Capital ship

Aircraft carriers form the main capital ships of most modern-era blue-water navies.
(c) Bundesarchiv, DVM 10 Bild-23-61-09 / CC-BY-SA 3.0
Battleships became the main form of capital ship after sailing vessels fell out of use, and remained so up to World War II. Shown is the German SMS Helgoland.
Ships of the line (of battle) were the capital ships of the era of sail. Pictured is the Spanish Santa Ana, a very large example with 112 guns.

The capital ships of a navy are its most important warships; they are generally the larger ships when compared to other warships in their respective fleet. A capital ship is generally a leading or a primary ship in a naval fleet.[1]

Strategic implications

There is usually no formal criterion for the classification, but it is a useful concept in naval strategy; for example, it permits comparisons between relative naval strengths in a theatre of operations without the need for considering specific details of tonnage or gun diameters.

A notable example of this is the Mahanian doctrine, which was applied in the planning of the defence of Singapore in World War II, where the Royal Navy had to decide the allocation of its battleships and battlecruisers between the Atlantic and Pacific theatres. The Mahanian doctrine was also applied by the Imperial Japanese Navy, leading to its preventive move to attack Pearl Harbor and the battleships of the U.S. Pacific Fleet.[2] The naval nature of the Pacific Theater of Operations, more commonly referred to as the Pacific War, necessitated the United States Navy mostly deploying its battleships and aircraft carriers in the Pacific. The war in Europe was primarily a land war; consequently, Germany's surface fleet was small, and the escort ships used in the Battle of the Atlantic were mostly destroyers and destroyer escorts to counter the U-boat threat.

Age of Sail

Before the advent of the all-steel navy in the late 19th century, a capital ship during the Age of Sail was generally understood as a ship that conformed to the Royal Navy's rating system of a ship of the line as being of the first, second, third or fourth rates:

  • First rate: 100 or more guns, typically carried on three or four decks. Four-deckers suffered in rough seas, and the lowest deck could seldom fire except in calm conditions.
  • Second rate: 90–98 guns.
  • Third rate: 64 to 80 guns (although 64-gun third-raters were small and not very numerous in any era).
  • Fourth rate: 46 to 60 guns. By 1756, these ships were acknowledged to be too weak to stand in the line of battle and were relegated to ancillary duties, although they also served in the shallow North Sea and American littorals where larger ships of the line could not sail.

Frigates were ships of the fifth rate; sixth rates comprised small frigates and corvettes. Towards the end of the Napoleonic Wars and into the late 19th century, some larger and more powerful frigates were classified as fourth rates.

Battleship / battlecruiser

The term "capital ship" was first coined in 1909 and formally defined in the limitation treaties of the 1920s and 1930s in the Washington Naval Treaty, London Naval Treaty, and Second London Naval Treaty. This applied mainly to ships resulting from the dreadnought revolution; dreadnought battleships (also known first as dreadnoughts and later as battleships) and battlecruisers.[1]

In the 20th century, especially in World Wars I and II, typical capital ships would be battleships and battlecruisers. All of the above ships were close to 20,000 tons displacement or heavier, with large caliber guns and heavy armor protection.

Cruisers, despite being important ships, were not considered capital ships. An exception to the above in World War II was the Deutschland-class cruiser. Though this class was technically similar to a heavy cruiser, albeit slower but with considerably heavier guns, they were regarded by some as capital ships (hence the British label "Pocket battleship") since they were one of the few heavy surface units of the Kriegsmarine. The American Alaska, Dutch Design 1047 battlecruiser and the Japanese Design B-65 cruiser, planned specifically to counter the heavy cruisers being built by their naval rivals, have been described as "super cruisers", "large cruisers" or even "unrestricted cruisers", with some advocating that they even be considered as battlecruisers, however they were never classified as capital ships.[3]

During the Cold War, a Soviet Kirov large missile cruiser had a displacement great enough to rival World War II-era battleships and battlecruisers, perhaps defining a new capital ship for that era. In regard to technical design, however, the Kirov is simply a supersized guided-missile cruiser with nuclear propulsion.

Aircraft carrier

An F/A-18C Hornet launching from the flight deck of a modern aircraft carrier

It took until late 1942 for aircraft carriers to be universally considered capital ships. Only full-size fleet carriers (whether purpose built, or converted from battleship/battlecruiser hulls) were regarded as capital ships, while light carriers (often using cruiser hulls) nor escort carriers (often using merchant ship hulls) were not. The U.S. Navy was forced[4][5][6] to rely primarily on its aircraft carriers after the attack on Pearl Harbor sank or damaged eight of its Pacific-fleet battleships.

