GB2569454A - Explosives neutralisation system - Google Patents

Abstract

An underwater charge placement system comprising a container 470 for housing one or more explosive charges 481. The charges 481 have a length of exploding fuse 490 associated therewith which can extend between the container 470 and a target. The charges 481 can be removed from the container 470 and placed on a target, and thereafter the or each charge 481 can be detonated by initiation from the container 470.

Description

The present invention relates generally to neuralisation of explosives, such as mines, and particularly, although not exclusively, to the deployment of multiple neutralising charges and their initiation.

A frequent requirement of explosives neutralisation and/or demolition operations is the initiation of a multiplicity of explosive charges either simultaneously or in rapid succession. One means of achieving this is provided by electronic delay detonators, each of which explodes a predetermined time after initiation by an electric pulse. Another is the use of shock tube non-electric detonators with a pyrotechnic delay. Another means of initiation of a multiplicity of charges is by interconnection by means of detonating cord, in which case delays are controlled by varying the lengths of detonating cord to control the time at which the initiation front arrives at an individual charge.

Detonating cord consists of a cord spun from plastics thread and usually clad by a sheath of thermoformed plastics all of which inert components confine a core of powdered explosive, which is most commonly pentaerythritol tetranitrate (PETN). Such cord usually has a diameter between three and six millimetres and an explosive load between five and twenty grams a metre.

A shock tube detonator is similar to a detonator initiated by shock tube except that the firing signal is sent using shock tube instead of detonating cord. Shock tube consists of flexible plastics tubing, typically having an external diameter of only 3mm, with its inner surface lined with a very thin coating of a mixture of a high explosive such as HMX mixed with fine aluminium powder. This is initiated at its proximal end by a relatively small initiating charge, such as a percussion cap, and an explosively generated shock wave travels its length without bursting the tube. The distal end of the shock tube is crimped into the mouth of a detonator which is initiated by the shock wave. The shock wave travelling through shock tube does not have sufficient energy to convey its shock to an adjacent length of shock tube and thus bring about its initiation.

Such detonating cord is reliably initiated either by a detonator which is usually attached to the side of the cord or by means of another strand of detonating cord held in contact with it. In the latter case a single strand of detonating cord can transfer the detonation to a multiplicity of strands of detonating cords suitably attached to it.

I

Attachment of one length of detonating cord to one or more other strands to which it is intended to convey detonation may be conveniently and reliably accomplished by taping them together using slightly elastic plastics tape, such as is commonly used for bunching and insulating electrical wires, or by means of plastics or metal clips which urge them into contact with each other. The first strand of detonating cord in such a sequence is itself initiated by a single detonator similarly attached.

The application of tape or plastic or metal clips for this purpose depends upon all the explosive components being easily accessible and bare hands being sufficiently agile to apply the tape or other means of attachment with firmness and accuracy. This requirement for dexterity is most difficult in low temperatures and in very wet conditions.

Particular difficulty occurs if the interconnection of detonating cords or shock tube for the initiation of a multiplicity of explosive charges is in a place where manual approach is impossible or unacceptable either because of inaccessibility or because danger of human access. Examples of such situations are: submarine; the presence of intense radioactivity, dangerous toxins, the possibility of explosion, or a significant probability of premature collapse of a seriously damaged building or other structure following an earthquake or a previous failed attempt at demolition.

In such circumstances all on-site preparations for the demolition may have to be carried out using remote-controlled vehicles (RCVs). The use of such vehicles means that the operator or operators may not be able to see directly the objects to be targeted by the explosive charges but have their vision limited to viewing no more than the images transmitted from cameras carried by the RCVs to computer screens. This remoteness renders impossible the use of tape to interconnect separate lengths of detonating cord.

In one aspect the present invention provides an underwater multi-charge placement system comprising a container for housing one or more explosive charges, the or each charge having a length of exploding fuse associated therewith which can extend between the container and a target, whereby the charge/s can be removed from the container and placed on a target, and thereafter the or each charge can be detonated by initiation from the container.

