'Little Boy' and 'Fat Man'

Correction: Originally I entitled this post "'Thin Boy' and 'Fat Boy'" referring to the two A-bombs used on Japan.  A couple of commenters have picked me up on this and suggested that they were called 'Little Boy' (Hiroshima) and 'Fat Man' (Nagasaki).  I took the nicknames directly from Bergamini's book (see below).  A very quick check seems to indicate that he got the names wrong but that may have come about from different organisations using variations.  For example, and at the risk of confusing you further, there was a 'Thin Man' developed at Los Alamos using a gun-type explosive charge to set off the chain re-action.  However, slight impurities in man-made plutonium might have resulted in the bomb going off 'half cock', so efforts were concentrated on surrounding the fissionable material with high explosive and driving it into itself.  This required a spherical shaped casing and thus 'Fat Man' was born.  Thank you to my commenters for putting me right and I have changed the text accordingly. 

http://www.lanl.gov/history/atomicbomb/littleboyandfatman.shtml

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In my previous post I mentioned a fact, hitherto unknown to me, that I had picked up concerning the attacks on Hiroshima and Nagasaki, to which my e-pal, 'JK', responded in a comment.  I thought it might be of interest to expand the story.

'Little Boy' was the nick-name for the Hiroshima bomb on account of its slim, elongated shape in which small pieces of uraniam-235 were held at one end and then fired at a large piece the other end thus causing the atomic fission.  'Fat Man' was the second bomb dropped at Nagasaki which used a different technology in which particles of a man-made element, plutonium, were packed round a cylinder and then driven into each other by conventional explosives thus causing a more efficient type of chain re-action.  The 509th Composite Group, USAAF, charged with dropping the bombs, had been practicing over Japan for a fortnight before the first real attack.  Always in threes, with one bomber and two observer aircraft, they had been spotted by the Japanese several times making mysterious runs across city centres and then dropping oddly shaped dummy bombs.  However, on August 6th 1945, 'Little Boy' was dropped for real by parachute in order to allow time for Enola Gay to make a run for safety and it exploded at 1,500 feet over the north west of Hiroshima.  Some 60,000 Japanese died instantly, either burnt or crushed.  A further 26,000 were scorched with atomic radiation which killed them off either immediately or over the next few days, weeks or months.  Nearly 7,000 buildings were immediately flattened and 4-square miles of the city were left burning and out of 45 hospitals, 3 were left standing and of their staffs only 28 out of 290 doctors, and 126 out of 1,780 nurses, were uninjured.  A final count taken 6 months later reckoned that around 90,000 civilians and 10,000 soldiers died.

'Fat Man' was scheduled to be dropped on August 11th but was rapidly brought forward on the grounds that the weather was forecast to close in around Japan for 5 days, however, the cynical correspondent for the NYT, William Laurence, observed drily, "I'll bet those weather forecasts came all the way from Potsdam!"  There, the Russians had alerted their allies that they intended to attack the Japanese in Manchuria starting midnight on the 8th.  On the morning of the 9th, the crew of Bock's Car took off with 'Fat Man' and plotted a route to its primary target, Kokura, meeting up with two camera planes en route.  The mission was plagued with a series of small but critical glitches.  First, the fuel pump to the auxilary tank meant that the plane would be short of fuel for the return journey, then there was an extraordinay breach of radio silence caused by the fact that a boffin due to fly in one of the observer planes and operate a very complex camera had been left behind and for half an hour the whole operating manual had to be read out over the airwaves with the Japanese listening in!  Then, suddenly, a warning light went on in the control box for 'Fat Boy' indicating that all the firing circuits were active.  An urgent (possibly frenzied!) investigation revealed that it was a faulty switch!

Kokura was one of four industrial cities lying close together in a flat plain and which have since merged completely to produce one big city, Kitakyushu.  It has been estimated that if Bock's Car had dropped 'Fat Man' there, it would have killed at least 300,000 inhabitants.  As it was, Bombardier Kermit Beahan could not find the arsenal which was his aiming point because of smoke from factory chimneys and after three bomb runs which had begun to attract the attention of enemy flak and fighter defences Maj. Sweeney, the commander, decided that with fuel running low he would divert towards the secondary target of Nagasaki.  This had cloud cover and Sweeney asked permission to use radar as a means of identifying the target.  This ran counter to President Truman's order that all A-bomb attacks must use visual means to identify targets and thus avoid errors.  Permission was granted by the local commander but in the event Bombardier Beahan spotted, through a break in the clouds, a stadium that he recognised as an aiming point.  He released the bomb but in fact he was nearly 2 miles away from the city centre and it exploded over the Urakami valley which housed the important Mitsubishi Ordnance Works and to a certain extent restricted the blast area.  A count taken six months later reported that just under 40,000 people had died but it was later estimated that Beahan's 'mistake' probably saved a further 50 to 75 thousand lives if 'Fat Man' had hit the city centre.  Apparently, after the event, Bombardier Beahan was extremely guarded in his remarks, claiming that he knew where he had dropped the bomb but the stadium he saw was an "alternate target".  It has been suggested that authorisation for this "alternate target" might have come from higher up in Gen. Spaatz's Strategic Air Command.

A total of approximately 140,000 people were killed in the two A-bomb raids, almost exactly the same number as the casualties inflicted by the Japanese on the Chinese during what came to be called the rape of Nanking some eight years earlier.

Source: Japan's Imperial Conspiracy by David Bergamini, Heinemann, 1971

Comments

[JuliaM]

And I always thought it was 'Little Boy'...!

[JK]

Thank you Mr. Duff,

As I indicated, "it had been awhile since..." actually in one of those pre-internet things called a report of some sort. I recall that I was in my 20's and since that admittedly was sometime ago, perhaps my "CRS" has affected me more severely than I've realized.

I admit, all I clearly recall reading had something to do with, "winds at altitude." But you've performed, as one might've heard, were one on a parade ground with especially shiny boots, "outstanding."

[Tim Newman]

I always seem to have thought the two were Little Boy and Fat Man. Are you sure this is right, David?

[David Duff]

Thanks, Julia and Tim, please note correction up above.

[JuliaM]

Sadly, I can't claim any historical bent here. Merely the words to OMD's 'Enola Gay':

"Enola gay, is mother proud of little boy today
Aha this kiss you give, its never ever gonna fade away"

[Kermit Beahan Jr., Lt Col. USAF (retired)]

My father new exactly where he was dropping the bomb. He used the stadium as a basepoint as an offset to target the Abomb on the industrial site. Having flown B17 missions from the start in Europe, his was trained in the strategic bombing mindset of targeting warmaking capability..Mitsubishi Ordnance Works. Every bomb has collateral damage as a bombadier... this new weapon obviously makes collateral damage a huge understatement in tactical terms.

[David Duff]

Welcome to D&N, Col., and I deliberately placed inverted commas round the word 'mistake' to indicate that your father knew precisely what he was doing. My source was Bergamini's book "Japan's Imperial Conspiracy", pp. 53/4, and as I understand it, he actually interviewed your father by telephone. Irrespective of this very slight controversy, the people of Kokura owe your father, and his fellow crewmen, some gratitude because if he had dropped it on that city the likely casualties would have exceeded 300,000.

In fact, the world owes your father and his crewmen a debt because their actions brought the war to a premature end and thus forestalled what could have been slaughter on a scale that would have put Hiroshima and Nagasaki in the shade.