Contract CR202 involves the design and construction of a 5km large-diameter tunnel between Fairways Drive and Sin Ming Walk. STEC undertakes the project in a joint venture with Obayashi Corporation. Two kilometres of the tunnel will under-cross the Central Catchment Nature Reserve. The bored tunnel will also cross underneath Eng Neo Avenue Forest, Windsor Nature Park, Peirce Secondary School, Pan Island Expressway (PIE), and Upper Thomson Road.

The tunnel - containing two mainline tracks - will be constructed with a large TBM, which measures approximately 12m in diameter. The contract also comprises a TBM launch shaft, transition tunnels to Future Underground Infrastructure, a Facility Building, and a Temporary Staging Area. OC-STEC CR202 JV's construction approach will optimise productivity while ensuring strict compliance with environmental requirements.