[0055] Referring to FIG. 1 of the drawings, it will be seen that the apparatus illustrated therein comprises a plastics box 1 with an approximately rectangular transverse section. Three semi-cylindrical plastics formers 2 are held against the inside of the lid 3 . If a layer of high explosive is attached to the inner or outer surface of each former 2 and all remaining space is filled with water, detonation of the explosive projects the water within the formers 2 violently through the lid 3 of the box 1 .

[0056] Referring to FIG. 2 of the drawings, an arrangement similar to that of FIG. 1 is provided with an inflatable plastics or rubber bag 4 in each of the formers 2 . Each of the three bags 4 is provided with an integral nozzle 5 which passes through holes in the lid 3 in order to allow filling with water once the lid 3 is in place. A further bag 6 occupies the space 7 behind the formers 2 and is filled with water through the nozzle 8 which passes through one end-wall of the box 1 .

[0057] Referring to FIG. 3 of the drawings, the former 2 for imparting the necessary shape to an explosive charge consists of a semi-cylindrical plastics extrusion. Its shape may conveniently be semi-cylindrical but other suitable concave shapes, including but not limited to a V-section or a parabolic shape, may also be used. A common form of explosive for application to such a liner consists of sheet explosive, typically between one and six millimetres thick, which is stuck to the outer or the inner surface. Alternatively detonating cord may be passed longitudinally to and fro between the ends along the outside of the former, passing through the notches and round the projections of the crenations 9 at each end. The explosive load may be increased by passing the detonating cord more than once between each corresponding pair of projections, or by passing in one direction along the outside of the former and back in the other direction along the inside.

[0058] Alternatively, light loads may be arranged by using less detonating cord, leaving the gaps between some adjacent projections empty. Sheet explosive may be used instead of detonating cord. It may conveniently be stuck to either surface of the former using an adhesive or double-sided sticky tape. One or more plastic cable ties 10 passing through pairs of holes in the former 2 provide a means of securing the tail of the detonating cord. If sheet explosive is used, a length of detonating cord 11 with a tubular explosive booster 12 at its end is secured so that the booster is urged into contact with the sheet explosive 13 .

[0059] Referring to FIG. 4 of the drawings, a transverse section of the invention shows sheet explosive 13 applied to the backs of the formers 2 and the flexible bags 4 & 6 inflated with projectile water 14 and tamping water 15 respectively.

[0060] Referring now to FIG. 5 of the drawings, the end view of an assembled disruptor shows the lengths of detonating cord 16 , 17 & 18 emerging through holes 19 in the wall of the box 1 and going to the point of initiation where a detonator 20 is held in contact with them. The detonating cord is held against the surface of the box 1 by means of a multiplicity of plastic ties 21 . It will be appreciated that the devious paths taken by the three strands of detonating cord 16 , 17 & 18 are so determined that each separate strand travels an equal distance between the point of initiation 20 and the former to which it leads in order that all strips of explosive 13 be initiated simultaneously.

[0061] The disrupter 30 of FIG. 6 comprises a former 31 with three semi-cylindrical recesses of which the central recess 32 is of greater volume than recesses 33 and 34 . Bag 35 of water substantially fills recess 32 , and bags 36 and 37 of sodium hypochlorite solution substantially fill recesses 33 and 34 The amount of explosive (not shown) for each recess is proportionate to the volume of the recess and the mass of the material in the recess.

[0062] In a variant, the amount of explosive in the central recess 32 is greater than the proportionate amounts in recesses 33 , 34 by volume and mass, so that the overall explosive effect will be greater in the central region. Clearly, the proportions of explosive material, the nature of the filling material, and the amounts and density/mass of filling materials, can be changed as required to provide different profiles of explosive effect. All these variants can be used with the disrupter of FIGS. 1 to 5 .

[0063] A particular advantage of this invention is that the device may be stored and transported with the explosive in situ, but containing no water. This considerably reduces the weight and susceptibility to damage by rough handling. When required for use, the inflatable bags may be quickly filled with water obtained locally without any need to open the outer container.

[0064] The invention is not limited to the use of detonating cord as a means of initiation. Sufficient simultaneity of initiation of each element can be assured by means of shock-tube detonators provided that equal lengths of shock-tube run between the point of initiation to the proximal part of each explosive charge increment.

