Venting and burning began about 4:40 p.m. on February 6, 2023. The preliminary record shows the decision, not that it was necessary.

What these records can and cannot carry

The report records that the venting happened, roughly when it began, the concern that preceded it, and the protective steps reported with it. It does not record the measurements, alternatives or criteria that would show a rupture was imminent or that venting and burning was the necessary choice.

Three wayside warnings, in the order the train passed them

Each number is the suspect bearing on the 23rd car, in degrees Fahrenheit above ambient, recorded by a hot bearing detector beside the track. These are bearing readings, not tank-car temperatures. The report gives no ambient temperature and no clock time for any of the three passes.

From first to third detector the reading rose 215°F above ambient over 30.09 milepost miles. The order and spacing are reported; the elapsed time is not.

Inspect a detector

Detector source ledger

What happened, at the time resolution the report gives

Solid badges carry a date or approximate clock time printed in the report. Dashed badges mean the report gives order only, or no date. Nothing here is interpolated from speed or distance.

1. Order only; no date or clock time reported

   Train 32N passes the first hot bearing detector, at MP 79.9; suspect bearing reads 38°F above ambient.

   First of three detector passes the report places before the derailment.

   Train 32N passed three HBD systems on its trip before the derailment.

   At MP 79.9, the suspect bearing from the 23rd car had a recorded temperature of 38°F above ambient temperature.

   Source: Preliminary report RRD23MR005, PDF p. 3, issued February 23, 2023.

2. Order only; no date or clock time reported

   Train passes the next detector, at MP 69.01; bearing reads 103°F above ambient.

   Report calls it the next detector.

   When train 32N passed the next HBD, at MP 69.01, the bearing’s recorded temperature was 103°F above ambient.

   Source: Preliminary report RRD23MR005, PDF p. 3, issued February 23, 2023.

3. Order only; no date or clock time reported

   Train passes the third detector, at MP 49.81, under dynamic braking; bearing reads 253°F above ambient and the detector sends a critical audible alarm to slow, stop and inspect a hot axle.

   Report calls it the third detector.

   Train 32N was operating with a dynamic brake application as the train passed a wayside defect detector on the east side of Palestine, Ohio, at milepost (MP) 49.81.

   The third HBD, at MP 49.81, recorded the suspect bearing’s temperature at 253°F above ambient.

   The wayside defect detector, or hot bearing detector (HBD), transmitted a critical audible alarm message instructing the crew to slow and stop the train to inspect a hot axle.

   Source: Preliminary report RRD23MR005, PDF pp. 2, 3, issued February 23, 2023.

4. After passing MP 49.81; order within this group partly stated

   The emergency brake application came during the deceleration the engineer began. The report does not state whether the derailment began before, during or after these brake events.

   1. Order only; no date or clock time reported

      Engineer increases the dynamic brake application to slow and stop.

      Reported as the response to the alarm.

      The train engineer increased the dynamic brake application to further slow and stop the train.

      Source: Preliminary report RRD23MR005, PDF p. 3, issued February 23, 2023.

   2. Order only; no date or clock time reported

      Automatic emergency brake application initiates during the deceleration; train comes to a stop.

      Report says it happened during this deceleration.

      During this deceleration, an automatic emergency brake application initiated, and train 32N came to a stop.

      Source: Preliminary report RRD23MR005, PDF p. 3, issued February 23, 2023.

   3. about 8:54 p.m., February 3, 2023

      Derailment of 38 railcars at about 47 mph.

      After all three detector passes; its position relative to the brake events is not stated.

      On February 3, 2023, about 8:54 p.m. local time, eastbound Norfolk Southern Railway (NS) general merchandise freight train 32N derailed 38 railcars on main track 1 of the NS Fort Wayne Line of the Keystone Division in East Palestine, Ohio.

      Train 32N was traveling about 47 mph at the time of the derailment, which was less than the maximum authorized timetable speed of 50 mph.

      Train 32N passed three HBD systems on its trip before the derailment.

      Source: Preliminary report RRD23MR005, PDF pp. 1, 2, 3, issued February 23, 2023.

5. Order only; no date or clock time reported

   After the stop, crew sees fire and smoke and notifies the Cleveland East dispatcher of a possible derailment.

