The
Industrial Revolution introduced steam-powered
ironclad warships seemingly impervious to
cast cannon. The inadequacy of naval artillery caused the
naval ram to reappear as a means of sinking armored warships. The rapidity of innovation through the last half of the 19th century caused some ships to be obsolete before they were launched. Maximum projectile velocity obtainable with gunpowder in cast cannon was approximately . Increased projectile weight through increased
caliber was the only method of improving armor penetration with this velocity limitation. Some ironclads carried extremely heavy, slow-firing guns of calibres up to . These guns were the only weapons capable of piercing the ever-thicker iron armour on the later ironclads, but required steam powered machinery to assist loading cannonballs too heavy for men to lift.
Explosive shells .|alt= Explosive
shells had long been in use in ground warfare (in
howitzers and mortars), but they were only fired at high angles and with relatively low velocities. Shells are inherently dangerous to handle, and no solution had been found to combine the explosive character of the shells with the high power and flatter trajectory of a high velocity gun. However, high trajectories were not practical for marine combat and naval combat essentially required flat-trajectory guns in order to have some decent odds of hitting the target. Therefore, naval warfare had consisted for centuries of encounters between flat-trajectory cannon using inert cannonballs, which could inflict only local damage even on wooden hulls. The first naval gun designed to fire explosive shells was the
Paixhans gun, developed by the French general
Henri-Joseph Paixhans in 1822–1823. He advocated using flat-trajectory shell guns against warships in 1822 in his
Nouvelle force maritime et artillerie, and developed a delaying mechanism which, for the first time, allowed shells to be fired safely in high-powered flat-trajectory guns. The effect of explosive shells lodging into wooden hulls and then detonating was potentially devastating. This was first demonstrated by Henri-Joseph Paixhans in trials against the two-decker
Pacificateur in 1824, in which he successfully broke up the ship. The first Paixhans guns for the
French Navy were manufactured in 1841. The barrel of the guns weighed about 10,000 lbs. (4.5 metric tons), and proved accurate to about two miles. In the 1840s, Britain, Russia and the United States adopted the new naval guns. The effect of the guns in an operational context was decisively demonstrated during the
Crimean War. The
incendiary properties of exploding shells demonstrated the obsolescence of wooden warships in the 1853
Battle of Sinop; but detonation effectiveness was limited by use of gunpowder bursting charges. Early
high explosives used in torpedo warheads would detonate during the acceleration of firing from a gun. After brief use of
dynamite guns aboard ,
picric acid became widely used in conventional naval artillery shells during the 1890s.
Breech-loading, rifled artillery .
William Armstrong was awarded a contract by the British government in the 1850s to design a revolutionary new piece of artillery—the
Armstrong Gun—produced at the
Elswick Ordnance Company. This marked the birth of modern artillery both on land and at sea. The piece was
rifled, which allowed for a much more accurate and powerful action. The necessary machinery to accurately rifle artillery was only available by the mid-19th century. The
cast iron shell fired by the Armstrong gun was similar in shape to a
Minié ball and had a thin lead coating which made it fractionally larger than the gun's bore and which engaged with the gun's
rifling grooves to impart spin to the shell. This spin, together with the elimination of
windage as a result of the tight fit, enabled the gun to achieve greater range and accuracy than existing smooth-bore muzzle-loaders with a smaller powder charge. His gun was also a breech-loader. Although attempts at breech-loading mechanisms had been made since medieval times, the essential engineering problem was that the mechanism couldn't withstand the explosive charge. It was only with the advances in
metallurgy and
precision engineering capabilities during the
Industrial Revolution that Armstrong was able to construct a viable solution. The gun combined all the properties that make up an effective artillery piece. The gun was mounted on a carriage in such a way as to return the gun to firing position after the
recoil. What made the gun really revolutionary lay in the technique of the construction of the gun barrel that allowed it to withstand much more powerful explosive forces. The "
built-up" method involved assembling the barrel with
wrought-iron (later
mild steel was used) tubes of successively larger diameter. The next tube would be heated to allow it to expand and fit over the previous tube. When it cooled the tube would contract to a slightly smaller diameter, which allowed an even pressure along the walls of the gun which was directed inward against the outward forces that the gun firing exerted on the barrel.
Built-up guns with
rifling made cast cannon obsolete by 1880. Armstrong's system was adopted in 1858, initially for "special service in the field" and initially he only produced smaller artillery pieces, 6-pounder (2.5 in/64 mm) mountain or light field guns, 9-pounder (3 in/76 mm) guns for
horse artillery, and
12-pounder (3 inches /76 mm) field guns. However, despite the gun's advantages, an 1863
Ordnance Select committee decided to revert to muzzle-loading artillery pieces on the grounds of cost and efficiency. Large-caliber
breech-loading naval artillery became practical with French development of the
interrupted screw obturator by
Charles Ragon de Bange in 1872. It was only after a serious accident on board in 1879 when the left muzzleloading gun in the forward turret exploded during practice firing in the
Sea of Marmora killing 11 and injuring a further 35, that the Royal Navy decisively changed to breech loading guns. Improved loading and handling procedures were also adopted, and Thunderer herself was re-equipped with long-calibre 10" breech-loaders. Breech loading artillery overcame barrel length limitations of cast cannon imposed by the necessity of retracting the cannon into the hull for reloading through the muzzle. Simultaneous availability of longer barrels and slower burning
brown powder increased projectile velocities to . Spin-stabilized elongated projectiles offered both reliable positioning of percussion
fuzes and improved armor penetration through increased
sectional density.
Gun turrets Before the development of large-calibre, long-range guns in the mid-19th century, the classic
battleship design used rows of port-mounted guns on each side of the ship, often mounted in
casemates. Firepower was provided by a large number of guns which could only be aimed in a limited arc from one side of the ship. Due to instability, fewer larger and heavier guns can be carried on a ship. Also, the casemates often sat near the waterline, which made them vulnerable to flooding and restricted their use to calm seas.
Turrets were
weapon mounts designed to protect the crew and mechanism of the
artillery piece and with the capability of being aimed and fired in many directions as a rotating weapon platform. This platform can be mounted on a
fortified building or
structure such as an anti-naval
land battery, or on a
combat vehicle, a
naval ship, or a
military aircraft. During the
Crimean War, Captain
Cowper Phipps Coles constructed a
raft with guns protected by a 'cupola' and used the raft, named
Lady Nancy, to shell the Russian town of
Taganrog in the
Black Sea.
Lady Nancy "proved a great success", and Coles patented his rotating turret after the war. Following Coles' patenting, the
British Admiralty ordered a
prototype of Coles' design in 1859, which was installed in the floating battery vessel, , for trials in 1861, becoming the first warship to be fitted with a revolving gun turret. Coles' design aim was to create a ship with the greatest possible all round
arc of fire, as low in the water as possible to minimise the target. The Admiralty accepted the principle of the turret gun as a useful innovation, and incorporated it into other new designs. Coles submitted a design for a ship having ten domed turrets each housing two large guns. The design was rejected as impractical, although the Admiralty remained interested in turret ships and instructed its own designers to create better designs. Coles enlisted the support of
Prince Albert, who wrote to the first Lord of the Admiralty, the Duke of Somerset, supporting the construction of a turret ship. In January 1862, the Admiralty agreed to construct a ship, , which had four turrets and a low freeboard, intended only for coastal defence. Coles was allowed to design the turrets, but the ship was the responsibility of the chief Constructor
Isaac Watts. Another of Coles' designs, , was completed in August 1864. Its existing broadside guns were replaced with four turrets on a flat deck and the ship was fitted with of armour in a belt around the waterline. Early ships like
Monitor and
Royal Sovereign had little sea-keeping qualities, being limited to coastal waters. Coles, in collaboration with Sir
Edward James Reed, went on to design and build , the first seagoing warship to carry her guns in turrets. Laid down in 1866 and completed in June 1869, it carried two turrets, although the inclusion of a forecastle and poop prevented the guns firing fore and aft. The gun turret was independently invented by the Swedish inventor
John Ericsson in America, although his design was technologically inferior to Coles'. Ericsson designed in 1861. Its most prominent feature was a large cylindrical gun turret mounted
amidships above the low-freeboard upper
hull, also called the "raft". This extended well past the sides of the lower, more traditionally shaped hull. A small armored
pilot house was fitted on the upper deck towards the bow, however, its position prevented
