Here one thinks there has been a cheating cannon. Cheating cannons were used to give the enemy the impression that they were in possesion of heavier shots and was to deter any intruder.

There were no big guns in Grovfjord but we know there were anti-aircraft-guns.
Mind the remains of the barbied wire fence which was all around the Kalvskinnet.
It happened that the soldiers practised shooting against the mountain on the other side of the fjord.