Oh, goody, a chance to discuss one of my ‘spare time’ specialist subjects!
Dynamite is properly a tradename originally owned by Nobel’s Explosives and consists of nitroglycerine stabilised by being absorbed in kieselghur (a type of absorbent clay). It made Alfred Nobel a very, very rich man. Nitroglycerine based explosives have a poor shelf life and are difficult to handle safely so nitroglycerine has never been popular as a basis for military explosives. Military plastic explosives (i.e. those used for sabotage or demolition operations) and shaped charges tend to be based on substances like RDX and HMX which have a higher velocity of detonation than NG (so they work better on metals and concrete) and are much more stable. TNT was primarily used as a filler in aircraft dropped bombs, hence its use as a baseline for explosive power comparisons with nuclear weapons. Nitroglycerine explosives are actually fairly difficult to get these days - their use is mainly confined to ‘permitted’ explosives - i.e. those certified for use in explosives atmospheres in (mainly) coal mines. Reasons for its use are largely historical - there aren’t many coal mines which rely on drill and blast these days (most coal is mined mechanically) so it’s not worth the explosives manufacturers doing the tests to formulate and certifiy new explosive mixtures which eliminate the NG. Most modern quarry and (non permitted) mining explosives are ammonium nitrate/fuel oil emulsions which are initiated by primers or detonating cords based on PETN, the primer in turn being initiated by a detonator based on lead azide. These days, ANFO emulsions are often delivered to quarries by tankers which keep the constituents separate (and hence unlikely to explode) until they actually enter the shot hole. I’ve been involved with this stuff for more than 30 years, in which time I’ve played with a very wide variety of different explosives, but I’ve never actually seen a real stick of Dynamite or a pound (let alone a ton) of TNT. Nevertheless, notwithstanding the rather snooty comments on the web page linked by Rich Nute, the point about the comparison between the energy in a pound of dynamite and a similar quantity of gasoline (petrol to us Brits!) is the message about the speed of delivery so comparing the explosive power of Dynamite vs a fuel/air cloud is rather missing the point. The world is rather a different place at 10,000 m/s! Nick. > On 19 Feb 2016, at 22:43, Brian O'Connell <[email protected]> wrote: > > Played with this stuff in the military. TNT is NOT the composition of > industrial or military 'dynamite'. > > Typical dynamite, at least the stuff we played with, is cornstarch binders > +oil +TNT+RDX; and there were some compositions that were buffered with > sodium carbonate. Dynamite, depending on the size of the stick and intended > end-use, will contain well under 20% TNT by both mass and volume. > Mechanical/chemical stabilization and reaction rates are more controlled in > modern 'dynamite. > > For large construction and mining stuff, dynamite yields poor results, so > tends to be limited to use for ignition of an oil+ammonium nitrate bulk-type > explosive. > > Brian > > > -----Original Message----- > From: Richard Nute [mailto:[email protected]] > Sent: Friday, February 19, 2016 1:45 PM > To: [email protected] > Subject: Re: [PSES] Energy in certain items > >> Does anyone know the energy [joules] in a standard stick of >> dynamite, or a gallon of gasoline? > > Not the answer, but may be useful: > > 4,184,000,000 J = 1 ton of TNT > > For a comparison of energy in dynamite and gasoline, and for "The nonsense > about gasoline and dynamite," see: > > http://home.earthlink.net/~jimlux/energies.htm#GasDynamite > > > Rich > > >> -----Original Message----- >> From: Macy [mailto:[email protected]] >> Sent: Friday, February 19, 2016 9:59 AM >> To: [email protected] >> Subject: [PSES] Energy in certain items >> >> Does anyone know the energy [joules] in a standard stick of >> dynamite, or a gallon of gasoline? > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > <[email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used > formats), large files, etc. > > Website: http://www.ieee-pses.org/ > Instructions: http://www.ieee-pses.org/list.html (including how to > unsubscribe) > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
