Was there a third atomic bomb target?

I know there was a target that was meant to be at a army training camp but was changed during flight during weather.

 

Not a "training camp" really, but Kokura (which held the Kokura Arsenal) was the primary target of the Nagasaki mission, curiously neither it nor Niigata were included on the new target list submitted August 14. That list, in order of priority was:

Sapporo, Hakodate, Oyabu, Yokosuka, Osaka, Nagoya. (see Downfall, Richard Frank; p.303)

There was an unused completed "fat man type" bomb sitting on Tinian when Nagasaki was hit, its plutonium core was called back from San Fran. and held at Los Alamos. When the Japanese announced their acceptence of the Potdam Declaration, it was simply held there while other cores were produced. The fourth set of cases were constructed while the third implosion type sat on Tinian, those two un-named bombs became Able and Baker in the Crossroads tests at Bikini Island in 1946.

 

In addition to the other sources refered to above find a copy of 'The Making of the Atomic Bomb' by Richard Rhodes. He went through the documents and interviews used by most other sources and compiled a extensive summary of the information. 886 pages including appendixes and indexes.

Rhoades concludes that actual production for the remainder of 1945 would have provided five more atomic bombs of the Plutonium type. That included the bomb in transit to Tinian. At least 18 more could have produced in 1946. All the Plutonium type. Earlier the decision had been made to use the faster plutonium production for bomb material with any weapons grade Uranium to be used for experiments or test shots. For this purpose three Plutonium breeder reactors were built at the Haniford site in Washington state. The haste and lack of experince caused a number of problems to develop in the Haniford reactors, so production would not reach the goals of one bomb every ten days. Soon after Japan surrendered all the reactors at Haniford were shut down and plans for rebuilding them set in motion.

 

Tibbets told Studs Terkel in 2002 that HE (Tibbets) was selected to drop the third bomb.

As far as a non-combat pilot dropping the third bomb... It seems more likely they'd want a seasoned pro doing it. After all, if the Japanese didn't surrenender after Nagasaki, that third A-bomb could very well have been the clincher.

 

There was a full set of components for a second uranium gun "Little Boy" device on Tinian; two full sets of hardware had been delivered, along with one target-bullet pair of uraniaum cores (the ones used) and IIRC a "target" element for the second set of components. Little Boy was assembled on Tinian from selected parts from both sets of components. Only the "bullet" - actually now known to have been the larger of the two uranium elements - needed ideally to be shipped.

The uranium gun devices were actually nearly as complicated as the Plutonium implosion dvices - for to prevent a "fizzle" or roll-forward....the "bullet" moving along the device faster or slower towards the "target", causing a part-explosion - or no explosion at all!....they were filled with a range of safety devices both mechanical and electrical - the latter were based on P51 tail warning radars - and manual arming devices to be set inflight.

As for "diminishing returns" - a central part of japanese anti-invasion preparations....for which they fully expected a ramping-up of the strategic bombing campaign anyway...was simply to train the urban populations out into the country and dump them there to fend for themselves!....

Which would of course have had the added benefit of reducing the potential human targets for further Atomic bombing!

 

This is incorrect, there were five "gun-type" (little boy) uranium devices produced, one was used on Hiroshima and no other "gun type" was shipped. The "implosion type" (fat man) was the new plutonium device which had been tested at Alamagordo since the "gun-type" was fool-proof and didn't need to be tested if the physics itself was correct. It was.

The third bomb at Tinian was a constructed (two shell halves) without the plutonium core halves. This was NOT a uranium bomb, but the two halves of the external implosion shell and guidance fins without the plutonium fission internals. These were halted at the San Francisco debarking terminal and returned to Los Alamos where they were held as the Imperial Japanese came to the acceptance of the Potsdam Declaration.

There were the "gadget" (Alamagordo proof of implosion plutonium type), the "Little Boy" uranium gun-type used at Hiroshima, the "Fat Man" plutonium implosion type dropped on Nagasaki, and a third "implosion type" plutonium set of cases sitting on Tinian when Nagasaki was bombed. This un-named plutonium implosion type was used in the "Crossroads" tests at Bikini, as was the next implosion type plutonium bomb which was also completed before the end of 1945.

