WO2003006916A1

WO2003006916A1 - Wall breach method and apparatus

Info

Publication number: WO2003006916A1
Application number: PCT/AU2002/000823
Authority: WO
Inventors: James Michael O'dwyer
Original assignee: Metal Storm Limited
Priority date: 2001-07-11
Filing date: 2002-06-25
Publication date: 2003-01-23
Also published as: TW200412419A

Abstract

A method and apparatus for breaching a wall or barrier (20) including a cluster of barrel assemblies (12), wherein said barrel assemblies are directed around the perimeter of a desired access, wherein the barrel assemblies include a plurality of projectiles axially disposed within a barrel and associated with discrete selectively ignitable propellant charges for propelling the projectiles from the barrel towards the perimeter of the desired access until the wall is breached. Suitably the barrel assemblies (12) are formed in a pod (13) mounted to a platform (17) of a robotic vehicle (10) by a turret (14), which vehicle includes stabilisers (15, 16) for supporting the platform during firing.

Description

TITLE WALL BREACH METHOD AND APPARATUS

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to breaching a wall, barrier or similar construction to facilitate access, such as for permitting the incursion through the construction by forces such as a military or emergency services force. In particular, the present invention relates to methods and apparatus for breaching a wall.

Discussion of the Background Art

Generally, two pieces of equipment may be conventionally used to assist in breaching buildings by doorways and by creating holes in exterior walls. One of these is explosive cutting tape used to blow a hole in wall large enough for a soldier to walk through. Use of this weapon requires a combat engineer, or a soldier assisted by a combat engineer, to approach the target, stick the charge to the wall or door, attach the booster, retreat a safe distance and fire the cutting tape. Support soldiers are then able to rush through the breach and neutralise any targets found within the building. Another breaching tool is a stand-off weapon such as may be used for breaching doorways. The intent of this weapon is for a soldier to fire an explosive round at the doorway from a minimum distance of about 10 meters. The charge does not penetrate the door; rather it detonates just in front of the door and relies on the shock wave to blow the door off its hinges. These technologies have several inherent problems such as additional exposure time to enemy fire and increased probability of detection by the enemy. Further examples of wall breaching equipment are described in US Patent Nos. 4856430 to Gibb et al., 5524546 to Rozner et al., and 5883328 to A'Costa.

Currently there are a number of techniques for breaching a building, which techniques might be conveniently grouped into three (3) categories, namely ballistic, manual and explosive. A ballistic breach of a building or a room entails the use of an automatic weapon to destroy the locking mechanism or hinges of the door. This is typically done with a machine gun or a shotgun. This is not a preferred method because it is unreliable in opening the door and lacks the surprise, speed, and energy required for the highest probability of success. Ricochets are also a major threat to friendly troops when using this method. Manual entry is used when ballistic and explosive entries are inappropriate.

Manual entry can involve, among other things, the use of a ram type device to break in a door or exaggerated claws to pry open a door.

Explosive entry is presently the preferred method for breaching a building. To maximise the effects of the blast the charge should be tamped whenever possible. Tamping is accomplished by putting just about anything over the charge to reflect shock waves back on the wall. Some of the materials that are used for tamping are sandbags, rubble, desks, chairs etc. Disadvantages to the use of explosive charges are that the detonation creates shrapnel, the blast won't remove reinforcing bars and the amount of explosive used is critical. Too little explosive and the wall won't be penetrated, too much and the whole building could be destroyed. These three breaching methods also have the inherent risks of additional exposure time to enemy fire and increased probability of detection by the enemy.

SUMMARY OF THE INVENTION Object of the Invention

Accordingly it is an aim of the present invention to provide an improved method and apparatus for breaching a wall, barrier or similar construction to permit the incursion therethrough by forces such as a military force, a firefighting force or other incursionary force or apparatus.

Disclosure of the Invention

The method of the present invention employs a cluster or pod of barrel assemblies of the type including a plurality of axially stacked projectiles for sequential firing from the barrel assembly. Accordingly the present invention provides a method for breaching a wall including the steps of firing a multiplicity of projectiles from a cluster of barrel assemblies, said firing being directed around the perimeter of a desired access through said wall or barrier, wherein the barrel assemblies include a plurality of projectiles axially disposed within a barrel and associated with discrete selectively ignitable propellant charges for propelling the projectiles from the barrel and wherein the firing is maintained until the wall is breached.

