 The expedition attempted the exploration of the Princess Ragnhild Coast by dog sled.The venture, however, was a failure and ended dramatically when all their supplies and sled dogs were unloaded on an ice floe that broke up almost immediately and began to drift.At the time of World War II Hallvard volunteered for military service in the spring of 1940 and took part in the Battle of Narvik as an Allied soldier of the Foreign Legion in French uniform, but partly under Norwegian command.