Battlecruiser



Battlecruisers were large warships of the first half of the 20th century. They evolved from armored cruisers and in terms of ship classification they occupy a grey area between cruisers and battleships. Generally, battlecruisers were similar in layout and armament to battleships but with significantly less armour allowing for gains in speed. However, different nations built to widely different designs. Some battlecruisers were smaller than battleships while others were larger than contemporary battleships. The chief similarity was the role specification. They were designed to hunt down and outgun smaller warships (or merchant ships in the case of the pocket battleships), and outrun larger warships that they could not outgun. Battlecruisers became obsolete in World War II as advances in design and technology allowed fast battleships to be developed, which combined or even exceeded the best features of World War I battlecruisers and slow battleships.

Originally, to achieve this, they deviated from the standard practice of providing a ship with sufficient armour to protect against its own guns. The weight saving from the reduced armour allowed more powerful engines to be fitted. This idea was mainly conceived by British Admiral Jackie Fisher who believed "speed is the best protection". Fisher's idea centred on battlecruisers operating with the fleet, the intention being that they would hunt down enemy cruiser squadrons and evade the battleships. The Germans by contrast sacrificed gun calibre instead of armour in order to raise speed. Despite the major difference in design philosophy, both performed the same task.

First battlecruisers
The first battlecruisers came from the Royal Navy. The same committee, instigated by Jackie Fisher, that produced the Dreadnought had been charged with the design of a new armoured cruiser. Compared to the most recent of the RN's cruisers they were quite different. They had 12 inch guns instead of 9.2, a displacement similar to Dreadnought but twice the power to give 25 knots. These were Inflexible, Invincible and Indomitable, all completed in 1908. They achieved speed at the expense of protection. They had armour 6 or 7 inches (150 to 180 mm) thick along the side of the hull and over the gunhouses, whereas a comparable battleship of the period had armour 11 or 12 inches (280 to 300 mm) thick. Originally thought of as simply a new type of armored cruiser (their armour was the same as that of the older armoured cruisers'), they were then designated "dreadnought cruisers". A tendency to think of them as somehow partially equal to a battleship led to the unofficial title "battleship cruisers" which led to battlecruisers in 1912. These early ships had a top speed of 26 knots (48 km/h) compared to 20 to 21 knots (37 to 39 km/h) for contemporary battleships. They were armed with 11 in (German) or 12 in (British) (281 or 305 mm) guns, just like battleships. Soon after the British, the Germans started building their own battlecruisers, starting with Von der Tann of 1911. Blucher, armed with 8.2 inch guns, was the initial German response to the "Invincibles", in the mistaken belief that the "Invincibles" would be carrying guns of 9.2 inch calibre. She was in effect only an armoured cruiser, and went down at the Battle of Dogger Bank. Von der Tann and most later German battlecruisers had 280 mm (11 in) guns, which were reckoned to be the equivalent to the British 12-inchers. They benefitted from the wider dockyards that they were built in. This allowed them to be built with a broader beam than the British ships giving rise to better protection in terms of both armour and internal layout than the British battlecruisers.

During the course of the First World War Fisher had a plan for operations in the Baltic Sea which required another radically different cruiser. These became known as "large light cruisers" - big ships (22,000 tons and some 750 ft long) with even less protection than the battlecruisers but carrying a few battleship calibre guns. One of the these was to carry 18-inch guns; albeit only two singly in turrets fore and aft. In the event, the planned Baltic operations never materialised and the three "large light cruisers" laid down HMS Furious (the 18-inch gun design), Glorious and Courageous would find use elsewhere as aircraft carriers.

Battle of Heligoland Bight
A force of British light cruisers and destroyers entered the Heligoland Bight to attack German shipping during World War I. When they met opposition from German cruisers, Admiral Beatty took his squadron of four battlecruisers into the bight and turned the battle, ultimately sinking three German light cruisers and killing a German commander, Rear Admiral Leberecht Maass.

