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Path: utzoo!henry
From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.tv.da
Subject: Re: TDA unrealistic (?)
Message-ID: <3381@utzoo.UUCP>
Date: Mon, 28-Nov-83 21:24:03 EST
Article-I.D.: utzoo.3381
Posted: Mon Nov 28 21:24:03 1983
Date-Received: Mon, 28-Nov-83 21:24:03 EST
References: <345@bbncca.UUCP>
Organization: U of Toronto Zoology
Lines: 45

Jon McCombie observes:

	The war depicted what MIGHT have happened if 10-megaton warheads
	were dropped.  It is my understanding that no major power maintains
	missles with < 20-megaton warheads; usual firepower is more like
	100-megatons.

Not true.  10 megatons is an *enormous* warhead for a missile, there are
no 20-megaton missiles that I'm aware of, and nobody has ever even tested
a 100-megaton bomb.  (The USSR did test a 67-megaton bomb that could most
likely have been upgraded to 100, which is where the 100-megaton number
comes from.)

The typical warhead for Minuteman missiles is a few hundred *kilotons*.
Poseidon warheads are typically 20 kilotons.  I'm not sure about MX and
Trident, but I believe they're similar.  The only US strategic weapons
that carry multi-megaton bombs are the manned bombers, and these days
even they tend to carry larger numbers of smaller warheads.  The Soviet
weapons are similar, although they do have one quite large ICBM that
might carry a few megatons.

Why?  Two reasons.  First, all those megatons aren't really necessary.
Remember that a measly 13 kilotons smashed Hiroshima, a sizeable city,
pretty badly.  Second, multi-megaton bombs are terribly inefficient.
Most of the power goes into re-re-re-devastating the central area.
The radius of destruction scales as somewhere between the square and
cube root of the power of the bomb, so it grows slowly with bomb size.
To get a bigger area of destruction, several small warheads are a
much better approach.  The really big bombs are useful only against
something like a deep-buried military base that needs to be smashed
*hard*.  Not many of those.  For ICBM silos, accuracy is more important.

In fact, a major argument against the development of the H-bomb in
the early 50's was that there was no legitimate military requirement
for it:  A-bombs of various types could meet all known needs.  This
is still true today, although it is often *easier* to build the more
substantial warheads as fusion bombs.

In short, hundred-megaton bombs are the stuff of poorly-written
novels (like Down To A Sunless Sea, a real turkey), not reality.
Most real warheads are small fractions of a megaton.  Of course,
they'll still kill you just as dead if you're under them...
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry