Zuikaku

Zuikaku was a Japanese fleet aircraft carrier of the Second World War, the sister of Shokaku and the last surviving carrier of the Kido Butai, the strike force that opened the Pacific War. Commissioned in September 1941, she took part in the attack on Pearl Harbor, the Battle of the Coral Sea, the Battle of the Eastern Solomons, and the Battle of the Santa Cruz Islands, and she survived when her sisters were sunk. By 1944, she was the only carrier left from the force that had attacked Pearl Harbor, and her air group, like the rest of Japanese naval aviation, had been destroyed and rebuilt with inexperienced pilots. In October 1944, Zuikaku sailed as the flagship of Admiral Jisaburo Ozawa’s decoy force at Leyte Gulf, with almost no aircraft aboard, to draw the American carriers away from the invasion beaches. On 25 October 1944, at the Battle off Cape Engano, American carrier aircraft sank her, with the loss of about 850 of her crew. Zuikaku’s sinking marked the end of the Kido Butai, and of Japan as a carrier power.

1. Key Facts

Class/Type	Shokaku-class fleet aircraft carrier
Launched	27 November 1939
Commissioned	25 September 1941
Displacement	About 25,675 tons standard; about 32,105 tons full load
Length	257.5 metres
Speed	About 34.2 knots
Complement	About 1,660 officers and men, plus aircrew
Armament	16 x 127 mm dual-purpose guns; 36 x 25 mm anti-aircraft guns
Aircraft	About 72 operational aircraft, with spares
Fate	Sunk by air attack at the Battle off Cape Engano, 25 October 1944

2. Development

The Shokaku Class

Zuikaku was built as part of the Shokaku class, the first Japanese carriers designed without treaty limits, after Japan withdrew from the Washington Naval Treaty in 1936. The class was designed to be the best carrier in the world: fast, with a large air group, with good protection, and with the range to operate across the Pacific. The design drew on the experience of the earlier carriers Akagi, Kaga, Soryu, and Hiryu, and it corrected their weaknesses: the Shokaku class had a larger hull, more fuel, better protection, and a larger air group. Zuikaku was laid down at Kawasaki’s Kobe yard in May 1938, launched on 27 November 1939, and commissioned on 25 September 1941, two months before Pearl Harbor. Her sister Shokaku was commissioned in August 1941, and the two ships formed the Fifth Carrier Division, which became the core of the Kido Butai.

Construction and Commissioning

Zuikaku’s construction was rapid by Japanese standards, taking about three years from laying down to commissioning, and she was completed just in time for the war. Her working-up period was short, and her air group, which had been training for months, was embarked in October 1941. The ship was assigned to the First Air Fleet, under Vice Admiral Chuichi Nagumo, and she sailed with the Kido Butai in November 1941 for the strike on Pearl Harbor. Zuikaku’s name means “Auspicious Crane”, and her sister’s name, Shokaku, means “Soaring Crane”, and the two ships were known as the Crane sisters. The names were fitting: the cranes were fast, graceful, and powerful, and they would fly further and fight longer than any other Japanese carriers, although both would be lost before the war ended.

3. Design

A Large, Fast Carrier

Zuikaku was 257.5 metres long, 26 metres wide, and about 25,675 tons standard displacement, rising to about 32,105 tons at full load. Her eight boilers fed four turbine sets, producing about 160,000 shaft horsepower, which gave her a speed of about 34.2 knots, faster than most battleships and fast enough to keep up with the Kido Butai. Her range was about 9,700 nautical miles at 18 knots, enough to cross the Pacific and return, although in practice the Kido Butai depended on oilers for sustained operations. Her flight deck was about 242 metres long, with three lifts, and her hangars were divided into upper and lower decks, with a capacity for about 72 operational aircraft, with spares bringing the total to about 84. Her island was on the starboard side, and her funnel was angled outboard, to keep smoke clear of the flight deck.

Protection and Seakeeping

Zuikaku’s protection was better than that of the earlier Japanese carriers, but it was still light by American and British standards. Her belt was about 46 millimetres thick over the machinery and magazines, and her deck was about 25 millimetres over vital spaces, with no armour on the flight deck. The navy accepted this because it wanted speed and aircraft capacity, and because it expected the carrier’s aircraft to keep enemy ships and aircraft at a distance. In heavy seas Zuikaku was a good sea boat, although her high speed made her wet forward, and her narrow hull rolled in a swell. Her steering and stability were adequate for fleet operations, and she could turn inside most battleships. The weakness was not in her handling but in her damage control: her fire mains, ventilation, and hangar arrangements made it hard to fight a large fire, and her crew had less training in damage control than their American counterparts, a weakness that would prove fatal at Leyte Gulf.

