Hendon Publishing - Article Archive Details
Explosive Handler’s Course
Written by Don Munson
Olive Security Training Center (formerly TEES) offers a three-day Explosive Handler’s course at its training facility in West Memphis, AR. This is a prerequisite to its four-day Explosive Entry course. While the Explosive Handler’s course is separate from the Explosive Entry course, it is often combined together into a full week of training. The Explosive Handler’s course is designed to teach safe handling techniques to people with little to no experience with explosives. The course is offered almost every month at OSTC and also on the road at host training sites around the country.
The main office of OSTC is in Nesbitt, MS, just south of Memphis. OSTC’s director of training is Alan Brosnan, the former owner of TEES. The Olive Group, a London-based company, bought TEES in October 2005. With this transition from TEES to OSTC also came an upgrade to the training facility. The facility grew from 16 acres to 780 acres with all new ranges, classrooms, a driving course and a proposed nine-square-block MOUT site.
The course instructor for Explosive Handler’s is John Mayer, a retired U.S. Army Special Forces engineer. Mayer spent the past few years of his 20-year career teaching explosive breeching to Special Forces units. Mayer had worked with Alan in the past and was his first choice to head up this section of OSTC’s training team.
The amount of information presented on the first day of training was almost overwhelming. What are the basics of an explosion? What are the different types of explosions? The students were taught that from any type of chemical change or explosion, three things are generated: heat, light, and pressure. This holds true to from a burning log to a stick of dynamite detonating. The big difference is in the amount of time this takes to happen.
Combustion, Explosion, Detonation
There are also three types of combustion. First, an ordinary combustion would be a simple lighting of a match. The second type is explosion. A car’s engine running best illustrates this: each cylinder experiences an explosion every time it fires. The third kind is detonation, which is an instantaneous combustion and the main focus of the course.
The class learned the difference between low-order and high-order detonations. Low orders are incomplete detonations, which occur for a variety of reasons. High-order detonations are the complete detonation of an explosive and the sign of a properly prepared charge.
Mayer explained the different effects of an explosion, which include blast pressure, heat and fragmentation. Each effect can vary from explosion to explosion depending on a wide variety of factors. From the design or make up of a charge to the location or structure where the charge is to be used.
Explosives were broken into four categories: Low explosives (black powder), primary high explosives (blasting caps), secondary high explosives (detonation boosters), and secondary high explosives (others). The most common form of low explosives would be a round of ammunition. Primary high explosives (blasting caps) are what set off a charge.
Secondary high explosives (boosters) are required when the final high explosive material has a low sensitivity and requires more of a shock wave to propagate the detonation through the entire charge. Secondary high explosives (others) are usually the final explosive material in the charge. This is the part of the charge that does the work.
The next step was to learn about detonation velocity. Detonation velocity varies from explosive to explosive. Low explosives have a detonation velocity less than 3,280 fps. High explosives have a detonation velocity of 3,280 to 29,000 fps. This is important because the detonation velocity directly affects the type of work a charge can do. Lower velocities like in dynamite events can be used for stumping, trenching, and quarrying because of their pushing power. Higher velocities such as in detonation cord use can be used for cutting because of its shattering power.
The Explosive Train
The class then learned about the sensitivity of explosives and how it can affect the explosive train. An explosive train consists of two to four different explosives operating as one charge. The number of steps in that train is directly related to the sensitivity of the explosives in the train. A round of ammunition would be a two-step explosive train (primer and gunpowder). A dynamite charge consisting of a safety fuse, a blasting cap and dynamite would be a good example of a three-step train.
Black powder is one of the most dangerous explosives due to its high sensitivity to heat, friction, shock and sparks. This is why pipe bombs are so dangerous and also so easy to make. No blasting cap is required, just a fuse, some black powder, a piece of pipe, and some pipe fittings.
