NTSB releases preliminary report of July train derailment in Mississippi

The National Transportation Safety Board last week published a preliminary report regarding the July 6 derailment of a CN train on the Grenada Railroad near Sardis, Mississippi, which resulted in a release of hazardous materials but no injuries. 

Twenty-one mixed freight cars derailed on the south end of a 130-foot-long bridge. The derailed equipment included four tank cars, two containing sulfuric acid and two containing sodium hydroxide. One of the tank cars was mechanically breached during the derailment and released about 10,500 gallons of sodium hydroxide, the report states.

The train crew consisted of one engineer, one conductor and one Grenada Railroad pilot who was operating on the Grenada Railroad to bypass a track outage on CN’s Yazoo Subdivision because of a derailment that occurred the previous day in Glendora, Mississippi.

At the time of the accident, the train was traveling about 24 mph —the maximum authorized speed at the location of the derailment was 25 mph — when an undesired emergency automatic brake application was initiated when the train’s air brake line lost pressure.

The investigation is ongoing. Future investigative activity will focus on Grenada Railroad track and bridge maintenance procedures, CN operating rules related to train operation and assembly, and in-depth analysis of event and image recorder data, according to the NTSB. In addition, rolling stock engineering and manufacturing processes will be reviewed as they relate to the derailed cars.