Earlier today, two German interurban trains collided near Bad Aibling, with loss of at least ten lives.
The trains collided at a bend on the Mangfall Valley Railway, a single-track regional rail line between the towns of Rosenheim and Holzkirchen, German Transport Minister Alexander Dobrindt said.

"There's a curve there, so we must assume that the train drivers must not have been able to see each other beforehand," he told reporters at a news conference.

One of the trains had "drilled" into the other, he said, leaving a carriage "totally dismantled."

He described the scene as a "horrible picture," saying it was estimated the trains had been traveling about 100 kph (62 mph) at the moment of impact.
The circumstances and the aftermath summon memories of the Labor Day, 1950 fatal collision on Milwaukee's Speedrail.

Movements of these German interurbans, however, are under the protection of what the Germans abbreviate as PZB (Punktförmige Zugbeeinflussung) which we render in railroadese as intermittent Automatic Train Stop.
Under normal conditions, the devices are used to stop trains travelling at up to 160mh/h from ending up heading towards each other on the same line.

The system uses magnets set up on the track bed to communicate with a device on board the train.

Magnets are placed at a pre-signal and again 1,000 metres further on at the main signal. If the main signal is showing a red light, this is also shown on the pre-signal, which will then set off an alarm in the driver's cabin.

Train drivers must press a button within four seconds of the PZB alarm sounding to confirm that they have seen the pre-signal – or else the train is automatically braked by the PZB system.
Our sympathies are with the families of the passengers and crew. The investigation might prove interesting.

German railroads currently use a form of continuous automatic train control on faster lines.  I wonder if there will be a mandate to install positive train control or to apply the continuous control on all passenger lines.

No comments: