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  • 1.
    Abbasi, Saeed
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Characterisation of airborne particles from rail traffic2011Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Since the investigation of wear particles in rail transport started in late-1910s, the high mass concentration of these particles has raised worries among researchers concerned with air quality. However, effective action has yet to be taken because of lack of relevant knowledge. This thesis provides applicable information for the airborne wear particles in rail transport. Some aspects of their characteristics such as diameter size, mass concentration, number concentration, and morphology of particles were investigated in field tests and laboratory tests.The effects on particle characterisations from different operational conditions in the field tests, and applying different braking materials, conducting tests in different applied loads or sliding velocities in the laboratory tests were studied. The main advantage of conducting laboratory tests was to focus on studying particles from one source. The possibility of repetition, using high sensitive instruments and conducting tests at low costs are the other advantages of laboratory studies. Paper A describes how a pin-on-disc machine was used to reproduce similar real operational conditions during mechanical braking in a train. The results were validated by comparing the field tests results with the laboratory studies. The particles morphology and size distribution were also studied.Paper B presents a summary of field tests results. The effects of curve negotiating and applying braking in different real conditions were investigated with an on-board measurement.The element composition of the particles and their potential sources were also investigated outside of the particles morphologies.Paper C presents comprehensive results from laboratory studies on airborne particles from different braking materials. The differences in the particle characteristics in similar test conditions were attributable to different material compositions and dominant wear mechanisms. A new index was introduced in this paper and is suggested to be used as a qualitative factor with regard to the airborne wear particle emission rate.Paper D is a review of the recent studies of exhaust emission and non-exhaust emission from rail vehicles. A summary of results, measurements, adverse health effects, and proposed or applied solutions are reviewed in this paper.

  • 2.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Technical note: Experiences of studying airborne wear particles from road and rail transport2013Inngår i: Aerosol and Air Quality Research, ISSN 1680-8584, Vol. 13, nr 4, s. 1161-1169Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Airborne particles and their adverse effects on air quality have been recognized by humans since ancient times. Current exhaust emission legislations increase the relative contribution of wear particles on the PM levels. Consequently, wearbased particle emissions from rail and road transport have raised concerns as ground transportation is developing quickly. Although scientific research on airborne wear-based particles started in 1909, there is almost no legislation that control the generation of wear-based particles. In addition, there is no accepted and approved standard measurement technique for monitoring and recording particle characteristics. The main objective of this study is to review recent experimental work in this field and to discuss their set-ups, the sampling methods, the results, and their limitations, and to propose measures for reducing these limitations.

  • 3.
    Abbasi, Saeed
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Teimourimanesh, Shahab
    Chalmers.
    Vernersson, Tore
    Chalmers.
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Olofsson, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Lunden, Roger
    Chalmers.
    Temperature and thermo-elastic instability of tread braking friction materials2012Konferansepaper (Fagfellevurdert)
  • 4.
    Amlinger, Hanna
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Leth, Siv
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Impact of PWM switching frequency on the radiated acoustic noise from a traction motor2017Inngår i: 2017 20th International Conference on Electrical Machines and Systems, ICEMS 2017, Institute of Electrical and Electronics Engineers Inc. , 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The radiated acoustic noise from a traction motor at low speeds is dominated by the noise of electromagnetic origin. For a motor operated from pulse width modulated (PWM) converters, the switching frequency of the converter will have a large impact on the noise. The total harmonic distortion of the motor phase currents and thus also the exciting forces, will decrease with increasing switching frequency. Furthermore, changing the switching frequency will shift the frequencies of the exciting forces, hence have an influence on the coincidence with structural resonances of the motor. Tests have been performed on a traction motor and a decrease in sound pressure level with increasing switching frequency has been quantified and analyzed.

  • 5.
    Andersson, Evert
    KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Green Train Concept proposal for a Scandinavian high-speed train: Final report,  part B2012Rapport (Annet vitenskapelig)
    Abstract [en]

    Gröna Tåget (English: Green Train) is a research and development programme, the aim of which is to define a concept and develop technology for future high-speed trains for the Nordic European market. The target is a train for Scandinavian interoperability (Denmark, Norway and Sweden), although the pan-European minimum standards must be applied.

    Gröna Tåget is a concept for long-distance and fast regional rail services. It should be suitable for specific Nordic conditions with a harsh winter climate as well as mixed passenger and freight operations on non-perfect track.

    Gröna Tåget delivers a collection of ideas, proposals and technical solutions for rail operators, infrastructure managers and industry. The programme aims to define a fast, attractive, environmentally friendly and economically efficient high-speed train concept based on passenger valuations and technical possibilities. Proposals do not take corporate policies into account as these may vary between companies and over time.

    This is one of the final reports, specifying the functional requirements for the train concept from a technical, environmental and economic perspective, with an emphasis on the areas where research and development have been carried out within the Gröna Tåget programme. It is not a complete specification of a new train, but concentrates on issues that are particularly important for successful use in the Scandinavian market. It should be regarded as a complement to the pan-European standards. Research and development within the Gröna Tåget programme, including analysis and testing activities, are summarized. References are given to reports from the different projects in the programme but also to other relevant work.

    Other summary reports deal with market, economy and operational aspects as well as a design for an attractive, efficient and innovative train from a traveller’s point of view.

