In article ,
wrote:
On Wed, 08 May 2013 23:23:46 -0500, -MIKE-
Of course, one could easily find out exactly what, why, and how it works
and how to make your own with a simple google search. But I don't care
to start a homeland security file on myself, so I'll pass. :-)

One thing I was wondering, did these Boston bombers make a practice
bomb first anywhere? Was there ever any mention of that? After all, if
someone intends to go out with their homemade bomb to do some damage,
they usually want to know if the damned thing will work before they
head out.

Usually, perhaps. A notable exception was the uranium-based atomic bomb
used at Hiroshima. There was no test bomb. The 1st atomic explosion WAS
a test of the plutonium-based bomb like the one used at Nagasaki.


--
The best argument against democracy is a five-minute conversation
with the average voter. (Winston Churchill)

Larry W. - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

On Thu, 09 May 2013 11:51:24 -0500, -MIKE- wrote:

That said, there have been many attempts in the US that have failed.
These don't make the headlines and when they do, it's not for long.

It's also said that a lot of the foiled plots were instigated by the
FBI :-). Wonder how many of the fanatics would have done anything but
bitch if they hadn't be pushed?

OTOH, if the FBI hadn't pushed them, someone else might have!

--
When fascism comes to America, it will be wrapped in the flag and
carrying a cross.

On 5/9/13 7:26 PM, Larry Blanchard wrote:
On Thu, 09 May 2013 11:51:24 -0500, -MIKE- wrote:

That said, there have been many attempts in the US that have failed.
These don't make the headlines and when they do, it's not for long.

It's also said that a lot of the foiled plots were instigated by the
FBI :-). Wonder how many of the fanatics would have done anything but
bitch if they hadn't be pushed?


Because that a good enough excuse.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On Thu, 9 May 2013 21:47:00 +0000 (UTC),
(Larry W) wrote:

In article ,
wrote:
On Wed, 08 May 2013 23:23:46 -0500, -MIKE-
Of course, one could easily find out exactly what, why, and how it works
and how to make your own with a simple google search. But I don't care
to start a homeland security file on myself, so I'll pass. :-)

One thing I was wondering, did these Boston bombers make a practice
bomb first anywhere? Was there ever any mention of that? After all, if
someone intends to go out with their homemade bomb to do some damage,
they usually want to know if the damned thing will work before they
head out.

Usually, perhaps. A notable exception was the uranium-based atomic bomb
used at Hiroshima. There was no test bomb. The 1st atomic explosion WAS
a test of the plutonium-based bomb like the one used at Nagasaki.

Yes, Uranium bombs are so trivial a test wasn't needed. In fact, the
only country that failed on its first attempt was N. Korea.

On Thu, 09 May 2013 12:08:01 -0500, -MIKE-
wrote:

On 5/9/13 12:03 PM, wrote:
On Wed, 08 May 2013 23:43:02 -0500, -MIKE-
wrote:

On 5/7/13 7:56 PM, Lew Hodgett wrote:
Lew Hodgett wrote:

Don't want to rain on your parade, but how big do you think those
pressure
cookers in Boston were/are?

BTW, a pressure relief valve is a must.

Even your hot water tank has one.
------------------------------------------------------------------

"-MIKE-" wrote:

I hope you're joking.
There was a lot more than air in those things.
--------------------------------------------------------------
Lew Hodgett wrote:

Absolutely not kidding, shrapnel is shrapnel regardless of the
source.
------------------------------------------------------------------

"-MIKE-" wrote:

That's kind of the point. There is no shrapnel when an air tank
"explodes."
-----------------------------------------------------------------
Lew Hodgett wrote:

What do you call the parts of the vessel that are created when
a vessel bursts?

Chopped liver?


Shrapnel: Fragments of a bomb, shell, or other object thrown out by an
explosion.
When an air tank fails from over pressure there is not enough energy to
create shrapnel.
Could a part come flying off, perhaps. But that is certainly a very
loose interpretation of the accepted definition when talking about true
explosions.


