Common Safety Methods Research Articles

Application of risk assessment methods in rail transport

This article presents the safety management issue in rail transport in the context of the principles defined in the European Union regulations, i.e., the Common Safety Methods (CSM) dedicated to risk assessment. It describes regulations applicable to the process of risk assessment process including risk analysis and evaluation. The most important challenges related to the application of risk assessment methods are also presented in the article. The regulations of the European Union do not precisely define the way in which risk assessment should be carried out in an organisation. Furthermore, the legislation only requires a risk assessment process to be carried out following a change to the railway system if such a change is assessed as a 'significant change'. This aspect remains problematic in the railway system, due to the considerable discretion left to the railway companies in their approach to conducting assessments of the significance of a change and the low percentage of so-called “significant changes”. As shown by some railway accidents and reports of the State Commission for Investigation of Railway Accidents, omissions in the process of risk assessment and inconsistency of approach of various undertakings to analogous situations may lead to an uncontrolled increase in the level of risk in railway transport.

AN APPROACH TO THE LEGAL REQUIREMENTS REGARDING RAILWAY TRANSPORT SAFETY MONITORING IN THE EUROPEAN UNION

The targeted liberalisation of the European Union railway market in 1998 could have lead to a decrease in the safety of rail transport. To prevent this, the European Commission developed and implemented new requirements in this area without explicitly deciding on the methods and tools to be used for their implementation. Entities operating in the market faced a new challenge, the development of a systems model approach to safety management. Only a correctly designed process model, along with the appropriate tools for monitoring and managing risk, allows the level of safety to be maintained at current levels or improved. As part of the research, solutions were developed for a systems approach to safety management in railway transport and the risk management and maintenance monitoring of railway vehicles. Safety is an essential criterion for assessing the functioning of a railway system, it determines its efficiency as well as – in a widely understood sense – the quality of its transport services. This paper describes the legal requirements and practical methods of implementation arising from the issue of Directive 2004/49/EC as it concerns the monitoring of railway safety (Chruzik et al. 2014). The directive enforces the gradual introduction of Common Safety Targets (CST) and Common Safety Methods (CSM) to maintain (or increase) the existing high safety levels after the opening up (liberalisation) of the rail market. The introduction of CST and CSM necessitates the development of methods for the evaluation of the level of safety and activity of operators, both at the level of the Member States and also at the level of the European Union. The paper describes the practical solutions developed for railway operators as part of the implementation of maintenance management systems (Sitarz et al. 2013; Chruzik et al. 2014).

Analysis of Big Data Streams to obtain Braking Reliability Information for Train Protection systems

Due to the long braking distance of railway systems and the high velocities achieved, railway operation needs to rely on train control systems. At the foundation of these systems are models to predict the motion of the trains, including their anticipated braking curve. Depending on the infrastructure manager, these braking curves need to be achieved with a given safety, which is typically in the rare event region of probabilities.In current settings, it is typical to develop these so called braking curves either by physical modelling of the train followed by a Monte Carlo simulation or following a heuristic approach, mostly based on the high level of safety over the past centuries. However, higher developed train protection and control systems, such as the European Rail Traffic Management System (ERTMS) or the Russian KLUB-U System together with current efforts towards quantitative risk analysis, e.g. the European Common Safety Methods, require a more formal approach to communicate the braking curve of a train between rolling stock and infrastructure. An a priori determined set of braking curves is feasible for trains running in fixed or a limited number of formations, such as multiple unit trains, however in the freight railway system due to its vast amount of different vehicles and possible train setups, the determination of the braking curves is prohibitive. In this work, a procedure is proposed to obtain the variation in braking force from accelerometer data onboard the vehicles. In order to allow for the large amount of data to be expected, the procedure is formalised in MapReduce form. The variation of the braking force from the expected value determined in this way can then be forwarded to a Monte Carlo Analysis using importance sampling methodologies to allow for an online calculation of braking curves based on the safety requirements communicated by the infrastructure manager. It is expected that such a procedure yields shorter braking curves than the safety factors currently proposed, leading to higher commercial speeds and thus higher infrastructure usage.

Modern regulations of safety assurance for maglev transportation

In article regulatory framework of maglev are considered, the international experience is analysed and conclusions for Russian practice are drawn. Modern management methods of safety of transport systems are based on principles of advance to occurrence of dangerous events. These principles include: - application of forecasting methods (aprioristic estimation methods) at an estimation of safety and substantiation of safety measures - a principle of «the new approach»; - estimation of safety taking into account risk from action of casual and systematic failures; - safety management in a complex with management of reliability, availability, maintainability, material support and life cycle cost. Necessity of application of «the new approach» to railway safety, including the high-speed railways, formally has been established by the Railway Safety Directive 2004/49/EC. This Directive orders to use: - analysis and management of risk at all life cycle stages of the technical systems participating in formation of traffic service, and at early stages of life cycle are made look-ahead estimations of risks which are compared with admissible values of risk; - common safety targets, common safety indicators and common safety methods on all space of the European Union; - common approaches to certification of safety and the harmonised supervision bodies; - common typical safety management system, based on ISO 9001principles. For activity expansion on performance of Railway Safety Directive of the European Committee for Electrotechnical Standardization CENELEC have been developed and now frame standards EN 50126, EN 50128, EN 50129 are applied.

Single site meta-analysis of 6% hydrogen peroxide whitening strip effectiveness and safety over 2 weeks

Objectives This research evaluated efficacy and safety of 6% hydrogen peroxide whitening strips from a clinical trials database accumulated over a multi-year period at a single site. Methods The inclusive meta-analysis involved seven different randomized clinical trials at one dental school. Each study used 6% hydrogen peroxide whitening strips twice daily for 30 min over a 2-week period. Common efficacy (digital images) and safety (examination and interview) methods were used across studies. Pooled subject-level data were analyzed using a general linear mixed model to determine overall response and effects of treatment duration on whitening. Results The 148 treated subjects were 18–71 years old, with b* (yellowness) ranging from 12 to 22, and L* (lightness) ranging from 69 to 80. After 1-week strip use, the adjusted mean (S.E.) for Δ b* was −1.6 (0.08), differing significantly from baseline ( p < 0.0001). After 2 weeks, the adjusted mean (S.E.) for Δ b* was −2.3 (0.07), differing significantly from Week 1 ( p < 0.0001). The estimated correlation between Weeks 1 and 2 for Δ b* was 0.74. Study-to-study variation contributed less than 2% of Δ b* variability. Results were similar for Δ L*, with Weeks 1 and 2 estimated means (S.E.) of 1.5 (0.13) and 2.0 (0.12). Occurrence of oral irritation (22%) and tooth sensitivity (20%) did not adversely affect whitening. Other side effects were unremarkable, and only 1 subject (0.7%) discontinued treatment early due to an adverse event. Conclusions The meta-analysis of multiple studies conducted at a single clinical site over several years establishes consistent, effective and safe vital bleaching with 6% hydrogen peroxide whitening strips.