European Commission logo
English English
CORDIS - EU research results
CORDIS
Content archived on 2024-06-18

Clean European Rail - Diesel

Final Report Summary - CLEANER-D (Clean European Rail - Diesel)

Executive Summary:
With the new emission level limits set by the European Directive 2004/26/EC coming into force in 2012, the ClearER-D, a 4 ½ year collaborative research project co-funded by the European Commission under its 7th Framework programme was launched in June 2009 to find technical solutions to the challenges faced in complying with this new regulation framework. The project also anticipated that further regulation will be likely and sought to provide the sector with dynamic and innovative solutions for future applications should new limits be introduced. Keeping this in mind, the project analysed hybrid technologies and their contribution to the reduction of energy consumption and CO2 emissions. In order to reach the goal of “greening” diesel vehicles, the consortium’s 25 partners from across Europe put forth a strong collaborative effort.
The project was structured in two main frameworks:
• The operational or demonstration part, where significant applications of railway vehicles were selected in order to give the opportunity to engine manufacturers to test their new concept engines conceived to migrate from compliance with IIIA to compliance with IIIB, in the short time frame granted by the NRMM directives.
• The scientific part which investigated innovative solutions, including hybrid applications, that focused on the further NRMM implementation phases and emission limits beyond IIIB. The potential technologies were studied and analysed with regard to sustainable solutions and the ratio cost/benefits was evaluated. Based on the results of the entire project recommendations were developed how to accelerate emission reduction of rail diesel traction in Europe.
The project’s main goal was to demonstrate the feasibility and reliability in service of railway rolling stock powered with diesel engines compliant with the requirements of state IIIB of the NRMM Directive.

Project Context and Objectives:
Summary description of project context and objectives

Railway proves to be generally the most energy efficient and environmental friendly mode of transport for passengers and freight, and it is of the utmost importance for the actors of the railway sector to keep this competitive advantage, while continuing to make progress in emission reduction, including carbon dioxide, also for the part of the fleet using diesel propulsion.
Even if electrification of railway lines is developing more and more in Europe, it shall be considered that for economic reasons a significant percentage of the traffic will continue to rely on diesel traction. This is in particular the case for regional branch lines that collect passengers for “feeding” the main electrified system, as well as for freight transportation secondary routes that are essential for avoiding the saturation of the main system by slow and heavy trains.
The CleanER-D project was essential for maintaining a sufficient level of profitability of the European regional and secondary lines operations and therefore essential for a sustainable development of the European land transportation as a whole.
The project addressed the following main issues and provided the following information to the European rail industry:
• analysis of the complete diesel NRMM IIIB compliant systems in the rail environment (reduction of the emissions of the whole propulsion system including after-treatment and in engine technology;
• research transparency and understanding of state of the art for diesel manufacturers;
• learning about potential problems (e.g. reliability, maintenance, implementation into the vehicles, weight, space, cost, waste heat, temperature levels of the cooling, etc);
• validation of diesel engines to show that the engine industry can deliver reliable, affordable engines that are suitable for railway applications and still meet stage IIIB of the directive. If not, show what is possible in the short term in terms of cost, size, weight and emissions;
• delivery of actual specifications in time for the vehicle manufacturers to design and build compliant products to meet customer orders;
• ensuring that the engines are optimised for the entire life cycle of the vehicle, through after-treatment experiments on test beds and service trials, as well as real life demonstration of the system on the whole range of railcars and locomotive applications, using the two types of engine defined by the Directive;
• a proactive approach to more innovative solutions for the medium and long term, including use of best practices from other industries as well as development of hybrid systems, with a view of delivering even better results in the future including the best trade off at vehicle level between reduction of pollutant emissions and of CO2.

