The Forth Bridge: greatest structure in the world?
As its successful application to gain UNESCO world heritage site status so eloquently states, “No bridge is so distinctive from others as is the Forth Bridge from its peers.” GARETH DENNIS explores why he thinks this iconic structure is one of the great wonders of the world.
A version of this article also appeared in Issue 872 (13th February 2019) of RAIL magazine as part of their Seven Railway Wonders series.
Built in the aftermath of one of the most infamous engineering failures in history and at a time of faltering confidence in British economic prowess, the Forth Bridge stands tall as a testament to the longevity of railway transport and is (in my opinion at least) the finest engineering monument humans have ever raised.
At the time of its opening, it connected the cities of the Scottish central belt with the coalfields and ports of Fife and the north. Strength was the name of the game, with the tapered towers and high degree of structural redundancy intended to resist the most aggressive winds that nature could throw at it without so much as a flinch.
Today, the 2.5 kilometre-long bridge is considered a symbol of Scotland and has made countless appearances in popular culture. I have a somewhat more personal relationship with this astonishing piece of infrastructure.
Making my way between Aberdeenshire and Devon in the 1990s in the back of dad’s Rover, the Forth Bridge marked the point at which a day’s drive became a longer holiday and merited a peak of excitement to match. I used to huff whenever he diverted us via Stirling (as he usually did on the way south) and whoop as we turned towards Moffat, Edinburgh and the Forth crossing on the way north. The views across to the railway’s enviable pulpit above the water from the rather more austere Forth Road Bridge were spectacular, not least in the run up to the new millennium when it had a gigantic countdown clock mounted upon it.
When I moved to Edinburgh as a student, I could travel to see it with ease on the Number 43 bus to South Queensferry (I’d strongly recommend the Italian restaurant opposite the Anchor Inn for its stunning panoramas and cracking pizza), and even had the privilege of abseiling off the southern approach viaduct for charity — more on this later.
There was no better inspiration (read: boot up the backside) for completing a degree in civil engineering than walking underneath the mighty blood-red beast that stood astride the great estuary cleaving North and South Queensferry apart, dramatically showing how the most hostile of Scottish geography was little match for the might of the railways.
The Forth Bridge’s Yorkshire roots
Even now that I am based in York, I still can’t escape the Bridge…
If it wasn’t for the 1881 conference held in the city between the North British Railway and the three English railway companies it collaborated with, the Forth Bridge Railway Committee would never have come to exist.
In what I imagine was a rather intense meeting, the cost of the bridge was proposed to be split four ways between the North British Railway (35%), the Midland Railway (30%), the North Eastern Railway (17.5%) and the Great Northern Railway (17.5%), all of whom stood to benefit greatly from their ability to run through-trains north of the Forth.
The Committee then took stewardship of the newly-established Forth Bridge Railway Company, at which point everything was in place to turn the proposals into reality.
Charged with erecting this vast masterpiece was Scottish civil engineering and construction company Sir William Arrol & Co., who called upon the very best in surveying, design, installation and assurance techniques available at the time. £3.2 million later (£400 million in 2017 prices), they had completed the first major steel structure in the world, and one that would still be doing its job 130 years later.
The design was headed by two legendary engineers: the Sheffield-born John Fowler, already famous as lead engineer on the world’s first dedicated underground passenger line (the Metropolitan Railway in London), was ably partnered by Benjamin Baker of Frome, Somerset, also a key collaborator on the Met (he would later pioneer the use of cast iron segments for deep “tube” tunnels in London and beyond). Both were the best of the best — Fowler had already been the youngest president of the Institution of Civil Engineers, and Baker would be president a few years after the Bridge opened — and their collective achievements far exceed others whose names may have remained more familiar.
Cantilevers, and that famous photo
The cantilever principle is probably most famously displayed by the photograph of Fowler, Baker and a nervous-looking Kaichi Watanabe (a Japanese engineer who worked on the Forth Bridge as a graduate) in between them. Taken in 1887 in the midst of the Forth Bridge’s construction, it clearly shows the balance fundamental to its design.
