On 4/18/2013 5:13 AM, Michael A. Terrell wrote:

wrote:

Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?


Don't most have an alarm clock function?


From the photos, it was just a small timer and battery.
Printed circuit board even.

I did some research (way back then) for my (licensed)
pyromaniac boss for a laptop controlled fireworks sequencer
circuit.

We found that TTL logic levels would safely and reliably fire
electrical squibs.

I still put a ground bar relay in it - just because I'm fond
of all my fingers!

But it did work quite well.

Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?

wrote:
Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?

The pictures I have looked at of the various parts looked like all
common discrete components not cell phone pieces.
The battery looks like a common RC car pack.
Then a cheap alarm clock for a timer/trigger.
Nails from any hardware/building supply place.
The ball bearings are probably slingshot ammo.


--
Steve W.

On Thu, 18 Apr 2013 00:01:27 -0500, wrote:

Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?

one could simply run a small insulated wire through a matching hole in
the body of the pot for an antenna. Its not rocket science and a
small hole wouldnt effect the pressure build up significantly.

wrote:

Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?


Don't most have an alarm clock function?

On 4/18/2013 6:34 PM, PrecisionmachinisT wrote:
http://www.ramseyelectronics.com/sit...search&x=0&y=0


Probably more like:
http://www.simplecircuitboards.com/Timer%20Boards.html
An LM-555 and a couple of caps and resistors.
Home made, untraceable (and no count down display like in the movies).

On 4/18/2013 8:31 PM, Lloyd E. Sponenburgh wrote:
Martin fired this volley in
:

cell phones in the Boston bombing...

I don't know if you recognize any of the common parts shown in the photos
of the debris, but there we

1) parts of a standard 7.2V NiCd 'hobby' style battery pack for models
(cars and planes)
2) parts of an electronic speed controller for RC cars or planes...
looked like a Great Planes or Novak component (in-line style) ESC.
3 parts of a Novak RC radio receiver for cars or planes (orange case,
very recognizable)

I'll let you guess from that whether or not cell phones were used as the
firing box. I'm guessin' your guessin' won't be swayed by this.

(I'm in an explosives-related biz, so ways to ignite things are
reasonably familiar to me)

Lloyd


It must be nice to have a fun job!

On 4/18/2013 9:09 PM, PrecisionmachinisT wrote:
wrote in message
...
On 4/18/2013 6:34 PM, PrecisionmachinisT wrote:
http://www.ramseyelectronics.com/sit...search&x=0&y=0


Probably more like:
http://www.simplecircuitboards.com/Timer%20Boards.html
An LM-555 and a couple of caps and resistors.

I know about the 555...it's covered extensively in the cmos cookbook..

Home made, untraceable (and no count down display like in the movies).

Not if it was triggered by cell phone...you don't want a telemarketer
setting it off, what you want an access code.




Still, I doubt it was a cell phone.
(besides the simple problem that the components in the pictures are not
phone parts)

A cell phone detonator would be great for a command detonated device.

But if that were the case, it seems like they would have had a much
higher body count.

On Apr 17, 11:01*pm, wrote:
Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?

All pressure cookers have holes in the lid for both a relief valve and
the cooker's weight spike. A wire could be run out either hole for an
antenna OR some kind of external trigger, timer, radio remote, mercury
switch, whatever. A high school kid could set it up and have it work,
no special genius-level explosives knowledge needed. There's a wide
variety of possible triggers, cell phones tend to be used in the -
stans because that's the fanciest electronics most folks have access
to and they tend to be fairly cheap. Lots more possibilities here
where there are a lot more RF-controlled devices. Or there's the
classic windup alarm clock trigger.

Stan

On Thu, 18 Apr 2013 00:01:27 -0500, aasberry wrote:

Speculation is that the bombs were set off by cell phone. I wonder if a
cell signal would penetrate the metal of a pressure cooker. Mine barely
works in my metal shop building; with the doors open. Any experts want
to weigh in?

Tape the phone to the outside of the pot, run the trigger wire inside.

I heard that kitchen timers were used -- they'd be a lot easier and
cheaper to set up, and harder to trace (if the bomber cared). Cell
phones would possibly me more satisfying to the profoundly sick sort of
mind that would do such a thing.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Tim Wescott wrote:

On Thu, 18 Apr 2013 00:01:27 -0500, aasberry wrote:

Speculation is that the bombs were set off by cell phone. I wonder if a
cell signal would penetrate the metal of a pressure cooker. Mine barely
works in my metal shop building; with the doors open. Any experts want
to weigh in?

Tape the phone to the outside of the pot, run the trigger wire inside.

I heard that kitchen timers were used -- they'd be a lot easier and
cheaper to set up, and harder to trace (if the bomber cared). Cell
phones would possibly me more satisfying to the profoundly sick sort of
mind that would do such a thing.