---------------------------------------------------------------------------------
"-MIKE-" wrote:

Why do I keep putting explodes in quotation marks? Because of the
very
misconception you have and others are having. The energy from a
bursting
air tank is no where near enough to cause shrapnel.

The energy caused by gun powder is many multitudes higher than an
air
tank. The velocity of the explosion is also many magnitudes higher.

Oh, and last time I looked at air compressors, non of the tanks were
packed with ball bearings, either. sheesh.
-----------------------------------------------------------------
Lew Hodgett wrote:

You seem to have difficulty understanding what is written.

I made no mention of gun powder, ball bearings or any other items of
IBS
(Intellectual Bull ****) you attempt to introduce to confuse the
issue.


Quit bull****ting and digging the hole deeper. We're talking air tanks
failing from over pressurization and you're the one who brought up the
marathon bombers' pressure cooker bombs. YOU are the one attempting to
confuse the issue by introducing a BOMB into a conversation about air
compressors.


My comment simply stated that the size of the vessel is totally
independent of it's ability to raise the havoc created if it were to
burst in an area where people were assembled.

What causes a vessel to exceed design specifications and fail
by bursting is a totally different discussion.

What remains relevant is that if a vessel bursts in an occupied area,
chances are pretty good that somebody is going to get hurt.

Nothing more, nothing less.

Lew


I can pop a balloon ("vessel burst") in an occupied area? Who gets hurt?

There has to be enough energy to create the shrapnel. Even without
shrapnel, there would have to be a enough energy released to create a
pressure wave for anyone to be injured seriously. How do you not get that?

An air compressor "vessel" "bursting" has a tiny fraction of the energy
of a bomb. Aren't you the engineer, here? How do you not see that?
Perhaps, but IF it fails catastrophically - like a brittle fracture
( and they DO happen very occaisionally) they ARE very dangerous.

A hydrogen embrittled 20 gallon tank, 1/8" thick, at 200 psi could do
greivous harm to anyone within 20 feet.or more if struck, by say, a
falling hammer or other flying debris.


But where is the evidence of this happening. I'm not talking about
damage or injury. I'm talking shrapnel, because that's what was brought
up early in this discussion.

I remember the mythbusters episode where they pumped up an air talk way
beyond normal operating pressure, having disabled the relief valve. They
proceeded to ram all kinds of stuff into it, even shooting it with a gun
and could not get it to "explode."
Years ago, when I was service manager at the Toyota dealership,
there was an article in one of the trade magazines - Canadian Service
Station Management or something like that, which showed the results of
an air compressor tank explosion. The tank had lap joints and the
welding process caused an HAZ (Heat affected zone) along that end cap
joint that met with the HAZ from where the mounting foot was welded on
and vibration from running with the legs on concrete floor without
rubber isolation fatiqued the joint. somebody dropped a wheel or
something that hit the tank and set it off. Severe damage to the
adjoining wall and injuries to people in the shop from flying bits.

Also, a small compressor manufacturer in Minnesota? back in the
sixties or seventies had several tank explosions that caused personal
injury when they let go, including one user with serious head and
facial injuries when the exploding tank fractured the drive pully and
flung it at the poor guy's head. Several hundred of those tanks
apparently failed with varying injuries reported..

In both cases, "shrapnel" was involved.

It is not common - but it IS the uncommon that is the most dangerous
since it is totally unexpected.

On 5/9/2013 9:52 AM, Leon wrote:
On 5/9/2013 12:11 AM, CW wrote:


"-MIKE-" wrote in message ...

On 5/6/13 2:37 PM, Leon wrote:


Pressure cookers are designed to release pressure, that hissing you
hear, at 15 lbs.

Assuming the thing wasn't plugged in, it's probably just a decent vessel
for a bomb and not a functional part of the explosion mechanism.

