Cruiser - Junyokan (English spelling) cruiser

Japanese: 巡洋艦 - じゅんようかん（英語表記）cruiser

A type of warship.

The concept of a cruiser is quite different before and after World War II. Until World War II, cruisers were surface combatants with displacement and gun power between battleships and destroyers, with great speed and cruising range, and excellent seaworthiness. They were used for a wide range of missions in both wartime and peacetime, including reconnaissance and surveillance of the front of the fleet, search for enemies, direct protection of the main force, commerce raiding, land bombardment, support for landing operations, and overseas security.

A modern cruiser is a surface combatant vessel equipped with one or more of the following: effective fleet air defense capabilities, surface strike power, anti-submarine capabilities, land attack capabilities, and command functions, and capable of operating alongside an aircraft carrier to provide direct escort for it, or acting as the core of a surface force itself. It is generally larger than a destroyer, with a standard displacement of approximately 5,000 tons or more, excellent seaworthiness and cruising range, and a high speed of 30 knots or more.

[Yasuo Abe]

History

In the age of sailing ships, frigates and corvettes were collectively called cruisers; they were more nimble than ships of the line and served as the eyes, ears, and feet of the fleet, searching for and observing the position of enemy fleets and reporting on them, or they performed independent searches, reconnaissance, protection of maritime traffic, escort, and commerce raiding.

[Yasuo Abe]

Just before World War I

In the mid-19th century, with the adoption of steam engines and iron and even steel hulls, frigates and corvettes developed into fast, agile fighting vessels primarily armed with guns and torpedoes; these also came to be called cruisers, and by the 1880s this term had become established as a type of warship.

Early cruisers developed into large ships of over 5,000 tons and medium and small ships below that size. In the 1890s, large armored ships evolved into armored cruisers equipped with strong side armor and turret guns. This type of ship had a displacement of 7,000 to 15,000 tons, and some of them had slightly reduced cruising range and speed, but strengthened gun power and defense, and were used to support battleships and fight capital ships. The Japanese ships of the Russo-Japanese War were typical examples, and after the war, large armored cruisers (Tsukuba class, Ibuki class) were built that had the same gun power as battleships and were about 2 knots faster. In 1907, Britain introduced battlecruisers with gun power equivalent to that of a dreadnought battleship and a speed of 26 knots thanks to the adoption of steam turbine engines, so armored cruisers no longer had much reason to exist.

Small and medium-sized ships were initially unprotected, but in the 1880s, the appearance of protected cruisers with thin armor on the middle deck replaced this. The Chilean Esmeralda (2,960 tons), completed in Britain in 1882, is said to be the first fully-fledged protected cruiser, and this type of ship was subsequently built in various countries, with large ships exceeding 10,000 tons appearing.

In the early 1900s, light cruisers, which were fast and very lightly protected, appeared and replaced the protected cruiser, and this type of ship developed significantly in various countries. In Britain, just before World War I, they were divided into medium-sized ships of over 5,000 tons that replaced the protected cruiser, and small ships of 3,000 tons that were lighter and faster and were used as flagships of torpedo squadrons or torpedo expulsion units. The former even appeared at the end of the war, with ships of just under 10,000 tons and equipped with 19 cm guns, which became the beginning of the construction of heavy cruisers. The latter made great strides in the early stages of the war, and developed into the 7,500-ton Emerald Class equipped with 15.2 cm guns just after the war, laying the foundation for modern cruisers. From the end of the war, cruisers began to be equipped with reconnaissance aircraft and anti-aircraft guns.

[Yasuo Abe]

Until the end of World War II

The Washington Naval Treaty (1922) limited the displacement and size of armaments of cruisers, and ships with an upper limit of 10,000 tons and 20.3 cm (8 inch) guns (treaty cruisers) were subsequently built by various countries. The 7,100-ton Furutaka, completed in 1926 (Taisho 15), was the world's first light cruiser equipped with 20 cm guns, and its superiority attracted worldwide attention, and Japan led the world powers in cruiser construction technology thereafter. The subsequent London Naval Treaty (1930) distinguished cruisers according to the type of guns they were equipped with, defining ships equipped with 15.5 cm (6.1 inch) to 20.3 cm guns as Class A or heavy cruisers, and ships equipped with guns of 15.2 cm or less as Class B or light cruisers, and stipulated the amount of guns to be possessed by the three countries: Japan, the United States, and the United Kingdom. Heavy and light cruisers continued to develop separately, and after the abolition of the disarmament treaty, anti-aircraft armaments, strengthened defense, and improved main gun performance increased the displacement, reaching 14,000 to 17,000 tons by the end of World War II, and the difference between the two types of ships in terms of both technology and performance disappeared. Some countries also built mine-laying cruisers with the ability to lay mines, and training cruisers for candidates to use on long-distance voyages. Just before and during World War II, ships with new uses also appeared, such as anti-aircraft cruisers (Britain, America) equipped with dual-purpose anti-aircraft and anti-surface guns to defend fleets and convoys, 30,000-ton large cruisers equipped with 30.5 cm (12 inch) guns to destroy heavy cruisers and counter medium-sized fast battleships, and cruisers to serve as flagships for submarine squadrons (Japan).

