Let's imagine that somehow the US gets the bomb 1 year earlier, with 3 ready by August 1944.
View attachment 382348
How far back can the P.O.D go? If different decisions are being made in Britain vis-à-vis Tube Alloys, can they also be made regarding engine development?
You're also forgetting the missing piece...the aircraft to lift it, the B-29 wouldn't likely be ready in time.
- Silverplating a Lancaster to carry and drop the first A bomb would have been easier and the aircraft was, at the time, more reliable than the new B29.
Short of putting RATO Bottles on a Lanc, there's no way to get it flying high enough(35,000 feet) and fast enough (350mph) to avoid getting destroyed by the bomb blast.
The crew has 43 seconds after release to be far enough way
"When the Nene appeared on the scene, Dorey set forth to put four of them in a Lancaster in place of the Merlins. We had calculated that the four-Nene Lancaster would exceed 400mph and fly well above 30,000ft. It would thus be immune to enemy action, either from fighters or AA fire. This project was never completed, because the war ended, but he did install two Nenes in a Lancastrian, leaving the inboard Merlins unaltered.
1. Sir Stanley Hooker, Not much of an Engineer: An Autobiography (Shrewbury: Livesly Ltd, 1991), 106.
"The Bombing of Hiroshima: August 6, 1945 ...
0905: Van Kirk announces Ten minutes to the AP. "The Enola Gay is at an altitude of 31,060ft with an airspeed of 200 miles an hour when the city of Hiroshima first comes into view."
2. "Hiroshima and Nagasaki Bombing Timeline", Atomic Heritage Foundation, https://www.atomicheritage.org/history/hiroshima-and-nagasaki-bombing-timeline .
Ploesti was captured by the Russians in July 1944 so that is off the list.
August 30th 1944. 2nd Jassy-Kishinev Offensive didn't kick off until 20th August 1944.