HMS Inflexible was one of three s built for the Royal Navy before World War I and had an active career during the war. She tried to hunt down the German battlecruiser and the light cruiser in the Mediterranean Sea when war broke out and she and her sister ship sank the German armoured cruisers and during the Battle of the Falkland Islands. Inflexible bombarded Turkish forts in the Dardanelles in 1915, but was damaged by return fire and struck a mine while maneuvering. She had to be beached to prevent her from sinking, but she was patched up and sent to Malta, and then Gibraltar for more permanent repairs. Transferred to the Grand Fleet afterwards, she damaged the German battlecruiser during the Battle of Jutland in 1916 and watched Invincible explode. She was deemed obsolete after the war and was sold for scrap in 1921.
Design The Invincible-class ships were formally known as armoured cruisers until 1911 when they were redesignated as battlecruisers by an Admiralty order of 24 November 1911. Unofficially a number of designations were used until then, including cruiser-battleship, dreadnought cruiser and battle-cruiser.Roberts, pp. 24–25
General characteristics Inflexible was significantly larger than her armoured cruiser predecessors of the . She had an overall length of , a beam of , and a draught of at deep load. She displaced at load and at deep load, nearly more than the earlier ships.Roberts, pp. 43–44
Propulsion Inflexible had two paired sets of Parsons direct-drive turbines, each of which was housed in a separate engine-room and drove an outboard and inboard shaft. The high-pressure ahead and astern turbines were coupled to the outboard shafts and the low-pressure turbines to the inner shafts. A cruising turbine was also coupled to each inner shaft; these were not used often and were eventually disconnected. The turbines were powered by thirty-one Yarrow water-tube boilers in four boiler rooms.Roberts, pp. 70–75 The turbines were designed to produce a total of , but reached nearly during her trials in 1908. She was designed for , but reached during trials.Roberts, pp. 76, 80 She carried of coal, and an additional of fuel oil that was to be sprayed on the coal to increase its burn rate.Roberts, p. 76 At full fuel capacity, she could steam for at a speed of .Preston, p. 24
Armament
Inflexible mounted eight BL Mk X guns in four twin hydraulically powered turrets. Her secondary armament consisted of sixteen QF Mk III guns. In 1915, the turret roof guns were transferred to the superstructure, and the total number of guns was reduced to twelve. All of the remaining guns were enclosed in casemates and given blast shields at that time to better protect the gun crews from weather and enemy action.Roberts, pp. 96–97 These guns were replaced by twelve 4-inch BL MK IX guns on CPI mountings during 1917.Roberts, p. 83
Her anti-aircraft armament consisted of a single QF 20 cwt AA gun on a high-angle MKII mount at the aft end of the superstructure that was carried from July 1915. A 3-pounder Hotchkiss gun on a high-angle MkIc mounting with a maximum elevation of 60° was fitted in November 1914 and used until August 1917. A 4-inch BL MK VII on a HA MkII mount was added in April 1917. Five submerged torpedo tubes were fitted on the Invincibles, two on each side and one in the stern. Fourteen torpedoes were carried for them.
Armour The armour protection given to the Invincibles was heavier than that of the Minotaurs; their waterline belt measured amidships in contrast to the belt of their predecessors. The belt was 6 inches thick roughly between the fore and aft 12-inch gun turrets, but was reduced to four inches from the fore turret to the bow, but did not extend aft of the rear turret. The gun turrets and barbettes were protected by of armour, except for the turret roofs which used of Krupp non-cemented armour (KNC). The thickness of the main deck was and the lower deck armour was . Mild steel torpedo bulkheads of 2.5-inch thickness were fitted abreast the magazines and shell rooms.Roberts, pp. 109, 112
After the Battle of Jutland revealed her vulnerability to plunging shellfire, additional armour was added in the area of the magazines and to the turret roofs. The exact thickness is not known, but it was unlikely to be thick as the total amount was less than .Burt, p. 48
Construction and career She was authorized in the naval expansion program of 1905, and built at the John Brown & Company shipyard on the Clyde. She was laid down on 5 February 1906, launched on 26 June 1907, and commissioned on 20 October 1908.Roberts, p. 41 Inflexible was initially assigned to the Nore Division of the British Home Fleet. She was the temporary flagship of Admiral of the Fleet Sir Edward Hobart Seymour while in New York for the Hudson–Fulton Celebration in September 1909. On 26 May 1911, she was in a collision with the battleship that damaged her bow. She was refitted in October–November 1911, where her fore funnel was also raised by to reduce smoke interference with the bridge.Roberts, p. 122
First World War Pursuit of Goeben and Breslau
