Seikan Tunnel 青函トンネル Seikan Tonneru or 青函隧道 Seikan Zuidō
Map of the Seikan Tunnel.
Info
Location	Beneath the Tsugaru Strait)
Coordinates	41°11′36″N 140°09′09″E / 41.1932, 140.1525Coordinates: 41°11′36″N 140°09′09″E / 41.1932, 140.1525
Status	Active
Start	Honshū
End	Hokkaidō
Operation
Opened	13 March 1988
Owner	Japan Railways (Hokkaido Railway Company)
Operator(s)	Hokkaido Railway Company
Technical
Track length	53.85 km (23.3 km undersea)
Electrified	Yes

The Seikan Tunnel (青函トンネル Seikan Tonneru or 青函隧道 Seikan Zuidō) is a 53.85 km (33.49 mile) railway tunnel in Japan, with a 23.3 km (14.5 mile) portion under the seabed. It travels beneath the Tsugaru Strait — connecting Aomori Prefecture on the Japanese island of Honshū and the island of Hokkaidō — as part of the Japan Railways Kaikyo Line. Although it is the longest traffic (railway or road) tunnel in the world, faster and cheaper air travel has left the Seikan Tunnel comparatively underused. Its claim to the record will be taken when the Gotthard Base Tunnel, another railroad tunnel, is completed around 2017. Image File history File links Seikantunnel_-_Tsugaru_street_detail. ... Tsugaru Peninsula and Tsugaru Strait Tsugaru Strait (津軽海峡 Tsugaru Kaikyō) is a channel between HonshÅ« and Hokkaidō in northern Japan connecting the Sea of Japan with the Pacific Ocean. ... Map of Earth showing lines of latitude (horizontally) and longitude (vertically), Eckert VI projection; large version (pdf, 1. ... Map of Earth showing lines of latitude (horizontally) and longitude (vertically), Eckert VI projection; large version (pdf, 1. ... Image File history File links Flag_of_Japan. ... This article does not cite any references or sources. ... Image File history File links Flag_of_Japan. ...   literally North Sea Circuit, Ainu: Mosir), formerly known as Ezo, Yezo, Yeso, or Yesso, is Japans second largest island and the largest of its 47 prefectural-level subdivisions. ... is the 72nd day of the year (73rd in leap years) in the Gregorian calendar. ... Year 1988 (MCMLXXXVIII) was a leap year starting on Friday (link displays 1988 Gregorian calendar). ... Japan Railway, more commonly called JR, is a collective term for the privatized descendants of the former Japanese National Railways, formed when JNR was divided into seven parts on April 1, 1987. ... The Hokkaido Railway Company (北海道旅客鉄道 Hokkaidō Ryokaku Tetsudō) is one of the constituent companies of Japan Railway. ... The Hokkaido Railway Company (北海道旅客鉄道 Hokkaidō Ryokaku Tetsudō) is one of the constituent companies of Japan Railway. ... A disused railway tunnel now converted to pedestrian and bicycle use, near Houyet, Belgium A tunnel is an underground passage. ... Tsugaru Peninsula and Tsugaru Strait Tsugaru Strait (津軽海峡 Tsugaru Kaikyō) is a channel between HonshÅ« and Hokkaidō in northern Japan connecting the Sea of Japan with the Pacific Ocean. ... Aomori Prefecture (青森県 Aomoriken or frequently Aomori-ken) is located in the Tōhoku Region of Japan. ... This article does not cite any references or sources. ...   literally North Sea Circuit, Ainu: Mosir), formerly known as Ezo, Yezo, Yeso, or Yesso, is Japans second largest island and the largest of its 47 prefectural-level subdivisions. ... Japan Railway, more commonly called JR, is a collective term for the privatized descendants of the former Japanese National Railways, formed when JNR was divided into seven parts on April 1, 1987. ... Kaikyo Line(海峡線) is a 87. ... The new Gotthard Base Tunnel together with the Zimmerberg Base tunnel form the northern part of the Gotthard axis of the Alptransit project (yellow: major tunnels, red: existing main tracks, numbers: year of completion). ...

