Patent Description:
For the purposes of this disclosure, aspects, embodiments, and general description and discussion of munitions, in terms of technical details or associated functionality, applies equally to submunition. This is discussed in more detail later in the disclosure.

Munitions are provided in a number of different forms, for a number of different applications. Typically, a particular munition will be used for a particular application or intention. A good example of this is when an application involves engaging with or generally interacting with an underwater object (e.g. a target).

When engaging an underwater target, a typical approach is to use a depth charge. The depth charge is dropped off the side of a vessel, or from a helicopter or similar, and the depth charge then descends in the water to a predetermined depth where the depth charge is activated (i.e. detonates). Ideally, this depth will be in the general vicinity of the object or target to be engaged, to damage or disable that target. While engaging a target with one or more depth charges has been relatively commonplace for decades, and is often effective, there are disadvantages. One of the main disadvantages is range. That is, while the depth charge may inflict the required damage on the underwater target, this may be difficult or impossible to achieve if the underwater target is not located immediately below the vessel engaged in that target, but is instead located some distance away from the vessel (e.g. measured across the surface of the water), for example hundreds of metres, or kilometres. Additionally, it may be difficult to engage the target with multiple depth charges simultaneously, or simultaneously from multiple vessels. Also, any explosion caused by the depth charge may, if in the vicinity of the vessel itself, risk damaging the actual vessel that deployed the depth charge.

While the use of helicopters can of course significantly increase the range of the use of depth charge from the vessel deploying the depth charge or helicopter, this then necessarily involves the use of a helicopter, which can be expensive or risky. Of course, it is not practical, and sometimes not possible, to use one or more, or a swarm, of helicopters in order to deploy multiple, or a swarm, of depth charges at any significant distance from the vessel. Also, even though helicopters are fast moving, it may take a significant amount of time for a helicopter to reach a target location, and deploy the depth charge. This is particularly the case when the helicopter is not already in flight, when a command or instruction to engage is issued.

Another approach involves the use of mortar bombs. Mortar bombs may be launched from the deck of a vessel, and into the surrounding water, where the mortar bombs then descend to a particular depth and explode to disable or damage the underwater target. While these mortar bombs perhaps have an increased range in comparison with the use of depth charges, their explosive capability is perhaps not as significant as a depth charge. Also, the firing accuracy is not ideal, and the range of the mortar bomb, is still limited.

A yet further approach to engaging underwater targets is the use of torpedoes, for example deck-launched torpedoes launched from the deck of a vessel, or those launched from a submarine, helicopter or airplane. The use of torpedoes might overcome some of the problems discussed above with regard to range, mainly because torpedoes are self-propelled. However, torpedoes are ultimately too expensive to be used speculatively, or too expensive to use multiple torpedoes at any one time to cause multiple explosions in or around the vicinity of an expected or determined location of the target.

Additionally, even when a munition is fired from a gun, achieving significant range with great accuracy, a natural (e.g. ballistic) trajectory will result in impact with a surface of a body of waterthat is likely to cause damage to the munition, a significant change of course of the munition, or generally result in the munition not functioning as perhaps initially intended.

Patent document <CIT> discloses a projectile, launched from a gun, used to form a chain of two mines connected by a rope. After a certain flight time, the mines are thrown out of the projectile by an explosive charge. Of the two mines in the projectile, the one in front is heavier than the one behind and thus a good blocking effect of the pair of mines is ensured.

Patent document <CIT> discloses a projectile submunition with a release device for a braking parachute towed in the rear area. The release device can be activated by a delay element which depends on the escape of a submunition released from the carrier projectile shell.

Patent document <CIT> discloses a submunition with electrical ignition device.

It is an example aim of example embodiments of the present invention to at least partially avoid or overcome one or more disadvantages of the prior art, whether identified herein or elsewhere, or to at least provide a viable alternative to existing apparatus and methods.

According to a first aspect of the present invention, there is provided a munition assembly adapted to engage an underwater target, The assembly is arranged to be launched from a gun, the assembly comprising: a carrier for a submunition, the carrier comprising a cavity in which the submunition is located; and a submunition, carried by the carrier in the cavity, the submunition arranged to be controllably expelled from the carrier; the submunition comprising: a submunition explosive charge; and a submunition fuze, wherein: the munition assembly is adapted to be launched, into the air, from a gun barrel, where the submunition is then arranged to be controllably expelled from the carrier and enter a body of water; and the submunition fuze is adapted to trigger the submunition explosive charge underwater. The submunition fuze is a programmable fuze and may be adapted to trigger the submunition explosive charge in accordance with one or more of: upon detection of a target sonar signature; upon detection of a target magnetic signature; upon detection of a target electric field signature; at a predetermined pressure under the water surface; at a predetermined depth under the water surface; at a predetermined salinity of water; at a predetermined temperature of water; or at a predetermined speed-of-sound in water.

