Dreadnought

The oldest remaining dreadnought, USS Texas, was launched in 1912 and is now a museum ship.

The dreadnought was the predominant type of 20th-century battleship. The first of the kind, the Royal Navy's Dreadnought had such an impact when launched in 1906 that battleships built after her were referred to as 'dreadnoughts', and earlier battleships became known as pre-dreadnoughts. Her design had two revolutionary features: an 'all-big-gun' armament scheme and steam turbine propulsion. The arrival of the dreadnoughts renewed the naval arms race, principally between the United Kingdom and Germany but reflected worldwide, as the new class of warships became a crucial symbol of national power.

The concept of an all-big-gun ship had been in development for several years before Dreadnought's construction. The Imperial Japanese Navy had begun work on an all-big-gun battleship in 1904, but finished the ship as a pre-dreadnought; the United States Navy was also building all-big-gun battleships. Technical development continued rapidly through the dreadnought era. Successive designs increased rapidly in size and made use of improvements in armament, armor, and propulsion. Within ten years, new battleships outclassed Dreadnought herself. These more powerful vessels were known as 'super-dreadnoughts'. Most of the dreadnoughts were scrapped after the end of World War I under the terms of the Washington Naval Treaty, but many of the newer super-dreadnoughts continued serving through World War II.

While dreadnought-building consumed vast resources in the early 20th century, there was only one battle between large dreadnought fleets. At the Battle of Jutland, the British and German navies clashed with no decisive result. The term 'dreadnought' gradually dropped from use after World War I, especially after the Washington Naval Treaty, as all remaining battleships shared dreadnought characteristics; it can also be used to describe battlecruisers, the other type of ship resulting from the dreadnought revolution.^[1]

Origins

The distinctive all-big-gun armament of the dreadnought was developed in the first years of the 20th century as navies sought to increase the firepower and range of their battleships. The majority of pre-dreadnought battleships had a main armament of four heavy guns of 12-inch (305 mm) caliber, a secondary armament of six to eighteen quick-firing guns of 4.7 inches (119 mm) to 7.5 inches (191 mm) caliber, and other smaller weapons. Some designs had an intermediate battery of 8-inch (203 mm) guns. By 1903, serious proposals for an all-big-gun armament were circulated in several countries.^[2]

All-big-gun designs commenced almost simultaneously in three navies. The Imperial Japanese Navy authorized the construction of Satsuma, designed with twelve 12-inch (305 mm) guns in 1904; she was laid down in May 1905.^[3] The Royal Navy began the design of HMS Dreadnought in January 1905; she was laid down in October.^[4] The U.S. Navy gained authorization for USS Michigan, carrying eight 12-inch guns in March;^[4] she was laid down in December 1906.^[5]

The move to all-big-gun designs was accomplished because a uniform, heavy-caliber armament offered advantages in both firepower and fire control. The newest 12-inch (305 mm) guns had more long-range firepower than a gun of 10-inch (254 mm) or 9.2-inch (234 mm) caliber.^[6] Most historians also cite advantages in fire control; at long ranges guns were aimed by observing the splashes caused by shells fired in salvos, and it was difficult to interpret different splashes caused by different calibers of gun. There is still debate as to whether this point was important.^[7]

Long-range gunnery

In naval battles of the 1890s the decisive weapon was the medium-caliber, typically 6-inch (152 mm), quick-firing gun firing at relatively short range; naval gunnery was too inaccurate to hit targets at a longer range.^{[A 1]} At these ranges lighter guns had good accuracy, and their high rate of fire delivered high volumes of ordnance on the target. At the Battle of the Yalu River in 1894, the victorious Japanese did not open fire until the range had closed to 3,900 metres (4,300 yd), but most of the fighting occurred at 2,000 metres (2,200 yd)^[8].

By the early 1900s British and American admirals expected that future battleships would engage at longer distances, as the range of the torpedo increased.^[9] In 1903, the U.S. Navy ordered a design of torpedo effective to 4,000-yard (3,700 m).^[10] Both British and American admirals concluded they needed to engage the enemy at longer ranges.^[10][11] In 1900, Admiral Sir John "Jackie" Fisher, commanding the Royal Navy Mediterranean Fleet, ordered gunnery practice with 6-inch guns at 6,000-yard (5,500 m).^[11] By 1904, the U.S. Naval War College was considering the effects on battleship tactics of torpedoes with a range of 7,000-yard (6,400 m) to 8,000-yard (7,300 m).^[10]

The range of light and medium-caliber guns was limited, and accuracy declined badly at longer range.^{[A 2]} At longer ranges the advantage of a high rate of fire also decreased; accurate shooting depended on spotting the shell-splashes of the previous salvo, which limited the optimum rate of fire.^[2]

In the early years of the 20th century the effective range of heavy guns increased. This had been established during gunnery exercises by 1904, and confirmed in combat during the action at Tsushima in 1905.^{[A 3]}

All-big-gun mixed-caliber ships

HMS Agamemnon, an all-big-gun mixed-caliber ship of the Lord Nelson class. She carried four 12-inch (300 mm) and ten 9.2-inch (230 mm).

One approach to making more powerful battleships was to reduce the secondary battery, and substitute additional heavy guns: typically 9.2-inch (234 mm) or 10-inch (254 mm). These ships, described as 'all-big-gun mixed-caliber' or later 'semi-dreadnought', included the British King Edward VII and Lord Nelson classes, the French Danton class, and the Japanese battleship Satsuma.^[12] The design process for these ships often included discussion of an 'all-big-gun one-caliber' alternative.^[13]

The June 1902 issue of Proceedings of the US Naval Institute contained comments by the U.S. Navy's leading gunnery expert Prof. P.R Alger proposing a main battery of eight 12-inch (305 mm) guns in twin turrets.^[14] In May 1902, the Bureau of Construction and Repair submitted a design for the battleship with twelve 10-inch guns in twin turrets, two at the ends and four in the wings.^[14] Lt. Cdr. H. C. Poundstone submitted a paper to President Roosevelt in December 1902 arguing the case for larger battleships. In an appendix to his paper, Poundstone suggested a greater number of 11-inch (279 mm) and 9-inch (229 mm) guns was preferable to a smaller number of 12-inch and 9-inch.^[2] The Naval War College and Bureau of Construction and Repair developed these ideas in studies between 1903 and 1905. Wargame studies begun in July 1903 "showed that a battleship armed with twelve 11-inch or 12-inch guns hexagonally arranged would be equal to three or more of the conventional type."^[15]

In the Royal Navy, the same trend occurred. A design had also been circulated in 1902–03 for "a powerful 'all big-gun' armament of two calibres, viz. four 12-inch and twelve 9.2-inch guns."^[16] However, the Admiralty decided to build three more King Edwards (with a mixture of 12-inch, 9.2-inch and 6-inch (152 mm)) in the 1903–04 naval construction program instead.^[17] The concept was revived for the 1904–05 program, the Lord Nelson class. Restrictions on length and beam meant the midships 9.2-inch turrets became single instead of twin, thus giving an armament of four 12-inch, ten 9.2-inch and no 6-inch. The constructor for this design, J.H. Narbeth, submitted an alternative drawing showing an armament of twelve 12-inch guns, but the Admiralty was not prepared to accept this.^[18] Part of the rationale for the decision to retain mixed-caliber guns was the need to begin the building of the ships quickly because of the tense situation produced by the Russo-Japanese War.^[19]

