View source for Mogami-class cruiser

{{Use dmy dates|date=March 2018}}
{{More footnotes needed|date=February 2008}}
{{Short description|Class of Japanese heavy cruisers}}
{|{{Infobox ship begin}}
{{Infobox ship image
| Ship image = File:Mogami1935.jpg
| Ship caption = ''Mogami''
}}
{{Infobox ship class overview
| Name = ''Mogami'' class
| Builders = *[[Kure Naval Arsenal]]
*[[Mitsubishi Heavy Industries]], [[Nagasaki]]
*[[Yokosuka Naval Arsenal]] 
*[[Kawasaki Heavy Industries|Kawasaki Dockyard]], [[Kobe]]
| Operators = {{navy|Empire of Japan}}
| Class before = {{sclass|Takao|cruiser|4}}
| Class after = {{sclass|Tone|cruiser|4}}
| Cost = 
| Subclass = 
| Built range = 1931&ndash;1937
| In service range = 
| In commission range = 1935&ndash;1944
| Total ships completed = 4
| Total ships lost = 4
}}
{{Infobox ship characteristics
| Hide header = 
| Header caption = 
| Ship type = [[Heavy cruiser]]
| Ship displacement = 8,500 tons (standard load, as reported) 10,980 tons (full load), approx. 11,000 tons (standard, actual displacement)
| Ship length = {{convert|201.6|m|ftin|abbr=on}}
| Ship beam = *{{convert|20.6|m|ftin|abbr=on}} (''Mogami'' class)
*{{convert|20.2|m|ftin|abbr=on}} (''Suzuya'' class)
| Ship draft = {{convert|5.5|m|ftin|abbr=on}}
| Ship depth = 
| Ship power = *8–10 [[Kampon]] boilers
*{{cvt|152,000|shp|kW|lk=on}}
| Ship propulsion = 4 shafts; 4 geared [[steam turbine]]s
| Ship speed = {{convert|37|kn|lk=in}}
| Ship range = {{convert|8000|nmi|lk=in|abbr=on}} at {{convert|14|kn}}
| Ship endurance = 
| Ship complement = 850
| Ship sensors = 
| Ship EW = 
| Ship armament = *(initial)
*5 × triple [[15.5 cm/60 3rd Year Type]] guns (replaced by 5 × twin [[20 cm/50 3rd Year Type naval gun#Mark II guns|20.3 cm/50 3rd Year Type 2 guns]] from 1939)
*4 × twin [[12.7 cm/40 Type 89 naval gun|{{convert|127|mm|in|abbr=on|0}}]] guns
*4 × single [[QF 2-pounder naval gun|{{convert|40|mm|in|1|abbr=on}}]] [[anti-aircraft|AA]] guns
*4 × triple {{convert|610|mm|in|abbr=on}} [[torpedo tube]]s
| Ship armor = *[[Belt armor|Belt]]: {{convert|100|mm|in|abbr=on}}
*Belt over magazine: {{convert|140|mm|in|abbr=on}}
*[[Deck (ship)|Deck]]: {{convert|35|mm|in|abbr=on}}
*[[gun turret|Turret]]s: {{convert|25|mm|in|abbr=on}}
*[[Magazine (artillery)|Magazine]]s: {{convert|127|mm|in|abbr=on}}
| Ship aircraft = 3 × [[Aichi E13A]] [[floatplane]]s
| Ship aircraft facilities = 
| Ship notes = 
}}
|}

The {{nihongo|'''''Mogami'' class'''|最上型}} was a [[ship class]] of four [[cruisers]] built for the [[Imperial Japanese Navy]] (IJN) during the 1930s. They were initially classified as [[light cruiser]]s under the weight and armament restrictions of the [[London Naval Treaty]]. After Japan abrogated that agreement, all four ships were rearmed with larger guns and reclassified as [[heavy cruiser]]s. All participated in [[World War II]] and were sunk.

==Design==
[[File:Mogami-1.jpg|left|thumb|Recognition drawing of the ''Mogami'' class, showing armament and armor arrangement]]
For the 1931 Fleet Replenishment Program, believing themselves understrength in cruisers, the IJN chose to build to the maximum allowed by the [[Washington Naval Treaty]]. This resulted in the choice of {{convert|155|mm|1|abbr=on}} guns in five triple [[gun turret|turret]]s (a first for Japan) in the ''Mogami''s, also capable of 55° elevation, making the ''Mogami''s one of the very few classes of cruiser to have a [[dual purpose gun|dual purpose]] (DP) [[main battery]]; this was coupled with very heavy [[anti-aircraft warfare|anti-aircraft]] protection, as well as the standard reloadable, turreted [[torpedo]] launchers, also unique to the IJN.<ref>Lacroix, pp. 434–435</ref>

To save weight and improve transverse stability, the class was given a more compact and lower [[superstructure]], made of [[aluminium]], which was [[welded]] rather than riveted.<ref>Lacroix, pp. 438–439</ref> Only ten [[boiler]]s could be fit under the weight limits (compared to twelve in the previous {{sclass|Takao|cruiser|5}} and {{sclass|Myōkō|cruiser|5}} classes), and the chimney arrangement was designed to minimize weight as well; the middle funnel featured no [[chimney]] of its own, instead venting its exhaust gasses into the underside of the forward chimney, which itself was reclined from its base so that, at its top, it merged with the aft funnel's chimney. The new [[Steam turbine#Marine propulsion|geared]] [[impulse turbine]]s added {{convert|22,000|shp|kW|lk=in}} over ''Atago'', increasing the top speed by {{convert|1.5|kn|lk=in}}. Protection, however, was not stinted on; the class proved able to take substantial punishment.

