International Journal of Railway Research
Year:2018 | Volume:5 | Issue:2|Papers Count:6

Apart from regular wheel wear such as decreasing wheel diameters and reduced flange thicknesses and heights, wheelflats (WF) and oval wheels (or OOR, Out-Of-Roundness) are the most common wheelset problems for railway vehicles. Within the FP7 Research Project “ Saferail” , APT has developed an innovative wheelset monitoring system so-called “ Wheelflat and Out of Roundness Monitoring (WORM) system” . The monitoring system is installed on the track and is based on the vibration signals measured during the passage of trains. The main advantages of vibration signals are the short measurement time of just a few seconds, and the very limited number of sensors to be installed. As a consequence, the track space required for the installation of the equipment is very limited and thus the associated installation cost is significantly reduced. Early detection of wheelflats combined with appropriate corrective action not only contributes to lower track stresses and wear, but also results in a longer wheel life. The WORM system reports all measured vehicles via a web interface so no user software installations are necessary. A historical overview of measurements and alarms can easily be retrieved from the proposed system. Immediate alerts can be programmed to be sent by email or text message. These advantages make the APT-WORM system as a strong device to increase the service life of the wheel and decrease the maintenance cost by optimizing the maintenance intervals.

A short survey on modern track maintenance methods is given, concentrating on the developments in recent years. The ongoing refinement of the machinery should be shown as the influence of ITsolutions should. On top the economic view to the track infrastructure is briefly demonstrated. Further developments in track hardware solutions must respect the obtained high level of track work mechanization. However, with respect to presentation time some other ongoing developments unfortunately are not discussed. Prominent amongst those are: the advent of high grade rail steels like heat-treated perlitic steels, the experiments with bainitic steels and the introduction of hydraulically driven turnouts with special high-speed-prone rail geometry or the latest machine sets for general subgrade rehabilitation.

Currently, road transportation is the main mode of freight transit in Iran. About 90% of freight transit is through this mode of transportation. This is not in line with the transportation policies. Based on such policies 70% of the freight transit need to be through road transportation and 30% of the freight transit need to go through rail transportation. However, Iran's railway network is very wide and the share of railway in freight transit can be increased. Therefore, it is important to recognize the effective factors that can increase the share of rail transit. The purpose of this research is to recognize the factors that can improve the utility of railway transit corridors and to advance the competitive position of railway in freight transit. The concepts of utility and transit are described. The factors affecting the utility of railway transit corridors from the perspective of the owner of goods are determined by making a literature review and investigating the opinions of experts. These factors include transportation cost, commercial speed, reliability, safety, the system of tracing wagons and service frequency. A utility function for Bandar Abbas-Sarakhs corridor is developed that is based on the aforementioned factors. A dynamic model to evaluate the utility of the corridor is developed. After verifying the model, it is used for simulation of 20 years of service by using PLE software. The results of the simulation show that with simultaneous improvement in reliability, the system of tracing wagons at commercial speed also offering discount on the cost of transportation according to the demand of the owner of goods can play a significant role in increasing the utility of Bandar Abbas-Sarakhs corridor. Changing only one factor will not result in major changes in the utility of the corridor.

The train transport is often confronted with greatly repeated changes in scope, vehicle travel well-being and transport safety because of the adjustments of wheel and rail profiles. These problems are frustrating and threatening. Thus, there is a requirement for an approach to predict the wear of wheel/rail to tackle these problems. A new theoretical ground is broken through the build-up of a modified structure motivated by dimensional analysis to predict the growth of the wheel profile by drawing on Li et al. ’ s seminal work on wheel profile. The principal difference between the current research and Li et al. ’ s work is the incorporation of additional wear profile parameters of fatigue strength and design factor. A framework is then developed for damped and undamped vibration circumstance with simulation results. The suggested approach could comparatively predict the needed parameters with the advantage of a wide scope of parametric coverage. The novel element of the paper is the unique way of predicting the desired parameters in a wider range of parametric observations. The probable use of the method is the state functional railway corporations in developing countries.

The influence of main quality tests on the overall quality of railway ballast materials is assessed in this study. The need to integrate all acceptance tests in a unified manner for precise evaluation of ballast quality is identified, and a technique of performing this is proposed. Using this approach, a new ballast quality index (BQI) is defined in which, the main acceptance tests including abrasive strength, abrasive hardness, fragmentation strength under external loads and weathering resistance, are considered. For the development of the new BQI, all tests results are combined, assigning justified coefficients to each test value according to its contribution on overall quality. Moreover, the comparison of the new index versus the Abrasion Number (AN) as a proposed approach of the Canadian Pacific Railroad for ballast selection is investigated. A practical use of the new index is finally presented with regard to the laboratory investigations on different ballast rocks, to indicate its capability and applicability.

Iran’ s geographical situation, in particular existing long-distance routes, makes rail transportation more attractive and efficient rather than the other modes of public transportation. Transport costs as well as passenger utility are main concerns for local and national authorities. Therefore, Hub location is an important problem in transport planning in which transport industries are looking for selected points for passengers to change trains from their origins to destinations. In this paper, a mathematical model for solving hub location problem is developed and validated on Iranian rail network. Passenger supplies and demand from origin to destination nodes are estimated using the well-known model of Gravity as well as the shortest path algorithm that is utilized for route assignment. Running the proposed procedure and model by GAMS revealed that choosing appropriate hubs, even in less sophisticated connectivity rail network, can significantly reduce the transport cost and enhance rail transport productivity over the rail network.