Salient Systems


Wheel Impact Load Detector, Weigh-in-Motion and Hunting Truck Detectors

Performance Monitoring and Predictive Maintenance

There are two primary goals of performance monitoring as it relates to the modern railway; safety and cost improvement. Passenger and freight railways are currently monitoring the health and safety of infrastructure and rolling stock which allows them to run a more profitable and safer operation.

L.B. Foster Salient Systems is helping railways on six continents to make these ideas a reality by:

  • Monitoring wheel impacts with WILD (Wheel Impact Load Detector) systems. 

  • Monitoring train and vehicle weights with Weigh-In-Motion (WIM) and Train Overload Imbalance Detectors. 

  • Monitoring high speed stability with the Hunting Truck Detector (HTD).  

  • Integrating all of these systems with other “smart sensors” to give decision-makers the complete picture of their railway system.

We're turning data into information!

L.B. Foster's Wheel Impact Load Detector (WILD) was the first detector in North America to have an AAR interchange rule written around it. This speaks volumes to the value and confidence the railways have in these systems. There are now Salient WILD systems installed on six continents around the globe.  

Railways are also moving forward with performance monitoring in a very smart way. They are creating “super-sites” or “mega-sites” which allow multiple detectors to take advantage of parallel assets such as enclosures, power and communications lines. This allows for a more cost-effective way of advancing these technological efficiencies. There are also “rules engines” being created to make predictive maintenance decisions on multiple issues such as wheel impacts and their correlation with faulty bearings.  

As new detectors are introduced, the railroads are working with vendors to integrate this new information into daily operations. We are refining the process of performance monitoring and predictive maintenance and are doing a great job of creating a safer and more efficient railway system. We are proud to be part of this movement not only in North American but in South America, Australia, Europe and Asia as well.

L.B. Foster Salient Systems continues to improve and evolve technology to meet the increasing demands of passenger and freight railways around the globe.

Wheel Impact Load Detector

The L.B. Foster Wheel Impact Load Detector (WILD) is the most widely used system in the world today, with nearly 300 installed to date, to detect and alarm on excessive wheel impacts for the targeted removal of defective wheels. An essential component of any performance-based wheel management program, the WILD continually monitors rail vehicle wheel health to ensure safe and productive train operations.

WILD systems evaluate millions of wheels per day throughout the international rail industry with proven accuracy and reliability.

The WILD is a hardened electronic data collection device that measures vertical wheel forces via rail-mounted strain gages. The WILD measures impact forces caused by damaged wheels. High impact forces damage vehicles, cargo, and infrastructure.

Hunting Truck Detector

L.B. Foster has developed a new, state-of-the-art Hunting Truck Detector (HTD) by building from the solid foundation that the WILD detector has provided the industry for more than 20 years. 

Customers are implementing the Hunting Truck Detector to prevent lading damage, as well as damage to vehicles and infrastructure.

Hunting trucks underneath rail cars can violently oscillate from one rail to the other as they traverse along tangent track. This motion can induce excessive lateral forces that significantly contribute to the accelerated wear of rail and vehicle in a relatively short time. This particular type of degraded vehicle performances is a leading cause of damage to delicate lading, customer complaints about ride quality, and increased fuel consumption.

Hunting trucks result in severe damage to truck components, which can cause derailments.


L.B. Foster has developed a state-of-the-art Weigh In Motion (WIM) system building on the solid foundation that the WILD detector has provided the industry for more than 20 years. The WIM system provides accurate vehicle weight. It alerts on overload, side-to-side imbalance, and end-to-end imbalance conditions.

Available as an add-on to the Wheel Impact Load Detector or as a stand-alone wayside installation, the Weigh In Motion system is a must-have for any railway.

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