[Warning: This document contains adult language]
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[Slide 1]
[Thurman] Okay, we’re starting chapter one. As I mentioned it is an introduction, and it is introduction here to explosives theory and explosion dynamics. What we’re doing here is talking about what happens when we have an explosion. The physics and the chemistry of the explosion. 
[Slide 2]
[Thurman] This is very apt. Explosives, they’re magic until the physics is understood. And the magic part you see all the time and it is getting even more crazy, if you will, in the movies and on television in special effects. Special effects explosives are absolutely phenomenal and it is magic. It’s phenomenal magic. And when you understand what’s going on and you think “Oh, that’s not that big of a deal.” And what do I mean by that? You’ve seen movies where there’s a horrendous explosion and stuff is blown all over the place and you’re wondering maybe if they do this on a set and it is real rather than digital—and I guess there is even less of this going on anymore; they can do a lot of stuff digital. You might wonder how in the world that the performers (the actors) can safely be that close to an explosion of that magnitude. Well, what happens is that they will have a pot, what they call a special effects pot, and it is a steel pot that is square at the top and it is like a speaker. It’s small at the bottom and big at the top. And in the bottom of that they will put a black powder charge wrapped in paper or whatever, but it is contained black powder. On top of that they will put sawdust or some type of material like that and then put diesel fuel on top of the saw dust so that—and the explosive is initiated with a squib, a little spark, and what it does is it initiates the black powder. The black powder is a lifting charge that froze the sawdust that is impregnated with diesel fuel or gas or kerosene or something like that, and that’s the fireball that you see. And the sound is like whoomp! That’s it. There’s no sound essentially. No sound. What they do, they take that, they take a sound of a hellacious explosion and put it on top of it, and you’re thinking “Man, that was a big explosion.” Wrong. And they can be fairly close to it. A car that just disintegrates. Well they go into it and they cut the hinges off the doors. They will put springs and rope like bungee cord holding the doors on with a very small explosive charge on that cord. And all kinds of things within there where everything is precut, and when the explosion takes place (maybe in the car) maybe it is another black powder charge. It looks horrendous. The doors go all over the place, because they are basically spring loaded to do that. So, what am I saying? Hey, it’s magic! Until the physics is understood. What’s going on here?
[Slide 3]
[Thurman] Okay our objectives here, there is a number of terms that you need to get familiar with. In all seriousness, if you know our objectives here, write these objectives down, you will do well on the subsequent exam. These are the points—the main points that I am going to cover. Yes, there are other things that I am going to cover, but these are the main points that I am going to cover. I’m not going to get really, really detailed with some of these explanations. There’s different levels that we can go. I’m not going there for you all. If you want to know more about they, hey it is in the textbook, you’re reading the textbook and it is a lot more detailed than what some of this is going to be. But anyway, some terms here. Explosion, deflagration, high explosives, low explosives, what a detonation is, velocity of explosion, velocity of detonation, and low explosives. Just differences between these and what they are. It’s kind of funny. As soon as I mentioned this is good stuff for test material, pens came up and papers opened up, and people started writing feverishly. [Laughter]
[Slide 4]
[Thurman] Okay the next area we’re going to look at is axle explosion. Four types of explosions. What are the four types of explosions? And we’re be talking some of the characteristics of those explosions. Then out of these explosions, what are the four effects of the explosions? We have the explosions and then what can we logically expect to happen when we have an explosion? An explosion here of what we’re talking about is generic, between the explosion of low explosives such as black powder or explosions (what we call a detonation) of C4 (dynamite) or something like that. Differences between them? Yes, but we still have the same type. Not devastation wise, but same type of effects. 

[Slide 5]
[Thurman] Then we’re going to look at explosive trains. What we’re talking about are fusing systems here. How we get our explosives to burn. In other words, how we get them to deflagrate or detonate. What progress do we go through? And there’s something really interesting in E here. And I do think you’ll be interested in this. These are configurations of explosives and how we can configure explosives to do different types of focused work by using actually less explosives. By using less explosives we can actually do more work, in another sense more damage. More damage by looking at specific configurations. 
