Sciencemadness Discussion Board - Detonation Safety Distance

Detonation Safety Distance

holmes1880 - 25-12-2010 at 17:14

I am particularly interested in appropriate critical safety distance from the explosive where you will not be harmed externally/internally from the blast wave pressure/brisance. *Let us ignore the shrapnel aspect of this relationship, since shrapnel can get you even at 1km.

Nobody is planning to have an accident, but for any contingency procedure it is good to know what risk your are taking while handling energetics. Sadly, the scientific research isn't substantial, so many things have to be based on precedents, personal tests.

Using 1g NG as the standard unit of measure, let's break down potential critical distances assuming extended arms' length measuring from the fingertips:

0.1g.........1cm
0.5g.........3 cm
5g............10cm (ear and eye damage is plausible here)
50g..........50cm (ear and eye damage is very likely)

This was largely speculations but things we do know from reported accidents:

1. 0.2g ETN has minimal if any brisance at 2cm(I tested it)
2. 50ml of MEKP will not dismember wrist at 10cm nor take away vision or hearing (I'm not sure about this report because it could have been a deflagration vs. full order)
3. 5-10g of TATP detonated in a metal container will not cause permanent loss of hearing or vision(not considering shrapnel).
4. Hitler survived 1kg of C4-type detonation being with 10 feet.

Any contribution to this database is much appreciated.

The WiZard is In - 25-12-2010 at 18:33

Quote: Originally posted by holmes1880

I am particularly interested in appropriate critical safety distance from the explosive where you will not be harmed externally/internally from the blast wave pressure/brisance. *Let us ignore the shrapnel aspect of this relationship, since shrapnel can get you even at 1km.

Let me take this where you probably never considered.
[I have a talent for this.]

YELVERTON, J.T. et al. 1973. Safe Distances from underwater
Explosions for Mammals and Birds. Lovelace Foundation for
Medical Educaticn and Research, Project Report:
DNA-NWED-M-012.

Or how about quail, chickens, geese or pigeons? –

Damon, E.G. The tolerance of Birds to Airblast. Project Report-
DNANWED-U99QAXM. Task A012. DH

If you are interested in effects ... and have a strong stomach...
eyeball —

J Rajs & et al
Explosion-Related Deaths in Sweden — A Forensic-Pathologic
and Criminalistic Study
Forensic Science International
34 (1987) 1-15

There is a tremendous amount of info available on blast trauma.

VII.10
Umbrella Effect of a Landmine Blast
War Surgery in Afganistan and Iraq : A Series of Cases, 2003-2007
SC Nessen & et al Editors
Office of the Surgeon General
US Army 2008

I a good reminder not to step on a landmine!

djh
---
Landmines are relative —
Between you and the enemy — Bad.
Between the enemy and you — Good.
© djh 2008

YOU will have to do the leg work.

holmes1880 - 25-12-2010 at 21:56

Wizard, these are awesome sources

As I skimmed the abstracts, I think I forgot to include into consideration the damage to the lungs/hyperventilation death.

I did a 60g ANNM test few weeks ago, and IF something that powerful goes off 100cm away from you, breathing would definitely get constricted for quite some time.....makes perfect sense.

[Edited on 26-12-2010 by holmes1880]

grndpndr - 26-12-2010 at 00:47

Blast injuries sound like a gruesome way to go if your not killed outright.Apparently air filled organs are the most subsceptible.Eardrums will be the first to rupture,if thats all your lucky.Then I dont know?Whether damaged lungs that can show up 48hrs later as it begins to get difficult to breath as your lungs fill w/fluid(white butterfly) or perhaps your intestines are perforated which will lead to sepsis ,blood poisoning..Slop painful death. Gruesome stuff.

Lots of factors involved besides overpressure,lenghth of the blast overpressure-FAE,enclosed space such as a cave etc.

Likely why hitler survived,supposedly protected from direct blast by a hardwood divider in the heavy table.Not secluded in a bunker but what appeared to be a home like structure w/windows etc.(Best of plans..)

Blasty - 26-12-2010 at 02:13

Many years ago I remember reading about a man who survived an explosion at an early dynamite factory. He was the plant's manager and was standing about 4 meters away from a 900 lb batch of nitroglycerin that accidentally went off. All the workers expected that the guy had been killed. He was actually literally "blown away" (i.e. he was sent flying through the air and landed on some trees!) by the explosion but survived to tell the tale.

quicksilver - 26-12-2010 at 07:34

Most all the points depicts one extreme lesson: the further the better. Anything you can do to put distance between you and the danger of energetic blast creates a safety element. As distance increases, blast damage diminishes therefore the rules about handling the cap by the leads or the fuse; keeping them away from vital areas of the body, etc. Distance becomes your "safety zone" more often than any other single issue.
There ARE scales that describe weight levels and proximity but they get back to that vital agenda.

The WiZard is In - 26-12-2010 at 09:11

Quote: Originally posted by holmes1880

To be killed by blast alone requires either a whole bunch of explosives or really bad luck.

Eyeballing my ever useful copy of —

Wound Ballistics
Office of the Surgeon General
Department of the Army 1962

[You can usually find copies for US $25 me thinks.]
NB - More than a few stomach turning photos. War is not pretty.

p. 105

@ 500 lbs peak pressure sq inch 50% killed
60-100 50% seriously injured.
15 eardrums ruptured

"At the nearest point, peak pressures would be between
seven and eight times greater on an object oriented at
right angles to the travel of the shock wave; at a distance
of 90 feet, the factor would be approximately four; and
at 150 feet about three."

Table 18 Peak pressure in pounds per square inch at
varying distances from point of detonation for
general-purpose bombs of various weights on a surface
parallel to direction of travel of shock wave.

At 30 feet 60 &c. &c.

100lb 17 4
500 80 6
1 000 200 20
2 000 400 50
4 000 1 000 170

---------
Deficiencies in the Testing and Classification of Dangerous Materials. J.E. Settles.
Annals New York Academy of Sciences
Volume 152, Art.1. Pages 199-205. 1968.

"A total of 103 persons suffered injuries in the 81 accidents. Seventy-eight fatalities
resulted from these 81 accidents.

"Of the 81 accidents included in this analysis, it was concluded that 23 of them
involved only fire, and the principal hazard was radiant heat. It was further concluded
that 44 of the accidents involved both fire and explosion. From information available, it
seemed justified to assume that no more then 14 of the accidents were characterized
by supersonic shock waves that would fall within the accepted definition of "detonating"
reactions.

"The 14 accidents in which detonating forces were present resulted in injuries to 35
persons and 34 fatalities. It appears from the information available that only one of
these 34 deaths resulted from the blast overpressures that are associated with a
detonating reaction. However, this one fatality was not the result of blast damage to
human tissue. Rather, the blast pressure caused this individual to be propelled as a
projectile. The other 33 persons who died in these 14 accidents were located at points
where the density of flying fragments, and in some cases, the lethal searing of radiant
heat were so great that their deaths were certain, even though there had been no blast
effects.

"A serious and disturbing inconsistency is related to the practice of accepting a "fire
hazard only" label on reactions of such violence and destructive energy as
medium-velocity detonation, low-velocity detonations, high-rate explosions,
medium-rate explosions, Iow-rate explosions, and even reactions that don't explode at
all but kill people by burning them to death."

djh
----
Don't worry about
the bullet with your
name on it — worry
about shrapnel labeled
occupant.

Murhpy's Laws of Combat

holmes1880 - 26-12-2010 at 10:00

Wizard,
Am I understanding that the blast heat generated is more of a lethal factor than the detonation wave?

@Blasty,
900lbs of NG at 4m........naw, that's as about impossible to survive as it is a fall from a 20 story building. 900g, I'd go for, but not 900lbs.

[Edited on 26-12-2010 by holmes1880]

Never underestimate bad luck

The WiZard is In - 26-12-2010 at 12:22

Hirsch, AE & AK Ommaya
Lethal Effects on Man of Underwater Detonation of a Firecracker
AGARD Conf. Proc. 88:15-1 1971

A firecracker exploded in contact with the skin within six inches of the skull base in a
young man while he was swimming underwater. The resulant severe head injury and
death appeared to be directly related to this underwater explosion. Reconstruction
of the mechanics of his injury indicate that when the head is subjected to impact
energies between 440 and 1800 in-lb and impact impulse between 1.8 and 3.5 lb. sec.,
both skull fracture and brain injury can occur. (Authors abstract)

I came upon this in my ever useful copy of —

Shilling and Werts
Underwater Medicine and Related Sciences : A Guide to the Literature
2 vols. Plenum Publishing 1973

I have a copy of the paper here somewhere do not be
remembering from were/how I obtained it.

