Ōu Main Line

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Ōu Main Line
Ou Honsen to Yamagata Jo 2005-12.jpg
Passing the moat of Yamagata Castle Site
left: Narrow gauge right:Standard gauge
Overview
Native name奥羽本線
StatusOperating
Owner JR logo (east).svg JR East
Termini
Stations102
Service
TypeMain line
System JR East
Technical
Track length486.3 km (302.2 mi)
Number of tracks2
CharacterElevated, rural
Track gauge 1,067 mm (3 ft 6 in)
1,435 mm (4 ft 8+12 in)
Electrification 20 kV AC, 50 Hz
Route map
Red indicates standard gauge tracks JR Ou Main Line linemap.svg
Red indicates standard gauge tracks

The Ōu Main Line (奥羽本線, Ōu-honsen) is a railway line in Japan, operated by the East Japan Railway Company (JR East). It connects Fukushima Station through Akita Station to Aomori Station. Since the opening of the Yamagata Shinkansen on July 1, 1992, the FukushimaYamagata section (as well as the YamagataShinjō section since 1999) is sometimes referred to as the Yamagata Line. The name of the line as a whole refers to the ancient provinces of Mutsu () and Dewa (), as it connects both ends of Mutsu by passing north–south through Dewa.

Contents

Route data

Services

The Ōu Main Line is split into the following four sections. Due to the differences in the tracks of these sections, there are no trains that go through more than one (with the exception of an Akita–Shinjō connection). Local and rapid services on the line are generally operated by 701 series (entire line) and 719 series (Fukushima - Shinjō only) electric multiple unit trains.

Fukushima–Shinjō (148.6 km)

On this section, the Ōu Main Line shares the tracks with the Yamagata Shinkansen. The rail gauge is 1,435 mm (4 ft 8+12 in) to allow the Yamagata Shinkansen to run on it. The Ōu Main Line is known as the Yamagata Line on this section.

Shinjō–Ōmagari (98.4 km)

Crossing the Yamagata-Akita border, there is little demand in this section, and all trains except one limited-stop "Rapid" train run as all-stations "Local" trains.

Ōmagari–Akita (51.7 km)

On this section, the Ōu Main Line shares the tracks with the Akita Shinkansen. Because the Ōu Main Line occasionally runs from Akita to Shinjō as a local train, this section contains one standard gauge track and two narrow gauge tracks. Also, the few Komachi trains running on this section have the priority.

Akita–Aomori (185.8 km)

Together with the San'in Main Line, Maizuru Line, Obama Line, Hokuriku Main Line (including the IR Ishikawa Railway, Ainokaze Toyama Railway, and the Nihonkai Hisui Line), part of the Shinetsu Main Line (including the Myoko Haneuma Line), Hakushin Line, and the Uetsu Main Line, this section of the Ōu Main Line is one of the express lines and freight lines that make up the Nihonkai Jūkan-sen (Sea of Japan Trans-Japan Line).

