Technology

Technology

Railway Technology Today 13 (Edited by Kanji Wako)

New Types of Guided Transport
Akira Nehashi
Monorails

Monorail cars run on rubber tyres thateither straddle a single rail girder or hangsuspended from it. The monorail offers anumber of advantages, such as: small
footprint of structural components on
ground; ability to negotiate relatively steep
gradients and tight curves; high ride
comfort; and no level crossings because
track entirely elevated.

The Monorail—From Early
Days to Present

The monorail was invented much earlier
than most people realize. The first recordof a monorail was one patented in Britain
in the 1820s, around the time the steam
locomotive was first put to practical use.
A motorized monorail line constructed in
Ireland in 1888 carried passengers andfreight over a distance of about 15 km andproved the feasibility of single-railtransport systems powered by an engine.
The suspended monorail was invented inGermany and put into operation in

Wuppertal in 1901. By 1957, it was clearthat the basic design of the Alweg(straddle-beam) monorail was safe andeffective. This was also true for the Safege(suspended) monorail by 1960.
Japan first gave serious attention to themonorail when a suspended type was
opened in 1958 in Tokyo’s Ueno Park.
One purpose of the project was to testmonorail technology and determine how
it could be used for urban transit.
During the 1960s, monorails weredeveloped and built in different parts of
the world. A number of Japanesecompanies developed their own systems,
and this resulted in considerable variety
in Japan. In the early days, monorails
were considered suitable only foramusement parks, but this changed in1964 when the Tokyo Monorail beganrunning along the edge of Tokyo Bay
between Hamamatsucho and Haneda
Airport. It was constructed to serve as anurban transport system. Researchcontinued into making the monorail moresuitable for urban transport and the basic
design was standardized by 1967.
The straddle-beam monorail became acomposite type that borrowed from anumber of designs, especially Alweg,
Lockheed, and Toshiba. The suspendedmonorail also evolved with improvements
to the Safege design. See Table 1 forfurther information on monorail
construction in different countries.

Straddle-beam Monorails
Cars
Straddle-beam monorail cars have 2-axle
bogies. The running wheels are rubber
tyres filled with nitrogen. The bogie frame
has two pairs of guide wheels on the upperside, while its lower side has one pair ofstabilizing wheels. The electrical system
is either 750 or 1500 Vdc.

Rail girders
Rail girders are generally made ofprestressed concrete, although composite
girders can be used when required.
Supporting columns are generally Tshaped and made of reinforced concrete,
but topographical or other conditions may
dictate steel columns in the shape of a Tor an inverted U. Figure 1 shows a typicalexample. At switches, the rail girder also
serves as the turnout girder, with one end
shifting to the other rail. The turnout girderis supported by a carriage that can be
moved by an electric motor.

Suspended Monorails
Cars

Tokyo Monorail serving Haneda Airport

58

Japan Railway & Transport Review 26 • February 2001

(Tokyo Monorail Co., Ltd)

Suspended monorail cars have 2-axle
bogies. Each bogie has four air-filled rubber
tyres for travelling and guidance. Auxiliary
wheels are also provided for each wheel
as a safety precaution in case a tyre loses
air. The suspension system uses air springs.
The suspension joins the bogies to the body,and is composed of suspension links, safety
cableways, oil dampers and stoppers. The
electrical system is 1500 V.

Copyright © 2001 EJRCF. All rights reserved.

Table 1

World Monorails

Year Country

LocationType1824 UK
1888 Ireland

LondonKerry County

Elevated
Straddle-beam(Lartigue type)1898 Belgium

Brussels

1901 Germany Wuppertal

Electric Displayed at exposition
Straddle-beam(Langen type) (C-type)Toyoshima Park, Suspended (C-type)Tokyo
1952 Germany Fuhlingen, Köln Straddle-beam(Alweg type)
Houston, Texas Suspended
1956 USA1957 Japan

1956 USA1957 Japan

Dallas, Texas
Suspended
Ueno Park, Tokyo Suspended (C-type)

