Operation Ten-Go

Operation Ten-Go
Part of World War II (the Pacific War)
Yamato under attack. A large fire burns aft of her superstructure and she is low in the water due to damage from torpedoes.
Date 7 April 1945 Location Pacific Ocean, between Kyushu, Japan and Ryukyu Islands Result U.S. victory
Belligerents
United States	Japan
Commanders and leaders
Marc A. Mitscher	Seiichi Ito
Strength
8 carriers, 386 aircraft	1 battleship, 1 light cruiser, 8 destroyers
Casualties and losses
12 killed; 10 planes destroyed	3,700 killed; 1 battleship, 1 light cruiser, 4 destroyers sunk

Operation Ten-Go (天号作戦 ten-gō sakusen) was the last major Japanese naval operation in the Pacific campaign of World War II. The Japanese battleship Yamato, the largest battleship in the world, along with seven other Japanese warships, sortied from Japan on an intentional one-way mission to attack the Allied invasion forces at Okinawa. The Japanese force was attacked, stopped, and almost completely destroyed before reaching Okinawa by U.S. carrier aircraft which sank Yamato and five other Japanese warships.

The battle emphasized the aerial control that the U.S. had attained in the Pacific theater as well as the vulnerability of surface ships to aerial attack. The battle also apparently exhibited Japan's willingness to sacrifice large numbers of its people in desperate and suicidal tactics in an attempt to slow or stop the Allied advance on the Japanese homeland.

Background

By spring, 1945, following the Solomon Islands campaign and Battles of the Philippine Sea and Leyte Gulf, the once imposing Imperial Japanese Navy's Combined Fleet was reduced to just a handful of operational warships and a few remaining aircraft and aircrew. The remaining Japanese warships in the combined fleet were stationed at ports in Japan.

With the invasions of Saipan and Iwo Jima, Allied, (primarily U.S.) forces began their campaign against the Japanese homeland itself. As the next step before a planned invasion of the Japanese mainland, Allied forces invaded Okinawa on April 1, 1945. In briefing Emperor Hirohito on Japan's response to the Okinawan invasion, Japanese military leaders explained that the Army was planning extensive air attacks, including the use of kamikaze. The emperor then reportedly asked, "But what about the Navy? What are they doing to assist in defending Okinawa?" Now feeling pressured by the emperor to mount some kind of attack also, Japan's Navy commanders conceived a kamikaze-type mission for their remaining operational large ships, which included the battleship Yamato.

The resulting plan called for Yamato and her escorts to attack the US fleet supporting the US troops landing on the west of the island. Yamato and her escorts were to fight their way to Okinawa and then to beach themselves between Higashi and Yomitan and fight as a shore batteries until they were destroyed. Once destroyed, the ship's surviving crewmembers were supposed to abandon the ships and fight U.S. forces on land. Very little, if any, air cover could be provided for the ships, which would render them almost helpless to concentrated U.S. air attacks.

Vice Admiral Ryunosuki Kusaka flew from Tokyo on April 5 to present the plan to the assembled commanders of the combined fleet, including Admiral Seiichi Ito, commander of the combined fleet. Upon first hearing of the proposed operation, the combined fleet commanders and captains unanimously rejected it as wasteful and useless. Admiral Kusaka then explained that the Navy's attack would help decoy U.S. aircraft away from the Army's planned air attacks on the U.S. fleet at Okinawa. He also explained that Japan's national leadership, including the emperor, were expecting the Navy to make their best effort to support the defense of Okinawa. Upon hearing this, the combined fleet commanders relented and accepted the proposed plan. The ship's crews were briefed on the nature of the mission and given the opportunity to stay behind if desired. None did. However, new, sick, and infirm crewmembers were ordered off the ships.

The battle

Routes of the Japanese Yamato force (solid black) and U.S. carrier aircraft (dotted red) to the battle area (X).

On 6 April at 15:00 hours, Yamato, with Admiral Ito on board, the light cruiser Yahagi, and eight destroyers left port at Tokuyama (near Hiroshima, see map at left). Two U.S. submarines, Threadfin, and Hackleback, sighted the Japanese force as it proceeded south through Bungo Suido but were unable to attack. However, they notified the U.S. fleet of the Japanese sortie.

