Spanning the arts, science and engineering
Three alumni from across the disciplines tell the story of their involvement in the bridges across the Forth.
The unique Forth Bridge is an icon of Scotland, its red, triple-humped criss-crossed structure recognised the world over and recently designated a World Heritage Site. It remains one of the longest bridges of its kind and, 125 years after it was built, is still a wonder of engineering.
For the past half-century it has shared many a photographer’s viewfinder with the equally striking Forth Road Bridge. In contrast to the muscularity of its neighbour, this suspension bridge appears to stretch across the Firth of Forth with a lean efficiency that defies gravity.
And soon there will be a third member of the bridges family. The needle-like towers of the new Queensferry Crossing are climbing skyward, and will soon rise above both the other bridges, ready to support a motorway that will carry thousands of cars across the Forth every day.
University of Edinburgh alumni are deeply associated with all three bridges. Here, three graduates from varied disciplines share their stories and their passion for these phenomenal structures that link the 19th, 20th and 21st centuries.
Forth Bridge
| Date of opening | 4 March 1890 |
|---|---|
|
Bridge type |
Steel cantilever |
| Designers | Benjamin Baker and John Fowler |
| Length |
2.5km. Two main spans: 521m each |
| Height | Highest point 110m. Railway 46m |
Global significance: Remains the world’s second longest cantilever bridge, and for 28 years after construction the two main spans were the world’s biggest spans. Was Britain’s first all-steel bridge.
Other facts: Carries around 200 trains a day. A 10-year restoration was completed in 2012, including the first ever full repaint.
Angelo Maggi
PhD Architecture 2003
Angelo Maggi is Associate Professor of Architectural History and Architectural Photography at the architecture, design and arts-focused Università IUAV di Venezia. He gained his PhD at Edinburgh College of Art in 2003.
He has written several books on architecture, including 'Rosslyn Chapel an Icon Through the Ages' (2008), 'Photo Graphic Pedia' (2014) and 'Re-visioning Venice 1893-2013' (2014).
His main research and teaching interests are contemporary architectural history, architectural photography, graphic design, history of art and visual communication.
Professor Maggi is co-author (with Michael Gray) of a book about Evelyn George Carey, the official photographer of the building of the Forth Bridge. A group of Professor Maggi’s students recently reproduced the “human cantilever” demonstration that was presented to the Royal Institution in London in 1887, and photographed by Carey, showing the principle of the design of bridge.
My bridge story
The image of the Human Cantilever obsessed me for many years while I was a regular visitor to the Edinburgh Central Library on George IV Bridge. I don’t know who put the photograph on the wall of the men’s toilets there, but I often had the Human Cantilever in the front of my eyes.
At the beginning I thought it was just a joke, but day after day I started thinking that composing an image like that in a very intricate way was something to understand better. When I was asked to write the book 'Evelyn George Carey - Forth Bridge' I enthusiastically started to dig for more information about the bridge, its history and the many people involved in the construction of this masterpiece.
Today, to remind me of those years, I have in my bathroom in Italy a big framed picture of the Human Cantilever.
Official photographer
Evelyn George Carey was an assistant engineer for the construction of the Forth Bridge, and the project’s official photographer. Only rarely do photographers fully understand the constructions they take pictures of and the aims of their creators the way Carey did.
Carey’s goal was to record as accurately as possible on glass negatives the progress of construction as the railway bridge rose above the Firth of Forth. Despite the considerable efforts required to handle his cumbersome camera equipment as he moved about the caissons and the maze of steel beams, Carey succeeded in telling a story through images.
Plainly expressing through his art what modern industrial civilization was capable of achieving, the photographer did not just reveal the new steel technology, but also chose to photograph the men who laboured at the site, his analysis an intense and original one, which seemed to penetrate the human side of the day-to-day events he witnessed. For Carey’s camera lens, the bridge played a dual role: it was both a monument under construction and a workplace.
Carey’s work is the exceptional recording of the genius of those who contributed to the realization of the project: engineers and workers who came from all over the world, including some from Italy. This photography allows us to understand the work that went on and gives us an idea of the worth of its inventor, the unique and magical phases involved, and helps us to truly visualise engineering.
