HMS Inflexible was a Victorian

Victorian era

The Victorian era of British history was the period of Queen Victoria's reign from 20 June 1837 until her death on 22 January 1901. It was a long period of peace, prosperity, refined sensibilities and national self-confidence...

 ironclad battleship

Battleship

A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

 carrying her main armament in centrally placed turret

Turret

In architecture, a turret is a small tower that projects vertically from the wall of a building such as a medieval castle. Turrets were used to provide a projecting defensive position allowing covering fire to the adjacent wall in the days of military fortification...

s. The ship was constructed in the 1870s for the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 to oppose the perceived growing threat from the Italian Regia Marina

Regia Marina

The Regia Marina dates from the proclamation of the Kingdom of Italy in 1861 after Italian unification...

 in the Mediterranean.

The Italian Navy had started constructing a pair of battleships, Duilio  and Dandolo

Italian ironclad Enrico Dandolo

Enrico Dandolo was an ironclad battleship built in Italy for the Regia Marina in the 1870s. Designed by Benedetto Brin, together with her sister ship , and armed with 100-ton, 450 mm muzzle-loading Armstrong guns, she was considered the most powerful battleship of the time...

, equipped with four Armstrong 15-inch (381 mm) guns weighing 35 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.

Packed with innovations, Inflexible mounted larger guns than those of any previous British warship and had the thickest armour

Armour

Armour or armor is protective covering used to prevent damage from being inflicted to an object, individual or a vehicle through use of direct contact weapons or projectiles, usually during combat, or from damage caused by a potentially dangerous environment or action...

 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

Zone of immunity

The zone of immunity around a warship is an area from which both plunging fire and direct enemy fire is less effective.The concept was a factor in battleship design and in tactics during engagements....

 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 by a horizontal armoured deck below the water-line rather than armoured sides

Belt armor

Belt armor is a layer of heavy metal armor plated on to or within outer hulls of warships, typically on battleships, battlecruisers and cruisers, and on aircraft carriers converted from those types of ships....

 along the waterline.

Design

The original concept was based upon an outline design similar to that for HMS Dreadnought

HMS Dreadnought (1875)

The fifth HMS Dreadnought of the British Royal Navy was a turret ironclad battleship built at Pembroke Dockyard, Wales.-Construction:Begun as Fury in 1870, the original design was recast for heavier armour and higher speed. The renamed ship was laid down in 1872 at Pembroke Dockyard and was...

, but with improved armament. The ship was conceptually constructed from three components, several outline studies being produced by Nathaniel Barnaby

Nathaniel Barnaby

Sir Nathaniel Barnaby, KCB was Chief Constructor of the Royal Navy from 1872 to 1885....

.

• A heavily armoured citadel 75 feet (22.9 m) wide and 110 feet (33.5 m) long 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.

• Unarmoured ends, but with a 3 inches (76.2 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 feet (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.

• A light superstructure to provide crew accommodation, and freeboard in rough weather, although anticipated to be seriously damaged in any major engagement.

Barnaby wanted a ship both broader then existing designs to mimimise rolling and as short as possible to reduce its size as a target. Making a ship broader compared to its length was known to reduce its speed, so the innovative technique of water tank tests on models, pioneered by William Froude

William Froude

William Froude was an English engineer, hydrodynamicist and naval architect. He was the first to formulate reliable laws for the resistance that water offers to ships and for predicting their stability....

, was used to finalise a design. This was ten feet wider than Duillo and twenty-one feet shorter, the smallest ever ratio of length to breadth in a metal first class warship.

Once the outline design was agreed, the detailed architectural design was done by William White

William Henry White

Sir William Henry White was a prolific British warship designer and Chief Constructor at the Admiralty....

 and she was laid down at Portsmouth

Portsmouth

Portsmouth is the second largest city in the ceremonial county of Hampshire on the south coast of England. Portsmouth is notable for being the United Kingdom's only island city; it is located mainly on Portsea Island...

 Dockyard on 24 February 1874.

