ASK THE ICE TEAM: Four more and then the last ones tomorrow…
Q: Did you consider removing some of the spikes on the CAT treads to increase the pressure per spike thus driving them further into the hard ice and reduce the slipping that you encountered on the “blue ice”? When you stop and winch, is there some extra anchor you deploy to keep from sliding? (by Peter)
A: We have considered reducing the overall quantity of spikes on the D6N Tracks. It is a question that has been asked quite a lot as well. I am sure it would have made some difference to remove some of the spikes, increasing the ground pressure on those remaining. However, it is somewhat time consuming to remove or install the spikes. Another important fact is that the spring that holds them in the adapter weakens each time the spikes are removed and therefore they do not stay in as well. When we were traveling south, we only encountered four blue ice fields at which we had to relay and each time we only needed to split the loads in half, doubling our number of trips across. The weights we were still towing across the ice were nearly double that of each bulldozer, an amazing accomplishment for the D6N’s. Although I agree that reducing the number of spikes in the tracks may have increased traction, I strongly doubt it would have increased it to the point of avoiding any relaying over these ice fields. As we were racing against time, we did not feel we had time to experiment. As the number of crossings was expected to be small, we accepted the fact that we would need to relay. Whenever we were using the winch lines to advance our cargo, the Cats held firmly in place as we reeled in the loads, as much as was safe for the winch lines anyways. The ice cleats installed on the tracks of the Cat D6N’s by Finning remain to this date, one of the most assisting modifications completed to the two machines.
Q: Have you been able to find a solution in terms of changes of equipment which would see you easily cross over crevasses to the South Pole? (by Karel)
A: Our biggest problem in respect of crossing crevasses is weight and that is something that we can’t do anything about. Many of the crevasses we have encountered were invisible on the surface and had snow bridges that were over 3 meters thick. Lighter loads and vehicles would have crossed many of these bridges without them collapsing.
Q: Given that you are surviving in a highly hostile environment, what are your most important items of safety equipment? (by T Llewellyn Jones)
A: That’s a very difficult question to answer as a lot of safety equipment only becomes really important when you have to use it and that’s something you hope you never have to do. At a basic level for us we need shelter, clothing, food and heat but if things go wrong communications, rescue equipment, medical facilities will rapidly come into play. The key to a well managed plan down here is to always think about contingencies – what happens if our living caboose catches fire or falls in a crevasse, what happens if the sledge carrying our food falls in a crevasse etc, etc. It leads us to try and spread our risks as best we can by doing such things as dividing our food amongst several sledges, having sleeping bags stored in the science caboose as backup, storing vital spare Iridium satellite phones in different places and making sure they are always fully charged, and many other small but potentially life saving and forward thinking plans.
Q: What has been you most ingenious solution to a problem? (by T Llewellyn Jones)
A: The techniques we have developed for moving large loads through serious crevassing definitely allowed us to push further south than we would otherwise have been able. When we reached the terrible point at which we realised we could not go any further we were in quite a nasty situation and we had the vehicles and cabooses separated from six fuel scoots by about 500m. When I first suggested that we might winch those scoots (eight tonnes each) instead of taking the Cat’s to collect them I got some bemused looks. Somehow we managed to rig up enough wire ropes, slings, strops and shackles to reach the full 500 m and although it took us four days in some quite nasty conditions (-40c with winds around 35 knots which put the windchill down in the minus 60s) it was certainly a good solution. It’s worth saying that whilst we were winching the Cat was parked next to a crevasse that was large enough to swallow the Cat without it even touching the sides so we were quite pleased not to be having to cross it with the vehicle.
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