The Atomic bombing of Germany 1945

OTL, had the decision been made to use composite cores, around 20 cores would have been ready by the end of 1945 link
Do you think that if a composite core is made in January 1945 would there be a need for a second Trinity style test or would Oppenheimer and Groves be confident enough that it would work?
 

marathag

Banned
Do you think that if a composite core is made in January 1945 would there be a need for a second Trinity style test or would Oppenheimer and Groves be confident enough that it would work?

I'm thinking that they would fissile material for a composite core test before they would have enough bomb grade Pu for a 100% Pu implosion test

If a composite core, or a pure HEU core is imploded first, I'm not sure they would do more test shots for the other variations.
But with implosion proven, I'd doubt they would make any gun stile bombs, unless OTL issues like the Navy demanding a bomb that could be carried by USN aircraft, like they did with the Neptune, that had a too small bomb bay for Fat Man, but could carry Little Boy
 
If OTL Japan is any indication, get ready for a whole lot more postwar "Poor Victim Germany" bullshit ITTL.

image-180287-galleryV9-ggny-180287.jpg


^^^ these assholes ATL counterparts aren't gonna give a damn about Dresden this time around
 
What if this timeline’s Little Boy was an HEU bomb? I mentioned that Los Alamos is still working on a uranium bomb. Groves needs to produce as many bombs as possible.
How many composite cores can be produced each month?
Ah, that's my area.
The historical production rates were (and I again refer to the Hull-Seaman memorandum of AUG1945 with some amendments from the Groves memorandum of 30JUL1945)
  • one MK3 (the Gadget) for the Trinity test in July.
  • one MK1 ('Little Boy') ready by the end of July (this contained ~64kg of HEU)
  • a second MK 3 ('Fat Man') by 19AUG1945
  • a third MK 3 by 01SEP1945 (this would be the 'Demon Core' that caused two radiological accidents post-war)
  • three more MK 3 bombc (mix of MOD0 and MOD1[2] configurations) by 30SEP1945
  • three or four additional MK 3 weapons in OCT1945
  • an additional MK 3 every ten days for the remainder of the year
  • an additional MK 1 available before the end of 1945

It should be noted that Groves proposed (without recommending[1]) the option of HEU and composite Pu/HEU cores for the implosion bombs on 30JUL, stating that if this was adopted immediately it would cause no delay in the production schedule but if adopted later it would introduce a ten day delay which he was confident would be compensated for within a month or so.

Now the use of fissionable materials were:
MK1 (uranium linear).
64kg HEU​
MK3 (plutonium implosion)
6.2kg Pu​
MK3-U (uranium implosion)
12kg HEU​
MK3-C (composite uranium/plutonium implosion)
2.4kg Pu and 4.8kg of HEU​


Hope this helps.



[1] "We could, if it were wise, change our plans and develop the combination bomb."

[2] Groves was unenthusiastic about switching to the MOD1 design, despite the increased explosive yield
 
Do you think that if a composite core is made in January 1945 would there be a need for a second Trinity style test or would Oppenheimer and Groves be confident enough that it would work?
Oppenheimer was certainly confident (even before Trinity) that the uranium and composite cores would work.
 
Would these be realistic production numbers if Groves orders the switch to composite cores at the end of August 44:

1 more MK-3 Fat Man at the end of August
September-October: 2 Mk-3 Composites each month
November-Dec-Jan: 3 MK-3 Composites.
So in February you have 14 bombs available. Are these numbers just right or too conservative?
Postpone Little Boy and use the HEU for composite cores.
I am not planning on using 14 bombs in this story. I just want a realistic maximum number available.
 
