The Land Transport Authority (LTA) has awarded a S$758 million contract to design and build a 5 km tunnel for the second phase of the Cross Island MRT Line (CRL), 2 km of which will pass beneath the Central Catchment Nature Reserve.

It also gave out a separate S$496 million contract for Punggol interchange station under the CRL Punggol extension.

Construction works for both projects are expected to start in the first half of 2023, with passenger service slated to begin in 2032, said the LTA on Monday (Dec 5).

A joint venture between Obayashi Corp and Shanghai Tunnel Engineering Co (Singapore) will construct the 5 km tunnel between Fairways Drive and Sin Ming Walk.

The LTA said a large tunnel boring machine with a diameter of around 12 m will be used for the tunnel, which will run up to 70 m underground – deeper than the usual 20 m to 30 m.

All measures to mitigate the project’s environmental impact will be carried out, the LTA said. These include reducing or relocating CRL construction sites that are close to ecologically sensitive areas.

The authority added that it will continue to engage stakeholders, including nature groups, when construction is under way.

Obayashi was involved in building Dhoby Ghaut station along the North-East Line (NEL), while Shanghai Tunnel Engineering is currently involved in the construction of Katong Park and Bayshore stations along the Thomson-East Coast Line (TEL).

Construction firm Woh Hup will build the CRL Punggol Interchange station, which is located in Punggol Central.

To minimise inconvenience to residents and motorists, the LTA said, traffic and utilities diversions to facilitate construction works will be done in phases.

The existing Punggol station will also undergo modifications to allow commuters to transfer between the NEL, the LRT line and the new CRL station.

Woh Hup is currently involved in the Tanjong Katong and Bayshore stations for the TEL, and the Kim Chuan Depot Extension. The company also completed the TEL Woodlands South station.

When the CRL Punggol extension is operational in 2032, commuters travelling from Punggol Central to Pasir Ris will be able to cut journey times by 25 minutes, from the current 40 minutes to 15 minutes.

The CRL is Singapore’s eighth MRT line. The first phase of the CRL was announced in 2019 and is 29 km long. Construction of the 12 stations under this stage has started and is expected to be completed by 2030.

The 15 km phase two, which has six underground stations from Turf City to Jurong Lake District, was announced in September 2022. When ready, the line will improve connections to the western part of Singapore.

LTA said details for the third stage of the CRL will be announced after ongoing engineering studies are completed.

The 7.3 km Punggol extension consists of four underground stations, three of which are interchange stations that will connect commuters to other lines.

Credit: Business Times