1,199 research outputs found
Modelling rail track deterioration and maintenance: current practices and future needs
As commercialisation and privatisation of railway systems reach the political agendas in a number of countries, including Australia, the separation of infrastructure from operating business dictates that track costs need to be shared on an equitable basis. There is also a world-wide trend towards increased pressures on rail track infrastructure through increases in axle loads and train speeds. Such productivity and customer service driven pressures inevitably lead to reductions in the life of track components and increases in track maintenance costs. This paper provides a state-of-the-art review of track degradation modeling, as well as an overview of track maintenance decision support systems currently in use in North America and Europe. The essential elements of a maintenance optimisation model currently under development are also highlighted
Modeling the energy consumption of trains by applying neural networks
[EN] This paper presents the training of a neural network using consumption data measured in the underground network of Valencia (Spain), with the objective of estimating the energy consumption of the systems. After the calibration and validation of the neural network using part of the gathered consumption data, the results obtained show that the neural network is capable of predicting power consumption with high accuracy. Once fully trained, the network can be used to study the energy consumption of a metro system and for testing the hypothetical operation scenarios.The realization of this paper was possible thanks to the collaboration agreement signed between the Universitat Politecnica de Valencia and Ferrocarrils de la Generalitat Valenciana, and funding obtained by the Spanish Ministry of Economy and Competitiveness, through the project "Strategies for the design and energy-efficient operation of railway and tramway infrastructure'' (Ref. TRA2011-26602).Pineda-Jaramillo, JD.; Insa Franco, R.; MartÃnez Fernández, P. (2018). Modeling the energy consumption of trains by applying neural networks. Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit. 232(3):816-823. https://doi.org/10.1177/0954409717694522S816823232
System energy optimisation strategies for DC railway traction power networks
Energy and environmental sustainability in transportation are becoming ever more important. In Europe, the transportation sector is responsible for about 32% of the final energy consumption. Electrified railway systems play an important role in contributing to the reduction of energy usage and C0 emissions compared with other transport modes. Previous studies have investigated train driving strategies for traction energy saving. However, few of them consider the overall system energy optimisation.
This thesis analyses the energy consumption of urban systems with regenerating trains, including the energy supplied by substations, used in power transmission networks, consumed by monitoring trains, and regenerated by braking trains. This thesis proposes an approach to searching energy-efficient driving strategies with coasting controls. A Driver Advisory System is designed and implemented in a field test on Beijing Yizhuang Subway Line. The driver guided by the DAS achieves 16% of traction energy savings, compared with normal driving. This thesis also proposes an approach to global system energy consumption optimisation, based on a Monte Carlo Algorithm. The case study indicates that the substation energy is reduced by around 38.6% with the system optimised operations. The efficiency of using regenerative braking energy is improved to from 80.6 to 95.5%
Maximum risk reduction with a fixed budget in the railway industry
Decision-makers in safety-critical industries such as the railways are frequently faced with the complexity of selecting technological, procedural and operational solutions to minimise staff, passengers and third parties’ safety risks. In reality, the options for maximising risk reduction are limited by time and budget constraints as well as performance objectives.
Maximising risk reduction is particularly necessary in the times of economic recession where critical services such as those on the UK rail network are not immune to budget cuts. This dilemma is further complicated by statutory frameworks stipulating ‘suitable and sufficient’ risk assessments and constraints such as ‘as low as reasonably practicable’. These significantly influence risk reduction option selection and influence their effective implementation.
This thesis provides extensive research in this area and highlights the limitations of widely applied
practices. These practices have limited significance on fundamental engineering principles and
become impracticable when a constraint such as a fixed budget is applied – this is the current reality
of UK rail network operations and risk management. This thesis identifies three main areas of weaknesses to achieving the desired objectives with current risk reduction methods as:
Inaccurate, and unclear problem definition;
Option evaluation and selection removed from implementation subsequently resulting in misrepresentation of risks and costs;
Use of concepts and methods that are not based on fundamental engineering principles, not
verifiable and with resultant sub-optimal solutions.
Although not solely intended for a single industrial sector, this thesis focuses on guiding the railway
risk decision-maker by providing clear categorisation of measures used on railways for risk reduction.
This thesis establishes a novel understanding of risk reduction measures’ application limitations and respective strengths. This is achieved by applying ‘key generic engineering principles’ to measures employed for risk reduction. A comprehensive study of their preventive and protective capability in different configurations is presented.
Subsequently, the fundamental understanding of risk reduction measures and their railway applications, the ‘cost-of-failure’ (CoF), ‘risk reduction readiness’ (RRR), ‘design-operationalprocedural-technical’ (DOPT) concepts are developed for rational and cost-effective risk reduction. These concepts are shown to be particularly relevant to cases where blind applications of economic and mathematical theories are misleading and detrimental to engineering risk management.
