Hong Kong bridges keep getting bigger and better. Over the last decade a flock of major crossings - Tsing Ma, Kap Shui Mun and Ting Kau, have sprung up around the island. The latest, the Stonecutter, promises to be the biggest of them all.
The landmark cable stayed structure will span more than 1,000m across the Rambler Channel, which forms the gateway to Hong Kong Harbour.
At 295m tall, the bridge's two concrete and steel towers will be 50% higher than the Tsing Ma and Ting Kau bridges. The main steel deck span, at 1,018m, will make it the longest cable stayed bridge in the world.
Run by Hong Kong Highways department, the bridge design competition called for illustrative designs for a signature gateway structure. The bridge will be the first view of Hong Kong for those arriving from the airport or New Territories and emerging from the Tsing Yi tunnel. It will also be seen from Victoria Peak in the city.
The winning entry - by a group comprising British consultants Halcrow and Flint & Neil, with Chinese engineer Shanghai Municipal Engineering Design Institute, and Danish architect, Dissing & Weitling - beat off 27 submissions by 18 groups to take first place, picking up HK$2M ($257,000) in prize money. 'It's a big scheme, we were delighted to get it, ' says Ian Firth, a partner with Flint & Neil.
The design uses a simple solution, with two single towers matching the height of the surrounding peaks of Tsing Yi island and the skyscrapers of Hong Kong. Independent technical and aesthetics panels agreed this was a better solution than a more conventional Aframe design by the second placed Scott Wilson/Leonhardt Andra team. The deck will be vented with twin parallel steel ribbed decks to improve aerodynamics. 'It will be something very different. The towers are very slender, ' says Robert Lloyd, Hong Kong Highways major works project manager.
The judges chose a cable stayed design for ease of construction and speed of delivery - the bridge is expected to take four years to build, compared with five for a suspension bridge.
Spanning between container terminal 9 on Tsing Yi and container terminal 8 at Kwai Chung in Kowloon, it will form part of Route 9, bypassing the existing Route 3 highway between the Lantau Link and Cheung Sha Wan which is expected to reach saturation in 2006.
Feng Shui experts have likened the bridge to a dragon guarding the entrance to the harbour, with lights on the towers becoming eyes, and the winding access roads forming its sinuous tail.
According to Firth, design of the bridge has been dictated by having to keep the busy Rambler Channel open.
'Normally for a bridge of this size we would expect to lift up the bridge sections from the water, but we are not allowed to block the waterway, so we have designed around cantilevering the deck out 500m, which should be interesting, ' he says. All major lifts and launches on site will have to be carefully timed around the typhoon season.
Under unusual Hong Kong treasury rules, the Halcrow-led team must now compete against other consultants to win the work to flesh out its illustrative design to a detailed design. This next stage of bidding will take place in the spring of next year, leading to the construction contract award in 2003. Construction is not expected to begin until March 2004 to allow time for the formation of container terminal 9, land for which is currently being reclaimed.