GB2407148A

GB2407148A - Projectile launcher for attack of underwater targets

Info

Publication number: GB2407148A
Application number: GB9614086A
Authority: GB
Inventors: Christopher David Lawrence
Original assignee: Qinetiq Ltd; UK Secretary of State for Defence
Current assignee: Qinetiq Ltd
Priority date: 1996-07-04
Filing date: 1996-07-04
Publication date: 2005-04-20
Anticipated expiration: 2016-07-04
Also published as: ITRM970366A0; GB9614086D0; GB2407148B; NO972422L; ITRM970366A1; DE19725396A1; FR2833341A1; NL1006303C2; FR2833341B1; IT1316423B1

Abstract

A weapon system for the attack of underwater targets such as a navl mine, comprises a projectile launcher 52 from which is launched, by propellant means 54, a projectile 61 containing a high explosive payload and a delay fuze. The projectile launcher is incorporated either in or on a remotely-operated vehicle, by which means the launcher is brought to a position at or adjacent to the target to be attacked. The projectile is accelerated along and fired from the launcher by expanding propellant gases after an annular protrusion 55 has been sheared off a rear cap 57 of the projectile. The projectile penetrates the casing of a mine and the delay fuze detonates the high explosive payload either immediately or when the remotely-operated vehicle has withdrawn to a safe distance. In an optional form, the all burnt condition of the propellant occurs after the projectile has exited the launcher. In this way the confining effect of water on the expanding propellant gases is used to continue to accelerate the projectile after it has exited the launcher which enables a shorter launcher to be used.

Description

1 24071 48

PROJECTILE LAUNCHER

This invention relates to a weapon system for use against underwater targets and in particular to such a system which is suitable for application either as a lightweight torpedo capable of defeating a multihulled vessel or as a naval mine disposal weapon.

In order, for example, to disable a submarine having a double-hulled structure, both ofthe hulls and any interhull structures must be breached. The breach in the inner hull must be above a certain critical size for the damage to the submarine to be fatal. If the breach in the inner hull is below the critical size then the flood of water through the breach can be contained from within and the submarine remains operational.

Certain types of submarines are known to possess inner and outer hulls in order to improve their resistance to attack, since the space between the two hulls is usually filled with water and may additionally contain complex interhull structures which are difficult to penetrate. A common method known in the prior art of defeating a double-hulled submarine using a torpedo is to detonate within the torpedo warhead a single conicallyrecessed shaped charge, having a high density liner, directed towards the submarine. The shaped charge jet thereby formed can penetrate the doublehulled structure and disable the submarine. The main disadvantage with this method is that the breach in the innermost hull can be smaller than the critical size mentioned above. This disadvantage is exacerbated if the space between the inner and outer hulls contains complex interhull structures which add to the target material to be penetrated by the shaped charge jet. It is difficult to overcome this problem because the shaped charge is constrained in diameter and explosive mass (and thus penetrating power) if it is to be used as a warhead for a torpedo, in particular a lightweight torpedo. A farther disadvanta,e of using a shaped charge warhead is that if the imer hull of the submarine is much smaller than the outer hull, the shaped charge jet may miss the inner hull altogether, especially for large angles of attack.

In the case of disposal ot'naval mines, the heretofore conventional methods of disposal rely on attempting tO detonate such a mine by placing a large blast charge alongside the mine and exploding it SO as to effect sympathetic detonation of the mine filling. However this technique has become increasingly ineffective due to the increasing insensitiveness of the modern polymer bonded explosive (PBX) fillings which are used in mines. As a result it is often possible to achieve sympathetic detonation only by approaching to within as little as 150 mm of the mine; however mine sensors will detect the incoming attack out to distances of 500mm at least and it is desired that the attack weapon should not approach to within less than 0.75 to 1.0 m ofthe target. A remote attack system is thus sought which is able to achieve penetration of the mine casing from a stand- offdistance of the order of I m.

The present invention seeks to overcome at least some ofthe aforementioned disadvantages of prior art systems for attacking and defeating both naval mines and multi- hulled vessels.

