Weather key to tricky bridge operation

PUBLISHED : Thursday, 28 March, 1996, 12:00am
UPDATED : Thursday, 28 March, 1996, 12:00am

Engineers building the Tsing Ma suspension bridge are hoping for a cold snap today when the last section of the $7.14 billion structure is expected to be hoisted in position at Ma Wan.

Cool weather will help contract the 18-metre-long steel unit making it easier for bridge builders Anglo-Japanese Construction to slot the section between the tower and the already completed one-kilometre long deck.

Ten 100-tonne jacks attached to the Tsing Yi tower will push the 50,000-tonne main deck like a giant pendulum up to 450 millimetres towards Tsing Yi to allow engineers more room to work at Ma Wan.

Project director Nick Hobson said if temperatures were cooler engineers would not have to jack the unit as far.

Once the segment has been joined to the main deck, about 100 welders will finish fixing all 50 segments together.

He said work was running on schedule, although the deck segment was originally due to be raised about six weeks ago.

'We decided to keep it on the ground while we rearranged other things,' he said. Highways Department project director Lau Ching-kwong, said the jacking operation was complex.

'It's very precise,' he said. The deck weighs the equivalent of 125 fully loaded Boeing 747s.

He said the project would be the world's longest combined road and rail suspension bridge when it was completed in May next year.