Reference Story SIL 4 PLC interlocking reduces lifecycle costs New PLC interlocking with COTS safety controllers offers SIL 4 safety and reduces lifecycle costs by 30% (Germany, Bruehl, 10/1/2014) ProRail, the state-owned Dutch railway infrastructure enterprise, commissioned consulting and engineering firm Movares with implementing a PLC interlocking based on industrial COTS (commercial off-the-shelf) hardware. The new interlocking concept relies on a HIMax controller system and satisfies ProRail requirements for supplier independence, safety, availability, easy operation and maintenance, and lower lifecycle costs, achieving approximately 30% lower costs than other electronic interlocking solutions. A pilot project was successfully implemented at the Santpoort Noord railway station. Santpoort Noord is the first PLC interlocking for main lines that satisfies the requirements of the highest safety level, SIL 4, in accordance with CENELEC. ProRail N.V. provides a secure, reliable, punctual and sustainable rail network and comfortable stations in The Netherlands. The state-owned enterprise provides services in three business segments: railway infrastructure, railway network and transport volume. "We are responsible for the construction and maintenance of the track, explains Jorn Pruntel, Department Manager, Railway Signaling Systems, at ProRail. We develop new lines and are also responsible for construction of the railway stations and for everything else in the neighborhood of the tracks. In addition, administration and safety are among ProRail's tasks. We must ensure that the lines we take care of have 100% failure-free availability."
Old railway relay interlockings will be replaced In 2004, ProRail concluded that relay-based interlockings built from 1953 to 1969 needed to be replaced. The old interlockings were not flexible and had high lifecycle costs. ProRail also faced the burden of being locked into proprietary systems that depended on specific providers for component purchase, engineering, maintenance and modifications. As part of its interlockings replacement program, ProRail intends to replace the current ATB system with ERTMS, the future European traffic management system for lines of the trans-european railway network. The new interlocking systems must satisfy the following requirements: better RAMS (Reliability, Available, Maintainability, Safety) performance, lower lifecycle costs per train kilometer, implementation of new functionalities, and a safer work environment for maintenance personnel on the line. Lower lifecycle costs through openness To achieve its RAMS goals and reduce lifecycle costs for its interlockings on the main lines, ProRail is committed to open technology. The independent Dutch consulting and engineering firm Movares proposed a solution that would enable ProRail to meet all of its goals without proprietary solutions and lengthy vendor lock-ins. The Movares solution got its start in 2004 with an ambitious R&D project. The company began developing a new type of PLC railway interlocking solution to satisfy safety standards and meet the following requirements: COTS (commercial off-the-shelf) hardware proven in safety-related applications in other industries SIL 4 certifiable solution, in accordance with CENELEC, that is based on open industry standards with interfaces for external devices High availability and easy plug and play Numerous I/O and communication interfaces Through the use of COTS components and supplier independence, Movares envisioned for its clients a solution to reduce lifecycle costs by 30% or more. In the search for a suitable supplier for safe controller technology, Movares discovered HIMA Paul Hildebrandt GmbH. The German-based safety expert offers safety solutions for interlockings, railway crossings, rolling stock and - 2 -
energy supply. HIMA solutions for the railway industry use state-of-the-art COTS components that are used widely in industrial automation. Pilot project - Santpoort Noord In 2009, ProRail commissioned Movares to replace the old relay interlocking at the Santpoort Noord railway station with a PLC interlocking. The station is on a main line with intercity traffic 10 to 12 trains per hour and freight train traffic. Initially, Movares executed the planning with HIMatrix controllers. After the more powerful and fully redundant HIMax controller received SIL 4 certification in February 2011 the first controller of this type ever to receive SIL 4 certification, as stipulated by CENELEC Movares transitioned to the newer controller. Movares quickly discovered that the scalable redundancy of the HIMax controller made it the right safety solution for railway stations and traffic hubs on main lines. Because HIMax is certified in accordance with Achilles Level 1, it also offers the highest level of