Abstract
Since 1975, Metal Mining Agency of Japan (MMAJ) has been making survey of mineral resources on the deep sea floor; manganese nodules, sea floor hydrothermal deposits and cobalt crusts. For more effective survey, Deep-sea Boring Machine System (DBMS) has been developed by MMAJ. DBMS has capability of 20m coring under 6, 000m depth of water. The size of DBMS is 3.5meters wide, 4.5meters long, 5.9 meters high and the weight is 5tons. DBMS has three legs and can keep up the right position up to 25 degree inclination. The subsurface hydro control includes proportional control over the bit weight, rotary rpm, and flushing water pressure. This report describes the outlines of DBMS.