Part VI
Part VI: B-29s over the Reich

The ground echelon of the 73rd Bomber Wing began to arrive in Great Britain July 1944. Construction was still being completed on the four airfields that would be home to the bomber wing. In fact construction would continue for the rest of the war. Priority had been given to getting the airfields ready for flight operations. Work had also been slowed down by D-Day as aviation engineer units began to deploy to France to build new airfields there. As a result when the ground echelons moved in one of their first tasks was finishing living quarters or spend the winter living in tents

The first B-29 had landed in Britain in March 1944. The YB-29 Hobo Queen visited USAAF bomber stations and was used to test the runways at the B-29 airfields. Hobo Queen later visited the Fifteenth Air Force bomber fields at Foggia as part of a disinformation campaign against German intelligence. The USAAF wanted the Germans to believe that Superforts might also be stationed in Italy. The YB-29 was also testing the feasibility of using B-29s to conduct shuttle raids to Italy. One emergency landing strip was completed in the Foggia airfield complex for the B-29s.

The first bombers of the 73rd Wing arrived in August 1944. Dauntless Dotty flown by Major Robert Morgan, commanding officer of the 869th Bomber Squadron, 497th Bombardment Group became the first combat-ready B-29 to land at RAF North Pickenham. Major Morgan had been the pilot of Memphis Belle, the first B-17 officially credited with completing 25 missions with the 8th Air Force. This would be Morgan’s second combat tour in Europe. Brigadier General Emmett “Rosie” O’Donnell commanding officer of the 73rd Wing flew aboard Dauntless Dotty as co-pilot. O’Donnell was greeted on the tarmac by Lieutenant General Jimmy Doolittle, Eighth Air Force commander and Lieutenant General Spaatz.

The 73rd’s bomb groups were based at the following stations:

500th Bombardment Group (VH)*: Marham

498th Bombardment Group (VH): Sculthorpe

499th Bombardment Group (VH): Lakenheath

497th Bombardment Group (VH) and 73rd Wing Headquarters: North Pickenham

XXI Bomber Command of the Twentieth Air Force set up Headquarters at High Wycombe under Brigadier General Haywood Hansell. Hansell was banned from flying any combat missions over enemy territory due to his knowledge of the Manhattan Project. This order came from Hap Arnold himself

In September all the 73rd’groups were in place. The 479th Fighter Group was assigned to XXI Bomber Command to provide fighter support. The 479th was initially flying P-38 Lightnings but was quickly converted over to P-51 Mustangs. The B-29 crews spent the month of September training for combat over Europe. The 73rd Wing’s first missions over hostile territory were bombing the German ports at St. Nazaire and La Rochelle. On October 2, 1944 the B-29s flew their first combat mission over Germany. The 73rd bombed the Ford Motor plant in Cologne**.

The raid on Cologne brought to light a major problem for the XXI Bomber Command and the Eighth Air Force. Hansell’s bombers had to borrow more fighters from the Eighth for bomber escort. The B-29 Wing also received all of its support from the Eighth Air Force. Generals Doolittle and Hansell agreed that it would be easier to coordinate operations if the 73rd Wing was attached to the Eighth Air Force. They informed General Arnold of their opinions. Arnold reluctantly agreed and the XXI Bomber Command became the de facto 4th Air Division of the Eighth Air Force.

The 73rd Bomber wing achieved good results on its bombing missions that October. General Doolittle was impressed with the capabilities of the B-29. However he felt that one combat wing of B-29s was not making an overall difference. The same bombing results could have been achieved by additional B-17s. General Ira Eaker, Commander-in-Chief of Mediterranean Allied Air Forces felt the new bombers would have been better used to reinforce the Fifteenth Air Force.

Haywood Hansell did not forget that part of his mission was to prepare the way for an atomic bombing mission against Germany. In November he ordered O’Donnell to start experimenting with sending out small sections of B-29s on missions. O’Donnell began sending out F-13s (the reconnaissance version of the B-29) on deep weather-recon missions into eastern Germany. B-29s also started acting as pathfinders for B-17 and B-24 formations.



*VH- Very Heavy bomber

**The October 2 mission was a real Eighth Air Force mission. OTL Mission 658: 110 B-17s bombed the Cologne Ford plant. 1 B-17 lost and 36 damaged.
 
Last edited:
  • a second MK 3 ('Fat Man') by 19AUG1945
  • a third MK 3 by 01SEP1945 (this would be the 'Demon Core' that caused two radiological accidents post-war)
Considering Fatman was dropped on 9 August, it can't have been built on 19 August...

I think you might be thinking of the third bomb there, and missed Fatman completely?
 
Part VII
Part VII: The 509th Composite Group



In December 19444 Detachment A of the 509th Composite Squadron arrived at Marham. The 509th was originally the 393rd Bombardment Squadron of the 504th Bombardment Group, 313th Bomber Wing. The squadron started out with 21 B-29 crews under the command of Lieutenant Colonel Thomas J. Classen. The squadron was “volunteered” for special duty at Fairmont Army Air Base in Nebraska. On September 14, 1944 the 393rd arrived at Wendover Army Air Field in Utah to begin training under a new commander, Lieutenant Colonel Paul Tibbets. The rest of the 504th Bomber Group would eventually deploy to North Field on the island of Tinian.

Paul Tibbets had been selected by Hap Arnold himself to train and lead the atomic bomb mission. Back in 1942, Tibbets had flown on the first bombing mission of the Eighth Air Force over Europe. He was interviewed by General Uzal Ent, commander of the Second Air Force. General Ent had led the August 1943 bombing mission against Ploesti. General Ent told LtCol. Tibbets that he was to prepare for attacking both Germany and Japan. After the meeting with General Ent, Tibbets traveled to New Mexico where he was introduced into the world of the Manhattan Project.

LtCol. Tibbets was pressed for time due to the December deadline set by Washington. He would fly one bomber as mission commander/lead crew. Captain Ted Van Kirk would be his navigator and Major Tom Ferebee would be the bombardier. Both Van Kirk and Ferebee had been part of Tibbet’s B-17 crew in England and North Africa.

LtCol. Tibbets took his new bomber crews on training missions at Wendover to evaluate their performance. The top fourteen crews were assigned Silverplate B-29s. Five crews were assigned normal B-29s. Tibbets decided he would use the extra crews as spare crew members for the Silverplates. Two crews were assigned to fly C-54 cargo planes. The squadron now began conducting “blind” training. They bomber crews practiced dropping “pumpkin” bombs. These were practice bombs made in the shape of the plutonium “Fat Man” bomb. Tibbets felt the squadron needed a lot more training but he was ordered by General Ent to be ready to move to deploy into the combat zone.

On Friday December 1, 1944 the 509th Composite Group was officially born. On Monday December 4, Tibbets and six other crews departed for England as Detachment A. Just like the rest of the B-29 Superfortress program there was a rush to get the 509th into action. Ground crews for the Silverplate B-29s were loaded aboard transport planes for the trip to England or they were flown to the east coast and loaded onto the first available transport ship headed to England. The majority of the 509th became Detachment B and headed for Tinian with the 313th Bomber Wing.

In Los Alamos the Manhattan Project continued to produce atomic bombs. At the end of August there were two plutonium cores. In September and October four more weapons were ready. General Groves ordered all work ended on the building of a Uranium 235 weapon and focus everything on the building of Fat Man bombs. In November Los Alamos switched to over to using composite cores of Plutonium and enriched Uranium (HEU). Three more weapons were produced that month and three more would come in December. By the end of 1944 there were twelve atomic bombs in the US arsenal.
 
Last edited:
Author's note: I kept the creation of the 509th close to what happened in OTL. The upcoming atomic bombing of Germany is going to be rushed job. The Americans have the bomb but they are limited on how to deliver it. The Silverplate B-29s that Tibbets has are the first one built so USAAF is literally making this up as they go along.
 
Last month, I bought a number of books at a book sale. One was a history of the 509th. A week or so later, I picked it up to read, and found on the title page a short message to the original owner, written and signed by van Kirk.
 
William Penney traveled to London with a copy of the atomic test film to brief Winston Churchill. Soon after Churchill sent a letter to Roosevelt where he stated he wanted RAF participation in any nuclear attack against Germany. Churchill also offered the use of British Lancaster bombers as a strike aircraft. The Prime Minister also inquired about using atomic bombs to retaliate for German V-1 and V-2 rocket attacks against Great Britain. Roosevelt urged the Prime Minister to be patient. Retaliation against the Nazis would be coming.

