I do believe that the Blucher was also targeted by shore based torpedoes in a narrow fjord leading up to Oslo.
She was actually sunk by two torpedoes from the shore battery after having received two hits from the 28 cm. guns on the fortress which ignited aviation fuel and damaged fire control systems onboard. Many more hits were scored by smaller-calibre batteries placed on both sides of the sound, outside the fortress proper.
Legend says that the fortress commander, Colonel Eriksen, visually corrected the faulty distance quoted by the fortress' range finder operator. There were three Krupp 28 cm. guns at the fortress, facing south, but Eriksen only had crews to operate two of them. He also estimated that he would not have time for a reload.
I have a minor personal interest in the matter as my grand-father, Leander Andersson, a Swedish Navy helmet diver, was on loan to Norway to assist in retrieving one of the guns, later named "Moses", after it fell into the water during the transfer to the fortress following a replenishment at Krupp's in Germany in 1905.
The other operational gun was named "Aron".
< Message edited by Leandros -- 8/11/2019 3:01:27 PM >