German cruiser Blücher

For the World War I-era ship, see SMS Blücher.
Blücher while on trials
History
Nazi Germany
Name: Blücher
Namesake: Gebhard Leberecht von Blücher
Laid down: 15 August 1936
Launched: 8 June 1937
Commissioned: 20 September 1939
Fate: Sunk in the Battle of Drøbak Sound on 9 April 1940
General characteristics
Class and type: Admiral Hipper-class cruiser
Displacement:
Length: 203.20 m (666 ft 8 in) overall
Beam: 22 m (72 ft 2 in)
Draft: Full load: 7.20 m (23.6 ft)
Propulsion:
  • 3 × Blohm & Voss steam turbines
  • 3 × three-blade propellers
  • 132,000 shp (98 MW)
Speed: 32 knots (59 km/h; 37 mph)
Complement:
  • 42 officers
  • 1,340 enlisted men
Armament:
  • 8 × 20.3 cm (8.0 in) guns
  • 12 × 10.5 cm (4.1 in) guns
  • 12 × 3.7 cm (1.5 in) guns
  • 8 × 2 cm (0.79 in) guns (20 × 1)
  • 6 × 53.3 cm (21 in) torpedo tubes
Armor:
  • Belt: 70 to 80 mm (2.8 to 3.1 in)
  • Armor deck: 20 to 50 mm (0.79 to 1.97 in)
  • Turret faces: 105 mm (4.1 in)
Aircraft carried: 3 aircraft
Aviation facilities: 1 catapult

Blücher was the second of five Admiral Hipper-class heavy cruisers of Nazi Germany's Kriegsmarine, built after the rise of the Nazi Party and the repudiation of the Treaty of Versailles. Named for Gebhard Leberecht von Blücher, the Prussian victor of the Battle of Waterloo, the ship was laid down in August 1936 and launched in June 1937. She was completed in September 1939, shortly after the outbreak of World War II. After completing a series of sea trials and training exercises, the ship was pronounced ready for service with the fleet on 5 April 1940.

Assigned to Group 5 during the invasion of Norway in April 1940, Blücher served as Konteradmiral Oskar Kummetz's flagship. The ship led the flotilla of warships into the Oslofjord on the night of 8 April, to seize Oslo, the capital of Norway. Two old 28 cm (11 in) coastal guns in the Oscarsborg Fortress engaged the ship at very close range, scoring two hits.[1] Two torpedoes fired by land-based torpedo batteries struck the ship, causing serious damage. A major fire broke out aboard Blücher, which could not be contained. After a magazine explosion, the ship sank, with major loss of life. The wreck remains on the bottom of the Oslofjord.

Construction

Recognition drawing of an Admiral Hipper-class cruiser

Blücher was ordered by the Kriegsmarine from the Deutsche Werke shipyard in Kiel.[2] Her keel was laid on 15 August 1936,[3] under construction number 246.[2] The ship was launched on 8 June 1937, and was completed slightly over two years later, on 20 September 1939, the day she was commissioned into the German fleet.[4] The commanding admiral of the Marinestation der Ostsee (Baltic Naval Station), Admiral Conrad Albrecht, gave the christening speech. Frau Erdmann, widow of Fregattenkapitän Alexander Erdmann, former commander of SMS Blücher, performed the christening.[5] As built, the ship had a straight stem, though after her launch this was replaced with a clipper bow increasing the overall length to 205.90 meters (675.5 ft).[6] A raked funnel cap was also installed.[7]

As launched, Blücher was 202.80 meters (665.4 ft) long overall, had a beam of 21.30 m (69.9 ft) and a maximum draft of 7.74 m (25.4 ft).[6] The ship had a design displacement of 16,170 t (15,910 long tons; 17,820 short tons) and a full load displacement of 18,200 long tons (18,500 t). Blücher was powered by three sets of geared steam turbines, which were supplied with steam by twelve ultra-high pressure oil-fired boilers. The ship's top speed was 32 knots (59 km/h; 37 mph), at 132,000 shaft horsepower (98,000 kW).[2] As designed, her standard complement consisted of 42 officers and 1,340 enlisted men.[8]