According to the present invention there is provided a weapon system for the attack of underwater targets which comprises a projectile launcher open at its forward end and having a propellant charge located at its reavard end, and a projectile which is slideably located forward ot'the propellant charge within the launcher, the said projectile containing a high explosive payload and a delay fuze and associated with said launcher, means for delivering the launcher to a position at or adjacent to the target to be attacked.

In the case where the target is a submarine the associated delivery means will comprise a lightweight torpedo vehicle and the launcher and projectile will form the warhead for the torpedo. The warhead in this case is preferably initiated by target sensor means at a predetermined stand-off distance from the target. This is advantageous especially if a delay fuze is used that is initiated by launch conditions because such a delay fuze would be based on the estimated time of flight of the projectile before it approaches the inner hull of the submarine target. Obviously varying the stand-off distance will vary the time of flight and thus v ary the position of the projectile when it is detonated. The predetermined stand-ofT'is chosen to ensure that the projectile achieves its maximum velocity just before it impinges on the target. If this is the case then the projectile will have its maximum kinetic energy when it impinges on the outer hull ofthe submarine so that the penetrating capabilities of the projectile are maxinised. In practice the preferred stand-off distance would typically be I to metres.

In the case of use as a mine attack weapon, the launcher is conveniently mounted either in or on a remotely operated underwater vehicle (ROY) which thus constitutes the delivery means for this type of weapon system. Here, the projectile is launched against the mine once the ROV operator has brought the system to within about 1 m ofthe mine.

In either case, after launch, the projectile is accelerated towards the target submarine or mine by the expanding propellant gases produced as the propellant charge is consumed. When it achieves its mxhnum velocity the projectile can breach the outer hull of a submarine or the casin<' of a mine and, in the case of the submarine, can at least partly breach any interhull structures which may be present.

For attack against double-hulled submarines the explosive payload ofthe projectile is detonated by the delay Size at a predetermined time which is chosen so that the projectile will be adjacent to the inner hull of the submarine when the explosive payload is detonated.

The water whicl1 is usually present in the interhull space has a confining effect on the blast produced when the explosive payload detonates and directs the blast towards the inner hull, thus enhancing the effect of the blast. The hole in the iMer hull thus produced can be several orders of magnitude greater than the hole produced by known torpedo warheads of a similar size and mass. Furthermore even if the projectile does not entirely breach the complex interhull structures whicl1 may be present before detonation, the blast produced can rip a hole in the inner hull above the critical size.

In the case of attack on a mine on the other hand, after penetrating the mine casing the projectile will come to rest in the mine filling which, in view of its rubbery nature, is very resistant to penetration. The explosive payload of the projectile is in this case detonated by the delay fuze at a predetermined time which is set to allow the launch vehicle (ROY) to withdraw and thus to avoid damage from the subsequent explosion ofthe mine.

Alternatively a relatively inexpensive and thus expendable ROV and launcher system may be employed in which case the fuse can be set for a minimal delay resulting in virtually instantaneous detonation of the mine albeit with consequential loss of the ROV.

Preferably the size of the propellant charge used in the torpedo warhead is chosen so that the all burnt condition of the propellant charge occurs after the projectile has exited the launcher. In this preferred form of the present invention the projectile is propelled along the launcher by expanding propellant gases which are confined within the launcher, as in conventional systems, but unconventionally when it exits the launcher the projectile continues to be accelerated by the expanding propellant gases because they are confined by the surrounding water. The expanding propellant gases continue to accelerate the projectile until the propellant gas pressure is equal tO the surrounding water pressure. At this point the projectile achieves its maximum velocity. In this preferred form of the torpedo warhead embodiment of the present invention a relatively short launcher can be used to accelerate a projectile to the same velocity as a longer launcher without the associated massive increase in the size of the propellant charge. Conventionally a short launcher requires a greater amount of propellant because the length through which the projectile can be accelerated (ie the length of the launcher) is reduced. However, in the case of present invention, because the propellant continues to burn after the projectile has exited the launcher and so to accelerate the projectile outside of the launcher (effectively increasing the length ofthe launcher) only a small increase in the amount or'propellant is necessary. Therefore, the torpedo warhead according to this aspect of the present invention can be light and compact while maintaining the required level of target penetration and damage, and therefore can be incorporated into a lightweight torpedo that can successfully disable a submarine.

