Taiho

Taiho was the Imperial Japanese Navy’s first aircraft carrier with an armoured flight deck, a ship designed to correct the weaknesses that had destroyed four carriers at Midway. Commissioned in March 1944, she was the largest and most modern Japanese carrier of the war, with a displacement of about 29,300 tons standard, a speed of about 33 knots, and an air group of more than 50 aircraft. She sailed as the flagship of Vice Admiral Jisaburo Ozawa’s Mobile Fleet to the Battle of the Philippine Sea in June 1944, the battle the Americans called the Great Marianas Turkey Shoot. On 19 June 1944, early in the battle, the American submarine USS Albacore fired a spread of torpedoes at Taiho, and one struck her starboard side. The damage seemed manageable at first, but petrol vapour from a ruptured aviation fuel tank spread through the ship, and a series of explosions tore her apart. Taiho sank that afternoon with the loss of about 1,650 of her crew. She had been in commission for barely three months, and she never launched a successful strike against an enemy ship.

1. Key Facts

Class/Type	Taiho-class fleet aircraft carrier
Launched	7 April 1943
Commissioned	7 March 1944
Displacement	About 29,300 tons standard; about 37,000 tons full load
Length	260.6 metres
Speed	About 33.3 knots
Complement	About 1,751 officers and men, plus aircrew
Armament	12 x 100 mm dual-purpose guns; 51 x 25 mm anti-aircraft guns; 6 x 28-barrel rocket launchers
Aircraft	About 53 operational aircraft, with capacity for up to 65
Fate	Sunk by torpedo and explosion at the Battle of the Philippine Sea, 19 June 1944

2. Development

The Lessons of Midway

Taiho was ordered after the Battle of Midway, in which Japan lost four fleet carriers in a single day. The Japanese navy concluded that its carriers were too vulnerable to bombs, and it ordered a new design with an armoured flight deck, enclosed hangars, and better protection for aviation fuel. The result was the largest carrier Japan built during the war, and the only one with an armoured flight deck comparable to British carriers. The design was approved in 1941, before Midway, but the lessons of that battle confirmed the need for armour and influenced the details of the finished ship. Taiho was laid down at Kawasaki’s Kobe yard in July 1941, launched on 7 April 1943, and commissioned on 7 March 1944. She was the first of a planned class, but her sisters were never built: the war’s demands, the shortage of steel, and the loss of skilled labour meant that Japan built smaller, simpler carriers instead.

A New Kind of Japanese Carrier

Taiho differed from every earlier Japanese carrier in her construction. Her flight deck was armoured with about 75 millimetres of steel over the hangars and magazines, enough to stop a 500-pound bomb, and her hangar sides were enclosed rather than open. Her aviation fuel tanks were protected and fitted with concrete, and her machinery was divided into separate compartments to limit flooding. She was also the first Japanese carrier with a funnel that was angled outboard and integrated into the island, a design that kept smoke clear of the flight deck. The price was size and cost: at about 29,300 tons standard she was nearly twice the displacement of Soryu, and she took more than two and a half years to build. By the time she was ready, Japan had lost most of its trained carrier pilots, and Taiho sailed to battle with an air group that was brave but inexperienced.

3. Design

Armoured Flight Deck

Taiho’s armoured flight deck was her defining feature. British carriers had used armoured decks since the 1930s, and the Japanese navy adopted the idea after seeing the vulnerability of its own ships. The deck was about 75 millimetres thick over the hangar, with thinner armour elsewhere, and it was supported by a hangar structure that was fully enclosed. The design made the hangar a closed box, which protected aircraft from weather and from bomb fragments, but also trapped petrol vapour if a fuel tank was damaged. That trap proved fatal on 19 June 1944, when vapour from a ruptured tank spread through the ventilation system and ignited. The British had learned to manage the same risk with careful ventilation and damage control, but Taiho’s crew, many of them new to the ship, did not. The armoured deck itself was never tested by a bomb, because the torpedo that sank her struck below the waterline.

Hull and Island

Taiho’s hull was 260.6 metres long and 27.7 metres wide, with a full-load displacement of about 37,000 tons. Her island was on the starboard side and carried the bridge, the funnel, and the fire control for her guns. Unlike earlier Japanese carriers, which had separate funnels, Taiho’s funnel was built into the island and angled outwards, which kept the flight deck clear of smoke. She had two hangar decks, served by two lifts, and her flight deck was about 252 metres long. Her machinery, four sets of geared turbines producing about 160,000 shaft horsepower, gave her a speed of about 33.3 knots, fast enough to operate with the fastest Japanese warships. Her range was about 8,000 nautical miles at 18 knots, enough for operations across the Pacific, although by 1944 Japan’s fuel shortage limited her movements.

