Technology

Technology

Railway Technology Today 6 (Edited by Kanji Wako)

Shinkansen Bogies
Isao Okamoto

In the previous issue we discussed someof the main features of bogies, and lookedat bogie structure for various carriages,
specific bogies for trains carrying commuters and other passengers over short distances, tilting carriages using pendulum
mechanisms, and steering bogies. Suchtrains run mainly on narrow-gauge trackin Japan, at maximum speeds of 120 to
130 km/h. This next article examinessome of the characteristics of bogies required for high-speed trains, particularly
shinkansen that travel at maximum speeds
over 200 km/h. I will also discuss the pastand present development of shinkansen
bogies, focusing particularly on their structure.

Technical Innovations

The first scheduled shinkansen run was
on 1 October 1964 but many prior technical developments were necessary before trains could travel at high speeds. The
following summarizes some of the important advances made in bogie developmentin the 1950s.
• Incorporated springs and oil dampers
in bogie suspension, significantly reducing vibration• Mounted traction motor on bogie frame
instead of using nose suspension system and also used parallel Cardan drive
system (see JRTR 18, p. 58) to transmit
power to wheelset via flexible couplingsand gears, greatly reducing bogie
weight, in turn permitting faster speeds
on shinkansen and other electric trains• Adopted press-welded structure forbogie frames, reducing frame weightconsiderably• Introduced disk brakes, increasing braking power, in turn permitting faster
speeds• Used air springs in carriage suspension
to improve ride comfort
These important technical innovations
raised bogie performance, lowered weight

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Japan Railway & Transport Review 19 • March 1999

and reduced vibrations. As a result,bogies could run at faster speeds, making
rapid shinkansen services possible.

Bogie Performance
Because shinkansen run at high speeds,
their bogies and carriages must not be
subjected to serious lateral vibrations,called hunting. As a train runs faster, hunting can increase to such an extent thatthe bogie vibrates severely side to side,which creates passenger discomfort, damages the track, and can even derail thetrain in extreme cases. To achieve operating speeds higher than 200 km/h, bogie
developers tried to solve the hunting problem through theoretical calculations andtrial runs using scale models and actual
carriages. These tests helped discovereffective ways to raise the speed at whichbogie hunting becomes a problem. Here,I will summarize the steps used to solvethese problems and produce a new bogie
design for shinkansen.

Graded wheel tread gradient
The outer rim of the wheel in contact withthe rail is called the wheel tread (see JRTR
18, pp. 52 and 57). The wheel tread generally has a gradient to help the train
negotiate curves more easily, and to maintain the carriage in a central position on
straight track. If the main aim is to achieve
high speeds, the wheel tread gradient is
kept low. On the other hand, if the main
aim is to maintain high performance on
curves, the wheel tread has a higher
gradient. The wheel tread gradient forshinkansen bogies takes into account boththe need for high speed and the need toensure that wheels do not continually run
on one side of the rail. The gradient used
to meet these conditions was 1:40 using
a conical wheel tread configuration.
However, circular wheel tread configurations were developed for the shinkansen
in the mid 1980s, and recently almost all

bolsterless shinkansen bogies use this typeof wheel tread. The circular configuration which is shaped like a large numberof arcs aligned next to each other, supposes a wheel tread that has already been
subjected to wear. This configuration
reduces contact bearing forces between
the wheel tread and the running surfaceof the rail. This means less wheel tread
wear, which in turn means better running
performance. The effective gradient ofshinkansen circular wheel treads is about
1:16, which meets demands for bothstability at high speeds and excellent running performance on curved track.

Axle box suspension ridigity
Important factors affecting bogie running
performance are: the structure of the axle
box suspension system supporting thewheelset on the bogie frame; the structure of the axle bearings; and the rigidityof the axle box suspension. In otherwords, the axle box suspension system
must be constructed so that it prevents
play due to wear over many years of operation. Moreover, the axle bearings must
be designed so that they prevent, as muchas possible, any play at all especially inthe axial direction. The rigidity of the axle
box suspension can be determined mainlyby theoretical calculations and tests using actual bogies. In the case of bogies
for older shinkansen, the rigidity requiredof the axle box suspension depends onthe carriage type (Table 1).

