The Circle Line Stage 3 C852 project is a build-only project which STECS undertook in a joint venture with Woh Hup and Alpine Mayreder. This project includes construction of Serangoon interchange station, the interconnecting tunnels from Serangoon station to Lorong Chuan station, and from Serangoon station to Bartley station. Two 6.35m diameter EPS machines were used to construct the bored tunnels. The contract value is S$155.95 million.