Patent Application
20120192704
Vehicle-borne improvised explosive devices (VBIEDs) have been used by terrorists with increasing effect in recent years. In the United States, neutralization of explosive devices is the role of bomb-disposal squads, which form part of the domestic first-responder network. However, there is at present no protocol for responding to VBIEDs. The percussion-actuated nonelectric (PAN) disruptor technologies currently used by domestic bomb squads are not suited for a vehicle-borne device in which the detonation train is not readily accessible. Solutions developed in Europe involve large amounts of explosives to drive water disruptors, which cause collateral damage that would be unacceptable in many areas in the United States.
Embodiments of the present invention may be better understood, and their numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference symbols in different drawings indicates similar or identical items.
Embodiments of systems and methods are disclosed that can neutralize an explosive substance in an Improvised Explosive Device (IED) using a projectile containing relatively small amounts of a reactive material. The impact of the projectile on the IED container initiates the reactive material, which causes a controlled reaction, e.g., a deflagration as opposed to a detonation, of the explosive. This reaction creates sufficient pressure to rupture plastic or steel containers producing a neutralization or render-safe outcome. Use of the projectile to neutralize an IED from a safe standoff distance improves bomb squad operational tactics and provides ability to rapidly neutralize explosive devices. Additionally, the limited deflagration leaves more of the IED intact and aids post mortem forensic analysis.
Referring to
Groove(s) 104 define the location(s) where the housing 102 will rupture upon impact and penetration into an explosive device due to stress concentrations on the thinnest parts of the wall of the housing 102. The reactive material will then leak out through the ruptured areas of the housing 102 into the explosive material. Groove(s) 104 can be oriented in any suitable direction along housing 102, such as along the longitudinal axis, around the circumference, and/or diagonally across the housing 102. For example, in some embodiments, housing 102 can be 3.5 inches long with an outer diameter of 0.725 inches. Six grooves 104 are positioned along the longitudinal axis of housing 102 at equal intervals around the outer diameter of housing 102. The grooves 104 can be approximately 2.5 inches long with a 0.625 inch radius arcuate cross-section approximately 0.0175 inches deep, and 0.18 inches wide. The mass of projectile 100 can be 65 grams, or other suitable mass depending on the thickness and rigidity of the outer shell of the explosive device. The shape of the explosive device, for example, the diameter of the container, is another factor to consider when selecting a particular size and mass for projectile 100. For example, containers with flatter surfaces may be easier to penetrate than containers with more rounded side walls. Other suitable dimensions, mass, and shapes for the projectile 100 and the groove(s) 104 can be used.
Projectile 100 further includes an inner chamber comprising a first hollow section 106 and a second hollow section 108. The cross-sectional area of the second hollow section 108 is typically smaller than the cross-sectional area of the first hollow section 106. In one embodiment, hollow sections 106, 108 have a cargo capacity of 8 cubic centimeters, which will hold approximately 16 grams of reactive material. Hollow sections 106, 108 can be configured to hold other suitable volumes, however.
A chamfered shoulder portion 110 can be included between the first and second hollow sections 106, 108 to gradually transition from the cross-sectional area of hollow section 106 to the cross-sectional area of hollow section 108. A rounded portion 112 can be included at the end of the second hollow section 108. The shoulder portion 110 and rounded end 112 reduce the pressure forces imposed by rapidly accelerating reactive material on the inner portion of the housing 102 when projectile 100 is fired or launched.
The housing 102 can further include forward section 114 adapted to receive a first nose member 116 and a rear section 118 adapted to receive a fin set 120. More than one nose member can be used in situations where projectile 100 is required to penetrate more than one layer of covering around the explosive substance. For example, the explosive device may be located in a truck or automobile, and the projectile 100 is required to penetrate a panel of the vehicle and then a sidewall of the explosive device. Accordingly, an expendable second nose member 122 can be attached to the first nose member 116 to absorb the shock of the impact with the first obstacle and help prevent the housing 102 from rupturing. The first nose member 116 is then available to penetrate the side wall of the explosive device.
Additionally, the external face of nose sections 116, 122 can be blunt, slightly rounded, or pointed. The threaded portion 204 of the first nose member 116 can be frangible so that the second nose portion 122 and the threaded portion 204 break off from the first nose portion 116 upon impact with the first obstacle.
Referring to
The fin set 120 further includes a plurality of longitudinal cuts 310 spaced around the circumference of the cylinder 302. The longitudinal cuts 310 extend through the sidewalls 304 of the cylinder 302 to form the individual fin portions 306. Lateral notches 312 can be formed or cut through the sidewalls 304 of the cylinder 302 at the base of the longitudinal cuts, adjacent the closed end 303 of the cylinder 302.
The fin portions 306 are configured to bend into a deployed position by blast pressure behind the fin set as the projectile 100 exits a muzzle of a gun or launcher.