    The main alternative proposed in this concept specification is a train for speeds up to 250 km/h, equipped with carbody tilt for short travel time on existing main-line track. The train is proposed to have high-power permanent magnet motors, low aerodynamic drag and modest adhesion utilization. It has low noise emissions and a track-friendly bogie design. The train should be equipped with active highperformance suspension to produce superior ride qualities on non-perfect track and minimize suspension motions. Due to the approximately 3.30 m interior width of the carbody, one more comfortable seat can be accommodated abreast, which will reduce cost and energy use per seat-km and also maximize the capacity of the train and of the railway system. One most important and critical issue is that the train must be able to run in a Nordic winter climate, where technologies have been tested, proposed and also compiled in a special report.

    Most technologies developed can also be used for modified train concepts, such as non-tilting trains, trains for higher speeds than 250 km/h, trains with continental width carbodies, and others. Further, many technologies developed in the programme are also useful for lower speeds. Newly developed technologies were type-tested in a special test train from 2006 to 2009. Endurance tests in commercial service were performed between 2009 and 2011.

  • 6.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Greenhouse gas emissions from rail services: Present and future2010Inngår i: Proceedings of Railways and Environment, 2010Konferansepaper (Fagfellevurdert)
  • 7.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Nelldal, Bo-Lennart
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    TOSCA. Rail freight transport: Techno-economic analysis of energy and greenhouse gas reductions2011Rapport (Annet vitenskapelig)
    Abstract [en]

    In Stage 1 of the EU/FP7-funded project TOSCA (Technology Opportunities and Strategies toward Climate-friendly trAnsport) the techno-economical feasibility of different technolo-gies and means to reduce greenhouse gas (GHG) emissions is being analysed for different modes of transport. This is made over the long-term perspective until 2050, with 2009 as the reference year. This is the report on the rail freight transport market, applicable to the European Union (EU-27).The analysis presented in this report estimates that a number of efficient technologies and means are available, individually and in combination, to significantly reduce energy use and the resulting GHG emissions on the rail freight market until 2050. The analysis has considered the following technologies and means:

    – heavy freight trains (high payload capacity per metre of train as well as longer trains)

    – eco-driving, including traffic flow management

    – energy recovery

    – high-efficiency machinery in locomotives and electric supply

    – low air drag

    – incremental improvements, in particular reduced tare mass of wagons.

    Despite anticipated higher train speeds in most future train operations the above-mentioned technologies and means have, according to the analysis, the potential to reduce the average energy use per net-tonne-km (tkm) of payload by 40–50 % until 2050. As a consequence also the direct and indirect GHG emissions will be reduced. Energy use and GHG emissions are measured per net-tonne-km, assuming representative load factors in different operations.

  • 8.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Nelldal, Bo-Lennart
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    TOSCA. Rail passenger transport: Techno-economic analysis of energy and greenhouse gas reductions2011Rapport (Annet vitenskapelig)
    Abstract [en]

    In Stage 1 of the EU/FP7-funded project TOSCA (Technology Opportunities and Strategies toward Climate-friendly trAnsport) the techno-economical feasibility of different technologies and means to reduce greenhouse gas (GHG) emissions is being analysed for the different modes of transport. This is made in the long-term perspective until 2050, with 2009 as the reference year. This is the report on rail passenger transport, applicable to the European Union (EU-27).The present report has been subject to review among railway experts, representing train suppliers, railway operators as well as academia. They have also responded to a questionnaire. Further, a workshop was held, where the report with assumptions and results was discussed.In the analysis presented in this report it is estimated that a number of efficient improvements that, individually and in combination, are available in order to significantly reduce energy use and the resulting GHG emissions on the rail passenger market until 2050. The analysis has considered different technologies and means:

    – low air drag

    – low train mass

    – energy recovery

    – eco-driving, including traffic flow management

    – space efficiency in trains (increasing payload per metre of train)

    – incremental improvements of energy efficiency, in particular reduced losses.

    Despite anticipated higher average train speeds in the future these combined approaches will, according to the analysis, have the potential to reduce the average specific energy use per passenger-km (pkm) in the order of 45–50 % in the very long term until 2050. As a consequ-ence also the direct and indirect GHG emissions will be reduced. The highest reductions are possible in city and regional rail operations. Reductions are more limited in high-speed opera-tions, because of the advanced technologies already applied. However, high-speed rail has today a comparatively low energy use per passenger-km, partly due to its high average load factor. To be consistent with other work packages of TOSCA, energy use and GHG emissions are measured per passenger-km, assuming representative load factors in different operations.

  • 9.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Stichel, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Casanueva, Carlos
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Rail Systems and Rail Vehicles: Part 2: Rail Vehicles2016 (oppl. 1)Bok (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    This compendium is mainly intended for MSc education in rail vehicle engineering at KTH Royal Institute of Technology, Stockholm, Sweden. The objective is to give an overview and fundamental knowledge of different rail systems, followed by a more thorough introduction to rail vehicles. In this way most rail aspects are covered. The compendium consists of 20 chapters.

