Design B-65 cruiser

Last updated
Design B-65.svg
A line drawing of the proposed Design B-65.
Class overview
NameDesign B-65
Operators Naval ensign of the Empire of Japan.svg Imperial Japanese Navy
Preceded by Amagi-class battlecruiser
Planned2
Cancelled2
General characteristics
TypeSuper Type A cruiser
Displacement
  • Standard: 31,905 t (31,401 long tons) [1]
  • Full-load: 35,000 t (34,000 long tons)
Length
Beam27.2 m (89 ft) [1]
Draft8.8 m (29 ft) (trial) [1]
PropulsionFour 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 33 kn (38 mph; 61 km/h) [2]
Endurance8,000 mi (13,000 km) at 18 kn (21 mph; 33 km/h) [1]
Armament
Armor
  • Belt: 190 mm (7.5 in) inclined 20 degrees
  • Barbettes: 210 mm (8.3 in) to 190 mm (7.5 in)
  • Conning tower sides: 180 mm (7.1 in)
  • Conning tower roof: 125 mm (4.9 in)
  • Deck: 125 mm (5 in) [3]

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.' [A 1] 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.

Contents

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. [4] [5] [6] [7] 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. [8]

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. [9]

The IJN assigned one division of fast battleships or battlecruisers to give additional firepower to the nocturnal attacks. The Kongō-class 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). [1] [10] [11]

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. [12] By this time, Japanese intelligence had learned the specifications for the United States Navy's Alaska-class large cruisers, [13] which had been authorized for creation by the passage of the Two-Ocean Navy Act and ordered on 5 September 1940. [12] [6] 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. [12] [14]

Design

Design work on the B-65s began in 1939. [5] 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. [1]

Yamato on her trials in 1941. Had the Design B-65 ships been built, they would have borne a striking resemblance to this ship. Yamato during Trial Service.jpg
Yamato on her trials in 1941. Had the Design B-65 ships been built, they would have borne a striking resemblance to this ship.

These plans called for ships that bore a striking resemblance to the Yamato-class battleships, with the same "clipper bow, flush-deck construction, and a generally similar superstructure", albeit at a reduced size. Primary weapons were to be nine 310 mm (12.2 in)/50 caliber guns in three triple turrets. Secondary weapons included sixteen 100 mm (3.9 in)/65 caliber Type 98 dual-purpose guns in dual mounts on either side of the superstructure, twelve paired Type 95 25 mm (1 in) anti-aircraft guns, and four 13.2 mm Hotchkiss machine guns. [1] [15] The weight of the main battery turrets was to be around 1,000 long tons (1,100 short tons; 1,000 t), with 350 long tons (390 short tons; 360 t) of that devoted to armor; however, no plans of how this latter figure was to have been distributed have survived. [16]

The cruisers were to be protected by 190 mm (7.5 in) belt armor sloped at 20° and 125 mm (4.9 in) deck armor. [1] Four geared turbine sets would have generated about 42,500  shp each; [12] for a total of about 167,674 shp, [12] [17] enough to power the ships through the water at 34 kn (39 mph; 63 km/h), [1] faster than the "fundamental design requirement" of 33 kn (38 mph; 61 km/h). [17]

In an attempt to counter the Alaska-class cruisers'305 mm (12.0 in) guns, a proposal to increase both the main battery to six 356 mm (14 in) and armor protection to resist against the same was put forth. However, the increase in displacement (to almost 40,000 long tons (45,000 short tons; 41,000 t)) and reduction in performance this entailed meant that nothing came of the proposed changes. [13] [16] [A 2]

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. [18]

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. [19] [20] [21]

See also

Notes

  1. ↑ 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."
  2. ↑ 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 8 in (203.2 mm)-gunned heavy cruisers the U.S. possessed. See: Gardiner and Chesneau, p. 122 and Pike, John (2008). "CB-1 Alaska Class". GlobalSecurity.org. Retrieved 19 October 2008.

Related Research Articles

<span class="mw-page-title-main">Battlecruiser</span> Large capital warship, typically faster than battleships

The battlecruiser was a type of capital ship of the first half of the 20th century. These were similar in displacement, armament and cost to battleships, but differed in form and balance of attributes. Battlecruisers typically had thinner armour and a somewhat lighter main gun battery than contemporary battleships, installed on a longer hull with much higher engine power in order to attain greater speeds. The first battlecruisers were designed in the United Kingdom, as a development of the armoured cruiser, at the same time as the dreadnought succeeded the pre-dreadnought battleship. The goal of the design was to outrun any ship with similar armament, and chase down any ship with lesser armament; they were intended to hunt down slower, older armoured cruisers and destroy them with heavy gunfire while avoiding combat with the more powerful but slower battleships. However, as more and more battlecruisers were built, they were increasingly used alongside the better-protected battleships.