It is not significant in the mine attack embodiment ofthe present invention that the all burnt condition of the propellant charge should occur after the projectile has exited the launcher. This is because fundamentally it is still more efficient with respect to the initial breech pressure to accelerate the projectile within the confines ofthe barrel, provided that a sufficiently ion' shot n-a\!el is available.

The design of the torpedo variant on the other hand is primarily driven by a length constraint to fit into the torpedo forebody. As a result it requires a relatively high breech pressure to accelerate the projectile prior to the projectile entering the water. In the case of a launcher used in the mine attack role however, the success of the design is driven primarily by the overall mass of the system. The longer projectile shot travel enables a lower pressure propellant charge system to be used to accelerate the projectile than is necessary t'or the torpedo variant. This is advantageous in the mine attack role as the launcher may then be made of even lower mass materials than are necessarily used on the torpedo variant with the resulting proportional reduction in overall mass.

In either embodiment, the projectile preferably has a truncated ogival nose with a stepped profile. The r adios of curvature of the ogive is most preferably between 1.25 and 1.75 times the diameter of the projectile. The diameter ofthe projectile is the diameter of the cylindrical main body of the projectile. The main advantage of using a projectile of this type is that the stepped nose profile breaks up the water producing a semi-cavitating flow around the projectile which reduces drag and lid. A reduction in drag means that the deceleration of the projectile by water resistance is reduced and a reduction in lift means that the projectile will deviate less from its trajectory. A warhead of this type has good target penetration characteristics with the added advantage that it is less likely to ricochet from the target at large attack angles. For a mine attack projectile this feature has the important consequence also that successful target engagement is possible over a wide operating window at attack angles of upto 45 obliquity and 12 azimuth for example, at a stand-off distance of 0.75 m, thus obviating the need for precise aiming by the ROV operator.

Preferably the projectile has a casing made of a material with a high compressive strength and more preferably the projectile casing is made from high tensile titanium. High tensile titanium has a high compressive strength and so a projectile with such a casing can pierce several layers ot'the targ;et without substantial deformation. Titanium also has an added advantage in that it is light in mass.

The explosive payload of the projectile is detonated by a delay fuze which is preferably initiated by launch conditions. In the case of mine attack, the delay is variable depending upon whether the ROV is regarded as being an expendable unit or whether it is to be recovered. For submarine attack on the other hand, the use of such a delay fuze is a reliable way of detonating the explosive payload when it is near to the inner hull of a submarine for a variety of attack angles and points of attack. As stated above a target submarine may have a comple:< interhull structure and so the structure that the projectile encounters may vary considerably depending on the attack angle and point of attack. The time it takes for the projectile to come near the inner hull is nevertheless found to be a fairly constant parameter on which to base the fuzing system. More preferably the delay fuze is electrical.

Preferably there is a rupturable connecting means between the projectile and the launcher. Lore pret'erably the rupturable connecting means is in the form of a protrusion of the projectile which engages a step in the internal surface of the launcher, the said protrusion being arranged to shear offthe projectile when subjected to a predetermined shear force. Therefore, in operation the projectile is secured within the launcher while the propellant <'ases generated behind the projectile build up to a predetermined pressure, at which point the protrusion shears off the projectile and the projectile is accelerated along the launcher. Such a rupturable connecting means is preferable because it optimises the thrust transmitted to the projectile from the propellant gases.

Preferably also, the launcher is at least ion, enough to completely house the projectile. This is advantageous because the launcher provides a support for the projectile and directs the projectile along its Axis so that the projectile is launched along a stable trajectory. Also, since the projectile contains an explosive payload, it is safer if the projectile is not exposed. In the present invention a longer launcher is slightly more propellant efficient than a shorter launcher. However, a shorter launcher is substantially lighter and more compact while still being relatively fuel efficient. In the torpedo warhead embodiment. the lengths chosen tor the launcher depends mainly on the amount of space available in the torpedo on which the warhead is to be mounted. For this reason it is preferable that the launcher has a length ot less than 900mm if it is to be mounted within the front end of a lightweight torpedo. For the mine attack embodiment it is preferred that the launcher should be less than 700mm in length.