 

No, no other Little Boy devices were shipped - what was shipped was two complete sets of components I.E. two of everything - not two complete bombs...so that on Tinian the proximity radar elements of the safety devices could be selected and finally assembled/calibrated there. What I meant that after Little Boy was assembled and used - they could have assembled the remaining set of parts - but didn't.

 

But not uranium bomb gun-types is what I'm saying. What was shipped were PLUTOIUM implosion cases of the "Fat Man" type. Not the gun-type "Little Boy" style. This is a major difference.

Plutonium was coming on-line at Hanford as the production fissle material for the next generation of atomics, HEU was NOT the direction the new "atomics" were headed.

In the final year of the war, and the atomic bombings of Japan one must remember that it went sort of like this. By recorded document:

July 23: Secretary Stimson, in Potsdam, receives a new target list. In order of choice it is:

Hiroshima, Kokura, and Niigata. He also receives an estimate of atomic bomb availability: The uranium gun-type "Little Boy" will be available for delivery on Aug. 1st. The second plutonium implosion-type "Fat Man" should be ready for use on Aug. 6th , and a third implosion-type might be ready between Aug.17/24th.

Additionally, since the production plants were finally approaching reasonable efficiency, three more plutonium cores should be available in September. With more being produced each month, topping off, or reaching seven a month or more by December.

July 30; The nuclear components are inserted into "Little Boy", bomb unit number L11 on Tinian.

July 31; The assembly of "Little Boy" is completed on Tinian. It is ready for use the next day with only it’s initiators needing to be inserted.

August 1; A typhoon approaching Japan prevents launching an attack with "Little Boy". Several days are required for weather to clear.

August 2; "Fat Man" (implosion type) bomb cases F-31 and F-32 arrive on Tinian (two half cases/one bomb), and "Fat Man" assembly begins.

Oppenheimer cables Groves with a shipping schedule, and Groves reports that the next plutonium core would be ready for shipment on August 12 or 13, with a bombing possible on August 17 or 18.

Aug.11; Oppenheimer believes that the third implosion case will arrive in the Pacific at this time (he missed by a day).

August 12; the un-named (implosion type) bomb cases F-33 and F-34 arrive on Tinian, but the next completed plutonium core that is to be placed in the un-named implosion type bomb sitting on Tinian is recalled from shipment when it arrives in San Francisco and returned to Los Alamos the next day, and not used until the Bikini Island "Operation Crossroads" test. This core and case becomes the "Able" bomb which is air dropped in '46 a year later.

Aug.14; a fourth implosion case is completed, and this unit becomes "Baker" in the Bikini "Crossroads" tests of ‘46 when it is exploded underwater.

So, does this help? There were a total of five "uranium" (HEU) gun-type bombs built, only one was used. The other four were dismantled, and their HEU used in the newer "combo" bombs which appeared by the end of the forties. These were the "concept" bombs which Groves turned down since producing them might retard the production of the original bombs by months.

General Groves felt that changing "design" at the time, and using both the HEU and Plutonium as the cores might be counterproductive as to getting the "atomic" to the field of conflict as fast as possible.

 

I think you're mising the point I'm making. I'm most definitely NOT saying that there was a second Little Boy "uranium gun" device sent to Tinian...

What was sent was two whole sets of mechanical and electrical parts - "just" two of everything - so that onsite the technicians could select, calibrate and assemble the parts THEY tested and selected for use...

Once these steps were completed - this left one whole set of mechanical/electrical bomb parts that were NOT used, were NOT assembled - but could have been.

 

I think you are missing the point I am making. There was a second set of cases of PLUTONIUM bomb types (implosion) existing and those were the two sets of cases existing on Tinian at the time. That they existed on Tinian at the time should be pointed out that they were NOT uranium bomb parts, but the two halves of the next PLUTONIUM type bomb.

I simply wish to point out that the two cases on Tinian were PLUTONIUM not URANIUM type bomb components, and only the cases with the cores held from shipment. You implied they were URANIUM (Little Boy) gun-types, and they were NOT. That is my point only.

