The Forth Bridge - An Enduring Icon Of Scotland
The Forth Bridge is a cantilever railway bridge in Scotland, spanning the Firth of Forth near Edinburgh. Completed in 1890, it's a UNESCO World Heritage site and a symbol of Scotland, known for its innovative design and scale.
Author:Callum FraserJun 20, 20251.1K Shares37.9K Views
The Forth Bridgeis a cantilever railway bridge that crosses the Firth of Forth in eastern Scotland, located 9 miles (14 kilometers) west of central Edinburgh. Finished in 1890, it is seen as a symbol of Scotland and was named the country's greatest man-made wonder in 2016. It is also a UNESCO World Heritage Site.
The bridge was designed by English engineers Sir John Fowler and Sir Benjamin Baker. Sometimes people call it the Forth Rail Bridge to differentiate it from the nearby Forth Road Bridge, though this isn’t its official name. Construction began in 1882, and it opened on March 4, 1890, by the Duke of Rothesay, who later became Edward VII.
The bridge carries the Edinburgh–Aberdeen line across the Forth between South Queensferry and North Queensferry and is 2,467 meters (8,094 feet) long. When it opened, it had the longest single cantilever bridge span in the world until 1919, when the Quebec Bridge in Canada surpassed it. It remains the second-longest single cantilever span with two spans of 1,709 feet (521 meters).
Earlier Proposals
Before the bridge was built, ferries were used to cross the Firth. In 1806, tunnels were proposed, one for each direction. In 1818, James Anderson designed a three-span suspension bridge near where the current bridge stands. Wilhelm Westhofen said that the bridge would have required about 2,500 tonnes of iron, making it look very light and slender.
Thomas Bouch created a roll-on/roll-off ferry for the Edinburgh and Northern Railway between Granton and Burntisland in 1850, which was so successful another was made for the Tay. Around late 1863, Stephenson and Toner were tasked to design a bridge for the Forth, but the job went to Bouch six months later.
Creating a suspension bridge that could carry railway traffic was difficult. Thomas Bouch, working for the North British Railway and Edinburgh and Glasgow Railway, was designing a single-track girder bridge over the Forth near Charlestown around 1863-1864.
There were concerns about setting foundations in the silty river bottom. Bouch conducted experiments showing that the silt could support weight. Experiments in late 1864 with weighted caissons achieved pressure on the silt, encouraging Bouch to continue.
By August 1865, Richard Hodgson suggested investing £18,000 to try a different kind of foundation. Bouch proposed using a large pine platform weighed down with pig iron, but the project was stopped before the platform was sunk due to financial issues. By mid-1867, work on both the Forth and Tay bridges was halted.
Design And Dimensions
The bridge spans the Forth between South Queensferry and North Queensferry and is 8,094 feet (2,467 meters) long with the double track elevated 150 feet (45.72 meters) above high tide. It consists of two main spans of 1,700 feet (518.16 meters), two side spans of 680 feet (207.3 meters), and 15 approach spans of 168 feet (51.2 meters).
Each main span has two 680-foot (207.3-meter) cantilever arms supporting a central 350-foot (106.7-meter) span truss. The superstructure weighs 50,513 long tons (51,324 tonnes), including 6.5 million rivets. The bridge also used 640,000 cubic feet (18,122 m³) of granite. The three four-tower cantilever structures are 361 feet (110.03 meters) tall, each tower resting on a separate granite pier. These were constructed using 70-foot (21-meter) diameter caissons.
Engineering Principles
The bridge uses the cantilever principle, where a cantilever beam supports a light central girder, a concept used for thousands of years. A demonstration in 1887 showed tension and compression in the bridge with Japanese engineer Kaichi Watanabesupported between Fowler and Baker sitting in chairs representing cantilevers.
Materials
The bridge was the first major structure in Britain made of steel; the Eiffel Tower in France was made of wrought iron. Large amounts of steel became available after the invention of the Bessemer process, patented in 1856.
In 1859, the Board of Trade imposed a limit of 77.22 N/mm² for maximum design stress in railway bridges, revised as technology improved. The original design needed 42,000 tonnes of steel for the cantilevers alone, partly supplied by Siemens' steel works in Wales and the rest from the Steel Company of Scotland near Glasgow.
