Jōshin Line

The corridor the line follows had long been a busy route — in the Edo period the Shimonita-michi served as a bypass of the Nakasendō highway. Momentum for modern transport grew after the government opened the Tomioka Silk Mill in 1871, and in 1873 a horse-omnibus service began between Honjō and Tomioka, though it failed commercially and a later plan for a wooden-railed horse tramway in 1881 was never completed. The opening of Nippon Railway's Takasaki Line in 1884 revived efforts at reform, and in 1895 local promoters established the Kōzuke Railway (上野鉄道, Kōzuke Tetsudō) to serve the Myōgi and Arafune mountain districts and to carry out ore and limestone from local mines.

The railway was built as a light line to the cheap 762 mm narrow gauge and worked by steam. It opened in stages through 1897: the Takasaki–Fukushima section (Fukushima is the present-day Jōshū-Fukushima) on 10 May, Fukushima–Nanjai on 7 July, and the final Nanjai–Shimonita section on 10 September, completing the 33.7 km route. Mixed passenger-and-goods trains worked the whole line in about two and a half hours. The line was formally designated a light railway under the Light Railway Act on 16 February 1911.

As traffic grew, the narrow-gauge light-railway standard became a constraint, and the company decided to regauge the whole line to 1,067 mm and electrify it at 1,500 V DC. In connection with a contemporary plan to extend the line along the Chikuma River to Nakagomi in Nagano Prefecture, the company was renamed Jōshin Electric Railway (then written 上信電気鉄道, Jōshin Denki Tetsudō) on 25 August 1921. The extension was never built, but the conversion went ahead: the Takasaki–Jōshū-Tomioka section was regauged and electrified on 3 October 1924 and the Jōshū-Tomioka–Shimonita section on 25 December 1924. Electric multiple units replaced the steam-hauled mixed trains for passengers and electric locomotives took over freight, cutting the end-to-end passenger journey to around an hour. The company adopted its present name, 上信電鉄 (Jōshin Dentetsu), on 11 May 1964.

In the post-war decades the line modernised its operations and adjusted its services. The block system was upgraded over the years, automatic block signalling and automatic signals were introduced in 1973, and a timetable revision on 25 November 1981 added express and semi-express trains on top of the existing rapid services. That push for faster running was checked by a serious accident: on 21 December 1984 a down train whose driver had fallen asleep collided head-on with an up train near the Akazu signal box between Sendaira and Shimonita, killing the up train's driver and injuring 125 people. After the accident the company introduced an automatic train stop (ATS) system on 25 December 1985 and shifted its emphasis from speed toward convenience.

From the 1990s the line's role narrowed toward local service. Express trains were discontinued in 1992, freight operations ended on 1 October 1994, and on 1 October 1996 the semi-express category was abolished and one-man operation introduced. Rather than chasing shorter journey times, the operator concentrated on stimulating demand by opening new stations and adding stops — Higashi-Tomioka in 1990, Takasaki-Shōka-Daigakumae in 2002, and Sanonowatashi, the line's newest station, on 22 December 2014.

Today the Jōshin Line remains a lifeline for western Gunma and a modest tourist route. Although ridership has trended downward in recent years, the 2014 inscription of the Tomioka Silk Mill and related sites as a World Heritage Site brought renewed attention to the line, whose Jōshū-Tomioka station is the gateway to the mill. The railway also markets itself through special services, including charter trains and a heritage electric locomotive, the DeKi 1 class supplied by Siemens of Germany for the 1924 electrification, which still occasionally hauls works and event trains.

• 1871The government opens the Tomioka Silk Mill, spurring momentum for modern transport in the district the line would later serve.
• 189413 September: a provisional licence for a Takasaki–Shimonita line is granted to the Kōzuke Railway (上野鉄道), promoted by Ozawa Takeo.
• 1895The Kōzuke Railway is established by local promoters; on 27 December the full licence is granted.
• 1897The line opens in stages as a 762 mm gauge, steam-hauled railway: Takasaki–Fukushima (now Jōshū-Fukushima) on 10 May, Fukushima–Nanjai on 7 July, and Nanjai–Shimonita on 10 September, completing the 33.7 km route.
• 191116 February: the line is designated a light railway under the Light Railway Act.
• 192125 August: in connection with a planned extension to Nakagomi in Nagano, the company is renamed Jōshin Electric Railway (上信電気鉄道, Jōshin Denki Tetsudō).
• 1924The line is regauged to 1,067 mm and electrified at 1,500 V DC: Takasaki–Jōshū-Tomioka on 3 October and Jōshū-Tomioka–Shimonita on 25 December; EMUs and electric locomotives replace steam-hauled mixed trains.
• 196411 May: the company adopts its present name, Jōshin Electric Railway (上信電鉄, Jōshin Dentetsu).
• 197328 December: automatic block signalling and automatic signals are introduced, and the Sano signal box is opened.
• 198125 November: a timetable revision introduces express and semi-express trains in addition to the existing rapid services.
• 198421 December: near the Akazu signal box between Sendaira and Shimonita, a down train whose driver had fallen asleep collides head-on with an up train, killing the up train's driver and injuring 125 people.
• 198525 December: an automatic train stop (ATS) system is introduced across the line.
• 199215 July: express trains are discontinued.
• 19941 October: freight operations on the line are discontinued.
• 19961 October: the semi-express category is abolished and one-man (driver-only) operation begins.
• 201422 December: Sanonowatashi Station, the line's newest station, opens; the same year, the Tomioka Silk Mill (served by Jōshū-Tomioka) is inscribed as a World Heritage Site.