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Continued...
There have been five sets of buildings at Halley since it opened,
and one of the biggest problems faced by all of them has been snow build-up, the
combination of snow quantity, low temperature and drifting resulting in any
structure on the Brunt ice shelf being buried relatively quickly. The first two
stations consisted of fairly traditional buildings with pitched roofs built
directly on the ground, while for Halley 3 and 4 the buildings were housed in
conduits - steel in the case of Halley 3 and plywood for Halley 4 - to provide
greater strength and insulation. All four designs required the buildings to be
accessed and interconnected by ramps and shafts as the snow enveloped them. When
Halley 1 was abandoned after ten years, it was 14 metres below the surface.
The essentially subterranean existence produced by building
directly on the surface in the interior of Antarctica prompted a number of
attempts to find an alternative. In 1969 Australia opened a new station with
buildings elevated on scaffolding which lasted for 20 years. However, this was
built on rock -- not on a floating ice shelf. In 1982 Germany built a small
station on a jackable platform - the same solution that the British Antarctic
Survey adopted for Halley 5, the current station, which came into operation in
1990.
Designed for the British Antarctic Survey by the German company
Christiani and Nielson, the original Halley 5 consisted of three separate
buildings on jackable legs set initially between four and 5.5 metres above the
surface.
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