:Design B-65 cruiser
{{Short description|Proposed class of Japanese WWII-era super-heavy cruisers}}
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{{Infobox ship image |Ship image=Design B-65.svg |Ship caption=A line drawing of the proposed Design B-65. }} {{Infobox ship class overview |Name=Design B-65 |Builders= |Operators={{flagicon|Empire of Japan|naval}} Imperial Japanese Navy |Class before={{sclass|Amagi|battlecruiser}} |Class after= |Subclasses= |Cost= |Built range= |In service range= |In commission range= |Total ships building= |Total ships planned=2 |Total ships completed= |Total ships cancelled=2 |Total ships active= |Total ships laid up= |Total ships lost= |Total ships retired= |Total ships preserved= }} {{Infobox ship characteristics |Hide header= |Header caption= |Ship class= |Ship type=Super Type A cruiser |Ship tonnage= |Ship displacement=*Standard: {{convert|31905|t|LT|abbr=on}}
|Ship length=*{{convert|240|m|ft|abbr=on}} length at the waterline
|Ship beam={{convert|27.2|m|ft|abbr=on}} |Ship height= |Ship draft={{convert|8.8|m|ft|abbr=on}} (trial) |Ship depth= |Ship hold depth= |Ship decks= |Ship deck clearance= |Ship ramps= |Ship ice class= |Ship power= |Ship propulsion=Four sets of geared turbines and eight Kampon boilers would yield 170,000 metric horsepower (167,674 shaft horsepower); this would have been able to drive the ship at {{convert|33|kn|mph km/h|abbr=on}}Lacroix and Wells II, p. 830 |Ship range= |Ship endurance={{convert|8000|mi|km|abbr=on}} at {{convert|18|kn|mph km/h|abbr=on}} |Ship boats= |Ship complement= |Ship crew= |Ship time to activate= |Ship sensors= |Ship EW= |Ship armament=*9 × {{convert|310|mm|in|1|abbr=on}}/50 caliber guns (3 × 3)
|Ship armor=*Belt: {{convert|190|mm|in|abbr=on}} inclined 20 degrees
|Ship aircraft= |Ship aircraft facilities= |Ship notes= }} |
Design B-65 was a class of cruisers planned by the Imperial Japanese Navy (IJN) before and during World War II. The IJN referred to this design as a 'Super Type A' cruiser; It was larger than most heavy cruisers but smaller than most battlecruisers, and as such, has been variously described as a 'super-heavy cruiser,' a 'super cruiser,' or as a 'cruiser-killer.'According to Conway's All the World's Fighting Ships 1922–1946, p. 178, the Japanese classified Super Type A cruisers as heavy cruisers; however, Garzke and Dulin assert in Battleships: Axis and Neutral Battleships in World War II, p. 86, that B-65 cruisers "would have satisfied every basic characteristic of the battlecruiser type." As envisioned by the IJN, the cruisers were to play a key role in the Night Battle Force portion of the "Decisive battle" strategy which Japan hoped, in the event of war, to employ against the United States Navy.
Begun in 1939, plans were far enough along that tests were conducted with the main armament and against the underwater protection. Even though the ships were approved for construction under a 1942 fleet replenishment program, the prioritizing of aircraft carriers and smaller ships due to the war, followed by Japan's defeat, ended any chance of the B-65's construction.
Design B-65 would have been similar to the United States' Alaska-class cruiser in terms of displacement, armament, and role. Both designs also straddled the line between heavy cruisers and battlecruisers. The envisioning of the 'large cruiser' or 'super-heavy cruiser' and, ultimately, the design of the Alaska-class itself may have been at least partly inspired by the desire to counter the Design B-65, or at least earlier IJN proposals.{{cite DANFS | title = Hawaii | url = http://hazegray.org/danfs/cruisers/cb3.txt | access-date=14 October 2008|short=yes|link=no| archive-url= https://web.archive.org/web/20080928005847/http://www.hazegray.org/danfs/cruisers/cb3.txt| archive-date= 28 September 2008 | url-status= live}}Scarpaci, 17. However, unlike the never-built Design B-65, the Alaska-class would see two ships completed.