In Europe it looked like the war against Nazi Germany might end before the bomb arrived. Privately this is what Secretary of War Stimson hoped would happen. The Allies broke out of Normandy in late July before the first atomic test was carried out. In August Operation Dragoon, the landings in Southern France was carried out. Paris was liberated on August 25th and a German Army was destroyed in the Falaise Pocket. In September the situation changed. The Allied Armies bogged down along the German border. Operation Market Garden failed in Holland. In the east, the Russians stalled in Poland. The Warsaw uprising was crushed by the Nazis and it appeared that Stalin allowed that to happen.

Wow! Very interesting and I never knew this. But don't forget the Nazi's still had an effective Atomic Bomb program until December 1944.
 
If OTL Japan is any indication, get ready for a whole lot more postwar "Poor Victim Germany" bullshit ITTL.

View attachment 354525

^^^ these assholes ATL counterparts aren't gonna give a damn about Dresden this time around

Japan was given lease on that with a whole "It was actually the military that did it" and that they weren't as bad as the Nazis post-war reconstruction historical assessment thing. Germany is not getting away with that. Not in actual post-war history. Not here.
 
"... still had an effective Atomic Bomb program until December 1944."

Not ??

IIRC, they had a bunch of different projects, but their physics was off. IIRC, their 'pile' moderators were not pure enough. Also, they were verrrry slowwwwly separating their U isotopes with what seems a Calutron, an industrial-strength mass spectrometer.
https://en.wikipedia.org/wiki/Calutron

Upside, it works.
Downside, they would need a lot longer than they had...
Best, IMHO, they could get would be low-end enrichment, a gun-type bomb with a seriously dirty fizzle. And, with a weight far beyond V2's throw, they'd have to deliver by submarine or bury as a monster mine...

OT: I can't find a 'strike-through' to go with italic, underline etc...
 
"... still had an effective Atomic Bomb program until December 1944."

Not ??

IIRC, they had a bunch of different projects, but their physics was off. IIRC, their 'pile' moderators were not pure enough. Also, they were verrrry slowwwwly separating their U isotopes with what seems a Calutron, an industrial-strength mass spectrometer.
https://en.wikipedia.org/wiki/Calutron

Upside, it works.
Downside, they would need a lot longer than they had...
Best, IMHO, they could get would be low-end enrichment, a gun-type bomb with a seriously dirty fizzle. And, with a weight far beyond V2's throw, they'd have to deliver by submarine or bury as a monster mine...

OT: I can't find a 'strike-through' to go with italic, underline etc...
From what I understand the Germans were about two years behind the Manhattan Project in 1945. According to the Atomic Heritage Foundation website After the war Werner Heisenberg the Physicist was interned by the British. He did not believe that the Americans had dropped Little Boy on Hiroshima when he was told the news in August 1945. The Germans had pretty much given up on seriously developing an Atomic bomb by the end of 1942.
 
Last edited:
"... still had an effective Atomic Bomb program until December 1944."

Not ??

IIRC, they had a bunch of different projects, but their physics was off. IIRC, their 'pile' moderators were not pure enough. Also, they were verrrry slowwwwly separating their U isotopes with what seems a Calutron, an industrial-strength mass spectrometer.
https://en.wikipedia.org/wiki/Calutron

Upside, it works.
Downside, they would need a lot longer than they had...
Best, IMHO, they could get would be low-end enrichment, a gun-type bomb with a seriously dirty fizzle. And, with a weight far beyond V2's throw, they'd have to deliver by submarine or bury as a monster mine...

OT: I can't find a 'strike-through' to go with italic, underline etc...


The most successful one appears to have been the Reichpost's work. Just imagine . . .

You have a message from the Reichspost:

Reichpost said:
Our Words Are Backed By
Nuclear Weapons!

The Reichspost announces the Christmas 1946 Stamps!
The Führer in Red on Green or Green on Red!
RM 1, RM 2, RM 5, and RM 10 values!
Available December 1!
 

marathag

Banned
From what I understand the Germans were about two years behind the Manhattan Project in 1945

By 1942, Iowa State University had refined more pure metallic Uranium than the Germans would do by Wars end.
They weren't even at the starting line, but still putting on their shoes in that race
 
Top