Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

mainichi.jp

Post reply on HN
Print view View original

11–20 of 46 posts

Re: Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

#11

Post by FatalLogic »

I wanted to know if this was plausible, so I located the Yawata Steel Works (the source of the smoke screen) and the Kokura Arsenal (the aiming point for the bomb) on a map. They were about 4.4km apart.

http://i.imgur.com/nJaJtH7.png (the site of the Steel Works is on the left)

Interesting, but I still don't know if it's true.

edit: Wikipedia's page on Smokescreens says "One 50 gallon drum of fog oil can obscure 60 miles (97 km) of land in 15 minutes", so I suppose it was easily possible for them to have hidden the target if the wind direction was right

Google Maps link: https://www.google.com/maps/place/%E4%B8%AD%E5%A4%96%E7%82%8...

Re: Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

#13

Post by mjfisher »

dangayle wrote: post #10
FatalLogic wrote: post #7

Earlier quoted context omitted.

They only had to obscure the target zone, which was a very small area (a single factory complex, the Kokura Arsenal), and by chance it happened to be obscured during the 30 minutes or so that the plane was overhead. This wasn't a normal bombing run. It had elements of an experiment - they wanted to understand how the bomb worked, so they wanted to control the drop precisely and be able to observe the effects. The aim…

That diary is a fantastic read. The language, the drama, the bird's eye view of one of the most pivotal moments in world history. Beats fiction any day.

Also interesting to note is the partial redaction of a sentence immediately after the bomb was dropped a few pages later. It's been literally cut out of the paper: http://www.mphpa.org/classic/COLLECTIONS/CG-ASPI/01/Pages/CG...

Re: Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

#14

Post by ckozlowski »

dangayle wrote: post #10
FatalLogic wrote: post #7

Earlier quoted context omitted.

They only had to obscure the target zone, which was a very small area (a single factory complex, the Kokura Arsenal), and by chance it happened to be obscured during the 30 minutes or so that the plane was overhead. This wasn't a normal bombing run. It had elements of an experiment - they wanted to understand how the bomb worked, so they wanted to control the drop precisely and be able to observe the effects. The aim…

That diary is a fantastic read. The language, the drama, the bird's eye view of one of the most pivotal moments in world history. Beats fiction any day.

I'm reading this page here: http://www.mphpa.org/classic/COLLECTIONS/CG-ASPI/01/Pages/CG...

Just thought I'd share some of my puzzlement here; but it sounded as if they'd dropped a third atomic bomb. I though this unlikely, unless the diary is revealing a secret kept (the drop sounds as if it'd failed), but then I came across this: http://en.wikipedia.org/wiki/Pumpkin_bomb

So, in addition to the nuclear models, they dropped identical conventional bombs of that type as well. Never knew that.

Re: Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

#15

Post by marvin »

ekianjo wrote: post #3
programmer_dude wrote: post #2

How much coal tar would you need to burn to block an airplane's view?

Not sure, but it seems a little bit unlikely that the smoke could be enough to obstruct the vision of a plane cruising at 30000+ feet.

Smokescreens were widely used as a defensive tactic during World War 2. Assuming that the bombing crews are attempting to hit a target rather than just indiscriminately bomb an area of several square kilometers, they were very effective before the advent of infrared cameras all-weather radar. Smokescreens do require relatively calm winds though.

You could e.g. read "Target Tirpitz" which is a historical account documenting among other things how smokescreens were used to defend Germany's biggest battleship against a large number of bombing runs. A battleship is pretty much the biggest target you could have on a battlefield, showing that this tactic is very effective against non-indiscriminate bombing.

Re: Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

#16

Post by outworlder »

Ok, so the target area was blocked. So what? This was not a precision ammo, it was an a-bomb! Even those early designs could just be detonated in the general area and still destroy the target and everything else.

Why did the bombers have to switch targets then?

Re: Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

#17

Post by adventured »

It's interesting to read Wikipedia's entry on this matter (claiming it was caused by a huge firebombing raid):

http://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_an...

"The delay at the rendezvous had resulted in clouds and drifting smoke from fires started by a major firebombing raid by 224 B-29s on nearby Yahata the previous day covering 70% of the area over Kokura, obscuring the aiming point."

Re: Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

#18

Post by iSnow »

outworlder wrote: post #16

Ok, so the target area was blocked. So what? This was not a precision ammo, it was an a-bomb! Even those early designs could just be detonated in the general area and still destroy the target and everything else. Why did the bombers have to switch targets then?

I am guessing here but I believe the bombings of Hiroshima and Nagasaki were also weapons tests. And you want a clear field of vision to perform a precise test.

Re: Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

#19

Post by colanderman »

FatalLogic wrote: post #11

I wanted to know if this was plausible, so I located the Yawata Steel Works (the source of the smoke screen) and the Kokura Arsenal (the aiming point for the bomb) on a map. They were about 4.4km apart. http://i.imgur.com/nJaJtH7.png (the site of the Steel Works is on the left) Interesting, but I still don't know if it's true. edit: Wikipedia's page on Smokescreens says "One 50 gallon drum of fog oil can obscure 60 m…

97 square kilometers? 97 kilometer radius? tsk tsk Wikipedia…

Re: Steel worker reveals blocking view of U.S. aircraft on day of atomic bombing

#20

Post by christudor »

outworlder wrote: post #16

Ok, so the target area was blocked. So what? This was not a precision ammo, it was an a-bomb! Even those early designs could just be detonated in the general area and still destroy the target and everything else. Why did the bombers have to switch targets then?

This is not quite true; the Nagasaki bomb missed its target by almost two miles because of cloud cover, and as a result only half the number of people were killed compared to Hiroshima. Even with an atomic bomb you had to be /relatively/ precise. (Source: https://www.youtube.com/watch?v=kYphE841lfY)
Post reply on HN