Station list

StationJapaneseDistance
(km)
RapidTransfersLocation
Fukushima 福島0.0 Fukushima Fukushima Prefecture
Sasakino 笹木野3.8
Niwasaka 庭坂6.9
Itaya 板谷21.2 Yonezawa Yamagata Prefecture
Tōge 24.5
Ōsawa 大沢28.8
Sekine 関根34.8
Yonezawa 米沢40.1
Oitama 置賜45.6
Takahata 高畠49.9 Shinkansen jre.svg Yamagata Shinkansen Takahata
Akayu 赤湯56.1 Nanyō
Nakagawa 中川64.4
Uzen-Nakayama 羽前中山68.3 Kaminoyama
Kaminoyama Onsen かみのやま温泉75.0 Shinkansen jre.svg Yamagata Shinkansen
Mokichi Kinenkan-mae 茂吉記念館前77.8
Zaō 蔵王81.8 Yamagata
Yamagata 山形87.1
Kita-Yamagata 北山形89.0
Uzen-Chitose 羽前千歳91.9 Senzan Line
Minami-Dewa 南出羽93.6
Urushiyama 漆山94.9
Takatama 高擶97.0 Tendō
Tendō-Minami 天童南98.3
Tendō 天童100.4 Shinkansen jre.svg Yamagata Shinkansen
Midaregawa 乱川103.4
Jimmachi 神町106.3 Higashine
Sakuranbo Higashine さくらんぼ東根108.1 Shinkansen jre.svg Yamagata Shinkansen
Higashine 東根110.6
Murayama 村山113.5 Shinkansen jre.svg Yamagata Shinkansen Murayama
Sodesaki 袖崎121.5
Ōishida 大石田126.9 Shinkansen jre.svg Yamagata Shinkansen Ōishida
Kita-Ōishida 北大石田130.8
Ashisawa 芦沢133.7 Obanazawa
Funagata 舟形140.3 Funagata
Shinjō 新庄148.6
Shinjō
Izumita 泉田154.2
Uzen-Toyosato 羽前豊里161.3 Sakegawa
Mamurogawa 真室川164.0 Mamurogawa
Kamabuchi 釜淵173.2
Ōtaki 大滝180.3
Nozoki 及位185.8
Innai 院内194.4 Yuzawa Akita Prefecture
Yokobori 横堀198.4
Mitsuseki 三関204.4
Kami-Yuzawa 上湯沢207.1
Yuzawa 湯沢210.4
Shimo-Yuzawa 下湯沢214.5
Jūmonji 十文字217.8 Yokote
Daigo 醍醐221.2
Yanagita 柳田224.4
Yokote 横手228.3 Kitakami Line
Gosannen 後三年234.7 Misato
Iizume 飯詰239.8
Ōmagari 大曲247.0 Daisen
Jingūji 神宮寺253.0
Kariwano 刈和野260.6
Mineyoshikawa 峰吉川265.4
Ugo-Sakai 羽後境271.9
Ōbarino 大張野280.0 Akita
Wada 和田285.4
Yotsugoya 四ツ小屋292.3
Akita 秋田298.7
Izumi-Sotoasahikawa 泉外旭川301.8 [a]
Tsuchizaki 土崎305.8
Kami-Iijima 上飯島308.3
Oiwake 追分311.7 Oga Line
Ōkubo 大久保318.9 Katagami
Ugo-Īzuka 羽後飯塚322.2
Ikawa-Sakura 井川さくら323.6 Ikawa
Hachirōgata 八郎潟327.5 Hachirōgata
Koikawa 鯉川333.0 Kotooka
Kado 鹿渡338.4
Moritake 森岳345.1 Yamamoto
Kita-Kanaoka 北金岡349.4
Higashi-Noshiro 東能代355.4 Gonō Line Noshiro
Tsurugata 鶴形360.3
Tomine 富根365.5
Futatsui 二ツ井372.2
Maeyama 前山379.5 Kita-Akita
Takanosu 鷹巣384.9 Akita Nairiku Line
Nukazawa 糠沢388.1
Hayaguchi 早口393.5 Ōdate
Shimokawazoi 下川沿397.7
Ōdate 大館402.9 Hanawa Line
Shirasawa 白沢409.4
Jinba 陣場416.5
Tsugaru-Yunosawa 津軽湯の沢422.3 Hirakawa Aomori Prefecture
Ikarigaseki 碇ヶ関427.2
Nagamine 長峰432.0 Ōwani
Ōwani-Onsen 大鰐温泉435.3 Kōnan Railway Ōwani Line
Ishikawa 石川440.7 Hirosaki
Hirosaki 弘前447.1 Kōnan Railway Kōnan Line
Naijōshi 撫牛子449.8
Kawabe 川部453.4 Gonō Line Inakadate
Kita-Tokiwa 北常盤456.6 Fujisaki
Namioka 浪岡462.1 Aomori
Daishaka 大釈迦467.2
Tsurugasaka 鶴ヶ坂473.4
Tsugaru-Shinjō 津軽新城478.8
Shin-Aomori 新青森480.6
Aomori 青森484.5

History

The Japanese national government built the Ōu Main Line, starting construction from Aomori in 1894, from Fukushima in 1899 and linking the two sections in 1905. In 1909 the formal name of the line was declared.

