Field of the Invention

This invention relates to a ship defence device and related system and includes an associated method for defending a ship, by deploying cables in water surrounding a ship.

Background of the Invention

Many ships and yachts have come under attack following the relatively recent resurgence of piracy on the seas. Some solutions for preventing persons from gaining access to the ship have resulted, including the addition of baffles, handrail covers or bulwarks making it harder to board a ship or to attach grabbing hooks to the ship. However, these solutions make it more difficult for legitimate people to go about their business on the ships' deck.

A pipe work system for supplying boiling water or steam to the sides of the ship has also been tried, but this relies on a steady and ready supply.

Prior Art

Existing systems include a movable handrail whereby under normal operating conditions the handrail is in a normal position, but under attack the handrail is tilted down and outwards forming a barrier to anyone trying to get onboard.

Chinese Patent Application CN-A-101475052 discloses a chain which encircles the ship having cutting devices spaced along its length. When a grappling hook reaches the ship, the cutting devices saw through the cable either rendering it too weak for purpose or completely cutting it. Another example of an intruder detection system, depioys wires around a gunwale. A change in tension in the wires is detected thus indicating the presence of intruders.

All of the abovementioned systems concern themselves with prevention or detection at the ships' hull thus providing limited all be it useful protection.

Detection systems, having cameras and/or image processors enable cameras to scan regions of water around the ship and when the image processor detects a boat or craft in the vicinity an alert is given. The detection system may be connected to a hosing machine to begin counterattack automatically. This has an advantage that the region of coverage is extended beyond the ships' hull giving more time to react and prepare. However, this type of system, together with many of the aforementioned systems are generally passive in nature and are of very little use in preventing an attack or unauthorised boarding of a vessel whilst at sea.

Another option is to ensure marshals or armed professionals are accompanying larger container ships and oil tankers but for many reasons this is not always practical or desirable.

Another system that entraps propellers of hostile ships is described at http://www.p-trap.eu and is sold under the Trade Mark P-Trap. The system consists of two booms and a number of reels that are supported on a main boom that is slung from a ship. A secondary boom is located below the main boom and shown slung from the main boom. The purpose of the secondary boom is to ensure the freeboard length of cable - ie the length of cable between reels around which cable is wound and where cables contact the water surface - is as short as possible. This ensures that the cables are entrained in the water. The sysiem however, is iarge and compiex to operate and because of its size and complexity likely to be cumbersome to install. It is also relatively heavy as it supports the weight of several reels of cable. Because of its size the system presents a relatively Iarge surface area to impinging waves, particularly when the ship is rolling in heavy seas.

The total weight of the system can be reduced by reducing the thickness (gauge) of the cables and so avoiding the need for larger storage reels. However, a disadvantage with using thinner cables is that they are less likely to entrap an outboard motor/engine and so effect permanent damage to the engine of a hostile vessel. The upshot of this is that only minor damage or inconvenience is caused to the propeller of a hostile craft, by thinner cables entangling the propeller, rather than permanent disablement of the engine.

The result is that attack vessels are temporarily disabled and after a short interval can be repaired and are quickly made seagoing enabling the vessel to attempt subsequent attacks.

Other examples of systems are disclosed International Patent Application WO-A1 -99/30966 (Kilvert) and WO-A1 -2008/145328 (Folgmann).

US Patent US-A-3 662 484 (DRES) and Belgium Patent Application BE-A- 905850 (Maralec) describe specialised boom equipment intended for use with fishing vessels.

From the foregoing it is apparent that the problem of piracy and hostile attacks to sea-going craft presents problems to mariners as well as operators and owners of ocean going craft. Another aim of the invention is to provide a system for inhibiting pirates. The present invention aims to provide a readily deployable system that is robust and suitable for preventing hostile attacks from water craft and one which is quickly and which is suitable for use in all sea states.

Another aim is to provide a cost effective solution that deters pirates and which is modular so that in the event of damage, only the damaged portion needs to be replaced, unlike prior art systems.

Summary of the Invention

According to the present invention there is provided a ship defence system comprising: a deployment device which in use deploys cables from a ship; a plurality of cables which in use are mounted on and supported by a cable support; and a boom with line feeds adapted to receive a cable and deploy the cable from the line feed in the water as close to the boom as possible.

Ideally line feeds are located on the boom and are relatively heavy with respect to the cables. Typically the lead lines are formed from a cable whose weight is in excess of 1 kg per meter, preferably in excess of 5 kg per meter.

Advantageously the length of the lead lines is such that the lower end is held, in normal use, just above the level of sea.

Ideally the lead lines are connected to the boom by way of a detachable device such as a quick fit connector or a carabiner. Lead lines are ideally at least 5 mm in diameter and are preferably more than 10 mm in diameter.

The floating 10 mm polypropylene line passes through the leadline via the caribinas or connectors or is attached directly to the leadline via a weak link. In use the 10mm polypropylene that immediately disables the hostile craft. In addition the cable leads ideally have a low friction surface over which cables pass so presenting minimum friction to the cables, thus facilitating rapid deployment.

