Dash119
Senior Airman
Ditto...
The Lancaster as a potential nuclear bomber in 1945
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FLYBOYJ
"THE GREAT GAZOO"
Actually it was LEMAY who made the comment - "After meeting on Guam with Col. Tibbets and Major Sweeney, General Curtis LeMay, chief of staff for the Strategic Air Forces, confronted Sweeney, stating "You f*#ked up, didn't you, Chuck?" to which Sweeney made no reply.
Charles Sweeney - Wikipedia
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
The things one learns here.
FLYBOYJ
"THE GREAT GAZOO"
I think the only reason why Sweeney wasn't court-martialed was because the mission objective was achieved and LeMay was all about results.
This is from pages 344-346 of Groves' Now it can be told:
"...One very serious problem came up just before take-off, which
placed Farrell in the difficult position of having to make a decision
of vital importance without the benefit of time for thought or con-
sultation. Despite all the care that had been taken with the planes,
the carrying plane was found at the last moment to have a defective
fuel pump, so that some eight hundred gallons of gasoline could not
be pumped to the engines from a bomb bay tank. This meant that
not only would the plane have to take off with a short supply of fuel,
but it would have to carry the extra weight of those eight hundred
gallons all the way from Tinian to Japan and back. The weather was
not good, in fact it was far from satisfactory; but it was good enough
in LeMay's opinion, and in view of the importance of dropping the
second bomb as quickly as possible, and the prediction that the
weather would worsen, Farrell decided that the flight should not be
held up. Just before take-off Purnell said to Sweeney, "Young man, do
you know how much that bomb cost?" Sweeney replied, "About $25
million." Purnell then cautioned, "See that we get our money's worth."
Because of the weather, instead of flying in formation, the planes
flew separately. To save fuel, they did not fly over Iwo Jima but went
directly to the coast of Japan. Their plan was to rendezvous over the
island of Yokushima, but this did not work out. The planes were not
in sight of each other during their overwater flight and only one of the
observation planes arrived at the rendezvous point. The missing plane
apparently circled the entire island instead of one end of it, as it was
supposed to do according to Sweeney's plans. Although Sweeney had
identified the one plane that did arrive he did not tell Ashworth. Un-
fortunately, because it did not come close enough, Ashworth was
unable to determine whether it was the instrument-carrying plane,
which was essential to the full completion of the mission, or the other,
which was not. Sweeney's orders were to proceed after a short delay
of fifteen minutes but he kept waiting hopefully beyond the deadline,
The result was a delay of over half an hour before they decided to go
on to Kokura, anyway.
At Kokura, they found that visual bombing was not possible, al-
though the weather plane had reported that it should be. Whether this
unexpected condition was due to the time lag, or to the difference
between an observer looking straight down and a bombardier look-
ing at the target on a slant, was never determined.
After making at least three runs over the city and using up about
forty-five minutes, they finally headed for the secondary target,
Nagasaki, On the way they computed the gasoline supply very care-
fully, Ashworth confirmed Sweeney's determination that it would be
possible to make only one bombing run over Nagasaki if they were
to reach Okinawa, their alternate landing field. If more than one run
had to be made they would have to ditch the plane they hoped near
a rescue submarine.
At Nagasaki, there was a thick overcast and conditions at first
seemed no better for visual bombing than at Kokura. Considering
the poor visibility and the shortage of gasoline, Ashworth and Sweeney
decided that despite their positive orders to the contrary, they had
no choice but to attempt radar bombing. Almost the entire bombing
run was made by radar; then, at the last moment, a hole in the clouds
appeared, permitting visual bombing. Beahan, the bombardier, syn-
chronized on a race track in the valley and released the bomb. Instead
of being directed at the original aiming point, however, the bomb was
aimed at a point a mile and a half away to the north, up the valley
of the Urakami River, where it fell between two large Mitsubishi
armament plants and effectively destroyed them both as producers of
war materials.
On the way to Okinawa warning ditching orders were announced;
but the plane made it with almost no gas left. Sweeney reported there
wasn't enough left to taxi in off the runway.
The Nagasaki bomb was dropped from an altitude of 29,000 feet.