The carrier may comprise: a carrier expulsion charge; and a carrier fuze, wherein the carrier fuze is adapted to trigger the carrier expulsion charge to controllably expel the submunition from the carrier
The submunition may be arranged to be expelled from a rear end of the carrier, optionally via a closure that is arranged to be opened before or during expulsion of the submunition.

The closure in one arrangement may be the base of a shell which comprises shearable threads or shearable pins.

The munition assembly may be arranged to be launched from a smooth bore. Optionally, the munition assembly when launched from a smooth bore may, the carrier may be fin-stabilised. Or, the munition assembly is arranged to be launched from a rifled bore.

The submunition may comprise: a deployable configuration that is arranged, when deployed, to slow the submunition in the air, after expulsion from the carrier, and before entry to the water. Optionally, the deployable configuration is arranged to deploy automatically after the submunition has been expelled from the carrier.

The deployable configuration may be a parachute; and/or the deployable configuration may comprise one or more wings or fins, optionally to provide autorotation.

The (or any) fins and/or wings may be controllable to provide directional control of said submunition, optionally via a moveable control surface.

The submunition may be arranged to transmit a communication signal, external to and away from the submunition after entering the water. This might, optionally, be arranged to happen: after a predetermined time period after entering the water; upon detection of a target sonar signature; upon detection of a target magnetic signature; upon detection of a target electric field signature; at a predetermined pressure under the water surface; at a predetermined depth under the water surface; at a predetermined salinity of water; at a predetermined temperature of water; at a predetermined speed-of-sound in water; or upon impact with a target under the water surface.

According to a second aspect of the present invention, there is provided an assembly (or apparatus), comprising: a gun, comprising a gun barrel; and a munition assembly according to the first aspect of the invention, wherein: the munition assembly is adapted to be launched, into the air, from the gun barrel.

According to a third aspect of the present invention, there is provided a method of launching a submunition, the method comprising: launching the munition assembly according to the first aspect of the invention into the air, from a gun barrel; expelling the submunition from the carrier of the munition assembly, and into the body of water.

It will be appreciated that one or more of the features described in relation to the munition assembly of the present invention may be used in combination with or in place of any one or more features of the reconnaissance projectile (including the related concept of sub-projectile), aspect. For instance, whereas the munition or submunition may be adapted to initiate the main charge according to certain criteria, the reconnaissance projectile or sub-projectile might be configured to initiate the reconnaissance function according to those particular criteria. Additionally, the launching, stabilizing, deceleration, and degree of directional control of the decent of the reconnaissance projectile or sub-projectile might be as described in relation to the same features of the munition or submunition aspect.

More generally, any one or more features described in relation to any one aspect may be used in combination with, or in place of, any one or more feature of any one or more other aspects of the invention, unless such replacement or combination would be understood by the skilled person to be mutually exclusive, after a reading of the present disclosure.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic Figures in which:.

As discussed above, there are numerous disadvantages associated with existing apparatus and methods for engaging underwater targets. These range from the limited range of some existing munitions used for such purposes, to the limited accuracy of existing munitions, or the significant expense associated with existing munitions. In general, there is exists no relatively inexpensive, rapidly deployable, and yet long-range and accurate, munition, or related assembly or methodology, for engaging or generally interacting with underwater objects (e.g. targets).

According to the present invention, it has been realised that the problems associated with existing approaches can be overcome in a subtle but effective and powerful manner. In particular, the present invention provides a munition. The munition comprises an explosive charge and a fuze. The munition is adapted to be launched, into the air. Significantly, the munition is adapted to be launched from a gun barrel. This means that the munition typically (and practically likely) includes, or is at least used in conjunction with, a propelling explosive, and is capable of being explosively propelled and withstanding such explosive propulsion. This is in contrast with, for example, a depth charge, or torpedo. Being launched from a gun barrel, this is also in contrast with a mortar bomb. The munition is adapted to be launched and then enter a body of water, typically within which body of water a target or object to be engaged would be located. The fuze of the munition is adapted to trigger the explosive charge of the munition under water, for example in accordance with pre-set criteria. The use of a gun barrel also ensures high degree of accuracy in terms of ranging and general targeting.