Japanese battleship <i>Yamato</i> Imperial Japanese Navy ship

Yamato was the lead ship of her class of battleships built for the Imperial Japanese Navy (IJN) shortly before World War II. She and her sister ship, Musashi, were the heaviest and most powerfully armed battleships ever constructed, displacing nearly 72,000 tonnes at full load and armed with nine 46 cm (18.1 in) Type 94 main guns, which were the largest guns ever mounted on a warship.

USS <i>Hawaii</i> (CB-3) Never-completed third member of the US Navy Alaska-class large cruisers

USS Hawaii (CB-3) was intended to be the third member of the Alaska-class large cruisers. It was the first United States Navy ship to be named after the then-Territory of Hawaii. Because Hawaii's construction was delayed by higher-priority ships like aircraft carriers, her keel was not laid until December 1943, about two years after her sister ship Guam.

<i>Alaska</i>-class cruiser Late WWII-era class of "large cruisers" of the U.S. Navy

The Alaska-class were six large cruisers ordered before World War II for the United States Navy (USN), of which only two were completed and saw service late in the war. The USN designation for the ships of this class was 'large cruiser' (CB), a designation unique to the Alaska-class, and the majority of leading reference works consider them as such. However, various other works have alternately described these ships as battlecruisers despite the USN having never classified them as such, and having actively discouraged the use of the term in describing the class. The Alaskas were all named after territories or insular areas of the United States, signifying their intermediate status between larger battleships and smaller heavy and light cruisers.

<i>Yamato</i>-class battleship Class of Japanese battleship

The Yamato-class battleships were two battleships of the Imperial Japanese Navy, Yamato and Musashi, laid down leading up to World War II and completed as designed. A third hull, laid down in 1940, was converted to an aircraft carrier, Shinano, during construction.

<i>Scharnhorst</i>-class battleship Kriegsmarine battleship class, built 1935–1939

The Scharnhorst class was a class of German battleships built immediately prior to World War II. The first capital ships of Nazi Germany's Kriegsmarine, it comprised two vessels: Scharnhorst and Gneisenau. Scharnhorst was launched first, and is considered to be the lead ship by some sources; they are also referred to as the Gneisenau class in some other sources, as Gneisenau was the first to be laid down and commissioned. They marked the beginning of German naval rearmament after the Treaty of Versailles. The ships were armed with nine 28 cm (11 in) SK C/34 guns in three triple turrets; plans to replace these with six 38 cm (15 in) SK C/34 guns in twin turrets were never realized.

Design A-150 battleship Planned class of Japanese super battleships

Design A-150, popularly known as the Super Yamato class, was a planned class of battleships for the Imperial Japanese Navy. In keeping with longstanding Japanese naval strategy, the A-150s would have carried six 51-centimeter (20.1 in) guns to ensure their qualitative superiority over any other battleship they might face. These would have been the largest guns ever carried aboard a capital ship.

O-class battlecruiser Proposed battlecruiser class of the German Navy

The O class was a planned class of three battlecruisers for the Kriegsmarine before World War II. Prompted by a perceived lack in ship numbers when compared with the British Royal Navy, the O class' design was born with the suggestion of modifying the P-class cruiser design with 380 mm (15 in) guns instead of 283 mm (11.1 in).

The Kii-class battleship was a planned class of four fast battleships to be built for the Imperial Japanese Navy (IJN) during the 1920s. Only two of the ships received names. They were intended to reinforce Japan's "eight-eight fleet" of eight battleships and eight battlecruisers after the United States announced a major naval construction program in 1919. However, after the signing of the Washington Naval Treaty in 1922, work on the ships was suspended; one pair was cancelled in November 1923 and the other in April 1924.

<i>Tosa</i>-class battleship Class of Japanese dreadnoughts that did not see service as battleships

The Tosa-class battleships were two dreadnoughts ordered as part of the "Eight-Eight" fleet for the Imperial Japanese Navy (IJN) during the early 1920s. The ships were larger versions of the preceding Nagato class, and carried an additional 41-centimeter (16.1 in) twin-gun turret. The design for the class served as a basis for the Amagi-class battlecruisers.

The Number 13-class battleship was a planned class of four fast battleships to be built for the Imperial Japanese Navy (IJN) during the 1920s. The ships never received any names, being known only as Numbers 13–16. They were intended to reinforce Japan's "eight-eight fleet" of eight battleships and eight battlecruisers after the United States announced a major naval construction program in 1919. The Number 13 class was designed to be superior to all other existing battleships, planned or building. After the signing of the Washington Naval Treaty in 1922, they were cancelled in November 1923 before construction could begin.