Preferably where the weapon system of this invention takes the form of a torpedo warhead, it is mounted within the fore body of a torpedo and is enclosed therein by a torpedo hull which has a frangible nose section. In this form the torpedo carrying the warhead can be launched from an airborne carrier, for example a helicopter that is difficult for the submarine to detect and accelerate away from. The warhead is enclosed as this makes the torpedo much safer to handle and protects the warhead from sea water. The nose cone of the torpedo hull is preferably frangible so that the projectile can break through the casing without dissipating a large amount of kinetic energy.

Likewise, where the weapon system comprises a mine attack system the launcher will be preferably enclosed either by the hull of the ROV if mounted internally thereof or by a separate closure means if the system is mounted externally of the ROV hull. In either case the closure will preferably have a frangible portion to allow the projectile to break through readily without losing too much of its kinetic energy.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure I is a longitudinal section taken through a torpedo embodiment ofthe present invention, the warhead of which comprises a semi-armour piercing projectile located within a launcher.

Figures PA to ED show a projectile similar to the projectile illustrated in Figure I at sequential stages as it is accelerated both inside and outside ofthe launcher.

Figure 3 is a grapi1 ot the projectile velocity plotted against time for a submarine attacl: weapon of the kind illustrated in Fitrure 1; and Figure 4 is a longitudinal section taken through a mine attack embodiment ofthe present invention.

In the torpedo embodiment of the weapon system according to the present invention and with reference particularly to Figure 1, the launcher part of the warhead is seen to comprise a breech assembly 1 and a launcher tube 2.

Referring first to the breech assembly I, this is made of high strength and low mass metal, preferably titanium alloy, and houses a main propellant charge 4. A primer tube 19 is also housed within the breech assembly I and is located at the centre of the main propellant charge 4. The primer tube 19 has a cylindrical metal casing 10 with holes pierced therethrouah at regular intervals. The cylindrical metal casing 10 contains a primer composition,.

A projectile, shown generally at I 1, is shown loaded into the warhead in Figure 1, being located within the launcher tube a. The projectile 11 has a projectile casing 8 which is made of higl1 strength and low mass metal, preferably titanium alloy. The casing 8 has a truncated ogival nose, the radius of curvature of the ogive being I.5 times the diameter of the projectile, and a stepped nose profile 1. The projectile casing 8 is threadedly secured to a rear cap 7 at interface I,.

The rear cap 7 is made of aluminium alloy and has an axial cylindrical hole bored in it for the location of a timed fuze 6. The timed fuze 6 extends into the cavity formed within the projectile casing 8 and the rear cap 7. This cavity is filled with a high explosive charge 9. The rear cap 7 has an annular protrusion 5 whicl1 has an external diameter equal to the external diameter of the front end of the breech assembly I. The launcher tube is smooth bored and has an internal diameter at its t'ront end which is equal to the largest external diameter of the projectile casin' 8, so that the projectile fits slideably within the launcher tube a. The launcher tube has a step 15 on its internal surface which corresponds to the annular protrusion 5 ot'the r ear cap,. The launcher tube is preferably made using lightweight technology from high performance fibres wrapped around a metallic liner, for example, from a titanium or a Low formed.nara<'in' steel tube overwound with a high strength fibre composite material. This produces a very lightweight, high strength component more suited to a lightweight torpedo.

The projectile 11 is fitted slideably into the breech assembly I until the annular protrusion 5 of the rear cap 7 engages with the forward end of the breach assembly 1. The projectile I I is then secured in place by threadedly securing the launcher tube 2 over the breach assembly I at interface 14. The step 15 on the internal surface of the launcher tube 2 fits over the annular protrusion 5 of the rear cap 7 and holds the rear cap 7 and thus the projectile I I firmly in place. A cavity 18 is left between the rear ofthe rear cap 7 and the main propellant charge 4.

The timed Size is an elecn-icaliy timed device in which the timing is initiated by the firing conditions when the projectile is launched. Alternatively other conventional timed fuzes can be used. The tinted laze 6 has an insulating plug 16 located at its rearward end to protect it from the main propellant charge 4.