Monitor from firing her guns straight forward. One of Ericsson's prime goals in designing the ship was to present the smallest possible target to enemy gunfire. The turret's rounded shape helped to deflect cannon shot. A pair of
donkey engines rotated the turret through a set of gears; a full rotation was made in 22.5 seconds during testing on 9 February 1862. Fine control of the turret proved to be difficult as the engine would have to be placed in reverse if the turret overshot its mark or another full rotation could be made. Including the guns, the turret weighed approximately ; the entire weight rested on an iron spindle that had to be jacked up using a wedge before the turret could rotate. The spindle was in diameter, which gave it ten times the strength needed in preventing the turret from sliding sideways. When not in use, the turret rested on a brass ring on the deck that was intended to form a watertight seal. In service, however, this proved to leak heavily, despite
caulking by the crew. The gap between the turret and the deck proved to be a problem as debris and shell fragments entered the gap and jammed the turrets of several s, which used the same turret design, during the
First Battle of Charleston Harbor in April 1863. Direct hits at the turret with heavy shot also had the potential to bend the spindle, which could also jam the turret. The turret was intended to mount a pair of
smoothbore Dahlgren guns, but they were not ready in time and guns were substituted. Each gun weighed approximately .
Monitors guns used the standard propellant charge of specified by the 1860 ordnance for targets "distant", "near", and "ordinary", established by the gun's designer Dahlgren himself. They could fire a round shot or shell up to a range of at an elevation of +15°. HMS
Thunderer represented the culmination of this pioneering work. An
ironclad turret ship designed by Edward James Reed, it was equipped with revolving turrets that used pioneering hydraulic turret machinery to maneouvre the guns. It was also the world's first mastless battleship, built with a central superstructure layout, and became the prototype for all subsequent warships. of 1871 was another pivotal design, and led directly to the modern battleship.
Armour-piercing shot , the first armour-piercing shot for
RML 7 inch gun, 1877. During the late 1850s, the development and implementation of the
ironclad warship carried
wrought iron armor of considerable thickness. This armor was practically immune to both the round
cast-iron cannonballs then in use and to the recently developed
explosive shell. The first solution to this problem was effected by
Major Sir W. Palliser. His
Palliser shot, approved in 1867, was made of
cast iron, the head being chilled in casting to harden it, using composite molds with a metal, water cooled portion for the head. At times there were defects that led to cracking in the projectiles but these were overcome with time.
Bronze studs were installed into the outside of the projectile so as to engage the rifling grooves in the gun barrel. The base had a hollow pocket but was not filled with powder or explosive: the cavity was necessitated by difficulties in
casting large solid projectiles without their cracking when they cooled, because the nose and base of the projectiles cooled at different rates, and in fact a larger cavity facilitated a better quality casting. At the
Battle of Angamos (8 October 1879) the Chilean
ironclad warships fired twenty 250-pound-Palliser gunshots against the Peruvian monitor , with devastating results. It was the first time that such piercing shells were used in actual combat. These chilled iron shots proved very effective against wrought iron armor, but were not serviceable against compound and
steel armor, which was first introduced in the 1880s. A new departure therefore had to be made, and
forged steel rounds with points
hardened by water took the place of the Palliser shot. At first, these forged-steel rounds were made of ordinary
carbon steel, but as armor improved in quality, the projectiles followed suit. From the 1890s onwards,
cemented steel armor became commonplace, initially only on the thicker armor of warships. To combat this, the projectile was formed of steel—forged or cast—containing both
nickel and
chromium. Another change was the introduction of a soft metal cap over the point of the shell – so called "Makarov tips" invented by Russian admiral
Stepan Makarov. This "cap" increased penetration by cushioning some of the impact shock and preventing the armor-piercing point from being damaged before it struck the armor face, or the body of the shell from shattering. It could also help penetration from an oblique angle by keeping the point from deflecting away from the armor face . Increased armor penetration became possible when projectile velocities of were obtained as
smokeless powder propellants replaced gunpowder around the turn of the 20th century.
