SMS Blücher (wreck)

 ship, First World War 1914-1918, shipwreck

SMS Blücher was the last armored cruiser of the German Kaiserliche Marine. She was built as a response to what German intelligence at the time believed were the specifications of the British Invincible class battlecruisers. Blücher was considered to be an intermediate stage toward the future German battlecruiser; she was larger than all preceding armored cruisers and carried more heavy guns, but was not equipped with guns as powerful as those on subsequent German battlecruisers.

Blücher was built at the Kaiserliche Werft in Kiel, between 1907 and 1909, and commissioned on 1 October 1909. The ship served in the I Scouting Group for the majority of her career, including activity in the early portion of World War I. She took part in the operation to bombard Yarmouth and the raid on Scarborough, Hartlepool and Whitby in 1914. At the Battle of Dogger Bank on 24 January 1915, Blücher was slowed significantly after being hit by gunfire from the British battlecruiser Princess Royal. Rear Admiral Franz von Hipper, the commander of the German squadron, decided to abandon Blücher to the pursuing enemy ships in order to save his more valuable battlecruisers. She was sunk at 13:10, having been subjected to heavy fire from the British ships.

Design

The design for the ship, ordered under the provisional name "E", was influenced by early reports of a new British class of armored cruisers, which were expected to simply be larger than their predecessors. In fact they were a substantially new type of ship, equipped with 30.5 cm (12.0 in) guns like battleships and, at Lord Fisher's recommendation, eventually classified as "battlecruisers". Being only an upgrade of the traditional armored cruisers, Blücher was significantly inferior to the ships of the new Invincible class in speed and firing power. The Germans had expected the new British ships to be armed with six to eight 9.2 in (23 cm) guns and therefore equipped Blücher with a larger number—12—of 21 cm (8.3 in) guns. One week after the final decision was made on Blücher, information from the British Naval Attache about the armament of Invincible class was leaked. It was too late to redesign Blücher and there was no available funding for a redesign, so work proceeded as scheduled. The last German armored cruiser was therefore rapidly superseded by newer battlecruisers, starting with Von der Tann, construction of which began in 1907.

General characteristics

Blücher was 161.1 meters long at the waterline and 161.8 m long overall. The ship had a beam of 24.5 m, and with the anti-torpedo nets mounted along the sides of the ship, the beam increased to 25.62 m. Blücher had a draft of 8.84 m forward, but only 8.56 m aft. The ship displaced 15,842 metric tons at her designed weight, and up to 17,500 tons at maximum displacement. Her hull was constructed with both transverse and longitudinal steel frames, and she had thirteen watertight compartments and a double bottom that ran for approximately 65% of the length of the hull.

German naval historian Erich Gröner, in his book German Warships 1815–1945, stated that Blücher was considered to have been a good sea boat by the German navy; the ship only had a minor pitch and had gentle motion. However, she suffered from severe roll, and at hard rudder, she heeled over up to 10 degrees. With the rudder hard over, the ship lost up to 55% speed. Blücher's metacentric height was 1.63 m. The ship had a standard crew of 41 officers and 812 enlisted men. When she served as a squadron flagship, she was manned by an additional 14 officers and 62 sailors. She carried a number of smaller vessels, including two picket boats, three barges, two launches, two yawls, and one dinghy.

Propulsion

Blücher was equipped with three vertical 4-cylinder triple expansion engines. Each engine drove a propeller, the inner screw being 5.3 m in diameter, while the outer two screws were slightly larger, at 5.6 m in diameter. The ship had a single rudder with which to steer. Each engine had a separate engine room. With six marine-type double boilers per room, the ship contained a total of 18 coal-fired boilers. The ship had a designed maximum speed of 24.5 knots, but during her trials, she achieved a speed of 25.4 knots. At a cruising speed of 12 knots, Blücher could steam for 6,600 nautical miles. At a speed of 18 knots, her range was cut down to 3,250 nautical miles. The ship was designed to carry 900 tons of coal, though fuel bunkers were expanded to allow up to 2,510 tons of coal. Electrical power for the ship was supplied by six turbo-generators that provided up to 1,000 kilowatts, rated at 225 volts.

Armament

Blücher was equipped with twelve 21 cm SK L/45 quick-firing guns in six twin turrets, one fore and aft, and two in wing turrets on either side of the superstructure. The guns were supplied with a total of 1,020 shells, or 85 rounds per gun. Each shell weighed 108 kg (238 pounds), and was 61 cm (24 in) in length. The guns could be depressed to -5 degrees, and elevated to 30 degrees; this provided a maximum range of 19,100 m. Their rate of fire was 4 to 5 rounds per minute.

