Waggin the Dragon's Tail?
David B. Greene
George Smith <smi...@ix.netcom.com> wrote:
>A former engineering student at WASU told me that in the early days of
>nuclear research some scientists would hold two pieces of radioactive
>material in their hands close enough together until they could see a
>building stream of light between the two ...for fun. This was supposed
>to be called "wagging the dragon's tail" and purportedly caused the
>death due to radiation exposure of those who played the game.
I don't know if this was ever done as a game but a fellow I work with who
has a background in chemical engineering manufacturing military ordinance
indicated controlled experiments of this type were done to veryfy the
critical mass calculations.
> Also I was told by the same source that if you are exposed to
>sufficient radiation from a nuclear explosion you will see the color
>blue as the retinas react and that this is an indication that you have
>been exposed to a lethal dose of radiation.
Dave Greene
Chuck Stewart
(The kitty is wearing a radiation suit while he nukes his dinner :)
David B. Greene wrote:
>
> George Smith <smi...@ix.netcom.com> wrote:
>
> >A former engineering student at WASU told me that in the early days of
> >nuclear research some scientists would hold two pieces of radioactive
> >material in their hands close enough together until they could see a
> >building stream of light between the two ...for fun. This was supposed
> >to be called "wagging the dragon's tail" and purportedly caused the
> >death due to radiation exposure of those who played the game.
>
> I don't know if this was ever done as a game but a fellow I work with who
> has a background in chemical engineering manufacturing military ordinance
> indicated controlled experiments of this type were done to veryfy the
> critical mass calculations.
>
Yes. Manhatten Project. "chasing the dragons tail."
From "The dragon chasing his tail", which was critical mass. Boom.
It was done by remote control to test the "k" factor in dritical mass.
A round segment of radioactive material was lowered into a hole in
another piece of the material
They were somewhat afraid it would be enough to set off an explosion
then and there. They were NOT holding it in their hands.
I never heard of anyone doing with their hands even in play.
> > Also I was told by the same source that if you are exposed to
> >sufficient radiation from a nuclear explosion you will see the color
> >blue as the retinas react and that this is an indication that you have
> >been exposed to a lethal dose of radiation.
I've read this too. It refers to Cherenkov radiation, which is where the
gamma rays traveling thru air hit a medium (your eyes) where the local
speed of light is slower. The rays give up their "extra" energy as
high-frequency visible light. Blue light.
It's the same thing that cause radioactives stored in water pools (for
shielding) to glow blue.
It does not _necessarily_ mean you are dead...
but it does mean that you should NOT BE wherever you are at that moment.
Move.
Fast.
If you can...
> Dave Greene
--
Chuck Stewart
Take out sphahmblohck for reply
zapkitty located at geocities lil' round thing com
"Anime-style catgirls: proof that the end is nearer than you think."
Peter Ceresole
In article <356E33E9...@geocities.com>,
Chuck Stewart <zapk...@sphahmblohck.geocities.com> wrote:
>A round segment of radioactive material was lowered into a hole in
>another piece of the material
>
>They were somewhat afraid it would be enough to set off an explosion
>then and there. They were NOT holding it in their hands.
I think that is a reference to Harvey (?) Slotin. He was involved with a
demonstration for some Los Alamos visitors of "chasing the dragon's tail"
in which two U235 lumps were teased together and would get visibly hot on
their adjacent faces, where radiation from each lump would sustain a near
chain reaction in the other. It was set up behind a protective screen but
the fissile lumps slipped and came far too close together (they really were
that careless in those days). Slotin realised that in a very short time,
shielding or no, everybody in the lab would receive a lethal dose of
radiation, so he stepped round the screen and separated the lumps by hand.
He then reported to the infirmary and died within the day. The progressive
failure of his body was the first live case study of the effects of massive
radiation damage on a human being.
--
Peter
Nathan Urban
A few corrections..
In article <B1941DBE...@cara.demon.co.uk>, pe...@cara.demon.co.uk (Peter Ceresole) wrote:
> I think that is a reference to Harvey (?) Slotin.
Louis Slotin.
> He was involved with a demonstration for some Los Alamos visitors
I don't think it was visitors, he was demonstrating it for another Los
Alamos scientist with other employees around.
> [...]
> He then reported to the infirmary and died within the day.
9 days.
> The progressive
> failure of his body was the first live case study of the effects of massive
> radiation damage on a human being.
Actually, nine months earlier there had been another radiation-induced
fatality at Los Alamos; Harry Daghlian accidentally dropped a block of
tamper material onto a stack of blocks surrounding fissionable material.
He died in 28 days.
For brief summaries of these and other nuclear accidents (1945-1970), see:
http://www.envirolink.org/issues/nuketesting/accident/critical.htm
Other deaths were from another Los Alamos accident at the end of 1958
where some poor guy got 12,000 rems and died 35 hours later, as well
as the infamous SL-1 experimental reactor explosion two years later
(detailed in the book _Set Phasers on Stun_) which killed three people
(due to the explosion, not the radiation).
Jim Carr
Yes, there is some folklore here. See the detailed answer posted
later on citing the article on George Walker's Trinity Site
(http://www.envirolink.org/issues/nuketesting/index.html).
[Did zapkitty see CNN's story showing the old ASCII Fatman design
on Carey Sublette's page as they talked about using the internet to
design nuclear weapons -- as if books were not available?]
The other references on this subject are an issue of "Los Alamos Science"
devoted to Plutonium research and criticality accidents (the exposure to
Pu often being a result of criticality accidents) and the excellent
history "The Making of the Atomic Bomb" by Richard Rhodes. AFU also
reviews a book http://www.urbanlegends.com/books/dragons_tail.html
I am not familiar with.
zapk...@sphahmblohck.geocities.com writes:
>(The kitty is wearing a radiation suit while he nukes his dinner :)
I hope you have your aluminum foil dunce cap on to ward off the
evil UFO (MOC for Francophiles) mind-control rays.
David B. Greene wrote:
}
} George Smith <smi...@ix.netcom.com> wrote:
} >A former engineering student at WASU told me that in the early days of
} >nuclear research some scientists would hold two pieces of radioactive
} >material in their hands close enough together until they could see a
} >building stream of light between the two ...for fun. This was supposed
} >to be called "wagging the dragon's tail" and purportedly caused the
} >death due to radiation exposure of those who played the game.
}
} I don't know if this was ever done as a game but a fellow I work with who
} has a background in chemical engineering manufacturing military ordinance
} indicated controlled experiments of this type were done to veryfy the
} critical mass calculations.
>Yes. Manhatten Project. "chasing the dragons tail."
>From "The dragon chasing his tail", which was critical mass. Boom.
>It was done by remote control to test the "k" factor in dritical mass.
>A round segment of radioactive material was lowered into a hole in
>another piece of the material
That is the "dragon's tail" experiment, but there was no accident
associated with that. After repeated runs the uranium slug got
warmer and swelled, probably slowing its descent so that the
apparatus produced a larger than expected burst of neutrons.
However, other experiments of the same type (i.e. to measure some
properties of a critical or near-critical mass) were called by
that name because of the huge danger involved.
Slotin was killed demonstrating an experiment with a beryllium
reflector. A sub-critical mass will go critical if escaping
neutrons are refelected back in. [See the "Los Alamos Primer"
for sample calculations.] The only way to know if the calculations
are correct is to do experiments, and these were done manually.
A slip caused the reflector to close and go critical.
Slotin knew he was dead, so he acted to save the others by
disassembling it manually and then stayed to mark where the
spectators were for dose calculations. IIRC they got his
dose estimate from neutron activation of his watch case.
>They were somewhat afraid it would be enough to set off an explosion
>then and there. They were NOT holding it in their hands.
In Slotin's case, he was. Or, rather, he was using a screwdriver
to keep the spheres apart and the other hand to guide the top.
He disassembled it with his hands. I don't know if it was his
or Dahlgren's hand I have seen a picture of after an estimated
14,000 rad dose. The hand got better (hands are tough and can
take a lot of radiation) but the scientist did not.
} > Also I was told by the same source that if you are exposed to
} >sufficient radiation from a nuclear explosion you will see the color
} >blue as the retinas react and that this is an indication that you have
} >been exposed to a lethal dose of radiation.
The air in the room glowed blue.
In addition to Cherenkov light, you get emission from the air due
to ionization of the atoms and molecules. Nuclear explosions are
supposed to have a spectacular violet hue from nitrogen lines that
never shows up in the photographs.
--
James A. Carr <j...@scri.fsu.edu> | Commercial e-mail is _NOT_
http://www.scri.fsu.edu/~jac/ | desired to this or any address
Supercomputer Computations Res. Inst. | that resolves to my account
Florida State, Tallahassee FL 32306 | for any reason at any time.
Peter Ceresole
In article <6klthl$9um$1...@crib.bevc.blacksburg.va.us>,
nur...@crib.bevc.blacksburg.va.us (Nathan Urban) wrote:
>A few corrections..
Thanks for those. I was remembering it from a story in, of all places,
Saturday Evening Post. I was about fifteen at the time (43 years ago,
figure it out) and I remember being very impressed, but the details had
faded in the interim...
--
Peter
Hans Moravec
from: http://www.envirolink.org/issues/nuketesting/accident/index.html
...
Criticality Accidents -- The Dragon Bites
-
The "Dragon Experiment" was the first attempt to create
a temporarily critical mass of fissionable material by
sliding a slug of Uranium-235 hydride through a larger
mass of the same substance. These manual experiments
continued with the hemispheres of plutonium used in the
Trinity test bomb, the Fatman, and the bombs used at
Operation Crossroads in 1946. There were numerous
"criticality accidents" with run-away output of energy
and radiation. Within a year of the Trinity test, these
accidents would claim the lives of two members of the
team that assembled the plutonium core at Trinity:
Harry Daghlian and Louis Slotin.
from: http://www.ratical.com/radiation/KillingOurOwn/KOO7.html
...
Another Los Alamos scientist named Harry Daglian caused his
own death in a process he called "tickling the dragon's tail."
By arranging a wall of tungsten-carbide bricks around a uranium
or plutonium source, Daglian could determine how much material
was needed to cause a chain reaction. But on August 21, 1945,
Daglian accidentally caused a plutonium source to go critical.
The air in his laboratory turned blue and radiation seared
Daglian's flesh. He died a horrifying death. Less than a year
later Daglian's boss, Louis Slotin, suffered a similar fate.
-
ref: Karl F. Hubner and Shirley Fry, "The Medical Basis
for Radiation Accident Preparedness," Proceedings of the
REAC/TS International Conference, Oak Ridge, Tenn.,
October 1979, p. 17.
from:
http://www.campus.bt.com/CampusWorld/pub/ScienceNet/database/Physics/Atomic/p00439c.html
...
At Los Alamos in May 1946, Louis Slotin was carrying out an
experiment using two hemispheres of plutonium. They were
mounted on a track and Slotin was edging them closer and closer
together using a screwdriver. When the two came together they
would exceed the critical mass and a chain reaction would begin.
Slotin intended to stop just short of this point, but his hand
slipped and the hemispheres came together. The room filled with
blue light. An atom bomb was going off. He wrenched the two
halves apart with his bare hands and the reaction ceased. There
were other people in the room and Slotin drew a diagram of their
positions on the blackboard to help work out their dose of
radiation. Nine days later he died, but the others survived.
from: http://www.pgs.ca/pages/nl/nlmkaku.htm
...
...a half a dozen accidental criticality incidences in the U.S.
Just one month after the bombing of Nagasaki, Harry Daghlian, a
26-year-old worker was building a reactor with plutonium on a
tabletop. One day he walked into the office and tripped. The
tungsten carbide fell into the plutonium. The neutrons were
reflected. Critical mass was attained, and an atomic bomb went
off in his face. The atomic bomb created a blinding blue flash
of light. It was not a chemical explosion that created the
implosion, 80 it was like a stick of dynamite. He was taken to
Los Alamos hospital. He was hit with 5,000 rads of radiation,
ten times the amount that will kill an ordinary person. He
literally disintegrated in the Los Alamos hospital in about
two weeks.