[Slide 6]
[Thurman] What we’re looking at here starting out now—we’re going through a number of definitions, and the definitions you need to understand because we will build on these definitions as a foundation. And what we’re going to cover first are explosives, not types of explosives but overall characteristics of some explosives and some definitions. Once we get through explosives and then we’ll go more detailed with these in chapter two, naming more specific types of explosives. Once we get through that, then we will start looking at what explosives do and the types of explosions that we just mentioned.
[Slide 7 contains no audio]
[Slide 8]
[Thurman] Okay, an explosion. What in the world is an explosion? It’s right here. This is an explosion. And I will say that these terms that we’re getting ready to go into here, it’s in two locations of your textbook. One, it is in chapter one and number two, in the glossary in the back of a textbook. You’ve got sixteen or nineteen pages of definitions in the glossary in the back of the textbook. So they’re all in one place so you don’t have to try and remember where it was that you read it or saw it in the text. Okay, the sudden and rapid production and escape of gases from a confined space accompanied by heat, shock, and noise. The confined space if anything basically. It can be a wrapper, it could be a container, it can be most anything. And it is sudden and rapid. And all an explosion is is either instantaneous or rapid burning of an oxidizer and a fuel. Oxidizer produces oxygen. And these are two components. We’ll get a little more into that a little bit later. Two main components of most any explosion. There are some examples of things that don’t have that, but we’re not going there. Fuel and oxide. And the reason we have the oxidizer is because it is so rapid that it cannot pull ambient air in to support combustion, like a fire in the fireplace. Because it is rapid, we have heat produces a shock wave, the shock wave produces noise. I’m getting ahead of myself. Lightening. Lightening is one of the four explosions. It produces heat. Know that lightening is really, really hot. It produces a shock wave in the area where the lightning occurs and it is noisy. It is noisy. 
[Slide 9]
[Thurman] Explosives. Any chemical compound or mixture whose function is to function by explosion. Any chemical compound or mixture whose purpose is to function by explosion. So that is telling us that we have explosives out there that are mixtures and we have explosives out there that are compounds. So what is an easy definition for a mixture? What is a mixture? Remember from your chemistry days? What is a mixture? Nobody took chemistry? Holy mackerel! I’m sorry? No. A mixture is the combination of two materials in which the two materials retain their own identity. It is a mixture. They don’t chemically combine. Explosives. Mixtures. Black powder. It looks like—okay, it is a solid. It looks like it’s probably a compound, but it’s not. It is a mixture of potassium nitrate, charcoal, and sulfur. That’s a mixture. The way it’s made is that those three ingredients or powder are mixed into a bin and then they are dumped into a giant crucible about half the size of this room. A stone crucible. Then on top of that there are two grinding wheels—yes, I used the word grinding wheels—set perpendicular to each other that are stone wheels that roll over this powder. And it is so much weight that it combines the powder into a solid. But they still retain their identity. There is no chemical reaction going on here unless something bad happens and then it explodes, right? But there is no chemical reaction to make black powder. On the other side, what is a compound then? A compound. A combination of two or more materials where a new material is formed and the ingredients lose their own identity. Nitroglycerin is an example. Everybody’s heard about nitroglycerin. You have glycerin that is nitrated by sulfuric and nitric acid. They lose their individual identity and in the end nitroglycerin is formed. Ergo that is the name. Let’s turn it around the other way. You have glycerin that is nitrated. Nitroglycerin. That’s what it is. It’s just nitrated glycerin

[Slide 10]
