North Landing Bridge (Mt. Pleasant Rd)". Archived from the original on 16 August 2016.
- ^ "Google Maps". Google Maps. Retrieved 17 February 2016.
- ^ "Historic "S" Swing Bridge". visitnc.com. Archived from the original on 26 February 2018. Retrieved 7 May 2018.
- ^ "West Seattle Connection: World's Only Hydraulically Operated Double-Leaf Concrete Swing Bridge" (PDF). City of Seattle Engineering Department. Archived (PDF) from the original on 3 March 2016. Retrieved 25 February 2014.
- ^ "Freight – Q324 Crosses the St. Joseph River on a wonderful may evening – Railroadfan.com Photo Gallery". Railroadfan.com. 9 June 2007. Archived from the original on 3 March 2016. Retrieved 17 February 2016.
- ^ Leaphart, David (2016). Walt Disney World Railroads Part 3: Yucatan Jewels (1st ed.). Steel Wheel on Steel Rail Studio. pp. 148–149. ISBN 978-1-533-03707-7.
- ^ "Google Maps". Google Maps. Retrieved 17 February 2016.
- ^ "Han River Bridge: Discover an iconic symbol of Da Nang City". vinwonders. 7 December 2024. Retrieved 19 April 2025.
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Swing bridge
View on Grokipediafrom Grokipedia
Overview
Definition and Purpose
A swing bridge is a type of movable bridge that rotates horizontally around a fixed vertical pivot axis, typically located at the center of a pier, to allow the passage of marine vessels beneath it.[3][4] This rotation opens the bridge span by aligning it parallel to the waterway, creating clear channels on either side, while in the closed position, the span aligns perpendicular to the waterway to support road or rail traffic.[1] The design may feature a center-bearing configuration, where the span's weight is primarily supported by a central pivot, or a rim-bearing setup, utilizing a circular track with rollers for load distribution.[3][4] The primary purpose of a swing bridge is to facilitate navigation over waterways by providing on-demand clearance for boats and ships, thereby minimizing disruptions to land-based transportation routes compared to fixed bridges that require permanent high clearances.[3][5] It serves as an efficient solution for crossing navigable channels where constructing elevated fixed spans would be uneconomical or structurally challenging due to approach grades and land constraints.[4] Unlike bascule or vertical lift bridges, swing bridges offer a balanced, mechanically simple operation suited to sites with limited vertical space or where counterweights for tilting mechanisms are impractical.[3][4] A key engineering principle underlying their function is the typical 90-degree rotation around the pivot, which swiftly transitions the span from obstructing the waterway to permitting full vessel transit without vertical movement.[1] This horizontal pivoting relies on the bridge's balanced structure to ensure stability and efficient load transfer during operation.[3]Basic Components
A swing bridge's central pivot serves as the foundational element, typically consisting of a fixed pier or turntable positioned at the bridge's midpoint to support the entire rotating structure. This pivot is anchored to a cylindrical base or equipped with roller bearings, such as center-bearing or rim-bearing systems, enabling horizontal rotation around a vertical axis while bearing the dead load of the span.[4][6] The pivot foundation is often constructed from concrete to provide stability against vertical and lateral forces.[4] The swing span forms the movable portion of the bridge, comprising a truss or plate girder superstructure that includes the roadway or railway deck surface, railings, and any necessary flooring. This section rotates to align with the fixed approaches, typically featuring two balanced arms or counterweighted designs to minimize unbalanced loads during movement.[6][7] Constructed primarily from steel for its strength and durability, the swing span must endure torsional stresses induced by wind, unbalanced loads, and the rotation process itself.[6] Abutments and approaches provide the fixed connections linking the swing span to the surrounding infrastructure. Abutments are sturdy end supports, often made of stone or concrete, that bear the weight of the closed span and transfer loads to the ground.[4] Approaches consist of non-movable spans or ramps supported by piers or bents, ensuring seamless transitions for vehicular or rail traffic to and from the rotating section.[4] Fender systems encircle the central pivot to safeguard it from potential collisions with passing vessels. These protective barriers, typically built from timber, steel, or concrete elements, absorb impact and prevent damage to the pier and rotating machinery.[4]History
Early Origins