Switch to all-big-gun designs

The replacement of the 6-inch (152 mm) or 8-inch (203 mm) guns with weapons of 9.2-inch (234 mm) or 10-inch (254 mm) caliber improved the striking power of a battleship, particularly at longer ranges. However, uniform heavy-gun armament offered many other advantages. One advantage was logistical simplicity. When the U.S. was considering whether to have a mixed-caliber main armament for the South Carolina class, for example, William Sims and Homer Poundstone stressed the advantages of homogeneity in terms of ammunition supply and the transfer of crews from the disengaged guns to replace wounded gunners.^[20]

A uniform caliber of gun meant streamlined fire control. The designers of Dreadnought preferred an all-big-gun design because it would mean only one set of calculations about adjustments to the range of the guns.^{[A 4]} Some historians today hold that a uniform caliber was particularly important because the risk of confusion between shell-splashes of 12-inch (305 mm) and lighter guns made accurate ranging difficult. However, this viewpoint is controversial; fire control in 1905 was not advanced enough to use the salvo-firing technique where this confusion might be important,^[21] and confusion of shell-splashes does not seem to have been a concern of those working on all-big gun designs.^{[A 5]} Nevertheless, the likelihood of engagements at longer ranges was important in deciding that the heaviest possible guns should become standard, hence 12-inch (305 mm) rather than 10-inch (254 mm).^{[A 6]}

Furthermore, the newer designs of 12-inch gun mounting had a considerably higher rate of fire, removing the advantage previously enjoyed by smaller calibers. In 1895, a 12-inch gun might fire one round every four minutes; by 1902, two rounds per minute was usual.^[22] In October 1903, naval architect Vittorio Cuniberti published a paper in Jane's Fighting Ships entitled "An Ideal Battleship for the British Navy", which called for a 17,000 ton ship carrying a main armament of twelve 12-inch guns, protected by armor 12 inches thick, and having a speed of 24 knots (28 mph/44 km/h).^[23] Cuniberti's idea—which he had already proposed to his own navy, the Regia Marina—was to make use of the high rate of fire of new 12-inch guns to produce devastating rapid-fire from heavy guns to replace the 'hail of fire' from lighter weapons.^[24] Something similar lay behind the Japanese move towards heavier guns; at Tsushima, Japanese shells contained a higher than normal proportion of high explosive, and were fused to explode on contact, starting fires rather than piercing armor.^[25] The increased rate of fire laid the foundations for future advances in fire control.^[22]

Building the first dreadnoughts

The Royal Navy's HMS Dreadnought, the world's first dreadnought

In Japan, the two battleships of the 1903–04 Program were the first in the world to be laid down as all-big-gun ships, with eight 12-inch (305 mm) guns. However, the armor of their design was considered too thin, demanding a substantial redesign.^[26] The financial pressures of the Russo-Japanese War and the short supply of 12-inch guns—which had to be imported from the United Kingdom—meant these ships were completed with a mixture of 12-inch and 10-inch (254 mm) armament. The 1903–04 design also retained traditional triple-expansion steam engines, unlike Dreadnought.^[27]

The dreadnought breakthrough occurred in the United Kingdom in October 1905. The new First Sea Lord, John Fisher, 1st Baron Fisher had long been an advocate of new technology in the Royal Navy and had recently been convinced of the idea of an all-big-gun battleship.^{[A 7]} Fisher is often credited as the creator of the dreadnought and the father of the United Kingdom's great dreadnought battleship fleet, an impression he himself did much to reinforce. However, it has been suggested Fisher's main interest was in developing the battlecruiser and not the battleship.^[28]

Shortly after taking office, Fisher set up a Committee on Designs to consider future battleships and armored cruisers.^[4] The Committee's first task was to consider a new battleship. The specification for the new ship was a 12-inch main battery and anti-torpedo-boat guns but no intermediate calibers, and a speed of 21 kn (39 km/h) which was two or three knots faster than existing battleships.^[29] The initial designs intended twelve 12-inch guns, though difficulties in positioning these guns led the chief constructor at one stage to propose a return to four 12-inch guns with sixteen or eighteen of 9.2-inch (234 mm). After a full evaluation of reports of the action at Tsushima compiled by an official observer, Captain William Christopher Pakenham, the Committee settled on a main battery of ten 12-inch guns, along with twenty-two 12 pounders as her secondary armament.^[29] The Committee also took the adventurous step of giving Dreadnought steam turbine propulsion. This was unprecedented in a large warship. The greater efficiency of the turbines meant the 21-knot (24 mph/39 km/h) design speed could be achieved in a smaller and cheaper ship than if reciprocating engines had been used.^[30] Construction took place at a remarkable rate; her keel was laid on 2 October 1905, she was launched on 10 February 1906, and she was completed on 3 October 1906—an impressive demonstration of British industrial might.^[4]

The first US dreadnoughts were the two South Carolina-class ships. Detailed plans for these were worked out in July–November 1905, and approved by the Board of Construction on 23 November 1905.^[31] However, building was slow; specifications for bidders were issued on 21 March 1906, the contracts awarded on 21 July 1906^[32] and the two ships were laid down in December 1906, after the completion of the Dreadnought.^[33]

Design

The designers of dreadnoughts sought to provide as much protection, speed, and firepower as possible in a ship of a realistic size and cost. The hallmark of dreadnought battleships was an ‘all-big-gun’ armament, but they also had heavy armor concentrated mainly in a thick belt at the waterline and in one or more armored decks. In addition, secondary armament, fire control, command equipment, protection against torpedoes also had to be crammed into the hull.^[34]

The inevitable consequence of demands for ever greater speed, striking power, and endurance meant that displacement, and hence cost, of dreadnoughts tended to increase. The Washington Naval Treaty of 1922 imposed a limit of 35,000 tons on the displacement of capital ships. In subsequent years a number of treaty battleships were commissioned designed to build up to this limit. Japan's decision to leave the Treaty in the 1930s, and the arrival of the Second World War, eventually made this limit irrelevant.^[35]

Armament

A plan of Bellerophon showing the armament distribution of early British dreadnoughts. The main battery is in twin turrets, with two on the 'wings'; the light secondary battery is clustered around the superstructure.

Tegetthoff-class battleship (SMS Szent István (1914)) with two-storeyed "triple gun turrets" With this layout, the ship was able to keep an enemy ship under fire with her entire main battery.

