Foundations for road tunnels about 50 per cent complete

Work on integrated transport corridor to be completed from 2027 after Covid-19 delay

- Kok Yufeng

A $7.47 billion project to build an integrated transport corridor from northern Singapore to the city is approaching the halfway point of its nine-year construction timeline, after Covid-19 delayed it by a year.

Work on the 21.5km North-South Corridor (NSC), which starts in Admiralty Road West and ends in East Coast Parkway near Republic Boulevard, started in 2018, and is on track to be completed from 2027 onwards.

Comprising an 8.8km viaduct in the north and 12.3km of underground road tunnels in the south, as well as continuous bus lanes and cycling trunk routes, the NSC promises to cut travel time from Woodlands, Sembawang, Yishun, and Ang Mo Kio to the city by up to 30 minutes when ready.

Providing an update on the progress of the project, the Land Transport Authority (LTA) told The Straits Times that the current work involves the installation of diaphragm walls and diversions of utilities and traffic that come with it - a key step before tunnel construction can begin.

Diaphragm walls are reinforced concrete walls that outline underground tunnels, acting both as a supporting structure during tunnel excavation and as a permanent foundation and wall after the tunnels are completed.

LTA has to make room for this construction work beforehand by diverting important utilities that cut across the NSC, such as power and telecommunication lines.