Swing bridges have roots in medieval Europe, where early forms resembled simple drawbridges hinged for rotation, though surviving examples are rare.[8] In the United States, the earliest documented instance dates to around 1768 over the Northeast Cape Fear River in North Carolina.[8] The design gained prominence in the early 19th century as a practical solution for movable crossings over waterways, credited to engineers addressing the challenges of expanding inland navigation during the Industrial Revolution. In the United Kingdom, one of the earliest notable implementations occurred with the completion of the Caledonian Canal in 1822, where cast-iron swing bridges, such as the Moy Bridge constructed around 1820, were installed to facilitate road traffic across the canal without obstructing boat passage.[9] Similarly, in the United States, swing bridges appeared on major canals shortly thereafter, with initial wooden and iron examples built across the Erie Canal following its opening in 1825 and the Chesapeake and Ohio Canal, enabling efficient crossings for growing canal commerce.[10] The development of these bridges was driven by the Industrial Revolution's demand for navigable canals and railroads that intersected urban waterways, necessitating structures that could rotate to allow vessel transit while supporting land transport. By the 1830s, swing bridges became key features in canal systems across the UK and US, often operated manually via winches or direct leverage, as exemplified by the timber swing spans on the Delaware and Raritan Canal, which used A-frame designs for simple hand operation.[11] Early designs were primarily wooden and hand-powered, constrained by material limitations to short spans typically under 100 feet, such as the 68-foot spans common on early American canal bridges.[10] By the mid-1800s, the shift to iron construction, accelerated by rising maritime trade and railroad expansion, permitted larger spans and greater durability, transitioning swing bridges from modest canal accommodations to vital infrastructure for heavier industrial loads.[10]Development and Evolution
The late 19th century represented a pivotal shift in swing bridge engineering, transitioning from wooden and iron constructions to steel frameworks that supported longer spans and heavier loads. This adoption of steel, particularly in the United States, enabled swing spans reaching up to 300 feet, facilitating the expansion of railroad networks across navigable waterways. For instance, by the 1890s, American railroads began constructing all-steel swing bridges to accommodate growing freight demands, marking a departure from earlier manual-operated wooden designs that limited structural integrity and span lengths.[12][13] In the early 20th century, mechanical advancements further refined swing bridge functionality, with the introduction of electric and hydraulic drive systems replacing manpower for operation. These innovations, emerging around the 1900s, provided smoother motion and reduced operational times, addressing previous limitations in speed and reliability. Hydraulic actuators, first widely applied in Europe during the 1950s, gained prominence globally for their high torque and variable speed capabilities, while electric motors became standard in many American installations for precise control. Post-World War II developments integrated these drives with early traffic signaling systems, enhancing coordination between road, rail, and maritime traffic in urban settings.[14][13] Swing bridges peaked in prevalence during the 1920s, with hundreds documented in the United States alone, driven by urban port expansions and infrastructure booms that necessitated movable crossings over busy waterways. In regions like Florida, surveys recorded 27 swing bridges in 1981, reflecting an earlier high of dozens per state during this era, though many were later repurposed or replaced. The global evolution of swing bridges paralleled colonial infrastructure projects, as European designs from 19th-century Britain spread to Asia and other territories through imperial engineering efforts, adapting local waterways for trade routes.[15][13] In the modern era, swing bridge construction has declined sharply due to escalating costs and the preference for vertical lift or bascule alternatives that minimize channel obstruction. However, retrofitting existing structures for heritage preservation has become common, incorporating sensors for structural health monitoring—such as strain gauges and accelerometers—to detect corrosion and fatigue in real time. Automation systems now enable remote operation and predictive maintenance, improving efficiency without full replacements. Current engineering trends emphasize sustainable materials, including corrosion-resistant alloys like weathering steel and duplex stainless steels, which extend service life in harsh marine environments and reduce long-term maintenance needs.[16][17][18]Design and Mechanics