The objective of this research was to develop, improve and integrate emissions reduction technologies for diesel locomotives and rail transportation vehicles. The quantitative target was to achieve emission levels below the limits established by the new European Directive 2004/26/EC and further upcoming regulations (which has been achieved) while, in addition to the topic description, evaluating the best possible innovative and hybrid solutions for a contribution to the reduction of CO2 emissions.
The main goals of the project were to demonstrate the feasibility and the reliability in service of railway rolling stock powered with diesel engines compliant to the requirements of stage IIIB of the Non-Road Mobile Machinery (NRMM) European Directive.
The project was also aimed to identify future emission reduction potential of the engines that were tested, in order to help the European Commission to decide on future stages beyond stage IIIB.
The complete system including the engine itself with all its technological improvements and the external equipment were investigated and tested in the railway environment, making possible an extrapolation to the entire life cycle of the vehicle, to find the most optimised solutions with the best trade-off between NRMM Directive requirements, carbon-dioxide reduction and overall technical and economical performances.
In particular, when the project has started, there was no existing experience with prototype after-treatment technology. No comparisons existed for rail applications of the advantages and disadvantages of Selective Catalytic Reduction vs. Exhaust Gas Recirculation. By testing the railway vehicles on both test bench and service trial, this project helped to identify advantages and inconvenience of different solutions in different kind of operation (DMU, railcars, main line and shunting locomotives), in terms of operational constraints and reliability of the additional equipment.
The potential problems that have already been identified, such as decrease in vehicle reliability and additional maintenance burdens, are investigated. The project made possible to solve, the issues of integration of the engine and its external equipment like after-treatment and cooling system, due to the general increase of weight and volume consequent to the implementation of solutions for emission reduction.
Hybrid solutions, like the use of on board energy storing capacity for reducing overall energy consumption also starts to be applied by the automotive sector. In the rail sector some tentative applications took place recently in the US (prototype heavy freight locomotives), in Germany (prototype application to a shunting locomotives), in Japan and in UK (experimental operation of intercity trains).
However, before the project, no systematic approach has ever been made for an independent and pre-competitive evaluation of the efficiency of such systems. The project therefore conducted this systematic study, which provided for the first time a reasonable impact evaluation based on different standardised duty cycles for different categories of railway diesel vehicles.

Project Results:
Main S&T results/foregrounds

SP1 - System Requirements
Acted as an umbrella for the work of the demonstration subprojects, the subproject achieved the following objectives: providing a platform to engine and vehicle manufactures as well as operators to collect, monitor and evaluate the results delivered by the demonstration subprojects. In addition to the coordination activity, the subproject was responsible for developing the FMEA (Failure Mode and Effects Analysis) and the LCC (Life Cycle Cost) model to achieve a common understanding on the availability, reliability, safety and cost details.
Thus this subproject acted as a facilitator for the exchange of information between the other demonstration subprojects. Moreover it coached the work progress of both subprojects Heavy Haul and Light Weight and contributed substantially to the delivery of results within the deadlines.

SP2 – Railcar
The results of the test bed and in-service trials provided by TEDOM are compiled along with the customer requirement specification and the technical specification. The report will support all stakeholders when planning future procurement activities of Diesel railcars and DMU vehicles because it obtains valuable information about the engine package system durability, reliability and endurance, as well as get experience and information about operational and maintenance aspects of IIIB emission reduction technology in rail application.

SP3 – Heavy Haul
The Heavy Haul main objectives consisted in the installation of a stage IIIB compliant engine into an already existing locomotive platform originally designed for an equivalent stage IIIA engine. This would allow to assess the cost-effectiveness of stage IIIB implementation in mainline locomotives in terms of impact on vehicle design and operational and maintenance aspects.
A stage IIIB compliant 16-C175 prototype engine developed by Caterpillar producing 2800kW was installed in the new Vossloh diesel-electric locomotive platform EUROLight. Exhaust Gas Recirculation (EGR) and a Diesel Particulate Filter (DPF) were the technologies chosen in order to comply with the stage IIIB emission limits without requiring the use of a second fluid (urea). In addition a pre-oxydation catalyst (DOC) integrated in the DPF system enabled its passive regeneration. The modification works on the locomotive in order to install the new engine package resulted in additional vehicle weight as well as required space, especially for the integration of the cooling plant.
Following the installation tasks, a complete set of stationary validation tests was carried out on the locomotive to ensure a correct integration of the new engine prototype. The test program included emissions measurements carried out by CMT Motores Térmicos of Universitat Politècnica de València which confirmed that the prototype met stage IIIB emission regulations and verified the DPF filtration efficiency.
Finally, the locomotive and its new engine package were tested on a field trial performed by Trenitalia Cargo. This permitted to evaluate the performance of the new emission reduction technologies under real rail conditions and duty cycle.

