Was the B-29 Superfortress a Failure?

[FLYBOYJ]

What do you base that on? The nuclear mission was part of the design process, important parts of the specifications, but the reason withheld from all but a few.

It was not initially.

The B-29 began development long before anyone was thinking about using it as the first nuclear delivery system (Boeing began studies as far back as 1938 into the development of a long range "superbomber"). The Official AAF solicitation that led to the B-29 was released in December, 1939 and I doubt anyone that far back envisioned "Boeing Model 345" as a nuclear bomber. If you have references to the contrary, please enlighten us.

As a matter of fact the Lancaster was briefly considered as the initial platform by Norman Ramsey, one of the architects of the atomic bomb, but that idea was quickly squashed by AAF brass.

Even after it was decided to put "all the eggs in one basket," modifications had to be made on the production line to those aircraft that would support the nuclear mission (Silverplate)

 

[SplitRz]

What do you base that on? The nuclear mission was part of the design process, important parts of the specifications, but the reason withheld from all but a few. Marshall's bio touches on that, and so tightly controlled that less than a couple dozen knew of the linkage of the bomb and B-29 before late '44. Note that VP didn't even know of the device.

Really? This is something of a brain-tickler for me.

The design work on the B29 commenced in 1938, the air-corps issued the specification in 1939 - and Boeing submitted their design proposals in 1940. I'm not saying that the design didn't have changes incorporated into it during production for the aircraft that carried the bomb into action, but it sounds like a huge leap to assert that the nuclear mission was incorporated into the original specification in any meaningful way. Surely it was more simply being designed as a state of the art bomber, designed to carry as big a bombload as fast, high and far as possible and delivered as accurately as possible, with a view to potentially bombing Germany from the USA? Those parameters would apply to large conventional weapons regardless of any future 'wonder weapon' - which in 1939 was purely theoretical.

No one at that stage knew if the bomb was a viable proposition, how long it would take to produce, or what size, weight or operational conditions it would entail. The Manhattan project that would begin to answer those questions didn't even properly initiate until 1941 - around about the time that Boeing was ALREADY receiving its initial production orders.

So, like I said, I can understand potential nuclear carriage design features being added into the established basic design later on in the production run once the basics of the bomb had been calculated and confirmed later on through '42/3/4 and 5 but I'm finding the assertion that it went back further than that difficult to swallow at the moment.

"important parts of the specifications".... I'm not being confrontational, but like what? What would differentiate them from any other state of the art bomber design? Logic would dictate that if they were inherent to the idea that a nuclear role was predicted back at the initial specification and design stage, that they must surely have also been written into the Consolidated Model 33 / B32 as the back up? Were they?

Sorry - firing lots of questions there.

 

[fannum]

Please, let's not nitpick and choose to interpret to fit your agenda. I know sites like this live on fans and minutiae, but let's leave the making data fit the agenda to the politicos.
Note that I said "design process" and not initial design.
Remember that the B-32 was conceived as a follow-on to the B-24, using the same design team and much of the technology. It was also planned to have pressurization and integrated turret fire control, but that was dropped quickly, basically so the less complex B-32 could back up the B-29 if it was delayed. By the time they were in production, the top decision makers made both nuclear capable so from some point in the process, both the bomb and these aircraft were linked in their development.
They all were tied to the mission, with specifications of each interlinked.

 

[FLYBOYJ]

Please, let's not nitpick and choose to interpret to fit your agenda. I know sites like this live on fans and minutiae, but let's leave the making data fit the agenda to the politicos.
Note that I said "design process" and not initial design.

Well it seems to me, by that statement you're trying to tip toe back - there's no political agenda here, just facts. Perhaps you should be more specific!

Remember that the B-32 was conceived as a follow-on to the B-24, using the same design team and much of the technology. It was also planned to have pressurization and integrated turret fire control, but that was dropped quickly, basically so the less complex B-32 could back up the B-29 if it was delayed. By the time they were in production, the top decision makers made both nuclear capable so from some point in the process, both the bomb and these aircraft were linked in their development.
They all were tied to the mission, with specifications of each interlinked.

I do not believe any B-32 was modified to carry a nuclear weapon, again, if you have a reference stating otherwise, please enlighten us and I'll accept your references with no agenda to the politicos!