Modifications required an additional 16,000 tonnes, half from the Steel Company of Scotland Ltd. and half from Dalzell's Iron and Steel Works in Motherwell. About 4,200 tonnes of rivets came from the Clyde Rivet Company of Glasgow. Around three or four thousand tons of steel were scrapped.
Approaches
After Dalmeny railway station, the track curves slightly east before reaching the southern approach viaduct. After crossing the bridge, it passes through North Queensferry railway station, curving west and then east again over the Jamestown Viaduct.
The approaches were built under separate contracts and designed by engineer James Carswell. The supports of the approach viaducts are tapered to prevent the appearance of widening columns as they reach the top.
An evaluation in 2007 by A. D. Magee of the University of Bath noted order throughout, including in the approach viaducts. Magee pointed out that the masonry was carefully planned, even in areas not immediately visible from the ground.
Construction
The plan to build the bridge was approved on May 19, 1882, after an eight-day investigation. The only complaints came from competing railway companies. On December 21, the construction contract was given to Sir Thomas Tancred, T. H. Falkiner, Joseph Philips, and Sir William Arrol & Co.
Arrol was a self-made man who started as a blacksmith apprentice at thirteen and later became very successful. Tancred was an experienced engineer who had worked with Arrol before but left the project during construction.
The steel was made by Frederick and William Siemens from England and Pierre and Emile Martin from France. Thanks to improvements in furnace design by the Siemens brothers and further developments by the Martin brothers, high-quality steel could be produced quickly.
Preparations
The construction team took over offices and storage areas that Arrol had built for Bouch's earlier bridge project. These were expanded over time. Reginald Middleton conducted a detailed survey to determine the exact location of the bridge and allow construction to begin. The old coastguard station on the Fife side had to be removed to make space for the north-east pier. The rocky shore was leveled to 7 feet (2.1 meters) above high tide to make room for equipment and materials. Workers' huts and other facilities were set up further inland.
At South Queensferry, the preparations were much larger and required terracing the steep hillside. Wooden huts and shops for the workers were built, along with brick houses for the supervisors and housing for leading hands and gangers. Drill roads, workshops, and a drawing loft measuring 200 by 60 feet (61 by 18 meters) were constructed to allow full-size drawings and templates to be laid out.
A cable was laid across the Forth to enable telephone communication between South Queensferry, Inchgarvie, and North Queensferry. Girders from the collapsed Tay Bridge were reused to provide access to the ground on the west side of the railway. Near the shore, a sawmill and cement store were built, and a jetty about 2,100 feet (640 meters) long was started early in 1883 and extended as needed. Railway sidings were added to bring vehicles among the shops, and cranes were installed to load and move materials delivered by train.
In April 1883, work began on a landing stage at Inchgarvie. Existing buildings, including 15th-century fortifications, were covered to create more space. The rock on the west side of the island was cut down to 7 feet (2.1 meters) above high water, and a seawall was built to protect against large waves. In 1884, a compulsory purchase order was made for the island because the area enclosed by the four bridge piers was too small to store all the materials. Iron staging reinforced wood in heavily used areas, eventually covering around 10,000 square yards (8,400 m²) and using over 1,000 tonnes of iron.
Movement Of Materials
The bridge required 55,000 tonnes of steel and 140,000 cubic yards (110,000 m³) of stone. Many materials, such as granite from Aberdeen, rubble from Arbroath, sand, timber, coke, and coal, could be taken directly to where they were needed. Steel was delivered by train, prepared at the South Queensferry yard, painted with boiled linseed oil, and then transported by barge to the required location.
The cement used was Portland cement made on the Medway. It had to be stored before use, and a former barge called the Hougoumont, moored off South Queensferry, could hold up to 1,200 tonnes of cement. At first, a paddle steamer was hired to move workers, but it was later replaced with one that could carry 450 men. Barges were also used to transport people. Special trains ran from Edinburgh and Dunfermline, and a steamer traveled to Leith during the summer.