The picture of a PCB fragment that has been shown certainly doesn't look
like a cell phone part.

"Gunner Asch" wrote in message
...
On Thu, 18 Apr 2013 00:01:27 -0500, wrote:

Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?

one could simply run a small insulated wire through a matching hole in
the body of the pot for an antenna. Its not rocket science and a
small hole wouldnt effect the pressure build up significantly.



I thought it was on the news that cell phone service was turned off in
Boston for the run...to prevent just this!

On Thu, 18 Apr 2013 11:56:58 -0500, "Pete C."
wrote:


Tim Wescott wrote:

On Thu, 18 Apr 2013 00:01:27 -0500, aasberry wrote:

Speculation is that the bombs were set off by cell phone. I wonder if a
cell signal would penetrate the metal of a pressure cooker. Mine barely
works in my metal shop building; with the doors open. Any experts want
to weigh in?

Tape the phone to the outside of the pot, run the trigger wire inside.

I heard that kitchen timers were used -- they'd be a lot easier and
cheaper to set up, and harder to trace (if the bomber cared). Cell
phones would possibly me more satisfying to the profoundly sick sort of
mind that would do such a thing.

The picture of a PCB fragment that has been shown certainly doesn't look
like a cell phone part.

Not as crude as offshore timer modules, but not nearly as fine as a
cell phone. Maybe some kind of hobby electronics, like the battery.

On Thu, 18 Apr 2013 09:26:53 -0700 (PDT), Stanley Schaefer
wrote:

On Apr 17, 11:01*pm, wrote:
Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?

All pressure cookers have holes in the lid for both a relief valve and
the cooker's weight spike. A wire could be run out either hole for an
antenna OR some kind of external trigger, timer, radio remote, mercury
switch, whatever.

I wonder what kind of insulative space needs to be kept for a cell
phone antenna through the lid so it doesn't short.


A high school kid could set it up and have it work,
no special genius-level explosives knowledge needed. There's a wide
variety of possible triggers, cell phones tend to be used in the -
stans because that's the fanciest electronics most folks have access
to and they tend to be fairly cheap. Lots more possibilities here
where there are a lot more RF-controlled devices. Or there's the
classic windup alarm clock trigger.

That's the problem with terrorism. There are so many possibles, they
can seldom be accounted for enough to prevent the act from happening.

--
Do not let your fire go out, spark by irreplacable spark.

In the hopeless swamps of the not quite, the not yet, and
the not at all, do not let the hero in your soul perish
and leave only frustration for the life you deserved, but
never have been able to reach.

The world you desire can be won, it exists, it is real,
it is possible, it is yours.
-- Ayn Rand

"Spehro Pefhany" wrote in message
...
On Thu, 18 Apr 2013 11:56:58 -0500, "Pete C."
wrote:


Tim Wescott wrote:

On Thu, 18 Apr 2013 00:01:27 -0500, aasberry wrote:

Speculation is that the bombs were set off by cell phone. I wonder if
a
cell signal would penetrate the metal of a pressure cooker. Mine
barely
works in my metal shop building; with the doors open. Any experts want
to weigh in?

Tape the phone to the outside of the pot, run the trigger wire inside.

I heard that kitchen timers were used -- they'd be a lot easier and
cheaper to set up, and harder to trace (if the bomber cared). Cell
phones would possibly me more satisfying to the profoundly sick sort of
mind that would do such a thing.

The picture of a PCB fragment that has been shown certainly doesn't look
like a cell phone part.

Not as crude as offshore timer modules, but not nearly as fine as a
cell phone. Maybe some kind of hobby electronics, like the battery.


http://www.ramseyelectronics.com/sit...search&x=0&y=0

The active part would be on top of the pot with the electronic
explosion cap through the regulator on top. So when the unit
blew the cap exploded by itself and the stuff on top would be flung
all over the place. The battery was heavy enough not to go far.

I suspect two numbers - speed calls - and away they went. Likely
each of the two perks did one each - in case one was caught hot handed.

Martin

On 4/18/2013 1:54 AM, Steve W. wrote:
wrote:
Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?

The pictures I have looked at of the various parts looked like all
common discrete components not cell phone pieces.
The battery looks like a common RC car pack.
Then a cheap alarm clock for a timer/trigger.
Nails from any hardware/building supply place.
The ball bearings are probably slingshot ammo.

Cells were turned off just after the first explosion.
The runners and their watchers all use cells. Runner at end
and watchers to each other along the race.

Martin

On 4/18/2013 12:07 PM, Tom Gardner wrote:
"Gunner Asch" wrote in message
...
On Thu, 18 Apr 2013 00:01:27 -0500, wrote:

Speculation is that the bombs were set off by cell phone. I wonder if
a cell signal would penetrate the metal of a pressure cooker. Mine
barely works in my metal shop building; with the doors open. Any
experts want to weigh in?

one could simply run a small insulated wire through a matching hole in
the body of the pot for an antenna. Its not rocket science and a
small hole wouldnt effect the pressure build up significantly.



