Energy consumption as an important factor for decision on proper transport mode selection

This paper deals with energy consumption as one of critical factors for transport mode selection. The comparison was made in passenger and cargo transport on selected model situations. The results in case of passenger transport show the advantage of the road transport vehicle (bus). In case of cargo transport the best values are for the rail transport but in practice it is very difficult to use only this transport mode alone. For the real case it is better to compare two modes – direct road transport and the combined transport. So the best choice in cargo transport is the combined transport

A novel methodology of risk assessment for railway freight wagons

This study proposes a new methodology for the accurate risk assessment of railway freight wagons that has real-world applications in the operation and maintenance of freight vehicles. The paper specifically focuses on the analysis of posterior reliability calculation methods using Weibull’s reliability model to calculate reliability indicators by which the probability of occurrence of individual failures can be estimated. The consequences of failure are calculated through an existing system from the General contract used for freight wagons (AVV). The formula for calculating the risk value is based on a classical risk theory, where the risk is defined as a combination of the occurrence of a negative phenomenon and the severity of its consequence. The reasoning for this approach was in an effort to maintain simplicity and clarity for potential users in practice. This is based on the information gathered in examining the current state of risk management in the sector of railway vehicles in Slovakia. The data used for risk calculations were taken from a maintenance workshop in Slovakia to provide a realistic picture of the failure rates of freight wagons. The proposed methodology uses historical data for prediction of reliability for the next years. Based on the reliability being a function of time, the risk associated with it is variable, increasing with time. These findings have broader implications for the maintenance systems taken appropriate maintenance actions necessary with respect to increased risk

Modelling and Experimental Analysis of Noise Transmission through Wall of a Railway Vehicle

The paper presents results of a grant research project dealing with acoustic properties of the walls and floor of a railway passenger coach investigated by means of the experimental analysis of noise produced during train runs and corresponding simulations. In the research, conditions and theoretical approaches for possible reconstructions of walls and floor of the railway passenger coach using new fibrous-microstructure acoustic materials were defined, with the aim of increasing the sound reduction index. The properties of the proposed materials were compared in terms of the acoustic energy transfer through the porous microstructure calculated by means of simulations. The final acoustic effects of different solutions for the incorporation of the materials in the floor structure and in the complete body of the rail passenger coach were evaluated. In this paper the effects on interior noise of the introduction of a new material for floor and wall are presented

Modelling and experimental analysis of noise transmission through wall of a railway vehicle

The paper presents results of a grant research project dealing with acoustic properties of the walls and floor of a railway passenger coach investigated by means of the experimental analysis of noise produced during train runs and corresponding simulations. In the research, conditions and theoretical approaches for possible reconstructions of walls and floor of the railway passenger coach using new fibrous-microstructure acoustic materials were defined, with the aim of increasing the sound reduction index. The properties of the proposed materials were compared in terms of the acoustic energy transfer through the porous microstructure calculated by means of simulations. The final acoustic effects of different solutions for the incorporation of the materials in the floor structure and in the complete body of the rail passenger coach were evaluated. In this paper the effects on interior noise of the introduction of a new material for floor and wall are presented

Model calculations of posterior reliability indicators for the proposal of the maintenance system

Designing the content and scale of maintenance of machines and equipment by a priori and posterior reliability methods in considered crucial to reducing the cost of the machine's life cycle, maintaining high operational readiness and reducing the consequences of failures. In the presented paper, attention is paid to the analysis of the calculation methods of posterior reliability for calculation indicators of reliability and to the use of the specified Weibull model for reliability calculations. The obtained results are further developed for models of optimal process calculations to perform scheduled maintenance interventions. Calculations of the other RAMS (reliability, availability, maintainability and safety) indicators that are critical to the design of an optimal engineering design with regard to maintenance and which do not receive sufficient attention in technical practice are also assessed

Model calculations of posterior reliability indicators for the proposal of the maintenance system

Designing the content and scale of maintenance of machines and equipment by a priori and posterior reliability methods in considered crucial to reducing the cost of the machine's life cycle, maintaining high operational readiness and reducing the consequences of failures. In the presented paper, attention is paid to the analysis of the calculation methods of posterior reliability for calculation indicators of reliability and to the use of the specified Weibull model for reliability calculations. The obtained results are further developed for models of optimal process calculations to perform scheduled maintenance interventions. Calculations of the other RAMS (reliability, availability, maintainability and safety) indicators that are critical to the design of an optimal engineering design with regard to maintenance and which do not receive sufficient attention in technical practice are also assessed

Use of risk assessment methods in maintenance for more reliable rolling stock operation

Operation of the rolling stock is associated with a number of risks. The consequences of failures are sometimes very serious - safety or the environment, sometimes only economic. A significant factor affecting the safe operation of railway vehicles is maintenance. The paper presents methods of risks assessment and possibilities of their reduction in design, operation and maintenance of railway vehicles. Special attention is given to the new "silent brakes" and safety related issues for freight wagons

Endovascular thrombectomy for acute ischaemic stroke with established large infarct: multicentre, open-label, randomised trial

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