Bogie rotational resistancePreviously, it was thought that bogie hunting could be prevented effectively by using friction to resist bogie rotation relative
to the car body. However, calculations
and test results showed that this bogie
hunting can be prevented more effectively
by using rotational moment obtained fromsprings to resist bogie rotation. However,such springs increase wheel lateral pressure on curved track and make the bogie
structure more complex, so Series DT200

Copyright © 1999 EJRCF. All rights reserved.

Table 1

Axle Box Suspension Stiffness

Series 0 and 200 carriages

Longitudinal: 3,000–4,000 kgf/mm per axle box
Lateral:1,500–2,000 kgf/mm per axle

Series 100 carriages

Longitudinal: 1,500–2,000 kgf/mm per axle box
Lateral:3,000–4,000 kgf/mm per axle

bogies use the frictional resistance obtained from side bearers that support theentire load of the car body.

shinkansen and conventional tracks
converted to standard gauge)
The following three sections describe thedevelopment of these three bogie types
and their structure.

Bogie Development
About 35 years have passed since theshinkansen began carrying passengers in
1964. Over the years, three types ofbogies have been used on shinkansen
carriages (Table 2). These are:
• Series DT200 bogies used for many
years after start of shinkansen• Bolsterless bogies introduced in 1992
for new types of shinkansen• Bolsterless bogies for Yamagata andAkita Shinkansen (running on both

Table 2Development of Series DT200
bogiesWhen the shinkansen started operations,
it was the first train in the world to attain
operating speeds of more than 200 km/h.
Safety at such speeds can only beachieved if the bogies perform properly,
so bogie designers and manufacturers
focused on the need to prevent thewheelsets and bogies from hunting dangerously, and the need to prevent failure
or other damage in important parts like

Shinkansen Bogie Series
Bogie Types

Carriage Types

DT200 Bogies from start of shinkansen(2,500 mm wheelbase)

Series 0
Series 100
Series 200

Bolsterless bogies for new shinkansen (1992〜)(2,500 mm wheelbase)

Series 300
Series 500
Series 700
Series E1
Series E2
Series E4

Bolsterless bogies for Yamagata and Akita shinkansen(2,250 mm wheelbase)

Series 400
Series E3

Copyright © 1999 EJRCF. All rights reserved.

bogie frames, wheels, axles, axle bearings,
and springs. In mid-1962, before theactual shinkansen cars were manufactured, six test cars were built each using a
different type of driving bogie (DT9001
to DT9006) and axle box suspension types(e.g., Minden, IS and Schlieren, etc.). Data
from trial runs on the Kamonomiya test
track (on part of the Tokaido Shinkansenline) were used in the design and manufacture of Series DT200 bogies. For theaxle box suspension, the Series DT200
bogie combined the advantages of the
Minden system with an improved IS system developed by the now defunct Japanese National Railways (JNR). The bogies
that actually went into service were lighter
than the test models, and were easier tomanufacture and maintain ( JRTR 18,
p. 56).
Spurred by the success of the Tokaido
Shinkansen, JNR built new shinkansen
lines to other parts of the country—first
the Sanyo Shinkansen, which began
operations to Hakata [Fukuoka] in 1975,
a n d n e x t t h e To h o k u a n d J o e t s ushinkansen, which opened between
Omiya and Morioka, and between Omiya
and Niigata in 1982. Carriages also saw
changes. The pioneer Series 0 shinkansen
was improved with the introduction of theSeries 100 that began operations on the
Tokaido and Sanyo shinkansen in 1985,
and Series 200 on the Tohoku and Joetsu
shinkansen in 1982. The Series 100
shinkansen use DT202 driving bogies andTR7000 trailing bogies. The Series 200
use DT201 driving bogies and TR7002
trailing bogies. Compared to the DT200
bogies for Series 0 shinkansen, the newer
bogies are lighter and easier to maintain.
The bogies for Series 200 trains on the
Tohoku and Joetsu shinkansen lines havealso been adapted to cope with the prevailing cold snowy winter conditions.
Despite these improvements, the basic
structure of the new bogies for those newseries shinkansen carriages was the sameas that of the DT200 bogies used by theJapan Railway & Transport Review 19 • March 1999

