KMS BLUCHER

[aurora]

The Blücher was a German Admiral Hipper-class heavy cruiser. The Kriegsmarine's newest ship at the outbreak of World War II, having been in commission for just over six months, she was sunk by Norwegian shore defences at the Battle of Drøbak Sound on April 9, 1940, the first day of the invasion of Norway (Operation Weserübung).
Blücher was the flagship of the naval flotilla Marine Gruppen 5, with heavy cruiser Lützow (formerly Deutschland), light cruiser Emden, with three small torpedo boats and eight small minesweepers, commanded by Rear Admiral Oskar Kummetz, transporting troops to capture Oslo in the initial stages of the German invasion of Norway - Operation Weserübung ("Weser Exercise").

aurora

[muskeg13]

I visited Blucher's resting place last week. Oslofjord is very narrow at that point. It's too bad the coast artillerymen and RN Navy couldn't have also sent Lützow and Emden to the bottom, or at least nflicted damage and forced them to withdraw. The heroic actions of Oscarsborg Commander Oberst Eriksen and Torpedo Battery Kommandorkaptein Anderssen should be better known, but even they pale in comparison to Kaptein Leif Welding-Olsen of the whaleboat Pol III, who raised the alarm and challenged the German battle fleet to either leave Norwegian territory immediately or surrender !! What a man. http://en.wikipedia.org/wiki/Leif_Welding-Olsen If more had shown half as much courage and fortitude, the German invasion would have stalled, giving the British and French time to deploy and reinforce Norway.

Geirr Haarr's book, "The German Invasion of Norway" is highly recommended for anyone interested in this subject.

[aurora]

Surprisingly, it seems that the German gunners did not have any targeting information should the task force have to fight its way past the Norwegian defences. At 0440, as Group V approached Kahlomen Island, searchlights again illuminated Bliicher.
Forty-one minutes later, the three main guns of Fort Oskarsborg opened fire, ending a ll German hopes of a quick and peaceful run into Oslo. Three 280mm shells slammed into the ill-fated flagship. The first destroyed the main flak-control platform. The second struck the aircraft hangar, igniting a huge sea of flame that engulfed the Ar 196 float plane and destroyed the port no. I ll 105mm mount. The third damaged the engine telegraphs, j amming the rudder to port. [/b[]Simultaneously, the 150mm battery at Drobak also entered the fray, scoring an incredible twenty hits from the twenty-five salvos it fired.
These hits left Bliicher heavily shaken. As its main armament gunners scrambled to find something at which to shoot, its light and medium anti-aircraft guns fired at anything remotely resembling a target. After ordering his stricken ship to open fire, Woldag rang for full speed ahead.

aurora

[muskeg13]

Surprisingly, German targeting intelligence was certainly deficient, almost as bad as their political intelligence which had convinced them that the Norwegians not only wouldn't fight, but would welcome the Germans with open arms. They seemed completely unaware of the hidden torpedo battery, which had been operational since 1901 and sank Blucher with torpedoes that were delivered in 1900. Kommandorkaptein Anderssen had been retired for 13 years when Oberst Eriksen called him to resume his old job as torpedo battery commander due to the illness of the normal commander.

Only 2 of the 3 1890s vintage Krupp 280mm cannon were fired in the battle. There was a severe shortage of trained personnel to man the Oscarsborg guns, as most of the fort's occupants were brand new conscripts who had just arrived. Moses and Aaron were manned by a small group of training cadre from the coast artillery school, some of who had to run back and forth from one cannon to the next in between shots. The landside gun crews also has a large percentage of untrained personnel, who received on-the job training that night.

Given that the battle was fought at night, with the longstanding politically neutral defenders roused from their peacetime sleep into a shootin' war in a few short hours, their gunnery was excellent. The opening shots were only from 950m, and the range decreased from there.

[aurora]

The Germans were unaware of a torpedo battery near Oscarsborg's main gun battery at North Kaholmen Island. Built in 1901, it was equipped with three shore-mounted dual elevators firing the torpedoes via underwater tunnels. The torpedoes were Austro-Hungarian-built Whitehead torpedoes (in the torpedo factory of Fiume, Hungarian Kingdom, now Rijeka, Croatia) of the same turn-of-the-century vintage. These torpedoes had been practice-launched well over 200 times before being fired in anger, and no-one was certain if they would function or not. They did.
Blücher received two direct hits, one near her forward turret Anton and the second in the engine room, leaving her drifting out of control in the narrow fjord. The torpedoes sealed her fate. The rest of the flotilla, seeing the torpedo explosions, mistakently believed that the Blücher had hit mines. As a result, the flotilla reversed out of the narrows, thus ensuring that Oslo would not be invaded at dawn as intended. Before the remaining ships of the invasion force could withdraw, the Lützow was hit three times by the Kopaas battery and her Anton and Bruno turrets were disabled. The damaged Lützow steamed at full-speed astern, into mist and out of the Norwegian shore batteries' zone of fire.

