Ensuring safety in the railway system through innovative vehicle maintenance

Even today, the railroad is one of the safest and most modern modes of transport in Europe. Data-driven software models and digitization initiatives provide extensive new potential for guaranteeing and increasing safety in rail transport technology: Above all, the automated collection and storage of those data that directly influence the condition of the vehicle or its safety-critical components is essential for a modern, safety-oriented maintenance strategy. Of particular importance is the multidimensional continuity of data and information flows during the operational use of the vehicles. Hence the interaction of all technical, logistical, topological and ecological operational influences, which ultimately have a direct or indirect impact on the safety-related operational status of a vehicle. Consequently, these influences and interactions have a direct impact on the maintenance and repair of rail vehicles and to ensure and document safe rail operations. Hence, this document contains central approaches that are decisive for safety in the railway industry.

Safety on Europe’s railways

As mentioned at the beginning of this article, according to the ERA (European Railway Association), the railroad is one of the safest modes of transport in Europe – also in comparison to other modes of transport. According to the ERA’s latest “Report on Railway Safety and Interoperability in the EU”, 1721 serious accidents, 885 deaths and 760 serious injuries were registered in the EU-28 countries in 2018. In Germany, an average of 2.7 accidents and 0.04 deaths per billion passenger kilometers can be expected.

The costs involved are high: According to serious estimates, they add up to around five billion euros per year – more than twice as much as the figures published in previous years show. This is mainly due to the significant increase in unit costs for accident victims, which are the most significant figure with 2,897 million euros. Serious injuries (379 million euros), material damage and delays (393 million euros) and other costs (142 million euros) are less significant in comparison. Overall, the topic of railway safety is a very broad and comprehensive subject, which is why this article focuses in particular on railrway safety in the area of vehicle maintenance of the parameters that influence this.

The role of ECM

The proper operation of railroad vehicles is the basis for the functioning of a safe railway system. The foundation of a safe operation of railroad vehicles is, on the one hand, a well-founded maintenance strategy and, on the other hand, ensuring the proper execution and documentation of the maintenance activities performed. A key factor is therefore the manageability of the maintenance process on the part of vehicle owners and maintenance workshops. The most frequent reasons for safety-relevant incidents on railroad vehicles recently included

• Bearing damage (especially cracks, contamination, wear, excessive loosening),
• Damage to brake systems (leaks, wear/heating/breakaway of pads, damage to valve camshafts and sudden imponderables),
• Damage to the suspension systems (fractures, breaks in the leaf springs, wear, contamination of the bogie steering bearings, sudden defects).

Based on these experiences, the legislator finally felt the need to introduce a corresponding set of rules on a European level, which emphasizes, regulates and defines the importance and responsibility of all entities involved in maintenance. These roles and responsibilities were defined in the Entity in Charge of Maintenance (ECM). The proper implementation of or compliance with the ECM is therefore considered a basic requirement and foundation for the safe functioning of railway systems.

Multidimensional continuity as a central factor

Although the responsibilities and boundaries between “the entities in charge of maintenance” are clearly regulated and defined in the ECM Regulation EU 2019/779, and the handover processes in terms of “technical operation approval” and “re-commissioning” are clearly described, the exchange of information between the responsible ECM entities is generally still considered to be particularly critical – and relevant. Especially in connection with the definition, tracking, assessment and derivation of measures for safety-critical components. Classically, information and knowledge in this regard can be found in different legal spheres, responsibilities and systems. A continuous exchange of data and information between these spheres is therefore a basic prerequisite for the further development of maintenance strategies and thus for increasing the overall safety of the railway system. In addition, according to the new regulation EU 2019/779, the entity in charge of maintenance has a new important responsibility. Namely, the monitoring and structured further development of safety-critical components. Therefore, the requirements for a multi-dimensional information flow on operating, operational and technical processes in the asset and component management of vehicle fleets are also increasing. The digital transformation creates new ways and means to guarantee the technical safety of railroad vehicles and their safety-critical components. This is because digital-based maintenance management software not only maps an integrated maintenance strategy and all associated processes, but also allows corrective and preventive maintenance measures to be derived on the basis of reliable information. Furthermore, the maintenance strategy summarizes the inspections according to the corresponding intervals and manufacturer specifications.