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Technology

Series 0. In other words, although they
have undergone some modifications overabout 30 years, shinkansen bogies continue to use a design based on the DT200.
During the same time frame, shinkansen
operating speeds rose to 220 km/h on the
Tokaido and Sanyo shinkansen in 1986,
and then to 230 km/h on the latter line in
1989. The Tohoku Shinkansen saw anincrease to 240 km/h in 1985, while
speeds on part of the Joetsu Shinkansenrose to 275 km/h in 1990.

Development of new shinkansen
bolsterless bogies
The success of the shinkansen prompted
European countries to develop their own
high-speed trains in the 1980s. In 1988,
the German ICE achieved 406.9 km/h,
and then the French TGV posted a newworld record of 515.3 km/h in 1990.
These impressive advances spurred Japanto further effort. In addition, better
expressways and improvements todomestic airports in Japan had resulted infaster road and air travel, posing anotherchallenge for the railways. Shinkansen
designers realized that they would haveto come up with a new type of train
capable of running at operating speeds of
270 to 300 km/h.
They knew that this target could only be
met by development of a light, high-performance bogie. Over the years they had
experimented with many test models, trying to develop a lighter shinkansen bogie
that would permit higher speeds andgreater ride comfort. But none of the test
models were good enough to go into production. Realizing they would need adifferent approach, in about 1980, JNR
designers began to develop a bolsterlessbogie for shinkansen. Just before JNR was
privatized in 1987, they built a numberof trial bogies (DT9022 to DT9026) andthen conducted experimental runs. However, these test designs could not meet therequired performance levels. As a result,after JNR was privatized and split into the48

Japan Railway & Transport Review 19 • March 1999

seven JRs, the Railway Technical ResearchInstitute (RTRI) was given the task. The
Institute chose the DT9023 trial bogie as
the basis for further development.
JR Central, one of the JR group, participated in new development trials by
mounting trial bogies on a Series 100
shinkansen and subjecting the train to
long-term experimental runs to test endurance levels. The company was trying tofind a suitable bogie for the Series 300
shinkansen being developed at the time.
Their efforts paid off in 1992 when the
Nozomi Series 300 shinkansen enteredoperation. Nozomi uses a bolsterless electrically driven TDT203 driving bogie andTTR7001 trailing bogie. It is smaller andlighter than the DT200 bogie, and offers
far greater stability at high speed, more
dependable performance on curves, andbetter ride comfort. As a result, it has been
adopted for all new shinkansen (Series
300 and later). For example, in 1997, JR
West adopted this bogie technology for
its Series 500 shinkansen that were designed to reduce aerodynamic noise andachieve a maximum operating speed of
300 km/h, thereby bringing Japan into theage of rail travel at 270–300 km/h.
The three shinkansen operators (JR East,
JR Central, and JR West) realized thathigher shinkansen speeds create environmental and other problems, including
noise, micro-pressure waves in tunnels,
ground vibration, and aerodynamic problems in tunnels when trains pass eachother at high speed. To resolve these problems and obtain data that could be used
to raise performance and ride comfort,
each company built a high-speed experimental train (STAR21, 300X, andWIN350) for running tests. The bogies
for these trains were based on the same
design principles as the above-mentioned
bolsterless bogie. During high-speed tests,
WIN350 ran at 350.4 km/h (August 1992),
STAR21 reached 425 km/h (December
1993), while 300X outran them both at
443 km/h (July 1996).