Disneyland
Straddle-beamTorinoStraddle-beam
Nara Dreamland Straddle-beam(Toshiba type)Inuyama, Aichi
1962 Japan
Straddle-beam
Prefecture(Alweg type)
Seattle1962 USA
Straddle-beam
Yomiuri Land
1963 Japan
Straddle-beam(Alweg type)
Haneda Airport– Straddle-beam
1964 Japan
Hamamatsucho(Tokyo)Higashiyama Zoo Suspended
1964 Japan(Safege type)
Mukogaoka
1966 Japan
Straddle-beam
Amusement Park (Lockheed type)1966 Japan
Ofuna–Yokohama Straddle-beam(Toshiba type)
Dreamland
1966 Japan
Himeji Station–
Straddle-beam
Tegarayama(Lockheed type)1970 Japan
Ofuna–Shonan
Suspended
Enoshima
1970 Japan
Expo 1970, Osaka Straddle-beam
1971 USA
Straddle-beam (TGZ)
Disney World
1976 Germany Dortmund
Suspended (II-Baln)
1959 USA1961 Italy
1961 Japan

1984 Germany Ziegenhain

Suspended (C-Baln)

1985 Japan
1988 Japan
1988 Japan

Straddle-beam
Straddle-beam
Suspended1988 Australia
1998 Japan
1995 USA
2003 Japan

Kita Kyushu
Osaka
Chiba Urban
Monorail
SydneyTama (Tokyo)
Las Vegas
Okinawa (underconstruction)

Length Power Purposeof line source
Horse Freight
15.0 km Steam Freight and passengers

Straddle-type(VON-ROLL)
Straddle-beam
Straddle-beam
Straddle-beam

13.3 km Electric Passengers
0.19 km Electric Tourism
1.7 km Electric Development trials
0.27 km 310 hp Experimental
engine0.49 km Electric Experimental
0.33 km Electric To test potential for urban
transit1.34 km Electric Tourism
1.16 km Electric Passengers
0.84 km Electric Serving amusement park
1.4 km Electric Passengers
1.5 km Electric Passengers
1.97 km Electric Serving amusement park
13.1 km Electric Passengers

Notes
Wooden columns. Said to be the world’s first monorail.
Track: A-shaped support Speed: 30 km/h
Operated until 1924
Said to be world’s first electric monorail
Invented by Eugen Langen in 1893 and called Langen or
Wuppertal type. Track: Supported on steel frame arches
Speed: 25 km/h (still in operation)
Single track; 33 seats; no longer in service
Track: Reinforced concrete, 2/5 scale for researchPrecursor of Hitachi/Alweg type
Track: Inverted J-shaped steel supports
Max. speed: 80 km/h
Track: T-shaped supports Speed: 94 km/h
Single track: two cars, fixed coupling; 31 seats
3-car train; 82 seats
3-car train; 297 seats
Single track; 3-car train; max. 360 people
Concrete single track Max. speed: 50 km/h
Seating: 360 in 6-car train
From downtown to Expo entrance
Track: Concrete Max. speed: 40 km/h
Seating: 140 in 3-car train; no longer in service
Track: Concrete with some steel Max. speed: 80 km/h
Seating: 95 per car; 6-car train

1.09 km Electric Passengers

Abandoned because unprofitable; 150 people max. capacity;
single track
Single track; max. 140 people; 2-car train

5.4 km Electric Passengers

Max. 265 people; 3-car train; not in service

1.63 km Electric Passengers

Abandoned because unprofitable

6.6 km Electric Passengers

Seating: 79 per car; 2-car train

4.3 km Electric Passengers
4.4 km Electric Passengers
0.9 km Electric Transport on university
campus
1.9 km Electric Transport within hospitalgrounds
8.4 km Electric Passengers
21.2 km Electric Passengers
15.2 km Electric Passengers

Dismantled after exposition
Max. 442 people; 6-car train
Seating: 42; 1 car

3.6 km Electric Passengers

Max. capacity 170 people: 6-car train

16.0 km Electric Passengers
1.2 km Electric Passengers
13.1 km Electric Passengers

Seating: 104 per car; 4-car train
Seating: 244 per train; 6-car train
Seating: 75 per car; 2-car train (4-car train planned)

0.47 km Electric Tourism

Linear motor Seating: 12; 1 car
Seating: 98 per car; 4-car train
Seating: 99 per car; 4-car train
Seating: 79 per car; 4-car train

Note: Track distances, January 2000

Copyright © 2001 EJRCF. All rights reserved.

