Rail operators depend on a hot axle box detection system to prevent failures, optimise maintenance, and improve railway safety. Wayside detectors, such as Hot Axle Box Detectors (HABDs), offer a well-established, non-intrusive solution but only capture data at specific points. In contrast, onboard monitoring provides real-time tracking and early fault detection but requires integration with train systems.
Understanding Hot Axle Box Detection Systems
A hot axle box detection system is essential for monitoring axle bearing temperatures and detecting early signs of overheating that could lead to catastrophic failures. The European standard EN 15437 outlines two key methods for axle box condition monitoring:
- EN 15437-1: Wayside (trackside) monitoring using HABDs that measure axle box temperatures as trains pass fixed detection points.
- EN 15437-2: Onboard monitoring with sensors installed on the train, continuously tracking axle box temperatures in real time.
Both approaches play a critical role in predictive maintenance, but they differ in effectiveness and implementation.
Key Differences Between Onboard and Trackside Monitoring
The most significant difference between onboard and wayside monitoring is data collection frequency. Onboard systems provide continuous, real-time monitoring, whereas wayside detectors only capture data when a train passes a fixed location.
The Advantages and Limitations of Trackside Monitoring
Trackside hot axle box detection systems have been widely used in railway networks for years, offering several benefits:
- Non-Intrusive Installation: No modifications to rolling stock are required.
- Proven Technology: Many rail networks already have trackside monitoring infrastructure in place.
- Effective for High-Traffic Routes: Frequent monitoring at fixed intervals ensures oversight of passing trains.
However, trackside monitoring has several limitations:
- Single-Point Detection: Can only measure temperature at specific locations, leaving gaps between monitoring points.
- Limited Detection of Internal Issues: HABDs measure outer axle box temperatures but may miss internal bearing failures.
- Delayed Fault Identification: Issues arising between detection points may go unnoticed until the next checkpoint.
- Standardised Approach: Lacks customisation for specific bogie designs or axle configurations.
- Reliance on Detector Placement: Unevenly distributed detectors can create blind spots.
The Advantages and Limitations of Onboard Monitoring
Onboard hot axle box detection systems address many of the shortcomings of trackside monitoring by offering:
- Continuous Data Collection: Real-time tracking of temperature fluctuations.
- Customisable Monitoring: Tailored to different train types for higher accuracy.
- Comprehensive Detection: Identifies temperature irregularities in both external and internal axle boxes.
- Early Fault Detection: Detects potential issues before they escalate, reducing failure risks.
- Reduced Maintenance Costs: Enables predictive maintenance, minimising downtime and costly repairs.
Despite these advantages, onboard monitoring comes with some challenges:
- Initial Installation and Integration: Requires onboard sensor installation and system integration.
- Power and Data Infrastructure: Needs onboard power supply and real-time data transmission capability.
Choosing the Right Hot Axle Box Detection System
The adoption of HABD systems depends on national safety regulations, railway standards, and local requirements. While many countries, particularly in Europe and North America, have recognised the safety benefits of HABD systems and have implemented regulations or guidelines encouraging their use, it is not universally mandated.
In Europe, High speed trains (250kmh or more) are required to have installed onboard hot axle box detection systems for safety reasons. At high speeds, there is an increased risk of bearing failures and overheating which could lead to catastrophic consequences. Therefore, early detection of increased temperatures is essential. Wayside systems are not sufficient for timely warnings at these speeds.
Onboard Hot Axle Box Detection System by EKE-Electronics
EKE-Electronics offers a SIL 2-certified onboard hot axle box detection system that continuously monitors axle box temperatures. Designed for high reliability and safety, this system is tailored to specific train characteristics, ensuring precise temperature tracking and timely alarm triggers when deviations occur.
Learn more about our Onboard Hot Axle Box Detection System.
