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hiroshima facts wrote in message
"Geoffrey Sinclair" wrote in message
. ..
hiroshima facts wrote in message
I tried to track down the 50% claim, and it apparently is based on
"Medical Effects of the Atomic Bomb in Japan" published by Oughterson
in 1956. I don't have that on hand, but I understand that on page 84,
they say that 48% of people within 2 km of ground zero were killed.
And "within 2 km of ground zero" was counted as the "affected area"
for the estimate I was quoting.
In which case the affected area being defined as significantly less than
the area of blast and fire damage. There were deaths and damage
beyond the 2 km/6,600 feet radius.

I'm guessing the estimate tried to pick the area where most of the
buildings were leveled, and came up with 2 KM. Since a modern nuclear
attack that wanted to level a city would use either large enough
warheads (or a large enough numbers of warheads) to level everything,
this seems fair to me, although perhaps I should use a more precise
term than "area affected".

Let us understand this, fair for nuclear weapons is looking at the
most damaged areas when computing lethality. Fair for conventional
weapons is looking at a much bigger area, where damage is not as
severe in places when computing lethality. Fair also seems to be
assuming multiple larger atomic attacks, presumably also against
unwarned populations.

It is also different to the measure used for Tokyo, since it does not
use dead plus homeless, substituting a 2 km circle instead. It makes
the atomic attacks look more lethal by changing the choice of
measurement. The comparison between the two as reported is
therefore invalid.
The Tokyo raid destroyed 16 square miles, which is the area of a
circle of around 2.25 miles or 3.6 km in radius, what was the death
toll like for the 2 km circle?
As far as I know, there was no concentration of deaths in the Tokyo
raid that would change the ratio if we focused on a smaller area.

Actually there were concentrations of deaths, the canals and rivers
became choked with bodies as people tried to escape the heat,
the incoming tide caused drownings.

It all came down to whether the fires cut off people's retreat, if they
did not more people survived. There was not an even x deaths per
square mile in the "affected area", as a simple exercise in logic
the people at the fringes had a better chance of escaping.

On a comparative scale Tokyo comes in at 7 to 8%, Hiroshima 31%
deaths when you count the dead and homeless as the "affected
population", making the atomic strikes about 4 times as lethal.
Though this ignores the reality Hiroshima was not under air raid alert
at the time but Tokyo was, which could account for much to even all
of the difference in lethality.

I don't think it could account for all of it.

There are precisely two atomic strikes against populations, in both
cases unwarned populations, it is clear moving the population to air
raid shelters would have made a significant difference to lethality.

In theory, assuming Little Boy had a 15,000 ton effectiveness,
Hiroshima works out to 1 death per 375 "pounds", Fat Man at
23,000 tons yield works out to around 1 death per 1,300 "pounds".

That is nearly a factor of 3.5 difference between these two strikes and
3.5 times the 7 to 8% Tokyo lethality is 24 to 28%, in the area of the
claimed atomic weapons lethality.

One of the first things to learn about WWII bombing is how variable
the results could be. It is clear from the atomic attack survivors many
were killed or lethally injured in the open and others were killed when
trapped in damaged/destroyed buildings that burnt. Put the population
in shelters and many/most of these injuries go away.

Hamburg was so lethal partly because the shelters were not designed
to cope with a firestorm, normally the best thing to do was head for the
shelters, on this night it would have been flee the area even as the
raid began. The Hamburg raid killed people at a rate 34 times the
average per ton of bombs dropped on Germany. And you want to
think a factor of 4 is somehow large between Tokyo and Hiroshima,
and that is after altering the definitions in favour of the atomic attack.

If the Oxford companion to WWII is correct air raids on Austria were
3 times as lethal per ton of bombs dropped on average than those
on Germany.

Are there *any* instances of conventional weapons ever killing more
than 8% (either of the "area affected" or the "area leveled")?

Yes night of 23/24 February 1945 RAF Bomber Command versus
Pforzheim. The city, pre war population of 80,000, had been the
target of Mosquito harassment raids by night plus some day strikes
in the order of 100 to 300 tons of bombs before the big raid. On
23/34 February 1945 some 1,740 tons of bombs caused a firestorm,
around 17,000 to 18,000 people killed on this night. This raid was
responsible for most of the damage to the city during hostilities.
Some 83% of the built up area destroyed for the war. In terms
of deaths per bomb it works out to a maximum of 1 death per 190
pounds of bombs, around 2/3 the lethality of the Hamburg firestorm.

Assuming no growth in population the Pforzheim raid's lethality works
out at 21 to 23% of the total population, but around 20% of the city
survived, so 5/4 times 21 to 22 is 26 to 28%.

This ignores the problems in determining a good population figure for
the city, let alone a subset of districts, given the attacks by definition
would destroy some of the records needed to determine the population
present.

Simply given the reality there are only two atomic strikes to go on
and their lethality per "ton" of bomb varied so much and they were
against unwarned populations, and the variability seen in WWII
conventional bombing means claims about how much more lethal
atomic weapons can be do not have solid evidence to back them.
Hopefully it stays this way. As I said before I would expect a higher
lethality for nuclear weapons thanks to the instantaneous nature of
much of the damage and the much higher "explosive" yield, how
much higher is another question.

The only comparable strikes to the atomic weapons in "explosive"
yield were the RAF Bomber Command strikes against Duisberg on
14 October 1944 by day and again that night, the two operations
put around 10,000 short tons of bombs on the city, about 5,000
tons each, around 16% incendiaries. No idea of casualties, the
city did not put together a final report but there were clearly not
Hamburg etc. casualty levels.

Geoffrey Sinclair
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