I thought it was on the news that cell phone service was turned off in
Boston for the run...to prevent just this!

Martin Eastburn fired this volley in
:

cell phones in the Boston bombing...

I don't know if you recognize any of the common parts shown in the photos
of the debris, but there we

1) parts of a standard 7.2V NiCd 'hobby' style battery pack for models
(cars and planes)
2) parts of an electronic speed controller for RC cars or planes...
looked like a Great Planes or Novak component (in-line style) ESC.
3 parts of a Novak RC radio receiver for cars or planes (orange case,
very recognizable)

I'll let you guess from that whether or not cell phones were used as the
firing box. I'm guessin' your guessin' won't be swayed by this.

(I'm in an explosives-related biz, so ways to ignite things are
reasonably familiar to me)

Lloyd

"Richard" wrote in message
...
On 4/18/2013 6:34 PM, PrecisionmachinisT wrote:
http://www.ramseyelectronics.com/sit...search&x=0&y=0


Probably more like:
http://www.simplecircuitboards.com/Timer%20Boards.html
An LM-555 and a couple of caps and resistors.

I know about the 555...it's covered extensively in the cmos cookbook..

Home made, untraceable (and no count down display like in the movies).

Not if it was triggered by cell phone...you don't want a telemarketer
setting it off, what you want an access code.

On Thu, 18 Apr 2013 09:24:47 -0500, Richard
wrote:

On 4/18/2013 9:09 PM, PrecisionmachinisT wrote:
wrote in message
...
On 4/18/2013 6:34 PM, PrecisionmachinisT wrote:
http://www.ramseyelectronics.com/sit...search&x=0&y=0


Probably more like:
http://www.simplecircuitboards.com/Timer%20Boards.html
An LM-555 and a couple of caps and resistors.

I know about the 555...it's covered extensively in the cmos cookbook..

Home made, untraceable (and no count down display like in the movies).

Not if it was triggered by cell phone...you don't want a telemarketer
setting it off, what you want an access code.




Still, I doubt it was a cell phone.
(besides the simple problem that the components in the pictures are not
phone parts)

A cell phone detonator would be great for a command detonated device.

But if that were the case, it seems like they would have had a much
higher body count.


One of the devices went off right in the middle of a crowd. You would
need to use bigger shrapnel and a higher order of explosive to get
more damage.

In one of the videos..the first blast went off..and hardly fazed any
of the runners..except for one guy..who evidently took a hit..and
dropped and rolled in pain.

The other device was in a stack of Stuff, next to a mail box..which
deflected the blast a great deal and it was out between the runners
and the crowd. Poor placement. To have done it right..it should have
been placed against the face of one of the stone buildings behind the
fans. It would have acted like a claymore.

Amatures..

Shrug

Gunner

On Thu, 18 Apr 2013 20:31:47 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Martin Eastburn fired this volley in
:

cell phones in the Boston bombing...

I don't know if you recognize any of the common parts shown in the photos
of the debris, but there we

1) parts of a standard 7.2V NiCd 'hobby' style battery pack for models
(cars and planes)
2) parts of an electronic speed controller for RC cars or planes...
looked like a Great Planes or Novak component (in-line style) ESC.
3 parts of a Novak RC radio receiver for cars or planes (orange case,
very recognizable)

I'll let you guess from that whether or not cell phones were used as the
firing box. I'm guessin' your guessin' won't be swayed by this.

(I'm in an explosives-related biz, so ways to ignite things are
reasonably familiar to me)

Lloyd


RC controlled blaster? Fascinating! Command detonated then.

What was the speed controller used for? The trigger pulse to the
ignitor, whatever that was? Nichrome wire/model rocket type ignitor
across the output?

I wonder why there was a 15 second delay between blasts? Channel
change?

So how far away from the two blasts could the command unit have been?

Gunner

Gunner Asch on Thu, 18 Apr 2013 19:51:34 -0700
typed in rec.crafts.metalworking the following:

A cell phone detonator would be great for a command detonated device.

But if that were the case, it seems like they would have had a much
higher body count.


One of the devices went off right in the middle of a crowd. You would
need to use bigger shrapnel and a higher order of explosive to get
more damage.

In one of the videos..the first blast went off..and hardly fazed any
of the runners..except for one guy..who evidently took a hit..and
dropped and rolled in pain.

The other device was in a stack of Stuff, next to a mail box..which
deflected the blast a great deal and it was out between the runners
and the crowd. Poor placement. To have done it right..it should have
been placed against the face of one of the stone buildings behind the
fans. It would have acted like a claymore.

Amatures..

