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Issue 2 2011 / 6 April 2011 /
Track21 is a major new research programme funded by the Engineering and Physical Sciences Research Council (EPSRC) with the aim of developing the fundamental science needed to bring about a step-change improvement in the performance of the UK’s railway track system.
Led by Professor William Powrie of the University of Southampton, Track21 brings together worldleading academics from the Universities of Southampton, Birmingham and Nottingham with key industry players to develop the scientific knowledge needed to inform not just incremental advances, but a step change in the way the existing track network is maintained and new lines designed and built. (more…)
Issue 2 2010 / 5 April 2010 /
The Chinese railway dates back approximately 130 years. The first railway line, Wu-Song, was built in 1876 in Shanghai with a length of 14.5km and a track gauge of 762mm. The first railway built by Chinese engineers is the Jingzhang-Railway (Beijing to Zhangjiakou), finished between 1905 and 1909 with a total length of 201.1km, a small curve radius of 182.5m and four tunnels with a length of 1.6km. The Chief Engineer, Zhan Tianyou, who used a switchback to overcome a steep gradient, is called the father of China’s railway due to his achievement in construction of this railway line. Since that time, the Chinese railway has written its own story. At the beginning of the modern era, 21,810km of railway lines were in operation. Due to the economic reforms up until the late 1980s, the Chinese railway begun to grow significantly to meet the requirements of the growing economy and population. Over the last decade, the topic of high-speed railway has become a very important one for the Chinese railway industry. (more…)
Issue 5 2009, Past issues / 26 September 2009 /
Since March 2008, Tilo Brandis has been President and CEO of RAIL.ONE GmbH. After his studies at various universities in Europe and at Harvard Business School, Brandis began his career at HBS Consulting Partners as a Project Manager and Management Consultant. In 1997, he moved to Siemens AG Transportation Systems. In 2003, he took charge of Siemens AG A&D Assembly Systems, with around 2,300 staff and with sales of approximately €600 million. Until he moved to RAIL.ONE, Brandis directed the acquisition of the US software company UGS for Siemens AG. With more than 800 employees and 18 locations in nine countries, RAIL.ONE is one of the world’s leading providers of railway track systems, with comprehensive consulting and engineering competence for all areas of application. (more…)
Issue 3 2009, Past issues / 15 May 2009 /
During spring 2008, a study of a slab track system for the new Ring Rail Line was conducted in Vantaa, Finland interlinked with the railway planning phase. The study concentrated on the seven kilometre long double tunnel system which would go under the Helsinki-Vantaa Airport area. The main task was to investigate the suitability of a slab track system as an alternative for a traditional ballasted track from the given starting points and in Finnish conditions. It was expected through international experience that slab track would present advantages concerning future maintenance, tunnel safety and also savings in tunnel excavations. The study was made for Finnish Railway Administration by Pöyry Infra Ltd and VR-Track Ltd Railway Consulting department.
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Issue 3 2009, Past issues / 15 May 2009 /
High-speed rail traffic – and, consequently, regularly scheduled train service at speeds over 230km/h – has demonstrated tremendous development since its beginnings in the late 1970s, and above all during recent years. The required rail lines, as well as interconnected high-speed rail networks have been vigorously and continuously expanded, especially in Asia and in Europe. As part of this process, the entire complex of railway technology has been further developed on an uninterrupted basis and has been adapted to the more demanding requirements encountered: with respect to rolling stock, train traffic control and supervision systems, and – not least – track technology. It is therefore unsurprising that not only the very latest in trains are using the new high-speed networks, but that the state-of-the-art in track technology is also being likewise implemented.
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Issue 1 2009, Past issues / 23 January 2009 /
Over recent years, minds have been focused on improving the system reliability of the Dutch railways. So far, it has proved possible to shoehorn the capacity requested by transport operators into the timetable each year, even though the network is one of the most intensively used in Europe. Now that reliability has been put in order, and the demand for capacity is increasing, the time is right for expansion and for raising capacity utilisation above traditional standards.
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Issue 6 2007, Past issues / 26 November 2007 /
The international increase in transportation volume throughout the world over recent years has led to a revival in railway traffic. This has in turn resulted in an appreciable number of technical innovations and an enhancement in railway technology in the areas of rolling stock, train control and track engineering.
