Track Record

The new year was barely a week old when the US rail network recorded its first major derailment of 2025.

Multiple freight cars overturned when a coal train slid from the track in Fluvanna County, Virginia on the morning of January 7th. 

With no reported injuries or environmental concerns, and recovery plans swiftly put in action, the incident will just be recorded as one of the first of more than one thousand derailments - if recent years are anything to go by - across the US network over the following 12 months (Source: Bureau of Transportation Statistics).

Although most incidents will be considered 'minor' – usually occurring in yards or private industrial sites – any network averaging three derailments a day is living with significant odds of more disruptive, potentially life-threatening incidents.

Which is a surprising level of tolerance. Because as well the obvious safety risks, there can also be major financial and reputational implications from a derailment. Even in one of those 'minor' incidents, the damage caused to vehicles, infrastructure and cargo, for example, can amount to $1m-$2m in repairs, reparations and lost business. Meanwhile incidents that, say, involve the clean-up of hazardous materials, can incur costs tens, or even hundreds, of times greater.

There are signs of the sector beginning to address this anomaly in US rail's otherwise strong safety performance. Following sharp criticism from the federal government after a spate of high-profile incidents – President Biden called the calamitous 2023 East Palestine derailment of 38 cars carrying hazardous materials ‘100% preventable’ - there is growing interest in the proven safety technologies and analytical models deployed in other territories.

A digital twin for track geometry

For almost two decades, Ricardo has partnered with the Dutch network infrastructure manager, ProRail, to develop PUPIL, an advanced digital twin proven to protect against derailment incidents.

With track defects recognised within the industry as the most common cause of derailments on the world’s railways, ProRail sought to better understand how track defects affect the dynamic behaviour of vehicles.

Using track geometric data generated by regular network surveys, PUPIL accurately models the influence of differing loads, speeds and driving directions on a variety of vehicle types (passenger, high speed, freight, locomotives etc).

Able to process thousands of kilometres of measured track data, PUPIL can identify the specific locations where vehicle behaviours exceed accepted tolerances, issuing maintenance teams with insights into the nature of the defect and advisory notes on appropriate and optimised responses, such as speed restrictions or targeted maintenance.

Where regular network surveys are not available, or the coverage is patchy, Ricardo’s engineers work hand-in-hand with customers to collect data on track geometry. By fitting unobtrusive, removable sensors to in-service vehicles, our complementary remote condition monitoring solutions can fill gaps where data is limited. This allows our customers to exploit the benefits of PUPIL, while also identifying network features and defects that may not be detected by regular network surveys. 

For Jake Cartmell, Ricardo’s Digital Program Manager for Rail products, PUPIL's gradual 20-year development timeline has allowed it to evolve into a tool unlike any other on the market.

“What makes PUPIL unique", says Jake, "is its ability to weave together different facets of track geometry. Other tools can assess level, alignment, cant variations and so on, but few can analyse how those facets interact, or ascertain the circumstances where they might combine to increase the risk of derailment. Nor can they simulate the behaviour of multiple vehicle types and multiple speed increments to optimise how our customers respond to track defects.”

Edward de Jong, Principal Consultant, has overseen Ricardo's partnership with ProRail in developing PUPIL. He believes the access to the 'real-world' environment that the relationship affords has enabled the team to adjust and enhance the tool's outputs. 

"Every modification has been driven by the needs of day-to-day operations," says Edward. "Such as 24/7 access to the reports, the expansive in-built library of vehicles, and meeting the requirements of relevant standards and regulations, such as EN 13848, the established European Standard for track geometry".

"ProRail believes it now identifies around 70% more defects on its network than would have been the case with standard evaluation tools. In 20 years of using PUPIL there hasn’t been a single derailment on the Dutch network for tracks analysed by PUPIL".  

Industry partners to help advance the tool's potential    

Whilst the partnership with ProRail continues, the Ricardo team are looking to work with partners in other territories to help extend the digital twin's capabilities.

“A specialist solution like PUPIL can only exist through collaboration”, explains Jake. “By accessing real-world data sources, we can continue to strengthen its modelling capabilities and extend its application to railways across the world".

“North America is an ideal environment for the next generation of PUPIL. It’s a market where track defects are most likely the root cause of many derailments - incidents that, for such a technologically advanced society, are happening with too great a frequency, and at a high cost to the industry, both financially and in terms of public scrutiny of its safety record.”

“In PUPIL we have a sophisticated low-cost tool with a proven record of enhancing safety and efficiency on modern railways. With the cloud technologies now available to us, there is more potential than ever to bring its capabilities to partners in territories who, in return, can help us to refine and shape the tool’s capabilities around their specific needs.

For more information about PUPIL, click here