Conventionally-Powered Fleet Aircraft Carrier
The IJN Zuikaku was sunk by airstrike in the Battle of Cape Engano on October 25th, 1944.
Authored By: JR Potts, AUS 173d AB | Last Edited:
The Japanese fleet carrier Zuikaku ("Lucky Crane") and her sister ship, Shokaku ("Happy Crane") were a two-strong class of modern aircraft carriers built in the 1930's. Both were laid down after the post-World War 1 Naval Treaties had expired which left the Imperial Japanese Navy (IJN) without any global naval building restrictions on new designs. Their armored decks, of 5.1" in thickness, were further strengthened to support more weight, allowing operations of heavier combat aircraft. The class was also designed to carry more fuel oil, giving the sister ships the long operational ranges required to wage war a prolonged campaign across the vast Pacific Ocean.
The IJN Zuikaku measured a running length of 844.81 feet (257.5m) with a beam of 91.86 feet (28m) wide and a draught of 29.19 feet (8.9m). The vessel displaced at 25,675 tons under a standard load and some 32,105 tons when heavy. Her top listed speed was approximately 34.2 knots thanks to the Geared Steam Turbine engines powered by 8 x Kanpon brand boilers producing 165,000 shaft horsepower to her 4 x shafts, each capped with five-bladed propellers. Before requiring refueling, the Zuikaku could steam out to 9,700 nautical miles at 18.
The standard operating crew of the Zuikaku generally comprised up to 1,660 officers and sailors. Her island was set to the starboard side of the flight deck and was relatively forward and small compared to her contemporaries. For aircraft and ship defense she was built with 16 x 5-inch 40 caliber dual-mounted cannons as well as 36 x 25mm dual-mounted antiaircraft guns. This served the vessel well in providing a network of guns to help protect the rather vulnerable carrier should she be found without her own fleet for protection. To counter small naval mines, her belt armor ranged from 1.8 inches to 6.5 inches in thickness however this left little in the way of protection against all manner of torpedoes. Her primary purpose was to carry aircraft into battle and, as such, the Zuikaku fielded up to 27 x Aichi D3A "Val" dive bombers, 27 x Nakajima B5N2 Model 12 "Kate" torpedo bombers and 18 x Mitsubishi A6M "Zero" fighters. The ship had room for the 72 aircraft with a reserve store of 12 additional aircraft for a grand total of 84 aircraft. By any regard, the Zuikaku could field a rather lethal array of fighting aircraft against any manner of foe.
In 1941, the Zuikaku was staffed with a trained crew, experienced naval pilots and capable maintenance personnel and further stocked with some of the then-best fighting aircraft anywhere in the world. She was ready to be assigned and was chosen, along with three other carriers, to join IJN Carrier Division 5 as part of the Kido Butai (Mobile Force) staging in Hittokapu Bay, Japan. This group was waiting for their sailing orders to attack the US naval facilities and fleet stationed at Pearl Harbor, Hawaii. The main prize was to knock out the American carrier force which presented a significant threat to ongoing Japanese expansion across the Pacific. For the Hawaii operation, the IJN assigned additional crew and placed onboard a further 12 disassembled spare aircraft of each type. The order came down and the battle force sailed towards Pearl on November 26th,1941. The US Navy was aware of the ship's movements based on reports from their own submarine actions in the area. However, contact was eventually lost with the groups and the Japanese naval attack force followed a secret route believed to be relatively safe from prying eyes. The route did prove successful and the carriers of Kido Butai launched their attack aircraft on December 7th, 1941.