In Figure I the system is mounted within the fore body of a lightweight torpedo 17 and is enclosed within the torpedo hull 21. The nose section ofthe torpedo hull 21 is preferably made of a fi angible material. The nose section is further weakened by machining a plurality of petal shaped grooves on the internal surface of the nose ofthe torpedo hull 21 with the points ot the petal shaped grooves meeting at the apex of the nose section. The torpedo 17 can be launched from an airborne carrier (not shown) for example a helicopter and directed towards the target. The torpedo 17 includes a target sensor (not shown) which guides the torpedo onto a target and initiates the warhead at a short stand-offfrom the target to ensure that the projectile reaches its maximum velocity before striking the target.

-

The warhead herein described operates as follows. The primer tube 19 is initiated by the target sensor within the torpedo 17 when the warhead is typically I to 2 metres from the target. The prime charge is therefore ignited and jets of flaming propellant shoot through the holes in the metal casing' 10 to initiate the main charge 4. The initiated propellant ot the main char<,e produces hot propellant gases. The pressure ofthe propellant gases within the cavity 18 builds up and when the pressure reaches a predetermined value the annular protrusion 5 shears offthe rear cap 7 at time To (see Figure 3). The projectile 11 is accelerated by the expanding propellant gases confined within the launcher 2 behind the projectile 11. The projectile easily breaks thTough the nose section of the torpedo hull 2 I without dissipating a large amount of kinetic energy. The initial thrust experienced by the projectile when the annular protrusion S shears off can be used to initiate the timed fuze 6.

Referring now to Figures HA to ED and Figure 3, Figure 2A shows the projectile 11 at time T. (see Figure 3) as it is just about to leave the launcher 2 tube ofthe warhead.

The expandin, gaseous propellant products 90 confined within the launcher tube 2 continue to expand and tllus accelerate the projectile 11.

Figure SIB shows the projectile I I at thee T. (see Figure a) as it has just left the launcher tube 2 of the warhead. The expanding gaseous propellant products 20 are confined by the surrounding water and continue to expand and thus further accelerate the projectile I I. The expanding gaseous propellant products 20 will continue to accelerate the projectile I I while the propellant gas pressure is Greater than the surrounding water pressure.

Figure TIC shows the projectile I I at time T. (see Figure a) when the propellant gas pressure equals the surrounding water pressure so that the projectile 11 ceases to be accelerated.

Therefore at time T the projectile I I reaches its maYhnum velocity, typically ofthe order of a few hundreds of metres per second.

Figure 2D shows the projectile 11 at a later time To and shows the projectile 11 in a cavitating flow regime. A cavitating flow regime is advantageous because it reduces the drag and the lift experienced by the projectile 1 1. .N cavitating, flow regime is encouraged by a projectile I I that has a stepped nose profile (shown at 12 in Figure 1). This is because the sharp corners of the nose profile breaks up the.vater.

Figure 3 is a graph of projectile velocity plotted against time. The velocity of the projectile 11 increases rapidly as it is accelerated within the launcher tube 2 from time To to time T.. The projectile velocity continues to increase from time To to time T3 as the projectile 11 is accelerated by the expanding propellant gases confined within the surrounding water The projectile 11 reaches its maximum velocity at time T3 when the propellant gas pressure becomes equal to the surrounding water pressure. From time T3 onwards the velocity of the projectile gradually decreases as it is decelerated because of water resistance Tl e projectile I I wl en launched t'rom the warhead herein described at a maximum velocity typically of a few hu wired.'netres per second will have sufficient kinetic energy to breach several layers of a t. ryer stricture before coming to a halt. The timed fuze 6 can be set so that the explosive payload 9 detonates as the projectile approaches a selected part of the target For e,xa nple where tl e target is a submarine the projectile 11 is capable of breaching tl e or ter hull and i. terl ull st Picture of a submarine at a large range of attack angles Tl e ti Red fuze is set so that the explosive payload 9 detonates as the projectile nears or contacts the inner l ull The ti He delay of the fuze is the estimated time of flight of the projectile before the projectile reaches the inner hull ofthe submarine. The detonation of the explosive payload 9 can.-ip a hole in the inner hull much larger than the critical size.