When using high explosives, a blasting cap is essential. There are three different types of blasting caps for the three different types of firing systems. The blasting cap contains a small amount of high explosives that is very sensitive. It can be initiated by flame, spark, or shock wave. Non-electric blasting caps are set off by a spit of flame that comes out of the end of the safety fuse. Electric blasting caps are set off when a spark is made across two contacts. Shock tube or “Nonel” blasting caps are set off by a shock wave of force that travels down the shock tube from the firing device.
As the morning came to a close, the original feeling of being overwhelmed had given way to a general understanding of the fact that each firing system had its own components. Because you now understood how those components worked together, it was easier to visualize how to put a firing system together.
Non-electric systems basically have some type of initiator that create a spark that lights the safety fuse that spits out a small flame that sets off its blasting cap. Electric systems use a wide variety of devices to generate electricity to run down a set of wires where a spark between the two leads sets off the blasting cap.
Nonel Shock Wave
Shock waves, or “Nonel” systems, have a wide variety of different styles of initiators. In essence, they all hold a shotgun shell primer that is struck by a pin. This sends a shock wave of energy through the Nonel tube, which has a small amount of explosive powder in it. Those students who inadvertently had their hands or palms on the tube when it went off compare it to a bee sting or when you hit a baseball with the wrong part of a bat. That shock wave hits the blasting cap and sets it off.
The Nonel system is by far the best system for tactical operations. With its compact size, ease of use and safety benefits (no RF hazards and static electricity), it’s not hard to see why. The afternoon consisted of a general high explosives overview where students got to see, TNT, C-4, Semtex, detonating cord, Deta sheet, dynamite, linier shape charge, explosive cutting tape, ammonium nitrate fuel oil (ANFO), binary explosives like the Omni “Helix” and Kinepack, composition B, and demolition explosive slurry (DEXS).
Mayer went over each explosive with a general history of its origin and how it was typically used. Next, the class was given a brief show-and-tell on secondary high explosive boosters. Boosters are necessary only with certain charges to increase the shock wave to ensure a high order in an end explosive that has a low sensitivity.
The students were all allowed to use the electric firing system and the non-electric firing system on the first day. Every step of the way, safety was stressed, from keeping your wires shunted (crossed on your electrical firing system until the final connections) to the proper way to crimp your blasting cap onto your safety fuse.
The great thing about this course is that you are actually taught to think. Every time you drop something down range, it is potential frag. Everything has its place from the small wire safety on your friction initiator to the crimpers on your belt, and it’s definitely not on the ground next to a live stick of dynamite.
Before the class was allowed to set off the first stick of dynamite, all safety precautions were covered, including minimum safe distances, range commands, misfires, extraneous electricity (cell phones, lightning, static electricity, etc.), and even the location of first-aid kits and emergency numbers. Once the instructor was comfortable that everyone understood the consequences for a mistake, the class moved on.
As with most courses, there has to be some technical classroom instruction. That part of the training was covered as quickly as possible, but not at the cost of safety. As the afternoon progressed, it was out of the classroom and onto the range for hands-on training. While setting off the dynamite with the different firing systems, students had a chance to observe one another’s safety practices, as well as the characteristics of an explosion. Each explosive has its own characteristic as far as flash, smoke, and sound.
Day 2 started out with a practice test. There were no surprises on the test because it was the nuts and bolts of the first day’s training. After a quick question-and-answer session, it was back out to the range for more hands-on training.
It was time to learn about detonation cord (det cord) and why it is so versatile. Det cord can be used as a primer for other explosives, to link multiple charges together, or as its own charge. While using det cord to link charges together, one must be careful not to cross two strands of it because it could possibly cut itself during detonation, causing a low order. Any branch lines of det cord need to be at least 45 degrees to the main line because of the high detonation velocity. Det cord could possibly cut itself at a hard angle. Just like a racecar going too fast into a tight curve, it’s going to go off the track.
Misfires were covered in greater detail on the range. Everything from blasting cap failure, det cord failure (low order) and charge explosion failure were covered. Depending on the situation, it could be as easy as attaching a new cap and refiring the system or using a countercharge to initiate the first charge.
