EMERGENCY STEEL elements for the Ting Kau bridge are being flown to Hong Kong at great expense following a catastrophic accident which wrecked a crucial deck section last month.
Miraculously, no-one was injured in the accident on 3 January when a gantry crane lifting a 13.5m by 19m steel deck frame collapsed. This caused the massive deck grid to fall 70m from the bridge on to a barge below.
The collapse is still being investigated by Hong Kong's labour department. But according to Friedrich Naeher, project engineer with German contractor Zblin, a weld failed in the frame attaching the gantry crane to a sliding sledge.
'The only question is how we managed to lift the 13 previous sections without the weld failing,' said Naeher. Ten gantry cranes, some up to 50 years old, are at work on the bridge, operating on six separate lifting fronts for the two main spans and two side spans.
The fall left the deck unit a mangled wreck on the barge below. It was to be the final cable supported unit for the south side of the Tsing Yi pier deck; the other side of the span from landside was being erected by crawler cranes.
The disaster is another blow for the Ting Kau Contractors joint venture which has been working to an extremely tight programme. Already delayed beyond its original summer 1997 opening, the elegant but complex bridge should now open in April. It was designed by German consultant Schlaich, Bergermann along with Hong Kong firm Binnie Consultants which had responsibility for the approach viaducts.
Time pressure meant that within a week of the disaster, the contracting joint venture led by Spanish firms Cubiertas and Entrecanales with Zblin, Australia's Downer and Hong Kong's Paul Y, sourced replacement high grade steel within Europe and arranged fabrication in Spain.
Girders were now arriving by air, said Naeher, and would be lifted into place individually and welded in position. He would not comment on the cost of air freighting other than to say it was 'expensive', but added: 'The alternative would have been to lose at least another four weeks, rather than keep on schedule.'