Forth Railway Bridge, 1882.
© Science Museum / Science & Society Picture Library
Silver-plated model (scale 1:480). When it was opened in 1890, this cantilever bridge over the Forth estuary in Scotland was the longest in the world, the largest steel superstructure ever built and a triumph of British engineering skill. It was designed by Sir Benjamin Baker (1840-1907) and Sir John Fowler (1817-1898) and took 7 years to be built. It is 2.5 km in length and the longest span is 521 m. This demonstration model was used to secure the approval of Parliament in 1882, and construction started in 1883.