The National Transportation Safety Board (NTSB) on Sept. 25 released the final report for its investigation of the March 9, 2023, derailment of a Norfolk Southern (NS) train on the Alabama East End District of its Gulf Division near Anniston, Ala.
The accident’s probable cause, according to the NTSB report (download below), “was the combination of the coupling together of two revenue waybill locomotives without alignment control couplers, in violation of Norfolk Southern Railroad rules, and excessive in-train forces created due to the build of the train. Contributing to the accident was the misidentification of couplers without alignment control during the Norfolk Southern Railroad inspection process.”
What Happened?
On March 9, at about 6:19 a.m. local time, westbound NS freight train 245A109 derailed two locomotives and 37 railcars. The derailment involved two sections of the train, resulting in two derailment sites. At the first site, located at the front of the train, two locomotives and 29 railcars derailed. At the second site, located near the rear of the train, eight railcars derailed. Three of the cars that derailed were tank cars carrying hazardous materials (hazmat); they remained intact and did not release hazmat. There were no fatalities or injuries, according to the NTSB, and NS estimated the damages to equipment, track, and signal infrastructure to be approximately $2.9 million. The federal agency noted that the visibility conditions were clear, with early morning daylight, and the weather was 57 degrees F with no precipitation at the time of the accident.
The crew of train 245A109 comprised one engineer and one conductor. The train was composed of six locomotives at the head end and 108 railcars; 34 railcars were loaded, 74 were empty, and two of the locomotives were being transported as waybill locomotives from Bluffton, Ind., to Mobile, Ala. The revenue waybill locomotives “were not equipped with alignment control couplers, which resist lateral coupler movement under compressive in-train forces,” according to the NTSB. “NS operating rule L-212 prohibits coupling together locomotives without alignment control couplers. The revenue waybill locomotives were coupled together and picked up from Bluffton, Ind., on Feb. 24, 2023. An NS inspection performed before the first movement involving the coupled waybill locomotives did not identify the absence of alignment control couplers.” The NTSB noted that the revenue waybill locomotives “were moved by four other trains before being added to train 245A109 on the day of the derailment.”
According to the NTSB, the first four locomotives in the consist were high-horsepower and owned by NS and Union Pacific. Two of the units were producing tractive and dynamic braking effort and the other two were isolated and not producing tractive or dynamic braking effort. RMEX 06 and 08, NTSB noted, were the fifth and sixth locomotives in the consist and were not used for tractive power or braking.
NTSB Analysis
The NTSB covered the following two safety issues:
1. “The coupling of locomotives RMEX-06 and -08, both equipped with nonalignment control couplers in violation of NS rules, exacerbated by these improper couplers not being identified during mechanical inspections.” According to the federal agency, an NS mechanical department employee conducted “in-tow locomotive inspections in Bluffton, Ind.,“ and “NS LDI 1-21 provides instructions and guidance to the mechanical department employees for completing this inspection. The mechanical employee completed the In Tow Unit Inspection Form … as required by NS LDI 1-21. In both cases, the mechanical employee checked the box “Yes” for the question, ‘Is this unit equipped with alignment control draft gear?’ The follow-up question, ‘Are stop blocks applied?’ was also checked yes. The presence of the stop blocks could have alerted the mechanical employee to the fact that the couplers on the locomotives were not alignment control couplers; however, it did not.” The NTSB said that in a post accident interview with the Federal Railroad Administration, the “mechanical employee stated that he did not know what an alignment control coupler was at the time of the inspection.” The NTSB noted that “[h]ad the mechanical employee been equipped with job aids in the field, support contacts for technical questions, references to the correct applicable NS rules, and information related to the risks associated with the use of nonalignment control couplers, the inspection and clearance of the locomotives could have been more accurate, and the pair of locomotives would have been moved in a special train or been uncoupled and moved in separate trains.”
Following the inspection of the RMEX locomotives, inspection forms were submitted via email to the NS clearance desk, the NTSB reported. ”Clearance desk employees questioned field mechanical leadership in Bluffton, Ind., concerning both boxes being marked ‘Yes’ for alignment control couplers and stop blocks being installed on the RMEX-08 form,” it reported. ”NS officials at the clearance desk asked if the mechanical employee who conducted the inspection had verified the presence of alignment control couplers and stop blocks. Further conversations between the clearance desk and field mechanical leadership gave the impression that stop blocks had been applied to the locomotive and the moves were approved without clarifying why both boxes were marked ‘yes.’”
The NTSB pointed out that the email communication between NS clearance desk and mechanical department officials “represented an opportunity for the railroad to catch the mistakes on the … forms, namely, that the locomotives were not equipped with alignment control couplers, despite indications on the forms that they were present.” Additionally, “[d]espite their awareness that something was not correct on the forms (both boxes should not be checked yes), NS did not hold movement of the train until verification of the type of couplers present occurred and the application of appropriate remedies applied (such as removing one or both locomotives in the train consist),” according to the NTSB. “It is not sufficient,” the NTSB said, “to simply state that the locomotive has stop blocks in place, as the stop blocks do not provide a centering force to the couplers in the same way an alignment control coupler. Even with the stop blocks applied, the movement of the two locomotives together was prohibited by NS rules. Therefore, the two locomotives coupled together could still be a risk to jackknife, leading to a rail-rollover event.”
Had NS provided mechanical job aids “that clearly stated that coupler stop blocks are not a replacement for alignment control couplers, and that the revenue waybilled locomotives must still comply with NS rule L-212, the locomotives would not have been coupled together and the derailment may have been prevented,” the NTSB said. “With the RMEX locomotives incorrectly identified as having alignment control couplers, the clearance notice did not include the warning language printed in red at the top of the notice to warn and provide guidance to employees in the field.”
2. “Train build rules that allowed the train to be built in a manner that excessively increased in-train forces on the head end of the train and locomotive consist.” According the NTSB, with the placement of a block of 32 empty cars in the head portion of the train and the loaded intermodal equipment that contained five well intermodal cars on the rear, train 245A109 “was not in compliance with NS’s equipment restriction rules.” However, the NTSB said, “the inclusion of the phrase ‘when practicable’ in these equipment restriction rules allowed NS the ability to prioritize railcar placement in the train for destination blocking and in a manner that did not comply with equipment restriction rules.” NS, post-accident, preformed modeling of in-train forces on train 245A109 to evaluate how train make up affected them, according to the NTSB. “The post-accident modeling showed how train build alone changes the amount of in-train forces,” the federal agency reported. “The modeling demonstrated a significant reduction in in-train forces, to the extent that had the train been built in compliance with NS’s equipment restriction rules instead of destination blocking, the derailment would have likely been prevented. The equipment restriction changes that NS put in place immediately after the accident require the train to be built to the second scenario[*], eliminating the ‘when practical’ language for empty blocks and loaded intermodal equipment.”
* The second scenario of modeling moved the heavy intermodal block “from the rear of the train and positioned directly behind the locomotives at the front of the train—as is prescribed in NS rules for making up a train,” according to the NTSB. “This scenario resulted in a substantial reduction of in-train forces, bringing the forces below 150,000 pounds.”
Separately, the NTSB on Sept. 24 issued the final report for its investigation of a Aug. 6, 2023, accident, in which a CSX Transportation conductor trainee was fatally injured during switching operations at the Class I railroad’s Cumberland, Md., rail yard; and in August released the final report for a fatal September 2022 collision on UP’s Sunset Route in Imperial County, Calif.
