Ten trains a day, each transporting 25,000 tonnes of iron ore along 414 km of rough terrain at up to 64 km per hour, can be damaging to railway tracks and infrastructure. Fortunately, the National Research Council of Canada (NRC) has developed an extremely accurate rail network health monitoring system that helps railway companies anticipate safety threats and operational challenges, and develop preventative maintenance plans to avoid them.
The Quebec North Shore and Labrador (QNS&L) Railway runs trains loaded with iron ore through the Canadian wilderness from a mine near Labrador City to the shipping port in Sept-Îles. Along the way, the network takes a lot of pounding from heavy trainloads. Maintaining the rail line owned by the Iron Ore Company of Canada is consistently challenging and expensive. Heavy loads from cyclical rail traffic, exposure to harsh weather and rough topography often lead to unforeseen wear and tear that create unsafe conditions and premature system deterioration.
Traditionally, the industry has relied on measuring a 3-dimensional map of track layouts, also known as track geometry, to identify problems arising from the heavy weight and high forces that are applied as trains pass over them. This method of inspection uses a dedicated car to measure and test several parameters as it travels along the track. But track geometry does not examine or consider all factors that can cause unsafe rail conditions such as train dynamics and lubrications. Nor can it anticipate locations that are exposed to the most damaging forces. As a result, if using only track geometry to monitor railway system health, railway operators may not know if they had a problem until after system deterioration is visible or an incident occurs.
In response, the NRC has designed and built a robust instrumented wheelset (IWS) system that collects and analyzes wheel-rail forces and interactions. In short, an IWS is developed by instrumenting a regular railcar wheelset with a series of strain gauges. This effectively transforms the wheelset into a dynamic, rolling load cell that continuously collects vast amounts of force data as the wheels roll along the rail tracks. The real value of this device lies within the analysis of the data that the IWS collects. The NRC IWS system provides companies like QNS&L with continuous monitoring of wheel-rail forces in near real-time during revenue train operations, and can identify potential maintenance and safety concerns before they escalate and result in potentially deadly incidents.
"In the past, using only track geometry, we knew that there were potential problems, but this method of inspection didn't give us the full picture," says Dominique Sirois, Principal Railroad Engineer at QNS&L Railway. "Our year-long research project with the NRC's IWS helped us to clearly understand where the potentially dangerous forces occur on our track and to proactively address these issues with targeted corrective maintenance. This has led to a new performance-based maintenance plan with significant cost reductions for QNS&L."
International recognition for the NRC's IWS technology has gained momentum as well. In a joint effort with QNS&L, the NRC–QNS&L team has presented the results of this successful study at numerous conferences, including the 2020 AREMA Conference and Expo. In addition, in April 2021, the team was pleased to learn that the project won a regional project innovation award from the Ordre des ingénieurs du Québec.
On the rails with real-time data
To conduct this research, the NRC equipped one of QNS&L's standard iron ore railcars with 2 IWS for a full year. Following the very first track run using the NRC's IWS, QNS&L received a detailed and accurate account of the condition of its track.
"In addition to measuring rail forces, car accelerations, in-train forces and brake system performance along the route during regular rail operations, we tested how well the IWS electronics could perform in such a rugged rail environment," says Albert Wahba, the NRC's Program Leader, Resilient Ground Transportation. "To transfer the ore from the railcar to shipping containers, a rotary dumper turns the entire rail car almost upside down. It's not a gentle process, and the IWS equipment that is fixed to the rail car was subjected to that harsh process. The IWS really proved its ability to operate in the most rugged rail environments."
"The IWS is the only tool that can measure the wheel-rail forces, in real time, along the entire rail route," says Jason Pierosara, Client Relationship Leader for the NRC's Rail Vehicle and Track Optimization program. Over the years, the technology has been tested for shorter periods, but this is the first time it has been applied long-term on an operating freight train in North America, and under such harsh operation conditions. The NRC IWS system also uses in-service cars as opposed to dedicated test cars, so it does not disrupt service or demand extra onboard staff to operate the technology. "If you know the forces applied to the rail, and can see how these change each time a train passes, you can predict future issues and act to mitigate them", adds Pierosara.
According to Dr. Yan Liu, the NRC's Principal Researcher and Team Leader, Vehicle Simulation and Data Analytics, IWS provides data from the first day it is used. To help operations managers and engineers to take advantage of the vast data influx collected by the IWS, Dr. Liu and his team have created the Rail Data and Analytics System (RDIAS). The RDIAS is an intuitive and insightful data analytics system that translates complex data into useful information that railway operators can use to make impactful and economical business decisions about their railway network health.
Getting ahead of the curve
Railways are the leading and most environmentally friendly land-based method for moving goods between the source and the market. Every year, some $310 billion dollars' worth of Canadian cargo is loaded onto 5 million rail carsFootnote 1 and transported to cities, ports and plants. Since 1836, rail has also been the most cost-effective overland way to ship everything from grain and lumber to minerals and fuel. And in addition to being the most eco-friendly method, it is also 4 times more efficient than trucking since 1 unit-train of freight can carry as much product as 300 trucks.
Dr. Liu foresees that rail transportation regulations will eventually be modernized to adopt safer and more efficient standards through the deployment of new technologies, and will lead to an increased performance-based approach toward rail maintenance and safety. "This is where the NRC IWS system helps railways to excel."