Forth Railway Bridge (1890) Scotland

The Forth Bridge, is a cantilever railway bridge over the Firth of Forth, 14 km (9 miles) west of Edinburgh in the east of Scotland. Often called the Forth Rail or Railway Bridge to distinguish it from the nearby and more recent Forth Road Bridge it was opened on 4th March 1890.​

It was planned in response to the growing use of rail in Scotland and the need to link up Edinburgh and Perth. In 1879 Thomas Bouch, builder of the earlier Tay Railway Bridge, began construction of a suspension bridge but with just one pier built work stopped following the disastrous collapse of the Tay Bridge in December of that year.​

Completely rethought in the light of the disaster, civil engineers Sir Benjamin Baker and Sir John Fowler produced a new design and work commenced on this in 1883.​

The new design was an enormous structure comprising three double cantilevers and was the first in the United Kingdom to be constructed of steel. The two main spans of 521m (1,710 ft) in length are flanked by two side spans 207m (680 ft) and fifteen 51m (168 ft) long approach spans. The cantilever arms which comprise the opening main spans are 207m (680 ft) long and support a central span truss of 107m (350 ft). The towers of the cantilever structures rise from granite piers and are 100m (330 ft) tall. The deck carrying two rail tracks is 48m (158 ft) above water level.

With an impressive overall length of 2,528m (8,296 ft) the bridge consists of two main spans of 521.3m (1,710 ft), two side spans of 207.3m (680 ft), and 15 approach spans of 51.2m (168 ft). Both of the main spans open and comprise two 207.3m (680 ft) cantilever arms supporting a central 106.7m (350 ft) span truss. The bridge weighs 51,324 tonnes.​

Considered one of the wonders of the world when it was built it became the subject of a popular but erroneous belief that it was so large that at one time it required constant repainting.​

Links: Wikipedia