Dreadnoughts mounted a uniform main battery of heavy-caliber guns; the number, size, and arrangement differed between designs. Dreadnought herself mounted ten 12-inch (305 mm) guns. 12-inch guns had been standard for most navies in the pre-dreadnought era and this continued in the first generation of dreadnought battleships. The Imperial German Navy was an exception, continuing to use 280-millimetre (11.0 in) guns in its first class of dreadnoughts, the Nassau class.^[36]

Dreadnoughts also carried lighter weapons. Many early dreadnoughts carried a secondary armament of very light guns designed to fend off enemy torpedo boats. However, the caliber and weight of secondary armament tended to increase, as the range of torpedoes and the staying power of the destroyers expected to carry them also increased. From the end of World War I onwards, battleships had also to be equipped with anti-aircraft armament, typically a large number of light guns.^[37]

Dreadnoughts also very frequently carried torpedo tubes themselves. In theory, a line of battleships so equipped could unleash a devastating volley of torpedoes on an enemy line steaming a parallel course. In practice, torpedoes fired from battleships scored very few hits, while there was a risk that a stored torpedo would cause a dangerous explosion if hit by enemy fire.^[38]

Position of main armament

The effectiveness of the guns depended in part on the layout of the turrets. Dreadnought, and the British ships which immediately followed her, carried five turrets: one forward and two aft on the centerline of the ship, and two in the 'wings' next to the superstructure. This allowed three turrets to fire ahead and four on the broadside. The Nassau and Helgoland classes of German dreadnoughts adopted a 'hexagonal' layout, with one turret each fore and aft and four wing turrets; this meant more guns were mounted in total, but the same number could fire ahead or broadside as with Dreadnought.^[39]

Dreadnought designs experimented with different layouts. The British Neptune class staggered the wing turrets, so all ten guns could fire on the broadside, a feature also used by the German Kaiser class. This, however, risked blast damage to parts of the ship over which the guns fired, and put great stress on the ship's frame.^[40]

If all turrets were on the centerline of the vessel, then the stresses on the ship's frame were relatively low. This layout also meant that the entire main battery could fire on the broadside, though fewer could fire end-on. It also meant the hull would be longer, which posed some challenges for the designers; a longer ship needed to devote more weight to armor to get equivalent protection, and the magazines which served each turret interfered with the distribution of boilers and engines.^[41] For these reasons HMS Agincourt, which carried a record fourteen 12-inch guns in seven centerline turrets, was not considered a success.^[42]

A superfiring layout was eventually adopted as standard. This involved raising one or two turrets so they could fire over a turret immediately forward or astern of them. The U.S. Navy adopted this feature with their first dreadnoughts in 1906, but others were slower to do so. As with other layouts there were drawbacks. Initially, there were concerns about the impact of the blast of the raised guns on the lower turret. Raised turrets also raised the center of gravity of the ship, and might reduce the stability of the ship. Nevertheless, this layout made the best of the firepower available from a fixed number of guns, and was eventually adopted generally.^[40] The U.S. Navy used superfiring on the South Carolina class, and the layout was adopted in the Royal Navy with the Orion class of 1910. By World War II, superfiring was entirely standard.

Initially, all dreadnoughts had two guns to a turret. However, one solution to the problem of turret layout was to put three or even four guns in each turret. Fewer turrets meant the ship could be shorter, or could devote more space to machinery. On the other hand, it meant that in the event of an enemy shell destroying one turret, a higher proportion of the main armament would be out of action. The risk of the blast waves from each gun barrel interfering with others in the same turret also reduced the rate of fire from the guns somewhat. The first nation to adopt the triple turret was Italy, in the Dante Alighieri, soon followed by Russia with the Gangut class,^[43] the Austro-Hungarian Tegetthoff class, and the U.S. Nevada class. British Royal Navy battleships did not adopt triple turrets until after the First World War, with the Nelson class. Several later designs used quadruple turrets, including the British King George V class and French Richelieu class.

Main armament power and caliber

Rather than try to fit more guns onto a ship, it was possible to increase the power of each gun. This could be done by increasing either the caliber of the weapon and hence the weight of shell, or by lengthening the barrel to increase muzzle velocity. Either of these offered the chance to increase range and armor penetration.^[44]

The workings of a dreadnought's main armament, based on the British 15-inch gun used on super-dreadnoughts

Both methods offered advantages and disadvantages, though in general greater muzzle velocity meant increased barrel wear. As guns fire, their barrels wear out, losing accuracy and eventually requiring replacement. At times, this became problematic; the U.S. Navy seriously considered stopping practice firing of heavy guns in 1910 because of the wear on the barrels.^[45] The disadvantages of heavier guns were twofold: first, the guns and turrets required weighed much more; and second, heavier and slower shells needed to be fired at a higher angle for the same range, which affected the design of turrets. However, the big advantage of increasing caliber was that heavier shells are also affected less by air resistance, and so retain greater penetrating power at long range.^[46]

Different navies approached the decision of caliber in different ways. The German navy, for instance, generally used a lighter caliber than the equivalent British ships, e.g. 12-inch (305 mm) caliber when the British standard was 13.5-inch (343 mm). However, because German metallurgy was superior, the German 12-inch gun was superior to the British 12-inch in terms of shell weight and muzzle velocity; and because the German guns were lighter than the British 13.5-inch, German ships could afford more armor.^[46]

On the whole, however, the caliber of guns tended to increase. In the Royal Navy, the Orion class, launched 1910, used ten 13.5-inch guns, all on the centerline; the Queen Elizabeth class, launched 1913, used eight 15-inch (381 mm) guns. In all navies, the caliber of guns increased and the number of guns tended to decrease to compensate. The fewer guns needed meant distributing them became less of an issue, and centerline turrets became entirely the norm.^[47]

A further step change was planned for battleships designed and laid down at the end of World War I. The Japanese Nagato class in 1917 carried 16-inch (406 mm) guns, which was quickly matched by the U.S. Navy's Colorado class. Both the United Kingdom and Japan were planning battleships with 18-inch (457 mm) armament, in the British case the N3 class. However, the Washington Naval Treaty meant these plans with their mammoth guns never got off the drawing board.^[48]

A 14-inch naval gun, as fitted to the King George V class treaty battleships

The Washington Naval Treaty limited battleship guns at 16-inch (410 mm) caliber.^[49] Later treaties preserved this limit, though reductions of the limit to 11, 12, or 14 inches were proposed.^[50] The only battleships to break the limit were the Japanese Yamato class, begun in 1937 (after the treaty expired), which carried 460 mm (18.1 in) main guns.^[51] By the middle of World War II, the United Kingdom was making use of 15-inch guns kept as spares for the Queen Elizabeth class to arm the last British battleship, Vanguard.^[52]

A number of World War II-era designs were drawn up proposing another move towards gigantic armament. The German H-43 and H-44 designs proposed 508-millimetre (20 in) guns, and there is evidence Hitler wanted calibers as high as 609-millimetre (24 in);^[53] the Japanese 'Super Yamato' design also called for 508 mm guns.^[54] None of these proposals went further than very preliminary design work.