Mission and plan
The Japanese navy's experience in the Russo-Japanese War of 1904–1905, especially the Battle of Tsushima, strongly influenced the creation of the IJN's "Decisive Battle" doctrine, which guided the development and deployment of the IJN's battle fleet into World War II. The Decisive Battle concept was the IJN's primary strategy for defeating the navies of the major Western powers, such as Great Britain or the United States, in the event of war. The strategy consisted of four main components: a decisive surface fleet engagement determined by big guns, attrition tactics against a numerically superior enemy, a reliance on quality over quantity in naval weaponry, and the employment of nighttime torpedo attacks.Evans and Peattie, pp. 129–130
After the Washington Naval Treaty of 1922 and the London Naval Treaty of 1930, each of which placed restrictions on the size of the IJN's fleet in comparison with the fleets of the western powers, notably the United States, the decisive battle strategy received increased emphasis within the IJN. In 1936, the IJN formed the Night Battle Force (Yasen Butai). As designed, the night battle force was to attack the hypothetical enemy's, usually envisioned by the Japanese to be the US Pacific Fleet, outer defense ring of cruisers and destroyers at night. After cracking the outer defense ring, IJN cruisers and destroyers were to launch torpedo attacks on the enemy's battleships. What remained of the enemy fleet was then to be finished-off by the IJN's main battleship line the following day.Evans and Peattie, pp. 273-276.
The IJN assigned one division of fast battleships or battlecruisers to give additional firepower to the nocturnal attacks. The {{sclass|Kongō|battlecruiser}} were initially assigned to this role and were upgraded to fast battleships over a seven-year period from 1933 to 1940. The IJN planned to eventually replace the four Kongō battleships with four heavy, "super" cruisers. As envisioned by the IJN in 1936, these ships, the B-65 cruisers, would mount 310 mm (12.2 in) guns, carry armor designed to withstand hits from 203mm (8 in) shells, and be capable of speeds up to 40 knots. They would be designated as "super-A-class cruisers" to signify their greater status than the A-class ships (heavy cruisers).Garzke and Dulin (1985), p. 86Evans and Peattie, pp. 275-277, 294; Lacroix and Wells II, pp. 250, 606.Perfect Guide to Japanese Battleships, p. 140
The plan for the cruiser class was finalized as part of the IJN's Circle Five and Circle Six warship construction plans of 7 January 1941. The plan called for six B-65s to be built in two increments, with the first two to be constructed in Circle 5 with the remainder in Circle 6. By this time, Japanese intelligence had learned the specifications for the United States Navy's {{sclass|Alaska|cruiser|0}} large cruisers,Garzke and Dulin (1985), pp. 86–87 which had been authorized for creation by the passage of the Two-Ocean Navy Act and ordered on 5 September 1940.{{cite web|url=http://www.globalsecurity.org/military/systems/ship/cb-1.htm|title=CB-1 Alaska Class|access-date = 19 October 2008|last=Pike|first=John|year=2008|publisher=GlobalSecurity.org}} The Japanese believed that these ships would form part of the American battle fleet's screen in times of war. Thus, the B-65s were now intended to counter the threat posed by the Alaska-class cruisers.Evans and Peattie, pp. 359-360.
Design
Design work on the B-65s began in 1939.Gardiner and Chesneau (1984), p. 178 Preliminary plans for the new class were finished by September 1940, and they were far enough along that tests of the lower protection—the armor intended to counter torpedoes and any shells that fell short but still hit the ship (albeit underwater)—and main armament were conducted from 1940 to 1941.
File:Yamato during Trial Service.jpg
These plans called for ships that bore a striking resemblance to the {{sclass|Yamato|battleship|1}}s, with the same "clipper bow, flush-deck construction, and a generally similar superstructure", albeit at a reduced size. Primary weapons were to be nine {{convert|310|mm|in|1|abbr=on}}/50 caliber guns in three triple turrets. Secondary weapons included sixteen 10 cm/65 Type 98 naval gun dual-purpose guns in dual mounts on either side of the superstructure, twelve paired Type 95 25mm gun anti-aircraft guns, and four 13.2 mm Hotchkiss machine guns.{{cite web|url=http://www.navweaps.com/Weapons/WNJAP_39-65_t98.htm|title=Japanese 10 cm/65 (3.9") Type 98|access-date=13 March 2009| last=DiGuilian|first=Tony|date=26 August 2007|publisher=Navweaps}} The weight of the main battery turrets was to be around {{convert|1000|LT|ST t|lk=in}}, with {{convert|350|LT|ST t|abbr=on}} of that devoted to armor; however, no plans of how this latter figure was to have been distributed have survived.Perfect Guide, p. 141
The cruisers were to be protected by {{convert|190|mm|in|abbr=on}} belt armor sloped at {{formatnum:20}}° and {{convert|125|mm|in|abbr=on}} deck armor. Four geared turbine sets would have generated about 42,500 shp each;Lacroix and Wells II (1997), p. 606 for a total of about 167,674 shp,Garzke and Dulin (1985), p. 87 enough to power the ships through the water at {{convert|34|kn|mph km/h|abbr=on}}, faster than the "fundamental design requirement" of {{convert|33|kn|mph km/h|abbr=on}}.
