North-South Corridor opening delayed to 2029 in Singapore

In Novena, broken rock and underground water seepage required additional preparatory works, along with a different and more complex mining method to ensure that the construction would not put the North-South MRT line at risk. An MRT line that is in operation is located just 1m away from the NSC tunnels.

Works in the Thomson area were affected by harder-than-expected rock formations underground, requiring rock blasting and ground stabilisation works before excavation could proceed.

When asked if completion dates could change again, an LTA spokesman said construction is being closely monitored and LTA will continue to work with contractors to manage the remaining works and address challenges promptly.

As for the extra costs caused by the delay, that can be determined only after the project is completed, the spokesman added.

When asked how any cost overrun will be calculated, the spokesman said figures will be compared against information provided to tenderers during the tender process.

LTA added that it expects contractors to have taken into account the construction risks involved when pricing their bids.

The contractors can submit claims if the actual ground conditions differ from the baseline information provided. LTA will assess the claims and consider additional payment if they are found to be valid under the provisions of the contract.

On Sept 15, reporters were allowed access to a work site in Novena, and could view the stretch between Revenue House and Novena Square, where the NSC crosses the North-South MRT Line.

At this section, the northbound and southbound NSC tunnels are stacked, with the MRT line sandwiched between them.

While the southbound tunnel has been completed, tunnelling is still under way for the northbound tunnel that passes below the MRT line.

The northbound tunnel needs to be excavated in two stages because of the distinct ground conditions. The top half of the tunnel cuts through softer ground with water seeping in, while the bottom half is built by excavating through solid rock.

For the top half, large tubes are inserted into the ground and steel support frames are erected to stabilise the ground and prevent the soil from loosening.

After excavators have advanced the tunnel by around 2m, concrete is sprayed onto the exposed surface to stabilise the ground. Another set of steel frames is then installed before excavation continues.

Excavation of the top half of the tunnel is expected to finish by 2026, before work can begin on the bottom half.

Controlled blasting will then be used to break the hard rock, as part of the mining work. This stage of the construction is projected to take up to 2028.

NSC construction works began in 2018, and were expected to end by 2026. However, the Covid-19 pandemic hit all building projects in Singapore, and the NSC end date was pushed back to 2029.

When completed, the NSC is expected to ease congestion on the Central Expressway and major arteries like Thomson Road and Marymount Road.

It will also widen access to upcoming developments in the northern region and link to key expressways like the Seletar Expressway, Pan-Island Expressway and East Coast Parkway.

With traffic being channelled away, the streets – in the future – will give priority to public transport, pedestrians and cyclists, while making more room for community spaces.

But for now, businesses and residents along the route face prolonged disruption.

“That will be a big problem,” said Eason Olongayo, manager of Tipsy Tikka restaurant at Novena Regency. “Every month, we’re losing money.”

“We barely get any walk-ins at all, so we’ve been trying everything to pull customers in, but it’s too hard to break even,” he said.

Dennis Chia, who lives in Marymount Road, said: “We have no other option… We just have to get through this together.”