The battlecruiser warship was formed as a capital ship-type design in the early part of the 1900s. Their armament suite was comparable to that of battleships but a reduced armor scheme (for the sake of improved cruise speeds) made them akin to cruiser warships. As such, the "battlecruiser" categorization was born and many of the global navy services of the early 1900s employed some form of the warship for a time.
HMS Indefatigable was a battlecruiser belonging to the British Royal Navy (RN). She was ordered as part of the 1908-1909 Naval Programme and awarded to Devonport Dockyard. Her construction began on February 23rd, 1909 and the ship was launched in October of that year. She was formally commissioned for service on February 24th, 1911 as HMS Indefatigable - the name meaning "to persist tirelessly".
As built, the ship displaced 18,500 tons (long) under standard load and up to 22,130 tons (long) under full load. Dimensions included a length of 590 feet, a beam of 80 feet and a draught of 29.8 feet. Power came from 31 x Babcock & Wilcox coal-fired boilers feeding 2 x Parsons direct-drive steam turbine sets producing 43,000 shaft horsepower to 4 x shafts. Maximum speed could reach 25 knots and range was out to 7,000 nautical miles.
Her profile was conventional with two main masts featured and two hull superstructures, one fore and the other aft. Three smoke funnels were seated inline near midships with two paired at the forward superstructure. Four primary turrets were set about the main deck, one fore and the other aft with the remaining two staggered near midships. Internally, she carried a crew complement of 800 personnel though this could be increased by as much as 200 in wartime. Armor ranged from 6" at the belt and 2.5 inches at the decks to 7 inches at the turrets and 10 inches at the conning tower.
Armament was led by 4 x 12" BL Mk X main guns in four primary twin-gunned turrets. This was supported by 16 x 4" Mk VII turreted guns in single-gunned mounts. 2 x 17.72" torpedo tubes were set in submerged positions along the sides of the vessel.
HMS Indefatigable was the lead ship of the Indefatigable-class which numbered three total vessels. They were an extension of the preceding Invincible-class (also numbering three) of 1908 but with greater dimensions and, therefore, increased internal volume and external displacement. Armoring was improved and the longer length allowed for the midships main gun turrets to be staggered and therefore, by way of a well-placed gap in her side profile, allow these guns to engage at either broadside. A common limitation of similar designs (lacking this gap) was that one side gun could not be brought to bear in a broadside attack.
With World War arriving in Europe during the summer of 1914, HMS Indefatigable found herself operating in the Mediterranean as part of the 2nd Battlecruiser Squadron. The ship failed to run down SMS Goeben and SMS Breslau on their way to Ottoman waters but saw fighting in the Dardanelles during early November as her guns bombarded Ottoman positions. Her career only lasted until May 31st, 1916 when she was lost in the Battle of Jutland - the largest naval battle of World War 1. HMS Indefatigable received a direct hit from enemy fire by the rear turret and began taking on water with a noticeable list to portside. More direct hits were aimed at her forecastle which ultimately ignited some magazine stores. Crippled, taking on water and on fire, the warship quickly sank with just two of her 1,019 wartime crew surviving - a terrible end to a powerful ship.