In some embodiments the link pays out from the container as the charged is removed and taken to a target (for example by an ROV). In other embodiments and ROV could swim out to the target, then swim back to the container, paying out link from the charge as it does so (whereupon it would be connected to the initiation system of the clump).

In a further aspect the present invention provides an underwater multi-charge placement system comprising a container for housing one or more explosive charges, the or each charge having a length of exploding fuse associated therewith which can pay out from the container, whereby the charge/s can be removed from the container and placed on a target, and thereafter the or each charge can be detonated by initiation from the container.

The length of exploding fuse may be, for example, detonating cord or the like.

Each charge may have an explosively initiatable link associated or associateable therewith. In some embodiments the links are received or receivable on a common dock provided on or by the container.

The initiation (simultaneous or individual) may be achieved by one or more firing cables or the like which extend from the container to the surface. The initiation event/s pass to the charge/s via the container. Multiple charges with a single firing system is achievable in this way.

When the container is deployed from the surface a float may stay on the surface, or such a float could be configured to pop up to the surface before firing. For example a master initiator may be released from the container after all charges have been placed and then be connected to a firing mechanism/device.

In some embodiments the link/s comprise detonating cord or the like. Particularly when operating on the seabed it may be helpful to provide small weights along the length of the cord.

The container may include a common dock, the dock comprises or can receive an explosive initiator for initiating all attached links in use leading to onward initiation of explosive devices connected thereto.

In some embodiments means are provided to allow a float to sink to a certain depth below the surface, such as a plummet sinker system. For example the depth you want the float to go to is determined and when the clump is dropped it pays out. When the clump hits the sea bed, a break comes on and pulls the float down to the pre-determined depth. This system could be useful when you do not want things visible on the surface. A timer could be used to allow the float to bob to the surface at a fixed time ready for receiving a fire signal, but avoids the float from going to great depths.

In one aspect the present invention provides an underwater multi-charge placement system comprising a weighted container for housing a plurality of explosive charges and a shareable dock to which a plurality of explosively initiatable links, which are associated or associable with the charges, are or can be attached, the dock comprises or can receive an explosive initiator for initiating all attached links in use leading to onward initiation of explosive devices connected thereto.

At great underwater depths it is difficult to keep equipment on the seabed. The present invention can be used to provide a base station, loaded with equipment (such as neutralising charges) and from which an R.OV or the like can operate.

In some embodiments the system is deployed in a safe state i.e. there is no initiator connected. For example the container could comprise a box (such as a wooden box filled with concrete). The box houses or holds a dock or “bunch connector” and a magazine of explosive charges. The dock is not connected to an initiator and the charges are not connected to the dock. The container can therefore be deployed safely, for example from the side of a marine vessel such as a boat, so that it sinks to the bottom of a marine environment. In some embodiments such a container is deployed with a line of detonating cord attached to the dock, the line pays out from the boat but is not at that stage connected to a detonator on the boat.

With the sunken container in position an R.OV could then pick up a charge and take it to a target. The charge may have detonating cord, shock tube or the like connected to it so that it pays out as the R.OV travels out to the target. For example reels of cord may be provided on or by the container (for example by the link). The other end of the cord may be pre-attached to a dock via a link, or the R.OV may travel back to the container and attached the link to the dock.

If shock tube is used, it can have a tendency to float. In some embodiments lengths of shock tube are pre-fitted with weights, or weights are attached as the shock tube pays out.

When all required charges are in position, at that point the system may be armed. For example the line from the container to the vessel may be connected to an initiator. In some embodiments an acoustic initiation system is used and could be armed once all charges are positioned.

A single initiation event can then be used and all of the links on the dock are actuated so that the initiation event is then propagated to each of the charges deployed on targets.

In some embodiments the system is presented as a gravity-driven “clump”. The clump could be likened to a toolbox which can be accessed by an R.OV. Depending on how the system is configured, the charges are not “live” during transport and deployment and even until after they are all deployed, which can be used to improve safety.

In some embodiments the initiator for initiating the links is situated remotely of the container. For example the initiator may be provided on a marine vessel from which the container is deployed.