Thank crom for that.
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

On 4/20/2013 12:14 PM, Ed Huntress wrote:
On Sat, 20 Apr 2013 11:46:00 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Ed fired this volley in
:

Somehow I'm not troubled by amateur pyros having some of their
freedoms restricted.

If you feel that way, you don't know much about the art.

I know nothing about the art. I do know that I'm not bothered by
people having to live with some restrictions on pyrotechnical
experiments.


"Amateur pyrotechnicians" are not "backyard bombers". They are, in fact,
the source of MOST of the new effects and techniques used in the
professional trade.

That's nice.


They pursue the ART of fireworking, preserving hundreds-of-years-old
traditional methods of Europe, the US, and the Mediterranean, and at the
same time advancing the science, the art, and the technique of fireworks
as you see them in the sky.

Great. Just as long as they don't mix their brews next door to me.


Fireworks is a small industry compared to many, but it's important, and
entertains millions safely, economically, and beautifully.

'Amateur' does not mean 'unskilled', nor does it mean unlicensed in many
cases. A large number of amateurs hold ATF licenses to do their work.
But at the same time, ATF has OFFICIALLY recognized (and promulgated
regulations) that their record is so good, and also their intentions,
that it is legal under federal law to manufacture fireworks for one's own
use. They cannot be _transported_ over the public roads by anyone but a
licensee, but they can be made without a permit or license. (local
ordinances may mitigate that permission).

You should not express negative opinions about people of whom you know
nothing. (I do it too, then always regret it)

Look, Lloyd, I'm not expressing negative opinions about amateur pyros.
I am expressing a combination of some experience with what propellants
and explosives can do, and about the uneven distribution of good sense
and responsibility among any large population.

When you talk in generalized abstractions, like the "freedoms" of
amateur pyrotechnicians, it's just not a field -- given the two points
in my last paragraph -- in which I'd get upset about some
restrictions.

On Jan. 1st of this year, San Francisco police reported 188 fireworks
injuries. Some of the stories were about "amateur pyrotechnicians."

What do you do when one of these guys blows the ears off of his
neighbors? Do you disown him? Take away his Amateur Pyrotechnician
club card? Claim he was never an amateur pyrotechnician in the place,
but only a poseur?

It's clearly a field that demands some intelligence, good judgment, a
strong sense of safety for oneself and others. Those are
characteristics that tend to be, as I said, unevenly distributed.

I don't disparage the activity or the practitioners. I'll just watch
from a long distance away, and hope they don't get all loose and
goosey about their "freedoms" at others' expense.

Ok?



Sounds vaguely familiar, Ed...

On 4/20/2013 1:32 PM, Ed Huntress wrote:
On Sat, 20 Apr 2013 00:31:37 -0500,
wrote:

On 4/20/2013 12:14 PM, Ed Huntress wrote:
On Sat, 20 Apr 2013 11:46:00 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Ed fired this volley in
:

Somehow I'm not troubled by amateur pyros having some of their
freedoms restricted.

If you feel that way, you don't know much about the art.

I know nothing about the art. I do know that I'm not bothered by
people having to live with some restrictions on pyrotechnical
experiments.


"Amateur pyrotechnicians" are not "backyard bombers". They are, in fact,
the source of MOST of the new effects and techniques used in the
professional trade.

That's nice.


They pursue the ART of fireworking, preserving hundreds-of-years-old
traditional methods of Europe, the US, and the Mediterranean, and at the
same time advancing the science, the art, and the technique of fireworks
as you see them in the sky.

Great. Just as long as they don't mix their brews next door to me.


Fireworks is a small industry compared to many, but it's important, and
entertains millions safely, economically, and beautifully.

'Amateur' does not mean 'unskilled', nor does it mean unlicensed in many
cases. A large number of amateurs hold ATF licenses to do their work.
But at the same time, ATF has OFFICIALLY recognized (and promulgated
regulations) that their record is so good, and also their intentions,
that it is legal under federal law to manufacture fireworks for one's own
use. They cannot be _transported_ over the public roads by anyone but a
licensee, but they can be made without a permit or license. (local
ordinances may mitigate that permission).

You should not express negative opinions about people of whom you know
nothing. (I do it too, then always regret it)

Look, Lloyd, I'm not expressing negative opinions about amateur pyros.
I am expressing a combination of some experience with what propellants
and explosives can do, and about the uneven distribution of good sense
and responsibility among any large population.

When you talk in generalized abstractions, like the "freedoms" of
amateur pyrotechnicians, it's just not a field -- given the two points
in my last paragraph -- in which I'd get upset about some
restrictions.

On Jan. 1st of this year, San Francisco police reported 188 fireworks
injuries. Some of the stories were about "amateur pyrotechnicians."

What do you do when one of these guys blows the ears off of his
neighbors? Do you disown him? Take away his Amateur Pyrotechnician
club card? Claim he was never an amateur pyrotechnician in the place,
but only a poseur?