 

[fannum]

Let's not belabor history with semantics and nitpicking.
I believe I was clear, and some subsequent statements jumped back to 'initial specifications.'
Note this was an over 6 year design to mission process, and many changes were made as the reality of the conflict dictated. Both aircraft were designed with a bomb bay to accommodate the weapons and vice versa. The "Silverplate" mods were Boeing specific, and as far as I know, by that time, the B-29 had proven itself, and B-32s were no longer considered for the mission.
If you visit the nuclear museum at Kirtland AFB, they had exhibits dealing with weapon delivery, and how the 'devices' were adapted to fit the potential vehicles. The first packages were far too long, too wide and/or too heavy for previous aircraft.
My key point is that the weapons and the aircraft were developed hand in hand.

 

[Thumpalumpacus]

My key point is that the weapons and the aircraft were developed hand in hand.

When the specification for what became the B-29 was released, there not only was not an atomic bomb in design, the proof-of-concept for that that weapon (Chicago, 1942) had not yet demonstrated the process of fission.

It follows that the design work on the B-29 was started without any nuclear weapons in mind except, perhaps, in the vaguest terms. The fact that the B-29 had to undertake Silverplate modifications in order to perform that mission is strong evidence that it was not designed to deliver the nukes that were eventually dropped.

That isn't semantics or nitpicking, it's just reading the design history of both programs.

No doubt that by 1942, mods to the B-29's design perhaps started being influenced by a possible nuclear mission, but even so, I think it's fair to say that it was not designed in conjunction with the first A-bombs, because the Boeing engineers had no idea what the Manhattan Project would present in terms of size and weight of ordnance. They didn't have the needed security clearances. But the historical timelines of both programs simply don't line up enough to allow for the plane to be designed for the bomb.

 

[GrauGeist]

The Manhattan Project was able to create Plutonium in 1942 and it would be still two years before they would know if it would be able to work in a bomb.

The B-29 was modified through the Silverplate program to be capable of carrying either bomb and it was ONLY the Silverplates that were capable of it.

The B-32 would have needed extensive modifications to carry either one of the Atom bombs, because of it's two bomb bays in relation to the main wing.

The only other WWII bomber that saw service in WWII, that had the lift ability, range and large enough bomb bay, was the Lancaster.

 

[SplitRz]

Please, let's not nitpick and choose to interpret to fit your agenda. I know sites like this live on fans and minutiae, but let's leave the making data fit the agenda to the politicos.
Note that I said "design process" and not initial design.
Remember that the B-32 was conceived as a follow-on to the B-24, using the same design team and much of the technology. It was also planned to have pressurization and integrated turret fire control, but that was dropped quickly, basically so the less complex B-32 could back up the B-29 if it was delayed. By the time they were in production, the top decision makers made both nuclear capable so from some point in the process, both the bomb and these aircraft were linked in their development.
They all were tied to the mission, with specifications of each interlinked.

I don't think Flyboy or I were 'nitpicking'. For my part, I was reacting to your exact words, if not their intended meaning. Even if both he and I (apparently coincidentally) misinterpreted them in the same way. You didn't say changes were made 'during development' or 'during production' - if you had, I doubt either of us would have questioned your premise at all. The difference historically speaking, between a purpose designed nuclear bomber and a bomber developed into being nuclear capable, would be pretty huge - and given the timeline, might start to stray into tin-foil hat/revisionist history territory (and it does happen round here from time to time!) GrauGeist pointed out that the B29s altitude and speed performance - the things you said which made it uniquely suited for it to carry out the nuclear role - were:

"... an unexpected benefit of the B-29's design, not intentional."

You challenged him and asked him where he got that, and then you stated that the nuclear role was part of the design and specification. But they were coincidental (if opportune), weren't they?

The relatively moderate improvements to speed and altitude by removing defensive guns and crew during development of Silverplate only put a gloss on the performance of an aircraft that had its form and design set several years before. Your wording made it possibly sound like you were suggesting that a nuclear role had been secretly entered into the performance specification from the get-go. You can see that?
If your initial proposition was unclear to some, just clarify it - no need for pejorative terms. People will entirely understand and get it (I've confused yards for feet in an earlier post, giving a Dragon Rapide a Harrier-like take-off performance. I've just had to clarify that! )

I have no idea what agenda you think either of us have. All I want to for my part is understand history and the tech. And as my knowledge is far from complete, I always like to ask questions and seek clarity!