Speaking of diving - years ago when I SCUBA'd someone came out
with a diver recall device it was a large salute/firecracker
in a 35mm aluminium film can. Underwater it made a crack
sounded like a piece of monofilament breaking.

Speaking of SCUBA my three best memories are being ...

SCUBA diving at Cozumel - swimming behind some sweet young
thing... watch her gluteus maximus mussels move her legs.
With just a hint of swamp spinach showing from 'round
her what Shakespeare called a nest of spices, taint
i.e., taint AH - taint pussy. AKA chin rest. Joy, &c., &c.

Wall of the Cayman Isl. Amazing down 'bout the 3 ledge like
looking down into a vast ink bottle .. jet black. One day
the dive boats captain sez "I was down at 170 feet and I saw you!"
True - however, I didn't think it wise to tell him that I was coming
up from 2XX feet. I wanted to get the hand on my
depth gauge to touch the stop pin... At that depth with every
breath you could see a drop in the air pressure gauge on the tank
which was empty when I came up. One quick dive!

An who .... after lunch having maxed out the tables we dove
in shallow waters. Crystal clear water like swimming in a giant
bath tub.

Lunch upon this day was chili and cheesewiz... Gawd! Swimming
along dropping conch shells on sleeping spotted-eagle rays...
O' no ... its shit or die. Back to the surface ... no way am
I being able to return to the boat. Back to the bottom...
undo tank strap, pull down trunks, pull knees up to chest,
roll over and BLOWWWW followed by a could of masticated
beans floating on the current through the pristine waters.
Absolutely the most comfortable dump I have ever taken.

Diving with the seal in the Galapagos. Amazing animals
underwater! They swim up and look into your mask, if you put
your hand out they muzzle it like a dog, which is good as they
have canines that would shame a tiger! Burst you bubbles.
An underwater pas du deux.

Now back on topic... most info on charge size vs. blast over
pressure was done in connection with structures not humans.
In simulations of special weapon explosions large amounts
of ANFO and spheres of pentolite were detonated.

Noted in passing explosives underwater

The WiZard is In - 26-12-2010 at 12:54

The use of explosives underwater by diver is covered briefly in —

Ye. P. Shikanov, Editor
Spravochnik Vodolaza (Handbook for Divers)
Moscow, Voyenizdat 1973
321 pages.

English translation by Joint Publications Research Service,
JPRS 60691. Sold by the NTIS.

My useful copy of the
1970 U.S. Navy Diving Manual
NAVSHIPS 0994-001-9010

p.94 change 1.

Appx. total force of an underwater blast wave.

P= 13,000 (cube root) W
----------------------------
d

P = force in ponds per square inch
W = weight of explosives in pounds
d= distance of explosion from diver (feet)

A pressure of 500 psi is sufficient to cause injury to the lungs
and intestinal track. Associated details follow.

This is repeated in —

the NOAA Diving manual : Diving for Science and Technology
Manned Undersea Science and Technology Office
US Dept of Commerce
1975
US Gov. Printing Office

Not found

Handbook U.S. Navy Diving Operations
1 April 1974
NAVSHIPS 0994-009-6010

Nice book the pages are plastic so you can them out diving and
not worry 'bout them getting wet. Should take my copy and
rinse the saltwater off it!

NB — This search was limited to what I shelve.

holmes1880 - 26-12-2010 at 13:40

Since a lot of underwater discussion is coming up, I have done a few underwater detonations, and I would NEVER dare to stick my arm in the water when it goes off, let alone jump in for a quick dip. When doing it off the concrete bank, it is absolutely humbling how hard the shockwave hits the reinforced concrete wall......it feels like someone drove a pick-up truck in it.

P.S. Wizard, that story about scuba dump was epic! I'd be concerned doing it at a depths.....I'm not sure how the pressure could affect things,

The WiZard is In - 26-12-2010 at 13:59

Quote: Originally posted by holmes1880

P.S. Wizard, that story about scuba dump was epic! I'd be concerned doing it at a depths.....I'm not sure how the pressure could affect things,

----
I have two on land dump stories. I will spare you (all of you) the sorted details!

There is a famous workman comp. case. A diver was in la
decompression chamber on the throne when someone outside
opened the wrong valve at the wrong time! Sucked his guts out
through his ..... YAHOOOO-OO! They couldn't remove him from
the chamber so they brought in a surgeon who operated on him
in situ!

I had suggested this to La Myth Busters as a follow up to their
airplane toilet myth....!

djh
----
Penthouse magazine founder Bob Guccione dies at 79 21x10

DALLAS – Bob Guccione tried the seminary and spent years trying to make it as an
artist before he found the niche that Hugh Hefner left for him in the late 1960s.
Where Hefner's Playboy magazine strove to surround its pinups with an upscale
image, Guccione aimed for something a little more direct with Penthouse.

Something a little more direct.

Gynecology through the picture study method comes to mind. /djh/

The WiZard is In - 26-12-2010 at 14:17

Quote: Originally posted by The WiZard is In

The use of explosives underwater by diver is covered briefly in —

NB — This search was limited to what I shelve.

Back from the shelves - I had forgotten my favorite diving book
it is a fun read.

Nicholas B Zinkowski
Commercial Oil-Field Diving
Cornell Maritime Press
2nd edition 1978

Chapter 8 - Use of explosives.

p. 45 Personal Problems Underwater

"I have known many divers who habitually and unabashedly
urinate in their dress, considering it one of the evils of the
trade."

Well sure in a dry suit, however, in a wet suit — one of life's
greatest and free pleasures!

Anyone remember the scene with John Glenn while in his Mercury capsule. Movie "The Right Stuff"?

djh
----
The problem with
l'ivresse des grandes profondeurs
[rapture of the deep]
is that you cannot
lay-back and enjoy it
for fear of loosing control.

I remember one female
carbon based unit who
overtaken by it dropped
her camera. (Cozumel Isl.
QR Mexico.) Id following
behind (hers) swam down
and retrieved it. Then swam
up and brought her back to
the reality that she was way
tooooo deep and should ascend.

holmes1880 - 26-12-2010 at 14:49

The pressure chamber incident is just....wow. I'm uncomfortable just thinking of what that could feel like.

I have a very useful inquiry/proposition for safety with charges. The particular explosive in mind is KinePak, where we basically add NM after the initiator is already inserted in the charge. Assuming NM does not sensitize NH4NO3 right away (the key assumption), it gives time to safely insert the initiator and then back up from the charge. The only thing to worry about is the small detonator. Any idea whether AN is #6cap sensitive immediately after adding NM, or does it take a few minutes? I'll probably have to test it out, but hate to waste good charge if it fails, even though that's the desired result.

I got the idea for this method from this video:
http://www.youtube.com/watch?v=nkYJ2-eDNEc

[Edited on 26-12-2010 by holmes1880]

Sickman - 26-12-2010 at 17:06

[rquote
@Blasty,
900lbs of NG at 4m........naw, that's as about impossible to survive as it is a fall from a 20 story building. 900g, I'd go for, but not 900lbs.

[Edited on 26-12-2010 by holmes1880][/rquote]

May have been a low order det.

50 psi seems to be the LD50 for human exposure to blast overpressure:

Blast waves and the human body

The WiZard is In - 26-12-2010 at 17:40

Quote: Originally posted by holmes1880

I got the idea for this method from this video:
http://www.youtube.com/watch?v=nkYJ2-eDNEc

Curious most LOX uses an absorbent combustible. See —

US Bureau of Mines
RI 3169
Absorbents for Liquid-Oxygen Explosives
April, 1932

----
US Bureau of Mines
Technical Paper 294
Progress of Investigations on Liquid-Oxygen Explosives
1923
(Can be DL'd)

Number 52A5.
22.1% aluminium dust
77.9% wood pulp

Lead block 1.44 that of 40% dynamite. [Straight?]

I expect silicon would fail the $$$ test. I also would like
to know how they computed the power of their mixture.

For an interesting report on actual use of LOX in mining I commend —

MH Kurlya and GH Clevenge
Liquid-oxygen Explosives a Pachuca
Transactions American Institute of Mining, Metallurgical and
Petroleum Engineers
Presented at the New York meeting, February 1923. p. 271-340.

The on site LO2 plant produced 25 l. (27.5 kg, 60.6 lb per hour.)

The life of their cartilages max out at 11.5 minutes. As has
been stated - LOX explosives cartridges are the ultimate safety explosive —
after a few minutes they are no longer explosive.

I was thinking of magic - once it is explained it is no longer
magic. I own this paper because a few years back I found
a bound copy of the complete year for sale at a good price.
Upon receipt I dis-bound it. Currently I am unable to find
the residuum.

