The Electrothermal Drill (aka Thermal Drill) melts an annulus around the ice cores it collects. It supplements the 4-Inch drills and can be substituted for the 4-Inch Drill sonde, using the same winching system, for use in ice warmer than about minus 10° C. The drill collects a 3-inch (76 mm) core and has been used to drill to approximately 200-meters. For depths shallower than 30-meters, a simpler tripod assembly for operation of the drill is available and has been used with good success. It is particularly useful in ice close to the pressure melting point, where electromechanical drills are at risk from melting and refreezing of the surrounding ice. The Thermal Drill has performed well in British Columbia, Alaska and in southeastern Greenland. The drill was most recently deployed and used successfully to drill through firn aquifer layers in SE Greenland during spring 2013 and spring 2015.
IDDO has one Thermal Drill ready for issue. A new 65-meter water-shedding cable was procured in 2015 to prevent the fibrous cable typically used with the Thermal and 4-Inch Drills from soaking with water in aquifer layers, refreezing and causing issues with travel over the upper sheave on the drill tower. IDDO began exploring upgrades to the Thermal Drill in PY 2018 to allow for coring to 300 meters. Primary upgrades will include new heat rings with current/temperature limiting features, a new 300 meter water-shedding cable, a magnetic tool to aid in core removal, and an ethanol delivery mechanism.
|Number in Inventory||1|
|Max. Practical Depth||200 meters|
|Hole Diameter||104 mm (4.1 inches)|
|Core Diameter||86 mm (3.4 inches)|
|Core Length||1 m|
|IDDO Driller Required?||Yes, 1 driller|
|Drill Fluid Required?||No|
|Power requirements/source||220 v, 5 kW generator|
|Light Aircraft Transportable?||Yes|
|Shipping Weight||1200 lbs|
|Comments||Shipping weight includes generator and 100 meter winch sled; complete operating weight is 800 lbs; uses 4-Inch Drill system winches|