It happened again in March of 1946. Dr. Louis Slotin had a
screwdriver and two pieces of plutonium. He was screwing these
two pieces together very slowly, watching the Geiger counter
needle rise, and then he would unscrew it. One day he slipped.
As a consequence critical mass was attained right in his face,
just like what happened to Harry Daghlian. This time Louis
Slotin lunged forward and grabbed the two hemispheres with his
bare hands, ripped them apart and took the full brunt of a
nuclear detonation right in his stomach. I have the autopsy
pictures of this, by the way, if you want to see these gruesome
pictures of American citizens that have been blown away by super
critical reactions, small nuclear bombs that went off right in
people's chests and faces...
from: http://www.milnet.com/milnet/nukeweap/Nfaq4-1.html
...
Critical mass values can be predicted with good
accuracy by extrapolation by taking neutron
multiplication measurements in a succession of
sub-critical tests using increasing quantities of
fissile materials. Such tests can be conducted
safety in the laboratory without special protective
equipment since each successive test allows
progressive refinements of critical mass estimates,
and allows the calculation of safe masses for the
next test. Tests intended to closely approach or
reach criticality must be conducted under stringent
safety conditions however. Even a very slight
degree of criticality in an unmoderated system can
produce a deadly radiation flux in seconds.
Accidents during critical mass experiments killed
two researchers at Los Alamos in 1945 and
1946 (Harry Daghlian and Louis Slotin) before
manual experiments were banned there.
Basic critical mass tests are basically non-
multiplying and do not measure alpha, the extremely
important fast neutron multiplication parameter.
Direct measurements of this require establishing
systems with significant levels of supercriticality
capable of creating rapid increases in neutron
populations.
A variety of laboratory tests can be used for
this. All of them depend on creating a supercritical
state that persists for a very short period of time
(milliseconds to microseconds) to prevent
melt-down (or worse). Such experiments necessarily
produce large neutron fluxes, and thus must
be conducted under remote control.
One type of experiment creates a transient
supercritical state by propelling a small fissile
mass though a larger slightly sub-critical mass. The
supercritical state exists while the small mass is
inserted, and terminates when the mass exits the
other side. Examples of this type of experiment
are the "Dragon" experiments conducted at Los Alamos
in early 1945, in which a fissile mass was dropped
through a hole bored in a subcritical assembly
(so-called because it was like "tickling the tail of
a dragon"). Shorter assembly times (and thus higher
multiplication rates) can be investigated by using a
gun instead of gravity to accelerate the fissile
projectile. This approach obviously extends naturally
to evaluating a full-up gun weapon design with only
the amount of fissile material in the bullet or target
differing from the actual deployment weapon. This type
of test was actually used by South Africa for
evaluating its gun assembly weapon (using a test
device named "Melba"). These experiments can explore
assembly durations in the range of 0.1-10 milliseconds.
Nathan Urban
> >George Smith <smi...@ix.netcom.com> wrote:
> >> Also I was told by the same source that if you are exposed to
> >>sufficient radiation from a nuclear explosion you will see the color
> >>blue as the retinas react and that this is an indication that you have
> >>been exposed to a lethal dose of radiation.
> This is crap. Radiation has absolutely nothing whatsoever to do with
> visible light.
Umm, he was almost certainly talking about Cherenkov radiation -- if
you see it, you're probably getting too much hard radiation through
other means, since it is generally associated with some very unhealthy
processes. :) In particular, in some of the criticality accidents
discussed in this thread, a blue glow _was_ visible at the time of
the accident.
(The phenomenon of Cherenkov radiation is discussed in the Relativity
FAQ entry, "Is there an equivalent of the sonic boom for light?", at
http://math.ucr.edu/home/baez/physics/cherenkov.html.)
Also, as Jim Carr pointed out, "In addition to Cherenkov light, you
get emission from the air due to ionization of the atoms and molecules.
Nuclear explosions are supposed to have a spectacular violet hue from
nitrogen lines that never shows up in the photographs."
[Note followups.]
Dave Wilton
Generally, I don't respond to messages crossposted to more than one
group, but here goes...
On Fri, 29 May 1998 00:51:20 GMT, da...@XOUT.u.washington.edu (David
B. Greene) wrote:
>George Smith <smi...@ix.netcom.com> wrote:
>
>>A former engineering student at WASU told me that in the early days of
>>nuclear research some scientists would hold two pieces of radioactive
>>material in their hands close enough together until they could see a
>>building stream of light between the two ...for fun. This was supposed
>>to be called "wagging the dragon's tail" and purportedly caused the
>>death due to radiation exposure of those who played the game.
>
>I don't know if this was ever done as a game but a fellow I work with who
>has a background in chemical engineering manufacturing military ordinance
>indicated controlled experiments of this type were done to veryfy the
>critical mass calculations.
It was not done for fun, nor done as described here. The experiment
was nicknamed "The Dragon Experiment" after Richard Feynman (who
else?) compared it to tickling the tail of a sleeping dragon.
The experimenters dropped a slug of U-235 through a hole in some
blocks of uranium hydride, allowing the material to achieve critical
mass for a brief instant. Uranium hydride was used because the chain
reaction was slower than in pure U-235 and would allow the experiment
to be done without a detonation (or so they hoped--Feynman and others
were skeptical and the experiment was done at a remote location). The
energy released in this brief moment of critical mass was measured and
gave the scientists confirmation about the theories of how much energy
an explosion would yield.
Following the war, a scientist was killed by a lethal dose of
radiation while trying to repeat the experiment. The slug got caught
on the uranium hydride blocks and the man separated them by hand to
prevent others from recieving a lethal dose of radiation. He died
shortly thereafter.
>> Also I was told by the same source that if you are exposed to
>>sufficient radiation from a nuclear explosion you will see the color
>>blue as the retinas react and that this is an indication that you have
>>been exposed to a lethal dose of radiation.
This is crap. Radiation has absolutely nothing whatsoever to do with
visible light.
--Dave Wilton
dwi...@sprynet.com
http://home.sprynet.com/sprynet/dwilton/homepage.htm
Edward Rice
> I think that is a reference to Harvey (?) Slotin...
> He then reported to the infirmary and died within the day. The
progressive
> failure of his body was the first live case study of the effects of
massive
> radiation damage on a human being.
Excluding the large number of deaths at Hiroshima and Nagasaki, you're
correct. But why do you exclude them?
Louis Slotin's accident was May 21, 1946. Harry Daghlian's was Aug. 21,
1945. Hiroshima and Nagasaki were August 6 and 9, 1945, respectively.
me...@cars3.uchicago.edu
In article <B1985518...@pm5-104.his.com>, ehr...@his.com (Edward Rice) writes:
>In article <B1941DBE...@cara.demon.co.uk>,
>pe...@cara.demon.co.uk (Peter Ceresole) wrote:
>
> > I think that is a reference to Harvey (?) Slotin...
> > He then reported to the infirmary and died within the day. The
>progressive
> > failure of his body was the first live case study of the effects of
>massive
> > radiation damage on a human being.
>
>Excluding the large number of deaths at Hiroshima and Nagasaki, you're
>correct. But why do you exclude them?
>
if at all possible to separate the effects of radiation form the
effects of the blast and burns. The vast majority of the victims in
Hiroshima and Nagasaki were killed by the explosion, not by radiation.
Slotin's was one of the few cases where a person was killed purely by a
big radiation dose and the progression could be observed in a hospital
environment.
Mati Meron | "When you argue with a fool,
me...@cars.uchicago.edu | chances are he is doing just the same"
Peter Ceresole
In article <B1985518...@pm5-104.his.com>,
ehr...@his.com (Edward Rice) wrote:
>Excluding the large number of deaths at Hiroshima and Nagasaki, you're
>correct. But why do you exclude them?
Because the study of the deaths of acute cases was extremely incomplete;
the dose wasn't known accurately and the acute cases dies before anybody
could study them. Hiroshima and Nagasaki after the bombs were a total mess;
nobody had time or the means to start proper studies until weeks and months
later. Slotin died at a lab which had facilities and specialists to examine
the process of his death in some detail.
The RERF's work since has been mostly on non-acute cases and on long term
cancer rates. The mechanisms are different from those in Slotin's case.
--
Peter
Jim Carr
... followups reduced to a more topical subset ...
pe...@cara.demon.co.uk (Peter Ceresole) wrote:
}
} > I think that is a reference to Harvey (?) Slotin...
} > He then reported to the infirmary and died within the day. The
} > progressive
} > failure of his body was the first live case study of the effects of
} > massive radiation damage on a human being.
ehr...@his.com (Edward Rice) writes:
>
>Excluding the large number of deaths at Hiroshima and Nagasaki, you're
>correct. But why do you exclude them?
It's not clear who "you" is in the quoted text. The statements above
are, in any case, wrong as was pointed out in other comments. Slotkin
took 9 days to die after the accident in the spring of 1946. Daghlian
took 28 days to die following an accident in late August of 1945.
>Louis Slotin's accident was May 21, 1946. Harry Daghlian's was Aug. 21,
>1945. Hiroshima and Nagasaki were August 6 and 9, 1945, respectively.
A more precise statement along the original lines would be correct.
The physicians in Hiroshima were also injured by the blast, and the
ones who were available to treat the wounded and dying did not know
what they were looking at. Have you read "Hiroshima" by Hersey? I
recommend it. They thought, from the burns, that it was a new kind
of fire bomb and did not understand the strange way people would have
their wounds start to heal and they get all sorts of other failures
of body systems. In that emergency situation, there was certainly
little record keeping and little information about where people were
at the time of the explosion.
More problematical as regards the question above, many people died of
other acute injuries before radiation could kill them. Worse, dose
reconstruction is difficult even if you know where the person was
and has been revised many times as more is understood about how the
weapon functioned. In contrast, the two radiation accidents had
reasonably well-known doses and the doctors knew what they were
looking at was due to radiation alone.
Much of what is known about radiation effects at the upper end of the
range is drawn from a fairly small sample of accident victims, a few
large exposures during tests, and model estimates for the Hiroshima
and Nagasaki populations that try to account for many unknowns.
Ray Depew
Hans Moravec (h...@cmu.edu) quoted several sources:
: from: http://www.ratical.com/radiation/KillingOurOwn/KOO7.html
: ...
: The air in his laboratory turned blue and radiation seared
: Daglian's flesh. He died a horrifying death. Less than a year
: later Daglian's boss, Louis Slotin, suffered a similar fate.
: -
: ref: Karl F. Hubner and Shirley Fry, "The Medical Basis
: for Radiation Accident Preparedness," Proceedings of the
: REAC/TS International Conference, Oak Ridge, Tenn.,
: October 1979, p. 17.
The mental images conjured up by this description do not match
those of other descriptions we've read here. I mean, this is
one of those old sci-fi movies where the scientist is screaming
in agony, clawing at his melting face and body, while the air
around him glows like a blue "neon" sign and really bad music
plays in the background. I wonder if the scientists attending
the conference booed Hubner and Fry off the podium, or if they
just got up and walked out.
: from:
: http://www.campus.bt.com/CampusWorld/pub/ScienceNet/database/Physics/Atomic/p00439c.html
: ...
: blue light. An atom bomb was going off. He wrenched the two
^^^^^^^^^^^^^^^^^^^^^^^^^^
: halves apart with his bare hands and the reaction ceased. There
This sounds like it was written by a journalism student with
more credit hours in the humanities than in science. (Apologies
to my English-professor friends here.)
This next one is the second-best one in the bunch. It's not
factual, parts of it were obviously fabricated, and again, the
writer has no understanding of the subject matter.
: from: http://www.pgs.ca/pages/nl/nlmkaku.htm
: ...
: Just one month after the bombing of Nagasaki,
...
: tabletop. One day he walked into the office and tripped. The
: tungsten carbide fell into the plutonium. The neutrons were
: reflected. Critical mass was attained, and an atomic bomb went
: off in his face.
...
: It was not a chemical explosion that created the
: implosion, 80 it was like a stick of dynamite. [...] He
: literally disintegrated in the Los Alamos hospital in about
: two weeks.
From the same reference, this is my favorite:
: Slotin lunged forward and grabbed the two hemispheres with his
: bare hands, ripped them apart and took the full brunt of a
: nuclear detonation right in his stomach.