Japan Railway & Transport Review 26 • February 2001

59

Technology

Signalling and safety devices(ATC)

Figure 1 Track Structure (prestressed concrete girders)

3,700

Floor level
Running wheel

Track girder(prestressed concrete)

1,130

5,180

2,420

170

2,980

Loop line for ATC
train detection

850

40

Bearing

Track 1505

Stabilizing wheel

Electrical(+) supply wire(–)

Centralized Traffic Control (CTC)
devices

Cable rack
6.6 kW
High voltage
distribution cable

Signal cable
Cable for DATC
train detection

1,500x1,500
ColumnGuard rail

Road

Height, from 4 to 22 m, approx.

Track 2440

Pantograph

1,500

Guide wheel(mm)

All rail girders are made of steel. Eachstandard girder is a 3-span continuous
girder. The inside is hollow with the lower
part slit open. The inside of the girder
has travel and guidance beams, electricalwiring and signalling equipment.
Supporting columns are generally Tshaped, although topographical or otherconditions may dictate an inverted-U
shape or racket shape. The standard
turnout is bidifferential. It is operated bya movable rail having both travel andguidance rails. The cross-section of the
moveable rail forms an inverted-T shape.

60

Technical Similarities
Between Suspended andStraddle-beam Monorails
Stations
Regardless of the monorail type, there are
two common platform configurations—anisland located between two guideways
and two platforms on opposite sides ofguideway(s). The chosen configuration
depends on local conditions. Stations are
generally located 300–1000 m apart. The
distance depends on factors as suchridership, location, and connections withother transport systems.

Japan Railway & Transport Review 26 • February 2001

Centralized Traffic Control (CTC) is used
to monitor traffic on all lines and control
all signals and turnouts from a central
location. The CTC equipment consists
primarily of traffic boards, remote control
consoles, television monitors showing
operations, communications and alarm
devices, other devices to transmit
information, and peripheral equipment.

Automatic Train Operation (ATO)
devices

Road

Rail girders

An on-board display indicates thepermissible relative distance to the ahead
train (the block section), and thepermissible speed (which depends on
guideway conditions). An Automatic
Train Control (ATC) system also stops or
slows the train when necessary.
Monorail tyres are rubber, so track circuits
cannot be used to detect trains on the line.
For this reason, signals indicating whether
a train has entered or left a block arereceived at the trackside.

Both types of monorail use automatic
devices to ensure that all traffic follows
uniform control standards and to provide
a high level of safety and service.
See Table 2 for more detailed information
on monorails in Japan.

Automated Guideway
Transit Systems
Automatic Guideway Transit (AGT)systems can be defined as medium-scaletransport using small, lightweight rollingstock running on rubber tyres on a
dedicated guideway that is usually
elevated. Unmanned AGT trains arecontrolled by computer. A number of AGT
systems have been developed worldwide,
the main differences being in theguidance, switching and braking systems.

Copyright © 2001 EJRCF. All rights reserved.

Table 2

Straddle-Beam Monorails in Japan
Straddle-Beam Monorails in JapanTokyo Monorail
Kita Kyushu Monorail
Osaka Monorail
Hamamatsu cho
Kokura–Kikugaoka
Osaka Airport–Haneda Airport–KadomaTerminal stations

Line length (km)Number of stations
Average distance
between stations (m)Single/double tracked

Suspended Monorails in Japan
Shonan Monorail Chiba Urban Monorail
Ofuna
Chishirodai–Shonan Enoshima–Chiba Minato;
Chiba–Kencho-mae

