| Box Width: | 30em |
| Yamagata Shinkansen | |
| Native Name: | 山形新幹線 |
| Native Name Lang: | ja |
| Mapcolor: | Orange (#) |
| Type: | Mini-shinkansen |
| Status: | Operational |
| Locale: | Fukushima and Yamagata Prefectures |
| Stations: | 11 |
| Open: | (–) (Yamagata–Shinjō) |
| Operator: | JR East |
| Depot: | Yamagata |
| Stock: | |
| Tracks: | Double-track (Single-track in some sections) |
| Electrification: | Overhead line |
| Maxincline: | 3.75% |
| Map Name: | Route Map (from Fukushima in blue) |
| Map State: | collapsed |
The is a Mini-shinkansen route in Japan, operated by East Japan Railway Company (JR East). It provides service between Tokyo and Shinjō in Yamagata Prefecture over the tracks of the Tohoku Shinkansen and the Ōu Main Line.
The term Yamagata Shinkansen refers to the segment that connects Fukushima and Shinjō. Because the shinkansen trains share tracks with local trains running on, it is often referred to as a "mini-shinkansen".
Trains consist of 7-car E3 and E8 series trainsets operating as Tsubasa services. Between and Fukushima, some trains run coupled to Yamabiko trains on the Tōhoku Shinkansen. Between Fukushima and Shinjō, the trains run on their own at a maximum speed of 130abbr=onNaNabbr=on and share the line with regular Ōu Main Line trains.[1]
As of July 2012, about 62 million passengers had ridden the line since it opened in July 1992.[2] The fastest trains connect Tokyo and Yamagata stations in two hours and 29 minutes.[2]
In April 2021, JR East started construction of a new approach line at Fukushima station. Currently, the Yamagata Shinkansen can only enter and exit the Tohoku Shinkansen through platform 14 at Fukushima Station. This current layout requires the Yamagata Shinkansen to cross the north bound tracks to reach the Tokyo bound tracks. This new approach line will pass under the Tohoku Shinkansen, which will allow Yamagata Shinkansen to enter the Tohoku Shinkansen on platform 11 removing the crossing and reducing the gravitude of transport disruption. Construction is expected to finish by the end of fiscal year 2026.[3]
Construction of a base tunnel on the Yamagata Shinkansen is proposed, with JR East having undertaken a survey of a planned route from Niwasaka to Sekine, just south of Yonezawa station.[4] 23.1km (14.4miles) of the proposed 24.9km (15.5miles) line would be in tunnel, mostly to the north of the existing 88km (55miles) Fukushima – Yamagata section. To be built on an improved alignment, the tunnel would lower journey times between Fukushima and Yamagata by ~10 min due to a proposed line speed of up to .[5]
The tunnel would avoid the Itaya Toge pass through the Ou mountains west of Fukushima. Gradients range from 3.0% to 3.8% and the line reaches an altitude of 548m (1,798feet). The curvature and steep grades limit train speeds to 55km/h or less, and the line is vulnerable to heavy rain and snowfall as well as high winds. Between 2011 and 2017 a total of 410 Yamagata mini-Shinkansen services were either suspended or delayed, and 40% of these incidents occurred on the line over the Itaya Toge pass.
If the base tunnel is authorised, detailed design would take five years and construction another 15 years.[6] The cost could increase by if the tunnel were to be built with a cross-section large enough to permit the line to be upgraded to the full Shinkansen Loading gauge.
| Station | Japanese | Distance (km) | Transfers | Location | ||
|---|---|---|---|---|---|---|
| From | From | |||||
| Japanese: 福島 | 272.8 | 0.0 | Fukushima | Fukushima | ||
| Japanese: 米沢 | 312.9 | 40.1 | Yonezawa | Yamagata | ||
| Japanese: 高畠 | 322.7 | 49.9 | Takahata, Higashiokitama District | |||
| Japanese: 赤湯 | 328.9 | 56.1 | Nanyō | |||
| Japanese: かみのやま温泉 | 347.8 | 75.0 | Kaminoyama | |||
| Japanese: 山形 | 359.9 | 87.1 | Yamagata | |||
| Japanese: 天童 | 373.2 | 100.4 | Tendō | |||
| Japanese: さくらんぼ東根 | 380.9 | 108.1 | Higashine | |||
| Japanese: 村山 | 386.3 | 113.5 | Murayama | |||
| Japanese: 大石田 | 399.7 | 126.9 | Ōishida, Kitamurayama District | |||
| Japanese: 新庄 | 421.4 | 148.6 | Shinjō | |||
As of March 2024, the following types are used on Yamagata Shinkansen services.