The stuff turns sort of granular when it's weathered, and I'm not at all sure that it's as safe in that condition. The burning / deflagration / detonation transitions tend to be easiest in heterogenous explosive mixtures. Also in stuff with cracks
Carl,
the primary ingredient in C4 is RDX explosive(approx 90%)...the old yellow C3 had about 80% RDX.
RDX and C4 are well established as non-volatile, very stable explosives.
C4 is considered so stable yet powerful that it is replacing PETN, tetrytol, dynamite and TNT in a wide variety of military applications such as, satchel charges, claymore mines, hand grenades, mortar rounds, blasting caps, and many other prepared charges. I have seen C4 charges shot repeatedly by a rifle from close range...nothing happened. i watched a rucksack with 85 pounds of C4 burn to nothing. it never got past the burning stage.
the guy who was killed due to a static electricity induced explosion of C4 (did he work at livermore? i have avague recollection of an incident in one of the testing labs there.) and the ammonium nitrate explosion on the ship were almost certainly caused by a dust initiator charge set off by the static. the other possibility is sabotage.
in production of C4, the RDX is ground to a fine white powder. this is often done in very large quantities (tons). ammonium nitrate is usually pelletized but not always...even so the pellets are very fragile and turn to dust if crushed at all. after mixing the rdx powder with a claylike substance and the ammonium nitrate with a petroleum product they both become a complete and very stable explosive...in fact a properly made ammonium nitrate charge is considered the most stable...it can be difficult to initiate even with a blasting cap. a 1/2 pound of TNT or C4 is often/usually included in the firing chin for ammonium nitrate.
i would explain the dust initiator charge in detail but i am not comfortable describing formulas for potential homemade devices on the internet. let me just say that anytime you have airborne flammable/explosive dust in a confined area the potential for an explosion exists...the dust particles moving around can cause the static electricity. once a shock wave has been started, all of the explosives in close proximity may detonate with it in a reaction known as sympathetic detonation.
but, no finished military explosives are in a powder form.
i have worked with C4 and all of the other explosives i mentioned. spontaneous detonation was a subject at every demo school i attended...yet i have never heard about a single incidence of spontaneous detonation of any finished US Military explosive since 1962. spontaneous detonation was an occasional problem prior to that due to the use of the very unstable nitroglycerin in some explosive mixes. nobody uses nitro now.
the only exceptions i am aware of have been a very infrequent misfire of an electrical blasting cap attributed to lightening or the introduction of an inadvertant cigarette spark to a non electric blasting cap causing it to detonate...i consider that operator error and not a spontaneous detonation of an explosive charge.
blasting caps are not stored with explosives until shortly before detonation.
electrical blasting caps are stored (even in prepared charges) with both wires twisted together. they are not untwisted until the cap is ready to become part of a series or it is attached to a blasting machine just prior to detonation.
non electric blasting caps are stored in secure little boxes totally covering the open end for a full one inch. before being placed in prepared charges, non electric caps are first crimped tightly onto time fuze which completely blocks the open end of the cap.
shipping and handling of unfinished, unstable explosive components and/or
not following prescribed procedures with blasting caps may have gotten some in trouble...but the explosives themselves remained quite stable.
uw |