SP4 – Light Weight
The Light Weight subproject had to achieve two objectives over the project duration. The core of the subproject consisted in carrying out a field trial with a modified freight locomotive from Deutsche Bahn AG compliant with the Stage IIIB emissions requirements. In addition, the subproject focused on monitoring the performance of a SNCF locomotive Type BB69400 equipped with a DPF.
A prototype 12V4000 engine that produces 1800 kW at 1800 rpm was developed by MTU. The engine was equipped with new engine technologies and connected to a diesel particulate filter to meet the emission regulation IIIB. The prototype IIIB system was calibrated to enable the operation of the DPF in a completely passive manner.
Deutsche Bahn AG installed this prototype system into a freight locomotive class 225, dating from 1971. Therefore, modifications to the engine bed, gearbox, cooling system and other assemblies were required to adapt the locomotive to its new power source. The German Federal Railway Authority (EBA) accepted the modifications, so that all obstacles to the homologation of the locomotive have been cleared.
After completion of integration, the locomotive started operation in regular service. A mobile emission measurement performed in the locomotive at the end of the field test measured gaseous and particulate emissions in steady state operation.
After rebuilt of the locomotive the DPF was inspected. The BB69419 locomotive from SNCF was equipped with a commercially available DPF system and a data logging system. SNCF operated the locomotive during common service. Different temperature- and pressure sensors gave an indication on how the system performed.

SP5 – Sustainability and Integration
The CleanER-D Sustainability Study has identified the framework conditions and major influencing factors for the future development of the European rail diesel vehicle fleet and related exhaust emissions. Using the UIC UNIFE Rail Diesel Study from 2006 as a starting point, CleanER-D fleet data have been improved with information coming from more recent studies and results from a CleanER-D questionnaire survey conducted in 2011 among the main European operators of rail diesel vehicles. The upgrade of the dataset includes especially the topic of replacement engines as well as the average mileage per vehicle type, power class and age/ emission class.
The CleanER-D fleet scenarios developed in the sub-project assume a further decline in the number of diesel locomotives which has been observed also in the years before 2008 and is expected to continue until 2020. In the same period, the number of DMUs will moderately increase due to high passenger transport demand. The developed fleet scenarios demonstrate that the migration of new exhaust emission reduction technologies into the fleet is comparably slow due to low numbers of new tendered and purchased diesel vehicles.
The projected fleet development and related diesel exhaust emissions suggest that strategies to quickly migrate new technologies into the fleet will further reduce emissions substantially and thus maximize societal and especially environmental benefits. Therefore market conditions have to be created which will increase the fleet and engine renewal rates.
The Sustainability Impact Assessment investigates the societal benefit of the introduction of NRMM stages IIIA and IIIB in terms of avoided external (or damage) costs from the decreasing total exhaust emissions until 2020.
Based on the Sustainability Impact Assessment, the Sustainability & Integration sub-project has develop sector-wide agreed recommendations on future emission reduction approaches and strategies of rail diesel traction in Europe, in order to further reduce emissions in the future.

SP6 – Emerging Technologies
As a first step, the state-of-the-art in after-treatment technologies were evaluated for rail and automotive applications in particular, which was used at a later stage to assess the most promising solutions. A specific task was dedicated to evaluate diesel particle filter (DPF) strategies and to assess emerging after-treatment technologies using stage IIIB emissions levels as a baseline but also researching the suitability of these solutions beyond IIIB.
The potential use of alternative fuels has been also investigated and the influence of fuel types on quality and emissions analysed. Detailed information and current state-of-the-art on biodiesel and alternative fuels have been collected and assessed.
For the analysis of future after-treatment technologies, a 560 kW engine model for railcar applications has been developed. In addition, simulation tools have been used to design and analyse the performance of the engine plus exhaust gas recirculation system (EGR) and of the DPF and Selective Catalytic Reduction (SCR) devices. The simulation activities also supported the consortium in generating primary data regarding space, weight and cooling requirements. In addition, a study of the influence of using the above mentioned technologies on the integration with the vehicles has been carried out.
All these previous activities supported to complete the assessment of technology innovations for future measures beyond IIIB on diesel railway applications.