4. Technical Specifications

Hull and Machinery

Taiho measured 260.6 metres in length, 27.7 metres in beam, and about 9.6 metres in draught at full load. Her standard displacement was about 29,300 tons, and her full-load displacement was about 37,000 tons, making her the largest Japanese carrier built during the war except for the converted battleship Shinano. Her eight boilers fed four turbine sets driving four shafts, and her designed speed was about 33.3 knots. Her complement was about 1,751 officers and men, with the air group adding several hundred more, so that about 2,150 men were aboard when she sailed for the Philippine Sea. Her armour included a belt of about 55 millimetres over the machinery and magazines, a deck of about 75 millimetres over the hangar, and protected fuel tanks. The figures vary between sources because Japanese displacement and armour data were recorded under different conditions.

Protection and Damage Control

Taiho’s protection was the best of any Japanese carrier, but it was not enough to save her. Her armoured deck and enclosed hangar were designed to stop bombs, not torpedoes, and her underwater protection was conventional: a torpedo bulge and compartmentalisation, but no deep system of the kind used on American carriers. The torpedo that struck her on 19 June 1944 flooded the forward elevator well and ruptured an aviation fuel tank, and the damage control teams made a fateful error: they opened the ventilation system to clear petrol vapour, and the vapour spread through the ship instead. When it ignited, the explosion wrecked the hangar, the lifts, and the fire mains, and the ship lost power. The loss showed that armour alone does not save a carrier: the crew’s training, the design of the ventilation system, and the handling of fuel were just as important, and Taiho’s crew had not had time to learn the ship.

5. Armament and Aircraft

Guns and Anti-Aircraft Defence

Taiho carried 12 100 mm dual-purpose guns in six twin mounts, a new weapon that was more effective than the 127 mm gun on earlier carriers, with a higher rate of fire and a better anti-aircraft shell. For close-range defence she carried 51 25 mm anti-aircraft guns in triple and single mounts, and six 28-barrel rocket launchers, a weapon that proved ineffective in service. Her anti-aircraft armament was heavier than that of earlier Japanese carriers, 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. Taiho’s guns were directed by optical sights, and her crew had little practice against fast, high-flying aircraft. At the Philippine Sea, her fighters, not her guns, were supposed to protect her, and when the fighters were destroyed, her guns could not stop the American attack.

The Air Group

Taiho’s air group in June 1944 consisted of about 53 aircraft: 27 A6M Zero fighters, 18 D4Y dive bombers, and 8 B6N torpedo bombers, with spares. The aircraft were modern types, and the D4Y Judy dive bomber was faster than its predecessors, but the pilots were not. Japan had lost its pre-war generation of carrier pilots at Midway and in the Solomons, and the men who flew from Taiho in 1944 had only a fraction of their flying hours. The air group was part of the First Mobile Fleet, which sailed to the Philippine Sea with about 430 aircraft across nine carriers. In the battle that followed, the Japanese lost about 400 aircraft and their pilots, a loss the navy could not replace. Taiho’s own aircraft were largely destroyed in the air, before she was torpedoed, and the ship’s loss completed the destruction of the force she led.

6. Service History

Working Up and the Voyage to the Philippines

Taiho was commissioned on 7 March 1944 and spent the next two months working up in the Inland Sea, training her crew and air group. Her working-up period was cut short by the American advance across the Pacific: the invasion of Saipan, which began on 15 June 1944, threatened the Japanese inner defence line, and Admiral Soemu Toyoda ordered the Mobile Fleet to sail and destroy the American fleet. Taiho sailed as the flagship of Vice Admiral Jisaburo Ozawa, with the carriers Shokaku and Zuikaku in her division. The fleet sailed from Japan to the Philippines, where it took on fuel and aircraft, and then moved east to meet the Americans. Ozawa’s plan was to use the range of his aircraft to strike the Americans from beyond the range of their own aircraft, a plan that depended on his pilots being able to find and hit the American carriers at long range.

The Battle of the Philippine Sea

The Battle of the Philippine Sea began on 19 June 1944, when Japanese aircraft flew out to attack the American fleet off Saipan. The American combat air patrol, guided by radar, intercepted the Japanese strikes far from the carriers, and the Japanese lost hundreds of aircraft in the air. The Americans called the battle the Great Marianas Turkey Shoot, because the Japanese pilots were shot down in such numbers. Taiho’s own aircraft took part in the strikes, and most of them did not return. While the air battle was still going on, the submarine USS Albacore, which had been tracking the Japanese fleet, fired a spread of six torpedoes at Taiho. One struck her starboard side, forward, flooding the elevator well and rupturing a fuel tank. The damage seemed minor, and Taiho continued to steam at 26 knots, but the vapour from the ruptured tank was spreading through the ship.

