Heat cuts Koralmbahn Railjet speeds and causes delays

Railjet trains on the Koralmbahn route were limited to 200 km/h instead of their advertised 230 km/h because of high temperatures, causing delays of several minutes, ORF reported. The restriction applied from the end of July until Friday.

Herbert Hofer, a spokesman for Austrian Federal Railways, or ÖBB, said the measure was necessary for safety. At high temperatures, power converters in the locomotives can overheat.

Power converters are electrical devices that transform electricity from the overhead lines for use by the main motor. According to information obtained by ORF Kärnten, the maximum speed would have to be reduced to 160 km/h if a converter reached more than 44 degrees Celsius. Hofer said that threshold had not been reached so far.

ÖBB Railjets have been travelling at their usual 230 km/h since Friday, Hofer said. It remains unclear why the safety instruction was lifted despite continuing high temperatures. Hofer said it had applied for a predetermined period, but a renewed speed restriction in the coming days could not be ruled out. ÖBB is monitoring converter temperatures more closely, he said.