Battle of the Falklands
The original battlecruiser concept proved successful at the Battle of the Falkland Islands when the British battlecruisers Inflexible and Invincible did precisely the job they were intended for when they annihilated a German cruiser squadron, consisting of the armoured cruisers Scharnhorst and Gneisenau with some light cruisers, commanded by Admiral Maximilian Graf Von Spee in the South Atlantic Ocean.

Battle of Dogger Bank
The vulnerability of the battlecruiser began to become apparent at the Battle of Dogger Bank, during which the German flagship Seydlitz escaped destruction only by emergency flooding of her after magazines. The Germans learned from the near-disaster and instituted improved measures. The British remained unaware of the weakness, to their great misfortune at the Battle of Jutland.

Battle of Jutland
At the Battle of Jutland 18 months later, both British and German battlecruisers were employed as fleet units. The British battlecruisers became engaged with both their German counterparts, the battlecruisers, and then German battleships before the arrival of the battleships of the British Grand Fleet. The result was a disaster for the Royal Navy's battlecruiser squadrons: Invincible, Queen Mary and Indefatigable exploded with the loss of all but a handful of their crews. The better armoured German battlecruisers fared better in part due to poor performance of British shells although Lützow was damaged and had to be scuttled, and Seydlitz was heavily damaged. No British or German battleship was sunk during the battle with the exception of the old German pre-dreadnought Pommern.

Post-war developments
Following the end of World War I many navies re-evaluated their ship designs. This led to a number of changes as many nations chose to reduce their battlecruiser fleet following the Washington Naval Arms Limitation Treaty rather than scrap valuable battleships.

British designs
The British had planned 4 G3 battlecruisers, which were cancelled by the Washington Treaty in 1922. They would have been superior to any World War I battleship and the battlecruiser name came from their high speed and armour relative to the planned N3 battleships they would serve alongside. The Royal Navy de-emphasized battlecruisers in the original sense of the word and all but three were scrapped by the mid-1930s. In the Royal Navy, the term was applied to ships with heavy armour, but that were still capable of speeds in excess of 25 knots.

HMS Hood, launched in 1918, was the last British battlecruiser to be completed, her three sisters of the Admiral class were cancelled. However, Hood was completed with armour that was thought to be capable of resisting her own weapons, the classic measure of a "balanced" battleship and her armour weaknesses were recognized and tackled to some extent during refits - the onset of the Second World War preventing her last planned rebuild.

The other two battlecruisers retained, HMS Renown and HMS Repulse were modernized significantly in a series of refits between 1920 and 1939. Of the three specialist battlecruisers, "large light cruisers" in the Royal Navy's terms, ships of substantial size but with only the armour of light cruisers intended to be armed with a few battleship calibre guns for operations in the Baltic Furious had already been converted to an aircraft carrier during the war. Glorious and Courageous too big and too heavily armed to fit in with the treaty definition of cruisers, followed rather than being scrapped.

Japanese Designs
The Imperial Japanese Navy improved the four battlecruisers of the Kongo class (Hiei, Haruna, Kirishima and Kongo) by increasing the elevation of the guns to 40 degrees, adding anti-torpedo bulges and additional armour, and building on a "pagoda" mast. The 3,800 tons of additional armour slowed their speed, but between 1933 and 1940 replacement of heavy equipment and an increase in the length of the hull by 26 ft (8 m) allowed them to reach up to 30 knots once again.

They were reclassified as "fast battleships", although their armour and guns still fell short compared to surviving World War 1-era battleships in American or British navies. In battle against true fast battleships of the South Dakota and North Carolina classes, the "fast battleship" refit would prove inferior to the real thing.

The Imperial Japanese Navy scrapped three of the four Amagi class battlecruisers (which were under construction), and converted the fourth, Akagi, into an aircraft carrier in 1927.

