HMS Indefatigable was the lead ship of her class of three battlecruisers built for the Royal Navy during the first decade of the 20th Century.

The ship bombarded Ottoman fortifications defending the Dardanelles on 3 November 1914, then, following a refit in Malta, returned to the United Kingdom in February where she rejoined the 2nd BCS.

A new Liberal Government had taken power in January 1906 and demanded reductions in naval spending, and the Admiralty submitted a reduced programme, requesting dreadnoughts but no battlecruisers.

The turbines were rated at 43,000 shaft horsepower (32,000 kW) and were intended to give the ship a maximum speed of 25 knots (46 km/h; 29 mph).

During her sea trials on 10 April 1911, Indefatigable reached a top speed of 26.89 knots (49.8 km/h; 30.9 mph) from 55,140 shp (41,120 kW) after her propellers were replaced.

[3] She carried enough coal and fuel oil to give her a range of 6,330 nautical miles (11,720 km; 7,280 mi) at a cruising speed of 10 knots (19 km/h; 12 mph).

[4] The Indefatigable class had a main armament of eight breech-loading BL 12-inch (305 mm) Mark X guns mounted in four hydraulically powered twin-gun turrets.

The other two were wing turrets mounted amidships and staggered diagonally: 'P' was forward and to port of the centre funnel, while 'Q' was situated starboard and aft.

Their armoured deck ranged in thickness between 1.5 and 2.5 inches (38 and 64 mm) with the thickest portions protecting the steering gear in the stern.

[9] Indefatigable received a single QF 3-inch 20 cwt[Note 1] anti-aircraft gun on a high-angle Mark II mount in March 1915.

Therefore, Milne stationed Inflexible and Indefatigable at the northern exit of the strait, expecting the Germans to break out to the west where they could attack French troop transports.

He stationed the light cruiser Gloucester at the southern exit, and sent Indomitable to coal at Bizerte, where she was ready for action in the Western Mediterranean.

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 at a leisurely 12 knots (22 km/h; 14 mph) for Cape Matapan, where Goeben had been spotted eight hours earlier.

[16] On 3 November 1914, Winston Churchill, then First Lord of the Admiralty, ordered the first British attack on the Dardanelles following the commencement of hostilities between Ottoman Turkey and Russia.

In a twenty-minute bombardment, a single shell struck the magazine of the fort at Sedd el Bahr at the tip of the Gallipoli peninsula, displacing (but not destroying) 10 guns and killing 86 Turkish soldiers.

Indefatigable remained in the Mediterranean until she was relieved by Inflexible on 24 January 1915 and proceeded to Malta for a refit; she then sailed to England on 14 February and joined the 2nd BCS upon her arrival.

Two minutes later, he ordered a course change to east south-east to position himself astride the German's line of retreat and called his ships' crews to action stations.

Hipper ordered his ships to turn to starboard, away from the British, to assume a south-easterly course, and to reduce speed to 18 knots (33 km/h; 21 mph) to allow three light cruisers of the 2nd Scouting Group to catch up.

[20] This began what was to be called the "Run to the South" as Beatty changed course to steer east south-east at 15:45, paralleling Hipper's course, now that the range closed to under 18,000 yards (16,000 m).

While still in the water, two survivors, Able Seaman Frederick Arthur Gordon Elliott and Leading Signalman Charles Farmer, found Indefatigable's captain, C.F.