FIELD TRANSPORTATION

VUWAE 15 was supplied with four Polaris motor toboggans and six Nansen sleds from Scott Base. In the course of the season the party experienced six major toboggan breakdowns and a number of sled breakages resulting in considerable lost time in the field, and in extra helicopter and Hercules time. However, delays were minimised by the excellent cooperation and support from both VXE-6 and the Scott Base staff. A description and discussion of the damage is given in some detail in a report by Barrett to Antarctic Division (March 1, 1971), and a brief summary of the report is given below.

Other less serious faults were dirty spark plugs, loose drive chains, and worn throttle cables, all inherited from the previous season.

In the first week in the Skelton Neve two areas of rough hard sastrugi totalling five miles across were encountered near Mt. Metschel, Continual working of the throttle was necessary to maintain control of the sleds and before the areas had been crossed cables had broken several times on two toboggans, and eventually could not be repaired. A piece of rope was used instead, but it was difficult to steer, watch the sled, and control the throttle effectively in the difficult terrain. New cables were fitted by base mechanics, with the aid of a welding torch to change the fittings, during the resupply three weeks later.

The Metschel sastrugi may have contributed to the breakdowns but they were not a major cause. A replacement toboggan flown in from Scott Base on December 12th had by January 6th acquired many small fractures around the petrol tank and cab floor. It had travelled less than 100 miles over moderate to good surfaces, and had not experienced the rougher Metschel sastrugi.

A review of the available information suggests that the dominant factor in the toboggan breakdowns was age. The machines are all about six years old, and as long ago as the 1967-68 season a DSIR party suffered a sheared axle and failure of sheet metal in the track unit (Massam, R. D. R. D 439). The toboggan breakdowns experienced by VUWAE 15 were of precisely the same type but occurred with greater frequency. A field mechanic could not have helped the party with the spares and tools available.

The party also had a number of sled breakages. In six instances the runners broke cleanly, suggesting that the wood was brittle and dry. Also the runners were lashed to the longitudinals with string, which was varnished. This gave a rigid join, in contrast to the flexible join obtained with the usual rawhide lashing. The poor throttle control and bad sastrugi added to the difficulties. Three other fractures were splintery and may have been due to driver error.

Recommendation 1: Toboggans should be stripped after each field season, and all moving and structural parts checked for wear and flaws or cracks. Chains should be soaked in graphite, cables oiled, and spark plugs, points and condenser replaced.

Recommendation 2: Adequate spare parts must be provided. VUWAE 15 was given fewer spares for four toboggans than the DSIR manual specified for one. (For list see Barrett, Report to Antarctic Division, 1 March 1971). Spares of parts that experience great stress or wear such as axles or clutches must be new.

Recommendation 3: Each toboggan must have a complete tool kit as recommended by the manufacturer, or as indicated by field experience.

Recommendation 4: Toboggans used by remote field parties should have no more than three seasons' use.

Recommendation 5: A toboggan of each type should be either kept in New Zealand, or flown back at the end of the season to be used for training future mechanics and field personnel. Field personnel with toboggan experience should be used for instruction because only they know the strong and weak points of the machines.