The Forth Bridge is a cantilever, railway bridge over the Firth of Forth in the east of Scotland, to the east of the Forth Road Bridge, and 14 km (9 miles) west of c
entral Edinburgh. It is often called the "Forth Rail Bridge" to distinguish it from the Forth Road Bridge. The bridge connects Scotland's capital Edinburgh with the Kingdom of Fife, and acts as a major artery connecting the north-east and south-east of the country. Described as "the one internationally recognised Scottish landmark",[1] it may be nominated by the British government as a UNESCO World Heritage Site.[2] The bridge and its associated railway infrastructure is owned by Network Rail Infrastructure Limited.
entral Edinburgh. It is often called the "Forth Rail Bridge" to distinguish it from the Forth Road Bridge. The bridge connects Scotland's capital Edinburgh with the Kingdom of Fife, and acts as a major artery connecting the north-east and south-east of the country. Described as "the one internationally recognised Scottish landmark",[1] it may be nominated by the British government as a UNESCO World Heritage Site.[2] The bridge and its associated railway infrastructure is owned by Network Rail Infrastructure Limited.Construction of an earlier bridge, designed by Sir Thomas Bouch, got as far as the laying of the foundation stone, but was stopped after the failure of another of his 
works, the Tay Bridge. On Bouch's death the project was handed over to Sir John Fowler and Sir Benjamin Baker, who designed a structure that was built by Sir William Arrol's company between 1883 and 1890. Baker - "one of the most remarkable civil engineers Britain ever produced" - and his colleague Allan Stewart received the major credit for design and overseeing construction work.
works, the Tay Bridge. On Bouch's death the project was handed over to Sir John Fowler and Sir Benjamin Baker, who designed a structure that was built by Sir William Arrol's company between 1883 and 1890. Baker - "one of the most remarkable civil engineers Britain ever produced" - and his colleague Allan Stewart received the major credit for design and overseeing construction work.Construction
The bridge is, even today, regarded as an engineering marvel. It is 2.5 km (1.5 miles) in length, and the double track is elevated 46 m (approx. 150 ft) above high tide. It consists of two main spans of 1,710 ft, two side spans of 675 ft, 15 approach spans of 168 ft, and five of 25 ft.[3] Each main span comprises two 680 ft cantilever arms supporting a central 350 ft span girder bridge). The three great four-tower cantilever structures are 340 ft (104 m) tall, each 70 ft diameter foot resting on a separate foundation. The southern group of foundations had to be constructed as caissons under compressed air, to a depth of 90 ft. At its peak, approximately 4,600 workers were employed in its construction. Initially, it was recorded that 57 lives were lost; however, after extensive 
research by local historians, the figure has been revised upwards to 98.[4] Eight men were saved by boats positioned in the river under the working areas.
research by local historians, the figure has been revised upwards to 98.[4] Eight men were saved by boats positioned in the river under the working areas.Hundreds more were left crippled by serious accidents, and one log book of accidents and sickness had 26,000 entries. In 2005, a project was set up by the Queensferry History Group to establish a memorial to those workers who died during the bridge's construction. In North Queensferry, a decision was also made to set up memorial benches to commemorate those who died during the construction of both the rail and the road bridges, and to seek support for this project from Fife Council.
More than 55,000 tons of steel were used, as well as 18,122 m³ of granite and over eight million rivets. The bridge was opened on March 4, 1890 by the Prince of Wales, later King Edward VII, who drove home the last rivet, which was gold plated and suitably ins
cribed.[5] A contemporary materials analysis of the bridge, circa 2002, found that the steel in the bridge is of good quality, with little variation.
The use of a cantilever in bridge design was not a new idea, but the scale of Baker's undertaking was a real pioneering effort, afterwards extensively followed in different parts of the world. Much of the work done was without precedent, including calculations for incidence of erection stresses, provisions made for reducing future maintenance costs, calculations for wind pressures made evident by the Tay Bridge disaster, the effect of temperature stresses on the structure, and so on.
Where possible, the bridge has used natural features such as Inchgarvie, an island, the promontories on either side of the firth at this point, and also the high banks of the land on either side.
cribed.[5] A contemporary materials analysis of the bridge, circa 2002, found that the steel in the bridge is of good quality, with little variation.The use of a cantilever in bridge design was not a new idea, but the scale of Baker's undertaking was a real pioneering effort, afterwards extensively followed in different parts of the world. Much of the work done was without precedent, including calculations for incidence of erection stresses, provisions made for reducing future maintenance costs, calculations for wind pressures made evident by the Tay Bridge disaster, the effect of temperature stresses on the structure, and so on.
Where possible, the bridge has used natural features such as Inchgarvie, an island, the promontories on either side of the firth at this point, and also the high banks of the land on either side.
Maintaining the Forth Bridge
A structure like the Forth Bridge needs constant maintenance and the ancillary work
s for the bridge included not only a maintenance workshop and yard but a railway "colony" of some fifty houses at Dalmeny Station. Maintenance of the bridge proved a hazardous occupation and on average one workman a year lost his life until 1994[citation needed]. The track on the bridge is of "waybeam" construction: 12 inch square baulks of timber 6 metres long are bolted into steel troughs in the bridge deck and the rails are fixed on top of these special sleepers known as waybeams. In 1992 the bridge was re-railed with standard BS113A rail(54 kg/m). Prior to 1992 the rails on the bridge were of a unique "Forth Bridge" Section.
Although modern trains put fewer stresses on the bridge than the earlier steam trains, the bridge needs constant maintenance, and this is currently undertaken by Balfour Beatty under contract to Network Rail.[6] Up to 190-200 trains per day crossed the bridge in 2006; the structure connects north and south Scotland by rail.[7] "Painting the Forth Bridge" is a colloquial term for a never-ending task (a modern rendering of the myth of Sisyphus), coined on the erroneous belief that, at one time in the history of the bridge, repainting was required and commenced immediately upon completion of the previous repaint. According to a 2004 New Civil Engineer report on contemporary maintenance, such a practice never existed, although under British Rail management, and before, the bridge had a permanent maintenance crew.
s for the bridge included not only a maintenance workshop and yard but a railway "colony" of some fifty houses at Dalmeny Station. Maintenance of the bridge proved a hazardous occupation and on average one workman a year lost his life until 1994[citation needed]. The track on the bridge is of "waybeam" construction: 12 inch square baulks of timber 6 metres long are bolted into steel troughs in the bridge deck and the rails are fixed on top of these special sleepers known as waybeams. In 1992 the bridge was re-railed with standard BS113A rail(54 kg/m). Prior to 1992 the rails on the bridge were of a unique "Forth Bridge" Section.Although modern trains put fewer stresses on the bridge than the earlier steam trains, the bridge needs constant maintenance, and this is currently undertaken by Balfour Beatty under contract to Network Rail.[6] Up to 190-200 trains per day crossed the bridge in 2006; the structure connects north and south Scotland by rail.[7] "Painting the Forth Bridge" is a colloquial term for a never-ending task (a modern rendering of the myth of Sisyphus), coined on the erroneous belief that, at one time in the history of the bridge, repainting was required and commenced immediately upon completion of the previous repaint. According to a 2004 New Civil Engineer report on contemporary maintenance, such a practice never existed, although under British Rail management, and before, the bridge had a permanent maintenance crew.
A contemporary repainting of the bridge commenced with a contract award in 2002, for a schedule of work expected to continue until March 2009, involving the application of 20,000 m² of paint at a cost estimate of £10M a year. This new coat of paint is expected to have a life of 20 years.
