How Does A Claymore Mine Produce Shotgun Velocities
benevenutogiorno
produce shot velocities of 1,100 fps and above, about the range of
shot from a shotgun. Yet the device is merely 3 layers:
- a (thin?) metal plate,
- a sheet of explosive material laid upon the plate,
- a matrix of epoxy with steel shot (about #4 shot) embedded in it.
#From the diagrams it looks like the detonators are blasting caps that
are inserted about 1/3 of the way from the edge of the plate inside
the explosive material.
How the heck does this generate such velocities? There's no cartridge
casing to contain the explosion, there's no barrel and the whole
device is free to recoil backward (following Newton's Third Law: for
every action there's an equal and opposite reaction). Why is a _thin_
plate sufficient? I would think a _heavy_ plate would be more
desirable.
Is there something special about the dynamics of an explosion
propagating along a metal plate? And why doesn't the metal plate need
to be heavy? Can whatever's going on here be used to make a better
shotgun?
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MR
Good question. I don't have an answer either, but suspect it is due to
using high explosives or whatever they call it vs reg. explosives. I saw
a demo on the History chann. once where an expert in explosives set up a
firing chamber gizmo that was only supported by a thin rod stuck into the
ground. He fired it at a thick piece of armor plate some 8-10 feet
away. It blew a fair size hole thru it. I know how armor piercing
projectiles work, but what amazed me was that the firing gizmo was only
supported by a thin rod. Applying Newton's law, it seems the firing gizmo
would have shot itself from the rod in the opp. direction and left the
armor plate intact. Real mystery.
Hope you get some good answers.
MR
Hammi
# How the heck does this generate such velocities?
Simply the difference between true explosives and the comparatively
tame, controlled deflagration that takes places in firearms.
The definition of a true detonation is that it propagates with a speed
greater than the specific speed of sound inside the explosive itself.
At this kind of energy release, you don't even need any fanciful
additional shrapnel loads any more (which were used in 'black powder'
shrapnel artillery shells of the late 19th and early 20th century,
like in http://upload.wikimedia.org/wikipedia/commons/c/c5/Brisanzgranate_1_db.jpg
).
Pack it with dynamite instead of 'gunpowder', and the explosive itself
will easily convert the shell's steel casing into a more lethal
shrapnel than you could ever hope to manufacture.
Don Staples
news:isadib$rrg$1...@news.albasani.net...
#I was reading about the Claymore Mine and was amazed that it can
# produce shot velocities of 1,100 fps and above, about the range of
# shot from a shotgun. Yet the device is merely 3 layers:
# - a (thin?) metal plate,
# - a sheet of explosive material laid upon the plate,
# - a matrix of epoxy with steel shot (about #4 shot) embedded in it.
I used to know this stuff, so I will take a shot at it. The metal plate
focuses the blast effect of the plastique, the pressure wave generated by
the plastique is extremely high velocity and provides the force behind the
shot.
That is not the technical answer, but close, I think, been 50 years since I
was allowed to play with such stuff.
Louis Boyd
http://upload.wikimedia.org/wikipedia/commons/thumb/0/09/Macleod_Claymore_patent.png/220px-Macleod_Claymore_patent.png
What metal plate? The only thing on the "friendly" side of the
propellant of a Claymore is a thin epoxy back cover which is totally
turned to powder when the Claymore detonates. The mass of air between
the friendlies and the Claymore protects them from the blast of
propellant gas and powdered epoxy, but the steel shot can penetrate the
air mass in front of the claymore with much better efficiency, at least
for a hundred yards. The important feature of a Claymore is that there
are no hard pieces thrown to the rear and no back support is needed.
From a physics standpoint the Claymore is a very inefficient device
since it needs a much larger mass of propellant compared to the mass of
the projectiles it throws. A typical shotgun uses propellant less than
a third the mass of the shot to achieve similar performance to the shot
in a Claymore. But who cares about efficiency? They do the
intended job. The propellant is NOT gunpowder. It's a high explosive
which produces very high propellant velocity. A Claymore works because
it doesn't have a shotgun wrapped around it which would be total
obliterated if it were present. A Claymore follows the same laws of
physics as a shotgun. It just changes the magnitude and velocity of the
various components.
Maybe some newer models do have a thin metal plate. If so it would be to
achieve a faster detonation propagation across the back of the explosive.
