[ CNN.com ]
To celebrate the 175th anniversary of Switzerland's first railway, the country's rail industry came together to run the world's longest-ever passenger train -- 100 cars, 2,990 tonnes and almost two kilometres long.
Formed of 25 new "Capricorn" electric trains the record-breaking 1,906-meter train took almost an hour to cover around 25 kilometers (about 15 miles) over the spectacular UNESCO World Heritage Albula Line from Preda to Alvaneu in eastern Switzerland.
In less than 25 kilometers, the train plummeted from 1,788 meters above sea level at Preda to 999.3 meters at Alvaneu, using a succession of spirals, soaring viaducts and tunnels.
...a route with notoriously tight curves, steep gradients, 22 tunnels and 48 bridges over deep valleys...
"We all know the Albula Line very well, every change of gradient, every incline," said lead driver Andreas Kramer, 46, ahead of the big day. "It goes without saying that we're going through the process again and again."
He added: "We need to be 100% synchronized, every second. Everyone has to keep their speed and other systems under control at all times."
An initial test run ended in failure before the train had even moved when it was discovered that the emergency brake system could not be activated and the seven drivers could not communicate with each other via radio or cellphone in the many tunnels.
Kramer, assisted by six other drivers and 21 technicians instead used a temporary field telephone system set up by the Swiss Civil Protection organization to maintain communications as the train ran at up to 35 km/h through countless tunnels and deep valleys.
Specially modified software and an intercom between the seven drivers allowed the 25 trains to work in harmony. Any mismatch in acceleration or deceleration during the journey would have exerted unacceptably high forces on tracks and power supplies, creating a major safety issue.