The case for successfully implementing this framework for maximum risk reduction within a fixed budget is further strengthened by applying, for the first time in railway risk reduction applications, the dynamic programming technique based on practical railway examples
Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets
This document is the Technical Design Report covering the two large
spectrometer magnets of the PANDA detector set-up. It shows the conceptual
design of the magnets and their anticipated performance. It precedes the tender
and procurement of the magnets and, hence, is subject to possible modifications
arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti
Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski,
Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy),
Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy
Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets
This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It
shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible
modifications arising during this process
Development of a maintenance possession scheduler for a railway
Thesis (MEng)--Stellenbosch University, 2022.ENGLISH SUMMARY: Maintenance of rail infrastructure is an important element in rail operations
in order to keep tra c moving. However, maintenance causes infrastructure
to be taken out of service, which impacts tra c
ow. In this study,
the requirements of a maintenance possession scheduler for a South African
application was investigated, and a proposed solution was subsequently developed.
The main objective of the scheduler was to minimise the deviation
of the train service on a subset of rail infrastructure while ensuring that the
required maintenance is done.
To achieve this, a literature study was done on a number of themes, which
include an overview of the local railway operator with a look at the role of
industrial engineering as a function in the railway operator business, railway
infrastructure and operations, planning of railway operations, and maintenance
in the context of rail operations. The topic of possession scheduling
was then studied; the previous themes helped the researcher to learn the
bigger picture while understanding possession scheduling is critical for this
study. Past and recent works were studied and research areas and trends
were synthesised, including time span of possession scheduling in optimisation
models, and whether it was done on microscopic, mesoscopic or macroscopic
level. The various optimisation objectives formulated by researchers
were also noted, among other subthemes.
An application case was identi ed as the railway infrastructure between
Bellville and Wellington in the Western Cape province of South Africa. A
novel mixed-integer linear programming model was formulated for this case
and implemented in Cplex, after which it was validated. The model can do
possession scheduling for 24 hours on a microscopic level. Finally, several
experiments were conducted to investigate the performance and results of
the model. It was found that the model delivered optimal results in less than eight minutes, which makes it a feasible maintenance possession scheduler
for day-to-day work in the immediate planning horizon.AFRIKAANS OPSOMMING: Instandhouding van spoorinfrastruktuur is 'n belangrike element in spoorwegoperasies
ten einde verkeervloei te verseker. Instandhouding veroorsaak
egter dat infrastruktuur uit diens geneem word wat verkeer weer belemmer.
In hierdie studie was die vereistes van 'n besitskeduleerder vir instandhouding
vir 'n Suid-Afrikaanse toepassing ondersoek, en die voorgestelde
oplossing was daarna ontwikkel. Die hoofdoelwit van die skeduleerder was
om die afwykings van die trein diens te minimeer op 'n gedeelte van spoorinfrastruktuur
terwyl verseker word dat die nodige instandhouding gedoen
word.
Om dit te bereik is 'n literatuurstudie op 'n aantal temas gedoen. Dit sluit
in 'n oorsig van die plaaslike spoorwegoperateur en die rol wat bedryfsingenieurswese
as funksie daarin vervul, spoorweginfrastruktuur en operasies, en
instandhouding in die konteks van spoorwegoperasies. Die onderwerp van
besitskedulering was daarna bestudeer; die vorige temas het die navorser
gehelp om die groter prentjie te verstaan, terwyl die studie van besitskedulering
kritiek was vir hierdie studie. Navorsingswerk uit die verlede asook
onlangse werk was bestudeer en navorsingsareas en tendense is deur sintese
bepaal. Dit sluit in die tydsduur van besitskedulering in optimeringsmodelle
en of dit op mikro-, meso- of makroskopiese vlak gedoen word. Die verskillende
optimeringsdoelwitte wat navorsers formuleer het is ook waargeneem,
asook met ander subtemas.
'n Gevallestudie vir toepassing van 'n besitskeduleerder vir instandhouding
is identi seer as die spoorweginfrastruktuur tussen Bellville enWellington in
die Wes-Kaap provinsie van Suid-Afrika. 'n Nuwe gemengde heeltal-line^ere
programmeringmodel was geformuleer vir hierdie gevallestudie en in Cplex
implementeer, waarna dit gevalideer is. Die model kan besitskedulering vir
24 uur doen op mikrovlak. Verskeie eksperimente is uiteindelik uitgevoer om die prestasie en resultate van die model waar te neem. Dit is bevind
dat die model optimale resultate in minder as agt minute kon lewer, wat
dit 'n aanvaarbare instandhouding besitskeduleerder maak vir dag-tot-dag
werk in die nabye beplanningshorison.Master
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