Mogami class
| Mogami class | |
|---|---|
|
|
| Overview | |
| Type: | Heavy cruiser |
| Units: | 4th |
| Predecessor class: | Takao class |
| Successor class: | Tone class |
| Technical data (original planning) |
|
| Displacement: | Draft: 8,500 tons. l. (Standard displacement) |
| Length: | over everything: 200.6 m |
| Width: | 18 m |
| Draft: | Draft: 5.5 m |
| Speed: | Peak: 37 kn |
| Crew: | 850 permanent crew |
| Range: | 8,000 nautical miles at 14 knots |
| Drive: | 4 screws over 4 shafts |
The Mogami class ( Japanese 上 型 重 巡洋艦 ) was a class of four cruisers of the Japanese Empire , officially designated as light cruisers under the restrictions of the 1930 Navy Treaty, planned from the start with the same specifications as heavy cruisers . The ships of the class were used in the Pacific War.
history
Design and construction
As a result of the Naval Conference in London in 1930, Japan was imposed a restriction on the construction of heavy cruisers. The only limit that distinguished a heavy cruiser from a light cruiser was the caliber of the main armament. With a caliber of over 15.5 cm one spoke of a heavy , up to 15.5 cm of a light cruiser.
Due to the ongoing massive expansion of its heavy cruiser fleet, Japan no longer had any leeway to build further ships of this type, as the total tonnage that Japan was granted for heavy cruisers in the agreement of April 1930 had already been exhausted. The construction of the actually intended ships of the "improved Takao class", a class of heavy cruisers, had to be abandoned as a result of the contracts. In order to still be able to build more heavy cruisers, they took advantage of the fact that the London agreement allowed the replacement of various light cruisers with newbuildings that, taken individually, were 10,000 tn.l. not exceeded.
planning
First, Japan changed its own classification system for cruisers from May 30, 1931 on accordingly. Until then, the ships had been classified according to their tonnage in "A-Class" over 7,000 tons for heavy and "B-Class" under 7,000 tons for light cruisers. According to the new definition, the only difference between the A and B classes was the caliber of the main guns. Up to and including 15.5 cm one spoke of "B-class" cruisers, regardless of the displacement. The order to build the first Mogami-class ships was placed at the end of 1931 - with a water displacement of 8,500 tons.
The Japanese designers were instructed to develop the ship type with five towers, each with three 15.5 cm / 60-year-3 ship guns . So the appearance of a light cruiser was initially preserved. Nonetheless, the requirements of the Navy for the designers from the beginning provided that 20-cm / 60-year-3 guns could be used as a replacement for the 15.5-cm weapons if necessary. The tasks that the Navy gave the developers of the Mogami-class for the ships in later use were identical to those of the "A-class" cruisers.
The other characteristics of the previous heavy cruisers, such as speed, armor and heavy torpedo armament, were almost completely retained. The ships were each given four sets of triple torpedo tubes, heavy armor that was supposed to withstand fire with 20 cm shells, and new turbines that were supposed to allow speeds of 37 knots.
The displacement of 8,500 tons, which was officially required and announced, could not be observed under these conditions. Although attempts were made to reduce the weight through new processing techniques such as electric welding , 9,500 tons were seen as a realistic planning basis.
displacement
The water displacement increased as a result of the modifications, so that the displacement of July 1935 was significantly lower for various cargo states than that of 1940 after the modifications of the ships:
- light: 10,379 t to 11,655 t
- Trials: 12,981 t to 14,146 t
- maximum: 13,980 t to 15,091 t
Improvements and consequences
Burden and typhoon
Similar to the previous classes , the design for the Mogami class was also pushed to the limits of what was feasible, so that it was again extremely bulky and the structural weaknesses of the hull and the new superstructures made of light metal to save weight became apparent. The last two ships in the class, Suzuya and Kumano , were modified before they were handed over to the Navy. They were given a smaller bridge structure and a two-meter wider hull to remedy these problems.
The first two ships, Mogami and Mikuma , on the other hand, had to be taken out of service one year after their completion in order to retrofit them accordingly and to repair weak points that had arisen from improper welding work. The Mogami had suffered severe damage in a typhoon on September 21, 1935, and the test firing of the main artillery had caused such tremors that damage to the hull had occurred in some places. The barbeds, which formed the support structure below the towers, were lengthened in order to partially absorb the recoil of the guns within their cylindrical structure and not let it act directly on the hull as before. The conversion from 1936 to 1938 increased the weight by a further 1,120 tons.
consequences
The data that became known about the Mogami class sparked an arms race among the light cruiser types and were responsible for the construction of the American Brooklyn class and the British Town class .
