BERLIN, Sept 26 — After successive summer heatwaves Germany’s public rail operator Deutsche Bahn is testing white-painted rails designed to reflect some rays and protect them from heat damage.

Experiments this summer succeeded in keeping the rails cooler, the firm said in a statement, meaning DB will now extend them to a kilometre-long stretch on the high-speed line between northern city Hanover and centrally-located Wuerzburg — one of the country’s busiest.

The environment-friendly paint’s resilience to dense traffic will be thoroughly tested on a 61-metre-high bridge near Melsungen in the federal state of Hesse.

Within a year, results should "form the basis for the extension of the project to other routes,” DB said.

As steel expands in the heat, longer, hotter summers can damage rails and the rail bed.

Initial tests have found white rails reflect more light and heat up "significantly less” than normal ones.

Swiss rail operator CFF has already tested white-painted rails, alongside spraying them with cool water.

Other options for DB include "extensive vegetation management” and high-tech solutions like aerogels or "new findings from bionics”, the company said. — AFP-Relaxnews