Whilst it may not look like it, the new Queensferry Crossing that opened in 2017 is based on the same principle, and with its three towers closely mimics the structural form of the Forth Bridge (albeit using slender modern materials).
It must be said that the safety record for the construction site was poor, with 73 attributable worker deaths compared to only 30 on New York’s Brooklyn Bridge completed a few years beforehand. Things have clearly improved for the better, but there’s still no room for complacency. During its construction in the early 1960s, the Forth Road Bridge claimed seven lives and, no less tragically, one worker was killed in the construction of the new Queensferry Crossing in 2016.
Nevertheless, countless innovations were adopted across numerous disciplines during the works, many being drawn up by William Arrol and Benjamin Baker themselves, and these went on to be adopted in engineering projects across the world.
Much like its younger siblings, the Forth Bridge’s design and installation may have been led by British engineers but across the ranks of workers was a significant international representation. Given the number of civil engineering mega-projects being undertaken across the globe at that time, it is little wonder that the variety of skills required were in short supply and justified travel from as far afield as the USA and Japan. Many, of course, were European.
As you might expect, the Forth Bridge is supported by as many superlatives as rivets (of which it contains more than 6.5 million), and so I am afraid these are going to be liberally scattered through my account of this wondrous edifice.
The volume of materials involved is astonishing, tapping into a hugely complex and diverse range of suppliers that spanned the country. The scale of this supply chain may be usefully revealed by the sources of steel used in the Bridge’s construction, totalling 62200 tonnes (some of which was used only in temporary works).
Those 6.5 million steel rivets I mentioned a moment ago weighed a hefty 4200 tonnes and were provided by the Clyde Rivet Company of Glasgow, but that’s only for starters. 12000 tonnes of structural steel came from Siemens’ steel works in south Wales and a further 38000 tonnes were supplied by the Steel Company of Scotland’s works (also based near Glasgow). 8000 tonnes of structural steel were provided late-on in construction by Dalzell’s Iron and Steel Works in Motherwell.
For comparison, Manchester’s new Ordsall Chord bridge — which was a leviathan in its own right when installed in 2017 — weighed less than 600 tonnes, pitching it at a meagre hundredth the size of the Forth Bridge.
As well as steel, a third of a million tonnes of masonry was used, filling a volume more than 25% greater than that of the Royal Albert Hall. So much Portland cement was required to stick it all together that, on delivery from the Medway, up to 1200 tonnes were stored at any one time in a huge barge. Strangely enough, the vessel converted for this task was the Hougoumont — the last ship used to “export” our thoroughbred convicts to Australia.
The ripple effect of major enhancements
As is often the case for major civil engineering projects, the connecting infrastructure ought to be more prominent in people’s minds — nearly 45 miles of connecting railway had to be constructed or heavily modified to enable utilisation of the new link, and despite the Forth Bridge itself formally opening on 4 March 1890, full operation was only enabled once these lines were completed three months later, quite a bit after originally planned.
This was thanks in no small part to the Forth Bridge Railway Committee being unconvinced of the need for additional high-quality two-track railway (as can be seen by the original drawings with only very short spurs connecting onto existing branch lines) until the engineers convinced it otherwise.
The opening of the new and upgraded railways in Fife and Lothian weren’t the end of the story, either, and from here on in the parallels to our generation’s major railway enhancements become ever clearer.
Following the massive upsurge in traffic, the old Waverley railway station and its two-track approaches were exposed as woefully inadequate for the task of platforming and marshalling the increased number of trains. A further upgrade was needed.
It was only in 1900 that the hugely complex infrastructure work through Edinburgh was completed, at a cost of £1.5 million (£180 million in 2017 prices), nearly half of the cost of the Forth Bridge itself. This included four-tracking the line between Corstorphine in the east to Abbeyhill in the west, driving three new tunnels to parallel existing ones, upping the number of platforms at Waverley to 19, totally rebuilding the station itself and reconstructing North Bridge above it.
Today, we find ourselves in exactly the same position, with infrastructure works elsewhere rippling back into central Edinburgh.