Tama Monorail
Tachikawa-kita–Tama Center

16.9
9
2,110

8.8
13
680

21.2
14
1,630

16.0
19
770

6.6
8
940

15.2
15
960

DoubleDoubleDoubleDoubleSingleDoubleSuspended (tyres)
Simple switch

Suspended (tyres)
Simple switch

ATS with driver andconductor
1,500

ATC with one driver

Straddle-beam (tyres) Straddle-beam (tyres) Straddle-beam (tyres) Straddle-beam (tyres)
Articulated switch
Articulated switch
Articulated switch
Articulated switch
ATC with one driver
Operations
ATC with driver and
ATO with one driver
ATC with one driver(planned)
conductor
1,500Electrical system (Vdc)
750
1,500
1,500
100 (siding, –)Minimum curve radius (m)120 (siding, 100)80 (siding, 50)
100 (siding, 50)
58
Max. gradient (per mill)
60
40
60(siding, –)(siding, 60)(siding, 60)(siding, –)25
Schedule speed (km/h)
43.5
28
35
65
Max. speed (km/h)
80
6575
2.98 x 3.75 x 15.50
Car width x height x
3.02 x 2.92 x 16.55
2.98 x 3.49 x 14.80
2.90 x 3.74 x 14.80(14.60)length (m)(15.20)(13.90)(13.90)4 (6 sets)
Cars in train set;
6 (19 sets)
4 (9 sets)
4 (8 sets)( ) = number of sets
owned
415
Seating per set
584
478
494
7 minutes 30 s
Time interval
4 minutes
6 minutes
6 minutes 42 s
Type
Switching system

Road

Road

68.1

115.3

Road
242.2

Road
5.3

133.7

1990

1998 (5.4 km)

1970

1988

Sea/road
21.1(extension, 67.6)

Opened1964 (13.0 km)

1985

Notes

Another extension now
under construction
from Haneda Kuko to
Shin-higashi Terminal(0.9 km)Copyright © 2001 EJRCF. All rights reserved.

228
7 minutes 30 s
1,824

Located overTotal construction cost(¥ billion)

Research and development of AGTs firstbegan in the USA in the 1970s andresulted in practical applications in the

2 (17 sets)

4,200(planned)

4,780

Development history

3 (7 sets)

3,952

8,760

• Hourly capacity between 2000 and
20,000 passengers bridging capacityof buses and conventional trains• Maximum speed of 50–60 km/h
• 60–70 seats per car• 4–6 cars per train• Computer-controlled headway

26
65
2.58 x 3.73 x 14.80

60(siding, 60)

158
4 minutes
2,370

Capacity (people/h)Some characteristics of Japanese AGTs arelisted below:

1,500
50 (siding, 50)

50 (siding, 50)
74(siding, –)29
75
2.58 x 3.69 x 12.75

Road

2.6 km line from
Banpaku Kinen Koen to
Handai Byoin-mae
opened in 1998; 2
stations

same decade. These achievements were
prompted by amendments in 1966 to the
Urban Mass Transportation Act and by anumber of debates and reports addressing
urban transport problems. Transpo ’72,
an exposition held at Washington Dulles
International Airport in 1972, introduced
four new types of transportation systems
and the featured AGT attracted interest
from around the world. Later, AGT
technology was introduced to a numberof American cities. One example is
AIRTRANS, serving Dallas/Fort WorthInternational Airport.
AGT systems are being developed inEurope as well, particularly in the UK,
France and Germany. The French VAL iswell known.
Japanese research into AGTs began in1968 with development of the Computer
Controlled Vehicle System (CVS)completed in 1976. Different
manufacturers of rolling stock, steel,heavy industrial products, motor vehicles,
signalling devices and other products
were conducting individual or joint R&D
in the field. As a result, quite a few
different AGT systems were proposed andsome were developed. However, most
AGT systems in Japan today have 4 to 6

Japan Railway & Transport Review 26 • February 2001

61

Technology• Track and bed clearance: Height,
3500 mm; width, 3000 mm• Lateral guidance spacing: 2900 mm• Design load (Axle load): 9 tonnes

Rolling stock
Aluminium and fibre-reinforced plastic(FRP) are two common materials incarriage construction. The trains tyres are
made of special rubber composites but
auxiliary steel wheels ensure that the train
can continue running for some distance
if a rubber tyre fails.

Guidance and switching systems

Kobe Port Liner running through city centre(Kobe New Transit Co., Ltd.)

cars, with 60 to 70 seats per car. The firstJapanese AGT urban transit system to enter
service was the Port Liner opened in 1981
between Kobe and Osaka.
Japan’s Ministry of Transport and Ministryof Construction established basic AGT
specifications by 1983, and uniform
technical standards were adopted.