[Thurman] Low explosives. The term low explosive doesn’t mean that it is not dangerous. Properly confined, it will bite you. It will bite you. Okay, let’s look at this for a minute. You have a solid mixture of chemicals which burn in the absence of air, but when confined can burn to deflagration. What in the sam hill does that mean? What does that mean? Well, look at the second line “…which burn in the absence of air.” That’s what we talked about just a minute ago, right? Fuel and oxidizer. You’ve got a fuel and an oxidizer. The oxidizer supports the fuel combustion. But low explosives—it says “…when confined can burn to deflagration.” Deflagration is rapid burning. So look at this in the opposite aspect. In order to get low explosives to deflagrate or explode, then what is it saying you have to do? It has to be confined. The photograph here on the slide is showing low explosives unconfined and it is burning. It may burn wildly and burn quickly, but it is still burning. It’s not exploding. And I grant you if we cut a hair really, really fine in these definitions, deflagration can refer to low explosives burning as you see here or it can refer to low explosives that are confined and the rapid burning causes an explosion. That’s cutting it fine. But for our purposes, deflagration means an explosion. When confined can burn to deflagration. Everybody understand this concept here? Low explosives have to be confined in order to explode. Example: how many in here have ever shot a shotgun, rifle, or a pistol? There’s where we have low explosives. We have smokeless powder in your cartridge, it’s confined with a projectile on top of it that is seated on top of the powder, the firing pin hits the primer in the back, it produces a little spark to initiate our smokeless powder, and an explosion ensues. Confinement is required. 
[Slide 11]
[Thurman] Deflagration. I think I said that. Rapid burning. This rapid burning—and I’ll mention this as we go through here. This rapid burning deflagration of low explosives sometimes gets people in mega trouble. Where am I going with this one? Well black powder (low explosive) has to be confined, has a nasty habit of prematurely exploding when it is being mistreated. Okay, you’ve got a wannabe bomb builder that didn’t pass bomb building 101. He gets—“Oh I’ve seen this on YouTube. I can do this. This is easy.” He goes out and he buys a length of pipe—small length of pipe that we call a pipe nipple. Make sure it is threaded on each end. He gets an end cap and screws it on. He gets that black powder out of a can. They usually come in 1 pound cans. He pours that down in the pipe. Not really watching what he’s doing he gets granules of black powder on the threads of that pipe. He takes the end cap and starts to screw it on and then you know what? He doesn’t hear the explosion, he doesn’t see the flame, he doesn’t hear anything. He just be dead. He just be dead. What do you do with victims that kill themselves like that making a bomb? Thank you very much. Yup. You get a shovel, you shovel them up, and put them in the trash. That’s what they’re worth. [Laughter] Hey, I’m honest with you, all right? I’m honest with you.
[Slide 12]
[Thurman] Okay, this is an anti-terrorism assistance program from state department video. It is a cool video. It is a pipe bomb that is being—and I don’t know if the sound in here is going to work or not, so we’re gonna try it here. I’ll tell you what’s going on and if you can hear the sound, the perfect. This is a pipe bomb in a test. It has smokeless powder on the inside with an initiator and they are going to film this and you are going to watch the pipe actually expand and start to bulge before there is an outward explosion. The video on this is a million frames per second. A million frames per second. It is moving. So let’s see if the sound is going to work. I hope it does. And I’ll play this twice. This is a pretty cool thing. [Scene displays video inside of PowerPoint slide] [Audio on video too low to decipher] Watch this sucker bulge out. Okay, we’re gonna do that one more time. 
[Slide 13]
[Thurman] Okay, that’s what happens. That’s what happens when low explosives in a pipe bomb. Okay, velocity of explosion is what we refer to as the rate of combustion. Here before it was called velocity of detonation, but in the true sense of physics and chemistry it is not a detonation, it is an explosion. So the rate at which we convert our solid here into our gases is called velocity of explosion. 