You know, the feedlots in Greeley and Longmont, Colorado haul
truckloads of this animal byproduct away every day. It makes
great fertilizer. And here's the author's credentials:
: I have the autopsy
: pictures of this, by the way, if you want to see these gruesome
: pictures of American citizens that have been blown away by super
: critical reactions, small nuclear bombs that went off right in
: people's chests and faces...
"... and I have the autopsy pictures to prove it, if you want to
see them." These people wouldn't know a nucular explosion from
a chupacabra attack.
My thanks to Hans for posting these. I had thought that the
American scientific IQ had progressed to the point that this
sort of garbage was no longer published. I guess I was wrong.
Regards
Ray "save us from amateur scientists
and scientific illiterates" Depew
Nathan Urban
> Hans Moravec (h...@cmu.edu) quoted several sources:
> : from: http://www.pgs.ca/pages/nl/nlmkaku.htm
> From the same reference, this is my favorite:
> : Slotin lunged forward and grabbed the two hemispheres with his
> : bare hands, ripped them apart and took the full brunt of a
> : nuclear detonation right in his stomach.
> And here's the author's credentials:
> : I have the autopsy
> : pictures of this, by the way, if you want to see these gruesome
> : pictures of American citizens that have been blown away by super
> : critical reactions, small nuclear bombs that went off right in
> : people's chests and faces...
> "... and I have the autopsy pictures to prove it, if you want to
> see them." These people wouldn't know a nucular explosion from
> a chupacabra attack.
Uh, you do know Michio Kaku's credentials, don't you? (You didn't
actually read the cited document, did you? The first few paragraphs
discuss this.) Perhaps he was being fanciful or reducing the explanation
for his audience, but I assure you, he knows what a nuclear explosion is.
Jim Carr
r...@fc.hp.com (Ray Depew) wrote:
}
} Hans Moravec (h...@cmu.edu) quoted several sources:
} : from: http://www.pgs.ca/pages/nl/nlmkaku.htm
}
} From the same reference, this is my favorite:
}
} : bare hands, ripped them apart and took the full brunt of a
} : nuclear detonation right in his stomach.
}
}
} : pictures of this, by the way, if you want to see these gruesome
} : pictures of American citizens that have been blown away by super
} : critical reactions, small nuclear bombs that went off right in
} : people's chests and faces...
}
} see them." These people wouldn't know a nucular explosion from
} a chupacabra attack.
nur...@vt.edu writes:
>
>Uh, you do know Michio Kaku's credentials, don't you?
Yes, which means he has no excuse for writing the above description.
Nowhere is there any indication that Slotin experienced a "detonation".
Saying he was "screwing the pieces together" with a screwdriver is
hysterical.
Further, he did not write it, it came from an interview, and I note a
few major factual errors in it. The very concept that Teller was
trying to recruit people for Los Alamos is laughable. The business
about "lethal x-ray doses" is scary, since he should know that most
cancer therapy is based on such doses, and if he had read the reports
on the plutonium experiments he could not possibly concluded that
people were injected with lethal amounts of Pu and then the doctors
watched them die. That is libelous.
>Perhaps he was being fanciful or reducing the explanation
>for his audience, but I assure you, he knows what a nuclear explosion is.
Probably, so the hyperbole is deliberate. I always find it interesting
that he describes himself as a "nuclear theorist". His agenda affects
his treatment of the facts.
Ray Depew
Nathan Urban (nur...@crib.corepower.com) wrote:
: In article <6l6p15$7...@fcnews.fc.hp.com>, r...@fc.hp.com (Ray Depew) wrote:
: > : bare hands, ripped them apart and took the full brunt of a
: > : nuclear detonation right in his stomach.
: > And here's the author's credentials:
: > : I have the autopsy
: > : pictures of this, by the way, if you want to see these gruesome
: > : pictures of American citizens that have been blown away by super
: > : critical reactions, small nuclear bombs that went off right in
: > : people's chests and faces...
: > "... and I have the autopsy pictures to prove it, if you want to
: > see them." These people wouldn't know a nucular explosion from
: > a chupacabra attack.
: Uh, you do know Michio Kaku's credentials, don't you? (You didn't
: actually read the cited document, did you? The first few paragraphs
: discuss this.) Perhaps he was being fanciful or reducing the explanation
: for his audience, but I assure you, he knows what a nuclear explosion is.
Yes, I did. The guy's a crackpot. He uses his credentials as
Professor of Theoretical Physics to establish his credibility, and
then he goes and spouts of mile after mile of misinformation and trash,
most of which the general public will take at face value.
For a Professor of Theoretical Physics to suggest that someone "took
the full brunt of a nuclear detonation right in his stomach" and live
long enough to tell about it is irresponsible -- even a lie.
Likewise, suggesting that a "small nuclear bomb[]" could go off in
someone's chest or face and there would be enough pieces to pick up
afterwards. That's not what happened, he had no business
characterizing it as such, and what he said distorted the public's
view of what really happened.
Here's what he had to say about the early pre-SDI weapons research
(from the Web page): "... George Chaplin who proposed a new type of
third-generation hydrogen warhead that can be detonated and produce
an s-ray beam which can shoot down enemy satellites. " That's an
awful distortion of SDI, too awful even to call it a simplification.
I agree that SDI was a crock, but that doesn't justify Kaku lying
to discredit it.
In the interview that makes up this Web page, the interviewer asks
him about Gulf War syndrome. One of three theories he discusses
is "One is that we exploded large quantities of uranium during the
Gulf War in the form of U-238, which is not fissile. It does not
sustain a chain reaction. However, uranium is quite heavy. If I were
to throw a piece of uranium and you were to catch it, it would drop
to the floor. It's unusually heavy because it's quite radioactive. So
we use it in the tips of our tanks." And he finds this theory
"plausible".
"It's heavy because it's radioactive"? "We use it in the tips of our
tanks"? "We exploded large quantities of it"? This guy is so
full of crap it's oozing out his ears.
The whole Web page is full of crap like this. He cites his connections
to other nuclear physicists in an attempt to bolster his credibility.
He talks about his Japanese-American parents' experiences in WWII
internment camps to collect sympathy. He goes on and on about
government conspiracies and eevil nucular scientists.
Nathan, at first I took your chastisement seriously and went and
read this Web page. Now I'm glad I did. Michio Kaku is a total
and complete crackpot. Instead of "Hyperspace", he should have
written a book called "Hyperhype", or "Hyperbole".
God save us from amateur scientists *and* second-rate scientists.
Regards
Ray
Ken Cox
Ray Depew wrote:
[Statements of Michio Kaku:]
> tanks"? "We exploded large quantities of it"? This guy is so
> full of crap it's oozing out his ears.
There is a kernel of truth, obviously, in that depleted uranium is
used in armor-piercing projectiles and does get scattered around
when the round detonates. However, I agree that his version of
this is so sloppy as to represent either ignorance, galloping
senility, or a political agenda.
--
Ken Cox k...@research.bell-labs.com
Ray Depew
Ken Cox (k...@research.bell-labs.com) wrote:
'Zactly. He even says in the interview that it's "plausible" because
there's a kernel of truth to it. But it's only a _tiny_ kernel,
and he wraps his lies around that kernel.
(Note: sci.skeptic,rec.org.mensa removed from Followup-to.)
Regards
Ray "'It's heavy because it's radioactive'???" Depew
Will Flor
In article <35780A...@research.bell-labs.com>, Ken Cox <k...@research.bell-labs.com> wrote:
>Ray Depew wrote:
>[Statements of Michio Kaku:]
>> "It's heavy because it's radioactive"? "We use it in the tips of our
>> tanks"? "We exploded large quantities of it"? This guy is so
>> full of crap it's oozing out his ears.
>
>There is a kernel of truth, obviously, in that depleted uranium is
>used in armor-piercing projectiles and does get scattered around
>when the round detonates.
the only DU rounds I know of are kinetic rounds, not high-explosive ones. Are
there really DU rounds that explode?
-Will Flor wi...@will-flor.spamblock.com
Appropriately adjust my return address to reach me via e-mail.
Jim Carr
... followups trimmed ...
Ken Cox <k...@research.bell-labs.com> wrote:
}
} Ray Depew wrote:
} [Statements of Michio Kaku:]
} > "It's heavy because it's radioactive"? "We use it in the tips of our
} > tanks"? "We exploded large quantities of it"? This guy is so
} > full of crap it's oozing out his ears.
}
} There is a kernel of truth, obviously, in that depleted uranium is
} used in armor-piercing projectiles and does get scattered around
} when the round detonates.
wi...@will-flor.spamblock.com (Will Flor) writes:
>
>the only DU rounds I know of are kinetic rounds, not high-explosive ones. Are
>there really DU rounds that explode?
Depends on what you mean by "explode".
Uranium is pyrophoric and, when pulverized, burns really fast. That
feature combined with the penetrability makes it very effective as
an anti-armor weapon. I see no reason that a "nuclear physicist"
like Kaku should misrepresent the facts as he does above. He is
either lying through half-truths or does not know what he is talking
about. Either way, he seems to convey the idea that there is no
difference between conventional and nuclear weapons by failing to
make that distinction, a very dangerous thing to do IMO.
Peter Ceresole
In article <6l970f$je2$2...@news.inc.net>,
wi...@will-flor.spamblock.com (Will Flor) wrote:
>the only DU rounds I know of are kinetic rounds, not high-explosive ones. Are
>there really DU rounds that explode?
They can burn after striking, but that's oxidation. It's not detonation.
And it's not nuclear.
--
Peter
Ami Llorta
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>-hub.interserv.net!news.sprynet.com!not-for-mail
>From: dwi...@sprynet.com (Dave Wilton)
>Newsgroups:
> alt.folklore.urban,alt.folklore.science,sci.physics,sci.skeptic,rec.org.mensa
>Subject: Re: Waggin the Dragon's Tail?
>Date: Sat, 30 May 1998 01:23:55 GMT
>Organization: Sprynet News Service
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>Message-ID: <35755ea3...@news.sprynet.com>
>References: <355F568C...@ix.netcom.com>
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> sci.physics:308831 sci.skeptic:361365 rec.org.mensa:264452
>Status: N
Don't call something crap when you don't know what you're talking about. This
is a URL that gives details about nuclear accidents, and it looks like you've
got your accidents mixed up.
http://www.envirolink.org/issues/nuketesting/accident/critical.htm
There is a uranium hydride accident in February of 1945 where no one was hurt,
and then the following accident that sounds kind of like what you're
describing:
>INADVERTENT SUPERCRITICALITY RESULTS IN
>DEATH
>Los Alamos, N. Mex., May 21, 1946
>A senior scientist [Louis Slotin] was demonstrating the technique of critical
>assembly and associated studies and measurements to another scientist. The
>particular technique employed in the demonstration was to bring a hollow
>hemisphere of beryllium around a mass of fissionable material which was resting in a
>similar lower hollow hemisphere.
>The system was checked with two one-inch spacers between the upper hemisphere
>and the lower shell which contained the fissionable material; the system was subcritical at this time.
>Then the spacers were removed so that one edge of the upper hemisphere rested on the lower shell
>while the other edge of the upper hemisphere was supported by a screwdriver. This latter edge was
>permitted to approach the lower shell slowly. While one hand held the screwdriver, the other hand
>was holding the upper shell with the thumb placed in an opening at the polar point.
>At that time, the screwdriver apparently slipped and the upper shell fell into position around the
>fissionable material. Of the eight people in the room, two were directly engaged in the work leading
>to this incident.
>The "blue glow" was observed, a heat wave felt, and immediately the top shell was slipped off and
>everyone left the room. The scientist who was demonstrating the experiment received sufficient
>dosage to result in injuries from which he died nine days later. The scientist assisting received
>sufficient radiation dosage to cause serious injuries and some permanent partial disability.
>The other six employees in the room suffered no permanent injury.
Note the "blue glow" reference.
Richard Herring
Ken Cox (k...@research.bell-labs.com) wrote:
: Ray Depew wrote:
: [Statements of Michio Kaku:]
: > "It's heavy because it's radioactive"? "We use it in the tips of our
: > tanks"? "We exploded large quantities of it"? This guy is so
: > full of crap it's oozing out his ears.
