Reference values for railway sidings track geometry

Railway sidings are operated at speeds much lower than those used on national railway lines; a typical speed is 6 km/h. In establishing reference values for maintenance of railway infrastructure in terms of the geometry for such operating conditions, it is noted that both national and European regulations do not provide specific information regarding railway sidings. The overall objective of the research is, therefore, the definition of possible reference values for track geometry, based on those adopted by European rail networks (European and national standards), which can guarantee the appropriate security level for low speed operation typical of railway sidings connected to the national network. The basic principle in defining these values is the maximization of technical-economic efficiency and the maintenance of the acceptability of the risk associated to railway operation. The research results can therefore provide useful information about the cost-effective management of maintenance and safe operation for railway sidings. For this purpose, the approach was inspired to that of Regulation 402/2013, which defines at European level a common safety method for risk analysis. Quantification of probabilities and damages should be based on simulation models because the available statistics do not allow significant results to be inferred. However, the research sector has not yet produced a consolidated modelling. For these reasons, and since it is not possible to quantify probabilities reliably, the proposals resulting from this research are based on the identification of situations where it can be shown that the hazard probability remains unchanged. The approach used to formulate possible reference values valid outside of national networks (railway sidings) is based on an understanding of the underlying principles of the codes of good practice, on the formulation of hypotheses conform to the same principles, and the proposals about mitigative measures of risk associated to the use of different reference values, such as to keep the risk of the railway within the limits of acceptability, acting conservatively so as to keep unchanged, or reduce, the probability of hazardous events.The assessment parameters, object of the first phase of the research referred to in this work and used here as an example, are longitudinal level and alignment of railway track. In the case of vehicles running at low speed, the study was conducted by varying the magnitude of the reference values by using values that belong to external intervals with respect to those in accordance with European and national codes of good practice, examining the corresponding effects on the physical quantities related to safety. The effects of their variations on the wheel-rail interaction forces were studied using a simple dynamic model (with one degree of freedom) and a random generated excitation given by track defectiveness and the corresponding random response in terms of vertical and lateral contact forces (Q and Y)

Virtualisation of the test environment for signalling

ERTMS is a well-known, well-performing technology applied all over the world but it still lacks flexibility when it comes to authorisation and certification procedures. The key of its success in the future lies as much in cost reduction as in simplification of placing in service procedures. This holds true for the implementation of a new subsystem and even more so for new software releases related to subsystems already in service. Currently the placing in service process of ETCS components and subsystems requires a large amount of tests due to the complexity of the signalling systems and the different engineering rules applied. The S2R Multi-Annual Action Plan states that the effort and time consumption of these onsite tests are at least 30% for any particular project. VITE research project (VIrtualisation of the Test Environment) aims at reducing these onsite tests to a minimum while ensuring that laboratory tests can serve as evidence for valid system behaviour and are accepted by all stakeholders involved in the placing in service process. This paper presents the first VITE results

Full-scale measurement and analysis of train slipstreams and wakes. Part 1: Ensemble averages

This paper describes a series of extensive and unique full-scale measurements of the slipstreams of trains of various types that were carried out as part of the EU-sponsored AeroTRAIN project, together with the analysis of the experimental data. These experiments were carried out with the fundamental aim of seeking to reduce the complexity of the current technical specifications for interoperability (TSI) testing methodology. Experimental sites in Spain and Germany were used, for a range of different train types - high-speed single-unit trains, high-speed double-unit trains, conventional passenger units and locomotive/coach combinations. The data that was obtained was supplemented by other data from previous projects. The analysis primarily involved a study of the ensemble averages of the slipstream velocities, measured both at trackside and above platforms. The differences between the flows around different train types were elucidated, and the effect of platforms on slipstream behaviour described. A brief analysis of the effects of crosswinds on slipstream behaviour was also carried out. Through a detailed analysis of slipstream velocity components, the detailed nature of the flow around the nose and in the near wake of the train was investigated, again revealing differences in flow pattern between different trains. Significant similarity in the far wake flows was revealed. These fundamental results form the basis for the detailed discussion of the proposed TSI methodology that will be presented in Part 2 of this paper. Overall the results enable the nature of the flow field around trains to be understood in far greater detail than before, and also allow the developments of a revised TSI methodology which is more efficient than current practice. © IMechE 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav

Limits and opportunities of risk analysis application in railway systems

Risk Analysis is a collection of methods widely used in many industrial sectors. In the transport sector it has been particularly used for air transport applications. The reasons for this wide use are well-known: risk analysis allows to approach the safety theme in a stochastic - rather than deterministic - way, it forces to break down the system in sub-components, last but not least it allows a comparison between solutions with different costs, introducing de facto an element of economic feasibility of the project alternatives in the safety field. Apart from the United Kingdom, in Europe the application of this tool in the railway sector is relatively recent. In particular Directive 2004/49/EC (the "railway safety directive") provides for compulsory risk assessment in relation to the activities of railway Infrastructure Managers (IMs) and of Railway Undertakings (RUs). Nevertheless the peculiarity of the railway system - in which human, procedural, environmental and technological components have a continuous interchange and in which human responsibilities and technological functions often overlap - induced the EC to allow wide margins of subjectivity in the interpretation of risk assessment. When enacting Commission Regulation (EC) No 352/2009 which further regulates this subject, a risk assessment is considered positive also if the IM or RU declare to take safety measures widely used in normal practice. The paper shows the results of a structured comparative analysis of the rail sector and other industrial sectors, which illustrate the difficulties, but also the opportunities, of a transfer towards the railway system of the risk analysis methods currently in use for the other systems