At dawn on 7 April, the Japanese force passed the Osumi Peninsula into the open ocean heading south from Kyushu towards Okinawa. They shifted into a defensive formation, with Yahagi leading Yamato and the eight destroyers deployed in a ring around the two larger ships. One of the Japanese destroyers, Asashimo, developed engine trouble and turned back. U.S. reconnaissance aircraft now began to shadow the main force of ships. At 10:00 hours, the Japanese force turned west to make it look like they were withdrawing, but, at 11:30, they turned back towards Okinawa.

U.S. aircraft, such as this divebomber, begin their attacks on Yamato (center left). A Japanese destroyer is in the center right of the picture.

Around 10:00 this same day (7 April), the U.S. Navy began launching almost 400 aircraft in several waves from eleven carriers of Vice Admiral Marc A. Mitscher's Task Force 58 (Hornet, Bennington, Belleau Wood, San Jacinto, Essex, Bunker Hill, Hancock, Bataan, Intrepid, Yorktown, and Langley). The aircraft consisted of fighters, dive bombers, and torpedo bombers. A force of of six battleships (Massachusetts, Indiana, New Jersey, South Dakota, Wisconsin, and Missouri), supported by cruisers (including Alaska and Guam) and destroyers was also assembled to intercept the Japanese fleet if the air-strikes did not succeed.

Due to the Japanese force not having any air cover, the U.S. aircraft were able to set-up for their attacks without fear of opposition from Japanese aircraft. U.S. attack aircraft arriving over the Yamato group, after their two-hour flight from Okinawa, were thus able to circle the Japanese ship formation just out of anti-aircraft range, methodically setting-up their attacks on the warships below.

Yahagi under intense bomb and torpedo attack.

The first wave of U.S. carrier aircraft engaged the Japanese ships starting at 12:30 hours. At 12:46, a torpedo hit Yahagi directly in her engine room, killing the entire engineering room crew and bringing her to a complete stop. Dead in the water, Yahagi was hit by at least six more torpedoes and 12 bombs by succeeding waves of air attacks. Japanese destroyer Isokaze attempted to come to Yahagi's aid, but was herself attacked, heavily damaged, and sank sometime later. Yahagi capsized and sank at 14:05 hours. Her survivors, left floating in the water, could see the Yamato in the distance, still apparently steaming south and fighting attacking U.S. aircraft. However, in reality, Yamato herself was only minutes away from sinking.

Yamato (upper right) dodging air attack during the battle.

During the first attack wave, Yamato was hit by two armor-piercing bombs and one torpedo. Her speed wasn't affected, but one of the bombs started a fire that was never extinguished. Also, during the first attack wave, Japanese destroyers Hamakaze and Suzutsuki were heavily damaged and taken out of the battle. Hamakaze sank sometime later.

Between 13:20 and 14:15, the second and third waves of U.S. aircraft attacked, heavily concentrating on the Yamato. During this time, Yamato was hit by at least eight torpedoes and up to 15 bombs. At 13:33, in a desperate attempt to keep the ship from capsizing, Yamato's damage control team counter-flooded both starboard engine and boiler rooms, mitigating the danger, but also drowning the almost 800 crewmen manning those stations. The lives of those 800 crewmen bought Yamato about 30 more minutes of life. At 14:02, after absorbing more damage from bombs and torpedoes and being informed that the ship was unavoidably sinking, Admiral Ito ordered the mission canceled, the crew to abandon ship, and for the remaining ships to begin rescuing survivors.

Yamato, afire, begins to capsize.

At 14:05, Yamato was stopped dead in the water and began to capsize. Admiral Ito and the captain of the Yamato decided to go down with the ship and refused to abandon her with the rest of the survivors. At 14:20, Yamato capsized completely and began to sink. At 14:23, she suddenly blew-up with an explosion so large that it was reportedly heard and seen 200km away in Kagoshima and sent up a mushroom-shaped cloud almost 20,000 feet into the air. The explosion is believed to have happened due to the the fires from the bomb hits reaching the main ammunition magazines.

Attempting to make it back to port, the Asashimo was bombed and sunk with all hands by U.S. aircraft. The Japanese destroyer Kasumi was also sunk by U.S. carrier aircraft attack during the battle. Suzutsuki, with her bow blown-off, was able to make it to Sasebo, Japan by steaming in reverse the entire way.