Quick-firing artillery Underwater hull damage possible with
torpedoes encouraged development of small, inexpensive
torpedo boats capable of sinking the largest warships. By the end of the 19th century, all warships required a defensive battery of
quick-firing guns capable of hitting fast, maneuverable torpedo boats. The Royal Navy first introduced the
quick-firing 4.7-inch gun in HMS
Sharpshooter in 1889, and the
quick-firing 6-inch MK 1 in , launched 1891. Other navies followed suit; the French Navy installed quick-firing weapons on its ships completed in 1894–95. Quick-firing guns were a key characteristic of the
pre-dreadnought battleship, the dominant design of the 1890s. The quick-firing guns, while unable to penetrate thick armour, were intended to destroy the superstructure of an opposing battleship, start fires, and kill or distract the enemy's gun crews. The development of heavy guns and their increasing rate of fire meant that the quick-firer lost its status as the decisive weapon of naval combat in the early 1900s, though quick-firing guns were vital to defend battleships from attack by
torpedo boats and
destroyers, and formed the main armament of smaller vessels. Most late-19th-century warships mounted naval artillery of more than one caliber because of uncertainty about the relative destruction possible from a few large shells (which might miss) in comparison to the increased hit probability of a larger number of less damaging small-caliber shells fired within the same time period. Quick-firing guns were initially breech-loading weapons firing ammunition small enough to be loaded by hand. Later substitution of brass
cartridges for silk powder bags allowed increased rates of fire using
sliding wedge breech blocks. Increasing mechanization ultimately enabled similar rates of fire from naval artillery calibers up to 8"/55 caliber gun#Mark 16|.
Fire control is shown in the centre of the drawing and is labelled "Gunnery Calculating Position". When gunnery ranges increased dramatically in the late 19th century, it was no longer a simple matter of calculating the proper aim point, given the flight times of the shells. Increasingly sophisticated
mechanical calculators were employed for proper
gunlaying, typically with various spotters and distance measures being sent to a central plotting station deep within the ship. There the fire direction teams fed in the location, speed and direction of the ship and its target, as well as various adjustments for
Coriolis effect, weather effects on the air, and other adjustments. The resulting directions, known as a firing solution, would then be fed back out to the turrets for laying. If the rounds missed, an observer could work out how far they missed by and in which direction, and this information could be fed back into the computer along with any changes in the rest of the information and another shot attempted. The situation for naval fire control was highly complex, due to the need to control the firing of several guns at once. In naval engagements both the firing guns and target are moving, and the variables are compounded by the greater distances and times involved. Rudimentary naval fire control systems were first developed around the time of
World War I.
Arthur Pollen and
Frederic Charles Dreyer independently developed the first such systems. Pollen began working on the problem after noting the poor accuracy of naval artillery at a gunnery practice near
Malta in 1900.
Lord Kelvin, widely regarded as Britain's leading scientist, first proposed using an analogue computer to solve the equations which arise from the relative motion of the ships engaged in the battle and the time delay in the flight of the shell to calculate the required trajectory and therefore the direction and elevation of the guns. Pollen aimed to produce a combined
mechanical computer and automatic plot of ranges and rates for use in centralised fire control. To obtain accurate data of the target's position and relative motion, Pollen developed a plotting unit (or plotter) to capture this data. He added a gyroscope to allow for the
yaw of the firing ship. Again this required substantial development of the, at the time, primitive gyroscope to provide continuous reliable correction. Trials were carried out in 1905 and 1906, which although completely unsuccessful showed promise. He was encouraged in his efforts by the rapidly rising figure of Admiral
Jackie Fisher, Admiral
Arthur Knyvet Wilson and the Director of Naval Ordnance and Torpedoes (DNO),
John Jellicoe. Pollen continued his work, with tests carried out on Royal Navy warships intermittently. Meanwhile, a group led by Dreyer designed a similar system. Although both systems were ordered for new and existing ships of the Royal Navy, the Dreyer system eventually found most favour with the Navy in its definitive Mark IV* form. The addition of
director control facilitated a full, practicable fire control system for World War I ships, and most RN capital ships were so fitted by mid 1916. The director was high up over the ship where operators had a superior view over any gunlayer in the
turrets. It was also able to co-ordinate the fire of the turrets so that their combined fire worked together. This improved aiming and larger optical rangefinders improved the estimate of the enemy's position at the time of firing. The system was eventually replaced by the improved "
Admiralty Fire Control Table" for ships built after 1927.