  • 10.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Kottenhoff, Karl
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Nelldal, Bo-Lennart
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Extra wide-body passenger trains in Sweden2001Konferansepaper (Fagfellevurdert)
  • 11.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Nelldal, Bo-Lennart
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Effektiva Tågsystem för framtida persontrafik – analys av förutsättningar och möjligheter för attraktiv tågtrafik1997Rapport (Annet vitenskapelig)
  • 12.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Nelldal, Bo-Lennart
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Sammanfattning av Effektiva Tågsystem för framtida persontrafik – analys av förutsättningar och möjligheter för attraktiv tågtrafik1997Rapport (Annet vitenskapelig)
  • 13.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Orvnäs, Anneli
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Persson, Rickard
    On the Optimization of a Track-Friendly Bogie for High Speed2009Inngår i: 21st International Symposium on Dynamics of Vehicles on Roads and Tracks, IAVSD'09, Stockholm, August 17-21, 2009., 2009Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    When designing and optimizing a rail vehicle there is a contradiction between, on the one hand, stability on straight track at high speed and, on the other hand, reasonable wheel and rail wear in small- and medium radius curves. Higher speeds require to some extent stiffer wheelset guidance to avoid hunting and ensure stability. However, with stiffer wheelset guidance the risk of increased wheel and rail wear in curves is imminent. In this paper, the process of developing and optimizing a track-friendly bogie is described. A multi-body system (MBS) simulation model was used, taking due consideration to nonlinearities in suspension and wheel-rail contact, as well as realistic flexibilities in the track. Adequate and systematic consideration is taken to a wide range of possible non-linear wheel-rail combinations. Dynamic stability is investigated both on straight track and in wide curves at high speeds. The balance between flange wear and tread wear is studied in order to maximize wheel life between re-profiling operations in the intended average operation. The result is a bogie with relatively soft wheelset guidance allowing passive radial self-steering, which in combination with appropriate yaw damping ensures stability on straight track at higher speeds. The bogie has been subject to both certification testing and long-term service testing in the Gröna Tåget (the Green Train) research and development programme.

  • 14.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Orvnäs, Anneli
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Persson, Rickard
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Radial self-steering bogies - Development, advantages and limitations2007Inngår i: ZE Vrail - Glasers Annalen: Zeitschrift fuer das gesamte System Bahn, ISSN 1618-8330, Vol. 131, nr Suppl., s. 248-259Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Considering the total cost of railway operations, It is important to reduce the deterioration caused to the track by rail vehicles and vice versa. Radial steering running gear, where the wheelsets take up approximate radial positions in curves, is an important mean of reducing rail and wheel wear. They also allow curves to be negotiated at higher lateral acceleration on non-perfect track, without exceeding stipulated limits for lateral track shift forces. In order to run dynamically stable at high speed, the damping of the bogie must be appropriate, in particular the yaw damping between bogies and car body. Since the mid-1970's radial self-steering bogles have been developed and used in about 1 200 passenger rail vehicles in Scandinavia. This development continues and during 2006 a test train with radial self-steering bogies is run in speeds up till 281 km/h as part of the Swedish R&D program "GrönaTå get" (GreenTrain). Although there are limitations in the performance of passively self-steering bogles they are a simple and proven solution. Ultimately, In the future actively controlled radial steering may be considered asan appropriate mean to achieve higher performance and track-friendliness.

  • 15.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Orvnäs, Anneli
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Persson, Rickard
    Radial Self-Steering Bogies: Recent Developments for High Speed2009Inngår i: 7th International Conference on Railway Bogies and Running Gears / [ed] István Zobory, 2009, s. 63-72Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Considering the total cost of railway operations, it is important to reduce the deterioration caused to the track by rail vehicles and vice versa. Radial steering running gear, where the wheelsets take up approximate radial positions in curves, is an important mean of reducing rail and wheel wear. They also allow curves to be negotiated at higher lateral acceleration on non-perfect track, without exceeding stipulated limits for lateral track shift forces. In order to run dynamically stable at high speed, the damping of the bogie must be appropriate, in particular the yaw damping between bogies and carbody. Radial self-steering bogies are used on more than 1200 rail passenger vehicles in Scandinavia since the early 1980’s. The maximum service speed of these vehicles ranges up to 210 km/h. Ongoing development seems to confirm that the use of such bogies can be extended into the very high-speed area of at least 250 km/h. There has previously been some scepticism on the feasibility of soft wheelset guidance for higher speeds, in particular with respect to running stability. Although there are some limitations in the performance of radial self-steering bogies, this solution is robust and well-proven since about 25 years. The ultimate future may be a mechatronic bogie, where the wheelsets are guided in the most optimal way through controlled and forced radial steering. Such bogies may be justified if performance is out of the possible range of passive self-steering solutions.

  • 16.
    Andersson, Evert
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Stichel, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG. KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Gröna Tåget - Green Train - Train for tomorrow's travellers2011Inngår i: ZEVrail, ISSN 1618-8330, Vol. 135, s. 140-153Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Gröna Tåget (Green Train) is a Swedish research and development programme aiming at defining a concept and developing technology for the next generation high-speed trains, suitable for the Northern European countries. The programme involves almost all major stakeholders in the railway business in Sweden. Main sponsors are Trafikverket (former Banverket) as well as the railway industry and operators (Bombardier, SJ and others). The total budget is around 15 million EUR. The technical coordination is with the Royal Institute of Technology (KTH) in Stockholm. The program started in 2005 and will continue until the end of 2011.