One example of such developments has been the establishment of ballastless track, not only for niche applications, but also as a standard product alongside conventional and more innovative ballasted tracks. Throughout the world today, new track projects and infrastructure expansions are being planned and engineered from the very beginning as ballastless track systems, which have proved to be safe, reliable and cost effective.
The RAIL.ONE Group (formerly ‘Pfleiderer track systems’) was involved from the earliest days in a leading role for the development of ballastless track systems for high-speed, heavy-haul and commuter traffic. Recently, the company has succeeded in profitably exploiting its experience in numerous projects for various countries and railway authorities. (more…)
Issue 4 2007, Past issues / 30 July 2007 /
ProRail manages an installed base which has an estimated replacement value of more than €30 billion. Tracks and turnouts are a significant part of the pie, amounting to more than €8 billion. Moreover, they consume more than 50% of total maintenance costs and 75% of renewal costs due to their usage-based, relatively rapid deterioration pattern and high cost of installation. Last but not least, track and turnouts, and especially high-speed turnouts are important because they are sources of failure and traffic disruption. This is why ProRail develops policy plans for track product and maintenance management.
This article briefly drafts ProRail’s product management and maintenance policy, which aims to deliver optimum performance levels of tracks and turnouts. The policy is a formal working document within ProRail, which sets out which track products, standards and maintenance strategies deliver best value for money1. (more…)
Issue 3 2007, Past issues / 6 June 2007 /
The fact that the slab track is more than just a product becomes apparent if the subject matter is approached from the perspective of the internationally active track construction company Heitkamp Rail, a subsidiary of the Dutch Heijmans group of companies.
Over a period of years, a very complex task field has developed around the slab track ranging from consulting and planning services to the execution of construction work and to internal developments. This task field is characterized by several track systems that – representing engineering projects by themselves – are often embedded in complex construction projects. (more…)
Issue 3 2007, Past issues / 6 June 2007 /
On 15 April 2007, the RPM-RS-900 from the SPTIZKE Group celebrated its construction première in Germany. For the first time, the machine works to improve the formation, cleaning and recycling of ballast – all in a single machine complex. Renewing the substructure of tracks is now performed by 200 metres of state-of-the-art high performance technology. (more…)
Issue 2 2007, Past issues / 3 April 2007 /
ÖBB, The Austrian Federal Railway Company, transports approximately 183.3 million passengers and 90.6 million tons of freight traffic per year. The ÖBB railway network consists of approximately 3,600 kilometres of main railway lines and in the region of 2,200 kilometres supplementary network (Figure 1).
At the moment, the maximum line speed is 200 kilometres per hour. This will increase to 250 km/h in the near future. The maximum axle loads are approximately 22.5 tons and the total length of our tracks is 10,500 kilometres. 7,100 kilometres of them are electrified and the network contains about 16,700 switches and crossing units.
Ballastless track at ÖBB
At the beginning of the 1980s, the ÖBB started using ballastless track systems. During the first phase (from 1982 until 1995), several different types of ballastless track systems were tested. In that period, approximately 22,600 meters of ballastless track were built. The main types used at that time were monolithic systems (RHEDA), booted sleeper systems (STEDEF) and precast slab systems (ÖBB/Porr). After this first period, the experience with the different systems gained by ÖBB was evaluated. The following main aspects were investigated:
- Specific design aspects (needed space etc.)
- Construction process (sensitivity in order to site situation)
- Quality (track quality, acoustic behaviour etc.)
- Economic situation (initial investment costs and life-cycle costs)
The result of this detailed investigation was that for use in the network of ÖBB, the ÖBB/Porr ballastless track system fitted best. Furthermore, it has been established that the main field of use of the ballastless track system are on tunnel-lines.
Due to these facts, only the ÖBB/Porr system has been used in the network of the ÖBB after 1995. For switches and crossing areas, special ballastless systems consisting of booted monobloc sleepers were developed and are still in use now.