cybersecurity. Thanks to its high scalability and easy extensibility, the controller platform is suitable for large and small interlocking tasks, and also for monitoring railway crossings and rolling stock applications. Moreover, it is open for ERTMS. That appealed to ProRail, which wanted the choice of competitive products and services throughout the lifecycle. The COTS solution requires no dependence on any single provider, neither for the engineering and commissioning, nor for changes and maintenance tasks. Modifications can be easily executed, and every certified engineering firm can work with it. Thanks to user-friendly functions, HIMax is easy to operate. This helps drastically reduce the number of application errors. Maintenance tasks for the redundant controller system are easy to plan. As a plug and play system with hot-swap functionality, it enables fast, cost-effective replacement of components during operation, thereby ensuring system availability. If maintenance is required, the owner can handle it within normal work hours, while railway operation continues undisturbed. Through the high-level diagnostics of the entire system, errors are quickly localized, and maintenance is facilitated. Due to the short delivery times of COTS hardware, spare parts do not have to be stored. - 3 -
Because it was compatible with the existing interlocking system, HIMax was easily integrated with the existing infrastructure at Santpoort Noord railway station. The SILworX engineering tool, used to program HIMax, became a favorite of Movares engineers. Movares programmers created about 25 standard function blocks that map interlocking functions and can be easily adapted to new requirements. Moreover, the interlocking function blocks improve the test and validation process for future applications. Programming errors are minimized through the tested, preprogrammed solutions. Test and commissioning costs are reduced. 30% lower lifecycle costs "The lifecycle costs of the PLC interlocking are significantly lower than with other electronic interlockings, says Jorn Pruntel, Department Manager, Railway Signaling Systems, at ProRail. The cost reduction of 30% and more that we calculated occurs through the initial project costs, through significantly lower maintenance and repair costs, lower costs of training the development and maintenance teams, and less-expensive COTS hardware. Pruntel emphasizes the system s greatest advantage is that it s not designed exclusively for ProRail. "The HIMA system is already SIL 4 certified, and everyone uses the same system. This increases competition. You do not need to have spare parts in stock, and multiple persons can make changes or extensions. Thus we have lower costs and can execute maintenance more quickly, or we can more quickly modify existing systems. Smooth operation The first PLC interlocking has been in operation at Santpoort Noord since July 2012. In December of the same year, ProRail approved implementation of the PLC interlocking solution from Movares across the entire Dutch railway network. Movares views the ProRail approval as a breakthrough in the area of train control. The combination of proven industrial hardware with railwayspecific applications will result in a cost-effective and flexible product. Since its commissioning, the PLC interlocking has worked reliably and flexibly, says Pruntel. "We are very satisfied. It is one of the best systems that we have." - 4 -
The next project is already in the starting blocks. By the end of 2014, Movares will implement a second PLC interlocking with COTS components from HIMA for ProRail at the Beverwijk railway station. This interlocking is scheduled to begin operation in 2015. Authors Frits Makkinga, Director Innovation & Business Development, Division Rail, Movares Nederland B.V. Peter Musters, Strategic Consultant, both of Movares Nederland B.V. About Movares Movares Nederland B.V. is an independent consulting and engineering firm in the areas of mobility, heavy rail, light rail, civil infrastructure, urban and regional planning, water and energy. The Dutch company, headquartered in Utrecht, plays a leading role in the rail industry as a supplier of project management, design and engineering of conventional and ERTMS systems. In the area of train control systems, Movares employees support the development of rail safety and control systems for railway customers. In that role they touch every project phase, from concept to commissioning, and beyond. Movares Nederland B.V. in Utrecht About ProRail ProRail N.V., headquartered in Utrecht, is the largest railway infrastructure company in the Netherlands. The state-owned enterprise provides services in the railway infrastructure, railway network and transport volume business segments. ProRail maintains approximately 7,000 km of railway line. - 5 -