[Slide 14]
[Thurman] Now here’s some points of low explosives. Yes? Go back? [Scene briefly returns to slide 13] The rate at which a combustion wave travels through a low explosive. That is velocity of explosion. You okay now? All right, good enough. Then if I go through these too quickly and you want to get more on there, just yell at me and I will slow down. [Scene returns to slide 14] Okay, here’s the point that we need to know about low explosives. It deflagrates. The material is usually a mixture, so that means that there’s some low explosives out there that are compounds. Yeah, that’s true. It’s initiated by heat. It can also be initiates by shock, it can be initiated by friction. In other words, low explosives are very, very easy to initiate. Very easy to initiate. And that is a hazard of low explosives. Confinement is required for our deflagration or explosion. In measurement wise we refer to the velocity of explosion at below 3,000 feet per second. Okay, even at this 3,000 feet per second you still have to have an extremely fast camera to catch it exploding like with a pipe bomb. So that 3,000 you may think “Well, that’s not a whole lot.” Well, it is. Okay, it is subsonic in the product. It is not like where we have in air the speed of sound, which is I think 1,058 feet per second or close to it. It is different in products—different types of products. So here it’s subsonic or less than the speed of sound within the product itself. And our examples: black powder, smokeless powder. There are more, yes, but let’s not worry about the rest of them right now. Black powder and smokeless powder. Everybody good with this?
[Slide 15]
[Thurman] Okay, we’re gonna have a burning here, unconfined, of different types of low explosives. The first one that you see here—and it is already started on our stop action here. This is an improvised low explosion. Yeah, it is really easy to improvise low explosives. The ingredients are easy to get. Don’t you be trying it. They’re easy to get and not a huge issue. The next type of explosive that you will see burn is smokeless powder. Smokeless powder produces smoke. The most accurate term for smokeless powder would be low smoke powder, but calling it low smoke powder I guess is tongue twisting, so they just go smokeless powder. And on the other side in comparison to black powder it doesn’t really produce any smoke. The next one is Pyrodex. Pyrodex is a black powder substitute. And then the last one will be black powder. And you can see the rate of burning of these materials. It’s quite different from each one. [Scene displays video playing in PowerPoint slide] Okay, again. Because if you blink you didn’t see the black powder burning. There’s our smokeless, Pyrodex, and then black powder. It’s hard to separate Pyrodex and black powder. Look at all the smoke here. I’ve often wondered back before smokeless powder was used in pistols and rifles (that Revolutionary War and Civil War) that you got literally thousands of people out there shooting black powder. And as much smoke as it produces, I don’t see how in the world they were able to—the first ball they went, how they were able to see the enemy on the other side of all the smoke. Shoot through the smoke. I don’t know. Just shoot through it, that’s close enough. And if any of you have ever been to particularly the Civil War reenactment where you’ve got a lot of people shooting, man there are huge clouds of smoke. 
[Slide 16]
[Thurman] Okay, high explosives. The technical definition of a high explosive is a substance—and it can be a mixture as well—mixture, or a compound that supports a detonation wave irregardless of condition. In other words, it does not have to be confined. And what we mean here, just on the technical side, a detonation wave is much, much faster than deflagration. And that’s what really internally—in the physics and chemistry of these materials, that’s what really separates them is this detonation wave. That is the key factor. So the bottom line with this, the difference is high explosives support a detonation wave. That’s the key. And they do not have to be confined.
