Abstract
Theoretical coal reserves under the sea in Japan are 3, 783 million tons and practical coal reserves possible to be mined are 417 million tons.
At Mitsubishi-Sakito coal mine, the shallow part of 80-100m under the sea is being mined by means of pneumatic stowing.
At Mitsubishi-Takashima coal mine, the deepest shaft (depth 910m) in Japan is being sunk and the development from-550m to-900m is planed.
At Ube-Nishiokinoyama coal mine, coal seam at 50m under the sea is mined by means of the land reclamation.
At Wakayama-Kaji coal mine, the small land is built and 2 shafts are sunk on it by drop shaft method.
There are many coal mines under the sea besides the above, which are Taiheiyo-Kushiro, Mitsui-Miike and others. Output of coal from under the sea is about 5.3 million tons which is about 12% of total output in Japan.
