Safety system was being installed at crash site

Railway signals were out while crews installed a safety system that could have prevented the exact type of crash that killed two people in South Carolina when an Amtrak train was diverted to a side track and slammed head-on into an empty freight train, authorities said Monday.

Automated signals that could have warned the passenger train to stop before reaching the switch sending it down the side track were turned off as workers installed a GPS-based system called positive train control, or PTC, National Transportation Safety Board Chairman Robert Sumwalt said.

A day before, Sumwalt told reporters “an operational PTC is designed to prevent this type of incident.”

The crew that parked the CSX freight train on the side track and left the padlocked switch in position to divert trains from the main line were interviewed Monday, along with the dispatcher keeping up with trains in the area as the signals weren’t working, Sumwalt said.

Sumwalt told reporters he had not been briefed about what the CSX workers said.

The Amtrak engineer sounded his horn seven seconds before the crash and applied emergency brakes three seconds before the train collided with the other locomotive at 50 mph, Sumwalt said, citing information from the passenger train’s data recorder.

“The expectation for the Amtrak crew is that they were clear,” Sumwalt said.

Positive train control is already installed in parts of the U.S. The system is designed to prevent two trains from travelling on the same track at the same time.

That’s what happened early Sunday in Cayce, South Carolina, when the New York-to-Miami Amtrak passenger train hit the parked CSX Corp. freight train.