Zuikaku launched her first wave, comprised of 25 dive bombers, and attacked the US Army airbase at Wheeler Field on the island of Oahu. Five Zeros lent their ferocity to attacking the airbase at Kaneohe. Her aircraft of the second wave consisted of 27 Kate torpedo bombers, these armed with bombs instead of their torpedo ordnance, and attacked the US Navy airbase at Hickam Field. A further 17 dive bombers struck the battleships USS Maryland and USS California who were moored at "Battleship Row" in Pearl Harbor proper. Maryland was damaged from the attacks but managed to survive. However, California was sunk by the attacking aircraft. After the second wave was retrieved back on the decks of the Zuikaku, it was determined that the American carrier force was not present at the harbor as intended. It was this fear of the missing carrier group that forced the IJN Mobile Force to withdraw and return to Japanese waters before further attacks could be carried out. Nevertheless, the United States formally declared war on the Empire of Japan to which the Japanese Empire returned the declaration - prompting Germany and Italy to join the Japanese side.
With the United States officially in the war by January of 1942, Zuikaku and her sister ship were sent to the South Pacific to assist in attacking Australian bases at Rabaul and Lae in New Guinea. The vessels returned to Japan for refitting and, in April of 1942,they formed the critical air wing of a IJN force sent to counter the British Navy in the Indian Ocean. The first step was to attack the British naval bases at Colombo and Trincomalee on Ceylon. IJN surface ships shelled the bases while the carrier aircraft bombed ships stuck in the harbor and in the surrounding ocean. The British Royal Navy aircraft carrier HMS Hermes and the heavy cruisers HMS Cornwall and HMS Dorsetshire were sunk along with other support ships. The sinking of an aircraft carrier and two capital ships and others by the aircraft of Zuikaku and her sister ship surpassed the all of the tonnage sunk during their assignment during the attack on Pearl Harbor.
In May of 1942, the IJN developed "Operation Mo" the invasion of Port Moresby, New Guinea. Ownership of the port would ensure a embarkation point for Japanese Army troops to support the future invasion of the Australian mainland. Zuikaku was assigned, again with her sister ship, to support the landings against possible Allied interference. The US Navy decrypted Japanese naval messages and dispatched the aircraft carriers USS Yorktown and USS Lexington to counter the invasion. The upcoming battle on May 8th, 1942, would be called the "Battle of the Coral Sea".
Zuikaku escaped visual detection from US Navy spotter aircraft by hiding under a passing rain squall, but her sister ship - Shokaku - was struck by three bombs, knocking out a flight deck elevator and damaging the flight deck to the point that launching and recovering planes was impossible. Aircraft from both carriers and torpedoes from IJN escorting destroyers sank the carrier USS Lexington. Zuikaku was undamaged but lost one fighter aircraft, eight dive-bombers, and fourteen torpedo planes including losses of fourteen pilots and applicable crew. She was then ordered to return to Japan with her sister for resupply and aircrew training. The loss of carrier air cover blunted the attack on Port Moresby and the damage to the carriers and loss of trained crews made both carriers unable to take part in the upcoming Battle of Midway in June 1942 - what turned out to be a decisive Allied victory in the Pacific.
In August of 1942 the US Navy was now on the offensive in the Solomon Islands. Zuikaku and the repaired Shokaku, supported by the light carrier Zuihonow, were assigned to Carrier Division One and ordered to sail forward to destroy the Americans. On August 24th, 1942, the Battle of the Eastern Solomons began and Zuikaku's airwing damaged the carrier USS Enterprise, who in turn was damaged by American carrier planes. After the battle - registered as another Allied victory - Zuikaku was sent to Truk to monitor allied naval activity in the area.
In October of 1942, "Lucky Crane" was involved in the Battle of the Santa Cruz Islands and, again, found herself facing the USS Enterprise. She helped to cripple the carrier USS Hornet, forcing the crew to be removed to awaiting USN ships. The Hornet was then sunk by Japanese destroyers. However, American naval aircraft found and attacked the Shokaku and Zuiho carriers and damaged both. Zuikaku was left to recover as many of the surviving aircraft from other damaged carriers plus her own planes. The US Navy took care of the majority of the Japanese planes still in the fight, leaving just 67 left to return to Zuikaku. She was recalled to Japan for a refit and new aircrew members but attrition was taking its toll. Even the Japanese Army had been beaten badly by United States Marines at Guadalcanal and forced Zuikaku to the area to supply air cover for the retreat. When completed, Zuikaku was to be assigned to attack the Americans at the Aleutian Islands but the operation was cancelled in 1943.
