- Brunel truss, Brunel truss bridge, and lenticular truss redirect here.
The Royal Albert Bridge (sometimes called the Brunel Bridge or Saltash Bridge) spans the River Tamar in the U.K. between Plymouth, on the Devon bank, and Saltash on the Cornish bank. It carries the Cornish Main Line in and out of Cornwall. A short distance to the north of Brunel's bridge, the Tamar is crossed by the Tamar Bridge carrying the A38, one of the two trunk roads connecting Cornwall to Devon.
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Construction
The bridge was designed in 1855 by Isambard Kingdom Brunel for the Cornwall Railway Company after Parliament rejected his original plan for a train ferry across the Hamoaze. The bridge consists of two main spans of 455 feet (139 m), 100 feet (30 m) above mean high spring tide, plus seventeen much shorter approach spans. Opened by Prince Albert on 2 May 1859, it was completed in the year of the great engineer's death. The structure was the third in a series of three notable wrought iron bridges built in the period, and was influenced by the preceding two, both by Robert Stephenson. The two central sections of the bridge are novel adaptations of the design employed for the High Level Bridge across the River Tyne in Newcastle Upon Tyne. These two spans are lenticular trusses with the top chord of each truss comprising a heavy tubular arch in compression, while the bottom chord comprises a pair of catenary shaped members. Each of the trusses is simply supported and therefore no horizontal thrust is exerted on the piers. Between these two chords are supporting cross bracing members and suspension members which trail beneath the bottom chord to carry the railway deck which is a continuous plate beam. The method of construction was similar to the Britannia Bridge across the Menai Strait in north Wales, in that the spans were constructed on land, then floated into position and raised. Unlike the Britannia, however, the central piers were built up in height three feet (1 m) at a time, and the spans raised that distance, until the design height was achieved. (For the Britannia, the piers were built to full height, and then the span hoisted to design height.) The difficulty of its construction rates it as one of Brunel's great railway achievements.
Inscription
The words I.K. BRUNEL, ENGINEER, 1859 appear in large type on either end of the bridge, added as a tribute after his death. In 1921, new access platforms were added that obscured the lettering. In 2006, Network Rail relocated the platforms, allowing the name to be seen again.
External links
- Official Site for the bridge with many pictures
- The Royal Albert Bridge website
- Royal Albert Bridge in the Structurae database
- The Brunel Museum - Based in Rotherhithe, London the museum is housed in the building that contained the pumps to keep the Thames Tunnel dry.
References
- Binding, John (1997). Brunel's Royal Albert Bridge: A Study of the Design and Construction of his 'Gateway to Cornwall' at Saltash. Truro: Twelveheads Press. ISBN 0-906294-39-8.
- Charles Matthew Norrie (1956). Bridging the Years - a short history of British Civil Engineering. Edward Arnold (Publishers) Ltd.
- [Brunel's Royal Albert Bridge unveiled in all its splendour] Network Rail press release
Mentions in popular culture
The Royal Albert Bridge is crossed and marveled at by major characters in the alternate history novel, Stars & Stripes Forever, by Harry Harrison. It is referred to as "The Amazing Bridge Across the Tamar River " and is pictured in an accurate woodcut-style drawing by Angela Tomlinson. Details of its design and construction are briefly discussed. The bridge is depicted in several paintings by mariner and painter Alfred Wallis. It is mentioned in the Show of Hands song "Cousin Jack".