The invention is subtle but powerful. The invention is subtle because it perhaps takes advantage of some existing technologies, in the form of firing a munition from a gun barrel. This means that the range of the munition would be hundreds of metres, or even kilometres, overcoming range problems associated with existing apparatus or methodology. At the same time, the munition will typically be a projectile, therefore being unpropelled and/or including no form of self-propulsion. This means that the munition is relatively simple and inexpensive. Altogether then, this means that the munition according to example embodiments can be used to accurately, cheaply, effectively, and generally efficiently engage with targets located at quite some distance from an assembly (e.g. a platform, vessel, vehicle, and so on, or a related gun) that launches the projectile. Also, the use of a munition that is capable of being launched from a gun barrel means that multiple munitions can be launched very quickly in succession from the same gun barrel, or in succession and/or in parallel from multiple gun barrels, optionally from different assemblies, or optionally being targeted onto or into the same location/vicinity of the same body of water. Again then, target engagement efficiency and effectiveness may be increased, in a relatively simple manner.

<FIG> schematically depicts an assembly in accordance with an example embodiment. In this example, the assembly comprises a vessel <NUM> located on a body of water <NUM>. The vessel comprises a gun <NUM> having a gun barrel <NUM>. In another example, the assembly need not include a particular vehicle, and could simply comprise a gun.

The munition <NUM> is shown as being explosively launched into the air. As discussed above, this gives the munition <NUM> significant range, and accuracy at range.

Prior to being launched into the air, the munition <NUM> (or more specifically its fuze) might be programmed in some way. The programming might take place within the gun <NUM>, within the barrel <NUM>, or even within a particular range after launch of the munition <NUM>, for example by a wireless transmission or similar. The programming might be undertaken to implement or change particular fuze criteria, for example to trigger explosive within the munition <NUM> in accordance with particular criteria. This will be explained in more detail below. Typically, in order to achieve this programming, the munition <NUM> will comprise a programmable fuze. That is, the fuze is able to be configured.

As is typical for munitions fired from a gun barrel, the munition will typically be arranged to be launched from a smooth bore gun barrel. Optionally, the munition may be fin-stabilised. Alternatively, the munition may be arranged to be launched from a rifled bore. The exact configuration will be dependent on the required application.

As discussed throughout, care will need to be undertaken to ensure that the combination of munition properties (e.g. size, weight, shape and so on) and launch specifications (e.g. explosive propulsion) is such that the munition <NUM> does not explode on launch. This might require particular care to be given to the explosive resistance of the munition <NUM>, or at least constituent parts located within the munition, typically associated with initiating an explosion of the munition <NUM>. Such concepts will be known or derivable from munitions technologies typically involved in gun-based launching.

<FIG> shows the munition as it is directed to and is about to enter the body of water <NUM>. Having been explosively launched from a gun barrel <NUM>, the munition <NUM> will enter the body of water <NUM> with significant speed. In a practical implementation, care will need to be undertaken to ensure that the combination of munition properties (e.g. size, weight, shape and so on) and impact speed with the water <NUM> is such that the munition <NUM> does not explode on impact. This might require particular care to be given to the impact resistance of the munition <NUM>, or at least constituent parts located within the munition, typically associated with initiating an explosion of the munition <NUM>.

In one example, a simple but effective feature which may assist in this regard is the head or tip <NUM> of the munition being ogive-shaped or roundly-shaped or tapering, in accordance with the typical shape of munitions. Again, this is in contrast with a depth charge or similar. However, this may not be sufficient in isolation, or even in combination with structural impact-resistant features of a munition, to prevent explosion of the munition <NUM> on impact with the water, or to damage the munition such that it does not work satisfactorily under the water <NUM>.

<FIG> shows that in addition to, or alternatively to, an impact resistant or accommodating structure of the munition <NUM>, the munition <NUM> may be provided with a deployable configuration that is arranged, when deployed, to slow the munition <NUM> in the air before entry into the water <NUM>. In order to successfully engage with an underwater target described herein, the speed of decent of the munition down, through the water <NUM> to the target may be less important than the speed of delivery of the munition from the gun to the location at/above the target. In other words, the munition <NUM> does not need to enter the water <NUM> at a particularly high velocity. Therefore, deceleration of the munition <NUM> prior to entering the water <NUM> is acceptable, and may actually be desirable. That is, slowing the munition <NUM> prior to entering the water <NUM> may be far simpler or easier to achieve than designing the munition to withstand high speed impact with the water <NUM>. This is because such a design might mean that the cost of the munition is excessive, or that the weight of the munition is excessive, or such that the space within the munition for important explosive material is reduced. In other words, some form of air brake might be advantageous.

<FIG> shows that, in one example, the deployable configuration could comprise a parachute <NUM>. The parachute could be deployed after a certain time from launch of the munition <NUM>, or could, with appropriate sensing or similar, be deployed upon particular distance proximity sensing with respect to the water <NUM>.