LOX Strength

The WiZard is In - 26-12-2010 at 17:53

Transactions American Institute of Mining, Metallurgical and
Petroleum Engineers
G St. J. Perrott
Properties of Liquid-oxygen Explosives 1925
p1248-1275

Table 6.—Propulsive Strength of L.O.X. Cartridges as Measured
by Ballistic Pendulum

Relative Strength by Volume Compared to Dynamite [40%]

1.16 Gas Black S, cartridge density 0.33
1.14 Four way tie.
1.13 One

holmes1880 - 26-12-2010 at 19:22

So, no info on how long it takes for NM to sensitize AN? Gerald Hurst's patent is no help, I skimmed it, and ............................nothing regarding duration.

Blasty - 26-12-2010 at 21:13

Quote: Originally posted by holmes1880

@Blasty,
900lbs of NG at 4m........naw, that's as about impossible to survive... 900g, I'd go for, but not 900lbs.

"Compare our next nitroglycerine incident. In 1886 Mr. Wilson P. Foss was manager of the Clinton Dynamite Company's plant at Plattsburgh, New York. He was inside a building and standing four yards from a wash tank that contained 900 lbs of nitroglycerine when an accidental gush of live steam from an open valve detonated the nitroglycerine, destroying the building and leaving a crater 30 ft deep. Workers at the plant hurried to the site, expecting to find Mr. Foss's remains among the wreckage. He had, however, been blown by the force of the explosion out of sight round the bend of a nearby frozen river, and to the startled incredulity of the workforce he reappeared to them striding on the ice around the river bend." - John Bond, "The hazards of life and all that: a look at some accidents and safety curiosities, past and present", CRC Press, 1996. Page 63.

Quote:

as it is a fall from a 20 story building.

http://untoldvalor.blogspot.com/2007/07/alan-mcgee-luckiest-...

Don't underestimate the quite frankly bizarre survival luck some people have had.

[Edited on 27-12-2010 by Blasty]

crazedguy - 26-12-2010 at 21:37

@ Blasty: The guy surviving 900 lbs of NG seems believable to be so close you are pushed with the pressure wave rather than crushed by it, but I have heard that story of the 20,000 foot fall before and find a piece of glass slowing the impact enough to save someones life hard to believe.

simply RED - 27-12-2010 at 03:18

"50g..........50cm"
Hahahahaha, that made my day....

The WiZard is In - 27-12-2010 at 07:46

Quote: Originally posted by crazedguy

@ Blasty: The guy surviving 900 lbs of NG seems believable to be so close you are pushed with the pressure wave rather than crushed by it, but I have heard that story of the 20,000 foot fall before and find a piece of glass slowing the impact enough to save someones life hard to believe.

------
Well the 900 NG story is A- true and B- has nuances. There being a
good description in Vangleder and Schlatter, I will scan it after
I finish reading the news on line and going out in the 6.3o F
cold to move some of the snow around.

bbartlog - 27-12-2010 at 08:13

Thing with 900 lbs of NG, one could readily believe that there might be some initial deflagration that would push the victim/survivor fast and far enough that once the DDT occurred he was already underway, so to speak, and thus at a distance where the real shockwave only accelerated him rather than crushing him to death. In cases like these our theoretical models about what should happen must give way to actual reports.

The WiZard is In - 27-12-2010 at 10:32

Quote: Originally posted by The WiZard is In

Quote: Originally posted by crazedguy

Finished moving the snow around, you should have seen the
smile on the Snow Man's face when he heard the snow blower
coming!

Broke the plow blade off my Gator, snapped 1/2" bolt, large
spring flew off into the snow, hope to find it comes April of May.

\

I shelve a 1998 Ayer Company aka Arno Press reprint of G & S 1927.

Jimbo Jones - 27-12-2010 at 11:54

Quote: Originally posted by simply RED

"50g..........50cm"
Hahahahaha, that made my day....

Nice way to clean your ear wax.

By the way, Hitler “survived, as did everyone else who was shielded from the blast by the conference table leg.”

The lightweight, wooden structure of the building loses even more from the performance of the used “plastic explosive”. If this 1 kilo was placed in bunker…..

The WiZard is In - 27-12-2010 at 13:29

Quote: Originally posted by Jimbo Jones

The lightweight, wooden structure of the building loses even more from the performance of the used “plastic explosive”. If this 1 kilo was placed in bunker…..

La Myth Buster's tested this last in the last week or two.

http://dsc.discovery.com/videos/mythbusters-debunking-the-bu...

Question - What explosive was used?

William L Shirer in his most excellent book, The Rise and Fall of
the Third Rich, 1960 sez they were the same as used in the Operation Flash, a failed attempt to blow up Hitlers plane.

"Schlabrendorff and Tresckow, after much experimenting, had
found that German bombs were no good for their purpose....
The British, they discovered, made a better bomb..... The R. A. F.
had dropped a number of these weapons over occupied Europe
to Allied agents for sabotage purposes—one had been used to
assassinate Heydrich*—and the Abwer had collected several of
them and turned them over to the conspirators."

The British expls. also came with a 10-min delay non smoking chemical fuse. Your typical dissolve the wire type.

In Nam the USAF dropped 500-pound bombs with chemical
fuses with up to 2-weeks delay - they sunk into the ground out of sight.

Used in WWII RDX based Composition B (cyclotol or RDX), B, B-1, B-2 , A, A-1, A-2, A-3, A-4 and C, C-2, C-3 during WW II, C-4 was a post war devopment.

* I will leave it to the reader to decide if the death of SS-Obergruppenführer Reinhard Tristan Eugen Heydrich
was worth the price paid by others vs. any gain in defeating the
Axis.

http://en.wikipedia.org/wiki/Reinhard_Heydrich

By da Shirer p. 1050 notes —

This was (Lagebaracke) far from being the flimsy wooden hut so often described . During the previous winter Hitler had the
original wooden structure reinforced with concrete walls 18
inches thick to give it protection against incendiary and splinter
aerial bombs that might fall nearby.

That said - it had a lot more windows than your typical underground bunker! Which it being a hot/humid day were
probable open.

DougTheMapper - 27-12-2010 at 13:48

http://c2.api.ning.com/files/g64JBXRPh0yB6BK99PdSBQxUuRMpWdp...

My personal favorite regarding blast injuries incurred via

1) Primary blast injury from the pressure wave
2) Secondary blast injury from shrapnel
3) Tertiary blast injury from bodily collision with stationary objects
4) Quaternary blast injury from infection of wounds

This paper has extensive data and simulations especially regarding the profound effect of pressure waves on the lungs as well as blast-mitigating armor and data concerning wave reflection off of stationary objects, e.g. in a city.

It's a good read.

[Edited on 27-12-2010 by DougTheMapper]

holmes1880 - 27-12-2010 at 18:41

Good read and good find Doug. Thank you. I skimmed it, and ton of info, indeed. We still have to find some reliable means of finding out safety ranges for the accidents. I just want to know whether it makes a difference to hold a 50g booster in my hand or by a 50cm line/fuse.......I mean, yeah, it's obviously better, but will I still sustain certain injuries and which kind. That's the question!

franklyn - 27-12-2010 at 23:13

The highest pressure from an explosion occurs a few centimeters away from the
surface of the explosive , as a result of the impact from the momentum of the
expanding gas products. This distance called standoff is proportional to the
volume of explosive and varies accordingly. The effect of the expanding shock
front diminishes according to the reciprocal of the square of the radius ( 1/ r ² ) .

The pressure is defined as the force per unit area A. The surface area of the
sphere is A = 4 ∏ r ², so the pressure actiing through each unit of surface is
by definition: Pressure = Force / 4 ∏ r ²
We see that pressure is inversely proportional to the square of the distance
away from the source:
p2 / p1 = r ²1 / r ²2 , double the distance and the pressure is reduced to a 1/4

This almost didn't get posted _
http://www.sciencemadness.org/talk/viewthread.php?tid=11195#...
http://www.sciencemadness.org/talk/viewthread.php?tid=4567#p...

How dangerous is high intensity blast ?
" simulations show that the skull is deformed only about 50 microns (the width of a human hair),
“ this is large enough to generate potentially damaging loads in the brain,” "
http://www.sciencedaily.com/releases/2009/08/090826152713.ht...

Effects of blast pressure on structures and the human body
http://www.cdc.gov/niosh/docket/pdfs/NIOSH-125/125-Explosion...

Thanks to DougTheMapper also for Explosion & Blast Related Injuries

Cited by Bowdlerize in this thread => http://www.sciencemadness.org/talk/viewthread.php?tid=13791.
Blast Overpressure and survivability calculations for various sizes of explosive charges
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA286212&Locati...
- where these charts are from -

The WiZard is In - 28-12-2010 at 12:07

Quote: Originally posted by DougTheMapper

http://c2.api.ning.com/files/g64JBXRPh0yB6BK99PdSBQxUuRMpWdp...

It's a good read.

