What Are Movable Bridges?

Bridge A bridge that can be rotated or moved. Also called open bridge. When the land transportation is not very busy, there are ships sailing on the river, and fixed bridges cannot be built above the navigable clearance, it is necessary to build movable bridges. Mostly built in the lower reaches of the river, near the intersection of water and land transportation in the city near the estuary. More steel structures are used.

Typical bridge

The double-leaf flyover spans up to 102 meters (336 feet) and is the Sault Ste. Marie Railroad Bridge between Michigan and Ontario, USA. The largest single-leaf span is the St. Charles Railway Bridge in Chicago, USA, with a span of 79 meters (260 feet). The Jiefang Bridge (formerly known as the Wenguo Bridge) in Tianjin, China, was completed in 1926 as a two-leaf type with an opening span of 46.94 meters (154 feet). It has now been converted into a fixed bridge.

Typical lifting bridge

The earliest lift bridge in the world was a 40-meter-long city bridge in Chicago, USA, named South Holstead Street Bridge. The largest spanning lift bridge is the Authur Kill bridge between Staten Island, New York, and Elizabeth, New Jersey, with a span of 170 meters (558 feet). It is a single-track railway bridge, built in 1959. Houghton, Michigan, USA has a highway-rail dual-use lift bridge that crosses the Portage Canal and was completed in 1959. The highway is on the upper level and the railway is on the lower level. The characteristics of this bridge are: when the ships sailing on the river under the bridge require a small headroom, the railway deck of the bridge span structure can be elevated to the highway deck, so that vehicles on the highway can continue to use the railway deck; when there is a height When larger ships pass, the bridge span structure is all raised to a higher position.

The Tanggu Haimen Lifting Bridge was completed in Tianjin, China in November 1985. It crosses the Haihe River at the southern end of Hebei Road in the center of Tanggu District. The main bridge is a 5-hole simply-supported underbolt bolt-welded truss girder with a span of 48 + 48 + 64 + 48 + 48 meters, and the middle 64-meter bridge span is a lifting hole. The two towers for elevators, electrical installations and counterweights are about 45 meters high.

Typical swing bridge

The Jintang Bridge in Tianjin, China, which was completed in 1903, originally belonged to this type of activity bridge. The longest swing bridge in the world is the Suez Canal Bridge in Egypt. It is a swing bridge with a span of 160 meters and a total opening width of about 320 meters. ^[1]