Shinkansen Bogies Isao Okamoto
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T Technology echnolo Railway Technology Today 6 (Edited by Kanji Wako) Shinkansen Bogies Isao Okamoto In the previous issue we discussed some and reduced vibrations. As a result, bolsterless shinkansen bogies use this type of the main features of bogies, and looked bogies could run at faster speeds, making of wheel tread. The circular configura- at bogie structure for various carriages, rapid shinkansen services possible. tion which is shaped like a large number specific bogies for trains carrying commut- of arcs aligned next to each other, sup- ers and other passengers over short dis- poses a wheel tread that has already been tances, tilting carriages using pendulum Bogie Performance subjected to wear. This configuration mechanisms, and steering bogies. Such reduces contact bearing forces between trains run mainly on narrow-gauge track Because shinkansen run at high speeds, the wheel tread and the running surface in Japan, at maximum speeds of 120 to their bogies and carriages must not be of the rail. This means less wheel tread 130 km/h. This next article examines subjected to serious lateral vibrations, wear, which in turn means better running some of the characteristics of bogies re- called hunting. As a train runs faster, hunt- performance. The effective gradient of quired for high-speed trains, particularly ing can increase to such an extent that shinkansen circular wheel treads is about shinkansen that travel at maximum speeds the bogie vibrates severely side to side, 1:16, which meets demands for both over 200 km/h. I will also discuss the past which creates passenger discomfort, dam- stability at high speeds and excellent run- and present development of shinkansen ages the track, and can even derail the ning performance on curved track. bogies, focusing particularly on their struc- train in extreme cases. To achieve oper- ture. ating speeds higher than 200 km/h, bogie Axle box suspension ridigity developers tried to solve the hunting prob- Important factors affecting bogie running lem through theoretical calculations and performance are: the structure of the axle Technical Innovations gy trial runs using scale models and actual box suspension system supporting the carriages. These tests helped discover wheelset on the bogie frame; the struc- The first scheduled shinkansen run was effective ways to raise the speed at which ture of the axle bearings; and the rigidity on 1 October 1964 but many prior tech- bogie hunting becomes a problem. Here, of the axle box suspension. In other nical developments were necessary be- I will summarize the steps used to solve words, the axle box suspension system fore trains could travel at high speeds. The these problems and produce a new bogie must be constructed so that it prevents following summarizes some of the impor- design for shinkansen. play due to wear over many years of op- tant advances made in bogie development eration. Moreover, the axle bearings must in the 1950s. Graded wheel tread gradient be designed so that they prevent, as much • Incorporated springs and oil dampers The outer rim of the wheel in contact with as possible, any play at all especially in in bogie suspension, significantly reduc- the rail is called the wheel tread (see JRTR the axial direction. The rigidity of the axle ing vibration 18, pp. 52 and 57). The wheel tread gen- box suspension can be determined mainly • Mounted traction motor on bogie frame erally has a gradient to help the train by theoretical calculations and tests us- instead of using nose suspension sys- negotiate curves more easily, and to main- ing actual bogies. In the case of bogies tem and also used parallel Cardan drive tain the carriage in a central position on for older shinkansen, the rigidity required system (see JRTR 18, p. 58) to transmit straight track. If the main aim is to achieve of the axle box suspension depends on power to wheelset via flexible couplings high speeds, the wheel tread gradient is the carriage type (Table 1). and gears, greatly reducing bogie kept low. On the other hand, if the main weight, in turn permitting faster speeds aim is to maintain high performance on Bogie rotational resistance on shinkansen and other electric trains curves, the wheel tread has a higher Previously, it was thought that bogie hunt- • Adopted press-welded structure for gradient. The wheel tread gradient for ing could be prevented effectively by us- bogie frames, reducing frame weight shinkansen bogies takes into account both ing friction to resist bogie rotation relative considerably the need for high speed and the need to to the car body. However, calculations • Introduced disk brakes, increasing brak- ensure that wheels do not continually run and test results showed that this bogie ing power, in turn permitting faster on one side of the rail. The gradient used hunting can be prevented more effectively speeds to meet these conditions was 1:40 using by using rotational moment obtained from • Used air springs in