Breakthrough in Japanese Railways 10

Railways and Bridges 2
Junichi Konishi

Concrete Construction

design and construction standards, Muneharu Okodo (1877-

Started with small arch culverts

the first draft of Specifications for Design and Construction of

Reinforced concrete construction was introduced to Japan

Reinforced Concrete Structures. Based on this, Instructions

during the first part of the 20th century. The first reinforced

for Design of Reinforced Concrete Bridges was publishedconcrete railway bridges started with arch culverts underneaththereafter in 1914. Furthermore, Standard Drawings ofembankments. The Shimadagawa Bridge completed in 1907

Reinforced Concrete Half-egg-shaped Arches, Standard(San’in main line, Shimane Prefecture) was the first and it was

Drawings of Reinforced Concrete Semi-circular Arches, andsmall with a span of 1.83 m and an axial length of 10.67 m.

Standard Drawings of Reinforced Concrete Box Culverts

Several small concrete arches were constructed with a span

were published one-by-one from 1916 to 1917. Finally,of less than 6.7 m through 1912 but since there were nostandard designs and drawings for bridge abutments,1960), who had returned from studying in Europe, prepared

bridge piers, well foundations etc., were established from
1917 to 1920; standards for construction and other civilengineering-related specifications were established in
1917, so systems for designing and constructing based on
concrete and reinforced concrete (replacing brick and stone)
and the application scope centred around small bridges
grew gradually.

Large arch bridge designed by two engineers
In 1919, the Sotobori Arch Bridge with a span of 38.1 m,
which was revolutionary at the time, appeared on the Tokyo
Metropolitan Elevated Line. It was designed by Dr Mikishi
Abe (1883-1905) of the Railway Agency and is a Melan-type
reinforced concrete arch. The seven-centred circular archapproximates the shape of pressure lines
Shimadagawa Bridge (San’in Line, Shimane Pref.) 

generated by weight. It is just north of the(Author)magnificent red-brick Tokyo Station so thesurface was covered by stone to make itlook like a stone arch bridge and it has fourvery large main pillars. The keystone hasa relief of a driving wheel and the bridge
has extraordinary focus on railway bridge
design. It is still in use but is not treated asa famous bridge, due to the metropolitan
expressway crossing over the top andthe loss of main pillars caused by track
expansion etc.
After completing the Sotobori Arch
Bridge, Dr Abe retired from the Railway
Agency, opened the Mikishi Abe Office

Sotobori Arch Bridge (Tohoku Line, Tokyo) (History of Railway Engineering Development Vol. 2)

Japan Railway & Transport Review No. 59 • Feb 201248

and designed many superb reinforced

Breakthrough in Japanese Railways 10

concrete structures. For railways, he designed t wo

Large span arch bridges during steel shortages

reinforced concrete arch bridges for the Hankyu Kobe

Due to difficulties in obtaining steel because of the war inLine with a span of 40.0 m in 1936 and contributed to the

China from 1935, many bridges for local lines were built

widespread use of urban railway reinforced concrete rigid-

using reinforced concrete in place of steel girders Thoseframe viaducts.

with a span of 30 m or more used an open-spandrel arch,

In 1925, a reinforced concrete filled spandrel arch

ultimately achieving spans of 45 m. In addition to single-

bridge with a span of 32.9 m was built where an elevatedspan bridges, multi-span bridges were also constructed.

railway track crosses the Kanda River between Tokyo

While never actually built, there are completed drawings

and Ueno. The design was by Muneharu Okodo of thefor a reinforced concrete arch with a span of 102 m

Government Railways. It was a normal reinforced concretefor the No. 3 Tadamigawa Bridge on the Tadami Line. The

structure that used steel rods and a transformed catenary

reinforced concrete arch bridges with a span of 30 m or

was used as the arch axis line. This shape matches themore constructed prior to 1941 are listed in Table 1.

arch axial lines with the arch pressure lines generated byloads on the top surface of the arch and is considered ideal
for flat low arches compared to span. Many large reinforced
concrete arches built during the 1930s and thereafter use atransformed catenary as the arch axial line.
Mr Okodo made a great contribution to advancing
reinforced concrete technology, playing a central role inwriting Reinforced Concrete Standards and Specifications
published by the Japan Society of Civil Engineers. He
retired from the Government Railways in 1931, becoming
a professor at the Imperial University of Tokyo and 25th
President of the Japan Society of Civil Engineers in 1937.