SP7 – Hybrid Solutions
The potential of hybridization to reduce fuel consumption as well as emissions was analysed and demonstrated in the Hybrid Solutions by using different Energy Storage Systems (ESS) for several vehicles on defined duty cycles as well as various system architectures. Today it can be concluded that the mainly beneficial applications are regional/suburban DMU and shunter locomotives. The results prove that a reduction of fuel consumption up to 20 % compared to eco-driving can be achieved for DMUs. Energy management strategies can allow even higher savings up to 25 %. The reduction of CO2-emissions is in the same range as for the fuel consumption.
A simultaneous overall reduction of all emissions including CO2, NOx and/or PM is contradictory in some use cases. This trade off can be solved by energy management strategies and appropriate system architectures.
Within the Cleaner-D project investigations for hybridization of diesel-driven rolling stock with energy management possibilities were analysed in detail for the first time by a European-funded project consortium. Operation and field experiences are still at the beginning, but an optimization of ESS with energy management and operational strategies can already be done. Generally every application or use case has to be assessed for the benefit of hybridization.


Potential Impact:
The potential impact of the project and main dissemination activities and exploitation of results

The following main conclusions were drawn based on the CleanER-D outcomes:
• From an economic and technical perspective, refurbishment of old existing vehicles with IIIB engines has to be carefully analysed.
• Vehicle authorisation, even due to the partial changes on the vehicle, could require significant time, and as a consequence have an impact on the availability of compliant vehicles on the market.
• The Life Cycle Cost model for diesel vehicles can be applied for all available diesel applications including various technology options such as the one using of urea.
• The total emissions from rail diesel traction are very low today compared to the whole transport sector (NOx: less than 2.5%; PM less than 4.5% in 2008). And emissions of NOx and PM have already decreased by about 35% from 1990 to 2008.
• The fleet and emission development scenarios until 2020 estimate a considerable further reduction of emissions (NOx more than 35% and PM more than 45%) with a share of stage IIIA and IIIB engines of 30% for locomotives and 41% for DMUs.
• An additional reduction of emissions would be possible if the migration of current engine technologies into the fleet will be accelerated, this is seen as the key factor to further reduce the fleet emissions.
• The migration of new technologies into the fleet can only be accelerated if adequate market conditions will be provided (legislation framework, i.e. time between new legislation, and incentives as well as technologies with low LCC), which increase the fleet renewal rates.
• The introduction of stages IIIA and IIIB will generate societal benefits from cumulated avoided external costs of about 1.4 billion € by 2020, whereas the costs for the railway sector for the introduction of stage IIIA and IIIB technology cumulate to 680 – 780 million €. However system integration and vehicle platform development costs for the industry could not be considered within the CleanER-D Project and would have to be included in any impact assessment.
• E merging after-treatment technologies can lead to further reduction of emissions. However, there are implications and trade-offs that can prove to be complex and potentially critical for their implementation, particularly those related to systems integration. Cutting the emission levels has the tendency to yield to heavier and bigger propulsion units. Thus, the key factor for simultaneous pollutant emissions and fuel consumption reduction is - and will be - the correct integration of those emerging technologies which needs further investment and time to develop.
• The outlook for meeting potentially more restrictive emission levels beyond Stage IIIB would require the use of a multi-technology after-treatment design.
• Hybrid technologies could substantially reduce fuel consumption and hence CO2 emissions up to 25 % as well as NOx and PM emissions depending on the duty cycle, system architecture and if appropriate energy management strategies will be applied. Furthermore a downsizing of the internal combustion engine can be achieved in some cases. LCC assessment shows that certain combinations of Energy Storage Systems (ESS), transmission and duty cycle can have lower LCC than corresponding non-ESS configurations. The positive results have to be further validated in full revenue service operation.

Summary of the Key Recommendations
Based on the results of the CleanER-D Project recommendations towards all involved stakeholder were derived how to activate further potential and accelerate the emissions reduction of rail diesel traction in Europe in the future.

List of Websites:
More information is available on the project’s website: www.CleanER-D.eu