World War II: Japanese Carrier Akagi

The aircraft carrier Akagi entered service with the Imperial Japanese Navy in 1927 and took part in the opening campaigns of World War II. Originally intended to be a battlecruiser, Akagi's hull was converted to an aircraft carrier during construction in compliance with the Washington Naval Treaty. In this new role, it helped pioneer carrier operations within the Imperial Japanese Navy and took part in the Japanese attack on Pearl Harbor on December 7, 1941. Akagi aided in the rapid Japanese advance across through Pacific until be sunk by American dive bombers at the Battle of Midway in June 1942.

Design and Construction

Ordered in 1920, Akagi (Red Castle) initially was designed as an Amagi-class battlecruiser mounting ten 16-inch guns. Laid down at Kure Naval Arsenal on December 6, 1920, work progressed on the hull over the next two years. This came to an abrupt halt in 1922 when Japan signed the Washington Naval Treaty which limited warship construction and placed constraints on tonnage. Under the terms of the treaty, signatories were permitted to convert two battleship or battlecruiser hulls into aircraft carriers so long as the new ships did not exceed 34,000 tons.

Assessing the ships then under construction, the Imperial Japanese Navy selected the incomplete hulls of Amagi and Akagi for conversion. Work resumed on Akagi on November 19, 1923. After a further two years of work, the carrier entered the water on April 22, 1925. In converting Akagi, designers finished the carrier with three superimposed flight decks. An unusual arrangement, it was intended to allow the ship to launch as many aircraft as possible in a short period of time.

In actual operation, the middle flight deck proved too short for most aircraft. Capable of 32.5 knots, Akagi was powered by four sets of Gihon geared steam turbines. As carriers were still envisioned as support units within the fleet, Akagi was armed with ten 20 cm guns for fending off enemy cruisers and destroyers. Commissioned on March 25, 1927, the carrier conducted shakedown cruises and training before joining the Combined Fleet in August.

Early Career

Joining the First Carrier Division in April 1928, Akagi served as Rear Admiral Sankichi Takahashi's flagship. Conducting training for most of the year, command of the carrier passed to Captain Isoroku Yamamoto in December. Withdrawn from frontline service in 1931, Akagi underwent several minor refits before returning to active duty two years later.

Sailing with the Second Carrier Division, it took part in fleet maneuvers and helped pioneer Japanese naval aviation doctrine. This ultimately called for carriers to operate in front of the battle fleet with the goal of using massed air attacks to disable the enemy before ship-to-ship fighting commenced. After two years of operations, Akagi was again withdrawn and placed in reserve status prior to a major overhaul.

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Reconstruction & Modernization

As naval aircraft increased in size and weight, Akagi's flight decks proved too short for their operation. Taken to Sasebo Naval Arsenal in 1935, work began on a massive modernization of the carrier. This saw the elimination of the lower two flight decks and their conversion into fully-enclosed hangar decks. The topmost flight deck was extended the length of the ship giving Akagi a more traditional carrier look.

In addition to engineering upgrades, the carrier also received a new island superstructure. Counter to the standard design, this was placed on the port side of the flight deck in an effort to move it away from the ship's exhaust outlets. Designers also enhanced Akagi's anti-aircraft batteries which were placed amidships and low on the hull. This led to them having a limited arc of fire and being relatively ineffective against dive bombers.

Return to Service

Work on Akagi came to an end in August 1938 and the ship soon rejoined the First Carrier Division. Moving into southern Chinese waters, the carrier supported Japanese ground operations during the Second Sino-Japanese War. After striking targets around Guilin and Liuzhou, Akagi steamed back to Japan.

The carrier returned to the Chinese coast the following spring and later underwent a brief overhaul in late 1940. In April 1941, the Combined Fleet concentrated its carriers into the First Air Fleet (Kido Butai). Serving in the First Carrier Division of this new formation with the carrier Kaga, Akagi spent the later part of the year preparing for the attack on Pearl Harbor. Departing northern Japan on November 26, the carrier served as flagship for Vice Admiral Chuichi Nagumo's Striking Force.