360° perspective

In this context, a holistic view of the vehicle is becoming increasingly important for railroad undertakings (RUs) in order to be able to control the complex maintenance processes and thus ensure railway safety. Only integrated fleet, asset and maintenance solutions that are fundamentally oriented towards and cover the processes of the ECM regulation will ensure effectiveness and, ultimately, above all, safety on rail. RAIL ASSET, a software solution from BOOM RAIL SOLUTIONS, is the starting point for this required multidimensional continuity. It enables a continuous flow of information via the ECM roles ECM2 – ECM4: BOOM RAIL SOLUTIONS as a standard software product of the international railway industry allows the compliance with documentation obligations according to ECM as the foundation of a safety-based maintenance strategy, maintenance planning and maintenance processing – and provides with an asset biography economic, technical and logistical parameters for a 360° view of the vehicle, 365 days a year. The BOOM RAIL SOLUTIONS orientate with its modules directly on the ECM roles and thus enable the “Digital Twin” of a rail vehicle, or entire fleets.

However, in order to ensure maximum safety, further data, condensed into information, is necessary: Only the direct linking of data with the corresponding component unit and its assignment to the vehicle allows conclusions to be drawn about the current status of the vehicle and forms the basis for innovative maintenance strategies such as “modular maintenance” or “condition-based maintenance”. With this 360°/365-day panoramic view, RAIL ASSET enables long-term optimization of vehicle deployment and maintenance. The core of the innovation in this context is the possibility of seamlessly connecting RAIL ENGINEERING with RAIL FLEET with RAIL ASSET with RAIL WORKSHOP, and using it as an integrative unit. The exchange of information and data is thus optimized throughout, and creates a holistic overview of all phases of the rolling stock life cycle – in conformity with ECM. On this interactive basis, maintenance strategies can be developed further proactively, tests and modifications can be initiated and thus new findings and measures for improving rail safety can be derived.

Rail-time maintenance

Above all, the automated acquisition and storage in real time of those data that directly influence the condition of the vehicle or its safety-critical components is essential for a modern and safety-oriented strategy. Consequently, real-time monitoring is becoming increasingly important: This enables the condition of individual components to be monitored in real time and the health state of vehicle components to be assessed directly and in a highly aggregated form for the entire vehicle. The BOOM RAIL SOLUTIONS standard software for rail applications is not only based on applied processes and international railway norms and standards, but is also designed, based on sensor technology and the use of telematics, for the automated transfer and interpretation of real-time data.

Complex wheelset management

Especially in the context of the wheelset, which is classified as a safety-critical component, the importance of continuous data acquisition with a 360° view can be seen: Due to the action of various forces and influences during the wheel-rail contact, the wheelset is subject to dynamic wear, which can result in damage to the wheel tires or axles. Rolling contact fatigue in railroad operations – i.e. the formation of cracks due to the repeated rolling of the wheels on rails – is often regarded by infrastructure managers as a very high or highest cost center. As an indication: In the EU, rolling contact fatigue causes about 300 million Euros in costs annually. Deutsche Bahn spends around 66 million euros per year on rail grinding and rail replacement in connection with rolling contact fatigue. The continuous increase in rail traffic in recent decades, the increase in axle loads and the introduction of powerful locomotives have recently led to an increase in rolling contact fatigue damage. Although the railroad is generally considered to be an extremely safe mode of transport, there have been accidents – such as the derailment of a train in Hatfield, UK, on October 17 in 2000, the consequences of which claimed four lives and injured over 70 people. The accident was due to rolling contact fatigue damage. The simulation and prognosis of rolling contact fatigue damage is therefore of particular importance in the railway industry. In addition, the wheel-rail contact is also largely responsible for the noise and noise levels of railroads.

In this context, it should be noted that in the BOOM RAIL SOLUTIONS, the documentation of the maintenance of the wheelset (defined in the DIN standard EN15313) can be done by automated assessment and measurement – for example with standardized profile measuring devices such as NextSense/Calipri. On the basis of this information, maintenance measures are derived and, ideally, processes are precisely aligned. In the field of wheelset management, this means the targeted planning of refurbishment or wheelset replacement.

So-called “Wheelset Predictions”, such as those found in the railway standard product BOOM RAIL SOLUTIONS, enable the visibility of the difference between typical, expected and actual wear curves – and thus prediction. Atypical load and wear profiles can also be applied to vehicles and fleets in order to optimize their remaining mileage and operational planning.