Pivot Mechanism
The pivot mechanism of a swing bridge enables horizontal rotation about a vertical axis, typically anchored to a central pier via a kingpost or turntable structure that serves as the rotational fulcrum.[4] This design allows the span to swing perpendicular to the waterway, opening a navigation channel. Swing bridges employ two primary pivot support systems: center-bearing, where the pivot directly supports the full dead load of the span for balanced rotation, and rim-bearing, where the dead load is primarily carried by peripheral rollers on a circular track, with the central pivot providing guidance and partial load sharing to distribute weight more evenly during operation.[2][3] In center-bearing configurations, live loads are transferred to end supports or the pivot when closed, while rim-bearing systems use the track to handle both dead and live loads more uniformly across the span.[2] Bearing systems minimize friction during rotation, commonly utilizing tapered roller bearings in rim setups or spherical thrust bearings in center pivots to accommodate axial and radial forces.[3] Gear mechanisms, such as pinion-rack arrangements, further reduce resistance by converting rotational input into linear motion along the pivot track.[3] The torque required for rotation is primarily to overcome frictional, inertial, and environmental resistances. For balanced spans, the net torque from weight is zero, but the drive system must provide sufficient torque, often calculated considering equivalent forces at the pivot radius; this ensures the drive system can overcome inertial and frictional resistances.[3] Drive mechanisms typically include electric motors coupled to gear reducers and pinions that engage a circular rack around the pivot, hydraulic rams or motors for direct slewing action, or manual cranks for emergency operation.[3] Power requirements scale with span length and weight, generally ranging from 50 to 100 kW, for example, 100 hp (approximately 75 kW) electric motors are used for a 480-foot span to achieve 90-degree rotations in under two minutes.[19][20] Precise alignment is critical for safe closure, achieved through centering devices and secured by wedges or lock bars that engage sockets to prevent movement under load.[19][3] Engineering challenges include managing unbalanced forces on the exposed pivot, such as wind loads that can induce overturning moments, mitigated by balance wheels rolling on a concentric track to maintain stability.[3] Vessel wakes introduce dynamic lateral impacts, addressed through guide rollers and buffers at the pivot ends to absorb deflections without compromising rotational integrity.[3]Span Configuration and Counterweights
Swing bridges typically feature a single central span that rotates horizontally around a vertical pivot axis, often by 90 degrees, to open a navigable channel for vessels.[21] This configuration allows the span to align perpendicular to the waterway when closed, providing continuous roadway support, while the rotation clears the path when open. For wider channels, double-span variants, such as double-arm or bobtail designs, extend the structure with a shorter rear arm to enhance stability and reduce the pivot's load.[6] In bobtail configurations, the rear span is typically 30-40% of the main span length to maintain balance.[6] Counterweight systems are essential for balancing the span's center of gravity relative to the pivot, minimizing the torque required for rotation and ensuring operational efficiency. In symmetrical designs, the span is inherently balanced, but small counterweights may correct transverse imbalances caused by factors like wind or uneven loading.[21] For asymmetrical bobtail spans, concentrated counterweights are mounted at the end of the shorter rear arm, while distributed weights can be integrated within the truss structure to offset the longer forward span's mass.[22] The counterweight mass is calculated using principles of moment equilibrium, where , with as the span mass, as the distance from the pivot to the span's center of gravity, and as the lever arm length to the counterweight.[7] These systems often employ concrete blocks or steel boxes, sometimes filled with water or dense materials like lead for fine-tuned adjustability during installation or maintenance.[21][23] Truss designs in swing bridges prioritize lightweight strength to reduce the overall mass and rotational inertia, commonly utilizing through-truss or deck-truss configurations for structural rigidity.[21] Through-trusses, which enclose the roadway between upper and lower chords, provide high stiffness with minimal depth, suitable for spans up to 500 feet, as seen in examples like the Coleman Bridge.