Circular Piers
The three towers of the cantilever bridge sit on four circular piers each. Since the foundations had to be built at or below sea level, they were dug out using caissons and cofferdams. Caissons were used in places that were always underwater, even at low tide, or where the foundation was on mud or clay.
Cofferdams were used where rock was closer to the surface, and work could be done during low tide. Six caissons were dug out using a pneumatic process by French contractor L. Coisea. This method used air pressure inside sealed caissons to allow dry working conditions at depths of up to 89 feet (27 meters).
These caissons were built and put together in Glasgow by Arrol Brothers, unrelated to W. Arrol, before being taken apart and shipped to South Queensferry. The caissons were mostly built before being floated to their final spots. The first caisson for the south-west pier at South Queensferry was launched on May 26, 1884, and the last one for the south-west pier at Inchgarvie was launched on May 29, 1885.
Once launched and moored, the caissons were extended upwards temporarily to keep water out while the granite piers were built. Above the foundations, which differ to match the different sites, are tapered circular granite piers. Each is 55 feet (17 meters) wide at the bottom and 36 feet (11 meters) tall.
Inchgarvie
The two northern piers at Inchgarvie are underwater at high tide. The site of the eastern pier is about half submerged, and the western one is three-quarters submerged. This meant work had to start at low tide. The southern piers at Inchgarvie are on solid rock with a slope of about 1 in 5. The rock was prepared with concrete and sandbags to create a landing spot for the caissons. Excavation was done by drilling and blasting, but no blasting happened within 1.5 feet (0.46 meters) of the caissons, and the remaining rock was carefully removed.
North Queensferry
Once the pier positions were set, the first task at the Fife end was to level the site of the northernmost piers. This bedrock of whinstone was 10 to 20 feet (3 to 6.1 meters) above high water and needed to be brought down to 7 feet (2.1 meters) above high water. The south piers at North Queensferry are on rock sloping into the sea, and the site was prepared by diamond drilling holes for explosives and blasting the rock.
South Queensferry
The four South Queensferry caissons were sunk using the pneumatic method and are identical except for height differences. A T-shaped jetty was built at the site so one caisson could be attached to each corner. Once launched, the caissons were tied to the jetty and allowed to rise and fall with the tide.
Excavation under the caissons was usually done at high tide when buoyancy supported them. As the tide fell, air pressure was reduced to let the caisson sink, and digging would begin again. In December 1884, the north-west caisson was moved into place, but an extremely low tide on New Year’s Day 1885 caused it to sink into the riverbed mud and tilt slightly.
When the tide rose, water flooded over the lower edge, filling the caisson. As the tide fell, water stayed inside, making the caisson top-heavy and causing it to tilt more. Divers bolted plates to raise the edge above water level, and wooden struts reinforced the caisson as water was pumped out.
However, pumping too quickly caused a hole between 25 and 30 feet (7.6 to 9.1 meters) long. A "barrel" made of large timbers was built inside the caisson for reinforcement. It took ten months to pump out the caisson and dig it free. The caisson was refloated on October 19, 1885, moved into position, and sunk with necessary adjustments.
Approach Viaducts
The approach viaducts to the north and south had to be raised 130 feet 6 inches (39.78 meters) above high water. They were built lower and then lifted as the masonry piers were constructed. The two viaducts have fifteen spans, each 168 feet (51 meters) long and weighing just over 200 tonnes. Two spans were connected to make a continuous girder with an expansion joint between each pair. Due to the hill's slope, girders were assembled at different heights and joined once level. Lifting was done with hydraulic rams in 3-foot 6-inch (1.07-meter) increments every four days.
Building The Cantilevers
Tubular parts were made in the No. 2 workshop up the hill at South Queensferry. Plates were heated in a gas furnace and pressed into the right curve. Curved plates were assembled on a mandrel, drilled for rivets, marked, and moved to the correct location. Lattice members and other parts were also assembled at South Queensferry using cranes and efficient hydraulic riveters.
Opening
The bridge was finished in December 1889, and load testing was done on January 21, 1890. Two trains, each with three heavy locomotives and 50 coal-filled wagons totaling 1,880 tons, were driven slowly from South Queensferry to the middle of the north cantilever, stopping often to measure the bridge's deflection.
