HMS Inflexible (1876)

HMS Inflexible with the pole masts fitted in 1885, replacing the original full sailing rig
Class overview
Succeeded by:	Ajax class
History
United Kingdom
Builder:	Portsmouth Dockyard
Cost:	£812,000
Laid down:	24 February 1874
Launched:	27 April 1876
Commissioned:	5 July 1881
Fate:	Scrapped 1903
General characteristics
Displacement:	10,880 tons 11,880 tons full load
Length:	320 ft (98 m) pp 344 ft (105 m) oa
Beam:	75 ft (23 m)
Draught:	26.3 ft (8.0 m)
Propulsion:	12 coal-fired boilers, two single-expansion Elder and Co. steam engines, 2 twin-bladed 20 ft (6.1 m) diameter screws
Speed:	14.73 knots (27 km/h) @ 6,500 hp (4.8 MW)
Range:	"Cross-Atlantic at economical speed"
Complement:	440–470
Armament:	4 × 16-inch (406.4 mm) 80-ton muzzle-loading rifles, 2 per turret 6 × 20-pounder breech loaders, replaced in 1885 with BL 4-inch (100 mm) guns, and replaced in 1897 with QF 4.7-inch (120-mm) guns 17 × machine guns 4 × 14-in (360 mm) torpedo tubes (two submerged bow tubes, two on carriages)
Armour:	24-in (610 mm) waterline belt + 17-in (432 mm) teak 3-in (76 mm) deck 20-in (508 mm) citadel (reducing to 16 inches) + 21-in (533 mm) teak 17-in (432 mm) front, 16-inch back, turrets 22-in bulkheads, reducing to 14 inches (360 mm)

HMS Inflexible was a Victorian ironclad battleship carrying her main armament in centrally placed turrets. The ship was constructed in the 1870s for the Royal Navy to oppose the perceived growing threat from the Italian Regia Marina in the Mediterranean.

The Italian Navy had started constructing a pair of battleships, Duilio and Dandolo, equipped with four Armstrong 17.7-inch (450 mm) guns weighing 100 tons each. These were superior to the armament of any ship in the British Mediterranean Squadron, and Inflexible was designed as a counter to them.

Inflexible mounted larger guns than those of any previous British warship and had the thickest armour ever to be fitted to a Royal Navy ship. Controversially, she was designed so that if her un-armoured ends should be seriously damaged in action and become water-logged, the buoyancy of the armoured centre section of the ship would keep her afloat and upright.

The ship was the first major warship to depend in part for the protection of her buoyancy on a horizontal armoured deck below the water-line rather than armoured sides along the waterline.

The original concept was based upon an outline design similar to that for HMS Dreadnought, but with improved armament. The ship was conceptually constructed from three components, several outline studies being produced by Nathaniel Barnaby.

A heavily armoured citadel 75 feet (23 m) wide and 110 feet (34 m) long was located amidships, which would keep the ship afloat and stable regardless of what happened to the ends. This citadel contained the main guns, the boilers and the engines. The ends were unarmoured, but with a 3-inch-thick (76 mm) armoured deck 6–8 ft below the waterline to limit damage to the underwater section to keep them buoyant. Coal bunkers were located over the armoured deck and surrounded by 4-foot-wide (1.2 m) compartments filled with cork. The ship had bunker capacity for 400 tons of coal below the deck for use during combat, when the above-deck bunkers would be inaccessible and possibly flooded. The structure above the armoured deck also contained a large number of watertight compartments to further preserve buoyancy. There was also light superstructure to provide crew accommodation, and freeboard in rough weather, although anticipated to be seriously damaged in any major engagement.