METHOD OF LAYING EXTENDED DEVICE UNDER ICE BLOCK Russian patent published in 1997 - IPC

FIELD: laying extended articles under ice. SUBSTANCE: two holes are made in ice; rear hole (in way of drift) is displaced from straight line passing through first hole in parallel with direction of drift to side selected beforehand. Then running end of flexible coupling to be paid of is lowered in first hole. Flexible coupling is provided with sinker-slide block and hydrodynamic otter located at some distance from it. Paying out the flexible coupling is continued till sinker lies on bottom and pulls coupling (due to friction) through length exceeding distance between holes. Then heavy grip, type grapnel is lowered through rear hole by means of rope till it gets in contact with bottom, after which sinker is remotely disconnected and paying-out coupling is pulled at rate sufficient for bringing its running end towards rear hole till it gets in contact with rope of grip which is then veered in and paying-out coupling is brought to surface of ice. EFFECT: enhanced reliability. 5 dwg