: There is a kernel of truth, obviously, in that depleted uranium is
: used in armor-piercing projectiles and does get scattered around
: when the round detonates. However, I agree that his version of
: this is so sloppy as to represent either ignorance, galloping
: senility, or a political agenda.
Perhaps this explains the gratuitous reference to nationality in
the reference to "gruesome pictures of American citizens...". Unless
Americans react differently to radiation than those of other
nations, that's a journo speaking, not a scientist.
--
Richard Herring | richard...@gecm.com | Speaking for myself
GEC-Marconi Research Centre |
M.C.Harrison
Jim Carr wrote:
>
> } when the round detonates.
> >the only DU rounds I know of are kinetic rounds, not high-explosive ones. Are
> >there really DU rounds that explode?
> Uranium is pyrophoric and, when pulverized, burns really fast. That
Does uranium which has burned still give off radiation? That is, does
uranium oxide pose the same threat of radiation that plain old uranium
poses?
Or does it break up by fission and stop being radioactive during the
fire?
> about. Either way, he seems to convey the idea that there is no
> difference between conventional and nuclear weapons by failing to
> make that distinction, a very dangerous thing to do IMO.
Just a bit. A 100 megaton weapon being dropped on Iraq would be an
entirely different matter to a bit of uranium being used in the shells.
I can see how the former would provoke a different response from neutral
observers, at any rate.
Jim Carr
Jim Carr wrote:
|
| } when the round detonates.
| >the only DU rounds I know of are kinetic rounds, not high-explosive ones.
| >Are there really DU rounds that explode?
|
| Depends on what you mean by "explode".
| Uranium is pyrophoric and, when pulverized, burns really fast. That
nos...@someplace.somewhere.somehow writes:
>
>Does uranium which has burned still give off radiation?
It is still U-238. All that happens is that the metal gets oxidized.
Perhaps I should say it is "rusted", but that does not convey the effect.
Pyrophoric means that it oxidizes quickly, burning like magnesium
powder but does so spontaneously. It has the same properties as before,
but with the complication that it is now in the form of dust which is
easily inhaled.
>That is, does
>uranium oxide pose the same threat of radiation that plain old uranium
>poses?
Yes. Alpha emitter and all that. Longer lived than U-235, so
depleted U is less radioactive than natural U by a small factor,
but not enough to worry about for estimating effects.
>Or does it break up by fission and stop being radioactive during the
>fire?
The heat of a fire, as great as it is, does not get into the range
of energies that affect nuclei.
| about. Either way, he seems to convey the idea that there is no
| difference between conventional and nuclear weapons by failing to
| make that distinction, a very dangerous thing to do IMO.
>Just a bit. A 100 megaton weapon being dropped on Iraq would be an
>entirely different matter to a bit of uranium being used in the shells.
I suspect he was really talking about the "friendly fire" aspect of
it. US troops were exposed more than the Iraqis. The Iraqis who
were around were killed by the weapons. Troops coming through after
are the ones who might breath in the dust.
If there was a problem, well known methods can be used to identify
the body burden and estimate the risk if they wanted to do so.
me...@cars3.uchicago.edu
In article <357C7C...@spammers.of.the.world.unite.etc>, "M.C.Harrison" <nos...@spammers.of.the.world.unite.etc> writes:
>Jim Carr wrote:
>>
>> } when the round detonates.
>> >the only DU rounds I know of are kinetic rounds, not high-explosive ones. Are
>> >there really DU rounds that explode?
>> Depends on what you mean by "explode".
>> Uranium is pyrophoric and, when pulverized, burns really fast. That
>
>uranium oxide pose the same threat of radiation that plain old uranium
>poses?
>
>Or does it break up by fission and stop being radioactive during the
>fire?
Of course not.
Marie V. Martinek
>>It was not done for fun, nor done as described here. The experiment
>>was nicknamed "The Dragon Experiment" after Richard Feynman (who
>>else?) compared it to tickling the tail of a sleeping dragon.
>>
>>The experimenters dropped a slug of U-235 through a hole in some
>>blocks of uranium hydride, allowing the material to achieve critical
>>mass for a brief instant. Uranium hydride was used because the chain
>>reaction was slower than in pure U-235 and would allow the experiment
>>to be done without a detonation (or so they hoped--Feynman and others
>>were skeptical and the experiment was done at a remote location). The
>>energy released in this brief moment of critical mass was measured and
>>gave the scientists confirmation about the theories of how much energy
>>an explosion would yield.
>>
>>Following the war, a scientist was killed by a lethal dose of
>>radiation while trying to repeat the experiment. The slug got caught
>>on the uranium hydride blocks and the man separated them by hand to
>>prevent others from recieving a lethal dose of radiation. He died
>>shortly thereafter.
A vector for the fictional version of this story would be the movie "Fat Man &
Little Boy", where (supposedly) it happened at Los Alamos during the A-bomb
research. In that movie, it was called "Twisting the Dragon's tail", and the
scientist (who had earlier been shown to be both quick thinking and selfless
by racing to a pile of high-explosives & yanking the wire when there was a
problem) saved everyone in the room when the half-sphere of (uranium,
plutonium?) slipped off its calipers -- he reached over the lead shield and
knocked it out of position.
A nice point after -- they spent the next five minutes of movie time with
everyone drawing chalk marks around their feet, emptying their pockets of all
metal objects, (removing things that might have become secondarily
radioactive) and then calculating dosages based on the registered peak.
Marie V. Martinek
Northwestern University, Evanston, IL. USA
mv-ma...@nwu.edu
Kenneth W. Davis
Jim Carr wrote:
> I see no reason that a "nuclear physicist" like Kaku should misrepresent the
> facts as he does above. He is
> either lying through half-truths or does not know what he is talking about...
I've decided to take pretty much anything that Kaku says with one or more grains of
salt. One example that comes to mind is when, in a PBS special (I think it was
Stephen Hawking's Universe) he related that Heisenberg's uncertainty principle was
due to the method of observation impinging on the particle being observed. After
all the years that physicists have been trying to dispell that particular myth...
Ken
>
Ken Cox
Will Flor wrote:
> >There is a kernel of truth, obviously, in that depleted uranium is
> >used in armor-piercing projectiles and does get scattered around
>
> the only DU rounds I know of are kinetic rounds, not high-explosive ones. Are
> there really DU rounds that explode?
Sorry, sloppiness on my part. You are correct, but do note that
the uranium is often ignited by the heat of impact, after which it
burns rapidly. Even if it fails to ignite, it is usually broken
up by the impact. In either case, it does get dispersed.
--
Ken Cox k...@research.bell-labs.com
Jim Carr
... followups reduced ...
Will Flor wrote:
} Ken Cox wrote:
} >There is a kernel of truth, obviously, in that depleted uranium is
} >used in armor-piercing projectiles and does get scattered around
} >when the round detonates.
}
} the only DU rounds I know of are kinetic rounds, not high-explosive ones.
} Are there really DU rounds that explode?
Ken Cox <k...@research.bell-labs.com> writes:
>
>Sorry, sloppiness on my part. You are correct, but do note that
>the uranium is often ignited by the heat of impact, after which it
>burns rapidly. Even if it fails to ignite, it is usually broken
>up by the impact. In either case, it does get dispersed.
Still sloppy. Uranium metal is pyrophoric. Haven't you read other
articles in this thread? It will ignite in air if you break it up
into smaller pieces. It will ignite if you machine it with a lathe
or cut it with a hacksaw in air. Heat is not required.
Also note that DU is used in armor, not just projectiles. Someone
can tell us if they use it in reactive armor or passive armor; I
don't know those details.
Ken Cox
> articles in this thread?
Not at the time when I replied. You are right, that would have been
a good idea.
> Also note that DU is used in armor, not just projectiles. Someone
> can tell us if they use it in reactive armor or passive armor; I
> don't know those details.
Do you know what techniques are used to keep the uranium in this
armor from igniting when dented or cracked by impacts?
--
Ken Cox k...@research.bell-labs.com
Laurence Doering
In article <6ln1h3$f6o$1...@news.fsu.edu>,
Jim Carr <j...@ibms48.scri.fsu.edu> wrote:
>
> ... followups reduced ...
>
>Will Flor wrote:
>}
>} the only DU rounds I know of are kinetic rounds, not high-explosive ones.
>} Are there really DU rounds that explode?
>
>>
>>Sorry, sloppiness on my part. You are correct, but do note that
>>the uranium is often ignited by the heat of impact, after which it
>>burns rapidly. Even if it fails to ignite, it is usually broken
>>up by the impact. In either case, it does get dispersed.
>
> into smaller pieces. It will ignite if you machine it with a lathe
> or cut it with a hacksaw in air. Heat is not required.
So what's actually dispersed is uranium oxide, not metallic
uranium.
> Also note that DU is used in armor, not just projectiles. Someone
> can tell us if they use it in reactive armor or passive armor; I
> don't know those details.
DU can be used in "passive" armor - some sources say it's a
component of Chobham armor, which is used on some modern tanks,
including the M-1 Abrams. (The actual composition of Chobham
armor is still classified, AFAIK.)
Reactive armor isn't really armor at all in the traditional
sense - it's basically blocks of explosive mounted on the
exterior of an armored vehicle. The original idea was to defeat
shaped-charge warheads by disrupting the warhead detonation
sequence (the nearest block of reactive "armor" would be
detonated by the impact, and its explosion would screw up
the shaped charge detonation.) I've also heard that reactive
armor can be somewhat effective against long-rod kinetic
penetrators by damaging the "dart" as it hits, before it
penetrates all the way, but it's really intended to defeat
shaped-charge antitank rounds.
To the best of my knowledge, though, reactive armor has
fallen out of favor. It has a number of disadvantages.
Once it's detonated, you have no additional protection on
that same part of the tank until somebody replaces the block
of reactive armor that was set off. It has obvious deleterious
effects on any infantry that may be accompanying your tank,
and I can't imagine it does much for the peace of mind of the
tank's crew either.
Depleted uranium has nothing to do with reactive armor.
ljd
Jim Carr
Ken Cox <k...@research.bell-labs.com> writes:
>
>Do you know what techniques are used to keep the uranium in this
>armor from igniting when dented or cracked by impacts?
No. I would imagine they just hope it keeps the anti-armor
weapon outside. I've talked to Gulf War vets, who describe the
tiny hole on the outside and the charred interior that usually
results from those weapons.
Mike Playle
On Mon, 08 Jun 1998 17:06:08 -0700, "M.C.Harrison"
<nos...@spammers.of.the.world.unite.etc> wrote:
>Does uranium which has burned still give off radiation? That is, does
>uranium oxide pose the same threat of radiation that plain old uranium
>poses?
Radiation is a process originating in the nucleus of an atom; the
nucleus breaks into multiple pieces, some of which may be small
enough to be an alpha or beta particle. Sometimes, the nuclear
decay gives rise to a gamma as a by product.
Burning (oxidation) is a chemical reaction, taking place at the
level of the molecules, and the electrons which form the
intermolecular bonds. What's going on at this level has little
or no bearing on the activity inside the nucleus.
So the atomic nuclei in uranium oxide will tend to have the same
level of radioactivity as the original uranium that was burned.
Kenneth W. Davis
Kenneth W. Davis wrote:
I went through my tape library last night, trying to find the referenced Kaku
statement, and discovered that it wasn't made in "Stephen Hawking's Universe". The
show in question was titled "Mysteries of The Universe".
Ken
Douglas S. Caprette
In a previous article, nos...@spammers.of.the.world.unite.etc (M.C.Harrison) says:
>Jim Carr wrote:
>>
>> } when the round detonates.
>> >the only DU rounds I know of are kinetic rounds, not high-explosive ones. Are
>> >there really DU rounds that explode?
>> Depends on what you mean by "explode".
>> Uranium is pyrophoric and, when pulverized, burns really fast. That
>
>Does uranium which has burned still give off radiation? That is, does
>uranium oxide pose the same threat of radiation that plain old uranium
>poses?
>
The activity of the uranium nuclei is largely unaffected by chemical
reactions (ignoring self-moderation etc). However, the oxide may well
take the form of a fine powder, more easily inhaled, ingested, etc.
