@Frank Sanoica brought up an interesting idea that intrigued me on another thread. I pose the question, would dynamite sticks placed carefully end to end on the ground, with a detonator cap in one end stick, detonate all the sticks? Since dynamite sticks have the most power to the length, would the force from the end be enough? We know compressed in a drilled hole or in a tube, that all will detonate, but out in the open ground, would just a few or maybe only the cap stick explode? The few times I used 60% to deepen a trench, the trench was already jackhammered 3" deep and I filled cardboard 6-foot tubes with compressed sticks and one capped stick in each tube. Then the trench was covered in heavy mud and the blast loosen the rocks enough for easier jackhammer work. How many of you knew dynamite doesn't explode in a fire. In fact disposal of old dynamite, generally over a year old, is burned. Very old dynamite that has been leaking and crystalized for years is extremely dangerous and while requiring careful handling is still burned. Putting a burning fuse in a stick of dynamite, will not detonate it. It requires a percussive blasting cap. My personal preference is the electric cap that comes in different timing. I have used the non el's that use a chemical-filled tube each with special timing and all taped together and detonated with one cap, either electric or fuse. These are great in areas of high electrical activity when used with a fused fulminate of mercury cap. Anyone know or care why detonator caps come in different timing?
@Faye Fox Another little-known fact about dynamite is that the shock needed to detonate it is not trivial. A bottle of nitroglycerin in liquid form when dropped to a concrete floor and broken will almost invariably not detonate. Been there, tried it! A pistol bullet will almost never detonate nitro or dynamite. However, a high-speed rifle bullet usually will. Dynamite caps are another thing altogether, containing primary high explosive intended to detonate high explosive. They have a tiny bead-shaped piece of explosive usually not much larger than a B-B, depending on the cap's intended use. When that little jigger explodes, sound much like a .22 rifle shot, it bursts the outer metallic shell propelling it's shrapnel through the air at thousands of feet per second! Frank
WHEW! Faye's discussion on explosives leaves me gasping! This woman knows more about dynamite and its applications than Alfred Nobel did! Hal
@Frank Sanoica Those little det caps are dangerous. One question nippers always had was, how come if you can hammer dynamite and it not explode, why can't one pack the dynamite in the hole hitting it hard. Why does the packing need to be done with a firm slow push? The answer is because the first stick in the hole has a percussion cap in it. Frank understands the chemistry better than I of how the caps are made with different amounts of chemicals that determine the time it takes from ignition source to detonation. In times before electric caps, fuse length determined time. Also, it might interest some that a fuse just burns, never explodes, whereas detonation cord may look like a fuse, but it explodes. No, Hal, my knowledge isn't even in the same world as old Freddie Nobel. Time for bending 6 strings held taut at different frequencies over a wooden box and then back to discuss why caps have different timing.