Owing to the significant growth of services in Scotland fuelled by central belt electrification, the reopening of the line into the Borders and more trains on both north-south mainlines, exactly the same problems are resurfacing. Waverley doesn’t have enough platforms, there isn’t enough through-capacity and the lines at either side of the station are clogged. Thankfully, a major upgrade is once again in the pipeline.
Yet these effects still being ignored elsewhere in the country, at least by those funding rather than specifying infrastructure upgrades, with the Ordsall Chord in Manchester being the freshest example I can think of.
Looking forwards to High Speed 2, there is a high risk that the remodelled Crewe and Sheffield stations (as two examples where the new line meets the current railway at-grade) will be inadequate to accommodate the traffic flows that high speed segregation can unlock on the existing network.
As ever, there is much to learn and apply today if you just glance over your shoulder for long enough.
On completion, the newly-raised Bridge didn’t please everyone. The designer, writer and activist William Morris (a proponent of the usually-ghastly Arts and Crafts style) certainly wasn’t a fan: “There never will be an architecture of iron, every improvement in machinery being uglier and uglier until they reach the supremest specimen of all ugliness — the Forth Bridge.” There were other loud and prominent critics, too.
However, the overwhelming feeling towards the Bridge was one of approval, awe and pride (particularly in Scotland), and the limited negative press from its detractors was soon forgotten.
It isn’t just me and a few other misty-eyed engineers that think the Bridge is a culturally significant and internationally unique location, either. In 2015 (the year of its 125th anniversary), UNESCO granted it world heritage status, joining such celebrities as the Acropolis, the Great Wall of China, the Pyramids of Egypt and the Taj Mahal, and it has been Grade A listed since 1973.
Thus the Forth Bridge grows ever-more beloved, and it remains equally impressive in its 130th year.
At 521 metres each, its two main cantilever spans are the second-longest in the world, with Canada’s Quebec Bridge pipping it to the post by only 28 metres, 28 years after its opening (an odd coincidence).
The Forth Bridge’s learning legacy
The second iteration of the Quebec Bridge’s design leaned heavily on the experience gained during construction of the Forth Bridge, with Irish engineer Maurice FitzMaurice (who worked closely with Benjamin Baker on the Bridge) holding a role on the committee into the infamous and tragic collapse of the first Quebec Bridge.
Despite its new protected status, the two tracks the Bridge carries are incredibly intensively used, with as many as 240 scheduled services (including ten freight trains) using it daily. That’s 25% more traffic than the East Coast Main Line has to carry between Doncaster and York.
Even with all of this traffic passing over it, the Bridge isn’t so much an inert structure as a living, breathing hive of activity.
As the sun beats down and heats up the steel, it expands quite significantly, giving a rippling effect on some of the surfaces that is visible if you get up close. Small parts are regularly being replaced and — yes, even after its big paint job between 2002 and 2011 — sections are still receiving a touch-up every now and then.
The Forth Bridge is a warren of footways, stairwells, lifts, platforms, bothies, cubby-holes, trapdoors and all manner of fixtures and fittings. I couldn’t get a number out of anyone, so I am presuming nobody really knows the labyrinthine lengths weaving along all levels of the Bridge.
Jamie McLaren is Network Rail’s Assistant Asset Engineer for Structures in Scotland (a justifiably hefty title), and has the privileged task of being in charge of both the Forth and Tay Bridges: “I’m learning about the Bridge every day — there’s still parts I’m finding that I didn’t know were there.”
Much like the Bridge itself, Jamie’s role is huge, but his modesty belies an intimate knowledge of the structure. His is the last signature on the page for the regularly-conducted structural examinations, and these then inform where immediate or longer-term interventions are required.
“I’m looking over examination reports for the Bridge that are hundreds of pages long, whereas on a normal, everyday bridge you’d maybe be looking at six pages worth of detail.”
“My duties include specifying work for the bridge, looking at long term strategies as well as urgent repairs, just everything repair-wise on the bridge. Every single day, we have our contractors out, carrying out steel repairs, painting and removing redundant assets that have been there for years but no longer get used.”
