| From: | Edward.Chegwidden@****.int Edward.Chegwidden@****.int |
|---|---|
| Subject: | Nuclear War |
| Date: | Wed, 17 May 2000 11:05:27 +1000 |
Gear Heads Indeed!!
*What would a tactical nuclear warhead do to a large city? Let me 'splain
further.
follow this link to see the effects of a nuclear blast:
http://www.enviroweb.org/issues/nuketesting/hew/Nwfaq/Nfaq5.html
Probably the most destructive thing produced would be the EMP. This would
disable (either temporarily or permenantly) electrical and electornic devices.
How it would work with optical circuits, I do not know, but power supplies and
the like would not be optical, so there would still be some disruption. I would
think the majority of effects would be temporary, based on replacement of power
supplies and the like. There is also a good case for the fact that a lot of
corperations will have shielded facilities (they do now a days even) to reduce
the effects of outside interferance. Whether this will be of use against a
Nuclear induced EMP remains to be seen (and hopefully will forever remain to be
seen).
The article above looks like it goes into a good amount of detail, and relevant
information can be easily gleaned from it, including the ranges for all effects
produced.
>From this link:
http://www.enviroweb.org/issues/nuketesting/hew/Library/Effects/index.html
The photo sequence below shows a wood-frame house exposed to a nuclear blast at
the Nevada Test Site. The test was Upshot-Knothole Annie, a 16 Kt tower
shot, on 17 March 1953. The house is 1100 meters from ground zero.
The exposure to thermal radiation was 25 cal/cm^2, about one-quarter of that
experienced at ground zero in Hiroshima.
The blast over pressure was 5 psi, and the blast wave created surface winds of
160 mph.
*In my campaign, said warhead might be detonated in San Francisco, sometime
in the near future. Having only pop-culture references to go from, I want
to know a couple of things:
*1) Is it realisitic to have a warhead, or partial warhead, that will fit
into a container approx .5m high x .5m wide x 2.5m long, a la the George
Clooney film The Peacemaker? I don't need a backpack "pocket" nuke, the
storyline will accomdate getting a warhead that size where I need it.
Surface bursts are useful if local fallout is desired, or if the blast is
intended to destroy a buried or very hard structure like a missile silo or a
dam. Shock waves are
transmitted through the soil more effectively if the bomb is exploded in
immediate contact with it, so ground bursts would be used for destroying buried
command
centers and the like. Some targets, like earth-fill dams, require actual
cratering to be destroyed and would be ground burst targets.
Couldn't find dimensions of a nuclear warhead, but why not use someone else's
research:
Tom Clancy's "The Sum of all Fears"
hang on - found something:
http://www.greenpeace.org/~comms/nukes/fig04.gif
with a description:
FIGURE 4 shows the case designs for two types of implosion configured nuclear
warheads. The smaller 'oil drum' container mimics a Soviet A-bomb design from
the mid-1960s with an all-up weight of about 120kg. This type o f A-bomb can be
reduced in size (particularly if a gun type is adopted) down to fit within the
case
of an 88mm diameter artillery shell, yielding between 0.5 to 5kt equivalent of
conventional high explosive. The other sketch depicts a modern thermonuclear
warhead, of about 170 to 200kt yield, suited to delivery by a cruise missile.
Note that a 200kt device can fit in an artillery shell, hence you have your
backpack bomb. Based on the effects detailed below I cannot see anyone wanting
a larger device.
Note that by my esitmation, a 200kt bomb produces a thermal effect (3rd degree
burns) out to 6km, a blast radius of 4.6psi overpressure, out to 4km, and a
500rem does of radiation out to 2km. The yield of a modern strategic warhead
is, with few exceptions, now typically in the range of 200-750 kt.
As a general guide, city areas are completely destroyed (with massive loss of
life) by overpressures of 5 psi, with heavy damage extending out at least to the
3 psi
contour. The dynamic pressure is much less than the overpressure at blast
intensities relevant for urban damage, although at 5 psi the wind speed is still
162 mph -
close to the peak wind speeds of the most intense hurricanes.
The ranges and effects for a 200kt blast are:
12 km from centre 1 psi Window glass shatters
Light injuries from fragments occur.
5.7 km from centre 3 psi Residential structures collapse.
Serious injuries are common, fatalities may occur.
4km from centre 5 psi Most buildings collapse.
Injuries are universal, fatalities are widespread.
2.5 km from centre 10 psi Reinforced concrete buildings are severely damaged
or demolished.
Most people are killed.
1.6km from centre 20 psi Heavily built concrete buildings are severely
damaged or demolished.
Fatalities approach 100%.
Radiation effects at the 2km range of 500 rem are described below:
400-600 REMS
Mortality rises steeply in this dose range, from around 50% at 450 rems to 90%
at 600 (unless heroic medical intervention takes place). Hematopoietic tissues
remain the major affected organ system. Initial symptoms appear in 0.5-2 hours,
and last up to 2 days. The latency period remains 7-14 days. The symptoms listed
for 200-400 rems increase in prevalence and severity, reaching 100% occurrence
at 600 rems. When death occurs, it is usually 2-12 weeks after exposure and
results from infection and hemorrhage. Recovery takes several months to a year,
blood cell counts may take even longer to return to normal. Female sterility
becomes probable.
Radiation will drop quite significently in the next km, being reduced by a
factor of 10 twice. at 2.5km, 50rems, at 3km 5rems. (I think)
*2) With that warhead in mind, what would it do?
I have jpegs posted at http://www.lowephoto.com/games/sr/maps/ that show
where I'm planning to do this. Keep in mind that there are two major
bridges within 5k of either side of the bridge, and the first mile or so
inland is landfill.
The majority of Downtown San Francisco would be in the 5psi range. Note not
having been to SF, I have not taken the hills into account, but a far bit of
shock will travel through the ground so damage will still be severe.
*Have fun.
*D.
David R. Lowe
Lowe Photography
^^^^^^^^^^^^^^^^
someone we need to send to seattle for photo's.
In the end this is just one big ouch!
regards,
Edward.
(gotta love the internet, my next post will describe how to build the 200kt
warhead, we then just have to orginise a run to gather the fissionable
materials.)