@faye Where explosives are used to raze large buildings, "timing" of multiple charges has become an art. This ensures that fractures occur where desired, in ordered succession, causing non-violent collapse of underpinning structures, resulting in the building collapsing often straight downwards..... And then, there are the Pyrotechnics, Fireworks, the most beautiful, timed, and colorful explosions of all! Frank
@Frank Sanoica Implosion has always interested me. I was involved with implosion on one construction project, where destruction was necessary to start construction. And yes, the timing is of utmost importance as is the placement of charges. The blast has to blow inward and must start at the bottom with each supportive structure falling inward in secession. (NOTE for future discussion: World trade towers.) Now if you are familiar with driving tunnel or in mining a drift, then you know why timing is important. A center hole is drilled and left unloaded. Then a few holes around this break hole are loaded with a 0-time cap. Then the next set of holes on each side and on top and bottom of this set of holes known as the burn, is loaded with 1's. Depending on the size of the tunnel several more holes are drilled and loaded around this with 2's. 3's. etc. To get the arch shape, holes are drilled and loaded with the next highest number. So you can visualize, the first break, then the second, etc., until you have the arch shape. Should you load all the holes or even just the first several holes with all 0's, then the whole thing would freeze and it would be a dangerous mess as bootlegs (misfires) can result. Back in the day of black powder or early dynamite and fuse, miners or tunnel drivers would cut the different lengths of fuses to get this timing and bind them together to light and hope to hell they all lit. Cautious ones and those desiring a longer lifespan would just do one layer at a time. Blow the burn resulting in a large hole, then drill and blast the hole bigger until they got the desired tunnel size and shape. Now, once all the rock has been blown inward, the final blast will be the footers that are drilled at floor level and loaded with at least a 2-second timing from the last blast. The reason for this is the workers need to hear the last blast to be sure all the rounds were successful plus it lifts the pile of rock from the face and heaves it back in a nice pile. Easier to clean up and also makes the face visible to inspect for misfires. OK, a story. I always loaded my footers with a 6-second delay from the last blast because it allowed for the loose rock to fall and be heaved back with the muck pile. I was on one job and we had a new foreman. The guys purposely didn't tell him I didn't use the 2-second rule. He was standing with us all out of the tunnel and when he hears the arch (called ribs) shot go off, but didn't hear the footers, he got serious and gave me a look like "stupid woman your footers didn't fire" and then BAM and he jumped like he was shot and the guys started laughing. He didn't like it but my work was the best and left the cleanest results, so he didn't argue with me and tried to be in his office at blasting time. He said his heart was too weak to take that delay. I always would time it differently. Sometimes 4 seconds and the longest was 10 seconds and that was even too much for the crew. "Damnit Faye, would you PLEASE stop trying to give up heart attacks." All I would say is a girl needs variety in her life. The guy's favorite story was when we came in and the previous shift left us a mess with bootlegs to cleanout. That was always scary and had me suffering urinary incontinence. What was funny was I went storming out of the tunnel headed to the mine foreman office. The geologist lady had a window where she could see me coming. She told the boss, "Faye is coming and her fuse is cut short and is burning fast." He told the geologist to tell me he wasn't in. She did, but I kicked in his office door anyway and ripped him a new one for not firing those high balling, ballless clowns that had never come close to my shifts daily footage, leaving the tunnel clean and ready for them to drill. I made him come in and look at the mess. The guys backed me up and said if it happened again we were all walking. He didn't fire the idiots, he just put them on another project.
My father would have been interested in your thread Faye. He entered the mines at the age of 16 and spent time above and below ground. Most think being a miner was just physical and back breaking work, but there was a training process to learn how to safely handle explosives. Once completed a miner was certified and actually received the title of miner. Previously he was just a laborer. Fire in the hole!
You wanna talk about implosion? You wanna talk about implosion? Consider imploding an 11-pound sphere of PU 239 (Plutonium) surrounded by 32 charges of TNT, all detonated at the same microsecond. This was done at 5:30 on the morning of July 16, 1945, in the desert of New Mexico, and resulted in an explosion equivalent to 20,000 tons of TNT by nuclear fission of the 11-pound sphere. Hal
C'MON, FRANK SANOICA...you're the only one I know on this Forum who knows what I'm talking about! Hal
A dynamite truck driver was being interviewed by a TV reporters as part of a series on "dangerous jobs". "What made you go into this kind of work?", asked the reporter. The dynamite truck driver's response: "Well, I drove a school bus for twenty years and lost my nerve...…"
Well, what the hell, Mr. Hal, just you and Mr. Frank? Feeling a bit disenfranchised here, sniff, sniff. Well, it was an implosive device that caused a massive explosion opening the nuclear age. The first nuclear bomb test. It happened on the Alamogordo bombing range. Again an implosive device that caused an explosion as opposed to an explosive device that might be used to cause an implosion.
Driving a truck loaded with dynamite is way safer than a school bus filled with kids and that is no joke!!! The driver knows the dynamite is unarmed, but a school bus driver takes a chance that a kid may have a gun or knife.