Kudos to Dough!

Checking the price of the book @ Amazon.com ($125) - I found mentioned this which I find, can be had from DTIC.MIL :—

Title: Biological Tolerance to Air Blast and Related Biomedical Criteria
Personal Author: White, Clayton S Bowen, I G Richmond, Donald R
Corporate Author: CIVIL EFFECTS TEST OPERATIONS (AEC) WASHINGTON DC
Source Code: 405021
Page Count: 256 page(s)
AD Number: ADA384737
Report Date: 18 OCT 1965

holmes1880 - 28-12-2010 at 21:59

Franklyn, those graphs are gold! Thanky.
Basing on them, it makes perfect sense handling an even 100g charge by a safety line/stick as the pressure will be more than survivable at 2 feet with no damage to the lungs. Hearing will be gone, though, that's for sure.

[Edited on 29-12-2010 by holmes1880]

Beware of things in the shadows. Takeo Shimizu

The WiZard is In - 29-12-2010 at 07:57

Florida Man Trapped in Lime Pit
NY Times 24 December 2010
By THE ASSOCIATED PRESS
Published: December 23, 2010

A blast team supervisor was trapped underwater and feared dead after the ground gave way at a lime rock mine on Thursday. The authorities say 35-year-old Kenneth Stephens Jr., of Beverly Hills, Fla., approached a lime pit after a routine blast at the Mazak Mine in Bushnell, about 50 miles northwest of Orlando. Mr. Stephens was about 30 feet from the blast area when the ground gave way and he collapsed into the lime pit. A pontoon boat was lowered into the pit by a crane, but rescue workers were unable to find him.

Beware of human shrapnel

The WiZard is In - 31-12-2010 at 17:15

From the UPI News Wire
ROSCOE, N.Y. (UPI) 4 July 1989_

Garret B, 25, was camping with a friend Monday evening at
Hunter Lake in the Catskill Mountains about 125 miles northwest of
New York City, when he lit an M-80 with a short fuse and it blew up
in his hand. He was first taken to Community General Hospital
where he was stabilized and then transferred by ambulance at
midnight to the Westchester County Medical Center, where he is in
serious but stable condition. Operated on early Tuesday morning
by a plastic surgeon and an eye surgeon. He lost his thumb, index
and little fingers on his right hand. A finger torn off by the explosion
lodged in his eye, causing him to lose the eye. He also suffered powder
burns on his face.

LTC SC Nessen & et al Editors
War Surgery in Afganisan and Iraq : A Series of Cases, 2003-2007
Office of the [US] Surgeon General 2008

V.9 Penetrating Scrotal Trauma

23-year host nation male… part of a mass casualty event after a
suicide bomb attack. … The right testicle was nonpalpable. A
radiograph … revealed a foreign body… scrotal examination. On
exploration, the foreign body was removed and was consistent
with a human rib fragment with attached intercostals musculature.
(Fig. 4) The scrotum was explored through a midline incision at
the median raphe. The patient had a ruptured right testicle. An
orchiectomy was performed. He recovered well and was
discharged on postoperative day 2.

-------
At no extra charge

Hand blown off – attacked by pit bull
http://tinyurl.com/yhw2vml

DougTheMapper - 1-1-2011 at 11:09

WiZard, what on earth do you use to dig up all of this wonderful content??

Also, Happy New Year everybody.

The WiZard is In - 1-1-2011 at 13:06

Quote: Originally posted by DougTheMapper

WiZard, what on earth do you use to dig up all of this wonderful content??

Also, Happy New Year everybody.

I am not sure this is worth the bandwidth ... however...

First I wouldn't use wonderful to describe what I posted,
having spent a lifetime collecting scars, a broken leg (the
doc said I turned the bones to crumbs. The ladder slipped
and I slammed my tibia into my calcaneus) the surgeon put in
four screws and did open reduction! After 12-weeks they removed
the open reduction and I promptly broke one of the screws! My
sister sez That's what happens when you buy your screws in Costco.

And having been assaulted (mugged 2 1/2 times) I am in tune
with the suffering of others.

Was reading between commercials last nigh Elsayed and Atkins
Explosion and Blast-Related Injuries from where I picked up
Human shrapnel.

Back in the days before La Net there were CompuServe and the
Source perhaps a third.

http://en.wikipedia.org/wiki/CompuServe**

http://en.wikipedia.org/wiki/The_Source_%28online_service%29

"The Source charged a start-up fee of about US$100 and hourly
usage rates on the order of $10 per hour. In 1984, the registration
fee was $49.95, and The Source charged $20.75 per hour between
7:00 a.m. and 6:00 p.m. Monday through Friday, and $7.75 per
hour on nights, weekends and holidays for 300 baud service. For
1200 baud service, there was an additional $5.00 per hour
surcharge during weekday hours, and a $3.00 per hour surcharge
at all other times. To place these costs for data services into an
historical context, The Source's base nighttime and weekend rate
of $7.75 per hour in 1984 was approximately twice the federal
minimum hourly wage in this same time period, placing the ability
to access data with a personal computer in the hands of
businesses and wealthy households only." Wiki-P.

Which/whatever one I used ... I could access the UPI and AP
Newswire (At work I received all their Telephoto pictures. 1930's
technology.) Every Saturday I search for Fireworks-Explosions-
Explosives-&c. I printed them all out - Good Move! For if I had
saved the files I wouldn't have them now - what with all the
changes in PC's over the years. I sold a copy of my weekly
gathering to American Fireworks News to cover some of my costs.
Thus the M80/eye story.

The Balls/Bone book ... eyeballed mention of it somewhere and
bought a copy.

To start off the New Year ordered one book yesterday —

Glorious Fourth of July, The: Old-Fashioned Treats
Diane C. Arkins

And one today —

The Threshold of Science: A Variety of Simple and Amusing
Experiments Illustrating Some of the Chief Physical and Chemical
Properties of Surrounding Objects, ... and the Effects upon Them
of Light and Heat"
Charles Romley Alder Wright

You can read it at Google.com/books. However, other then using
your screen saver you cannot print/save it.

Lastly I have a PhD in serendipity and The Polymorphic Perverse
(as the term was used by Woody Allen.)

** PDP computers when I worked in la MOC (Minicomputer
Operations Center) we had PDP whatever/VAX 1170's and
a SL of smaller computers all running Unix.

Lots and lots of X2.5 ports. You needed a datascope to really appreciate X2.5

-----
Speaking of PhD's - In Woody Allen's 1975 movie Sleeper
what subject was Luna Schlosser (Diane Keaton) PhD in?

Hint - Think tennis balls & garden hoses, car bumpers.

crazedguy - 1-1-2011 at 19:42

According to mythbusters around 100 psi is where death is certain although 30 psi for a certain amount of time can kill 100 psi is the guaranteed, so just to the math to see how far away a blast has 100 psi.

Engager - 2-1-2011 at 18:00

There is common set of equations witch can be used for calculation of blast wave from explosive charges, it's called Sadovsky formulas. It works regardless on nature of explosion and depends only on TNT equivalent of explosive charge. All this calculations are based on energy similarity law for explosions witch stated that all blast wave parameters are function of two variables: first is explosion energy and second is distance from explosion origin.

Important thing is that if you rise energy of explosion (and correspondingly explosive mass) you will get the same drawing of property-range dependence but it will just be scaled, so you only need only one experimental dependence for some standard explosive charge then you can simply scale it to suit your particular case.

1. Sadovsky formula for blast wave from TNT explosion on open air at standard atmospheric pressure 1 atm and standart air temperature:

In this formula mass (m) is in kilograms (kg), and distance from origin is (r) in meters (m), overpressure is in atm.

2. Sadovsky formula for blast wave from TNT explosion on earth surface at standard atmospheric conditions:

In this formula mass (m) is in kilograms (kg), and distance from origin is (r) in meters (m), overpressure is in atm.

3. Same formulas can be applied to any explosive using TNT equivalent Kt = Qexplosive/Qtnt, where Q are energies of explosion for example in MJ/kg (Qtnt = 4.19 MJ/kg). Formula for air blast becomes:

In this formula mass (m) is in kilograms (kg), and distance from origin is (r) in meters (m), overpressure is in atm.

4. Sadovsky formula for positive shock phase duration for TNT blast wave:

In this formula mass (m) is in kilograms (kg), and distance from origin is (r) in meters (m), resulted time is in seconds (sec).

5. Theory of blast waves shows that all other blast wave parameters are can be expressed as functions of overpressure. Formulas below are for blast wave in air at standard ambient conditions:

Velocity of shock front (in m/sec, overpressure dP is in atm):

Velocity of gas behind shock front (in m/sec, overpressure dP is in atm):

Temperature of gas in shock wave front (in K, overpressure dP is in atm):

Sonic velocity in shock wave front (m/sec, overpressure dP is in atm):

As one can see this set of equations allow you to determine all blast wave parameters for explosion of any explosive at any range from origin. However one should remember that sadovsky formulas are quite precise then overpressure is below 10 atm, for very proximity of origin this formula is not so precise but still can be used for aproximate calculations.