7. Notable Actions

The Torpedo from USS Albacore

USS Albacore, under Commander James Blanchard, had been following the Japanese fleet since the morning of 19 June 1944. At about 08:10, Blanchard fired six torpedoes at Taiho from a range of about 5,300 metres. A Japanese pilot, Sakio Komatsu, who was taking off from Taiho at the time, saw the torpedoes and deliberately crashed his aircraft into one of them, sacrificing himself to save the ship. The pilot’s action destroyed one torpedo, but another struck Taiho’s starboard side. The explosion flooded the forward elevator well and damaged the fuel system, and the ship took on water, although she remained afloat and under way. The crew’s initial assessment was that the damage was manageable, and Ozawa continued to direct the air battle from Taiho’s bridge. The fatal error came later, when the damage control teams tried to clear petrol vapour by running the ventilation system at full speed, spreading the vapour through the ship.

The Explosion and the Sinking

At about 14:30, about six hours after the torpedo hit, a massive explosion tore through Taiho’s hangar. The petrol vapour that had spread through the ship ignited, and the explosion blew the flight deck up, wrecked the lifts, and started fires that the crew could not fight. The ship lost power, listed to starboard, and began to settle. Ozawa transferred his flag to the cruiser Haguro, and the crew abandoned ship. Taiho sank at about 16:28, with the loss of about 1,650 of her crew of about 2,150, including many of her aircrew and engineers. The destroyers Wakatsuki and Hatsuzuki rescued about 500 survivors. The loss of Taiho and Shokaku, sunk the same day by the submarine USS Cavalla, destroyed the core of Ozawa’s fleet, and the Japanese navy never again mounted a major carrier operation.

8. Fate

Sunk on 19 June 1944

Taiho sank on the afternoon of 19 June 1944, in the Philippine Sea, about 500 kilometres west of Saipan. She had been in commission for only 104 days, and she had never launched a strike that sank an enemy ship. Her loss was the direct result of a single torpedo, but the torpedo alone did not sink her: the explosion of petrol vapour, caused by a ruptured fuel tank and a ventilation error, destroyed the ship from inside. The Japanese navy investigated the loss and concluded that the damage control procedures had been wrong, but the lesson came too late to help. Taiho’s wreck has never been located, and she lies in deep water in the Philippine Sea, with most of her crew. Her name was not reused for a later Japanese carrier.

Aftermath for the Mobile Fleet

The Battle of the Philippine Sea destroyed Japanese naval aviation. The Japanese lost about 400 aircraft and most of their pilots, and the carriers that survived, Zuikaku and the light carriers, sailed home with almost no aircraft. The American navy, by contrast, lost about 130 aircraft and recovered most of its pilots. The battle secured the American invasion of Saipan and opened the way to the Philippines, and it left the Japanese fleet without the air power it needed to resist. Taiho’s loss, together with the loss of Shokaku on the same day, marked the end of Japan as a carrier power. The navy continued to build carriers, but it had no pilots to fly from them, and the remaining carriers were used as decoys at Leyte Gulf in October 1944.

9. Legacy

The Armoured Carrier That Came Too Late

Taiho was the carrier Japan needed in 1942, but she arrived in 1944, when Japan had lost the pilots to fly from her and the fuel to operate her. Her armoured flight deck was a sound idea, and it influenced post-war carrier design, but it could not compensate for the loss of trained aircrew and the weakness of Japanese damage control. The British carriers, which had armoured decks from the start of the war, survived bomb hits that would have destroyed Japanese carriers, because their crews were trained to fight fires and their fuel systems were designed to limit vapour. Taiho’s loss showed that an armoured deck is only part of the answer: the whole ship, from its ventilation to its damage control, must be designed to survive a hit. The American navy, which built its carriers with open hangars and strong damage control, drew the same lesson from a different direction.

Memory of Taiho

Taiho is remembered in Japan as the great carrier that was lost before she could fight, and as a symbol of the Japanese navy’s late-war decline. Her short career, 104 days in commission, is one of the shortest of any fleet carrier of the war, and her loss is often contrasted with the long careers of American carriers such as Enterprise. The pilot who sacrificed himself to intercept a torpedo, Sakio Komatsu, is remembered in Japan as an example of self-sacrifice, although his action could not save the ship. For historians, Taiho stands as a case study in how a sound design can fail when the crew, the training, and the industrial base that support it have been destroyed. She was the best carrier Japan built, and she was lost to a single torpedo and a ventilation error.

