TTC OPERATED BY ENSCO, RAILWAY AGE AUGUST 2025 ISSUE: Preventing derailments is critical to rail transportation to enable its safe and efficient operation. In the worst-case scenario, a derailment can lead to casualties and property damage. But even in the best-case scenario they lead to network delays that increase costs for the economy. Looking over the last several decades, North American freight rail transportation has made tremendous improvements decreasing derailments. There was a significant reduction in derailments from 2004 to 2024 according to the Federal Railroad Administration (FRA) derailment statistics. This reduction can be attributed to many factors including the widespread deployment of track and rolling stock automated inspection technology. However, from 2014 to today the total number of derailments has been flat. Track caused derailments have continued to decrease since 2014, but Human Factors and Miscellaneous caused derailments have increased.
One of the best methods to further decrease derailments is the investigation process. Conducting an accurate and scientific investigation is paramount to understanding the root cause (or combination of causes) to properly identify and implement an effective prevention strategy.
Investigation Fundamentals
From July 22-24, 2025, the Transportation Technology Center in Pueblo, Colo., hosted a workshop with more than eighteen freight and passenger railways to learn, collaborate, and discuss the art and science of derailment investigation and prevention. Some of the skills that were taught are from the first steps of arriving at the site of the derailment, including sketching basics, finding the Point of Derailment (POD), reviewing the Locomotive Event Recorder and several other aspects of the investigation process. Most importantly, the workshop included hands-on activities with track and both freight and passenger rolling stock. Unique TTC hands-on activities included creating a site sketch of derailment pile of cars, performing track measurements at and around the POD, and performing a first derailed car
truck inspection.
At a high level, there are three main types of derailments: 1) a human factor that affected operations such as an incorrectly lined switch, 2) a component that catastrophically failed such as a broken rail and 3) a vehicle/track interaction condition resulting in a wheel permanently leaving the rail. At the workshop, each of these three types were fully explored and discussed. Catastrophic component failures can be challenging to solve. For instance, broken rail can be caused by many different factors. However, at a derailment site there can be numerous pieces of broken rail. How can you tell if the derailment was caused by a broken rail, and which piece caused it? The workshop team addressed that question along with many more.
Investigating Wheel/Rail interaction type derailments can be the most challenging of all three types to identify the primary cause, often because there are multiple contributing factors working together to cause the derailment. There are three types of vehicle/track interaction derailments. First is wheel climb where the first derailed wheel climbs up and over the rail. In this scenario there is a distinctive wheel climb mark at the POD. Second is a wheel drop where the track gauge is spread and a wheel drops within the gauge. Lastly is rail rollover where a rail rolls outward often causing the wheel flange to fall into the web of the rail. All three types can be caused by numerous different factors including track geometry, rail wear, tie and fastener conditions, ballast condition, wheel wear, truck conditions, train handling and train make-up to name a few.
An important topic the workshop discussed is how to scientifically determine what is the primary cause and what are contributing causes. Important tools to make this assessment are simulation packages to evaluate “what-if” scenarios. Examples include TEDS for track/train dynamics and VAMPIRE for vehicle/track interaction. These simulation tools are invaluable to assess what is the effect of each cause and enabling the ability to quantify how much each contributed to the end result of the derailment. The conclusion of any derailment investigation is the identification of the root cause. Next comes preventing the next derailment.
Advances in Derailment Prevention
Derailment prevention can take many forms. These can include updating internal rules and practices, and making changes to infrastructure or rolling stock. But it can also include the adoption of safety technology. A major success story of preventing derailments has been autonomous or unmanned track geometry measurement systems. They have a major advantage in that they can operate continuously in revenue trains without the need for a crew. This greatly increases the number of miles that can be surveyed while also dramatically decreasing survey costs. The first U.S. system was developed as an FRA R&D project started in 2008. Since then, that research facilitated the adoption and growth of the technology to be utilized by all Class I railroads and many passenger and transit systems. FRA derailment statistics show that from 2008 to 2024 there has been a reduction of 231 track geometry caused derailments, a 65% reduction.[1] Closing out the TTC Derailment Investigation and Prevention Workshop, the team discussed best practices of derailment prevention and case histories. A 2026 event is planned, and further information can be found at ttc-ensco.com/derailment-workshop.
Conclusion
Each year, ENSCO hosts the annual TTC Conference and Tour with this year’s event being held Oct. 7-8. The event is unique in that it brings together all stakeholders of the railway community to hear users of the TTC talk about their latest research, testing, and technology projects. Additionally, attendees get to visit the site to witness hands-on demonstrations of TTC testing capabilities and meet with suppliers that are leading with new and emerging technologies and offerings.
At the 2025 event, a hands-on demonstration with a supplier’s emerging technology will close the tour day with a freight car derailment equipped with Railway Metrics and Dynamics’s (RMD) latest Derailment Monitoring System. A single wheel or truck can derail and can be dragged for a long distance before a full derailment occurs, typically occurring at a switch or grade crossing. RMD’s system will be tested at the demonstration to detect the derailed wheel in real-time to enable slowing or stopping of the train to greatly reduce damage. More details can be found at ttc-conference.com.
Reference
1. https://data.transportation.gov/stories/s/Accident-Detail-Listing-3-18-/vq2r-5pm7/