[Yasuo Abe]

Modern cruisers

After World War II, the development of airplanes, missiles, submarines, electronic weapons, and nuclear weapons made the existence of cruisers with guns and torpedoes as their main weapons worthless. Instead, ships equipped with anti-aircraft, anti-ship, and anti-surface missiles, anti-submarine equipment, and electronic warfare equipment were built to deal with modern naval battles. In addition, command cruisers, which are mainly equipped with command, communication, and electronic devices, and can be used to comprehensively command fleets and to carry the nation's highest leaders to provide strategic command from the sea in times of emergency, were built or modified. The American USS Northampton (17,200 tons), completed in 1953, was the first of this type of ship. Immediately after World War II, importance was placed on air defense capabilities, and some ships that had not been completed during the war were modified to accommodate them, and then, as soon as anti-aircraft missiles became practical, they were equipped on existing and newly built ships. Since 1961, the United States has built many 5,700 to 14,700-ton guided missile cruisers, including nuclear-powered ships, whose main role is to escort aircraft carrier task forces and whose main equipment is anti-aircraft missiles and secondary anti-submarine equipment. The latest Ticonderoga Class (the first ship was completed in 1983) is an Aegis ship with high anti-aircraft combat capabilities due to the Aegis air defense system, and many of them (27 ships) were built by 1994, and some ships were later given the ability to intercept ballistic missiles. All ships except Long Beach, which was built as a cruiser from the beginning, are under 10,000 tons and were initially designed as guided missile frigates or guided missile destroyers, but were later changed to cruisers. The Long Beach (14,200 tons), completed in 1961, was the first surface ship to adopt nuclear propulsion, and with two nuclear reactors it had 80,000 horsepower, a speed of 30 knots, and a long cruising range of 100,000 nautical miles at full speed and 360,000 nautical miles at 20 knots. Since then, efforts have been made to make the reactors smaller, and ships of 7,600 to 10,000 tons have been built to escort nuclear aircraft carriers.

The Soviet Union developed anti-ship missiles and completed a ship equipped with them in 1962, primarily for the purpose of attacking American aircraft carrier task forces. Since then, improved versions have appeared one after another. These ships were 4,500 to 15,000 tons and equipped with eight anti-ship missile launchers, as well as anti-aircraft and anti-submarine weapons, and some were even built to prioritize anti-submarine missions by replacing the anti-ship missiles as their main weapon. In 1980, the Kirov Class (19,000 tons), a large cruiser for general-purpose combat roles, appeared, equipped with a variety of powerful equipment, mainly 20 anti-ship missile launchers. It is the only nuclear-propelled ship other than American ships, and uses a CONOS (Combine Nuclear or Steam Turbine) propulsion system with an auxiliary boiler for cruising.

Recent ships carry one to three anti-submarine helicopters, but helicopter cruisers equipped with flight decks and hangars and carrying a considerable number of helicopters for anti-submarine and amphibious operations have appeared in Italy, France, the former Soviet Union, and other countries since the mid-1960s. Steam turbines had long been used as the propulsion system for cruisers other than nuclear-powered ships, but gas turbines began to be widely used around 1980. By around 2005, many cruisers, including most nuclear-powered ships, had been decommissioned due to aging, outdated performance, and high maintenance costs, and as of 2010, there was only one large nuclear cruiser in Russia, 22 first-class (Aegis) guided missile cruisers in the United States, four second-class cruisers in Russia, one in Peru, and one helicopter cruiser in France.

[Yasuo Abe]

"New Modern Warships" by Hori Motomi and Ebata Kensuke (1987, Hara Shobo)" ▽ "Fukui Shizuo Collected Works 4: The Story of Japanese Cruisers" (2008, Kojinsha)" ▽ "Fukui Shizuo Collected Works 7: The Story of World Cruisers" (2009, Kojinsha)" ▽ "World's Ships Special Issue No. 89: Modern Cruisers" (2010, Kaijinsha)" ▽ "Stephen Saunders Jane's Fighting Ships 2010-2011 (2010, Jane's Information Group)"

Cruiser Gettysburg
The 18th Ticonderoga-class guided-missile cruiser of the United States Navy. Commissioned in 1991. Equipped with the Aegis system. Displacement 9,600 tons, overall length 173 m, overall width 17 m, speed over 30 knots © Koji Ishiwata ">