    Gröna Tåget is intended to be a fast, track-friendly, electric tilting train that can not only maintain higher speeds than conventional trains on sections with curves, but special versions could allow 300 km/h or more on future dedicated high-speed lines. Gröna Tåget shall be more attractive and more cost effective both to travellers and to operators than today’s trains. Environmental perfor­mance (energy use per passenger, noise) is expected to be still better than existing trains at lower speed. 

  • 17.
    Arvidsson, Therese
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Bro- och stålbyggnad.
    Andersson, Andreas
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Bro- och stålbyggnad.
    Karoumi, Raid
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Bro- och stålbyggnad. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Train running safety on non-ballasted bridgesManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    The train running safety on non-ballasted bridges is studied based on safety indices from the vertical wheel–rail forces. A 2D train–track–bridge interaction model that allows for wheel–rail contact loss is adopted for a comprehensive parametric study on high-speed passenger trains. The relation between bridge response and vehicle response is studied for more than 200 theoretical bridges in 1–3 spans. The bridge's inuence on running safety and passenger comfort is differentiated from the influence of the track irregularities. The Eurocode bridge deck acceleration limit for non-ballasted bridges is 5 m/s2 based on the assumed derailment risk at 1g from wheel–rail contact loss. This study shows that the running safety indices are not compromised for bridge accelerations up to 30 m/s2. Thus, accelerations at 1g do not in itself lead to contact loss and there is potential to enhance the Eurocode safety limits for non-ballasted bridges.

  • 18.
    Arvidsson, Therese
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Bro- och stålbyggnad. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Li, Jiajia
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Bro- och stålbyggnad. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Dynamic analysis of a portal frame railway bridge using frequency dependent soil structure interaction2011Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    With the development of high-speed railroads the dynamic behaviour of railroad bridges is increasingly important to explore. Deeper knowledge about the influence of different factors and what should be included in a model is essential if the designer shall be able to make reliable estimates of responses in existing and new structures. One factor is the soil-structure interaction (SSI), describing how the foundation of the bridge and the soil properties affect the behavior of the bridge under dynamic loading.

    In this thesis, the influence of including SSI in a model of a portal frame railway bridge is studied, and an analysis procedure in the frequency domain for models with frequency-dependent boundary conditions is described. A 3D finite element model of an e isting bridge has been built up, based on the theory of linear elasticity. The model has been given three different types of boundary conditions: clamped, static stiffness and frequency-dependent stiffness from SSI. Results from simulated train passages, with a train set consisting of two wagons, were compared for the different boundary conditions. The models have also been compared with measurement data from the bridge, which has given indications about which model describes reality in the best way.

    The results show that the model in which SSI is included by frequency dependent boundary conditions is in slightly better agreement with measurement data than the clamped model and the model with static stiffness. The model gives a slightly better damping of the free vibrations and the natural frequencies correspond better with experimental data. The difference in maximum acceleration from a train passage is very small between the different models, even if it is found that the clamped model generally has lower accelerations and hence is non-conservative. It appears that the train speed affects the maximum acceleration, the size of the free vibrations and the natural frequencies that are present in the free vibrations in the models.

    Further studies are suggested where it is emphasized that an analysis with longer trains, which give resonance phenomena, should be made to see how the different eigenfrequencies in the models affect the accelerations at different speeds. It is also noted that more measurements would be needed in order to draw more general conclusions about the degree of correspondence between the measurements and the models, and to calibrate the parameters of the model against measurement data.

  • 19. Bhiwapurkar, M. K.
    et al.
    Saran, V. H.
    Harsha, S. P.
    Goel, V. K.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Effect of magnitudes and directions (mono-axis and multi-axis) of whole body-vibration exposures and subjects postures on the sketching performance2011Inngår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 225, nr F1, s. 71-83Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Whole-body vibrations in trains are known to affect the performance of sedentary activities such as reading, writing, sketching, working on a computer, etc. The objective of the study was to investigate the extent of disturbance perceived in sketching task by seated subjects in two postures under mono-and multi-axis Gaussian random vibration environment. The study involved 21 healthy male subjects in the age group of 23-32 years. Random vibrations were generated both in mono-and multi-axial directions in the frequency range of 1-10 Hz at 0.5, 1.0, and 1.5 m/s(2) rms (root mean square) amplitude. The subjects were required to sketch given geometric figures such as a circle, triangle, rectangle, and square with the help of ball-point pen under given vibration stimuli in two postures (sketch pad on lap and sketch pad on table). The deviation in distortion with respect to the given figure is represented in terms of percentage distortion. The influence of vibrations on the sketching activity was investigated both subjectively and by two specifically designed objective methods, namely, RMS (root mean square methodology) and area methods. The judgements of perceived difficulty to sketch were rated using seven-point semantic judgement scale. The percentage distortion and difficulty in sketching activity increased with an increase in vibration magnitude. Both subjective evaluation and the RMS method revealed that the task was affected more while sketching on the table. The percentage distortion was affected similarly and maximum in all the vibration directions except for the vertical, while sketching difficulty was found to be higher only with longitudinal and multi-axis vibration direction. The subjective evaluation also revealed that there was no effect of the type of entity chosen on the sketching difficulty.

