Thread by @garius

Right. It's Friday. So have a (relatively) short history thread!

Let's talk about the plan to use Lancasters, not B29s drop the first atomic bombs.

Because I've noticed this story popping up a fair bit again recently. And there's truth in it, but often surrounded by myth. /1

Let's get one thing out of the way first:

Lancaster bombers COULDN'T have done the Hiroshima/Nagasaki raids, as flown. This is the thing I've been seeing thrown around and it's just plane wrong. (😉)

Got that? Coolio.

But there's a nugget of truth here. Here's what happened:

Meet Norman Ramsey Jr. Ramsey headed up the E-7 Group within the Manhattan Project. He was the chap in charge of working out how to actually get the big explodey bombs (once built) to the target.

This was not easy. From the beginning, it was clear they'd be rather big.

More critically, it looked like the bombs would be rather long. This was because, at this point, gun-type bomb was looking likely. For this, you literally shoot a bunch of radioactive material into more radioactive material to get a big explosion.

"Thin Man" was 5m long (!!)

So Ramsey started looking at possible delivery options, and very quickly realised there was a problem. The Americans LITERALLY didn't have a bomber in service that could carry something that size.

But he suspected the RAF did: The Lancaster.

So Ramsey starts trying to find out if a Lancaster can carry the atomic bomb. Without actually being able to TELL anyone he wanted it to carry an atomic bomb.

Luckily, he learned that Roy Chadwick, the Lancaster's legendary designer, was visiting Canada.

He hops over to see him

Through what I presume was a lot of nudges, winks, scrawled notes and deliberately NOT asking certain questions in a way that meant that were implied, the two engineers managed to work out together that you could probably adapt a Lanc to carry gun-type atom bombs.

So Ramsey returns to the US, satisfied that he has at least ONE option on the table. But it's not his preferred one. Because the US has ONE plane, in development, that MIGHT be able to do it.

The B29.

Assuming Boeing can stop their prototypes crashing and catching fire.

Ramsey believes "crashing and catching fire" is a bad trait in a potential atomic bomber.

But there's also another problem: on paper it's bomb bay is long enough, but when he sneaks a look at one on a tour of Boeing he realises there's a spar running across the middle of it.

So Ramsey goes to General Groves, head of the Manhattan Project, and tells him that they may, MAY have to ask the British for some Lancs.