The initiator may comprise a detonator or the like.

The links may be formed separately of and be attachable to the dock.

The links may be attachable to the dock by magnetic means. One or more magnets may be provided for this purpose.

In some aspects and embodiments the present invention relates to a mine neutralisation system.

Some aspects and embodiments provide a mine neutralisation weapon datum system (which may be referred to as a “clump”).

The mine neutralisation system may provide a method of deploying explosive neutralisation charges in future mine countermeasures operations.

Remote surface vessel carries a number of weighted “clumps” which may be remotely released and which drop to the sea bed.

Each clump holds one or more explosive charges, a remote firing system and seabed-surface connections.

Built in safety features remove any risk of unintended initiation of charges.

R.OV collects charge from clump and places next to target.

Charges are connected to the clump, not the surface float removing the risk of charge being pulled off target.

In some embodiments the clump may have an explosive spigot to which the charges are connected.

In some embodiments it is the fact that individual charges are all connected back to a central clump that is key.

The system can be configured for magnetic influence mines in:

Deep Water Mine Clearance Operations

Shallow Water (VSW) Operations

Ground Mines

Moored Mines

Some advantages of apparatus and method formed and conducted in accordance with the present invention include:

System does not require contact with the target mine

No risk of charge being pulled off the target by swell and tides

Shaped Charge design is not constrained by legacy designs

Charge capable of being fired through mud, sand and water

It will enable an R.OV to be used more effectively in that it will be capable of deploying a wider variety of weapons systems in a single mission.

The removal of existing weapon systems from an R.OV will greatly reduce the overall magnetic signature.

It is a purpose of some aspects and embodiments of the present invention to provide a reliable means of connecting one or more lengths of detonating cord which have been previously attached to each individual charge or group of charges to a common means of their simultaneous initiation after each such charge has been secured to the part of a target upon which they are to function.

Features of such a system could be used in combination with the underwater system described herein.

According an aspect of to the present invention there is provided a device for common initiation of a multiplicity of explosive devices, comprising a shareable dock to which a plurality of explosively initiatable links (receptors) can be attached. The dock comprises or can receive an explosive donor for initiating all attached receptor links in use leading to onward initiation of explosive devices connected thereto.

The “initiator” can be a detonator or other charge that initiates the donor and starts the explosive detonation chain.

The dock may comprise a panel, for example a generally flat structure. In some embodiments, for example, the dock is formed as a board-like article.

In some embodiments links are attachable to the dock by magnetic means. For example the dock may include a metal grill to which links are attached magnetically in use.

The device may further comprise link attachments for receiving a link and which are attachable to the dock. For example the link attachments may include magnetic means for attaching to the dock. The link attachments may be formed separately from the dock; for example the attachments may comprise carriers into, onto or through which a link is passed so as to be held securely adjacent the dock in use.

In some embodiments the explosive donor comprises a sheet of explosive material. It may, for example, be sandwiched between a back board and a front grill.

The receptor links may comprise detonating cord, shock tube or other such means of conducting detonation from one component to another.

In some cases charges may be remotely placed using robots and then connected together using lengths of detonating cord or shock tube.

In some embodiments the present invention is provided in the form of an explosive board into which the ends of detonating cord links are stuck using magnets.

A main board may be made from a piece of wood with magnets on the back to attach it to the target. On the front is a layer of sheet explosive and on top of that is a layer of steel mesh. The detonating cord tails are terminated with a magnetic connector that sticks onto the mesh.

A variant has two opposing magnetic pads that self-align to connect two lengths of detonating cord or detonating cord to shock tube

It will be understood that detonating cord is shown as a means of conducting detonation from one component to another. Shock tube may alternatively be employed.

In some embodiments the device is deployed and used as follows.

A connector device formed in accordance with the present invention is deployed by an R.OV and positioned on a target. The connector device is a magnetic board with a steel mesh cover which can be loaded with sheet explosives.

Demolition charges are fitted with detonating cord or shock tube and detonator on the end of which is a magnetic pad.

The charges are positioned and the magnetic pads thereof are then attached to the connector.