In another example, a similar munition <NUM> is shown. However, this similar munition <NUM> comprises a different deployable configuration in the form of one or more deployable wings or fins <NUM>. These deployable wings or fins <NUM> may be deployed in the same manner as the parachute <NUM> previously described. The wings or fins <NUM> might optionally provide a degree of auto rotation to slow or further slow the munition <NUM>. As discussed above, it is desirable for the munition to reach the location of the target object, or its surrounding area quickly and effectively, while at the same time being relatively inexpensive and having maximum effectiveness. It is therefore desirable not to pack the munition with complicated or advanced guiding or directionality mechanisms, which might be used to control the directionality of the descent of the munition. However, in some examples the fins and/or wings <NUM> previously described may be controllable to provide directional control of the descent of the munition <NUM>, for example via a moveable control surface provided in or by the fins or wings. Such control is typically not to be used during projectile-like flight of the munition <NUM>, for example immediately after launch, but instead might be used for a degree of tuning control of the descent of the projectile into the body of water. This might improve engagement accuracy and effectiveness with a target located in the body of water <NUM>. However, as alluded to above, in other examples the munition according to example embodiments may be free of such directional (descent) control, to ensure that the cost and complexity of the munition is minimised, and such that any related cost or space budget is taken up with more core aspects, such as volume of explosive.

After entering the body of water, the munition may be arranged to retract or dispose of the deployable configuration, so that the deployable configuration does not slow (or slow to too great an extent) the descent of the munition toward the target. For similar reasons, the munition might be free of any such deployable configuration, such that there is no impact on descent in the water. Descent through the water may need to be as fast as possible (e.g. to avoid the object moving to avoid the munition).

After entering the body of water, the munition will descend within the body of water. The fuze within the munition is adapted to trigger the explosive charge within the munition in the water (that is under the water surface). This triggering can be achieved in one of a number of different ways. <FIG> give typical examples.

<FIG> shows that the fuze may be adapted to trigger <NUM> explosive within the munition <NUM> in order to successfully and effectively engage an underwater target <NUM>. This might be achieved by triggering the explosive charge after a particular time <NUM>, for example from one or more of a combination of launch from the gun barrel described above, and/or a predetermined time period after entering the water <NUM>. This time period will typically equate to a particular depth <NUM> within the water <NUM> (e.g. based on expected or calculate rate of descent). Alternatively, the triggering <NUM> may occur at the particular depth <NUM> in combination with or irrespective of the timing <NUM>. For example, an alternative or additional approach might involve the direct detection of depth (via one or more sensors or similar). Depth may be detected based on time, as above, or perhaps based on water pressure under the surface, the salinity of the water, the temperature of the water, or even at a predetermined speed-of-sound in the water. All of these may be indicative of depth within the water, for example which may be known in advance from mapping of the area, and/or sensed by the munition <NUM> via one or more sensors when descending through the water.

Of course, the fuze may be also be adapted to trigger the explosive charge upon impact with the target <NUM>. However, it may be safer to employ some form of depth-activation, so that the munition explodes at/near the depth of the target, avoiding possible unintentional explosions at or near objects that are not targets.

As above, the fuze may be programmed with such criteria, or related criteria necessary for the fuze to trigger the explosive as and when intended.

<FIG> shows a different adaptation for triggering <NUM> an explosive charge of the munition <NUM> under the water, this time upon magnetic detection <NUM> of a target magnetic signature <NUM>. In a crude sense, the target magnetic signature could simply be the detection of anything magnetic, indicating the presence of a magnetic or magnetisable structure. For instance, once a detected magnetic a field strength is above a relevant threshold, the munition <NUM> might explode. In a more sophisticated manner, it may be known or derivable in advance to determine what the expected magnetic signature <NUM> of the particular target <NUM> might be, might look like, or might approximate to. This might equate to field strength, or field lines, or changes therein. In this example, the munition <NUM> might not be triggered <NUM> to explode until the magnetic detection <NUM> detects a very particular magnetic signature <NUM>, and not simply any magnetic field or change therein.

While <FIG> discusses the use of magnetic fields, much the same principle may be used to detect electric field signatures. <FIG> shows another example of triggering. In this example, the triggering <NUM> of the explosive charge in the munition <NUM> is undertaken based on the detection of pressure waves in the water <NUM>, thereby implementing a sonar-like system <NUM>. The system may be implemented in one of a number of different ways. In one example, the munition <NUM> may be arranged to detect a pressure wave <NUM> emanating from target object <NUM>. This could be a sonar pulse <NUM> originating from the object <NUM>, or simply detection of sound generated by the object <NUM>, or could instead be a reflection <NUM> of a sonar pulse <NUM> originating from the munition <NUM>. That is, the projectile <NUM> may not only detect pressure waves, but may emit pressure waves. As with the magnetic field examples given above, the explosive charge may be triggered <NUM> when a target sonar signature is detected <NUM>, and this could be when any pressure wave is detected, or more likely when a pressure wave above a certain threshold is detected, or when a particular pressure wave or a series of pressure waves is detected which is indicative of the presence of a particular target <NUM>.

