1913, the battlecruiser achieved for a speed of while at the unusually high displacement of . Maximum bunkerage was of coal and an additional of fuel oil to be sprayed on the coal to increase its burn rate. At , the ship's range was . Armament Princess Royal was armed with eight BL 13.5-inch Mk V guns ("BL" for breech-loading) in four twin hydraulically powered turrets, designated 'A', 'B', 'Q' and 'X' from bow to stern. Her secondary armament consisted of 16 BL 4-inch Mk VII guns, most of which were mounted in casemates in the superstructure. The two guns mounted on the deck above the forward group of casemates were fitted with gun shields in 1913 and 1914 to better protect their crews from enemy fire. The battlecruiser was built without anti-aircraft (AA) guns, but from October 1914 to December 1916 she was fitted with a single QF 6-pounder Hotchkiss gun ("QF" for quick-firing) on a high-angle mount. A single QF 3-inch 20 cwt AA gun was added in January 1915 and carried until April 1917. Princess Royal received a fire-control director between mid-1915 and May 1916 that centralised fire-control under the gunnery officer who now fired the guns. To align their guns on the target, the turret crewmen had to follow pointers whose position was transmitted from the director. This greatly increased accuracy as it was easier for the director to spot the fall of shells and eliminated the shell spread caused by the ship's roll as the turrets fired individually. By early 1918, Princess Royal carried a Sopwith Pup and a Sopwith 1½ Strutter on flying-off ramps fitted on top of 'Q' and 'X' turrets. The Pup was intended to shoot down Zeppelins while the 1½ Strutter was used for spotting and reconnaissance. Each platform had a canvas hangar to protect the aircraft during inclement weather. Armour The armour protection given to Lion and Princess Royal was heavier than on the Indefatigables. The waterline belt of Krupp cemented armour measured thick amidships; this thinned to 4 inches towards the ships' ends, and did not reach the bow or stern. The upper armour strake had a maximum thickness of 6 inches over the same length as the thickest part of the waterline armour and thinned to abreast of the end turrets. The gun turrets and barbettes were protected by of armour, except for the turret roofs which used