In article ,
"Kevin Brooks" wrote:

"Chad Irby" wrote in message
. com...
In article ,
Alan Minyard wrote:

I am always amazed by the number of people that believe in "suitcase"
nukes. Can a physics package be small? Sure. Can one tote it around
in a suitcase? NO!!!

The "physics package" of a Minuteman III/Mk-12 is about 250 pounds once
you take it out of the reentry vehicle, and has a yield of 170 kilotons
or so.

Only if you disregard the HE required to get it to go boom;

Nope. The 250 pounds *is* with explosives included. You don't need a
lot more mass to increase a small nuke to make a much bigger bang. If
you double the mass of the fissionables, you get a *lot* more than twice
the yield, and don't need much more explosives, either. Efficiency for
very small weapons is pretty pathetic, actually.

the W-79 was a fairly good sized warhed all-up, with a diameter of
around 21 inches and a length of a bit over five feet.

You mean W-78, right? I was referring to the Mk-12 W-68 warhead, not
the -12A. The W-68 "package" was only about 20 inches in diameter and
about 40 inches long. Slightly bigger in volume than a golf club bag.

And I doubt any 250 pound "physics package"
has a yield of 170 Kt.

Well, you'd be wrong, according to your own source:

http://gawain.membrane.com/hew/Usa/Weapons/Allbombs.html

If that were the case, the freefall bombs like the
the B-61, which did not need all of the protection an RV has to have, would
have weighed in at less than the 700 pounds or so that they do.

Not so much. The airframe and fuzing mechanisms for any airdropped bomb
are, by themselves, moderately heavy. You don't design that sort of
thing for lightness, you design it for reliability. You don't want a
bird strike to wipe out your multimillion dollar nuke. The B-61
airframes I've seen were *definitely* not lightweight constructions.

The W-44 ASW warhead was about 170 pounds, and was certainly small
enough to fit into a suitcase or trunk (less than 1 foot diameter), with
a yield of 10 kilotons or so.

No, the W-44 was about 14 inches in diameter, and over 25 inches long. See:
http://gawain.membrane.com/hew/Usa/W.../Allbombs.html

The W-44, *inside its ASW casing*, was about that big. It takes a good
bit of metal to handle slamming into the water at a good clip.

You should note, that unless otherwise mentioned, the specs for the
weapons on that page are inside their casings, ready to fire or drop.

The W-25 warhead for the Genie AAM was about 220 pounds, and gave a
yield of about 1.7 kilotons.

Any of these could be considered a "suitcase" nuke, but not a
"briefcase" one.

The smallest warhead we ever fielded was the W-54, at around sixty or so
pounds and a diameter of around 12 inches. When configured into your
"suitcase" (hate that term) mode as SADM, the weight went up a bit, to a bit
over 100 pounds.

The SADM had a much tougher casing and was designed to be
tamper-resistant. Kicked the weight up a *lot*.

The W-54 was about 51 pounds all by itself, and could easily fit into a
large suitcase or small trunk.

But in fact the miniturization has not advanced all that much since the days
of the earlier devices like the W-54. You are stuck with a 12 plus inch
dimension any way you go aout it for a spherical device; you can go lower
with linear implosion, but then your length increases.

Which means that, instead of a basketball and a laptop, you have two
footballs and a laptop.

Not a briefcase, but certainly man-portable.

The dimensions and weight of the 155mm rounds did not dramatically
change (W-48 from 1963 at 6.5 inches by 33 inches and 118 pounds
versus the W-82 cancelled in 1990, at 34 inches and 95 pounds) over
the decades.

Take the mechanism out of the steel artillery round, and there you go.
About four inches in diameter, and a couple of feet long. Remember that
the W-82 weight and size were ready to fire, inside a heavy steel shell.

The whole apparatus would have to be no larger than a couple of
footballs (or a basketball plus a laptop computer), and less than 50
pounds, for a yield of a kiloton or so.

Less than 50 pounds? I doubt that. W-54 remains king of lilliputs as of now,
and it was 59 pounds, with a maximum yield of around a quarter of a kiloton.

....and a lot of that weight was 1960s-era electronics, with a mechanical
PAL lock.

Knock ten pounds off least for a modern design.

And, in an operational situation, if the gadget weighed as much as 200
pounds, you'd put it on wheels and roll it around. Look at any transit
location and notice the large number of people with wheeled cases.

--
cirby at cfl.rr.com

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Slam on brakes accordingly.