Editing Cruiser (section)

==Mid-20th century==
[[File:Armando Diaz AllenGren3.jpg|thumb|right|Italian cruiser {{ship|Italian cruiser|Armando Diaz||2}}.]]

Naval construction in the 1920s and 1930s was limited by international treaties designed to prevent the repetition of the [[Dreadnought]] arms race of the early 20th century. The Washington Naval Treaty of 1922 placed limits on the construction of ships with a [[standard displacement]] of more than 10,000 [[ton]]s and an armament of guns larger than 8-inch (203&nbsp;mm). A number of navies commissioned classes of cruisers at the top end of this limit, known as "[[treaty cruiser]]s".<ref>Gardiner and Chumbley, pp. 2, 167</ref>

The [[London Naval Treaty]] in 1930 then formalised the distinction between these "heavy" cruisers and light cruisers: a "heavy" cruiser was one with guns of more than 6.1-inch (155&nbsp;mm) calibre.<ref>Friedman cruisers, p. 164</ref> The [[Second London Naval Treaty]] attempted to reduce the tonnage of new cruisers to 8,000 or less, but this had little effect; Japan and Germany were not signatories, and some navies had already begun to evade treaty limitations on warships. The first London treaty did touch off a period of the major powers building 6-inch or 6.1-inch gunned cruisers, nominally of 10,000 tons and with up to fifteen guns, the treaty limit. Thus, most light cruisers ordered after 1930 were the size of heavy cruisers but with more and smaller guns. The [[Imperial Japanese Navy]] began this new race with the {{sclass|Mogami|cruiser|4}}, launched in 1934.<ref>Gardiner and Chumbley, p. 190</ref> After building smaller light cruisers with six or eight 6-inch guns launched 1931–35, the British Royal Navy followed with the 12-gun {{sclass|Southampton|cruiser|4}} in 1936.<ref>Gardiner and Chumbley, pp. 30–31</ref> To match foreign developments and potential treaty violations, in the 1930s the US developed a series of new guns firing "super-heavy" armor piercing ammunition; these included the [[6"/47 caliber gun|6-inch (152&nbsp;mm)/47 caliber gun Mark 16]] introduced with the 15-gun {{sclass|Brooklyn|cruiser|1}}s in 1936,<ref>{{Cite web|url=http://www.navweaps.com/Weapons/WNUS_8-55_mk12-15.php|title=USA 8"/55 (20.3 cm) Marks 12 and 15|website=www.navweaps.com – NavWeaps}}</ref> and the [[8"/55 caliber gun|8-inch (203&nbsp;mm)/55 caliber gun Mark 12]] introduced with {{USS|Wichita|CA-45|6}} in 1937.<ref>{{Cite web|url=http://www.navweaps.com/Weapons/WNUS_6-47_mk16.php|title=USA 6"/47 (15.2 cm) Mark 16|website=www.navweaps.com – NavWeaps}}</ref><ref>Friedman cruisers, pp. 217–220</ref>

===Heavy cruisers===
{{see also|Heavy cruiser}}
[[File:USS Salt Lake City (CA-25) during the early 1930s.jpg|thumb|[[USS Salt Lake City (CA-25)|USS ''Salt Lake City'' (CA-25)]]]]
The heavy cruiser was a type of cruiser designed for long range, high speed and an armament of naval guns around 203&nbsp;mm (8&nbsp;in) in calibre. The first heavy cruisers were built in 1915, although it only became a widespread classification following the London Naval Treaty in 1930. The heavy cruiser's immediate precursors were the light cruiser designs of the 1910s and 1920s; the US lightly armored 8-inch "treaty cruisers" of the 1920s (built under the Washington Naval Treaty) were originally classed as light cruisers until the London Treaty forced their redesignation.<ref>Bauer and Roberts, pp. 136–138</ref>

