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18-631: The Niagara Cantilever Bridge or Michigan Central Railway Cantilever Bridge was a cantilever bridge across the Niagara Gorge . An international railway -only bridge between Canada and the United States , it connected Niagara Falls , New York , and Niagara Falls , Ontario . It was replaced by the Michigan Central Railway Steel Arch Bridge in 1925. Michigan Central Railway commissioned

36-423: A balanced cantilever ; when they attach to a solid foundation, the counterbalancing arms are called anchor arms . Thus, in a bridge built on two foundation piers, there are four cantilever arms: two which span the obstacle, and two anchor arms that extend away from the obstacle. Because of the need for more strength at the balanced cantilever's supports, the bridge superstructure often takes the form of towers above

54-505: A bridge that could handle differential settlement of the foundations. Engineers could more easily calculate the forces and stresses with a hinge in the girder. Heinrich Gerber was one of the engineers to obtain a patent for a hinged girder (1866) and is recognized as the first to build one. The Hassfurt Bridge over the Main river in Germany with a central span of 124 feet (38 metres)

72-797: A cantilever structure with their arms. Watanabe returned to Japan in 1888, where he became the chief engineer of the Nippon Doboku Company . He then worked at a number of other companies, including the Hokuestsu Railway Company. He was president of the Sangu Railway Company , Keio Electric Tramway , the Ishikawajima shipyard in Tokyo, and the Kansai Gas company. Conductor Takashi Asahina

90-464: Is available to support the tension in the upper chord of the span during construction, usually limiting this method to the spanning of narrow canyons. World's longest cantilever bridges (by longest span): Kaichi Watanabe Kaichi Watanabe ( 渡邊 嘉一 , Watanabe Kaichi , 22 March 1858 – 4 December 1932) was a Japanese engineer who studied and worked in Scotland , United Kingdom during

108-465: The Navajo Bridge ) are built using pure cantilever spans from each side, with neither falsework below nor temporary supporting towers and cables above. These are then joined with a pin, usually after forcing the union point apart, and when jacks are removed and the bridge decking is added the bridge becomes a truss arch bridge . Such unsupported construction is only possible where appropriate rock

126-584: The University of Glasgow from 1885 and graduated with a Civil Engineering and Bachelor of Science degree, and worked as a construction foreman on the Forth Bridge, which crossed the Firth of Forth in eastern Scotland in 1890. Watanabe's image became well known in the 1887 photograph illustrating the cantilever principle, in which he poses with Fowler and Baker, suspended between the engineers who form

144-760: The 1880s. He was one of the first Japanese engineers who came to study in the UK. He is best known for his work with Sir John Fowler and Sir Benjamin Baker in cantilever bridge construction, notably on the Forth Bridge . Watanabe studied under Henry Dyer , the Scottish engineer associated with technical education in Japan . After obtaining a degree from the Faculty of Technology of the University of Tokyo , he studied at

162-435: The 19th century understood that a bridge that was continuous across multiple supports would distribute the loads among them. This would result in lower stresses in the girder or truss and meant that longer spans could be built. Several 19th-century engineers patented continuous bridges with hinge points mid-span. The use of a hinge in the multi-span system presented the advantages of a statically determinate system and of

180-585: The Niagara Cantilever Bridge as a more cost effective alternative to leasing from the Lower Arch Bridge . Charles Conrad Schneider , the architect, chose a cantilever design due to the geography of the Niagara Gorge . Construction began in 1883. Boston cement was used for the foundation. The bridge was completed within months as a deadline was imposed by the railway: the steel sections gained approximately 3.8 meters each day and

198-415: The action of the outer foundations. Cantilever Bridge.—A structure at least one portion of which acts as an anchorage for sustaining another portion which extends beyond the supporting pier. A simple cantilever span is formed by two cantilever arms extending from opposite sides of an obstacle to be crossed, meeting at the center. In a common variant, the suspended span , the cantilever arms do not meet in

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216-440: The bridge entirely. When deconstructing the bridge, significant damage to the girders were noted, and the materials were scrapped. Cantilever bridge The steel truss cantilever bridge was a major engineering breakthrough when first put into practice, as it can span distances of over 1,500 feet (450 m), and can be more easily constructed at difficult crossings by virtue of using little or no falsework . Engineers in

234-423: The center; instead, they support a central truss bridge which rests on the ends of the cantilever arms. The suspended span may be built off-site and lifted into place, or constructed in place using special travelling supports. A common way to construct steel truss and prestressed concrete cantilever spans is to counterbalance each cantilever arm with another cantilever arm projecting the opposite direction, forming

252-416: The central section was built in a total of five days. When the bridge was finished, a crowd watched the final tests conducted by engineers and this was reported on by The New York Times . The bridge could handle two trains crossing simultaneously. The Niagara Cantilever Bridge became less useful as locomotives became heavier. Another steel arch was added in 1923 as an intermediate measure, with plans to replace

270-648: The foundation piers. The Commodore Barry Bridge is an example of this type of cantilever bridge. Steel truss cantilevers support loads by tension of the upper members and compression of the lower ones. Commonly, the structure distributes the tension via the anchor arms to the outermost supports, while the compression is carried to the foundations beneath the central towers. Many truss cantilever bridges use pinned joints and are therefore statically determinate with no members carrying mixed loads. Prestressed concrete balanced cantilever bridges are often built using segmental construction . Some steel arch bridges (such as

288-431: The structural principles of the suspended span cantilever by sitting in chairs and supporting their colleague, Kaichi Watanabe , in between them, using just their arms and wooden poles. The suspended span, where Watanabe sits, is in the center. The wooden poles resist the compression of the lower chord , while the outstretched arms support the tension of the upper chord. The placement of the brick counterweights demonstrates

306-522: Was 275 feet (84 metres) deep and took full advantage of the fact that falsework, or temporary support, is not needed for the main span of a cantilever bridge. The Forth Bridge is a notable example of an early cantilever bridge. This bridge held the record for longest span in the world for twenty-nine years until it was surpassed by the Quebec Bridge . The engineers responsible for the bridge, Sir Benjamin Baker and Sir John Fowler , demonstrated

324-550: Was completed in 1867 and is recognized as the first modern cantilever bridge. The High Bridge of Kentucky by C. Shaler Smith (1877), the Niagara Cantilever Bridge by Charles Conrad Schneider (1883) and the Poughkeepsie Bridge by John Francis O'Rourke and Pomeroy P. Dickinson (1889) were all important early uses of the cantilever design. The Kentucky River Bridge spanned a gorge that

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