Some train services on the Wairarapa Line were forced to travel at reduced speeds due to heat restrictions last week, causing delays for travellers.
However, on the upside, upgrades to the line between Upper Hutt and Masterton have reduced additional journey time due to heat restrictions from 16 minutes in 2021 to 3.5 minutes
as of October this year, according to KiwiRail chief planning officer David Gordon.
“Heat restrictions are a common problem with rail networks around the world,” Gordon said.
As rails are made from steel, the metal expands as it gets hotter, which can then cause misalignments on the tracks, he said.
“Temporary speed restrictions are sometimes introduced as a precautionary measure.”
The rail network is remotely monitored and when the rail temperature reaches a certain point, usually 40 degrees Celsius, inspections are done.
Gordon said work is done throughout the year in preparation for the warmer temperatures, minimising the need for heat restrictions and the interruptions they cause.
“An extensive amount of heat de-stressing takes place across the network each year,” he said.
“This involves stretching the rail to protect against track buckling during hot weather.”
Rail asset engineers are tasked with regular inspections of the network, and they will apply speed restrictions in any instances where the section of line does not meet the required standard.
The heat season for the rail tracks, where temperatures can reach about 40degC, runs from October through to the end of March.
Have track temperature always been same if yes then why did they weld all the expansion joints 🤔? That’s right they went click click click to noisy. Put some expansion joints back in ? Just an idea 💡.