The declared weight was 8,500 tons, though the true design weight was 9,500 and at trials they would displace 11,169 tons.<ref>Brown, p. 74</ref>  “They must be building their ships out of cardboard or lying” said the Royal Navy’s Director of Naval Construction (DNC) in 1935 when briefed by Naval Intelligence about the public displacement figure announced by the Japanese.<ref>[https://naval-encyclopedia.com/ww2/japan/mogami-class-cruisers.php Naval Encyclopedia. "Mogami class cruisers (1934)" retrieved November 2, 2023.]</ref>

The designers, however, had overreached; excessive topweight led to instability, and gunnery trials revealed cracking hull welds. Hull bulges were retrofitted to ''Mogami'' and ''Mikuma'', and added to ''Kumano'' and ''Suzuya'', increasing [[beam (nautical)|beam]] to {{convert|20.5|m|ft|abbr=on}} and [[Tonnage#Weight-based systems|displacement]] to 11,200&nbsp;tons, cutting speed by {{convert|2|kn}}.<ref>Lacroix, pp. 439–442</ref>

Following Japan's withdrawal from the [[Second London Naval Treaty]], plans were made to modernize and expand the entire fleet. Beginning in 1939, the class was brought in for substantial reconstruction, replacing the triple 155&nbsp;mm turrets with twin [[20 cm/50 3rd Year Type naval gun#Mark II guns|203&nbsp;mm (8-inch) guns]], turning over the 155&nbsp;mm turrets for the [[battleship]]s of the {{sclass|Yamato|battleship|4}}.<ref>Lacroix, pp. 442–443</ref> Indeed, the designers had designed the class in mind so that the 6-inch guns could be switched with 8-inch batteries, in effect making them heavy cruisers and skirting the [[London Naval Treaty#Circumventing the Treaty|London Naval Treaty]], though the Japanese had withdrawn from the conference and were not signatories to the [[Second London Naval Treaty]] of 1936.

Torpedo bulges were also added; in all, displacement rose to over 13,000&nbsp;tons, and speed dropped to {{convert|35|kn}}.

==War service==
[[File:Japanese Cruisers of the Seventh Squadron.jpg|thumb|''Kumano'' (foreground), ''Mikuma'' (center) and ''Suzuya'' in [[Ise Bay]], 1938.]]
All four ships participated in the Japanese invasion of the [[Dutch East Indies]]. ''Mogami'' and ''Mikuma'' were present at the [[Battle of Sunda Strait]] and contributed to the sinkings of the cruisers {{HMAS|Perth|1934|6}} and {{USS|Houston|CA-30|6}}.

In June 1942, all four took part in the [[Battle of Midway]], where ''Mogami'' and ''Mikuma'' collided trying to avoid a [[submarine]] attack; ''Mikuma'' was finished off on 6 June 1942 by aircraft from [[aircraft carrier]]s {{USS|Enterprise|CV-6|6}} and {{USS|Hornet|CV-8|2}}. The heavily damaged ''Mogami'' limped home and spent ten months in yard, during which her afterparts were completely rebuilt, and "X" and "Y" turrets were replaced by a flight deck (with the intention to operate 11 aircraft).

In October 1944, the survivors were reunited at the [[Battle of Leyte Gulf]]. ''Mogami'', heavily damaged by a collision with the cruiser {{ship|Japanese cruiser|Nachi||2}}, cruiser gunfire, and aerial attack, was [[Scuttling|scuttle]]d by the destroyer {{ship|Japanese destroyer|Akebono|1930|2}}, while ''Kumano'' limped into [[Manila]] harbor on one boiler, to be sunk by [[William F. Halsey|Halsey]]'s aviators on 25 November 1944; the US [[escort carrier]] planes mauled ''Suzuya'' at Leyte, which was scuttled by the destroyer {{ship|Japanese destroyer|Okinami||2}} on 25 October.