  • 20. Bhiwapurkar, M. K.
    et al.
    Saran, V. H.
    Harsha, S. P.
    Goel, V. K.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Influence of Mono-axis Random Vibration on Reading Activity2010Inngår i: Industrial Health, ISSN 0019-8366, E-ISSN 1880-8026, Vol. 48, nr 5, s. 675-681Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recent studies on train passengers' activities found that many passengers were engaged in some form of work, e.g., reading and writing, while traveling by train. A majority of the passengers reported that their activities were disturbed by vibrations or motions during traveling. A laboratory study was therefore set up to study how low-frequency random vibrations influence the difficulty to read. The study involved 18 healthy male subjects of 23 to 32 yr of age group. Random vibrations were applied in the frequency range (1-10 Hz) at 0.5, 1.0 and 1.5 m/s(2) rms amplitude along three directions (longitudinal, lateral and vertical). The effect of vibration on reading activity was investigated by giving a word chain in two different font types (Times New Roman and Anal) and three different sizes (10, 12 and 14 points) of font for each type. Subjects performed reading tasks under two sitting positions (with backrest support and leaning over a table). The judgments of perceived difficulty to read were rated using 7-point discomfort judging scale. The result shows that reading difficulty increases with increasing vibration magnitudes and found to be maximum in longitudinal direction, but with leaning over a table position. In comparison with Times New Roman type and sizes of font, subjects perceived less difficulty with Anal type for all font sizes under all vibration magnitude.

  • 21.
    Björklund, Lena
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Bro- och stålbyggnad. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Dynamic Analysis of a Railway Bridge subjected to High Speed Trains2005Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
  • 22.
    Boysen, Hans
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transporter och samhällsekonomi (stängd 20110301), Trafik och Logistik (stängd 20110301). KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Developments in railway freight transportation between Scandinavia and Germany2010Inngår i: Proceedings of the 6th SoNorA University Think Tank Conference, 2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper investigates recent and ongoing developments in freight transportation by railbetween Scandinavia and Germany. Present capacity constraints are identified. Infrastructureinvestment plans until about 2020 are reviewed. Technical standards between the national railwaynetworks are compared and common best practices are proposed. Among the conclusions arerecommendations to unify the operation of long freight trains, to raise axle loads and to adoptenlarged, flat-top loading gauges.

  • 23.
    Boysen, Hans
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    The Fran-Scan hi-cube intermodal corridor2011Inngår i: Proceedings of the 7th SoNorA University Think Tank Conference, 2011Konferansepaper (Fagfellevurdert)
  • 24.
    Brabie, Dan
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Andersson, Evert
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Analysis of vehicle features influencing train derailment processes and consequences2008Inngår i: ZEVrail Glasers Annalen, ISSN 1618-8330, Vol. 132, s. 172-184Artikkel i tidsskrift (Fagfellevurdert)
  • 25.
    Brabie, Dan
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Andersson, Evert
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    High-Speed Train Derailments: Minimizing Consequences through Innovative Design2008Inngår i: Proceedings of the World Congress of Railway Research (WCRR'08), 2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In the current paper, various possibilities of minimizing consequences of high-speed rail vehiclederailments have been studied through a combination of empirical observations and multi bodysystem (MBS) simulations. In order to assess the appropriate measures and features for an increasedderailment-worthy design, a comprehensive MBS model is developed to predict the pre and postderailmentvehicle behaviour. Preventing wheel flange climbing derailment after axle journal failureson curved track is accomplished by implementing mechanical restrictions in the bogie frame. Threealternative substitute guidance mechanisms are presented and a systematic feasibility analysis forone of them, a low-reaching axle journal box, is presented. Three conventionally coupled passengertrailing cars are investigated after derailments on tangent and curved track as a function of themaximum centre coupler yaw angle, carbody height of centre of gravity, coupler and bogie transversalbeam height. Furthermore, the articulated train concept is investigated as a function of different intercarbodydamper characteristics.

  • 26.
    Brabie, Dan
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Andersson, Evert
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Means of Minimizing Post-Derailment Consequences by Alternative Guidance Mechanisms2007Inngår i: Proceedings of the 7th International Conference on Railway Bogies and Running Gears (BOGIE'07), 2007, s. 303-310Konferansepaper (Fagfellevurdert)
  • 27.
    Brabie, Dan
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Andersson, Evert
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Post-derailment dynamic simulation of rail vehicles: Methodology and applications2008Inngår i: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 46, nr Suppl. S, s. 289-300Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An earlier developed multi-body system post-derailment module. that predicts the wheelsets' behaviour after impact with concrete sleepers, is upgraded to account for possible wheel-rail fastener impact after train derailments at high speed. The vertical stiffness describing the wheel-fastener impact behaviour is calibrated and validated based on two authentic derailment cases. Geometrical specifications that permit it brake disc and a bogie frame to act as substitute guidance mechanisms after Hart e climbing derailments on Curved track are presented for an X 2000 trailer car. Further, an introductory analysis on the post-derailment vehicle behaviour on tangent track after a 'flange on rail head' derailment condition is also presented its a function of bogie yaw resistance. The risk of carbody overturning after derailments on tangent track is assessed as a function of coupler height and carbody centre of gravity as well as bogie transversal beam position.