Development of bolsterless bogies
for Yamagata and Akita shinkansen
We have looked at two different types ofshinkansen bogies—the DT200 bogie forthe first and early shinkansen trains, andthe bolsterless bogie for more recent
shinkansen. A third type is a bogie fortrains running on shinkansen tracks withthrough operations on conventional tracks
converted to shinkansen standard gauge.
Examples are the Yamagata Shinkansen
trains that began operations between
Fukushima and Yamagata in 1992, and
the Akita Shinkansen that began operations between Morioka and Akita in 1997.
These are the so-called mini-shinkansen
operated by JR East. For these trains,
the bogies have to be capable of stablerunning at about 270 km/h on shinkansen
tracks, as well as be able to negotiate
sharp curves of approximately 400-m
radius on conventional tracks.
After the JNR privatization, RTRI obtained
funding from the national government todevelop a trial DT9027 bogie for experiment. The result of this research was abogie with a shorter wheelbase of 2250
mm, the first time a shinkansen bogie hadvaried from the 2500 mm wheelbase. The
Institute proposed giving the axle box suspension system optimum rigidity and thewheel tread optimum shape, to ensure an
ideal balance between stability at highspeeds and excellent running performance on curved track. JR East manufactured trial bogies (DT9028, DT9029,
DT9030) that also adopted hollow-bored
axles and a wheel diameter of 860 mm
for Series 400 trains to Yamagata. These
trial bogies were made lighter using techniques obtained during development of
the shinkansen bolsterless bogie. For
example, they used an aluminium gearbox, and three different axle suspension
systems. After many trials, the company
decided to base its bogie design on theDT9030, which had a rubber/leaf spring
system for the axle box suspension system. The new DT204 bogie was madeCopyright © 1999 EJRCF. All rights reserved.

Figure 1 DT200 on Series 0 Shinkansen
for Series 400 shinkansen. A trial run in1991 on the Joetsu Shinkansen using
bogies with the same smaller wheelbase
of 2250 mm achieved 345 km/h.

Structure of Series DT200 Bogies
for First Shinkansen Trains
and Some Subsequent Models
Figure 1 shows the composition of theDT200 bogie for shinkansen trains. The
bogie has a bolster with air springs
mounted on its upper surface. These air
springs support the carriage body directly.
As I will explain later, the bolster has been
eliminated from recent shinkansen bogies
in order to lighten the bogie and gain
extra performance.
The main characteristics of the DT200
bogie are shown in Table 3. The main
components of the DT200 bogie—theaxle box suspension, bolster system, bogie
frame, wheelset, and driving gear box are
described briefly below.

(RTRI)

Bogie frame

Axle box
Traction
motor

Axle box suspension
After comparing results from tests of several types of axle box suspension systems
mounted on trial shinkansen bogies, theIS type was chosen. The IS axle box suspension system had been developed previously by JNR. A supporting plate (leafspring) is attached to the front and rear of
the axle box, with rubber bushings
mounted on the front and rear ends of the
supporting plates. The positioning of therubber bushings ensures that the wheelset
and axle box are suspended from thebogie frame in a relatively rigid manner
longitudinally, yet in a relatively flexible
manner laterally. Two advantages of thisaxle box suspension system are that thevertical movement of the axle springs is
not obstructed, because vertical movement deflects the supporting plates andrubber bushings, and that the various parts
have no play and are not subject to abrasion or wear. However, one disadvantage
is that the bogie must be made longer than

Copyright © 1999 EJRCF. All rights reserved.

Bolster

Air spring

Axle spring
Driving
gear box

Rubber bushingBrakecylinder

Brake
shoe

Leaf spring(Japan Overseas Rolling Stock Association)

Table 3Characteristics of DT200

Bogie wheelbase

2,500 mm

Wheel diameter

910 mmBogie weight

10,100 kg (unsprung mass, 4,660 kg) for Series 0 shinkansen
9,870 kg (unsprung mass, 4,630 kg) for Series 100 shinkansen

Traction motor

DC 180 kW for Series 0 shinkansen
DC 230 kW for Series 100 and 200 shinkansen

Japan Railway & Transport Review 19 • March 1999

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Technology

ideal, because the supporting plates arearranged in series. This type of axle box
suspension system was adopted for Series
0, 100, and 200 shinkansen.