An authorisation framework for actively controlled running gear

A Shift2Rail funded research project called RUN2Rail has investigated a range of new technologies for railway rolling stock. The project included a task on the use of active suspensions, and one of the subtasks was to propose a strategy supporting the authorisation by safety authorities for highly innovative mechatronic vehicles to be placed on the market. The incorporation of electronics and control into suspension systems is still at an early stage, so this paper provides a framework for a practical and efficient authorisation strategy, primarily based upon existing European regulations and standards but in general applicable worldwide

Track geometry monitoring by an on-board computer-vision-based sensor system

This article illustrates some outcomes of the EU project Assets4Rail, founded within the Shift2Rail Joint Undertaking. Nowadays, Track recording vehicles (TRV) are equipped with laser/optical systems with inertial units to monitor track geometry (TG). Dedicated trains and sophisticated measurement equipment are difficult, costly to acquire and maintain. So the time interval between two TRV recordings of the TG on the same line section cannot be too close (twice per month to twice per year). Recently, infrastructure managers have been more interested in using commercial trains to monitor track condition in a cost-effective manner. TRVs' expensive and constantly maintained optical systems make them unsuitable for commercial fleets. On-board sensor systems based on indirect measurements such as accelerations have been developed in various studies. While detecting the vertical irregularity is a straightforward method by doubling the recorded acceleration, it is yet an unsolved issue for lateral irregularities due to the complicated relative wheel-rail motion. The proposed system combines wheel-rail transversal relative position data with on-board lateral acceleration sensors to detect lateral alignment issues. It includes a functional prototype of an on-board computer vision sensor capable of monitoring Lateral displacement for TG measurements. This eliminates measurement errors due to wheelset transverse displacements relative to the track, which is essential for calculating lateral alignment. The sensor system prototype was tested in Italy at 100 km/h on the Aldebaran 2.0 TRV of RFI, the main Italian Infrastructure Manager. It was found that the estimated lateral displacement well corresponds to the lateral alignment acquired by the Aldebaran 2.0 commercial TG inspection equipment. Moreover, due to the lack of measurement of the acceleration on board the Aldebaran 2.0 TRV, a Simpack® simulation provide with axle box acceleration values, to evaluate the correlation between them, LDWR and track alignment issues

Editorial: Functional Genomics in Fruit Trees: From 'Omics to Sustainable Biotechnologies

This Research Topic of Frontiers in Plant Science collects 8 manuscripts, focused on fruit crops of high commercial interest, such as bayberry, blueberry, pear, grapevine, citrus, and walnut. The breadth of solutions and approaches that omics offer us today, and the applications and perspectives that are looming over a short time horizon, are illustrated with a particular focus on fruit qualitative traits, related to firmness and post-harvest (Cappai et al.), ripening (Honaas et al.), and lignin accumulation (Cao et al.), on improving knowledge on secondary metabolites, such as phenolic compounds (Saxe et al.), as well as on investigating earliest responses to pathogens (Wei et al.). Moreover, the Research Topic illustrates a technological application path from whole-genome sequencing (Wu et al.) to the resequencing (Tanaka et al.), to achieve the ultimate objective of modulating genes using the New Breeding Techniques (Salonia et al.)

Comprehensive characterization of active chitosan-gelatin blend films enriched with different essential oils

Natural extracts and plant essential oils (EOs) have long been recognized as valid alternatives to synthetic food additives owing to their proved wide-spectrum antimicrobial capacity. The main aim of this study was to characterize the physical, mechanical, water barrier, microstructural and antimicrobial properties of chitosan-gelatin blend films enriched with cinnamon, citronella, pink clove, nutmeg and thyme EOs. The film microstructure determined by scanning electron microscopy, showed that all active films had heterogeneous surface: in particular, films including cinnamon, nutmeg and thyme EOs showed remarkable pores on the surface. The possible interaction of chitosan-gelatin blend film with incorporated EOs was investigated using Fourier-transform infrared (FT-IR) spectroscopy. Presence of new bands and changes in the FT-IR spectra confirmed intermolecular interactions between the chitosan-gelatin matrix and the EOs. The antimicrobial activity of films was determined using the disk diffusion assay. Active films inhibited the growth of four major food bacterial pathogens including Campylobacter jejuni, Escherichia coli, Listeria monocytogenes and Salmonella typhimurium and, among the tested EOs, thyme was the most effective (p < 0.05). The active films can be considered as effective barriers against UV light. The incorporation of EOs to the chitosan-gelatin film increased thickness, moisture content, water vapor permeability, b* and ΔE* values (p < 0.05) while it decreased L* value, light transparency and opacity (p < 0.05). Overall, the characterization of functional properties revealed that chitosan-gelatin films incorporated with EOs could be used as environmentally friendly active food packaging with antimicrobial properties and potential to extend the shelf-life of food products