Forth Rail Bridge
Firth of Forth at Queensferry, Edinburgh, UK
associated engineer
Sir John Fowler
Sir Benjamin Baker
date 1882 - 21st January 1890
UK era Victorian |
category Bridge |
reference NT133795
ICE reference number HEW 71
photo PHEW
The construction of the Forth Bridge was first large scale use of steel in bridges — a pioneering project in the change from using wrought and cast iron to steel in structures.
See also
The Forth Rail Bridge article in Explore Why ...
The Forth Bridge Company was formed in 1873 by the four main railway companies interested in rail traffic on the east coast of Scotland with the aim of constructing a suspension bridge design by Thomas Bouch. The site had long been selected for some sort of crossing, though none had proceeded until now.
Preparatory work had begun when disaster befell Bouch's other major project, the Tay Bridge, which collapsed. Public confidence fell and Bouch's Forth design was abandoned.
The railway companies thoroughly tested alternatives and settled on Fowler and Baker's continuous girder bridge that uses cantilevers and central girders. The enabling Act was passed in July 1882.
Large steel fabrication workshops were set up on the north shore and all parts of the bridge were constructed on site. Special plant was designed for the erection of the bridge. Riveting was done using hydraulic machines. Many new construction techniques were developed.
The steelwork received two coats of red lead, one of iron oxide primer and a final coat of Indian red externally and the interior of the tubes one of red lead and two coats of white lead. The painted area was calculated as 145 acres.
The Forth Rail Bridge was the largest cantilever span and largest spanning bridge in the world at the time of its construction. Its overall length is 2,465m and longest span 521m. The bridge at Quebec took over as the largest cantilever span in 1917.
Contractors included William Arrol & Co (Glasgow)
Apprentice with Arrol: Adam Hunter