This was more than twice the design load, and the deflection matched expectations. A few days earlier, a violent storm produced the highest recorded wind pressure at Inchgarvie, but the cantilevers moved less than 25 mm (1 inch). The first full crossing happened on February 24 when a train with two carriages carrying railway company chairmen made several trips.
The Duke of Rothesay, later King Edward VII, opened the bridge on March 4, 1890, driving home a gold-plated rivet. The key for the opening was made by Edinburgh silversmith John Finlayson Bain, commemorated with a plaque. When opened, it had the longest single cantilever span in the world until the Quebec Bridge in Canada was completed in 1919. It remains the second-longest single cantilever span at 1,709 feet (521 meters).
To use the bridge fully, several new railway connections were built to bring mainline routes to the bridge. Some lines were only completed on June 2, 1890, delaying full express train service until then. Even then, there was significant congestion at Edinburgh Waverley station as portions of the new, intensive train service were rearranged.
Accidents And Deaths
At its peak, around 4,600 workers were employed in building the bridge. Wilhelm Westhofen recorded 57 deaths in 1890. In 2005, the Forth Bridge Memorial Committee was formed to honor those lost, and local historians worked to name all who died. By 2009, 73 deaths were linked to the bridge's construction and aftermath.
It is thought that the figure of 57 excluded those who died working on the approaches, subcontracted separately, and those who died after the Sick and Accident Club stopped. Of the 73 recorded deaths, 38 were from falling, 9 from being crushed, 9 drowned, 8 struck by falling objects, 3 in a fire, 1 from caisson disease, and the cause of five deaths is unknown.
The Sick and Accident Club was founded in 1883, and membership was mandatory for all contractors’ employees. It provided medical treatment, paid workers unable to work, covered funeral costs within limits, and gave grants to widows or wives of permanently disabled men. Eight men were saved from drowning by rowing boats placed under the work areas.
In 2019, it was reported that historians discovered that at least 21 more men died building the Forth Bridge than previously thought, bringing the death toll to 78. This arguably makes the Forth Bridge deadlier than the Tay Bridge, considering the 59 known deaths from the Tay Bridge Disaster and 14 during its construction.
Later History
Race To The North
Before the Forth Bridge opened, the train journey from London to Aberdeen took about 13 hours. Trains left Euston Station and used the west coast route via the London and North Western Railway and Caledonian Railway.
When a new east coast route opened, run by the Great Northern, North Eastern, and North British railways starting from King’s Cross, unofficial races began between the two routes. These races cut the traveltime to around 8½ hours on overnight trips.
The competition peaked in 1895 with daily newspaper reports about the "Race to the North." After the excitement died down, journey times settled at about 10½ hours.
World Wars
During the First World War, British sailors timed their trips to or from the naval base at Rosyth by asking when they would pass under the bridge. In the Second World War, the first German air attack on Britain happened over the Forth Bridge on October 16, 1939, six weeks into the war. Known as the "Forth Bridge Raid," the bridge was not the target and wasn’t damaged.
Twelve German bombers led by two reconnaissance planes reached the Scottishcoast in four groups of three. The real target was ships near the Rosyth naval base, about 2 miles (3.2 kilometers) west of the bridge. The Germans hoped to find HMS Hood but focused on other ships since the rules of engagement limited attacks to targets on water, not in dockyards.
The cruisers Edinburgh and Southampton, the carrier Furious, and the destroyer Jervis were attacked. Sixteen Royal Navy crew members died, and 44 were injured, though this wasn’t made public at the time. British Spitfires from 603 Squadron intercepted the raiders and shot down the first German plane brought down over Britain during the war.
One bomber crashed into the sea off Port Seton, another near Crail, and a third in the Netherlands due to damage from the raid. Later that month, a German reconnaissance plane crashed near Humbie, but photos of this crash were mistakenly used to describe the October 16 raid, confusing whether a third plane had been shot down.