In general, the munition may be able to detect or infer entry into the water, or making contact with the water. This might be useful in initiating or priming fuze activity, for example starting a timer, taking a base or initial reading of pressure, salinity, temperature, and so on (or any relevant criteria), or anything which may assist in the subsequent use of the fuze to trigger the explosive. This sensing or inference could be via an environmental sensor or similar that is (already) present in order to perform another function, for example those discussed or alluded to above. Alternatively, the sensing or inference could be via a dedicated sensor, for example a dedicated impact or water/moisture sensor, ortemperate sensor, pressure sensor, salinity sensor, and so on. In general terms, the munition may be able to detect or infer entry into the water, or making contact with the water, for safety reasons, where some (e.g. explosive) function is prevented prior to water contact/entry.

As discussed above, a main principle discussed herein is that the munition is adapted to be launched, into the air, from a gun barrel. This gives good range, and good targeting accuracy, good engagement speed, all at relatively low cost. To this extent, the munition may be described as, or form part of, an artillery shell. <FIG> shows such an artillery shell <NUM>. The artillery shell <NUM> comprises a munition <NUM> according to any embodiment described herein. The munition <NUM> will typically comprise a fuze <NUM> (likely a programmable fuze, as discussed above), which is adapted to trigger an explosive charge <NUM> also located within a munition. The artillery shell <NUM> will also comprise a primer <NUM> and an explosive propellant <NUM> which may be cased (as shown) or bagged. A casing <NUM> might also be provided, to hold the munition <NUM>, explosive <NUM>, and primer <NUM>.

In another example, and typical in munitions, the fuze could be located in the nose of the munition (e.g. as opposed to behind the nose as shown in <FIG>).

It is envisaged that a practical presentation of the invention would take the form of the artillery shell of <FIG>, or something similar to that depiction, as opposed to a munition in isolation. In any event, as discussed above, the munition according to the present invention is capable of withstanding explosive propulsion-based launch from a gun barrel, in contrast with for instance a depth charge or torpedo. The munition and/or artillery shell (which could be the same thing) will typically have a diameter of <NUM> or less, in contrast with depth charges. The gun barrel-munition/artillery shell assembly typically will be such that the munition has a range of well over <NUM> metres, typically over <NUM> metres, and quite possibly in excess of <NUM> to <NUM> kilometres. Again, this is in contrast with a depth charge and a mortar bomb. Balanced with the ranging and target accuracy that launching from a gun barrel gives, the munition will be projectile-like, that is not including any self-propulsion, in contrast with a torpedo or similar. To summarise, then, the approach described above allows for relatively cheap, accurate, rapid, effective and efficient engagement of underwater targets at a significant range. One or more assemblies can be used to launch one or more munitions with such range and effectiveness, in contrast with the launching of depth charges, helicopters including such depth charges, or multiple torpedoes.

<FIG> schematically depicts general principles associated with the method of launching a munition according to an example embodiment. As discussed above, the munition comprises an explosive charge, and a fuze. The munition is adapted to be launched, into the air, from a gun barrel, and enter a body of water. The fuze is adapted to trigger the explosives charge under the water. Accordingly, the method comprises launching the munition into the air, from a gun barrel <NUM>. The launch is configured such that the munition is launched into the body of water <NUM>, such that, as discussed above, the fuze may then be adapted to trigger the explosive charge under the water <NUM>.

In the embodiments discussed above, a munition has been described and detailed. The munition includes an explosive charge. However, in accordance with alternative examples not forming part of the invention, many of the principles discussed above can still be taken advantage of, but without using a projectile including an explosive charge. That is, the above principles can be used to ensure that a projectile can be launched from a gun barrel and into a body of water, when the projectile is then arranged to interact or engage with an object in the water, but without necessarily including an explosive charge to disable or damage that object. In particular, the present disclosure additionally provides a reconnaissance projectile. The reconnaissance projectile is adapted to be launched, into the air, from a gun barrel, and then into contact with a body of water (onto the water surface, or to descend below the surface). Again then, the projectile may be launched at a high range, with a high degree of accuracy, relatively cheaply and quickly. The reconnaissance projectile is arranged to initiate a reconnaissance function when in contact with the body of water (which includes when impacting the water, when on the body of water, or, as above, typically when located under the surface of the water). The reconnaissance function could be anything of particular use in relation to the particular application, but would typically comprise emission and/or detection of a pressure wave in the body of water, in a manner similar to that discussed above in relation to <FIG>.

