Service Disruptions Service Disruptions

Rails in direct sunshine can be as much as 20℃ hotter than the air temperature. Because rails are made from steel, they expand as they get hotter, and this can cause defects. The rail network is monitored by a remote system, which measures the temperature of the track and the air temperature. When these reach a certain point, heat inspections are carried out. Temporary speed restrictions may be introduced in selected locations as a precautionary measure.

Normally, work is completed throughout the year to prepare the rail for warmer weather in Summer and to minimise the impact of speed restrictions due to heat. Rails are artificially stretched to allow room for expansion. This is called de-stressing. However, because of the extent of KiwiRail’s recent track repair and replacement work, significant sections of line are yet to be de-stressed. The de-stressing work is currently being undertaken and is due to be completed between March and April 2021.

As a result, the disruption caused by higher temperatures will be greater over the next few weeks, when temperatures are higher. These disruptions may impact services into the evening as rail temperatures reduce. To manage these impacts, selected services may be cancelled, which helps limit wider network performance impacts.

We continue to work with KiwiRail, ensuring they have access to the network to complete the de-stressing work as quickly as possible after track repairs and replacements are completed.

We apologise for any disruption to services that you experience as a result of these ongoing works.