Secondary armament

The first dreadnoughts tended to have a very light secondary armament intended to protect them from torpedo boats. Dreadnought herself carried 12-pounder guns; each of her twenty-two 12-pounders could fire at least 15 rounds a minute at any torpedo boat making an attack.^[55] The South Carolinas and other early American dreadnoughts were similarly equipped.^[56] At this stage, torpedo boats were expected to attack separately from any fleet actions. Therefore, there was no need to armor the secondary gun armament, or to protect the crews from the blast effects of the main guns. In this context, the light guns tended to be mounted in unarmored positions high on the ship to minimize weight and maximize field of fire.^[57]

12-pounder anti-torpedo boat guns mounted on the roof of a turret on Dreadnought

Within a few years, the principal threat was from the destroyer—larger, more heavily armed, and harder to destroy than the torpedo boat. Since the risk from destroyers was very serious, it was considered that one shell from a battleship's secondary armament should sink (rather than merely damage) any attacking destroyer. Destroyers, in contrast to torpedo boats, were expected to attack as part of a general fleet engagement, so it was necessary for the secondary armament to be protected against shell splinters from heavy guns, and the blast of the main armament. This philosophy of secondary armament was adopted by the German navy from the start; Nassau, for instance, carried twelve 150-mm (5.9 in) and sixteen 88-mm (3.45 in) guns, and subsequent German dreadnought classes followed her lead.^[39] These heavier guns tended to be mounted in armored barbettes or casemates on the main deck. The Royal Navy increased its secondary armament from 12-pounder to first 4-inch (100 mm) and then 6-inch (150 mm) guns, which were standard at the start of World War I;^[58] the U.S. standardized on 5-inch (130 mm) caliber for the War but planned 6-inch guns for the ships designed just afterwards.^[59]

The secondary battery also served several other roles. It was hoped that a medium-caliber shell might be able to score a hit on an enemy dreadnought's sensitive fire control systems. Also, it was felt that the secondary armament could play an important role in driving off enemy cruisers from attacking a crippled battleship.^[60]

The secondary armament of dreadnoughts was, on the whole, unsatisfactory. A hit from a light gun could not be relied on to stop a destroyer. Heavier guns could not be relied on to hit a destroyer, as experience at the Battle of Jutland showed. The barbette mountings of heavier guns also proved problematic; being low in the hull, they proved liable to flooding, and on several classes some were removed and plated over. The only sure way to protect a dreadnought from destroyer or torpedo boat attack was to escort it with its own destroyer squadron. After World War I the secondary armament tended to be mounted in turrets on the upper deck and around the superstructure. This allowed a wide field of fire and good protection without the negative points of barbettes. Increasingly through the 1920s and 1930s the secondary guns were seen as a major part of the anti-aircraft battery, with high-angle, dual-purpose guns increasingly adopted.^[61]

Armor

This section of Bellerophon shows a typical dreadnought protection scheme, with very thick armor protecting the turrets, magazines and engine spaces tapering away in less vital areas; also note the subdivided underwater compartments to prevent sinking.

Much of the displacement of a dreadnought was taken up by the steel plating of its armor. Designers spent much time and effort to provide the best possible protection for their ships against the various weapons they would be faced with. However, only so much weight could ever be devoted to protection, without compromising speed, firepower or seakeeping.^[62]

Central citadel

The bulk of a dreadnought's armor was concentrated around the 'armored citadel'. This was a box, with four armored walls and an armored roof, around the most important parts of the ship. The sides of the citadel were the 'armored belt' of the ship, which started on the hull just in front of the forward turret and ran to just behind the aft turret. The ends of the citadel were two armored bulkheads, fore and aft, which stretched between the ends of the armor belt. The 'roof' of the citadel was an armored deck. Within the citadel were the boilers, engines, and the magazines for the main armament. A hit to any of these systems could cripple or destroy the ship. The 'floor' of the box was the bottom of the ship's hull, and was unarmored.^[63]

The earliest dreadnoughts were intended to take part in a pitched battle against other battleships at ranges of up to 10,000 yd (9,100 m). In such an encounter, shells would fly on a relatively flat trajectory, and a shell would have to hit at or just about the waterline to damage the vitals of the ship. For this reason, the early dreadnoughts' armor was concentrated in a thick belt around the waterline; this was 11 inches (280 mm) thick in Dreadnought. Behind this belt were arranged the ship's coal bunkers, to further protect the engineering spaces.^[64] In an engagement of this sort, there was also a lesser threat of indirect damage to the vital parts of the ship. A shell which struck above the belt armor and exploded could send fragments flying in all directions. These fragments were dangerous, but could be stopped by much thinner armor than what would be necessary to stop an unexploded armor-piercing shell. To protect the innards of the ship from fragments of shells which detonated on the superstructure, much thinner steel armor was applied to the decks of the ship.^[64]

While the thickest protection was reserved for the central citadel in all battleships, some navies also extended a thinner armored belt and armored deck to cover the ends of the ship, or extended a thinner armored belt up the outside of the hull. This 'tapered' armor was used by the major European navies—the United Kingdom, Germany and France. This arrangement gave some armor to a larger part of the ship; for the very first dreadnoughts, when high-explosive shellfire was still considered a significant threat, this was useful. However, it tended to result in the main belt being very short, only protecting a thin strip above the waterline; some navies found that when their dreadnoughts were heavily laden, the armored belt was entirely submerged.^[65] The alternative was an 'all or nothing' protection scheme, developed by the U.S. Navy. The armor belt was tall and thick, but no side protection at all was provided to the ends of the ship or the upper decks. The armored deck was also thickened. The 'all-or-nothing' system provided more effective protection against the very-long-range engagements of dreadnought fleets and was adopted outside the U.S. Navy after World War I.^[66]

During the evolution of the dreadnought, armor schemes changed to reflect the greater risk of plunging shells from long-range gunfire, and the increasing threat from armor-piercing bombs dropped by aircraft. Later designs carried a greater thickness of steel on the armored deck;^[67] Yamato carried a 16-inch (410 mm) main belt, but a deck 9-inch (230 mm) thick.^[68]

Underwater protection and subdivision

The final element of the protection scheme of the first dreadnoughts was the subdivision of the ship below the waterline into several watertight compartments. If the hull was holed—by shellfire, mine, torpedo, or collision—then, in theory, only one area would flood and the ship could survive. To make this precaution even more effective, many dreadnoughts had no hatches between different underwater sections, so that even a surprise hole below the waterline need not sink the ship. However, there were still a number of instances where flooding spread between underwater compartments.^[69]

The greatest evolution in dreadnought protection came with the development of the Anti-torpedo bulge and torpedo belt, both attempts to protect against underwater damage by mines and torpedoes. The purpose of underwater protection was to absorb the force of a detonating mine or torpedo well away from the final watertight hull. This meant an inner bulkhead along the side of the hull, which was generally lightly armored to capture splinters, separated from the outer hull by one or more compartments. The compartments in between were either left empty, or filled with coal, water or fuel oil.^[70]

Propulsion

Paris on speed trials

Dreadnoughts were propelled by two to four screw propellers.^[71] Dreadnought herself, and all British dreadnoughts, had screw shafts driven by steam turbines. However, the first generation of dreadnoughts built in other nations used the slower triple-expansion steam engine which had been standard in pre-dreadnoughts.^[72]

