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Not to put too fine a point on it but what was Chadwick going to say? No, our bomber can't handle it? Of course he's going to say yes. His comment doesn't really mean anything in the scheme of the discussion other than an interesting aside.
While I agree that people not actually involved in the project wouldn't be given specific details, the idea that "a foreign national" wouldn't be allowed access to the programme is absolutely not correct. The British were heavily involved in the Manhattan Project, indeed Roosevelt was suggesting the US actively engage with Britain on nuclear weapons as early as October 1941...and a whole bunch of the "British" participants had very non-British names. I know it's Wikipedia but take a look at British contribution to the Manhattan Project - Wikipedia for more details.
For my money, if Chadwick said it could be done, then you could take that to the bank.
Yes, as I have pointed out, there were even New Zealanders involved, but the point was that Chadwick WAS NOT involved, therefore he would not be privvy to secret information. Ramsey would have supplied him what he could, not necessarily specifics, so Chadwick would have to make an educated guess based on what he knew. The presumption that he received specific details such as engineering drawings, dimensions and such like is hearsay and can only be proven if we know for certain exactly what he received. It is highly unlikely he would have been aware of the code names Thin Man and Fat Man as in 1943 these were used within the Manhattan Project alone.
Again, see above. Unless we know exactly what Ramsey sent him, what these details were, then any stipulation that it could definitely carry a Fat Man is merely speculation until proven otherwise, NOT guaranteed fact. And, as I have pointed out repeatedly before, the drag aspect to carrying such a bomb would be enormous and it would be barely flyable, with the engines working hard to overcome the extra drag - see the definition of drag coefficient, which would eat away at its fuel quantities. It's just not a practicable proposition. Just a heads up, I studied aerodynamics when doing my engineering training, so I do know a little about this sort of thing, but it doesn't take a qualified engineer to see that carrying such a bulbous load underneath it would severely impact its performance.
I was thinking about Sweeney's mission and led me to wonder.
Suppose Bockscar was one of these unicorn Lancasters - would it have been able to follow the exact timeline of eventsbas the actual B-29 or would it have been lost in action?
I've seen a great deal of effort to try and "fit" a Pumpkin Bomb into it's bomb bay, so let's assume the fuselage was widened enough to safely accommodate it's dimensions.
Would it have had enough fuel to not only made the trip from Tinian to the rendezvous point, then on to the primary and secondary target then on to Iwo Jima (Okinawa only in an emergency)? For the record, the Silverplate B-29s had a capacity of 7,250 gallons of fuel.
And what about both the imposed drag penalty of the bulging fuselage as well as additional fuel burn for extended (unscheduled) loiter time?
Nearly an hour was spent trying to find a bombing solution for Kokura before moving on to Nagasaki. Additionally, and extra 15 minutes was spend at Yakushima.
Add to that, the extra fuel consumed during the mission with the altitude change due to bad weather.
And finally, because if the faulty fuel transfer pump, Bockscar could not use 640 gallons if fuel, but instead, had to carry that weight home.
So taking all of these actual events into consideration, could a modified Lancaster have made the exact same journey under the exact same conditions?
Right - due to alternate cruise altitude, exceeding planned loiter time at rendezvous point, nearly an hour spent at Kokura and the diversion to Nagasaki and a faulty fuel transfer pump, meant that there was literally not enough fuel remaing to taxi to the ramp at Yontan field.Sweeney ended up diverting to Okinawa due to lack of fuel. This doesn't negate the main point though.
Right - due to alternate cruise altitude, exceeding planned loiter time at rendezvous point, nearly an hour spent at Kokura and the diversion to Nagasaki and a faulty fuel transfer pump, meant that there was literally not enough fuel remaing to taxi to the ramp at Yontan field.
Someone else brought up the point of unfavorable wind conditions earlier and this may have been the case for the inbound leg. The rendezvous was changed from Iwo Jima to Yakushima and the cruise altitude was raised to 17,000 feet due to "poor weather". As it happens, the poor weather was actually a monsoon - which explains why Kokura, Nagasaki and everything else was obscured by clouds.
Something else that might be interesting to note, is that three hours into the mission, Fat Man armed itself. Ashworth and an assistant actually worked on the bomb and resolved the issue (two switches had been reversed) - a point that is often overlooked in this thread: the bomb (Little Boy and Fat Man) needed to be accessed by the Weaponeer.
The presumption that he received specific details such as engineering drawings, dimensions and such like is hearsay and can only be proven if we know for certain exactly what he received. It is highly unlikely he would have been aware of the code names Thin Man and Fat Man as in 1943 these were used within the Manhattan Project alone.