Ownership
Before the bridge opened, the North British Railway (NBR)had tracks on both sides of the Firth of Forth but couldn’t connect them without going far west to Alloa or using rival companies’ lines. The only other option was a ferry at Queensferry, which the NBR bought in 1867.
To solve this, the NBR supported building the Forth Bridge to create an independent link. A meeting in York in 1881 formed the Forth Bridge Railway Committee, with the NBR contributing 35% of the cost. The rest came from three English railways running trains to London over NBR tracks: the Midland Railway (30%), and the North Eastern and Great Northern Railways (17.5% each).
This group built and maintained the bridge. In 1882, the NBR was given the option to buy the bridge, but never did. By 1923, the bridge was still jointly owned by these railways, so ownership passed to their successors: the London Midland and Scottish Railway (30%) and the London and North Eastern Railway (70%).
The Forth Bridge Railway Company was nationalized in 1948 under the Transport Act 1947, becoming part of British Railways. Shareholders received stock based on their shares in the bridge company.
Operation
Traffic
The bridge has speed limits: 50 mph (80 km/h) for high-speed trains and diesel units, 40 mph (64 km/h) for regular passenger trains, and 30 mph (48 km/h) for freight trains. The route allows up to 190–200 trains per day, but freight trains above a certain size can’t pass each other on the bridge.
Maintenance
"Painting the Forth Bridge" is a phrase meaning a never-ending task, based on the mistaken idea that painting was constant. While there was always a maintenance crew, weathered areas got more attention. Between 2001 and 2011, the bridge was coated with a new paint designed to last 25 years, ending the need for regular painting.
Restoration
In 1990, floodlights were added, and the track was replaced between 1992 and 1995. British Rail spent £1 million yearly to maintain the bridge, but paused painting to save money. After privatization, Railtrack took over. A £40 million upgrade began in 1998, and Network Rail took responsibility in 2002.
In 2002, work started to fully repaint the bridge for the first time in its history under a £130 million contract awarded to Balfour Beatty. Up to 4,000 tonnes of scaffolding covered the bridge, and computer modeling studied wind effects. The bridge was wrapped in a climate-controlled membrane for proper painting conditions.
Old paint was removed using copper slag fired at high speeds, exposing the steel for repairs. A special three-coat paint system developed for the bridge covered 255,000 square meters. It doesn’t need repainting for at least 20 years, and the top coat can be reapplied indefinitely, reducing future maintenance.
In Culture
In The Media
The Forth Bridge has appeared in TV shows and movies, including Carry On Regardless, Alfred Hitchcock's 1935 film The 39 Steps, and its 1959 remake. A.G. Barr used the bridge in posters for its soft drink Irn-Bru with the slogan: "Made in Scotland, from girders." In 2005, the BBC lit the bridge red for Comic Relief.
That same year, a Channel 4 documentary called Jump Britain showed Sébastien Foucan, a French freerunner, climbing along one of the highest parts of the bridge without a harness. The first episode of the UK TV series Britain's Greatest Bridges featured the Forth Bridge and aired on Spike UK on January 12, 2017.
In General Culture
The location of the Forth Bridge has made it part of other cultural works. In 1998, a countdown clock sponsored by the Royal Bank of Scotlandwas placed on top of the bridge as part of the Millennium celebrations. Iain Banks wrote a novel called The Bridge, set on a fictional version of the bridge that connects "The City" (Edinburgh) and"The Kingdom" (Fife).
In Alan Turing’s famous paper on artificial intelligence, one challenge given to a subject in an imagined Turing test is: "Please write me a sonnet about the Forth Bridge." The subject responds, "Count me out on this one. I never could write poetry." The bridge also appears in the video game Grand Theft Auto: San Andreas, renamed the Kincaid Bridge, serving as the main railway bridge in the fictional city of San Fierro, alongside a virtual version of the Forth Road Bridge.
In his 1917 book On Growth and Form, the mathematical biologist D'Arcy Thompson compared the structure of the Forth Bridge to the skeleton of an ox. He noted how the piers of the bridge resemble legs, and the cantilevers resemble the spine: In a typical cantilever bridge like the Forth Bridge, each pier supports its own double-armed cantilever, connected by a short girder to the next section but not transmitting weight between sections.