[0065] The great advantages of using water as the working fluid in the invention are its suitable density, lack of flammability, fire-quenching and heat absorbing properties, cheapness, availability, and complete lack of toxicity; however, the invention is not limited to the use of pure water as its working fluid. Indeed, the use of separate flexible bags for containing the working fluid and the tamping liquid respectively enables the invention to be employed with two different fluids, of which one provides the projectile and the other the tamping and the means of modifying collateral effects. Thus, and by way of example, the water may have its density raised by the dissolution of inorganic salts, its coherence increased by the addition of long-chain polymeric substances such as the sodium salt of carboxymethylcellulose, and its fire quenching properties augmented by the addition of sodium borate or sodium bicarbonate. For use in cold climates the freezing point of the water may be depressed by the addition of such anti-freeze substances as ethylene glycol, methanol or calcium chloride. The tamping effect of the fluid surrounding the rear and sides of the charge may be enhanced by increasing its density. This may be achieved by the dissolution of inorganic salts or by the incorporation of solid, particulate, substances such as sand or sodium bicarbonate.

[0066] Water may also be replaced by a suitable pressed or melt-cast solid material. Since explosive materials are less easily initiated by the impact of materials of low melting point, suitable substances are inorganic salts with a high proportion of water of crystallisation. One such substance which has been found particularly effective is disodium hydrogen phosphate dodecahydrate. Another suitable material is sodium bicarbonate which, upon heating, decomposes with the liberation of water and carbon dioxide.

[0067] The invention is of particular usefulness if it is required to disrupt a device known or believed to contain a biological pathogen, such as a live bacterium or the spores thereof, or an extremely toxic chemical, such as a nerve gas. In this case, disruption of the target munition is likely to disperse the pathogen in the manner intended by the maker of the target. By the use of a concentrated solution of sodium hypochlorite, or some other suitable decontaminant, as the projectile liquid, any such dispersed target material will be intimately mixed with a finely divided cloud of decontaminant and thus rapidly neutralised.

[0068] A particular advantage of the invention is that it is a powerful disruptor suitable for large targets even when made such a size as to be easily portable by a single operator. This, as well as its flat, rectangular shape, enables arrays of similar charges to be quickly assembled on a fixed or mobile frame in order to form an array so configured as to attack a target in the most advantageous Way.

[0069] By way of example:

[0070] A disruptor having a similar cross-section to that shown in FIG. 4 was made in a plastics box 350 mm wide and 550 mm long with a height of 100 mm. Three semi-circular plastics formers were fitted, edge to edge, against the inner face of the lid. Each former was covered on its convex surface by a layer of Detasheet plastic explosive 6 mm thick. This gave a total explosive load of approximately 2.5 kg.

[0071] The disruptor was filled with water and placed opposite that part of a transit van within which were stood two plastic bins containing approximately 960 kg of explosive consisting of prilled ammonium nitrate sensitised by the addition of nitromethane and diesel and containing cartridges of gelignite. Initiation of the disruptor opened a wide hole in the distal side of the van and ejected the explosive-filled bins through the opposite side of the vehicle, most of which was also removed. The bins were ripped apart and the explosive they contained widely dispersed. There was no evidence to suggest that any of the explosive target material had been detonated. The vehicle did not catch fire.

[0072] FIGS. 7 to 15 show features of another form of disrupter 40 which consists of two major components, one being a water-filled enclosure 41 placed within the concavity in the explosive charge 42 and the other a water-filled enclosure 43 placed on the convex side of the explosive.

[0073] By providing enclosure 43 with a recessed area 44 extending for most of its length, a space is created to receive the explosive charge 42 . The volume of this space is a function of the distance between enclosure 41 and enclosure 43 which is determined by the height of ridges 45 at each end of component 43 upon which the ends of enclosure 31 rest.

[0074] It is necessary for enclosures 41 and 43 to be held closely together after the explosive charge 42 has been placed between them. This is done by end-caps 46 into which the ends of both enclosures 41 and 43 may be fitted so that the peripheral walls 47 of the end-caps 46 constrain them. The end-caps 46 may be prevented from falling off the ends of enclosures 41 and 43 by providing them with one or more small projections 48 which fit into corresponding peripheral grooves 49 in the outer surfaces of enclosures 41 or 43 or both.

[0075] Since it is advantageous on occasion to fire a close array of charges simultaneously, these may conveniently be held in suitable juxtaposition by forming a multiplicity of end-cap sections in a linear array (see FIGS. 12, 16 and 17 ). Individual end-cap sections comprising such an array may be mutually attached by means of a pair of interlocking ridges 50 on each side. Thus the two major elements of disruptor 40 (namely enclosures 41 and 43 ) are supported, preferably but not necessarily in close proximity, with an explosive charge 42 trapped between them.

[0076] The disruptor 40 may comprise a single unit with two enclosures 41 and 43 having a charge between them. Alternatively, the disrupter 40 may be a linear array of parallel closely-spaced charges, all pointing in the same general direction. Additionally, disrupter 40 may be formed of two or more units arranged end-to-end in order to increase the overall length of the assembly.