Again, see above. Unless we know exactly what Ramsey sent him, what these details were, then any stipulation that it could definitely carry a Fat Man is merely speculation until proven otherwise, .
What you are proving is that no amount of evidence will ever be sufficient for you:
Ramsey was assigned to head the Delivery Group of the Ordnance Division and later
served as deputy to Pasion." His immediate tasks were to design the bomb casings that
would carry the gun-assembly bomb and implosion bomb. By the end of 1943 it had
already been established that the gun-type bomb-Thin Man-would weigh on the order
of five tons. Ramsey assumed that the implosion bomb would weigh approximately the
same. Given their size and weight, there were only two possible choices for an aircraft to
deliver the weapons, the British Lancaster or the American B-29, which had begun
production in September.
Ramsey favored the Lancaster and traveled to Canada in early October 1943 to meet Roy
Chadwick, the plane's chief designer, Chadwick was in Canada to observe the initial
Lancasters coming off the production line at the Victory Aircraft Works, Milton Airdrome,
in Toronto. Ramsey showed Chadwick preliminary sketches of the large-thin-shaped and
stubby shaped-bombs and later wrote with more details.(12) Chadwick assured Ramsey that
the Lencaster could accommodate them.
When Ramsey returned, he wrote to Parsons suggesting that the Lancaster be seriously
considered and planned a memo to General Groves recommending that a modified
Lancaster be used.(13)The bomb bay was thirty-three feet long and sixty-one inches wide.
The depth was only thirty-eight inches, but this could be modified. The Lancaster's ceiling
was 27,000 feet, its speed 285 miles per hour, and takeoff required only 3,750 feet of runway
-a critical matter wherever it would be based.
(12). Norman F, Ramsey Jr. to Roy Chadwick, October 23, 1943, Folder Dr. Norman Ramsey, Box 6,
Tolman Files, RG 227/81, NARA.
(13). Memo, N. F, Ramsey to Capt. W. . Parsons, October 14, 1943, Lancaster Aircraft, Folder Dr Norman Ramsey... NARA
" (Norris, pages 316-317 Racing for the Bomb)
Again, the actual FAT MAN width was 60.25in or less.
That sounds like SOP for normal B-29's. The FI engine in the Silverplate was better, but still needed the crew on their A game.The Grand Slam carrying B.I Specials were dogs to fly and even in the Lancaster I and III's handling notes, at MTOW the aircraft can only be flown straight and level until its weight is below 63,000lbs. Oil temps in the climb were at their highest levels before the engines overheated and the climb had to be skillfully managed, the engines themselves reached extreme temperatures and handling was severely degraded. Not the best condition to be in on a long haul bombing operation of such importance.
As to the drag question, again it rather depends on the changes made to the Lancaster to perform the mission. The Lancaster's overall drag could be considerably reduced by removing the H2S blister and mid-upper turret, and replacing the front turret and perhaps the bomb aimer window with a more streamlined design. Such changes would introduce some trade space from a performance perspective.
you won't give up on trying to smear Ramsey and Chadwick's competence:
(1)With aircraft that are heavily laden, around 20 percent of their total fuel load is used just to get off the runway (a value roughly calculated in a class exercise using a 747, its total fuel load and its MTOW versus its speeds and acceleration).
(2) Nothing of the sort, so watch it.
(3) So your argument, which comprises an utter lack of understanding of the basics of aviation, fabrications and sheer fantasy are not an insult to their efforts? Lancaster VIs with miracle engines that never fail??? Silverplate Lincolns??? The ability to carry Fat Man with no impact on the aircraft's performance at all??? Fantasy fuel loads???
1) Twenty percent?
(2) Sure sounds like it.
If a careful start up, taxi, run-up and extra checklist followed because of the payload and mission, I'd say more like 10 to 20 minutes. Even in the tropics, I don't see the engine oil warming up to TO temps in less than 5 minutes. Shoot, when I fly my 172 it could take 5 minutes just to get to the run-up area and that's when I'm the only one on the field!Fuel consumption for TO = fuel burned for warm-up and taxi and then fuel burned at full throttle during the acceleration to TO speed, and given that the runways are less than 10K ft long, this cannot exceed ~1min.
1) Yup, 20 percent. You really don't know about this stuff, do you...
2) Nope, again, you are seeing something and misinterpreting it.
The original target for the atomic bomb was Germany, not Japan, and that eliminates some of the issues with the Lancaster's range.
1) Rather than admit to a rather obvious mistake, you double down on it..