Bolster system
The main components of the bolster system are: a bolster that supports the carriage body, air springs, lateral dampers,
side bearers, a bolster anchor that transmits tractive force between the bogie andthe carriage body, and the centre pin. The
centre pin allows the bogie to rotate relative to the body on curved track, while
the side bearers apply frictional resistanceto prevent hunting. The bolster is madeby pressing 9-mm thick steel plates andthen welding these plates together into abox. The hollow part of the box serves as
an auxiliary air chamber for the air springs.
The experimental version of the bogie
used a triple-folded bellow-type air spring,but the bogies installed on actual bodies
have a special diaphragm self-sealing air
spring. This type of air spring permits
lateral rigidity, so designers could eliminate the swing bolster hanger found on
conventional bogies at that time. The air
spring is mounted as high as possible tocontrol carbody rolling.

Bogie frame
The DT200 bogie frame consists of twoside beams (left and right), a central crossbeam, and end beams. The beams areformed by pressing 9-mm thick SS400(rolled steel for ordinary structural purposes) steel plates, then welding them into
box sections. These beams are thenwelded together to fabricate the bogie
frame. The end beams were originally
6-mm thick, but this was later increased
to 9 mm. Since 1976, SM400B steel plates
have replaced the SS400 steel plates,
which tend to contain layers of impurities embedded during rolling. SM400B
steel plates are very suitable for welding
purposes.

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Japan Railway & Transport Review 19 • March 1999

Wheelset and driving gear
Axles for the DT200 bogie are made of
S38C (carbon steel suitable for mechanical structures) that has been heat-treatedby induction hardening. This processchanges only the surface into hard martensite, and at the same time generates
residual compressive stress at the axle
surface, raising the fatigue strength of thematerial to extremely high levels. Induction-hardened axles are used for all
shinkansen bogies, to ensure greater
strength in mating parts that are prone tofretting corrosion.
For safety, the bogie uses solid rolledwheels. Designers were concerned aboutwear and tear on the wheel tread overdaily long-distance travel, so they performed tests on three different types ofcandidate wheel materials. However, inthe end, they chose STY-80 that had already been used for many years.
The driving gear used a parallel Cardan
system. The basic technology of this system was being put to practical use as earlyas the Kodama limited express on the old
Tokaido main line. The designers wereconcerned that the gears might not be able
to withstand the higher speeds and thatlubrication problems could develop, but
no problems were found in different tests
using prototypes.

system began in earnest in about 1980.
After the JNR privatization, efforts focusedon the DT9023, a bogie type that JNR had
tested. It was realized that a number of
improvements would be required, including:• Reduce high-frequency chatter in car
floor immediately above bogie• Reduce car vertical and rolling oscillations to improve ride comfort• Achieve superior stability at high speeds
while ensuring excellent running performance on curves• Eliminate end beams on bogie frame
and reduce bogie size to reduce weightof bogie between beams• Reduce unsprung mass of bogie (e.g.,
mass of wheelset, axle box and gear system)
When the improved trial bogie was tested
at RTRI, no stability problems were foundeven at extremely high speeds of 450 to
500 km/h, and the bogie also proved
effective in reducing oscillations. Later
two endurance tests of the bogie on a
Series 100 shinkansen of JR Central eachcovering about 300,000 km, validated
the result of the running test. By about
1990, it was clear that bolsterless bogies
were suitable for shinkansen and they are
now used for all Series 300 and later
shinkansen.

