SMS Derfflinger

The Derfflinger class was authorised for the 1911 fiscal year under the 1906 naval law, with design work beginning in early 1910. Once the British started putting 34.3 cm guns in their battlecruisers, the German naval command concluded that a step up from 28 cm to 30.5 cm was necessary. To hold down cost the number of guns was cut from the ten of the earlier Seydlitz to eight, arranged in a more efficient superfiring layout. Derfflinger's keel was laid at Blohm & Voss in Hamburg on 30 March 1912 under the provisional designation "K".

She was named for Georg von Derfflinger, a Prussian field marshal of the Thirty Years' War. Her launch on 14 June 1913, with General August von Mackensen giving the speech, failed: the yard had used three wooden sledges instead of four, the centre sledge took too much weight and squeezed out its lubrication, and the ship moved only 30 to 40 centimetres. The centre sledge was removed entirely and a second attempt on 12 July succeeded. She commissioned on 1 September 1914, with a crew largely returned from a tour in the East Asia Squadron.

She was 210.4 m long overall on a 29 m beam, displacing 26,600 tonnes normally. Two pairs of high- and low-pressure turbines drove four propellers on steam from fourteen coal-fired water-tube boilers, rated at 63,000 metric horsepower for 26.5 knots; in March 1915 the boilers were modified to burn supplemental fuel oil. Her belt was 300 mm through the citadel over magazines and machinery, her turret faces 270 mm, her conning tower walls 300 mm. She was the largest and most powerful German battlecruiser of her day.

Her first combat operation was the raid on Scarborough, Hartlepool and Whitby. Hipper left the Jade at 03:20 on 15 December 1914 with Seydlitz leading, then Derfflinger, Moltke, Von der Tann and Blücher, with light cruisers and two torpedo boat squadrons. Off the English coast the force split: Derfflinger and Von der Tann went south to shell Scarborough and Whitby while the others struck Hartlepool. Room 40 had decrypted messages about the plan, and Beatty was waiting on the withdrawal route, but confused signalling let the German battlecruisers slip away to the northeast.

At Dogger Bank on 24 January 1915 the British caught them. Hipper turned south but was held to 23 knots by the older armoured cruiser Blücher while Beatty's ships came on at 27. The Germans opened fire at 10:11, concentrating on Lion; Derfflinger was hit once by a heavy shell early on, which forced two hull plates inward and flooded some protective coal bunkers. At 11:18 two of her 30.5 cm shells hit Lion, one striking the waterline and penetrating the belt, letting seawater into the port feed tank and forcing Beatty's flagship out of the line.

Signal confusion then sent the whole British line onto Blücher, which was hit by more than 70 shells and capsized about 13:10, while Moltke, Seydlitz and Derfflinger escaped. On 24–25 April 1916 she took part in the bombardment of Yarmouth and Lowestoft under Konteradmiral Friedrich Boedicker, Hipper being on sick leave. At Lowestoft the battlecruisers destroyed two 152 mm shore batteries and some 200 houses from about 13,000 m. Visibility off Yarmouth was so bad that the other ships fired a single salvo each; Derfflinger fired fourteen rounds from her main battery.

She was second in Hipper's line of five on 31 May 1916, ahead of Seydlitz and astern of the flagship Lützow. British communication errors left her unengaged for the first ten minutes of the action. Her gunnery officer, Korvettenkapitän Georg von Hase, later wrote: "By some mistake we were being left out. I laughed grimly and now I began to engage our enemy with complete calm, as at gun practice, and with continually increasing accuracy."

Losing sight of Lion after Lützow's hits, she shifted at 17:16 to Queen Mary. Seydlitz was firing at the same target, and under their combined fire Queen Mary was hit repeatedly in quick succession — observers on the ships ahead and astern reported three shells of one salvo of four striking together — before a huge explosion amidships broke her in two. Later, with the 3rd Battlecruiser Squadron ahead of the German line, Lützow and Derfflinger concentrated on Invincible; Derfflinger fired her final salvo at 19:31, and shortly after the British ship's forward magazine detonated and she disappeared in a series of explosions.

When Scheer's second turn took the German fleet into the centre of the British line, he sent Derfflinger, Seydlitz, Moltke and Von der Tann charging at high speed to disrupt the formation and buy his main force time. By 20:17 they had closed to within 7,000 m of Colossus. In the night action Derfflinger was hit several times, and at 21:34 a heavy shell put her last working turret out of action. By the time Hipper reported to Scheer at 03:55, she and Von der Tann had only two operational guns each.

Over the battle she was hit 17 times by heavy shells and nine times by secondary guns, fired 385 rounds from her main battery, 235 from her secondaries and one torpedo, and lost 157 men killed and 26 wounded — the highest casualty toll of any ship that survived the action. For that resistance the British nicknamed her "Iron Dog". She went to Kiel on 10 June for repairs and a new tripod mast with fire-control equipment, and was not back with the fleet until 16 October.

By the time she returned, the Germans had abandoned offensive use of the surface fleet in favour of the U-boat campaign, and she spent the last two years mostly on patrol in the German Bight, guarding waters through which the submarines and minesweepers worked. She sortied during the Second Battle of Heligoland Bight on 17 November 1917 to help II Scouting Group, arriving after the British raiders had fled north, and covered a minelaying operation off Terschelling in April 1918.

Hipper's last chance came on 23 April 1918, an operation to fall on one of the Norway convoys while the High Seas Fleet waited to catch the covering British battle squadron. Wireless traffic was kept to a minimum to defeat British interception. Some 60 kilometres southwest of Bergen, Moltke lost an inner propeller and wrecked her engines, and had to be taken under tow. Hipper pressed north regardless, crossed the convoy route several times, and found nothing: the convoy had sailed a day later than the German staff expected.

She was to have taken part in the fleet's final sortie in October 1918, an operation intended to inflict as much damage as possible on the Grand Fleet whatever the cost. As Derfflinger and Von der Tann passed through the locks between Wilhelmshaven's inner harbour and the roadstead, some 300 men from the two ships climbed over the side and disappeared ashore. Mutinies on other battleships from the night of 29 October forced the order to sail to be rescinded, and the revolution and the Armistice followed.

Interned at Scapa Flow from 21 November 1918 with her breech blocks removed, she went down with the rest of the fleet on 21 June 1919 when Ludwig von Reuter, believing the British were about to seize his ships, gave the order to scuttle. Derfflinger sank at 14:45. Raised in 1939, she lay capsized off the island of Risa until 1946, earning the distinction of having spent more time afloat upside down than right way up, and was broken up at Faslane by 1948. One of her bells went to the German Federal Navy in 1965; the other stands outside St Michael's Roman Catholic Church on Eriskay.