Controversy

Inflexible was launched 27 April 1876. Later that year member of Parliament

Member of Parliament

A Member of Parliament is a representative of the voters to a :parliament. In many countries with bicameral parliaments, the term applies specifically to members of the lower house, as upper houses often have a different title, such as senate, and thus also have different titles for its members,...

 Edward Reed

Edward James Reed

Sir Edward James Reed , KCB, FRS, was a British naval architect, author, politician, and railroad magnate. He was the Chief Constructor of the Royal Navy from 1863 until 1870...

, formerly Director of Naval Construction

Director of Naval Construction

The Director of Naval Construction was a senior British civil servant post in the Admiralty, that part of the British Civil Service that oversaw the Royal Navy. The post existed from 1860 to 1966....

, visited the Italian ships and subsequently questioned their stability if the unarmoured ends were flooded.

As Inflexible was of similar design, he raised grave concerns about it too. When he failed to persuade the Admiralty

Admiralty

The Admiralty was formerly the authority in the Kingdom of England, and later in the United Kingdom, responsible for the command of the Royal Navy...

, in June 1877 he publicised his charges in The Times

The Times

The Times is a British daily national newspaper, first published in London in 1785 under the title The Daily Universal Register . The Times and its sister paper The Sunday Times are published by Times Newspapers Limited, a subsidiary since 1981 of News International...

. An editorial in the same edition, 18 June, said "it is said that the unarmoured ends are, in fact, the corks on which she floats, that she cannot swim without them, and it would appear that if she lost one she would capsize".

Further exchanges followed until in July, construction was halted on Inflexible (and two other smaller ships, and whilst a hastily convened committee examined the design. In their report published in December 1877, they concluded that it would be hard for gunfire to completely flood the unarmoured but heavily compartmentalised and partially cork-filled ends. However, if this was managed then the ship would just be stable, capsizing at about 35 degrees heel.

Work restarted on the ship in December 1877, and the ship was commissioned 5 July 1881, under Captain Jackie Fisher, although she was not completed until 18 October. Her eventual cost was £812,000 .

Main guns

To counter the perceived threat from the Italians, Inflexible was to be equipped with four of the largest guns available, weighing 60 tons each. In October 1874 it was decided to modify the design of Inflexible to use an even bigger gun which Armstrongs was producing, a 16-inch (406 mm) gun weighing 81 tons. The Italians responded by changing their design to take even larger 100-ton 17.7-inch (450 mm) Armstrongs guns. As these could not be fitted to Inflexible, four examples were ordered by the British Government, two each for the coastal defences around Gibraltar

Gibraltar

Gibraltar is a British overseas territory located on the southern end of the Iberian Peninsula at the entrance of the Mediterranean. A peninsula with an area of , it has a northern border with Andalusia, Spain. The Rock of Gibraltar is the major landmark of the region...

 and Malta

Malta

Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...

 respectively. Two of these guns still exist, at Fort Rinnella on Malta and at the Napier of Magdala Battery on Gibraltar.

The four 81-ton muzzle-loading rifles

Muzzle-loading rifles

A muzzle-loading rifle is a gun in which the projectile and propelling charge is loaded through the muzzle , in contrast to a breech loading rifle, and "rifling" grooves cut on the inside of the barrel cause the projectile to spin rapidly in flight, giving it greater stability and hence range and...

 were mounted in two 33 in 10 in (10.31 m) turrets mounted en echelon, with the forward turret mounted on the port side of the ship and the after turret on the starboard side. The superstructure both fore and aft was very narrow to allow one gun in each turret to fire axially, i.e. directly forward or directly aft. In practice, as in previous ships, it was found that axial fire led to so much blast damage to the ship's superstructure that it was impractical. However, the en-echelon arrangement also meant that at least three guns could fire on bearings close to fore and aft. All four guns could be fired broadside.

The en-echelon configuration was retained for the two ships of the Colossus class

Colossus class battleship (1882)

The Colossus class battleships were ironclad warships, carrying their main armament in turrets, which served in the Victorian Royal Navy from 1882...

, but subsequently abandoned in the Royal Navy in favour of centreline mounts at either end of the ship. The en-echelon configuration did not reappear in Royal Navy capital ships until launched in 1909.