[21] Deck-trusses place the roadway above the main structure, offering a lower profile for clearance constraints. These designs support live loads for vehicular traffic, with capacities governed by standards allowing up to approximately 50 tons depending on the bridge class and regional specifications.[6] To ensure precise closure and prevent misalignment, swing bridges incorporate alignment aids such as guide rails along the abutments and protective fenders at the span ends.[22] These elements interface with the fixed approaches to guide the rotating span into position, compensating for any pivot-induced deviations. Hydraulic jacks may be employed post-rotation to make minor corrections, maintaining a flush deck surface for safe traffic flow.[21]Operation
Opening and Closing Process
The opening and closing of a swing bridge begins with preparation to ensure safe clearance of land traffic. Upon receiving a request from marine traffic, the bridge operator activates signals, turning traffic lights to red, sounding an alarm bell, and lowering gates or barriers to halt vehicular and pedestrian movement on the approaches. Locks securing the span to the abutments are then disengaged, often using hydraulic or mechanical retractors, while end lift mechanisms such as wedges, rollers, or jacks raise the span ends slightly to free them from the resting piers and prevent binding during rotation.[3][6][24] The rotation sequence follows, where electric motors or hydraulic systems drive the span via pinions engaging a curved rack on the central pivot pier, turning the bridge horizontally up to 90 degrees to align perpendicular to the waterway and create navigable channels. Position sensors monitor progress, pausing at mid-rotation if needed to verify clearance for vessels, with the full 90-degree turn typically completing in 1 to 3 minutes for most modern bridges. The process is overseen by operators in a control house or through automated programmable controllers that detect obstacles and enable emergency stops to halt movement if anomalies arise.[19][3][20] Closing reverses the sequence, with the drive system rotating the span back to its original alignment, decelerating precisely to dock within 1/4 inch of the abutments for seamless connection. End lift devices then lower the span onto the piers, and locks—such as center wedges or tail locks—engage hydraulically or mechanically to secure it against live loads and impacts, restoring structural integrity. Once verified, traffic signals switch to green, gates lift, and alarms cease, reopening the crossing; the entire cycle from closed to open and back typically takes under 6 minutes in automated systems.[19][20][6] Timing variations exist based on bridge size and actuation method: smaller manual swing bridges may require 5 to 10 minutes per cycle due to hand-cranked or simpler gearing, while larger automated ones achieve under 2 minutes for rotation through redundant motors and interlocked controls. Throughout, brief references to control systems ensure procedural adherence without delving into detailed protective features.[3][24]Safety and Control Systems
Swing bridges employ centralized control interfaces to manage precise rotational movements, typically featuring operator consoles equipped with switches, indicator lights, and joysticks or similar handles for manual slewing control, often integrated with programmable logic controllers (PLCs) that automate sequencing and monitor equipment status in real time.[20][25] These systems ensure coordinated operation during the bridge's rotation, with PLCs handling diagnostics and fault detection to prevent errors.[25] Key safety features include limit switches that halt movement at predefined positions, such as stopping lift mechanisms within one inch of full stroke with a backup at three-quarters inch, alongside obstruction detectors using linear position sensors to continuously monitor bridge alignment and detect deviations.[20] Redundant power supplies, such as multiple hydraulic pumps with one as standby and diesel generators for outages, maintain operational integrity during failures.[20] Additionally, fail-safe brakes, mandated by AASHTO standards since the 1980s, engage automatically via spring-set mechanisms when power is lost, preventing uncontrolled drift and limiting deceleration forces.[25] Operational protocols integrate maritime signaling requirements under U.S. Navigation Safety Regulations, including automatic audio and visual alarms to alert vessels and traffic, alongside traffic gates and lights controlled by the PLC.[26] For aviation proximity, some systems incorporate FAA-compliant lighting and obstruction marking to mitigate hazards.