Cruiser Gettysburg

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

軍艦の一種。

　第二次世界大戦までと、その後とで巡洋艦の概念はかなり違っている。第二次世界大戦までの巡洋艦は、排水量と砲力が戦艦と駆逐艦の間にあり、速力と航続力が大きく、優れた航洋性を有する水上戦闘艦艇をいった。艦隊前面の偵察・警戒、索敵、主力部隊の直衛、通商破壊、陸上砲撃、上陸作戦支援、海外警備など、戦時、平時を通じてあらゆる任務に用いられた。

　現代の巡洋艦は、有力な艦隊防空能力、水上打撃力、対潜能力、陸上攻撃能力、指揮機能などを一つ、またはいくつか備え、航空母艦と行動をともにしてその直衛にあたるか、あるいは自ら水上部隊の中核として行動しうる能力をもち、駆逐艦より一般的に大きく、おおむね基準排水量5000トン以上、航洋力、航続力に優れ、30ノット以上の高速を有する水上戦闘艦艇をいう。

［阿部安雄］

沿革

帆船時代には、戦列艦より軽快で艦隊の耳目(じもく)・手足として敵艦隊の捜索・態勢観測およびその報告、あるいは単独索敵、偵察、海上交通保護、護衛、通商破壊などの任務にあたるフリゲート、コルベットなどを巡洋艦（クルーザー）と総称していた。

［阿部安雄］

第一次世界大戦直前まで

19世紀中ごろ、蒸気機関および鉄製さらには鋼製船体の採用により、フリゲート、コルベットなどは、砲と魚雷を主兵装とする優速軽快な戦闘艦艇に発達し、これらも巡洋艦と呼称され、1880年代に至り軍艦の艦種名称として定着した。

　初期の巡洋艦は、5000トン以上の大型艦とそれ以下の中・小型艦に分かれて発達した。大型装甲の艦は1890年代に強固な舷側甲鈑(げんそくこうはん)と砲塔砲を備えた装甲巡洋艦armored cruiserに発展した。この艦種は、排水量が7000～1万5000トンにもなり、そのなかには、航続力と速力を若干減じ、砲力、防御力を強化して戦艦を補助し主力艦との戦闘に用いられるものも出現した。日露戦争の日本艦はその典型で、戦後には戦艦と砲力同等、約2ノット優速の大型装甲巡洋艦（筑波(つくば)型、伊吹(いぶき)型）が建造された。1907年、砲力はド（弩）級戦艦と同等、速力は蒸気タービン機関の採用により26ノットの巡洋戦艦がイギリスに出現したため、装甲巡洋艦はその存在価値を失った。

　中・小型の艦は最初無防備だったが、1880年代に、中甲板に薄い装甲を施した防護巡洋艦protected cruiserが出現してこれにかわった。1882年イギリスで完成したチリのエスメラルダEsmeralda（2960トン）が最初の本格的防護巡洋艦といわれ、以後この艦種は各国で建造され、1万トンを超す大型艦も現れた。

　1900年代初頭には、高速かつきわめて軽防御の軽巡洋艦light cruiserが出現して防護巡洋艦にかわり、この艦種は各国で著しい発展を遂げた。イギリスでは第一次世界大戦直前に、防護巡洋艦にかわる5000トン以上の中型艦と、より軽快高速力で水雷戦隊旗艦や敵水雷部隊の撃攘(げきじょう)にあたる3000トン級の小型艦とに分かれ、前者は大戦末期に1万トン弱、19センチ砲装備の艦まで出現、後の重巡洋艦建造の端緒となった。後者は大戦初期に飛躍的進歩を遂げ、大戦直後には15.2センチ砲装備、7500トン級のエメラルド級Emerald Classに発達して近代巡洋艦の基礎を築いた。大戦末期から、巡洋艦は索敵用飛行機と高角砲を装備するようになった。

［阿部安雄］

第二次世界大戦終了まで

ワシントン海軍軍縮条約（1922）で巡洋艦の排水量と備砲の大きさが制限され、その上限である1万トン、20.3センチ（8インチ）砲搭載艦（条約型巡洋艦）が、その後各国で建造された。1926年（大正15）完成の古鷹(ふるたか)は7100トン、世界最初の20センチ砲搭載軽巡洋艦で、その優秀性は世界の注目を集め、以後日本は巡洋艦建造技術で列強をリードした。続くロンドン海軍軍縮条約（1930）で備砲により巡洋艦が区別され、15.5センチ（6.1インチ）～20.3センチ砲の装備艦を甲級または重巡洋艦heavy cruiser、15.2センチメートル以下の砲装備艦を乙級または軽巡洋艦と規定し、日本、アメリカ、イギリス3か国の保有量を定めた。重・軽巡洋艦はその後それぞれに発達し、軍縮条約廃棄後は、対空兵装および防御力強化、主砲の性能向上などで排水量を増し、第二次世界大戦末期には1万4000～1万7000トンに達し、技術、性能両面で両艦種の相違はなくなった。ほかに機雷敷設能力をもつ敷設巡洋艦、候補生の遠洋航海に用いる練習巡洋艦を建造した国もある。第二次世界大戦直前および戦中には、対空・対水上両用砲を搭載して艦隊・船団防空にあたる防空巡洋艦（イギリス、アメリカ）、重巡洋艦撃滅・中型高速戦艦対抗用の30.5センチ（12インチ）砲搭載の3万トン級大型巡洋艦（アメリカ）、潜水戦隊旗艦用巡洋艦（日本）など、新用途の艦も出現した。