Groves, seeing the political shitstorm of dropping their first bomb from a British plane, gives him serious side-eye. They delay a decision.

~~~ wobblylines ~~~

Time passes. Groves/Ramsey are starting to worry. They need to make a decision soon and the whole explodey, crashy, weird spar placementy B29 saga is still ongoing.

Groves realises he's gonna need to go to Air Chief Hap Arnold, and warn him of the Lanc thing

Now Groves has two reasons for doing this. Firstly: because they need to start test flights soon, and that means if they ARE going to use Lancs eventually, they need to start it soon.

But also because he knows EXACTLY what Hap's reaction will be.

Here's how Groves' conversation with Hap Arnold over their likely heavy bomber options for the bomb went:

Now here's the critical thing to understand, which the myths about this tend to skip over:

Groves DIDN'T want to use Lancs. He wanted B29s and he was, essentially, gambling on Arnold losing his shit to such a level that he stuck a rod so far up Boeing's arse they'd deliver.

But he also wasn't stupid. And he kept the Lancaster plan theoretically on the table as a 'last ditch' backup option, if Boeing couldn't deliver a reliable plane in time and if Project Silverplate (the plan to adapt the B29 for the bomb) didn't work.

Groves' plan worked. Arnold stuck a fire under Boeing and Silverplate produced a workable delivery platform.

This was helped by delays to bomb construction which meant the testing date slipped. And then Japan, not Germany, became the target, which favoured a B-29 drop as well.

So THAT is the story behind Lancs potentially dropping the A bomb.

Indeed Groves and Ramsey, because they were good at their jobs, still clearly kept one eye on reverse Lend-Leasing Lancs and modding them as an emergency quick backup plan well into the delivery project.

We know this because there's an account of Colonel Tibbets, who flew Enola Gay and led the overall bombing mission, in which he admits Groves got him to cert for the Lancaster.

But he ALSO said that Groves told him he hoped not to use them, and it would help scare Arnold.

So that is the complete, myth-free story of how close Lancs came to dropping the bomb.

Not very close, in terms of timelines, but it would ONLY have taken the B29 to run into even more problems for it to become a choice between that or delaying a drop into 1946.

Cool. Now with the facts done, let's address the two big elephants in the room:

1) Talk of mysterious RAF 'Black Lancasters' being trained up to drop the A Bomb.
2) Could Lancs have actually carried out the mission as it ended up happening?

Black Lancasters first. The story normally goes something like:

A small number of unmarked, Black Lancasters showed up at Enstone in 1943. They began training to drop the bomb in secret, then were disbanded when the target shifted to Japan and/or the Silverplate B29s were ready.

Sounds cool/likely, right? Indeed it pops up in lots of places as fact.

Well I've looked into this many times over the years. I've NEVER found evidence of it that doesn't trace back to one single report by a local farmer after the war. Recorded here: chippingnorton.net/Features/aviat…

So unless someone out there has evidence that the RAF thought it was a good idea to train a bunch of special bombers REALLY OBVIOUSLY (if you wanted to keep it secret you don't paint them a different colour and remove their markings ffs) I'm calling 'tall tale' on it.

Not to mention that, if Tibbets is to be trusted (and he was not prone to tall tales) then even if the plan HAD involved Lancs, it wouldn't have been the Crabs flying them.

It'd be US Pilots. And they'd probably be modded Lancs made by the Canadians, to help preserve op secrecy.

Which brings us to the final question:

Could the Lanc have pulled off the mission as it went down? No.

The Lanc was the FINEST bomber of its generation. But by 1944 even the RAF knew it was old tech pushed to its absolute limit.

But they COULD have used it differently.

No one wants me to go into detail here. And, frankly, the easiest way to pick a fight on an aviation message board is to ask 'innocently' if a Lanc could have done the A bomb mission.

It couldn't. They didn't have the range AS BUILT in near-tropical conditions.

But (and this is the thing that aviation math nerds tend to forget) THAT'S OKAY.

Because the bombing mission was designed around the B-29's capabilities.

No B-29? You design it round the Lanc instead.

What's important is that a Lancaster, given sufficient love as the B-29 was with Silverplate to address its key issues, probably COULD fly high enough to do the missions solo, and probably could pull off enough of a handbrake turn-and-dash to survive the blast.

But it COULDN'T do the range. So they would have had to modify the operational stages or do in flight refueling.

On the basis of 'keep it simple' you can probably assume it would have been the former, not the latter.

(Which the Lanc could do. Ask me about Tiger Force sometime)

So the likely result, if it WAS Lancs, is that they'd be American flown, modified Lancs still staging from Tinian Island (out of Japanese attack range, which was seen as critical), but without the legs to get back.

Tinian > Targets > Okinawa would have been the outcome.

Very much not ideal. A MUCH higher risk profile (as you risk losing the returning planes and observers before they can refuel and leave Okinawa).

But needs must.

And this is actually what Sweeney, in Bock’s Car had to do after Nagasaki due to fuel issues.

Anyway. There you go. Lancs and A Bombs. The full story. Myth free.

And (in my opinion) it doesn't need any myths. It's bloody fascinating without.

/END

Yes. You'd likely be looking at something similar to the B.I. Specials.

Without going full nerd (nobody wants that) the key thing would be better engines for greater ceiling/speed, lopping off turrets and a guppy belly to deal with the Fat Man bomb.

https://twitter.com/graemefowler/status/1433824670739046400

You'd never get enough range to do Tinian > Target > Tinian though. People wave the Operation Catechism (sinking of the Tirpiz) numbers around as evidence the Lanc had range. But they forget:

1) tropical operation hits fuel harder
2) nasty Pacific head winds.

But tbh this is why I tend to blank out when it pops up on Aviation forums as an argument.

It turns into a bunfight on whether a Lanc could do the EXACT same mission as the B-29s did.

But that's not how operational planning WORKS. You plan around what you have. Simples.

I'll deffo do a thread on Tiger Force at some point. That involved testing both saddle tanks and IFR on Lancs. And IFR worked.

You wouldn't for the atomic drops though.

Why?

Too many planes. Bomber + 2 observers. That's a LOT of complexity/risk to fuel.

https://twitter.com/concretebadger/status/1433830457389555717

Oh, and obviously as usual if this was interesting or useful (feel free to wave it at someone the next time they tell you tall Lancaster tales) then you can buy me a coffee, here:

ko-fi.com/garius

Yup. There's a whole side thread that can be done on how the development of an implosion device meant that the Lanc's length was less necessary by time of drop.

But Chadwick saw the implosion dimensions and was confident a Lanc could do it if needed.

https://twitter.com/BachPropagate/status/1433835166443708439

I think you need a lot of things to go differently before you can, with any confidence, say that the original target would have been in Germany.

Most critically: D-Day has to fail. First official target committee met after D-Day.

https://twitter.com/gcw09/status/1433841673163919362

I know I mention it up thread in passing, and that's because it IS the first target mentioned in the earliest conversations.

So it was true at the point we were at in the thread - i.e. very early on - but by the time of official planning it was long past a consideration.

Basically, at no point did Groves end up needing to plan for an atomic attack on Germany. By the time the Project was mature enough for that level of detail, it was pretty clear Germany was done.