History

Connecting the islands of Honshū and Hokkaidō by a land route had been considered since the Taishō period (1912-1925), but serious survey only commenced in 1946, due to the loss of overseas territory at the end of World War II and the need to accommodate returnees. In 1954, five ferries, including the Toya Maru, sank in the Tsugaru Strait during a typhoon, killing 1,430 passengers. The following year the Japanese National Railways (JNR) expedited the tunnel investigation.^[1] is the 114th day of the year (115th in leap years) in the Gregorian calendar. ... Year 1946 (MCMXLVI) was a common year starting on Tuesday (link will display full 1946 calendar) of the Gregorian calendar. ... is the 269th day of the year (270th in leap years) in the Gregorian calendar. ... Year 1954 (MCMLIV) was a common year (link will display full calendar) of the Gregorian calendar. ... This page meets Wikipedias criteria for speedy deletion. ... is the 82nd day of the year (83rd in leap years) in the Gregorian calendar. ... Also Nintendo emulator: 1964 (emulator). ... is the 271st day of the year (272nd in leap years) in the Gregorian calendar. ... Year 1971 (MCMLXXI) was a common year starting on Friday (link will display full calendar) of the 1971 Gregorian calendar. ... is the 27th day of the year in the Gregorian calendar. ... Year 1983 (MCMLXXXIII) was a common year starting on Saturday (link displays the 1983 Gregorian calendar). ... March 10 is the 69th day of the year (70th in leap years) in the Gregorian calendar. ... This article is about the year. ... is the 72nd day of the year (73rd in leap years) in the Gregorian calendar. ... Year 1988 (MCMLXXXVIII) was a leap year starting on Friday (link displays 1988 Gregorian calendar). ... This article does not cite any references or sources. ...   literally North Sea Circuit, Ainu: Mosir), formerly known as Ezo, Yezo, Yeso, or Yesso, is Japans second largest island and the largest of its 47 prefectural-level subdivisions. ... The Taishō period (Japanese: 大正時代, Taishō-jidai, period of great righteousness) is a period in the history of Japan dating from 30 July 1912 to 25 December 1926. ... This page meets Wikipedias criteria for speedy deletion. ... Japanese National Railways (日本国有鉄道 Nippon Kokuyū Tetsudō), abbreviated Kokutetsu (国鉄) or JNR, was the national railway network of Japan from 1872 to 1987. ...

Also of concern was the increasing traffic between the two islands. A booming economy saw traffic levels on the JNR-operated Seikan (a contraction of principal cities Aomori and Hakodate^[2]) Ferry doubled to 4,040,000 persons/year from 1955 to 1965, and cargo levels rose 1.7 times to 6,240,000 tonnes/year. In 1971, traffic forecasts predicted increasing growth that would outstrip the ability of the ferry pier facility, which was constrained by geographical conditions. In September 1971, the decision was made to commence work on the tunnel. A Shinkansen-capable cross section was selected, with plans to extend the Shinkansen network.^[1] Aomori (Japanese: ; Aomori-shi) is the capital city of Aomori Prefecture (青森県; Aomori-ken), the north end of Honshū. The city faces Mutsu Bay connecting Tsugaru Channel and the Hakkoda Mountains lie in the southern part of Aomori. ... Hakodate ) is a city and port located in Oshima, Hokkaidō, Japan. ... For the record label, see Shinkansen Records. ...

Arduous construction in difficult geological conditions proceeded. 34 workers were killed during construction.^[3]

On January 27, 1983, Japanese Prime Minister Yasuhiro Nakasone pressed a switch that set off a blast that completed the pilot tunnel. Similarly on March 10, 1985, Minister of Transport Tokuo Yamashita symbolically holed through the main tunnel.^[1] is the 27th day of the year in the Gregorian calendar. ... Year 1983 (MCMLXXXIII) was a common year starting on Saturday (link displays the 1983 Gregorian calendar). ... Yasuhiro Nakasone (中曽根 康弘 Nakasone Yasuhiro, b. ... March 10 is the 69th day of the year (70th in leap years) in the Gregorian calendar. ... This article is about the year. ...

However, the project's success was questioned. The 1971 traffic predictions were overestimates. Instead of the traffic rate increasing to 1985, it peaked in 1978 and then proceeded to decrease — attributed to the slowdown in Japan's economy since the first oil crisis in 1973 and to advances made in air transport facilities and longer-range sea transport.^[4]

Commemorative 500 yen coin

The tunnel was opened on March 13, 1988, at a cost of 538.4 billion yen (US$3.6 billion).^[5] Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Japanese 10 yen coin (obverse) showing Phoenix Hall of Byodoin Yen is the currency used in Japan. ... is the 72nd day of the year (73rd in leap years) in the Gregorian calendar. ... Year 1988 (MCMLXXXVIII) was a leap year starting on Friday (link displays 1988 Gregorian calendar). ...

