Tube section sunk in vital phase of airport railway

TWO massive barge-mounted cranes, supported by more than 20 technicians, successfully installed the first immersed tube tunnel section for the airport railway yesterday.

The trouble-free operation began just after 8am when the Franco-Japanese contractors consortia, Dragages-Penta Ocean-Bachy Soletanche (DPB), began to lower the partially submerged tunnel section into a specially prepared trench of rock and sand on the sea bed.

One end of the tube was held by a 900-tonne crane, specially brought in from China, the other supported by a 250-tonne machine.

Lunchtime crowds lined the elevated walkway near the Shun Tak Centre to watch the giant 80-metre long section slowly disappear about 12.30pm. At 3.45pm the massive 8,500-tonne reinforced concrete tube was resting on the bottom of Victoria Harbour.

Mass Transit Railway Corporation engineer, Quentin Earle, said co-ordination between the two cranes had to be precise.

The consortia's project director, William Dousse, said there was only a 5cm margin of error in placing the unit. Divers ensured it was properly located.