Due to the need for accurate exploration of deep-sea scientific research, drilling techniques by combining the operational advantages of the Jiaolong manned submersible is considered one of the most feasible methods for deep-sea bedrock drilling. Based on deep sea bedrock cutting model and discrete element simulation, as well as efficient drilling as the design criterion, the development of a deep sea 7000 m electromechanical coring apparatus was carried out. The outstanding feature of this technology is that the bit load produced by the drill pressure is usually within the range 100–400 N while the recommended load for diamond drilling is 1–3 KN or even more. Therefore, searching for the drilling bits that can drill in extremely hard formations with minimal load and acceptable rates of penetration and rotary speed is the necessary step to prove the feasibility of electromechanical deep-sea drilling technology. A test has been designed and constructed to examine three types of drill bits. The results of experiments show that the new low-load polycrystalline diamond compact (PDC) bit has the highest penetration length of 138 mm/15 min under a 300 N load and 250 rpm rotary speed. Finally, field tests with the Jiaolong submersible were used to conduct deep sea experiments and verify the load model, which provides theoretical and technical data on the use of a low-load core sampling drill developed specifically for a deep sea submersible.

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The remarkable progress in deep submergence science with manned submersibles in the past 50 years has made it possible for us to directly explore the inaccessible underwater extreme environment. Basic research carried out at depths over 1,000 m in the deep ocean has provided dramatic and unique insights into some of the most compelling scientific questions ever posed. Deep research manned submersibles have been widely recognized as indispensable platforms for conducting deep-sea research. Whereas all deep-sea submersibles share the unique feature of direct observation function by scientists and pilots from the cabin, all manned submersibles are equipped with different tools to implement a wide range of jobs in different exploration purposes. These can directly affect productivity and each dive's outcomes, such that it would be meaningful to study the samplers, sensors, and other devices that have been installed on the different deep-sea research manned submersibles around the world. This article will also introduce the research and development status of the JiaoLong manned submersible's operational tools, which have been researched and tested during the sea trials and test operational phase over the past 9 years. Based on developed technologies, state-of-the-art tools are essential to achieve a high-efficiency use for each dive. The article brings forward discussion and suggestions for the development of JiaoLong's operational tools, followed by a conclusion from the perspective of JiaoLong's operation team.