Turbines offered more power than reciprocating engines for the same volume of machinery.^[73][74] This, along with guarantee on the new machinery from the inventor, Charles Parsons, persuaded the Royal Navy to use turbines in Dreadnought.^[74] It is often said that turbines had the additional benefits of being cleaner and more reliable than reciprocating engines.^[75] However, by 1905, new designs of reciprocating engine were available which were cleaner and more reliable than previous models.^[73]

Turbines were not without disadvantages. At cruising speeds, much slower than maximum speed, turbines were markedly less fuel-efficient than reciprocating engines. This was particularly important for navies which required a long range at cruising speeds—and hence for the U.S. Navy, which was planning in the event of war to cruise across the Pacific and engage the Japanese in the Philippines.^[76]

The US Navy experimented with turbine engines from 1908 in the North Dakota, but was not fully committed to turbines until the Pennsylvania class in 1916. In the preceding Nevada class one ship, the Oklahoma, received reciprocating engines, while the Nevada received geared turbines. The two New York class ships of 1914 both received reciprocating engines, but all four ships of the Florida (1911) and Wyoming (1912) classes received turbines.

The disadvantages of the turbine were eventually overcome. The solution which eventually was generally adopted was the geared turbine, where gearing reduced the rotation rate of the propellers and hence increased efficiency. However, this solution required technical precision in the gears and hence was difficult to implement.^[77]

One alternative was the turbo-electric drive where the steam turbine generated electrical power which then drove the propellers. This was particularly favored by the U.S. Navy, which used it for all dreadnoughts from late 1915–1922. The advantages of this method were its low cost, the opportunity for very close underwater compartmentalization, and good astern performance. The disadvantages were that machinery was heavy and vulnerable to battle damage, particularly the effects of flooding on the electrics.^{[A 8]}

Turbines were never replaced in battleship design. Diesel engines were eventually considered by a number of powers, as they offered very good endurance and an engineering space taking up less of the length of the ship. However, they were also heavier, took up a greater vertical space, offered less power, and were considered unreliable.^[78]

Fuel

The first generation of dreadnoughts used coal to fire the boilers which fed steam to the turbines. Coal had been in use since the very first steam warships, but had many disadvantages. It was labor-intensive to pack coal into the ship's bunkers and then feed it into the boilers. The boilers became clogged with ash. Coal produced thick black smoke which gave away the position of a fleet. In addition, coal was very bulky and had comparatively low thermal efficiency. Coal was, however, quite inert and could be used as part of the ship's protection scheme.^[79]

Oil-fired propulsion had many advantages for naval architects and officers at sea alike. It reduced smoke, making ships less visible. It could be fed into boilers automatically, rather than needing a complement of stokers to do it by hand. Oil has roughly twice the thermal content of coal. This meant that the boilers themselves could be smaller; and for the same volume of fuel, an oil-fired ship would have much greater range.^[79]

These benefits meant that, as early as 1901, Fisher was pressing the advantages of oil fuel.^[80] There were technical problems with oil-firing, connected with the different distribution of the weight of oil fuel compared to coal,^[79] and the problems of pumping viscous oil.^[81] However, the main problem with using oil for the battle fleet was that, with the exception of the USA, every major navy would have to import its oil. This meant that a number of navies adopted 'dual-firing' boilers which could use coal sprayed with oil; British ships so equipped, which included dreadnoughts, could even use oil alone at up to 60% power.^[82]

The US was a major oil producer, and the U.S. Navy was the first to wholeheartedly adopt oil-firing, deciding to do so in 1910 and ordering oil-fired boilers for the Nevada class, in 1911.^[83] The United Kingdom was not far behind, deciding in 1912 to use oil on its own in the Queen Elizabeth class;^[82] shorter British design and building times meant that Queen Elizabeth was commissioned before either of the Nevada class. The United Kingdom planned to revert to mixed firing with the subsequent Revenge class, at the cost of some speed—but Fisher, returned to office in 1914, insisted that all of the boilers should be oil-fired.^[84] Other major navies retained mixed coal-and-oil firing until the end of World War I.^[85]

Dreadnought building

Dreadnoughts were developed as a move in an international battleship arms-race which had begun in the 1890s. The British Royal Navy had a big lead in the number of pre-dreadnought battleships, but a lead of only one dreadnought.^[86] This has led to criticism that the British, by launching HMS Dreadnought, threw away a strategic advantage.^[87] However, most of the United Kingdom's naval rivals were themselves contemplating or even building warships that featured a uniform battery of heavy guns. Both the Japanese Navy and the US Navy ordered "all-big-gun" ships in 1904–05, with the Satsuma and South Carolina ships, respectively. Germany's Kaiser Wilhelm II had advocated a fast warship armed only with heavy guns since the 1890s. By securing a head start in dreadnought construction, the United Kingdom ensured that its dominance of the seas continued.^[88]

The battleship race soon accelerated once more, placing a great burden on the finances of the governments which engaged in it. The first dreadnoughts were not much more expensive than the last pre-dreadnoughts, but the cost per ship continued to grow thereafter.^{[A 9]} Modern battleships were the crucial element of naval power in spite of their price. Each battleship was a signal of national power and prestige, in a manner similar to the nuclear weapons of today.^[89] Germany, France, Russia, Italy, Japan and Austria all began dreadnought programs, and second-rank powers including the Ottoman Empire, Argentina, Brazil, and Chile commissioned dreadnoughts to be built in British and American yards.^[90]

Anglo-German arms race

King George V (left) inspects HMS Neptune.

The building of Dreadnought coincided with increasing tension between the United Kingdom and Germany. Germany had begun to build a large battlefleet in the 1890s, as part of a deliberate policy to challenge British naval supremacy. With the conclusion of the Entente Cordiale between the United Kingdom and France in April 1904, it became increasingly clear that the United Kingdom's principal naval enemy would be Germany, which was building up a large, modern fleet under the 'Tirpitz' laws. This rivalry gave rise to the two largest dreadnought fleets of the pre-war period.^[91]

The first German response to Dreadnought came with the Nassau class, laid down in 1907. This was followed by the Helgoland class in 1909. Together with two battlecruisers—a type for which the Germans had less admiration than Fisher, but which could be built under authorisation for armored cruisers, rather than capital ships—these classes gave Germany a total of ten modern capital ships built or building in 1909. While the British ships were somewhat faster and more powerful than their German equivalents, a 12:10 ratio fell far short of the 2:1 ratio that the Royal Navy wanted to maintain.^[92]

In 1909, the British Parliament authorized an additional four capital ships, holding out hope Germany would be willing to negotiate a treaty about battleship numbers. If no such solution could be found, an additional four ships would be laid down in 1910. Even this compromise solution meant (when taken together with some social reforms) raising taxes enough to prompt a constitutional crisis in the United Kingdom in 1909–10. In 1910, the British eight-ship construction plan went ahead, including four Orion-class super-dreadnoughts, and augmented by battlecruisers purchased by Australia and New Zealand. In the same period of time, Germany laid down only three ships, giving the United Kingdom a superiority of 22 ships to 13. The British resolve demonstrated by their construction program led the Germans to seek a negotiated end to the arms race. While the Admiralty's new target of a 60% lead over Germany was near enough to Tirpitz's goal of cutting the British lead to 50%, talks foundered on the question on whether British Commonwealth battlecruisers should be included in the count, as well as non-naval matters like the German demands for recognition of her ownership of Alsace-Lorraine.^[93]