On June 19th, 1944, the Battle of the Philippine Sea was underway, and the Japanese forces were outnumbered in both available carriers and aircraft. However, Admiral Toyoda gave the "Green Light" to "Operation A-Go". American submarines trailed the IJN fleet and sank the carriers Taiho and Shokaku with most of these crews going down with their respective ships. Zuikaku was hit by a bomb the next day but survived and retired to safety under her own power. In total, the IJN lost a further 243 planes to the American loss of 29 planes. The Battle of the Philippine Sea became another decisive Allied victory and mounted additional losses onto already-stretched Japanese fighting capability.
Zuikaku was repaired and returned to duty in October of 1944, now assigned as the flagship of Admiral Jisaburo Ozawa's Northern Force for the upcoming "Operation Sho-Go 1" ("The Second Battle of the Philippine Sea" (also called the "The Battle for Leyte Gulf"). This conflict would develop into the largest naval battle of the war thus far with the Japanese plan set to lure US Navy Admiral Halsey's 3rd Fleet away from their protection of the northern flank of the Leyte beachhead so an IJN northern force, supported by the battleship Yamato, and a southern naval force could converge to destroy the American landing forces attempting to go ashore. The bait would be a carrier force led by Admiral Ozawa's northern contingent comprised of the Zuikaku (his flag ship) and the light carriers Zuiho, Chitose, and Chiyoda. Additionally, they would be supported by two semi-converted WW1-era battleships (featuring small carrier flight decks) - the Hyuga and Ise - and three light cruisers, the Oyodo, Isuzu and Tama - further supported by nine destroyers. The plan - amounting to a suicide mission - was a desperate heave by the Japanese government with the IJN understanding that if the Philippines were taken back by the Americans, the war for Japan was all but lost. Only 108 planes with training crews were assigned as bait for Halsey's mighty 3rd fleet.
Halsey did, however, take the bait and left the northern flank unprotected when chasing Ozawa's "Hollow Fleet". Halsey saw the chance to destroy the last IJN carrier fleet, perhaps for personal glory or perhaps as a tactical victory. As Halsey's ships closed in on Ozawa's force on October 24th, 1944, there launched 77 dive bombers, 54 torpedo planes and 85 fighters towards the IJN fleet at 16:30. Ozawa had only a few planes in his stables and these were mostly shot down in the ensuing combat. The American air strikes continued all day with Task Force 38 having flown 527 total sorties, resulting in the sinking of the carriers Chitose and Zuiho as well as the destroyer Akizuki resulting in heavy loss of life.
At 1:00pm the American aircraft now found Zuikaku and swarmed over her with 50+ combat aircraft who preceded to assault her with 9 direct bomb hits and 7 torpedo strikes. At 1:58pm, the damaged proved too terrible and the official order was given to the crew of the Zuikaku to abandon ship. Her crew was arranged on deck to be told that her captain had decided to go down with the ship which promoted a Banzai cheer from the group before making their way to their lifeboats. The Zuikaku slowly rolled over and sank into the deep blue sea, aft down, at 2:14PM, taking with her Captain Takeo, 48 officers and 794 crewmen. Some 47 officers and 815 crew were rescued by the responding IJN destroyers Wakatsuki and Kuwa.
For the Americans, the death of the Zuikaku was a complete one for the savage attack on Pearl Harbor had finally been revenged in full, the IJN Zuikaku being the only carrier left from the December 7th, 1941 operation that had not yet been sunk until now. Within time, the tremendous losses inflicted against the IJN and IJA would form a stranglehold against the Empire of Japan, ultimately formulating in her unconditional surrender on September 2nd, 1945 - marking the official end of World War 2, the occupation of the Japanese mainland, the loss of all of her conquered territories and the dismantling of her military capability.