   Report says this was after the train stopped.

   After the train stopped, the crew observed fire and smoke and notified the Cleveland East dispatcher of a possible derailment.

   Source: Preliminary report RRD23MR005, PDF p. 3, issued February 23, 2023.

6. February 5, 2023; no time of day

   Responders mitigate the fire.

   Dated in the report; year taken from the derailment date in the same report.

   On February 5, responders mitigated the fire, but five derailed DOT-105 specification tank cars [...] carrying 115,580 gallons of vinyl chloride continued to concern authorities because the temperature inside one tank car was still rising.

   Source: Preliminary report RRD23MR005, PDF p. 3, issued February 23, 2023.

7. February 5, 2023; no time of day

   Five derailed vinyl chloride tank cars still concern authorities because the temperature inside one tank car is still rising; no value is reported.

   Same dated sentence as the fire mitigation.

   On February 5, responders mitigated the fire, but five derailed DOT-105 specification tank cars [...] carrying 115,580 gallons of vinyl chloride continued to concern authorities because the temperature inside one tank car was still rising.

   This increase in temperature suggested that the vinyl chloride was undergoing a polymerization reaction, which could pose an explosion hazard.

   Source: Preliminary report RRD23MR005, PDF p. 3, issued February 23, 2023.

8. Not in the report

   Between the reported rise and the venting, the report gives no tank temperature value, unit, reading time, rate, car number, measurement method or pressure reading.

9. Date not stated

   Responders schedule controlled venting, expand the evacuation zone to a 1 by 2 mile area, and dig containment ditches.

   Reported as a response to the concern; scheduling must precede the venting it scheduled. No date is given.

   Responders scheduled a controlled venting of the five vinyl chloride tank cars to release and burn the vinyl chloride, expanded the evacuation zone to a 1-mile by 2- mile area, and dug ditches to contain released vinyl chloride liquid while it vaporized and burned.

   Source: Preliminary report RRD23MR005, PDF p. 3, issued February 23, 2023.

10. about 4:40 p.m., February 6, 2023

    Controlled venting and burning of the five vinyl chloride tank cars begins and continues for several hours.

    Dated and timed in the report; year from the derailment date.

    The controlled venting began about 4:40 p.m. on February 6 and continued for several hours.

    Source: Preliminary report RRD23MR005, PDF p. 3, issued February 23, 2023.

11. February 23, 2023 (issue date)

    Preliminary report issued (evidence cutoff).

    Issue date printed on the report.

    Issued: February 23, 2023 Preliminary Report RRD23MR005

    This information is preliminary and subject to change.

    Source: Preliminary report RRD23MR005, PDF p. 1, issued February 23, 2023.

Reported observation, preliminary interpretation, and what is not yet established

Narrowest defensible public statement

First record to request

Unanswered by this record

• At what clock times did train 32N pass the detectors at MP 79.9, 69.01 and 49.81, and when did the critical alarm sound?
• What was the ambient temperature at each detector? Without it, the absolute bearing temperatures are unknown.
• Did the detectors at MP 79.9 and MP 69.01 send the crew any message?
• What did the other bearing on the same axle read? The 115°F same-axle criterion cannot be applied without it.
• At what milepost did the derailment begin, and how far was that from the MP 49.81 detector?
• Did the derailment begin before, during or after the automatic emergency brake application?
• Do the milepost differences equal track miles between the detectors?
• What internal tank-car temperatures were read, in what unit, at what times, and how fast was the rise?
• Which of the five vinyl chloride tank cars showed the rising temperature?
• How, where on the car and by whom was the tank temperature measured?
• Were tank pressures read, and did any pressure relief device operate?
• Was a polymerization reaction actually under way in any car?
• Was a tank rupture expected, and on what time scale?
• Which organization or person decided to vent and burn?
• When was the controlled venting scheduled?
• Which alternatives were weighed, and by what criteria was venting and burning chosen?
• Why were all five cars vented when a rising temperature is reported for one?

What the report says about named organizations

Complete source ledger

Every excerpt used on this page, verbatim, with its PDF page. Bracketed dots mark text left out between two exact segments.