Shin-Kanmon Tunnel

33°57′57.4″N 130°57′47.2″E The Shin-Kanmon Tunnel (新関門トンネル, shin-kanmon tonneru) is a 18.713-kilometre (11.628 mi) long undersea railway tunnel under the Kanmon Straits connecting Shin-Shimonoseki Station and Kokura Station.^[1]

Shin-Kanmon Tunnel

Tunnel entrance
Overview
Line	Sanyō Shinkansen
Location	Honshu–Kyushu
Operation
Opened	March 10, 1975
Owner	JR West
Operator	JR West
Character	Passenger
Technical
Line length	18.713 km (11.628 mi)
No. of tracks	2
Track gauge	1,435 mm (4 ft 8+1⁄2 in)
Operating speed	300 km/h (185 mph)

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. It is also the longest tunnel section on the entire Sanyo/Tokaido Shinkansen line.

Overview

• Starting point: Ichinomiya Gakuencho, Shimonoseki City, Yamaguchi Prefecture
• End point: 2-chome, Shimotomino, Kokurakita-ku, Kitakyūshū, Fukuoka
• Overall length: 18,713 metres (11.628 mi)
• Undersea bed section: 880 metres (960 yd)
• Below sea level section: 66 metres (72 yd)
• Tunnel gradient: 18/1000
• Track gauge: 1,435 mm
• Electrification: 25 kV AC, 60 Hz, overhead catenary

The construction of the new tunnel started as a project to connect Honshu 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 1,140-metre (1,250 yd) long).

There is a 1,000 km (620 mi) distance marker about 1.8 km (1.1 mi) from the middle point of the tunnel. This is the only 1000 km railway marker in Japan.

Undersea Kanmon Tunnel between Honshu and Kyushu islands in Japan

Coordinates

• Shimonoseki entrance: 34°00′11″N 130°56′53″E
• Moji entrance: 33°52′58″N 130°53′55″E

References

1. 百科事典マイペディア,世界大百科事典内言及. "新関門トンネルとは". コトバンク (in Japanese). Retrieved 2021-08-12.