US divisions for Coronet 1946

[Carl Schwamberger]

Seems like the 1st, 6th, 8th, and 10th army headquarters would all be likely to be committed, so all things being equal, that's Hodges, Kruger, Eichelberger, and Stilwell, presumably.

I'd understood Stilwell remained commander of the 10th Army, which did not have a role in Japan. Theres also claims MacArthur lacked interest in Stilwell as one of his commanders. There were some plans for secondary operations on the mainland & 10th Army may have been tagged for overseeing those.

[Pips]

Excellent detail of invasion forces.
So all in all, how many ground troops were to be committed?

[BobTheBarbarian]

Excellent detail of invasion forces.
So all in all, how many ground troops were to be committed?

From "History of Planning Division, ASF" Volume 6, part 1

"Operations Against Honshu (Tokyo Plain)"
ASF-P-SL-1
11 December 1944

"Proposed Troop Strength:"

D to D+15: 375,000 men (14 Div at 25,000; 5 Fighter Groups at 5,000)
D+30: 527,000 men (17 Div at 27,500; 8 Fighter and 4 Medium Bomber Groups at 5,000)
D+60: 780,000 men (20 Div at 35,000; 10 Fighter, 6 Medium Bomber Groups at 5,000)
D+90: 945,000 men (23 Div at 35,000; 15 Fighter, 10 Medium Bomber Groups, 3 Heavy Bomber Groups at 5,000)
D+120: 1,160,000 men (26 Div at 37,500; 20 Fighter, 12 Medium Bomber Groups, 5 Heavy Bomber Groups at 5,000)
D+150: 1,360,000 men (29 Div at 40,000; 20 Fighter, 12 Medium Bomber Groups, 8 Heavy Bomber Groups at 5,000)
D+180: 1,480,000 men
to
D+310: 2,000,000 men (Increase of 3 Div. per month to total of 45 Div at 40,000 and 40 Air Groups at 5,000)
D+360: 2,000,000 men (End of Hostilities)
D+600: 1,000,000 men (At end of hostilities, force will decrease by approximately 120,000 men per month until garrison strength is reached at D+600)

Note that this excluded British/Commonwealth forces or troops in Kyushu. By the end of the war several significant changes had been made, for example in "Staff Study Operations "Coronet"" (15 August 1945) (https://cgsc.contentdm.oclc.org/digital ... 5711/rec/1), the expected rate of deployment was considerably more aggressive: By Y+60 expected forces on-shore are quoted as 25 divisions, 637,550 ground combat troops, 432,409 service personnel, and 115,205 air forces personnel (total 1,171,646) along with 222,514 motor vehicles. The deployment of reserves was also accelerated compared to the 1944 study: four divisions per month instead of 3, beginning in May 1946 (i.e, after 2 months from Y-Day, 1 March 1946).

Strategic reserves amounted to 3 divisions from the Philippines (c. 120,000 men) and 17 from the United States (425,000 Army Ground Forces personnel, 45,000 Army Air Force (11 groups), 255,000 Army Service Forces personnel, and 10,000 misc. - total 735,000) Source: History of Planning Division, ASF vol. 9 part 7, p. 329 (https://cgsc.contentdm.oclc.org/digital ... 1794/rec/3)

So overall still something like 2 million US personnel alone, to be reached by September 1946 (Y+210 as opposed to D+310 in the 1944 study)

[daveshoup2MD]

Seems like the 1st, 6th, 8th, and 10th army headquarters would all be likely to be committed, so all things being equal, that's Hodges, Kruger, Eichelberger, and Stilwell, presumably.

I'd understood Stilwell remained commander of the 10th Army, which did not have a role in Japan. Theres also claims MacArthur lacked interest in Stilwell as one of his commanders. There were some plans for secondary operations on the mainland & 10th Army may have been tagged for overseeing those.

Given the scale of the offensive, including those noted above as having already returned from the ETO to CONUS, that's a total of 38 US divisions:

13th, 20th armored divisions; 1st Cavalry; 2nd, 4th, 5th, 6th, 7th, 8th, 10th Mountain, 24th, 25th, 27th, 31st, 32nd, 33rd, 37th, 38th, 40th, 41st, 44th, 77th, 81st, 86th, 87th, 93rd, 95th, 96th, 97th, 98th, 104th, and Americal, as well as 1st, 2nd, 3rd, 4th, 5th, and 6th Marine divisions; include the mooted three Commonwealth and two French divisions, and it's 43, plus however many more US divisions are transferred from the ETO.

Seems an awful lot for three army headquarters split between Kyushu and Honshu.

[Pips]

Thanks for that Bob.