A gigantic precast unit, possibly Asia’s largest ever precast unit, is set to arrive in Hong Kong next month to be installed as part of the Central-Wanchai Bypass.
“The whole precast unit is being manufactured at a casting yard in mainland China. When ready, it will be towed to Hong Kong by sea. The unit has been designed to float during the towing operation,” the Civil Engineering and Development Department said in an email statement issued through Development Bureau.
The unit is being constructed as part of contract HK/2010/06 for which the main contractor is the Gammon/Leader joint venture.
“Definitely this is the largest piece unit in this part of the world. Hopefully this unit will be towed by end of March this year,” chairman and executive director of Build King Holdings (0240) Derek Zen Wei-peu said.
Build King is the parent company of Leader.
According to CEDD, the precast unit is “the size of a football pitch” measuring 130 metres long by 50 metres wide by 12 metres high.
As an indication of its size, the volume of water of nearly 21 Olympic standard swimming pools could fit into the volume of the unit.
CEDD said the contractor was finalizing details of the towing operation and expected no major problems during transport and final installation.
“It sits on 51 piles and is different from other submerged tubes which sit on level bedding and is a lot easier [to install]. Also this unit is irregular shape, which also adds to the difficulty of construction as well as placing,” Zen said.
CEDD said the Central-Wanchai Bypass would consist mainly of a tunnel however part of the tunnel would cross above the MTRC’s Tsuen Wan Line tunnels to immediately to the west of the Hong Kong Convention and Exhibition Centre.
“To ensure that the reclamation at that location and the concerned section of CWB tunnel would not impose additional load on the MTR tunnel, the works would be constructed in the form of precast concrete structure to be supported by bored piles driven along both sides of the existing MTR tunnel,” CEDD said in its statement.
The CEDD contract, worth HK$705 million, was awarded to Gammon/Leader in January 2011.