In a second embodiment the present invention provides an apparatus for breaching a wall to permit the incursion therethrough by forces such as a military force, a firefighting force or other incursionary force or apparatus. Accordingly the present invention provides an apparatus for breaching a wall including a cluster of barrel assemblies, wherein said barrel assemblies may be directed around the perimeter of a desired access, wherein the barrel assemblies include a plurality of projectiles axially disposed within a barrel and associated with discrete selectively ignitable propellant charges for propelling the projectiles from the barrel towards the perimeter of the desired access until the wall is breached.

The present invention has particular application to barrel assemblies of the type described in International Patent Application Nos. PCT/AU94/00124 and PCT/AU96/00459. Such barrel assemblies include a barrel; a plurality of projectiles axially disposed within the barrel for operative sealing engagement with the bore of the barrel, and discrete propellant charges for propelling respective projectiles sequentially through the muzzle of the barrel.

The projectiles may be round, conventionally shaped or dart-like and the fins thereof may be offset to generate a stabilising spin as the dart is propelled from a barrel that may be a smooth-bored barrel. In a preferred form the projectiles incorporate an explosive charge that is detonated on impact with the wall. In an alternative form the projectiles may be of the kinetic energy type, suitably including a sabotted elongate penetrator made of tungsten or similar material. In a further form, the projectiles may incorporate incendiary matter for burning through a barrier. If required, the projectiles of different types, ie. high explosive, kinetic energy and/or incendiary, may be loaded into different barrels or into each barrel in a desired sequence, in order to breach a particular kind of barrier.

The projectile charge may be in the form of a solid block and assist in operatively spacing the projectiles in the barrel. Alternatively, the propellant charge may be encased in metal or other rigid case which may include an embedded primer having external contact means adapted for contacting a pre-positioned electrical contact associated with the barrel. For example the primer could be provided with a sprung contact which may be retracted to enable insertion of the cased charge into the barrel and to spring out into a barrel aperture upon alignment with that aperture for operative contact with its mating barrel contact. If desired the outer case may be consumable or may chemically assist the propellant burn. Furthermore an assembly of stacked and bonded or separate cased charges and projectiles may be provided for reloading a barrel.

Each projectile may include a projectile head and extension means for at least partly defining a propellant space. The extension means may include a spacer assembly that extends rearwardly from the projectile head and abuts an adjacent projectile assembly. Such an extension means may assist the detent in the barrel in supporting the projectiles in position within the barrel when a leading charge is fired.

A spacer assembly may extend through the propellant space and the projectile head whereby compressive loads are transmitted directly through abutting adjacent spacer assemblies. In such configurations, the spacer assembly may add support to the detent and extension means. The extension means may be a thin cylindrical rear portion of the projectile head. Furthermore the extension means may form an operative sealing contact with the bore of the barrel to prevent burn leakage past the projectile head.

The spacer assembly may include a rigid collar that extends outwardly to engage a thin cylindrical rear portion of a malleable projectile head in operative sealing contact with the bore of the barrel. Thus axially compressive loads are transmitted directly between spacer assemblies thereby avoiding deformation of the malleable projectile head.

Complementary wedging surfaces may be disposed on the spacer assembly and projectile head respectively whereby the projectile head is urged into engagement with the bore of the barrel in response to relative axial compression between the spacer means and the projectile head. In such arrangement the projectile head and spacer assembly may be loaded into the barrel and there after an axial displacement is caused to ensure good sealing between the projectile head and barrel. Suitably the extension means may be urged into engagement with the bore of the barrel.

The projectile head may define a tapered aperture at its trailing end into which is received a complementary tapered spigot disposed on the leading end of the spacer assembly. Relative axial movement between the projectile head and the complementary tapered spigot causes a radially expanding force to be applied to the projectile head.

The barrel may be non-metallic and the bore of the barrel may include recesses that may fully or partly accommodate the ignition means. In this configuration the barrel houses electrical conductors which facilitate electrical communication between the control means and ignition means. This configuration may be utilised for disposable barrel assemblies that have a limited firing life. The ignition means and control wire or wires therefor can be integrally manufactured with the barrel.

A barrel assembly may alternatively include ignition apertures in the barrel and the ignition means are disposed outside the barrel and adjacent the apertures. A non-metallic outer barrel may surround the barrel. The non-metallic outer barrel may include recesses adapted to accommodate the ignition means. The outer barrel may also house electrical conductors that facilitate electrical communication between the control means and ignition means. The outer barrel may be formed as a laminated plastic barrel that may include a printed circuit laminate for the ignition means.

