Kincardine Swing Bridge
The longest swing bridge in Europe when constructed.
Period of construction:
1900 - 1949
Transport Trust plaque:
Silver Street, Kincardine FK10 4NS
Across the Firth of Forth at Kincardine is this magnificent road bridge whose central span, 111 m (364 ft) long, is pivoted on a central pier. This span was opened by electric controls to allow the passage of shipping.â€¨ Since 1988 this function has been closed.
For many years ferries have linked the north and south shores of the Firth of Forth, but most of the road traffic for central Scotland has had to make the crossing of the Forth at Stirling. In 1922 the average number of vehicles crossing Stirling Bridge in an hour was 150, but in 1935 this figure had risen to 400.â€¨To relieve the congestion, the County Councils of Fife, Stirling and Clackmannan decided to build a new road bridge across the Forth. The site finally chosen was at Kincardine, below Alloa. Kincardine Bridge was designed by Sir Alexander Gibb and Partners, of London, and built by the Cleveland Bridge and Engineering Company, Ltd., of Darlington. The structure has a total length of 822 m (2,696 ft). At the northern or Kincardine end of the bridge the first three steel spans, each measuring 19 m (62.5 ft), are built on a curve over the track of the former railway. The curve was necessary to make a junction with a special approach road avoiding the streets of the town. The roadway on the curve is banked and at this end of the bridge is 4.5 m (15 ft) higher than at the southern end.
The next seven spans, also of steel, are each 30.5 m (100 ft) long and their design is of particular interest. The supporting system adopted is that of the cantilever. Every alternate 30.5 m (100 ft) span is made up of a central section, 15 m (50 ft) long, which rests at either end on girders, 7.5 m (25 ft) in length, projecting from adjacent spans. This method of construction permitted the use of the arched girders that are a pleasing and characteristic feature of the bridge. Each span consists of six arched girders which support a roadway 9 m (29.5 ft) wide. The roadway is flanked by two 1.5 m (5 ft) footways, which are carried on curved brackets cantilevered out from the bridge sides. The bridge piers comprise tapered cylinders of reinforced concrete, arranged in pairs which are joined by curved portal beams carrying the span girders.
In midstream is the magnificent central span. At the touch of an electric control wheel this could be swung on its supporting pier, leaving a clear passage of 46 m (150 ft) on either side for shipping. This swing span, weighing 1,600 tonnes, is 111 m (364 ft) long and its girder work towers 24 m (80 ft) above high-water level. When closed, the swing span provides 9 m (30 ft) of headroom above high water.
South of the swing span is another series of seven 30.5 m (100 ft) steel spans. Next are nine 15 m (50 ft) spans of reinforced concrete. A viaduct, also of reinforced concrete, provides the link with the southern bank of the river. This viaduct is 81 m (265 ft) long, and sweeps slightly downward in a reverse curve to meet the lower level of the south approach. Apart from this reverse curve, however, the bridge is upswept from either end towards the centre span, giving it a graceful appearance when viewed from either shore.
The bridge was granted a Category A Listing by Historic Scotland and was given an upgrade in 2008. A new Upper Forth crossing - the Clackmannanshire Bridge - was opened earlier that year.
Addison, Sir William, The Old Roads of England, Batsford, ISBN 0 7134 1714 5 (1980)
Forth Road Bridge Joint Board, The Forth Road Bridge: The Official Story, City of Edinburgh Publicity Department & Tourist Information Service, ASIN: B0000CMCAP (1964)
Harrison, David, The Bridges of Medieval England: Transport and Society 400-1800, Oxford University Press, ISBN-10: 0199226857 (2007)
Reynolds, John, Kincardine 1848-1948, Stan Brown, ISBN-10: 0969089910 (1984)
Sheldon, G., From Trackway to Turnpike, Oxford University Press, ASIN B001N2GS2S (1928)
Watt, Archibold, Highways and Byways Round Kincardine, Gourdas House, ISBN-10: 0907301096 (1985)
How To Find:
By road: OnÂ A876 south of Kincardine.
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