Initially, all cruisers built under the Washington treaty had torpedo tubes, regardless of nationality. However, in 1930, results of war games caused the US [[Naval War College]] to conclude that only perhaps half of cruisers would use their torpedoes in action. In a surface engagement, long-range gunfire and destroyer torpedoes would decide the issue, and under air attack numerous cruisers would be lost before getting within torpedo range. Thus, beginning with {{USS|New Orleans|CA-32|6}} launched in 1933, new cruisers were built without torpedoes, and torpedoes were removed from older heavy cruisers due to the perceived hazard of their being exploded by shell fire.<ref>Friedman cruisers, p. 150</ref> The Japanese took exactly the opposite approach with cruiser torpedoes, and this proved crucial to their tactical victories in most of the numerous cruiser actions of 1942. Beginning with the {{sclass|Furutaka|cruiser|4}} launched in 1925, every Japanese heavy cruiser was armed with {{convert|24|in|adj=on}} torpedoes, larger than any other cruisers'.<ref name=Watts1>Watts, pp. 79–114</ref> By 1933 Japan had developed the [[Type 93 torpedo]] for these ships, eventually nicknamed "Long Lance" by the Allies. This type used compressed oxygen instead of compressed air, allowing it to achieve ranges and speeds unmatched by other torpedoes. It could achieve a range of {{convert|22000|m|yd}} at {{convert|50|kn}}, compared with the US [[Mark 15 torpedo]] with {{convert|5500|m|yd}} at {{convert|45|kn}}. The Mark 15 had a maximum range of {{convert|13500|m|yd}} at {{convert|26.5|kn}}, still well below the "Long Lance".<ref>{{cite web | title = Torpedo History: Torpedo Mk15 | url = http://www.history.navy.mil/museums/keyport/html/part2.htm | access-date = 25 May 2016 | archive-date = 15 September 2014 | archive-url = https://web.archive.org/web/20140915054904/http://www.history.navy.mil/museums/keyport/html/part2.htm | url-status = dead }}</ref> The Japanese were able to keep the Type 93's performance and oxygen power secret until the Allies recovered one in early 1943, thus the Allies faced a great threat they were not aware of in 1942. The Type 93 was also fitted to Japanese post-1930 light cruisers and the majority of their World War II destroyers.<ref name=Watts1/><ref name=Watts2>Watts, pp. 124–158</ref>

Heavy cruisers continued in use until after World War II, with some converted to guided-missile cruisers for air defense or [[SSM-N-8 Regulus#Ships fitted with Regulus|strategic attack]] and some used for shore bombardment by the United States in the [[Korean War]] and the [[Vietnam War]].

===German pocket battleships===
The German {{sclass|Deutschland|cruiser|4}} was a series of three ''Panzerschiffe'' ("armored ships"), a form of heavily armed cruiser, designed and built by the [[Reichsmarine|German Reichsmarine]] in nominal accordance with restrictions imposed by the [[Treaty of Versailles]]. All three ships were launched between 1931 and 1934, and served with Germany's [[Kriegsmarine]] during [[World War II]]. Within the Kriegsmarine, the Panzerschiffe had the propaganda value of capital ships: heavy cruisers with battleship guns, torpedoes, and scout aircraft. (The similar Swedish ''Panzerschiffe'' were tactically used as centers of battlefleets and not as cruisers.) They were deployed by Nazi Germany in support of the German interests in the Spanish Civil War. Panzerschiff ''Admiral Graf Spee'' represented Germany in the [[Fleet review (Commonwealth realms)#George VI|1937 Coronation Fleet Review]].

The British press referred to the vessels as pocket battleships, in reference to the heavy firepower contained in the relatively small vessels; they were considerably smaller than contemporary battleships, though at 28 knots were slower than battlecruisers. At up to 16,000 tons at full load, they were not treaty compliant 10,000 ton cruisers. And although their displacement and scale of armor protection were that of a heavy cruiser, their {{convert|280|mm|abbr=on}} main armament was heavier than the {{convert|203|mm|abbr=on|0}} guns of other nations' heavy cruisers, and the latter two members of the class also had tall conning towers resembling battleships. The Panzerschiffe were listed as Ersatz replacements for retiring Reichsmarine coastal defense battleships, which added to their propaganda status in the Kriegsmarine as Ersatz battleships; within the Royal Navy, only battlecruisers HMS ''Hood'', HMS ''Repulse'' and HMS ''Renown'' were capable of both outrunning and outgunning the Panzerschiffe. They were seen in the 1930s as a new and serious threat by both Britain and France. While the Kriegsmarine reclassified them as heavy cruisers in 1940, ''Deutschland''-class ships continued to be called ''pocket battleships'' in the popular press.

