US train engineer slammed on emergency brakes

The engineer of a US passenger train traveling at more than 150 km/h slammed on the emergency brakes just before it derailed in Philadelphia, leaving at least seven people dead, investigators said.

The speed was more than twice the approved limit, and the brakes barely slowed the train before the cars tumbled off the track late yesterday, leaving more than 200 people injured, some with broken ribs and collapsed lungs.

The National Transportation Safety Board cautioned that its first assessment of the data was preliminary, and that it would need more time to piece together what happened to Amtrak Train 188, headed from Washington to New York.

Experts were at the scene searching for evidence, and the locomotive and train cars were being moved to a secure location for analysis. The initial information came in part from the train's "black box" data recorders.

"Our mission is to find out not only what happened, but why it happened, so that we can prevent it from happening again," the NTSB's Robert Sumwalt told reporters, saying his team would be on the ground for a week.

The engineer's "full emergency brake application" only slowed the train speed from 170 km/h to 164 km/h, Mr Sumwalt said, noting: "It takes a long time and distance to decelerate a train."

The speed limit entering the curve was just 80 km/h.

He said a speed control system used along Amtrak's well-traveled Northeast Corridor between Washington and New York was not yet in place in the area of the crash.

"We feel that had such a system been installed in this section of track, this accident would not have occurred," he said.