  • 28. Bruni, Stefano
    et al.
    Vinolas, Jordi
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Polach, Oldrich
    Stichel, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG. KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Modelling of suspension components in a rail vehicle dynamics context2011Inngår i: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 49, nr 7, s. 1021-1072Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Suspension components play key roles in the running behaviour of rail vehicles, and therefore, mathematical models of suspension components are essential ingredients of railway vehicle multi-body models. The aims of this paper are to review existing models for railway vehicle suspension components and their use for railway vehicle dynamics multi-body simulations, to describe how model parameters can be defined and to discuss the required level of detail of component models in view of the accuracy expected from the overall simulation model. This paper also addresses track models in use for railway vehicle dynamics simulations, recognising their relevance as an indispensable component of the system simulation model. Finally, this paper reviews methods presently in use for the checking and validation of the simulation model.

  • 29. Bucca, Guiseppe
    et al.
    Carnevale, Marco
    Collina, Andrea
    Facchinetti, Alan
    Drugge, Lars
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Fordonsdynamik.
    Jönsson, Per-Anders
    Stichel, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG. KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Differentiation of pantographs’ preloads as a mean to improve multiple collection and speed upexisting lines2011Inngår i: Proceedings of 22nd Symposium of the International Association for Vehicle System Dynamics / [ed] Simon Iwnicki, 2011Konferansepaper (Fagfellevurdert)
  • 30. Coviello, N.
    et al.
    Chiara, B. D.
    Nelldal, Bo-Lennart
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    An assessment model of the single-track line carrying capacity: Influence of the signalling system and application to the Trans-Mongolian railways2014Inngår i: Ingegneria Ferroviaria, ISSN 0020-0956, Vol. 69, nr 7-8, s. 627-651Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Trans-Mongolian railway represents an interesting study case within the Trans-Asian connections, since - in these years - they have been subject to radical upgrading intended to increase its carrying capacity. This article presents a study aimed at quantifying the potential benefits that may be expected from the introduction of signalling systems based on radio block, (radio cab signalling), as the level 2 and level 3 ERTMS/ETCS; the study will resort to a dedicated analysis methodology which takes into explicit consideration the particularities of the single-track railway service and the need to set up the appropriate timetables in order to exploit at its best the potential of a more effective signalling system. To this purpose, beside the technical parameters, two operational ones are introduced, in the intent of modelling the train fleeting or platooning effects. Once the appropriate analysis formula was defined, it has been applied to the Mongolian line, thus obtaining results in the form of daily capacity maps, which are presented and discussed.

  • 31.
    Darvish, Parviz
    et al.
    ESSEC Business School.
    Abbasi, Saeed
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Risk Hedging Optimal Capacity in the European Hub-based Natural Gas Market Network: A Model-based ApproachArtikkel i tidsskrift (Fagfellevurdert)
  • 32.
    Enblom, Roger
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Deterioration mechanisms in the wheel-rail interface with focus on wear prediction: a literature review2009Inngår i: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 47, nr 6, s. 661-700Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Wheel-rail interface management is imperative to railway operation and its maintenance represents a major share of the total maintenance cost. In general, the course of events usually called wear is a complicated process involving several modes of material deterioration and contact surface alteration. Thus material removal or relocation, plastic flow and phase transformation may take place at, just below, or in-between the contacting surfaces. A higher degree of predictability of deterioration mechanisms and a firm basis for optimisation of the wheel-rail system are anticipated to reveal a great potential for cost savings. Wear in the sense of material loss and related wheel-rail profile evolution represents one of several modes of damage. The purpose of this survey is to explore research on wear simulation, to some degree extended to neighbouring disciplines. It is believed that a cross-disciplinary approach involving, for instance, adhesive and abrasive wear, surface plasticity, and rolling contact fatigue opens new perspectives to improved damage prediction procedures.

  • 33.
    Enblom, Roger
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Emerging engineering models for wheel/rail wear simulation2005Inngår i: Proceedings of the 8th International Conference Railway Engineering, London, June 29-30, 2005, 2005Konferansepaper (Fagfellevurdert)
  • 34.
    Enblom, Roger
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Impact of non-elliptic contact modelling in wheel wear simulation2008Inngår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 265, nr 9-10, s. 1532-1541Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Advances in simulation of railway wheel wear in the sense of material removal have drawn the attention to the importance of wheel–rail contact modelling. As a further step of enhancing the used simulation procedure in direction of increased generality and reduced need for application-dependent calibration, the focus of this investigation is the influence of non-elliptic contact models on the wheel wear rate and profile shape. To facilitate evaluation the semi-Hertzian contact procedure Stripes, developed by INRETS in France, has been implemented.

    To investigate the capabilities of Stripes to assess the contact area and pressure, shape comparisons have been made with other numerical methods for a set of wheel–rail contact situations. The referenced results are based on the linear elastic half-space assumption, elastic finite element analysis, and elastic–plastic finite element analysis. For reference also the elliptic contact area according to Hertz is shown as given by the contact data table of the multi-body simulation code.

    After exploring the properties of the Stripes procedure with respect to contact area estimation and pressure distribution, the focus is moved to the influence on wear rate, being the principal objective of this investigation. First the wear distribution over the contact patch is studied and compared to results using the elliptic model from the MBS code Gensys and the non-elliptic approach with Kalker's code Contact. Finally the evolution of the wheel profile is simulated for a few typical cases.

