1 Jul 2011

Is China’s bridge really the longest in the world?

China’s latest engineering marvel, the Qingdao bridge, has been hailed as the world’s longest bridge over water. But the claim has ruffled feathers in America, previous owners of the title.

China’s Qingdao bridge opened to the public yesterday after four years of construction.

The bridge is over 26 miles long and carries its eight lanes of traffic over the Qingdao bay. Motorists will be able to travel from downtown Qingdao to the Huangdao city centre in about 20 minutes, saving themselves a 40-minute journey around the bay’s edge.

The fact that it crosses over the bay means that it has been entered into the Guinness World Records as the longest bridge over water, which according to the Guinness World Records team means it is “2.53 miles longer than the former record holder, the Lake Pontchartrain Causeway in Louisiana”.

However the general manager of the Causeway in Louisiana is not going to relinquish this title without a fight and said that the Chinese bridge team were “a bunch of wannabees”.

Causeway General Manager Carlton Dufrechou said his bridge, built in the 1950s and traversing the Lake Pontchartrain in a straight 24-mile line, deserves to hold on to the title.

‘We’re proud of that record and we think we still hold that’Carlton Dufrechou, Causeway Commission

Dufrechou told Channel 4 News that while he agreed the Qingdao bridge is a “magnificent bridge”, he believes the 54-year-old Causeway bridge still holds the record by eight miles.

Terminology appears to be at the heart of the dispute. Dufrechou maintains that because the Qingdao bridge is curved, it is using part of that curvature over the water to add to its length of 26 miles.

If you were to measure the distance from the start of the bridge to the end of the bridge as the crow flies, it would only measure a distance of 16 miles over the water, he argues. His bridge by comparison is a straight 24 miles from end to end over the water (you can see the Causeway on the map below).

However the Guinness World Records has come down on the side of the Chinese. Its editor-in-chief Craig Glenday says their title, for the Longest Bridge over Water, “recognises an incredible feat of engineering.” and explains how they award it:

“It is calculated by the actual length of the bridge and not the size of the body of water it covers or the distance between two land masses that it spans.”

Defrechou seemed undeterred by the Guinness World Records response. “I understand that measurement,” he said, “but we believe the open span over the water is the proper measurement – we’re proud of that record and we think we still hold that.”

Chinese bridge-building has been making waves recently with the sheer speed and scale of its construction.

‘The west is competing with China with doing projects in its own back yard’ – Alistair Lenczner, Foster + Partners

Alistair Lenczner, partner at Foster and Partners who were behind the Millau Viaduct in France, explained what a force Chinese construction has become.

“You have to be impressed the rate and the magnitude of the projects they’re doing,” he told Channel 4 News. “It’s probably unprecedented in terms of the volume of infrastructure in such a short number of years.”

View Larger Map

Previously, Lenczner said, western consultants would be invited to Chinese construction projects, while their own engineers stood by and watched and learned. Now they have developed their own industry and have become world leaders, exporting their skills.

“The tide has turned – the west is competing with China with doing projects in its own back yard.”

Lenczner knows how well the Chinese have progressed. Among its several world records, the Millau bridge also held the record for the highest road bridge deck in the world. Now he says the Chinese have broken that record “a dozen times over”.

But Lenczner points out that in terms of records the real holy grail for the bridge designer is the “longest span” record – that is to say, the part of length of the bridge between any supporting columns.

Both the Qingdao bridge and the Louisiana Causeway may have length on their side, but they have a lot of columns beneath them, creating very small spans. The owner of the longest bridge span title is in Japan.

Competitors take part in the ‘Viaduc’ race (23,550 km) on the Millau viaduct.