“The upgrade work is beyond regular repairs and maintenance work that can be done within the two golden hours after daily services finish for the day,” said Lee Kim-hung, the MTR Corp’s chief of operations engineering and maintenance.

The MTR Corp and the government recently discussed the prospect of service disruptions with some lawmakers as a result of a HK$65 billion (US$8.3 billion), five-year investment plan, to 2027, to maintain railway assets.

On July 28, 50 large metal hangers used for more than 40 years to hang power cables from the ceiling of a tunnel near Yau Ma Tei station will be replaced. As the electricity supply will be cut off for the upgrade, services at Prince Edward, Mong Kok and Ho Man Tin will be suspended.

The corporation will take the opportunity to upgrade other tunnel facilities at the four stations.

Passengers on the Kwun Tong line will need to change over to the Tsuen Wan line at Prince Edward station only.

The Kwun Tong line will continue to operate between Tiu Keng Leng and Prince Edward, as well as between Ho Man Tin and Whampoa.

Prince Edward, Mong Kok and Yau Ma Tei stations will still be open for trains on the Tsuen Wan line, and Ho Man Tin station for the Tuen Ma line, as they do not share tunnels with the Kwun Tong line.

Cheris Lee Yuen-ling, the rail firm’s chief of operating and metro segment, said passengers would need to wait an extra minute or two.

“There are alternative routes within our network of 98 stations,” she said.

Those travelling between Yau Ma Tei and the next stop, Ho Man Tin, will have to circle through Jordan, Tsim Sha Tsui and Hung Hom stations.

Lee said the MTR Corp would pay for KMB routes 8 and 30X between Yau Ma Tei and Whampoa on July 28 so passengers would get free trips, with rail services to resume the next day.

04:27

The story behind Hong Kong's colourful MTR stations

The story behind Hong Kong's colourful MTR stations

Citybus said it would monitor its paid routes 20A, 106, 109, 115, 118, 795X, A25, E21A, E21B, E23 and E23A serving Prince Edward, Mong Kok, Yau Ma Tei and Ho Man Tin and strengthen services based on demand.

Lawmaker Michael Tien Puk-sun said: “The biggest challenge and my biggest worry is whether they can complete the upgrade within one day.”

The corporation will step up publicity about the July 28 arrangements, and encourage commuters to use the MTR mobile app for alternative routes to get to their destinations.

Quentin Cheng Hin-kei, spokesman for commuter concern group the Public Transport Research Team, said utilising franchised bus services to bridge the missing link between Yau Ma Tei and Whampoa was new.

He said the overall arrangements were acceptable as all 98 MTR stations would be operating on July 28 and commuters were unlikely to be seriously inconvenienced.

The MTR Corp said it would postpone the upgrade if a No 8 typhoon or adverse weather threatened the works, with efforts then delayed to August 4, the following Sunday.

Lawmaker Gary Zhang Xinyu, who used to work as an operations manager at the MTR Corp, said the upgrade was a priority as ageing equipment was like a time bomb and posed safety hazards.

The Kwun Tong line came into service in 1979 and was subsequently expanded to run between Whampoa in Hung Hom and Tiu Keng Leng in Tseung Kwan O, with 17 stations. The Tsuen Wan line, with 16 stations between Tsuen Wan and Central, debuted in 1982.

The asset review last year was triggered by two high-profile incidents in 2022.