4. Technical Specifications

Hull and Machinery

Zuikaku measured 257.5 metres in length, 26 metres in beam, and about 8.8 metres in draught at full load. Her standard displacement was about 25,675 tons, and her full-load displacement was about 32,105 tons, making her one of the largest Japanese carriers of the war. Her eight boilers fed four turbine sets driving four shafts, and her designed speed was about 34.2 knots. Her complement was about 1,660 officers and men, with the air group adding several hundred more, so that about 2,000 men were aboard when she sailed for Leyte Gulf. Her armour included a belt of about 46 millimetres and a deck of about 25 millimetres over vital spaces, and her fuel capacity was about 5,000 tons of oil. The figures vary between sources because Japanese displacement and armour data were recorded under different conditions, and because the ship was modified during the war.

Air Group Capacity

Zuikaku’s air group in December 1941 consisted of 18 Zero fighters, 27 D3A dive bombers, and 27 B5N torpedo bombers, for a total of 72 operational aircraft, with spares. The air group was the largest of any Japanese carrier at the time, and it was flown by some of the most experienced pilots in the Japanese navy. The Zero was the finest carrier fighter in the Pacific in 1941, and the D3A and B5N were proven strike aircraft. The air group’s weakness, which became clear as the war went on, was the loss of trained pilots: Japan had no system for replacing experienced aircrew at the rate the war demanded, and the men who flew from Zuikaku at Pearl Harbor were, in many cases, irreplaceable. By 1944, Zuikaku’s air group was a shadow of its former self, with inexperienced pilots and fewer aircraft, and at Leyte Gulf she carried only about 65 aircraft, many of them flown by pilots who had never flown from a carrier in combat.

5. Armament and Aircraft

Guns and Anti-Aircraft Defence

Zuikaku carried 16 127 mm dual-purpose guns in eight twin mounts, four on each side of the flight deck, which could engage both surface targets and aircraft. For close-range air defence she carried 36 25 mm anti-aircraft guns in triple and single mounts, a weapon that proved disappointing in service because of its short range and low rate of fire. The Japanese navy relied on the fighter screen to protect its carriers, and Zuikaku’s own guns were a last line of defence. By 1944, the ship’s anti-aircraft armament had been increased, with more 25 mm guns and with rocket launchers, but it was still weaker than the armament of contemporary American carriers, which carried large numbers of 40 mm Bofors guns and 20 mm Oerlikons with radar fire control. At Leyte Gulf, Zuikaku’s guns could not stop the American dive bombers and torpedo bombers that sank her, because the American attack was too large and too well coordinated.

The Air Group

Zuikaku’s air group was the heart of the ship, and it was the finest in the Japanese navy in 1941. The group consisted of 72 aircraft, with the Zero, the D3A, and the B5N, and it was flown by pilots who had trained for years. The air group could launch a strike of about 50 aircraft, enough to cripple a battleship force or a small carrier group, and it did so at Pearl Harbor, at the Coral Sea, and at Santa Cruz. The air group’s losses were heavy: at the Coral Sea, Zuikaku’s air group was so depleted that the ship could not take part in the Battle of Midway, a fact that may have changed the outcome of that battle. At Santa Cruz, the air group was again depleted, and the ship was damaged. By 1944, the air group had been rebuilt with new pilots, but the pilots were inexperienced, and the aircraft were fewer, and the group could not match the American air groups it faced at Leyte Gulf.

6. Service History

Pearl Harbor and the Coral Sea

Zuikaku sailed with the Kido Butai in November 1941 for the strike on Pearl Harbor. Her aircraft took part in both waves of the attack on 7 December, her torpedo bombers striking battleships and her dive bombers hitting airfields. In the months that followed, Zuikaku supported the invasions of the Dutch East Indies and took part in the raid on Darwin, Australia, in February 1942. In May 1942, she took part in the Battle of the Coral Sea, the first carrier battle in history, in which her aircraft sank the American carrier Lexington and damaged Yorktown, but at the cost of heavy losses to her own air group. The losses were so heavy that Zuikaku could not take part in the Battle of Midway a month later, and her absence may have contributed to the Japanese defeat at Midway, where four carriers were lost. Zuikaku’s survival at the Coral Sea, and her absence from Midway, were the two facts that defined her early career.

Santa Cruz and the Solomons

In August 1942, Zuikaku took part in the Battle of the Eastern Solomons, and in October 1942, she took part in the Battle of the Santa Cruz Islands, the last carrier battle of 1942. At Santa Cruz, her aircraft sank the American carrier Hornet and damaged Enterprise, but at the cost of heavy losses to her air group, and the ship herself was damaged by American dive bombers. After Santa Cruz, Zuikaku returned to Japan for repairs and for a new air group, and she spent much of 1943 in home waters, training new pilots and waiting for the next battle. In June 1944, she took part in the Battle of the Philippine Sea, where her air group was largely destroyed in the Great Marianas Turkey Shoot, and the ship herself was damaged by a bomb. After the Philippine Sea, Zuikaku was the only surviving carrier of the Kido Butai, and she was the flagship of the decoy force that sailed to Leyte Gulf in October 1944.

