Sangar Strait (Tsugaru) between the Japanese islands of Honshu and Hokkaido. The railway tunnel Seikan

The Sangar Strait, otherwise known as Tsugaru, is located between the Japanese islands of Honshu and Hokkaido. It connects the Sea of Japan and the Pacific, while under it is Seikan - a railway tunnel stretching from Aomori prefecture to the city of Hakodate.

Information about the Strait

The width of Tsugaru varies from 18 to 110 km, depending on the place of measurement, the length is 96 km. The depth of the navigable part depends on the time of the ebb and flow, therefore it can vary from 110 to almost 500 meters.

Its name was received in honor of the semi-island of Tsugaru, located at the northern extremity of Honshu. The same was so named from the ethnonym of the tribe who lived in the area.

Until the middle of the twentieth century. The official name was the Sangara Strait, since the first map with its image was drawn up by Admiral Kruzenshtern, who gave him exactly such a toponym.

Despite the abundance of anchorages, Tsugaru is well blown by the winds due to the lack of closed spaces. Both banks, adjacent to the strait, have an uneven terrain (mostly mountainous), covered with dense forest.

The closest cities to Tsugar are Aomori, located on the south side, and Hakodate on the island of Hokkaido (Japan). Also in relative proximity are Sapporo and Yubari.

The main course in Tsugaru is directed to the east, but it has the property to branch out and change the course of its movement, reaching a speed of about 6 km / h, while the tidal wave goes at a speed of 2 m / sec.

The regime of the Sangarska Strait

Prior to the Second World War, the passage of merchant and military vessels across the Sangarskiy Strait was free. Since up to that time no agreement had been concluded regulating the Tsugaru regime, the Land of the Rising Sun actively used this omission against the USSR. Thus, with the advent of World War II, Japan blocked access to the strait to all foreign ships, declaring it a defensive zone of the state.

For many years, Soviet courts have lost the opportunity to go a short way to the Pacific Ocean. This was of great importance, since the Sea of Japan (on the map it is easy to find) is closed and Tsugaru was the only strait connecting it with open waters.

Therefore, after the end of the war, together with the defeat of imperialism in the Land of the Rising Sun, the question of the mode of passage of ships was put differently. As a result, at the 1951 conference in San Francisco on a peace treaty with Japan, the Soviet Union put forward a proposal on the demilitarization of the strait and its opening to merchant ships of all countries and military transport of coastal states. However, the initiative of the Soviet Union was rejected, despite its prudence in terms of ensuring freedom and safety of navigation.

Today the Sangarsky Strait is a free zone for the passage of any ships, but its regime largely depends on the discretion of Japan and at any time it can change.

Tsugaru and the Sea of Japan

On the map this reservoir is located in the Pacific basin, separated from it by the islands of Japan and Sakhalin. Its area is 1.062 million square meters. Km.

In winter, the northern part of the water is icebound, and the only unfrozen section of the sea in this direction is the Tsugaru Strait. This makes it extremely demanded for merchant ships of coastal regions of Russia as the shortest route to the Pacific Ocean. In addition, Japan's current military policy has greatly reduced territorial waters - up to 3 nautical miles (instead of the prescribed 20) from the coast, so that the US Navy can freely pass through the Sangara Strait without violating the law prohibiting the presence of nuclear weapons in the Land of the Rising Sun.

The Sea of Japan, otherwise known as the Eastern Sea, is washed by the shores of Russia, Korea and Japan - the military courts of these states, according to the plan of the USSR, were to gain access to Tsugar.

Also, the Sangara Strait is used for catching fish, harvesting crabs and algae.

Seikan

The Sékan railway tunnel, 53.85 km long, with a 23.3 km fragment under the water at a depth of 100 meters below the seabed, was considered the longest in the world before the Gotthard base tunnel was built. Because of the low cost of air travel within Japan is not popular with local residents, because it is considerably inferior in duration of time enroute.

This tonnel lies under the Sangar Strait, forming a railway connection between the islands of Honshu and Hokkaido, being part of the line Kaikyō (Kaikyo). Its name is formed from the abbreviation of the names of the cities between which it spread - Aomori Prefecture and Hakodate.

In addition, Seikan is the second time the construction of an underwater tunnel after Cammon, connecting the islands of Honshu (Japan) and Kyushu.

History of the tunnel

Designing Seikan took 9 years. It was built 24 years between 1964 and 1988. The construction involved more than 14 million people who built a seamless path.

This is a special type of railroad construction, in which welded rail rails are used, the length of which considerably exceeds the standard one. Due to this technology, the welded path is more durable and reliable during operation, however it requires special attention and care, since the consequences of the malfunction are often fatal.

The impetus for the construction of the tunnel was the 1954 event: a large-scale sea disaster took place in the Tsugaru Strait, which claimed more than 1,000 lives. All these people were passengers of five ferries cruising between Honshu and Hokkaido. The government of Japan reacted to the incident almost instantly - the next year completed the exploration work, on the basis of which it was decided to build Seikan. The cost of its construction in the prices of that time amounted to about $ 4 billion.

On March 13, 1988, the tunnel was opened for freight and passenger traffic.

Modernity

On March 26 of this year, the Shinkansen movement was launched in the Seikan tunnel - high-speed trains passing a distance of about 900 km between Tokyo and Hakodate (Hokkaido islands) in 4 hours.

As it was said above, nowadays the tunnel continues to be relatively free, because even the replacement of the ferry crossing to the railway tunnel could not stop the decrease of the passenger flow in this direction. For eleven years since the beginning of the operation of Sakan, it has declined by more than 1 million people. Previously, the volume of the flow was more than 3 million passengers, but by 1999 it fell to less than 2 million.