The rear end of the projectile may include a skirt about an inwardly reducing recess such as a conical recess or a part-spherical recess or the like into which the propellant charge portion extends and about which rearward movement of the projectile will result in radial expansion of the projectile skirt. This rearward movement may occur by way of compression resulting from a rearward wedging movement of the projectile along the leading portion of the propellant charge it may occur as a result of metal flow from the relatively massive leading part of the projectile to its less massive skirt portion.

Alternatively the projectile may be provided with a rearwardly divergent peripheral sealing flange or collar which is deflected outwardly into sealing engagement with the bore upon rearward movement of the projectile. Furthermore the sealing may be affected by inserting the projectiles into a heated barrel which shrinks onto respective sealing portions of the projectiles. The projectile may comprise a relatively hard mandrel portion that cooperates with a deformable annular portion. The deformable annular portion may be moulded about the mandrel to form a unitary projectile which relies on metal flow between the nose of the projectile and its tail for outward expansion about the mandrel portion into sealing engagement with the bore of the barrel.

The projectile assembly may include a rearwardly expanding anvil surface supporting a sealing collar thereabout and adapted to be radially expanded into sealing engagement with the barrel bore upon forward movement of the projectile through the barrel. In such a configuration it is preferred that the propellant charge have a cylindrical leading portion which abuts the flat end face of the projectile.

The projectiles may be adapted for seating and/or location within circumferential grooves or by annular ribs in the bore or in rifling grooves in the bore and may include a metal jacket encasing at least the outer end portion of the projectile. The projectile may be provided with contractible peripheral locating rings that extend outwardly into annular grooves in the barrel and which retract into the projectile upon firing to permit its free passage through the barrel. The electrical ignition for sequentially igniting the propellant charges of a barrel assembly may preferably include the steps of igniting the leading propellant charge by sending an ignition signal through the stacked projectiles. The ignition of the leading propellant charge may arm the next propellant charge for actuation by the next ignition signal. Suitably all propellant charges inwardly from the end of a loaded barrel are disarmed by the insertion of respective insulating fuses disposed between normally closed electrical contacts. The fuses are set to burn to enable the contacts to close upon transmission of a suitable triggering signal, with each insulating fuse being open to a respective leading propellant charge for such ignition. Ignition of the propellant may be achieved electrically or ignition may utilise conventional firing pin type methods such as by using a centre-fire primer igniting the outermost projectile and controlled consequent ignition causing sequential ignition of the propellant charge of subsequent rounds. This may be achieved by controlled rearward leakage of combustion gases or controlled burning of fuse columns extending through the projectiles.

In another form the ignition is electronically controlled with respective propellant charges being associated with primers which are triggered by distinctive ignition signals. For example the primers in the stacked propellant charges may be sequenced for increasing pulse width ignition requirements whereby electronic controls may selectively send ignition pulses of increasing pulse widths to ignite the propellant charges sequentially in a selected time order. Preferably however the propellant charges are ignited by a set pulse width signal and burning of the leading propellant charge arms the next propellant charge for actuation by the next emitted pulse.

A number of projectiles can be fired simultaneously, or in quick succession, or in response to repetitive manual actuation of a trigger, for example. In such arrangements the electrical signal may be carried externally of the barrel or it may be carried through the superimposed projectiles which may clip on to one another to continue the electrical circuit through the barrel, or abut in electrical contact with one another. The projectiles may carry the control circuit or they may form a circuit with the barrel.

Generally the desired access will be sized to readily allow the incursion of the force. For example, for an incursion by a small team of people an access may be desired to be sized so that the people may pass unencumbered through the access, either one at a time or in groups. For providing access for a machine, manned or unmanned, the access will be positioned to be readily accessed and be of sufficient size to allow passage therethrough. The cluster of barrel assemblies may be in the form of a pod. Such a pod may include barrels that are capable of independent alignment or alternatively the barrel assemblies may be fixed relative to each other and the pod may be mounted on a turret or similar rotatable mount.

The projectiles may preferably be fired sequentially to limit the recoil effect on the cluster of barrel assemblies. The projectiles may be fired in a pattern that follows the perimeter of the desired access. The pattern may track the sequentially around the perimeter or may sequentially hit intermediate points around the perimeter and subsequent firings hit the remainder of the perimeter. Alternatively if immediate access is required then a plurality of projectiles may be fired simultaneously from a number of barrel assemblies.