7. Notable Actions

The Battle of the Coral Sea

The Battle of the Coral Sea, fought on 7-8 May 1942, was the first battle in history in which the opposing ships never saw each other, and in which all the fighting was done by aircraft. Zuikaku’s aircraft, together with those of Shokaku, sank the American carrier Lexington and damaged Yorktown, but the Japanese lost the light carrier Shoho and suffered heavy losses to their air groups. The battle was a tactical victory for Japan, but a strategic defeat, because it stopped the Japanese invasion of Port Moresby, and because it cost Japan the air groups it needed for Midway. Zuikaku’s air group lost so many pilots that the ship could not sail for Midway, and the Japanese went into that battle with four carriers instead of five. The Coral Sea showed that carrier battles were battles of attrition, in which the side that lost its pilots lost the war, even if it sank more ships.

The Battle of Santa Cruz

The Battle of the Santa Cruz Islands, fought on 26 October 1942, was the last carrier battle of 1942, and it was the last Japanese carrier victory of the war. Zuikaku’s aircraft, together with those of Shokaku and the light carrier Zuiho, sank the American carrier Hornet and damaged Enterprise, but at the cost of heavy losses to the Japanese air groups, and the ship herself was damaged by American dive bombers. The battle was a Pyrrhic victory: Japan sank an American carrier, but it lost the pilots it needed to replace its losses, and the American navy, which could build new carriers and train new pilots, recovered quickly. After Santa Cruz, Zuikaku was the only Japanese fleet carrier that was still operational, and she spent the next year in home waters, training new pilots and waiting for the next battle. The battle marked the end of the period in which Japanese carrier aviation was superior to American carrier aviation.

8. Fate

Sunk at Leyte Gulf

On 25 October 1944, at the Battle off Cape Engano, Zuikaku was sunk by American carrier aircraft. She had sailed as the flagship of Admiral Ozawa’s Northern Force, a decoy force of four carriers with only about 100 aircraft between them, whose task was to draw the American carriers away from the invasion beaches at Leyte. The decoy worked: Admiral William Halsey took his carriers north to attack Ozawa, leaving the invasion beaches unprotected, but the American aircraft that found Zuikaku were too many and too well coordinated for her to survive. She was hit by seven torpedoes and nine bombs, according to American reports, and she sank at about 14:14, with the loss of about 850 of her crew, including Rear Admiral Kaoru Arima, the commander of the carrier division, who remained aboard and went down with the ship. The destroyers Wakatsuki and Kuwa rescued about 1,000 survivors.

Aftermath for the Japanese Navy

The loss of Zuikaku and her three sister carriers at Leyte Gulf, Chitose, Chiyoda, and Zuiho, destroyed the last of Japanese naval aviation. Japan still had carriers under construction, but it had no pilots to fly from them, and the navy never again mounted a major carrier operation. The Japanese navy continued to fight, with battleships, cruisers, and kamikaze aircraft, but it had lost the carrier force that had opened the war. Zuikaku’s wreck has never been located with certainty, although surveys in the Leyte Gulf area have identified wrecks of other ships from the battle. Her name was not reused for a later Japanese carrier, and her loss remains one of the four carrier sinkings that mark the end of the Kido Butai, the force that had attacked Pearl Harbor less than three years earlier.

9. Legacy

The Last Carrier of the Kido Butai

Zuikaku is remembered as the last surviving carrier of the Kido Butai, the force that opened the Pacific War and was destroyed in less than three years. Her career, from Pearl Harbor to Leyte Gulf, spans the whole of the Pacific War, and she is the only Japanese carrier that fought in every major carrier battle of the war, except for Midway, which she missed because of her losses at the Coral Sea. Her survival, when her sisters were sunk, was due to a combination of luck and timing: she was absent from Midway, damaged at Santa Cruz, and in home waters during the Philippine Sea, and she survived to be the decoy at Leyte Gulf. Her loss marked the end of the Kido Butai, and of Japan as a carrier power, and it is often used to illustrate the speed with which naval power could be destroyed in the age of the aircraft carrier.

Memory and the Crane Sisters

Zuikaku and her sister Shokaku, the Crane sisters, are remembered in Japan as the finest carriers the navy ever built, and as the ships that carried the best air group in the world in 1941. The sisters are remembered in histories of Pearl Harbor, the Coral Sea, and Santa Cruz, and their loss, Shokaku at the Philippine Sea and Zuikaku at Leyte Gulf, is often contrasted with the long careers of American carriers such as Enterprise. For historians, Zuikaku stands as an example of a ship that was superbly effective as an offensive weapon and fatally vulnerable once its air group was destroyed, a balance that defined carrier warfare for the rest of the Second World War. Her name, “Auspicious Crane”, is fitting for a ship that flew further and fought longer than any other Japanese carrier, and that died as a decoy, drawing the enemy away from the invasion beaches.