[Byron Angel]

It is my understanding that Blucher's achilles heel was the fact that her hangar had been loaded with ammunition and supplies for the landing force and one of the coastal battery hits ignited an uncontrolable fire.

Can anyone provide additional detail on this point?


B

[paulcadogan]

the Lützow was hit three times by the Kopaas battery and her Anton and Bruno turrets were disabled.

Lutzow only had one 11-inch turret forward - which was hit on its center gun immobilizing the whole turret. Her aft turret was undamaged but could not bear on the target. The other two hits were in her sick bay and on the port boat crane respectively.

It is my understanding that Blucher's achilles heel was the fact that her hangar had been loaded with ammunition and supplies for the landing force and one of the coastal battery hits ignited an uncontrolable fire.

From her 1st Officer Erich Heyman:

Port side of the ship ripped wide open. Fire raging all round the aircraft hangar and on several decks. The aircraft, fuel and the troop's motor cycles in flames. Ammunition either exploding in the fire or thrown overboard. Fire parties unable to operate due to hoses having ben slashed by splinlters.

The fires are speading and wreaking more and more destruction with no possibility of combating them from the ship herself. In all departments men are working calmy and competently, but without adequate equipment.

According to Cajus Bekker's book "Hitler's Naval War" the ship's fate was finally sealed by a magazine explosion at 0630 after which she heeled further to port. When her list reached 45 degrees shortly before 0700 her captain gave the order to abandon. At 0732 she finally went down, lying on her side for a few moments with "the burning deck reared upwards and the flames flaring out over the sea as if still trying to engulf the erstwhile crew and passengers, now swimming for their lives."

Her chief engineer reported that 10 minutes after she sank there was a "mighty under-water explosion that was both heard and felt and immediately afterwards a tongue of flame leapt from under the sea".

[aurora]

At 0440, as Group V approached Kahlomen Island, searchlights again illuminated Bliicher. Forty-one minutes later, the three main guns of Fort Oskarsborg opened fire, ending a ll German hopes of a quick and peaceful run into Oslo. Three 280mm shells slammed into the ill-fated flagship. The first destroyed the main flak-control platform. The second struck the aircraft hangar, igniting a huge sea of flame that engulfed the Ar 196 float plane and destroyed the port no. I ll 105mm mount. The third damaged the engine telegraphs, j amming the rudder to port. Simultaneously, the 150mm battery at Drobak also entered the fray, scoring an incredible twenty hits from the twenty-five salvos it fired.
These hits left Bliicher heavily shaken. As its main armament gunners scrambled to find something at which to shoot, its light and medium anti-aircraft guns fired at anything remotely resembling a target. After ordering his stricken ship to open fire, Woldag rang for full speed ahead.

aurora

[muskeg13]

"as soon as Oscarsborg fired, the batteries at Kolpaas and Husvik fired, raking the cruiser with 15cm and 57mm shells. Between 22 and 24 15cm shells were fired from Kolpaas and a further twenty five to thirty 57mm shells from Husvik, virtually all hitting the cruiser before she was through the fire zone. The 15cm guns at Kolpaas in particular -positioned above the fjord and firing down onto Bliicher's superstructure- had a devastating effect. Because of the short distance, most of the shells hitting the superstructure penetrated, exploding on the opposite side, turning seventy to seventy-five meters of port center section of Bliicher, between the two 28-cm hits, into a mass of burning debris. Most of the electricity gave out and utter chaos reigned."

(edited), p. 134 The German Invasion of Norway by Geir Haarr

Sorry for the lack of Norsk and Deutch characters.
This must have been an absolute gunner's dream. A big juicy target, they almost couldn't miss, their shots were effective and they could see their handy-work. Yeee-haw!! This battle occurred just down the hill, within sight, of where my wife's family cabin (hytte) is located, so, as a former gunner, this event has special meaning for me. One of the ammunition or communications bunkers for the Drobak batteries still remains a few hundred meters from the cabin.

