| 摘要 |
A drilling bit for penetrating an iceberg a predetermined distance to establish an anchor point for towing the iceberg to a predetermined location. The drilling bit has three sections for achieving its goal. It has a cutting head, a torque transmission body and a driving end for coupling to a power-twisting device which energizes the bit. The bit has separate passageways therein to permit the bit to remove water and ice produced by the cutting head during a drilling operation. The drill has a passageway for circulating liquid nitrogen therein to cause the water remaining in the hole to freeze to the drill bit solidly into the iceberg. The drill bit is also provided with a heating coil resistor to melt the area where the bit is held captive by the frozen ice.
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