<FIG> shows a reconnaissance projectile <NUM> in accordance with an example embodiment. The reconnaissance projectile <NUM> comprises a sensor <NUM>. The sensor may be used to detect when the projectile <NUM> has come into contact with a body of water, and/or provide some other sensing functionality, for example one or more of the sensing or initiation criteria described above in relation to the munition. For example, the sensor <NUM> may be arranged to detect a particular passage of time, or a particular pressure change, or particular depth, and so on. The reconnaissance projectile <NUM> also comprises a transceiver <NUM>, in this example. The transceiver may be arranged to emit and/or detect pressure waves in the body of water. The sensor <NUM> may initiate or process transmission or detection of the waves by transceiver <NUM>. The sensor <NUM> might, instead or additionally, be or comprise a processor for processing implementing one or more of these functions.

Of course, it will be appreciated that the reconnaissance projectile may take one of a number of different forms, similar or different to that shown in <FIG> is shown simply as a way of schematically depicting what such a projectile <NUM> might look like.

Much as with the munition described above, the reconnaissance projectile <NUM> might be used or fired or launched in isolation in some way. However, it is likely that the projectile, being explosively propelled, might take the form of, or form part of, an artillery shell <NUM>. The artillery shell <NUM> might comprise much the same primer <NUM>, explosive <NUM> and casing <NUM> as is already described above in relation to the arrangement of <FIG>. Referring back to <FIG>, a difference here is that the artillery shell <NUM> comprises a non-explosive projectile <NUM>, as opposed to an explosive-carrying munition.

As might now be understood, it will be appreciated that some embodiments described above might be a combination of both explosive-concept, and reconnaissance-concept. For instance, it will be appreciated that the embodiments of <FIG> and <FIG>, at least, already have a degree of in-built reconnaissance, assisting in the initiation of the explosives charge.

It will be appreciated that the above explosive-recon examples could be used in isolation or combination. For instance, a reconnaissance projectile may be launched into a body of water in order to perform a reconnaissance function in relation to a target. That reconnaissance projectile may be provided with a transmitter for transmitting reconnaissance information back to the assembly from which the projectile was launched. This reconnaissance information or data may then be used in the programming of subsequently fired or launched explosive munitions according to example embodiments. Indeed, a volley of projectiles may be launched toward an underwater target in accordance with an example embodiment. One or more of those projectiles may be a munition as described herein, and one or more of those projectiles may be a reconnaissance projectile as described herein. The munitions projectile and the reconnaissance projectile may be arranged to communicate with one another. This means that, for instance, a first-fired reconnaissance projectile may enter the body of water and detect or otherwise the presence of a target, whereas a subsequently fired munitions projectile, which may be in the air or in the body of water at the same time as a reconnaissance projectile, may receive reconnaissance information from a reconnaissance projectile and use this in the initiation (or otherwise) of the explosive charge of the munitions projectile. This may mean that the munitions projectile does not need to carry sophisticated (or as sophisticated) transmission or sensing equipment, which could reduce overall cost or system complexity. Alternatively, the reconnaissance projectile described above could actually be a munitions projectile, for example one of those shown in relation to <FIG> and <FIG>. One or more munitions projectiles may be arranged to perform a reconnaissance functionality, but not necessarily initiate the explosive charge. Any acquired information on the target may be used to initiate the explosives charge of subsequently launched munitions projectiles. Or, or more reconnaissance projectiles may be arranged to perform an explosive function, but not necessarily use the reconnaissance function.

<FIG> shows a projectile <NUM> with reconnaissance functionality <NUM>, <NUM> entering the body of water <NUM> in the vicinity of the target <NUM>. Reconnaissance functionality <NUM>, <NUM> might include emission <NUM> and/or detection <NUM> of pressure waves. As discussed previously, the reconnaissance functionality <NUM>, <NUM> may be completely independent of any explosives charge that the munition <NUM> is, or is not, provided with. That is, the projectile <NUM> might have explosive capability, reconnaissance functionality, or a combination of both. Different projectiles <NUM> launched into the water may have different combinations of such explosive/reconnaissance functionality.

Details of the explosive, fuze and general structure of the munition will vary depending on the required application. For example, the explosive charge could be cartridged or bagged charge. The casing could be reactive. Any explosive might be dependent on how the system is to be used, for example getting the munition near the target, or simply close enough. In the former, an explosive yielding a high bubble effect might be useful. In the latter, simply the level of blast might be more important.

As alluded to earlier in the disclosure, the invention also relates to very closely related concepts, but in submunition or sub-projectile form, as in a munition or projectile carried by and then expelled from another (carrier) projectile. This is because further advantages can be achieved, by applying all of the above principles, but in an assembly where the munition or reconnaissance projectile is more particularly a submunition of a munition assembly, or a reconnaissance sub-projectile of a reconnaissance projectile assembly. The submunition or reconnaissance sub-projectile is the object for which controlled entry into, and functionality in, the water is achieved, whereas a carrier of the assembly is simply a tool to get the submunition or reconnaissance sub-projectile to, or proximate to, a target location.