Different aspects and embodiments of the invention may be used separately or together.

Further particular and preferred aspects of the present invention are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with the features of the independent claims as appropriate, and in combinations other than those explicitly set out in the claims.

The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings.

The example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternative forms and should not be construed as limited to the examples set forth herein.

Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.

Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealised or overly formal sense unless expressly so defined herein.

In the following description, all orientational terms, such as upper, lower, radially and axially, are used in relation to the drawings and should not be interpreted as limiting on the invention.

In Figure I a marine vessel (460) is located above a site with two submerged targets A, B.

The vessel (460) carried a clump (465) shown in more detail in Figure 2. The clump (465) comprises a box (470) which is weighted, in this embodiment by concrete blocks (475). The box (470) carries a magazine (480) of charges (481). In addition a dock (485) is provided. Attached to the dock (485) are charge links (486) - one for each charge (481). The links (486) are connected to their respective charges (481) by detonating cord (490), which in this embodiment is provided on reels that can pay out from the links. Attached to the dock is an initiator link (487), which connects to a length of detonating cord 488 that pays out from the vessel.

The clump (465) is deployed from the vessel and sinks to the seabed under the weight of the blocks (475) as shown in Figure 3.

An R.OV (495) can then approach the clump and collect a charge (481). The R.OV can then travel with the charge to a target A, B and attach the charge thereto. The R.OV can then return to the clump and collect another charge for the next target etc.

When all of the charges are placed the cord (488) is then and only then connected to a detonator. When the detonator is activated this causes detonation at the dock, which in turn propagates to each of the attached detonating cords. In turn this therefore causes detonation of the charges on the targets

Figures 4 to 12 illustrate certain features and functionality of embodiments of the present invention.

Referring now to Figures I 3 to 16, the present invention incorporates a plate of rigid material (I) which for the sake of convenience may, for example, be rectangular. This is provided with one or more magnets (2). One convenient configuration consists of an array of four, one being located at each corner and located on the side of the plate which is to be placed in contact with the target structure, for example. It will be understood that, for target structures of little or no magnetic susceptibility, the attachment of the pads to the plate may be enabled by the use of a suitable adhesive.

Upon the other side of the plate (I) is a sheet of explosive donor (3) which may most conveniently have a contour slightly smaller than that of the rigid plate (I). Upon the explosive sheet (3) is placed a steel plate which may advantageously bear a multiple array of perforations and thus constitute a grille (4). The three components (I), (3) and (4) are held together by four threaded rods (5) which may be made of plastics material and each may be integral with rectangular plastics enclosures (6) containing the magnets (2) on all but one large surface. A nut (7) applied to each threaded rod (5) secures each corner of the array of components (I), (3) and (4) and urges each on them into contact with its fellows (this could be replaced by a screw).

The assembly comprising components (I) to (7) may conveniently be provided with a projecting handle which enables the assembly to be easily gripped by the jaws of an RCV and io offered to a suitable, preferably elevated, point on the structure to be acted upon by the explosive charge or charges to which it attaches itself by means of the array of magnets (2).

As shown best in Figure I 3, each explosive charge to be initiated simultaneously or in rapid succession (not shown) is attached to a length of detonating cord (8) of which one end serves to initiate the charge, with or without a supplementary explosive booster. The free end of each length of detonating cord (8) is attached to a generally flat plastics component (9) with an elongate groove (10) on one side in which a length of detonating cord can be secured by plastic tape and which incorporates magnets (11)- see Figure 16. When this component (9) is addressed by the RCV to the exposed surface of the steel grill (4) it becomes magnetically attached thereunto.

When each charge of an array to be initiated is thus individually connected to the grill (4) the assembly is ready for the means of initiation off all charges attached thereunto. Referring to Figure 3, to this end the robotic arm delivers the charge's initiator (12) consisting of a plastics moulding which incorporates one or more magnets (13) and which contains a sufficiently powerful mass of explosive (14) to transfer detonation to the sheet of explosive (3) across the metal grille (4).The detonating sheet of explosive (3) in turn transmits detonation back through the metal grille (4) and thus initiates the detonation of each strand of detonating cord (8) which is urged against the surface of the grille (4) and thus brings about the initiation of each explosive charge attached thereunto.

