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Immediate Report of Victoria University Of Wellington Antarctic Expedition 1987-88: VUWAE 32

D3B LGP operation

D3B LGP operation

The towed load for the D3 was quite high as indicated by the necessity to remain in 2nd gear on soft dry-cold snow in the area from Ross Island to the McMurdo Ice Shelf. We estimate that each Cantago sledge with cargo had a dead weight of about 5 ton giving a total dead weight of 15 ton. There was no method available to measure draw bar pull directly, however, this was estimated from published D3 performance curves to be about 8000 lbs (35 kN) on soft snow in 2nd gear, reducing to about 3000 lbs (15 kN) in 3rd gear on thin snow-smooth sea ice. This would seem to be a sensible maximum load for long distance travel when a variety of surface conditions are encountered. The D3 performed very satisfactorily with only a few minor problems. The ether cold start facility was required at temperatures below −5°C and the batteries require heating below −15° to −12°C. A Herman Nelson heater should be considered a necessary accessory for the D3 when in the field, especially in the October-November period. A field rescue kit consisting of 2 heavy duty snatch blocks, chain and materials to make a deadman anchor should also accompany any bulldozer while in the field. This was not required by us this season but recent experience has highlighted the advantage of such equipment.

We had minor problems with clogging of the primary fuel filter which is in a different priming pump configuration than shown in the operator's manual. Perhaps a manually operated priming pump should be used in Antarctic conditions. There was also a leaky engine seal which required regular additions of oil. The loss of oil however decreased as the atmospheric temperature increased and as the engine accumulated more operating hours. The winch-wind wire became damaged while extracting the D5 on 1 November. This problem reoccurred in New Harbour and required cutting the winch wire and enlarging pan of the gap between winch drum and cheek to remove the crushed page 22 wire. A new wire was provided later in the season. The gap between winch drum and cheek should be reduced because the problem will easily reoccur.

A running log for the D3 is shown in table 1 with an analysis of fuel consumption for varying conditions.