Figure ills strafes a wa.-l ead system.. for mine attack shown generally at 50, in which a breech assen.bly 51 and an integn-al launcher tube 52 comprise the launcher for projectile 61 The breecl, assembly houses a main propellant charge 54. A primer tube 70 has a cylindrical metal casing 71 witl. holes pierced therethrough at regular intervals. The cylindrical metal casing 71 contains a primer co nposition 72.

A projectile, sl own generally at 61, is shown loaded into the launcher tube 52. The projectile 61 has a casing SS wl.ich is made of high strength and low mass metal such as titanic rn alloy Cast.. 55 has a t,- unc; ted oyival nose, the radius of curvature of the ogive being' 1 5 rd.. es tl e dia.. eter ot the p.-ojectile. and a stepped nose profile 62.

The projectile 6] is fitted with a fuse 56 having a rear cap 57. The rear cap 57 has an annular protrusion 5 j which has an external diameter equal to the external diameter of the front end of the breech assembly 51. The launcher tube 52 is smooth bored and has an internal diameter at its front end which is equal to the largest external diameter ofthe projectile casing SS, so that the priojectile fits slideably within the launcher tube 52. The launcher tube 52 has a step 65 on its internal surface which corresponds to the annular protrusion 55 of the rear cap 57 Launcher tube 59 is preferably made using lightweight materials technology from high performance fibres wrapped around a metallic liner, for example an aluminium alloy tube overwound with a higl1 strength fibre composite matenal.

This produces a very lightweight, high strength component of minimal diameter more suited to use with a ROV Projectile 61 is fitted slideabiy into the breech assembly 51 until the annular protrusion 55 ot'the rear cap 57 engages with step 65 at the forward end ofthe breech assembly Projectile 61 is then secured in place by tlreadedly securing the locking ring 66 into the breech assembly 51 at intert'ace 64 thus holding the projectile 61 firmly in place. A cavity 68 is let's between to rear of the fuse rear cap 7 and the main propellant charge 54.

Tile timed fuze 56 is preferably electrical in operation in terms ofthe delay function.

However a relatively simple electro/mechanical fuze with a chemical delay may be preferable for an expendable ROV system. For the electrical fuze variant the timer and detonator firing circuitry is powered by charging a capacitor within the fuze just prior to projectile launch Power is transmitted to the tuze via wire 73 The wire 73 is routed through the breech wall via a pressure proof bulkhead fitting 74. Timer countdown is initiated by the severance of the wire 74 as the projectile begins to move along the launcher tube during the firing sequence After the predetermined delay time has elapsed a firing pulse is sent to the detonator and this initiates the explosive train within the projectile.

In the case of a simple eiectro/mechanical fuze the chemical delay element will be initiated by the Set back forces gene! ated durin_ tiring via a conventional striker/stab sensitive detonator an-angement

Claims

1. A weapon system for the attack of underwater targets which comprises a projectile launcher open at its forward end and having a propellant charge located at its rearward end, and a projectile which is slideably located forward of the propellant charge within the launcher, the said projectile containing a high explosive payload and a delay faze; and associated with said launcher, means for delivering the launcher to a position at or adjacent to the target to be attacl<ed.

2. A weapon system according to claim I characterized in that the delivery means is a torpedo vehicle and the launcher is mounted within the forebody thereof

3. A weapon system accordin, to claim I characterized in that the delivery means is a remotely operated submersible vehicle.

4. A weapon system according to any one of claims I to 3 characterized in that the projectile has a truncated Rival nose with a stepped profile, the radius of curvature of the ogive being between 1.95 and 1.75 times the diameter ofthe projectile.

S. A weapon system according, to any of the previous claims characterized in that the projectile has a casing made c,{ a material with a high compressive strength.

6. A weapon system according to claim 5 characterized in that the casing is made of high tensile titanium.

7. A weapon system according to any of the previous claims wherein the delay fuze is initiated by launch conditions.

8. A weapon sy steno accordinmo claim 7 wherein the delay fuze is an electrical fuze.

9. A weapon system according to claim 7 wherein the delay fuze is an electro/rnechanical fuze.

10. A weapon system according to claim 2 characterized in that the all burnt condition ofthe propellant charge occurs after the projectile has exited the launcher.

