Zuikaku in November 1941.

Construction and launch

Zuikaku was laid down on the 25th of May 1938, launched on the 27th of November 1939, and formally commissioned on the 25th of September 1941. On the day of commissioning, Zuikaku departed on her maiden voyage from Kobe to Kure. Under the command of Captain Yokokawa Ichibei, Zuikaku departed for Oita Bight on October 7, arriving at her destination the next day where for the first time she joined her sister ship Shōkaku. Both ships made up Carrier Division 5.^[3]

World War II

 

Japanese aircraft carrier Shokaku 翔鶴 commencing its attack on Pearl Harbor 7th Dec 1941
Mitsubishi A6M2 "Zero" fighters (fighter division commander Tadashi Kaneko) from Shōkaku preparing for the attack on Pearl Harbor.

 

Pearl Harbor and subsequent operations

Zuikaku and the aircraft carrier Kaga preparing to attack Pearl Harbor, December 7th 1941

On 26 November 1941, she left Hitokappu Bay for the attack on Pearl Harbor as part of the Kido Butai ('Mobile Force'). Her aircraft complement consisted of 18 Mitsubishi A6M fighters, 27 Aichi D3A dive bombers, and 27 Nakajima B5N torpedo bombers. On 7 December, she launched two waves of aircraft against American military installations on the island of Oahu. In the first wave, 25 Val dive bombers attacked Wheeler Army Airfield and five Zero fighters attacked the airbase at Kaneohe. In the second wave, 27 high-level Kate bombers attacked the airbase at Hickam Field.

On the 24th of December, Zuikaku arrived back at Kure alongside Shōkaku, Kaga, and Akagi (Sōryū and Hiryū departed to attack Wake Island), and she was drydocked from the 30th to January 3. Meeting Shōkaku on the 5th, they departed Hiroshima Bay on the 8th, arriving at Truk on the 14th. In aid of the Japanese conquest against Pacific islands, on January 20 they launched 19 dive bombers and 6 fighters to attack Rabaul, then the next day struck both lae and Salamaua, and on the 23rd launched strikes to aid the successful landings on both Rabaul and Kavieng before returning to Truk on the 29th. Zuikaku finally took part in a failed attempt to sweep for allied aircraft carriers on February 1 before departing back to Japan, arriving at Yokosuka on the 13th, where her pilots took part in vigorous training exercises until the 28th.^[3]

 

Indian Ocean Raid from 31st March to 10th April 1942

The Japanese inflicted disproportionate damage on the enemy. They damaged port facilities, sank one carrier and two cruisers, destroyed a third of enemy ground-based fighters and nearly all of the enemy ground-based strike aircraft. In addition, 23 merchant ships, totalling 112,312 tons, were sunk, including those by the separate Japanese Malay Force. In return, the Japanese lost only 18 aircraft (six fighters, ten dive-bombers and two high-level bombers), with damage to about 31 more. Conversely, they failed to destroy, or even locate, the main bulk of the British Eastern Fleet.

Japanese carrier naval sortie to attack British forces in East India known as Indian Ocean raid 31st Mar to 10th Apr 1942
Japanese operation in the Northern Indian Ocean and Bay of Bengal in 1942. Nagumo's forces are shown at the bottom of the map.

 

Sinking of British aircraft carrier HMS Hermes 9th Apr 1942.

Zuikaku would play a key role in the Indian Ocean Raid throughout April, where the Kido Butai (excluding Kaga who scraped her hull on a reef) attacked various British warships and positions in a multiple day raid. On the 5th, Zuikaku's air group attacked Columbo in an event since named the Easter Sunday Raid. Her torpedo bombers sank the destroyer HMS Tenedos, while her dive bombers damaged the tanker San Cirilo. Later that night, alongside Shōkaku, her aircraft engaged and sank the heavy cruisers HMS Cornwall and HMS Dorsetshire.^[4][5][6] On the 9th, Zuikaku and Shōkaku raided Trincomalee, where they destroyed the cargo ship SS Sagaing and damaged the monitor HMS Erebus.

Sinking of British aircraft carrier HMS Hermes 9th Apr 1942

Later that night, a Japanese floatplane launched from the battleship Haruna managed to locate the light carrier HMS Hermes, and Zuikaku's air group was the first to respond, quickly followed by Shōkaku. Bombers from the pair hit Hermes almost 40 times, smashing the carrier into a burning hulk. The pair were then joined by planes from the fellow aircraft carrier Akagi, who on her own sank the destroyer HMAS Vampire. The floating wreck of Hermes rapidly sank, having only managed to shoot down six attacking planes.^[5][6] Zuikaku, alongside Shōkaku became the first carrier verses carrier battle in history; that resulted in the sinking of another enemy aircraft carrier in combat.

