JAPAN PLANS UNDERSEA TUNNEL

Manawatu Times, Volume 60, Issue 196, 21 August 1935, Page 16

JAPAN PLANS UNDERSEA TUNNEL

Longest Tube in the Orient

Japan has decided to build the longest undersea tunnel in the Orient, linking up the main island, Honshiu, with Kyushu and connecting the towns of Shimoneseki (Akamagaseki) and Moji. The length of the tunnel will bo about one and two-thirds mile—one mile being under water. The estimated cost is 15,000,000 yen (a little over £1,000,000 at present rates of exchange). Construction work will begin in 1936 and will probably last for several years, as the work of boring a passage below the fast running Kammon Straits, which connect tho Sea of Japan with the Inland Sea, presents considerable engineering and technical difficulties. The builders of the Moji-Shjmone-seki tunnel will be obliged to make haste slowly, becauso of tho very great physical strain involved in wording under the water. It is estimated that seven hours of rest will bo required for every hour of work. Tho project which has been provisionally approved calls for tho construction of the tunnel in the form of a round tube, about 2S feet in diameter. It will be built 21.6 feet under the bottom of the channel and over 120 feet below sea level. Tho tunnel will slope down from the two sides of the straits to a level passage beneath the surfaco of the sea. After the tunnel is completed, through train service will be inaugurated from Aomori, at the northern end of Honshiu, to Kagoshima, in South Kyushu. Tho idea of such a tunnel was first proposed in 191 S. Since that time some preliminary engineering work has been carried out. Boring tests have been made in tho sea-bed beneath the straits, and surveys of tho depth, speed and direction of currents and countercurrents w'ere conducted. For a timo tho depressed state of the State railToad finances caused tho project to be shelved indefinitely. The Home Office in 1931 proposed to supplement tho existing ferry service between Moji and Shimoneseki with a

suspension bridge. This would have been cheaper and easier to construct the tunnel. But the military authorities took strong exception to the proposal, arguing that a suspension bridgo Would bo a target for hostile aircraft in tho evedf of war and that the wreckage of tho bridgo would obstruct communication through tho Kamiuon Straits. So the idea of building a bridgo was dropped and the project of the undersea tunnel has now been definitely decided on. When the tunnel is completed it will be possible to save an hour and 20 minutes in the time required for transport communication. Moreover, the tunnel, provided that Japan regains mastery of tho straits, would be 'impervious to attack in the event of war. Tho more favourable state of the railroad finances has douotless promoted tho decision to construct tho tunnel. Moreover, tho project is characteristic of tho present tendency of tho Japanese Government to sustain employment by liberal expenditure on public works, especially when these possess potential military and strategic advantages. Shimoneseki. tho northern terminus of tho tunnel, possesses a number of Japanese historical associations. The bombardment of the town by a combined fleet of British, French, American and Dutch worships in 1864, -.pis a reprisal for the action of tho feudal lord of the region, who had persistently fired on foreign ships which were passing through tho straits, was an important factor in bringing about the opening up of Japan to foreign trade and intercourse. It was in Shimoneseki that peaco was signed after Japan's successful war -with China in 1895. Shimoneseki is only 150 miles from Fusan, Korea; and tho regular night and day eight-hour shipping service between these two points represents tho shortest sea passago between Japan and tho Asiatic mainland. Both Shimoneseko and Moji are towns of about 100,000 population.