<i>Satsuma</i>-class battleship Class of Japanese semi-dreadnoughts

The Satsuma class was a pair of semi-dreadnought battleships built for the Imperial Japanese Navy (IJN) in the first decade of the 20th century. They were the first battleships to be built in Japan and marked a transitional stage between the pre-dreadnought and true dreadnought designs. They saw no combat during World War I, although Satsuma led a squadron that occupied several German colonies in the Pacific Ocean in 1914. Both ships were disarmed and expended as targets in 1922–1924 in accordance with the terms of the Washington Naval Treaty of 1922.

<i>Amagi</i>-class battlecruiser Class of Japanese battlecruisers

The Amagi class was a series of four battlecruisers planned for the Imperial Japanese Navy (IJN) as part of the Eight-eight fleet in the early 1920s. The ships were to be named Amagi, Akagi, Atago, and Takao. The Amagi design was essentially a lengthened version of the Tosa-class battleship, but with a thinner armored belt and deck, a more powerful propulsion system, and a modified secondary armament arrangement. They were to have carried the same main battery of ten 41 cm (16.1 in) guns and been capable of a top speed of 30 knots.

Design 1047, also known as Project 1047, was a series of plans for a class of Dutch battlecruisers prior to the Second World War. These large capital ships were intended to counter the threat posed by Japanese aggression towards the Dutch colonies in the East Indies.

Japanese battleship <i>Tosa</i> Planned battleship of the Imperial Japanese Navy

Tosa (土佐) was a planned battleship of the Imperial Japanese Navy. Designed by Yuzuru Hiraga, she was envisioned as the lead ship of the Tosa class of two 39,900-long-ton (40,540 t) ships. The battleships would have been armed with ten 410 mm (16.1 in) guns and brought Japan closer to its goal of an "Eight-four" fleet. All work on the ship was halted after the Washington Naval Conference and the signing of the Washington Naval Treaty. As the vessel had to be destroyed in accordance with the terms of the treaty, the incomplete Tosa was then subjected to tests to gauge the effect of Japanese weaponry before being scuttled on 9 February 1925.

<i>Bismarck</i>-class battleship Class of German World War II-era fast battleships

The Bismarck-class was a pair of fast battleships built for Nazi Germany's Kriegsmarine shortly before the outbreak of World War II. The ships were the largest and most powerful warships built for the Kriegsmarine; displacing more than 41,000 metric tons normally, they were armed with a battery of eight 38 cm (15 in) guns and were capable of a top speed of 30 knots. Bismarck was laid-down in July 1936 and completed in September 1940, while the keel of her sister ship, Tirpitz, was laid in October 1936 and work finished in February 1941. The ships were ordered in-response to the French Richelieu-class battleships, themselves laid-down in-response to the Italian Littorio-class battleships. The Bismarck-class was designed with the traditional role of engaging enemy battleships in home waters in mind, though the Oberkommando der Marine envisioned employing the ships as long-range commerce raiders against British shipping in the Atlantic Ocean. As such, their design represented the strategic confusion that dominated German naval construction in the 1930s.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Garzke and Dulin (1985), p. 86
  2. ↑ Lacroix and Wells II, p. 830
  3. ↑ Lacroix and Wells II, p. 606
  4. ↑ "Hawaii". DANFS. Archived from the original on 28 September 2008. Retrieved 14 October 2008.
  5. 1 2 Gardiner and Chesneau (1984), p. 178
  6. 1 2 Pike, John (2008). "CB-1 Alaska Class". GlobalSecurity.org. Retrieved 19 October 2008.
  7. ↑ Scarpaci, 17.
  8. ↑ Evans and Peattie, pp. 129–130
  9. ↑ Evans and Peattie, pp. 273-276.
  10. ↑ Evans and Peattie, pp. 275-277, 294; Lacroix and Wells II, pp. 250, 606.
  11. ↑ Perfect Guide to Japanese Battleships, p. 140
  12. 1 2 3 4 5 Lacroix and Wells II (1997), p. 606
  13. 1 2 Garzke and Dulin (1985), pp. 86–87
  14. ↑ Evans and Peattie, pp. 359-360.
  15. ↑ DiGuilian, Tony (26 August 2007). "Japanese 10 cm/65 (3.9") Type 98". Navweaps. Retrieved 13 March 2009.
  16. 1 2 Perfect Guide, p. 141
  17. 1 2 Garzke and Dulin (1985), p. 87
  18. ↑ Evans and Peattie, p 360.
  19. ↑ Garzke and Dulin (1985), p. 84–85
  20. ↑ Lacroix and Wells II, p. 829.
  21. ↑ Jentschura, p. 40.

Bibliography

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.