===Large cruiser===
The American {{sclass|Alaska|cruiser|4}} represented the supersized cruiser design. Due to the German [[Deutschland-class cruiser|pocket battleships]], the {{sclass|Scharnhorst|battleship|4}}, and rumored Japanese "super cruisers", all of which carried guns larger than the standard heavy cruiser's 8-inch size dictated by naval treaty limitations, the ''Alaska''s were intended to be "cruiser-killers". While superficially appearing similar to a battleship/battlecruiser and mounting three triple turrets of [[12"/50 caliber Mark 8 gun|12-inch guns]], their actual protection scheme and design resembled a scaled-up heavy cruiser design. Their hull classification symbol of CB (cruiser, big) reflected this.<ref>Friedman cruisers, pp. 286–305</ref>

===Anti-aircraft cruisers===
A precursor to the anti-aircraft cruiser was the Romanian British-built protected cruiser ''[[NMS Elisabeta|Elisabeta]]''. After the start of World War I, her four 120&nbsp;mm main guns were landed and her four 75&nbsp;mm (12-pounder) secondary guns were modified for anti-aircraft fire.<ref>John Evelyn Moore, ''Jane's Fighting Ships of World War I'', Military Press, 1990, p. 294</ref>

The development of the anti-aircraft cruiser began in 1935 when the Royal Navy re-armed {{HMS|Coventry|D43|6}} and {{HMS|Curlew|D42|6}}. Torpedo tubes and {{convert|6|in|mm|adj=on|0}} low-angle guns were removed from these World War I light cruisers and replaced with ten {{convert|4|in|mm|adj=on|0}} high-angle guns, with appropriate fire-control equipment to provide larger warships with protection against high-altitude bombers.<ref>Friedman, Norman "Anti-Aircraft Cruisers: The Life of a Class" ''United States Naval Institute Proceedings'' January 1965 p. 86</ref>

A tactical shortcoming was recognised after completing six additional conversions of {{sclass2|C|cruiser|1}}s. Having sacrificed anti-ship weapons for anti-aircraft armament, the converted anti-aircraft cruisers might themselves need protection against surface units. New construction was undertaken to create cruisers of similar speed and displacement with [[dual-purpose gun]]s, which offered good anti-aircraft protection with anti-surface capability for the traditional light cruiser role of defending capital ships from destroyers.

The first purpose built anti-aircraft cruiser was the British {{sclass|Dido|cruiser|4}}, completed in 1940–42. The US Navy's {{sclass|Atlanta|cruiser|0}} cruisers (CLAA: light cruiser with anti-aircraft capability) were designed to match the capabilities of the Royal Navy. Both ''Dido'' and ''Atlanta'' cruisers initially carried torpedo tubes; the ''Atlanta'' cruisers at least were originally designed as destroyer leaders, were originally designated CL ([[light cruiser]]), and did not receive the CLAA designation until 1949.<ref>Friedman cruisers, pp. 224–229</ref><ref>Bauer and Roberts, p. 150</ref>

The concept of the quick-firing dual-purpose gun anti-aircraft cruiser was embraced in several designs completed too late to see combat, including: {{USS|Worcester|CL-144|6}}, completed in 1948; {{USS|Roanoke|CL-145|6}}, completed in 1949; two {{sclass|Tre Kronor|cruiser|2}}s, completed in 1947; two {{sclass|De Zeven Provinciën|cruiser|2}}s, completed in 1953; {{ship|French cruiser|De Grasse|C610|2}}, completed in 1955; {{ship|French cruiser|Colbert|C611|2}}, completed in 1959; and {{HMS|Tiger|C20|6}}, {{HMS|Lion|C34|6}} and {{HMS|Blake|C99|6}}, all completed between 1959 and 1961.<ref>Friedman, Norman "Anti-Aircraft Cruisers: The Life of a Class" ''United States Naval Institute Proceedings'' January 1965 pp. 96–97</ref>

Most post-World War II cruisers were tasked with air defense roles. In the early 1950s, advances in aviation technology forced the move from anti-aircraft artillery to anti-aircraft missiles. Therefore, most modern cruisers are equipped with surface-to-air missiles as their main armament. Today's equivalent of the anti-aircraft cruiser is the '''guided-missile cruiser''' (CAG/CLG/CG/CGN).