    This investigation of wear distributions over non-elliptic patches under different operating conditions indicates significant differences compared to both Contact and the applied Hertzian approach. The expansion from single contact occasions to complete simulations indicates comparable material removal rates but relocation towards the flange side. This tendency is apparent in all of the cases shown, however limited to initial wear in tangent run or reasonably mild curve negotiation.

  • 35.
    Enblom, Roger
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Proposed procedure and trial simulation of rail profile evolution due to uniform wear2008Inngår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 222, nr 1, s. 15-25Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A procedure for numerical simulation of rail wear and the corresponding profile evolution has been formulated. The wear is assumed to be uniform in the sense that the profiles remain constant along the track portion to be investigated. A simulation set is selected defining the vehicles running on the track, their operating conditions, and contact parameters. Several variations of input data may be included together with the corresponding occurrence probability.

    Simulation of multi-body dynamics is used to calculate contact forces and positions, and Archard's wear equation is applied for the calculation of wear depth. Wear coefficients as a function of contact pressure and relative sliding velocity are collected from different test results.

    Trial calculations of four non-lubricated and two lubricated curves with radii from 303 to 802 m show qualitatively reasonable results in terms of profile shape development and difference in wear mechanisms between gauge corner and rail head. The wear rates related to traffic tonnage are, however, overestimated and the lubrication efficiency underestimated.

    It is expected that model refinements in terms of environmental influence and contact stress calculation are useful to improve the quantitative results.

  • 36. Evans, J.
    et al.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Challenges in simulation of rail vehicle dynamics2009Inngår i: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 47, nr 8, s. 1023-1048Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Rail vehicle dynamic simulation has progressed a long way from its origins as a research tool. Modern multibody software packages are used as an essential part of the design process for new vehicles and for investigating service problems with existing vehicles. Increasingly, simulation is being used as part of the vehicle acceptance process in place of on-track testing. This state of the art paper for the 21st IAVSD Symposium in Stockholm in August 2009 surveys the current applications for rail vehicle dynamic modelling. The process of reducing a complex mechanical system to a mathematical representation is invariably subject to compromise and open to individual interpretation. The level of detail and choice of idealisation of suspension components will depend on the application, and in the real world it also depends on the availability of information about the system. This paper discusses appropriate modelling choices for different applications, and comments on best practice for the idealisation of suspension components, wheel/rail contact conditions and modelling inputs such as track geometry. The validation of simulation results is increasingly important, and this paper discusses recent trends in this area. Finally, the paper takes a brief look forward to future simulation issues.

  • 37.
    Forsberg, Tobias
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG. KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Berg, Mats
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Stichel, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Andersson, Evert
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, Spårfordon.
    Condition Monitoring of Train Ride Stability2007Inngår i: Proceedings of the 7th International Conference on Railway Bogies and Running Gears, BOGIE'07, Budapest, September 3-6, 2007, 2007, s. 271-280Konferansepaper (Fagfellevurdert)
  • 38.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transporter och samhällsekonomi (stängd 20110301), Trafik och Logistik (stängd 20110301). KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Anläggningskostnader för järnvägar i Sverige 1989-20092009Rapport (Annet vitenskapelig)
  • 39.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Green train. Basis for a Scandinavian high-speed train concept. Final report, part A2012Rapport (Annet vitenskapelig)
    Abstract [en]

    The Green Train (in Swedish ‖Gröna Tåget‖) is a high-speed train concept, that is economical, environmentally friendly and attractive to travellers. It is suited to specific Nordic conditions with a harsh winter climate, often varying demand and mixed passenger and freight operations on non-perfect track. The main proposal is a train for speeds up to 250 km/h equipped with carbody tilt for short travelling times on electrified mainlines. The concept is intended to be a flexible platform for long-distance and fast regional passenger trains, interoperable in Scandinavia, i.e. Denmark, Norway and Sweden.

    The Gröna Tåget programme delivers a collection of ideas, proposals and technical solutions for rail operators, infrastructure managers and industry. This is part A of the final report, dealing with market, economy and service aspects, with an emphasis on the areas where research has been done within the Gröna Tåget research and development programme.

    Passenger valuations and economy in train traffic exposed to competition are controlling factors in the design of the train concept. One important measure to achieve better economy in the train traffic with 15% lower total costs and the possibility to reduce fares is to use wide-bodied trains that can accommodate more seats with good comfort. Travel on some studied routes in Sweden may increase by 30% compared to today’sexpress trains through shorter travelling times, lower fares and more direct connections, which are possible with shorter, flexible trainsets.

    Gröna Tåget will be designed to give good punctuality even during peak load periods. Doors, interior design, luggage handling and vestibules with lifts for disabled travellers must be dimensioned for full trains. A well-considered design reduces dwell times and delays.

    Capacity utilisation on the lines increases with greater speed differences between express trains and slower trains in mixed traffic. Punctual stops and skip-stop operation for regional trains are a few of the measures that compensate for the increase in capacity utilisation and reduce disruptions.

