MONTPELIER, Vt. (AP) — Special fences protect railroad tracks from rock slides in some parts of the country, but the head of Amtrak said Tuesday it's unclear if the mechanisms could have prevented a derailment that injured seven people in Vermont.
The fences are installed in known rock-slide areas and are designed to send signals if they are hit with debris, Amtrak CEO Joseph Boardman said.
Boardman said slide fences are used in parts of New York, but Vermont transportation officials said it's not believed that any are in the state.
"Whether it would work here or not it's unclear, I don't know," Boardman said of the location where the Amtrak Vermonter derailed Monday morning, pitching two cars over a steep embankment and derailing three others.
The National Transportation Safety Board is now investigating the derailment. The investigation could take some time, Boardman said at a news conference.
"They will make recommendations once they find out, confirm the reasons for this derailment, of something that will help," he said.
The Vermonter was carrying 98 passengers and four crew members when it hit rocks that had fallen from a ledge onto the tracks in Northfield, about 20 miles south of Montpelier. The crash sent the locomotive and first car down an embankment.
Gov. Peter Shumlin said the most seriously injured person, a conductor who had been in the locomotive along with the engineer, was released from the hospital Tuesday.
Boardman said he felt "very blessed and thankful" none of the injuries was more severe.
Numerous derailments around the world have been caused by debris on tracks, many linked to heavy rains that trigger slides. In 2010, a train in Beijing hit mounds of debris left on the track following a landslide, killing 19 people.
Federal safety rules for tracks that carry passengers require at least two inspections every week, with at least one day between inspections. A freight train had gone through the area where the Amtrak derailment occurred Sunday night with no problem.
Rock slides are common in Vermont, but most occur in areas where they don't affect people or property, said state geologist Marjorie Gale.
The Vermont Transportation Agency has developed a rating system for rock-slide danger along the state's major highways. In a number of locations the ledges have been cut back to reduce the risk of rocks falling into travel lanes.
The system has not been applied to the state's rail lines.
Slide fences as described by Boardman are typically used in areas with a history of rock slides, said Amtrak spokesman Craig Schulz.
It's unclear if the area where Amtrak derailed Monday had such a history.
Transportation Secretary Chris Cole said after the news conference he did not believe any of the rock-slide warning systems are in use anywhere in Vermont.
Cole said fences that are designed to keep rock from falling into roadways — without sending a warning signal — are in use in different parts of the state.
Shumlin said that in spite of all the money spent on those highway projects, rocks still fall from ledges.
"The point is the nature of ledges. It cracks, it moves, it slides, whether it's on a highway or a rail bed," Shumlin said.
Meanwhile, cleanup of the site of the Northfield derailment was underway Tuesday, and Shumlin said it's hoped the line can be reopened by the weekend.
About 900 gallons of diesel fuel that had been in the locomotive when it crashed is unaccounted for, but emergency crews have found no evidence it reached the stream below where the derailment occurred.
While the track is out of service, passengers scheduled to travel on Amtrak will be carried by bus to and from Springfield, Massachusetts.