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Immediate report of Victoria University of Wellington Antarctic Expedition 1989-90: VUWAE 34

Field Transport

Field Transport

Motor Toboggans

A last minute decision led to the new Alpine Toboggans being moth balled and in their place we were issued two Grizzlys, G7 and G8. Initial reservations about taking these old machines on a long traverse proved to be unwarranted as both machines performed well. For the most part loads were relatively light but towards the end of the trip each machine was pulling about 2000 lbs and finding it hard work.

Each machine covered 950 km, towing an average of about 1400 lbs, total fuel consumption was 790 l, giving an average fuel consumption of 2.7 km/l.

Icing was a serious problem on the Lower Staircase, warm conditions and deep soft snow caused ice keels to form between the tracks preventing steering. In addition the tracks became frozen completely if stopped for more than a few seconds.

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Once stopped the only way to get going again was to roll the machine and chip away the keel and the ice from around the tracks.

The magnitude of the problem is exemplified by the fact that it took us over 2 hours and 12 km of driving to turn two toboggans around and align them with two sledges after we stopped to reconfigure the train. Turning circles were upwards of 300 m in diameter and stopping resulted in instant freezing. The rule seems to be if you encounter these conditions don't stop!

Contaminated fuel was a major problem on the leg between Mt Metschel and Portal Mountain, extreme care must be taken not to send rusty drums into the field. Many hours were lost because of this and it resulted in us being unable to reach our planned destination before bad weather closed in.

Helicopter Operations

Helicopter resupplies were made at Mt Metschel, Mt Crean and Mt Fleming, the party was pulled out by helo from just south of Mt Bastion.

Without exception resupplies arrived late, either because of weather or mechanical problems, however this had no impact on the smooth running of the event.

The pull out from Mt Bastion was seriously affected by weather and resulted in a helicopter becoming trapped overnight at our camp. Four Tamworth sledges were underslung to Vanda and proved very difficult to fly, strapping them to the skids seems the best option if they must be flown externally. Moderate damage was done to the sledges either in flight or during landing. Additional damage may have resulted from the sledges being blown around on the pad at Vanda, such loads should be placed some distance from the pad to prevent tumbling caused by rotor wash.

Hovercraft Operations

The hovercraft managed to deploy a depot near Fishtail Point in weather conditions which were too bad for sledge travel suggesting that it offers a viable means of Ice Shelf transportation even in marginal conditions.

However, the depot was not placed where we wanted it nor where they told us it was! The problem arose when the hovercraft encountered the rift field off Fishtail Point and decided they could go no further. Had the crew or one of the two Scott Base staff onboard been properly briefed prior to departure the depot could have been placed a further 70 km from base without any problems at all. The route up the Skelton Glacier and indeed the rifts which caused the problem were clearly marked on a map left at Scott Base. This map should have been made available to the hovercraft but it wasn't.

Even when the depot had been deployed on the Ice Shelf, 3.5 miles off Fishtail Point and north of the mouth of the Skelton we were told that it was at Fishtail Point. Only after clearing the rifts and struggling across a sastrugi field did we discover that there was no sign of the depot at Fishtail Point. Bad weather prevented us from back tracking out onto the Shelf for some days. A number of days travel may have been saved if we had been given the correct position of the depot in the first place.

In retrospect we recommend that in future where depots are to be deployed by hovercraft without event personnel, that a briefing be organised with the crew prior to the Events departure, in the same way that this is done for deep field LC-130 operations.