Because of the configuration of the terrain around ground zero, the
crew felt five distinct shock waves.
The missing observation plane, which fortunately was the one
without the instruments, saw the smoke column from a point about
a hundred miles away and flew over within observing distance after
the explosion. Because of the bad weather conditions at the target, we
could not get good photo reconnaissance pictures until almost a week
later. They showed 44 per cent of the city destroyed. The difference
between the results obtained there and at Hiroshima was due to the
unfavorable terrain at Nagasaki, where the ridges and valleys limited
the area of greatest destruction to 2.3 miles (north-south axis) by
1.9 miles (east-west axis). The United States Strategic Bombing Sur-
vey later estimated the casualties at 35,000 killed and 60,000 injured.
While the blast and the resulting fire inflicted heavy destruction on
Nagasaki and its population, the damage was not nearly so heavy as
it would have been if the correct aiming point had been used. I was
considerably relieved when I got the bombing report, which indicated
a smaller number of casualties than we had expected, for by that
time I was certain that Japan was through and that the war could
not continue for more than a few days."
So Sweeny was truly between a rock and a hard place, and was forced by circumstances to make on the spot decisions
"...One very serious problem came up just before take-off, which
placed Farrell in the difficult position of having to make a decision
of vital importance without the benefit of time for thought or con-
sultation. Despite all the care that had been taken with the planes,
the carrying plane was found at the last moment to have a defective
fuel pump, so that some eight hundred gallons of gasoline could not
be pumped to the engines from a bomb bay tank. This meant that
not only would the plane have to take off with a short supply of fuel,
but it would have to carry the extra weight of those eight hundred
gallons all the way from Tinian to Japan and back. The weather was
not good, in fact it was far from satisfactory; but it was good enough
in LeMay's opinion, and in view of the importance of dropping the
second bomb as quickly as possible, and the prediction that the
weather would worsen, Farrell decided that the flight should not be
held up. Just before take-off Purnell said to Sweeney, "Young man, do
you know how much that bomb cost?" Sweeney replied, "About $25
million." Purnell then cautioned, "See that we get our money's worth."
Because of the weather, instead of flying in formation, the planes
flew separately. To save fuel, they did not fly over Iwo Jima but went
directly to the coast of Japan. Their plan was to rendezvous over the
island of Yokushima, but this did not work out. The planes were not
in sight of each other during their overwater flight and only one of the
observation planes arrived at the rendezvous point. The missing plane
apparently circled the entire island instead of one end of it, as it was
supposed to do according to Sweeney's plans. Although Sweeney had
identified the one plane that did arrive he did not tell Ashworth. Un-
fortunately, because it did not come close enough, Ashworth was
unable to determine whether it was the instrument-carrying plane,
which was essential to the full completion of the mission, or the other,
which was not. Sweeney's orders were to proceed after a short delay
of fifteen minutes but he kept waiting hopefully beyond the deadline,
The result was a delay of over half an hour before they decided to go
on to Kokura, anyway.
At Kokura, they found that visual bombing was not possible, al-
though the weather plane had reported that it should be. Whether this
unexpected condition was due to the time lag, or to the difference
between an observer looking straight down and a bombardier look-
ing at the target on a slant, was never determined.
After making at least three runs over the city and using up about
forty-five minutes, they finally headed for the secondary target,
Nagasaki, On the way they computed the gasoline supply very care-
fully, Ashworth confirmed Sweeney's determination that it would be
possible to make only one bombing run over Nagasaki if they were
to reach Okinawa, their alternate landing field. If more than one run
had to be made they would have to ditch the plane they hoped near
a rescue submarine.
At Nagasaki, there was a thick overcast and conditions at first
seemed no better for visual bombing than at Kokura. Considering
the poor visibility and the shortage of gasoline, Ashworth and Sweeney
decided that despite their positive orders to the contrary, they had
no choice but to attempt radar bombing. Almost the entire bombing
run was made by radar; then, at the last moment, a hole in the clouds
appeared, permitting visual bombing. Beahan, the bombardier, syn-
chronized on a race track in the valley and released the bomb. Instead
of being directed at the original aiming point, however, the bomb was
aimed at a point a mile and a half away to the north, up the valley
of the Urakami River, where it fell between two large Mitsubishi
armament plants and effectively destroyed them both as producers of
war materials.