Blücher's primary armament was eight 20.3 cm (8.0 in) SK L/60 guns mounted in four twin gun turrets, placed in superfiring pairs forward and aft.[lower-alpha 1] Her anti-aircraft battery consisted of twelve 10.5 cm (4.1 in) L/65 guns, twelve 3.7 cm (1.5 in) guns, and eight 2 cm (0.79 in) guns. The ship would also have carried a pair of triple 53.3 cm (21.0 in) torpedo launchers abreast of the rear superstructure. She had four triple 53.3 cm (21.0 in) torpedo launchers, all on the main deck next to the four FLAK range finders.[9][10] The ship was equipped with three Arado Ar 196 seaplanes and one catapult.[8] Blucher never had more than two seaplanes on board, and en route to Oslo one had to rest on the catapult as one of the hangars was used for storing bombs and torpedoes.[11] Blücher's armored belt was 70 to 80 mm (2.8 to 3.1 in) thick; her upper deck was 12 to 30 mm (0.47 to 1.18 in) thick while the main armored deck was 20 to 50 mm (0.79 to 1.97 in) thick. The main battery turrets had 105 mm (4.1 in) thick faces and 70 mm thick sides.[2]

Service history

Blücher launching at Kiel, 8 june 1937

Blücher spent the majority of November 1939 fitting out and finishing additional improvements. By the end of the month, the ship was ready for sea trials; she steamed to Gotenhafen in the Baltic Sea.[12] The trials lasted until mid-December, after which the ship returned to Kiel for final modifications. In January 1940, she resumed her exercises in the Baltic, but by the middle of the month, severe ice forced the ship to remain in port. On 5 April, she was deemed to be ready for action, and was therefore assigned to the forces participating in the invasion of Norway.[13]

Operation Weserübung

Main article: Operation Weserübung

On 5 April 1940, Konteradmiral Oskar Kummetz came aboard the ship while she was in Swinemünde. An 800-strong detachment of ground troops from the 163rd Infantry Division also boarded. Three days later, on 8 April, Blücher left port, bound for Norway; she was the flagship for the force that was to seize Oslo, the Norwegian capital. Organized as Group 5 of the invasion force[14] she was accompanied by the heavy cruiser Lützow, the light cruiser Emden, and several smaller escorts. While steaming through the Kattegat and Skagerrak, the British submarine Triton spotted the convoy and fired a spread of torpedoes; the Germans successfully evaded the torpedoes, however, and proceeded with the mission.[13]

Blücher en route to Norway, as seen from the light cruiser Emden

Night had fallen by the time the German flotilla reached the approaches to the Oslofjord. Shortly after 23:00 (Norwegian time) the flotilla was spotted by the Norwegian patrol boat Pol III. The German torpedo boat Albatros attacked Pol III and set her on fire, but not before the Norwegian patrol boat raised the alarm with a radio report of being attacked by unknown warships.[15] At 23:30 (Norwegian time) the south battery on Rauøy spotted the flotilla in the searchlight and fired two warning shots.[16] Five minutes later, the guns at the Rauøy battery fired four rounds at the approaching Germans, but visibility was poor and no hits were scored.[16] The guns at Bolærne fired only one warning shot at 23:32. Before Blücher could be targeted again, she was out of the firing sector of these shore guns and was seen no more by them after 23:35.[17]

The German flotilla steamed on at a speed of 12 knots (22 km/h; 14 mph).[18] Shortly after midnight (Norwegian time), an order from the Commanding Admiral to extinguish all lighthouses and navigation lights was broadcast over the NRK (Norsk rikskringkasting) [Norwegian Broadcasting Corporation].[19] The German ships had been ordered to fire only in the event they were directly fired on first.[13] Between 00:30 and 02:00, the flotilla stopped and 150 infantrymen of the landing force were transferred to the escorts R17 and R21 (from Emden) and R18 and R19 (from Blücher).[20]

The R-boats were ordered to engage Rauøy, Bolærne and the naval port and city of Horten.[20] Despite the apparent loss of surprise, the Blücher proceeded further into the fjord to continue with the timetable to reach Oslo by dawn. At 04:40, Norwegian searchlights again illuminated the ship and at 04:21 the 28 cm (11 in) guns of Oscarsborg Fortress opened fire on Blücher at very close range, beginning the Battle of Drøbak Sound with two hits on her port side.[13] The first was high above the bridge, hitting the battle station for the commander of the anti-aircraft guns, killing AO II Kapitänleutnant Hans-Erich Pochhammer.[21] The main range finder in the top of the battle mast was knocked out of alignment, but Blücher had four more major rangefinders (B-turret, on the bridge roof, the aft battle station (Nachtstand) and C-turret) and many smaller on the bridge and the four rangefinder stations for the AA. The commander in D-turret, Oberstückmeister Waldeck, stated that the first 28 cm hit had no influence on the battle capability of the 20.3 cm guns.[22] Blücher immediately returned fire.