Of course, one could easily find out exactly what, why, and how it works
and how to make your own with a simple google search. But I don't care
to start a homeland security file on myself, so I'll pass. :-)
================================================== ===============
The pressure cooker is a needed part of the bomb. The pressure relief
valve is not an issue. The pressure build up is too fast for it to vent
it fast enough to make any difference. You could put the same components
in a paper bag instead of the pressure cooker and all you would get is a
fire.




I believe the vessel would have been better had it been stronger than a
pressure cooker. Like a circuit breaker that protects the wiring in a
house the 15 lb relief valve is to protect the cooker. I highly suspect
that the lid popped off long before the potential was reached with the
powder burn.
Agreed.

--
Jeff

"woodchucker" wrote in message
...

On 5/9/2013 9:52 AM, Leon wrote:
On 5/9/2013 12:11 AM, CW wrote:


"-MIKE-" wrote in message ...

On 5/6/13 2:37 PM, Leon wrote:


Pressure cookers are designed to release pressure, that hissing you
hear, at 15 lbs.

Assuming the thing wasn't plugged in, it's probably just a decent vessel
for a bomb and not a functional part of the explosion mechanism.

Of course, one could easily find out exactly what, why, and how it works
and how to make your own with a simple google search. But I don't care
to start a homeland security file on myself, so I'll pass. :-)
================================================== ===============
The pressure cooker is a needed part of the bomb. The pressure relief
valve is not an issue. The pressure build up is too fast for it to vent
it fast enough to make any difference. You could put the same components
in a paper bag instead of the pressure cooker and all you would get is a
fire.




I believe the vessel would have been better had it been stronger than a
pressure cooker. Like a circuit breaker that protects the wiring in a
house the 15 lb relief valve is to protect the cooker. I highly suspect
that the lid popped off long before the potential was reached with the
powder burn.
Agreed.
================================================== ===============================================
If that was the case, it would amount to a shaped charge, pointed straight
up. It would be hell on ceilings and it would make it rain ball bearings.
The pressure build would be so fast that, by time the locking lugs yielded,
the pressure would be so high that the whole thing would fracture. Consider
to that pressure cookers are cast. Cast aluminum is quite brittle. Chances
are high that the lid let go before the rest of it. Maybe a pico second
before.

--
Jeff

On Thu, 09 May 2013 21:45:13 -0400, wrote:
Yes, Uranium bombs are so trivial a test wasn't needed. In fact, the
only country that failed on its first attempt was N. Korea.

Actually, I believe the first atomic bomb test was in New Mexico.

On Fri, 10 May 2013 11:05:31 -0400, wrote:

On Thu, 09 May 2013 21:45:13 -0400, wrote:
Yes, Uranium bombs are so trivial a test wasn't needed. In fact, the
only country that failed on its first attempt was N. Korea.

Actually, I believe the first atomic bomb test was in New Mexico.

That was a Plutonium bomb. A test was needed to prove the implosion
technique needed to make the PT supercritical. Uranium only takes the
equivalent of a cannon barrel and a couple of shells. The first
"test" of the Uranium bomb was over Nagasaki. It worked.

"CW" wrote:
"woodchucker" wrote in message ...

On 5/9/2013 9:52 AM, Leon wrote:
On 5/9/2013 12:11 AM, CW wrote:


"-MIKE-" wrote in message ...

On 5/6/13 2:37 PM, Leon wrote:


Pressure cookers are designed to release pressure, that hissing you
hear, at 15 lbs.

Assuming the thing wasn't plugged in, it's probably just a decent vessel
for a bomb and not a functional part of the explosion mechanism.

Of course, one could easily find out exactly what, why, and how it works
and how to make your own with a simple google search. But I don't care
to start a homeland security file on myself, so I'll pass. :-)
================================================== ===============
The pressure cooker is a needed part of the bomb. The pressure relief
valve is not an issue. The pressure build up is too fast for it to vent
it fast enough to make any difference. You could put the same components
in a paper bag instead of the pressure cooker and all you would get is a
fire.




