Safety systems for heavy-haul rail transport

by J. Groh - 2024-02-14

Rail freight transport is growing worldwide – and with it, the demands on infrastructure, maintenance and safety technology. In heavy-haul transport in particular, enormous forces act on tracks, points and vehicles.

At InnoTrans in Berlin, Progress Rail is therefore showcasing systems designed specifically for this sector: from points actuators and track inspection to hot axle box detection systems and sensors for accident prevention. The company has been part of the Caterpillar Group since 2006 and specialises in railway technology within the group. The focus is primarily on so-called heavy-haul applications – that is, heavy-haul traffic with particularly high axle loads and long freight trains, as are mainly used in the USA. It is precisely these extreme loads that significantly alter the requirements for track construction and maintenance. Whilst mixed networks of passenger and freight traffic often dominate in Europe, North American heavy-haul transport presents entirely different load scenarios.

Progress Rail develops systems for points and track inspection

Several technical systems covering different areas of railway infrastructure will be presented at the exhibition stand. These include buffer stops to arrest trains, point motors for box-type sleepers, and new systems for automated track inspection. A particular focus is on a new track inspection system. Among other things, this monitors the track gauge, the position of fastenings, the condition of the rail surface and the correct positioning of individual components within the track area. Unlike traditional optical methods, the system uses ultrasound technology, according to the company. This is intended to achieve greater accuracy in condition analysis.

This precision plays a particularly important role on heavily used lines. Even the slightest changes to fastenings or rail profiles can quickly develop into safety-critical damage under high axle loads. Key components of the systems presented:

• Point motors for heavy-duty lines
• Track inspection using ultrasonic technology
• Buffer stops to arrest vehicles
• Shock sensors for monitoring train movements
• Hot axle box detection systems with infrared sensors

There is also another objective: to extend maintenance intervals. In the USA in particular, individual sections of track are sometimes required to be replaced after just six months due to extreme loads. The pressure to deploy more durable systems and more precise monitoring technology is correspondingly high.

Heavy haul is changing the demands on rail infrastructure

This difference is particularly evident when it comes to heavy haul. This refers to freight trains with axle loads of more than 35 tonnes and extremely long trainsets, some comprising over 100 wagons. Such transport operations place enormous demands on rails, points and track bed. The stresses differ significantly from European networks with heavier passenger traffic.

Progress Rail therefore describes the USA as its most important home market. There, the company is regarded as the market leader in the heavy haul segment. At the same time, the group is increasingly expanding into Europe, Australia and, in the future, into South-East Asia and the Middle East. The strategic development in Europe is particularly interesting. Following the acquisition of a British points manufacturer, the company is further expanding its presence on the European market. Australia, in particular, is also regarded as an important target market, as similarly heavy freight trains are used there for the transport of raw materials as in North America.

Hot-axle detection systems are designed to prevent derailments

Another key focus is on safety-critical sensor systems. So-called hot-axle detection systems are particularly relevant in this context. These systems monitor the temperatures of axle bearings, wheels and brakes whilst the train is in motion. Sensors measure temperature changes directly on passing vehicles. The basic principle is relatively simple: track switches first detect the train’s axles and count them. Infrared sensors then measure the temperature of individual components.

If a defined threshold is exceeded, the system reports exactly which axle is in a critical condition. The information can then be forwarded directly to train dispatchers or control centres. The stakes are high. Overheated bearings can fail and, in the worst case, lead to derailments. The discussion refers, among other things, to the serious accident in Viareggio, Italy, where a technical fault had catastrophic consequences. According to the company, the hot-box detection system presented is already in its third generation. The first systems were reportedly deployed as early as the mid-1990s.

Data analysis is becoming a key issue for the future

In addition to the sensor technology itself, data analysis is increasingly taking centre stage. This is precisely where Progress Rail sees one of the most important trends for the coming years. Customers no longer wish to simply record condition data locally, but to analyse it over the long term, compare it and use it for so-called trend analysis. The aim is to achieve more proactive maintenance.

As a result, traditional rail infrastructure is increasingly evolving into a data-driven system. Sensors continuously provide information on load, temperature, wear or material condition. This data allows maintenance schedules to be planned more precisely and potential damage to be detected earlier. This approach could have significant economic implications, particularly in heavy goods transport. This is because unplanned track closures or damage to heavily used freight lines incur enormous costs. The presentation at InnoTrans therefore showcases not only new individual products, but a fundamental shift in the rail sector: away from purely mechanical infrastructure, towards permanently monitored, networked and data-based track technology.