Yamagata Shinkansen

The Yamagata Shinkansen (Japanese: 山形新幹線) 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 Tōhoku 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 conventional lines it is often referred to as a "mini-Shinkansen".

Trains consist of 7-car E3 and E8 series trainsets operating as Tsubasa services. Between Tokyo and Fukushima, most trains run coupled to Yamabiko limited-stop service trains on the Tōhoku Shinkansen. Between Fukushima and Shinjō, the trains run on their own at a maximum speed of 130 kilometres per hour (81 mph) 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]

• All stations listed below are located on the Ōu Main Line.

As of March 2024, the following types are used on Yamagata Shinkansen services:

• E3-2000 series: 7 car sets, since 20 December 2008 (to be replaced by E8 series in 2026)
• E8 series: 7-car sets, since 16 March 2024^[3]

• E3-2000 series set in original livery
• E3-2000 series set in new livery
• E8 series set

• 400 series: 7-car sets (originally 6-car sets) withdrawn by 18 April 2010
• E3-1000 series: 7-car sets, in service from 4 December 1999 until 18 March 2024.^[4]

• 400 series, 6-car set in original livery
• E3-1000 series set in new livery

• Class E926 "East i"

• Class E926 "East i" train

The tracks of the Ōu Main Line were re-gauged between 1988 and 1992 to create the Yamagata Shinkansen. Tsubasa services began on 1 July 1992, operating between Tokyo and Yamagata using six-car 400 series trainsets coupled to 200 series trains on the Tōhoku Shinkansen between Tokyo and Fukushima. On 1 December 1995, the trains were lengthened to seven cars, and the line was subsequently extended northward to Shinjō on 4 December 1999. All cars were designated non-smoking from 18 March 2007.

A major rolling stock transition occurred on 20 December 2008, when E3-2000 series trainsets entered service, replacing the earlier 400 series, which were fully withdrawn on 18 April 2010. Operations were severely disrupted following the 2011 Tōhoku earthquake and tsunami on 11 March 2011, which led to the suspension of all services. Partial operations resumed between Fukushima and Shinjō on 31 March 2011, and full through-services between Tokyo and Shinjō were restored on 12 April 2011, albeit at approximately half of the previous capacity.^[5]

Services were disrupted on 13 February 2021, when operations north of Nasushiobara Station were suspended following the 2021 Fukushima earthquake.^[6]

In March 2020, JR East announced two major projects to improve the line. The first was the introduction of the E8 series trains, designed to increase maximum speeds on the Tōhoku Shinkansen to 300 kilometres per hour (190 mph) and reflect the landscape and cultural identity of Yamagata Prefecture.^[7] Delivery began in 2023 and is scheduled to conclude in 2026, when the E8 series will replace the remaining E3 series.^[8][9] The second project is the construction of a new approach line at Fukushima Station to remove a bottleneck. Previously, southbound Yamabiko services coupling with Tsubasa trains had to cross the northbound main line twice to access Platform 14. The new track will branch from the Ōu Main Line, pass beneath the elevated Shinkansen, and connect directly to Platform 11, eliminating at-grade crossings and allowing simultaneous arrivals and departures, improving timetable flexibility. Completion is scheduled for 2026.^[8][10][11]

On 9 June 2022, the line celebrated its 30th anniversary; an E3 series trainset was wrapped in a commemorative livery and remained in service until November 2022.^[12]

The E8 series entered service on 16 March 2024.^[3] On 17 June 2025, four E8 series trainsets experienced auxiliary power unit (APU) malfunctions.^[13][14][15] The APU converts electricity collected from the overhead lines into the appropriate forms required by onboard systems, including traction motors and cooling equipment. Each trainset is equipped with two APUs to provide redundancy.^[16][17]

The E8 series entered service on 16 March 2024.^[3] On 17 June 2025, four E8 series trainsets suffered malfunctions of their auxiliary power units (APUs), which convert electricity from overhead lines for onboard systems.^[13][14][15] In one case, a trainset stopped on the Tōhoku Shinkansen, blocking the line, stranding passengers, cancelling 86 services, and delaying 138 others across the Tōhoku, Yamagata, and Akita Shinkansen lines.^[13][18][19] JR East suspended independent E8 operation, limiting them to multiple working and temporarily reinstating some E3 trains, reducing Yamagata Shinkansen service to roughly 80% of normal.^[14][20][21] Investigations found that an electrical issue, combined with high summer temperatures, caused protective components to fail, allowing excess current to reach and damage sensitive electronic systems. After installing stronger protective components and revising settings, independent operation and through services gradually resumed from 1 August 2025.^[22][21]

JR East has proposed the construction of a base tunnel through the Ōu Mountains west of Fukushima, with a surveyed route between Niwasaka and Sekine.^[23] Of the proposed 24.9-kilometre (15.5 mi) line, 23.1 kilometres (14.4 mi) would be underground, located mostly north of the existing line, and follow a more direct alignment intended to reduce journey times by approximately 10 minutes through a proposed line speed of up to 200 kilometres per hour (120 mph).^[24] The tunnel would bypass the Itaya Toge pass, where gradients of 3.0–3.8% and an altitude of 548 metres (1,798 ft) currently limit speeds to 55 kilometres per hour (34 mph) or less and leave the line vulnerable to heavy rain, snow, and high winds;^[23] between 2011 and 2017, 410 Tsubasa services were delayed or suspended, 40% of which occurred on the Itaya Toge section.^[23] If authorized at an estimated cost of ¥150 billion, detailed design would take five years and construction a further 15 years,^[25] with an option to build the tunnel to the full Shinkansen loading gauge for an additional ¥12 billion.^[23]

• Stations of Yamagata Shinkansen (JR East) (in Japanese)