I believe the vessel would have been better had it been stronger than a
pressure cooker. Like a circuit breaker that protects the wiring in a
house the 15 lb relief valve is to protect the cooker. I highly suspect
that the lid popped off long before the potential was reached with the
powder burn.
Agreed.
================================================== ===============================================
If that was the case, it would amount to a shaped charge, pointed
straight up. It would be hell on ceilings and it would make it rain ball
bearings. The pressure build would be so fast that, by time the locking
lugs yielded, the pressure would be so high that the whole thing would
fracture. Consider to that pressure cookers are cast. Cast aluminum is
quite brittle. Chances are high that the lid let go before the rest of
it. Maybe a pico second before.


It looked when the bombs went off that most of the blast went up. And not
all pressure cookers are heavy cast aluminum, many are made from much
lighter weight rolled stainless steel.
http://www1.macys.com/shop/product/f...7C-%7CK6XTOYMJ

Leon wrote:

And not
all pressure cookers are heavy cast aluminum, many are made from
much
lighter weight rolled stainless steel.
------------------------------------------------
Like mine which is at least 25 years old.

Lew

"Lew Hodgett" wrote:
Leon wrote:

And not
all pressure cookers are heavy cast aluminum, many are made from
much
lighter weight rolled stainless steel.
------------------------------------------------
Like mine which is at least 25 years old.

Mine is closer to 80 years old. Belonged to my grandmother and still works
fine. I've replaced the seals and pressure safety gasket a few times in the
fifty years I've owned it, along with the regulator, which was lost in a
move, about 15 years ago.

--
www.ewoodshop.com (Mobile)

On 5/11/2013 1:16 AM, Leon wrote:
It looked when the bombs went off that most of the blast went up. And not
all pressure cookers are heavy cast aluminum, many are made from much
lighter weight rolled stainless steel.

Based on the number of leg and lower torso injuries it looks the bombs
were designed to send shrapnel into the horizontal directions.

This is what makes these guys actions so deplorable. It appears they
design the bombs to not kill people but to destroy their legs, which the
runners were very proud of and dependent for their enjoyment.

On 5/11/13 12:16 AM, Leon wrote:
"CW" wrote:
"woodchucker" wrote in message
...

On 5/9/2013 9:52 AM, Leon wrote:
On 5/9/2013 12:11 AM, CW wrote:


"-MIKE-" wrote in message
...

On 5/6/13 2:37 PM, Leon wrote:


Pressure cookers are designed to release pressure, that
hissing you hear, at 15 lbs.

Assuming the thing wasn't plugged in, it's probably just a
decent vessel for a bomb and not a functional part of the
explosion mechanism.

Of course, one could easily find out exactly what, why, and how
it works and how to make your own with a simple google search.
But I don't care to start a homeland security file on myself,
so I'll pass. :-)
================================================== ===============


The pressure cooker is a needed part of the bomb. The pressure relief
valve is not an issue. The pressure build up is too fast for it
to vent it fast enough to make any difference. You could put
the same components in a paper bag instead of the pressure
cooker and all you would get is a fire.




I believe the vessel would have been better had it been stronger
than a pressure cooker. Like a circuit breaker that protects the
wiring in a house the 15 lb relief valve is to protect the
cooker. I highly suspect that the lid popped off long before the
potential was reached with the powder burn.
Agreed.
================================================== ===============================================


If that was the case, it would amount to a shaped charge, pointed
straight up. It would be hell on ceilings and it would make it rain
ball bearings. The pressure build would be so fast that, by time
the locking lugs yielded, the pressure would be so high that the
whole thing would fracture. Consider to that pressure cookers are
cast. Cast aluminum is quite brittle. Chances are high that the lid
let go before the rest of it. Maybe a pico second before.


It looked when the bombs went off that most of the blast went up.
And not all pressure cookers are heavy cast aluminum, many are made
from much lighter weight rolled stainless steel.
http://www1.macys.com/shop/product/fagor-elite-


As to the context of our discussion, a 13-20 gallon compressor bursting
from over pressurization isn't going to take off any legs or arms, let
alone kill anyone.