==Ships==
{|class="wikitable plainrowheaders"
|+ Construction data
|-
! scope="col" | Name
! scope="col" | Kanji
! scope="col" | Subclass
! scope="col" | Builder 
! scope="col" | [[Laid down]]
! scope="col" | [[Ceremonial ship launching|Launched]] 
! scope="col" | Completed 
! scope="col" | Fate
|-
! scope="row" | {{ship|Japanese cruiser|Mogami|1934|2}}
| {{lang|ja|最上}}
| rowspan=2 | ''Mogami''
| [[Kure Naval Arsenal]]
| style="text-align: right;" | 27 Oct 1931
| style="text-align: right;" | 14 Mar 1934
| style="text-align: right;" | 28 Jul 1935
| [[Scuttled]] after massive battle damage during the [[Battle of Leyte Gulf#The Battle of Surigao Strait (25 October)|Battle of Surigao Strait]], 25 Oct 1944
|-
! scope="row" | {{ship|Japanese cruiser|Mikuma||2}}
| {{lang|ja|三隈}}
| [[Mitsubishi Heavy Industries]], Nagasaki Yard
| style="text-align: right;" | 24 Dec 1931
| style="text-align: right;" | 31 May 1934
| style="text-align: right;" | 29 Aug 1935
| Sunk during the [[Battle of Midway]], 6 Jun 1942
|-
! scope="row" | {{ship|Japanese cruiser|Suzuya|1934|2}}
| {{lang|ja|鈴谷}}
| rowspan=2 | ''Suzuya''
| [[Yokosuka Naval Arsenal]]
| style="text-align: right;" | 11 Dec 1933
| style="text-align: right;" | 20 Nov 1934
| style="text-align: right;" | 31 Oct 1937
| Sunk during the [[Battle off Samar]], 25 Oct 1944
|-
! scope="row" | {{ship|Japanese cruiser|Kumano||2}}
| {{lang|ja|熊野}}
| [[Kawasaki Heavy Industries|Kawasaki Dockyard Company]], Kobe Yard
| style="text-align: right;" | 5 Apr 1934
| style="text-align: right;" | 15 Oct 1936
| style="text-align: right;" | 31 Oct 1937
| Sunk by American aircraft during the [[USS Ticonderoga (CV-14) and damaged by the USS Johnston (DD-557)#Philippine campaign|Philippine campaign]], 25 Nov 1944
|}

==References==
{{Reflist|30em}}

==Bibliography==
*{{cite book
 | last = Blair
 | first = Clay
 | year = 1975
 | title = Silent Victory 
 | url = https://archive.org/details/silentvictoryuss00blai
 | url-access = registration
 | publisher = Lippincott
 | location = London
}}
*{{cite book
 | last = Dull
 | first = Paul S.
 | year = 1978
 | title = A Battle History of the Imperial Japanese Navy, 1941-1945
 | publisher = Naval Institute Press
 | location = Annapolis, Maryland
 | isbn = 0-87021-097-1
 | url-access = registration
 | url = https://archive.org/details/battlehistoryofi0000dull
 }}
*{{cite book|last= Jentschura|first= Hansgeorg|first2= Dieter |last2=Jung|first3=Peter |last3=Mickel| year= 1977|title= Warships of the Imperial Japanese Navy, 1869–1945|publisher= United States Naval Institute| location= Annapolis, Maryland|isbn = 0-87021-893-X|name-list-style=amp}}
*{{cite book
 | last1 = Lacroix
 | first1 = Eric
 | first2 = Linton
 | last2= Wells II
 | year = 1997
 | title = Japanese Cruisers of the Pacific War
 | publisher = Naval Institute Press
 | location = Annapolis
 | isbn = 0-87021-311-3
 | oclc= 21079856
 }}
*{{cite book
 | last = Preston
 | first = Antony
 | year = 2004
 | title = World's Worst Warships
 | publisher = Conway's Maritime Press
 | location = London
}}
* {{cite book|last=Rohwer|first=Jürgen|title=Chronology of the War at Sea 1939–1945: The Naval History of World War Two|publisher=Naval Institute Press|location=Annapolis, Maryland|year=2005|edition=Third Revised|isbn=1-59114-119-2 |author-link=Jürgen Rohwer}}
* {{cite book|title=Conway's All the World's Fighting Ships 1922–1946|editor1-last=Chesneau|editor1-first=Roger|publisher=Conway Maritime Press|location=Greenwich, UK|year=1980 |isbn=0-85177-146-7 |chapter=Japan |author-first=Ian|author-last=Sturton}}
* {{cite book|last=Whitley|first=M. J.|title=Cruisers of World War Two: An International Encyclopedia |publisher=Cassell |location=London|year=1995|isbn=1-86019-874-0|author-link=Michael J. Whitley}}

==External links==
{{Commons category|Mogami class cruiser}}
*{{cite web
 | last = Hackett
 | first = Bob
 |author2=Sander Kingsepp
 | year = 2006
 | url = http://www.combinedfleet.com/mogami_c.htm
 | title = Mogami class
 | work = Imperial Japanese Navy Page (Combinedfleet.com)
 | access-date = 2006-06-14
}}

{{Mogami class cruiser}}
{{WWII Japanese ships}}{{Treaty Cruisers}}
[[Category:Cruiser classes]]
[[Category:Mogami-class cruisers| ]]
[[Category:Cruisers of the Imperial Japanese Navy]]
[[Category:Ships built in Japan]]