Each turret weighed 750 tons and was protected by an outer layer of 9 inches (228.6 mm) of compound armour

Compound armour

Compound armour was a type of armour used on warships in the 1880s. By the end of the decade it had been rendered obsolete by nickel-steel armour.-Prior armours:...

, an inner layer of 7 inches (177.8 mm) wrought iron

Wrought iron

thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...

, with a total of 18 inches (457.2 mm) of teak backing. The turrets were rotated hydraulically, taking around a minute to perform a complete rotation.

Inflexibles guns were muzzle loaded, and because of their length could not be reloaded from inside the turrets. Consequently reloading was done using hydraulic rams fitted outside of the two turrets underneath an armoured glacis

Glacis

A glacis in military engineering is an artificial slope of earth used in late European fortresses so constructed as to keep any potential assailant under the fire of the defenders until the last possible moment...

. To reload the guns, the turret was rotated to align the guns with the rams, and the guns depressed so that the rams could push the gunpowder charge and 1,684-pound shell into it. The rams had to be extended twice: First, to extinguish any burning material remaining inside the gun using a sponge and water jet fixed to the end of the ram, and then again after charge, shell and wadding had been placed on a loading tray in front of it to be driven into the gun. The shell had a copper disk at its base which engaged with rifled grooves cut into the barrel to spin the shell, rather than zinc studs used on earlier designs. Tests showed that the normal full charge of 450 pounds of brown prismatic gunpowder

Gunpowder

Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...

 would produce a muzzle velocity

Muzzle velocity

Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...

 of 1590 feet per second (484.6 m/s), which could penetrate 23 inches (584.2 mm) of wrought iron armour at 1000 yards (914.4 m). The muzzle loading took between 2.5 and four minutes.

Ram

She was also equipped with a ram – ramming was considered a practical means of sinking an enemy battleship at that time. The Italian Re d'Italia had been rammed and sunk by the Austrian flagship, Ferdinand Max, at the Battle of Lissa

Battle of Lissa (1866)

The Battle of Lissa took place on 20 July 1866 in the Adriatic Sea near the Dalmatian island of Lissa and was a decisive victory for an outnumbered Austrian Empire force over a superior Italian force...

 in 1866. This had started a vogue for ramming (which persisted until the 1890s), and many naval experts even believed this was the most effective weapon a ship could have. For example Gerard Noel won the 1874 Royal United Services Institute

Royal United Services Institute

The Royal United Services Institute for Defence and Security Studies , officially still known by its old name, the Royal United Services Institution, is a British defence and security think tank. It was founded in 1831 by The Duke of Wellington.RUSI describes itself asIt won Prospect Magazine's...

 essay contest with an article that asserted that "[i]n a general action I do not hold that the guns will be the principal weapon".

This was less surprising than it might seem to modern eyes, because it was expected that naval battles would be fought at a range of only a couple of thousand metres. The advent of steam power meant that ships were no longer restricted in manoeuvring by wind direction and had led to a belief that it would be possible to steer into enemy ships. Rams turned out to be a handicap in retrospect, as several warships were accidentally sunk by them - for example
by in 1875, and by in 1893. Whilst this showed the considerable potency of a ram, it also demonstrated the inadequate manoeuvring characteristics of many of the ships equipped with them. The ram was designed to be removable to avoid damage during accidental collisions, but although other ships customarily carried theirs detached, Inflexible seems to have kept hers in place. The ram was a solid iron forging supported by an extension of the 3 inches (76.2 mm) armoured deck which turned downwards behind it.

Torpedoes

The ship was fitted with two underwater torpedo tubes. These were cast-iron cylinders attached to a swivel joint in the hull, one on each bow. Inside the ship the opposite end was attached to a graduated scale for targeting. There was a watertight door at either end of the tube. The 14 inches (355.6 mm) torpedoes were loaded placed inside a brass cylinder which slid into the iron casting. To fire the torpedo, the outer door was opened and a 10 feet (3 m) guide was extended which helped the torpedo clear the currents around the ship. A piston in the brass cylinder forced out the torpedo when it was to be fired, and at the same time its own compressed air motor was started.

