Editing Cruiser (section)

===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]].