Construction of the entrance to the Arens Inclined Shaft on the west coast of Tsushima has finally begun, with detailed surveying for the location of the entrance taking place over three days from May 4th to 6th. A 200m boring survey had already been carried out, and the small hole served as a landmark, but the Backhoe excavator made a loud noise as it dug the small hole, and construction began.
A 6m diameter tunnel entrance will be installed here, and it will proceed at an angle that drops 1m for every 4m it travels. A few hundred meters away it will reach the Aren Coast and the Korea Strait, and 60km away it will reach Geoje Island in South Korea, and it will head west along the seabed towards there. Based on the results of this survey, it is aimed to install the tunnel entrance by the end of July, and construction methods such as box culverts or liner plates will be considered, with full-scale construction to begin in June.
Two years ago, a road was constructed for construction vehicles to use to reach the site, and the site was leveled to accommodate offices, warehouses, material storage areas, and equipment installation areas. After that, a ground-breaking ceremony was held by those involved, and construction will then proceed. This time, the mine entrance is scheduled to be located at the red and white "chobari" marking, which can be seen in the photo.
Tsushima's geology is the same as that of the Korean Peninsula, and it is a rocky island. There is little arable land suitable for rice cultivation, and the "Wei Zhi Wajin Den" (Records of the Wa People) states, "The land is mountainous and steep, with many deep forests, and the roads are like deer paths. There are over 1,000 households. There are no good rice paddies, so people survive by eating seafood and travel by boat from north to south."
Tsushima is a majestic island that sits calmly in the middle of the strong winds and rough waves of the Genkai Sea and has connected Japan and Korea since ancient times. Even today, the natural environment remains unchanged, and even airports have had to be built on mountains. The geological strata are hard and the island is characterized by the lack of earthquakes. As construction progresses, modern civil engineering and construction technology will shed light on Tsushima's geology.
International Highway Foundation Newsletter June 2014 (PDF view/download)
