In order to reduce joule loss due to ripple current in multiphase current reversible chopper, an attempt was made to use electromagnetic coupling for an air-core reactor. The relationships among the amplitude of ripple current, duty factor and electromagnetic-coupling coefficient was deduced. It turned out that a specific optimal coefficient of electromagnetic coupling reduces current ripple both on each phase and on total combined. The hypothesis was verified experimentally with newly manufactured reactors, which achieved the optimal electromagnetic coefficient. The weight of the new reactor is 44% lighter than conventional three-phase reactors.

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In order to evaluate performance of a bogie more accurately in its planning stage, a rapid prototype bogie has been developed on which performance tests can be conducted on a rolling stock test plant without having to manufacture vital test components. The tests were executed by installing several actuators which were controlled to emulate the desired test dampers or rubber bushes. This paper describes the rapid prototype bogie and the results from actuator control tests on damper test equipment and from emulated running tests on the rolling stock test plant.

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A caliper is a device that pinches brake discs with any given force to create braking force. RTRI has developed a pneumatic floating caliper that is endowed with simplicity and outstanding maintainability without requiring the use of a pneumatic-hydraulic conversion device (i.e. a booster cylinder) and is interchangeable with existing lightweight and compact hydraulic calipers used on Shinkansen vehicles. It is further possible to configure it to the same size as a hydraulic caliper. Testing on a braking test bench has verified that the pneumatic floating caliper offers a level of brake performance equivalent to that of the hydraulic caliper, and that the increase in temperature of the diaphragm has been suppressed to a level that does not adversely affect its lifespan thanks to the adiabatic piston arranged between the diaphragm and the brake lining.

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It is common knowledge that at the transition zones between ballastless and ballast track, track irregularity becomes locally discontinuous; therefore, hanging sleepers are likely to occur. As a countermeasure for local track irregularity, the authors have developed a track structure which uses automatic irregularity-correcting sleepers called AICS. In this paper, the authors performed cyclic loading tests with full-scale track models, simulating transition zones. The authors thereby clarified that the AICS has superior performance in the prevention of hanging sleepers and that elastic sleepers have some degree of efficacy.

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A prototype track measuring device was developed adopting the inertial mid-chord offset method, which can be mounted on commercial railway vehicles. The device was installed on a track inspection car which was then tested to evaluate its practical measuring accuracy and durability over the long term. Initial results showed that the accuracy of the device was lower when used at low speed. A method was therefore sought to compensate accuracy at low speed. This paper describes the outline of the developed car body mounted device, the results of running tests on commercial lines and the compensation method used to raise track measuring accuracy even at low speed.

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Study on the adhesion of wheel/rail system includes many research fields such as tribology, rolling contact mechanics, material science, structural dynamics, heat transfer and others. The authors focused on several parameters, which play very important roles in the adhesion coefficient of wheel/rail interface. Those parameters are running speed, water temperature, wheel load and surface roughness of the wheel and rail, which have a great influence on hydro-lubrication behavior of water film formed at the wheel/rail interface from the tribological point of view. This paper describes the relation between those parameters and their influence on the adhesion coefficient by means of both theoretical and experimental approaches. Numerical analysis was based on mix-lubrication theory and laboratory experiments were conducted with a twin-disc rolling contact machine. The numerical solutions and the experimental results indicated that the effects of running speed, water temperature and surface roughness of wheel/rail interface on the adhesion coefficient were significant.

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An experience-based software was developed to help prevent human errors using point and call checks. The five functions comprising point and call checks help prevent human error. Learners were able to experience each error prevention function by going through tasks in the developed software, which corresponded to the five abovementioned functions. The effectiveness of this software in the training for conductors and train operators was also validated. The respective mean subjective ratings for the five functions in point and call checks before and after training were compared. The result indicated that the learners were more convinced of the method's effectiveness after the training than before it. Some railway companies use this software in their safety education and training programs.

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In order to consider passengers' on-board safety, passenger behavior in the event of a train collision was examined by means of numerical simulation. Taking the hypothesis of a commuter train colliding with a car at a level crossing, key points and measures to reduce the probability of injury to passengers were investigated. Results made it clear that fittings such as handrails or partitions installed at bench seat to divide sitting passenger groups could reduce the probability of injury to passengers. It was also made apparent that shape of bench-end partitions and length of baggage racks also played a role in safety.

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An evidence-based training method was developed to encourage station and on board staff to follow rules on making passenger announcements. The effectiveness of this method was then investigated. The rules in question govern how to make passenger announcements when resuming railway operations after a disruption due to an accident or other type of incident. The first step in building the training method was to determine what evidence to selects as the foundation and then how this evidence should be presented and explained. A DVD was then compiled bringing these two elements together. Employees watched the DVD as part of their job training and were then asked to answer a questionnaire. Responses indicated that as a result of watching the DVD, 90% of the employees showed interest in the material and their understanding regarding the efficacy of the rules increased. Furthermore, the results of a subsequent survey conducted one month after watching the DVD indicated that rule compliance increased by 13%, in the group which had watched the DVD compared to the group which had not. These results confirmed the efficacy of education and training using evidence-based explanations.

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