The Probert Encyclopaedia of Warfare

OPERATION GUNNERSIDE

Operation Gunnerside was the British SOE operation to destroy the supplies of heavy water at the heavy water factory in telemark region, Norway in 1942 during the Second World War. Eight SOE agents from the Norwegian section gained entrance to the factory, detected only by a Norwegian night-watchman who surrendered and was released when they left. The explosive charges destroyed only the heavy water tanks, and were not heard over the factory noise and the sabotage was undetected until the following morning by which time the agents had escaped, no shots were fired and there were no casualties to the operation.
Research Operation Gunnerside