Longer waits for CCL trains from Jan 17 to April 19 due to tunnel works between three stations

SINGAPORE – Passengers using the Circle Line (CCL) will face delays of up to 30 minutes from Jan 17 to April 19, 2026, as work is carried out to strengthen the tunnels linking Mountbatten, Dakota and Paya Lebar stations.

This stretch of underground tunnels was built in soft marine clay, making them more prone to deformation. Minor defects such as water leaks have already surfaced.

Although there is no immediate safety risk, not addressing these defects in the tunnel structure could lead to severe service disruptions, said the Land Transport Authority (LTA) on Dec 1.

At three months, this will be one of the longest planned MRT service disruptions so far.

During this time,

shuttle trains will run on a single platform at 10-minute intervals

connecting Mountbatten, Dakota and Paya Lebar stations. This is up from the current three-minute frequency.

Passengers will need to switch to another train at Mountbatten or Paya Lebar to continue their journey on the CCL.

There will be slightly longer waits between trains along the entire length of the CCL during this period.

The 20-station stretch between HarbourFront and Paya Lebar will see peak-hour intervals rise from two to three minutes. Train intervals between Mountbatten and the Dhoby Ghaut and Marina Bay stations will also go up, from six to 10 minutes.

An average of 480,000 passengers will be affected each day.

Acknowledging that the tunnel works “will cause some inconvenience”, LTA advised commuters to factor in more waiting time.

Passengers should expect CCL interchange stations, such as Bishan, Serangoon and Buona Vista, to be crowded during morning and evening peak periods.

“During these periods, additional waiting time could extend to up to 30 minutes compared with typical travel times,” LTA said.

Passengers may also want to avoid the stretch between Mountbatten and Paya Lebar, and use other bus and rail connections instead, it said.

Several shuttle bus routes will also operate during weekday peak hours to provide alternative connections between various stations not affected by the works.

This will start on Jan 5, about two weeks before the start of the tunnel closure, so that passengers can familiarise themselves with alternative travel routes, LTA said.

Sixty-two shuttle buses will be deployed for a start, LTA said, adding that it would monitor demand and make adjustments if needed.

Those travelling during morning and evening peak periods may find it faster and more convenient to travel on other MRT routes, avoiding crowded stretches on the CCL, LTA said.

For example, passengers travelling from the north-east region on the North East Line (NEL) to one-north, Kent Ridge or Buona Vista can transfer to the CCL at HarbourFront, instead of making the transfer at Serangoon.

300 engineers, workers involved in 24/7 works

The CCL comprises 33 stations, 30 of which are in operation. The remaining stations – Keppel, Cantonment and Prince Edward Road – are expected to open by June 2026. LTA said it aims to complete the tunnel works before the opening of the remaining stations.

The tunnels connecting Mountbatten, Dakota and Paya Lebar stations will be closed one at a time to allow the installation of steel plates, LTA said. This affected 450m stretch also includes a portion of the tunnels between Stadium and Mountbatten stations.

These plates will reinforce the circumference of the tunnels, which were built in soft marine clay that gradually compresses over time. This can cause the circular tunnel to become more elliptical or oval-shaped in a phenomenon called “tunnel squatting”.

LTA said its expert consultants have confirmed that train operations can continue safely while the strengthening works are carried out.

Dr Goh Kok Hun, its group director of infrastructure design and engineering, said: “We have carried out engineering assessments and confirmed that the tunnels remain safe for rail operations.”

Minor defects, such as water leaks, had cropped up in the tunnels more prone to squatting, LTA said. These leaks have been sealed by grouting, a construction method that entails filling voids or cracks with a dense fluid mixture.

“While we have addressed these issues, we decided to carry out precautionary strengthening works to reduce the risk of affecting rail services if left unaddressed,” LTA said.

The authority said it has been monitoring the situation over the past decade, and had started studying possible long-term solutions in January.

LTA noted that this issue is not unique to Singapore, and that cities such as Shanghai, Taipei, Busan, Barcelona and Lisbon have encountered similar challenges and adopted comparable solutions.

The installation of steel plates requires heavy equipment, specialised machinery and multiple work teams. More than 300 workers and engineers will be deployed, supported by engineering wagons and locomotives equipped with robotic arms and cranes.

Because of the scale and complexity of the works, extended engineering hours are needed, and LTA opted to close the tunnels in turn, so that works can be carried out around the clock.

“We cannot rule out the need for further works, as tunnel squatting is the result of geological processes,” it added. “We will continue to monitor the tunnel and ground to ensure they have stabilised even after works are completed.”

Passengers can refer to LTA’s MyTransport.SG mobile app and social media platforms, as well as those of CCL operator SMRT, for more information.

LTA said it will also conduct roadshows and engage the public at some CCL stations and key transport points before the service adjustments start.

Posters and announcements will be rolled out at all CCL MRT stations and selected stations on MRT lines that intersect with CCL stations, LTA said.

Station staff will also be deployed at affected stations to help passengers, especially seniors and those with mobility issues.

Thanking the public for their understanding, Dr Goh said the works will “maintain the safety and reliability of our rail system for the long term”.

Similar tunnel works were conducted on the CCL in 2023 along the tunnel section between

Promenade and Nicoll Highway stations

, affecting services at seven stations. As the area is built on reclaimed land, the LTA said tunnels along this stretch had been “subject to greater pressure”. The service adjustments lasted about two weeks.

In November, Acting Transport Minister Jeffrey Siow said

Singapore’s rail network will see more planned closures

lasting longer to allow major MRT upgrades.

The current nightly maintenance window of about 3½ hours leaves only around two engineering hours, after factoring in the time needed to deploy and extract heavy equipment, which is insufficient for substantial works, he said.

An international panel of rail experts had also recommended extending scheduled shutdowns of network segments, so critical maintenance and renewal projects can be completed safely and efficiently.

Passengers brace themselves for longer journeys

Dakota resident Peter Wong, who works at the Marina Bay Financial Centre, usually spends about 30 minutes on his daily CCL commute. Mr Wong, 35, is concerned that the service adjustment may double his travel time.

The finance professional, however, said he intends to continue taking the train to work, as buses are often crowded in the morning and there is no shelter from the bus stop to his office building when it rains.

He also asked whether LTA had already known that some tunnels would need to be reinforced when it built the CCL.

Mr Ching Sheng Seng, lives between Mountbatten and Aljunied stations.

The 36-year-old’s journey to his workplace, a hospital laboratory near Little India, includes taking the CCL. The service changes will lengthen his journey, he said, and he has “no choice” but to wake up about 30 minutes earlier.

He will also have to wake his toddler earlier, to take her to school in Mountbatten by 7.30am.

Another Dakota resident, Mr Yao Guang, said he was surprised to learn of the planned service disruption. “I assumed that such works were done overnight,” said the 34-year-old.

Mr Yao, who works in advertising, said he would have to wake up about 30 minutes earlier to get to work on time. “LTA is doing their best in the given situation,” he said, and “residents will have to adjust”.

But he hopes that the authority will take into account passengers’ feedback when the service adjustments begin and try to ease their journeys during the three months.

For pre-school teacher Nadzirah Nazir, 32, the worry is that she will not get home on time to prepare dinner for her family. She lives in Pasir Ris, and while her husband drives her to her workplace in Dakota, she needs to get home by train.

“I have to make some changes,” she said. She intends to travel on other MRT lines to make it home, and finds it frustrating not knowing how long her journey would take.

“Grab might be expensive,” she added.