The dreadnought race stepped up in 1910 and 1911, with Germany laying down four capital ships each year and the United Kingdom five. Tension came to a head following the German Naval Law of 1912. This proposed a fleet of 33 German battleships and battlecruisers, outnumbering the Royal Navy in home waters. To make matters worse for the United Kingdom, the Imperial Austro-Hungarian Navy was building four dreadnoughts, while the Italians had four and were building two more. Against such threats, the Royal Navy could no longer guarantee vital British interests. The United Kingdom was faced with a choice of building more battleships, withdrawing from the Mediterranean, or seeking an alliance with France. Further naval construction was unacceptably expensive at a time when social welfare provision was making calls on the budget. Withdrawing from the Mediterranean would mean a huge loss of influence, weakening British diplomacy in the Mediterranean and shaking the stability of the British Empire. The only acceptable option, and the one recommended by First Lord of the Admiralty Winston Churchill, was to break with the policies of the past and make an arrangement with France. The French would assume responsibility for checking Italy and Austria-Hungary in the Mediterranean, while the British would protect the north coast of France. In spite of some opposition from British politicians, the Royal Navy organised itself on this basis in 1912.^[94]

In spite of these important strategic consequences, the 1912 Naval Law had little bearing on the battleship force ratios. The United Kingdom responded by laying down ten new super-dreadnoughts in her 1912 and 1913 budgets—ships of the Queen Elizabeth and Revenge classes, which introduced a further step change in armament, speed and protection—while Germany laid down only five, focusing resources on the Army.^[95]

United States

USS New York making full steam in 1915.

The American South Carolina-class battleships were the first all-big-gun ships completed by one of the United Kingdom's rivals. The planning for the type had begun before Dreadnought was launched. While there is some speculation the U.S Navy design was influenced by informal contacts with sympathetic Royal Navy officials,^[96] the American ship was very different.

The U.S. Congress authorized the Navy to build two battleships, but of only 16,000 tons or lower displacement. As a result, the South Carolina class were built to much tighter limits than Dreadnought. To make best use of the weight available for armament, all eight 12-inch (305 mm) guns were mounted along the centerline, in superfiring pairs fore and aft. This arrangement gave a broadside equal to Dreadnought with fewer guns; this was the most efficient distribution of weapons and was a precursor of the standard practice of future generations of battleships. The principal economy of displacement compared to Dreadnought was in propulsion; South Carolina retained triple-expansion steam engines, and could manage only 18.5 kn (34.3 km/h) compared to 22.5 kn (41.7 km/h) for Dreadnought.^[97] It was for this reason that the later Delaware class would be described by some as the U.S. Navy's first dreadnoughts;^[98][99] only a few years after their commissioning, the South Carolina class could not operate tactically with the newer dreadnoughts due to their low speed, and were forced to operate with the older pre-dreadnoughts.^[100][101]

The two ships of the Delaware class were the first U.S. battleships to match the speed of British dreadnoughts. The decision to use a 10-gun 20,500 ton ship over a 12-gun 24,000 ton in this class was criticized, because the secondary battery was 'wet' (suffering from spray) and the bow was low in the water. The alternative 12-gun design had many disadvantages as well; the extra two guns and a lower casemate had 'hidden costs'—the two wing turrets planned would weaken the upper deck, be almost impossible to be adequately protected against underwater attack, and force magazines to be located too close to the sides of the ship.^[98][102]

The U.S. Navy continued to expand its battlefleet, laying down two ships in most subsequent years until 1920. The U.S. continued to use reciprocating engines as an alternative to turbines until the Nevada class, laid down in 1912. In part this reflected a cautious approach to battleship-building, and in part a preference for long endurance over high maximum speed.^[103]

Japan

The Japanese battleship Settsu

With their victory in the Russo-Japanese War of 1904–05, the Japanese became concerned about the potential for conflict with the USA. The theorist Sato Tetsutaro developed the doctrine that Japan should have a battlefleet at least 70% the size of that of the U.S. This would enable the Japanese navy to win two decisive battles, the first early in a war against the U.S. Pacific Fleet, and the second against the U.S. Atlantic Fleet which would inevitably be dispatched as reinforcements.^[104]

Japan's first priorities were to refit the pre-dreadnoughts she had captured from Russia and to complete Satsuma and Aki. The Satsumas were designed before Dreadnought, but financial shortages resulting from the Russo-Japanese War delayed her completion and resulted in her carrying a mixed armament, so she was known as a 'semi-dreadnought'. These were followed by a modified Aki-type: Kawachi and Settsu. These two ships were laid down in 1909 and completed in 1912. They were armed with twelve 12-inch (305 mm) guns, but they were of two different models with differing barrel lengths, meaning that they would have had difficulty controlling their fire at long ranges.^[105]

In other countries

Provence, a Bretagne-class battleship

Compared to the other major naval powers, France was slow to start building dreadnoughts, instead finishing the planned Danton class of pre-dreadnoughts, laying down five in 1907 and 1908. It was not until September 1910 that the first of the Courbet class was laid down, making France the eleventh nation to enter the dreadnought race.^[106] In the Navy Estimates of 1911, Paul Bénazet asserted that over the period of 1896 to 1911, France dropped from being the world's second-largest naval power to fourth; he attributed this to problems in maintenance routines and neglect.^[107] However, the closer alliance with the United Kingdom made these reduced forces more than adequate for French needs.^[106]

The Italian navy had received proposals for an all-big-gun battleship from Cuniberti well before Dreadnought was launched, but it took until 1909 for Italy to lay down one of her own. The construction of Dante Alighieri was prompted by rumours of Austro-Hungarian dreadnought building. A further five dreadnoughts of the Cavour class and Andrea Doria class followed as Italy sought to maintain its lead over Austria-Hungary. These ships remained the core of Italian naval strength until World War II. The subsequent Caracciolo class were cancelled on the outbreak of WWI.^[108]

In January 1909, Austro-Hungarian admirals circulated a document calling for a fleet of four dreadnoughts. However, a constitutional crisis in 1909–10 meant no construction could be approved. In spite of this, two dreadnoughts were laid down by shipyards on a speculative basis, and later approved along with an additional two. The resulting ships, all Tegetthoff class, were to be accompanied by a further four ships, but these were cancelled on the outbreak of World War I.^[109]

