The is a 18.713 km long undersea railway tunnel under the

Kanmon Straits The or the Straits of Shimonoseki is the stretch of water separating Honshu and Kyushu, two of Japan's four main islands. On the Honshu side of the strait is Shimonoseki (, which contributed "Kan" () to the name of the strait) and on the Kyushu ...

connecting Shin-Shimonoseki Station and

Kokura Station in Kokurakita-ku is the main railway station in Kitakyushu, Japan. It is part of the JR Kyushu network and the San'yō Shinkansen stops here. It is the second largest station in Kyushu with 120,000 users daily. In the late 1990s, the Kokura st ...

. At the time of opening in March of 1975, it was the longest railway tunnel in Japan before being overtaken by in 1988 the opening of the

Seikan Tunnel The Seikan Tunnel ( ja, 青函トンネル, or , ), is a dual-gauge railway tunnel in Japan, with a portion under the seabed of the Tsugaru Strait, which separates Aomori Prefecture on the main Japanese island of Honshu from the northern isl ...

. It is also the longest tunnel section in the entire

Sanyo Shinkansen , stylized as SANYO, is a Japanese electronics company and formerly a member of the ''Fortune'' Global 500 whose headquarters was located in Moriguchi, Osaka prefecture, Japan. Sanyo had over 230 subsidiaries and affiliates, and was founded by ...

and

Tokaido Shinkansen The is a Japanese high-speed rail line that is part of the nationwide Shinkansen network. Along with the Sanyo Shinkansen, it forms a continuous high-speed railway through the Taiheiyō Belt, also known as the Tokaido corridor. Opened in 196 ...

line.

Overview

* Starting point: Ichinomiya Gakuencho, Shimonoseki City,

Yamaguchi Prefecture is a prefecture of Japan located in the Chūgoku region of Honshu. Yamaguchi Prefecture has a population of 1,377,631 (1 February 2018) and has a geographic area of 6,112 km2 (2,359 sq mi). Yamaguchi Prefecture borders Shimane Prefecture t ...

* End point: 2-chome, Shimotomino,

Kokurakita-ku, Kitakyūshū is a ward of Kitakyūshū, Fukuoka, Japan. It is the north part of what used to be Kokura City before the merger of five cities to create the new city of Kitakyūshū in 1963. JR Kyūshū's Kokura Station is the main rail hub of Kitakyūshū, ...

Fukuoka is the sixth-largest city in Japan, the second-largest port city after Yokohama, and the capital city of Fukuoka Prefecture, Japan. The city is built along the shores of Hakata Bay, and has been a center of international commerce since anc ...

* Overall Length: * Undersea bed section: * Below sea level section: * Tunnel gradient: 18/1000 *

Track gauge In rail transport, track gauge (in American English, alternatively track gage) is the distance between the two rails of a railway track. All vehicles on a rail network must have wheelsets that are compatible with the track gauge. Since many ...

: 1,435 mm * Electrification: 25 kV AC, 60 Hz,

overhead catenary An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as: * Overhead catenary * Overhead contact system (OCS) * Overhead equipmen ...

The construction of the new tunnel started as a project to connect

Honshu , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island se ...

and Kyushu with a high-speed railway. The tunnel was constructed at the shortest section in the Kanmon Strait between Dannoura, Shimonoseki City - Mekari, Mojiku, Kitakyushu. Although the entire Shin-Kanmon Tunnel is 5 times longer, the undersea section is shorter than conventional line Kanmon Tunnel (Kanmon Tunnel undersea bed section is long). There is a distance marker about from the middle point of the tunnel. This is the only 1000 km railway marker in Japan.

Coordinates

* Shimonoseki entrance: * Moji entrance:

References

{{Tunnel-stub Railway tunnels in Japan Undersea tunnels in Asia West Japan Railway Company Sanyō Shinkansen