東急新横浜線

Overview

The Tokyu Shin-yokohama Line (SH) runs 5.8 km from Shin-yokohama through Shin-tsunashima to Hiyoshi, three stations in all. It opened on 18 March 2023 and is almost entirely underground, with no level crossings; it only comes into the open on the approach to Hiyoshi.

It was never meant to be used on its own. It is Tokyu's half of the Sotetsu–Tokyu link (相鉄・東急直通線), and it opened on the same day as Sotetsu's extension to Shin-yokohama. Trains come off Sotetsu's lines at Shin-yokohama and carry on at Hiyoshi onto the Toyoko Line towards Shibuya or the Meguro Line towards Meguro. It was the first time in the Kanto region that the lines of two different major private railways had been joined directly, without a subway in between. The 東急 is part of the official name, because Sotetsu's half is also called the Shin-yokohama Line.

Along the route

Shin-yokohama grew up around the Tokaido Shinkansen station that opened among farmland in 1964. From the platforms that Sotetsu and Tokyu share, trains head north into the 3.3 km Shin-yokohama Tunnel, as much as 57 m below the surface, which passes under the Tsurumi River and directly beneath the Toyoko Line near Okurayama.

Shin-tsunashima's platform is 34.9 m down, about five floors below ground, because the line has only just come up from under the river. The station stands on the site of a radium hot-spring bath house whose forerunner was run by the company that built the Toyoko Line: Tsunashima was once a spa town, and before that a peach-growing district. The name won a public vote in 2020, ahead of the write-in "Tsunashima Onsen" and 東綱島. The Toyoko Line's Tsunashima station is only about 200 m away, but the two are separate stations with no transfer between them.

From there a single-track tunnel climbs at up to 37 per mille, steeper than the 35 ‰ that Japan's railway technical standards normally allow, and comes into the open beside the Toyoko Line's viaduct. The line ends at Hiyoshi, the semi-underground station it shares with the Toyoko and Meguro lines.

Why play it

Three stations and 34 keystrokes make this one of the shortest runs you can pick, so a couple of letters decide it. The first two names both begin with 新, and they treat the ん differently. 新横浜 is shinnyokohama: before よ the ん takes a doubled n, and a single n followed by y is refused. 新綱島 is shintsunashima, where one n will do before つ. A doubled n is always accepted for ん, so typing the second name like the first costs nothing, but typing the first like the second leaves you stuck on the y. 日吉, hiyoshi, then finishes the run in seven keys.

In Kanji mode, remember that 新綱島 has only existed since 2023. If your IME doesn't know it as one word, convert 新 and 綱島 separately and commit them in order, since the board accepts a name committed piece by piece. Leave out the 新, though, and 綱島, the Toyoko Line's station, is refused outright.