AGT StructureStandard basic specifications
Minimum basic specifications have been
established within a range that ensures

future technical innovations will not be
impeded. These specifications can besummed up as follows:
Basic concept:• About 75 seats per car; unmanned
operations
Other basic specifications:• Guidance: Lateral• Switching: Mobile horizontal• Electrical system: 750 V dc (in principal)• Rolling stock clearance: Height,
3300 mm; width, 2400 mm• Gross weight: Under 18 tonnes

Figure 2 Guidance Systems
Running wheel
Guide wheel(a) Centrally-mounted
beam guidance system

62(b) Lateral guidancesystemJapan Railway & Transport Review 26 • February 2001(c) Central channel
guidance system

Current specifications indicate that lateraland mobile horizontal guidance systems
will become the future standard. Some
previous guidance and switching systems
include: a centrally-mounted beam
guidance system; a central channel
guidance system; a sink-and-float typeswitching system; a rotary switchingsystem; and a horizontal rotary switchingsystem. Figure 2 shows three guidancesystems.

Automatic Train Operation (ATO)
devices
Like the monorail, the AGT system can alsouse ATO devices. For more information
on AGT systems in Japan, see Table 3.

Linear-Motor Subways
The small size and relative light weight of
the under-floor linear motor permits
smaller carriages than conventional cars.
Linear-motor subways have beendeveloped because the smaller subway
cars permit construction of networks using
smaller cross-section tunnels, which
greatly reduces construction costs,
particularly in urban areas. Actually, cars
with an even smaller cross-section could
be manufactured to meet tunnelling
constraints if there is no need to transporta large number of passengers.

Copyright © 2001 EJRCF. All rights reserved.

Table 3

Automated Guideway Transit (AGT) Systems in Japan
Yamaman Co.,Ltd.

Terminal stations

Line length (km)Number ofstations
Average distance
between stations(m)Single/double
trackedYukarigaoka
Line
Yukarigaoka–Yukarigaoka(loop)
4.1
6683

Seibu Railway
Co., Ltd.

Kobe Shinkotsu Co., Ltd.

Saitama
Shintoshi Kotsu
Co., Ltd.
Ina Line

Hiroshima
Kosoku Kotsu
Co., Ltd.
Astram Line

Yamaguchi Line

Port Island Line

Rokko Island
Line

Omiya
–Uchijuku

Seibu Yuenchi–Kyujo-mae

Sannomiya–Naka Koen

Sumiyoshi–Marine Park

Hon-dori–Koiki Koen

12.6
13

2.8
3

6.4
9

4.5
6

18.4
21

Yokohama
Shintoshi Kotsu
Co., Ltd.
Kanazawa
Seaside Line
Shin Sugita–Kanazawa
Hakkei
10.8
14

980

1,400

800

1,125

920

815

Tokadai
Osaka Municipal
Yurikamome
Shin Kotsu Co.,
Government
Co., Ltd.
Ltd.
Tokadai Line Nanko Port Town
Rinkai LineLine
Komaki
Suminoe Koen
Shimbashi–Tokadai–Naka Futo
–AriakeHigashi
7.4
6.6
11.9
7
8
12 (11 when line
opened)
1,230
940
1,000

Maruyama–
SingleSannomiya–
DoubleDoubleDoubleDoubleDoubleDoubleUchijuku, single
Naka Koen,
Omiya–
doubleMaruyama,
Other track,
doublesingleGuidance
CentrallyLateral guidance Lateral guidance Lateral guidance Lateral guidance Lateral guidance Lateral guidanceCentrallyLateral guidance Lateral guidancesystemmounted beam
rails
rails
rails
rails
rails
rails
mounted beamrails
Switching
Mobile track
MobileMobile guidance Sink-and-float
MobileMobileMobile guidance Horizontal rotary
MobileMobile guidancesystemhorizontal rotary
horizontal
platessystemhorizontal
horizontal
platessystemhorizontal
platessystemguidance plates
guidance plates guidance plates
guidance plates
Operations
ATS; one driver ATC; one driver ATS; one driver ATO; unmanned ATO; unmanned
One driver
ATC; one driver ATC; one driver ATO; unmanned ATO; unmanned
Electrical system
750 V dcThree-phase
750 V dcThree-phase
Three-phase
750 V dc
750 V dc
750 V dcThree-phase
Three-phase
600 V ac
600 V ac
600 V ac
600 V ac
600 V ac
Minimum curve
40
25
60
30
60
30
30
100
70
45
radiusMax. gradient
45
59
50
50
58
45
40
60
25
50
(per mill)
Total
21
304
39
437
419
1,760
650
313
420
1,661
construction cost
( ¥ 100 million)
OpenedCapacity(people/h)Schedule speed(km/h)
Max. speed(km/h)
Time interval

Seating (onetrain)

Single; loop

1982
1,630

1983
3,480

1985
–

1981
3,840

1990
972

1994
5,720

1989
4,320

1991
965

1981
4,428

1995
7,200

24

31

25

22

27

30

26

30

27

31

50

60

50

60

63

60

60

55

60

60

8 minutes

16 minutes–

3 minutes
20 sec.

