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Victoria University Antarctic Research Expedition Science and Logistics Reports 1971-72: VUWAE 16

FIELD TRANSPORTATION

page 20

FIELD TRANSPORTATION

VUWAE 16A - PARTS 1 & 3 (McMurdo area)

Kyle and Jennings were flown either by UH1N twin turbine or the smaller Sikorsky turbine helicopters on nine occasions. Kyle twice requested close support, totalling less than 2 hours, from the pilot to reach outcrops not accessible from the ground. On two other occasions close support was obtained after a request through the Scott Base leader. The support was extremely valuable and the cooperation of the pilots excellent. Twice landings were made under extremely poor weather conditions.

Two Polaris toboggans were used by Kyle and Jennings in the first two weeks of the season to collect from Cape Royds and to test the toboggans before going north to the Evans Neve. Minor stoppages were apparently caused by air locks in the fuel line. One machine developed a leak in the gear box, which was repaired at Scott Base. Another breakdown was caused by a broken drive sprocket key.

A toboggan was requested to map a large area on the slopes of Mt. Morning for the last two weeks of the season. Permission from Antarctic Division to use the new Johnson toboggan with ice cleats was denied, and the party took one of the less powerful Sno-tric toboggans. This was adequate as a personnel carrier until an axle broke, but the rubber tracks had no traction for pulling sleds on the icy slopes. This forced the party to camp at a much lower elevation than planned, and only about a third of the area could be covered.

PART 2 (Evans Neve)

The party was provided with three Polaris motor toboggans and five sledges. Toboggan breakdowns seriously handicapped the expedition, but the strong support of the Scott Base Leader (J. Barker), his efficiency in arranging for spare parts to be dropped, and the generally fine weather for the latter part of the trip allowed some of the planned programme to be completed. A detailed report and discussion of the damage is being prepared for Antarctic Division, but a summary is given below.

Breakdowns involved destruction of two clutch shoes and two drive pulleys, the malfunctioning of a coil, a broken steering column, and several other more minor breakages.

The damage to the clutch assemblies was the most serious and potentially the most dangerous. The toboggan used by Kyle and Jennings gave trouble after approximately 12 hours running after put-in in the Evans Neve. It would not reverse, only moved slowly in forward, and a rattling sound came from the clutch assembly. The drive pulley was removed but no malfunction was found. The engine was started (ill-advisedly, as it turned out) and the clutch shoe disintegrated, a page 21 flying part of it giving Jennings a flesh wound in the hand. The cause of the original malfunction has still to be determined.

The clutch system of the toboggan used by Andrews and Laird disintegrated after approximately 18 hours running from the Evans Neve depot. On examination it was discovered that one clutch shoe had sheared off and in its flight ripped open the clutch pulley and the cover. Lining was absent from the inside of the clutch pulley, which was deeply scored, and it appears that the clutch shoe had snagged rivets normally covered by the lining inside the clutch pulley, the suddenly increased friction causing the shearing. The lack of clutch lining (none was found adhering to the fragments of clutch pulley, and only two small separate pieces were found in the snow) seems to have been the prime cause of the incident.

The other major breakdown was caused by a malfunctioning coil, which resulted in the abandonment of the toboggan involved because of lack of a replacement coil. The coil failure and several of the other defects, notably the fracture of the steering column may, in part, be attributable to the age of the toboggans which were purchased in 1964 and 1965. Some of last season's toboggan failures were also attributed to age and wear (Barrett and Kohn, 1971).

page 22

VUWAE 16B - PARTS 1 & 2

All air support was by twin turbine UH1-N helicopter. The Shapeless Mountain put-in was planned for C-130 because of the 4500 pound load, but was rescheduled by VX6 for four helos. In the early part of the season the limit of each helo load was normally about 1200 lbs, due mainly to lack of space. Later, the crewman was dispensed with and loads of 1800 lbs, i.e. a complete party of four and all equipment, could be moved as one. Two hours of close support was planned (Appendix I) for each of five areas and we were disappointed that close support was available on only two occasions for a total of 2 hours. This was apparently due to the heavy demands on helicopter work this season, as the requests were passed on from Scott Base.

Two Sno-tric motor toboggans were used for reaching the outcrop and moving camp. Both machines were powered by a 10 HP Kohler engine, replacing the 18 HP Sachs. The toboggans not surprisingly were underpowered, and reduced our mobility considerably (p. 16). The disadvantages of the Kohler-powered Sno-tric were clearly stated in last year's report (Barrett and Kohn, 1971), but it was not then realised that the low temperatures early in the season could incapacitate the machines due to the stiffening effect of the cold on the rubber track. A detailed report on the Sno-tric toboggans by A. Chinn has been passed to the Leader, Scott Base.

Reference;

Barrett, P. J., and Kohn, B.P. 1971: Immediate report of Victoria University of Wellington Antarctic Expedition 1970-71. Wellington, N. Z. 32 pp.