The British Antarctic Survey have had a research base located at Halley in the Antarctic since 1956, with the latest station, the Halley VI Research Station, commisioned in 2006 and put into operation in 2012 after being built for 4 years. Approximately 1.2 m of snow accumulate each year on the Brunt Ice Shelf and buildings on the surface become covered and eventually crushed by snow. This part of the ice shelf is also moving westward by approximately 700m per year. There have been six Halley bases built so far. The first four were all buried by snow accumulation and crushed until they were uninhabitable. Various construction methods were tried, from unprotected wooden huts to steel tunnels. Halley V had the main buildings built on steel platforms that were raised annually to keep them above the snow surface. However, as the station’s legs were fixed in the ice it could not be moved and its occupation became precarious, having flowed too far from the mainland to a position at risk of calving as an iceberg.