Requirements for Successful Recovery

We consider the best chance of recovering the corer to come from attaching a line by which it can be hauled vertically to the surface. This could most easily be done by a party on the fast ice with an ROV, winch and crane. Dr Powell's ROV would be suitable for attaching a purpose-built device (yet to be constructed) to the corer. We envisage the device to comprise a hook to grab the corer, a spool of doubled line on a pulley and a means of attaching this all to and releasing from the ROV. There would be no trailing line to the surface, which caused the previous recovery attempts to fail. Once the ROV had located the corer and hooked it, the spool would be released but for the ends of the double line which the ROV would carry back to the surface. Then a stronger line could be drawn down from the surface around the pulley, and finally the (pre-tested) winch rope itself to haul the corer to the surface.

We understand Dr Powell's ROV would be available for this purpose next November for 3 to 4 days, as he has scientific work planned in the area.

We also considered the possibility of recovery by trawling from a ship, but believe this has little chance of success. The boulders scattered on the sea floor would make it difficult or impossible to know whether the trawl had caught the corer or boulders before it was brought to the surface. Boulders in the trawl would most likely add to the damage caused by the trawling process. Also, pinpointing the location of the corer would require a ship with dynamic positioning, not available on ice breakers.