[27] Wind speed limits restrict operations, with maximum gusts typically not exceeding 35 mph during opening to ensure stability, as per design criteria aligned with AASHTO guidelines.[28] Post-1980s swing bridges incorporate enhanced fail-safe brakes and emergency stop circuits that halt motion in under 10 seconds by de-energizing motors and centering valves, reflecting advancements in AASHTO specifications for movable structures.[20][25] Annual inspections are standard for assessing corrosion, pivot alignment, and mechanical integrity, using access ladders and retraction procedures to minimize downtime while complying with national bridge safety management programs.[29][30] In emergencies, manual overrides allow operators to activate high-pressure emergency slewing or halt systems via dedicated stop buttons, with evacuation signals triggered through integrated alarms to clear personnel and traffic.[20] These procedures, supported by redundant circuits and watchdog timers in PLCs, ensure rapid response to malfunctions without compromising overall safety.[25]Advantages and Disadvantages
Key Advantages
Swing bridges provide exceptional navigational efficiency by rotating the entire span horizontally around a central vertical pivot, granting full unobstructed clearance to the waterway below without any vertical displacement of the structure. This horizontal movement is particularly beneficial for accommodating tall ships or vessels with high masts, as it avoids the limitations imposed by vertical clearance requirements in other movable bridge types like bascules or vertical lifts.[6] The design ensures minimal disruption to maritime traffic, allowing vessels to pass through the opened channel swiftly and safely.[31] In terms of cost-effectiveness, swing bridges are advantageous for medium-length spans, typically under 200 feet, where construction expenses are lower than those for bascule bridges due to simpler machinery and the use of plate girder spans rather than complex truss systems. For instance, the replacement of a 163-foot single-track swing bridge was completed at a total cost of $3.5 million, well below the $10 million threshold often associated with comparable bascule or lift designs for similar spans.[32][6] Additionally, the horizontal operation reduces wind-induced moments on the structure, minimizing material requirements and overall engineering complexity.[31] Swing bridges maintain minimal impact on headroom and surrounding airspace, as they lack the tall counterweights or lifting towers found in vertical lift or bascule designs, thereby preserving scenic aesthetics and avoiding conflicts with low-altitude air traffic. Operationally, the rotational motion enhances traffic flow efficiency.[6][31] Their versatility extends to their adaptability for multiple uses, including rail, roadway, or pedestrian traffic, through modular configurations that support double-deck arrangements without requiring vertical elevation. This multi-modal capability makes them suitable for diverse urban and industrial settings.[6] While these benefits are significant, swing bridges do necessitate ongoing maintenance of the pivot and bearing systems to ensure reliable performance.[31]Primary Disadvantages
Swing bridges require substantial space for the rotation of the moving span, necessitating wide landing areas adjacent to the waterway to accommodate the bridge when it swings open parallel to the waterway. This spatial demand often limits their applicability in densely populated urban environments, where available land for such clearances is scarce and upgrading or duplicating the structure for higher traffic volumes becomes challenging.[33][34] Maintenance of swing bridges is particularly demanding due to the high wear on pivot mechanisms and bearings, which support the full weight of the span during rotation and are subject to constant mechanical stress from numerous moving parts. Common issues include worn machinery, lack of lubrication, misalignments, and broken supports, making routine inspections and repairs more inaccessible and labor-intensive compared to fixed bridges. These factors contribute to significant ongoing costs, with movable bridges in general posing elevated operating and maintenance expenses for owners.[33][6][35] In operation, swing bridges cause notable traffic disruptions for land users, as frequent openings to allow marine passage can lead to delays, exacerbated by the longer time required for the complex mechanical process of swinging the span compared to other movable bridge types. Additionally, these bridges are vulnerable to environmental conditions such as icing on mechanical components or high winds, which can hinder safe operation and necessitate closures.[33][6] Seismic retrofitting for older swing bridges is costly due to the need to reinforce pivot piers and spans against earthquake forces. This has contributed to a decline in swing bridge construction since the 1970s, as fixed high-level bridges have become preferred alternatives for navigable waterways, offering greater reliability without movable components.[36][4] Swing bridges also present environmental risks through potential oil leaks from hydraulic systems used in operation, which can contaminate adjacent waterways and harm local aquatic fauna and flora if not properly contained.Types and Variations