 

Having checked my last posts I never said nor implied anything about the availability or not of Plutonium implosion devices. In fact the only mention I made of them at all was this...

I'm not sure how this can be construed as implying anything else about the plutonium bombs.

 

The problem here is that the HEU "gun-type" was NOT duplicated on Tinian, only the plutonium "implosion" type was. There wans't a second uranium type, bomb available at the time on Tinian. There was a third "implosion" type plutonium cases set there. That is the only point I am making.

Your original statement was that there was/were more URANIUM type bombs on Tinian. There weren't. The plutonium type cases were assembled, the plutonium cores were withheld, but the simple gun-types bombs were not SHIPPED to the PTO. Nor were their projectiles, and target HEU fissile materials.

Why should this be a problem? Your original post claimed more "uranium" bombs, that this is wrong is my only point.

 

Unfortunately - this is not correct.

A total of at least six complete Little Boy cases were sent to Tinian; one, L1, was assembled, weighted and practise-dropped on the 23rd of July....followed by four more. This means the "live" Hiroshima bomb, L11, was casing number six used. These were the "bomb units" plural that the Indianapolis carried to Tinian along with the U-235 "bullet" element. Logic would say that there were at least 11 cases if they were numbered L1-11 - but at present I can only evidentially account for the six described above.

(Incidently, there were a total of four test-dropped Fat Man casings before August 9th. This is in addition to the PUMPKIN devices, dummy Fat Man sized and shaped bombs filled with conventional explosives that were dropped on live Japanese targets when training in the mission profile)

 

didn't they test three, the trinity? in new mexico, and in the ocean and somewhere else in the desert? big man and little man, or was that the two for Japan? there were not three bombs ready, and the surrender was there so no need to keep fighting with it.

 

on you tube they have some vids of the trinity and the underwater bomb test. actual military vids. and i read that most of the sailors died not too long after the test, within a few years. they tried to see if the old coast guard carrier vessel could survive an atom bomb. the ship looked like a melted piece of metal, and the guys who salvaged it after the nukes blew in the water , they really got ill first, and worst, the officers on the ships watching the test with the binoculars, and all those seamen, cancer and radiation sickness. but you can also watch them smoking cigarrettes. what a strange time period.

 

No, they only tested a single implosion type plutonium bomb at Alamogordo in the code-named "Trinity" test. The device was simply called "the gadget" and was far to large to be an air-dropped bomb. It was a test of concept, Robert Oppenheimer chose to name this the "Trinity" test, but the name was inspired by the poems of John Donne, not three tests.

 

There were however multiple other tests of nuclear weapons afterwards. A couple at Bikini Atol. Others in the American desert and a fair number underground. In August of 45 there were aparently all the components needed for a 3rd bomb but and it was deployed to the Pacific prior to assembly.

 

Yes there were a great many "tests" post war, both in the Pacific, on American soil, in American airspace, and in space itself.

But, it was on August 12th 1945; that the un-named (implosion type) bomb cases F-33 and F-34 arrive on Tinian. However the next completed plutonium core that is to be placed in the un-named implosion type bomb sitting on Tinian is recalled from shipment when it arrives in San Francisco and returned to Los Alamos the next day, and not used until the Bikini Island "Operation Crossroads" test. This core and case becomes the "Able" bomb which is air dropped in '46 a year later.

By Aug.14th 1945 ; a fourth implosion case is completed, and this unit becomes "Baker" in the Bikini "Crossroads" tests of ‘46 when it is exploded underwater.

Plutonium production is halted at the Hanford plant to see what the Japanese would do, and isn't "re-started" in earnest for quite sometime.

 

Maybe it was because Nagasaki, Hiroshima and Kokura are all in the extreme west of Japan. Maybe the planners wanted to impress some Japanese in the Kanto and east.

 

My understanding was that those plants had been running at overcapacity for some time (monnths). There may have been some worries about what would happen if they stayed in operation too much longer. When the immediate need went away taking them off line and checking them out became a very attractive option.