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Research holds the key to commercial success

01 Jul 2005

Lower noise, higher speeds and lower costs rank among the top targets for today's research teams. Murray Hughes reviews current railway research activities

RAILWAY BUSINESSES ignore the disciplines of engineering and technological research at their peril. As the commercial realities of the 21st century lever up competitive pressures across the transport industry, the technical performance demanded from infrastructure and rolling stock rises ever higher.

The long-term future of the railway industry hinges on its ability to cope with these demands, or as Roger Lundén at the Department of Applied Mechanics of Chalmers University of Technology (Charmec) in Sweden puts it, 'there is much work in the area of developing safer and more reliable track, wheels and axles which we consider to be of great strategic importance to the railways.'

Railways remain under constant threat from competing modes. Freight is facing a sustained attack from road haulage, especially in Europe, where road hauliers have low margins, making competition ferocious. Complacency and a failure to respond will jeopardise rail's ability to compete, and action is urgently needed to develop cheaper and more reliable services attractive enough to win back lost customers. Operators must also recognise that the needs of the freight market have changed dramatically with the arrival of global commerce.

Visitors to the Transport Logistic 2005 event in München last month could view a 60 tonne three-section lorry reminiscent of Australia's road trains and able to carry three 20ft containers. What, we ask, are Europe's rail operators doing to counter the potential gain in productivity that this offers Europe's road hauliers?

Many passenger services too face an uncertain future as low-cost airlines carve a slice out of the inter-city market where they are taking traffic from rail and generating new flows as well. To meet these challenges railways urgently need to raise the productivity of their staff and assets and bring down costs.

Lower maintenance costs

There is a strong consensus that track maintenance costs must fall. Charmec, which specialises in the mechanical interaction between track and train, cites work it is carrying out to improve the design of turnouts and crossings to give better reliability and availability and to cut the 'large maintenance costs' - there are about 10000 switches and crossings in Sweden.

Louis Cléon of SNCF's research department says that available data on maintenance is currently being analysed to determine how costs can be cut. Work includes improving the performance of ballast, and here SNCF is working in partnership with French universities, while in North America discrete element models are being used in simulations of ballast behaviour. A short section of ballastless track is being built on TGV Est, but there is no sign of the French adopting this on the same scale as on high speed lines in Germany.

Roy Allen, President of TTCI in the USA, highlights a project 'to improve rail field welding which will eliminate chronic weak points in the track structure that result in service disruptions and additional maintenance cost'. He points to new technologies such as the gas pressure weld which has shown laboratory performance equivalent to that of the flash-butt weld. 'Gas pressure welds will be designed for closure welds and will therefore be suitable for repair purposes', says Allen.

This is part of a major research effort 'to reduce the stress state of the railroad' which will 'reduce the capital intensity of the industry and improve its service reliability'.

Bringing about this objective will be no mean feat. While the need to reduce stresses in the infrastructure is widely acknowledged, commercial pressures mean that North American railways are simultaneously seeking to operate more trains with heavier axleloads. One consequence is that axle and wheel fatigue issues are increasing as wagons have grown bigger and tare weights have decreased. A review of axle designs is being undertaken.

Tools being developed by TTCI and its railway partners include better rail flaw inspection with laser-based technology allowing the entire rail cross-section to be checked for defects. Another area for investigation is improved performance of bonded insulated joints, which tend to deteriorate rapidly under heavy axleloads.

The technical limits

Agreement exists among several research organisations that the technical limits of today's railway infrastructure are still far off. In terms of axleloads, the All-Russian Railway Research Institute says that in 2005 the limit on the RZD network will be raised to 25 tonnes, with 30 tonnes contemplated in the near future. In Australia, iron ore carrier BHP Billiton is pushing the envelope to levels that were not contemplated some years ago, with 40 tonnes in prospect.

But Allen warns that 'there are signs in North America that we may be closing in on the limits', although he expects technology to advance to overcome the current problems. 'Higher hardness rail and the accompanying decrease in fracture toughness may become a problem with axleloads higher than 36 tonnes', he says, pointing to some indications of this emerging on the FAST test track at Pueblo, Colorado.