World War II Begins

Sailing in company with five other carriers, Akagi began launching two waves of aircraft early on the morning of December 7, 1941. Descending on Pearl Harbor, the carrier's torpedo planes targeted the battleships USS Oklahoma, USS West Virginia, and USS California. The dive bombers of the second wave attacked USS Maryland and USS Pennsylvania. Withdrawing after the attack, Akagi, Kaga, and the carriers of the Fifth Carrier Division (Shokaku and Zuikaku) moved south and supported the Japanese invasion of New Britain and the Bismarck Islands.

After this operation, Akagi and Kaga fruitlessly searched for American forces in the Marshall Islands before launching raids on Darwin, Australia on February 19. In March, Akagi helped cover the invasion of Java and the carrier's aircraft proved successful in hunting Allied shipping. Ordered to Staring Bay, Celebes for a brief period of rest, the carrier sortied on March 26 with the rest of the First Air Fleet for a raid into the Indian Ocean.

Attacking Colombo, Ceylon on April 5, Akagi's aircraft assisted in sinking the heavy cruisers HMS Cornwall and HMS Dorsetshire. Four days later, it mounted a raid against Trincomalee, Ceylon and aided in the destruction of the carrier HMS Hermes. That afternoon, Akagi came under attack from British Bristol Blenheim bombers but did not sustain any damage. With the completion of the raid, Nagumo withdrew his carriers east and steamed for Japan.

Battle of Midway

On April 19, while passing Formosa (Taiwan), Akagi and the carriers Soryu and Hiryu were detached and ordered east to locate USS Hornet (CV-8) and USS Enterprise (CV-6) which had just launched the Doolittle Raid. Failing to locate the Americans, they broke off the pursuit and returned to Japan on April 22. A month and three days later, Akagi sailed in company with Kaga, Soryu, and Hiryu to support the invasion of Midway.

Arriving at a point approximately 290 miles from the island on June 4, the Japanese carriers opened the Battle of Midway by launching a 108-plane strike. As the morning progressed, the Japanese carriers evaded several attacked by Midway-based American bombers. Recovering the Midway strike force just before 9:00 AM, Akagi began spotting aircraft for an attack on the recently discovered American carrier forces.

As this work progressed, American TBD Devastator torpedo bombers commenced an assault on the Japanese carriers. This was repulsed with heavy losses by the fleet's combat air patrol. Though the American torpedo planes had been defeated, their attack pulled the Japanese fighters out of position.

This allowed arriving American SBD Dauntless dive bombers to strike with minimal aerial resistance. At 10:26 AM, three SBDs from USS Enterprise dove on Akagi and scored a hit and two near misses. The 1,000 lb. bomb that struck penetrated to the hangar deck and exploded among several fully fueled and armed B5N Kate torpedo planes causing massive fires to erupt.

Sinking Ship

With his ship badly stricken, Captain Taijiro Aoki ordered the carrier's magazines to be flooded. Though the forward magazine flooded on command, the aft did not due to damage sustained in the attack. Plagued by pump problems, damage control parties were not able to bring the fires under control. Akagi's plight worsened at 10:40 AM when its rudder jammed during evasive maneuvers.

With fires breaking through the flight deck, Nagumo transferred his flag to the cruiser Nagara. At 1:50 PM, Akagi came to a stop as it engines failed. Ordering the crew to evacuate, Aoki stayed aboard with the damage control teams in an effort to save the ship. These efforts continued through the night but to no avail. In the early morning hours of June 5, Aoki was forcibly evacuated and Japanese destroyers fired torpedoes to sink the burning hulk. At 5:20 AM, Akagi slipped bow first beneath the waves. The carrier was one four lost by the Japanese during the battle.