Once the tunnel was completed, all railway transport between Honshū and Hokkaidō utilised the tunnel. However, for passenger transport, 90% of people use air due to the speed and cost. For example, to travel between Tokyo and Sapporo by train takes more than 10 hours and 30 minutes, with several transfers. By air, the journey is 3 hours and 30 minutes, including airport access times. Deregulation and competition in Japanese domestic air travel has brought down prices on the Tokyo-Sapporo route, making rail more expensive in comparison.^[6] However, the Hokutosei overnight train service, which began service after the completion of the Seikan Tunnel, is still popular among travellers. The newer and more luxurious Cassiopea overnight train service is frequently fully booked. For other uses, see Tokyo (disambiguation). ... Sapporo redirects here. ... The Hokutosei (北斗星) is an overnight train service in Japan operated by Japan Railways. ... Tail end of Cassiopeia The Cassiopeia (カシオペア) is considered to be the most luxurious overnight train service in Japan. ...

Surveying, construction and geology

Typical tunnel cross section. (1) Main tunnel, (2) service tunnel, (3) pilot tunnel, (4) connecting gallery.

In-train display showing progress through tunnel

Surveying started in 1946. In 1971, 25 years later, construction began. In August 1982, less than 700 m remained to be excavated. First contact between the two sides was in 1983.^[5] Image File history File links Seikan_Tunnel_3d_cross_section_1a. ... Image File history File links Seikan_Tunnel_3d_cross_section_1a. ... Image File history File links Download high resolution version (2833x1583, 384 KB) Summary Taken using Olympus Trip camera October 1994 by Alex Sims in southbound train in Seikan Tunnel near the deepest point of the tunnel. ... Image File history File links Download high resolution version (2833x1583, 384 KB) Summary Taken using Olympus Trip camera October 1994 by Alex Sims in southbound train in Seikan Tunnel near the deepest point of the tunnel. ... Year 1983 (MCMLXXXIII) was a common year starting on Saturday (link displays the 1983 Gregorian calendar). ...

The Tsugaru Strait has eastern and western necks, both approximately 20 km across. Initial surveys undertaken in 1946 indicated that the eastern neck was up to 200 m deep with volcanic geology. The western neck had a maximum depth of 140 m and geology consisting mostly of sedimentary rocks of the Neogene period. The western neck was selected, with its conditions considered favourable for tunnelling.^[7] Tsugaru Peninsula and Tsugaru Strait Tsugaru Strait (津軽海峡 Tsugaru Kaikyō) is a channel between Honshū and Hokkaidō in northern Japan connecting the Sea of Japan with the Pacific Ocean. ... Neogene Period is a unit of geologic time consisting of the Miocene, Pliocene, Pleistocene, and Holocene epochs. ...

Geology of the undersea portion of the tunnel consists of volcanic rock, pyroclastic rock, and sedimentary rock of the late Tertiary era.^[2] The area is folded into a nearly vertical anticline, which means that the youngest rock is in the centre of the Strait, and encountered last. Divided roughly into thirds, the Honshū side consists of volcanic rocks (andesite, basalt etc); the Hokkaidō side consists of sedimentary rocks (Tertiary period tuff, mudstone, etc); and the centre portion consists of Kuromatsunai strata (Tertiary period sand-like mudstone).^[8] Igneous intrusions and faults caused crushing of the rock and complicated the tunnelling procedures.^[7] Pyroclastic rocks or pyroclastics (derived from the Greek πῦρ, meaning fire, and κλαστός, meaning broken) are debris thrown from volcanoes during an eruption. ... Tertiary geological time interval covers roughly the time span between the demise of the non-avian dinosaurs and beginning of the most recent Ice Age, approximately 65 million to 1. ... Anticline with syncline visible at far right- USGS In structural geology, an anticline is a Fold (geology) that is convex to the youngest beds—youngest sediments are on back of hand, older under the palm. ... The Tertiary period is one of the major divisions of the geologic timescale, from the end of the Cretaceous period about 64 million years ago to the start of the Quaternary period about 1. ... Welded tuff at Golden Gate in Yellowstone National Park Tuff (from the Italian tufo) is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. ... Mudstone is a fine-grained sedimentary rock whose original constituents were clays or muds. ... For other uses, see strata (novel) and strata title. ...