In a preferred embodiment the cluster of barrel assemblies is mounted on a robotic vehicle. The use of robotic vehicles in the present invention to breach an urban obstacle may reduce the risk to the troops attempting to access a location. Remote control or tele-operation technology may enable troops to target the desired areas for breaching and fire the breaching device from a remote and safe position.

In this preferred embodiment the breaching apparatus may fire a dense array of kinetic projectiles to impact and breach the wall or the breaching apparatus may deploy explosive shells or projectiles to the wall in a very tight pattern. In either case, the projectiles selected may be determined in the field based on the construction of the wall to be breached.

In another embodiment the weight of the gun pod could be relatively light and be able to be carried by a soldier. The cluster of barrel assemblies has the potential to generate a significant recoil force. In order that the projectiles may be fired in rapid succession the system preferably is capable of absorbing the recoil of firing. This recoil could be considerable. Either the support structure has sufficient mass and hence inertia to be relatively unaffected by the recoil or recoil abatement strategies may need to be employed. If the weapon, were used to provide a pattern of explosive projectiles, the required delivery velocities could be reduced considerably and the recoil reduced accordingly. The weapon could deliver these explosive projectiles in a very focused pattern to amplify their impact on the wall. The structure, be it in the form of a fixed platform or a mobile robot, may be anchored or braced onto the ground.

BRIEF DETAILS OF THE DRAWINGS In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a typical embodiment of the invention and wherein: FIG. 1 is perspective view of a tactical mobile robot having a gun pod of an embodiment of the invention;

FIG. 2A shows a tactical mobile robot as shown in FIG. 1 for use in breaching a wall;

FIG. 2B shows the tactical mobile robot getting into position to breach the wall;

FIG. 2C shows the tactical mobile robot in position and the gun pod firing at the selected point of breach;

FIG. 2D shows the resulting breached wall; FIG. 3 shows a cross section of a pod of barrel assemblies of another embodiment of the invention;

FIG. 4 is a cross-sectional view of the barrels of the gun pod employed on the robot of FIG. 1 ; and FIG. 5 is a side elevational view of the tactical mobile robot of FIG. 1.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION In wall breaching for military applications, the weapon preferably blows a hole in a wall that is large enough for a fully dressed, and preferably equipped, soldier to pass through. The weapon may be mounted on a tele-operated platform that will be driven to the point to be breached. In the embodiment depicted in FIG. 1 , the platform is a mobile robot vehicle 10 propelled by wheels 11 and having a cluster of barrels 12 in a pod 13 which is mounted on a movable turret 14.

We estimate a hole of at least one (1 ) meter in diameter is required for this application. For this requirements analysis, we assume the wall 20 with the breaching point 21 is made of concrete, see FIG. 2A. Concrete here is a mixture of water, cement, aggregate, air, and admixtures. The average strength of concrete is 3940 psi (27.165 MPa), but concrete may vary in strength from actual tests from 2020 psi (13.93 MPa) to 6090 psi (42.00 MPa). The specified compressive strength is measured from compression tests conducted on 6 inch (152.4 mm) by 12-inch (304.8 mm) sample cylinders of concrete.

It is also assumed that a projectile is 40 mm in diameter, which equates to a surface area of 0.785 in² (506 mm²). In the hyper-velocity region, ie. for muzzle velocities in the region of 1400 ft/s (427 m/s) and over, a 40 mm projectile will normally make a clean penetration through a concrete wall. For a one (1) meter diameter access hole, we would theoretically require 491 barrels for the weapon.

By removing half the material for 50% porosity, the weapon still requires 246 barrels. This is still considered to be too many barrels for any practical application.

In one embodiment of our invention we fire a ring of projectiles to make a complete circle or a perimeter pattern, as depicted by the cross-sectional view of the pod 30 in the FIG. 3. In that configuration approximately 79 barrels would be required to form a circular hole. If the projectile is subsonic, we will assume that each projectile will create a six (6) inch (152.4 mm) diameter hole. It will be appreciated that a cluster of outwardly divergent barrels may provide a more compact pod, but achieve a similar impact pattern

Another option would be to take advantage of double-tap and triple-tap operations where firing a series of projectiles in quick succession and the natural recoil of the weapon could be timed to achieve up to a 6-tap motion.