US Designs
The United States Navy retasked two battlecruiser hulls as aircraft carriers: USS Lexington and Saratoga were both designed as battlecruisers (the hull designations were originally CC-1 and CC-3) but converted part-way through construction, although this was only considered marginally preferable to scrapping the hulls outright (the remaining four: Constellation, Ranger, Constitution and United States were indeed scrapped). The Lexington class battlecruisers if completed would have been closer in concept to the later fast battleships, being both swift and well-armored without sacrificing firepower.

They were planned to be armed with 16" guns and armored against light battleship-caliber weapons; the engines required to propel these vessels at 33 knots (their design speed) made them into fast, flexible and tough aircraft carriers with large growth margins. The heavy use of Saratoga during World War II, however (at one point she and Enterprise were the only carriers in the Pacific), precluded her from having a postwar career: Severe and repeated bomb and torpedo damage took their toll and by 1946 the hull was simply worn out. She was thus used as a target in the Bikini atomic experiments in 1946.

Rearmament
As war became more likely nations began to rebuild their forces. At first lip-service was paid to the Treaty of Versailles and the Washington Naval Treaty, but as war became more likely the designs became more ambitious.

German designs
The German pocket battleships (German:Panzerschiffe - armored ship: Deutschland, Admiral Scheer, and Admiral Graf Spee), built to meet the 10,000 ton displacement limit of the Treaty of Versailles, were another attempt at a battlecruiser-like concept. Rather than construct a lightweight battleship which sacrificed protection in order to attain high speed, the pocket battleships were relatively small vessels with only six 11 inch (280 mm) guns &mdash; essentially large heavy cruisers. They attained fairly high speeds of 26 knots (52 km/h), and reasonable protection, while staying close to the displacement limit, by using welded rather than riveted construction, triple main armament turrets, and replacing the normal steam turbine power with a pair of massive 9 cylinder diesel engines driving each propeller shaft. They were later reclassified as "heavy cruisers", having heavier guns and armour than regular heavy cruisers at the cost of speed. Unfortunately, they were outclassed by British WW1-era true battlecruisers in speed, weaponry, and protection. (They in fact had basic cruiser armour, except for the turrets.)

Two more ships were built later in the 1930s, the Scharnhorst and Gneisenau, which were considerably more powerful. At 38,900 tons full load they were somewhat larger than the French Dunkerque class and very well armoured. They were designed to carry six 15 inch (380 mm) guns in three twin turrets, but instead was fitted with 11 inch (280 mm) guns in three triple turrets instead (it was planned to rearm them during the war, but this plan was abandoned). At the time, treaty requirements allowed the production 12+ inch guns at 1 a year, which along with the very time consuming production of naval guns, kept these two ships with 11 inch guns. The Royal Navy categorised them as battlecruisers since they followed the Imperial German Navy design lineage of trading off gun size for protection and speed. The German Navy nonetheless categorised them as battleships.

French designs
As a response to the German pocket battleships the French decided to build the Dunkerque class in the 1930s. They were labelled "fast battleships" and were armed with 13 inch (330mm) guns arranged in two quadruple turrets located forward. They were considerably larger, faster and more powerfuly armed than the ships they were designed to hunt. This last design illustrated inter-war technological developments. The ultimate limit on ship speed was drag from the water displaced (which increases as a cube of speed) rather than weight, so heavier armour slowed World War II battleships by only a couple of knots (4 km/h) over their more lightly armoured brethren. Heavy guns mounted on fast and well armoured fast battleships invalidated the concept of the battlecruiser as a ship class in its own right, although the development of the aircraft carrier overshadowed all big-gun vessels including the fast battleship.

Commerce raiding
In the early years of the war the German ships each had a measure of success hunting merchant ships in the Atlantic. The pocket battleships were deployed alone and sank a number of vessels, causing disruption to the trade routes which supplied the UK. They were pursued by the Royal Navy and on one occasion, at the Battle of the River Plate in 1939, the hunter became the hunted. Allied battlecruisers such as Renown, Repulse, Dunkerque and Strasbourg were employed on operations to hunt down the commerce raiding German battlecruisers, but they rarely got close to their targets. The exception was when the Bismarck was sent out as a raider and was intercepted by HMS Hood and the battleship Prince of Wales in May 1941. However, the modern German battleship was not suitable prey for the elderly British battlecruiser and the Bismarck’s 15 inch shells caused a magazine explosion reminiscent of the Battle of Jutland. Only three men survived.