On the outbreak of the First World War, Inflexible was flagship of the Mediterranean Fleet. Accompanied by , under the command of Admiral Sir Archibald Berkeley Milne she encountered the German battlecruiser and the light cruiser on the morning of 4 August 1914 headed east after a cursory bombardment of the French Algerian port of Philippeville, but Britain and Germany were not yet at war so Milne turned to shadow the Germans as they headed back to Messina to recoal. All three battlecruisers had problems with their boilers, but Goeben and Breslau were able to break contact and reached Messina by the morning of the 5th. By this time, war had been declared, after the German invasion of Belgium, but an Admiralty order to respect Italian neutrality and stay outside a limit from the Italian coast precluded entrance into the passage of the Strait of Messina where they could observe the port directly. Therefore, Milne stationed Inflexible and Indefatigable at the northern exit of the Strait of Messina, still expecting the Germans to break out to the west where they could attack French troop transports, the light cruiser at the southern exit and sent Indomitable to recoal at Bizerte where she was better positioned to react to a German sortie into the Western Mediterranean.Massie, p. 39
The Germans sortied from Messina on 6 August and headed east, towards Constantinople, trailed by Gloucester. Milne, still expecting Rear Admiral Wilhelm Souchon to turn west, kept the battlecruisers at Malta until shortly after midnight on 8 August when he set sail for Cape Matapan at a leisurely , where Goeben had been spotted eight hours earlier. At 14:30, he received an incorrect signal from the Admiralty stating that Britain was at war with Austria; war would not be declared until 12 August and the order was countermanded four hours later, but Milne followed his standing orders to guard the Adriatic against an Austrian breakout attempt, rather than seek Goeben. Finally on 9 August, Milne was given clear orders to "chase Goeben which had passed Cape Matapan on the 7th steering north-east". Milne still did not believe that Souchon was heading for the Dardanelles, and so he resolved to guard the exit from the Aegean, unaware that the Goeben did not intend to come out.Massie, pp. 45–46 Indomitable remained in the Mediterranean to blockade the Dardanelles, but Inflexible was ordered home on 18 August.Preston, p. 25
Battle of the Falklands
The West Indies Squadron of Rear Admiral Christopher Cradock was destroyed by the German East Asia Squadron commanded by Admiral Graf von Spee during the Battle of Coronel on 1 November 1914. In response, the Admiralty ordered that a squadron be sent to destroy the Germans. The squadron, under the command of Admiral Sir Doveton Sturdee, consisted of Invincible (flag) and Inflexible. They departed on 11 November and rendezvoused with several other cruisers under Rear Admiral Stoddard at Abrolhos Rocks, off the coast of Brazil on the 26th. They departed the following day and reached Port Stanley on the morning of 7 December.Massie, pp. 248–251
Spee – making a leisurely voyage back to the Atlantic – wished to destroy the radio station at Port Stanley, so he sent the armoured cruiser and the light cruiser to see if the harbor was clear of British warships on the morning of 8 December. They were spotted at 07:30, although the pre-dreadnought , grounded in Stanley Harbor to defend the town and its wireless station, did not receive the signal until 07:45. It mattered little because Sturdee was not expecting an engagement and most of his ships were coaling. Furthermore, the armoured cruiser and the light cruiser had one or both of their engines under repair. The armed merchant cruiser Macedonian was patrolling the outer harbor entrance while the armoured cruiser was anchored in the outer harbor, scheduled to relieve the Macedonian at 08:00. The Germans were not expecting any resistance and the first salvo from Canopuss guns at 09:20 caused them to sheer off from their planned bombardment of the wireless station and fall back on Spee's main body.Massie, pp. 254–261
Sturdee's ships did not sortie from the harbor until 09:50, but they could see the retreating German ships on the southwest horizon. The Invincibles, fresh out of dry dock, had a advantage over Spee's ships which all had fouled bottoms that limited their speeds to at best. The light cruiser was lagging behind the other ships and Inflexible opened fire on her when the range dropped to at 12:55. Invincible opened fire shortly afterwards and both ships began straddling Leipzig as the range closed to . At 13:20, Spee ordered his squadron to separate and ordered his light cruisers to turn to the southwest while his armoured cruisers turned to the north east to cover their retreat. The German ships opened fire first at 13:30 and scored their first hit at 13:44 when hit Invincible, although the shell burst harmlessly on the belt armour. Both sides fired rapidly during the first half-hour of the engagement before Sturdee opened up the range a little to put his ships outside the effective range of the German guns. British gunnery was very poor during this period, scoring only four hits out of 210 rounds fired. The primary cause was the smoke from the guns and funnels as the British were downwind of the Germans.Massie, pp. 261–266