[Slide 17]
[Thurman] We refer to high explosives that they detonate. Detonation is instantaneous combustion as opposed to deflagration which is rapid combustion. Rapid versus instantaneous. Let’s see, since I have the photograph here, this is a detonation. August 1980 state line Nevada. The night before, a van pulls up to the back door of this gambling casino which is at the bottom end of Lake Tahoe and it literally state line, because down the middle of the street Nevada is on one side which is gaming and California is on the opposite side which is non-gaming. State line, it goes right through the middle of town. Well apparently this guy lost too much money and he decided he wanted to get some money back, so he build a 1,000 pound dynamite bomb, encases it in a metal case—I can’t remember the gauge of the metal, at least a quarter of an inch—and puts a very intricate—I can’t say sophisticated, but an intricate fusing system on it and a package on top of it and he gets his son or sons and some other people to put it in a van, take it to the casino, and wheel it into the casino. They were at the back door and our bomb here had a tarp on it and it said Xerox or IBM or something like that. The security guard was at the back door and they were some pretty cool folks. They said “Oh we’ve got a delivery for you.” They said “Oh, okay.” The security guard opens the door and in they go. This is no lie; this is fact. They find an office in the casino and put the bomb in there and arm it and get it started. Timer countdown. And then they alter the lock on the door so people can’t get in. Well the next morning security guard is making his rounds before everybody gets there and he had another way to get in that office. He wondered what was wrong with the door handle or the lock; he couldn’t get his key in the lock. Well seems that as you walk into the office—it was a smaller office and it didn’t have the tarp on it and it had a letter on this—what he didn’t know was a bomb. So he reaches over, almost sits on top of the bomb—because he couldn’t get around the desk—to get this note. He gets the note and he’s like leaning up against it like this and he reads it—I can just imagine. He’s reading this and he goes “This is a bomb—holy shit! What am I doing here?!” You know? [Laughter] Out he goes. It’s an extortion. To make a long story short, the hotel is evacuated, the bomb squad is called in, and as you see what they did did not work. It blew up. A thousand pounds went woo bye. Blew half of the casino apart. It didn’t collapse, but it had a nice hole in it. State line Nevada 1980.
[Slide 18]
[Thurman] Okay, velocity of detonation or VOD here. The rate at which the combustion wave travels through the explosive. High explosives. Remember deflagration and velocity of explosion is the rate at which the combustion travels through a low explosive. Well detonation is the same thing, only now it is through a high explosive. Chemistry wise and physics we say that this occurs with a speed of over 3,300 feet per second. Now that’s the theoretical side. To my knowledge I don’t know of any explosives—and that’s why I put a caveat on it. To my knowledge I don’t know of any high explosives that detonate at a velocity less than 5,500 feet per second. So what you’re looking at here is the theoretical side. This is theoretical. 

[Slide 19]
[Thurman] Okay high explosives. Here’s our points on high explosives now. Summarizing this. It undergoes a detonation without confinement. Material is a compound normally, not always. It’s initiated by shock or heat. Don’t try to—okay. There are some types of high explosives that are extremely sensitive and they can be initiated by heat (a spark). Other types of high explosives require an explosion (shock) in order to detonate. We’ll get more specific with these down the road. Exactly. And the comment up here that you didn’t hear is that C4 you can light it and it will burn and won’t explode. Since you mentioned that, let’s go to another story. When I was in EOD school I was taught C4, if it is on fire do not try to put it out; don’t try to stomp it or put it out, because it will detonate. Well that has been proven to be a myth by whomever—whom? Mythbusters! They did a terrific job on this. They had an anvil that they suspended over a burning block of C4 and then remotely they cut the anvil lose, it falls down and hits the C4, and goes whomp! It just smashes it. Splatters it all over the place. It did not explode. Okay, we’re gonna ratchet this up a little bit and see what’s going to happen. So they get C4, put it down range, they get a rifle—C4 is bullet safe which means it won’t detonate when you hit it with a 308 round, sideways there. They lit off the C4 and shot a round into the C4 and all it did was splatter it. It did not detonate. Okay, that was a wives tale that proved to be wrong in EOD school, what else did they teach me that was wrong too? I’m scratching my head on that one. Not really. But I had that in my head for thirty some years until it was proven wrong. What I’m telling you is as ancient as I am, I still learn stuff. It’s fun. [Laughter] Okay it’s supersonic in the product. It is fast. Has a high brisance, which means a shattering effect. And our VOD as we talked about is over 3,300 feet per second. Down at the bottom are some examples: dynamite, ammonium nitrate and fuel oil a basting explosive called ANFO, and explosive called PETN, a very brisant high explosive. Now as far as compounds and mixtures—since we’re here let’s just fill this out and I’ll say it again so you’ll remember it. Dynamite is a mixture. PETN is a compound. Why is dynamite a mixture? Well dynamite is a mixture because you’ve got carbantous material that will burn, you’ve got ammonium nitrite, like fertilizer if you will, you’ve got nitrous cellulose, and then you’ve got nitroglycerin and it is a mixture. That is not a compound. The ammonium nitrate is a compound that’s in it. Nitrous cellulose, it’s a compound that’s in it. And nitroglycerin is a compound that’s in it. But the explosive itself is a mixture.