Students’ reconstruction
My students are not only interested in photography but also need to understand architectural construction. I decided to let them invent and perform a new Human Cantilever, inspired by the original demonstration that was presented to the Royal Institution in 1887 to show the principle of the design of the Forth Bridge. We decided to make our experimental study a big event open to the public: Art Night 2014 in Venice. The IUAV Human Cantilever was performed by 180 students who in 18 different ways demonstrated the construction principles of the bridge – from those similar to Cary’s image to more light-hearted interpretations.
I spent the best years of my life in Edinburgh and I feel the majestic power of the Forth Bridge as one of the greatest achievements of the late 19th century.
Forth Road Bridge
| Date of opening | 4 September 1964 |
|---|---|
|
Bridge type |
Suspension |
| Length |
2.5km. Main span between towers: 1,006m |
| Height | Towers 156m. Shipping clearance: 44m |
Global significance: Was the fourth longest suspension bridge in the world, and the longest outside the USA, when opened.
Other facts: Carried around 2.5 million vehicles in its first year; today carries around 24 million vehicles a year. When the Queensferry Crossing opens in 2016, the Forth Road Bridge will be used primarily for public transport, cyclists and pedestrians.
Chris Waite
MA Fine Art 1994
Chris Waite is Media and Communications Manager for the Forth Bridges Unit of Amey, the infrastructure support services group responsible for the Forth Road Bridge.
After his MA at Edinburgh College of Art, Chris gained a postgraduate publishing degree and entered the publishing industry in London. He later moved into communications, first in the financial services sector, then the public sector including the National Health Service. He has led communications for the Forth Road Bridge since 2006, through a period of dramatic developments for the bridge, and rapid and constant change in communication technology and habits.
Over the past decade, Chris’s communication responsibilities have included the campaign to build a new crossing after the discovery of corrosion in the bridge’s main cables. Throughout 2014 Chris led major celebrations for the 50th anniversary of the Forth Road Bridge.
Responsibility for the Forth Road Bridge passed from the public sector to Amey in June 2015, and in 2016 responsibility for the new Queensferry Crossing will also be transferred to Amey.
My bridge story
It’s been a fascinating time to work at the Forth Road Bridge. We have put in place vital services to get information to the people who rely on the bridge, and my role has also been to manage the reputation of the bridge authority over the years, at strategic and operational level.
Just before I started work here, serious corrosion had been discovered on the bridge, and a big part of my job has been to reassure people about what is going on and to build trust among the media, the public and politicians. Another part of my role has been successfully campaigning for the new bridge to be built.
Shock discovery
In 2004, the Forth Estuary Transport Authority became the world’s first major bridge operator to open up the main cables of a suspension bridge and look inside. It was a big shock to find broken wires and corrosion, and that the bridge cables had lost about 10 per cent of their strength. Other suspension bridges with similar cables have since followed our lead and discovered much worse problems.
The Forth Road Bridge is efficient – its construction used less material than older suspension bridges such as the Golden Gate Bridge or the Brooklyn Bridge. But there is a safety factor of 2.5 times, and the bridge can safely afford to lose about 20 per cent of its strength before loading restrictions would need to be considered.
After the corrosion was discovered, we installed a dehumidification system, which dries out the air inside the cables. Since then we have regularly inspected the cables, and the loss of strength appears to have flattened out. We think this will extend the life of the bridge for decades, as long as the dehumidification system continues to work.
The art of engineering
I work for an organisation of engineers, but I went to art college. I have a different perspective, and perhaps I can help people see the bridge in a different way. When I first got to climb around on the bridge, underneath the deck and up the towers, I really got to appreciate the structure and what an immense achievement it is, a real monument of Scotland.
A driver stuck in traffic perhaps does not appreciate that. We try to promote the bridge as an icon, a monument of engineering, worthy of sitting alongside the world-renowned rail bridge.
For the 50th anniversary celebrations in 2014, I tried to help people see the bridge in a different way. I commissioned an artist in residence, and we really tried to bring the public in, organising trips to the tops of the towers, for example. The culmination was the largest fireworks display in Scotland, spanning the length of the bridge. We had a flotilla of boats, and it was a highlight of my career to watch from the top of one of the towers.