[0077] The casing 41 of the assembled disruptor 40 , which consists of the enclosures 41 and 43 with the explosive 42 between them, may conveniently be generally rectangular. Since, however, the water most adjacent to the longitudinal corners of casing 41 defining such a rectangle and most distal from the explosive charge 42 contributes little to the tamping effect on the explosive charge for which it is intended, these corners may advantageously be ablated. In this way, the total weight of the assembly may be reduced without diminishing significantly its performance. In order better to support casing 41 , the end-caps may be provided with a correspondingly shaped internal wall 52 although retention of the generally rectangular peripheral wall of the end-caps facilitates the provision of a strong means of inter-attachment, such as the interlocking members 50 .

[0078] A suitable method of producing the water-filled enclosures 41 and 43 is blow-forming. Though it is possible to form vessels with thick walls by this method, a greater volume of water and explosive can be contained within a given outer envelope by forming relatively thin walls. In order to reduce the tendency of liquid-filled, thin-walled vessels to undergo deformation as a result of internal hydraulic pressure, the peripheral grooves 49 may advantageously extend round the outward facing sides of casing 41 in planes perpendicular to the longitudinal axis of the charge.

[0079] The inner surface enclosure 43 can be depressed so as to provide space for the explosive 42 . Space for the explosive could alternatively be obtain by the provision of a raised area of the other water-containing enclosure 41 .

[0080] Further depressions 55 can be provided in either water-filled components to accommodate such other pieces of priming explosive as may ensure reliable initiation of the main charge 42 by a primary means of initiation such as a detonator.

[0081] It is desirable that explosive charges incorporate a strong means of attachment of the means of initiation, which include an electric detonator, a shock-tube detonator, a detonating cord booster or detonating cord, to the assembly. This is in order to prevent accidental separation or, in the case of electric detonators, accidental violent pulling of the electric wires through the end plug. Thus, the end-caps 46 may be provided with one or more projections 57 in the form of a hoop or hook to which detonating cord or detonator leads may be secured.

[0082] Thus disruptor 40 is based around a structure having two or more end-cap portions in line, with adjacent end-cap portions having an intervening web portion. In this way, there may be provided strips of end-caps (e.g. each strip having six end-caps in line with intervening web portions) which can be separated into single end-caps, pairs or whatever by cutting through web portions as appropriate. The end-caps are used to hold together all the other elements of the structure in a disruptor, namely the former, the box parts, the top and the explosives.

[0083] The strip of end-caps constitute a line of end-caps with intervening webs; the end-caps may be of shapes other than square or rectangular e.g. triangular (whether in identical orientations or in alternating opposite orientations), or hexagonal. The end-caps may be in two-dimensional blocks rather in one-dimensional lines, e.g. to provide a curved arrangement after selective cutting out of some end caps.

[0084] The intervening web between adjacent end-cap portions may be rigid and/or solid. Alternatively, the web may be flexible and/or expandable.

[0085] In one embodiment, the disruptor comprises units in a parallel array in a concave or a convex plane in order to concentrate, or focus the disruptive forces or, conversely, to generate a divergent mass of projectile material.

[0086] The end-caps may employ flexible means of attachment. Interconnection, for example, by blocks of flexible plastic or rubber foam enable an array to be flexed into a curved (convex or concave) configuration. When the material is stiff but crushable (as with paper or thin plastic honeycomb), then the hinge is made deformable but inelastic, thus facilitating rapid adjustment. The end-cap may have an expandable web.

[0087] FIG. 13 shows an alternative means of providing an adjustable means of inter-connection between end-caps in order to allow variable convergence or divergence of adjacent components of an array. A circular and rotatable turret-like insert 60 is passed through a hole 61 in the end-cap 46 and is constrained in that position by an integral external lip 62 . The ability of insert 60 to rotate after insertion in the end-cap 46 may be prevented by the teeth 63 on the periphery of the lip 62 which engage in any of a multiplicity of possible positions in the teeth 63 surrounding the hole 61 on the inside of the end-cap 46 . The insert 60 has a transverse hole 61 which may conveniently be rectangular. Insertion of a rigid rectangular sectioned lath 64 through the holes 61 in an array of interlocked end-caps 46 stiffens the assembly and provides a means of grasping and manipulating the array by remote means.

[0088] By rotating the inserts 60 in the end-caps 46 of two or more casings 41 , an array 70 may be assembled by passing a pair of laths 64 through the holes 61 in the inserts 60 in which the individual charges project the matter contained within enclosures 41 in a convergent or a divergent manner, thereby to suitably direct or spread the effect of the disrupter as appropriate.