Lundén suggests that dedicated freight tracks would be one answer for high axleloads, and he considers that it will be possible to raise axleloads in Europe 'at reasonable cost'. He points out that a general increase in axleload limits in Europe will require specific knowledge to determine where the necessary investment should be spent.

Towards 400 km/h

The future maximum operating speed of passenger trains is primarily of interest in Europe and Japan, but China is keeping a close watch on developments before taking final decisions on the future Beijing - Shanghai high speed line which may be designed for 350 km/h. In the Swedish context Charmec favours 'lines with moderately high speed' for 200 to 250 km/h because moving to higher speeds would be 'at very high cost'.

In France, however, 320 km/h is already achieved on a short section of TGV Méditerranée, and this will be the normal operating speed on TGV Est when it opens in 2007. In Germany, 330 km/h is permitted on the Köln - Frankfurt Neubaustrecke, but attempts to introduce 350 km/h operation in Spain have fallen well behind schedule with late delivery of the Velaro E trains from Siemens and continuing problems with signalling and train control equipment on the partly-completed new line between Madrid and Barcelona.

In Japan the first car for JR East's prototype Series E954 eight-car Fastech 360 S trainset was offloaded from a ship at Sendai on June 7, and trials between Sendai and Kitakami on the Tohoku Shinkansen were due to start last month. These will encompass tests at 405 km/h, although the maximum speed envisaged in commercial service is 360 km/h. This would make JR East the operator of the world's fastest trains.

SNCF has begun a serious assessment of the requirements for running at speeds higher than 320 km/h (RG 5.05 p255). Behind this thinking are future TGV lines that could be built to serve Bordeaux and Toulouse and several cross-border routes. Cléon says the work covers the technical problems of running at 350 km/h on a daily basis. He notes that over 2000 km were run at 400 km/h or more during preparations for the world speed record of 515·3 km/h attained by TGV set 325 in May 1990.

Providing sufficient traction power at 350 km/h, says Cléon, is not a problem, but braking certainly is. Disc brakes cannot be used at this speed, and the option of eddy-current rail brakes is being investigated again following trials in the 1970s and in the 1990s. While heating of the rail was once considered a problem, Cléon says this is manageable and rails were hotter during the heatwave in 2003. Experience has in any case been gained in Germany with the ICE3 fleet (RG 4.05 p179).

More difficult, says Cléon, is the unsuspended mass of eddy-current brakes on the bogie frame. Trials are envisaged in the next two or three years, but no decision has yet been made.

Closely related is the problem of longer braking distances which could potentially reduce line capacity - although this could be offset by the anticipated increase in capacity possible with ERTMS.

An expected increase of around 4dB(A) in lineside noise can perhaps be mitigated by use of bogie skirts and fairings between the cars. These measures will improve aerodynamics, to which end longer nose forms, similar to those used on Japan's latest Shinkansen trains, may be developed.

New materials

Cutting energy costs is of growing significance as fuel prices rise. Cléon points out that saving a kilogramme of mass is much more worthwhile in aviation than on a TGV, and he stresses that new techniques need to function well and be affordable.

In Germany, Siemens is investigating modular hybrid bodyshell construction in its eSIE-CAR project, with a demonstration structure now complete. The company had concluded that the options for lowering the cost of integral aluminium bodyshell construction have been exhausted, and it is therefore exploring the use of stainless steel alloys that have been successfully applied in the car industry. Such alloys are moderately priced and can be transported at relatively low cost in containers. Combined with laser welding and other new joining techniques, they can be used to form modules that are quickly and easily assembled.

The prototype shell has a load-bearing inner structure using high-strength H400¨ stainless steel with an outer skin of lightweight sandwich material or GRP pultruded profiles.

Partners in the project include the Fraunhofer Institute for Laser Technology, Aachen Technical University, Röchling Haren KG and Invent GmbH.

Several experiments in the past have seen the use of composite materials in a structural role, but price is one of the issues militating against progress.