Once you have calculated overpressure and positive phase duration for your particular case you can convert it to psi and msec respectively and get a point on lethality diagram from posts above:

You can also use the following general observations on action of blastwave on overage human (1 kg/cm2 ~ 1 atm):

1. dP is > 26 kg/cm2. Instant death, full body disintegration.
2. dP is > 8 kg/cm2. Instant death, body throw back, disintegration of body parts.
3. dP is > 5 kg/cm2. Fatal damage, 99% chance of lethal outcome. Disintegration of body parts, massive damage to soft and bone tissue.
4. dP > 3.8 kg/cm2. Heavy damage, 75% chance of lethal outcome. In lucky case hospitalization for at least 2-3 months.
5. dP > 2.5 kg/cm2. Moderate damage, 10% risk of fatality or hospitalization for 1-2 months.
6. dP > 2.1 kg/cm2. Light injuries, hospitalization for 7-15 days.
7. dP > 1.6 kg/cm2. Disruption of neural system up to loss of consciousness.
8. dP > 1.1 kg/cm2. Rupture of tympanic membranes for average human.
9. dP > 0.5 kg/cm2. Minimal safe distance for artilleryman.
10. dP > 0.35 kg/cm2. Minimal distance of possible rupture of tympanic membranes.

Action on buildings. Note: Damages below are listed in assumption that all building lies within corresponding hazard radius, if parts of the building are in different hazard zones damage in different places of building will vary.

1. dP > 2.5 kg/cm2. Destruction of concrete steel constructions, bridges e.t.c.
2. dP > 1.75 kg/cm2. Destruction or heavy dammage to earthquakeproof steel reinforced concrete constructions.
3. dP > 1.0 kg/cm2. Full destruction of all buildings, except earthquakeproof steel reinforced concrete constructions.
4. dP > 0.65 kg/cm2. Collapse of steel framework buildings and light steel reinforced concrete constructions.
5. dP > 0.25 kg/cm2. Significant damage to big city buildings.
6. dP > 0.15 kg/cm2. Partial collapse of buildings.
7. dP > 0.05 kg/cm2. Light dammage to buildings, break of glass in windows.

[Edited on 3-1-2011 by Engager]

Engager - 3-1-2011 at 17:41

Formulas i've posted above are pretty easy to implement, however to make understanding their use easier i post practical example of their use. Let's calculate shock wave parameters for 1 kg PETN charge placed on the ground. Heat of explosion for PETN is 5.756 MJ/kg so Kt = Qexp/Qtnt = 5.756 / 4.19 = 1.373. Now we can use formula (2) from post above substituting M with Kt*M = 1.373 * 1 = 1.373, we can in same way use formula (4). For each distance from explosion origin we can use this formula to get overpressure (dP) and duration of positive (compression) phase in shockwave (T+), and then use dP to calculate other parameters at this range: speed of shock wave front (Vf), speed of gas behind shock wave front (Vg) and temperature in shock wave front (Tf). Results of calculations for case with 1 kg PETN are shown below (for convenience of use for damage estimation overpressure graphs are plotted in both psi and kg/cm2 units):

Now let's look how much safe can be a man who stands in 1.5 meters from explosion origin, and how safe can be another man standing 4 meters away from origin. Graphs above for 1.5 meter distance show overpressure ~8.137 atm (kg/cm2) witch is equal to ~118 psi with ~1.67 msec positive shock phase, at distance of 4 meters we get overpressure ~0.844 atm (kg/cm2) witch is equal to ~12 psi with ~2.741 msec positive shock phase duration.

Comparing results with tabled values in post above we can conclude that first person must suffer instant death with throw back of body with possible body part disintegration, while second one is relatively safe but can suffer rupture of tympanic membranes.

Note: Don't forget that this calculations assume that explosive charge was without shell and there are no shell fragments around. Fragments of charge shell are far more deadly and in case if shell was metallic will surely kill at such close distance. Calculations above take to account only pure damage done by shockwave itself.

[Edited on 4-1-2011 by Engager]

franklyn - 5-1-2011 at 02:01

Engager's two posts immediately above here
in pdf Attachment: Blast Effect Calculation.pdf (155kB)
This file has been downloaded 7795 times

.

Lord Emrone - 5-1-2011 at 15:10

Quote: Originally posted by holmes1880

2. 50ml of MEKP will not dismember wrist at 10cm nor take away vision or hearing (I'm not sure about this report because it could have been a deflagration vs. full order)

I suppose you mean my accident ?
I was a full order detonation. But the glass jar (perfume bottle, thick glass) , in which the MEKP/AP was stored also functioned as a shield for my right hand, which was nearest. My pointing finger was almost undamaged, because I held it on the glass.
I can't tell what would have happened if the explosive wasn't in a glass jar. I will not test it :-)

in attachment a pic of my hand, 2 weeks after. You can see, my other hand was damaged too.

[Edited on 5-1-2011 by Lord Emrone]

Assessing Protective Clothing for the Explosive Industry

The WiZard is In - 11-1-2011 at 13:35

http://www.bay-publishing.com/article.php?article_id=69

holmes1880 - 12-1-2011 at 09:24

@Lord Emrone

Yeah, reference was exactly to your accident. That's insane that this is a pic of 2 weeks later, but it was a very large amount....50ml. Here's a question, the MEKP just detonated for any unknown reason?

Lord Emrone - 15-1-2011 at 05:41

Static. I decanted some of it in a piece of rubber tube to test for use in caps. By cutting the tube it caught a lot of static which apparently wasn't released when I touched the piece before I decanted the MEKP/AP in.

quicksilver - 15-1-2011 at 07:11

Thank you for posting that picture: most people do not own up to a mistake / injury. -- In fact you simply don't hear from them (posting) again.
It would also be extremely inappropriate for anyone to add insult to injury in this case because I can promise you that MOST of the injuries don't get posted back on Forums such as this and they occur in alarming frequency.

Folks, I can damn well ASSURE you that injuries of this and much worse happen in an alarming percentage and that the individual had this understanding to mention static is well founded. Peroxides (& several other materials) are especially sensitive to static initiation. The misnomer is to characterize items as "unstable" (this is the concept of chemical decomposition which is altogether different than "sensitive"). Joule-level initiation unfortunately doesn't give the whole picture.

I am also NOT lecturing. These injuries happen MUCH MORE than most people are aware of!
Whether it be on safety or proximity issues; my short dialog here is to underline the fact that there should ALWAYS certain facts kept in mind. There are procedures established to prevent things like this from happening and the fucking moment that anyone deviates from those established procedures a tragedy may occur to anyone regardless of the length of time they have handled energetic materials.
If anyone does handle active energetics, they should have the honestly to ask themselves if they REALLY know (as well as understand) those procedures and if they put them into play at every opportunity they may contact the materials.

If that is not the case; have the sense enough to find out & don't handle them (especially without having IN PLACE methods for eliminating static)!
The above gentleman was lucky he didn't loose his hand or sight. Don't EVER fool yourself that "it can't happen to you" because that is the moment that you loose vigilance over the whole of safety procedures.

holmes1880 - 15-1-2011 at 16:26

@quicksilver

You constantly hear about static sensitivity of Flash Powder, but never about Peroxides' sensitivity to that same static.

That's true, people who have an accidents tend to not come back to the forums because they become too fearful of the subject or because they are dead.

quicksilver - 16-1-2011 at 14:19

Yes sir! They simply don't come back. I happen to have had several direct conversations with fellows who were honest and open about it and I respect anyone who LEARNS from a mistake.
Quite frankly I have heard some "horror stories" that are quite sad. I once spoke w/ a guy who lost and eye and thumb via NG another guy who lost sight in one eye from flash (wasn't even a candidate for a cornea implant as the tissue was SO damaged) and another guy who lost most all of his right hand (& on TOP of that got in trouble w/ the law......) - {peroxides on that one} - & on & on. I NEVER reproached them & they knew I wouldn't. Realistically I wanted to clearly understand the tragedy. Static was #1, friction / impact #2. After a few years of hearing this stuff I began to see the patterns and issues much more clearly.

The use of "spray-on" antistatic materials is somewhat false insurance as the static can start picking back up from walking. Weather conditions are VERY significant. A dry climatic condition (indoors it can happen from an air conditioner OR heating) is big trouble. The TYPE of shoes worn and the flooring are obvious. There are very insidious ones also.