Fire starts

The second 28 cm shell struck near the aircraft hangar and started a major fire. As the fire spread, it detonated explosives carried for the infantry, hindering firefighting efforts.[21] The explosion set fire to the two Arado seaplanes on board: one on the catapult and the other in one of the hangars.[23] The explosion also probably punched a hole in the armored deck over turbine room 1. Turbine 1 and generator room 3 stopped for lack of steam and only the outboard shafts from turbine room 2/3 were operational.[24]

The Germans were unable to locate the source of the gunfire. Blücher increased speed to 32 knots (59 km/h; 37 mph) in an attempt to get past the Norwegian guns.[13] The 15 cm (5.9 in) guns on Drøbak, some 400 yd (370 m) on Blücher's starboard side, opened fire as well.[25] At a distance of 500 metres (1,600 ft) Blücher entered the narrows between Kopås and Hovedbatteriet (the main battery) at Kaholmen. The Kopås battery ceased firing at Blücher and engaged the next target, Lützow, scoring multiple hits.[26] First engineer Leitende Ingenieur Fregattenkapitän Dip. Ing. Karl Thannemann wrote in his report that the hits from the guns on Drøbak, which were fired on the starboard side, were all between section IV and X in a length of 75 metres (246 ft) amidships, between B-turret and C-turret. However, all damage were on the port side.[27] The shells must have traversed most of the superstructure before exploding.

One of the 28 cm guns at Oscarsborg Fortress

After the first salvo from the 15 cm batteries in Drøbak, the steering from the bridge was disabled. Blücher had just passed Drøbakgrunnen (Drøbak shallows) and was in a turn to port. The commander got her back on track by using the side shafts, but she lost speed.[28] Normally the rudder is controlled electrically from the bridge to the motors forward of the Handsteuerraum (hand steering room) deep under the armored deck, forward of the rudder. In an emergency it can be switched within seconds to manual steering, but orders from the bridge to the rudder may be delayed.[29] At 04:34 Norwegian land-based torpedo batteries scored two hits on the ship.[25] The targeting device in the torpedo battery was very primitive. The speed of the torpedo was known and set, but the speed of the target had to be adjusted by Dead reckoning (guessing).[30]

According to Admiral Kummetz' report, the first torpedo hit Kesselraum 2 (boileroom 2, just under the funnel) and the second hit Turbinenraum 2/3 (the turbine room for the side shafts). Boiler 1 had already been destroyed by gunfire. Only one boiler remained, but the steam pipes through boiler 1 and 2 and turbine room 2/3 had been damaged and turbine 1 for the main shaft lost its power.[28] By 04:34, the ship had been severely damaged, but had successfully passed through the firing zone; the Norwegian guns could no longer bear on her. The 15 cm guns in the Kopås battery were all standing in open positions with a wide sector of firing. After the torpedo hits, Blücher was still within range. The battery asked for orders, but Eriksen concluded: The fortress has served its purpose.[31] With all propellers stopped, about 60% of the electric power gone, Blucher quickly lost speed and at about 04:50 dropped anchors at Askoholmene.

Sinking

Blücher sinking in Drøbak Sound

After passing the gun batteries, the crew of Blücher, including the personnel manning the guns, were tasked with fighting the fire. By that time she had taken on a list of 18 degrees, although this was not initially problematic. The fire eventually reached one of the ship's 10.5 cm ammunition magazines between turbine room 1 and turbine room 2/3, which exploded violently. The blast ruptured several bulkheads in the engine rooms and ignited the ship's fuel stores.[25] The battered ship slowly began to capsize and the order to abandon ship was given.[32] Blücher rolled over and sank at 07:30, with significant casualties.[33] Naval historian Erich Gröner states that the number of casualties is unknown,[4] but Henrik Lunde gives a loss of life figure ranging between 600 and 1,000 soldiers and sailors.[18] Jürgen Rohwer meanwhile states that 125 seamen and 195 soldiers died in the sinking.[34]