Rim-Bearing Swing Bridges
In rim-bearing swing bridges, the weight of the movable span is primarily supported by a series of peripheral rollers that bear on a circular track encircling the pivot island or pier. This design transfers the dead load of the superstructure through radial beams or a circular girder to the rollers, which are typically tapered or beveled to accommodate rotation while maintaining alignment. The central pivot serves mainly as a guide to keep the rollers centered, though it may carry a minor portion of the load in some configurations.[37][21] These bridges were commonly applied in late 19th- and early 20th-century railroad constructions, for spans including heavy and long ones up to over 400 feet, where the distributed support allowed for handling heavy rail traffic over navigable waterways. For instance, the Center Street Bridge in Cleveland, Ohio, completed in 1901, exemplifies this type with its rim-bearing mechanism supporting a swing span for rail and road use. The approach suited sites requiring balanced load transfer without excessive central concentration.[38][39] A key advantage of rim-bearing designs lies in their simpler construction relative to more centralized systems, as the peripheral track facilitates straightforward assembly of the rolling elements and provides easier access for routine maintenance and lubrication of the rollers. Additionally, the distributed support enhances load balancing during rotation and reduces sensitivity to uneven pier settlements.[24] Load distribution occurs across multiple contact points, with the weight shared evenly among the rollers spaced along the circular track to ensure even pressure and prevent localized stress.[39] Rim-bearing swing bridges were common from the 1890s to the 1920s for a range of spans, though center-bearing designs became more prevalent afterward for longer and heavier applications due to advancements in pivot technology. Notable historical examples include older UK canal bridges, such as the Eastwood Swing Bridge on the Nottingham Canal, which utilized rim-bearing mechanisms for accommodating narrowboat traffic.[39][40]Center-Bearing Swing Bridges
Center-bearing swing bridges represent a subtype of swing bridges where the entire dead load of the movable span is supported by a central pivot bearing when the bridge is in the open position, allowing for rotation around a vertical axis on a central pier or pedestal. This design utilizes a single large bearing, often a mechanical pivot such as a lenticular bronze disc between hardened steel concave discs, or more modern spherical antifriction bearings, to concentrate the load at the center turntable.[2][6] In the closed position, the span is supported by the center bearing and two end rest piers, distributing the load across three points, while balance wheels at the ends provide additional resistance to tilting and maintain alignment. When opening, retractable wedges or supports at the ends shift the full weight to the central bearing, enabling smooth horizontal rotation with minimal vertical movement. This configuration contrasts with rim-bearing designs by eliminating reliance on peripheral tracks for primary load support during operation, though a brief reference to rim-bearing simplicity highlights its use in smaller-scale applications.[6][2] These bridges are particularly suited for longer spans, such as the 300-foot center-bearing swing spans historically constructed for railroads, due to their enhanced structural integrity and ability to handle extended lengths without excessive complexity. Post-1950s developments have established center-bearing as a standard for heavy traffic environments, incorporating advanced spherical bearings for improved durability and load distribution under demanding conditions like rail or highway use.[39][2] Key advantages include reduced wear on the support tracks, as properly balanced spans position the end wheels to clear the track by approximately 0.2 inches during operation, minimizing contact and friction. Additionally, the central load concentration provides higher stability under varying loads, with lower susceptibility to wind forces compared to lifting-type movable bridges, ensuring reliable performance for spans subjected to dynamic traffic.[2][6] Modern adaptations often integrate computer-based control systems for precise operation, including automated monitoring of alignment, load shifting, and rotation mechanics, enhancing safety and efficiency in contemporary installations. These systems, part of broader electrical controls for movable bridges, allow for real-time adjustments and integration with traffic management infrastructure.[41][16]Notable Examples