The explosive (14) within the initiator (12) may incorporate an electric detonator or, alternatively, the distal end of a long length of detonating cord to be paid out by the withdrawing RCV or led from the point of initiation by the RCV as it approaches the array of explosive charges for the last time before withdrawal, only when all main charges have been put in position and require no more adjustment before they are detonated. If detonating cord is thus employed it will either be deployed by the RCV back to the point of initiation.

In Figure 17 a connector (100) formed according to a further embodiment is shown and includes:

Initiator = detonator or booster assembly that initiates the sheet explosive.

Donor = the sheet explosive in the magnetic board.

Receptor = detonating cord/shock tube link that picks up from the magnetic board and goes to the main charges.

Three lengths of detonating cord (108) are shown. Each length is fitted into an open conduit (109) on a plastic pad fitted with a strong magnet. When attached to the front steel mesh on the connector the detonating cord is in close proximity to the underlying sheet explosive (103), but there is a gap between the two corresponding to the thickness of the grille). A final initiator (114) is also fitted onto the front of the connector device and when initiated will cause detonation of the explosive sheet/s and onward initiation of the links (and subsequently initiation of main charges attached to a target).

In Figure 18 the connector (100) is shown fitted to a target (120). Demolition charges (115) are positioned on the target and detonating cord links extend from the charges to the connector where they are attached using magnetic carriers.

Some advantages of the device and system of the present invention include:

Simplify ROV charge attachment and re-attachment as necessary.

Reduce the total quantity of detonating cord.

By raising all explosive links off of the ground, it will greatly reduce ROV snagging hazards.

Time delay detonators can be fitted for sequential initiation.

The connector and detonating cord connections will be visible from outside of the exclusion area.

Figure 19 shows an explosive receptor formed according to an alternative aspect of the present invention.

Each receptor is able to “stick” onto the back of the next one and still be initiated. It is possible thereby to make something consisting of a series of explosive pucks (220) that stack up. The receptors need not be round, and may or may not have magnets; for example they could stack on a spigot in order to be aligned.

Figure 20 shows an explosive receptor formed according to an alternative aspect of the present invention.

Two plates (350, 355) are provided and each includes a groove (351, 356) into which a length of detonating cord (352, 357) can be pressed and retained. Each plate also comprises a magnet (353, 358) and the opposite side of the plate includes a threaded rod (354, 359) useful for manipulating the plates.

Magnetic polarity can be used to align and position two parallel lines of detonating cord such that one will initiate the other in use.

Features of the devices represented in Figures I 3 to 20 could be used in combination with the underwater clump systems represented in Figures I to 12 and vice versa.

Further aspects and embodiments are described below by way of the following numbered paragraphs.

1. An underwater multi-charge placement system comprising a container for housing one or more explosive charges, the or each charge having a length of exploding fuse associated therewith which can extend between the container and a target, whereby the charge/s can be removed from the container and placed on a target, and thereafter the or each charge can be detonated by initiation from the container.

2. An underwater multi-charge placement system comprising a container for housing one or more explosive charges, the or each charge having a length of exploding fuse associated therewith which can pay out from the container, whereby the charge/s can be removed from the container and placed on a target, and thereafter the or each charge can be detonated by initiation from the container.

3. A system as claimed in paragraph I or claim 2, in which the fuse/s are associated with the container by a link.

4. A system as claimed in paragraph 3, in which the link/s are receivable on a common dock.

5. A system as claimed in any preceding paragraph, in which the charge/s are initiated remotely of the container.

6. An underwater multi-charge placement system comprising a weighted container for housing a plurality of explosive charges and a shareable dock to which a plurality of explosively initiatable links, which are associated or associable with the charges, are or can be attached, the dock comprises or can receive an explosive initiator for initiating all attached links in use leading to onward initiation of explosive devices connected thereto.

7. A system as claimed in paragraph 6, in which the initiator for initiating the links is situated remotely of the container.