In another embodiment, the cluster of barrels may consist of a horizontal row of six barrels spaced C six (6) inches apart, such as the pod 13 depicted in FIGs. 1 and 4. The gun pod could be approximately 31.5 inches (800 mm) wide W and three inches (76.2 mm) tall. The barrels 12 may have a bore of 1.57 inches (40 mm) in diameter, with a half-inch (12.7 mm) tube wall. If we assume a chamber pressure between 10,000 - 20,000 psi (68.95 - 137.90 MPa) this will result in a muzzle velocity of about 250 m/sec.

The weapon pod 13 may have the following dimensions, for 6-tap operation as depicted in FIG. 4. The weapon will be a minimum of 30 inches (762 mm) long, having barrels containing six (6) axially disposed projectiles each 5 inches (127 mm) long, plus free barrel length. We will initially assume a free barrel length of three feet (915 mm). To compress the concrete at 3940 psi, a compressive force of 2067 Ibf (9.194 kN) will be required. Working the applicable equations of motion in reverse, we require a minimum barrel length of 0.78 feet (20 mm). However, longer barrels improve projectile travel, and we prefer a three-foot (915 mm) long barrel. This, together with the projectile stack length of 30 inches, the overall length of the gun barrel will be 66 inches (1676 mm) long.

The weapon has been tested with pressure of 8,000 psi, generating a force of 15,479 Ibf (68.83 kN) on a 40 mm projectile. This force represents a magnitude of fifteen (15) times greater than the compressive strength of concrete.

In reviewing recoil data from existing artillery weapons, we estimate that the recoil force is 3000 Ibf (13.34 kN). With a lever arm of 48 inches (1219 mm), it requires a force to counter a 12,000 ft-lbf (16.26 kN.m) moment. The tele-operated platform of the embodiment is a skid-steered robotic vehicle 10 that weighs 2420 lb (1097 kg). The centre of gravity of the vehicle is at the centre of the vehicle 10 and with a moment arm of 1.35 feet (411.5 mm) to the centre of the rear tyre, this produces a counter moment of 3267 ft-lbf (451.4 Nm). This is well short of what is required and it is preferred that a stabiliser be used. The stabiliser member 15 on the platform 17 of the embodiment extends back L from the centre of gravity 18 by 60 inches (1.52 m), see FIG. 5.

In the embodiment, the gun pod 13 suitably has the following dimensions: it has six (6) barrels 12 with a bore of 1.57 inch for a 40 mm projectile of tungsten. Its construction will be six individual barrels, three bulkheads, and a thin aluminium skin to stiffen the structure. The skin will counter any torsion in the gun box structure. This weapon will handle 6 rounds of shots and the timing of firing the projectiles is analysed to space the shots 6 inches (152.4 mm) apart on centre in a 6-tap configuration, as represented by FIG. 4. It will be appreciated that recoil causes the pod 13 to move marginally upwardly during firing. This recoil may be used to advantage in conjunction with a precisely controlled rate of fire, thereby resulting in the illustrated spacing of shots on the target. The marginal movement resulting from recoil is represented by the arrow 40 in FIGs 4 and 5. A preliminary mass estimate was made with the gun box 13 weighing approximately 440 Ibm (200 kg), not including projectiles, explosives, electrical power, or any of the electronics that are required for triggering the weapon.

More detailed data about this mass estimate is provided in the following table:

Table 1 : Unmanned Guided Vehicle Gun Pod The mass of the weapons could be reduced to 84 Ibm (38 kg), which mass allows the weapon to be man-portable.

The robotic vehicle 10 may be tele-operated into position, facing the wall 20 to be breached as depicted in FIG. 2B. The vehicle 10 lowers the stabilizer 15 and the weapon is fired as depicted in FIG. 2C. The weapons pod 13 is arranged for a 6- tap firing. This produces an opening 21 greater than 1 -meter in diameter in the wall

20 with no explosive residual lingering in the air that has to be cleared.

The barrel assemblies are alternatively suitably arranged in a circular configuration, having a diameter of approximately one metre. In this configuration the projectiles fired from the barrel assemblies will provide a breach having a diameter also of approximately one metre. In a preferred configuration such a pod of barrel assemblies may be splayed so as to obtain a larger breach in the wall or may be constrained so as to obtain a smaller breach. In the preferred configuration the pod assembly may be capable of being varied with respect to its splaying so that the size of the breach can also be controlled.