Edit is grateful to John Guy (MBChB 1963) for sharing a stunning collection of photographs he took as a student, including those of the Forth Road Bridge under construction. Visit Medicine then and now to see more of John’s photographs and to watch him in conversation with a current student, and visit The Alumni Flying Corp to read about his involvement in a project to build a replica First World War biplane.
Queensferry Crossing
| Date of opening | December 2016 |
|---|---|
|
Bridge type |
Three-tower, cable-stayed |
| Length |
2.6km; longest span between towers 650m |
| Height | Towers 207m above high tide. |
Global significance: World’s longest three-tower, cable-stayed bridge, and by far the longest to feature cables that cross mid-span, providing extra stiffness.
Other facts: Latest techniques and technologies mean the road surface will be continuous (no expansion gaps) and the bridge will not need to be closed in high winds.
John Redpath
BSc Civil Engineering 1980
John Redpath has more than 30 years’ experience as a civil engineer, mostly in the design, maintenance and strengthening of bridges. Since becoming chartered in 1986, he has worked within a number of international consulting practices, and for the last 14 years has been with Jacobs, based in Glasgow. He has been involved in the design and strengthening of a number of Scotland’s most important bridge projects.
As a Senior Consultant in Jacobs’ Highways and Bridges section, John is a member of the Jacobs-Arup joint venture forming part of Transport Scotland’s Employer’s Delivery Team for the new Queensferry Crossing, a three-tower, cable-stayed bridge being constructed alongside the Forth Road Bridge and the Forth Bridge. His role is to ensure that construction progresses in compliance with the contract and entails the detailed review of technical processes and methods for both temporary works and the permanent structure.
Initially responsible for the south tower, he has moved on to the deck construction, which for the next year will see the cable stayed bridge deck balanced cantilevers extending from the towers. The Queensferry Crossing is due to open in 2016.
My bridge story
Edinburgh is my home city, and for those who live, work and study in Edinburgh, the historic Forth Bridge and the Forth Road Bridge are a significant part of the city’s and Scotland’s identity. They have been the backdrop to many a photograph of friends and family and have provided an engineering skyline to be shown off with pride to visitors. The opportunity to work on the new bridge was, of course, not to be missed and it was my great fortune that my company, Jacobs, was selected as one of the joint venture partners.
The new bridge will be elegant and beautiful alongside its predecessors. With three concrete towers (monopoles) exceeding 200m in height, fans of slender cables will descend to a slim steel bridge deck spanning 2,638 metres in total across the Forth estuary. Its cable-supported length will form the longest three-tower, cable-stayed bridge in the world and will be the third in a unique triplet; three major bridges, one each from the 19th, 20th and 21st centuries.
Minimalist design
For me, the application of science is the true meaning of engineering, and the design and construction of the new bridge is an illustration of state-of-the-art bridge science in action. The remarkably slender towers and minimalist deck cross section are possible only because of the accumulated knowledge and understanding of major bridge structural behaviour and the construction expertise of the multinational construction consortium.
For all those who remember studying in Edinburgh, the variable climate will be no doubt feature in that memory, and weather is most definitely a feature of work on the bridge site. Wind, rain, cold and height combine to make the morning trip to the towers and deck “interesting”. However, when the sun shines and the wind drops, it’s difficult to say whether the view of the new bridge is trumped by the 360˚ view from the bridge.
It’s a busy environment and memorable moments tend to pass unnoticed until recalled some weeks or months later. Among those are the world record underwater concrete pour – 16,869 cubic metres of concrete poured below water for the south tower foundation in a continuous 15 day pour (Civil Engineers will appreciate that!), the arrival of the first shipment from China carrying bridge deck components and the steady transformation of the tower stubs emerging from the water to the slender tapered towers now rising above the Forth Road Bridge towers to the east.
The meeting moment
The moment most anticipated by me, and I think most on site, is not the completion of the bridge, but the point at which the bridge decks being built out from the towers in six huge balanced cantilevers will have nearly met. The gap at the centres of the two 650m spans, just about to be closed, I think is the point at which everyone can understand the art of bridge engineering.
Of course, driving over the bridge for the first time will be a moment for pride, and relief among many fellow bridge users that the long peak-hour delays will be a thing of the past.