Aluminium-bodied wagons with high payloads have had a major impact on the productivity of North American railroads hauling coal. Allen reports that plastics 'are showing promise for ties, and concrete is becoming the most common material for new bridge construction. But wheels and rails continue to top the list of railroad expenditure and new materials could have a large impact with newly-developed materials continually improving the performance of these components.'

Low-wear rail

Rail steels remain a fruitful area of investigation as the search goes on for low wear and resistance to rolling contact fatigue. Today's head-hardened rail steels with an average Brinell hardness of 395 provide a 12·5% improvement in wear resistance, as evaluated at FAST, in comparison to the previous generation of rail with average hardness of 365HB. Allen says that 'newer rail developed with hardness of approximately 420HB is likely to provide further improvement, and the newest rail is to begin evaluation at FAST this year.' He adds that new high-hardness perlitic rail steels 'are somewhat of a metallurgical breakthrough as it was thought at one time that a fully perlitic rail material with a hardness of 400HB was not possible, but suppliers are now producing rail with 420HB.'

Research into materials used for wheels also promises significant progress. The continued development of the spall-resistant alloy wheel could significantly reduce wheel damage on rolling stock and routes where spalling is a problem. The wheel alloy has shown a reduction of 43% in spall depth (the formation of martensite on the wheel tread caused by wheel slide). Additionally, the North American Wheel Defect Prevention Research Consortium is looking into wheel spalling issues which may be addressed using wheel modifications and alloying to inhibit shelling. Allen says research on this will start this year.

Tomorrow's traction

Permanent magnet traction motors could soon reach the point of practical application, and developments are expected to be announced later this year in France. Other projects to watch for include super-capacitors and energy storage devices. SNCF confirms that a hybrid shunter with energy storage technology is to be tested in the near future.

In the USA, GE is working on plans for a 4 400hp hybrid loco under its 'Eco-magination' programme. This will collect and store braking energy in lead-free onboard batteries, and the energy will then be available for traction purposes when required with an additional 2000hp on tap.

Both GE and rival Electro-Motive Diesel offer locos that meet the latest Tier II emissions regulations, and both suppliers and railroads are also looking at cleaner technologies for retrofitting to older locomotives. Allen says 'application of aftertreatment technologies to older switch engines to reduce particulate matter is being tested', adding that 'creative power replacement concepts with cleaner burning engines are being considered', as well as the use of fuel cells.

Allen remarks that the task of identifying funds for emissions research is complicated in railroad applications owing to the limited numbers of new locomotives purchased each year and the long life of the hardware, typically upwards of 30 years. With a total Class I fleet of some 20000 units, the replacement rate is usually less than 5% per year. He points out that many of the gains in emissions reductions and equally important fuel improvements in engine technology 'could use a boost in federal research dollars, as has been heavily done with on-highway diesel engines'. In most cases, technology gains in 'on-highway' technology applications are not directly transferable to railroads.

In Russia, research continues into gas turbine traction as one method of 'providing low emission levels of harmful agents'. Related work covers alternative fuels, non-cooled exhaust collectors for diesel engines and neutralisers for exhaust gases. The All-Russian Railway Research Institute is firmly convinced that 'electrification is the best way to solve the problem of environmental pollution and the most efficient method of energy consumption.'

Comfort on board

Cléon draws attention to a major programme of work at SNCF into 'the most important parameters for passenger comfort' on its future trains. These include psychological factors, and SNCF is keen to understand precisely what passengers feel when travelling so that this can be fed into the research. Questionnaires are being used to quiz passengers on their reactions to noise and vibration, with measurements being taken simultaneously. Areas for investigation include better ergonomics, lighting, air-conditioning, colour scheme and new types of toilet.

Similar work has taken place in Japan, one result being the introduction of active suspension on the latest Shinkansen trains.

Obstacles to progress

Changes across the railway industry have altered the way research is funded and carried out. Railways in Europe and North America expect supply companies to conduct their own research, and this is particularly true of the locomotive and passenger rolling stock builders.