One of the main advantages is that the assembly as a whole, and particularly an outer carrier for carrying the submunition or sub-projectile, can be well or better configured for launch from a gun, with the range and accuracy that such configurations brings. For example, the assembly or the carrier can be bullet-shaped, ogive-shaped or roundly-shaped or tapering, in accordance with the typical shape of munitions. However, and at the same time, the submunition or sub-projectile can then have any desired shape, since the submunition or reconnaissance sub-projectile does not need to be configured for being fired from a gun. This means that the submunition or reconnaissance sub-projectile can then be more easily and readily configured for controlled descent toward and into the water, reducing or preventing damage that might otherwise occur if the munition was fired directly into the water.

Whereas expulsion of the submunition or reconnaissance sub-projectile from its carrier could be achieved underwater, greater benefits are achieved by expulsion in the air, since delicate submunition or reconnaissance sub-projectile components are then not subjected to the force of entry into the water from a natural ballistic, gun-launched, trajectory. Also, the submunition or reconnaissance sub-projectile will be travelling more slowly than a 'conventional' munition, and therefore the water entry shock loading should be reduced, accordingly.

<FIG> shows a munition assembly <NUM>, arranged to be launched from a gun, much as with the munition of previous examples. The assembly <NUM> comprises a carrier <NUM> for a submunition <NUM>. A nose of the carrier <NUM> is ogive-shaped or roundly-shaped or tapering, for greater aerodynamic performance. The carrier <NUM> comprises (which includes defines) a cavity in which the submunition <NUM> is located. The cavity retains and protects the submunition <NUM>, and so shields the submunition <NUM> during launch and flight conditions of the assembly <NUM>.

The assembly <NUM> may be launched and generally handled much as with the munition of earlier examples. However, in previous examples, controlled descent of the entire launched projectile, in the form of the (single-bodied) munition, is implemented. In the present examples, the submunition is expelled from its carrier, and controlled descent of the submunition is implemented, in the same manner as with the munition of previous examples. Again, then, the advantage of the present examples is that munition assembly can be tailored for launch and flight conditions, and the submunition can be tailored for descent and target engagement. The two-body approach allows for tailoring of a two-part problem.

<FIG> shows that the submunition <NUM>, initially carried by the carrier <NUM> in the cavity, is arranged to be controllably expelled from the carrier. This might be achieved by use of a fuze and an expulsion charge, for example a carrier fuze <NUM> and a carrier expulsion charge. The carrier fuze <NUM> may operate on a timer, triggering the carrier expulsion charge to expel the submunition at or proximate to a target location, for example above a location of a target. As with the fuze of the (sub)munition, the carrier fuze may be programmed with a particular timing, or any other set of conditions, for example location-based activation, environmental sensing-based activation, and so on.

The submunition <NUM> is expelled via a rear end of the carrier <NUM>. This is advantageous, as this might better ensure the maintenance of a predictable ballistic trajectory of the submunition <NUM> or carrier <NUM>, or prevent the carrier <NUM> from impacting upon the submunition <NUM>. As above, it is the submunition <NUM> for which slow, controlled descent is desirable, and so leaving the carrier <NUM> via a rear end allows for much more design and functional control, in implementing this.

The submunition may be arranged to be expelled from a rear end of the carrier via a closure <NUM>. The closure might generally close or seal off the submunition <NUM> within the carrier <NUM>. This might be useful for handling or safety reasons, or assist in shielding the submunition from launch and flight conditions. The closure <NUM> is arranged to be opened before or during expulsion of the submunition <NUM>. This could be an active opening, for example via a controlled electronic or pneumatic switch or opening mechanism. However, it is likely to be simpler for this opening to be relatively passive or responsive, in that the closure <NUM> is arranged to open, for example via a shearing action, due to pressure of the expulsion charge on the opening, either directly, or indirectly via contact with the submunition <NUM> itself.

As with the munition of previous examples, the submunition <NUM> comprises a deployable configuration <NUM> that is arranged, when deployed, to slow the submunition <NUM> in the air, after expulsion from the carrier <NUM>, and before entry to the water. The deployment could be active, for example based on sensing of air flow or submunition release, and an electrical or mechanical system actively deploying the configuration <NUM>. However, a more passive, automatic deployment may be simpler to implement, and more reliable. For example, <FIG> shows that wings or fins <NUM> might automatically deploy, to provide a degree of auto rotation to slow or further slow the munition <NUM> during its descent. The wings or fins <NUM> could be spring loaded, in a compressed or closed state, when in carrier <NUM>, and then automatically uncompress or open when expulsion is implemented. Alternatively, the act of air flow during or after expulsion may force the wings or fins <NUM> to deploy.