 

Battle of the Coral Sea from 4th to 8th May 1942

Japanese carrier Zuikaku during Battle of the Coral Sea 4-8th May 1942
Nakajima B5N2 Kate taking off from Japanese carrier Zuikaku during battle of the Coral Sea 4-8th May 1942

 

In May 1942, she was assigned along with Shōkaku to support Operation Mo, the invasion of Port Moresby, New Guinea. On the 7th, a large US naval force was located by spotters from the heavy cruisers Furutaka and Kinugasa, prompting both ships to launch their planes, fearing US carriers in the area. However, once attacked, it was discovered to only be a US convoy. Not wanting their efforts to go to waste, planes from both Zuikaku and Shōkaku combined to sink the destroyer Sims and the oil tanker Neosho.^[7][8]: 189–190 

Alerted by intercepted and decrypted Japanese naval messages, the Americans dispatched the carriers USS Yorktown and Lexington to stop the operation. On the same day as the carrier's initial attack, the US planes located the light carrier Shoho, where Lexington's aircraft crippled Shoho, before Yorktown's aircraft finished her off. Both Zuikaku and Shōkaku sent out plane squadrons to scout for the US carriers, but failed to make contact on the 7th.^[8]: 198–206 

Zuikaku launching a Val dive bomber during the battle of the Coral Sea 8th May 1942

On the 8th, a spotter plane from Lexington located both Zuikaku and Shōkaku and both carriers attacked with their air groups. Hidden by a rain squall, Zuikaku escaped detection, but Shōkaku was hit three times by bombs and was unable to launch or recover her aircraft. In return, Zuikaku's planes located the American carriers, and proceeded to wreak havoc on both ships. First, Zuikaku's torpedo bombers, commanded by Shigekazu Shimazaki caught Lexington in an anvil attack, hitting the flat top with two torpedoes, cutting her speed to 24 knots and punching through the gasoline storage tanks, leaking gas fumes throughout the ship. Her dive bombers, commanded by Tamotsu Ema then attacked and crippled Yorktown with a bomb hit that caused severe damage to her hanger bay and aviation storage rooms and over a dozen near misses. Shōkaku's dive bombers then hit Lexington with three bombs to her flight deck, starting a large fire.^[9][10][8]: 198–206 

Damage control efforts quickly persisted on Lexington, putting out the fires from Shōkaku's bomb hits. However, gas fumes from Zuikaku's torpedo hits leaked throughout the ship. When the fumes reached electric motors, a chain reaction of explosion after explosion riddled Lexington with fatal damage. Lexington began to sink, as her crew was evacuated and to make sure she hit the ocean floor and wasn't captured by Japanese forces, Lexington was scuttled by escorting destroyers.^[10]

Zuikaku was undamaged in the battle, but sustained severe losses in aircraft and aircrew. This required her to return to Japan with her sister ship for resupply and aircrew training, and neither carrier was able to take part in the Battle of Midway in June 1942, where every carrier that participated in the Pearl Harbor attack besides the two Shōkaku class ships was sunk by American carrier-based aircraft. Both ships returned to Kure, Shōkaku still operating under her own power despite immense damage. On the 21st, Zuikaku was targeted by the submarine USS Pollack, but was not damaged. She spent the rest of June and July transiting to various ports and naval facilities.^[3]

 

Battle of the Eastern Solomons took place on 24–25th August 1942

In August 1942, commanded by Captain Tameteru Notomo, Zuikaku was dispatched as part of the First Carrier Division along with the repaired Shōkaku and their escorts to oppose the American offensive in the Solomon Islands. Their goal was to sink US shipping operating in the Solomons to aid in recapturing Henderson Field, an ex-Japanese air base which was captured by American forces and being used against Japanese shipping to great effect.^[3]

On the 24th, a floatplane launched from the heavy cruiser Chikuma spotted a large American task force, consisting of the aircraft carriers USS Enterprise and USS Saratoga, and their escorts, battleship USS North Carolina, four cruisers, and eleven destroyers. Subsequently, both Zuikaku and Shōkaku launched 37 aircraft and attacked the US ships. Due to the haste of Japanese pilots, almost all attacks were focused on Enterprise to heavy results. The effectiveness of US anti aircraft, particularly of North Carolina's part, shot down many attacking aircraft, but in the end, both carriers crippled Enterprise with three bomb hits. They nearly sank her, with a squadron of seven dive bombers, three from Shōkaku and four from Zuikaku, nearly delivering the final blow when North Carolina shot down every single attacking plane.^[3][11]