Kandagawa Arch Bridge (Tohoku Line, Tokyo) (Author)Table 1 Reinforced Concrete Arches before 1941 (span larger than 30 m)
Name

Railway Line

Place

Span (m)Spandrel

Const. Year

Sotobori

Tohoku

Tokyo

38.1

filled1918

Kanda-gawaTohoku

Tokyo

32.9

filled1925

MeganeYonesaka

Yamagata

34.0

filled1934

No. 3 Otobuke

Shihoro †Hokkaido

32.0

filled1936

NadaHankyu-Kobe

Hyogo

40.0

filled1936

HaradaHankyu-Kobe

Hyogo

40.0

filled1936

No. 4 Hiraishi-gawa

Tadami

Niigata

40.0

filled1937

Tsunanose

Hinokage †Miyazaki

45.0

open

1937

Motodani-gawa

Dosan

Kochi

35.0

open

1937

Shinkai

Dosan

Kochi

40.0

open

1938

Funahira

Dosan

Kochi

40.0

open

1938

Otani-gawa

Tadami

Fukushima

45.0

open

1939

Otanba-gawa

Hikawa †

Tokyo

45.0

open

1941

†: line closed

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Japan Railway & Transport Review No. 59 • Feb 2012

Megane Arch Bridge (Yonesaka Line, Yamagata Pref.)(Civil Engineering, 1935)

Tsunanose Arch Bridge (Takachiho Railway, Miyazaki Pref.)(Civil Engineering, December 1936)

Yamobe Bridge (on coastal Uchibo Line, Chiba Pref.) 

Sogogawa Bridge (on coastal San’in Line, Yamaguchi Pref.) (Shigeru Onoda)(Author)

The Megane Arch Bridge on the Yonesaka Line is aplanned in 1889 for the Shimbashi–Ueno section of thefilled-spandrel arch with a span of 34.0 m. It is a Melan type

Tokyo Metropolitan Elevated Line. However, construction

and the arch shape is a transformed catenary. The open-

was delayed and the viaduct built mainly of brick arches inspandrel arch Tsunanose Bridge on the Hinokage Linethe south section of Tokyo Station was completed in 1909.

(Takachiho Railway) had the longest span prior to 1941 at

The Tokyo–Manseibashi section completed in 1919

45.0 m.

used a girder structure and rigid frame structure as well as
reinforced concrete arch with brick exterior.

Girder bridges

A reinforced concrete rigid frame structure was used

The beam takes straight for ward advantage of thethroughout for the elevated section between Tokyo and Ueno

characteristics of reinforced concrete in girder, rigid-frame,

completed in 1925. In Tokyo and Kanagawa, many elevatedand slab-girder bridges.

lines of both government and private railways, such as the

The first fully fledged reinforced concrete railway

Ochanomizu–Ryogoku section of the Sobu main line were

girder bridge is the Yamome Bridge (Uchibo Line, Chiba

constructed in reinforced concrete. Around Osaka and Kobe,

Prefecture) completed in 1920. Since the line follows thefollowing the completion of the Tenjinbashi-suji Viaduct oncoast, it was decided to use reinforced concrete and a row ofHankyu Railway’s Senri Line in 1925, elevated railways were

16 T-shaped girders made up of two 9.14-m long T-shaped

constructed one after another by government and private

beams. This bridge is still in use and reinforced concreterailways. Excluding over-road bridges, most structures usedgirders were used for many bridges on local lines thereafter.

reinforced concrete rigid frame construction.
A well-known reinforced concrete rigid frame bridge not

Viaducts

in an urban area is the Sogogawa Bridge on the San’in main

Elevated railways are now common in many rural cities asline along the Japan Sea coast, It is a two-tier rigid frame

well as large metropolises, but the first elevated railway wasbridge for a single-track railway and has a height of 11.6 m

Japan Railway & Transport Review No. 59 • Feb 201250

Breakthrough in Japanese Railways 10

Intermediate support of the three-span continuous truss of Saigawa Bridge(Author)Abandoned Usuigawa Bridge with max. span of 70 m as RC railway
arch bridge on 66.7‰ grade (Author)continuous half through plate girders were constructed as the
Fujigawa Bridge on the up track of the Tokaido main line. It
was a revolutionary long span for a plate girder railway bridge.

