Network Rail's Air Operations team has been testing an advanced camera system that combines high-resolution photography, laser surveys, and near-infrared imaging to provide engineers with an exceptional view of the railway network.
The Multi-Angle Camera System (MACS) is housed in a pod beneath the company's Twin Squirrel helicopter, which can cover extensive stretches of railway in a single shift, carrying both a pilot and an aerial surveyor.
The Rail Innovation and Development Centre in Melton, near Nottingham, has served as the testing ground for MACS. The helicopter has conducted multiple missions along the 13-mile test track, offering engineers a detailed view of the route. A recent landslip, now fully repaired, highlights the track's similarity to the public railway in terms of challenges.
MACS features an onboard laser that generates a "point cloud" with up to 300 points per square meter, enabling the creation of a 3D model of the railway, including overhead wires, bridges, and more.
Additionally, three 150-megapixel RGB cameras capture images from forward, sideways, and downward (nadir) perspectives. These images are geometrically corrected (orthorectified) for engineering use, while a fourth camera captures near-infrared images to assess plant and tree health.
All images are linked through an inertial measurement unit to provide precise location data. The system can also produce digital terrain maps devoid of trees or buildings, aiding geotechnical engineers in clearly visualising the railway and understanding the nature of any failures, potentially allowing for pre-emptive action.
Data from MACS will form a robust foundation for training machine learning algorithms across various disciplines. This will pave the way for the use of survey-grade drones capable of flying longer distances as Beyond Visual Line of Sight (BVLOS) capabilities advance.
MACS will be available to Network Rail regions as part of the suite of equipment that can be carried by the helicopter, including thermal imaging and standard cameras.
Sean Leahy, from Network Rail Air Ops, said: “Passengers and freight customers deserve a reliable railway and the best way to provide that is to know as much about our network as we can, to spot problems before they happen and maintain it to the highest standards. We have brilliant colleagues who are able to work wonders but they can’t be everywhere on the 20,000 miles of track we look after. The MACS is one of the ways we can help them by giving them the best data we can.”
Bradley Sparkes, of Network Rail’s Technical Authority team said: “We operate one of the busiest railways in the world, with over seven million train movements per year making traditional boots-on-ballast inspections a real challenge. When we do ultimately decide to send an engineer on-site for a closer inspection, we need to be sure we’re basing such a deployment on comprehensive and robust prior intelligence. This will help to drive a reduction in inspection related emissions, improvements in worker safety and enhanced asset intelligence.”
Image and video credit: Network Rail