11. A weapon system according to any one of the preceding claims characterized in that there is provided a rupturable connecting means between the projectile and the launcher.

12. A weapon system according to claim 11 characterized in that the rupturable connecting means is a protrusion of the projectile which engages a step in the internal surface of the launcher the said protrusion being arranged to shear off the projectile when subjected to a predetermined shear force.

13. A weapon system according to any one of claims 4 to 12 when dependent on claim 2 characterized in that launch or'the projectile is initiated by target sensor means at a predetermined distance fi one a target.

14. A weapon system according lo claim 13 claracterised in that the said predetermined distance is between I and metres.

15. A weapon system according to claim 3 or any one of claims 4 to 12 when dependent on claim 3 characterized in that there is further provided means whereby an operator ofthe remotely operated vehicle is enabled to initiate launch ofthe projectile against a target.

16. A weapon system as hereinbefore described with reference to Figures 1 to 3.

16. A weapon system according to claim 15 wherein said means comprises means for detenninin=, the closeness of approach ot'tle velic!e to the mine target and for displaying such data to the operator ot'tle e!icle.

l 7. A weapon system according to any of the previous claims wherein the launcher is at least long enough to house the projectile completely.

18. A weapon system according to any of the previous claims wherein the launcher has a length of less than 900mm.

l9. A weapon system according to claim 2 or to any subsequent claim dependent thereon wherein the launcher is completely enclosed within the forebody of the torpedo vehicle by the torpedo hull which has a frangible nose section.

20. A weapon system accordin, to claim, or to any subsequent claim dependent thereon characterised in that the launcher is either completely enclosed within a part ofthe remotely operated vehicle or is carried externally thereof 21. A weapon system as hereinbefore described with reference to Figures l to 4. iC

Amendments to the claims have been filed as follows 1. A weapon system for the attack of underwater targets which comprises a projectile launcher open at its forward end and having a propellant charge located at its rearward end, and a projectile which is slideably located forward of the propellant charge within the launcher, the said projectile containing a high explosive payload and a delay fuze; and associated with said launcher, means, comprising a remotely operated submersible vehicle, for delivering the launcher to a position at or adjacent to the target to be attacked.

2. A weapon system according to claim I characterized in that the projectile has a truncated ogival nose with a stepped profile, the radius of curvature of the ogive being between 1.25 and 1.75 times the diameter ofthe projectile.

3. A weapon system according to claim 1 or claim 2 characterized in that the projectile has a casing made of a material with a high compressive strength.

4. A weapon system according to claim 3 characterized in that the casing is made of high tensile titanium.

5. A weapon system according to any of the proceeding claims wherein the delay fuze is initiated by launch conditions.

6. A weapon system according to claim 5 wherein the delay fuze is an electrical fuze.

7. A weapon system according to claim 5 wherein the delay fuze is an electro/mechanical fuze.

8. A weapon system according to any one of the preceding claims characterized in that there is provided a rupturable connecting means between the projectile and the launcher. i:

9. A weapon system according to claim 8 characterized in that the rupturable connecting means is a protrusion of the projectile which engages a step in the internal surface of the launcher the said protrusion being arranged to shear off the projectile when subjected to a predetermined shear force.

10. A weapon system according to any of the proceeding claims characterized in that there is further provided means whereby an operator of the remotely operated submersible vehicle is enabled to initiate launch ofthe projectile against a target.

1 1. A weapon system according to claim l O wherein said means comprises means for determining the closeness of approach of the vehicle to the target and for displaying such data to the operator of the vehicle.

12. A weapon system according to any of the proceeding claims wherein the launcher is at least long enough to house the projectile completely.

13. A weapon system according to any of the proceeding claims wherein the launcher has a length of less than 900mm.

14. A weapon system according to any of the proceeding claims wherein the launcher has a length of less than 700mm.

15. A weapon system according to any of the proceeding claims characterized in that the launcher is either completely enclosed within a part of the remotely operated vehicle or is carried externally thereof.