In June 1909, the Imperial Russian Navy began construction of four Gangut class dreadnoughts for the Baltic Fleet, and in October 1911, three more Imperatritsa Mariya class dreadnoughts for the Black Sea were laid down. Of seven ships, only one was completed within four years of being laid down, and the Gangut ships were "obsolescent and outclassed" upon commissioning.^[110][111] Taking lessons from Tsushima, and influenced by Cuniberti, they ended up more closely resembling slower versions of Fisher's battlecruisers than Dreadnought, and they proved badly flawed due to their smaller guns and thinner armor when compared with contemporary dreadnoughts.^[110][112]

Spain commissioned three ships of the España class, with the first being laid down in 1909. The three ships were the smallest dreadnoughts ever built. While built in Spain, the construction was reliant on British assistance; for example, construction on the third ship, Jaime I, took nine years from her laying down date to completion because of non-delivery of critical material, especially armament, from the United Kingdom.^[113][114]

Brazil's Minas Geraes at sea in early 1910, soon after her commissioning

Brazil was the third country to begin construction on a dreadnought.^[115] Although three pre-dreadnoughts had been ordered from the United Kingdom, construction was halted in favor of a much improved design^[116]—new plans called for a dreadnought mounting a heavier main battery than any other battleship afloat at the time (twelve 12 in (30 cm)/45 caliber guns).^[117] Minas Geraes was laid down on by Armstrong (Elswick) on 17 April 1907, and her sister, São Paulo, followed thirteen days later at Vickers (Barrow).^[118] Although many naval journals in Europe and the US speculated that the ships were really acting as a proxy for one of the naval powers and would hand the ships over to them as soon as they were complete, both ships were commissioned into the Brazilian Navy in 1910;^[117][118] the US commissioned the first South Carolina, Michigan, on 4 January, just one day before Minas Geraes.^{[119][120][121]}

The Netherlands intended by 1912 to replace its fleet of pre-dreadnought armored ships with a modern fleet comprising at least five dreadnoughts. Constant fiddling with the designs and slow political decision making meant the ships were not ordered until the summer of 1914, when the outbreak of World War I put an end to the ambitious fleet plan.^[122][123]

Turkey ordered two dreadnoughts from British yards, which were seized by the British on the outbreak of World War I, in order to reinforce the Royal Navy and prevent the ships falling into enemy hands. The ships Reshadiye and Sultan Osman I became HMS Erin and Agincourt respectively. The seizure of the ships was followed by Germany's gift to Turkey of two warships, the battlecruiser Goeben and the cruiser Breslau. This became an important factor in the decision of the Ottoman Empire to join the Central Powers.^[124]

Greece had ordered a dreadnought from Germany, but work stopped on the outbreak of war. The main armament for the Greek ship had been ordered in the United States, and the guns consequently equipped a class of British monitors. Greece in 1914 purchased two pre-dreadnoughts from the United States Navy, renaming them Kilkis and Limnos in Royal Hellenic Navy service.^[125]

Super-dreadnoughts

The Orion-class battleships in line

Within five years of the commissioning of Dreadnought, a new generation of more powerful "super-dreadnoughts" were being built. The arrival of the super-dreadnought is commonly held to start with the British Orion class. 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.^[126]

British super-dreadnoughts were joined by other nations as well. The U.S. Navy New York class, laid down in 1911, carried 14-inch (356 mm) guns in response to the British move and this caliber became standard. In Japan, two Fuso class super-dreadnoughts were laid down in 1912, followed by the two Ises in 1914, with both classes carrying twelve 14-inch (356 mm) guns. In 1917, the Nagato class was ordered, the first dreadnoughts to mount 16-inch (406 mm) guns, making them arguably the most powerful warships in the world. All were increasingly built from Japanese rather than imported components. In France, the Courbets were followed by three super-dreadnoughts of the Bretagne class, carrying 340 mm (13.4 in) guns; another five Normandies were canceled on the outbreak of World War One.^[127] The aforementioned Brazilian dreadnoughts sparked a small-scale arms race in South America, as Argentina and Chile each ordered two super-dreadnoughts from the US and the United Kingdom, respectively. Argentina's Rivadavia and Moreno had a main armament equaling that of their Brazilian counterparts, but were much heavier and carried thicker armor. Both of Chile's battleships were purchased by the British on the outbreak of the First World War. One, Almirante Latorre, was later repurchased by Chile.^[128][129]

Later British super-dreadnoughts, principally the Queen Elizabeth class, dispensed with one turret, so weight and volume were freed up for larger, oil-fired boilers. The new 15-inch (381-mm) gun gave greater firepower in spite of the loss of a turret, and there was a thicker armor belt and improved underwater protection. The class had a 25-knot (46-km/h) design speed, and they were considered the first fast battleships.^[130]

The Argentine Rivadavia, first of her class, under construction

The design weakness of super-dreadnoughts, which distinguished them from post-World War I designs, was armor disposition. Their design emphasized the vertical protection needed in short-range battles. These ships could engage the enemy at 20,000 yd (18,000 m), but were vulnerable to the high-angle ('plunging') fire at such ranges. Post-war designs typically had 5 to 6 inches (130 to 150 mm) of deck armor to defend against this. The concept of zone of immunity became a major part of the thinking behind battleship design. Lack of underwater protection was also a weakness of these pre-World War I designs which were developed only as the threat of the torpedo became real.^[131]

The United States Navy's 'Standard type battleships', beginning with the Nevada class, were designed with long-range engagements and plunging fire in mind; the first of these was laid down in 1912, four years before Jutland taught the dangers of long-range fire to European navies. Important features of the standard battleships were 'all or nothing' armor and 'raft' construction, a philosophy under which only the parts of the ship worth giving the thickest possible protection were worth armoring at all, and enough reserve buoyancy should be contained within the resulting armored "raft" to keep afloat the entire ship in the event the unarmored bow and stern were thoroughly riddled and flooded. This design was proven in battle at the Naval Battle of Guadalcanal, when an ill-timed turn by South Dakota silhouetted her to Japanese guns. In spite of receiving 26 heavy hits, her armored raft remained untouched and she remained both afloat and operational at the end of action.^[132]

In action

HMS Audacious sinks after hitting a mine, October 1914.

The First World War was almost an anticlimax for the great dreadnought fleets. There was no decisive clash of modern battlefleets to compare with Tsushima. The role of battleships was marginal to the great land struggle in France and Russia; it was equally marginal to the First Battle of the Atlantic.^[133]

By virtue of geography, the Royal Navy could keep the German High Seas Fleet bottled up in the North Sea with relative ease, but was on the other side unable to break the German superiority in the Baltic Sea. Both sides were aware, because of the greater number of British dreadnoughts, a full fleet engagement would result in a British victory. The German strategy was therefore to try to provoke an engagement on favourable terms: either inducing a part of the Grand Fleet to enter battle alone, or to fight a pitched battle near the German coast, where friendly minefields, torpedo boats, and submarines could even the odds.^[134]

The first two years of war saw conflict in the North Sea limited to skirmishes by battlecruisers at the Battle of Heligoland Bight and Battle of Dogger Bank, and raids on the English coast. In the summer of 1916, a further attempt to draw British ships into battle on favourable terms resulted in a clash of the battlefleets at Jutland; it was indecisive.^[135]