4 minutes

3 minutes

5 minutes

12 minutes

2 minutes
45 sec.

3.5–4 minutes,
morning &evening rush
hours

215

375
(6-car train)

302

450

228

286

360

193

297

352

Development history
In 1979, Japanese researchers began
examining ways to reduce the cross-sectionof subway tunnels. Technical development
began in this field in 1981 and R&D
continued until 1987 with the aim of
constructing a commercial linear-motor
subway. By 1988, it was clear that linearmotor technology could be used on acommercial line. Soon after, the decision
was made to construct linear-motor
subways in Tokyo and Osaka. Tokyo’s firstlinear-motor subway was opened as theLine No.12 (later called Oedo Line)between Hikarigaoka and Nerima in 1993,
reached Shinjuku in 1997 and was thenextended to Kokuritsu-kyogijo in April
2000. It became Tokyo’s first loop subway
on 12 December 2000. Figure 3 gives
more information on the linear-motor
subway in Osaka.

Copyright © 2001 EJRCF. All rights reserved.

TMG Oedo Line

(TMG)

Japan Railway & Transport Review 26 • February 2001

63

Technology

Figure 3 Comparison of Osaka Linear Motor Subway (Nagahori Tsurumiryokuchi Line) and Conventional Osaka Subway Line

500

500

4,300
5,300

550

Linear Motor Subway(Nagahori Tsurumi-ryokuchi Line,
operated by Osaka Municipal Government)

5,700
6,800

550

Conventional Subway Line(mm)

Figure 4 Linear Motor Subway

Linear motor

Rail

Reaction plate
Linear motor subway
Less friction
Advantages
offered by steel
wheels and rails

No need for a special support or guidance structure
Easy switching
Rails can be used as track circuit
Rails return power

Linearmotor
systemAdvantages
offered by linear
motor
technology

Lower structure

Lower carriage floor; smaller
tunnelNo motor gearbox

Less noise; easy maintenanceNon-adhesive
propulsion

Steeper gradients (80 per mill)

Fewer restrictions
on bogie design

Steeringbogies

Sharp curves(R = 50 m)
No wheel squeal

Structure of linear-motor subway
A linear-motor subway uses steel wheels
and rails to support and guide the rollingstock. As a result, it enjoys the advantagesof the track circuit control system and thelinear motor propulsion system.
The linear motor permits construction ofsmaller tunnels and broadens the choiceof where the line can be constructedbecause steering bogies can be used andbecause the non-adhesive propulsion
permits use on steeper grades and sharper
curves. This means that less land needbe acquired to construct the line, reducing
costs substantially. Some merits of thissystem are shown in Figure 4.
The following summarizes some of the
major developments achieved in order tocommercialize the linear motor subway.
• Cars with smaller cross-section
dimensions
Vehicle floor height can be lowered
to 700 mm by using smaller wheels
and reducing the size of under-floor
equipment. The result is a low-profile,lightweight car that can be used intunnels with an internal diameter ofjust 4 m.
• Able to negotiate tight curves
A bogie steering mechanism changes
the axle angle, permitting cars to runsmoothly on curves with a radius ofonly about 50 m.
• Able to run on steep gradients
The linear motor provides nonadhesive propulsion that does not relyon the friction between the steel rails
and wheels so cars can climb steeper
gradients. It can also be used as a
braking system for safer operations.
• Low noise levels
The lighter cars generate less runningnoise and a bogie steering mechanism
prevents wheel squeal on tighter
curves.

Advantages of Linear Motor Subway

Other developments
The principle of the linear motor generates

64Japan Railway & Transport Review 26 • February 2001

Copyright © 2001 EJRCF. All rights reserved.

