The European rail industry is showing signs of steady recovery after a long period of decline. The technological advances in train design have led to the manufacturing of faster, greener and more comfortable trains making rail transport a more attractive option for passengers in comparison with other means of transportation.
The ever growing need for society to employ more environmentally friendly transportation policies is expected to further underline the economic and societal role of rail transport in achieving sustainable mobility across Europe in the years to follow. The European rail network is continuously getting busier with trains travelling at higher speeds and carrying more passengers and heavier axle loads than ever before.
The combination of these factors has put considerable pressure on the existing infrastructure leading to increased demands in inspection and maintenance of rail assets. The expenditure for inspection and maintenance has thus grown over the last few years without however being followed by a significant improvement of the industry s safety records.
A large proportion of all infrastructure related accidents in the rail industry is due to rail failure. The continuous increase in train traffic, axle loads and speeds means that the failure of a rail section may result in very serious derailments (such as the one that took place in Hatfield UK in 2000), causing loss of life, injuries, severe disruption in the operation of the network, unnecessary costs, and loss of confidence in rail transport by the general public.
INTERAIL sought to practically eliminate rail failures by developing and successfully implementing an integrated high-speed system for the fast and reliable inspection of rail tracks. The application of the high-speed system was complemented through the implementation of novel semi-automated testing equipment which was deployed for the verification and evaluation of the defects detected during high-speed inspection.
The INTERAIL consortium developed and implemented an integrated high speed inspection system based on a modular design, which will enable a faster and more reliable inspection of rail tracks at faster speeds compared to the available ones.
The major objectives were:
- To overcome the limitations of current inspection procedures of rail tracks through the successful implementation of an integrated high-speed inspection system based on automated visual, Alternated Current Field Measurement (ACFM) and ultrasonics techniques, combined in a single architecture as shown in the figure presented;
- To develop advanced verification and evaluation procedures of the defects detectable by the high-speed system based on ACFM, ultrasonic phased arrays, and high-frequency vibration analysis equipment;
- To achieve higher levels of PoD of rail defects leading to the substantial improvement in the actual reliability of the European rail network;
- To decrease inspection times and associated costs by up to 75% through the integration of three different rail track evaluation techniques that will complement each other as part of a functional single high-speed NDE;
- To develop the required software and intelligent control unit to enable automatic and real-time analysis of the defects detected and minimise human subjectivity during the interpretation and analysis of results;
- To contribute to the harmonisation of inspection procedures and network reliability across Europe.
The work content of the project was divided in five technical work packages (WP) as follows:
- WP A: Sample procurement and system specification. Within this WP the consortium will collect and analyse data from the existing literature, rail infrastructure managers, rail track inspection providers, rail track maintenance companies and rail manufacturers in order to thoroughly evaluate the deficiencies that are currently associated with rail inspection and maintenance procedures and their effect on European rail transport.
- WP B: Novel high-speed inspection system. This WP consists in the development of the integrated inspection system combining three main modules based on three different non-destructive evaluation technologies: ACFM, Ultrasonics and Automated Vision.
- WP C: Positioning, sensor adjustment and defect marking subsystem. In this WP the positioning, sensor adjustment and defect marking system will be developed.
- WP D: Manual defect verification inspection techniques. Development of a special equipment will be developed for the verification and evaluation of rail defects which are detected with the high-speed system.
- WP E: Integration and validation. The integration of the output of WP B and WP C will carried out in a single high speed rail inspection system. The validation of the system and of the defect verification techniques will be the basis for the system assessment.
The successful integration and validation tests of the INTERAIL high-speed rail inspection system, defect verification and evaluation techniques were accompanied by field trials and demonstration of the system's capability at the consortium railway operators.
Integrated inspection strategies coupled with measurable innovation in inspection technology, leading to significant improvements in operational cost efficiency and reliability without the requirement for a fundamental shift in the existing understanding of the inspection process and standards. This allows the rail industry to move towards the adoption of integrated inspection procedures based on existing commercial systems available in the market.
When using appropriate techniques integrated together in a way so as to complement the capabilities of each other, substantial improvements in rail non-destructive evaluation can be achieved. Developments in which conventional ultrasonic probes have been integrated with other types of inspection systems, have demonstrated this.
The application of novel non-destructive evaluation techniques for both manual and automated inspection of rail tracks under actual conditions.
The project has demonstrated an integrated high speed inspection system based on a modular design, which will enable the fast and reliable inspection of rail tracks at speeds up to 320 km/h. The project had combined automated visual inspection and probes into a single high-speed inspection vehicle.
- An efficient and integrated mobility system: Acting on transport safety (saving thousands of lives)
- Innovating for the future (technology and behaviour): A European Transport Research and Innovation Policy