Opening dates for the individual sections are as follows.

Ōu North Line

Ōu South Line

Webb and Thompson large staff instruments used on the Ou South Line Webb&TomsonTablet.JPG
Webb and Thompson large staff instruments used on the Ōu South Line

Line upgrading

Various sections of the line have been double-tracked since 1963.

The section between Niwasaka and Akaiwa stations proved to be geologically unstable, with one of the original tunnels collapsing in 1910. A realignment involving two new tunnels was opened a year later. Geological instability was suspected as the cause of a derailment on the section in 1948 that killed three crewmen, and another realignment was undertaken when the section was double-tracked in 1968.[ citation needed ]

Itaya station was originally a reversing station, and was realigned as a through station in conjunction with the gauge conversion work (see below) in 1990.

Electrification

The Fukushima to Yonezawa section was electrified at 1,500 V DC in 1949, and the Uzen-Chitose–Yamagata section in conjunction with the Senzan Line (also at 1,500 V DC) in 1960. Trials on the Senzan Line subsequently resulted in the adoption of 20 kV AC for all further electrification, and the abovementioned sections were converted to the new standard when the Yonezawa to Yamagata section was electrified in 1968. The Aomori to Akita section was electrified (at 20 kV AC) in 1971, as was the Akita to Uzen-Chitose section in 1975.[ citation needed ]

Former connecting lines

Akayu human-powered tramway Akayu Jinsha Tramway.jpg
Akayu human-powered tramway
Kosaka Railway sulphuric acid train in its final year of operation Kosaka Smelting Kosaka-line.JPG
Kosaka Railway sulphuric acid train in its final year of operation
Kawabe station with a Konan Railway train bound for Kuroishi in 1997 Konan Kuroishi Line01.jpg
Kawabe station with a Konan Railway train bound for Kuroishi in 1997

The company also opened a 5 km 762 mm gauge line to the Hanaoka mine in 1914 including a bridge over the Ōu Main Line at Odate, which was converted to 1,067 mm gauge in 1951 to enable ore wagons to be forwarded via JNR trains. Freight services ceased in 1983 and the line closed in 1985.

Gauge conversion

Full standard Shinkansen lines are constructed using 1,435 mm gauge track on a separate alignment, with a high speed (240–320 km/h or 150–200 mph) and a commensurately high construction cost. Following privatisation and regionalisation of the JNR network in 1987, the JR East company decided to convert the Fukushima–Yamagata section of the 1,067 mm gauge Ōu Main line to 1,435 mm gauge, enabling Shinkansen trains from Yamagata to travel on the Tohoku Shinkansen line through to Tokyo. Called Mini-shinkansen, this was a cost-effective way of providing an improved level of service on the line, although only purpose-built Shinkansen trains can travel on such lines, as the loading gauge was not changed, nor the voltage (full standard Shinkansen lines use 25 kV AC). The Yamagata Shinkansen opened in 1992, and although the maximum speed is 130 km/h (81 mph), the overall transit time to places beyond Fukushima is improved due to the elimination of the need to change trains at the junction.

The success of this project led to the conversion of the Omagari to Akita section in conjunction with the opening of the Akita Shinkansen in 1997, and the extension of the Yamagata Shinkansen to Shinjo in 1999. These projects also created parallel 1,435 and 1,067 mm gauge lines between Omagari and Akita and between Yamagata and Uzen-Chitose respectively, and a dual-gauge section between Jinguji and Minejoshikawa (on the Omagari to Akita section), enabling Shinkansen trains to pass at speed on the mostly single-track line.

Additionally, local services continue to be provided on the gauge-converted lines by 701-5000 series standard-gauge suburban/interurban rolling stock.

Notes

  1. Rapid Resort Shirakami doesn't stop at the station

References