Design Of Railway Systems Research Articles

Utilization of the Adams system for simulating collisions of wagons equipped with elastomeric buffers

The article introduces an innovative method for modeling elastomer buffers using a rheological structure. This approach entails a detailed mathematical description of buffer properties, seamlessly integrated into the ADAMS/Rail computer code for simulating impacts between two wagons. The simulation within ADAMS/Rail provides insights into the dynamic behavior of elastomer buffers during wagon impacts, considering forces, deformations, and overall responses. Serving as a valuable optimization tool for railway system design, this methodology contributes to improved safety and efficiency. The study’s comprehensive yet concise insights bridge the gap between theoretical modeling and practical application, enhancing our understanding of elastomer buffer dynamics and their pivotal role in railway operations.

Systematic Evaluation and Usability Analysis of Formal Methods Tools for Railway Signaling System Design

Formal methods and supporting tools have a long record of success in the development of safety-critical systems. However, no single tool has emerged as the dominant solution for system design. Each tool differs from the others in terms of the modeling language used, its verification capabilities and other complementary features, and each development context has peculiar needs that require different tools. This is particularly problematic for the railway industry, in which formal methods are highly recommended by the norms, but no actual guidance is provided for the selection of tools. To guide companies in the selection of the most appropriate formal methods tools to adopt in their contexts, a clear assessment of the features of the currently available tools is required. To address this goal, this paper considers a set of 13 formal methods tools that have been used for the early design of railway systems, and it presents a systematic evaluation of such tools and a preliminary usability analysis of a subset of 7 tools, involving railway practitioners. The results are discussed considering the most desired aspects by industry and earlier related studies. While the focus is on the railway signaling domain, the overall methodology can be applied to similar contexts. Our study thus contributes with a systematic evaluation of formal methods tools and it shows that despite the poor graphical interfaces, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">usability</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">maturity</i> of the tools are not major problems, as claimed by contributions from the literature. Instead, support for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">process integration</i> is the most relevant obstacle for the adoption of most of the tools. Our contribution can be useful to R&D engineers from railway signaling companies and infrastructure managers, but also to tool developers and academic researchers alike.

Railway System Design by Adopting the Merry-Go-Round (MGR) Paradigm

Public transport systems can be characterised by a schedule-based or a frequency-based framework according to the kind of service to be operated. In the former case, specific departure and arrival times are set for each run and disclosed to the users; in the latter, instead, it is necessary to maintain a certain headway between two successive runs, rather than a specific timetable structure. This paper focuses on modelling frequency-based systems, which can be described by means of the so-called Merry-Go-Round (MGR) paradigm. The paradigm is first discussed and the related analytical formulation is presented; the role of the terminal station layout is then investigated within this framework. Finally, in order to show the effectiveness of the proposed formulation, it was implemented in the case of a real-scale metro line.

Electrokinematical Simulation for Flexible Energetic Studies of Railway Systems

Simulation is a valuable tool to evaluate energy consumptions and design of railway systems. The system limitations have an important influence on the system behavior and must be taken into account in the simulation. Especially, the electromechanical limitations have a major impact on the kinematical behavior. However, such limitations are often neglected in classical studies. This paper deals with the development of an adaptive electrokinematical simulation to adapt the kinematical behavior of the system according to its limitations. A flexible simulation tool is thus obtained by taking into account electrical, mechanical, as well as kinematical limitations. This tool is validated by experimental results on a real railway track. It is then used to study different solutions to increase the transport capacity of a subway system, even when limitations occur.

Supporting the design of railway systems by means of a Sobol variance-based sensitivity analysis

Recently the growing demand in railway transportation has raised the need for practitioners to improve the design of railway systems. This means to identify a configuration of the infrastructure components (e.g. number of rail tracks, type and layout of the signalling system, layout of station tracks) and the operational schedule (e.g. train headways, scheduled dwell times) that improves given measures of performance such as the level of capacity, the punctuality of the service and the energy saving.Planners and designers involved in this process have the hard task of determining sound design solutions in order to achieve certain levels of network performances in a cost-effective way, especially when investment funds are limited. To this aim, a sensitivity analysis can support early decisional phases in order to better understand dependencies between performances and design variables and drive the decisional process towards effective solutions.In this paper, the Sobol variance-based method is applied to this purpose. A practical application has been carried out for a mass transit line in the city of Naples. Such study has investigated how train delays and energy consumption are affected by variations in design variables relative to the operational plan, the signalling system and factors related to the layout of station platforms. Results highlight the ability of this analysis in explaining the effects of different design solutions from a statistical point of view and finding the most influential factors for a given performance. This aspect suggests to practitioners the usefulness of this approach in addressing decisions towards cost-effective interventions.

Rail Human Factors-Human-centred design for railway systems

Abstract In our Rail Human Factors approach, we define the human as the starting point for our interdisciplinary research on the design of human-machine interfaces in railway systems. Our research is based on three key issues: understanding the user (operator), evaluating existing systems, and developing and testing new concepts. Furthermore, we develop new methods for evaluation and design of railway systems. In the present paper we explain our approach and give examples for its application.

Quantified risk assessment in railway system design and operation

AbstractOver the last few years quantified risk assessment (QRA), a technique developed in the process industries, has moved into the railway and mass transport arenas. Many quantified risk assessments are now appearing covering varying aspects of railway operation and design.This paper highlights the strengths and weaknesses of the QRA technique, with specific reference to its use in railway system design and operation. Suggestions are made as to how best to manage and present a QRA, and these are illustrated in a section explaining the systematic approach of Cross Rail, a joint London Underground/British Rail/Railtrack £2 billion railway for London.Throughout this paper it is stressed that good QRA comes from management of the process and not of the ‘final figure’. The paper concludes with a listing of recommendations that are considered to be the minimum needed for the future progress of railway QRAs. Consequently the paper will be of special interest to those railway organizations undertaking or managing a QRA for the first time. Special reference is made to the use of QRAs in the presentation of Railway Safety Cases and project design.