Protection

The central citadel in particular was exceptionally heavily armoured. At the waterline, the armour consisted of a 4 feet (1.2 m) layer of 12 inches (304.8 mm) armour plate backed by 11 inches (279.4 mm) of teak. Behind this was another 12 inches (304.8 mm) armour plate backed by 6 inches (152.4 mm) of teak. Finally on the inside of this were two 5/8 in layers of shell plating. This 41 inches (1,041.4 mm) layer of protection weighed 11,000 pounds per square foot. 24 inches of armour was considered almost completely proof against any contemporary gun and is still the thickest armour which has ever been used on a battleship.

The armour was reduced to 20 inches (508 mm) thick above the waterline, with a 12 inches (304.8 mm) outer plate and an 8 inches (203.2 mm) inner one, with the thickness of teak increased to 21 inches (533.4 mm) to maintain the same overall thickness of protection. Below the waterline, again there was a 12 inches (304.8 mm) outer plate, but with a 4 inches (101.6 mm) inner plate, with 25 inches (635 mm) of teak backing in total to maintain the overall thickness of protection at 41 inches.

Outside of the citadel, above the 3 inches (76.2 mm) armoured deck were a large number of small watertight compartments used to hold coal and stores. Between them and the hull were 4 feet (1.2 m) compartments filled with cork

Cork (material)

Cork is an impermeable, buoyant material, a prime-subset of bark tissue that is harvested for commercial use primarily from Quercus suber , which is endemic to southwest Europe and northwest Africa...

 and containing a 2 foot (0.6096 m) coffer dam. The dam was filled with oakum

Oakum

Oakum is a preparation of tarred fiber used in shipbuilding, for caulking or packing the joints of timbers in wooden vessels and the deck planking of iron and steel ships, as well as cast iron plumbing applications...

 and canvas

Canvas

Canvas is an extremely heavy-duty plain-woven fabric used for making sails, tents, marquees, backpacks, and other items for which sturdiness is required. It is also popularly used by artists as a painting surface, typically stretched across a wooden frame...

 which had been shown to help reduce the size of the hole made by a projectile passing through the coffer dam. All of these materials were treated with calcium chloride

Calcium chloride

Calcium chloride, CaCl2, is a salt of calcium and chlorine. It behaves as a typical ionic halide, and is solid at room temperature. Common applications include brine for refrigeration plants, ice and dust control on roads, and desiccation...

 to try to reduce their flammability. Experiments were carried out with firing 64-pounder shells into full scale replicas of the cork compartments and coffer dams.

Propulsion

With a slenderness ratio of 4.6:1 Inflexible was a stable gun platform. Work by the hydrodynamicist William Froude

William Froude

William Froude was an English engineer, hydrodynamicist and naval architect. He was the first to formulate reliable laws for the resistance that water offers to ships and for predicting their stability....

 had demonstrated that such a short length for the ship's width would not require excessive installed power at the design speed of 14.75 knots (28.9 km/h). However, the same proportions were adopted in the similar but smaller and , but resulted in a serious lack of directional stability in those ships.

The ship had two compound steam engines manufactured by John Elder and company. Each had one high-pressure and two low-pressure cylinders connected to a crankshaft. The connecting rods were 9 inches (228.6 mm) in diameter attached to 17.5 inches (444.5 mm) bearings on the crankshaft. A hollow steel shaft drove each of the two screws at a maximum 75 rpm. There were two boiler rooms, one each end of the engine room. Each contained two 17 feet (5.2 m) and two 9 feet (2.7 m) boilers operating at 61 psi. Similar high pressure systems had been used on HMS Alexandra

HMS Alexandra (1875)

HMS Alexandra was a central battery ironclad of the Victorian Royal Navy, whose seagoing career was from 1877 to 1900. She spent much of her career as a flagship, and took part in operations to deter Russian aggression against Turkey in 1878 and the bombardment of Alexandria in 1882.-Background:At...

 launched in 1875 and Temeraire

HMS Temeraire (1876)

