The service life of jointed rails is governed mainly by the fatigue fracture at the joints. Static loading tests and field tests were carried out to measure the stresses around fish bolt holes. Based on these results and FE analysis, we developed a method to evaluate the stresses at the edges of fish bolt holes when fish bolts were fastened and trains passed. An S-N curve of rails with bolt holes was obtained from the results of bending fatigue tests. As a result of this study, we established a method to evaluate the fatigue life of jointed rails.

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In planning a new railway line, important factors when deciding the track structure are environmental preservation, construction cost, maintenance cost, durability and construction workability. A low-noise solid-bed track with removable ties was proposed as one of the candidates for new lines. To confirm its performance, this track was laid and tested at the Test Site of Railway Technical Research Institute (RTRI) and revene lines. Through these tests, authors concluded that it had satisfactory performance as a low-maintenance and low-noise track.

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Ballasted tracks generally need periodical maintenance work, because they are gradually destroyed by repeated trainloads. Enormous expenditure is spent, therefore, to maintain tracks under good conditions. As an alternative to ballasted tracks, concrete slab tracks are widely used in Japan. However, the noise levels on slab tracks are higher than on ballasted tracks. In order to solve this problem, the authors proposed a low noise solid bed track on asphalt pavement for new railway lines, and carried out performance tests. This paper describes the structure of solid bed track on asphalt pavement and results of performance tests.

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In estimating the risk of flange-climb derailment, it is generally thought that a wheel will not derail if the derailment coefficient is smaller than the critical value calculated with "Nadal's equation." To estimate derailment coefficient, time-series simulation is often performed, but this needs a long calculation time. As a quicker method, we propose to estimate the derailment coefficient from analytically calculated lateral and vertical wheel loads, based on analytic equations and measured data. This paper describes the equations used, shows how the derailment coefficient is calculated, and compares it with the results achieved by measurements.

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An inevitable problem of the inertial measuring method is that the waveform is distorted by the high-pass filtering process for stabilizing the double integration of acceleration. We designed a method to overcome this problem, by combining characteristics of the inertial measuring method and mid-chord offset method. We call it an "inertial midchord offset method." By using a prototype track inspection device that applies the new method, we confirmed that it provides track irregularity waveforms similar to those obtained by the mid-chord offset method. Moreover, as part of that equipment, we developed a sensor to measure vertical and horizontal rail displacements at the same time.

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In this paper, we deal with modeling the optimal maintenance schedule for track irregularities. Through appropriate maintenance activities at ballasted track, railway track irregularities must be kept at a satisfactory level with the optimal cost. In practice, however, most maintenance strategies focus only on sustaining railway track irregularities at an allowable limit, as they are difficult to treat quantitatively. In order to determine effective maintenance strategies, we developed a mathematical programming model for an optimal schedule of multiple tie tamper (MTT) operation based upon both maintenance costs and the level of surface irregularities that reflect riding quality and safety. By using the model, we can obtain the optimal tamping schedule with an MTT. The schedule indicates the divisions for which tamping must be executed in a specified term (10 days). Then, we apply the model to an assumed railway network and confirm that it is effective and useful from the results of the application.

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The vehicle/track interaction caused by a vehicle negotiating a sharply curved track is very important to analyze vehicle running stability and materials integrity. Wheel flange /gauge face wear is influenced by the vehicle/track interaction, such as the attack angle of wheelset and lateral force interacting between wheel and rail, while the worn profiles of flange and gauge corners have an influence on vehicle/track interaction. In this study, some track site measurements have been carried out for two years on Shinkansen sharp curved tracks to investigate the influence of gauge face wear on vehicle/track interaction, and also on narrow-gauge sharp curved tracks to investigate the effect of lubrication on vehicle/track interaction. This paper describes the detailed arrangements and results of measurements.

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The Railway Technical Research Institute has adopted four items as the goal of the research and development until fiscal 2004. It aims at the realization of a "High reliability railway," "Low cost railway," "Attractive railway" and "Railway compatible with the environment." This paper introduces the research and development activities of track technology corresponding to these four items. They include prevention of flange-climb derailment and rail defect, track inspection technology and track maintenance planning system, speed-up and improvement of riding quality, reducing CO₂ discharge and recycle of track materials.

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Wrong:The age at which their present eyesight began is as follows; 0 year-15, P to 9 years-10, 10 to 19 years-19, 20 to 29 years-10, 30 to 39 years-3, 40 to 49 years-6, 50 to 59 years-S
Right:The age at which their present eyesight began is as follows; 0 year-15, 1 to 9 years-10, 10 to 19 years-19, 20 to 29 years-10, 30 to 39 years-3, 40 to 49 years-6, 50 to 59 years-4

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Wrong:Table 3 shows the number of persons who use the bar type tactile tiles for each purpose, and their percentage to the 67 persons.
Right:Table 3 shows the number of persons who use the dot type tactile tiles for each purpose, and their percentage to the 67 persons.

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Wrong:Of the interviewees, 76% utilize bar type tactile tiles crossing dot type tactile tiles at a right angle as a cue to detect stairs. We asked 58% of interviewees who knew such arrangement of bar type tactile tiles whether or not they needed these tactile tiles.
Right:Of the interviewees, 76% utilize bar type tactile tiles crossing dot type tactile tiles at a right angle as a cue to detect stars. We asked 58 persons of interviewees who knew such arrangement of bar type tactile tiles whether or not they needed these tactile tiles.

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Wrong:Thirty-three males participated in the experiment. Fourteen were in their 30 s; 13 in their 20 s and others in their 40 s or 50 s. Their mean stature was 171.3 cm.
Right:Thirty-two males participated in the experiment. Fourteen were in their 30 s; 13 in their 20 s and others in their 40 s or 50 s. Their mean stature was 171.3 cm.

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