SIX months into the massive site preparation contract at Chek Lap Kok, about 10 per cent of the transformation from island into airport platform has been completed. Working hard to complete the scheme is the largest dredging fleet assembled for a single project in the world. The combined marine fleet includes 14 trailer suction hopper dredgers, three cutter suction hopper dredgers, two bucket dredges and seven grab dredges, all working on a 24-hour roster. On the land side of the works, 60 huge dump trucks, operated by Yamazaki, of Japan, and Roche Brothers, of Australia, are running 24 hours a day. They are moving the mountains of rubble generated by the daily production involving between 50 and 80 tonnesof explosives. The total earth-moving production, including the land and marine works, has been estimated at 400,000 cubic metres a day. The island of Chek Lap Kok now employs about 1,350 people. The Provisional Airport Authority, which oversees the massive site preparation contract, was given breathing space last week when the Finance Committee of the Legislative Council approved the allocation of $562 million to keep the authority going. ''We are very encouraged by the support of the Legislative Council,'' said the authority's chief executive Hank Townsend. The decision was also a matter of relief for the staff and to morale of the PAA. It is now funded at least until the end of this financial year. The PAA's key task now is to get the overall financing plan agreed to with the Chinese on the Airport Committee. By March next year, the PAA hopes to be prepared for the award of preliminary foundation works for the terminal building, the baggage handling equipment, and the people-mover system. The three contracts are worth more than $2 billion.