The Gneisenau and the Scharnhorst hunted together and were initially successful at commerce raiding, sinking the British armed merchant cruiser Rawalpindi in 1939. Following repairs from damage during the Norwegian campaign, the two battlecruisers set out commerce raiding once again in 1941 and sank 22 merchant ships. They returned to Brest in northern France but found this port was vulnerable to Royal Air Force attacks and were obliged to return to Germany. They did so in the Channel Dash, a daring and successful run up the English Channel. However, they were both damaged by mines and although Scharnhorst was repaired, Gneisenau was damaged again in RAF bombing raids and was eventually disarmed and sunk as a blockship. Scharnhorst was employed once more to attack commerce and attempted to raid the Arctic convoys in December 1943. However, she was cornered by the battleship HMS Duke of York with the heavy cruisers Jamaica, Norfolk and Belfast at the Battle of North Cape and sunk on 26 December 1943.

The use of battlecruisers as commerce raiders was curtailed following an attack by the Admiral Scheer on a convoy guarded by the HMS Jervis Bay, an armed merchant cruiser. It persuaded the British Admiralty that convoys had to be guarded by battleships (or battlecruisers). The older R-class battleships and the un-upgraded Queen Elizabeths (Malaya and Barham) were used for this task, and subsequently the smaller German ships were forced away from their quarry. Additionally, the air gap over the North Atlantic closed, Huff-Duff (radio triangulation equipment) improved, airborne centimetric radar was introduced and convoys received escort carrier protection. The results of some of these developments were illustrated by the successful defence of convoys at the Battle of the Barents Sea and the Battle of the North Cape.

Norwegian campaign
The Royal Navy and the Kriegsmarine both deployed battlecruisers during the Norwegian Campaign in April 1940. The Gneisenau and the Scharnhorst both engaged HMS Renown and although they had stronger armour than their counterpart, the British ship could hit them harder and at a longer range. They disengaged after Gneisenau sustained damage.

Later in the campaign they returned and sank the light aircraft carrier HMS Glorious (a converted battlecruiser herself) and her destroyer escort. One of the destroyers (HMS Acasta) succeeded in damaging the Scharnhorst with a torpedo, and later a submarine did the same to Gneisenau, forcing both ships to spend several months in repair. The pocket battleship Lützow was similarly damaged by HMS Spearfish during the campaign.

Mediterranean
The French battlecruisers had fled to North Africa following the fall of France. In July 1940 Force H under Admiral James Somerville was ordered to force their surrender or destroy them. The Dunkerque was damaged by shells from HMS Hood at Mers-el-Kebir but escaped to join the Strasbourg at Toulon. Both ships were scuttled on 27 November 1942, although Strasbourg was raised and used by the Italian navy before being sunk again in an air attack on 18 August 1944.

Pacific War
The first battlecruiser to see action in the Pacific War was Repulse when she was sunk near Singapore on December 10 1941 whilst in company with HMS Prince of Wales. She had received a refit to give extra anti-aircraft protection and extra armour between the wars, however despite these additions and her agility, without aerial protection she was unable to avoid the continuous waves of Japanese torpedo bombers indefinitely.

The Japanese Kongo class "fast battleships" were used extensively as carrier escorts for most of their wartime career. However, in the Naval Battle of Guadalcanal on 12 November the Hiei was sent out to bombard US positions. She was badly damaged by gunfire from US cruisers and destroyers. She was attacked by US aircraft from Guadalcanal’s American held airfield (Henderson Field the next day and left to sink north of Savo Island. A few days later on 15 November 1942 Kirishima, engaged the U.S. battleships South Dakota and Washington, and was scuttled following damage from 75 hits inflicted by the Washington and supporting heavy cruisers. In contrast South Dakota survived 42 hits and was back in operation four months later. She did, however, lose all electric power in the action and did not contribute to the destruction of the Japanese force. The Kongo survived the Battle of Leyte Gulf, but was eventually sunk on 21 November 1944 in the Formosa Strait by three torpedoes from the U.S. submarine Sealion. Haruna was involved in bombardment operations at Guadalcanal, the Battle of the Philippine Sea and the Battle of Leyte Gulf. She was attacked by American carrier aircraft of Task Force 38 and B-24 bombers of the United States Army Air Forces while at Kure on 28 July 1945 and sank at her moorings.

New US designs
Part way through the war the US built the two Alaska class "large cruisers", Alaska and Guam with a main armament of nine twelve-inch guns in three triple turrets. They were designed to hunt down the Japanese heavy cruisers. They were built to cruiser standards, with a cruiser-like secondary battery and they lacked the armoured belt and torpedo defense system of true capital ships. Their percentage of armor tonnage at 16% was similar to that of contemporary cruisers and far less than that of true battlecruisers and battleships (the HMS Hood had 33%, while the German Bismarck and USS North Carolina had 40% weight in armor). Their protection could only withstand fire from their own caliber of gun in a very narrow range band. As with the never-completed Lexington class battlecruisers, the Alaska class ships were an outgrowth of contemporary American cruiser design, rather than being a new battlecruiser class to occupy the middle ground between heavy cruisers and fast battleships.

However, they resembled contemporary battleships in appearance and tonnage, with the familiar 2-A-1 main battery, massive columnar mast and cluster of 5"/38 DP guns along the sides of the superstructure. The easiest way to tell the Alaska class ships from the battleships was by the dual 5"/38 mount superfiring over the fore and aft main batteries.

Like the contemporary Iowa-class fast battleships, their speed made them ultimately more useful as carrier escorts and bombardment ships than as the sea combatants they were developed to be, as well as the ignominious defeat of the fleets of Japanese heavy cruisers that were their raison d'être. (In fact, the majority of Japanese heavy cruisers were sunk by aircraft or submarines instead of surface combat.) A planned additional four ships of the Alaska class were cancelled after the war.

Along with Renown, the two Alaskas were the only "battlecruisers" to survive WWII (not including Turkish Yavuz - ex SMS Goeben, which did not fight during the war).

Cold War designs
The Soviet Union planned to build several large cruiser classes, that would be a response for Scharnhorst, then Alaska classes in the 1940s and early 1950s, but these plans were abandoned. In Russia, they were called "heavy cruisers" (thyazholyi kreyser).

The first design were project 69 (Kronshtadt) cruisers, with 35,240 tons standard load, 9 guns 305 mm (12 in) and a speed of 32 knots. Two ships were laid in 1939. In 1940 it was decided to complete them according to the project 69I, with 6 guns 380 mm (15 in), bought in Germany, but the German attack on the USSR put an end to these plans and all works were canceled in a favour of more useful ship types, like submarines.

Next design were project 82 (Stalingrad) cruisers, with 36,500 tons standard load (42,300 tons full load), 9 guns 305 mm and a speed of 35 knots. Three ships were laid in 1951-52, but after Stalin's death they were canceled in April 1953. Apart from high costs, the main reason was, that gun-armed ships became obsolete with an advent of guided missiles. Only a central armoured hull section of the first cruiser Stalingrad was launched in 1954 and then used as a target for rockets.

