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).