By Allen George
Lying 35 fathoms deep, at the northern end of the Drøbak Sound 15 nautical miles south of Oslo, is the wreck of the German heavy cruiser BLÜCHER, still detectable on the echo sounders of passing ships. She was sunk by shells and torpedoes from the Oskarborg island fortress which guards the entrance to the Norwegian capital, a testament to Norway’s ability and willingness to fight the German invasion of April 1940, and the courage and initiative of a 64 year old Norwegian officer, who acted without orders.
Outbreak of hostilities:
The early months of 1940 were a time of anxiety for Norway, and a growing awareness the country would have to prepare for war, despite being neutral, if it was to protect its freedom. The country was under pressure from Great Britain, which wanted to stop the coastal iron ore trade from Narvik in the north to Germany, but was hampered as the traffic sailed within Norwegian territorial waters. Throughout, the story was murky, because while Norway could be seen to be in breach of its neutrality through allowing the German access to its coastal waters, it had given Finland artillery and shells to help in the Winter War against Russia. Furthermore, it had also allowed Great Britain use of its territory to also transfer arms to Finland. Despite the building tensions, Norway was unprepared for the German invasion when it came on the night of 8/9 April 1940, and there was little resistance, making the capture of Narvik, Trondheim, Bergen, Stavanger and Kristiansand relatively easy and swift.
A major objective of the German operation was to take the capital Oslo and capture the Government and Royal Family. But it was in Oslofjord where the Germans met the fiercest resistance, very much thanks to one man, the 64-year-old Oberst (Colonel) Birger Eriksen, commander of Oskarborg Fortress. Built on an island, the Fortress guarded the seaward entrance to the capital. However apart from the officers and NCOs, almost all soldiers manning the fortress were fresh recruits, having only been conscripted seven days before. Colonel Eriksen had not received any clear orders and no notice as to whether the approaching warships were German or Allied, but on his own initiative he decided to open fire on the approaching group of ships lead by BLÜCHER. At 0421, 9 April, Col Eriksen ordered the fortress’s main battery to fire at the leading ship of the unknown vessels. After giving the command he made the heroic statement: “Either I will be decorated or I will be court martialled. Fire!”
The fortress was armed with three, 11 inch guns manufactured by Krupp more than 40 years previously, plus an underwater torpedo battery built at the turn of the century, and set inside a cave. This battery was unknown to the Germans. Its torpedoes were made in 1900 at the Whitehead torpedo factory in Fiume, then part of Austria-Hungary. There was also a number of 5.9 inch and smaller guns on the mainland. In the event there were only enough artillerymen to man one of the 11-inch guns. But they managed to get two into action by splitting the trained men between two guns and supplementing them with spare hands, including cooks. The two guns fired were named ‘Aaron’ and ‘Moses’. Both scored hits on BLÜCHER at close range, about 2,000 yards, although because of the lengthy reload time they weren’t able to get off any more rounds before the cruiser passed out of the arc of fire. It wasn’t possible to get the third gun, ‘Josva’, into action. The first shell hit BLÜCHER just ahead of her main mast and set most of her midships ablaze. It penetrated a magazine containing depth charges, and bombs for the cruiser's Arado Ar 196 seaplanes. The blast blew out bulkheads, obliterated electrical circuits to the main armament rendering it useless, and ignited oil, setting off a fierce fire. The second round struck one of her forward gun turrets, causing considerable damage and further fires. In addition to the 5.9-inch batteries at Oskarborg, there were similar batteries on the eastern shore of Oslofjord, which all joined in .....................