It's clearly a field that demands some intelligence, good judgment, a
strong sense of safety for oneself and others. Those are
characteristics that tend to be, as I said, unevenly distributed.

I don't disparage the activity or the practitioners. I'll just watch
from a long distance away, and hope they don't get all loose and
goosey about their "freedoms" at others' expense.

Ok?



Sounds vaguely familiar, Ed...

It should. It's the way most people think about topics that involve
demonstrably dangerous activities and that depend upon good judgment
on the part of people they don't know.

If they have any sense, they know that depending on someone else's
good judgment is not a wise thing to do.



Doctors, airline pilots, machinist, high school teachers?
Miners, race car drivers, astronauts, etcetera...

And I love the way you got that "most people" in there.

A majority opinion again?

On 4/20/2013 2:19 PM, Ed Huntress wrote:

I'd bet my house on it. The average person on the street has more
common sense than most people who post here.


I'd not argue against that!

But as for the "average person", that's what I mentioned the other
day. There ain't no such thing.

People tend to believe that everybody else is just like them, and
they are just like everybody else.

Normal.
Average.
Right.

But everybody can me average. The math just doesn't work that way.

I will, however, allow that there is a strong cultural bias that
many people see as "the norm".

So it's something of a shock when New Jersians migrate to Texas
and find about about all those "Crazy Texans".

You ask around your neighborhood.
I'll ask around mine.

On 4/20/2013 3:18 PM, ATP wrote:
"Ed wrote in message

It's clearly a field that demands some intelligence, good judgment, a
strong sense of safety for oneself and others. Those are
characteristics that tend to be, as I said, unevenly distributed.

I don't disparage the activity or the practitioners. I'll just watch
from a long distance away, and hope they don't get all loose and
goosey about their "freedoms" at others' expense.

Ok?



Sounds vaguely familiar, Ed...

It should. It's the way most people think about topics that involve
demonstrably dangerous activities and that depend upon good judgment
on the part of people they don't know.

If they have any sense, they know that depending on someone else's
good judgment is not a wise thing to do.

--
Ed Huntress

Every time I snowboard I depend on the good judgement of other riders and
skiers on the mountain. They are not tested, certified or licensed.



Every time you drive down the street you do the same.

THOSE people are licensed too!

On 4/20/2013 3:56 PM, Lloyd E. Sponenburgh wrote:
fired this volley in
:

If they have any sense, they know that depending on someone else's
good judgment is not a wise thing to do.

--
Ed Huntress

Every time I snowboard I depend on the good judgement of other riders
and skiers on the mountain. They are not tested, certified or
licensed.

Yep. What Ed completely misses is, that in a 'healthy' society, we
presume folks will use good judgement, and we penalize only those who do
not. It becomes an incentive to consider ones actions. People in such a
society learn that freedom of choice equates to responsibility for their
actions.

In Ed's perfect world, we would penalize the entire society by taking
away all the good things 'normal' people deserve in order for the
government to better "protect us all" from the dull-witted scumbags that
our Islamic Ayatollah-in-chief wants to elevate to "favored son" status.

And Ed, that's exactly where we are headed. The government is
progressively taking over every aspect of our lives, to eventually leave
us all as subservient to it's "loving care". The last thing they want is
for citizens to have means - any means - of protecting themselves against
the government.

'Sounds like George Orwell's Ingsoc to me!

LLoyd



Couldn't have said it better myself, Lloyd.

On 4/20/2013 4:20 PM, Ed Huntress wrote:
On Sat, 20 Apr 2013 16:18:41 -0400, "ATP"
wrote:


"Ed wrote in message
...
On Sat, 20 Apr 2013 00:31:37 -0500,
wrote:

On 4/20/2013 12:14 PM, Ed Huntress wrote:
On Sat, 20 Apr 2013 11:46:00 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Ed fired this volley in
:

Somehow I'm not troubled by amateur pyros having some of their
freedoms restricted.

If you feel that way, you don't know much about the art.

I know nothing about the art. I do know that I'm not bothered by
people having to live with some restrictions on pyrotechnical
experiments.


"Amateur pyrotechnicians" are not "backyard bombers". They are, in
fact,
the source of MOST of the new effects and techniques used in the
professional trade.

That's nice.


They pursue the ART of fireworking, preserving hundreds-of-years-old
traditional methods of Europe, the US, and the Mediterranean, and at
the
same time advancing the science, the art, and the technique of
fireworks
as you see them in the sky.

Great. Just as long as they don't mix their brews next door to me.


Fireworks is a small industry compared to many, but it's important, and
entertains millions safely, economically, and beautifully.