Big-gun battleships greatly improved the accuracy of gunnery at the turn of the 20th century.|alt= Significant gunnery developments occurred in the late 1890s and the early 1900s, culminating with the launch of the revolutionary in 1906. Sir
Percy Scott was given command of HMS
Scylla in 1896, where he was able to implement his new theories on gunnery, scoring the unprecedented success of 80% during the 1897 gunnery trials. This was totally unprecedented, as the average in the Royal Navy was just 28%. Scott noted that night time signalling between ships in the fleet was slow and inaccurate. He addressed this in two ways: he devised training aids and put his signallers under instruction and he devised a new more effective flashing lamp. The new efficiency of his ship's signalling was adopted by the whole Mediterranean fleet. He devised a new sub-calibre gun which involved fitting a one-inch-calibre rifled barrel inside the barrel of the main armament but which used the main gun's controls. He also came up with new sights employing
telescope optics and new training targets. In the Navy's 1901 prize firing,
Terrible achieved the same score of 80%, and Scott's gunnery practices were adopted by other ships in the fleet. Later, Scott taught at the naval gunnery school at
Whale Island, Hampshire. a largely honorary role which he held until promotion to flag rank in 1905. The development of the torpedo meant that it became necessary to engage an enemy at ranges outside torpedo range. This in turn meant that the old system whereby a gunlayer in each turret pointed and fired the turret guns independently could no longer be expected to achieve a significant hit rate on an opposing ship. Scott was instrumental in encouraging the development and installation of director firing, a system whereby the guns were all pointed, elevated and fired from a single point, usually at the top of the foremast. By firing all the guns simultaneously it was possible to observe the simultaneous splashes produced and correct the aim visually. for defence against torpedo boats are mounted on the roof. As battle ranges were pushed out to an unprecedented , the distance was great enough to force gunners to wait for the shells to arrive before applying corrections for the next
salvo. A related problem was that the shell splashes from the more numerous smaller weapons tended to obscure the splashes from the bigger guns. Either the smaller-
calibre guns would have to hold their fire to wait for the slower-firing heavies, losing the advantage of their faster rate of fire, or it would be uncertain whether a splash was due to a heavy or a light gun, making ranging and aiming unreliable. Italian naval architect
Vittorio Cuniberti first argued for the concept of an all-big-gun battleship in 1903, proposing an "ideal" future British battleship of , with a main battery of a dozen 12-inch guns in eight turrets, 12 inches of
belt armour, and a speed of .
First Sea Lord Sir John Fisher pushed through the Board of Admiralty a decision to arm the next battleship with 12-inch guns and that it would have a speed no less than . The result was HMS
Dreadnought, which rendered all previous ships immediately obsolete on its launch in 1906. The ship mounted the 45-
calibre BL 12-inch Mark X gun in five twin
gun turrets. These could deliver a broadside of a maximum of eight guns and could be elevated up to +13.5°. They fired projectiles at a
muzzle velocity of ; at 13.5°, this provided a maximum range of with
armour-piercing (AP) 2
crh shells. At 16° elevation, the range was extended to using the more aerodynamic, but slightly heavier 4 crh AP shells. The rate of fire of these guns was one to two rounds per minute. The ships carried 80 rounds per gun. Within five years of the commissioning of
Dreadnought, a new generation of more powerful "super-dreadnoughts" was being built. The arrival of the super-dreadnought is commonly believed to have started with the British . What made them 'super' was the unprecedented 2,000-ton jump in displacement, the introduction of the heavier
13.5-inch (343 mm) gun, and the placement of all the main armament on the centerline. In the four years between
Dreadnought and
Orion, displacement had increased by 25%, and
weight of broadside had doubled. In comparison to the rapid advancement of the preceding half-century, naval artillery changed comparatively little through
World War I and
World War II. Battleships remained similar to
Dreadnought, torpedo boats evolved into
destroyers, and ships of intermediate size were called
cruisers. All ship types became larger as the calibre of heavy guns increased (to a maximum of 40 cm/45 Type 94 naval gun| in the s), but the number of guns carried remained similar. Smaller ships used smaller-calibre weapons which were also used on battleships as the defensive secondary armament.