Figure 5 Linear Motor Subway

Shield tunnel (single track)Cut-and-cover tunnel

Elevated line
Internal width (7,000)

3,850

strong attractive and propulsive magnetic
forces between the reaction plates on the
track and the coils in the carriages. To
overcome these forces, a new durable rail
track was developed to attach the reaction
plates to the sleepers. In addition, themotor (65-kW rated output) is mounted
on the bogies using an innovative methodof direct attachment and the system iscontrolled by a Variable Voltage Variable
Frequency (VVVF) inverter. Safety is
assured by four types of braking: service;
emergency; security; and holding.
Electrical wiring is routed to permit
operation on tight curves.
Figure 5 compares the linear-motor
subway with a conventional subway.

Internal diameter,
straight line section(4,000)

3,200

3,200

Comparison of Line Structures(mm)

Safety evaluation
Construction of a commercial line could
not have begun without determining
whether the technology was sufficiently
safe for a commercial railway system.
Trial runs and tests were conducted tocheck the major safety factors as follows:
Unique features and performance ofsystem• Factors affecting car clearance andtrack clearance in small-section
tunnels• Separation of tracks; emergency
procedures• Performance on sharp curves—
measures to prevent derailing at tightcurves; bogie steering• Performance on steep slopes—
starting, acceleration and braking on
relatively steep slopes
New technology factors• Linear motor technologies• Steering bogies with small-diameter
wheels• Reaction plates—track structure, startup strength, attachment to track
Other factors• Linear motor undercar clearance—

Copyright © 2001 EJRCF. All rights reserved.

flexibility of reaction plate and othercomponents; dynamic gap change• Safety of lighter cars
• Safety of non-adhesive linear
propulsion systems
Trial runs on the Osaka Nanko Test Trackexamined the above items and verified
that the linear motor subway system wascompletely safe.

Flexible Intelligent
Transportation System

But these measures are still not enough tosolve the problems.
As a result, some quite futuristic systems
have been proposed in the last few years.
They aim to combine the advantages
offered by tracks—speed, large capacity
and accurate scheduling—with the doorto-door convenience of the car. The lastpart of this article examines one proposal
called the Flexible Intelligent
Transportation System (FITS).

What is FITS?

The extensive system of expressways,
shinkansen trains, and other advanced
surface transport modes has dramatically
boosted the Japanese economy, raised thestandard of living and expanded travel
opportunities. However, there are still
serious problems, including roadcongestion in cities, rush-hour
overcrowding on urban railways,
widespread air pollution, etc.
To counter these problems, Japan has
developed and constructed the various
urban transit systems described in thisarticle. Strides are also being taken inother areas, including more efficient buses
and promotion of ‘park and ride’ systems.

Although they are not physically coupled,
FITS vehicles run something like a train
in a dedicated lane at high speed in single
file (Figure 6). The FITS concept envisions
an intelligent transportation system thatis safe and reliable, can carry large
volumes of passengers at high speed, andoperates in accordance with demand.
Passengers may transfer at points that
correspond to today’s stations, or may
proceed without making a transfer to aplace close to their destination. Such asystem would offer flexibility andexpanded choice.
The basic concept proposes a system thatwill:
• Span wide areas and increase mobility

Japan Railway & Transport Review 26 • February 2001

65

Technology

Figure 6 Illustration of FITS

for all, especially the elderly• Permit passengers to travel directly
and easily to their destinations• Be responsive with reasonable fares• Complement existing local and interregional transport systems, ensuring
mutually profitable operations• Benefit local economies• Have low construction, maintenanceand management costs• Be environment friendly

Transport method

Figure 7 FITS Specifications
Vehicle structure
5
4
1 2

6

3

7 8

4

1 Generator
2 Speed gear
3 Generator engine
4 Batteries
5 Inverter
6 Motor
7 Speed reducer
8 Transmission brakeSpecifications
EngineMotor
Batteries

Measurements

Displacement
OutputType
OutputType
WeightCapacity
LengthHeightWidth
Minimum roadclearance

Minimum turning radius
Vehicle weight
Axle load
Climbing capability
Braking performance
Vehicle entry/exit and door
position
Auxiliary wheels/ Groundside structure
Extent of impact on auxiliary
wheels66

