Spiral bridge

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Hastings Spiral Bridge, 1895

A spiral bridge, loop bridge, or pigtail bridge is a road bridge which loops over its own road, allowing the road to climb rapidly. This is useful in steep terrain, or where the approach road to a bridge would terminate too far from the bridge's end. The shape of the bridge forms a helix, not a spiral.

Many multi-storey car parks feature such a design as this.

Pigtail bridge[edit]

A pigtail bridge on Iron Mountain Road

In the Black Hills of South Dakota, a particular form of spiral bridge, locally called a 'pigtail bridge' was introduced in 1932 by Cecil Clyde Gideon, the self-taught superintendent of Custer State Park turned highway designer. He called them “spiral-jumpoffs”. During the planning for Iron Mountain Road, there was a need to negotiate sudden elevation drops while preserving natural features for this scenic highway; the corkscrew design allowed for a spectacular - although expensive - solution to this problem. In order to blend the bridges with their surroundings, natural materials such as local timber were used.

Most pigtail bridges were built by the Civilian Conservation Corps in the 1930s.

List of spiral road bridges[edit]

Name Location Year Comment
Spiral Bridge at Hastings High Bridge United States Hastings, Minnesota, USA 1895-1951
South Dakota Highway 87 in Wind Cave National Park United States South Dakota, USA
Steinmen Crossing on Oregon Highway 273, part of Historical U.S. Highway 99 through the Siskiyou Mountains. United States Oregon, USA
A bridge on US Highway 441 between Gatlinburg, Tennessee and Cherokee, North Carolina at Bearpen Hollow in the Great Smoky Mountains Nat'l Park United States North Carolina, USA
Three bridges on Iron Mountain Road United States South Dakota, USA 1930s
Lincoln Tunnel approach road to west portal. United States Weehawken, New Jersey, USA
Astoria–Megler Bridge south approach. United States Oregon, USA
General Artigas Bridge Uruguay Uruguay and Argentina Argentina From Colón, Entre Ríos, Argentina to Paysandú, Paysandú Department, Uruguay, across the Uruguay river. Cantilever bridge with a spiral on the Uruguay side.
Wiadukt Stanisława Markiewicza Poland Warsaw, Poland 1904 In Ulica Karowa which connects Krakowskie Przedmiescie to river level,
C-345 Spain Málaga, Spain
Thames Tunnel (planned, not constructed) England England 1825-1843 Originally planned to have an underground spiral giving access to road traffic, but this was never built.[1]
Sa Calobra Spain Majorca, Spain 39°49′55″N 2°48′57″E / 39.831968°N 2.81574°E / 39.831968; 2.81574
N8 Bypass Brienzwiler Switzerland Switzerland 46°45′02″N 8°06′32″E / 46.750521°N 8.108833°E / 46.750521; 8.108833
Isenfluh Switzerland Switzerland
A6 Highway Italy Italy 44°19′13″N 8°22′38″E / 44.320409°N 8.377118°E / 44.320409; 8.377118
Antirio to Lamia highway (E65) Greece Greece on the climb of Mount Parnassos to Delphi, Greece. 270° spiral using an overpass.
Rongqiao Road Spiral Bridge China Chongqing, China
Nanpu Bridge interchange China Puxi, Shanghai, China 2004
Ma On Shan Bypass Hong Kong Ma On Shan, New Territories, Hong Kong
New Clear Water Bay Road Hong Kong New Kowloon, Hong Kong 22°19′54″N 114°13′29″E / 22.331717°N 114.224617°E / 22.331717; 114.224617
Kawazu-Nanadaru Loop Bridge Japan Kawazu, Japan 1981 Double loop bridge. 34°47′28″N 138°56′17″E / 34.791°N 138.938°E / 34.791; 138.938
Mizukami Loop Bridge, Japan Mizukami, Kumamoto, Japan 32°18′54″N 131°00′36″E / 32.315°N 131.01°E / 32.315; 131.01
Yurikamome approach to Rainbow Bridge Japan Tokyo, Japan From the mainland.
Cahill Expressway Australia Sydney, New South Wales, Australia. Spiral turns left in order to turn right.

Spiral bicycle bridges[edit]

The Nesciobrug over the Amsterdam-Rijnkanaal in Amsterdam

Spiral pedestrian bridges[edit]

  • 1998-2004, Glass Spiral Bridge, Millennium Place, Coventry, England

See also[edit]

References[edit]

  1. ^ J.W. Parker, The roads and railroads, vehicles, and modes of travelling, of ancient and modern countries, p. 154

External links[edit]