RESEARCH AND DEVELOPMENT OF A SELF-WALKING VERTICAL MINING SYSTEM USING DTH DRILLING UNIT AND THE SCALE MODEL TEST

摘要

Traditional subsea mining systems use a heavy subsea crawler, which has a big drill and scrapes the mineral deposit horizontally and have limitations of seafloor inclination, roughness and softness. Those traditional systems also have issues from operational and economical points of view. Furthermore, traditional on-board drilling machines and seabed drilling machines are used for core sampling by drilling to analyze mineral contents of seafloor deposits at the stage of mineral resource estimation before the production but operational and economical efficiencies are required to those traditional systems as well. The objective of this research is to develop an innovative Self-Walking Vertical Mining System (SW-VMS) that overcomes these issues. The system is a fully submerged eight-legged jack up platform and is able to walk autonomously on a rough, soft and inclined seafloor. The SW-VMS can be used both as the mining system to mine seafloor deposits and as the sample drilling system to analyze mineral contents in-situ and on-land efficiently before the mining with a DTH drilling unit. This paper introduces the detail of the SW-VMS as the mining system at first and then introduces the concept of the SW-VMS as the sample drilling system and finally the results of the scale model test of the SW-VMS on-land are shown. The scale model test has been carried out to confirm the walking ability of the SW-VMS from the structural and autonomous control points of view. The scale of the test model is approximately 1/40 of the preliminary design of the SW-VMS which has been already completed. The test consists of test cases of walking on a flat foundation, on a flat foundation including partially soft foundations and on inclined foundations of up to 45 degrees.