［阿部安雄］

現代の巡洋艦

第二次世界大戦後、飛行機、ミサイル、潜水艦、電子兵器、核兵器などの発達により、砲と魚雷を主兵装とする巡洋艦は存在価値を失った。かわって、現代の海上戦闘に対応して対空・対艦・対地ミサイル、対潜装備、電子戦装備をもった艦が建造されるようになり、また指揮、通信、電子装置を装備の主体とし、艦隊などの総合指揮や、有事に国家最高指導者を乗せ海上より戦略指揮を行う指揮巡洋艦が、新造あるいは改造により出現した。1953年完成したアメリカのノーサンプトンNorthampton（1万7200トン）は、この艦種の最初のものである。第二次世界大戦直後は、防空能力が重視され、若干の戦時未成艦がこれに適するように改造され、ついで対空ミサイルが実用化するや既成艦、新造艦に装備された。アメリカは1961年以降、空母機動部隊の護衛を主任務として、対空ミサイル装備を主とし対潜装備を従とした、原子力推進艦を含む5700～1万4700トンのミサイル巡洋艦を多数建造した。最新のタイコンデロガ級Ticonderoga Class（第1艦は1983年完成）はイージス防空装置の装備により高い対空戦闘力をもつイージス艦で、1994年まで27隻と多数が建造され、その後一部の艦には弾道ミサイル迎撃能力が付された。当初から巡洋艦として建造されたロング・ビーチLong Beach以外は1万トン以下で、最初ミサイル・フリゲートあるいはミサイル駆逐艦とされたが、のちに巡洋艦に変更された。1961年完成のロング・ビーチ（1万4200トン）は、原子力推進を採用した最初の水上艦で、原子炉2基により8万馬力、30ノットの能力を有し、全速力で10万海里、20ノットで36万海里もの長大な航続力を得た。その後は、原子炉の小型化が図られ、原子力空母の護衛用として7600～1万トンの艦が建造されている。

　ソ連は、対艦ミサイルを開発し、アメリカの空母機動部隊攻撃を主目的にこれを装備した艦を1962年に完成、以後順次改良型が出現した。これらは4500～1万5000トン、対艦ミサイル発射機8基のほか、対空、対潜兵装を備え、さらには主兵装の対艦ミサイルも対潜ミサイルにかえて対潜任務重視型のものも建造された。1980年に至り、対艦ミサイル発射機20基を主体とする有力な各種装備をもつ汎用(はんよう)戦闘任務の大型巡洋艦キーロフ級Kirov Class（1万9000トン）が出現した。アメリカ艦を除く唯一の原子力推進艦で、巡航用に補助ボイラーを併載したCONOS（Combine Nuclear or Steam Turbine）推進方式を採用している。

　最近の艦は、対潜ヘリコプターを1～3機ほど搭載するが、さらに飛行甲板や格納庫を設け、相当の機数を搭載し、対潜、揚陸作戦などにあたるヘリコプター巡洋艦が、1960年代の中ごろからイタリア、フランス、旧ソ連などで出現している。原子力推進艦以外の巡洋艦の推進機関には、長らく蒸気タービンが使用されてきたが、1980年ごろからガスタービンが広く用いられるようになった。2005年ごろまでにほとんどの原子力推進艦を含む多くの巡洋艦が老朽化、性能の陳腐化、高額な維持経費などの理由で除籍されており、2010年時点で大型原子力巡洋艦はロシアに1隻、ミサイル巡洋艦はアメリカに1級（イージス艦）22隻、ロシアに2級4隻、ペルーに1隻、そしてヘリコプター巡洋艦がフランスに1隻存在しているだけである。

［阿部安雄］

『堀元美・江畑謙介著『新・現代の軍艦』（1987・原書房）』▽『『福井静夫著作集4　日本巡洋艦物語』（2008・光人社）』▽『『福井静夫著作集7　世界巡洋艦物語』（2009・光人社）』▽『『世界の艦船増刊第89集　近代巡洋艦』（2010・海人社）』▽『Stephen SaundersJane's Fighting Ships 2010-2011（2010, Jane's Information Group）』