A new, modified version of the cable-suspended Ice and Bedrock Electromechanical Drill (IBED) was designed for drilling in firn, ice, debris-rich ice and rock. The upper part of the drill is almost the same for all drill variants and comprises four sections: cable termination, a slip-ring section, an antitorque system and an electronic pressure chamber. The lower part of the IBED comprises an auger core barrel, reamers, a core barrel for ice/debris-ice drilling and a conventional geological single-tube core barrel or custom-made double-tube core barrel. First, the short and full-scale field versions of the IBED were tested at an outdoor testing stand and a testing facility with a 12.5 m-deep ice well. Then, in the 2018–2019 summer season, the IBED was tested in the field at a site ~12 km south of Zhongshan Station, East Antarctica, and a ~6 cm bedrock core was recovered from a 198 m-deep borehole. A total of 18 d was required to penetrate the ice sheet. The retrieved core samples of blue ice, basal ice and bedrock provided valuable information regarding the Earth's paleo-environment.

No abstract

No abstract

No abstract

Electromechanical cable-suspended drilling technology is considered one of the most feasible methods for subglacial bedrock drilling. The outstanding feature of this technology is that the bit load produced by the drill weight is usually within the range 1.5-4 kN while the recommended load for diamond drilling is 10-30 kN or even more. Therefore, searching for the diamond bits that can drill in extremely hard formations with minimal load and acceptable rates of penetration and torque is the necessary step to prove the feasibility of electromechanical subglacial drilling technology. A special test stand has been designed and constructed to examine the impregnated, surface-set, toothed and specially manufactured bionic drill bits. The results of experiments with ten types of drill bits show that the toothed diamond drill bit has the highest penetration rate of 3.18 m h -1 in very hard and abrasive granite under a 3 kN load. The torque (28.7 Nm) and power consumption (1.5 kW) of toothed drill bits are acceptable for cable-suspended drilling. The penetration rates of bionic drill bits may also be considered suitable and fall within the range 1.0-1.69 m h -1 under the lowest tested load.