When a railway vehicle overturns in an accident, the carbody cross section is likely to take on a parallelogram shape as a result of side impact, and the survival space for passengers and crew is reduced as a result. To secure the survival space available, an innerring structure can be formed by uniting sub-frames attached to the inside of the carbody as non-structural members. The authors performed strength tests and FE analysis to verify the possibility of improving carbody strength against loads from the side by creating such a ring structure.

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Fuel cells are currently receiving attention for their potential to clean and highly efficient power-supply systems. The authors have been developing a new type of fuel cell-powered railway vehicle to replace conventional diesel vehicles in non-electrified sections. In this work, a hybrid system using fuel cells and batteries was installed on test vehicles, which were then subjected to running tests on a test track. This paper describes the development of fuel cells and batteries hybrid test vehicles and the evaluation of this hybrid system's energy efficiency and fuel consumption rate.

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On Shinkansen trains, single-step braking is applied for deceleration from high-speed running to stop without releasing the brake. As a result, marked scoring is often observed on the surface of abrasive blocks installed in wheel tread cleaner and on tread brake shoes found on conventional trains. The development of this phenomenon causes wheels to wear in a concave shape, and wear fragments may also fall onto rails. Eventually, it causes unusual vibration and extraordinary noise. In this study, attempts were made to reproduce wear fragment using a dynamo brake test stand with a view to resolving these problems. A control technique to restrain wear fragments was consequently identified, and its effectiveness was confirmed in a running test. This paper introduces the results of the dynamo test and the running test.

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In this study, the authors performed case studies and model experiments to investigate the mechanism behind seismic damage to mountain tunnels and their aseismic performance, and the conditions under which such damage tended to be severe were clarified. Model experiments were performed with focus on damage to shallow tunnels or those in ground characterized by poor geological conditions, and the degree and extent of disasters caused by mountain seismicity were successfully reproduced. The experiments clarified the damage mechanism and seismic performance of tunnels in question. It was concluded that sound tunnels and those with inverts are less susceptible to seismic damage, and it was also confirmed that such damage tends to be greater when tunnels have voids above the lining and a lack of thickness, or when local displacement acts on them.

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Modeling the phase characteristics of earthquake ground motion is important in synthesizing a design earthquake motion consistent with a given set of response spectra. We assume that earthquake ground motion can be expressed by a convolution of the three time functions of source, path and site effect. This paper presents a new methodology to model the phase characteristics of earthquake motion using the concept of group delay time. The group delay times of source effects caused by rupture propagation on the fault plane are theoretically calculated, while those of the path and site effects are empirically modeled from observed records using the inversion technique. We also demonstrate that earthquake motion can be synthesized based on our newly developed phase model.

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Stations are normally congested during rush hour periods. In recent years, the number of complex stations that include commercial facilities has increased, and the nature of passenger traffic lines at stations has become increasingly diversified. It has therefore become more important to consider comfortable walking conditions for passengers when planning stations. Although the authors previously clarified passenger flow at a station using simulation technology, there was no established technique to evaluate the degree of discomfort passengers experience during conditions of congestion. Accordingly, efforts were made to clarify the relationship between the degree of congestion and passenger discomfort. In this study, repeated walking experiments and monitor-based evaluation tests were performed using a mock-up station (referred to as a station simulator). The results provided indicators that could be used to evaluate the degree of discomfort passengers feel and to improve existing passenger flow simulation.

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When a high-speed train enters a tunnel equipped with branches, micro-pressure waves emit from the portals of the branches as well as from those of the main tunnel. They can cause environmental problems related with high-speed railways, especially in urban areas. In this study, we investigate a countermeasure against the micro-pressure wave from the portals of the branches. It is shown that a branch divided in two parts by a partition inside near the portal with the end of one part closed and that of the other open, can be effective to reduce the magnitude of the micro-pressure wave.

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Rare earth high-temperature superconducting wire (RE wire) has electrical and mechanical properties superior to those of conventional superconducting wire. It was clarified that a superconducting magnet with a simpler structure and higher reliability than the conventional type could be achieved for maglev system by applying this type of wire. A characteristic test was then carried out for RE wire, and an electric properties test was run on a trial coil of the wire in a small racetrack shape. The electrical properties of RE wire formations varying from a single wire shape to a wound coil shape were thus confirmed. The results obtained are expected to be useful to allowing the application of RE wire to superconducting magnet for maglev system.

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We are currently developing a superconducting magnetic bearing and a non-contact permanent magnetic clutch applicable to flywheel energy storage systems for railways. This paper reports on electromagnetic force analysis concerning these developments. In the analysis, the electromagnetic force generated in superconducting magnetic bearings and non-contact permanent magnetic clutches was estimated based on the magnetic field distribution ascertained through 3D numerical analysis. The validity of this analysis was then evaluated by comparing the results with experimental outcomes, and the two were found to be consistent. It was therefore confirmed that the analysis was an effective way of estimating the electromagnetic force of electromagnetic equipment containing the bulk superconductor for use in application design.

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