Greens MP Winfried Hermann, who is also chairman of the Bundestag’s transport committee, told the Passauer Neue Presse that rail operator Deutsche Bahn urgently needed to overhaul its trains. New trains should be fitted with more powerful air conditioners and the old rolling stock modernised, he said.

“One consequence has to be that new trains are designed for higher temperatures,” he said. “The air conditioners must be able to cope with outside temperatures of up to 45 degrees. You also have to expect greater extremes of cold.”

The revelation follows widespread condemnation of Deutsche Bahn over an incident last weekend in which the air conditioning system broke down on a high-speed ICE train, sending temperatures soaring to as much as 50 degrees Celsius. Federal police are investigating the incident, which put nine people in hospital, to see whether train staff acted negligently.

Deutsche Bahn boss Rüdiger Grube said he could not rule out further AC breakdowns in the coming days when temperatures are expected frequently to reach well above 30 degrees Celsius. On Thursday it was revealed that the air conditioning systems are only built to cope with temperatures of up to 32 degrees.

“We are making every effort that such things don’t happen,” he told broadcaster Deutschlandfunk, but added that he couldn’t make promises in “such extreme weather conditions.”

Grube added that an overhaul of the trains’ cooling systems was being examined. The older ICE models would be equipped with new cooling units that could cope with higher temperatures.

The general overhaul of the ICE II models would begin in the second half of the year, he said.

Replacing the air conditioner units had not previously been considered because there had not been conspicuous problems, he said – though this was naturally now being reviewed.

“We are analysing whether it wouldn’t be better to also rework the corresponding air conditioners,” he said.

Grube hit back at accusations the rail operator had cut back on maintenance and servicing in preparation for going public on the share market. Purchases of materials for long-distance trains had risen from €298 million to €405 million from 2004 to 2009, while maintenance staffing costs had been lifted from €84 million to €96 million over the same period, he said.

“Of course there is no excuse here,” Grube said, adding that the failures were “not acceptable.”

Nevertheless, the operator was following international standards in the way it had equipped its trains, he said.

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