the ship was allocated to group 1 for the norwegian portion of operation weserübung. the group's task was to transport the 139th mountain infantry regiment ("139. gebirgsjäger regiment") and the headquarters of the 3rd mountain division ("3. gebirgs-division") to seize narvik. the ships began loading troops on 6 april and sailed the next day. "giese" fell behind the rest of group 1 as the result of oil leaks, machinery breakdowns, and contaminated fuel oil. she fell further behind when lieutenant commander (korvettenkapitän) karl smidt turned the ship about to recover a soldier who had been washed overboard by the high seas. "giese" had little usable fuel left by this time and was forced to continue at a slower speed to conserve fuel. when the ship arrived at her destination on 9 april, she landed her troops in the herjangsfjord (a northern branch of the ofotfjord) to reinforce the other troops previously landed there in order to capture the norwegian army armory at elvegårdsmoen. later in the day, "erich giese" moved to narvik harbor, but was not able to refuel before she was ordered to return to the herjangsfjord well before dawn together with her sisters "wolfgang zenker" and "erich koellner".