As Heritage
UNESCO named the bridge a World Heritage Site on July 5, 2015, calling it "an extraordinary and impressive milestone in bridge design and construction during the period when railways came to dominate long-distance land travel."
It is the sixth World Heritage Site in Scotland. In 2016, a VisitScotland survey voted the Forth Bridge "Scotland's greatest man-made wonder," beating places like Stirling Castle, the Caledonian Canal, the Scott Monument, Bell Rock Lighthouse, and Melrose Abbey.
The Forth Bridge has been featured on a 2004 one-pound coin issued by the Royal Mint. It has also appeared on banknotes, including the 2007 series from the Bank of Scotland, which highlights different Scottish bridges as examples of engineering.
The £20 note features the Forth Bridge. In 2014, Clydesdale Bank announced the introduction of Britain’s second polymer banknote, a £5 note featuring Sir William Arrol and the Forth Bridge (the first polymer note was issued by Northern Bank in 2000). It was released in 2015 to mark the 125th anniversary of the bridge’s opening and its nomination as a UNESCO World Heritage Site.
Visitor Attraction
Network Rail plans to add a visitor center to the bridge. This would include a viewing platform on the North Queensferry side or a bridge-climbing experience on the South Queensferry side. In December 2014, Arup was awarded the design contract for the project.
In September 2019, Network Rail submitted plans to build a visitor center on the South Queensferry side to serve as the base for the bridge-climbing experience, called "The Forth Bridge Experience." The plans were approved in early 2020 but paused due to the COVID-19 pandemic. Revised plans were submitted in February 2022.
Frequently Asked Questions
Can Visitors Walk On Or Across The Forth Bridge?
No, the Forth Bridge is a railway bridge and is not open for pedestrian access. However, there are excellent viewpoints nearby, such as in South Queensferry, where visitors can enjoy panoramic views and take photographs of the bridge.
Are There Guided Tours Or Visitor Centers Related To The Forth Bridge?
While you cannot walk on the bridge itself, there are visitor centers and exhibitions in the area, such as the Contact and Education Centre, that provide historical information, interactive displays, and guided walks around the vicinity.
What Is The Best Time Of Year To Visit The Forth Bridge For Photography?
The bridge is photogenic year-round, but many visitors prefer spring and summer for clear skies and vibrant scenery. Early morning or late afternoon light often provides the best photographic conditions.
Are There Any Special Events Or Experiences For Tourists At The Forth Bridge?
Occasionally, special events like "Your View at the Forth Bridge" allow visitors to ascend to viewing platforms for unique perspectives. These events are not regular and should be checked in advance.
How Does The Forth Bridge Contribute To Local Communities Today?
The bridge continues to play a vital role by supporting rail transport for both passengers and freight, connecting communities and supporting the local economy through tourism and daily commutes.
Conclusion
The Forth Bridge stands as a remarkable symbol of engineering innovation and Scottish heritage. While its primary function remains as a railway link, the bridge also draws visitors from around the world who come to admire its design and historical significance. With its UNESCO World Heritage status and ongoing role in modern transport, the Forth Bridge continues to inspire awe and connect communities across the Firth of Forth
Callum Fraser
Author
Callum Fraser isn't just a writer about Scotland; he's a product of its rugged landscape and rich history. Born and raised in Perthshire, with the Highlands as his backyard, his love for the nation's stories was kindled by local storytellers and long walks through ancient glens.
This passion led him to pursue a degree in Scottish History from the University of Edinburgh. For over 15 years, Callum has dedicated himself to exploring and documenting his homeland, fusing his academic knowledge with essential, on-the-ground experience gained from charting road trips through the Cairngorms, hiking the misty Cuillins of Skye, and uncovering the secrets of traditional recipes in his family's kitchen.
As the Editor-in-Chief and Lead Author for Scotland's Enchanting Kingdom, Callum's mission is simple: to be your most trusted guide. He combines meticulous research with a storyteller's heart to help you discover the authentic magic of Scotland — from its best-kept travel secrets to its most cherished traditional recipes.
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