Operation Downfall, Part II

olympic

Con­tin­ued from Part I.

Down­fall would have been the largest amphibi­ous land­ing in his­tory, includ­ing 42 air­craft car­ri­ers, 24 bat­tle­ships, 400 destroy­ers and other ships. Four­teen U.S. divi­sions A divi­sion is a large mil­i­tary unit usu­ally con­sist­ing of around ten to twenty thou­sand sol­diers. would take part also as they used Oki­nawa as a stag­ing base and then seized the south­ern por­tion of the island of Kyushu. The inva­sion was sched­uled to start on Novem­ber 1, 1945. But there were some other con­sid­er­a­tions that the plan­ners had to take into account.

There was, nat­u­rally, to be a decep­tion plan lead­ing up to the Olympic inva­sion. By hav­ing such a plan it was hoped, as all decep­tion plans in war were, that Allied casu­al­ties would be min­i­mized because the enemy force would believe that it needed to focus itself else­where. The plan to pre­cede Olympic was Oper­a­tion Pas­tel, wherein which the Joint Chiefs of Staff would attempt to fool the Japan­ese into think­ing that a direct inva­sion of the south­ern islands had been rejected and instead that the Allies would focus first on Japan­ese forces still in main­land China. The first strike would be a false Allied attack on China’s Chusan-Shanghai area, with a fic­tional land­ing date of Octo­ber 1, 1945. This was to be fol­lowed by one of the smaller south­ern Japan­ese islands, Shikoku. After this the Allies hoped to sur­prise the Japan­ese with the Olympic invasion.

All of this was lead­ing up to X-Day, as it was called, where the All­lied forces would invade Kyushu along the east­ern, south­east­ern, south­ern and west­ern coasts of the island near the towns of Miyazaki, Ari­ake, and Kushikino. The inva­sion force was to con­sist of three main groups land­ing on 35 dif­fer­ent beaches, all code­named after makes of auto­mo­biles. The East­ern Assault Force con­sist­ing of the 25th, 33rd and the 41st Infantry Divi­sions, would land near Miyaski and quickly move inland to cap­ture Miyazaki and its nearby air­field. The South­ern Force which was to con­sist of the 1st cav­alry Divi­sion, the 43rd Divi­sion and Amer­i­can Divi­sion would land inside Ari­ake Bay and cap­ture Shibushi and to cap­ture, fur­ther inland, the city of Kanoya and its sur­round­ing air­field. On the west­ern shore of Kyushu near Kushikino the 2nd, 3rd, and 5th Marine Divi­sions would land and split, part of which would head inland to cap­ture Sendai while the other half cap­tured the port city of Kagoshima. Once these areas were secured more Allied rein­force­ments con­sist­ing of three Amer­i­can divi­sions would be brought in each month to strengthen the hold on the occu­pied por­tion of Kyushu.

Before and dur­ing all of this activ­ity the U.S. Twen­ti­eth Air Force would be bomb­ing strate­gic tar­gets such as rail­roads, air­fields and the var­i­ous beaches that were to be hit. With a suc­cess­ful bomb­ing cam­paign it was hoped that they could min­i­mize any fast means that rein­force­ments could uti­lize to arrive at the var­i­ous inva­sion points.

The four month timetable for Olympic was not to con­quer the entire island but to gain a foothold for the Allies to jump off of and use as a stag­ing ground for the even big­ger inva­sion — Coro­net. More on it in part 3.

(The info for this piece came, once again, from Wikipedia, the the Com­bined Arms Research Library)

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