The chemical form can have a big effect on the threat of contamination
and exposure and consequently on dose.
--
DS Caprette
"There's a little truth in all jive, and a little jive in all truth."
-- Leonard Q. Barnes
Michael McNeil
au...@cleveland.Freenet.Edu (Douglas S. Caprette) writes:
>nos...@spammers.of.the.world.unite.etc (M.C.Harrison) says:
>>Jim Carr wrote:
>>>>>when the round detonates.
>>>>the only DU rounds I know of are kinetic rounds, not high-explosive
>>>>ones. Are there really DU rounds that explode?
>>>Depends on what you mean by "explode".
>>>Uranium is pyrophoric and, when pulverized, burns really fast.
>>
>>Does uranium which has burned still give off radiation? That is, does
>>uranium oxide pose the same threat of radiation that plain old uranium
>>poses?
>The activity of the uranium nuclei is largely unaffected by chemical
>reactions (ignoring self-moderation etc). However, the oxide may well
>take the form of a fine powder, more easily inhaled, ingested, etc.
>
>The chemical form can have a big effect on the threat of contamination
>and exposure and consequently on dose.
I thought I'd point out here that "depleted" uranium (that is, uranium
which has been enriched in U-238 beyond its normal abundance of 99.27
percent) is not very radioactive; its half-life is 4.51 billion years.
>DS Caprette
--
Michael McNeil
memc...@netcom.com
Jim Carr
au...@cleveland.Freenet.Edu (Douglas S. Caprette) writes:
}
} The activity of the uranium nuclei is largely unaffected by chemical
} reactions (ignoring self-moderation etc). However, the oxide may well
} take the form of a fine powder, more easily inhaled, ingested, etc.
}
} The chemical form can have a big effect on the threat of contamination
} and exposure and consequently on dose.
memc...@netcom.com (Michael McNeil) writes:
>
>I thought I'd point out here that "depleted" uranium (that is, uranium
>which has been enriched in U-238 beyond its normal abundance of 99.27
>percent) is not very radioactive; its half-life is 4.51 billion years.
True, but U-235 has a half-life of 0.704 billion years, so pure U-238
is only a factor of six or seven less radioactive (specific activity)
than pure U-235. Since, as you note, U-235 is always a small part of
natural uranium, the difference in activity is not very significant
between natural and depleted U.
Dave/Kristin Hall
Laurence Doering (l...@mail.bcpl.lib.md.us) wrote:
: To the best of my knowledge, though, reactive armor has
True, but not for the reasons stated....
: Once it's detonated, you have no additional protection on
: that same part of the tank until somebody replaces the block
: of reactive armor that was set off.
Big deal. If my tanks can survive 50% of what is thrown at them, I'm
gonna kick some ass!
: It has obvious deleterious
: effects on any infantry that may be accompanying your tank,
Two comments:
1) You already have a warhead going off in the area. The infantry
guys are already toast.
2) As a general, I'd trade 10 infantry for a tank every time.
: and I can't imagine it does much for the peace of mind of the
: tank's crew either.
If it works, the crews will love it, no matter how strange it might seem.
Look at kevlar vests...Bulky, hot, and made out of plastic (This is
supposed to protect me??), but very popular. Because they work.
Now, back to the question of why reactive armor is falling out of favor...
...because it is easily defeated with a duel shaped charge warhead. IE, a
very small shape charge is placed on the end of a probe on the front of
the missile. When the missile first impacts, this charge is initiated.
The reactive armor responds by detonating and messing up the gas jet from
this first "warhead". The main warhead then detonates and obliterates the
tank (obviously, we're dealing with a very short timeline here). Which
means that (in effect) you have put two bullets (impacts) on the exact
same spot. So, you've spent a lot of money on tank armor and your opponent
spent very little (additional) money to waste you anyway.
Thus, reactive armor costs a lot and accomplishes little. Thus, it's
fallen out favor.
--
David Hall
Propulsion Performance Office (Code 4732H0D)
Naval Air Warfare Center - Weapons Division
China Lake, CA 93555
Carl Fink
On 16 Jun 1998 17:32:00 -0700, Brian Trosko <btr...@primenet.com> wrote:
>
> . . . later-generation Russian ERA, like Kontakt-5, explodes
>outward with enough force to not only defeat two-staged HEAT warheads, but
>also (and this is a first), long-rod penetrators, which have hitherto been
>the surest way to defeat ERA. Current top-line Russian tanks with this
>ERA can survive close-range front-turret hits by modern US tanks.
How do you know? Have we done some test-firing for them?
More seriously: don't modern U.S. tanks use kinetic-energy rounds
(tungsten or DU darts) rather than HEAT?
--
Carl Fink ca...@dm.net
Q. Why do some people take astrology seriously?
a. Because they have unusually small brains. --Dave Barry
Peter Ceresole
In article <6m77p6$8t$1...@carlf.dialup.access.net>,
ca...@panix.com (Carl Fink) wrote:
>More seriously: don't modern U.S. tanks use kinetic-energy rounds
>(tungsten or DU darts) rather than HEAT?
Yes; those are the long rod penetrators that Brian referred to. If the
latest Russian reactive armour can defeat those then we're in for a new
twist in the gun/armour battle; probably something like tandem
explosive/rod projectiles, something like that.
--
Peter
Brian Trosko
Carl Fink <ca...@dm.net> wrote:
: >the surest way to defeat ERA. Current top-line Russian tanks with this
: >ERA can survive close-range front-turret hits by modern US tanks.
: How do you know? Have we done some test-firing for them?
No; the 120mm Rheinmetall smoothbore on the Abrams series is the same gun
used by front-line tanks of several other nations.
: More seriously: don't modern U.S. tanks use kinetic-energy rounds
: (tungsten or DU darts) rather than HEAT?
Both long-rod penetrators and HEAT rounds are used by US forces. That's
what makes this new ERA so nasty; it can potentially defeat APFSDS.
John C. Kalinowski
> More seriously: don't modern U.S. tanks use kinetic-energy rounds
> (tungsten or DU darts) rather than HEAT?
> Carl Fink ca...@dm.net
Yep. Goes through most armor like shit through a goose.
If you are in the neighborhood, stop off and visit Aberdeen Proving
Grounds, MD, just off of I-95. That's where we take the latest available
equipment and poke holes through it. The T-90 is nice but won't stand up
to an M-1 MBT. Although the Russkies have come along way, the basic
strategy remains Uncle Joe's "Quantity has a quality all it's own."
I expect that the calculated M-1 versus T-90 kill ratio exceeds 5 to 1.
(5 T-90s for each M-1). Crew training and FC systems have a lot to do
with it.
Major K
Noli copulare cum pedestribus.
Brian Trosko
Peter Ceresole <pe...@cara.demon.co.uk> wrote:
: Yes; those are the long rod penetrators that Brian referred to. If the
: latest Russian reactive armour can defeat those then we're in for a new
: twist in the gun/armour battle; probably something like tandem
: explosive/rod projectiles, something like that.
Or an upgunning; I know the Germans were thinking of a move to a 130mm gun
for a while, but scrapped the plan because of cost/complexity issues.
John C. Kalinowski
>
> Yes; those are the long rod penetrators that Brian referred to. If the
> latest Russian reactive armour can defeat those then we're in for a new
> twist in the gun/armour battle; probably something like tandem
> explosive/rod projectiles, something like that.
>
> Peter
>
I did my first Command and General Staff College research paper on
reactive armor versus super high velocity discarding sabot kinetic
energy rounds. I suggested reviving reckless rifle technology with
tandem RAP (rocket assist projectile) darts. It was much easier to
change the TOW missle to the TOW 2 with a flyover shoot down warhead.
Why whack the hard armor? Just kill it from above.
Major K.
Brian Trosko
John C. Kalinowski <john.ka...@droll.net> wrote:
: equipment and poke holes through it. The T-90 is nice but won't stand up
: strategy remains Uncle Joe's "Quantity has a quality all it's own."
Which it does; witness the Sherman in WWII. Who cares that a Tiger could
wax limitless numbers of Shermans? There weren't enough of them.
: I expect that the calculated M-1 versus T-90 kill ratio exceeds 5 to 1.
: (5 T-90s for each M-1). Crew training and FC systems have a lot to do
: with it.
Let's see how that M-1 fares when, while it's killing 4 T-90s, the 5th
puts an APFSDS thought the rear armor.
Brian Trosko
John C. Kalinowski <john.ka...@droll.net> wrote:
: Why whack the hard armor? Just kill it from above.
Umm...all the pictures of RA-equipped tanks I've seen included a few
blocks on the top armor just for good measure. If it can defeat a
conventional HEAT round, it should have no problem at all with an EFP.
Carl Fink
>Yes; those are the long rod penetrators that Brian referred to.
Oh. I was thinking of the double-explosive warhead, with a small
charge on the end of a "long rod" preceding the main (HEAT) charge, so
the smaller charge sets off the reactive armor before the HEAT warhead
arrives.
Peter Ceresole
In article <3587FE...@droll.net>,
"John C. Kalinowski" <john.ka...@droll.net> wrote:
>I did my first Command and General Staff College research paper on
>reactive armor versus super high velocity discarding sabot kinetic
>energy rounds. I suggested reviving reckless rifle technology with
>tandem RAP (rocket assist projectile) darts. It was much easier to
>change the TOW missle to the TOW 2 with a flyover shoot down warhead.
I was thinking of that; the Norwegians were the first to do the shoot-down
warhead (HEAT) with the Bill missile, weren't they?
>Why whack the hard armor? Just kill it from above.
That's true with the old fashioned armour; you have to be sparing with it
because it weighs so much. The beauty of reactive armour is that it's
relatively light. It doesn't take layers of ceramic and copper (or whatever
they use in Chobham armour) which weighs tons and stops you armouring a
vehicle all over (as does conventional steel armour, of course). For the
first time you could envisage putting the armour on the top as well and
still have a tank capable of movement... and that would stymie your plan.
If the Russians have got this right, they would be able to defeat
self-forging warheads too. Potentially it's the first real armour
revolution since the sloping plate of the T-34. You could envisage much
lighter armoured vehicles with much better performance. We live in
interesting times.
--
Peter
Carl Fink
On 17 Jun 1998 15:22:01 -0700, Brian Trosko <btr...@primenet.com> wrote:
>No; the 120mm Rheinmetall smoothbore on the Abrams series is the same gun
>used by front-line tanks of several other nations.
True, but aren't we the sole users of depleted uranium rounds?
(Honest question, I don't remember.)
Peter Ceresole
In article <6m9qdg$1pu$1...@carlf.dialup.access.net>,
ca...@panix.com (Carl Fink) wrote:
>True, but aren't we the sole users of depleted uranium rounds?
>(Honest question, I don't remember.)
No; everybody uses them. It's depleted uranium sintered with things like
tungsten and cobalt and various components (I forget which) to make the tip
very hard and keep the rod coherent while it burns its way in.
--
Peter
Peter Ceresole
In article <6m9h9v$ib$1...@carlf.dialup.access.net>,
ca...@panix.com (Carl Fink) wrote:
>Oh. I was thinking of the double-explosive warhead, with a small
>charge on the end of a "long rod" preceding the main (HEAT) charge, so
>the smaller charge sets off the reactive armor before the HEAT warhead
>arrives.
Those are the "tandem" HEAT warheads that have also been mentioned here.
But it's not so much a rod between the warheads, more a cylindrical
structure.
The kinetic energy rounds nowadays *are* long rods. They are dart shaped,
fin stabilised, without spin. The basic penetrating action involves the tip
of the rod striking with such energy that the rod and the armour form a
plasma at the point of impact; the rod keeps moving into a deeper and
deeper plasma "hole", consuming itself as it goes. This all happens pretty
fast, obviously, less than a millisecond. When the hole burns through, the
remainder of the penetrator causes a lot of physical damage inside, but the
interior of the target is also filled with flame from the plasma which, I
suspect, causes the main damage.
The depleted uranium content also catches fire and burns, generating what
was described to me by a tank man as a "toxic white gas". Not a good place
to be, really.
--
Peter
John C. Kalinowski
Brian said:
> : Why whack the hard armor? Just kill it from above.