All-welded construction trusses
As described above, the first all-welded construction
truss was for the Tenryugawa Bridge designed in 1955
and thereafter continued with the Kisogawa Bridge (1957)
and the Shin-Jintsugawa Bridge (double track, 1959).
Three-span continuous half through plate girder of up line of
Fujigawa Bridge 

Thereafter, all the trusses for the Tokaido Shinkansen wereof all-welded construction.

(Author)

Stiffened arches
above the pier foundation, a span of 10.0 m, and an overall

Stiffened arches named Langer girder and Lohse girder

length of 180 m.

were used for large-span bridges in cities.
In 1959, the first Lohse girder was constructed on the

Postwar Bridges

Harumi Bridge of the port line of the Tokyo Bureau of Ports andHarbours. It was designed by Japanese National Railways.

Construction for railways restarted after WWII following
the old prewar specifications until new specifications wereReinforced concrete arches

established in 1956.

There are few reinforced concrete arches, but rigid frame
arches were constructed for the Mattogawa Bridge on theContinuous girders

Kitakami Line (span 52.0 m, 1960), the Shin-Usuigawa Bridge

In 1953, a three-span continuous deck truss was designedon the Shin’etsu main line (span 70.0 m, flat open-spandrel

for the No. 3 Tadamigawa Bridge. This was followed in 1955

arch, 1963), the Oyobitosawa Bridge on the Chuo Line (spanby a welded three-span continuous Warren truss constructed58.0 m, rise 20.0 m, open-spandrel arch, 1966), etc., andwithout any vertical members to replace the Tenryugawa

a maximum span of 70 m was reached. Larger spans were

Bridge on the Iida Line. Similarly, in 1957, a three-spanachieved using pre-stressed concrete construction.

continuous Warren truss without vertical members was
designed and three welded trusses were constructed on the

Reinforced concrete girder bridges

Kisogawa Bridge on the down track of the Tokaido main line,

The maximum span for a reinforced concrete girder bridge

and two riveted trusses was constructed on the Saigawa

is the 32-m Hanamigawa Bridge on the Sobu main line

Bridge on both the up and down tracks of the Shin’etsu

completed in 1957. It is a three-span continuous box girder

main line. These experiences were carried over to continuous

bridge for a double track with span lengths of 16.0, 32.0,

trusses for the shinkansen. In 1956, three of three-span

and 16.0 m.

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Japan Railway & Transport Review No. 59 • Feb 2012

Pre-stressed concrete bridges
Research on pre-stressed concrete started in the 1930s but
full construction only started with the Daiichi-Daidogawa
Bridge (1954); it is a post-tensioned pre-stressed concrete
girder bridge on today’s Shigaraki Kougen Railway (Shiga
Prefecture). The No. 8 Tonegawa Bridge on the down trackof the Joetsu Line (Gunma Prefecture) completed in 1963 isa pre-stressed concrete π-shaped rigid frame bridge with aspan of 62.0 m. It has a shapely appearance with a span aslong as the trusses.

Modern Bridges
Daidogawa Bridge—start of PC bridge advancement  (Shigaraki Kougen Railway)

Tokaido Shinkansen Bridges
The shinkansen is fully grade-separated from all otherrailways and roads. Trains are all EMUs and controlled froma central location.
The first Tokaido Shinkansen is characterized by theextensively used reinforced concrete rigid-frame viaducts
in place of embankments and the welded steel continuous
Warren trusses. Both were thoroughly standardized anddeployed on all sections. The track of the shinkansen isbasically straight course in plan, and structures were
designed in rectilinear shape, completely changing the rural
Japanese landscape.