Back in 1995, British Rail claimed that the Bridge was costing them £1 million a year (£1.8 million in 2017 prices) to maintain, and so its successor at privatisation justified spending £40 million to repair and repaint it.
As was Railtrack’s style, they gave up on the task having spent most of the money and a new contract for £140 million was let to Balfour Beatty for a major programme of refurbishment that was only completed in 2011. So successful was this project that Balfour Beatty have remained Network Rail’s contractor in charge of maintaining the Forth Bridge ever since.
So how much is today’s annual maintenance budget, roughly speaking?
“We have an annual maintenance contract worth around £1 million” says Jamie. “The work carries on, maintenance contract after maintenance contract.”
If you take inflation into account, the refurbishment works have gained significant savings, but there is no avoiding the fact that such a massive structure will always be tricky (and therefore costly) to maintain. For example, 4000 tonnes of specialist scaffolding were used during the Bridge’s ten-year rejuvenation.
In any case, I’d say £1 million is a bargain considering the strategic importance of the link.
Making this point to both funders and local politicians is another part of Jamie’s role: “There are many stakeholders involved with these major structures and the job involves a fair bit of stakeholder management.”
He also gets to take visitors and guests from all walks of life to the Bridge — “The fun part!” as he puts it — ensuring that the public’s fascination with the structure is constantly rejuvenated.
And what does he think of the UNESCO world heritage site status? “Having world heritage is something I’m very proud of. We gained world heritage just after I started in the role, and it certainly made me feel a little more pride working here, doing what we do.”
Forth Bridge factules
In many ways, the Forth Bridge has remained an anomalous feature on the British railway network since its opening, collecting dozens of strange and intriguing facts along the way.
The first train to cross the Bridge was driven by — rather surprisingly for the time — a woman. Candida Louise Hay (née Bartolucci), the Marchioness of Tweeddale, was at the controls of this lucky locomotive (which I sadly couldn’t identify) on 24 January 1890.
Whilst commonly being attributed as another major steel structure thus a contemporary of the Forth Bridge, Paris’ Eiffel Tower (completed in 1889) was actually built using the more primitive wrought iron (a common building material at the time). You could fit six Eiffel Towers within the Forth Bridge’s main structure, and even Gustave Eiffel himself loved the Bridge, declaring it to be “the greatest wonder of the century”.
In the years following its opening, the Bridge had a 40mph speed limit for all services, but by many accounts this was not well observed by drivers presumably reassured by the gargantuan structure they were passing over. Today, the speed limit for passenger multiple units is 50mph, with a more onerous 20mph limit for heavy trains.
The total painted area of the Forth Bridge is 230,000 square metres — that’s about as big as the floor space in New York’s Grand Central Station, or the equivalent of 33 football pitches.
Its original owners, the Forth Bridge Railway Company, were never bought out by the North British Railway and thus avoided being absorbed at the time of Grouping in 1923, remaining in place until nationalisation in 1948.
To make sure nobody forgets it’s there, over 1000 floodlights were installed on the Forth Bridge in 1991, connected by nearly 25 miles of cabling. 500 of these are located at the base of each cantilever, pointing upwards to give the impressive night-time vistas we’ve become so familiar with.
Far earlier, though, the first electric light illuminating either North or South Queensferry was one attached to the Forth Bridge.
It is the only major structure not to have a dedicated reference number: underbridge ECN2/28 (Station Road, Dalmeny) is located immediately to the south, and underbridge ECN2/29 (Old Edinburgh Road, North Queensferry) is located immediately to the north. It is known by most simply as “the Bridge”.
However, it did briefly have its own namesake railway station, with “Forth Bridge” being renamed “Dalmeny for Forth Bridge” on 28 April 1890. The station is still open today as “Dalmeny”.
Thanks to the efforts of Jaimie and his many colleagues, the Forth Bridge is still gainfully employed launching trains across the Firth of Forth without faffing about with ferries or dog-legging via Stirling. Dig into some of the numbers, though, and you’d be forgiven for thinking that the Bridge was moonlighting in a second job.