On the way to Okinawa warning ditching orders were announced;
but the plane made it with almost no gas left. Sweeney reported there
wasn't enough left to taxi in off the runway.
The Nagasaki bomb was dropped from an altitude of 29,000 feet.
Because of the configuration of the terrain around ground zero, the
crew felt five distinct shock waves.
The missing observation plane, which fortunately was the one
without the instruments, saw the smoke column from a point about
a hundred miles away and flew over within observing distance after
the explosion. Because of the bad weather conditions at the target, we
could not get good photo reconnaissance pictures until almost a week
later. They showed 44 per cent of the city destroyed. The difference
between the results obtained there and at Hiroshima was due to the
unfavorable terrain at Nagasaki, where the ridges and valleys limited
the area of greatest destruction to 2.3 miles (north-south axis) by
1.9 miles (east-west axis). The United States Strategic Bombing Sur-
vey later estimated the casualties at 35,000 killed and 60,000 injured.
While the blast and the resulting fire inflicted heavy destruction on
Nagasaki and its population, the damage was not nearly so heavy as
it would have been if the correct aiming point had been used. I was
considerably relieved when I got the bombing report, which indicated
a smaller number of casualties than we had expected, for by that
time I was certain that Japan was through and that the war could
not continue for more than a few days."
So Sweeny was truly between a rock and a hard place, and was forced by circumstances to make on the spot decisions
ThomasP
Senior Master Sergeant
Hey guys,
Do we have any idea how much the effective range of the Bockscar (or Enola Gay for that matter) was reduced by the winds aloft? If the winds aloft had a significant effect that might eliminate the possibility of the Lancaster as a delivery platform. At least if making it back to Tinian is a requirement during planning.
Do we have any idea how much the effective range of the Bockscar (or Enola Gay for that matter) was reduced by the winds aloft? If the winds aloft had a significant effect that might eliminate the possibility of the Lancaster as a delivery platform. At least if making it back to Tinian is a requirement during planning.
FLYBOYJ
"THE GREAT GAZOO"
Agree 100% - the mission was always priority but any kind of risk mitigation played second fiddle. The chain of events started with the faulty fuel pump and just escalated. Fortunately it all worked out
FLYBOYJ
"THE GREAT GAZOO"
Great question, one would have to examine what the winds aloft were doing those days but they will be a major consideration.
ThomasP
Senior Master Sergeant
I was wondering if we could use the flight times and the IAS to figure a rough estimate. I have not seen any detailed flight plan/record for these missions, just overall times point-to-point and loiter. If we knew the IAS and altitudes for the different legs we might be able to calculate at least a ball park figure. If the B-29s only used a 100-200 gallons extra it might not matter, but if they were using 500 gallons extra it would matter.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
Not sure about wind conditions, but for Sweeny's mission, the planned cruise to rendezvous @ 9,000 ft. was changed to 17,000 ft. due to the bad weather.
This would have also contributed to additional fuel consumption.
This would have also contributed to additional fuel consumption.
swampyankee
Chief Master Sergeant
- 3,974
- Jun 25, 2013
I suspect that the a fairly small modification to the spec to which the B-29 and B-32 were built (and the XB-30 and XB-31 were designed for) would make the B-29 impossible to modify for carriage of the atomic bomb by making it impossible to modify the bomb bay to fit either Little Boy or Fat Man.
Does anybody here happen to have knowledge of the B-29's detailed design documents, including how the dimensions of the bomb bays was determined?
Does anybody here happen to have knowledge of the B-29's detailed design documents, including how the dimensions of the bomb bays was determined?
FLYBOYJ
"THE GREAT GAZOO"
If the spec indicated a maximum fuselage length.
It was coordinated between the bomb scientist and Material Command.
"On November 30, 1943, the United States Army Air Forces sent instructions to its Army Air Forces Materiel Command at Wright Field, Ohio, for a highly-classified B-29 modification project. Scientists at working on the Manhattan Project would deliver full-sized mockups of the Little Boy and Fat Man weapons shapes to Wright Field by mid-December, where engineers there would modify the B-29 and equip it for use in bomb flight testing.