carriage suspension a conical wheel tread configuration. springs to resist bogie rotation. However, to improve ride comfort However, circular wheel tread configura- such springs increase wheel lateral pres- These important technical innovations tions were developed for the shinkansen sure on curved track and make the bogie raised bogie performance, lowered weight in the mid 1980s, and recently almost all structure more complex, so Series DT200 46 Japan Railway & Transport Review 19 • March 1999 Copyright © 1999 EJRCF. All rights reserved. bogie frames, wheels, axles, axle bearings, and springs. In mid-1962, before the Table 1 Axle Box Suspension Stiffness actual shinkansen cars were manufac- tured, six test cars were built each using a Series 0 and 200 carriages Longitudinal: 3,000–4,000 kgf/mm per axle box different type of driving bogie (DT9001 Lateral: 1,500–2,000 kgf/mm per axle to DT9006) and axle box suspension types Series 100 carriages Longitudinal: 1,500–2,000 kgf/mm per axle box (e.g., Minden, IS and Schlieren, etc.). Data Lateral: 3,000–4,000 kgf/mm per axle from trial runs on the Kamonomiya test track (on part of the Tokaido Shinkansen line) were used in the design and manu- facture of Series DT200 bogies. For the axle box suspension, the Series DT200 bogies use the frictional resistance ob- shinkansen and conventional tracks bogie combined the advantages of the tained from side bearers that support the converted to standard gauge) Minden system with an improved IS sys- entire load of the car body. The following three sections describe the tem developed by the now defunct Japa- development of these three bogie types nese National Railways (JNR). The bogies and their structure. that actually went into service were lighter Bogie Development than the test models, and were easier to Development of Series DT200 manufacture and maintain (JRTR 18, About 35 years have passed since the bogies p. 56). shinkansen began carrying passengers in When the shinkansen started operations, Spurred by the success of the Tokaido 1964. Over the years, three types of it was the first train in the world to attain Shinkansen, JNR built new shinkansen bogies have been used on shinkansen operating speeds of more than 200 km/h. lines to other parts of the country—first carriages (Table 2). These are: Safety at such speeds can only be the Sanyo Shinkansen, which began • Series DT200 bogies used for many achieved if the bogies perform properly, operations to Hakata [Fukuoka] in 1975, years after start of shinkansen so bogie designers and manufacturers and next the Tohoku and Joetsu • Bolsterless bogies introduced in 1992 focused on the need to prevent the shinkansen, which opened between for new types of shinkansen wheelsets and bogies from hunting dan- Omiya and Morioka, and between Omiya • Bolsterless bogies for Yamagata and gerously, and the need to prevent failure and Niigata in 1982. Carriages also saw Akita Shinkansen (running on both or other damage in important parts like changes. The pioneer Series 0 shinkansen was improved with the introduction of the Series 100 that began operations on the Tokaido and Sanyo shinkansen in 1985, Table 2 Shinkansen Bogie Series and Series 200 on the Tohoku and Joetsu shinkansen in 1982. The Series 100 Bogie Types Carriage Types shinkansen use DT202 driving bogies and DT200 Bogies from start of shinkansen Series 0 TR7000 trailing bogies. The Series 200 (2,500 mm wheelbase) Series 100 use DT201 driving bogies and TR7002 Series 200 trailing bogies. Compared to the DT200 bogies for Series 0 shinkansen, the newer Bolsterless bogies for new shinkansen (1992～) Series 300 (2,500 mm wheelbase) Series 500 bogies are lighter and easier to maintain. Series 700 The bogies for Series 200 trains on the Series E1 Tohoku and Joetsu shinkansen lines have Series E2 also been adapted to cope with the pre- Series E4 vailing cold snowy winter conditions. Bolsterless bogies for Yamagata and Akita shinkansen Series 400 Despite these improvements, the basic (2,250 mm wheelbase) Series E3 structure of the new bogies for those new series shinkansen carriages was the same as that of the DT200 bogies used by the Copyright © 1999 EJRCF. All rights reserved. Japan Railway & Transport Review 19 • March 1999 47 Technology Series 0. In other words, although they seven JRs, the Railway Technical Research Development of bolsterless bogies have undergone some modifications over Institute (RTRI) was given the task. The for Yamagata and Akita shinkansen about 30 years, shinkansen bogies con- Institute chose the DT9023 trial bogie as We have looked at two different types of tinue to use a design based on the DT200. the basis for further development. shinkansen bogies—the DT200 bogie for During the same time frame, shinkansen JR Central, one of the JR group, partici- the first and early shinkansen trains, and operating speeds rose to 220 km/h on the pated in new development trials by the bolsterless bogie for more recent Tokaido and Sanyo shinkansen in 1986, mounting trial bogies on a Series 100 shinkansen.