When the British Antarctic Survey (BAS) set out the brief for its new £19M research station, Halley VI, it demanded that the structure be jackable and moveable.
Halley VI must be raised each year out of the snow drifts that accumulate during the Antarctic winter. And it must be periodically relocated as the Brunt Ice Shelf, on which it will stand, recedes (NCE 2 December 2004).
Consultant aberMaunsell, with specialist in moving structures Bennett Associates and architect Hugh Broughton - who won BAS's design competition, delivered a scheme of lightweight modular living, working and plant 'pods' on telescopic hydraulic legs. Each pod has six legs, with a large ski-like foot at the end of each. These can be raised clear of the snow, one at a time, so snow can be packed underneath or drifting snow can be bulldozed away. When units need moving they will be winched by paired bulldozers, and will 'ski' from one place to the other.
Pods will stand at a constant 4m above ground level: The legs will extend over the course of each year as snow accumulates beneath them. To compensate for uneven bearing pressures in the snow, legs will be equipped with load sensors linked to tilt and level sensors inside the pods. This will ensure the weight of the pods remains evenly distributed between all the legs.
The entire research station will be relocated every 10 years as the ice shelf recedes. Modules will be detached from the cluster one by one and temporarily decommissioned. They will be dropped to 2m height for transport.
'While the whole design is special and unique, we have not used untried component technology to realise it anywhere, ' says FaberMaunsell project designer Mike Wright. 'It's a human life support system and needs to be free of uncertainty.' Halley I ill e prefabricated as a kit of parts in the UK during the next 12 months following construction trials in Scandinavia this winter. It will be assembled on the Brunt Ice Shelf during the Antarctic summers, December 2006-January 2007, and 2007-8.