High-angle artillery (dual purpose, anti-aircraft and anti-surface) on c. 1940. Although naval artillery had been designed to perform within the classical broadside tactics of the age of sail, World War I demonstrated the need for naval artillery mounts capable of greater elevation for
defending against aircraft. High-velocity naval artillery intended to puncture side armor at close range was theoretically capable of hitting targets miles away with the aid of fire control directors; but the maximum elevation of guns mounted within restrictive armored
casemates prevented reaching those ranges. The
QF 4 inch Mk V naval gun was one of the first artillery pieces to be adapted as an anti-aircraft gun and mounted on ships for defence. It was first used in 1914 as a secondary armament on s in a high-angle anti-aircraft role. Most naval artillery on ships built after World War I was capable of elevating to at least 45°, and some guns as large as 20 cm/50 3rd Year Type naval gun#Type E| were capable of elevating to 70° for potential use against aircraft. The Japanese used their large caliber guns for anti-aircraft defense when employing
San Shiki "beehive" shells.
Dual purpose guns were devised to protect ships against both torpedo boats and aircraft, and for WWII they comprised the primary armament on frigates and destroyers, and the secondary armament on cruisers and battleships. Dual purpose guns such as the US Navy's
5-inch (127 mm) /38 caliber guns functioned as heavy anti-aircraft artillery, firing VT shells (
proximity fuzed-shells) that would detonate when they came close to an enemy aircraft, and could also aim into the water to create waterspouts which could bring down low flying aircraft such as torpedo planes. The light anti-aircraft artillery typically consisted of autocannons such as the
Bofors 40 mm anti-aircraft guns and 65 single
Oerlikon 20 mm cannon. As destroyers began to assume
ASW roles to include protection of the fleet from
submarines, they were fitted with high-angle
depth charge mortars (called Y-guns, K-guns or
squid).
Naval bombardment of
Scarborough by the
Imperial German Navy in 1914. Battleships were used in support of
amphibious operations since the late 19th century in the form of
naval bombardment. Under international law such bombardments are regulated by the general law of war and the "
Bombardment by Naval Forces in Time of War (Hague Convention IX)"; 18 October 1907. At the beginning of World War I, its principal practitioner was the
Royal Navy. During the War RN ships fired against targets at
Gallipoli, the
Salonika front and along the Belgian Coast. In the
Aegean, the problems were not especially challenging, and enemy coastal defences (forts, shore-batteries etc.) were fairly unsophisticated; but along the Belgian Coast the
Germans constructed an extensive, well-equipped and well-coordinated system of gun-batteries to defend the coast. Ports, such as
Ostend and
Zeebrugge were of major importance to the
U-boat campaign and were frequently bombarded by British
monitors operating from Dover and Dunkirk. techniques, then experimenting with night-bombardment and moving on to adopt
indirect fire. Finally, in the summer of 1918, monitors were equipped with Gyro Director Training gear, which effectively provided the Director with a gyro-stabilised Artificial Line of Sight, and thereby enabled a ship to carry out Indirect Bombardment while underway. This was a very significant advance, and established a firm foundation for naval bombardment as practiced by the Royal Navy and
United States Navy during World War II. The practice reached its zenith during World War II, when the availability of man-portable
radio systems and sophisticated relay networks allowed forward observers to transmit targeting information and provide almost instant accuracy reports—once troops had landed. Battleships, cruisers and destroyers would pound shore installations, sometimes for days, in the hope of reducing fortifications and attriting defending forces. Obsolete battleships unfit for combat against other ships were often used as floating gun platforms expressly for this purpose. However, given the relatively primitive nature of the
fire control computers and radar of the era combined with the high velocity of naval gunfire, accuracy was poor until troops landed and were able to radio back reports to the ship. Naval gunfire could reach as far as inland, and was often used to supplement land-based artillery. The heavy-calibre guns of some eighteen battleships and cruisers were used to stop German
Panzer counterattack at
Salerno. Naval gunfire was used extensively throughout
Normandy, although initially the surprise nature of the landings themselves precluded a drawn-out bombardment which could have reduced the
Atlantic Wall defences sufficiently, a process that fell to
specialist armoured vehicles instead. ==Artillery ranges==