Neither Zuikaku or Shōkaku were damaged during the battle, although Shōkaku barely avoided being bombed by Enterprise. However, together they lost 25 aircraft out of 37 launched, and planes from Saratoga sank the light carrier Ryūjō, while planes from Henderson Field sank the destroyer Mutsuki and the troopship Kinryu Maru. The battle is considered a US victory as Zuikaku and the other Japanese ships retreated without sinking a single American vessel.^[3][12]

Battle of Santa Cruz was fought during 25–27th October 1942

While the US still maintained air superiority through Henderson field, their carrier force was greatly diminished. After her big action, Saratoga was crippled by a torpedo fired from the submarine I-26, putting her out of action, while in September the aircraft carrier USS Wasp was sunk to three torpedo hits fired by the submarine I-19. These actions left USS Hornet as the only American fleet carrier operating in the Pacific, shortly joined by the repaired Enterprise. Taking advantage of this, Zuikaku and Shōkaku were sent out to attack the remaining US carriers in a decisive battle, now joined by the aircraft carrier Junyō and the light carrier Zuihō and their escorts. This would culminate into the Battle of the Santa Cruz Islands.

The force set out on October 11. On the 15th, a Japanese patrol plane spotted the destroyer USS Meredith towing a barge that carried fuel and bombs for US forces at Guadalcanal. Zuikaku's air group quickly responded, and in a ten minute battle hit Meredith with three torpedoes and a number of bombs, causing the destroyer to roll over and sink.^[13] The force continued on, and on the 26th was spotted by a Catalina seaplane, shortly followed by the attacks of both Hornet and Enterprise, just as the Japanese wanted. Dive bombers from Enterprise hit Zuihō with a bomb that prevented her from recovering aircraft, while dive bombers from Hornet scorched Shōkaku with at least 3-4 (and potentially up to 6) bomb hits and damaged the heavy cruiser Chikuma with two bombs.^[3]

In return, the Japanese planes wreaked havoc on American shipping. Fighters from Zuihō shot down an American torpedo bomber, which in a bamboozling series of events launched its torpedo as it crashed in a friendly fire incident that sank the destroyer USS Porter, while Junyō damaged the battleship USS South Dakota and the light cruiser USS San Juan with bomb hits.^[14] Zuikaku focused her attacks on Hornet, and hit her with three bombs. Two of her bombers that were shot down proceeded to crash into Hornet, one of which still had its bomb equipped which exploded on impact. Meanwhile, planes from Shōkaku hit Hornet with two torpedoes. The damage from both ships left Hornet dead in the water and heavily listing.^[3]

Under tow from the heavy cruiser USS Northampton, damage control efforts attempted to correct the list on the crippled, but not sunk Hornet in an attempt to save the ship. However, further air attacks persisted. A flight of nine torpedo bombers from both Shōkaku and Junyō attacked the flat top, and while Junyō's planes missed, Shōkaku hit Hornet with a third and fatal torpedo which caused the US to abandon all efforts to save Hornet.^[15]

Zuikaku hit Hornet with another bomb, and crippled Enterprise with two bomb hits. Enterprise was forced to evacuate the battle while US destroyers attempted to scuttle Hornet (though due to the quality of US torpedoes, all either missed or failed to explode). Hornet slowly sank, and was listing at a 45 degree angle when she was discovered by the destroyers Akigumo and Makigumo. They fired their torpedoes, claiming three hits. Because of this, they are sometimes credited with sinking Hornet, but she was already sinking to damage from the previous air attacks, and would have sunk regardless of any further damage, meaning it's debatable whether they deserve credit for Hornet's sinking as opposed to the carrier's loss being pinned solely on the Shōkaku twins.^[3]

Of the 110 aircraft launched by the Japanese carriers, only 67 returned to Zuikaku. She then returned to the home islands via Truk for training and aircraft ferrying duties.

In February 1943, she covered the evacuation of Japanese ground forces from Guadalcanal. In May, she was assigned to a mission to counterattack the American offensive in the Aleutian Islands, but this operation was cancelled after the Allied victory on Attu on 29 May 1943. Later in 1943, under the command of Captain Kikuchi Tomozo, she was again based at Truk and operated against U.S. forces in the Marshall Islands, but never managed to see combat throughout the rest of the year.

Zuikaku started off 1944 by entering drydock at Kure on January 8, and leaving drydock on the 17th.On February 13, Zuikaku was assigned to carrier division 1 alongside Shōkaku, and over 2 days received her air group, but her new pilots were poorly trained and inexperienced, a grand fall from the glory days of the Kido Butai. However, they were sufficient enough to score Zuikaku another kill when on the 27th of February, her torpedo bombers hunted down the submarine USS Grayback and quickly sank her with a single 250-kilogram (551 lb) bomb hit.^[16][3] After ferrying aircraft to Singapore and being drydocked, she joined Shōkaku and the new armored aircraft carrier Taihō

Battle of the Philippine Sea fought between 19–20th June 1944

Japanese aircraft carrier Zuikaku (center top) and two destroyers maneuvering during the Battle of the Philippine Sea June 1944

Japanese plan for a decisive battle

From the very start of the conflict in December 1941, the Japanese war plan had been to inflict such severe and painful losses on the US military that its public would become war weary and the American government would be convinced to sue for peace and allow Japan to keep its conquests.