Energetics should NEVER be stored in glass or even high strength plastic. The "snap top" film container has resulted in some vicious shots from the snapping of the top & that plastic will slice very deeply: enough to sever tendons. ALL materials should be clearly kept from "contact surfaces" (rims or tops). Teflon plumbing tape should be wrapped on threaded containers of the lightest construction and materials kept at or below gram level, etc. But I have NO intention of seeming to lecture or advise: it's obviously not my place to do so.

Peroxides are perhaps one of the top injury materials. Only opinion - but it is a variety of situations that makes this so. One of them is actually familiarity & the (false) predilection of predictability. Peroxides easily degenerate! They must be kept at certain temperature levels and exposure to various gases makes this degeneration much faster. They also alter as they degenerate. There is a great deal of study done on the Trimer (of TATP) and it's stability. HMTP is certainly more stable but again this is only in a realistically temp & air controlled environment. One of the larger issues with flash is that it's easy for the Al to "air float" and it's conductivity is extremely high.

The WiZard is In - 16-1-2011 at 19:39

Quote: Originally posted by quicksilver

Thank you for posting that picture: most people do not own up to a mistake / injury. -- In fact you simply don't hear from them (posting) again.
It would also be extremely inappropriate for anyone to add insult to injury in this case because I can promise you that MOST of the injuries don't get posted back on Forums such as this and they occur in alarming frequency.

]snip]

Sodium Chlorate

Why The WiZ gets pains in his round-and-fuzzies when someone
mentions-- SODIUM CHLORATE

A message on the West Coast Pyro Board and a recent article in "Special F/X
Newsletter" have made mention of the use of Sodium Chlorate. There are
one hundred and two really good reasons why this oxidizer has not found
use.

Reasons number; one, two, three - # 100 - IT IS NOT SAFE MIXED WITH
- ANY THING. PERIOD.

Added: Sodium chlorate is commonly used in "oxygen candles" and Solidex
(sp?) rods for welding. However, I doubt that anyone would undertake home
brew of these devices.

WANA DIE YOUNG? USE SODIUM CHLORATE!!!

Case in point -- On the 27th of March 1952, four people were killed and
several injured in the chemistry building of Howard University, Washington,
D.C. when 400 pounds of sodium chlorate (possibly contaminated with
cardboard) being removed from a basement storage room exploded.
(Presumable from a electric spark generated when a worker grasped the
metal handles of the loaded hand truck.)

A 1979 edition of the German medical journal "Plastische Chirugie" (Plastic
surgery) contain an article entitled: Mikrochirurgisch-plasticsche Versorgung
der explosionsverletzten Hand. (Mico-plastic surgery for severe explosion
injury to the hand.) "During the last two years, 16 severe explosion injuries of
the hand have been treated with plastic microsurgery in our hospital. The
injury had arisen in seven cases FROM THE MIXTURE SUGAR + SODIUM
CHLORATE. This substance mixture may already be caused to explode by
slight vibrations and the warmth of the hands."

Photos accompanying the article show either; a victims hand, or a squirrel
that met a eighteen wheel'r while crossing the interstate! No doubt an
amazing bit of surgery. Well; I guess .... two and a half fingers, and a toe are
better then no hand! Must of hurt a bit though.

What we have here is a classic case of a low melting point fuel and a low
melting point oxidizer. A combination likely to be more then a little
sensitive/unstable.

By-the-by, one of the other cases was the resulted of the mixing Potassium
chlorate and red phosphorus. (For further info on this combination, see my
two articles in the American Fireworks News.)

Reason one-hundred-one is -- it is hygroscopic. (Which may explain its
sensitivity. For it is believed that the cycle of; absorption of moisture followed
by drying creates large unstable crystals, a' la lead azide.)

Reason one-hundred-two is -- It contains (obviously) Sodium, which will
create a strong yellow light obliterating other colors.

While POTASSIUM chlorate has be used to good effect as an igniter &c.
when mixed with table sugar, and in combination with lactose for smoke
mixtures, it is NEVER to be combined with finely powdered sugar such as
confectionery sugar. For, combustion mybe a lot faster than you planned on.
To your great regret.

THE WiZ 16 XI 89

In the FDR the BKA (Bunderskriminalamt) reports (Werner Wildner. New
Measurements Studies on the Effects of The IEDS. In- Proceeding of the
International Symposium of the Analysis and Detections of Explosives, FBI
Academy Quantico, Virginia March 29-31, 1983.) "..... a very common home-
made explosive in the German crime scene. It consists of a herbicide
containing sodium chlorate with 25% sodium chloride, and of sugar.

Blasty - 16-1-2011 at 22:15

Quote: Originally posted by The WiZard is In

I find the reports on the dangers of chlorate-sugar mixtures to be a bit exaggerated. I have tinkered with them myself for several years, and not even with the finest confectioners' sugar can they burn faster than a good black powder (at least not in relatively small quantities), let alone detonate when unconfined without using a strong blow or a blasting cap. Not even Berge's blasting powder, which is the fastest chlorate-sugar mixture I have ever seen (thanks to the presence of a chromate), truly detonates unless it's either given a sharp blow or a blasting cap or flash powder charge is used to set it off. I have kept small samples of granulated Berge's blasting powder in closed plastic containers for more than a year, and there was no sign of appreciable deterioration or increase in sensitivity.

Chlorate-sugar mixtures which are moistened with alcohol and/or other flammable liquids are even less prone to be set off accidentally and have been used as explosives and propellants in the past:

http://www.google.com/patents?id=DYJBAAAAEBAJ&printsec=a...

http://www.google.com/patents?id=yJpvAAAAEBAJ&printsec=a...

[Edited on 17-1-2011 by Blasty]

The WiZard is In - 17-1-2011 at 06:40

Quote: Originally posted by Blasty

In the greatness of the statistical universe — individual experience
is of no use.

Reminds me of the person in a NY City Housing apartment
building who put his head through he the window in the
elevator door to see where the elevator was..... who knows how
many times he had done it before.....!

djh
----
Hudson Maxim Dynamite Stories 1916
SCATTERED

I WAS once called as an expert to visit a dynamite plant where a new kind of
high explosive was being manufactured instead of the ordinary nitroglycerin
dynamite. It consisted of a mixture of chlorate of potash [potassium chlorate],
sulphur, charcoal and paraffin wax. Its inventor had given it the reassuring name
of Double X Safety Dynamite.

A quarryman in a nearby town had, with his safety-ignoring habitude, attempted
to load a hole with the stuff, using a crowbar as a rammer, with the result that he
set off the charge, and the crowbar went though his head.**

This unscheduled eventuation aroused the apprehension of the president of the
company, who was also its backer. He began to grow suspicious about the safety
of the material. Being so much interested, he went with me on my first visit of
inspection.

We left the train at a siding about a mile from the works, and had just started in
their direction when there came a sudden boom and roar, and the earth shook.
Over the powder works there rose a huge column of black smoke, flaring wide
into the sky.

We found a great crater where the mixing house had stood. Three men were
working in the building when the explosion occurred. A fortunate survivor who
had left the place a moment before to go for a bucket of drinking water, was
walking about the crater, apparently searching for something among the
scattered remnants. As we approached him, he sadly said:

"I can't find much of the boys. I guess you'll have to plow the ground if you want to bury them."

djh
------
** Reminds me of Phineas Gage

http://en.wikipedia.org/wiki/Phineas_Gage.

Blasty - 17-1-2011 at 07:40

Quote: Originally posted by The WiZard is In

In the greatness of the statistical universe — individual experience
is of no use.

It consisted of a mixture of chlorate of potash [potassium chlorate],
sulphur, charcoal and paraffin wax. Its inventor had given it the reassuring name of Double X Safety Dynamite.

A quarryman in a nearby town had, with his safety-ignoring habitude, attempted to load a hole with the stuff, using a crowbar as a rammer,with the result that he set off the charge, and the crowbar went though his head.**

Unfortunately, that "statistical universe" is quite packed with knuckleheads who do things such as above described in your post, thus contributing to give a worse reputation to something which when more properly handled does not deserve it.

The WiZard is In - 17-1-2011 at 08:30

Quote: Originally posted by Blasty

I find the reports on the dangers of chlorate-sugar mixtures to be a bit exaggerated.

I apply the same philosophy (actual I have raised it to
an epistemology) to these reports that I apply to movie/books
reviews. If they get a good review ... they maybe good...
if they get a bad review... they probable are stinkers.

The WiZard is In - 17-1-2011 at 08:46

Quote: Originally posted by quicksilver

Granted a rather liberal use of the noun Firework.

Hand-Injures-fromFireworks-1.jpg - 407kB

Hand-Injures-fromFireworks-2.jpg - 338kB

quicksilver - 17-1-2011 at 10:20

Many people avoid looking at the injuries, however they are a damn potent reminder of just what the consequences are.
I remember SEEING "Hand Injuries" & I just can't place it. It may even have been posted on someone's page. I don't think that was AFN.....(?) Was it?