At the moment, approximately 130 kilometres of ballastless track systems are under operation within the ÖBB railway network – used mainly in tunnels but also on bridges and on surface lines. For noise and vibration reduction, many of these systems are combined with floating slabs. The system is tested for a maximum train speed of more than 300km/h and has a certification for a maximum train speed of 330km/h. The system is licensed for use in the Austrian, German and Swiss railway network.
Worldwide use of ballastless track systems
The development of ballastless track systems started in the second half of the 20th Century in Japan (due to high speed train traffic). A few years later, these developments reached Europe. The Japanese developments focused on precast elements, but the developments in Switzerland were based on booted sleeper systems while in Germany, the developments were based on monolithic cast in place systems. The worldwide distribution of the main ballastless track system is shown in Figure 2.
Use of the ÖBB/Porr system outside Austria
Due to the very good experiences gained by ÖBB with the ÖBB/Porr Slab Track System, many other railway companies showed interest in the system. Therefore, this ballastless track system has been used at new, large railway connection projects in Berlin: North-South intercity railway connection and East-West connection near the Lehrter Bahnhof. In total, there are approximately 18 kilometres of the ÖBB/Porr ballastless track system currently under operation. The system is situated in tunnels and on bridges with short sections on earthwork.
Main features of the ÖBB/Porr system
The ÖBB/Porr system was designed to replace the typical behaviour of the ballasted track by several elastic elements in the ballastless system. The typical behaviour of a ballasted track shows the elasticity in the ballast itself and in the rail fastening system. These two elastic elements have to be copied by the elasticity of the rail fastening system in the ballastless track and of the elasticity of a second layer which is situated at the bottom of the prefabricated slabs.
This system (shown in Figure 3) leads to a distribution of the elasticity between the elastic coating of the slabs and the rail fastening system of 10% to 90%. Usually, the rail fastening system IOARV 300-1 from Vossloh realises the needed elasticity in the rail fasteners. The elastic coating consists of a PUR-bound granular rubber.
During train operation this leads to rail deflections of 1.5 millimetres under a Taurus locomotive (about 22.5 tons axle load). The main advantages of the system are:
- Very small space needed (width of slabs is 2.40m and can be reduced down to 2.10m, thickness of slabs is 16cm which leads to a construction height of 50cm from top of rail down to e.g. tunnel floor) which leads to reduction of the necessary cross-section of e.g. tunnels
- Very good vibration attenuating performance (the system can be addressed as a floating track slab system with about 1 ton per meter sprung mass)
- Use of the standard rail fastening system Vossloh IOARV 300-1 which makes an easy maintenance possible
- Simple construction procedure on site (most of the sensitive works are transferred into the prefabrication site)
- High track quality standard is documented by intensive measurements of all realised projects up to no
- Quick construction procedure on site because of use of only few concrete on site (most of the fabrication is done at the prefabrication site)
- Easy and effective repair concept (exchange of rail fasteners or whole slabs can be done very easily in very short time)
- Very good-natured behaviour in order to extra ordinary events as for example derailment
- Nearly no regular maintenance work necessary
Possible use of the system for the Turkish railway network
Today, the situation of the Turkish federal railway company, TCDD, shows the following statistic performance (source: www.tcdd.gov.tr): 8,700km main lines, 11,000km total network, about 8,000 units switches and crossings. The maximum line speed is V = 140km/h at the moment. The yearly transportation volume is approximately 77 million passengers and in the region of 20 million tons of freight traffic.
This means that in comparison with ÖBB, the length of the network of TCDD is of comparable size but the transportation volume is significantly lower. These facts have to be reflected – having in mind that the country is several times larger than Austria – which leads to the following statements:
Statement 1
A lot of additional railway lines would be needed to reach a similar density of railway network and furthermore a lot of improvements of the existing network would be necessary to enlarge the transportation volume of the net. Especially the differences in the number of switches and crossings are an indicator for the improvement needs of the existing network.
Statement 2
At the moment, and in the near future, a couple of new high-speed railway lines will be built in Turkey. The maximum line speed of these projects is up to V = 250km/h. Therefore, questions of superstructure are of major importance. Not only in tunnels but also on viaducts, ballastless systems lead to economic (especially in order of long-time aspects) and safety advantages.
