Civil Engineering heritage: Scotland - Lowlands and Borders
Date 2007
Event ID 606008
Category Descriptive Accounts
Type Publication Account
Permalink http://canmore.org.uk/event/606008
Dumbarton Bridge was built in 1765 by John Brown, a builder of considerable repute who was responsible for several public buildings in Scotland. It is of masonry with five segmental arches comprising three spans of 62 ft and two of 42 ft. The clear width between parapet faces was 20 ft.The Leven is fast flowing with a bed of alluvial material of unknown depth. Almost immediately on completion there was failure of one pier and a collapse of two arches. Smeaton, in May 1768, reported on the sunken pier, of which the bottom was about 17 ft below low water. He advised that because of the difficulty and expense of getting the pier out and the great uncertainty of better success with its replacement ‘that the best probable chance’ was to found a new pier on the ruins of the old, lightening the spandrels above by means of three longitudinal cavities, similar to the practice he adopted at Perth Bridge.
This measure is thought by the present maintainers to have been implemented and the pier is still in service.
The bridge was widened in 1884 with 8 ft 6 in. wide cantilevered footpaths carried on steel beams. In 1933 this
steelworkwas found to be badly corroded and was replaced in reinforced concrete during a complete refurbishment of the bridge in 1934 by F. A. Macdonald and Partners. In 1999 the bridge failed a structural assessment, but was again successfully refurbished and reopened in 2005.
R Paxton and J Shipway 2007
Reproduced from 'Civil Engineering heritage : Scotland - Lowlands and Borders' with kind permission of Thomas Telford Publishers.