<FIG> shows that the submunition <NUM> functions largely as the munition <NUM> of previous examples, descending toward and eventually onto or into the body of water <NUM>, for engagement with a target. A submunition fuze is then adapted to trigger a submunition explosive charge, under water.

<FIG> shows a more detailed view of the munition assembly <NUM>. The munition assembly <NUM> is arranged to be launched from a gun. The assembly <NUM> comprises: a carrier <NUM> for a submunition <NUM>. The carrier comprises a cavity <NUM> in which the submunition <NUM> is located. The carrier <NUM> may be, or may form, a (carrier) shell.

The submunition <NUM>, carried by the carrier <NUM> in the cavity <NUM>, is arranged to be controllably expelled from the carrier <NUM>. The carrier <NUM> comprises a carrier expulsion charge <NUM> and a carrier fuze <NUM>, the charge <NUM> being located in-between the submunition <NUM> and the fuze <NUM>. The fuze is typically located in a nose of the assembly <NUM> or carrier <NUM>. The carrier fuze <NUM> is adapted to trigger the carrier expulsion charge <NUM> to controllably expel the submunition <NUM> from the carrier <NUM>, via the closure <NUM> at the rear of the carrier <NUM>.

The submunition <NUM> comprises wings or fins <NUM>, arranged to auto-deploy upon expulsion, so as to slow down the descent of the submunition toward and into the water. Such a deployable configuration is typically located at a rear (in terms of eventual descent direction) end of the submunition, to maintain descent stability.

The submunition comprises a submunition (main) explosive charge <NUM>, and a submunition fuze <NUM>. The submunition fuze <NUM> is typically located at a rear (in terms of eventual descent direction) end of the submunition <NUM>, to reduce the risk of damage to any sensitive components, during impact with the water. The munition assembly <NUM> is adapted to be launched, into the air, from a gun barrel, where the submunition <NUM> is then arranged to be controllably expelled from the carrier <NUM> and enter a body of water, and the submunition fuze <NUM> is adapted to trigger the submunition explosive charge <NUM> underwater.

Again, descent of the submunition, and activation of its fuze, may be implemented as described above in relation to the munition embodiments.

All of the principles described in relation to the submunition apply equally to a reconnaissance sub-projectile carried by a carrier of a reconnaissance projectile assembly. That is, the reconnaissance sub-projectile has the benefits of being carried and deployed like the submunition as described above, but also with the reconnaissance functionality, as described above.

Any of the projectiles described herein, including munitions, submunitions, or reconnaissance projectiles or sub-projectiles, may be arranged to communication with, ortransmit to, other objects. For example, munitions, submunitions, or reconnaissance projectiles or sub-projectiles, may be arranged to transmit a communication signal, external to and away from the submunition after entering the water, and optionally after a predetermined time period after entering the water; upon detection of a target sonar signature; upon detection of a target magnetic signature; upon detection of a target electric field signature; at a predetermined pressure under the water surface; at a predetermined depth under the water surface; at a predetermined salinity of water; at a predetermined temperature of water; at a predetermined speed-of-sound in water; or upon impact with a target under the water surface. The communication with, or transmission to, could be in relation to a remote weapon or platform, which could engage with the target depending on the communication or transmission. For instance, a submunition or reconnaissance sub-projectile may provide a warning shot, or a detection function, in advance of a more escalated engagement from the remote weapon or platform (e.g. a submarine, or torpedoes from a submarine).

Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification.

Claim 1:
A munition assembly (<NUM>) adapted to engage an underwater target, the assembly arranged to be launched from a gun, the assembly (<NUM>) comprising:
a carrier (<NUM>) for a submunition (<NUM>), the carrier (<NUM>) comprising a cavity in which the submunition (<NUM>) is located; and
a submunition (<NUM>), carried by the carrier (<NUM>) in the cavity, the submunition (<NUM>) arranged to be controllably expelled from the carrier (<NUM>);
the submunition (<NUM>) comprising:
a submunition explosive charge (<NUM>); and
a submunition fuze (<NUM>),
wherein:
the munition assembly (<NUM>) is adapted to be launched, into the air, from a gun barrel, where the submunition (<NUM>) is then arranged to be controllably expelled from the carrier (<NUM>) and enter a body of water; and
wherein the submunition fuze (<NUM>) is a programmable fuze adapted to trigger the submunition explosive charge (<NUM>) underwater in accordance with one or more of:
upon detection of a target sonar signature (<NUM>);
upon detection of a target magnetic signature (<NUM>);
upon detection of a target electric field signature;
at a predetermined pressure under the water surface;
at a predetermined depth under the water surface;
at a predetermined salinity of water;
at a predetermined temperature of water; or
at a predetermined speed-of-sound in water.