Referring to
In some embodiments, projectile 100 is configured to survive launch breech pressure of approximately 45,000 psi, acceleration of approximately 105 g, and cargo pressure of 15,000 psi; (2) deploy fins symmetrically and survive muzzle blast pressure of approximately 4300 psi to 6000 psi; (3) transition to stable flight in less than 10 meters; (4) impact drum at small (˜10°) yaw angle; and (5) impact within a defined velocity range.
The reactive material is configured to initiate from ballistic impact shock and react inside the explosive device. The impact of projectile 100 with the explosive device can create a critical mass (approximately ½ kg to 1 kg) of ANFO Crush Zone (CZ) to react with the reactive material. The velocity of the projectile 100 should be high enough to penetrate the explosive device without detonating the explosive device. If combustion is too slow, the reactive material may not deflagrate a sufficient amount of the explosive material to rupture the container.
Examples of common explosive substances used in IEDs for which this technology is suitable include but are not limited to Ammonium Nitrate Fuel Oil (ANFO), powdered ammonium nitrate and aluminum powder (AN/AI) and urea nitrate. The reactive material is chosen to cause a vented deflagration when the reactive material is released into the explosive substance. Examples of suitable reactive materials include: conventional thermites, e.g micrometer particle size aluminum and copper oxide; conventional thermites with gas generation additives, e.g. sodium azide; and aluminum in both nanometer and micrometer particle size with liquid oxidizers, e.g. perfluoropolyether.
Experimental testing demonstrated that the reactive material causes a controlled reaction of a sufficient mass of ANFO and AN/AI so that the resulting pressurization from the controlled reaction of the explosive causes the container to rupture without transitioning to a detonation. Experimental trials demonstrated that both plastic and steel containers containing between 40 lb and 110 lb of ANFO could be successfully rendered safe using 16 grams of reactive material. Other combinations of amounts of explosive material and reactive material can be used.
In another series of experiments conducted with steel pipe bombs, it was established that 6 grams of reactive material consistently gave rise to a propagating reaction in the ANFO in which a quarter to half of the ANFO was consumed in a deflagration. It was also found that only a few hundred grams of burning ANFO produced sufficient gas to rupture a container without fragmentation. Tests conducted on a six-inch pipe bomb containing 660 g (1.5 lb) of ANFO demonstrated a repeatable deflagration with fracture of the pipe bomb using 6 grams of reactive material.
Consequences of the rupture are that the ANFO bulk is no longer detonatable. Moreover, the ANFO is exposed and can be further neutralized by spraying the explosive material with water or other anti-inflammatory substance.
Thus, a method for neutralizing explosive material within a container using projectile 100 can include filling a projectile with a reactive material. The reactive material is formulated to react with a portion of the explosive material to build internal pressure and rupture the container without detonating the explosive material. One or more nose portions 116, 122 are selected for the projectile based on one or more factors such as but not limited to predicted impact velocity of the projectile with the container, the material strength and shape of the container, distance to the container, the mass of the projectile, and the type of explosive material. A fin set 120 is also selected for the projectile 100 based on blast pressure behind the projectile when the projectile is fired from a gun; length, diameter, and mass of the housing, mass; and mass of the reactive material.
If the explosive device is hidden in a vehicle, e.g a panel truck or other thin skin structure, the explosive device may be exposed using a relatively low-speed projectile containing a thermobaric (TBX)—type explosive fired into the vehicle. The pressure output of the TBX could be controlled by the initiation scheme. Reaction of the low explosive within the vehicle would remove the sides of the cargo compartment, revealing the explosive device.
Alternatively, a back-scatter X-ray system can be used to locate the explosive device inside a vehicle or other structure. One or more projectiles 100 with two nose portions 116, 122 could be fired through the side of the vehicle/structure into the explosive device. The dual nose configuration of the projectile 100 would allow penetrate through the wall of the vehicle but not release the reactive material until the projectile 100 penetrated the container of the explosive device.
If a firing circuit on the explosive device is visible, the circuit could be disabled with conventional PAN disruptor projectiles. But if the circuit is not visible, the explosive device would be rendered safe by shooting the projectile 100 through the container. The outcome of the impact will either be massive spillage of explosive material from the container, or at the very least a large hole into the container. In the latter case, a high-pressure water stream would be directed into the hole, which will dissolve the exposed contents.
While the present disclosure describes various embodiments, these embodiments are to be understood as illustrative and do not limit the claim scope. Many variations, modifications, additions and improvements of the described embodiments are possible. For example, those having ordinary skill in the art will readily implement the processes necessary to provide the structures and methods disclosed herein. Variations and modifications of the embodiments disclosed herein may also be made while remaining within the scope of the following claims. The functionality and combinations of functionality of the individual modules can be any appropriate functionality. Additionally, limitations set forth in publications incorporated by reference herein are not intended to limit the scope of the claims. In the claims, unless otherwise indicated the article “a” is to refer to “one or more than one”.
This invention was made with government support under 2007-DE-BX-D002 awarded by National institute of Justice. The government has certain rights in the invention.
| Number | Date | Country | |
|---|---|---|---|
| 61424598 | Dec 2010 | US |