The ship had a secondary battery of eight 15 cm SK L/45 quick-firing guns mounted in MPL C/06 casemates, four centered amidships on either side of the vessel. These guns could engage targets out to 13,500 m. They were supplied with 1320 rounds, for 165 shells per gun, and had a sustained rate of fire of 5 to 7 rounds per minute. The shells were 45.3 kg (99.8 lb), and were loaded with a 13.7 kg (31.2 lb) RPC/12 propellant charge in a brass cartridge. The guns fired at a muzzle velocity of 835 meters per second (2,740 ft/s), and were expected to fire around 1,400 shells before they needed to be replaced.

Blücher was also armed with sixteen 8.8 cm SK L/45 quick-firing guns, placed in both casemates and pivot mounts. Four of these guns were mounted in casemates near the bridge, four in casemates in the bow, another four in casemates at the stern, and the remaining four were mounted in pivot mounts in the rear superstructure. They were supplied with a total of 3,200 rounds, or 200 shells per gun,[3] and could fire at a rate of 15 shells per minute. Their high explosive shells weighed 10 kg (22.05 lb) and were loaded with a 3 kg (6.6 lb) RPC/12 propellant charge. These guns had a life expectancy of around 7,000 rounds.

Blücher was also equipped with four 45 cm torpedo tubes. One was placed in the bow, one in the stern, and the other two were placed on the broadside, all below the waterline. The ship carried a total of 11 torpedoes.

Armor

As with other German capital ships of the period, Blücher was equipped with Krupp armor. The armored deck was between 50 and 70 mm in thickness; more important areas of the ship were protected with thicker armor, while less critical portions of the deck used the thinner armor. The armored belt was 180 mm thick in the central portion of the ship, and reduced to 80 mm in less important areas of the hull. The belt tapered down to zero at either end of the ship. The thickest portion of the belt was backed by 120 mm-thick shields; behind the entire length of the belt armor was an additional 30 mm of teak. The armored belt was supplemented by a 35 mm-thick torpedo bulkhead.

The forward conning tower had an armored roof that was 80 mm thick and 250 mm-thick sides. The rear conning tower was significantly less well armored, with a roof that was 30 mm thick and sides that were only 140 mm thick. The central citadel of the ship was protected by 160 mm-thick armor. The main battery turrets were 80 mm thick in their roofs, and had 180 mm thick sides. The 15 cm turret casemates were protected by 140 mm worth of armor.

Service history

SMS Blücher pre-war, circa 1913–1914

Blücher was launched on 11 April 1908, and commissioned into the fleet on 1 October 1909. She served as a training ship for naval gunners starting in 1911. In 1914, she was transferred to the I Scouting Group along with the newer battlecruisers Von der Tann, Moltke, and the flagship Seydlitz.

Bombardment of Yarmouth

On 2 November 1914, Blücher, along with the battlecruisers Moltke, Von der Tann, and Seydlitz, accompanied by four light cruisers, left the Jade Estuary and steamed towards the English coast.[6] The flotilla arrived off Great Yarmouth at daybreak the following morning and bombarded the port, while the light cruiser Stralsund laid a minefield. The British submarine D5 responded to the bombardment, but struck one of the mines laid by Stralsund and sank. Shortly thereafter, Hipper ordered his ships to turn back to German waters. On the way, a heavy fog covered the Heligoland Bight, so the ships were ordered to halt until visibility improved and they could safely navigate the defensive minefields. The armored cruiser Yorck made a navigational error that led her into one of the German minefields. She struck two mines and quickly sank; only 127 men out of the crew of 629 were rescued.

Bombardment of Scarborough, Hartlepool, and Whitby

Admiral Friedrich von Ingenohl, commander of the German High Seas Fleet, decided that another raid on the English coast should be carried out in the hopes of luring a portion of the Grand Fleet into combat where it could be destroyed. At 03:20 on 15 December 1914, Blücher, Moltke, Von der Tann, the new battlecruiser Derfflinger, and Seydlitz, along with the light cruisers Kolberg, Strassburg, Stralsund, and Graudenz, and two squadrons of torpedo boats left the Jade estuary. The ships sailed north past the island of Heligoland, until they reached the Horns Reef lighthouse, at which point the ships turned west towards Scarborough. Twelve hours after Hipper left the Jade, the High Seas Fleet, consisting of 14 dreadnoughts and 8 pre-dreadnoughts and a screening force of 2 armored cruisers, 7 light cruisers, and 54 torpedo boats, departed to provide distant cover to the bombardment force.