The arrangement appears to work well for relatively large companies, and Allen points out that rail steel manufacturers conduct their own research to improve their products and have achieved a tremendous improvement in rail longevity. But he warns that the model does not work as well in other areas, particularly where suppliers of components are small companies.

Separation of infrastructure management from operations opens up the possibility of the critical area of wheel-rail interaction being neglected, but Cléon feels that the impact of RFF being established as a separate organisation has not had many consequences in this field. 'We work together on interface issues', he says, and cites the Europac programme on pantograph-catenary interaction as one example. Intended to improve the interoperability and reduce the maintenance costs of overhead line equipment, the project is being co-ordinated by SNCF with UIC, six other railway operators and infrastructure managers, three suppliers and three academic institutions. Total cost is €4·7m, of which the EU is contributing €2·6m.

Lundén considers it essential for 'the infrastructure manager to carry on a dialogue, and he must have the knowledge to create well-defined interfaces and must state acceptable levels and limits for the interface parameters'.

In North America, Allen believes 'the model of the AAR/TTCI research programme being conducted on behalf of the railroads is sound. I also believe that understanding and researching the vehicle-track interface is crucial for efficient and safe operations.'

So could the North American model be replicated on a railway where there is separation of the major functions? One model to consider, suggests Allen, is an industry organisation funded by a consortium of stakeholders from the infrastructure and train operators. This would be given a clear remit and be held responsible to deliver the results on budget and in time, 'but it cannot and should not have any supplier representation. It should be a body that is non-profit but it could use any outside consultants and expertise to achieve the results, just as the AAR-TTCI and FRA do in the USA. The other important factor in achieving successful research results is a long-term vision of five to 10 years, with each task or project having an implementation phase.'

Separation can be managed, but there is some agreement that industry fragmentation leads to technical choices that are not necessarily the best. Allen concurs with this suggestion: 'the greater the segmentation, the harder the management task of delivering transportation services. This is apparent even in an integrated system with the various departments not communicating with each other or not working together. The difficulty is heightened in the case of technical solutions, as no good result is worth the money if it cannot be properly implemented.'


Priority projects at TTCI

AAR and its member railroads have accelerated six projects which they believe will provide significant benefits to the North American railways. These six projects are:

  • Improved rail flaw detection
    Develop a laser-based ultrasonic rail inspection system to test railhead (including transverse defects masked by surface spalling and shelling), rail web, and rail base defects.
  • Effects of heavy axleloads on insulated rail joints
    Foster the development of improved performance bonded insulated joint designs for heavy-axleload service. Develop performance requirements and design guidelines, evaluate advanced designs and provide recommendations.
  • Cracked wheel detection
    Develop a lineside ultrasonic inspection system using laser generation and air-coupled reception of ultrasonic waves to detect cracks in railway wheels. A prototype is focused on a single system designed to detect shattered rim cracks as well as tread and flange surface cracks.
  • FAST/HAL operations
    Investigate performance of new designs and materials for track components, such as rail steels, new designs and materials for special trackwork, insulated joints, open-deck steel bridges with advanced joints, two types of concrete bridges, improved rail welding, plastic and wooden sleepers, new designs of tie plates and fasteners. Evaluate mechanical components that may improve performance or economics of 37·5 tonne axleloads, including lightweight bogies with 914mm diameter wheels. Continue economic analysis of operating HAL wagons.
  • HAL axle design
    Expand revenue-service data relating to axle stress and wheel load environment of 32·5 tonne (Class F) axles in cold ambient temperatures by taking data in loaded coal service operations on UP and CSXT. Develop and conduct crack initiation and crack growth testing on 32·5 tonne axles in the bearing lab at TTC.
  • Car inspection and maintenance procedures
    Develop inspection and maintenance procedures for poorly-performing cars, based on measurements from lineside detectors - in particular Truck Performance and Hunting detectors.

