More than 188,000 cubic metres of concrete were used in the construction of bridges, connecting roads, approach ramps and cut-and-cover tunnels on the Hong Kong side of the Western Harbour Crossing. Gammon Construction Ltd carried out the work as subcontractors of Nishimatsu Construction Co, a joint-venture partner in the $7.5 billion tunnel project with Kumagai Gumi Co. The contract involved constructing a ventilation building, a total of 17 bridges, extensive ground improvement work to support the structures, one footbridge, 330 metres of a dual three-lane approach road and all related road works. Martin Hadaway, Gammon Group managing director, said the project called for a massive co-ordination effort, careful planning and close liaison with the utility companies to complete each part of the project in sequence and on time. He said the construction work which was carried out at Sai Ying Pun, Western district, presented several unique challenges to the company, including varying ground quality on the former government tip, working in an extremely congested area of road networks, heavy traffic and the need to avoid a 275Kv high voltage cable which supplied the entire Central district with power. 'There were a few surprises but these were quickly overcome by our team of experienced professionals,' Mr Hadaway said. The close co-operation between the constructors, various government departments and the designers allowed unforeseen problems to be solved by adopting construction and design methods that met the overall preliminary design requirements in an effective and economical way. Gammon co-ordinated a steering committee to set up and administer the numerous traffic diversions that needed to be implemented during the construction and to keep disruption of traffic flow to a minimum. A utilities co-ordination group was also formed and met regularly with representatives of the water, gas, electric and tramways companies and the highways department to ensure everyone was kept up to date with the current and proposed works. When it was discovered the project would be delayed for nine months while Hong Kong Electric re-routed the high voltage power cable, Gammon adopted special construction techniques to suit the situation and work around the cable. The foundations for seven bridges were affected and needed to be redesigned. The number of piles for a particular section were either changed in number, diameter or depth. In some cases, the piles were sunk to a depth of 76 metres. Mr Hadaway said the combination of a first-class management team, which included contracts manager K. Y. Leung, project manager Rayland Lee, assistant project manager Leonard Leung and project engineer Brian McArdle, helped to maintain good relationships with all interested parties.