Structure of Bolsterless Bogies
for New Shinkansen Trains

Structure of bolsterless
shinkansen bogie

Bolsterless bogie development
As explained, the DT200 bogie was used
for many years on shinkansen, but a new
type was needed to meet the demands oftrains travelling at maximum speeds of
270 to 300 km/h. The required improvements included:• Greater stability at high speed• Higher running performance on curves• Less vibration and greater ride comfort• Smaller size and lower weight to reduce
track wear and tearDevelopment of a bolsterless suspension

Figure 2 shows the structure of abolsterless shinkansen bogie. Like its
DT200 predecessor, each bogie has two
air springs that support the carriage body
directly. However, unlike the older
bogies, these air springs are not supported
by a bolster. Instead, they are mounted
directly on the upper surface of the bogie
frame.
The main characteristics of this bolsterlessbogie are shown in Table 4.
Some important features of the components of the bolsterless bogie for Series
300 shinkansen are described below.

Copyright © 1999 EJRCF. All rights reserved.

Figure 2 Bolsterless Bogie on Series 300 and Later Shinkansen(RTRI)

Centre pin

Air spring

Bogie frameBrakecaliper
Axle spring
Axle box

Gear boxcylindrical laminated rubber/wing-typespring system. In this system, the verticalload on the axle springs is borne mainly
by coil springs that have linear deflection
capabilities; the longitudinal and lateralloads are borne mainly by the cylindricallaminated rubber parts, which also support and guide the axle box. Because thecoil springs and cylindrical laminated rubber parts are arranged symmetrically (in awing shape) at the front and rear of theaxle box, the support and guidance of theaxle box is smooth. Moreover, because
the optimum degree of longitudinal andlateral support rigidity was given to thecylindrical laminated rubber parts, stability is achieved even at high speeds andrunning performance with reduced lateralpressure remains high on curves. The axle
damper works in both directions and theincrease in damping force reduces vertical vibrations in the bogie.
A number of axle box suspension systems
are used to simplify the structure and permit easier maintenance. Some systems
for bolsterless shinkansen bogies have anaxle beam type of construction, whilesome others have a rubber/leaf spring typeof construction.

Anti-yaw damper

Carriage body support system

Axle damper(JORSA)

Axle spring and axle box
suspension
The axle spring and axle box suspensionof the trial bogie included a conical laminated rubber structure. This would have

Copyright © 1999 EJRCF. All rights reserved.

made construction easy, but it was unsuitable for high-speed rolling stock, because
the dynamic spring constant of the axle
spring was too high. Therefore, the designers decided to use coil springs and a

The carriage body support system has nobolster so it is described as bolsterless.
Instead, the body is supported directly by
air springs, thereby permitting considerable horizontal displacement. When thebogie rotates relative to the car body on
curves, this relative angular displacement
is absorbed through horizontal distortionof the air springs. Longitudinal forces
between the car body and bogie are transmitted via the monolink or Z link, which
is mounted at the virtual rotational centreof the bogie.
As explained above, side bearers are usedon DT200 bogies to prevent hunting athigh speeds. However, in the case ofbolsterless bogies, rotation relative to thebody is controlled by anti-yaw dampers

Japan Railway & Transport Review 19 • March 1999

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Technology

Figure 3 Axle Box Suspension of New Shinkansen Bolsterless Bogies

Wheelset, driving gear, etc.

Axle damper
Side beam

Coil spring

CylindricalrubberTable 4Characteristics of Bolsterless Bogie

Bogie wheelbase

2,500 mm

Wheel diameter

860 mmBogie weight

6,600 kg (unsprung mass, 3,500 kg) for Series 300 shinkansen

Traction motor

AC 300 kW for Series 300 shinkansen

mounted between the car body and bogie
frame outside of and parallel to the side
beams of the bogie frame. The damping
force of the anti-yaw dampers and the rigidity of the rubber bushings at both endsof the damper both greatly improve thestability of bogies running at high speeds.

