Singapore’s Land Transport Authority (LTA) has awarded a S$242m ($178.6m) contract for the design and construction of more tunnels for its Cross Island Line (CRL) to a joint venture between Nishimatsu Construction and Okumura Corporation’s Singapore branch.

The major contract falls under phase 2 of the CRL, part of the country’s Mass Rapid Transit system, and will see 2.4km twin tunnels bored between Singapore’s West Coast Station and Jurong Lake District Station.

The tunnels will reach depths of up to 40m and are set to travel underneath the Sungei Pandan canal, the West Coast Highway, and the Ayer Rajah Expressway, with work set to begin in the fourth quarter of 2024.

The two companies involved in the joint venture have both completed tunnelling projects in Singapore before, with Nishimatsu currently finishing construction on tunnels between Tampines North station and Defu station on the CRL.

LTA’s selection of the joint venture comes only weeks after the authority awarded a S$530m contract for the construction of a new station and further tunnels for CRL phase 2.

The CRL project consists of three phases of construction for LTA, with the 29km CRL phase 1 set to be complete in 2030, the 15km long CRL phase 2 set for 2032, and CRL phase 3 still in the precursory planning stage.

While final details on the construction of phase 2, phase 1 of the line saw costs reaching S$13.3bn, making it one of the most expensive construction projects of 2022.