No. 8 Tonegawa Bridge down line Tokaido Shinkansen truss bridge, 1965 (Author)

Saigawa Bridge on Hokuriku Shinkansen during bridge decking
construction (The Railway Museum)

Tokaido Shinkansen viaduct, 1965 Japan Railway & Transport Review No. 59 • Feb 2012

(Author)(The Railway Museum)52

Breakthrough in Japanese Railways 10

Truss girders were refined based on the experience of

resulting in large angular rotation and expansion andthe parallel-chord welded Warren continuous truss without

contraction at both ends of the bridge and tower supports,

vertical members as mentioned above. Welding was used

so extraordinary structural work is required. Therefore, aalso for all kinds of other girders. Thereafter, railways incontinuous stiffening truss system was used and an auxiliary

Japan shifted completely to welded structures.

girder for controlling angle change and expansion (transition

The later San’yo Shinkansen (west of Okayama), Tohoku

track girder with expansion joint) was developed.

Shinkansen, and Joetsu Shinkansen use slab track with

Steel bridges without any coating made ofweather-resistant steel

rails attached directly to the reinforced concrete slab. With
the development of the steel truss girder using a concreteslab to reduce noise, more concrete bridges were built thansteel bridges. One photograph on the previous page shows

Unclad bridges with weather-resistant steel plates

the deck of the Saigawa Bridge (truss) on the Hokuriku

One of the cost problems of steel girders is re-coating (re-Shinkansen.

painting). Construction using weather-resistant steel without
coating is based on the method that uses rust to prevent

Bridges between Honshu and Shikoku

rust. The first bridge without coating is the deck truss girder

Railways on Japan’s main island of Honshu are connectedof the No.3 Okawa Bridge on Aizu Railway completed into Kyushu and Hokkaido by undersea tunnels but Honshu

1980. After that, several steel girders were constructed

is connected to Shikoku by three bridges. The middle routein rural area based on bare specification using weather-linking Okayama Prefecture and Kagawa Prefecture is a

resistant steel, reflecting various technical developements

dual-use road and railway (narrow gauge) bridge. On a very

and improvements.

long suspension bridge or cable-stayed bridge hung by

Steel arch bridges in scenic landscapecables, the passage of heavy trains causes large deflection,

After aesthetic design considerations, steel arch bridges
and steel π-shaped rigid frame bridges were adopted
over the scenic Hozugawa River. Seen from the side, theindividual bridges look elegant but when seen from tourist
boats, they may seem incompatible with the scenery of the
Hozugawa valley. This may not be a problem of design but
may be a problem of route location. Concrete slab bridges
are increasingly being used in favour of open-floor bridges
to prevent noise and support slab track.

Pre-stressed concrete long bridges
The era of long steel truss railway bridges continued for along time but, recently, long-span pre-stressed concrete
bridges have been used extensively in various shapes andforms. In terms of design limits, these pre-stressed concrete

Honshu Shikoku Bridge Authority’s Shimotsuiseto Bridge with auxiliary
girders for controlling angle change on Honshu side (Author)bridges have superior appearance because they offer ahigher degree of design freedom than steel bridges. In the
25 years since the JNR division and privatization, many
recent railway bridges are especially impressive.

Deck-type pre-stressed concrete deck-stiffened arch
(Langer type)
The Akatanigawa Bridge on the Joetsu Shinkansen (Gunma
Prefecture) completed in 1979 during the JNR era has
an arch span of 116 m, exceeding the 100-m mark for a
concrete arch bridge for the first time. It is not a pure archbridge, having girders of high rigidity. The arch ribs are thin
Akatanigawa Bridge (Joetsu Shinkansen, Gunma Pref.) and draw polylines, and the girders are reinforced by this(Author)thin plate arch rib.

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Japan Railway & Transport Review No. 59 • Feb 2012

No. 2 Chikumagawa Bridge 

Sannaimaruyama Overbridge (JRTT)

No. 2 Agatsumagawa Bridge (S. Saito)(Author)the Hokuriku Shinkansen opened in 1998. It has two spansof 139.9 m and a girder length of 270 m; the main towerheight is 65 m above the bridge surface. Although symbolicfrom the aesthetic standpoint due to its high towers, thegirder height had to be increased to 3 m to raise the rigidityof the main girders for use as a shinkansen bridge withstringent deflection restrictions. Problems such as departurefrom essential structural characteristics of a cable-stayed
bridge, long period deflection of girders due to the effectsof concrete creep and drying shrinkage, and inspectiondifficulties due to the height of the towers have been noted.

