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IED’s have become an extremely significant and dangerous force protection issue in the wake of Operation Iraqi Freedom (OIF) and the Global War on Terror (GWOT). Insurgents and terrorists are using a variety of asymmetric techniques to attack militarily superior coalition forces with military ordnance components combined with commercial off the shelf explosives, electronics, and digital subsystems.
Landmines, improvised explosive devices (IEDs), and other homemade bombs struck 6,461 people worldwide in 2015, killing at least 1,672, according to a report by the International Campaign to Ban Land Mines and Cluster Munition Coalition. Survivors are often left with devastating injuries. In a study published in BMJ Open, 70 percent of people hit by IEDS in Afghanistan required multiple amputations. According to the UN Mine Action Service, landmines kill 15,000–20,000 people every year (mostly children) and maim countless more across 78 countries.
An improvised explosive device (IED) is a bomb constructed and deployed in ways other than in conventional military action. It may be constructed of conventional military explosives, such as an artillery shell, attached to a detonating mechanism. IEDs are commonly used as roadside bombs. An IED has the operative word being Improvised. There is no specifications for the explosive, detonator or trigger. It is simply made from whatever is at hand. There is no specification for the type of explosive, the amount of explosive, the type of detonator, or the trigger mechanism. All is simply what happens to be at hand.
Each landmine consists of three components; the case which may be metal, wood,plastic or mixed, the explosive material which may be TNT, RDX, mixed RDX/TNT, Tetryl, or other high explosives, and an initiator which may include a pressuresensor, an electronic sensor or any other sensor. IEDs are triggered by various methods, including remote control, infrared or magnetic triggers, pressure-sensitive bars or trip wires (victim-operated). In some cases, multiple IEDs are wired together in a daisy chain to attack a convoy of vehicles spread out along a roadway.
Many technologies are used to IED Neutralization and Detection (INDET) for ground forces protection against remotely controlled improvised explosive devices (IED) and related insurgent/terrorist explosive threats. INDET technologies can neutralize (detonate) remotely controlled IEDs by replicating the coded radio frequency transmissions from garage door openers, car alarms, etc. that the adversary uses to control the IEDs, exploding the devices before the arrival of their intended target. The hostile remote triggering of remotely controlled IEDs can then be prevented through the use of tailored barrage jamming through high power electromagnetic (EM) energy directed at the IED.
The working principle of the application of high-power lasers for the neutralization of explosive devices is based on thermal effects. Heating of the IEDs main charge may occur either by direct irradiation of the explosive material or by heat transfer through the main charge’s confinement. The aim of the application of the laser is to achieve a low order burning reaction of the explosive charge and thus a controlled neutralization of the IED. Since laser beams allow for the directed transport of energy, this technique can be applied over long stand-off distances and has thus potential for an increase of the safety of clearing forces and population in the case of terroristic attacks in a civilian environment.
Robotic vehicles and drones are also being increasingly employed for mind detection and clearing, to reduce the risk to the personnel.
New Water Cannon Technology a Breakthrough for Bomb Squads
Improvised explosive devices (IEDs) are a constant and ever-changing threat to the security of our nation. Their extreme destructive potential demands innovative solutions. That’s where the Reverse Velocity Jet Tamper (ReVJeT) comes in.
The Department of Homeland Security (DHS) Science and Technology Directorate (S&T), in partnership with the Federal Bureau of Investigation (FBI), has fully transitioned this versatile tool to each and every one of the hundreds of state and local bomb squads across the country through the FBI’s Hazardous Device School. In the span of about two years, the concept was discovered, specifications were developed, prototypes were built and field-tested, and the final product was delivered directly into the hands of first responders.
“It was one of those eureka moments,” said FBI Supervisory Special Agent Dr. Ian Vabnick, who accidentally discovered the technology behind ReVJeT while testing something else. “This is probably the biggest advancement in water cannon technology in the last 50 years. There have been other improvements, but when it comes to firing fluid jets, ReVJeT is the most significant advancement in stabilizing that jet.”
ReVJeT breaks apart IEDs by targeting a stream of high-velocity liquid, such as water. It does not detonate the device, but rather disarms it from a distance and allows bomb technicians do their jobs faster, safer, and more effectively. ReVJeT improves upon existing platforms by a conservative 300% and can enhance any propellant-driven disrupter system, making it capable of neutralizing various IEDs.
The genius behind the technology is that it enhances efficiency by combating a phenomenon in hydrodynamics known as the reverse velocity gradient. Within a water cannon, there are millions of individual molecules of water. As the cannon fires, and a jet of water streams out, the molecules of water move at different speeds. The water in the front does not have as much velocity as the water in back, so its momentum is lower.
Another way to think about it is to picture a train with the caboose moving faster than the engine. If the conductor hits the brakes, but the back is still moving fast, then the train cars in the middle will all get knocked off the track. That is what happens to a jet of water as it comes out of a cannon. The back end is moving faster than the front and overtakes it. The water in the middle gets pushed out of the way. As a result, the jet breaks itself apart as it travels toward the target, the IED.
“There is an exponential drop-off in performance with distance as you move a disruptor away from a bomb, but not with ReVJeT,” said Vabnick. “There isn’t an exponential drop off because you’ve gotten rid of one of the biggest inefficiencies in the system, which is this reverse velocity gradient phenomenon.”
The ReVJeT effort is part of DHS S&T’s Response and Defeat Operations Support (REDOPS) program, which provides a collaborative structure for addressing IED response and defeat capability gaps identified by federal, state, and local bomb technicians, including the National Bomb Squad Commander’s Advisory Board. Throughout the testing and development process, ReVJeT benefitted from direct end-user involvement. The technology was given to real first responders, so they could evaluate and train with it. ReVJeT is now part of the formal training curriculum at the only school that teaches bomb technicians in the United States.
