"The Forth Railway Bridge" by Dr. Miles Oglethorpe, Head of Industrial Heritage, Historic Environment Scotland: Edinburgh Meeting of 4 April 2017

Scotland's greatest engineering icon and best-loved structure, the Forth Railway Bridge is now a UNESCO World Heritage Site. Dr Miles Oglethorpe of Historic Environment Scotland told us how it has entered the national psyche in an eclectic presentation marking Scotland's year of history, heritage and archaeology.

With the challenge of maintaining the Bridge acting as the driver of events these last twenty years, World Heritage listing is a game-changer that puts into a new context the ways in which the image of Scotland's greatest engineering icon has been used.

These include the promotion of drinks (alcoholic and IrnBru) and of Fife Council, appearances in films and television programmes like Thunderbirds (the Bridge Over the River Kwai bore a resemblance), comics like Commando Magazine and as a political symbol e.g. in the recent anti-Trump protest "our bridges are better than walls" or when after the 2015 general election Nicola Sturgeon gathered her 56 MPs for a photocall.

Lessons from the fall of the Tay Bridge were learned in its rebuilding and in the redesign of the Forth Bridge, both by Sir William Arrol. The famous photograph demonstrating the cantilever principle features young Japanese engineer Kaichi Watanabe who went on to form the Toyo Denki Company, which is still producing electric traction units, these days for Shinkansen. The documentation of construction was exceptionally good, and the measures of its dimensions indicate that two Eiffel Towers could be fitted inside each cantilever: but in the case for World Heritage listing a typo went uncorrected saying that the Bridge was 2.5 metres long!

In Scotland, the banknotes of the Clydesdale Bank testify to us throwing our World Heritage sites at our money, but less so money at our World Heritage: a recent consequence is the Bridge sharing the Clydesdale polymer ©5 note with the Titan crane at Clydebank. However, back in 2010, the UK Department of Culture, Media and Sport took the view that World Heritage status was a burden, whilst UNESCO itself asked well-represented nations to slow down their rate of nomination to less-prolific countries a chance. Historic Environment Scotland believed in the "joy of six", adding the Forth Bridge to the five sites (St Kilda, Edinburgh Old and New Towns, New Lanark, Neolithic Orkney and the Antonine Wall) already designated, and research by James Rebanks on a bid for the Lake District provided an important analysis of the potential benefits.

The conservation programme which followed Tam Dalyell's protest against BR's maintenance holiday in the 1990s required scaffolding which made the Bridge not the prettiest of sights, but followed strict environmental requirements, with all lead-based paint blasted from its surface being captured rather than allowed to fall into the Firth below. After a spoof suggestion of using yellow paint had been seen off in favour of the traditional red (which some schoolchildren believed was to cover up the blood of those injured in its constructionand maintenance!), up to 1,500 people worked on its restoration, applying 240,000 litres of paint and at no time were the 200 trains daily using the Bridge disrupted.

Completion in 2012 cleared the way for nomination even as celebration of its status ran the risk of the "dentist's nightmare", a build-up of plaquescaused by serial awards and commemorations! The nomination document prescribed a management plan and sought a demonstration of the site's Outstanding Universal Value according to one or more of six cultural criteria - in this case, creative genius, interchange of human ideas, type of building - with the first and third of these proving sufficient. New Mexico-based consultant Eric Deloney had completed a study for TICCIH of world bridges which noted that another cantilever railway bridge at Quebec City, while boasting a longer arch, had only a single span. The comparative study also found that the Vizcaya Transporter Bridge at Bilbao was the only Bridge so far to have achieved WH statussolely as bridge, rather than as part of a wider site (excluding the re-built bridge at Mostar).

Scottish culture secretary Fiona Hyslop's reaction to visiting the top of the Bridge in person and experiencing its curvaceous shape first hand was that every angle was amazing and were definitely those of a girl! Getting each chief executive's digital signature was definitely the most difficult task in finalising the management plan, and an April Fool subsequently suggested that an extra crossing prompted by the Bridge becoming dedicated to celebrating its WH status would be called the Fourth Forth Bridge. A buffer zone generally assumed to be required for other WH sites was avoided by invoking the protection of already-designed natural and cultural sites and area around the Bridge, ensuring statutory protection. A measure of the submission's relative brevity was that it weighed a mere 898 gm compared with 27kg for the subsequent printed version for the Lake District, which goes forward to the next World Heritage Committee meeting in Krakow.

Mark Watson of Historic Environment Scotland took the submission in person to the UK Ambassador to UNESCO in Paris for his signature and subsequent formal submission. A technical evaluation mission by UNESCO expertsensued, who were advised by Network Rail archivist Vicky Stretch on the extraordinary original documentation that survives. In the UNESCO World Heritage Committee session held in the old Federal German parliament building at Bonn, the UK team was sat next to the US in sight of a monitor showing the proceedings only in French, the language in which the nomination was read to the 21 nations comprising the current World Heritage designation committee. Lebanon in particular was uneasy about lack of a buffer zone, but the case for the Bridge was succinctly presented by ICOMOS and the then Scottish local government minister, Marco Biagi,delivered the best acceptance speech of the session. The same session also saw two other pieces of Scottish industrial heritage inscribed onto the World Heritage List as part of "The Sites of Japan's Meiji Industrial Revolution" - a Clyde-built Giant Cantilever Cranecommissioned in 1913, and Kosuge Dock built for Thomas Blake Glover in 1863 by Hall Russell of Aberdeen, both for the Mitsubishi Company in Nagasaki.

UNESCO gave the Scottish Government a logo to denote the Bridge's designation, and the hope is that engineering skills from its building will be revived in places like the new Engine Shed skill-centre, Scotland's dedicated building conservation centre based in Stirling which, run by Historic Environment Scotland, serves as a central hub for building and conservation professionals and the general public. In 2014. The then Scottish First Minister Alex Salmond provided funding for Historic Scotland and the Glasgow School of Art (who formed the CDDV partnership - the Centre for Digital Documentation and Visualisation) to digitally document all three bridges at Queensferry for a 3D model which shows them in an entirely new light (see https://youtu.be/ikLjgXXAMas (external link)). Each year, World Heritage is celebrated on 18th April asInternational Monuments Day, and increasing numbers of tourists embark on tours of World Heritage Sites, with an announcement just made that Network Rail will soon be seeking listed building consent for a Sydney-style bridge-climb and viewing platform on the South Cantilever.

Report and photograph of Dr. Miles Oglethorpe by John Yellowlees.