'Amateur' does not mean 'unskilled', nor does it mean unlicensed in
many
cases. A large number of amateurs hold ATF licenses to do their work.
But at the same time, ATF has OFFICIALLY recognized (and promulgated
regulations) that their record is so good, and also their intentions,
that it is legal under federal law to manufacture fireworks for one's
own
use. They cannot be _transported_ over the public roads by anyone but
a
licensee, but they can be made without a permit or license. (local
ordinances may mitigate that permission).

You should not express negative opinions about people of whom you know
nothing. (I do it too, then always regret it)

Look, Lloyd, I'm not expressing negative opinions about amateur pyros.
I am expressing a combination of some experience with what propellants
and explosives can do, and about the uneven distribution of good sense
and responsibility among any large population.

When you talk in generalized abstractions, like the "freedoms" of
amateur pyrotechnicians, it's just not a field -- given the two points
in my last paragraph -- in which I'd get upset about some
restrictions.

On Jan. 1st of this year, San Francisco police reported 188 fireworks
injuries. Some of the stories were about "amateur pyrotechnicians."

What do you do when one of these guys blows the ears off of his
neighbors? Do you disown him? Take away his Amateur Pyrotechnician
club card? Claim he was never an amateur pyrotechnician in the place,
but only a poseur?

It's clearly a field that demands some intelligence, good judgment, a
strong sense of safety for oneself and others. Those are
characteristics that tend to be, as I said, unevenly distributed.

I don't disparage the activity or the practitioners. I'll just watch
from a long distance away, and hope they don't get all loose and
goosey about their "freedoms" at others' expense.

Ok?



Sounds vaguely familiar, Ed...

It should. It's the way most people think about topics that involve
demonstrably dangerous activities and that depend upon good judgment
on the part of people they don't know.

If they have any sense, they know that depending on someone else's
good judgment is not a wise thing to do.

--
Ed Huntress

Every time I snowboard I depend on the good judgement of other riders and
skiers on the mountain. They are not tested, certified or licensed.

Everyone has his own personal risk/reward ratio.g

And it applies to them selves only!

Not society as a whole.


One assumes that your likelihood of getting your ankles sheared off is
quite low. I skiid for years, and I never came close to a collision I
couldn't avoid.

But my chances of outrunning an explosion are pretty remote.

Your chances of even SEEING an explosion are vanishingly small.

Except on TV.


And there
is no reward for me. So the risks I'll tolerate are rather lower than
in situations where I'm getting something out of it that I like.



Once again, it's a matter of good sense.

Yes, but who's?

On 4/20/2013 4:31 AM, Richard wrote:
On 4/20/2013 2:19 PM, Ed Huntress wrote:

I'd bet my house on it. The average person on the street has more
common sense than most people who post here.


I'd not argue against that!

But as for the "average person", that's what I mentioned the other
day. There ain't no such thing.

People tend to believe that everybody else is just like them, and
they are just like everybody else.

Normal.
Average.
Right.

But everybody _can't_ be average. The math just doesn't work that way.

I will, however, allow that there is a strong cultural bias that
many people see as "the norm".

So it's something of a shock when New Jersians migrate to Texas
and find about about all those "Crazy Texans".

You ask around your neighborhood.
I'll ask around mine.



Stupid spell checker.
It doesn't have a clue what I'm trying to say!

Ed, you area very very bad influence!

I just replied to a 120 line message.

And it's all YOUR FAULT!

On Apr 18, 9:31*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:


(I'm in an explosives-related biz, so ways to ignite things are
reasonably familiar to me)

Lloyd

The media has put on hours of broadcasting about the bombing, but I
have seen nothing that gives any details about the bombs. That may be
intentional, no point in inspiring people to build bombs. But I am
curious what was the explosive. The fact that the bombs were pressure
cooker bombs pretty much says the explosive was not commercial ,
except it could have been black powder.

So does anyone know what was used?


Dan

On Sat, 20 Apr 2013 05:07:49 -0700 (PDT), "
wrote:

On Apr 18, 9:31Â*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:


(I'm in an explosives-related biz, so ways to ignite things are
reasonably familiar to me)

Lloyd

The media has put on hours of broadcasting about the bombing, but I
have seen nothing that gives any details about the bombs. That may be
intentional, no point in inspiring people to build bombs. But I am
curious what was the explosive. The fact that the bombs were pressure
cooker bombs pretty much says the explosive was not commercial ,
except it could have been black powder.

So does anyone know what was used?


Dan

Know? Nothing.

Based on the cloud of whitish/grey smoke and the low velocity of the
explosion as shown by the videos..black powder or something along that
order. It couldnt have been commercial firearms powder..least...its
not likely to have been. the blast would have been a higher order and
the smoke would not have been nearly white. While the possiblity of
it being a commercial firearms powder does..does exist..something fast
like Bullseye pistol powder would pressure up fast enough to act
similarily...my gut feeling says no..based on the display of the
pressure cooker body shown on TV and the lack of a particulate based
fireball, which would likely have shown up brightly if a nitro based
powder had been ignited. If it had been a nitrobased "gun powder"..the
blast would likely have been brilliant as the unburned powder
particles were ignited in mid air after the pressure cooker had broken
open.