Admiral Isoroku Yamamoto had grown wary of this strategy, but he was killed in Operation Vengeance on 18 April 1943. The following day, Admiral Mineichi Koga succeeded Yamamoto as commander-in-chief of the Combined Fleet, and Koga wanted the Imperial Japanese Navy to engage the American fleet in the "single decisive battle" in early 1944. On 31 March 1944 Koga was killed when his aircraft (a Kawanishi H8K) flew into a typhoon and crashed.[11] Koga's chief of staff, Vice Admiral Shigeru Fukudome, was flying in an accompanying plane and carrying the Z Plan documents, and also crashed. Fukudome survived, but the Z Plan briefcase did not sink with the destroyed aircraft and was recovered by Filipino guerillas who over the next few weeks transported the documents to General Douglas MacArthur's Military Intelligence Service (MIS) in Brisbane, Australia. MIS forwarded the translated Z Plan to Admiral Chester Nimitz in Honolulu, and the Japanese plans were quickly dispatched to the fleet commanders in the Philippine Sea in June. A new commander-in-chief of the Combined Fleet, Admiral Soemu Toyoda, was appointed, and he finalized the Japanese plans known as Plan A-Go or Operation A-Go. Operation A-go did not change much from the Z Plan, so the U.S. Navy knew exactly what was going to happen during the upcoming naval battle.[12] The plan was adopted in early June 1944. Within weeks, an opportunity arose to engage the American fleet now detected heading for Saipan.

The Japanese had some advantages they hoped would turn the battle in their favor. Though outnumbered in ships and aircraft, they planned to supplement their carrier airpower with land-based aircraft.

In June she was assigned to Operation A-Go, an attempt to repulse the Allied invasion of the Mariana Islands. On 19 June, in the Battle of the Philippine Sea, Taihō and Shōkaku were both sunk by American submarines, leaving Zuikaku, the only survivor of Carrier Division One, to recover the Division's few remaining aircraft. On 20 June, a bomb hit started a fire in the hangar, but Zuikaku's experienced damage control teams managed to get it under control, and she was able to escape under her own power. After this battle, Zuikaku was the only survivor of the six fleet carriers that had launched the attack on Pearl Harbor.

Battle off Cape Engaño fought between 25-26th October 1944

Zuikaku and destroyer Wakatsuki underway during U.S. carrier plane attacks. The carrier Zuiho is in the background.

In October 1944, she was the flagship of Admiral Jisaburo Ozawa's decoy Northern Force in Operation Shō-Gō 1, the Japanese counterattack to the Allied landings on Leyte. On 24 October, as part of the depleted (just 108 aircraft across four carriers) Third Carrier Division, she launched aircraft along with the light carriers Zuihō, Chitose, and Chiyoda in an ineffective strike against the U.S. Third Fleet. Several of these aircraft were shot down, and the majority of the surviving aircraft did not return to the carriers, instead landing at Japanese land bases on Luzon. However, some of her aircraft made kamikaze attacks and helped sink the light carrier USS Princeton; and most of the others were sent to other surviving carriers and air bases, to later sink the escort carrier USS St. Lo during the Battle off Samar after again using the new kamikaze tactics.

The next day, during the Battle off Cape Engaño, she launched her few remaining aircraft for combat air patrol, search, or to join the aircraft already on Luzon. She then came under heavy air attack and was hit by seven torpedoes and nine bombs. With Zuikaku listing heavily to port, Ozawa shifted his flag to the light cruiser Ōyodo. The order to abandon ship was issued at 13:58 and the naval ensign was lowered. Zuikaku rolled over and sank stern-first at 14:14, taking the lives of Rear Admiral (promoted from captain 10 days earlier) Kaizuka Takeo and 842 of the ship's crew; 862 officers and men were rescued by the destroyers Wakatsuki and Kuwa. Before her loss, Zuikaku was the last surviving Japanese carrier to have attacked Pearl Harbor. She was also the only Japanese fleet carrier (as opposed to a light carrier) to have been sunk by aircraft-launched torpedoes, as all others were sunk by dive bombers or submarine-launched torpedoes.^[2]

Japanese carrier Zuikaku begins to sink 25th Oct 1944
Well disciplined crew yell a defiant Banzai cry as the flag is lowered and Zuikaku begins to sink 25 Oct 1944