Now there are about half a dozen of us who are in the 40's & 50's, (& even 60's!) and have been around the block on this issue & there is actually one MORE thing that could be said without any type of finger pointing, etc......Back when many of us used to discuss this issue on REC.PYROTECHNICS & ALT.ENGINEERING. EXPLOSIVES (UseNet) folks used to discuss this more openly because of the increased sense of anonymity. And I certainly understand that.

DO NOT EVER attempt to work in chemistry or pyrotechnics if you are least bit "off".
Lack of sleep, fatigue, liquor, being high, or even not paying deep and square attention to what you're doing (radio or TV, phone, etc). - THAT is perhaps one of the most potent disasters waiting to happen.
Because all the issues [that you may be aware of] may be by-passed by the lack of strict attention!
And for goodness sake - PLEASE keep an open mind to those who may post safety issues. They are NOT doing so for any reason but to help minimize tragedy. There is always room for an open mind. Plenty of materials are seemingly direct.....like black powder can be a source of vicious injury. But tragedies strike even with those IF the fellow doesn't keep a clear head and strict attention. If you feel the LEAST bit "off" that day - let it go! - "Know thy self."

I personally have a long list of things that I would do if I still were very active in this subject aside from study and reading. One of which is keeping the amounts DOWN! If you have curiosity about a material, synthesis of a milligram level can accomplish the same thing as a weighty amount and it will tend to minimize any tragedy.

Common sense? Of course. Even toxins such as heavy metal salts can do less harm in accordance to amount. I'm speaking here to chemistry as a whole not just energetic formats.
I only wish that those old posts were still around because there was a great deal to be learned from them. but that should never minimize materials that are new (or new to you).

I told myself i would not continue to add to this as it may appear to be lecturing & I'm no one who has been so perfect as to do so. Even Spooneburger (of ballmill-book fame, etc) made a serious error......I honestly don't mean to do that; however it's such an important subject that I almost feel compelled to stand in the "Amen" column. As years add up I can promise anyone that these discussions will bear their own witness to a vital issue with chemistry. Please, people, keep an open mind.

I am NOT directing my comments at any individual: I give you my word on that. I deeply want to prevent anyone from the physical and mental anguish of a mistake and tragedy because in hindsight (unfortunately) nearly every one could have been prevented.

[Edited on 17-1-2011 by quicksilver]

Blasty - 20-1-2011 at 00:13

Quote: Originally posted by Blasty

To give an idea of what I am talking about, for those who haven't actually tried any of these things themselves. Plain chlorate-sugar mixtures react pretty much like this when ignited:

http://www.youtube.com/watch?v=Szpb65u3BPI

They can't burn faster than a good, well-mixed black powder. Unless given a strong blow, there just is no way that they will explode unconfined (let alone by something as puny as "the warmth of the hands", as that report claims!)

Chlorate-sugar mixtures that use chemicals that accelerate the reaction, like a chromate, burn way faster even when unconfined:

http://www.shrani.si/?3L/RO/1vKCzI7K/berges-blasting-powder-...

But they will not explode unconfined just by igniting them (on purpose or accidentally.) In very large quantities they could, since even black powder can do so if a large enough quantity of it is ignited, but not in the normal quantities handled by a person.

If ignited by a fuse while confined, these mixtures explode in a black powder-like manner (i.e. a violent bursting of the container), not like a high explosive. In order to get a detonation, you need to set them off with a strong blow.

About 15 grams of Berge's blasting powder set off by a mercury fulminate cap:

http://www.shrani.si/?12/8Q/2aTECRia/berges-blasting-powder-...

franklyn - 28-3-2011 at 22:47

Charts for determining safe separation distance and exclusion area for quantities of explosive
applying the fornmula top of page 75 ( D = K ³√W ) Distance = Factor(K) times cube root of weight of explosive.
http://www.sciencemadness.org/talk/files.php?pid=205394&...
login to access references

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PHILOU Zrealone - 29-3-2011 at 07:04

:mad:

Beware to what is written down here...
There is Chlorate of sodium and what is another story chlorate of potassium!

In the past I have made a lot with NaOClO2 it was widely found as 60% concentration mixed with 40% NaCl...with that concentration it was relatively comparable to black powder...because the NaCl was tempering the burning reaction rate...
Also it depends what type of sugar you use cristaline or utrafine grinded...and the intimity of the mix (coarse or grinded ingredients)!
I did large batches of coarse 5kg sugar with 5kg NaOClO2 60% and it burns in less than a minute with a height of about 3 meters flamme and about 70 cm diameter...

When I did use 99% NaOClO2 or 100% KOClO2 it was really another story. It is much more dangerous and faster.

I did a lot of experiments with Sulfur, carbon black of fume and CaCO3...
-with the NaOClO2 60% and coarse you get slow burning rate (except if confined). It is a bit like blackpowder but more energetic.
-with the same ingredients reduced to a fine dust you get much faster burning rate.
-with corase 99% NaOClO2 or 100% KOClO2; burning rate was about as fast as dusty mix hereabove.

Confinement always resulted in deflagration

But with fine ingredients and fine 99% NaOClO2 or 100% KOClO2 burning rate was so fast that no confinement was needed to cause a detonation...
A 3 cm high hard copper pipe 3 cm diameter and 2 mm thickness was fully disintegrated while the tube had 2 openings and was simply placed on the ground and filled with one coffee spoon of the mix...thus about 10g

I was surprised by the speed of the straw fuse I was using with that mix...usually with 60% NaOClO2 fine powder it was like 15-20 seconds for a plastic straw of 30 cm (and 2.5 mm diameter) filled with the mix...with that dangerous mix fuse burned in less than 1/2 second...I think it was even faster because the plastic of the straw had not realised yet it had to melt owing to the flame that had burned into it...

Thus beware when someone claims generalities that there is no risk with chlorate and suggar mixes...it is absolutely untrue.

Blasty - 14-4-2011 at 13:06

Tenney L. Davis on the relative safety of chlorate-sugar mixtures (from Sugars in Fireworks and Explosives):

Quote:

The chlorine dioxide which sulfuric acid liberates from potassium chlorate attacks many combustible substances and sets them on fire. The mixing of powdered chlorate with red phosphorus is an extremely dangerous operation and can be accomplished without an explosion only when the materials are thoroughly wet with water. Mixtures of sulfur and chlorate explode from percussion or when ground in a mortar. Sugar has the advantage that its mixture with chlorate can be made up and handled fairly safely, and the mixture burns without offensive fumes. The ignition of such a mixture by a drop of concentrated sulfuric acid is an interesting lecture experiment. A quantity of sugar-chlorate mixture wrapped up, with a glass bulb containing concentrated sulfuric acid in the middle of it, makes an incendiary device which will take fire when crushed by the heel or by the wheel of a vehicle. Time bombs employing this principle, the bulb being broken by the hammer of an alarm clock’s bell, were reportedly used by enemy agents during World War I.

Notice that not even the crushing action of a wheel from a moving vehicle is reliable enough to ignite them, thus why the sulfuric acid vial was included in such incendiary devices.

[Edited on 14-4-2011 by Blasty]

quicksilver - 15-4-2011 at 07:15

Field testing of materials or disposal has had certain techniques that bear importance to this overall discussion. Whenever any energetic material is disposed, a (somewhat narrow) hole should be dug within the earth of several feet. This allows the focusing of the blast upwards and not "outward" as a widening cone-shape. Many people have been injured by energetic material placed on ground level and debris (rock, pebbles, etc) are forced outward in a flatter "cone" within a blast radius. By digging a hole & planting the material to be disposed of within, the force is channeled upward and dissipated to an extent as those objects that could be propelled are marginalized into the sides of the hole in the earth.

pjig - 15-4-2011 at 07:55

From a blasting or demolition perspective, one may also consider covering the narrow hole that Quicksilver discribed, with a large pile of dirt to contain any debris that may result from the explosion. Blast mats are too expensive and heavy for small projects, earth is much better in confining debris and sound ( as long as enough is put over the hole).

Jimbo Jones - 12-5-2011 at 06:08

http://www.youtube.com/watch?v=1wAtCmC6F2M&feature=chann...

Energetic materials testing ground......

pjig - 12-5-2011 at 20:31

LOL.... Thats just wrong.... :cool:

franklyn - 19-12-2011 at 18:52

The Effects of Blast Phenomena on Man

http://www.dtic.mil/dtic/tr/fulltext/u2/074028.pdf

franklyn - 29-7-2012 at 22:13

U P D A T E D _ Link trom this post
http://www.sciencemadness.org/talk/viewthread.php?tid=15150&...