  • 40.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Gröna tåget: Ett attraktivt snabbtågskoncept2011Konferansepaper (Annet vitenskapelig)
  • 41.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Gröna tåget: Resande och trafik2011Konferansepaper (Annet vitenskapelig)
  • 42.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Market effects of regional high-speed trains on the Svealand line2005Inngår i: Journal of Transport Geography, ISSN 0966-6923, E-ISSN 1873-1236, Vol. 13, nr 4, s. 352-361Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    When the Svealand line in Sweden opened in 1997, it replaced an older railway line between Eskilstuna and Stockholm (a distance of 115 km). Service on the Svealand line is operated with regional high-speed trains. In a case study of the effects of regional high-speed train services, changes in knowledge, valuations and travel behaviour have been analysed. The Svealand line has sparked an increase in regional rail travel of up to seven times compared to the old railway between Eskilstuna and Stockholm. Additionally, the market share has risen from 6% to 30%. Travelling times are valued highly and motorists, particularly, place great value on the high-speed train mode of transport.

    A general conclusion is that regional high-speed train services have had a major impact on the travel market and on travel behaviour. The improved accessibility to Stockholm, in particular, is especially noticeable among residents living close to the railway stations.

  • 43.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transporter och samhällsekonomi (stängd 20110301), Trafik och Logistik (stängd 20110301). KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Modelling operational costs of a future high-speed train2006Inngår i: Conference proceedings to CIT 2006 conference, 2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In the Swedish Green Train research project, a model for calculation of operational costs has been developed. The model is intended as a tool for making a new high-speed train concept efficient and economically feasible. Some results indicate that seating density, i.e. the number of seats per metre of train length, is one of the most important factors to achieve economic train operation. The load factor needs to be high. However, to select service and comfort levels and other supply factors, travel demand and passengers’ willingness to pay also need to be considered.

  • 44.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Perspectives for a future high-speed train in the Swedish domestic travel market2008Inngår i: Journal of Transport Geography, ISSN 0966-6923, E-ISSN 1873-1236, Vol. 16, nr 4, s. 268-277Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Gröna tåget (the Green Train) is a research and development project with the aim to develop a high-speed tilting train concept for the Swedish and Nordic markets. Competition with other modes needs to be evaluated, especially as regards travelling times and fares, with special attention paid to domestic airlines.

    For new trains, gains in travelling times and lower operational costs can be expected. Model calculations of operational costs for domestic air stages and high-speed trains, respectively, show that high-speed trains have lower costs per available seat kilometer. Train operators can meet competition with fares from coaches and air carriers provided they introduce yield management. The primary competition is about travelling times. Gröna tåget would increase the train’s attractiveness and win over some travel from airlines.

  • 45.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Regional tågtrafik: kollektivtrafik som når längre2012Konferansepaper (Fagfellevurdert)
  • 46.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Resande och trafik med Gröna tåget2010Rapport (Annet vitenskapelig)
  • 47.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Svealandsbanan: Tågtrafik som bidrar till regional utveckling2003Inngår i: Vid vägs ände?, Järnvägsforum and Banverket, Stockholm , 2003Kapittel i bok, del av antologi (Fagfellevurdert)
  • 48.
    Fröidh, Oskar
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    The 'Gröna Tåget' project: An activity approach for information communication technologies2009Inngår i: Green and ITS: an overview of innovations for a sustainable transport system in Stockholm, Sundbyberg: Sweco , 2009Kapittel i bok, del av antologi (Fagfellevurdert)
  • 49.
    Fröidh, Oskar
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Byström, C.
    Competition on the tracks - Passengers' response to deregulation of interregional rail services2013Inngår i: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 56, s. 1-10Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    On the West Coast Line (WCL) in Sweden, de facto competition in interregional rail travel has been in effect since 2009. While the Öresund trains are subsidized by regional authorities, SJ runs interregional services on a commercial basis in parallel. How do passengers' valuations affect demand?This paper presents the findings of a study conducted to examine the newly deregulated market for train journeys and travelers' preferences as regards two different train operators and several service levels. A stated choice study was conducted among existing train travelers, and a multinomial logit model structure was applied in the study to examine the benefits derived from choosing a specific train. The models are estimated on segments of the train travelers in order to investigate how the preferences differ among different categories of travelers. In addition, more questions were asked on the supply to provide better understanding of the effects.The findings show that fares and short travel times are important factors for interregional passengers (more than 100. km) when they choose an operator on the WCL. Frequency of departures is also important but seems to be less significant when respondents are asked about suitable departure times. However, the importance of traveling time and comfort increases with longer journeys, which gives advantages for the commercial operator (SJ) over Öresund trains. Moreover, well-known SJ was ranked higher than Öresund trains by all passengers except a group of particularly price-sensitive travelers.This case shows that operators together have achieved a better supply and a widened travel market for interregional journeys and also that segmentation has occurred between price-sensitive and time-sensitive passengers.

  • 50.
    Fröidh, Oskar
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Jansson, Kjell
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Kottenhoff, Karl
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap, Trafik och logistik. KTH, Skolan för teknikvetenskap (SCI), Centra, Järnvägsgruppen, JVG.
    Kollektivtrafik värd priset för integrerad arbetsmarknad, fallstudie Mälardalen2007Rapport (Annet vitenskapelig)
1234 1 - 50 of 199
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