>
> Umm...all the pictures of RA-equipped tanks I've seen included a few
> blocks on the top armor just for good measure. If it can defeat a
> conventional HEAT round, it should have no problem at all with an EFP.
>
That's why a two dart system would be deployed. First dart for reactive
armor, second for the kill. Makes everyone have to upgrade.
John Flanagan
A more realistic question is, can the makers of the T-90 afford enough
of
them to exceed a 5 to 1 ratio these days, taking into account the
numbers
of M-1s we already have? ;-)
Brian Trosko
Carl Fink <ca...@dm.net> wrote:
: True, but aren't we the sole users of depleted uranium rounds?
: (Honest question, I don't remember.)
Perhaps, but there's not a lot of difference in performance between DU and
regular tungsten rounds; the density of both rounds is virtually
identical, and the pyrophoric effects of DU rounds are, well, pretty
incidental.
Brian Trosko
Peter Ceresole <pe...@cara.demon.co.uk> wrote:
: fin stabilised, without spin. The basic penetrating action involves the tip
: of the rod striking with such energy that the rod and the armour form a
: plasma at the point of impact; the rod keeps moving into a deeper and
: deeper plasma "hole", consuming itself as it goes. This all happens pretty
: fast, obviously, less than a millisecond. When the hole burns through, the
: remainder of the penetrator causes a lot of physical damage inside, but the
: interior of the target is also filled with flame from the plasma which, I
: suspect, causes the main damage.
Not quite; the round doesn't turn into plasma and burn though the armor.
It's straight plastic deformation what does it, with the armor of the tank
yielding to the hideous pressures of that much weight striking that small
an area at that high a velocity.
: The depleted uranium content also catches fire and burns, generating what
: was described to me by a tank man as a "toxic white gas". Not a good place
: to be, really.
If you're inside a tank when the armor gets breached by APFSDS, a toxic
white gas is the absolute least of your problems.
Brian Trosko
: No; everybody uses them.
Nope. We use it because we've got a lot of it laying around, really.
It's comparable in performance to tungsten rounds, and we've got several
decades worth of nuclear-age byproducts lying around. Nations without a
nuclear program of their own don't use it; I don't believe Germany uses
it, for example. During the Gulf War, Iraq was using sabot rounds made
out of plain steel, which explains part of their abysmal performance.
me...@cars3.uchicago.edu
In article <6mc53o$a...@nntp02.primenet.com>, Brian Trosko <btr...@primenet.com> writes:
>Peter Ceresole <pe...@cara.demon.co.uk> wrote:
>
>: The depleted uranium content also catches fire and burns, generating what
>: was described to me by a tank man as a "toxic white gas". Not a good place
>: to be, really.
>
>If you're inside a tank when the armor gets breached by APFSDS, a toxic
>white gas is the absolute least of your problems.
If you're there you've no more problems.
Mati Meron | "When you argue with a fool,
me...@cars.uchicago.edu | chances are he is doing just the same"
Peter Ceresole
In article <6mc53o$a...@nntp02.primenet.com>,
Brian Trosko <btr...@primenet.com> wrote:
>Not quite; the round doesn't turn into plasma and burn though the armor.
>It's straight plastic deformation what does it, with the armor of the tank
>yielding to the hideous pressures of that much weight striking that small
>an area at that high a velocity.
Interesting; I was told by an ordnance chap at Fort Halstead that locally,
the rod and the armour form a plasma and that this was the mechanism that
leads to the penetration. Maybe he was exaggerating?
>If you're inside a tank when the armor gets breached by APFSDS, a toxic
>white gas is the absolute least of your problems.
Indeed. The slomo film I used of APC targets being struck by rod
penetrators shows flame coming out of every orifice.
--
Peter
Peter Ceresole
In article <6mc57g$a...@nntp02.primenet.com>,
Brian Trosko <btr...@primenet.com> wrote:
>: No; everybody uses them.
>
>Nope. We use it because we've got a lot of it laying around, really.
I thought that DU was extremely cheap, and freely traded? It's certainly
used for any number of civilian purposes, all over the world?
--
Peter
Brian Trosko
Peter Ceresole <pe...@cara.demon.co.uk> wrote:
: >
: >Nope. We use it because we've got a lot of it laying around, really.
: I thought that DU was extremely cheap, and freely traded? It's certainly
: used for any number of civilian purposes, all over the world?
Is it? I know it's used for sabot rounds, because it's so dense, and for
counterweights for aircraft control surfaces, because it's so dense, but
what else is it used for?
Peter Ceresole
In article <6me004$k...@nntp02.primenet.com>,
Brian Trosko <btr...@primenet.com> wrote:
>Is it? I know it's used for sabot rounds, because it's so dense, and for
>counterweights for aircraft control surfaces, because it's so dense, but
>what else is it used for?
Keels for yachts is one almost trivial use. In aircraft too, there's a lump
of DU in B747s which is used to balance the aircraft. I don't have any more
specific uses in my head, but it seems to be an extremely common substitute
for lead these days, as a weight, presumably because it's so much less
toxic.
--
Peter
Jim Esler
These uses of plutonium and the relative toxicity are interesting when
you consider the uproar concerning its use as a power source on
satellites. Is this going to start that thread again?
--
Jim Esler
Jim Carr
Peter Ceresole <pe...@cara.demon.co.uk> wrote:
:
: I thought that DU was extremely cheap, and freely traded? It's certainly
: used for any number of civilian purposes, all over the world?
Brian Trosko <btr...@primenet.com> writes:
>
>Is it? I know it's used for sabot rounds, because it's so dense, and for
>counterweights for aircraft control surfaces, because it's so dense, but
>what else is it used for?
A colleague here says he got an offer for a "titanium Master Card";
maybe "depleted uranium Visa" will be next.
--
James A. Carr <j...@scri.fsu.edu> | Commercial e-mail is _NOT_
http://www.scri.fsu.edu/~jac/ | desired to this or any address
Supercomputer Computations Res. Inst. | that resolves to my account
Florida State, Tallahassee FL 32306 | for any reason at any time.
Charles W. Shults III
Brian Trosko wrote:
>
> Peter Ceresole <pe...@cara.demon.co.uk> wrote:
> : >
> : >Nope. We use it because we've got a lot of it laying around, really.
>
> : used for any number of civilian purposes, all over the world?
>
> counterweights for aircraft control surfaces, because it's so dense, but
> what else is it used for?
Nuclear shielding, for one. It's better than lead. DU has quite
an industry behind it. In past research projects, I've gotten familiar
with companies that custom fabricate DU artifacts and shields.
Cheers!
Chip Shults
Chuck Stewart
(The kitty gets ready to fire a plutonium APFSDS round at a tank... :)
Jim Esler wrote:
>
> These uses of plutonium ....
Uh, the subject under discussion is depleted uranium.
Mildly radioactive, and extremely dense.
Unlike plutonium, it is not considered a nuclear weapons risk, and the
Department of Energy is looking for a way to dump many thousands of
tons of it on the market for a profit.
So far it's primary uses are in anti-tank weapons, armor, shielding of
much more radioactive stuff, and anyplace you need a dense material for
weight or counter-weight.
--
Chuck Stewart
Take out sphahmblohck for reply
zapkitty located at geocities lil' round thing com
"Anime-style catgirls: Proof that the end is nearer than you think :)"
Douglas S. Caprette
In a previous article, James....@cdc.com (Jim Esler) says:
>>
>> Keels for yachts is one almost trivial use. In aircraft too, there's a lump
>> of DU in B747s which is used to balance the aircraft. I don't have any more
>> specific uses in my head, but it seems to be an extremely common substitute
>> for lead these days, as a weight, presumably because it's so much less
>> toxic.
>
>These uses of plutonium and the relative toxicity are interesting when
>you consider the uproar concerning its use as a power source on
>satellites. Is this going to start that thread again?
>--
I hope not. This discussion is about DU (Depleted Uranium) mostly
U-238. _NOt_ Plutonium.
--
DS Caprette
"There's a little truth in all jive, and a little jive in all truth."
-- Leonard Q. Barnes
Jim Carr
Peter Ceresole wrote:
}
} Brian Trosko <btr...@primenet.com> wrote:
} >Is it? I know it's used for sabot rounds, because it's so dense, and for
} >counterweights for aircraft control surfaces, because it's so dense, but
} >what else is it used for?
}
} of DU in B747s which is used to balance the aircraft. I don't have any more
} specific uses in my head, but it seems to be an extremely common substitute
} for lead these days, as a weight, presumably because it's so much less
} toxic.
Jim Esler <James....@cdc.com> writes:
>
>These uses of plutonium and the relative toxicity are interesting when
>you consider the uproar concerning its use as a power source on
>satellites. Is this going to start that thread again?
DU is "depleted uranium". Uranium is not plutonium.
The specific activity goes as the inverse of the lifetime. Thus the
difference between the 4.5 billion year half life of U-238 and the
88 year half life of the Pu-238 used in Cassini is, ah, significant.
me...@cars3.uchicago.edu
In article <358A98...@cdc.com>, Jim Esler <James....@cdc.com> writes:
>Peter Ceresole wrote:
>>
>> In article <6me004$k...@nntp02.primenet.com>,
>>
>> >Is it? I know it's used for sabot rounds, because it's so dense, and for
>> >counterweights for aircraft control surfaces, because it's so dense, but
>> >what else is it used for?
>>
>> Keels for yachts is one almost trivial use. In aircraft too, there's a lump
>> of DU in B747s which is used to balance the aircraft. I don't have any more
>> specific uses in my head, but it seems to be an extremely common substitute
>> for lead these days, as a weight, presumably because it's so much less
>> toxic.
>
>you consider the uproar concerning its use as a power source on
>satellites. Is this going to start that thread again?
He was talking about depleted uranium, not plutonium.
Andy Dingley
On 18 Jun 1998 15:44:00 -0700, Brian Trosko <btr...@primenet.com>
wrote:
>Nope. We use it because we've got a lot of it laying around, really.
>It's comparable in performance to tungsten rounds, and we've got several
>decades worth of nuclear-age byproducts lying around.
How "easily available" is that really ? I'm assuming that any
depleted uranium produced as uranium hexafluoride tailings from
centrifuge plants etc. This will still require reduction to the
metallic form, which is an expensive process for uranium (bomb
reduction with magnesium is still the process of choice, AFAIK)
What's the cost of metallic depleted uranium, compared to natural
isotope mix metallic uranium, or compared to tungsten carbide (as
used in many sabot rounds) ?
Brian Trosko
Jim Esler <James....@cdc.com> wrote:
: These uses of plutonium and the relative toxicity are interesting when
: you consider the uproar concerning its use as a power source on
: satellites. Is this going to start that thread again?
Not unless a whole bunch of other people confuse depleted uranium with
plutonium.
Brian Trosko
Dave/Kristin Hall <theh...@ridgecrest.ca.us> wrote:
: Interesting. I had not heard this. So how does it stand up to a Maverick?
I'm sure it would work just fine. I'd be hard-pressed to imagine ERA
that'd stand up to several hundred pounds of high-explosive.
The penetration of a HEAT warhead depends on the warhead detonating at an
optimum distance from the armor. ERA reduces HEAT penetration both by
forcing it to detonate at a less-than-optimum distance, and by seriously
disrupting the resultant jet of high-pressure fluid. The new ERA
supposedly explodes with sufficient force to hurl a metal plate outward to
literally break a long-rod penetrator into pieces before it can punch
though. But HE doesn't care about any of that, so I don't see 300 lbs. of
Maverick warhead being tremendously upset by ERA that is supposed to be
able to interfere with a dinky 40 lb. chunk of depleted uranium.
: Seriously. The Maverick has been fast falling out of favor due to it's
: large size and weight.
What? A superbly reliable, fire-and-forget missile with a warhead big
enough to kill just about anything you'd shoot it at? Who's it falling
out of favor with?
: But if the latest RA negates the smaller missiles
: such as Hellfire....
Hellfire is even larger than TOW, and can top-attack if the spotter puts
the beam in the right place.
: ...Or could it be time to revive the German Mistel-1(*)?
Gee...whaddya think a Tallboy would do to a T-72?