[Slide 20]
[Thurman] Okay, brisance. Brisance is the shattering effect. Different types of explosives have a different type of shattering effect. In other words, the higher the velocity of the explosion or detonation, the more brisant that explosive will be. Don’t worry about the bottom part, just know that brisance is the shattering effect. 
[Slide 21]
[Thurman] And here’s some examples. In the pipe bomb on the upper left it’s pretty much intact. This pipe bomb was loaded with half of a quantity—it didn’t go through a whole pipe—of black powder. Half loaded with black powder. Because it was black powder and there was only half a load here, it did not shatter the pipe. All it did was spit-off, as we say, the end cap. Now we move over to the upper right and we’ve got a very different effect here. We’ve got fragments of a pipe nipple. In this pipe nipple we had smokeless powder fully loaded and a squib that was—no it was a detonator. A detonator that was used to initiate smokeless powder. Do you see the different shattering effect that our smokeless powder—smokeless powder is more powerful, more of a shattering effect, than black powder by a long shot. Now the bottom left we have partial remains that was found of a pipe bomb. This pipe bomb had a half of a cartridge of dynamite in it. It did not fill the entire pipe. Again because it didn’t fill the entire pipe, we’ve got quite a bit remaining here, but the metal here is twisted and torn and folded back onto itself, again characteristic of a high explosive. Characteristic of a high brisance versus a low explosion. And then the last one on your bottom right, there’s not much left. We have C4 in that one. C4 is extremely brisant. In other words, it does more damage. So we go from black powder to smokeless powder, dynamite, and then C4. 
[Slide 22]
[Thurman] An initiator. Initiator is anything that is going to start a deflagration or detonation. It starts this whole process. Starts the whole process. And these are the different types of initiators that are found in commercial world, commercial blasting, rock blasting, as well as the improvised terrorist world. Detonators, squibs, electrical match, safety fuse, hobby fuse, and then anything that can be improvised on top of that. Okay, let’s get a little specific here. I’ll cover this again, but as an entrée to where we’re going to this let’s look at high explosives. Dynamite. Dynamite can only be initiated with one of the six—well let’s forget about improvised right now. One of the five initiators here. Only one of the five, and that’s a detonator. Dynamite cannot be initiated with what you see on television or in the movies of somebody taking a cartridge of dynamite, a safety fuse, jamming it in there, lighting the safety fuse, and then throwing it and it explodes. That no workie. No workie at all. You’ve got to have the detonator. Dynamite is a detonator sensitive explosive. It requires an explosion in order for it to explode. That explosion is a detonator. What is a detonator? It is about the size of my little finger. It has an extremely small quantity of explosives in it; however if I was stupid enough to put that in my hand and initiate that in my hand, my hand would be gone, my wrist would be gone, and part of my arm would be gone. It is just that powerful. Very, very small quantity of explosive. Okay, low explosives on the other hand are really easy to initiate, including a detonator here that can initiate low explosives—they initiate with an electric match, hobby fuse, squib, and safety fuse. Okay, you’re probably wondering what hobby fuse is. This is fireworks fuse. Squibs and electric matches are very, very similar. Current of electricity goes through the wire, at the end we have a pyrotechnic material, and it just goes [Thurman makes sound effect] literally an electric match. Like a regular match but it is electrically initiated. And safety fuse is what we use to initiate our detonator. Safety fuse burns through, it initiates the detonator, okay?