Initial geological investigation occurred from 1946 to 1963, and involved: drilling the sea-bed, sonic surveys, submarine boring, observations using a mini-submarine, and seismic and magnetic surveys. However, to establish a greater understanding, horizontal pilot boring was undertaken, in both the service and pilot tunnels.^[7] Illustration of echo sounding. ...

Tunnelling occurred simultaneously from both the northern and southern ends. The dry land portions were tackled with traditional mountain tunnelling techniques, with a single main tunnel.^[7] However, for the 23.3 km undersea portion, three bores were excavated with increasing diameters respectively: an initial pilot tunnel, a service tunnel, and finally the main tunnel. The service tunnel was periodically connected to the main tunnel with a series of connecting shafts, at 600 to 1,000 m intervals.^[8] The pilot tunnel served as the service tunnel for the 5 km centre portion.^[7]

Beneath the Tsugaru Strait, the use of a tunnel boring machine (TBM) was abandoned after less than 2 km due to the variable nature of the rock and difficulty in accessing the face for advanced grouting.^[2][7] Blasting with dynamite and mechanical picking were then used to excavate. A tunnel boring machine that was used at Yucca Mountain. ...

Maintenance

A 2002 report by Michitsugu Ikuma described, for the undersea section, that "the tunnel structure appears to remain in a good condition".^[9] The amount of inflow has been decreasing with time, although it "increases right after a large earthquake".^[9]

Structure

Currently, only narrow gauge track is laid through the twin tunnels, but the Hokkaidō Shinkansen project (which started construction in 2005) will include laying dual-gauge track and linking the tunnel into the Shinkansen network, so Shinkansen trains can traverse the tunnel to Hakodate (scheduled for 2015) and eventually Sapporo. The tunnel has 52 km of continuous welded rail.^[10] The Hokkaido Shinkansen (北海道新幹線) is a high-speed rail line currently under construction between Aomori (HonshÅ«) and Hokkaido through the Seikan Tunnel. ... Sunlight reflects off dual-gauge tracks near Chur, Switzerland Mixed-gauge track and pointwork (4 ft 8½ in (1435 mm) and 3 ft 6 in (1067 mm)) at Odawara in Japan Dual-gauge tram tracks in Katwijk, The Netherlands Dual-gauge or mixed-gauge railway is a special configuration of... For the record label, see Shinkansen Records. ... View of Hakodate from Mountain Hakodate (函館市; -shi) is a city and port located in Oshima, Hokkaido, Japan. ... Sapporo redirects here. ... Rail tracks. ...

Two stations are located within the tunnel: Tappi-Kaitei Station and Yoshioka-Kaitei Station. The stations serve as emergency escape points. In the event of a fire or other disaster the stations provide equivalent safety of a much shorter tunnel. The effectiveness of the escape shafts located at the emergency stations is enhanced by exhaust fans to extract smoke, television cameras to route passengers to safety, thermal (infrared) fire alarm systems and water spray nozzles.^[5] Previously, both the stations contained museums detailing the history and function of the tunnel, and could be visited on special sightseeing tours. Now only Tappi-Kaitei remains as a museum, Yoshioka-Kaitei was demolished on March 16, 2006 to make way for Hokkaidō Shinkansen preparations.^[11] The two stations were the first train stations in the world built under the sea. Map showing the Seikan Tunnel and the two underground stations Tappi-Kaitei Station ) is a train station within the Seikan Tunnel on the Kaikyo Line in Sotogahama, Aomori, Japan. ... View of Yoshioka-Kaitei Station Yoshioka-Kaitei Station ) is a train station within the Seikan Tunnel on the Kaikyo Line in Fukushima, Hokkaido, Japan. ... March 16 is the 75th day of the year (76th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... The Hokkaido Shinkansen (北海道新幹線) is a high-speed rail line currently under construction between Aomori (HonshÅ«) and Hokkaido through the Seikan Tunnel. ...

See also

• Channel Tunnel, an undersea railway tunnel connecting Great Britain and France.
• Seikan Tunnel Tappi Shako Line

The British terminal at Cheriton in west Folkestone, from the Pilgrims Way. ... The Seikan Tunnel Tappi Shakō Line , Seikan Tunnel Tappi Inclined Passage Line) is Japanese funicular line in Sotogahama, Aomori, operated by Seikan Tunnel Museum. ...

References

Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 128th day of the year (129th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 144th day of the year (145th in leap years) in the Gregorian calendar. ...

External links

Wikimedia Commons has media related to:

Seikan Tunnel

• Aomori Prefecture Government site about Hokkaidō shinkansen