10. Frequently Asked Questions

What was Taiho?

Taiho was Japan’s first aircraft carrier with an armoured flight deck, built to correct the weaknesses shown at Midway, where Japan had lost four carriers in a single day. Commissioned in March 1944, she was the largest and most modern Japanese carrier of the war, with a displacement of about 29,300 tons standard and a speed of about 33 knots. She sailed as the flagship of Vice Admiral Jisaburo Ozawa’s Mobile Fleet to the Battle of the Philippine Sea in June 1944. She was sunk there on 19 June 1944, after barely three months in commission, and she never launched a successful strike against an enemy ship.

How was Taiho sunk?

Taiho was hit by a single torpedo from the submarine USS Albacore on 19 June 1944, during the Battle of the Philippine Sea. The torpedo ruptured an aviation fuel tank, and petrol vapour spread through the ship, helped by a damage-control error: the crew ran the ventilation system at full speed to clear the vapour, and it spread through the ship instead. About six hours later, at about 14:30, the vapour ignited and an explosion tore through the hangar, wrecking the lifts and fire mains and leaving the ship without power. Taiho listed, settled and sank at about 16:28, destroyed from inside rather than by the torpedo alone.

How long was Taiho in service?

Taiho was in commission for only about 104 days, from 7 March 1944 to 19 June 1944, a very short career. She spent the next two months working up in the Inland Sea, training her crew and air group, but that period was cut short by the American advance across the Pacific. The invasion of Saipan threatened the Japanese inner defence line, and the Mobile Fleet was ordered to sail and destroy the American fleet. Taiho sailed as flagship to the Philippine Sea, where she was sunk on the first day of battle, never having sunk an enemy ship.

How many aircraft did Taiho carry?

Taiho carried about 53 operational aircraft, with capacity for up to 65. Her air group in June 1944 was 27 Zero fighters, 18 D4Y dive bombers and 8 B6N torpedo bombers, including the fast D4Y Judy dive bomber. The weakness was not the aircraft but the pilots: Japan had lost its generation of carrier pilots at Midway and in the Solomons, and the men who flew from Taiho in 1944 had only a fraction of their flying hours. Most of her aircraft were destroyed in the air over the Philippine Sea before she was torpedoed, and the force she led was destroyed.

How many crew were lost when Taiho sank?

About 1,650 of her crew of about 2,150 were killed when Taiho sank, including many of her aircrew and engineers. After the explosion, the ship lost power, listed to starboard and began to settle, and Vice Admiral Ozawa transferred his flag to the cruiser Haguro before the crew abandoned ship. About 500 survivors were rescued by the destroyers Wakatsuki and Hatsuzuki. The loss was part of a disastrous day for Japan, since Shokaku was sunk the same day by the submarine USS Cavalla, and the two sinkings destroyed the core of Ozawa’s fleet. The Japanese navy never again mounted a major carrier operation after the Philippine Sea.

What was the Great Marianas Turkey Shoot?

The Great Marianas Turkey Shoot was the American name for the air battle on 19 June 1944, in which Japanese carrier aircraft were shot down in large numbers by American fighters guided by radar. The American combat air patrol intercepted the Japanese strikes far from the carriers, and the Japanese lost about 400 aircraft and most of their pilots that day. The American navy lost about 130 aircraft and recovered most of its pilots. Taiho’s aircraft took part in the strikes and most of them did not return. The battle secured the American invasion of Saipan and left the Japanese fleet without the air power it needed.

11. Sources

1. Wikipedia, “Japanese aircraft carrier Taiho” — construction, specifications, Philippine Sea, and sinking.
2. Mark Stille, “Imperial Japanese Navy Aircraft Carriers 1921-45” (Osprey, 2005) — design and armoured deck.
3. Jonathan Parshall and Anthony Tully, “Shattered Sword” (Potomac Books, 2005) — carrier design and damage control.
4. Hansgeorg Jentschura, Dieter Jung, and Peter Mickel, “Warships of the Imperial Japanese Navy, 1869-1945” (Naval Institute Press, 1977) — specifications.
5. Combinedfleet.com, “Taiho” tabular record of movement — service history and movements.
6. Samuel Eliot Morison, “History of United States Naval Operations in World War II, Vol. VIII: New Guinea and the Marianas” (Little, Brown, 1953) — the Battle of the Philippine Sea.