Queensferry Crossing
The Queensferry Crossing is one of the most spectacular feats of modern civil engineering in Europe, carrying the M90 motorway across the Firth of Forth between South Queensferry in Edinburgh and North Queensferry in Fife. Opened in September 2017 by First Minister Nicola Sturgeon, it is the longest three-tower cable-stayed bridge in the world, stretching 2.7 kilometres from shore to shore. The sheer scale of the structure is astonishing even to those who have seen it in photographs — the three towers rise to 210 metres above sea level, taller than the Eiffel Tower's first two floors, and the bridge carries some 24 million vehicles per year, relieving the historic Forth Road Bridge of traffic and allowing that older structure to be preserved for public transport and emergency vehicles.
The history of crossings at Queensferry reaches back over a thousand years. The very name derives from Queen Margaret of Scotland, wife of King Malcolm III, who in the eleventh century established a ferry service to help pilgrims crossing the Forth on their way to the shrine of Saint Andrew at St Andrews. For centuries, the ferry was the only practical way across this wide tidal estuary. The famous Forth Railway Bridge, opened in 1890 and now a UNESCO World Heritage Site, was the first fixed crossing. The original Forth Road Bridge followed in 1964, a triumph of mid-century suspension bridge engineering that for decades was the longest suspension bridge outside the United States. By the early 2000s, however, the Road Bridge was suffering from stress corrosion in its cables and facing significant maintenance challenges, prompting the decision to commission an entirely new road crossing beside it. The Queensferry Crossing was the result — a project that employed up to 1,400 workers at peak construction and required engineering innovation on multiple fronts.
In person, the Queensferry Crossing is a breathtaking sight. The three slender towers taper elegantly as they rise, and the fans of white cables spreading from each tower give the structure an almost harp-like quality when seen from certain angles. The bridge deck appears impossibly light and thin for its scale. Unlike many modern motorway bridges that feel purely functional and anonymous, the Queensferry Crossing has a genuine aesthetic ambition to it — the design by Ramboll, Arup and FABER MAUNSELL was chosen partly for its visual character, and from the shore it really does look like a landmark rather than mere infrastructure. The sound from nearby is a constant low rush of traffic above, punctuated on windy days by a faint tonal hum from the cables, which are engineered to suppress the Aeolian vibration that can afflict cable-stayed bridges in strong winds.
One of the most remarkable technical features of the Queensferry Crossing is its cable-sharing system, in which the cables from adjacent towers are linked to one another along the deck. This innovation, unique at this scale, means the bridge is self-stabilising in high winds and does not require the stiffening trusses that older cable-stayed bridges often need. This is particularly important given that the Forth is notorious for ferocious gales; the original Forth Road Bridge beside it frequently had to be closed to high-sided vehicles and motorcycles in bad weather. The new crossing is designed to remain open to all traffic in winds up to 65 mph, a major practical improvement. Additionally, the towers are hollow and contain internal inspection lifts, allowing maintenance workers to access the full height without external scaffolding.
The surrounding landscape is magnificent. The Firth of Forth at this point is several kilometres wide, a great silver-grey arm of tidal estuary reaching inland from the North Sea. Looking west from the bridge on a clear day, you can see the estuary narrowing toward Stirling, with the Wallace Monument visible on its hilltop. Looking east, the firth opens dramatically toward the Bass Rock and the distant coast. The low drumlin hills of Fife rise to the north, while the southern bank is flanked by the burgh of South Queensferry and the wooded estate of Hopetoun House. The three bridges — Victorian railway, mid-century suspension, and twenty-first century cable-stayed — all visible simultaneously from certain viewpoints on the shore, form one of the great panoramas of Scottish engineering history. The Forth Rail Bridge in particular, with its massive cantilever structure painted blood-red, provides a striking contrast to the slender white lines of the new crossing.
Practically speaking, most visitors experience the Queensferry Crossing by driving across it on the M90, but the views from the road are limited by safety barriers and the speed of traffic. The best views are obtained from the ground. The town of South Queensferry on the southern shore is an excellent starting point, offering car parking, cafés, and a charming historic high street with buildings dating to the seventeenth century. From the waterfront promenade, visitors can see all three bridges in alignment, and on calm days the reflections in the water are extraordinary. Hawes Pier, from which the last Forth ferries once departed, is just steps from the old town. On the north side, the village of North Queensferry has a small beach and viewing area directly beneath the bridges that is among the best vantage points of all. The area is accessible by train from Edinburgh Waverley, with stations at Dalmeny on the south side and North Queensferry on the north, and the ScotRail service takes barely fifteen minutes from the city.
A handful of unusual details make the Queensferry Crossing still more interesting on closer inspection. The central tower of the bridge is founded on the rock of Beamer Rock, a tiny islet that once bore a lighthouse warning sailors of the reef. This rock was incorporated into the foundation of the middle pylon, meaning the tower effectively rises from the middle of the river with no approach road for its entire height. During construction, the towers were built using a self-climbing formwork system that crept upward as concrete was poured, a process which could advance the tower height by around three metres per week. The bridge also contains an innovative dehumidification system running through the hollow cables to prevent internal corrosion — a lesson learned from the fate of the cables on the adjacent 1964 Road Bridge. When lit at night, the towers glow white against the dark sky, and the cable fans catch the light to create an ethereal, almost otherworldly effect visible from considerable distances across the Edinburgh skyline.