# Ōimachi Line

The Ōimachi Line (大井町線, Ōimachi-sen) is a railway line in Japan operated by the private railway operator Tokyu Corporation. It extends from Ōimachi in Shinagawa, Tokyo to Mizonokuchi in Kawasaki, Kanagawa.

## Stations

All-stations "Local" services are classified as blue and green. The latter runs on the express track between Futako-Tamagawa and Mizonokuchi and does not stop at Futako-Shinchi or Takatsu. Limited-stop "Express" services are also provided.
On weekends, two seven-car express trains per days are operated to/from Ōimachi and Nagatsuta on the Tokyu Den-en-toshi Line. Also, a few trains are operated through down to Saginuma in the late evenings. A few express trains during the holidays also serve from Chūō-Rinkan in the mornings, down in the evenings.
| No. | Station | Japanese | Distance (km) | Stops | Stops | Stops | Transfers | Location | Location |
| No. | Station | Japanese | Distance (km) | "Blue" Local | "Green" Local | Express | Transfers | Location | Location |
| OM01 | Ōimachi | 大井町 | 0.0 | ● | ● | ● | JK Keihin-Tohoku Line (JK19) R Rinkai Line (R07) | Shinagawa | Tokyo |
| OM02 | Shimo-shimmei | 下神明 | 0.8 | ● | ● | | | | Shinagawa | Tokyo |
| OM03 | Togoshi-kōen | 戸越公園 | 1.5 | ● | ● | | | | Shinagawa | Tokyo |
| OM04 | Nakanobu | 中延 | 2.1 | ● | ● | | | A Toei Asakusa Line (A03) | Shinagawa | Tokyo |
| OM05 | Ebaramachi | 荏原町 | 2.7 | ● | ● | | | | Shinagawa | Tokyo |
| OM06 | Hatanodai | 旗の台 | 3.2 | ● | ● | ● | IK Tokyu Ikegami Line (IK05) | Shinagawa | Tokyo |
| OM07 | Kita-senzoku | 北千束 | 4.0 | ● | ● | | | | Ōta | Tokyo |
| OM08 | Ōokayama | 大岡山 | 4.8 | ● | ● | ● | MG Tokyu Meguro Line (MG06) | Meguro | Tokyo |
| OM09 | Midorigaoka | 緑が丘 | 5.3 | ● | ● | | | | Meguro | Tokyo |
| OM10 | Jiyūgaoka | 自由が丘 | 6.3 | ● | ● | ● | TY Tokyu Toyoko Line (TY07) | Meguro | Tokyo |
| OM11 | Kuhombutsu | 九品仏 | 7.1 | ● | ● | | | | Setagaya | Tokyo |
| OM12 | Oyamadai | 尾山台 | 7.8 | ● | ● | | | | Setagaya | Tokyo |
| OM13 | Todoroki | 等々力 | 8.3 | ● | ● | | | | Setagaya | Tokyo |
| OM14 | Kaminoge | 上野毛 | 9.2 | ● | ● | | | | Setagaya | Tokyo |
| OM15 | Futako-tamagawa | 二子玉川 | 10.4 | ● | ● | ● | DT Tokyu Den-en-toshi Line (DT07) | Setagaya | Tokyo |
| DT08 | Futako-shinchi | 二子新地 | 11.1 | ● | | | | | DT Tokyu Den-en-toshi Line (DT08) | Takatsu-ku, Kawasaki | Kanagawa |
| DT09 | Takatsu | 高津 | 11.7 | ● | | | | | DT Tokyu Den-en-toshi Line (DT09) | Takatsu-ku, Kawasaki | Kanagawa |
| OM16 | Mizonokuchi | 溝の口 | 12.4 | ● | ● | ● | DT Tokyu Den-en-toshi Line (Limited through service) (DT10) JN Nambu Line (Musashi-Mizonokuchi Station, JN10) | Takatsu-ku, Kawasaki | Kanagawa |
| ↓ Limited through services into the Den-en-toshi Line. "Blue" local trains for Saginuma; Express trains for Chūō-rinkan ↓ ||||||||||

## Rolling stock
### Local services

* 9000 series five-car EMUs
* 9020 series five-car EMUs
* A 9000 series EMU in December 2021
* A 9020 series EMU in December 2021

### Express services

* 6000 series seven-car EMUs (since March 2008, originally delivered as six-car sets)
* 6020 series seven-car EMUs (from March 2018)
* A 6000 series EMU in March 2018
* A 6020 series EMU in December 2018

### Former rolling stock

* 8000 series
* 8090 series
* 8590 series
* 8500 series

## History

* 6 July 1927: The section between Ōimachi and Ōokayama was opened by the Meguro-Kamata Electric Railway (目黒蒲田電鉄).
* 1 November 1929: The section between Jiyūgaoka and Futako-tamagawa was opened by the Meguro-Kamata Electric Railway.
* 25 December 1929: The section between Ōokayama and Jiyūgaoka was opened by Meguro-Kamata Electric Railway.
* 29 June 1938: The Meguro-Kamata Railway was absorbed into the Tokyo-Yokohama Electric Railway (東京横浜電鉄).
* 15 January 1958: Electric supply was raised to 1,500 V DC.
* 11 October 1963: The line was renamed the Den-en-toshi Line, together with the section south of Futako-tamagawa.
* 16 November 1977: Through running started between Shibuya and Nagatsuta.
* 12 August 1979: The line was renamed the Ōimachi Line and separated from the Den-en-toshi Line south of Futako-tamagawa.
* 23 February 2008: ATS was replaced by ATC.
* 28 March 2008: Express services started.
* 11 July 2009: The Ōimachi Line was extended to Mizonokuchi from Futako-tamagawa.
Express services on the line were lengthened from six to seven cars in late fiscal 2017, and the platforms at Ōimachi, Hatanodai, and Jiyūgaoka were lengthened to handle the longer trains. Since December 2018, "Q Seat" reserved seating has been implemented on some express services that run between Ōimachi and Nagatsuta stations.