File:Yamato3.jpg

Yamato explodes.

The remaining three, less-damaged, Japanese destroyers (Fuyuzuki, Yukikaze, and Hatsushimo) were able to rescue 280 Yamato survivors (out of a crew of 2,700), plus 555 survivors from Yahagi (out of a crew of 1,000) and just over 800 survivors from Isokaze, Hamakaze, and Kasumi. However, 3,700 Japanese naval personnel perished in the battle.

A total of 10 U.S. aircraft were shot down by anti-aircraft fire from the Japanese ships. But, some of the aircrews were rescued by amphibious aircraft or submarine. In total, the U.S. lost 12 killed. Some of the Japanese survivors reported that U.S. fighter aircraft machine-gunned Japanese survivors floating in the water. This may have been a war crime or it may have been a legitimate attempt to protect downed U.S. aircrew who were floating in the water nearby awaiting rescue.

During the battle, the Japanese Army conducted an air attack on the U.S. naval fleet at Okinawa as promised, but didn't sink any ships. Around 115 aircraft, many of them kamikaze, attacked the U.S. ships throughout the day of 7 April. Kamikaze aircraft hit the Hancock, battleship Maryland, and destroyer Bennett causing moderate damage to Hancock and Maryland and heavy damage to Bennett. About 100 of the Japanese aircraft were lost in the attack.

Aftermath

Ten-Go was the last major Japanese naval operation of the war and the remaining Japanese warships had little involvement in combat operations for the rest of the conflict. Suzutsuki was never repaired. Fuyuzuki was repaired but hit a U.S. air-dropped mine at Moji, Japan on August 20, 1945 and wasn't subsequently repaired. Yukikaze survived the war almost undamaged. Hatsushimo hit a U.S. air-dropped mine on July 30, 1945 near Maizuru, Japan and was the 129th, and last, Japanese destroyer sunk in the war.

Okinawa was captured by Allied forces by June, 1945, after an intense and costly battle. Japan surrendered unconditionally in August, 1945, after being bombed twice with nuclear weapons by the U.S. The apparent willingness of Japan to sacrifice so many of their people using suicidal tactics such as Operation Ten-Go and in the Battle of Okinawa reportedly was a factor in the Allied decision to employ nuclear weapons against Japan.

The sacrifice by the almost 4,000 Japanese sailors during Operation Ten-Go in a brave, selfless, but futile, symbolic effort to defend their homeland is revered to some degree in modern Japan as evidenced by appearances of the story in popular Japanese culture.

References

Books

• Feifer, George (2001). "Operation Heaven Number One". The Battle of Okinawa: The Blood and the Bomb. The Lyons Press. ISBN 1585742155.
• Hara, Tameichi (1961). "The Last Sortie". Japanese Destroyer Captain. New York & Toronto: Ballantine Books. ISBN 0-345-27894-1.- First-hand account of the battle by the captain of the Japanese cruiser Yahagi.
• Skulski, Janusz (1989). The Battleship Yamato. Annapolis, Maryland: Naval Institute Press. ISBN 087021019X.
• Spurr, Russell (1995). A Glorious Way to Die: The Kamikaze Mission of the Battleship Yamato, April 1945. Newmarket Press. ISBN 1557042489.
• Yoshida, Mitsuru (1999). Requiem for Battleship Yamato. Annapolis, Maryland: Naval Institute Press. ISBN 1557505446. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)- First-hand account of the battle by a surviving officer of Yamato.

External links

• "navweaps.com: Order of Battle". Retrieved 2006-04-22.
• "CombinedFleet.com: Chronological history of Yamato and actions during Ten-Go". Retrieved 2006-04-22.
• "NOVA documentary: Sinking the Supership". Retrieved 2006-04-23.- Official site of the NOVA documentary with additional information on the subject.

Audio/visual media

• {{cite AV media}}: Empty citation (help)- One-hour documentary on Operation Ten-Go
• {{cite AV media}}: Empty citation (help)- Animated series set in the future in which the wreck of the Yamato is lifted off of the ocean floor, rebuilt as a spaceship, and sent into outer space on a lone mission to defend against alien invaders who are ruthlessly bombarding the earth with huge fire bombs.
• {{cite AV media}}: Empty citation (help)- Japanese movie that dramatizes Operation Ten-Go from the perspective of Yamato's crew.