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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Air-tractor sledge | 2/4 | https://en.wikipedia.org/wiki/Air-tractor_sledge | reference | science, encyclopedia | 2026-05-05T12:37:17.942524+00:00 | kb-cron |
=== Crash === A series of public demonstrations were planned in Australia to assist in fund-raising, the first of which was scheduled for 5 October 1911 at the Cheltenham Racecourse in Adelaide. During a test flight the day before, excessive pressure in the fuel tank caused it to rupture, almost blinding Watkins. That problem resolved, Watkins took Frank Wild, whom Mawson had hired to command a support base during the expedition, on another test flight the morning of the demonstration. In Watkins' account, which he addressed to Vickers' Aviation Department, he wrote: "[we were] about 200 ft. up. I got into a fierce tremor, and then into an air pocket, and was brought down about 100 ft., got straight, and dropped into another, almost a vacuum. That finished it. We hit the ground with an awful crash, both wings damaged, one cylinder broken, and the Nose bent up, the tail in half, etc." Although the two men were only slightly injured, the plane was damaged beyond repair. Mawson decided to salvage the plane by converting it into a motorised sledge. He fitted the skis, and removed the wings and most of the sheathing to save weight. In his official account of the expedition, The Home of the Blizzard, Mawson wrote that the advantages of this "air-tractor sledge" were expected to be "speed, steering control, and comparative safety from crevasses owing to the great length of the runners". No longer needing a pilot, and believing him to be responsible for the crash, Mawson dismissed Watkins. The air-tractor sledge was taken to Hobart, where the expedition ship SY Aurora was being loaded. It was secured on board in a crate lined with tin, which weighed far more than the sledge itself, on top of the ship's forecastle and two boat-skids. To fuel the sledge, along with the motor launch and the wireless equipment, the Aurora also carried 4,000 imperial gallons (18,000 L) of benzine and 1,300 imperial gallons (5,900 L) of kerosene. Fully loaded, the ship left Hobart on 2 December 1911.
== In Antarctica ==
The Aurora reached the Antarctic mainland on 8 January 1912, after a two-week stop on Macquarie Island to establish a wireless relay station and research base. The expedition's main base was established in Adélie Land, at Cape Denison in Commonwealth Bay. While the Aurora was unloading, a violent whirlwind lifted the 300-pound (140 kg) lid off the air-tractor's crate, throwing it 50 yards (46 m). The main hut was erected immediately, but the strong winds meant that work on the air-tractor's hangar was delayed until March. When the winds abated, a 10-foot (3.0 m) by 35-foot (11 m) hangar was constructed next to the main hut, from empty packing cases. Bickerton began work on the air-tractor sledge on 14 April 1912. His first job was to repair the sledge, which had been damaged in transit when a violent storm hit the Aurora. A giant wave had slammed into the crate containing the sledge, driving the fuselage 4 feet (1.2 m) through its side. With the repair completed, Bickerton began the serious work of converting the plane into a sledge. He constructed brakes from a pair of geological drills, and a steering system from the landing gear. Bickerton painted the engine and fuel tank black to absorb heat better and protect them from freezing. By June he had the engine running properly, and during a lull in the winds in early September he fitted the skis. Finally, he raised the fuselage 5 feet (1.5 m) off the ground to allow the propeller free movement.
On 27 October 1912, Mawson outlined the summer sledging program. Seven sledging parties would depart from Cape Denison, surveying the coast and interior of Adélie Land and neighbouring King George V Land. They were required to return to the base by 15 January, when the Aurora was due to depart; any later, it was feared, and she would be trapped by ice. Bickerton was to lead one of the parties, which would use the air-tractor to haul four sledges and explore the coast to the west of the hut. Most of the parties left in early November, but Bickerton's Western party delayed until December, in the hope of avoiding the ferocious winter winds. Work on the air-tractor sledge was delayed by the fierce winds, and the first trial took place on 15 November, between the main base and Aladdin's Cave—a depot which had been established on the plateau above Cape Denison. The air-tractor reached a speed of 20 miles per hour (32 km/h), covering the 5 miles (8.0 km), expedition member Charles Laseron recorded, "in great style". Soon, the sledge began hauling cargo up the slope, laying depots for the summer sledging parties.