Dead weight/ Loaded
weightFront/ Rear
Braking distanceJapan Railway & Transport Review 26 • February 2001

1,500 cc
25 kW
AC Induction
70 kW
Sealed lead (24)500 kg
60 Ah/3h
10,520 mm
3,340 mm2,490 mm
145 mm
8.3 m
2.5 m
11,940 kg/15,625 kg
5,675 kg/9,950 kg
43‰
19 m (50 km/h)
Stepless front
and mid-car entry
Automatic housing system/
Concrete guide walls
Max. of 4G on front and back(left and right)

The envisioned dedicated lane will serve
as a main line on which vehicles will
operate at high speed in single file, much
like a train, but at a fixed distance fromeach other. At nodes (stations), somevehicles may leave the file and enter an
expressway or ordinary road to carrypassengers to their destinations like a bus
serving a local route. Capacity will befrom 8000 to 14,000 people per hour, oneway, with a service every 3 minutes.

VehiclesAs presently envisioned, a gasoline engine
will drive a generator to store electricity
in batteries. This electricity will power
the vehicle’s two electric motors. The
low-floor vehicle will follow a dedicatedlane marked by magnetic pins. Sensors
on the vehicle will detect the magnetic
pins to control the steering. Switching
the polarity of the magnetic lane markers
will permit control of vehicles leaving andentering the dedicated lane. The distance
between vehicles will be controlled by afront radar and vehicle interval control
system that can apply the brakes whennecessary. At high speeds, the distance
between vehicles will be about 15 m.
Figure 7 shows a diagram of the vehicle
and the proposed specifications.

Lane structure
A single row of columns will bear the lane
girders at a height of 5 m. The proposed
concrete or asphalt road will have a width

Copyright © 2001 EJRCF. All rights reserved.

Figure 8 FITS Infrastructure Concept
Track profile

Track structure (with lane markers), and system configuration
Lane
FITS infrastructureA

Magnetic sensor

7.5 m

Lane marker
configuration

Leaky coaxial cable

Leaky coaxial cableA

Lane marker

Lane markers(magnetic pins, etc.)
5.0 m

Sidewalk

Road

Road

Magnetic
sensorSteeringmechanism

Sidewalk

Cross section
System controlling distance between vehicles• Prevents collisions when lead vehicle slows or stops in emergency• Simplified configuration of vehicle interval sensor and inter-vehicle
signalling system
Lead vehicle

10.0 msecond vehicle

Wirelesssignals

Vehicle intervalsignalling device

Longitudinal view
Radar

Vehicle interval
control system

of 7.5 m and the construction methods
will take durability, maintenance, and costeffectiveness into consideration. The
vehicle wheels will be strengthened withsteel fibers or other materials. There will
be no need for special electrical orsignalling equipment, nor for a vehicle
shed. Figure 8 shows some more details.

administrative environment will make iteasier to develop systems (like FITS) that
exploit the advantages of both road andrail, and to propose, develop andconstruct new transportation systems
based on new technologies.
With new technology, the transport sector

The future

Kanji Wako

Once FITS is operational, it could spreadto many areas; it offers great promise not
only for conventional transport industries
but also for new types of industry. The
Society for New Transportation Systems
is presently examining various issues witha view to promoting FITS.
The Japanese government has restructured
its ministries and agencies this year. The
Ministry of Land, Infrastructure andTransport has jurisdiction over all land, sea
and air transport. Hopefully, this new

Copyright © 2001 EJRCF. All rights reserved.

Brakemechanism
Enginecan help society serve aging populations,combat global pollution, and develop
even better lifestyles for all.
■Mr Kanji Wako is Director in charge of Research and Development at the Railway Technical Research Institute (RTRI). He
joined JNR in 1961 after graduating in engineering from Tohoku University. He is the supervising editor for this series on
Railway Technology Today.

Akira Nehashi
Mr Nehashi is Director of Corporate Planning Department in Taiwan High-speed Railway Headquarters
at Japan Railway Technical Service (JARTS). He joined JNR in 1970 after graduating in civil engineeringfrom the University of Tokyo and worked both in the construction and shinkansen planning departments.
He also held many positions at, National Land Agency and Japan Railway Construction Public
Corporation before assuming his present post at JARTS.

Japan Railway & Transport Review 26 • February 2001

67