Extra-dosed cable stayed bridges
Compared to a standard cable-stayed bridge with highmain towers, this bridge type has lower main towers andYashiro Minami Overbridge 

increased main girder rigidity, making it closer to a girder(Author)bridge than a suspension bridge. The angle of the diagonal
cables is closer to horizontal than a cable-stayed bridge
because the towers are low, reducing stress fluctuations in

Cable-stayed bridges

diagonal members due to live loads and preventing fatigue

These bridges hang oblique pre-stressed concrete girders

failure. Furthermore, inspection and maintenance of towers

by cables from high towers (pylons). An example with aand diagonal members is easy, making the design ideal for

span longer than 100 m is the No. 2 Chikumagawa Bridge on

railway bridges.

Japan Railway & Transport Review No. 59 • Feb 201254

Breakthrough in Japanese Railways 10

Pre-stressed concrete continuous girder with finback
shaped side wall
Matching the bending moment of the continuous girder,
part of the main girder of bridges of this type protrudes on
the bridge pier like a dorsal fin on the top side of the girders
and PC cables are embedded inside. This helps reduce
the height from the rail surface to the bottom surface of thegirders. The waves generated by the dorsal fin and curved
side surface of the girders give the bridge a soft impression
unlike previous railway bridges. The first example is the sixspan continuous through-type girders of the Narusegawa
Bridge on the JR East Senseki Line completed in June 2000.
Himekawa Bridge 

The Himekawa Bridge on the Hokuriku Shinkansen (total(JRTT)

length of 462 m, seven span, completed in 2007) uses asimilar design.

Through-type concrete deck-stiffened arch (Langer type)
Through-type steel Langer girders started with the
Sumidagawa Bridge on the Sobu main line in 1932; asimilar through-type concrete deck stiffened arch (Lohsetype) girder was constructed for the first time in Nagano
Prefecture in 1936 and then became commonplace. Useof the through type reinforced concrete deck stiffened arch
started relatively recently. Thin arch ribs are added to the topof through type reinforced concrete or pre-stressed concrete
Haruda Overbridge girders, resulting in increased girder rigidity. It reduces the(JRTT)

girder height and lessens deflection. In addition to reduced
girder height, the bridge arch alleviates oppressiveness,making it ideal for viaducts; it could be further improved by

The Yashiro -minami Overbridge on the Hokuriku

design efforts, such as adding unevenness to the girders

Shinkansen (max. span 105 m), the Onogawa Bridge

and arch side surfaces. There are several bridges of thison the Kyushu Shinkansen (max. span 113 m), and thetype on the JR East Nanbu and Agatsuma lines. More

Sannaimaruyama Overbridge on the Tohoku Shinkansen

recent examples are the Harada Overbridge on the Kyushu(max. span 150 m) are all shinkansen bridges with maximum

Shinkansen (span length of 61.0 m) completed in 2002.

spans exceeding 100 m.

Concrete sheathed cable-stayed bridges
This extra-dosed cable stayed bridge has PC cable diagonal
members covered with concrete. The Ganter Bridgein Switzerland with PC cables radiating from a low tower
and covered with triangular-shaped concrete slabs wascompleted in 1980 to worldwide acclaim.
The diagonal members covered with concrete reduce
worries about cable corrosion. The overall bridge rigidity
is high and the deflection is small, making it an ideal

Junichi Konishi

design for a railway bridge. JR East completed the 108-m

Professor Konishi is professor emeritus at Shinshu University. He
earned his PhD in engineering at Kyoto University in 1979. His related
publications are: Japan Society of Civil Engineers (ed.) A Survey ofHistoric Iron and Steel Bridges in Japan 1873–1960, 2002 (http://library.jsce.or.jp/jscelib/committee/2003/bridge/brtop.htm); andNaruse Teruo (ed.) Historic Iron and Steel Bridges in Japan, Tokyodo Shuppan, 1994 (co-author) Japan Society of Civil Engineers (ed.)
What has been built in Japan?–Exploration of historical infrastructure
in Japan, Sankaido, 1995.

Natorigawa Bridge on the Tohoku main line in 1996 and has
had good results with several other bridges thereafter. The
Sendaigawa Bridge (96 m) on the Kyushu Shinkansen wascompleted in 2002. The No. 2 Agatsumagawa Bridge on the
JR East Agatsuma Line with a centre span of about 167 m
was completed in 2010.

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Japan Railway & Transport Review No. 59 • Feb 2012