Europe
Europe's dense network of canals and navigable rivers, particularly in countries like the Netherlands and the United Kingdom, fostered the widespread adoption of swing bridges from the 19th century onward to accommodate maritime and inland traffic without impeding navigation.[42][43] These structures proliferated due to the need for efficient crossings over busy waterways, with many now preserved as heritage sites reflecting industrial-era engineering ingenuity. For instance, the Rewley Road Swing Bridge in Oxford, UK, originally built in 1851 as a cast-iron railway swing span, underwent restoration in 2023 to maintain its historical integrity.[44][45] A prominent example is the Tyne Swing Bridge in Newcastle upon Tyne, UK, completed in 1876 and designed by William Armstrong to span the tidal River Tyne. This center-bearing swing bridge, measuring 560 feet in length and weighing over 1,300 tons, was one of the largest of its kind at the time and facilitated access to expanding shipyards and ports during the Industrial Revolution.[46][47] Its hydraulic mechanism historically allowed a full 90-degree rotation in under two minutes, adapting to the river's tidal fluctuations while supporting both road and pedestrian traffic. The bridge has been unable to swing open since 2019 due to mechanical issues, with restoration work underway to resume operations by 2026, and is recognized for its architectural and historical importance in connecting Newcastle and Gateshead.[48] In the Netherlands, the De Hef railway bridge in Rotterdam, initially constructed as a swing bridge in 1878, exemplifies early adaptations for canal and port navigation. Originally a pivot swing span to allow tall-masted ships passage, it was later modified into a bascule design in 1927 due to increasing traffic demands but retains its historical significance as a symbol of Rotterdam's maritime heritage.[49] The country's extensive canal system, exceeding 6,000 kilometers, necessitated numerous such swing bridges, many of which feature center-bearing mechanisms for balanced rotation over narrow waterways.[42] France's Colbert Bridge in Dieppe, opened in 1889, stands as one of Europe's last operational 19th-century hydraulic swing bridges, spanning the tidal Arques River near the port, which underwent comprehensive restoration completed in October 2025. Designed by engineer Paul Alexandre with a 70.5-meter pivoting span, it was engineered to handle tidal variations and heavy maritime traffic, opening via hydraulic rams powered by a steam engine originally.[50][51][52] Damaged during World War II, it underwent reconstruction in 1947 using original components where possible, preserving its status as a protected historic monument. In busy ports like Dieppe, such bridges open multiple times daily around high tide to accommodate shipping, typically twice per tidal cycle.[53][54] Germany's Rendsburg area featured significant rail swing spans prior to 1913, including parallel rotating bridges built between 1887 and 1895 over the Kiel Canal to support expanding naval and commercial traffic. These center-bearing designs allowed 360-degree rotation for large vessels but were replaced by the current high-level viaduct due to canal enlargements; their historical role underscores adaptations to tidal and industrial waterways.[55][56] In Estonia, the Admiral Bridge (Admiralisild) in Tallinn's Old City Harbour, completed in 2021, represents a modern automated swing bridge for pedestrian use, pivoting hydraulically to permit marine access in the port area. It highlights ongoing evolution in Baltic automation for tidal environments.[57][58]North America
