Kaga (carrier)

Kaga (carrier)
Ship name	Kaga
Caption	IJN Kaga underway, 1930s
Ship class	Aircraft carrier (converted)
Builder	Kure Naval Arsenal
Laid down	1920 (as battleship Tosa)
Launched	1921
Commissioned	1928
Fate	Sunk 1942 during Battle of Midway
Displacement	27,300 long tons (standard)
Length	248 m
Beam	27.3 m
Propulsion	Steam turbines
Speed	28 kn
Complement	~1,320
Aircraft	~60 (varied)

Kaga (carrier) Kaga was an Imperial Japanese Navy Imperial Japanese Navy aircraft carrier converted from a Tosa-class battleship hull and commissioned in 1928. She served alongside contemporaries such as Akagi, Soryu, and Hosho in carrier divisions that formed the core of Japan's Combined Fleet aviation striking power during the 1930s and early Pacific War. Kaga participated in major operations from the Second Sino-Japanese War through the opening campaigns of World War II and was lost at the Battle of Midway.

Design and construction

Kaga began as one of the incomplete Tosa-class battleship hulls laid down at Kure Naval Arsenal under the Eight-eight fleet program and the constraints of the Washington Naval Treaty. Following treaty limitations and lessons from Washington Naval Treaty conferences, Japanese planners directed conversion into an aircraft carrier to augment the Imperial Japanese Navy's First Air Fleet carrier strength. Design influences included captured observations of British carriers such as HMS Furious and German shipbuilding practice at Kure Naval Dockyard, while naval architects incorporated features developed for Akagi and the experimental carrier Hōshō.

Original conversion work at Kure Naval Arsenal involved removing battleship armor and installing hangars, flight decks, and islandless profile similar to Akagi for centerline superstructure experiments. Naval engineers from the Imperial Japanese Naval Technical Department redesigned machinery rooms and installed powerplants derived from Yamato-class battleship practices. Armament revisions and aviation handling systems reflected influences from naval aviation thinkers such as Admiral Isoroku Yamamoto, Admiral Heihachiro Togo's strategic legacy, and doctrinal shifts after exercises like Combined Fleet maneuvers of the 1920s and 1930s.

Specifications

Kaga displaced approximately 27,300 long tons standard and up to 39,400 long tons full load, with an overall length near 248 metres and a beam of about 27.3 metres. Her propulsion comprised geared steam turbines powered by oil-fired boilers enabling speeds near 28 knots, comparable to contemporaries Soryu and Shokaku class. Armor protection retained elements from the original Tosa-class battleship layout including belt and deck armor revisions, while anti-aircraft batteries evolved with additions of Type 96 25 mm AA gun mounts and later upgrades influenced by combat experience in Second Sino-Japanese War operations.

Kaga's aviation capacity typically ranged around sixty aircraft in multiple hangar decks serviced by hydraulic lifts and fuel handling systems adapted from Japanese naval aviation development programs. Embarked air groups included types such as the Mitsubishi A5M, Mitsubishi A6M Zero, Nakajima B5N "Kate", and Aichi D3A "Val" as doctrine and refit schedules advanced. Fire control and communications equipment integrated systems used across the Combined Fleet including radio gear from Nippon Telegraph and Telephone-era suppliers and fire-direction systems paralleling those on Kongo-class battlecruiser upgrades.

Service history

After commissioning in 1928, Kaga joined Kaga Carrier Division elements of the First Air Fleet, conducting peacetime fleet exercises, long-range aviation training, and goodwill visits such as port calls to Shanghai and Kobe. During the 1930s she participated in carrier doctrine experiments with units including Akagi, Soryu, Hosho, and the Combined Fleet under commanders like Admiral Isoroku Yamamoto and Admiral Osami Nagano. Kaga's air groups took part in operations supporting Second Sino-Japanese War land campaigns and maritime interdiction around Shanghai, Hangzhou Bay, and the China coast.

Refits in the late 1930s and early 1940s altered flight deck arrangements and anti-aircraft armament in response to developments observed during Spanish Civil War and regional naval engagements. During the Attack on Pearl Harbor planning, Kaga formed part of the Kido Butai carrier strike force and trained with carrier air wings including Tadashi Sugimoto-led squadrons and unit commanders such as Lieutenant Commander Chuichi Nagumo's staff in preparation for Pacific offensive operations. Kaga departed with the strike force to project air power across the Central Pacific and South Pacific theaters.

World War II engagements

Kaga participated in the Attack on Pearl Harbor strike package in December 1941, contributing aircraft to attacks that impacted USS Arizona (BB-39), USS West Virginia (BB-48), and Ford Island facilities. Following Pearl Harbor she took part in operations across the Philippine Campaign, Dutch East Indies campaign, and the Indian Ocean Raid alongside carriers such as Akagi and Soryu. Kaga's air groups executed strikes against Cavite Navy Yard, Corregidor, Java Sea targets, and Ceylon facilities during coordinated carrier raids planned by Combined Fleet staff.

In early 1942 Kaga's embarked aircraft composition evolved to include more Mitsubishi A6M Zero fighters and newer models of Nakajima B5N torpedo bombers to increase strike effectiveness. Kaga provided air cover and offensive sorties during the Battle of the Coral Sea planning phases and was part of the carrier concentration that later engaged US forces in the Battle of Midway in June 1942, where opposing carriers such as USS Yorktown (CV-5), USS Enterprise (CV-6), and USS Hornet (CV-8) contested Japanese control of the Central Pacific.

Loss and aftermath

During the Battle of Midway on 4–6 June 1942, Kaga was attacked by dive bombers and torpedo bombers launched from USS Enterprise (CV-6), USS Yorktown (CV-5), and USS Hornet (CV-8) task forces directed by Admirals Frank J. Fletcher and William Halsey Jr. Support from Task Force 16 and Task Force 17 elements culminated in concentrated dive-bomber attacks that struck Kaga's flight deck and hangars, igniting fueled aircraft and ordnance aboard. Fires and secondary explosions rendered firefighting efforts ineffective; Kaga capsized and sank, joining sister carrier losses that included Akagi, Soryu and widely altering carrier balance in the Pacific Theater.

Kaga's sinking marked a pivotal shift in naval aviation and affected strategic planning within the Imperial Japanese Navy and Allied commands including Admiral Chester W. Nimitz's staff. Wreckage later located on the seafloor near Midway Atoll became of interest to oceanographers, historians, and salvage researchers including teams affiliated with institutions such as the Scripps Institution of Oceanography and maritime archaeology groups. The loss influenced subsequent carrier design priorities observed in later Japanese projects and highlighted vulnerabilities in armored flight deck philosophy that informed carrier developments across navies including lessons referenced in postwar analyses by entities like the United States Navy and naval historians documenting the Pacific War.

Category:Aircraft carriers of the Imperial Japanese Navy