[aurora]

Attempts were made to run Blücher aground on the Nesodden peninsula, but they failed. At 06.00 hours, the damaged and now sinking Blücher dropped anchor at Askholmen. The purpose was to let wind and current swing the stern closer to Askholmene to rescue more of the crew and soldiers onboard. Askholmene is 6 nautical miles (11 km) south of Oslo and out of the arc of fire from the Norwegian shore batteries. Her torpedoes were fired into the sides of the fjord to prevent them from exploding aboard the ship. At 06.23 the fires reached the 10.5 cm ammunition magazine which detonated, dooming the ship.
By 7.00 with no hope of containing the fires, the order to abandon ship was given. At 7.22 hours, the Blücher capsized and sank. Of the 2,202 crew and troops on board, some 830 died (at least 320 of them crewmen). Most either drowned or burnt to death in the flaming oil slick surrounding the wreck. The survivors came ashore on either side of the fjord. The Blücher's sailors were ordered to give up their life jackets (all sailors are expected to be able to swim) to the troops on board, thus saving the lives of a significant number of soldiers. Her Commanding Officer, Kapitan zur See Heinrich Woldag, survived the sinking, but was killed in a plane crash eight days later.


aurora

[Natter]

The Germans were unaware of a torpedo battery near Oscarsborg's main gun battery at North Kaholmen Island. Built in 1901, it was equipped with three shore-mounted dual elevators firing the torpedoes via underwater tunnels. The torpedoes were Austro-Hungarian-built Whitehead torpedoes (in the torpedo factory of Fiume, Hungarian Kingdom, now Rijeka, Croatia) of the same turn-of-the-century vintage. These torpedoes had been practice-launched well over 200 times before being fired in anger, and no-one was certain if they would function or not. They did.

I realize this is an old post, but just to point out the facts:
Kaholmen torpedobattery at Oscarsborg was no secret and known to the germans, as well as the Kvarven torpedobatery protecting the inlet to Bergen on the norwegian west-coast. Kvarven was included in the german attackplans, but they mistakenly assumed Kaholmen was decomissioned.

The torpedoes were Whitehead Model Vd torpedoes. The warheads original 90 kg guncotton-charge had been replaced with 150 kg TNT in the fall of 1939.
The claim of noone knowing wether they would work is nonsense. The torpeoes were used regulary for both training of the crew as well as technical verification - as normal with all weaponsystems. ¨Their age of 40+ years were admittably old, but not uniqe in any way (for example, we used the ex-german G7a(TI) torpedoes until 2001: They were designed in the late 1920s and in operational service from 1934).

[Byron Angel]

The Germans were unaware of a torpedo battery near Oscarsborg's main gun battery at North Kaholmen Island. Built in 1901, it was equipped with three shore-mounted dual elevators firing the torpedoes via underwater tunnels. The torpedoes were Austro-Hungarian-built Whitehead torpedoes (in the torpedo factory of Fiume, Hungarian Kingdom, now Rijeka, Croatia) of the same turn-of-the-century vintage. These torpedoes had been practice-launched well over 200 times before being fired in anger, and no-one was certain if they would function or not. They did.

I realize this is an old post, but just to point out the facts:
Kaholmen torpedobattery at Oscarsborg was no secret and known to the germans, as well as the Kvarven torpedobatery protecting the inlet to Bergen on the norwegian west-coast. Kvarven was included in the german attackplans, but they mistakenly assumed Kaholmen was decomissioned.

The torpedoes were Whitehead Model Vd torpedoes. The warheads original 90 kg guncotton-charge had been replaced with 150 kg TNT in the fall of 1939.
The claim of noone knowing wether they would work is nonsense. The torpeoes were used regulary for both training of the crew as well as technical verification - as normal with all weaponsystems. ¨Their age of 40+ years were admittably old, but not uniqe in any way (for example, we used the ex-german G7a(TI) torpedoes until 2001: They were designed in the late 1920s and in operational service from 1934).

Hello Herr Natter,
Wonderful post. Thank you. Question: In your opinion, what was the principal cause of Blucher’s sinking - the torpedoes or the 28cm gun battery firing at point blank? Having looked at a map, gun range cannot have been more than a few thousand yards.

Good wishes for 2024.

Byron

[Natter]

Question: In your opinion, what was the principal cause of Blucher’s sinking - the torpedoes or the 28cm gun battery firing at point blank? Having looked at a map, gun range cannot have been more than a few thousand yards.

My main interest is the technical aspects of torpedoes, mines and coastal defences, and I have limited knowledge on ship-architecture and details regarding all damages inflicted on Blücher, but I can't think anyone would disagree that the cruiser sank due to the fact that the torpedoes created two gaping holes in her hull. Obviously, other damages inflicted by both torpedoes and artillery fire contributed massivly to major damages on the ship, but wether they would lead to it sinking in the end is impossible to tell for sure.

[RF]

It is likely that without the torpedo hit midships the Blucher would have stayed afloat, albeit very heavily damaged from shell hits and the resultant fires. The initial torpedo hit in the bow section forward of Anton turret was too far forward to cause significant damage, it was the second hit midships that was the fatal blow.

[marcelo_malara]

Old rule, it is difficult to sink a ship by gunfire alone. For sure the torpedoes were the main culprit.