A side-spar cable-stayed bridge may be an otherwise conventional

cable-stayed bridge A cable-stayed bridge has one or more ''towers'' (or ''pylons''), from which cables support the bridge deck. A distinctive feature are the cables or stays, which run directly from the tower to the deck, normally forming a fan-like pattern o ...

but its cable support does ''not span the roadway'', and is instead

cantilever A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a canti ...

ed from one side. The

Esplanade Riel Esplanade Riel is a pedestrian bridge located in Winnipeg, Manitoba. It was named in honour of Louis Riel. It is a side-spar cable-stayed bridge which spans the Red River connecting downtown Winnipeg with St. Boniface; it is paired with a vehic ...

illustrated is located in

Winnipeg Winnipeg () is the capital and largest city of the province of Manitoba in Canada. It is centred on the confluence of the Red and Assiniboine rivers, near the longitudinal centre of North America. , Winnipeg had a city population of 749,6 ...

Manitoba Manitoba ( ) is a Provinces and territories of Canada, province of Canada at the Centre of Canada, longitudinal centre of the country. It is Canada's Population of Canada by province and territory, fifth-most populous province, with a population o ...

, Canada. This bridge is intended for pedestrian use only and has a restaurant in its base. In the example below the cable paths are aligned with the bridge centerline, so that structurally it differs only in the transfer of stresses through the tower to the foundation. Calatrava Bridge in Jerusalem (18997244269)

Calatrava Bridge in Jerusalem (18997244269)

The side-spar principle is not limited to a straight bridge, however. The tower could be offset and the bridge deck wrap around the spar in an arc, e.g.,

Chords Bridge The Chords Bridge ( he, גשר המיתרים, ''Gesher HaMeitarim''), also called the Bridge of Strings or Jerusalem Light Rail Bridge, is a side-spar cable-stayed bridge in Jerusalem. The structure was designed by the Spanish architect and eng ...

in Jerusalem. Such a bridge would be particularly suited for use in the confines of a canyon, where the road is brought in the upstream direction down one side, crosses a stream, and turns back to a downstream direction on the other side. By placing a large portion of the turn on the bridge, rather than on the approaches, the turn may be made more gentle, allowing faster traffic. This would require more torsional (twisting) rigidity in the roadbed than would a straight bridge. A bridge of this type (supported by a spar), traveling through a much smaller arc, was one of the original proposals for the

eastern span replacement of the San Francisco-Oakland Bay Bridge Eastern may refer to: Transportation *China Eastern Airlines, a current Chinese airline based in Shanghai *Eastern Air, former name of Zambia Skyways *Eastern Air Lines, a defunct American airline that operated from 1926 to 1991 *Eastern Air Li ...

. Similar bridges, without the spar, could be supported by cables anchored in the canyon walls (where conditions are suitable). This subtype should not be confused with an asymmetrical single tower cable-stayed bridge, which possesses a single tower on one side of the gap to be crossed (see

Rama VIII Bridge The Rama VIII Bridge ( th, สะพานพระราม ๘, , ) is a cable-stayed bridge crossing the Chao Phraya River in Bangkok, Thailand. It was built to alleviate traffic congestion on the nearby Phra Pinklao Bridge. Construction of the ...

), nor with the

cantilever spar cable-stayed bridge A cantilever spar cable-stayed bridge is a modern variation of the cable-stayed bridge. This design has been pioneered by the structural engineer Santiago Calatrava in 1992 with the Puente del Alamillo in Seville, Spain. In two of his designs t ...

, which has span supporting cables on only one side of the tower along the direction of the roadbed.

Image gallery

Image:SideSparCableStayBridge1.jpg, Esplanade Riel, Winnipeg Image:WinnepegBridge.jpg, Esplanade Riel, Winnipeg Image:Esplanderiel.jpg, Esplanade Riel, Winnipeg Image:Jerusalem Chords Bridge 5.JPG, Chords Bridge, Jerusalem Image:Jerusalem Chords Bridge, Israel (1).jpg, Chords Bridge, Jerusalem Image:Jerusalem Chords Bridge.JPG, Chords Bridge, Jerusalem Image:Newcastle-upon-Tyne-bridges-and-skyline cropped.jpg, Millennium Bridge in Newcastle upon Tyne

Image gallery

See also