Bogie frame
The bogie frame is constructed in an ‘H’shape. The two side beams (left and right)
made of 8-mm thick rolled steel(SM490YA killed steel suitable for welded
structures) are welded to a cross beam
made of 9-mm or 12-mm thick seamless

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Japan Railway & Transport Review 19 • March 1999

cm shorter than the DT200 bogie, and it
weighs about 3.3 tonnes less, although thewheelbase is the same (2500 mm).

steel pipe (STKM18B). The top of the side
beams is made as flat as possible and thecross beam is made of seamless pipe tokeep the bogie frame structure simple andto prevent welding defects. The crossbeam is hollow, permitting creation of an
auxiliary air chamber for the air springs.
The DT200 bogie frame has end beams
on which brake parts and other equipment
are mounted. For the newer bogie frame,
small caliper disk brakes were developed
and mounted on the cross beam locatedacross the bogie centre. This design eliminated the end beams. As a result, thebolsterless shinkansen bogie is about 80

The wheels and axles of the bolsterlessbogie are basically the same as those of
the DT200 bogie but the wheel diameter
was reduced from 910 mm to 860 mm,
and a 60-mm straight hole was bored longitudinally through the centre of the axle
to reduce the unsprung mass as much as
possible. Furthermore, at fabrication, thevector sum of the dynamic unbalanced
mass in the wheelset is set below 5 kgf•cm
to ensure that when the wheels rotate athigh speed, any centrifugal force createdby unbalanced weight distribution will notcause high frequency vibration in the carriage body, or ride discomfort.
The DT200 bogies use two types of axle
bearings simultaneously: cylindrical roller
bearings designed to bear radial loads,
and ball bearings designed to bear thrustloads. More recent versions of the cylindrical roller bearings have had a thrustcollar, to bear thrust loads at the sametime. When bolsterless shinkansen bogies were first produced, they used collared roller bearings, because it wasthought this would minimize the lateralplay of the roller bearings. The bolsterlessaxle box was also made smaller andlighter. However, it was later discoveredthat tapered roller bearings could actually
reduce lateral play themselves, so tapered
roller bearings are now used for bolsterless
shinkansen bogies.
The axle box and gearbox of DT200
bogies are made of cast steel, but on thebolsterless bogie they are made ofaluminium alloy to reduce the bogie
unsprung mass. There were fears thattrack ballast might fly up and damage thislighter material, but tests using flying
stones proved these fears unfounded, permitting its introduction.

Copyright © 1999 EJRCF. All rights reserved.

Future Possibilities
for Shinkansen Bogies
Over more than three decades ofshinkansen operations, no passenger lives
have been lost because of a defective
bogie. This excellent record is largely due
to the extremely high reliability and standards of the bogies’ structure and maintenance.
To meet the demands of passengers today
and in the future, Japan’s shinkansen operators will have to make further improvements—for example, higher speeds, better
running performance on curved track,
greater ride comfort, less running noise,and better labour-saving maintenancemethods. At the same time, every priority must be placed on safety and reliability. The areas requiring further efforts are
as follows:• Research into bogie structure andmanufacturing techniques to develop
greater precision in components• Considerable reduction in bogie weight
between primary and secondary springs
and unsprung mass by developing
smaller lighter bogies• Development of simpler bogie structurewith fewer welded parts and greater reliability of welded parts• Improvements of semi-active and active
suspension systems, and their morewidespread use• Development of pendulum tilt system
for shinkansen• More effective use of dampers, particularly anti-yaw dampers between cars
• Further study of aerodynamic causes ofcarriage vibration when high-speed
trains pass in tunnels■

Figure 4 Bolsterless Bogie on Series E2 Shinkansen(RTRI)(JORSA)

Kanji Wako
Mr Kanji Wako is Director in Charge of Research and Development at RTRI. He joined JNR in 1961 after graduating inengineering from Tohoku University. He is the supervising editor for this series on Railway Technology Today.

Isao Okamoto
Mr Okamoto is General Manager of the Vehicle Technology Development Division of the JR Railway
Technical Research Institute. He joined JNR in 1972 after obtaining a Masters degree in mechanicalengineering from the graduate school of Waseda University. He worked in the Rolling Stock Design
Office of JNR before transferring to RTRI.

Copyright © 1999 EJRCF. All rights reserved.

Japan Railway & Transport Review 19 • March 1999

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