In the course of about 3 seconds we went from drilling a normal ice core to having a disconnected and very expensive lump of steel sitting alone and still at the bottom of a 92 meter hole.  The cable had simply broken at the surface level and spiralled out of sight and into the hole.  Disconnected from the winch and without power supply, the drill deep down there seemed to have surrendered itself to the Big Ice.  My heart was broken – not just for loosing the drill but for the possibility of not being able to complete the drilling projects left on the traverse. 

How did it happen?  We still don’t know.  Going past 91 meters we entered the realm of the unknown for this particular drill setup, but nothing pointed to its failure.  There was no indication of any stress on the cable prior to the break, the load cell was working well, there was no bouncing or spinning, and so far we have not been able to uncover any mechanical issues that could have caused the break.  But the cable snapped, and as far as we knew the cable and the drill were beyond our reach down at 92 meters.  What to do?

Zoe was the first one to come to assistance, sending Bob Hawley’s Borehole Optical Stratigraphy System – a camera – down the hole.  With this we found a matted mess of cable suspended at 62 meters.  Then Svein put his ingenuity and welding torch to use and quickly designed and fabricated a “fish hook” out of plate steel and bolts.  As soon as the camera came up, the hook went down, attached to the remaining part of the winch cable. It looked like something from the 12th century, and Svein even spat on it before sending it down the hole

We knew the matted mess was at 62 meters so we sent the hook to 62,5.  By gently swinging the hook in the 10+cm diameter hole and yanking up we managed to hook the cable on the first try!  Twelve anxious sets of eyes watched as the hook slowly brought the cable closer and closer to the surface.  Fifty meters - forty meters – thirty meters… A violent yank had everyone up in a startled jump, but it was just the sudden unravelling of a tangle on the cable. Twenty meters – another tangle jump – eleven meters – and another yank.  Alas, the load cell showed that the weight had gone. We had lost the “fish”.

Over the next 36 hours we made several new attempts to retrieve the cable, each time running the camera down between hook runs to make sure we knew the depth of the cable.  On each run we would loose the cable closer and closer to the surface. Finally, on the fifth attempt, the camera showed that the hook had caught a wadded mess of cable tail that would never slip.  We were able to pull it up to 3,3 meters depth, but there the cable would give no more.  The drill seemed to be frozen firmly into the Antarctic ice cap.  We were able to dig down to fetch the cable tail and reconnect the drill to the winch and the surface, but we could not pull it up without risking a terminal cable break.  What now?

The “12th century fish hook with its catch, sitting in suspense over the plywood covered bore hole 3,3 meters below the snow surface.  Photo: Lou Albershardt.