The signalling and transport information division of RTRI aims to contribute to enhancing safety, reliability, and convenience through research and development in signalling systems, communication network technology, transportation planning and traffic management, and condition monitoring technology for railway facilities. This paper outlines the recent trends in research and development aimed at new train operation and control technology for safer and more stable transportation services. This paper further reports on recent development in technology for detecting obstacles on the track, to reduce railway traffic accidents.
Technological development in various industrial fields including the railways has been brought about by advances made in component technology. Material technology contributes to component technology in many aspects. When developing materials, it is important to fully understand the properties of various kinds of material. One way to achieve this is to classify materials and gain a rough understanding of their properties. This paper classifies materials according to their compounds and/or components, and introduces aspects of materials research and development applicable to railway facilities and vehicles, depending on their classification.
Environmental problems along railway lines caused by passing trains include noise, low-frequency sound, micro-pressure waves radiating from tunnel portals, ground vibration, etc. It is necessary to mitigate the impact of these phenomena to make the railways more environmentally-friendly. This paper outlines recent studies with this objective in mind, carried out by the Railway Technical Research Institute, and focused on issues related to faster Shinkansen running speeds in particular.
When bringing radio communication train control systems into service, it is essential to establish conditions that will allow stable radio communications, and take into account train operating conditions. As such a radio telecommunications and train operations simulator to forecast train operation was developed, that takes into account radio wave propagation and telecommunications networks. In addition, using the simulator, a system design flow chart was designed to ensure that certain basic criteria are met. This paper describes the simulator, and the design flow chart, and presents the results from a case study carried out using the simulator.
One of the technical problems encountered when dispatching trains using computation is how to reflect all the conditions or criteria that influence a decision that form part of the tacit knowledge that train dispatchers have acquired from experience in conventional rescheduling systems. A method has been developed from operation performance records, to generate decisions that would have been made by dispatchers with a high probability under specific conditions, namely operational dispatching rules (ODRs). A train rescheduling algorithm was created based on the mechanisms related to ODRs and its validity by comparing actual operation planning results with computed outputs.
The object of this study is to develop a quantitative evaluation method of the convenience of public transportation networks in regional cities. In this paper, first, the theory of the quantitative evaluation method of the convenience of public transportation networks in regional cities is shown. Then, the findings concerning the way of public transportation actually used in the certain regional city obtained from the field survey in that city, and the development of the system for carrying out calculations of the convenience of transportation networks automatically are shown. Finally, the course of the development plan in the future is showed.
In Japan, materials used in railway rolling stock are classified according to their behavior during Japanese standard fire tests for railway rolling stock materials in accordance with the relevant Ordinances. Fire test standards were established to contribute to rolling stock safety from fire. However, the thermal radiation cited in standard fire tests is relatively low and some criteria are only qualitative. A number of serious fires over the past few years demonstrated that some test conditions in the standard fire tests were underestimated. Consequently, this illustrated the importance of conducting a quantitative study to examine the effect of thermal radiation from large fires on the combustion performance of materials used in railway rolling stock. Cone calorimeter fire tests were therefore carried out to investigate the impact of large thermal radiation on a series of products used in rolling stock.
The authors carried out a basic study on a power storage coil made of MgB2 superconducting wires which was expected to require less cooling and lower manufacturing costs. First, for manufacturing the storage coil, the basic characteristics of MgB2 superconducting wire were evaluated. The characteristics at 20 K under 1.5 T were a critical current of 170 A for the in-situ MgB2 wire and 200 A for the ex-situ MgB2 wire. Based on these results, MgB2 conductors and prototype storage coils were produced and their performance was evaluated. The prototype was successfully energized to 600 A under 1.5 T at less than 25 K, which are the basic requirements for several 10 kJ class coils, and there was no significant deterioration through conductor and coil processing.
An external load applied to a roller bearing is distributed among the rolling elements. This distribution of the rolling element load changes according to the axial clearance of the bearing, and will affect the rolling contact fatigue life of the bearing. In this study, the rolling element load was measured using an optical fiber sensor that was inserted into one of the rollers in the double row tapered roller bearing to be measured, and the effect of the axial clearance on the rolling element load was investigated. As a result, it was clarified that the load distribution factor decreases as axial clearance increases.
Aerodynamic bogie noise generated from Shinkansen trains is the main source of the noise when they are running at above 300 km/h and noise reduction is important for preserving the quality of the environment around railway lines. In order to reduce bogie noise effectively, it is important to evaluate the contribution of the bogie components to the aerodynamic bogie noise. The purpose of this paper is to estimate their contributions at the measurement point close to the track by a wind tunnel test. Both the noise contribution of each component and the measures to reduce the aerodynamic noise are investigated by arranging the component in the bogie model.
The running safety of railway vehicles exposed to strong cross winds is evaluated by means of an aerodynamic coefficient obtained from wind tunnel tests. There are many types of section topography along actual railway lines, but the aerodynamic coefficient is sought for seven standard types of structure. Many lines close to the coast or rivers are often flanked by a slope on one side and a bank on the other (half-bank half-cut sections), and sections like this are treated as embankments. However, in sections with a high cut on the downwind side, the lateral aerodynamic force acting on the train is different from that in sections of normal embankments. Therefore, wind tunnel tests were conducted to obtain the aerodynamic coefficient for half-bank half-cut sections.
Vibrations caused by running trains sometimes lead to environmental issues. Train-induced vibrations are caused by moving static and dynamic axle loads. In numerical simulations of train-induced vibration, the type of excitation force greatly affects the relevant structure and ground responses. This study evaluated the influence of excitation force types on ground responses. Numerical simulations demonstrated that at frequencies below or equal to 31.5 Hz, a large part of the ground vibration caused by moving excitation forces consists of averaged components such as moving static axle loads. On the other hand, the simulations also showed that at frequencies equal to or over 40 Hz, a large part of the ground vibration due to moving excitation forces consists of varying components such as dynamic axle loads. Furthermore, it was found that there is a frequency at which the moving excitation force accelerance nears the point force excitation accelerance. It was then clarified that the point force excitation accelerance at that frequency can be used as a substitute for moving excitation forces.