In North America, swing bridges have played a crucial role in supporting industrial and urban infrastructure, particularly in regions with heavy maritime traffic like the Great Lakes and the Mississippi River basin, where they facilitate rail and highway crossings while allowing passage for commercial vessels. These structures emerged prominently in the late 19th and early 20th centuries to meet the demands of expanding rail networks and growing industrial shipping, enabling efficient transport of goods such as grain, lumber, and manufactured products across vital waterways.[59][60] A notable example is the Fort Madison Bridge in Iowa, constructed between 1925 and 1927, which spans the Mississippi River and features the world's longest double-decker swing span at 525 feet, accommodating rail traffic on the upper level and vehicular traffic on the lower. This bridge, listed on the National Register of Historic Places, exemplifies the engineering adaptations for dual-use in industrial settings and opens frequently—more than 2,000 times per year—for barge traffic supporting agriculture and manufacturing in the Midwest.[61][62] In the Great Lakes area, the Manistee River Swing Bridge in Michigan, a rare plate girder design built for the Marquette Rail system, underscores the regional emphasis on rail connectivity for timber and iron ore transport, with its pivot mechanism allowing swings for lake freighters. Similarly, Canada's Peterborough Railway Swing Bridge, operational since the early 20th century for Canadian Pacific Railway, bridges the Otonabee River and handles both train and boat movements in an urban-industrial corridor. These bridges often exceed 300 feet in total length, balancing structural efficiency with navigational needs.[63][60] The Government Bridge, linking Rock Island, Illinois, and Davenport, Iowa, across the Mississippi since 1896 (with reconstructions), represents urban applications with its full 360-degree swing capability for combined road and rail use, aiding commerce in the Quad Cities manufacturing hub and opening over 100 times annually for river traffic. In Canada, the historic Wasauksing Swing Bridge, completed in 1912 on Georgian Bay, connects First Nations communities and supports local industry, with its 140-foot span pivoting for small vessels.[64] Post-1990s earthquakes, such as the 1994 Northridge event, prompted seismic reinforcements for many North American swing bridges in vulnerable zones, including the addition of energy-dissipating devices and pier strengthening to mitigate lateral forces during swings, as outlined in federal guidelines for movable structures. For instance, assessments and retrofits on Mississippi River spans incorporated base isolation and bracing to enhance performance under seismic loads, ensuring continued reliability for industrial operations.[36][65]Other Regions
In regions beyond Europe and North America, swing bridges often embody colonial engineering legacies from British and French influences in Asia and Africa, while contemporary designs in developing ports address expanding trade demands. These structures highlight adaptations to local environments, including hybrid configurations for canal systems and measures against tropical corrosion from humidity, saltwater, and microbial activity, which can degrade steel components up to twice as fast as in temperate zones.[66] Australia's Pyrmont Bridge, opened in 1902 in Sydney's Darling Harbour, exemplifies early 20th-century colonial innovation as one of the world's oldest electrically operated swingspan bridges, now repurposed as a heritage-listed pedestrian and cycling link across Cockle Bay.[67] In China, the Qingling swivel bridge in Wuhan, completed in 2019, represents modern engineering prowess with its 252-meter main span and 46-meter width—claimed as the longest and widest swivel bridge at the time of completion—facilitating urban expressway traffic over the Yangtze River while minimizing waterway disruption.[68] South Africa's V&A Waterfront Swing Bridge, inaugurated in 2019 in Cape Town's historic harbor, serves as a cable-stayed pedestrian link between the Victoria and Alfred basins, enhancing tourism in one of Africa's busiest ports and drawing on colonial dockyard foundations.[69] In India, the Kidderpore Swing Bridge in Kolkata, constructed in the 1890s by British firm Westwood, Baillie & Co., remains operational after over 130 years, rotating 180 degrees to access Kidderpore Docks and illustrating enduring colonial infrastructure in a major Asian trade hub.[70] Vietnam's Han River Bridge in Da Nang, built in 2000, marks the country's first swing bridge, rotating 90 degrees nightly to permit maritime passage and symbolizing post-colonial urban renewal in Southeast Asia.[71] Further exemplifying hybrid designs, the Panama Canal's Miraflores swing bridge, installed in 1942 by the U.S. Army Corps of Engineers, integrated directly with lock gates to allow vehicle crossings over the Pacific entrance, addressing logistical needs in a tropical canal zone prone to corrosion until its replacement in the 1960s.[72] These global implementations underscore swing bridges' versatility in diverse climates, from corrosion-resistant coatings in humid tropics to efficient pivoting for port efficiency.[66]References
- https://commons.wikimedia.org/wiki/Category:Eastwood_Swing_Bridge