Abukuma Express Line

The route began as a project of Japanese National Railways (JNR). After the corridor was approved as a construction line by the Railway Construction Council on 12 May 1961, earthwork started on the Tsukinoki–Marumori section on 1 December 1964 and on the Fukushima–Marumori section on 30 September 1966. On 1 April 1968 JNR opened the first 17.4-kilometre segment as the Marumori Line (丸森線), running between Tsukinoki and Marumori, but the planned extension on to Fukushima was never finished under state ownership.

As JNR's finances deteriorated, the partly built line was caught up in the nationwide programme of route rationalisation. On 18 September 1981 the Marumori Line was designated a Specific Local Transport Line — one of the lightly used rural lines slated for closure or conversion. Rather than see the line abandoned, local interests moved to take it over as a third-sector railway, and the company Abukuma Express was established for that purpose.

The transition was rapid. An operating-licence application was submitted on 24 December 1984, the licence was granted on 27 February 1985, and construction approval followed on 2 March 1985. On 1 July 1986 ownership of the existing Tsukinoki–Marumori section passed from JNR to Abukuma Express, which began operations with diesel railcars on the still-unfinished line.

Abukuma Express then completed the work the national railways had left undone. On 1 July 1988 the long-planned extension from Marumori through to Fukushima opened, joining the two ends into a continuous 54.9-kilometre route, and the entire line was electrified at 20 kV 50 Hz AC at the same time — allowing electric operation across the whole corridor for the first time. A further infill station, Fukushima Gakuin-mae, was added on 11 March 2000.

The line has been repeatedly knocked out by natural disasters and rebuilt each time. The Great East Japan Earthquake suspended the whole line on 11 March 2011, with services restored in stages until full operation resumed on 16 May 2011. On 12 October 2019 Typhoon Hagibis (the 2019 East Japan Typhoon) inflicted heavy damage and again closed the entire line; service was brought back section by section, and full operation between Fukushima and Tsukinoki was not restored until 31 October 2020, more than a year later. An earthquake off the Fukushima coast forced another suspension in March 2022, after which the line reopened in stages and full operations resumed on 27 June 2022.

• 196112 May: the corridor is approved as a construction line by the Railway Construction Council.
• 19641 December: earthwork begins on the Tsukinoki–Marumori section.
• 196630 September: earthwork begins on the Fukushima–Marumori section.
• 19681 April: Japanese National Railways opens the first segment, the Marumori Line, between Tsukinoki and Marumori (17.4 km).
• 198118 September: the Marumori Line is designated a Specific Local Transport Line, marking it for closure or conversion amid JNR's financial deterioration.
• 198424 December: an operating-licence application is submitted for the third-sector takeover.
• 198527 February: the operating licence is granted; construction approval follows on 2 March.
• 19861 July: ownership of the Tsukinoki–Marumori section passes from JNR to the newly established Abukuma Express, which begins operating with diesel railcars.
• 19881 July: the extension from Marumori to Fukushima opens, completing the 54.9 km through route, and the entire line is electrified at 20 kV 50 Hz AC.
• 200011 March: the infill station Fukushima Gakuin-mae opens.
• 201111 March: the Great East Japan Earthquake suspends the whole line; service is restored in stages, with full operation resuming on 16 May 2011.
• 201912 October: Typhoon Hagibis (the 2019 East Japan Typhoon) causes heavy damage and closes the entire line; full operation between Fukushima and Tsukinoki is not restored until 31 October 2020.
• 2022An earthquake off the Fukushima coast in March forces another suspension; the line reopens in stages and full operations resume on 27 June 2022.