On 26 August 1914, the German light cruiser Magdeburg had run aground in the Gulf of Finland; the wreck was captured by the Russian navy, which found code books used by the German navy, along with navigational charts for the North Sea. These documents were then passed on to the Royal Navy. Room 40 began decrypting German signals, and on 14 December, intercepted messages relating to the plan to bombard Scarborough.[7] The exact details of the plan were unknown, and it was assumed that the High Seas Fleet would remain safely in port, as in the previous bombardment. Vice Admiral Beatty's four battlecruisers, supported by the 3rd Cruiser Squadron and the 1st Light Cruiser Squadron, along with the 2nd Battle Squadron's six dreadnoughts, were to ambush Hipper's battlecruisers.

During the night of 15 December, the main body of the High Seas Fleet encountered British destroyers. Fearing the prospect of a nighttime torpedo attack, Admiral Ingenohl ordered the ships to retreat. Hipper was unaware of Ingenohl's reversal, and so he continued with the bombardment. Upon reaching the British coast, Hipper's battlecruisers split into two groups. Seydlitz, Moltke, and Blücher went north to shell Hartlepool, while Von der Tann and Derfflinger went south to shell Scarborough and Whitby. During the bombardment of Hartlepool, Seydlitz was hit three times and Blücher was hit six times by the coastal battery. Blücher suffered minimal damage, but 9 men were killed and another 3 were wounded. By 09:45 on the 16th, the two groups had reassembled, and they began to retreat eastward.

The High Seas Fleet's disposition on the morning of 16 December

By this time, Beatty's battlecruisers were in position to block Hipper's chosen egress route, while other forces were en route to complete the encirclement. At 12:25, the light cruisers of the II Scouting Group began to pass through the British forces searching for Hipper. One of the cruisers in the 2nd Light Cruiser Squadron spotted Stralsund and signaled a report to Beatty. At 12:30, Beatty turned his battlecruisers towards the German ships. Beatty presumed that the German cruisers were the advance screen for Hipper's ships, but the battlecruisers were some 50 km (31 mi) ahead.[11] The 2nd Light Cruiser Squadron, which had been screening for Beatty's ships, detached to pursue the German cruisers, but a misinterpreted signal from the British battlecruisers sent them back to their screening positions. This confusion allowed the German light cruisers to escape and alerted Hipper to the location of the British battlecruisers. The German battlecruisers wheeled to the northeast of the British forces and made good their escape.

Both the British and the Germans were disappointed that they failed to effectively engage their opponents. Admiral Ingenohl's reputation suffered greatly as a result of his timidity. The captain of the Moltke was furious; he stated that Ingenohl had turned back "because he was afraid of eleven British destroyers which could have been eliminated … under the present leadership we will accomplish nothing." The official German history criticized Ingenohl for failing to use his light forces to determine the size of the British fleet, stating: "He decided on a measure which not only seriously jeopardized his advance forces off the English coast but also deprived the German Fleet of a signal and certain victory."

Battle of Dogger Bank(1915)

In early January 1915, it became known to the German naval command that British ships were conducting reconnaissance in the Dogger Bank area. Admiral Ingenohl was initially reluctant to attempt to destroy these forces, because the I Scouting Group was temporarily weakened while Von der Tann was in drydock for periodic maintenance. Konteradmiral Richard Eckermann, the Chief of Staff of the High Seas Fleet, insisted on the operation, and so Ingenohl relented and ordered Hipper to take his battlecruisers to the Dogger Bank.

On 23 January, Hipper sortied, with Seydlitz in the lead, followed by Moltke, Derfflinger, and Blücher, along with the light cruisers Graudenz, Rostock, Stralsund, and Kolberg and 19 torpedo boats from V Flotilla and II and XVIII Half-Flotillas. Graudenz and Stralsund were assigned to the forward screen, while Kolberg and Rostock were assigned to the starboard and port, respectively. Each light cruiser had a half-flotilla of torpedo boats attached.

Again, interception and decryption of German wireless signals played an important role. Although they were unaware of the exact plans, the cryptographers of Room 40 were able to deduce that Hipper would be conducting an operation in the Dogger Bank area. To counter it, Beatty's 1st Battlecruiser Squadron, Rear Admiral Archibald Moore's 2nd Battlecruiser Squadron and Commodore William Goodenough's 2nd Light Cruiser Squadron were to rendezvous with Commodore Reginald Tyrwhitt's Harwich Force at 8:00 on 24 January, approximately 30 mi (48 km) north of the Dogger Bank.