One of Blücher's anchors is now at Aker Brygge in Oslo

The loss of Blücher and the damage done to Lützow caused the German force to withdraw. The ground troops were landed on the eastern side of the fjord; they proceeded inland and captured the Oscarborg Fortress by 09:00 on 10 April. They then moved on to attack the capital. Airborne troops captured the Fornebu Airport and completed the encirclement of the city, and by 14:00 on 10 April it was in German hands. The delay caused by the temporary withdrawal of Blücher's task force, however, allowed the Norwegian government and royal family to escape the city.[18]

Blücher remains at the bottom of the Drøbak Narrows, at a depth of 35 fathoms (210 ft; 64 m).[35] The ship's screws were removed in 1953, and there have been several proposals to raise the wreck since 1963, but none have been carried out.[4] When Blücher left Germany, she had about 2,670 cubic metres (94,000 cu ft) of oil on board. She expended some of the fuel en route to Norway, and some was lost in the sinking, but she was constantly leaking oil. In 1991 the leakage rate increased to 50 liters (11 imp gal; 13 U.S. gal) per day, threatening the environment. The Norwegian government therefore decided to remove as much oil as possible from the wreck. In October 1994 the company Rockwater AS, together with deep sea divers drilled holes in 133 fuel tanks and removed 1,000 t (980 long tons; 1,100 short tons) of oil; 47 fuel bunkers were unreachable and may still contain oil. After being run through a cleaning process, the oil was sold. The oil extraction operation provided an opportunity to recover one of Blücher's two Arado 196 aircraft. The plane was raised on 9 November 1994 and is currently at the Flyhistorisk Museum, Sola aviation museum near Stavanger.[36]

The shipwreck was protected as a war memorial on 16 June 2016, but also protected by law by Norwegian Directorate for Cultural Heritage for those who actually have their burial at the bottom of the fjord. The intention was to protect the ship from wreck looters.[37]

Footnotes

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Notes

  1. ↑ "L/60" denotes the length of the gun in terms of calibers. The length of 60 caliber gun is 60 times greater than it is wide in diameter.

Citations

  1. ↑ Binder & Schlünz, p. 90.
  2. 1 2 3 4 Gröner, p. 65.
  3. ↑ Williamson, p. 22.
  4. 1 2 3 Gröner, p. 67.
  5. ↑ Koop & Schmolke, p. 113.
  6. 1 2 Koop & Schmolke, p. 13.
  7. ↑ Williamson, p. 35.
  8. 1 2 Gröner, p. 66.
  9. ↑ Koop & Schmolke, p. 22.
  10. ↑ Binder & Schlünz, p. 97.
  11. ↑ Koop & Schmolke, p. 115.
  12. ↑ Williamson, pp. 23–24.
  13. 1 2 3 4 5 Williamson, p. 24.
  14. ↑ Rohwer, p. 18.
  15. ↑ Tamelander & Zetterling, p. 72.
  16. 1 2 Fjeld et al., p. 179.
  17. ↑ Fjeld et al., p. 180.
  18. 1 2 3 Lunde, p. 220.
  19. ↑ Berg, p. 9.
  20. 1 2 Binder & Schlünz, p. 74.
  21. 1 2 Binder & Schlünz, p. 92.
  22. ↑ Binder & Schlünz, p. 119.
  23. ↑ Binder & Schlünz, p. 93.
  24. ↑ Binder & Schlünz, p. 126.
  25. 1 2 3 Williamson, p. 33.
  26. ↑ Fjeld et al., p. 189.
  27. ↑ Binder & Schlünz, p. 83.
  28. 1 2 Koop & Schmolke, p. 126.
  29. ↑ Koop & Schmolke, p. 42.
  30. ↑ A.n. Hovland;Centralsikteapparat for torpedobatteriet, Verdens Gang 13. April and 6. May 1953. (Comments by the inventor of the targeting device)
  31. ↑ Lislegaard, Othar; Børte, Torbjørn:Skuddene som reddet Norge?, H.Aschehaoug &co (W. Nygaard) Oslo 1975, p 42
  32. ↑ Williamson, pp. 33–34.
  33. ↑ Williamson, p. 34.
  34. ↑ Rohwer, p. 19.
  35. ↑ Gardiner & Chesneau, p. 229.
  36. ↑ Binder & Schlünz, p. 180.
  37. ↑ "Blucher" protected by law to prevent looting NRK 6/16/2016 (Norwegian)

References

Coordinates: 59°42′N 10°35.5′E / 59.700°N 10.5917°E / 59.700; 10.5917

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