Skip lifting is a new concept of mechanical lifting system for deep-sea mining. It is expected that the skip lifting is capital cost effective and energy efficient compared to hydraulic pump lifting system. Furthermore, the less by-products of seawater and sediment is very attractive in the aspect of environment. This paper presents fundamental results of scaled model test conducted for the purpose of technological feasibility study on skip-lifting system. Main measurement factors are system configuration, angular response and horizontal acceleration of buffer station. It will provide reference data for the pilot test and the commercial realization. The hydrodynamic resistance of skips obtained from single skip test can explore the main composition of water resistance.
Polymetallic nodules are found on the deep-seabed of oceans worldwide. With the decrease of land minerals resources, value and attraction of the marine mineral resources are increasing. After preliminary exploration the highest density of the nodule are found in Clarion- Clipperton Zone (CCZ) (e.g., Hein, 2016; Keisuke Nishi, 2018). If the human beings' investigation and research of Ocean polymetallic nodules can be described as scientific exploration from the nodules found by Challenger research vessel to 1960s. Then into the 1960s the establishment of OMI, OMA, OMCO, in particular, the successful trial mining of poly metallic nodules in the Pacific Ocean in 1978s marked that human beings have entered the stage of large-scale research on deep-sea mining, (e.g., Xiao, L.J, 2000).Thus far, concepts of deep-sea mining system typically consist of mining vessel, lifting pipeline system (including steel pipe, intermediate tank, hose) and ore collecting unit. (e.g. Li, TT 2018). The geometric scale of the lifting pipeline is very large (e.g. Chen, YX 2014), so it is always the most vulnerable and critical part of the whole mining system. In 2014, Nautilus Minerals came up with a design concept of mechanical hoist to lift nodules.