After lunch on the second day, it was out to the range to practice what had been learned about det cord systems. Then the class was given a demonstration on the Nonel/shock tube firing system. It is not hard to see why Nonel is the firing system of choice. To finish out the day, the class members did a comparison group shot on the range. They used one charge of dynamite, C-4, Omni “Helix” binary explosive and two different sizes of ANFO charges (2 pounds and 5 pounds).
The two ANFO charges were placed in a quart container and then a gallon container, respectively. The ANFO charges also were buried just below the surface. Most of us know that Timothy McVeigh used ANFO as his main explosive ingredient for the Oklahoma City bombing. The explosions each had their very own characteristics, but the large ANFO charge was truly impressive.
Not only was the size of the explosion and the amount of debris impressive, but the huge crater that was left behind was truly amazing. The small ANFO container left a small crater about 18 inches across and about 12 inches deep. The large container left a crater big enough for 5 students to stand inside almost waist deep. Day 2 ended with another practice test, but at this point, most students could repeat the answers on request without hesitation.
Det Cord Sizes
Day 3 started on the range with a demonstration of the different sizes of det cord (grains) on a wooden door. The Formica-covered pressboard doors gave enough resistance that the lower grain det cords only scarred the surface, while the heavier grain det cords cut through the door. This was also the first chance students were able to see the amount of frag that a charge would cause on the backside of a wooden door. After the wood door, the class moved on to steel cutting.
The Monroe Effect is when a charge is shaped and given standoff. This will force the blast to be focused to a spear point to cut the steel. Standoff is basically giving a little extra distance between the charge and the target to allow the maximum Monroe Effect with a charge.
Linear Shape Charge (LSC) is a concaved copper jacketed explosive. Explosive Cutting Tape (ECT) is a charge placed into a foam strip to give it a natural standoff without the copper jacket frag issues of LSC. Throughout the comparison on different sizes of steel, it was obvious that LSC was much more effective than ECT but also more dangerous because of the copper jacketing.
Before lunch on Day 3, students were allowed to build their own claymores and platter charges. The claymores were built out of 3-inch PVC, nuts, bolts, screws, polystyrene, bulk C-4 and some duct tape. The platter charges were made up of a round piece of plate steel placed over a 3-inch PVC pipe powered by bulk C-4. The charges then were taken to the range and set up for a little competition. The claymores, while effective, were obviously not as deadly as a platter charge. Platter charges currently are being employed against our troops in Iraq.
The afternoon of Day 3 started out with a demonstration of a half-dozen improvised explosive device (IED) firing systems. We learned that IEDs could be set off by almost any kind of device. An IEDs firing device is only limited to the designer’s imagination. Participants were given a box of electrical switches and some batteries and asked to design their own firing systems to be tested on the range. The most ingenious device was a normal-looking pack of cigarettes that would fire the device when one was removed from the pack. It was easy to see how someone could construct a bomb out of any household item.
The OSTC Explosive Handler’s course is a basics class that will appeal to anyone with an interest in explosives. We covered a huge amount of information in three days. Classroom time was kept to a minimum to allow the maximum amount of hands-on range time. When you leave OSTC’s Explosive Handler’s course you know the why—not just the how.
This course is the first step, of course, for the tactical explosive entry operations, and it also is a great introduction for those considering more serious EOD work. This is also the right class for those who transport and handle explosives, even if they are not the ones who set the charges. With explosives, it is always good to have an extra set of eyes and hands. This is an excellent and safe first exposure to explosives in law enforcement scenarios.
Don Munson is a deputy sheriff with the Benton County, IN Sheriff’s Department and the point man with the multi-agency response team. He can be reached at firstname.lastname@example.org.
Published in Tactical Response, Sep/Oct 2006
Rating : 5.8
Related CompaniesOSTC (Olive Security Training Center)
Related ProductsANFO (Ammon Nitrate and Fuel Oil Bomb)BombsIEDs (Improvised Explosive Devices)TrainingTraining Courses
Click to enlarge images.