In the other naval theatres, there were no decisive pitched battles. In the Black Sea, Russian and Turkish battleships skirmished, but nothing more. In the Baltic Sea, action was largely limited to convoy raiding and the laying of defensive minefields.^[136] The Adriatic was in a sense the mirror of the North Sea: the Austro-Hungarian dreadnought fleet remained bottled up by British and French blockading fleets. And in the Mediterranean, the most important use of battleships was in support of the amphibious assault at Gallipoli.^[137]

The course of the war also illustrated the vulnerability of battleships to cheaper weapons. In September 1914, the U-boat threat to capital ships was demonstrated by successful attacks on British cruisers, including the sinking of three elderly British armored cruisers by the German submarine U-9 in less than an hour. Mines continued to prove a threat when a month later the recently commissioned British super-dreadnought Audacious struck one and sank. By the end of October, British strategy and tactics in the North Sea had changed to reduce the risk of U-boat attack.^[138] While Jutland was the only major clash of battleship fleets in history, the German plan for the battle relied on U-boat attacks on the British fleet; and the escape of the German fleet from the superior British firepower was affected by the German cruisers and destroyers closing on British battleships, causing them to turn away to avoid the threat of torpedo attack. Further near-misses from submarine attacks on battleships and casualties amongst cruisers led to growing paranoia in the Royal Navy about the vulnerability of battleships.^[139]

For the German part, the High Seas Fleet determined not to engage the British without the assistance of submarines, and since submarines were more needed for commerce raiding, the fleet stayed in port for much of the remainder of the war.^[140] Other theatres also showed the role of small craft in damaging or destroying dreadnoughts. The two Austrian dreadnoughts lost in 1918 were the casualties of torpedo boats and of frogmen.

Battleship building from 1914 onwards

California, one of the US' two Tennessee-class battleships, steaming at high speed in 1921.

The outbreak of World War I largely halted the dreadnought arms race as funds and technical resources were diverted to more pressing priorities. The foundries which produced battleship guns were dedicated instead to the production of land-based artillery, and shipyards were flooded with orders for small ships. The weaker naval powers engaged in the Great War—France, Austria-Hungary, Italy and Russia—suspended their battleship programs entirely. The United Kingdom and Germany continued building battleships and battlecruisers but at a reduced pace.^[141]

In the United Kingdom, the government's moratorium on battleship building and the return of Fisher to the Admiralty in 1914 meant a renewed focus on the battlecruiser. The final units of the Revenge and Queen Elizabeth classes were completed, though the last two battleships of the Revenge class were redesigned as battlecruisers of the Renown class. Fisher followed these ships with the even more extreme Courageous class; very fast and heavily armed ships with minimal, 3-inch (76 mm) armor, called 'large light cruisers' to get around a Cabinet ruling against new capital ships. Fisher's mania for speed culminated in his suggestion for 'HMS Incomparable', a mammoth, lightly armored battlecruiser.^[142]

In Germany, two units of the pre-war Bayern class were gradually completed, but the other two laid down were still unfinished by the end of the War. Hindenburg, also laid down before the start of the war, was completed in 1917. The Mackensen class battlecruisers, designed in 1914–15, were begun but never finished.^[143]

In spite of the lull in battleship building during the World War, the years 1919–1922 saw the threat of a renewed naval arms race between the United Kingdom, Japan and the USA. The Battle of Jutland exerted a huge influence over the designs produced in this period. The first ships which fit into this picture are the British 'Admiral' class battlecruisers, designed in 1916. Jutland finally persuaded the Admiralty that lightly armored battlecruisers were too vulnerable, and therefore the final design of the Admirals incorporated much increased armor, increasing displacement to 42,000 tons. However, the initiative in creating the new arms race lay with the Japanese and United States navies. The United States Naval Appropriations Act of 1916 authorized the construction of 156 new ships, including ten battleships and six battlecruisers. For the first time, the United States Navy was threatening the British global lead.^[144] This program was started slowly (in part because of a desire to learn lessons from Jutland), and never fulfilled entirely. However, the new American ships (the Colorado class battleship and Lexington class battlecruiser), took a qualitative step beyond the British Queen Elizabeth class and Admiral class by mounting 16-inch (406 mm) guns.^[145]

At the same time, the Imperial Japanese Navy was finally gaining authorization for its 'eight-eight battlefleet'. The Nagato class, authorized in 1916, carried eight 16-inch guns like their American counterparts. The next year's naval bill authorized two more battleships and two more battlecruisers. The battleships, which became the Kaga class, were to carry ten 16-inch guns. The battlecruisers, the Amagi class, also carried ten 16-inch guns and were designed to be capable of 30 knots, capable of beating both the British Admiral and the U.S. Navy's Lexington class battlecruisers.^[146]

Matters took a further turn for the worse in 1919 when Woodrow Wilson proposed a further expansion of the United States Navy, asking for funds for an additional ten battleships and six battlecruisers in addition to the completion of the 1916 program (the South Dakota class not yet started). In response, the Diet of Japan finally agreed to the completion of the 'eight-eight fleet', incorporating a further four battleships.^[147] These ships, the Kii class would displace 43,000 tons; the next design, the Number 13 class, would have carried 18-inch (457 mm) guns.^[148] Many in the Japanese navy were still dissatisfied, calling for an 'eight-eight-eight' fleet with 24 modern battleships and battlecruisers.

The British, impoverished by World War I, faced the prospect of slipping behind the U.S. and Japan. No ships had been begun since the 'Admiral' class, and of those only HMS Hood had been completed. A June 1919 Admiralty plan outlined a post-war fleet with 33 battleships and eight battlecruisers, which could be built and sustained for £171 million a year (approximately £5.83 billion today); only £84 million was available. The Admiralty then demanded, as an absolute minimum, a further eight battleships.^[149] These would have been the 'G3' battlecruisers, with 16-inch guns and high speed, and the 'N3' battleships, with 18-inch (457 mm) guns.^[150] Germany did not participate in this three-way naval building competition. Most of the German dreadnought fleet was scuttled at Scapa Flow by its crews in 1919; the remainder were handed over as war prizes.^{[A 10][151]}

Instead of the cripplingly expensive expansion program, the major naval powers concluded the Washington Naval Treaty in 1922. The Treaty laid out a list of ships, including most of the older dreadnoughts and almost all the newer ships under construction, which were to be scrapped or otherwise put out of use. It furthermore declared a 'building holiday' during which no new battleships or battlecruisers were to be laid down. The ships which survived the treaty, including the most modern super-dreadnoughts of all three navies, formed the bulk of international capital ship strength through the 1920s and 1930s and, with some modernisation, into World War II. The ships built under the terms of the Treaty to replace outdated vessels were known as treaty battleships.^[152]

From this point on, 'dreadnought' became less widely used. Most pre-dreadnought battleships were scrapped or hulked after the World War I,^{[A 11]} so the term 'dreadnought' became less necessary. Nevertheless, the battleships of World War II were sometimes referred to as dreadnoughts.

Notes

References

Bibliography

External links

• British and German Dreadnoughts