In an attempt to counter the Alaska-class cruisers{{'}} {{convert|305|mm|in|abbr=on}} guns, a proposal to increase both the main battery to six {{convert|356|mm|in|0|abbr=on}} and armor protection to resist against the same was put forth. However, the increase in displacement (to almost {{convert|40000|LT|ST t|abbr=on}}) and reduction in performance this entailed meant that nothing came of the proposed changes.Alaska-class cruisers were originally designed and ordered by the United States Navy because of mistaken intelligence reports stating that Japan was constructing "super cruisers" that would be much more powerful than the {{convert|8|in|mm|1|abbr=on}}-gunned heavy cruisers the U.S. possessed. See: Gardiner and Chesneau, p. 122 and {{cite web|url=http://www.globalsecurity.org/military/systems/ship/cb-1.htm|title=CB-1 Alaska Class|access-date=19 October 2008|last=Pike|first=John|year=2008|publisher=GlobalSecurity.org}}
Final plans and cancellation
As war with the United States loomed in 1941, the navy found that it had a more pressing need for aircraft carriers and auxiliary vessels. This need, plus a desire to complete the ongoing Circle Three and Four construction programs, delayed initiation of the Circle Five plan.Evans and Peattie, p 360.
Following the Japanese navy's defeat at the Battle of Midway in June 1942, the Circle Five plan was significantly revised and Circle Six was postponed indefinitely. The new plan still called for the construction of two ships of Design B-65, which were given the hull numbers 795 and 796 with projected commissioning dates of 1945 and 1946, respectively. As the war progressed, however, strategic requirements further delayed the plans for the two cruisers. In the end, the B-65s' plans were never finalized and no contracts for their construction were ever placed.Garzke and Dulin (1985), p. 84–85Lacroix and Wells II, p. 829.Jentschura, p. 40.
See also
- List of battlecruisers of Japan
- {{sclass|Deutschland|cruiser|1}} - German counterpart
- {{sclass|Alaska|cruiser|1}} - US counterpart
- {{sclass|Stalingrad|battlecruiser|1}} - Soviet Counterpart
Notes
{{Reflist|group=A}}
References
{{Reflist}}
Bibliography
{{Refbegin}}
- {{cite book
| last = Evans
| first = David C.
| last2 = Peattie
| first2 = Mark R.
| title = Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887–1941
| location = Annapolis, Maryland
| publisher = Naval Institute Press
| year = 1997
| isbn = 0-87021-192-7
| oclc = 36621876
| author-link2 = Mark Peattie
}}
- {{cite book|author1=Gardiner, Robert |author2=Chesneau, Roger | title=Conway's All the World's Fighting Ships 1922-1946|publisher=Naval Institute Press|year=1980|isbn=0-87021-913-8|oclc=18121784}}
- {{cite book| last1 = Garzke| first1 = William H.| last2 = Dulin| first2 = Robert O.| title = Battleships: Axis and Neutral Battleships in World War II| location = Annapolis, Maryland| publisher = Naval Institute Press| year = 1985| isbn = 0-87021-101-3| oclc = 12613723}}
- {{cite book
| last = Jentschura
| first = Hansgeorg |author2=Jung, Dieter |author3=Mickel, Peter
| year = 1977
| title = Warships of the Imperial Japanese Navy, 1869-1945
| publisher = United States Naval Institute
| location = Annapolis
| isbn = 0-87021-893-X
}}
- {{cite book| last1 = Lacroix| first1 = Eric| last2 = Wells| first2 = Linton| title = Japanese cruisers of the Pacific War| location = Annapolis, Maryland| publisher = Naval Institute Press| year = 1997| isbn = 0-87021-311-3| oclc = 21079856}}
{{Refend}}
{{Large cruisers}}
{{Good article}}
{{DEFAULTSORT:Design B-65 Cruiser}}
Category:Battlecruiser classes