What am I on about? Well, in 2018 the Forth Bridge helped various charities raise a whopping £640,000 by enabling them to hold fundraising events on its numerous lofty podiums, and by the end of 2019 the total figure raised is set to exceed £3 million.
This is thanks in no small part to the support of Network Rail and their contracted custodians of the Forth Bridge, Balfour Beatty.
Jamie Mclaren: “The Forth Bridge is arguably Scotland’s most recognisable landmark and these figures demonstrate the value that people place on being able to access the structure. We’re enormously proud to have been able to help our charity partners.”
The charities are pretty happy about it, too. “It is an honour to be able to work with Network Rail and Balfour Beatty to share this incredible event at the iconic bridge with our supporters” says Jane-Claire Judson, chief executive of Chest Heart & Stroke Scotland.
Martin Crewe, the director of Barnardo’s Scotland (who organised the hugely successful #YourView2018 experience), agrees: “The success of the event allowed us to take 1250 supporters up onto the viewing platform on the north cantilever of the Bridge, raising over £65,000.”
The feeling that participants at these events get is unparalleled — and I say this as someone who climbed over one of its walkway’s parapets, overcame nature’s strongest instincts, and let go — and not just because of the colossal feeling of exposure you get when bracing against the wind whipping along the estuary.
Graham Clarkson of the Rotary Club of South Queensferry, summarises it nicely: “By permitting us to run an annual abseil from the Forth Bridge, Network Rail offers the club a perfect opportunity to show Rotary in action, benefiting numerous charities and giving people from all over the country a unique experience at a World Heritage site.”
As with the Christmas dinner events for the homeless hosted in stations across the country (the team behind 2017’s dinner in Euston was given a Judges’ Special Award at RAIL’s National Rail Awards in 2018), the railway is full of examples of goodwill, some large, many small. All of us who know and love the industry must do a better job of shouting them from the rooftops, and where better than a scaffold platform mounted 110m above the Forth?
In this and many other ways, the fortunes of the Bridge mirror those of the UK at the time.
The need to fuel Britain’s empire at its greatest extent generated a further leap in traffic through the Edwardian period and a strengthening scheme was initiated in 1913, though the outbreak of war delayed completion until 1921.
Economic stagnation and a shrinking of public investment into the early 1990s being reversed by the 2000s was reflected in the condition of the Bridge, too; there are (possibly apocryphal) tales of pieces of rust big enough to crush a car falling onto North Queensferry, and it was only the refurbishment of the structure through the 2000s that reversed decades of degradation.
Last year, as engineers attempted to squeeze every last drop of capacity out of the British rail network, a re-signalling scheme was completed allowing seamless bi-directional running (i.e. trains running the wrong way along the opposite track) to speed up recovery at times of disruption.
Even as we look to the electric-only Britain of the future, the Bridge is still moving with the times. Plans are afoot for electrification of the lines into Fife, and there’s a strong possibility we’ll see wires across the Forth before the end of the 2020s (for the Bahnnerds — the bridge is already gauge-cleared to W7 so this shouldn’t be overly complex).
The third Forth Bridge
Early on in the design process for what is now called the Queensferry Crossing, Transport Scotland were scratching their chins and deciding on the specification for the third major bridge across the Forth, ensuring that they accounted for any possible functions it might have to fulfil within its proposed lifespan.
Having picked up the phone for a chat with Network Rail, they were slightly taken aback at the response they received when asking the ostensibly reasonable question: “should the new bridge include provision for a heavy rail connection?”
“Oh, I wouldn’t worry about that… It’s stronger than the rock it’s built on!” laughed Network Rail’s asset engineer at the time. Indeed, Network Rail’s rather conservative estimates set the bridge’s remaining life as well in excess of 100 years.
Today, the Forth Bridge is one of three record-topping structures spanning the Forth at Queensferry, with each representing a subsequent century of civil engineering.
Whilst it may be the eldest of the three, I’d argue that it is also the best representative of what the future holds for transport infrastructure.
What is undoubtedly true is that the majestic and instantly-recognisable Forth Bridge easily merits its position as one of the wonders of Britain’s railways.
