Water Street Bridge (Manchester)
The original bridge carried the Liverpool and Manchester Railway over Water Street.
It was the first cast iron bridge constructed to carry a main line railway (as distinct from a tramway). It took the railway into the terminus station, now the home of Manchester's Museum of Science and Industry.
After crossing the River Irwell into Central Manchester, George Stephenson was faced with the problem in getting the railway across Water Street to the terminus. The difficulty arose because the authorities imposed strict requirements on the clearance for traffic and pedestrians using Water Street. The height/width envelope was problematic, especially since the bridge had to be skewed. An arch bridge would be too restrictive, unless the track level was raised appreciably, which would bring its own major problems. Stephenson found the answer in a novel way - using cast iron beams of long span. Five shallow beams supported transverse beams, from which were spring brick jack arches. The ends of the main beams were supported on masonry blocks, which were in turn supported by fluted cast iron columns. The beams spanned the road (24 ft 6"), and not the 6 ft wide walkways, which were spanned by brick jack arches. The cast iron parapets did not contribute to the strength of the bridge.[1]
1897 photo here[2]. Zooming in shows the five longitudinal beams. These beams support transverse beams which appear to support jack arches (presumably brick). The transverse beams are arched, and the bottom flanges increase in width from the ends to the centre.
The bridge was designed by George Stephenson, using the principles established by Eaton Hodgkinson following extensive experimentation, latterly under the sponsorship of Fairbairn and Lillie, who also produced the beam castings for the bridge. Hodgkinson made some observations on the Water Street beams in a paper in 1831 [3]
1898 photo here.
The bridge was subsequently replaced by a steel girder bridge in 1904 (see photo).
More information and illustrations here.
See Also
Sources of Information
- ↑ Liverpool Road Station, Manchester. An historical and architectural survey, by R S Fitzgerald, Manchester University Press, 1980
- ↑ [1] Manchester City Council local images collection. Image m05466
- ↑ [2] 'Theoretical and experimental researches to ascertain the Strength and best forms of Iron Beams; by Eaton Hodgkinson: Memoirs of the Literary and Philosophical Society of Manchester, 2nd series, Vol V, 1831, pp.529-30
- ↑ [3] Manchester City Council local images collection. Image m79819