Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  2  
Author: Subject: Detonation Safety Distance
The WiZard is In
International Hazard
*****




Posts: 1617
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 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.
View user's profile View All Posts By User
DougTheMapper
Hazard to Others
***




Posts: 145
Registered: 20-7-2008
Location: Michigan, USA
Member Is Offline

Mood: Energetic

[*] posted on 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]




Victor Grignard is a methylated spirit.
View user's profile View All Posts By User
holmes1880
dushbag





Posts: 194
Registered: 13-12-2010
Location: http://highexplosivesforum.forumotion.com/
Member Is Offline

Mood: Egregious

[*] posted on 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!
View user's profile Visit user's homepage View All Posts By User
franklyn
International Hazard
*****




Posts: 3016
Registered: 30-5-2006
Location: Da Big Apple
Member Is Offline

Mood: No Mood

[*] posted on 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 ) .
Inverse square law.gif - 17kB
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 -
Overpressue at Distance.gif - 12kB Blast Trauma.gif - 41kB

.

View user's profile View All Posts By User
The WiZard is In
International Hazard
*****




Posts: 1617
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 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

View user's profile View All Posts By User
holmes1880
dushbag





Posts: 194
Registered: 13-12-2010
Location: http://highexplosivesforum.forumotion.com/
Member Is Offline

Mood: Egregious

[*] posted on 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]
View user's profile Visit user's homepage View All Posts By User
The WiZard is In
International Hazard
*****




Posts: 1617
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 29-12-2010 at 07:57
Beware of things in the shadows. Takeo Shimizu


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.
View user's profile View All Posts By User
The WiZard is In
International Hazard
*****




Posts: 1617
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 31-12-2010 at 17:15
Beware of human shrapnel


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





View user's profile View All Posts By User
DougTheMapper
Hazard to Others
***




Posts: 145
Registered: 20-7-2008
Location: Michigan, USA
Member Is Offline

Mood: Energetic

[*] posted on 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.




Victor Grignard is a methylated spirit.
View user's profile View All Posts By User
The WiZard is In
International Hazard
*****




Posts: 1617
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 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.


View user's profile View All Posts By User
crazedguy
Hazard to Others
***




Posts: 143
Registered: 12-11-2010
Member Is Offline

Mood: You can't fix stupid

[*] posted on 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.



Warning: i do stupid things
http://www.youtube.com/user/Craz3dguy
View user's profile View All Posts By User
Engager
National Hazard
****




Posts: 288
Registered: 8-1-2006
Location: Moscow, Russia
Member Is Offline

Mood: No Mood

[*] posted on 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]




View user's profile View All Posts By User
Engager
National Hazard
****




Posts: 288
Registered: 8-1-2006
Location: Moscow, Russia
Member Is Offline

Mood: No Mood

[*] posted on 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]




View user's profile View All Posts By User
franklyn
International Hazard
*****




Posts: 3016
Registered: 30-5-2006
Location: Da Big Apple
Member Is Offline

Mood: No Mood

[*] posted on 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 7072 times

.
View user's profile View All Posts By User
Lord Emrone
Harmless
*




Posts: 30
Registered: 5-2-2010
Member Is Offline

Mood: No Mood

[*] posted on 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]

DSC001391.JPG - 89kB
View user's profile View All Posts By User
The WiZard is In
International Hazard
*****




Posts: 1617
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 11-1-2011 at 13:35
Assessing Protective Clothing for the Explosive Industry


http://www.bay-publishing.com/article.php?article_id=69
View user's profile View All Posts By User
holmes1880
dushbag





Posts: 194
Registered: 13-12-2010
Location: http://highexplosivesforum.forumotion.com/
Member Is Offline

Mood: Egregious

[*] posted on 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?
View user's profile Visit user's homepage View All Posts By User
Lord Emrone
Harmless
*




Posts: 30
Registered: 5-2-2010
Member Is Offline

Mood: No Mood

[*] posted on 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.
View user's profile View All Posts By User
quicksilver
International Hazard
*****




Posts: 1820
Registered: 7-9-2005
Location: Inches from the keyboard....
Member Is Offline

Mood: ~-=SWINGS=-~

[*] posted on 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.




View user's profile View All Posts By User
holmes1880
dushbag





Posts: 194
Registered: 13-12-2010
Location: http://highexplosivesforum.forumotion.com/
Member Is Offline

Mood: Egregious

[*] posted on 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.
View user's profile Visit user's homepage View All Posts By User
quicksilver
International Hazard
*****




Posts: 1820
Registered: 7-9-2005
Location: Inches from the keyboard....
Member Is Offline

Mood: ~-=SWINGS=-~

[*] posted on 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.




View user's profile View All Posts By User
The WiZard is In
International Hazard
*****




Posts: 1617
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 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.


NaClO3-Hand-1.jpg - 342kB

NaClO3-Hand-2.jpg - 390kB

NaClO3-Hand-3.jpg - 387kB NaClO3-Hand-4.jpg - 275kB NaClO3-Hand-5.jpg - 332kB NaClO3-Hand-6.jpg - 148kB NaClO3-Hand-7.jpg - 308kB NaClO3-Hand-8.jpg - 243kB
View user's profile View All Posts By User
Blasty
Hazard to Others
***




Posts: 108
Registered: 25-7-2008
Member Is Offline

Mood: No Mood

[*] posted on 16-1-2011 at 22:15


Quote: Originally posted by The WiZard is In  



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."

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.


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]
View user's profile View All Posts By User
The WiZard is In
International Hazard
*****




Posts: 1617
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 17-1-2011 at 06:40


Quote: Originally posted by Blasty  


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.



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.

View user's profile View All Posts By User
Blasty
Hazard to Others
***




Posts: 108
Registered: 25-7-2008
Member Is Offline

Mood: No Mood

[*] posted on 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.
View user's profile View All Posts By User
 Pages:  1  2  

  Go To Top