It would need to be pulverized on detonation to not be a danger to the
friendly troops. Sure, a heavy mass would make the Claymore a little
more efficient but at the expense of killing your own troops.
SaPeIsMa
http://en.wikipedia.org/wiki/M18_Claymore_anti-personnel_mine
Oh wait
The reference is Wiki..
Well here we go with another flame war...
Rubaiyat of Omar Bradley
wrote:
# I was reading about the Claymore Mine and was amazed that it can
# produce shot velocities of 1,100 fps and above
My references indicates that a claymore produces about 1,200 *meters*
per second velocity, which is about 3,937 *feet* per second.
The reason that it works so well is because of the curvature of the
backing plate. This focuses and intensifies the explosion. Google on
"shaped charge" or "shaped explosive" for more info.
Bob Holtzman
# On Jun 3, 4:38 am, benevenutogiorno <benevenutogio...@yahoo.com>
# wrote:
# # I was reading about the Claymore Mine and was amazed that it can
# # produce shot velocities of 1,100 fps and above
#
# My references indicates that a claymore produces about 1,200 *meters*
# per second velocity, which is about 3,937 *feet* per second.
#
# The reason that it works so well is because of the curvature of the
# backing plate. This focuses and intensifies the explosion. Google on
# "shaped charge" or "shaped explosive" for more info.
I think you have it backwards. The projectiles are projected from the
*convex* side in an arc. No focusing involved.
--
Bob Holtzman
Larry Fishel
# I think you have it backwards. The projectiles are projected from the
# *convex* side in an arc. No focusing involved.
I thought so too, but it's a 3D compound curve. Convex horizontally,
concave vertically. Of course, this is somewhat of a different concept
than what is normally referred to as a shaped charge. Yes, it's a
charge and yes, it's carefully shaped, but it's more about keeping the
resulting projectiles low to the ground in a horizontal arc to avoid
missing small targets at a distance than "focusing" the energy to turn
one guy into a pink mist.
T.Alan Kraus
# On 2011-06-03, Rubaiyat of Omar Bradley<cowar...@yahoo.com> wrote:
# # On Jun 3, 4:38Ā am, benevenutogiorno<benevenutogio...@yahoo.com>
# # wrote:
# # # I was reading about the Claymore Mine and was amazed that it can
# # # produce shot velocities of 1,100 fps and above
# #
# # My references indicates that a claymore produces about 1,200 *meters*
# #
# # The reason that it works so well is because of the curvature of the
# # "shaped charge" or "shaped explosive" for more info.
#
# I think you have it backwards. The projectiles are projected from the
# *convex* side in an arc. No focusing involved.
#
Actually, phased arrays, which is what the convex backplate acts as, are
counter intuitive. For example the sound from a phased array of vertical
speaker tends to cover a wider area in the x axis then a single speaker,
and if one puts them side by side then they will cover a narrower
horizontal span , wider in the vertical. It has to do with wavelength
and phase. The same thing happens with a high explosive detonation which
travels 20 to 30 times faster then the speed of sound and whose
wavelengths and phases are measured in fractions of inches.
Gunner Asch
wrote:
#On 2011-06-03, Rubaiyat of Omar Bradley <cowar...@yahoo.com> wrote:
## On Jun 3, 4:38 am, benevenutogiorno <benevenutogio...@yahoo.com>
## wrote:
## # I was reading about the Claymore Mine and was amazed that it can
## # produce shot velocities of 1,100 fps and above
##
## My references indicates that a claymore produces about 1,200 *meters*
## per second velocity, which is about 3,937 *feet* per second.
##
## The reason that it works so well is because of the curvature of the
## backing plate. This focuses and intensifies the explosion. Google on
## "shaped charge" or "shaped explosive" for more info.
#
#I think you have it backwards. The projectiles are projected from the
#*convex* side in an arc. No focusing involved.
Actually ...it is a shaped explosive and is "focused"...chuckle..in a
wide dispersion pattern.
Gunner Asch
<benevenu...@yahoo.com> wrote:
#
##From the diagrams it looks like the detonators are blasting caps that
#are inserted about 1/3 of the way from the edge of the plate inside
#the explosive material.
#
#How the heck does this generate such velocities? There's no cartridge
#casing to contain the explosion, there's no barrel and the whole
#device is free to recoil backward (following Newton's Third Law: for
#every action there's an equal and opposite reaction). Why is a _thin_
#plate sufficient? I would think a _heavy_ plate would be more
#desirable.