My agenda is simply to learn.

 

[SplitRz]

The only other WWII bomber that saw service in WWII, that had the lift ability, range and large enough bomb bay, was the Lancaster.

It just needed another 12,000ft of ceiling carrying that weight not to be reduced to aluminium ingots, I suspect

Actually, thats an interesting point. Given that even Skyraiders were nuclear capable later on, what were the minimum distances dictated by speed and altitude to escape the blast of those early nukes?

Lift, range and bomb bay aside, what about being able to get far enough away either through altitude or speed (or both) from the explosion?

 

[GrauGeist]

I'm not sure of the minimum allowable clearance for the blast radius.
I know I've read it in the past, but I'm sitting on the porch, on this crappy cellphone at the moment - perhaps one of the others might know?

The Lancaster did improve over the years (as most types did) and I beleive in 1944, Avro made a limited production of Lancs that *may* have worked, it was the Mk.VI and had a performance close to what was required of the B-29.

We actually had a great discussion about this very thing a few years back, too.

 

[FLYBOYJ]

Let's not belabor history with semantics and nitpicking.

That's fine - I think my historical facts were quite clear and free of "semantics and nitpicking.

I believe I was clear, and some subsequent statements jumped back to 'initial specifications.'

If you say so...

Note this was an over 6 year design to mission process, and many changes were made as the reality of the conflict dictated.

Agree 100%

Both aircraft were designed with a bomb bay to accommodate the weapons and vice versa. The "Silverplate" mods were Boeing specific, and as far as I know, by that time, the B-29 had proven itself,

The only B-29s that had modified bomb bays were the Silverplate models. Production model B-29s had bomb bay doors known as "Briggs Doors" which consisted of four units. The Silverplate prototype, known as "Pullman" began modifications in November 1943 and first flew at Muroc in March 1944. The first 17 Silverplate B-29s were ordered in August 1944.

Silverplate modified B-29s were actually completed at the Martin Facility, Omaha Nebraska.

The first B-29 arrived at Wright Field, Ohio, on December 2 and underwent extensive modification to the bomb bay. To accommodate the length of the gun-type shaped weapon (Little Boy was originally supposed to be approximately 17 ft, but was later reduced to 10 ft), engineers removed the B-29's four bomb bay doors and the fuselage section between the bays and replaced them with a single 33 ft bomb bay. This modification project resulted in the removal of all the rear gun stations. Each plane was designed to carry either type of device; either Little Boy type in the forward bay or Fat Man type in the rear. New bomb suspensions and bracing were also implemented and separate twin-release mechanisms were mounted in each bay. Engineers also placed motion picture cameras in the bays to record the test of the new release mechanism.

Project Silverplate - Nuclear Museum

Project "Silverplate" was the code name for the program to produce a special version of the B-29 capable of delivering the atomic bomb.

www.atomicheritage.org

No semantics, no nitpicking, just facts!

and B-32s were no longer considered for the mission.

So you agree, no B-32s were ever modified in the same fashion as Silverplate?

If you visit the nuclear museum at Kirtland AFB, they had exhibits dealing with weapon delivery, and how the 'devices' were adapted to fit the potential vehicles. The first packages were far too long, too wide and/or too heavy for previous aircraft.

I have and there's also nice display at Wendover Airport with an actual "Little Boy" (of course de-armed) on display.

My key point is that the weapons and the aircraft were developed hand in hand.

And my key point is they didn't start out that way - no nitpicking, no semantics, just facts!

 

[Thumpalumpacus]

I'm not sure of the minimum allowable clearance for the blast radius.
I know I've read it in the past, but I'm sitting on the porch, on this crappy cellphone at the moment - perhaps one of the others might know?

I don't know the exactments, but I'm pretty sure there was a high-speed diving turn involved, at least with the two wartime drops. The toss-bombing thing with subsonic jets was also partly caused by the need to get away from blast-radius as well, to my understanding.

 

[GrauGeist]

The yield of Little Boy and Fat man were much less than later versions.
Going by memory, the delivering B-29 and the monitoring B-29s were all at a level course.