Due to the advantages of the ÖBB/Porr system described in this article, in theory it seems to fit very well for the Turkish Railway network. Especially for use in tunnels, which is the main area of application, seems to be effective as well as in Austria. The reasons for that are the much reduced maintenance necessities, the safe run of the trains and the good behaviour of the system in case of derailment events. Furthermore, it is possible to equip the ÖBB/Porr system with a lot of optional elements. For example it is possible to make the whole system rideable for road vehicles (e.g. fire engines, ambulance) by using additional elements. To increase the safety of railway tunnels, this field of usage gets more and more important in Austria. As mentioned above, the system is well suited for combination with noise and vibration attenuating systems (floating track slab systems).
The basic characteristic of the system – most of the construction work takes place in pre¬fabrication sites – makes it useable with a minimum of high-qualified people on site and ensures a very good track quality. Nevertheless, most of the works for the system can be done by local people either in the prefabrication process or on site. The ÖBB/Porr track system can be combined with usual high-elastic rail fastening systems as for example IOARV 300-1 from Vossloh.
Conclusions
At the moment, and in the near future, the Turkish railway network will be enlarged and improved. Therefore, ballastless track forms will be needed as well. The ÖBB/Porr system for ballastless tracks which consists of elastically supported precast concrete slabs is very well suited for the specific situation in Turkey. It shows a lot of advantages for applications in tunnels, on bridges and on surface lines. Due to the prefabrication principle, a very good track quality can be realised with a minimum of high-qualified people on site.
The ÖBB/Porr ballastless track system would be a good contribution to the extension and modernisation of the Turkish railway network. The following points of reference were used for information to help complete this article:
- TCDD: www.tcdd.gov.tr. RPC Department Statistics Office, Ankara
- Schilder, R.: Experience in ballastless track gained on ÖBB. European Slab Track Symposium, Brussels, Belgium, 22 February 2005
- Schilder, R.: Ballastless track application in existing tunnels – experience gained on Austrian Federal Railways. Rail Engineering International Edition 1993 Number 4
- Schilder, R.: Improvement of ballastless track designs for turnouts: experience gained on Austrian Federal Railways. Rail Engineering International Edition 1999 Number 1
Figure 1: Lines of the ÖBB railway network
Figure 2: Distribution of ballast-less systems worldwide
Figure 3: Rail fastening system Vossloh IOARV 300-1
About the author
Rudolf Schilder has a diploma in Civil Engineering from the University of Graz, Austria. He also worked there as a university assistant in the Institute of Railway Technology from 1979 to 1983. During these years he received a Doctors degree in Technical Sciences. In 1983 he joined Austrian Federal Railways and occupied several functions. In 1996, as head of Track&Structure Department, Mr. Schilder was in charge of Track Technologies. Since 2005, Mr. Schilder has been Head of Permanent Way Department at ÖBB Bau AG. Mr. Schilder is a member of several national and international working groups, such as OeNorm (Austrian Standardization Office), ÖVG (Austrian Society for Traffic and Transport Science, Working Committee on Railway Technology), CEN (Committee for European Normalization), UIC (International Railway Union), AEIF (European Association for Railway Interoperability) and ERA (European Railway Agency).
Issue 2 2007, Past issues / 3 April 2007 /
Present requirements of safety and quality in high-speed lines, considering the demand of increased traffic and higher reliability, lead to the introduction of more and more complex analyses in order to guarantee accurate track maintenance. In this context, systematic application of track tests, both dynamic control (measuring vehicle accelerations) and geometric one (measuring levelling, alignment, cant and gauge), is the key-tool in order to plan corrective work on track.
In general, results deduced by track test regarding degradation disagree with formula from theoretical analyses. Reality is different from predicted results: there is a large amount of factors that change predicted track behaviour. Certainly, factors that traditionally have been identified as causes of track degradation (traffic, speed, axle load) are not enough to explain track geometry progression. In this sense, stability of infrastructure has relevant influence on process of track degradation: high earthworks or structures that modify vertical stiffness of track are able to generate punctually intensive degradation. Difficulty to quantify influence of these factors is due to the stochastic characteristics of most of them. (more…)
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