Effects of blast pressure on structures and the human body
www.cdc.gov/niosh/docket/archive/pdfs/NIOSH-125/125-ExplosionsandRefugeChambers.pdf

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quicksilver - 30-7-2012 at 10:25

The old MKII "Pineapple" iron hand-grenade (mfg in the USA) was replaced with the 30-series of internal coil for several reasons. One of which was the retention of energy on the container particles. In the iron grenade, the particles were larger & maintained energy for approximately 250yd, the coil spring (30-series) grenade broke down to very small particles with poor retention of energy (bit's of spring, thin aluminum body, etc). This provided a safety feature (somewhat...) in the the tiny light bits would not maintain driving energy, etc. Their distance for lethality diminishes.
[Authors; Person and] several others authors had mentioned the vital important of safety shielding, light weight, and extremely light containerization. Once a weight level is reached in a high explosive the blast alone becomes a serious danger, yet if the material is kept low in weight and the container has minimal energy retention characteristics, the level of danger is somewhat less than ignoring those factors.

detonator - 31-8-2012 at 23:21

A blasting safety distance calculation methods.
From China.

[Edited on 1-9-2012 by detonator]

Attachment: Blasting safety distance calculation..doc (87kB)
This file has been downloaded 2510 times

[Edited on 1-9-2012 by detonator]

[Edited on 1-9-2012 by detonator]

franklyn - 1-12-2012 at 00:58

http://www.sciencemadness.org/talk/viewthread.php?tid=16612

http://www.sciencemadness.org/talk/viewthread.php?tid=22554

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Sadovsky Formulas

Joelinho - 9-5-2013 at 10:28

Quote: Originally posted by Engager

There is common set of equations witch can be used for calculation of blast wave from explosive charges, it's called Sadovsky formulas. It works regardless on nature of explosion and depends only on TNT equivalent of explosive charge. All this calculations are based on energy similarity law for explosions witch stated that all blast wave parameters are function of two variables: first is explosion energy and second is distance from explosion origin.

Hi,

I was wondering regarding the Sadovsky Formulas. They define blast overpressure as a function of distance from blast origin. I was wondering if they would also be applicable in the following situation.

I use KNO3 and Sucrose in an enclosed container(pipe). The KNO3 decomposes with heat and produces O2. This O2 is then used in the combustion of the sucrose. The rapid spike in gases causes the rupture of the container. The rupture pressure for the pipe I use is about 1800 psi.

Are the formulas applicable to this kind of blast wave or are they only for High Explosives?

Oscilllator - 13-5-2013 at 01:03

The show mythbusters regularly blow up bricks of C-4 (and other explosives) and measure the resultant blast waves using devices that blow out at a certain pressure. If you could be bothered, it would be very easy to obtain lots of data on the distance required before death and/or injury.

Fantasma4500 - 19-5-2013 at 11:09

there was this russian guy on youtube called Fesss88 or something alike.. anyhow he used to make this sugar dynamon (95 - 5 AN Sugar)
one day he had a fuse malfunction..
500g went off when he got just as much as 2-3 metres from the charge
full detonation for sure, in a metal can

he didnt really say much about it tho.. russian mentality i guess.. havent found him on youtube since as his account was deleted

there have been back in time when they found out about yellow powder (KNO3 K2CO3 and Sulfur) some big .. well discovery.. unknown amount tho and unknown distance, relatively weak anyways

also if others havent been mentioning this yet ''life after detonation'' is a sticky thread i believe in energetics
might give aswell some idea off a powerful bang within 'reach' literally

testimento - 5-1-2014 at 07:51

Is there any general algorithm or rule of thumb to calculate the required amount of explosive to produce similar pressure on determined distance? Like 3 bars at 2 meters, how much would stuff be needed at 4 meters or 8 meters?

Fantasma4500 - 19-1-2014 at 07:13

mythbusters had some fancy tubes with a specific thickness aluminium foil covering the ends, this was supposedly showing the lethal radius
they did some stuff with being underwater if anybody cares to search for it
it was something about if you jump underwater while an above water explosion happens, would you be able to survive then?

i have felt 26.5g flash from a commercial firecracker go as close to ringing ears without actually getting ringing ears in urban enviroment, tall buildings all around, about 20m away
40g flash approx 12m away open ground nearly ringing ears
and 11.5g flash about 10m away a hard blow to right ear as i miscalculated fuse burn time, no ringing ears

im sure there must be a limit of bar to collapse lungs etc
and that limit could be found by getting hold of the same devices the mythbusters used -- tubes with specific thickness aluminium foil at the ends
the foil gets blown inwards if pressure reaches specific mass (if you can call it that?)

Ral123 - 19-1-2014 at 08:31

Quote: Originally posted by quicksilver

The old MKII "Pineapple" iron hand-grenade (mfg in the USA) was replaced with the 30-series of internal coil for several reasons. One of which was the retention of energy on the container particles. In the iron grenade, the particles were larger & maintained energy for approximately 250yd, the coil spring (30-series) grenade broke down to very small particles with poor retention of energy (bit's of spring, thin aluminum body, etc). This provided a safety feature (somewhat...) in the the tiny light bits would not maintain driving energy, etc. Their distance for lethality diminishes.
[Authors; Person and] several others authors had mentioned the vital important of safety shielding, light weight, and extremely light containerization. Once a weight level is reached in a high explosive the blast alone becomes a serious danger, yet if the material is kept low in weight and the container has minimal energy retention characteristics, the level of danger is somewhat less than ignoring those factors.

Isn't some of the energy going to escape between the wires, while the iron is expected to balloon uniformly and achieve greater energies?

Fantasma4500 - 30-3-2014 at 09:01

found this video
not sure how much they fill in landmines... its a IED apparently, so nobody can know for sure but it looked somewhat like 500g

https://www.youtube.com/watch?v=GlN1qDoTAp4

puts some pictures to the word ''fragments''

Fantasma4500 - 29-4-2014 at 12:56

''Fuller account:

I was about the age of many of our newer members... Old enough to drive & buy alcohol, not old enough to know I was mortal. This was BEFORE I got involved with display pyrotechnics & special effects professionally.

Alcohol WAS involved. I learned my lesson, you may have a beer or handle energetic materials/weapons, not both.

My face wasn't really bruised, but my abdomen and chest were- The parts closest to the explosion and directly facing the source. I had a full beard at the time and needed to trim it off as the bottom part on the left side was kind of half melted. I had short hair, my left cheek and forehead had the beginnings of a 1st degree burn- Pink and felt hot for a day, but didn't lose the skin.

Scenario:

Finished a hot, sweaty project of cutting up a large rusted out water tank too big to move in 1 piece without heavy equipment, using a borrowed cutting torch and rented gas bottles. The work site was a vacation home on an island, with no one else around.

Put away the torch and cracked a beer to celebrate being done. It was such a waste to return the bottles still partly full, or so it seemed after the 2nd beer... So the torch came back out, along with a roll of kitchen garbage bags and some "visco" fuse.

The largest welding head was set to the leanest possible setting, just short of "torch pop", extinguished by tapping against a wooden plank and then inserted into the bag. When the bag was full, top was tied in a knot and a nice long piece of visco was taped against a corner of the bag. Bag positioned against a boulder facing out over the river, I knew enough not to do this with direct line of sight to the windows of the house.

I was still wearing my work outfit of blue jeans, boots, long sleeved heavy cotton welder's shirt, and glasses fortunately.

Bent over to light the fuse, straightened up and started to turn to my right and run- Then I was in the river, treading water within arms reach of the bank. Don't remember getting there. Climbed out. The world is a little odd looking, kind of blurry. Nothing but a high pitched tone in both ears, no wind, waves on the shore or insect noises heard. Then I noted the blood coming out of my nose and things "clicked" back into focus. My glasses were still in the river.

It was about 45 minutes by boat to the nearest town with a hospital and emergency room, so I put on dry clothes and headed there. The staff were quite surprised when I told them I'd blown myself up with welding gas- The ER intake guy said, "Oh, when we get a welder in here, he usually dies".

They did a full chest X-ray set when they saw my chest, but found no broken ribs. Looked in the ears, rinsed out the river water and gave me oral antibiotics & some ear drops, along with a can of some soft waxy stuff to plug my ears with while showering. No more swimming for the rest of that summer.

Both ear drums eventually closed up again, the right in about a month, it took nearly 2 months for left (the side towards explosion). I don't require hearing aids for my commercial drivers license, though my hearing IS permanently degraded, especially high frequency responses. If I set the sound system up, no one else likes the bass/treble balance... '' -Anonymous

to get away with an experience is never a bad thing, in my opinion, however the victim had permanent hearing damages..

i would never expect such power from acetylene mix, to get straight up knocked out.. always be insanely careful when handling fuses near gas mixtures..