8. A system as claimed in paragraph 6 or paragraph 7, in which the initiator comprises a detonator.

9. A system as claimed in any of paragraphs 6 to 8, in which the links are formed separately of and are attachable to the dock.

10. A system as claimed in paragraph 9, in which the links are attachable to the dock by magnetic means.

I I. A device for common initiation of a multiplicity of explosive devices, comprising a shareable dock to which a plurality of explosively initiatable links can be attached, the dock comprises or can receive an explosive initiator for initiating all attached links in use leading to onward initiation of explosive devices connected thereto.

12. A device as claimed in paragraph I I, in which the dock comprises a panel.

13. A device as claimed in paragraph I I or paragraph 12, in which links are attachable to the dock by magnetic means.

14. A device as claimed in paragraph I 3, in which the dock includes a metal grill to which links are attached magnetically.

15. A device as claimed in any of paragraphs I I to 14, further comprising link attachments for receiving a link and which are attachable to the dock.

16. A device as claimed in paragraph 15, in which the link attachments include magnetic means for attaching to the dock.

17. A device as claimed in any of paragraphs II to 16, in which the explosive initiator comprises a sheet of explosive material.

18. A device as claimed in any of paragraphs II to 17, in which the links comprise detonating cord or shock tube.

19. A device as claimed in any of paragraphs II to 18 forming part of a system according to any of claims I to 10.

20. A device for use in initiation of a plurality of explosive devices, comprising a receptor body into which an explosively initiatable link can be received, the device being stackable with one or more other such devices so that initiation of any one of a stack is use causes initiation of all of the links for onward initiation of explosive devices connected thereto.

21. A device as claimed in paragraph 20, in which the device is magnetic.

22. A device as claimed in paragraph 20 or paragraph 21, in which the body comprises a stacking orifice to permit stacking on a post or the like.

23. A device for use in initiation of a plurality of explosive devices, comprising a plate comprising a groove for receiving an explosively initiatable link.

24. A device as claimed in paragraph 23, in which plates is provided with one or more magnets.

25. A device as claimed in paragraph 24, in which magnetic polarity is used to align and position two links such that one will initiate the other.

26. A device as claimed in any of paragraphs 20 to 25 forming part of a system according to any of claims I to 10.

Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiments shown and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined 5 by the appended claims and their equivalents.

Claims (12)

1. An underwater charge placement system comprising a container for housing one or more explosive charges, the or each charge having a length of exploding fuse associated therewith which can extend between the container and a target, whereby the charge/s can be removed from the container and placed on a target, and thereafter the or each charge can be detonated by initiation from the container.

2. A system as claimed in claim I, in which the exploding fuse/s pay/s out from the charge and/or the container.

3. A system as claimed in claim I or claim 2, in which the container has one or more deployable arms/bays each carrying one or more charges, the arms/bays are movable from a stowed position to a deployed position.

4. A system as claimed in any preceding claim, in which the container has a single initiator link usable to cause initiation of all charges.

5. A system as claimed in claim 4, in which the initiator link is associated or associable with a float.

6. A system as claimed in any preceding claim, further comprising buoyancy means and a sinker, the sinker is attached to the container by a mooring cable.

7. A system as claimed in any preceding claim, in which each of the exploding fuses are attached or associated with a common dock provided on or by the container.

8. A mine neutralisation weapon datum comprising a container for housing one or more explosive charges, the or each charge having a length of exploding fuse associated therewith which can extend between the container and a target, whereby the charge/s can be removed from the container and placed on a target, a single firing cable is provided to extend between the container and a firing device, and thereafter the or each charge can be simultaneously detonated.

9. A datum as claimed in claim 8, in which a float is provided and the firing cable is associated with the float.

10. A datum as claimed in claim 9, in which the float remains on the water surface as the container sinks to the seabed.

5

I I. A datum as claimed in claim 9, in which the float is deployable from the container.

12. A datum as claimed in any of claims 8 to I I, comprising a float and cable reel provided in a float and cable reel housing, a charge housing section and a sinker.