[Slide 23]
[Thurman] Okay, we’ve covered this but now we’re going back to it. The two main constituents of all explosives for our purpose is a fuel and oxidizer. A fuel burns, the oxidizer supports the combustion. The combination of these to make an explosive and the percentages is called oxygen balance. I don’t know why they call it oxygen balance versus fuel balance, but it is the same. It is the percentage of fuel versus an oxidizer in the explosive. There are differences in oxygen balance between commercial explosives and military explosives. That’s all you have to remember of that. There’s differences involved. And basically—okay, we’re still running here on definitions, as you may have seen. We’re still running on definitions for your understanding, so when we start talking about these later on you’ll understand what we’re talking about. Everybody good with this?

[Slide 24]
[Thurman] Okay, I cannot emphasize enough—and you can take this one to the bank—how important this block diagram is. And it is in your textbook on page eleven, twelve, or something like that. What is it? Thirteen. How important that is for your overall understanding of chapter one and chapter two. You should use this in studying for our subsequent exam, because we’re gonna bifurcate out a lot of products here and you can use this to help keep things straight in your mind. Basically for the exam, no you’re not going to have to write this out, but you should be so familiar with this diagram once we finish it that you can write it out on a piece of paper and start listing everything underneath that we’ll be talking about, okay? So take that as a hint. That’s the best way to study for an exam. Okay, explosives. We’ve already seen we have high explosives and low explosives.
[Slide 25]
[Thurman] Low explosives. Already shown you this, but we’re gonna do it again. Deflagrates. Usually a mixture. Initiated by heat. Confinement is required. Reactions are subsonic. The velocity is below 3,000 feet per second. Black powder and smokeless powder are examples. On the table there in the photograph are containers of chemicals for improvised explosives smokeless powder and black powder. Basically black powder here in metal cans. Smokeless powder here. Plastic container. Yeah, there’s still some packaged in metal containers, but not as much as the plastic containers.
[Slide 26]
[Thurman] High explosives. Again the same thing. Material undergoes a detonation without confinement. It can be a compound or a mixture. Initiated by shock or heat. Supersonic in reaction. High brisance. VOD above 3,300 feet per second. Dynamite, ANFO, PETN. Everybody get that the first time around?
[Slide 27]
[Thurman] Next one, accessories. Accessories are fusing systems, initiation systems. Accessories are fusing or initiation systems. It’s what we require and what we need to get our high and low explosives to explode. 
[Slide 28]
[Thurman] And here are the types of components that we’re talking about. Don’t get all concerned that you don’t know what all this stuff is. By the end of chapter two you will know what these materials are. All types of detonators, safety and hobby fuse, detonating cords, boosters, shock tube, electric matches, and squibs. Now as you see already I think based on what we’ve done, some of these materials in here have low explosives in them, such as safety fuse. They have low explosives. Detonating cord, boosters, they have high explosives in them. Detonators, high explosives. Electric matches and squibs, pyrotechnics. So we have materials that are considered low explosives and high explosives that are a part of our fusing systems. Accessories. 