CAPTION: The first Fastech 360 S car for JR East is currently being commissioned in the railway's Shinkansen maintenance depot at Sendai. These could soon be the world's fastest trains in commercial service

CAPTION: Passenger comfort is a major area of research where ride quality is of prime importance. This TB201 bogie was developed by Prose of Switzerland for use on 20 Type Edm sleeping cars being built by Talgo Oy for Finnish Railways to run at up to 200 km/h

CAPTION: Siemens is exploring new methods of bodyshell construction under the eSIE-CAR project being carried out with Aachen Technical University and other industrial partners

CAPTION: North American Class I railroads are not earning enough return on investment to cover their cost of capital, according to STB figures. Roy Allen says research at TTCI is focusing on ways to 'reduce the capital intensity of the industry and improve its service reliability'

CAPTION: Rail freight companies need to respond to the possibility of 60 tonne lorries being authorised to operate more widely on Europe's roads. This vehicle able to carry three 20ft containers was exhibited at the Transport Logistic 2005 event in München in June

La recherche détient la clé du succès commercial

Réduire l'intensité capitallistique de l'industrie est un objectif vital pour la recherche ferroviaire dans un monde de plus en plus compétitif. Les pressions à court terme relèguent souvent la recherche au bas de l'ordre du jour, mais l'impératif commercial consistant à faire rouler plus de trains, plus lourds, signifie que des travaux approfondis dans le domaine de l'interface roue-rail sont essentiels. Dans ce tour d'horizon des programmes de recherche ferroviaire d'aujourd'hui, les organisations de recherche et développement sont persuadés que la technologie peut aider à augmenter encore plus les charges par essieu et que le contröle-commande des trains, basé sur les télécommunications, peut augmenter la capacité des lignes au-delà des pratiques admises aujourd'hui. Dans le même temps, les chercheurs doivent trouver les moyens de réduire le bruit des trains et parvenir à un équilibre entre rentabilité, consommation d'énergie et rejets afin de s'assurer que les chemins de fer conservent leur statut d'ami de l'environnement

Forschung als Schlüssel zum wirtschaftlichen Erfolg

Die Verminderung der Kapitalbindung der Industrie ist ein Grundziel für die Forschung im Eisenbahnwesen in einer zunehmend konkurrenzierenden Welt. Kurzfristiger Druck schiebt die Forschung in der Wichtigkeit oft nach unten, aber die wirtschaftliche Notwendigkeit, häufigere und schwerere Züge zu führen bedeutet, dass weitere Arbeiten im kritischen Bereich der Rad-Schiene-Schnittstelle essentiell sind. In dieser Übersicht über die Forschungsprogramme der heutigen Bahnen sind führende Forschungs- und Entwicklungs-Organisationen zuversichtlich, dass neue Technologien die Achslasten weiter erhöhen können, und dass Kommunikations-basierte Zugleitsysteme die Streckenkapazitäten über das durch heutige Praxis akzeptierte Mass hinaus steigern können. Gleichzeitig müssen die Forscher Wege finden, um den Lärm zu reduzieren und ein Gleichgewicht zwischen Wirtschaftlichkeit, Kraftstoffverbrauch und Emissionen zu finden, um sicher zu stellen, dass die Bahnen ihren Status an Umweltfreundlichkeit halten können

La investigación es la clave del éxito comercial

Reducir la intensidad en capital de la industria es un objetivo vital para la investigación del ferrocarril en un mundo cada vez m? s competitivo. A menudo, las presiones a corto plazo empujan a la investigación hasta el último lugar dentro de la agenda comercial, pero la necesidad de que circule un mayor número de trenes y m? s pesados implica que es fundamental trabajar m? s en la interfaz rueda-carril. En esta evaluación de la actual agenda de investigación del ferrocarril, organizaciones destacadas del ? mbito de la investigación y el desarrollo est? n convencidas de que la tecnología puede ayudar a aumentar m? s las cargas por eje y de que un control de los trenes basado en las comunicaciones puede aumentar la capacidad de las líneas m? s all? de lo comúnmente aceptado hoy en día. Al mismo tiempo, los investigadores deben encontrar formas de reducir el ruido de los trenes y alcanzar un equilibrio entre la rentabilidad, el consumo de combustible y las emisiones para asegurar que el ferrocarril siga respetando el medio ambiente