At 08:14, Kolberg spotted the light cruiser Aurora and several destroyers from the Harwich Force.Aurora challenged Kolberg with a search light, at which point Kolberg attacked Aurora and scored two hits. Aurora returned fire and scored two hits on Kolberg in retaliation. Hipper immediately turned his battlecruisers towards the gunfire, when, almost simultaneously, Stralsund spotted a large amount of smoke to the northwest of her position. This was identified as a number of large British warships steaming towards Hipper's ships. Hipper later remarked:

The presence of such a large force indicated the proximity of further sections of the British Fleet, especially as wireless intercepts revealed the approach of 2nd Battlecruiser Squadron...They were also reported by Blücher at the rear of the German line, which had opened fire on a light cruiser and several destroyers coming up from astern...The battlecruisers under my command found themselves, in view of the prevailing [East-North-East] wind, in the windward position and so in an unfavourable situation from the outset...

Hipper turned south to flee, but was limited to 23 knots (43 km/h), which was Blücher's maximum speed at the time. The pursuing British battlecruisers were steaming at 27 knots (50 km/h), and quickly caught up to the German ships. At 09:52, Lion opened fire on Blücher from a range of approximately 20,000 yards (18,300 m); shortly after, Queen Mary and Tiger began firing as well. At 10:09, the British guns made their first hit on Blücher. Two minutes later, the German ships began returning fire, primarily concentrating on Lion, from a range of 18,000 yards (15,460 m). At 10:28, Lion was struck on the waterline, which tore a hole in the side of the ship and flooded a coal bunker.[15] At 10:30, New Zealand, the fourth ship in Beatty's line, came within range of Blücher and opened fire. By 10:35, the range had closed to 17,500 yards (16,000 m), at which point the entire German line was within the effective range of the British ships. Beatty ordered his battlecruisers to engage their German counterparts. Confusion aboard Tiger led the captain to believe he was to fire on Seydlitz, which left Moltke able to fire without distraction.

By 11:00, Blücher had been severely damaged after having been pounded by numerous heavy shells from the British battlecruisers. At 11:48, Indomitable arrived on the scene, and was directed by Beatty to destroy the battered Blücher. She was already on fire and listing heavily to port; one of the ship's survivors recounted the destruction that was being wrought:

The shells...bore their way even to the stokehold. The coal in the bunkers was set on fire. Since the bunkers were half empty, the fire burned merrily. In the engine room a shell licked up the oil and sprayed it around in flames of blue and green...the terrific air pressure resulting from an explosion in a confined space...roars through every opening and tears its way through every weak spot...Men were picked up by that terrific air pressure and tossed to a horrible death among the machinery.

However, this was interrupted due to reports of U-boats ahead of the British ships; Beatty quickly ordered evasive maneuvers, which allowed the German ships to increase the distance to their pursuers.[17] At this time, Lion's last operational dynamo failed, which reduced her speed to 15 knots (28 km/h). Beatty, in the stricken Lion, ordered the remaining battlecruisers to "Engage the enemy's rear," but signal confusion caused the ships to solely target Blücher. She continued to resist stubbornly, sustaining over 70 hits from the British battlecruisers and light cruisers, and continuing to fire her own guns until she rolled over and sank at 13:10. As the ship was sinking, British destroyers steamed towards her in an attempt to rescue survivors from the water. However, the German zeppelin L5 mistook the sinking Blücher for a British battlecruiser, and tried to bomb the destroyers. The destroyers were forced to withdraw, having picked up only 237 of the crew of 792. Among those who had been rescued was Kapitan zur See Erdmann, the commanding officer of Blücher. He later died of pneumonia while in British captivity.

The concentration on Blücher allowed Moltke, Seydlitz, and Derfflinger to escape. Admiral Hipper had originally intended to use his three battlecruisers to turn about and flank the British ships, in order to relieve the battered Blücher, but when he learned of the severe damage to his flagship, he decided to abandon the armored cruiser. Hipper later recounted his decision:

In order to help the Blücher it was decided to try for a flanking move...But as I was informed that in my flagship turrets C and D were out of action, we were full of water aft, and that she had only 200 rounds of heavy shell left, I dismissed any further thought of supporting the Blücher. Any such course, now that no intervention from our Main Fleet was to be counted on, was likely to lead to further heavy losses. The support of the Blücher by the flanking move would have brought my formation between the British battlecruisers and the battle squadrons which were probably behind.

By the time Beatty regained control over his ships, after having boarded Princess Royal, the German ships had too far a lead for the British to catch them; at 13:50, he broke off the chase. Kaiser Wilhelm II was enraged by the destruction of Blücher and the near sinking of Seydlitz, and ordered the High Seas Fleet to remain in harbor. Konteradmiral Eckermann was removed from his post and Admiral Ingenohl was forced to resign. He was replaced by Admiral Hugo von Pohl.