From: rubin@skiing.cis.ohio-state.edu (Daniel Rubin)
Subject: Re: Flywheel batteries as
Followup-To: rec.pyrotechnics
Organization: The Ohio State University Dept. of Computer and Info. Science
Date: Wed, 13 Jan 1993 00:52:19 GMT

In article <639.442.uupcb@ozonehole.com> gerald.belton@ozonehole.com (Gerald Belton)  writes:
>>>You are totally wrong!  Black powder is NOT a primary explosive.  It will
>>>NOT "detonate" if burned in the open.  It will not "detonate" if it is plac
>>>in a conceal container such as a bullet casing and ignited.  All BP does is
>>>deflagrate and produce a large quantity of gasses.  Do you understand the
>>>difference between detonation and deflagration?  The only way to possiblly
>>>get black powder to detonate is with a very powderfull detonation to start
>>>the process.  It is extremly difficult and blasting caps will not do it.  Y
>>>may be thinking of nitrocellulose or "gun powder" it can be made to detonat
>>>but again that is extremely difficult.  A substance is said to detonate if
>>>the rate of probagation of the burning front through the substance is faste
>>>the the speed of sound.  A substance is said to deflagrate when it burn
>>>slower than the speed of sound and does not produce a large shock wave whic
>>>is the result of detonation.
>
>>Consult the Hazmat database, or the DOT classification schedule. Black
>>powder is most definitely classed as an explosive while nitrocellulose
>>propellant powder is classed as a flamable solid. You can ship smokeless
>>gunpowder UPS, but black powder must be transported by special hazardous
>>materials carriers licensed to transport explosives. There is only one
>>black powder plant in the US. It is completely remotely operated because
>>of the extreme explosion hazard offered by black powder. That's the Hogdon
>>Powder Works. In the 19th century, black powder mills were notorious for
>>exploding from static electricity or other trivial ignition sources. There
>>were only two mining explosives, blasting powder (aka black powder) and
>>nitroglycerin in the 19th century. Both were considered extremely dangerous
>>to handle. Nobel made his fortune by inventing a safer explosive, dynamite.
>
>I was awakened one night by an blast that shook the windows of my house.
>A short time later I saw a number of emergency vehicles and walked down
>the road to see what had happened.  It turned out that someone had
>dropped a 1 lb. can of black powder on a concrete garage floor, and it
>exploded.  All the windows were blown out of the garage, and the guy
>that dropped the can was seriously injured.
>

I most certainly can tell you that it was not black powder.  If the poor 
sole who was involved told the authorities that it was black powder he was
not telling the truth and messing with more serious stuff.  Black powder 
will not explode on impact and even so it will not produce such a serious
shock unless in was in a VERY strong container...

Unless maybe he was making a pipe bomb and there was a spark from the threads
when he sealed it off.  That would produce a lot of painfull shrapnel and
pretty loud boom, but even in that case the black powder would not detonate.

later                                                             - Dan

-- 

             Daniel Joseph Rubin     rubin@cis.ohio-state.edu 
     
                       GO BENGALS!      GO BUCKS!
Newsgroups: sci.electronics