10. Frequently Asked Questions

What was Zuikaku?

Zuikaku was a Japanese fleet aircraft carrier commissioned in September 1941, the sister of Shokaku and the last surviving carrier of the Kido Butai. She took part in the attack on Pearl Harbor, the Battle of the Coral Sea, the Battle of the Eastern Solomons and the Battle of the Santa Cruz Islands. She survived when her sisters were sunk, and by 1944 she was the only carrier left from the force that had attacked Pearl Harbor. She was sunk at Leyte Gulf on 25 October 1944, and her sinking marked the end of the Kido Butai, and of Japan as a carrier power.

How was Zuikaku sunk?

Zuikaku was sunk by American carrier aircraft at the Battle off Cape Engano, on 25 October 1944, during the Battle of Leyte Gulf. She was hit by seven torpedoes and nine bombs, according to American reports, and she sank with the loss of about 850 of her crew. She had sailed as the flagship of Admiral Jisaburo Ozawa’s decoy force at Leyte Gulf, with almost no aircraft aboard, to draw the American carriers away from the invasion beaches. Her air group, like the rest of Japanese naval aviation, had been destroyed and rebuilt with inexperienced pilots, and she could not fight as a carrier.

Why was Zuikaku absent from Midway?

Zuikaku was absent from Midway because her air group had been so depleted at the Battle of the Coral Sea in May 1942 that she could not sail. She had fought at Pearl Harbor and the Coral Sea, and the losses at the Coral Sea left her without the aircraft and pilots she needed. Her absence left the Japanese carrier force weaker at Midway, a battle that decided the fate of the carriers she had sailed with. Zuikaku survived the war’s great carrier battles, from Pearl Harbor to Santa Cruz, and by 1944 she was the only carrier left from the force that had attacked Pearl Harbor.

How many aircraft did Zuikaku carry?

Zuikaku carried about 72 operational aircraft, with spares bringing the total to about 84. Her usual air group in 1941 was 18 Zero fighters, 27 D3A dive bombers and 27 B5N torpedo bombers, a balanced force for fighting, striking and scouting. She was a large, fast carrier, about 257.5 metres long, with a speed of about 34.2 knots and a displacement of about 25,675 tons standard. By 1944 her air group had been destroyed and rebuilt with inexperienced pilots, and at Leyte Gulf she sailed with almost no aircraft aboard.

What was the Kido Butai?

The Kido Butai was the Imperial Japanese Navy’s carrier strike force, which attacked Pearl Harbor on 7 December 1941. It consisted of six carriers: Akagi, Kaga, Soryu, Hiryu, Shokaku and Zuikaku, the force that opened the Pacific War. Zuikaku was the last surviving carrier of the Kido Butai, and she survived when her sisters were sunk, until she was sunk at Leyte Gulf on 25 October 1944. Her sinking marked the end of the Kido Butai, and of Japan as a carrier power, because the force that had opened the war was gone.

What happened to Zuikaku’s sister Shokaku?

Shokaku, Zuikaku’s sister, was sunk at the Battle of the Philippine Sea on 19 June 1944, by the submarine USS Cavalla. Zuikaku was the only carrier of the Kido Butai left after that battle, and by 1944 she was the only carrier left from the force that had attacked Pearl Harbor. The two sisters were Shokaku-class fleet carriers, large and fast, and Zuikaku had been commissioned in September 1941, shortly before the war began. Zuikaku herself was sunk four months later, on 25 October 1944, at the Battle off Cape Engano, with the loss of about 850 of her crew.

11. Sources

1. Wikipedia, “Japanese aircraft carrier Zuikaku” — construction, specifications, Pearl Harbor, Coral Sea, Santa Cruz, and Leyte Gulf.
2. Mark Stille, “Imperial Japanese Navy Aircraft Carriers 1921-45” (Osprey, 2005) — design, air group, and service.
3. Jonathan Parshall and Anthony Tully, “Shattered Sword” (Potomac Books, 2005) — carrier design and the Kido Butai.
4. Hansgeorg Jentschura, Dieter Jung, and Peter Mickel, “Warships of the Imperial Japanese Navy, 1869-1945” (Naval Institute Press, 1977) — specifications.
5. Combinedfleet.com, “Zuikaku” tabular record of movement — service history and movements.
6. Samuel Eliot Morison, “History of United States Naval Operations in World War II, Vol. XII: Leyte” (Little, Brown, 1958) — Leyte Gulf and Cape Engano.