Dave/Kristin Hall
Brian Trosko (btr...@primenet.com) wrote:
: Except it hasn't; later-generation Russian ERA, like Kontakt-5, explodes
: outward with enough force to not only defeat two-staged HEAT warheads, but
: also (and this is a first), long-rod penetrators, which have hitherto been
: the surest way to defeat ERA. Current top-line Russian tanks with this
: ERA can survive close-range front-turret hits by modern US tanks.
Interesting. I had not heard this. So how does it stand up to a Maverick?
Seriously. The Maverick has been fast falling out of favor due to it's
large size and weight. But if the latest RA negates the smaller missiles
such as Hellfire....
(For those not aware: Despite it's reputation as a tank killer, the
Maverick was not designed to kill tanks. It was designed to kill bunkers,
pillboxes, etc. IE, things with several feet of reenforced concrete. As
a result, killing a tank with a Maverick is akin to smashing a cockroach
with a sledge hammer.....consider that warhead on the Hellfire missile is
sometihng like 25 lbs. The Air Force version of the Maverick's warhead
is 125 lbs and the Navy's (IRRC) 300 lbs.)
...Or could it be time to revive the German Mistel-1(*)?
-Dave
(*) The Mistel-1 was a WWII anti-battleship cruise missile (sort of...
It was a modified Ju-88 that would be controlled by an FW-190 (that
was strapped to the Ju-88 much the same way the Space Shuttle gets
strapped to a 747) until the last few second of flight...at which
time the FW-190 would separate and the Ju-88 would (hopefully) ram
the target.) with a 7700 lb shaped charge warhead designed to penetrate
24 *FEET* of steel. As with many of Germany's wonder weapons, it was
developed too late to see action.
--
David Hall
Propulsion Performance Office (Code 4732H0D)
Naval Air Warfare Center - Weapons Division
China Lake, CA 93555
Ami Llorta
>Peter Ceresole <pe...@cara.demon.co.uk> wrote:
>: >
>: >Nope. We use it because we've got a lot of it laying around, really.
>
>: I thought that DU was extremely cheap, and freely traded? It's certainly
>: used for any number of civilian purposes, all over the world?
>
>Is it? I know it's used for sabot rounds, because it's so dense, and for
>counterweights for aircraft control surfaces, because it's so dense, but
>what else is it used for?
I think people coat electron microscope specimens with uranium.
Dave/Kristin Hall
Brian Trosko (btr...@primenet.com) wrote:
: : Seriously. The Maverick has been fast falling out of favor due to it's
: : large size and weight.
: What? A superbly reliable, fire-and-forget missile with a warhead big
: enough to kill just about anything you'd shoot it at? Who's it falling
: out of favor with?
The Navy and Marines for starters. The current plan is to replace Maverick
with the Hellfire III. They figure "Maverick is overkill for 99.9% of
what we shoot at and we can carry a *lot* more Hellfires under a wing than
we can Mavericks."
: Hellfire is even larger than TOW, and can top-attack if the spotter puts
: the beam in the right place.
Heh, tell taht to the Longbow people.
Brian Trosko
Dave/Kristin Hall <theh...@ridgecrest.ca.us> wrote:
: The Navy and Marines for starters. The current plan is to replace Maverick
: with the Hellfire III. They figure "Maverick is overkill for 99.9% of
: what we shoot at and we can carry a *lot* more Hellfires under a wing than
: we can Mavericks."
I suppose that's a good point, but what's Hellfire III? Hellfire is the
original laser-guided missile, ranged about 6km. Hellfire II I understand
to be a MMW radar-guided, fire-and-forget weapon with about an 8km range.
What's the third variant?
Superdave the Wonderchemist
Andy Dingley (din...@codesmiths.com) wrote:
: On 18 Jun 1998 15:44:00 -0700, Brian Trosko <btr...@primenet.com>
: wrote:
: >Nope. We use it because we've got a lot of it laying around, really.
: >It's comparable in performance to tungsten rounds, and we've got several
: >decades worth of nuclear-age byproducts lying around.
: How "easily available" is that really ? I'm assuming that any
: depleted uranium produced as uranium hexafluoride tailings from
: centrifuge plants etc. This will still require reduction to the
: metallic form, which is an expensive process for uranium (bomb
: reduction with magnesium is still the process of choice, AFAIK)
: What's the cost of metallic depleted uranium, compared to natural
: isotope mix metallic uranium, or compared to tungsten carbide (as
: used in many sabot rounds) ?
I would be interested in knowing whether the reason for using depleated U
may have more to do with the factthat U is pretty darn dense. Remember,
cross-sectional density is one major component in ballistic calculations.
--
--"The gods do not deduct from man's allotted span the hours
spent in fishing." -- Babylonian proverb
-Superdave The Wonderchemist
(an inside joke)
Theoretical Chemistry Grad student (read slave)
NDSU Fargo, ND (read middle of nowhere)
Disclaimer:
I speak for no one but myself unless I am wrong, then I speak
on behalf of someone else. (read whatever)
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me...@cars3.uchicago.edu
In article <6mmei7$ohu$2...@node2.nodak.edu>, thw...@prairie.NoDak.edu (Superdave the Wonderchemist) writes:
>Andy Dingley (din...@codesmiths.com) wrote:
>: On 18 Jun 1998 15:44:00 -0700, Brian Trosko <btr...@primenet.com>
>: wrote:
>
>: >Nope. We use it because we've got a lot of it laying around, really.
>: >It's comparable in performance to tungsten rounds, and we've got several
>: >decades worth of nuclear-age byproducts lying around.
>
>may have more to do with the factthat U is pretty darn dense. Remember,
>cross-sectional density is one major component in ballistic calculations.
>
and Tantalum have a similar density (if you want to go all out, you
may use Osmium or Iridium but this is getting kinda expensive). The
point is that Tungsten and Tantalum have lots of other uses, while DU
doesn't. Other than its high density it has no especially useful
properties.
Uncle Al
Depleted uranium rounds possess tow very useful and unique properties
beyond emre density:
1) They surface slough during passage through armor, lubricating
their way through,
2) The round heats white hot from its passage. When it exits it
fragments and pyrophorically explodes.
Nice.
--
Uncle Al Schwartz
Uncl...@ix.netcom.com ("zero" before @)
http://uncleal.within.net/
http://pw2.netcom.com/~uncleal0/uncleal.htm
http://www.ultra.net.au/~wisby/uncleal.htm
http://www.guyy.demon.co.uk/uncleal/uncleal.htm
(Toxic URLs! Unsafe for children, Democrats, and most mammals)
"Quis custodiet ipsos custodes?" The Net!
Brian Trosko
Uncle Al <Uncl...@ix.netcom.com> wrote:
: 1) They surface slough during passage through armor, lubricating
: their way through,
At those pressures, all materials behave like fluids; any additional
lubrication would be secondary.
: 2) The round heats white hot from its passage. When it exits it
: fragments and pyrophorically explodes.
: Nice.
But entirely superfluous, and not reason to use DU in preference to
tungsten; when a metal dart moving at over 1000mps penetrates your armor,
the last question you'll think of asking yourself is, "But is it on fire?"
Dave/Kristin Hall
Brian Trosko (btr...@primenet.com) wrote:
: I suppose that's a good point, but what's Hellfire III? Hellfire is the
: original laser-guided missile, ranged about 6km. Hellfire II I understand
: to be a MMW radar-guided, fire-and-forget weapon with about an 8km range.
: What's the third variant?
The third variant...is under development. There was, however, a brief
mention of it in Av Week a month or two back.
Mark Folsom
me...@cars3.uchicago.edu wrote in message ...
>In article <6mmei7$ohu$2...@node2.nodak.edu>, thw...@prairie.NoDak.edu
(Superdave the Wonderchemist) writes:
>>Andy Dingley (din...@codesmiths.com) wrote:
>>: On 18 Jun 1998 15:44:00 -0700, Brian Trosko <btr...@primenet.com>
>>: wrote:
>>
>>: >Nope. We use it because we've got a lot of it laying around, really.
>>: >It's comparable in performance to tungsten rounds, and we've got
several
>>: >decades worth of nuclear-age byproducts lying around.
>>
>>I would be interested in knowing whether the reason for using depleated U
>>may have more to do with the factthat U is pretty darn dense. Remember,
>>cross-sectional density is one major component in ballistic calculations.
>>
>That's certainly one of the reasons, but not the only one. Tungsten
>and Tantalum have a similar density (if you want to go all out, you
>may use Osmium or Iridium but this is getting kinda expensive). The
>point is that Tungsten and Tantalum have lots of other uses, while DU
>doesn't. Other than its high density it has no especially useful
>properties.
>
Uranium is also pyrophoric. It makes burning fragments on passing through
heavy armor. Sets things on fire.
--
Mark Folsom, P.E.
Consulting Mechanical Engineer
http://www.redshift.com/~folsom
Brian Trosko
Mark Folsom <fols...@redshift.com> wrote:
: Uranium is also pyrophoric. It makes burning fragments on passing through
: heavy armor. Sets things on fire.
Again, so what? Not only is this entirely superfluous to the killing of
an enemy tank, it makes it more difficult to machine the rounds, since you
now have to worry about spontaneous combustion of any tailings, and
presents a possible battlefield hazard. I wouldn't want to inhale even a
very very weak alpha emitter, thank you.
me...@cars3.uchicago.edu
In article <6n0ihm$g1f$3...@supernews.com>, "Mark Folsom" <fols...@redshift.com> writes:
>me...@cars3.uchicago.edu wrote in message ...
>>In article <6mmei7$ohu$2...@node2.nodak.edu>, thw...@prairie.NoDak.edu
>(Superdave the Wonderchemist) writes:
>>>Andy Dingley (din...@codesmiths.com) wrote:
>>>: On 18 Jun 1998 15:44:00 -0700, Brian Trosko <btr...@primenet.com>
>>>: wrote:
>>>
>>>: >Nope. We use it because we've got a lot of it laying around, really.
>>>: >It's comparable in performance to tungsten rounds, and we've got
>several
>>>: >decades worth of nuclear-age byproducts lying around.
>>>
>>>I would be interested in knowing whether the reason for using depleated U
>>>may have more to do with the factthat U is pretty darn dense. Remember,
>>>cross-sectional density is one major component in ballistic calculations.
>>>
>>That's certainly one of the reasons, but not the only one. Tungsten
>>and Tantalum have a similar density (if you want to go all out, you
>>may use Osmium or Iridium but this is getting kinda expensive). The
>>point is that Tungsten and Tantalum have lots of other uses, while DU
>>doesn't. Other than its high density it has no especially useful
>>properties.
>>
>
>heavy armor. Sets things on fire.
>
round, it doesn't catch fire but it still enter the inside of the tank
accompanied by a spray of molten steel which is quite good in setting
things on fire. And consider the effect of a hard item penetrating at
a velocity of 1000 m/h and bouncing inside the tank couple hundred
time before coming to rest. Especially the effect on items made of
soft tissue.
Harry H Conover
Brian Trosko (btr...@primenet.com) wrote:
: Mark Folsom <fols...@redshift.com> wrote:
:
:
: : Uranium is also pyrophoric. It makes burning fragments on passing through
: : heavy armor. Sets things on fire.
: Again, so what? Not only is this entirely superfluous to the killing of
: an enemy tank
Actually, it's a highly integral part of the "killing of an enemy tank."
A primary goal is to ignite the ordnance within the tank, causing it to
self destruct.
"HEAT" munitions are constructed with the same goal in mind, except
that they employ a shaped explosive charge to pierce the armor rather
than kinetic impact.
The minimal radioactivity risks associated with DU are of little or
no consequence vis-a-vis other battlefield hazards.
Harry C.
Chuck Stewart
(The kitty wears a gas mask... DU dust fears? Nope... The smog outside
today is a REAL hazard... Headers trimmed a little...)
Harry H Conover wrote:
> The minimal radioactivity risks associated with DU are of little or
> no consequence vis-a-vis other battlefield hazards.
>
> Harry C.
I would modify that statement a little...
I don't know if DU is the hazard it's opponents claim, I 've read of no
studies that reached any conclusions.
But say that the opponents have at least some validity to their fears:
Enemy tanks, aircraft, and troops, and even friendly fire are more
dangerous hazrds than DU dust while on the battlefield...