The Soviet Kirov class of Raketny Kreyser (Missile Cruiser), displacing approximately 26,000 tons, is classified as a battlecruiser in the 1996-7 edition of Jane's Fighting Ships, even though in actuality they are very large missile cruisers. Their classification as battlecruisers arises from their displacement, which is roughly equal to that of a World War I battleship, and the fact that they possess more firepower than nearly every other surface ship. However, the Kirov-class lacks the heavy armour that distinguishes battlecruisers from regular cruisers and they are classified as "heavy missile cruisers" in Russia. There were four members of the class completed, Kirov, Frunze, Kalinin, and Yuri Andropov. As the ships were named after Communist personalities, after the fall of the USSR they were given traditional names of the Imperial Russian Navy, respectively Admiral Ushakov, Admiral Lazarev, Admiral Nakhimov and Petr Velikiy. Due to budget constraints two members of this class have been decomissioned, although Petr Velikiy is in active service and Admiral Nakhimov is in refit, expected to return to service in 2006 or 2007.

Problems with the idea
In practice, battlecruisers rarely saw the type of independent action for which they were designed. The increase in gunnery technology was so swift in the years following 1905, that there was a blurring of the distinction between the battleship and battlecruiser. At Jutland the guns on Beatty's flagship, HMS Lion were 13.5 inch, which was larger than most German and many British battleships.

In most cases, the temptation to add extra big guns to the main fleet proved hard to resist. As a result, battlecruiser squadrons were added to the line of battle &mdash; a role for which they were not designed and one that exposed them to great risk. The armour on a battlecruiser remained that of (or slightly more than) a normal cruiser. Thus the ships could dish out a lot more punishment than they could absorb. Any advantage they had in speed was lost when locked into formation at the speed of the slowest battleship in the line of battle. Heavy shells from opposing capital ships could easily penetrate their thinner armour. During Jutland, both British and German battlecruisers scored hits on each other. The British ships came off poorly, where the German ships' fared better due to better internal protection and poor performance of the British shells.

In the Second World War, large fleet actions did not happen. Battlecruisers were paired with battleships in roles such as raiding (German), convoy escort, or as part of task forces. In operations where battlecruisers did fight battleships, such as Hood and Bismarck, Scharnhorst and Duke of York, Kirishima and Washington, the battlecruiser was destroyed by gunfire. They were equally vulnerable to aircraft, and during World War II many were lost in this way.

Science fiction
In science fiction, the meaning of the word "battlecruiser" is generally somewhat different. Usually it denotes a vessel more comparable to the fast battleships of World War II: A large, fast and tough vessel with both high firepower and enough protection to dish out and take considerable amounts of damage. In many Science Fiction universes, a Battlecruiser is either a ship specifically in-between a Heavy Cruiser and a Battleship in design, without the specific requirement that it can either outgun or evade any other capital ship, or the term is interchangeable with "heavy cruiser," with the distinction that the "good guys" use heavy cruisers and the "bad guys" use battlecruisers.
 * In Star Trek, Klingon "battlecruisers" often menaced the Starship Enterprise - which was classified as a "heavy cruiser", and just as often faced her on even terms.
 * In "The Mote in God's Eye" (Larry Niven) a battlecruiser (named "McArthur") is seen as intermediate in power between a battleship and a heavy cruiser.
 * In David Weber's Honorverse, a battlecruiser (BC) is in-between a battleship (BB) and a heavy cruiser (CA). In the Honorverse, battleships, dreadnaughts (DN), and superdreadnaughts (SD) are considered capital ships. Cruisers, destroyers, and frigates are interstellar warships but not capital ships. The BCs is alternately considered a capital ship and non-capital ship. It is however not considered a "ship of the wall" (c.f. ship of the line); only SDs and DNs are wall ships. The BBs are alternately considered a wall ship and non-wall ship.
 * In the MMOG EVE Online, a battlecruiser has much better protection and somewhat greater firepower than an ordinary cruiser, but is clearly inferior to a battleship, for example in that it only uses weapons intended for cruisers, as opposed to the larger battleship armaments. (Spaceships of EVE Online)
 * In the computer strategy game StarCraft, the battlecruiser is the most powerful unit of the Terran race and can be seen as the flagship for many Terran generals.