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.
The modifications, which were done completely by hand, were extensive and time-consuming. The process required more than 6000 man-hours of labor and the first B-29 prototype was not complete until February 20, 1944."
Project Silverplate
- Thread starter
- #473
Good question. Let's examine what's actually being said:
Ramsey showed Chadwick preliminary sketches of the large-thin-shaped and stubby-shaped bombs and later wrote with more details. Chadwick assured Ramsey that the Lancaster could accommodate them."
This all sounds convincing enough, but it requires a bit of a leap of faith to go from "preliminary sketches" and "a few more details" to Thin Man and Fat Man as they appeared. Under the circumstances its hard to to believe that Ramsey would give specific details of such an important secret project away to anyone, let alone a foreign national, regardless of why. There is no way that he would have even mentioned the code names for the bombs at all. Chadwick had no idea that these shapes were to be nuclear weapons and again, this statement above doesn't provide us exactly what "more details" actually means, but I'm willing to bet Ramsey didn't specify exact weights, precise diameters and configuration of fins etc.
Let's consider this:
"As luck would have it, Chadwick had crossed the Atlantic to view Lancasters being built at the Avro Canada works in Toronto, and Ramsey seized the chance to show Chadwick some preliminary sketches of both the gun and the implosion weapon casings. Chadwick assured Ramsey that the Lancaster could accommodate either bomb and promised whatever support might be needed, but he was well-used to wartime secrecy; Chadwick did not ask why the weapons had such unusual shapes."
From here: Operation Silverplate - The Aircraft of the Manhattan Project
Chadwick did not know that these were nuclear weapons and with the scarcity of what he was presented with would not have been able to determine what kind of modifications were required to carry the bombs, nor what mission parameters needed to be met to deliver them nor even a potential target. For him to say, "yes, the Lancaster can carry them" tells us little of use within the context of the discussion we are having, but one thing is certain, this in no way confirms that the Lancaster could carry the Fat Man bomb as it finally appeared.
- Thread starter
- #474
I think we can excuse this statement as Thin Man was the 17 foot long bomb, not Little Boy. I think I pointed this out ages ago... I think we are going round in circles...
FLYBOYJ
"THE GREAT GAZOO"
Yes, just quoting the articleI think we can excuse this statement as Thin Man was the 17 foot long bomb, not Little Boy. I think I pointed this out ages ago... I think we are going round in circles...
- Thread starter
- #476
Yeah, I gathered that Joe, same as last time, it was more to demonstrate that we aren't covering anything we haven't covered before!
Peter Gunn
Master Sergeant
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.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
Now I do recall reading in the past, that if atomic weapons were to be used in Europe, it was to be carried to target by the Lancaster.
So for the atomic Lancaster enthusiasts out there, this much is in their favor.
As for the bomb design, yeild, weight, shape, at al, I have no idea - but I imagine that given the ranges in Europe, it would have been up to the task.
So for the atomic Lancaster enthusiasts out there, this much is in their favor.
As for the bomb design, yeild, weight, shape, at al, I have no idea - but I imagine that given the ranges in Europe, it would have been up to the task.
buffnut453
Captain
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.
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That makes no sense. Roy Chadwick was presented with drawings and dimensions of several bomb casing and asked whether the Lancaster could carry them. Given his work load. and the myriad demands being made on Avro for Lancasters, it would have been reprehensible for Chadwick to have falsely claimed that the Lancaster could carry the bomb designs if it couldn't and given that he didn't know the nature of the bombs, he was under no pressure to make extravagant claims. If the bombs wouldn't fit Chadwick would have said so and Ramsey would have also have known by looking at the Lancaster specs, as presented by Chadwick. We know the Lancaster B-B specs and we know the Fat Man specs and Fat Man will fit.
The fact is that the Lancaster could carry either bomb design, and this has been confirmed by well documented statements from Ramsey, Chadwick and Groves. There hasn't been any properly referenced data presented that the Lancaster couldn't carry a Fat Man bomb.
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