But DU, if it is a hazard, would be the one you took home with you.
And unless they jammed a counter down your trachea you would never
know...
(And mayby not even then... Lungs are great hiding places for dust...)
--
Chuck Stewart
Take out sphahmblohck for reply
zapkitty located at geocities lil' round thing com
"Anime-style catgirls: proof that the end is nearer than you think."
Brian Trosko
Harry H Conover <con...@tiac.net> wrote:
: : Again, so what? Not only is this entirely superfluous to the killing of
: : an enemy tank
: Actually, it's a highly integral part of the "killing of an enemy tank."
: A primary goal is to ignite the ordnance within the tank, causing it to
: self destruct.
Anytime you throw a big chunk of metal through another big chunk of metal
at 1000mps, you're going to end up with a bunch of red-hot chunks of metal
spraying around. If you hit the ammo compartment, the ammo is going to
explode. If you hit the crew compartment, the crew is chunky salsa. In
both of these cases, the tank is quite dead, and the fact that some of the
chunks of metal may be on fire is rather unimportant.
: "HEAT" munitions are constructed with the same goal in mind, except
: that they employ a shaped explosive charge to pierce the armor rather
: than kinetic impact.
HEAT and APFSDS both pierce armor in the exact same way: by concentrating
an enormous amount of kinetic energy on a small area of the armor facing.
HEAT generates this kinetic energy by a directed explosion near the
target, and APFSDS does so by weighing a lot and traveling real face, but
the mechanism of penetration, what actually goes on *at* point of contact
with the armor, is virtually identical in both cases. HEAT doesn't burn
through the armor, or turn it to plasma, or anything else; it punches
through just like APFSDS does.
: The minimal radioactivity risks associated with DU are of little or
: no consequence vis-a-vis other battlefield hazards.
For the most part, I'll agree. I'm more concerned about troops poking
through the dead tanks afterword.
Fred Doebbler
On 26 Jun 1998 10:04:00 -0700, Brian Trosko <btr...@primenet.com>
wrote:
>Mark Folsom <fols...@redshift.com> wrote:
>
>
>: Uranium is also pyrophoric. It makes burning fragments on passing through
>: heavy armor. Sets things on fire.
>
>Again, so what? Not only is this entirely superfluous to the killing of
>an enemy tank, it makes it more difficult to machine the rounds, since you
>now have to worry about spontaneous combustion of any tailings, and
>presents a possible battlefield hazard. I wouldn't want to inhale even a
>very very weak alpha emitter, thank you.
I fired a whole bunch of 20mm DU ammo from a couple of Navy CIWS
systems during the 80's and spent a considerable amount of time in a
poorly-ventilated ammo mag crowded with 30K of the little brothers.
The Navy had a little panic when they found out most of the fleet had
received ammo that didn't really qualify as depleted (for years
apparently, but they never were specific).
I also fed a large amount of this stuff to the fish at about 3800 feet
per second through a lot of PAC-fires (shooting so the computer can
determine the muzzle velocity and the relative alignments of the gun
and radar), to the tune of a couple of thousand rounds at a time. It
depended mostly on whether the O's wanted to see some churned up water
from the aluminum pushers. We never told most of them the rounds were
nearly invisible when they hit the ocean several miles further out.
As well as damaging the ocean's ecosystem, we also managed to burn a
lot of tax dollars on rounds (each of the rounds used to cost $20,
later around $12) and system wear and tear. We did get real good at
pre/post-fire maintenance.
You're right about the round's pyro qualities. When we weren't firing
at the air or ocean we also fired at towed target sleeves made of next
to nothing, except for a little metal turnbuckle at the front (CIWS
radar liked that) and some metal tail fins. If we hit the turnbuckle
the game was over and the TDU headed for the water at 350kts. When we
hit the body you couldn't see anything until the TDU went by and the
swiss cheese pattern showed. When we hit one of the little tail fins
there was a big bright streak even in full daylight. Theory was a
single round could flash a fuel tank or warhead. I figured we'd only
need one good hit on a missile and each system popped 50 a second.
DU is good for it's density, pyro quality, and the fact it would
shatter rather than deform. The pyro quality meant we fired
sub-caliber (about 13mm with the remaining 7mm in the nylon sabot that
protected the barrel and kept down the dust. There were some serious
long-term heath effects from DU's heavy metal nature but these were
pretty much ignored in light of the much more immediate danger of
electrically-fired rounds blowing up in your hands because somebody
kicked on a radar or radio by accident.
I saw a picture of a Russian armored personnel carrier that could
carry around 20 passengers. The military (US) placed small cubes in
each seat at chest level and popped a single 30mm DU round through the
front armor from a mile away. The resulting shrapnel would have
killed everyone inside. It looked like someone had gone wild with a
cutting torch inside. We always figured (unsubstianted) we could take
most of the superstructure off a destroyer with one of our mounts and
do likewise to a cruiser with both of them - all in about 30 seconds.
Fred
Uncle Al
Fred Doebbler wrote:
[snip]
> I saw a picture of a Russian armored personnel carrier that could
> carry around 20 passengers. The military (US) placed small cubes in
> each seat at chest level and popped a single 30mm DU round through the
> front armor from a mile away. The resulting shrapnel would have
> killed everyone inside. It looked like someone had gone wild with a
> cutting torch inside. We always figured (unsubstianted) we could take
> most of the superstructure off a destroyer with one of our mounts and
> do likewise to a cruiser with both of them - all in about 30 seconds.
Good. Second on the food chain is dead.
"Don't you die for your country. Let the other poor sonofabitch die for
his country."
Jim Hunter
Fred Doebbler wrote:
> I saw a picture of a Russian armored personnel carrier that could
> carry around 20 passengers. The military (US) placed small cubes in
> each seat at chest level and popped a single 30mm DU round through
the
> front armor from a mile away. The resulting shrapnel would have
> killed everyone inside. It looked like someone had gone wild with a
> cutting torch inside. We always figured (unsubstianted) we could
take
> most of the superstructure off a destroyer with one of our mounts and
> do likewise to a cruiser with both of them - all in about 30 seconds.
Most likely that would be a sure thing, assuming no mechanical
problems with the CIWS and no return fire. You might not be
able to literally take the superstructure off, but with only
1/4 to 1/2 aluminum in the way, whatever systems were inside
would definitely be degraded. The hull isn't very thick
either on modern ships. A patrol craft with several CIWS
could probably sink a destroyer.
---
Jim
Jim Hunter
Grant Edwards wrote:
>
> Jim Hunter (jim.hunter@REMOVE_TO_EMAIL.jhuapl.edu) wrote:
>
> : > We always figured (unsubstianted) we could take most of the
> : > superstructure off a destroyer with one of our mounts and do
> : > likewise to a cruiser with both of them - all in about 30
> : > seconds.
> :
> : Most likely that would be a sure thing, assuming no mechanical
> : problems with the CIWS
>
> once met a gunnary officer who remarked that CIWS actually stood for
>
> "Christ, It Won't Shoot!"
>
> Perhaps they've worked some of the bugs out since those days...
I've never fired one myself. But, I can tell you that
they have been debugged and do shoot.
> : and no return fire.
>
> Always a nice assumption. :)
When your playing wargames, it's always rigged so
that the other guy loses. That's one of things
field commanders always hated about armchair
generals.
---
Jim
Grant Edwards
Jim Hunter (jim.hunter@REMOVE_TO_EMAIL.jhuapl.edu) wrote:
: > We always figured (unsubstianted) we could take most of the
: > superstructure off a destroyer with one of our mounts and do
: > likewise to a cruiser with both of them - all in about 30
: > seconds.
:
: Most likely that would be a sure thing, assuming no mechanical
: problems with the CIWS
Back when I designed gun-mounts and missile launchers and the like, I
once met a gunnary officer who remarked that CIWS actually stood for
"Christ, It Won't Shoot!"
Perhaps they've worked some of the bugs out since those days...
: and no return fire.
Always a nice assumption. :)
--
Grant Edwards
Jim Carr
zapk...@sphahmblohck.geocities.com writes:
>
>But DU, if it is a hazard, would be the one you took home with you.
>And unless they jammed a counter down your trachea you would never
>know...
There are established ways of doing body counts for U and Pu,
most based on the fact that the body does eliminated some of
it, even if inhaled.
Chuck Stewart
(The kitty sells tickets to see the punctured tank... Geiger counter
rental is extra, of course :)
Jim Carr wrote:
>
> There are established ways of doing body counts for U and Pu,
> most based on the fact that the body does eliminated some of
> it, even if inhaled.
Yes, and I didn't mean to imply there wasn't.
Mea culpa on the phrasing :)
(In fact I recently read news articles about DU being found in a
soldiers sperm, of all places)
But such deals are after the fact.
I was thinking of a soldier ducking inside a DU blasted APC to check it
out, taking a shower afterwards, and no evidence till he or she started
eliminating the DU.
I see wasted enemy armor perhaps becoming a "no-go" zone for soldiers in
the future and a basic counter becoming part of standard field gear if
this keeps up.
Of course it would be diffilcult to keep local civilians out afterward.
> --
> James A. Carr <j...@scri.fsu.edu>
> http://www.scri.fsu.edu/~jac/
You're a marked man, Mr. Carr.
Bookmarked, in fact... :)
Jim Carr
>
> .... and spent a considerable amount of time in a
>poorly-ventilated ammo mag crowded with 30K of the little brothers.
>The Navy had a little panic when they found out most of the fleet had
>received ammo that didn't really qualify as depleted (for years
>apparently, but they never were specific).
Uranium (both isotopes) are alpha emitters. That means a little
extra helium in the room but not much else unless there is U dust
in the area. That is a direct hazard. Uranium also emits fairly
low energy gammas, but the activity is low. U-235 has about seven
times the activity of U-238, which would be the only reason for
concern about the difference. Seven times the tiny percentage of
U-235 found naturally is not a big effect.
The indirect hazard is from radon, and the longer lived Rn-222 is
in the U-238 decay chain so its level is not changed. However,
to get much radon you have to have a buildup of the parent nuclei,
which are very long lived. More a problem when the U has been
around for geologic times than in storage if I had to guess.
--
Carey Sublette
Jim Carr wrote in message <6o0pts$gpg$1...@news.fsu.edu>...
>fre...@mail.idt (Fred Doebbler) writes:
>>
>> .... and spent a considerable amount of time in a
>>poorly-ventilated ammo mag crowded with 30K of the little brothers.
>>The Navy had a little panic when they found out most of the fleet had
>>received ammo that didn't really qualify as depleted (for years
>>apparently, but they never were specific).
>
> Uranium (both isotopes) are alpha emitters.
Make that THREE isotopes. Natural uranium also contains U-234 (0.0055%),
which is an indirect decay product of U-238:
U-238 -> (4.51 billion years, alpha) -> Th-234
Th-234 -> (24.1 day, beta) -> Pa-234
Pa-234 -> (6.75 hr, beta) -> U-234 (Half Life 247 thousand years )
>That means a little
> extra helium in the room but not much else unless there is U dust
> in the area. That is a direct hazard. Uranium also emits fairly
> low energy gammas, but the activity is low. U-235 has about seven
> times the activity of U-238, which would be the only reason for
> concern about the difference. Seven times the tiny percentage of
> U-235 found naturally is not a big effect.
>
> The indirect hazard is from radon, and the longer lived Rn-222 is
> in the U-238 decay chain so its level is not changed. However,
> to get much radon you have to have a buildup of the parent nuclei,
> which are very long lived. More a problem when the U has been
> around for geologic times than in storage if I had to guess.
U-234 naturally accounts for half of the activity of uranium since it exists
in decay equilibrium with its parent U-238, and as you observe the
contribution of U-235 is small.
Since U-234 is even lighter than U-235, it tends to be depleted to an even
greater degree than U-235. Depleted uranium is thus a bit more than half as
radioactive as U-238 due to the U-234 stripping.
Since U-234 is the third stop on the U-238 decay chain, and it is stripped
off and will take a quarter of a million years to build up to equilibrium
levels again, we can safetly say that radon evolution will be greatly
reduced.
Carey Sublette