By Stuart Matthews
It’s not just construction that benefits when bridges get built
Bridges are like icebergs. Not only are they cool, but the bit you see is only part of the story, with much of the action going on beneath your feet.
This point first struck me crossing Grafton Bridge in my old home town of Auckland. From above, the structure is innocuous and functional. It spans a narrow but deep gap and is flat. Construction started in 1907 and took a modest three years to complete, by which time it was among the largest single-span concrete bridges in the world. Its most striking feature is a 97 metre concrete arch, which still makes for an impressive sight, 100 years after the structure was finished.
Grafton Bridge was a new city’s small triumph over a rugged natural environment. Like many bridges, it combines the best design and engineering features available at the time, into something born of sheer functionality; plus it looks pretty amazing too.
Frequently sweeping and attractive structures, which are, by the very nature of their function, often set among great scenery, the fact that bridges work to overcome natural barriers has helped to make many of them emblems of the cities where they are built. Sydney, San Francisco and Amsterdam all have bridges that have made postcard printers a little wealthier.
But bridges aren’t just about emblematic and adventurous engineering, they are about economics too. They are built to boost business, cut travel times and ease access to busy hubs. They serve to speed the flow of commerce by quite literally bridging a gap.
Think of the Scandinavian and Chinese efforts to span vast stretches of water, or France’s spectacular Millau Viaduct; each one a bid to build closer economic ties between neighbouring commercial centres.
Local examples are easy to find too. For those who’ve spent a few years in Dubai, do you remember the collective sense of relief when the new Garhoud Bridge opened? It rapidly eased the daily coagulation of traffic caused when the city outgrew the original structure.
Bridges also make for useful landmarks. What driving directions to the city of Abu Dhabi don’t start with the phrase: ‘from the Maqta Bridge…’?
Now Abu Dhabi has a new structure to serve as both emblem and economic stimulus. The Sheikh Zayed Bridge, which sits alongside the existing Maqta Bridge, just beyond the tiny island fortress, is, as I write, on the verge of opening to traffic. The straight flat lanes have been made possible by some clever engineering, which also had to cope with the emblem effect created via Zaha Hadid’s design.
While it looks simple and elegant enough, it has been labeled the most difficult bridge to build in the world. But building symbols of success is never easy. Extending up to 842 metres, and testing the limits of engineering, it was a complex and testing project for those involved. While the scheduled completion date moved back on a few occasions, this has not detracted from the quality of the result.
Abu Dhabi’s commerce will soon get to benefit from the billion dirham project. If other bridges are anything to go by, the postcard printers won’t be far behind.
Stuart Matthews is the senior group editor of ITP Business' construction & design tiles.