[Slide 29]
[Thurman] Next we bifurcate out our high explosives. So the top rung we have low explosives, high explosives, and accessories. Now we’re going to define different types of high explosives, and these are primary explosives and secondary explosives. Primary means what? Any word, not with—what’s primary mean? First. These are the first explosives that detonate in high explosives. In other words—okay, where am I going with this? Where I’m going with this is C4—how do you get C4 to detonate? In other words, what comes first, the chicken or the egg? And the answer is high explosives initiate high explosives but we have different sensitivities of high explosives. The most sensitive is a primary explosive, and that’s easy to initiate, and when that detonates then we can have other types of high explosives then detonate as a chain reaction. It’s just like oversimplified that you go—like it’s been here, it is twenty degrees below zero. You’ve got a fireplace in your apartment or in your house and you want to build a fire. You get a log, if you put that on there and strike a match and put it under the log (a log an inch in diameter) it’s not going to do anything is it? Your match is gonna go out. So what you do is you build up to where you can get that log to catch on fire. You have kindling, small branches maybe, paper, bigger pieces of branches, and then that 1 inch log. You light the paper, hopefully the paper will burn and catch the kindling on fire (twigs), the twigs then catch the bigger pieces of wood on fire, and they in turn produce more heat to catch our 1 inch log on fire. It is building g up, and that’s exactly what we’re doing here in starting out with primary explosives. Primary explosives is like the match. This is where we start. We wouldn’t have any explosives in the world today that would work unless we started with a primary explosive. Even dynamite you can’t initiate that reliably—okay, you can shoot it with a gun and it will detonate, but you can’t blast that way. And I use dynamite a lot because a lot of people are familiar with dynamite and not anything else in high explosives, because a cartridge is a cartridge of dynamite versus anything else. Anyway, so we have to have this primary explosive. This primary explosive is actually up here in accessories. When we talk about it down here it is just an explosive by itself; it’s not in a detonator.  And that’s what it is in, a detonator. We will get into that a little bit later. And we have secondary explosives. Which our secondary explosives is what the big explosions come from. 
[Slide 30]
[Thurman] Okay, primary. Primary explosives. Those explosives which require a very small quantity of energy to be initiated. By their nature they are extremely sensitive to heat, shock, and friction. Sometimes the different types of primary explosives, they are more sensitive to heat, shock, and friction than some of our low explosives. They have less power than our secondary explosives that we’re getting ready to go into. We don’t want raw power here to do damage, if you will—to blow up something. We just want primary explosives to get this chain reaction started. Classified as a high explosive, used only in detonators and initiation systems, because of why? Because it is so sensitive. Used in very small quantities. And down on the bottom are some examples and some names. Lead azide, mercury fulminate. This material is so sensitive that if you have on—well, if it’s on a hard floor, you walk on it with your shoe, it will detonate. It is that sensitive. Okay, everybody got it?
[Slide 31]
[Thurman] Secondary explosives. Those explosives which require a large quantity of energy in order to be initiated. Compared to primary explosives, they are relatively insensitive to heat, shock, and friction. More powerful than primary explosives. They are detonator or booster sensitive, and we’ll talk about the differences with that later on. And they’re normally used in greater quantities. Okay, what do I mean by greater quantities? Well, the military could get a block of C4 and use that one block of C4, which is 1.25 pounds, to do damage to whatever. In the commercial blasting world ANFO—I’ve been on mine sites where they’re loading holes to remove what we call overburden so they can get to the coal. The drill has drilled down 192 feet. No, they’re not going for water. One hundred and ninety-two feet. The bore hole is 11.5 inches in diameter. Each hole they are putting in 10,000 pounds of ANFO in each hole. On one shot—one shot, which I’ve seen—over 1,000,000 pounds of ANFO goes. And in the commercial blasting world for moving rock it is totally unimpressive. One million pounds. Okay, why? Because it doesn’t have all of the flames and the dirt and the heat and everything coming up out of the holes. No. What they want is that to be contained. They want all that energy to be in the ground to shatter rock. The Earth goes up. The Earth goes back down. Oh, that’s was totally unimpressive except it shook the pee diddle out of you like an earthquake. It rumbles. Earth shock is much faster than sound, and all of a sudden you feel the ground literally shaking under you and then you hear a rumble [Thurman makes sound effect]. That’s about it. I do more impressive things out on our explosive range with 200 grams than what I see with 1,000,000 pounds. I kid you not. No big deal. Okay, we’re gonna stop here. We’re gonna stop here for the day. Where we will pick up is that we’re going to take secondary explosives and we’re going to bifurcate them out as you see in the diagram. Bifurcate them out and then talk about those explosives. We have any questions today? Okay, take care. See you later.
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