It’s been compared to the topsy-turvy circuit of a Mario Kart race track. The two-lane Eshima Ohashi Bridge in Japan – dubbed the “Rollercoaster Bridge” – is a marvel of civil engineering that puts vertigo-induced terror firmly in the driving seat.
Having given us everything from hydrogen cars to high-speed bullet trains, Japan is renowned for its groundbreaking contributions to transport design. But what was the impetus behind the stomach-churning Eshima Ohashi Bridge, a construction that appears to belong in an adrenalin-charged theme park?
The structure was built to service two cities on the northern coast of Honshu Island. Located in Shimane Prefecture, the city of Matsue – known as the “Water City” owing to its lakes and canals – is a humid, rainy place with a population of around 200,000.
Some 12 miles further east is the relatively small city of Sakaiminato in Tottori Prefecture – the hub of western Japan’s fishing fleets. Its international seaport is vital to the country’s economy and has been trading with the outside world for more than a century.
Between the two cities is the sprawling saltwater lake of Nakaumi, whose name means “middle sea.” The Eshima Ohashi Bridge was built to span Nakaumi’s waters, but there was one big problem: the height of passing ships.
In the days before the bridge, the two cities were served by the frustratingly inefficient Naka-ura-suimon Bridge, a drawbridge that closed for up to eight minutes every time a vessel transited. Motor vehicles weighing more than 14 tons, meanwhile, couldn’t use it at all.
In engineering, the “elegant solution” to a problem is the one that’s the simplest and most direct. Thus the Eshima Ohashi Bridge was designed to climb rapidly to 144 feet, which would facilitate the uninterrupted flow of both ships and ground vehicles.
Yet while it may look hair-raising from the ground, the bridge is extraordinarily strong thanks to its superstructure being tightly integrated into its substructure. It is the largest bridge of its style in Japan and is only trumped in size by two other bridges in the whole world.
Reflecting the inherent challenges of rigid-frame design, the structure was, though, costly and time-consuming to build. Work on the Eshima Ohashi Bridge began in 1997 and concluded seven years later in 2004. Its price tag? Just under 23 billion Japanese yen, or $214 million.
Maintained by the Sakaiminato Management Association, the bridge is over a mile long and 37 feet wide. Yet although it is an impressive and clever example of modern civil engineering, Japanese bridge building is actually an ancient and sophisticated tradition.
Once famously depicted by impressionist painter Claude Monet, the traditional Japanese bridge is a serene and aesthetic construction that echoes the careful sense of proportion associated with the classical Japanese garden. The most beautiful, of course, were built long before the car came along.
One of the country’s earliest surviving garden bridges was built in Kyoto’s Byōdō-in garden in the 11th century. Representing a passage to heaven – ultimately symbolized by the elaborate Buddhist Phoenix pavilion – it’s a far cry from the modern Eshima Ohashi Bridge.
Japan is, then, home to some of the world’s most interesting bridges – and yet the prize for the world’s highest and most terrifying goes to China. The 4,000-foot-long Sidu River Bridge crosses a valley with a horrifying 1,627-foot drop. And in case you were wondering, the world’s second and third highest bridges are also in China.
The highest bridge in the U.S., by comparison, is Colorado’s Royal Gorge Bridge, which spans the Arkansas River from a height of 955 feet. Built in 1929, it was the planet’s highest bridge until 2001; now it’s only in 14th place.
Japan’s Eshima Ohashi Bridge is humble when compared to the high-altitude crossings of China, but it’s certainly captured the public imagination. And if anyone deserves credit for publicizing the bridge’s rollercoaster incline, it is Japanese car manufacturer Daihatsu.
The last thing motorists want on the Eshima Ohashi Bridge is to stall or roll backwards. So, to demonstrate the capabilities of its Tanto minivans, Daihatsu released a commercial showing the vehicle climbing what appears to be an extraordinarily steep approach.
It wasn’t long before international news outlets got hold of the advert and shared gut-wrenching images of the bridge. Eshima Ohashi Bridge – and specifically its terrifying incline – had gone viral.
Not everything, though, is quite as it seems. The bridge’s approach appears to climb at a horrifying 45-degree angle, but this is actually an optical illusion created by a telephoto lens compressing the perspective.
The bridge’s actual gradients are an easygoing 5.1 percent on the Sakaiminato side and 6.1 percent on the Matsue side. Any average vehicle is quite capable of crossing Eshima Ohashi; no Tanto Minivan is required.
Eshima Ohashi Bridge may not be the crazy Mario Kart ride it appears to be, but it’s still an impressive feat of engineering. Yes, despite the media hyperbole, it deserves a place in the world bridges hall of fame.