FOR almost 30 years one of the biggest construction companies in Japan has been helping to shape Hong Kong, with work on the Bank of China, the Cultural Centre and several tunnel projects in the territory among its achievements. Kumagai Gumi's links with Hong Kong go back to the 1960s, when the company worked on a water tunnel at Plover Cove in the New Territories. Since then the company, which was incorporated 55 years ago, has played a part in many of the territory's key infrastructure projects, including the extension of the Kai Tak runway in 1973, the MTR tunnel between Admiralty and Tsim Sha Tsui, and the Eastern Harbour Crossing. The latter, including related projects such as the Kwun Tong bypass, was the company's biggest project in Hong Kong to date, worth about $4.4 billion. Currently, Kumagai Gumi has about 25 Japanese engineers working with Nishimatsu Construction on the six-lane Western Harbour Crossing. Work began in early August and the project is due to be completed by June 30, 1997 - 47 months. Although this is longer than it took to build the Eastern Harbour Crossing - 39 months - there are particular problems with the new project. ''There was a delay in the handover of the site,'' said Hisayoshi Yoshikawa, deputy general manager of Kumagai Gumi's main regional branch in Hong Kong. ''This was mainly due to arrangements for traffic flow and the need for some reclamation work, so the time period is quite tight. However, we are confident we will meet the deadline.'' The immersion tubes for the tunnel are being built in Shek O. From there they will be towed to the site and then sunk. ''This is a delicate operation, as part of the route is over the open sea,'' said Naotake Saito, the company's general manager. ''But we have experience of this; it was necessary to transport similar tubes over about 95 kilometres of open sea for the 2.3-km-long Sydney Harbour Crossing Tunnel. ''From a technical point of view, the construction methods for the project are all tried and tested,'' he said. Kumagai Gumi's experience in tunnel construction speaks for itself. As well as the projects in Hong Kong and Australia, it was also involved in the construction of the world's longest undersea tunnel, the 53.8-km-long Seikan Tunnel in northern Japan, 23.3 km of which is under water. Other impressive infrastructure projects the company has worked on or is working on include the Akashi Bridge, part of a series linking the main Japanese island of Honshu to Shikoku, which will be the longest bridge in the world, the 14.4-km-long Rogers Pass Tunnel in Canada, the longest in North America, and Kansai International Airport in Osaka Bay, which is scheduled to open next year. In the latter project, Kumagai Gumi is involved in the transport and placement of the sand and gravel required for the island in Osaka Bay on which the airport will be located. It is also working on a 3.75-km combination railway and highway bridge. Despite the large number of foreign projects in Kumagai Gumi's portfolio, contracts completed in Japan last year accounted for about three quarters of all finished works. At home, it is perhaps best known for having built many of the country's largest dams, but has also left its mark on the Tokyo skyline, having worked on part of the prestigious Metropolitan Government Office in Shinjuku. The company's latest bid in Hong Kong is for sections of the MTR link to the new airport at Chek Lap Kok, and it also plans to tender for Route 3, a build-operate and transfer scheme (BOT). BOT projects in the territory are nothing new for the company. As well as being involved in the construction of the Eastern Harbour Crossing, it is the biggest shareholder in the New Hong Kong Tunnel Company, which operates it, with a stake of about 50 per cent. ''At present, the daily average volume is about 85,000 vehicles, higher than expected,'' said Mr Saito. ''But revenues are lower than expected.'' Mr Yoshikawa said negotiations were about to start on raising the toll. As well as construction projects, the company has left its mark in Hong Kong in another way, having spawned a local offshoot. ''Kumagai Gumi [Hong Kong] was set up about 20 years ago,'' said Mr Saito. ''We have a good working relationship with them, talking with them about projects the companies are tendering for. ''In addition, about 30 of our engineers are working for the Hong Kong company - in which we still maintain a small stake - on a temporary basis.''