These "pressure cooker bombs" seemed to do quite a good job at it,
however.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 5/11/2013 9:15 AM, Keith Nuttle wrote:
On 5/11/2013 1:16 AM, Leon wrote:
It looked when the bombs went off that most of the blast went up. And
not
all pressure cookers are heavy cast aluminum, many are made from much
lighter weight rolled stainless steel.

Based on the number of leg and lower torso injuries it looks the bombs
were designed to send shrapnel into the horizontal directions.

This is what makes these guys actions so deplorable. It appears they
design the bombs to not kill people but to destroy their legs, which the
runners were very proud of and dependent for their enjoyment.


Well that is what happened but the runners do not enjoy their legs any
more that any one else that walks around. I don't know about you but I
am not a runner and am dependent on my legs for much of my enjoyment. ;~)

On Sat, 11 May 2013 10:15:00 -0400, Keith Nuttle
wrote:

On 5/11/2013 1:16 AM, Leon wrote:
It looked when the bombs went off that most of the blast went up. And not
all pressure cookers are heavy cast aluminum, many are made from much
lighter weight rolled stainless steel.

Based on the number of leg and lower torso injuries it looks the bombs
were designed to send shrapnel into the horizontal directions.

This is what makes these guys actions so deplorable. It appears they
design the bombs to not kill people but to destroy their legs, which the
runners were very proud of and dependent for their enjoyment.

I *highly* doubt it was "designed" to do anything but make a bang and
kill people. The lid obviously stayed intact (as I would have
expected) so much of the energy would be naturally out the side. I
doubt that this was in any way a "design" goal. I'm sure a compressor
tank would have been even better.

"Leon" wrote in message
...

On 5/11/2013 9:15 AM, Keith Nuttle wrote:
On 5/11/2013 1:16 AM, Leon wrote:
It looked when the bombs went off that most of the blast went up. And
not
all pressure cookers are heavy cast aluminum, many are made from much
lighter weight rolled stainless steel.

Based on the number of leg and lower torso injuries it looks the bombs
were designed to send shrapnel into the horizontal directions.

This is what makes these guys actions so deplorable. It appears they
design the bombs to not kill people but to destroy their legs, which the
runners were very proud of and dependent for their enjoyment.


Well that is what happened but the runners do not enjoy their legs any
more that any one else that walks around. I don't know about you but I
am not a runner and am dependent on my legs for much of my enjoyment.
================================================== ================================
After 15 months in a wheelchair, I realize how important they are.

On Sat, 11 May 2013 14:33:19 -0400, wrote:
I *highly* doubt it was "designed" to do anything but make a bang and
kill people. The lid obviously stayed intact (as I would have
expected) so much of the energy would be naturally out the side. I
doubt that this was in any way a "design" goal.

I agree. These weren't very sophisticated bombs. The nails and ball
bearings were the only 'design' aspect part and intended to cause as
much carnage as possible

On 5/11/2013 1:33 PM, wrote:
On Sat, 11 May 2013 10:15:00 -0400, Keith Nuttle
wrote:

On 5/11/2013 1:16 AM, Leon wrote:
It looked when the bombs went off that most of the blast went up. And not
all pressure cookers are heavy cast aluminum, many are made from much
lighter weight rolled stainless steel.

Based on the number of leg and lower torso injuries it looks the bombs
were designed to send shrapnel into the horizontal directions.

This is what makes these guys actions so deplorable. It appears they
design the bombs to not kill people but to destroy their legs, which the
runners were very proud of and dependent for their enjoyment.

I *highly* doubt it was "designed" to do anything but make a bang and
kill people. The lid obviously stayed intact (as I would have
expected) so much of the energy would be naturally out the side. I
doubt that this was in any way a "design" goal. I'm sure a compressor
tank would have been even better.




The lid was found about 200' down the street on top of about a 7 story
building. The lid blew off and way up high.