HMS Temeraire was an ironclad battleship of the Victorian Royal Navy which was unique in that she carried her main armament partly in the traditional broadside battery, and partly in barbettes on the upper deck.-Design and construction:...

 in 1876, but they were a recent innovation and more economical than the previous low pressure engines. Gangs of stokers were continuously bringing coal from the bunkers to feed the fires. The ship had a further 39 smaller engines for various purposes including bilge pumps capable of shifting 300 tons of water per hour, pumps for cooling water through the steam condensers, fans to draw air through the ship through a system of ventilation ducts, steering gear, hydraulic pumps for the guns, air compressors, winches and for generating electricity. The engine room was noisy, wet, greasy, oily and steamy. It would be a normal occurrence for engines to leak steam and for bearings to run hot so that they had to be hosed down to keep them operating. All the essential equipment was contained within the armoured citadel.

Although she was propelled principally by steam, she was equipped with a pair of masts and yards, so that 18500 square feet (1,718.7 m²) of sail could be deployed. This was to help exercise and train the crew, especially as such an area of sail (less than 2 square foot (0.18580608 m²) per ton) would hardly move the ship. The masts and sails were removed after four years in service, and replaced by simple pole masts for carrying signal flags and circular fighting tops, platforms carrying quick firing guns.

Innovations

She was also the first Royal Navy ship to be completely lit by electricity

Electricity

Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

, and the first to have underwater torpedo

Torpedo

The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

 tubes. The electrical installation provided 800 volts DC

Direct current

Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...

 to power arc light

Arc Light

Arc Light is the debut novel by Eric L. Harry, a techno-thriller about limited nuclear war published in 1994 and written in 1991-2.As China and Russia clash in Siberia in June 1999, nuclear missiles strike the United States. The U.S. retaliates against Russia, and World War III begins...

s in the engine and boiler rooms and Swan incandescent bulbs in other parts of the ship. The circuitry was complicated because the lighting consisted of sets of 18 Swan lamps and an arc lamp arranged in series. Each incandescent bulb was fitted with an automatic mechanism to switch in a resistor to maintain continuity should it fail, so that the set of 19 lights would not be extinguished if one failed. The arrangement also led to the first fatal electrocution

Electric shock

Electric Shock of a body with any source of electricity that causes a sufficient current through the skin, muscles or hair. Typically, the expression is used to denote an unwanted exposure to electricity, hence the effects are considered undesirable....

 on a Royal Navy ship, in 1882, after which the Navy adopted an 80 volt standard for its ships.
The ship was equipped with many other novelties, including water tanks to dampen the roll, which turned out to be useless. Much of the ship was without natural illumination, and Fisher had different deck levels painted in contrasting colours to make it easier for crew members to find their way around the ship.

Service history

On completion the ship was sent to join the Mediterranean squadron. She took part in the bombardment of Alexandria

Bombardment of Alexandria (1882)

The Bombardment of Alexandria, in 1882, by the British Mediterranean Fleet took place on 11–13 July 1882. Admiral Sir Frederick Beauchamp Seymour was in command of a fleet of fifteen Royal Navy ironclad ships which sailed to Alexandria...

 on 11 July 1882 during the Urabi Revolt

Urabi Revolt

The Urabi Revolt or Orabi Revolt , also known as the Orabi Revolution, was an uprising in Egypt in 1879-82 against the Khedive and European influence in the country...

, firing 88 shells and was struck herself twice; one 10-inch (254mm) shell killed the ship's carpenter, mortally wounded an officer directing the fire of a 20-pounder breech-loader, and injured a seaman. The blast from Inflexibles own 16 inches (406 mm) guns did considerable damage to upperworks and boats.

She was refitted in Portsmouth in 1885, when the full sailing rig was removed. She was in the Fleet Reserve until 1890, except for brief service in the 1887 review and the manoeuvres of 1889 and 1890. She was re-commissioned for the Mediterranean Fleet from 1890 to 1893, serving thereafter as Portsmouth guard ship until 1897. From there she went to Fleet Reserve, and in 1901 to Dockyard Reserve until sold at Chatham in 1903 for scrap.

External links