Auckland Transport (AT) says potentially one in three train services will be cancelled from 3pm today and the commuter chaos could run through summer and into March.

AT’s director of public transport, Stacey van der Putten, said trains have not stopped but potentially every third train will be cancelled at peak hours. An AT spokesperson said some days may see a third of trains cancelled but on other days more services could operate.

From 3pm today, 19 services will be cancelled - due to restrictions on the city’s rail network.

Trains across Auckland were cancelled yesterday afternoon due to the “heat” - causing significant disruption to rush-hour commuters. By 7pm, 35 trains had been cancelled.

Today, AT confirmed that 80 total train services were cancelled yesterday. Of those, there were 30 cancellations related to temporary speed restrictions on the network. 24 cancellations related to heat which were in part caused by the other speed restrictions, 15 cancellations related to a temporary train manager shortage and 11 cancellations due to a passenger alarm being activated and the train being temporarily disabled.

“Today we’re looking at about one in six,” an AT spokesperson said.

“Different per day ... Slightly different each hour and different on different train lines. One in three is what we had to deal with yesterday. Realistically going forward, that is a likely something we’re going to see.

“Potentially, every third train will be cancelled in order to maintain a productive network, otherwise it just wouldn’t work.”

KiwiRail said the heat had caused the steel in the rail lines to move if the trains pass over them too quickly, leading to speeds on the line being slowed and subsequently fewer services being able to run.

Van der Putten said with the current weather conditions, there will be restrictions on the lines until the underlying problems are resolved.

The issues could continue until March, van der Putten said.

She said off-peak trains run at a frequency that is not affected by the restrictions but during the peak hours when trains are running every 10 minutes, the services had to be staggered.

AT plans to issue messages about the cancellations today.

Auckland Mayor Wayne Brown is hauling transport bosses into his office to explain ongoing train disruptions and to stop the blame game.

“The frequent disruptions on the Auckland train network have become unacceptable,” Brown raged yesterday.

In a letter to AT chief executive Dean Kimpton, KiwiRail chief executive Peter Reidy and One Rail chief executive Martin Kearney, whose company runs the city’s trains, Brown has asked for a meeting to explain what is being done to fix the disruptions and quickly restore public confidence.

The latest disruptions follow KiwiRail’s two-plus years $330 million rebuild of large parts of the metro network affecting the northern, southern and eastern lines from 2022, designed to prepare the existing network for the City Rail Link, due to open in 2026.

This work followed two years of shutdowns and speed restrictions in 2020 and 2021 to replace track and sleepers.

In a 2022 report on the governance of the CRL, Auditor-General John Ryan said AT and KiwiRail have signalled that between now and 2036, a further $7.5b will have to be spent on the rail network to realise the full benefits of the CRL.

The $7.5b bill is for additional tracks and trains, lengthening platforms for 9-car trains, removing all level crossings on the southern and western lines, and a signalling upgrade.