The projectiles used in the barrel assembly may range from kinetic energy type penetrators, high explosive types and incendiary types. In one application, it may be desirable to fire an elongate tungsten penetrator type projectile to loosen the concrete, followed by one or more high explosive rounds to remove more concrete, and perhaps subsequently by incendiary rounds to weaken any reinforcing rods that may be present in the wall. It will be appreciated that the cluster of barrel assemblies may include barrels containing specific types of round, although it would be desirable to load the barrels with a predetermined sequence of projectile types suited to the desired breaching application. FIG. 5 shows a tactical mobile robot 10 having a gun pod 13 mounted on the transportable platform 17 by a turret 14. A stabilising ground engaging bar 16 linked to the platform by stabilising members 15 is used to retain the robot in position during the firing of the projectiles from the gun pod 13. If required, the pod 13 may be arranged in a gimbal mounted turret on the platform. It will of course be realised that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as is herein set forth in the following claims.

Claims

1. A method for breaching a wall or barrier, said method including the steps of firing a multiplicity of projectiles from a cluster of barrel assemblies, said firing being directed around the perimeter of a desired access through said wall or barrier, wherein the barrel assemblies include a plurality of projectiles axially disposed within a barrel and associated with discrete selectively ignitable propellant charges for propelling the projectiles from the barrel and wherein the firing is maintained until the wall is breached.

2. The method of claim 1 wherein the projectiles are fired sequentially to limit the recoil effect on the cluster of barrel assemblies.

3. The method of either claim 1 or claim 2 wherein the projectiles are fired in a pattern that follows the perimeter of the desired access.

4. The method of claim 3 wherein the firing pattern tracks sequentially around the perimeter.

5. The method of claim 3 wherein the firing pattern initially sequentially hits intermediate points around the perimeter and subsequent firings hit the remainder of the perimeter.

6. The method of claim 3 wherein a plurality of projectiles are fired simultaneously from a number of barrel assemblies in order to provide immediate access.

7. An apparatus for breaching a wall, said apparatus including a cluster of barrel assemblies, wherein said barrel assemblies may be directed around the perimeter of a desired access, wherein the barrel assemblies include a plurality of projectiles axially disposed within a barrel and associated with discrete selectively ignitable propellant charges for propelling the projectiles from the barrel towards the perimeter of the desired access until the wall is breached.

8. The breaching apparatus of claim 7 wherein the cluster of barrel assemblies are in the form of a pod.

9. The breaching apparatus of claim 8 wherein the pod includes barrels that are capable of independent alignment.

10. The breaching apparatus of claim 8 wherein the barrel assemblies are fixed relative to each other.

11. The breaching apparatus of any one of claims 8 to 10 wherein the pod is mounted on a turret or similar rotatable mount.

12. The breaching apparatus of any one of claims 7 to 11 wherein the cluster of barrel assemblies is mounted on a robotic vehicle.

13. The breaching apparatus of claim 12 wherein the robotic vehicle is remotely controlled or tele-operated technology, enabling the desired areas for breaching to be targeted and fired upon from a remote and safe position.

14. The breaching apparatus of any one of claims 7 to 13 wherein said barrels are loaded with any one or more different projectile types, including kinetic energy type, high explosive type and/or incendiary type.

15. The breaching apparatus of claim 14 loaded with different projectile types, wherein the projectile type may be selected in the field based on the construction of the wall to be breached.

16. The breaching apparatus of either claim 14 or claim 15 wherein different types of projectile are loaded into respective barrels.

17. The breaching apparatus of either claim 14 or claim 15 wherein different types of projectile are loaded into one barrel of said cluster of barrel assemblies, in accordance with a desired breaching application.

18. The breaching apparatus of claim 14 including barrels containing kinetic type projectiles, whereby said breaching apparatus may fire a dense array of kinetic projectiles to impact and breach the wall.

19. The breaching apparatus of claim 14 including barrels containing explosive shells, whereby said breaching apparatus may fire explosive shells to the wall in a very tight pattern.

18. The breaching apparatus of claim 14 including barrels containing incendiary type projectiles whereby combustion of the wall or barrier may be initiated.

20. The breaching apparatus of any one of claims 8 to 10 wherein the weight of the pod is sufficiently light that the pod may be carried by a person.

21. The breaching apparatus of any preceding claim arranged for absorbing recoil in order that the projectiles may be fired in rapid succession.

22. The breaching apparatus of claim 20 including a support structure which has sufficient mass so as to be relatively unaffected by the recoil.

23. The breaching apparatus of claim 22 including a support that is anchored or braced onto the ground.

24. The breaching apparatus of claim 22 wherein the support structure comprises a fixed platform.

25. The breaching apparatus of claim 22 wherein the support structure comprises a robotic vehicle.