 

[wuzak]

Note this was an over 6 year design to mission process, and many changes were made as the reality of the conflict dictated. Both aircraft were designed with a bomb bay to accommodate the weapons and vice versa.

Really?

The first nuclear device detonation was in July 1945. It was of the same design as Fat Man, which would be dropped on the second mission. Note that Fatman could not fit or be carried inside a standard B-29 bomb bay. It required a different rack system using a British-style single point lug (US bombs had 2 lugs).

The first bomb dropped over Japan was Little Boy. It was a gun type device. It too would not fit in a standard bomb bay, requiring a different bomb rack with a British-style single point lug.

But Little Boy was not the first gun type device. That was Thin Man, which used plutonium instead of uranium, and was 7 feet longer at 17 feet overall. Thin Man could not fit in the B-29's forward bomb bay, nor would it fit in the rear bomb bay. It was the reason the Lancaster was considered at all for carrying the bomb. It is why the B-29 modification program started, and why the first Silverplate modifications were more extensive than the production Silverplate versions.

 

[Thumpalumpacus]

The yield of Little Boy and Fat man were much less than later versions.
Going by memory, the delivering B-29 and the monitoring B-29s were all at a level course.

These more or less repeat what I've read in books over the years:

The bomber, piloted by the commander of the 509th Composite Group, Colonel Paul Tibbets, flew at low altitude on automatic pilot before climbing to 31,000 feet as it neared the target area. At approximately 8:15 a.m. Hiroshima time the Enola Gay released "Little Boy," its 9,700-pound uranium gun-type bomb, over the city. Tibbets immediately dove away to avoid the anticipated shock wave.

Manhattan Project: The Atomic Bombing of Hiroshima, August 6, 1945

The device reached its detonation altitude of 1,890 feet agl in 83 seconds. In that brief time, Tibbets had to get the Enola Gay to a slant range of at least eight miles from the blast. Using an escape maneuver he had practiced over Utah, he muscled the airplane into a 60-degree-bank, 155-degree right turn. He lost 1,700 feet and leveled off heading directly away from the target at maximum power. This left his tail gunner, George Caron, with the best view of a sight "beyond imagination."

https://www.aopa.org/news-and-media/all-news/2020/august/pilot/musings-enola-gay

 

[GrauGeist]

Ok, found the thread about the Lancaster as a possible platform for Atom bomb delivery.

The reason why I thought it may be relevant, is because of the mountain of information regarding the B-29s involved.

The Lancaster as a potential nuclear bomber in 1945

Okay, so I thought instead of continuing to hijack the other thread, I'd make a new one, because despite my objection to the initial suggestion (and I'll reveal why soon) whykickamoocow's thoughts on this are intriguing and have some merit, and have obviously sparked a bit of discussion. So...

ww2aircraft.net

 

[FLYBOYJ]

Ok, found the thread about the Lancaster as a possible platform for Atom bomb delivery.

The reason why I thought it may be relevant, is because of the mountain of information regarding the B-29s involved.

The Lancaster as a potential nuclear bomber in 1945

Okay, so I thought instead of continuing to hijack the other thread, I'd make a new one, because despite my objection to the initial suggestion (and I'll reveal why soon) whykickamoocow's thoughts on this are intriguing and have some merit, and have obviously sparked a bit of discussion. So...

ww2aircraft.net

We had several threads about this, lots of information and many reasons to show that the use of the Lancaster was not a good idea in the end.

 

[GrauGeist]

We had several threads about this, lots of information and many reasons to show that the use of the Lancaster was not a good idea in the end.

Agreed, however, aside from great data behind the Silverplates and the bombs, there's also several references where the higher-ups ruled out the Lancaster (for several reasons).

*if* the B-29 had been designed with atom bomb delivery in mind from the outset, here would not have been any discussion at all about the Lancaster as an option by the AAF.

 

[FLYBOYJ]

I believe someone posted a pretty detailed drawing that showed Fat Man would not fit in the Lancaster, or it it did there was just about no clearance on either side of the bomb bay.

 

[GrauGeist]

I recall that as well.

Without going through the thread, I seem to recall that Fat man was close to the dimensions (width) of the British Upkeep bomb that the Lanc delivered and that took some heavy mods and created quite a bit of drag, since it could not be carried completely in the bomb bay.