Tanimachi Line

The line was built and operated by the Osaka Municipal Transportation Bureau, the city's municipal subway authority, and opened in stages over sixteen years. The first section, between Higashi-Umeda and Tanimachi-yonchōme, opened on 24 March 1967, a distance of 3.5 km worked initially by two-car trains and equipped from the outset with automatic train control (ATC) and centralised traffic control (CTC). In its first months the line also hosted basic trials of automatic train operation (ATO), run on the northbound track between Tanimachi-yonchōme and Higashi-Umeda after the last service each night.

The railway then pushed south. On 17 December 1968 the Tanimachi-yonchōme–Tennōji section (3.8 km) opened, four-car operation began, and the Tennōji depot was established. The route was still identified only by its number at this point; the name "Tanimachi Line" was formally adopted on 6 December 1969. Construction of the line's planned extensions was overshadowed by tragedy on 8 April 1970, when a gas explosion at an extension work site near Tenjinbashi-suji rokuchōme — the Ten-roku gas explosion — caused a major fire and one of the worst accidents in the history of Japanese subway construction.

The northern half of the line was opened next. On 29 May 1974 the Miyakojima–Higashi-Umeda section (3.1 km) opened, and on 6 April 1977 the line was extended from Miyakojima to Moriguchi (5.4 km), at which point the line was worked as two overlapping services and a new depot at Dainichi took over stabling duties. Train lengths grew with demand: six-car operation began in October 1976.

The southern end was completed in 1980. On 27 November 1980 the Tennōji–Yaominami section opened, at 10.5 km the longest single extension in the line's history, carrying trains out to the southern suburbs in Yao and bringing a new depot at Yao into use. With the bulk of the route now in place, the line had taken on essentially its modern shape, lacking only a short link at its northern tip.

That final link came on 8 February 1983, when the access tracks to the Dainichi depot were upgraded to revenue service and the Dainichi–Moriguchi section (1.8 km) opened, completing the line through from Dainichi to Yaominami. With through running established end to end, service frequencies on the central and outer portions were tightened. Over the following decades the line was modernised steadily: new rolling stock arrived from 1989, the 1997 station renamings updated several stops, and women-only cars were introduced on weekday mornings in 2003.

The most significant institutional change came on 1 April 2018, when the Osaka municipal subway was corporatised and the Tanimachi Line — together with the rest of the network — passed from the Osaka Municipal Transportation Bureau to a new private company, Osaka Metro (Osaka City Transportation, K.K., trading as 大阪市高速電気軌道). Modernisation has continued under the new operator, with platform screen doors progressively installed across the line and new 30000A-series trains entering service in 2025; daytime headways on the line have been shortened to six minutes.

• 196724 March: the first section, Higashi-Umeda–Tanimachi-yonchōme (3.5 km), opens with two-car trains, ATC and centralised traffic control (CTC).
• 196817 December: the Tanimachi-yonchōme–Tennōji section (3.8 km) opens; four-car operation begins and the Tennōji depot opens.
• 19696 December: the name 'Tanimachi Line' is formally adopted (the line had until then been identified by its route number).
• 19708 April: a gas explosion at an extension work site near Tenjinbashi-suji rokuchōme (the Ten-roku gas explosion) causes a major fire, one of the worst accidents in Japanese subway-construction history.
• 197429 May: the Miyakojima–Higashi-Umeda section (3.1 km) opens.
• 1976October: six-car operation begins (started 25 October, completed 31 October).
• 19776 April: the line is extended from Miyakojima to Moriguchi (5.4 km); the new Dainichi depot takes over stabling and the line is worked as two overlapping services.
• 198027 November: the Tennōji–Yaominami section (10.5 km) opens — the longest single extension in the line's history; the Yao depot opens.
• 19838 February: the Dainichi–Moriguchi section (1.8 km) opens, completing the line from Dainichi to Yaominami; service frequencies on the central and outer sections are tightened.
• 198917 May: the second-generation Series 20 trains enter service.
• 199729 August: Sekime Station is renamed Sekime-takadono and Shitennōji-mae is renamed Shitennōji-mae-Yūhigaoka.
• 200315 December: women-only cars are introduced from the first weekday train until 09:00.
• 20181 April: with the corporatisation of the Osaka municipal subway, the line passes from the Osaka Municipal Transportation Bureau to the new private operator Osaka Metro (Osaka City Transportation, K.K. / 大阪市高速電気軌道).
• 20201 February: the line's first platform screen doors enter service, at Higashi-Umeda Station; daytime headways are later shortened to six minutes (14 March).
• 202524 October: the new 30000A-series trains enter service on the line.