In the 21st century, the aircraft carrier is the last remaining capital ship, with capability defined in decks available and aircraft per deck, rather than in guns and calibers. The United States possesses supremacy, in both categories of aircraft carriers, possessing not only 11 active duty supercarriers each capable of carrying and launching nearly 100 tactical aircraft, but an additional 9 amphibious assault ships as capable (in the "Sea Control Ship" configuration) as the light VSTOL carriers of other nations.[7]

Despite their significance to modern fleets, the U.S. Navy has never named aircraft carriers after U.S. states as was the practice when battleships (e.g. Iowa) were considered capital ships.[a] Instead, U.S. state names are today applied to nuclear submarines while aircraft carriers are named after famous Navy personnel and presidents, such as Chester W. Nimitz and Gerald R. Ford.

Nuclear submarines

Ballistic missile submarines (or "boomers"), while important ships and similar in tonnage to early battleships, are usually counted as part of a nation's nuclear deterrent force and do not share the sea control mission of traditional capital ships. Nevertheless, many navies, including the Royal Navy and the United States Navy, consider these ships to be capital ships and have given some of them names previously used for battleships, e.g. Dreadnought and Vanguard.


Some navies reserve specific names for their capital ships. Names reserved for capital ships include chiefs of state (e.g. Bismarck), important places, historically important naval officers or admiralty (e.g. De Ruyter), historical events or objects (e.g. USS Constitution), and traditional names (e.g. HMS Ark Royal). However, there are some exceptions to the rule.

Beginning with USS Texas (the first U.S. battleship), U.S. capital ships have traditionally been named after U.S. states.[a] Lesser vessels are named after U.S. territories (e.g. Alaska-class cruisers just before and during World War II), major U.S. cities (e.g. cruisers), or U.S. presidents (e.g. early attack submarines and late aircraft carriers). Prior to and during World War II the Imperial Japanese Navy also followed the practice of naming battleships after provinces (e.g. Yamato).

Beginning with the first class of Trident-equipped ballistic missile submarines (i.e. the Ohio class), state names have been applied to U.S. nuclear submarines, indicating their status as capital ships. Previous ballistic missile submarines (e.g. Poseidon missile-equipped submarines) had not been named for states. After the completion of the last Ohio-class ballistic missile submarine, state names were applied to attack submarines (e.g. Virginia class). Earlier attack submarines had been named for major cities (e.g. Los Angeles class) – as was previously the practice for cruisers (e.g. USS Indianapolis).

In fiction

The term has been adopted into science fiction literature and culture to describe large spaceships used in military contexts, particularly where other naval terms have also been adopted in similar fashion; for example, sci-fi capital spaceships are often "carriers", that carry small fighters analogous to the way the real world naval equivalent carries fighter aircraft, as well as functioning as "battleships".

See also


  1. ^ a b Only one US battleship ever carried a non-state name: USS Kearsarge


  1. ^ a b Keegan, John (1989). The Price of Admiralty. New York: Viking. p. 276. ISBN 0-670-81416-4.
  2. ^ "Welcome to the website of the Force Z Survivors Association". Archived from the original on 2018-10-10. Retrieved 2011-07-12.
  3. ^ Chesneau, p. 388; Garzke & Dulin, p. 86; Friedman 1984, p. 288; McLaughlin 2006, p. 104
  4. ^ Pacific Fleet not at Pearl
  5. ^ Pacific Fleet at Pearl
  6. ^ Pearl Harbor
  7. ^ James F. Amos "Gen Amos' speech to Surface Navy Association." Archived January 17, 2011, at the Wayback Machine

Media files used on this page

Navío santa ana de 112 cañones.jpg
Picture from XIX. Century. Capital ship "Santa Anna".
An F-A-18C Hornet launches from the flight deck of the conventionally powered aircraft carrier.jpg
Pacific Ocean (Aug. 17, 2005) – An F/A-18C Hornet, assigned to the "Golden Dragons" of Strike Fighter Squadron One Nine Two (VFA-192), launches from the flight deck of the conventionally powered aircraft carrier USS Kitty Hawk (CV 63). Kitty Hawk and embarked Carrier Air Wing Five (CVW-5) are currently returning to their homeport after a scheduled deployment in the 7th Fleet area of responsibility.
Bundesarchiv DVM 10 Bild-23-61-09, Linienschiff "SMS Helgoland".jpg
(c) Bundesarchiv, DVM 10 Bild-23-61-09 / CC-BY-SA 3.0
For documentary purposes the German Federal Archive often retained the original image captions, which may be erroneous, biased, obsolete or politically extreme. Info non-talk.svg
Linienschiff "SMS Helgoland" Linienschiff "S.M.S. Helgoland" der Helgoland-Klasse, Ansicht der Backbord-Seite
HMS Ark Royal USS Nimitz Norfolk2 1978.jpeg

An aerial view of the U.S. nuclear-powered aircraft carrier USS Nimitz (CVN-68) and the British aircraft carrier HMS Ark Royal (R09) tied up at piers at Norfolk Naval Station, Virginia (USA), maybe between 14 and 21 August 1978.

Note: The photo may have been taken in 1975 when Ark Royal was having her catapults repaired. Also, Nimitz was having extensive flight deck work in 1978. In the National Archives description, the left hand carrier is wrongly identified as HMS Hermes (R12) on 26 June 1987.