Trinity device fails to detonate

[acgoldis]

From the Wikipedia page on the test:

The code name "Trinity" was assigned by J. Robert Oppenheimer, the director of the Los Alamos Laboratory, inspired by the poetry of John Donne. The test was of an implosion-design plutonium device, informally nicknamed "The Gadget", of the same design as the Fat Man bomb later detonated over Nagasaki, Japan, on August 9, 1945. The complexity of the design required a major effort from the Los Alamos Laboratory, and concerns about whether it would work led to a decision to conduct the first nuclear test. The test was planned and directed by Kenneth Bainbridge.

Fears of a fizzle led to the construction of a steel containment vessel called Jumbo that could contain the plutonium, allowing it to be recovered, but Jumbo was not used.

In TTL, the test fizzles and the plutonium is lost. It is unclear why the bomb does not detonate and people need to start trying to figure out what happened (and obtain more plutonium in the process).

This leaves the US with one bomb which is expected to work. It is dropped on Hiroshima as IOTL. The Soviets then declare war on Japan. Now what? Remember that Japanese officials naturally assumed the US had only one bomb.

 

[thevaliant]

So, original bomb fails to work. Second is successful (but on first target) so Hiroshima is hit on 9th August.

Whilst the US didn't have a third YET, that yet is only about a month away. I'm sure someone on here did say that follow up bombs could be three and four in September and October, but then a delay for bombs five onwards until 1946.

However, the US just tells Japan that they have more and are willing to use them. September will prove them right, and Japan surrenders 1st October instead of 1st September.

The big winner (perhaps were you are going) is the Soviet Union who have an entire extra month to grab as much land as they can. Probably all of Korea is the real difference which will have long term impact down the line.

 

[acgoldis]

So, original bomb fails to work. Second is successful (but on first target) so Hiroshima is hit on 9th August.

Whilst the US didn't have a third YET, that yet is only about a month away. I'm sure someone on here did say that follow up bombs could be three and four in September and October, but then a delay for bombs five onwards until 1946.

However, the US just tells Japan that they have more and are willing to use them. September will prove them right, and Japan surrenders 1st October instead of 1st September.

The big winner (perhaps were you are going) is the Soviet Union who have an entire extra month to grab as much land as they can. Probably all of Korea is the real difference which will have long term impact down the line.

What type of weapon were those extra bombs? Uranium bombs or plutonium bombs? If they were plutonium bombs, would they be delayed while they tried to figure out what happened with Trinity? Or could the gun-type device be used with any type of fissile material?

I was thinking about Soviet involvement and them getting deeper into Japan -- right.

 

[xeny]

The extra bombs in the pipeline were plutonium bombs (https://www.osti.gov/opennet/manhattan-project-history/Events/1945/trinity.htm), so if there's a fundamental design flaw the raw material is at least available to do another test relatively quickly, but there's nothing available to drop until the problem is resolved.

 

[gatordad699]

They would not have had enough uranium until December for another gun type device. You can’t use Pu-239 that has trace amounts of Pu-240 in it for a gun type. That was what Hanford made. Pu-240 has too many spontaneous fissions. This would cause a critical mass and destroy the device before all the material became a critical mass. They made a few more gun types in 1946 when they had problems with plutonium production at Hanford. They would have needed to fix/figure out the implosion type device. Bomb grade U-235 is very difficult to make/separate.

 

[marathag]

In TTL, the test fizzles and the plutonium is lost. It is unclear why the bomb does not detonate and people need to start trying to figure out what happened (and obtain more plutonium in the process).

Well if there is no fission, the plutonium is around somewhere, and it worth the time to collect what's left.
Cue thousands of GIs collecting evwry metal scrap from 1.mile around the tower.

Core #2, the OTL Nagasaki core will be used inside the Jumbo Container for Gadget part two, Electric Boogaloo, or the ideas on using the more plentiful U-235 for implosion get moved up from theory to test, or the composite core Pu/U.
Those theories preceded Gadget, and were not followed up on til postwar, when the far higher U-235 production

Depending how that advances things, Core #3, the 'Demon' core is set for combat use innthe 3rd week of August.
Sadly, the U-235 production totals for 1945 and 1946 are lumped together, so the dates for gun type devices being used are in guess territory, other than OTL HEU production at Oak Ridge far exceeded Hanford's Pu production til HEU production was stopped

 

[Hammerbolt]

Some poor sood draws short straw to grab a hammer and go check the bomb...

 

[Athelstane]

A lot depends on why it's a fizzle.

If the fix is straightforward, then it's conceivable they can try another test of the plutonium design in reasonably short order, and maybe it only delays deployment of a plutonium bomb a couple months.

The bigger question I have is whether it affects the green light to drop Little Boy. Because even though the design is different, it might create a crisis of confidence in this design, too, by senior leadership, no matter how confident Oppenheimer and his boys are.

If they decide to risk dropping Litte Boy anyway, as the OP posits, and it detonates, it is quite possible that this (plus the Soviet invasion of Manchuria) would be enough to force the emperor to intervene with the War Cabinet to force a surrender.

 

[ObssesedNuker]

Relevant Restricted Data Blog Post:

What if the Trinity test had failed?

If the first nuclear weapons test had been a flop, would the world be better or worse off?

blog.nuclearsecrecy.com

 

[Athelstane]

Relevant Restricted Data Blog Post:

What if the Trinity test had failed?

If the first nuclear weapons test had been a flop, would the world be better or worse off?

blog.nuclearsecrecy.com

I feel like we should just delete all the posts in this thread and just read this instead.

But if the test had totally failed to give a nuclear yield — I think they would have had to do another test. That was certainly their original plan in the event of a failure. That would have taken several weeks to prepare, at best. The original Trinity test had taken months to prepare, but a Trinity failure would still have done damage to the tower, and probably contaminated the site with plutonium. A “quick and dirty” Trinity test, where they just set one off somewhere, wouldn’t have given them the data they needed (and in the face of a total failure, I don’t see them thinking “quick and dirty” would be the way to go — especially given how precious their plutonium stockpile was). So I think that would have essentially set back the possibility of using a plutonium bomb on Japan by a month or so at the minimum.

So looks like perhaps I was too pessimistic about the delay.

And fascinating to see Wallerstein sharing my concern of a bust on top policymakers:

But the policymakers and military brass would probably have been a lot less confident. Outside of Groves, none of the other military leaders had a deep understanding of the bomb, and several expressed extreme pessimism about its prospects prior to Trinity. A Trinity failure would have reinforced these perspectives. It’s possible they might have judged the entire thing not ready for prime time, and scuttled any use plans until they were confident that it wouldn’t be an embarrassment.

I tend to think that Truman and Stimson would still go ahead with Little Boy on schedule, but I wouldn't give more than 2 to 1 odds for it.

I also think Wallerstein is right to think that you probably do not need the second bomb to get the 3-3 War Cabinet vote and force the emperor's intervention. Of course, U.S. leaders had no clear way of knowing that, since it's not like they were listening in on the cabinet meetings.

Still, as he says, the Trinity failure would still have other political ripples, even if the Japanese surrender on schedule.

 

[marathag]

And per the other thread, the Japanese keep killing civilians wholesale thruout what was left of the Co-Prosperity Sphere with every day passing, while Curtis LeMay is working out his 'making the Rubble Dance' ideas with conventional raids.