CLOVIS — A BNSF freight train derailed April 17 near Fort Sumner because a 51-degree swing in temperature created “a thermal misalignment in the track,” according to the company.
The eastbound train that derailed near the Pecos River Bridge northwest of Fort Sumner included 116 cars, 10 of which left the tracks and tumbled down an embankment. The train was traveling from Belen to Clovis when it left the track about 3:30 p.m. The cars were carrying grain.
“The temperature swing caused a thermal misalignment in the track,” said BNSF Director of Public Affairs Joe Faust.
Thermal misalignments are caused by tracks expanding and/or compressing because of temperature variations.
At a weather collection location five miles south of Fort Sumner, the National Weather Service reported the high temperature on April 17 was 85 degrees, and the low was 45 degrees.
On the day of the derailment, the National Weather Service recorded gusts of up to 53 mph, while sustained winds were at 37 miles per hour. According to National Weather Service wind-chill calculator, the wind chill would have brought temperatures to about 34 degrees.
With wind chill taken into consideration the track would have seen a 51-degree temperature swing.
Faust said the damaged tracks were repaired shortly after the derailment and normal traffic resumed.
“Even though we have crews that monitor, examine, and maintain the tracks, there are unforeseen circumstances that may result in a track misalignment,” Faust said. “This is one of those circumstances.”
There were no policy changes after the derailment, he said.
The April 17 derailment was the second to happen within a month in the Pecos River Bridge area. A derailment in March was a result of high winds.