As the likelihood of war began to increase in 1939, the 6 "treble turrets on all four cruisers were eventually replaced by 8" twin towers.
Mogami class ships
Although later officially classified as heavy cruisers, the ships were given the names of rivers, while the other heavy cruisers, with the exception of the clays, were given the names of mountains.
Mogami
The Mogami was laid down in Kure in October 1931 and launched in March 1934. After an extensive stay in the shipyard, she performed her regular service from 1940 and took part in several operations during the Pacific War from December 1941 . In early 1942 she was involved in the battle of Sunda Strait and in August 1942 in the attack in the Indian Ocean . It was badly damaged by a collision in the battle of Surigao Strait on October 25, 1944 , and suffered further damage from aerial bombs on its march back, so that it had to be abandoned.
Mikuma
The Mikuma was laid down in Nagasaki in December 1931 and launched in May 1934. After a short period of service, it had to go to the shipyard for extensive repair work and was only completed shortly before the start of the Pacific War. She was involved in the Battle of Sunda Strait at the beginning of 1942 and was later one of the units that fought in the Battle of Midway in June 1942 . Damaged by a collision with the Mogami , the Mikuma was the target of American carrier aircraft and had to be abandoned on June 6th after several bomb hits and fires on board.
Suzuya
The Suzuya was laid down in Yokosuka in December 1933 and launched in November 1934. She took part in numerous operations in the Pacific War, such as in December 1941 in the hunt for Force Z and in November 1942 in the bombardment of the American airfield on Guadalcanal . During the Battle of Leyte in October 1944 she was badly damaged by aerial bombs and had to be abandoned on October 25th after the explosion of one of her torpedo tube sets.
Kumano
The Kumano was laid down in Kobe in April 1934 and launched in October 1936. She took part in numerous operations in the Pacific War and survived longer than her three sister ships. In September 1942 and July 1943 it was slightly damaged by aerial bombs in the course of the battles for the Solomon Islands . At the Battle of Leyte in October 1944, she was hit by a torpedo on the bow, damaged by aerial bombs the next day and hit by two more torpedoes a few days later. It then had to be moved to Santa Cruz on Luzon for repairs . There she was attacked by carrier aircraft on November 25, 1944 and sunk.
Evidence and references
Remarks
- ^ "B-Class" cruiser in Japanese naval terminology from May 30, 1931.
- ↑ A-class cruiser in Japanese naval terminology from May 30, 1931.
- ↑ so became after Japanese Cruisers of the Pacific War. P. 434 the construction of four ships of this class is possible and two more with 8,450 tonnes each without exceeding the total tonnage for replacement structures of 50,955 tonnes.
literature
- Eric LaCroix, Linton Wells: Japanese Cruisers of the Pacific War. US Naval Institute Press, 1997, ISBN 0-87021-311-3 .
- Mogami class. Gakken Pacific War Series, number 38, Gakken, Tokyo, 2002, ISBN 4-05-602880-X .
- Japanese cruisers. Ships of the World. Volume 441, Kizu T., Tokyo 1991.
Web links
Footnotes
- ↑ Eric LaCroix, Linton Wells: Japanese Cruisers of the Pacific War. P. 809.
- ^ A b Eric LaCroix, Linton Wells: Japanese Cruisers of the Pacific War. P. 437.
- ↑ for "Mogami" in July 1935 after Japanese Cruisers of the Pacific War. P. 451.
- ↑ for March 1940 according to Japanese Cruisers of the Pacific War. P. 451.
- ↑ David C. Evans, Mark R. Peattie: Kaigun: Strategy, Tactics and Technology in the Imperial Japanese Navy, 1887-1941. US Naval Institute Press, 2003, ISBN 0-87021-192-7 , pp. 239, 244.
- ↑ Eric LaCroix, Linton Wells: Japanese Cruisers of the Pacific War. P. 449.
- ↑ Potter, Elmar B./Chester W. Nimitz: Sea power - from antiquity to the present. Bernard & Graefe, Munich 1974, ISBN 3-7637-5112-2 , p. 461.
