 Expedition vessels also supplied the trapping stations with equipment financed by the Arctic Trading Co. "(Arktisk Næringsdrift)", a company that Hallvard had helped to set up.In the period between 1926 and 1933 Hallvard wintered in Northeast Greenland for six years, mostly in Myggbukta Station, where he was a meteorology assistant, radio telegraphist and leader of expeditions that were undertaken with the station as a base.By 1932 about 80 cabins manned by Norwegian trappers and fishermen were built in different areas of East Greenland, including some in the distant King Frederick VI Coast and Storfjord Station in the Kangerlussuaq Fjord.