Train derailments can be catastrophic, with widespread and long-lasting consequences – from loss of life and injury to passengers and crew, to major damage to infrastructure and rolling stock.
When it comes to heavy haul rail, lost or damaged cargo and ensuing production delays can easily end up costing an operator millions of dollars.
Broken rails are responsible for up to 35 per cent of major derailments on rail networks worldwide.
According to Roy Leslie, Business Development Manager for Automated Management Solutions at Siemens Mobility in Perth, this has reinforced the need for technology to mitigate the risk of potential rail failures.
Leslie explained that traditionally, track circuits have provided broken rail detection as a by-product of their train control function. However, new signalling technologies such as axle counter-based Centralised Train Control (CTC) and Communications-Based Train Control (CBTC) do not have this capability.
“Changes to signalling technology have removed the role of track circuits, making their installation and maintenance as the basis for broken rail risk mitigation a stand-alone investment,” Leslie said.
In advance of a planned CBTC signalling upgrade, one of Siemens Mobility’s customers recognised the need for an alternative broken rail detection method that doesn’t rely on track circuits.
Fortunately for the customer, Siemens Mobility has developed a solution that combines patented electromagnetic sensors with advanced navigation and communications systems.
The technology, known as Broken Rail Detection (BRD), has been refined through sensor simulation, laboratory testing, and field trials under heavy haul conditions.
Simply put, it checks the condition of the rail network during operation, identifies any damage, and reports it to the customer.
The instrumentation itself – On-board Broken Rail Detection (OBRD) – consists of sensors that can quickly and easily be installed on the bogie of a train operating within regular revenue service, or on other rail-based vehicles.
The solution uses a magnetic field to detect if there’s a discontinuity in the rail, and then reports that back to a trackside Back Office System, or BOS.
“The BOS maintains a ‘Track Map’ database of known discontinuities, or ‘features’, and flags unexpected detections to the customer’s Train Control Centre,” Leslie said.
“The system also provides a highly accurate GPS position for the discontinuity, so the customer can take appropriate risk mitigation measures as soon as possible. The technology increases throughput, because tracks can be quickly maintained and released for operation, instead of being blocked for days due to damage.”
Over the long term, through Siemens Mobility’s BRD technology, more than 10 million kilometres of heavy haul network surveys have been conducted, including those in turnouts and on mainline track that can’t be detected by traditional track circuits.
“The technology can detect transverse rail discontinuities as narrow as one millimetre, with 98 per cent probability,” Leslie added.
“It works even in hard-to-reach and ‘dark territory’, detecting rail failure in areas without track circuits or wireless data communications, and before a complete break or electrical discontinuity has occurred.
“The system improves rail safety and operation by significantly exceeding the performance limitations of current detection technologies.”
Because BRD is deployed on trains operating in normal revenue service, it continuously monitors rail condition without the need for additional track-based detection equipment or planned inspection possessions.
“This saves operators money on equipment as well as labour costs, while minimising the exposure of maintenance crews to live rail environments – keeping them out of harm’s way.”
Reducing operational impact
When a rail break is reported, operators must immediately implement risk reduction measures to prevent a derailment. This typically involves closing the affected section of track or imposing speed restrictions until the integrity of the rail can be confirmed and repairs completed.
Leslie noted that the operational impact of this can be significant.
“Line closures and speed restrictions disrupt normal train operations, reducing network capacity and throughput and potentially causing delays across the wider rail system,” he said.
“In heavy haul and freight environments, this can result in lost production, delayed deliveries and increased operating costs, while in passenger networks it can lead to service interruptions and reduced timetable reliability.”
He said downtime varies depending on the location and severity of the break, as well as access conditions, but traditional approaches often require extended maintenance windows and precautionary restrictions while crews locate and assess the fault.
“BRD’s ability to detect rail discontinuities early helps prevent major failures and derailments that can result in extensive infrastructure damage, prolonged line closures and high recovery costs,” he said.
“When issues are identified, BRD provides highly accurate location data, enabling maintenance teams to target specific sections of track rather than carrying out broad, time-consuming inspections.
“This targeted maintenance approach reduces downtime, shortens repair windows and allows assets to be returned to service more quickly, improving network availability.”
A growing dataset
By continuously monitoring rail conditions during standard operations, BRD generates an expanding, high-quality dataset on track integrity that can be integrated into broader digital maintenance and asset management systems.
“Each pass of a BRD-equipped vehicle adds to a growing dataset that builds a detailed picture of track condition across the network,” Leslie explained.
“Over time, this data allows operators to identify patterns, trends and recurring anomalies at specific locations, such as areas subject to higher stress, environmental exposure or repeated minor discontinuities.
“Rather than responding only once a rail has failed, maintenance teams can prioritise inspections and interventions based on early indicators of deterioration, reducing the likelihood of sudden breaks and unplanned disruptions.”
He said implementing a smart, vehicle-mounted solution positions an operator’s network as a data-driven, digitally-enabled asset rather than a purely reactive piece of infrastructure.
“As networks progress towards higher levels of automation, including semi autonomous and ultimately autonomous train operations, having reliable, real-time insight into infrastructure conditions becomes critical.”
