Mike and I followed the "Norway Mortar" thread by Max Caliber with interest and it reminded us of one of the most unusual and successful uses of coast artillery, ever. A powerfull squadron of Nazi Germany's ships led by the Heavy Cruiser, Blucher, followed by the Pocket Battleship, Lutzow forced a passage north through Oslo fjord toward the old Oscarsburg Fortress. Part of the German Invasion of Norway, Group #5, their mission was to capture Norway's government, the Norwegian Royal family and any armories in Norway's capitol city, Oslo and install a German Military occupation government with Quisling assistance. They knew about the fortress, but discounted it as old and obsolete, a fatal mistake. The fortress had four main weapons. There were three 28 cm (11") coast artillery rifles, named Joshua, Moses and Aron mounted in 1893 at the top of the fortress on front-pintle, barbette mounts. Only two were manned. Also, unknown to the Germans, an underground torpedo battery was located on another island opposite the fortress guns. Three antiquated, but functional, 40 year old, Whitehead torpedoes awaited the Kreigsmarine's newest ship, Blucher.
On April 9th 1940 all these elements came together and resulted in the sinking of the heavy cruiser, Bulcher and the loss of a large contingent of Nazi SS troops and 163rd infantry regiment troops and Kreigsmarine sailors, between 650 and 800 went to the bottom with the ship; 550 survived. This action also resulted in the halt of the invasion squadron #5. In fact, the Battleship Lutzow went as fast as she could in reverse to get out of the narrow fjord. Only two shells from the old Krupp rifles, Model 1892, were fired, but they hit, and started massive fires and cut critical electrical power to the ship's guns. When the flaming cruiser came in front of the torpedo tubes, two were fired and both hit with disastrous results for the Nazis.
The link provided includes photos of the guns and some comments about the Oscarsborg Fortress and the battle. Go to the Bottom Menu Item first, then the sinking page second, to get the complete story.
http://www.admiral-hipper-class.dk/bluecher/bluecher_menu.htmlFYI,
Tracy and Mike