Claymore explosive is C4.
C4 has a detonation velocity of 8,092 m/s (26,550 ft/s).
http://www.youtube.com/watch?v=btNdSroBIns&feature=related
You will note in the video..the wide area beyond the target..replay as
necessary to note how the charge is focused by the thin steel plate and
spews the shot in a wide arc
#Is there something special about the dynamics of an explosion
#propagating along a metal plate? And why doesn't the metal plate need
#to be heavy? Can whatever's going on here be used to make a better
#shotgun?
There are low order to high order explosives. C4 is a moderately high
order explosive and the thin plate tends to focus the burn of the charge
from the back out to the front rather than in a 360' pattern.
Gunner
Dillon Pyron
#"benevenutogiorno" <benevenu...@yahoo.com> wrote in message
#news:isadib$rrg$1...@news.albasani.net...
##I was reading about the Claymore Mine and was amazed that it can
## produce shot velocities of 1,100 fps and above, about the range of
## shot from a shotgun. Yet the device is merely 3 layers:
## - a (thin?) metal plate,
## - a sheet of explosive material laid upon the plate,
## - a matrix of epoxy with steel shot (about #4 shot) embedded in it.
#
#I used to know this stuff, so I will take a shot at it. The metal plate
#focuses the blast effect of the plastique, the pressure wave generated by
#the plastique is extremely high velocity and provides the force behind the
#shot.
Shapped charge + 22,000+ fps energy output = "ouch" * 1000.
#
#That is not the technical answer, but close, I think, been 50 years since I
#was allowed to play with such stuff.
As someone else pointed out, if one were to put the same weight of C4
into a 12 ga hull, the chamber would become the most dangerous part of
the weapon. That and your left forearm.
Jim Yanik
the explosion.The ball bearings just ride the explosion wavefront.
As you stated,it's a high velocity wavefront.
http://en.wikipedia.org/wiki/Misznay-Schardin_effect
http://en.wikipedia.org/wiki/Claymore_mine
When the M18A1 is detonated, the explosion drives the spheres out of the
mine at a velocity of 1,200 m/s (3,937 ft/s),[1] at the same time breaking
the matrix into individual fragments. The steel balls are projected in a
60° fan-shaped pattern that is 6.5 feet high and 50 m (55 yd) wide at a
range of 50 m (55 yd). The force of the explosion deforms the relatively
soft steel fragments into a shape similar to a .22 rimfire projectile.[1]
These fragments are moderately effective up to a range of 100 m (110 yd),
with a hit probability of around 10% on a prone man-sized 1.3-square-foot
(0.12 m2) target. The fragments can travel up to 250 m (270 yd). The
optimum effective range is 50 m (55 yd), at which the optimal balance is
achieved between lethality and area coverage, with a hit probability of 30%
on a man-sized target.
The development of the M18A1 mine dates back to work done during World War
II. The Misznay-Schardin effect was independently discovered during World
War II by Misznay, a Hungarian, and Dr. Hubert Schardin, a German. When a
sheet of explosive detonates in contact with a heavy backing surface (for
example, a metal plate), the resulting blast is primarily directed away
from the surface in a single direction. Schardin spent some time developing
the discovery as a side-attack anti-tank weapon, but development was
incomplete at the end of the war. Schardin also spent time researching a
"Trench mine" that used a directional fragmentation effect.[1]
--
Jim Yanik
DockScience
Effect.
And it's the reason why the energy goes mostly in one direction.
But I suspect that over 1/2 lb of C4 doesn't hurt either.
haraoi_conal
#
# Oh wait
# The reference is Wiki..
# Well here we go with another flame war...
You think that is bad, try to link to a web page that merely has a
REFERENCE to facebook....
Snag
Actually the reason it works at all is because of the way the charge is
initiated . Same principle as a shaped charge - if you initiate it on the
back side , the detonation head travels toward the front , carrying the shot
with it .
--
Snag
GeoW
# Actually the reason it works at all is because of the way the charge is
# initiated . Same principle as a shaped charge - if you initiate it on the
# back side , the detonation head travels toward the front , carrying the shot
# with it .
It's the nature of the beast... smokeless powder in a shotgun shell is
a propellent where C4 is an explosive.
I wouldn't recommend using C4 as a substitute for smokeless powder in
a shotgun shell as someone ask
if would make a better shotgun shell. It would make that 1100 an
excellent pipe bomb :)