The How and Why of L/V-based Thresholds
by Jeff Tuzik The L/V ratio is a ubiquitous measurement in the world of wheel/rail interaction. It is typically combined with the Nadal limit, functioning as shorthand for wheel climb derailment risk for a given set of conditions. But the L/V ratio and the various formulae used to set risk …
Simulation and Digital Twins: A System-Based Approach to Predictive Maintenance
by Jeff Tuzik Rail transit systems collect a lot of data. This is data collected from many sources—wheels, rail, track, and vehicles—and from many types of measurement devices. Some of the data must be collected per regulatory requirements, but much of it is collected because it’s valuable. Transit systems use …
30 Years of Evolution in the Field of Wheel/Rail Interaction
by Jeff Tuzik What do 30 years of advances in wheel/rail interaction look like? Thirty years ago, the field of wheel/rail and vehicle/track interaction was largely unknown outside a coterie of specialists and researchers. Railroads operated within confined departmental siloes with vehicles on one side of the ledger, track on …
Using Elastic Components to Improve Rail, Tie, and Ballast Life
by Jeff Tuzik Track condition is about more than rails and ties. It includes everything below the rail and ties, too. Track components, ballast, and subgrade are all part of the package; they all affect overall track condition. And, as Brazil’s MRS Logística’s track renewal programs have shown, improving track …
Fuel Savings and Wear Reduction: A Case for Locomotive Wheel Flange Lubrication
by Jeff Tuzik The benefits of friction management are well known and often touted. But one benefit in particular—fuel savings—receives far less attention than the others. But as railroads race to meet greenhouse gas reduction targets and ultimately net-zero goals that they have set for themselves, fuel savings have become …
On-Board Top of Rail Friction Modifier Application: A More Efficient Approach?
By Jeff Tuzik Friction modifiers—whether gage-face lubricants (greases) or top-of-rail (TOR) friction modifiers (FM)—are a well-established, and indeed, a common part of the wheel/rail optimization toolkit. In the railroader’s mind, these technologies tend to be associated with wayside application equipment and installations, but vehicle-mounted wheel-flange lubricators and wheel-tread friction modifiers …
Switch Point Inspection & Wheel-Climb Derailment Prevention
by Brad Kerchof This article originally appeared in the September 2025 issue of Railway Track and Structures. It is reprinted here at their courtesy. Do you have experience arguing about derailment causes with another department? If so, chances are you have negotiated the cause of a switch-point wheel-climb derailment. The …
Mitigating Track Buckling on São Paulo’s Metropolitan Train Network
by Jeff Tuzik On passenger rail systems, disruption is never good. With tight headways and packed cars, a small disruption of service doesn’t stay small for long. Major disruptions, such as those that require taking a track out of service for repair, are worse yet. On São Paulo’s Metropolitan Train …
Extending Wheel Life Through Rail Grinding
by Jeff Tuzik Rail grinding is typically the go-to approach to addressing rail-related issues like corrugation, RCF, profile degradation, and a slew of others. It works. And on transit (and other closed-loop) systems, rail grinding can also be used to address wheel-related issues, as well. Greater Cleveland Rail Transit Authority’s …