Accident Investigation Animation

Railroad Accident Investigation:
Derailment of Amtrak Train No. 58, City of New Orleans, near Flora, Mississippi, April 6, 2004

Video is available in wmv format, and was presented at the Board meeting July 26, 2005 in Washington, D.C., for the Flora, MS Railroad Accident Investigation.

Disclaimer: This three dimensional animation shows railroad track features in the accident of Amtrak Train Number 58, City of New Orleans, which derailed near Flora Mississippi on April 6, 2004. This animation is for representational purposes only and does not depict weather or visibility conditions at the time of the accident. The accident occurred on track owned and maintained by the Canadian National Railway Company.

This animation graphically demonstrates track features present in the accident, and shows how the train derailed as it moved over a bowed portion in the right rail. TrackFeatures.wmv Video = 3.84MB Running Time: 00:02:20 Includes audio narration

Narration:

This animation graphically demonstrates track features present in the accident. On January 29th, a welding crew arrived to replace a segment of the rail. The blue rail represents the rail that was removed. The rail temperature was 60 degrees Fahrenheit at the time of the replacement. Let's look at the rail contraction in detail.

As the arrow indicates, when the welder cut the rail, it rapidly contracted because the steel was cold. Therefore, the gap between rail ends became larger. The red rail represents the rail that was inserted. The replacement rail had to be two and a half inches longer than the rail that was taken out.

About two months after the rail segment was replaced, with warmer spring weather, the rail temperature had increased significantly, producing expansion of the continuously welded rail. On the day of the accident, the rail temperature had increased to about 114 degrees Fahrenheit due to the warmer temperatures and radiant heating of the rail by the sun.

The excess rail from the winter repair and the lack of adequate rail restraints allowed the rail to expand above the shoulder of the tie plates at this location. The rail moved upward and then outward, creating a "bow" in the rail that allowed the train's wheels to drop in between the rails.

This arrow shows the direction of the accident train. Please note the wide gage condition ahead of the arrow. The train derailed as it moved past this bowed portion in the right rail.

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