I lost a good friend some 10 or more years ago, who was burning old
skunky powder by pouring it into an open flame, a small portion at a
time..bonfire. When he decided to rush it..he tossed a gallon glass
jar into the flames of the bonfire and the fireball that resulted
seared him into a 3rd degree flambe along with his son, who was within
10' of the firepit. And by all reports..lit up the neighborhood like
a flare..despite it being a sunny day and mid afternoon.

He lived for another year or two..but was never right after that and
soon died.

" fired this volley in news:dea88c27-
:

So does anyone know what was used

Dan,
One of my infrequent jobs is to do for-pay forensic studies of fireworks
accident scenes, in order to find the cause(s). Part of that involves
doing chemical analyses on the various combustion residues in the area.

In this case, I cannot analyze them chemically, but can still evaluate
the flame-front velocity, the fireball size, the smoke output, and the
smoke color for ideas of what the substance was.

The burn rate and fireball size were consistent with a potassium nitrate
or potassium perchlorate-based composition that was fairly fast-burning
under the degree of containment afforded by the pressure cookers. Keep
in mind, they won't hold much more than about 60-80psi before the break
their little lock tabs, so the pressures wouldn't be as high as they
would be in a 'real' bomb casing.

Black powder is fairly scarce these days for casual purchases. It's
expensive, too. But it can pretty easily be homemade, and can be made to
a quality as good as Goex's shutzen powders.

The BP substitute, Pyrodex, _claims_ to be low-smoke, but in fact makes
as much white smoke as black powder does. Pyrodex is potassium
perchlorate-based, and burns roughly at the same speed as black powder,
with about the same explosive force, volume-for-volume (NOT weight-for-
weight.) Pyrodex is MUCH less dense than BP, which is 1.7g/cc solid
density, and about 1.0g/cc mass density in granulated form.

So... a 6-quart pressure cooker would hold as much as 12 pounds of Black
powder. That would make quite a 'whack', suitably contained.

You'll also note that the containment failed before the lid fragmented.
See the distorted lid pictures. The shrapnel injuries must've been the
result of shards of the pot base, or the nail-shot additions to the load.

There are a couple of other mixtures, pyrotechnic in nature, that would
give the same basic profile of fireball, smoke, and propulsive force.

One thing for sure... it was NOT "flash powder" (the stuff that kids so
often try to collect from firecrackers to make bigger ones). Flash
powder is so fast-burning under containment as to be categorized for
storage and transportation as a high explosive (although it's not
really). It also makes a small and compact, bright-white fireball.

LLoyd

On 4/20/2013 5:41 PM, Ed Huntress wrote:
On Sat, 20 Apr 2013 04:54:30 -0500,
wrote:

Ed, you area very very bad influence!

I just replied to a 120 line message.

And it's all YOUR FAULT!

Hey, you have to take personal responsibility for your actions. Pay
attention to the incentives. d8-)



No way! That's totally unfair.

Somebody's gotta pay for this.

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
" fired this volley in news:dea88c27-
:

So does anyone know what was used

Dan,
One of my infrequent jobs is to do for-pay forensic studies of fireworks
accident scenes, in order to find the cause(s). Part of that involves
doing chemical analyses on the various combustion residues in the area.


Were you involved in the investigation of the Grucci fireworks plant that
exploded on Long Island in the 1980's?

"ATP" fired this volley in
:

Were you involved in the investigation of the Grucci fireworks plant
that exploded on Long Island in the 1980's?


No, although our company helped pick up some of their manufacturing load
until the Gruccis finished re-building. We were in NJ, so close enough
to lend a hand. (I'm no longer with that company)

The Grucci organization (Pyrotechnique by Grucci, Inc) is still one of my
clients, although my prior employer no longer interacts with them.

LLoyd

On 4/18/2013 9:31 PM, Lloyd E. Sponenburgh wrote:
Martin Eastburn fired this volley in
:

cell phones in the Boston bombing...

I don't know if you recognize any of the common parts shown in the photos
of the debris, but there wet

1) parts of a standard 7.2V NiCd 'hobby' style battery pack for models
(cars and planes)
2) parts of an electronic speed controller for RC cars or planes...
looked like a Great Planes or Novak component (in-line style) ESC.
3 parts of a Novak RC radio receiver for cars or planes (orange case,
very recognizable)

I'll let you guess from that whether or not cell phones were used as the
firing box. I'm guessin' your guessin' won't be swayed by this.

