熊谷組
Contract 705 for the design and construction of the Boon Keng and Potong Pasir two-level civil defence underground stations, of twin bored tunnels and of cut and cover tunnels, was awarded to Kumagai Gumi-Sembawang Engineering-Mitsui Joint Venture at a contract value of S$217 million (US$ million). Initially, the station was planned to be just a "shell station", but it was decided to build the whole station as it would be more expensive for the station to be fitted later.