Forth Bridge

Thomas Bouch, engineer to the North British Railway, proposed a stiffened steel suspension bridge in 1871; Parliament authorised it in August 1873, and work began in September 1878 with a brick pier at the western end of the mid-Forth island of Inchgarvie.

The collapse of Bouch's Tay Bridge in 1879 stopped the work. Henry Cadogan Rothery's public inquiry found that bridge "badly designed, badly constructed and badly maintained", with Bouch "entirely responsible" for the defects in design, having failed to account for the effect of high winds; the Board of Trade then required bridges to take a lateral wind loading of 56 lb per square foot, where Bouch, on the advice of the Astronomer Royal, had designed for 10. His Forth scheme was formally abandoned on 13 January 1881.

An Act authorising the redesigned bridge passed on 19 May 1882, and in December the contract went to Sir Thomas Tancred, T. H. Falkiner and Joseph Philips with Sir William Arrol & Co. It was designed by John Fowler and Benjamin Baker, and was the first major structure in Britain to be built of steel. It runs 2,467 metres between South and North Queensferry on three four-tower cantilever structures 110 metres tall, with 6.5 million rivets in a superstructure weighing 50,513 long tons.

The bridge was completed in December 1889. On 21 January 1890 two trains of three locomotives and 50 loaded coal wagons, together 1,880 tons and more than twice the design load, were run out to the middle of the north cantilever; deflection was as expected. Its single cantilever span was the longest in the world until the Quebec Bridge was completed in 1919. The Duke of Rothesay, later Edward VII, opened the bridge on 4 March 1890 and drove home the last rivet, gold-plated and inscribed.

Some 4,600 workers were employed at the peak. Wilhelm Westhofen recorded in 1890 that 57 men died. After the Forth Bridge Memorial Committee was formed in 2005, local historians naming the dead had connected 73 deaths to the bridge and its immediate aftermath by 2009; the earlier figure is thought to have excluded men who died on the approaches, which a subcontractor built, and those who died after the Sick and Accident Club stopped. Of the 73, 38 fell, 9 were crushed, 9 drowned, 8 were struck by a falling object, 3 died in a fire in a bothy and 1 of caisson disease; five causes are unknown. In 2019 the Queensferry Historian Group reported at least 21 further deaths, taking the toll to 78.

The Sick and Accident Club, founded in 1883, had compulsory membership for all contractors' employees and paid for medical treatment, funerals and grants to widows. Rowing boats stationed beneath the working areas saved eight men from drowning.

London to Aberdeen had taken about thirteen hours by the west coast route; with the east coast route open over the bridge, unofficial racing cut the overnight runs to about eight and a half hours, climaxing in the press reports of 1895.

The first German air attack on Britain in the Second World War came over the Forth Bridge on 16 October 1939. Twelve Junkers Ju 88 bombers attacked shipping from the Rosyth naval base two miles to the west; the bridge was not the target and was not damaged. Spitfires of 603 "City of Edinburgh" Squadron intercepted the raiders and shot down the first German aircraft downed over Britain in the war. The cruisers Edinburgh and Southampton and the destroyer Mohawk were damaged, sixteen Royal Navy crew died and 44 were wounded, none of which was made public at the time.

The bridge was built and maintained by the Forth Bridge Railway Committee, to which the North British Railway subscribed 35 per cent and three English railways the rest; at the 1923 Grouping it passed to the London and North Eastern Railway and the London Midland and Scottish, and the Forth Bridge Railway Company was nationalised into British Railways on 1 January 1948. Railtrack took over at privatisation, and as of April 2017 the bridge and its railway were owned by Network Rail Infrastructure Limited. It has been a category A listed building since 1973.

A £130 million contract awarded to Balfour Beatty in 2002 repainted the structure fully for the first time. UNESCO inscribed the bridge as a World Heritage Site on 5 July 2015 as "an extraordinary and impressive milestone in bridge design and construction". Network Rail's plans for a visitor centre and bridge climb at South Queensferry, approved in early 2020 and paused in the pandemic, were resubmitted in February 2022.