大井町線

Overview

The Tokyu Oimachi Line (OM) runs 16 stations from Oimachi to Mizonokuchi, 12.4 km across the south-western wards of Tokyo and over the Tama River into Kawasaki. Most of Tokyu's lines fan out from the city centre like spokes; this one cuts across them, and that is its whole purpose. At Hatanodai it meets the Ikegami Line, at Ookayama the Meguro Line, at Jiyugaoka the Toyoko Line, and at Futako-tamagawa and Mizonokuchi the Den-en-toshi Line.

The Meguro-Kamata Electric Railway, Tokyu's predecessor, opened the first section between Oimachi and Ookayama on 6 July 1927, and the line reached Futako-tamagawa at the end of 1929. From 1963 to 1979 it did not even have its own name: it was part of the Den-en-toshi Line, and became the Oimachi Line again only when Den-en-toshi trains started running through to Shibuya instead. Rebuilt as a bypass to take pressure off the crowded Den-en-toshi Line, it gained express trains in 2008, and since July 2009 its trains have continued past Futako-tamagawa to Mizonokuchi.

That last 2.0 km is the reason the station count needs a note. Beyond Futako-tamagawa the Oimachi trains use the inner pair of the Den-en-toshi Line's four tracks, and the two stations in between, Futako-shinchi and Takatsu, have platforms only on the outer pair. Tokyu numbers Mizonokuchi OM16 but gives those two only Den-en-toshi numbers, so the run here follows Tokyu and goes straight from Futako-tamagawa to Mizonokuchi.

Along the route

Oimachi is a terminus beside the JR and Rinkai Line stations, and the line leaves it westward on a viaduct. At the west end of Shimo-shimmei the tracks form the middle layer of a three-level crossing, with JR's Hinkaku Line — Yokosuka Line and Shonan-Shinjuku trains — below and the Tokaido Shinkansen overhead. Togoshi-koen and Nakanobu follow, where Toei's Asakusa Line runs beneath the main road, and then Hatanodai, where the Ikegami Line passes underneath.

Ookayama is the only underground station on the line, built so that Oimachi and Meguro Line trains stop on either side of the same platform. The Institute of Science Tokyo, formerly the Tokyo Institute of Technology, starts right outside. Midorigaoka comes next, then Jiyugaoka, where the line ducks under the Toyoko Line. Kuhombutsu is named after the nine Amida Buddha statues at Joshin-ji temple north of the station; its platform is boxed in by level crossings, so on the five-car local trains one car's doors stay shut. Todoroki is the stop for the Todoroki Valley, a wooded ravine that is often called the only valley in Tokyo's 23 wards, and Kaminoge sits in a cutting below Kanpachi-dori, a short walk from the Gotoh Museum. Then the line climbs onto a viaduct into Futako-tamagawa and crosses the Tama River into Kawasaki.

Why play it

Sixteen stations with no long names, but hardly a plain reading in them. 等々力 is とどろき, and the 々 means nothing to the reading. 上野毛 is かみのげ, 九品仏 is くほんぶつ, and 北千束 ends in せんぞく. 大岡山 has three o's in a row (おおおかやま), which is easy to cut to two. 荏原町 ends in まち, 下神明 is しもしんめい, and 二子玉川 starts with ふたこ, not ふたご.

Tokyu's English signs follow Hepburn, so the board shows Shimo-shimmei and Kuhombutsu while you type n for the ん in both. In Kanji mode, Midorigaoka and Jiyugaoka come back to back, both written with a hiragana が, and 旗の台 and 溝の口 use a hiragana の. The finish is the trap: JR's station next door is 武蔵溝ノ口 with a katakana ノ, and an IME that has learned one will happily offer it for the other.