Last week the authority said it closed lines between Linköping and Kalmar, Linköping and Västervik, and Berga and Oskershamn due to the heat.
“The unique thing about these closures is they affect passenger trains. Usually it largely only applies to goods and freight trains,” Joanna Ljunggren from Trafikverket explained.
Trafikverket is concerned the heat may cause parts of the tracks to buckle or shift, a phenomenon known as “sun kinks”, with freight trains generally the ones that run on the sections most sensitive to the heat.
Two freight trains have already derailed in Sweden in July – one near Mariannelund and one outside Nyköping.
“Sun kinks happen every summer really, but this year there are far more because it’s so warm. It’s a record year,” Ljunggren noted. Trafikverket expects there to have been more than double as many compared to 2017.
Last year there were 20 sun kinks reported, but this year the figure is likely to be around the 90 of record-setter 2008.
“We can’t rule out more closures, even though we have no indications of it just now. We’d rather close down and put safety first,” Ljunggren concluded.