(I'm in an explosives-related biz, so ways to ignite things are
reasonably familiar to me)

Lloyd


I saw the battery brand (good one) that's used in RC stuff, I'd bet it
was just simple kitchen-type timers probably set for the same time and
were only ten or so seconds apart.

Tom Gardner Mars@Tacks fired this volley in
:

I saw the battery brand (good one) that's used in RC stuff, I'd bet it
was just simple kitchen-type timers probably set for the same time and
were only ten or so seconds apart.

WHY would they use a PWM-controlled ESC with a kitchen timer? And why
would they use a Novak RC receiver with a kitchen timer?

Nahh... look at the pictures!

Lloyd

On 4/20/2013 8:55 AM, Gunner Asch wrote:
On Sat, 20 Apr 2013 05:07:49 -0700 (PDT), "
wrote:

On Apr 18, 9:31 pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:


(I'm in an explosives-related biz, so ways to ignite things are
reasonably familiar to me)

Lloyd

The media has put on hours of broadcasting about the bombing, but I
have seen nothing that gives any details about the bombs. That may be
intentional, no point in inspiring people to build bombs. But I am
curious what was the explosive. The fact that the bombs were pressure
cooker bombs pretty much says the explosive was not commercial ,
except it could have been black powder.

So does anyone know what was used?


Dan

Know? Nothing.

Based on the cloud of whitish/grey smoke and the low velocity of the
explosion as shown by the videos..black powder or something along that
order. It couldnt have been commercial firearms powder..least...its
not likely to have been. the blast would have been a higher order and
the smoke would not have been nearly white. While the possiblity of
it being a commercial firearms powder does..does exist..something fast
like Bullseye pistol powder would pressure up fast enough to act
similarily...my gut feeling says no..based on the display of the
pressure cooker body shown on TV and the lack of a particulate based
fireball, which would likely have shown up brightly if a nitro based
powder had been ignited. If it had been a nitrobased "gun powder"..the
blast would likely have been brilliant as the unburned powder
particles were ignited in mid air after the pressure cooker had broken
open.

I lost a good friend some 10 or more years ago, who was burning old
skunky powder by pouring it into an open flame, a small portion at a
time..bonfire. When he decided to rush it..he tossed a gallon glass
jar into the flames of the bonfire and the fireball that resulted
seared him into a 3rd degree flambe along with his son, who was within
10' of the firepit. And by all reports..lit up the neighborhood like
a flare..despite it being a sunny day and mid afternoon.

He lived for another year or two..but was never right after that and
soon died.





Darwin? In retrospect, why didn't he mix it with water and use it as
fertilizer. I'm not a smart guy but even I know better...EVERYBODY
knows better! Was he not aware of how to handle powder?

On 4/20/2013 8:59 AM, Lloyd E. Sponenburgh wrote:
" fired this volley in news:dea88c27-
:

So does anyone know what was used

Dan,
One of my infrequent jobs is to do for-pay forensic studies of fireworks
accident scenes, in order to find the cause(s). Part of that involves
doing chemical analyses on the various combustion residues in the area.

In this case, I cannot analyze them chemically, but can still evaluate
the flame-front velocity, the fireball size, the smoke output, and the
smoke color for ideas of what the substance was.

The burn rate and fireball size were consistent with a potassium nitrate
or potassium perchlorate-based composition that was fairly fast-burning
under the degree of containment afforded by the pressure cookers. Keep
in mind, they won't hold much more than about 60-80psi before the break
their little lock tabs, so the pressures wouldn't be as high as they
would be in a 'real' bomb casing.

Black powder is fairly scarce these days for casual purchases. It's
expensive, too. But it can pretty easily be homemade, and can be made to
a quality as good as Goex's shutzen powders.

The BP substitute, Pyrodex, _claims_ to be low-smoke, but in fact makes
as much white smoke as black powder does. Pyrodex is potassium
perchlorate-based, and burns roughly at the same speed as black powder,
with about the same explosive force, volume-for-volume (NOT weight-for-
weight.) Pyrodex is MUCH less dense than BP, which is 1.7g/cc solid
density, and about 1.0g/cc mass density in granulated form.

So... a 6-quart pressure cooker would hold as much as 12 pounds of Black
powder. That would make quite a 'whack', suitably contained.

You'll also note that the containment failed before the lid fragmented.
See the distorted lid pictures. The shrapnel injuries must've been the
result of shards of the pot base, or the nail-shot additions to the load.

There are a couple of other mixtures, pyrotechnic in nature, that would
give the same basic profile of fireball, smoke, and propulsive force.

One thing for sure... it was NOT "flash powder" (the stuff that kids so
often try to collect from firecrackers to make bigger ones). Flash
powder is so fast-burning under containment as to be categorized for
storage and transportation as a high explosive (although it's not
really). It also makes a small and compact, bright-white fireball.

LLoyd




I think they used my dogs' farts...quite deadly!