According to another aspect there is provided a ship defence system comprising: a deployment device which in use is attached to a ship; and a plurality of cables which in use are supported on reels not located on the boom and the cables are deployed in the sea so as to entrap the propulsion means of hostile vessels.

Ideally the deployment system includes a boom which is preferably in the form of a single steel and deployed from a ship by way of a tensioner.

The boom typically is in the form of a steel structure or carbon fibre structure and includes a plurality of suspension or tensioning means, such as wires.

The structure may comprise a pole or series of poles interlinked by way of pole connectors. The former arrangement permits shorted poles to be used so as to reduce storage space and facilitate shipment.

The ship defence system according to the invention is essentially a propeller arrester whereby the propeller of an incoming vessel is snagged by one or more cables which lie on/in the water around the ship, essentially parallel to the direction of travel of the ship. They operate by preventing hostile vessels getting close to the ship as well as preventing them from leaving the vicinity of the ship and so hampering their escape from the ship being defended.

Advantageously one or more weak links are provided in the cable so as to break at a predetermined breaking strain. Typically this is in excess of 2000 Newtons. Preferably, the deployment device includes: a reel associated with each cable. The cable may be rolled up around the reel or at least partially deployed therefrom. In a preferred embodiment the deployment device includes a boom from which the cables are deployed. Reels may be mounted on rails or other supports of the ship so that individual lines can be fed through suitable guides formed on the boom. An advantage of this is the weight of the boom (and therefore its size) can be kept to a minimum. Another advantage of this is that the boom can be made longer and it is also cheaper to fabricate and install.

The boom advantageously has at least one reel attached thereto enabling deployment of the cable. Reels are ideally removable and replaceable so as to permit repair and use of different grade cables with different breaking strains.

Preferably the boom has several cable carriers and several reels are adapted to feed cable to the carriers attached to the boom. In use cables tend to align with streamlines so that they lie substantially parallel with respect to the hull of the ship.

In a preferred embodiment, the boom when in use is movable between two positions: a first position where the boom is substantially parallel to a ships' hull and a second or deployed position where the boom is substantially perpendicular to the ships' hull.

Preferably, one or more of the reels attached to the boom is movable along at least a part of the length of the boom.

In a preferred embodiment, the cable comprises a number of different sections including one of more of a main or floating section; a weak link; a lead line; and a drag float. In an alternative arrangement lines can be affixed or connected separately to the boom.

The system according to the invention enables a ship to increase its effective width and length when at sea by providing a plurality of cables which are deployed from reels which may be attached to booms and the stern located around the ship's hull. The cables therefore not only provide a deterrent to pirates as it will be apparent that the ship is well protected but also snag the pirate vessels including propellers at a distance from the ship rendering them ineffective against the ship.

According to another aspect of the invention there is provided a method of protecting a ship comprising the steps of: providing at least one cable capable of deployment from the ship; and providing a deployer for deploying the at least one cable from the ship; whereby when the at least one cable is deployed from the ship using the deployer, the footprint of the ship is extended providing a defence system for the ship.

Preferably, the deployer comprises one or more of a reel and a boom. It is preferred that the deployer is movable from a first position to a second position.

According to a yet further aspect of the invention there is provided a method of detecting a hostile attack to a vessel comprising the steps of: providing at least one cable capable of deployment from the ship; providing a sensor associated with the cable for sensing a variation in a cable characteristic and transmitting an alarm in dependence upon the variation of the characteristic being associated with a hostile event.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:- Brief Description of the Drawings

Figure 1 is a plan view of a ship having a system according to the invention;

Figure 2 is a plan view of an alternate design of a system according to the invention;

Figures 3a and 3b are perspective views of reels according to a preferred embodiment of the invention;

Figure 4 is a cross-section through a reel according to the invention;

Figure 5 is an enlargement of part A of Figure 4;

Figure 6 is a transverse view of a boom according to the invention;

Figure 7 is a transverse view of a boom according to the invention;

Figure 8 is a transverse view showing attachment of a boom according to the invention;

Figures 9a and 9b are perspective views of a single boom formed form carbon or steel according to the invention;

Figures 10a - 10d are diagrammatical views of an alternative embodiment of the invention; and

Figure 11 is a diagrammatical overview of a system including a hostile attack detection device and remote alert system.

Detailed Description of the illustrated embodiment Figure 1 shows the footprint or outline 10 of a ship using a defensive system or propeller arrester according to the invention. At the stern or rear 12 of the ship a number of reels 100 are provided. Around both sides 14, 16 of the ship a number of booms 200 are provided, each of which has at least one reel 100 attached thereto.

The reels 100 provided at the stern 12 of the ship are suspended, in this example, from brackets 20 attached to the outer hull 18. The working and possible designs of the reels are discussed further in relation to Figures 3, 4 and 5. Reels may be attached to hand rails, gunwales, the hull or any other part of the superstructure of a ship, as crew see fit. Suitable connector plates, bosses or other quick release brackets (not shown) may be located around the ship so as to facilitate rapid deployment of booms and/or reels.

Booms 200 are provided on each side 14, 16 of the ship. In this example four booms are provided on each side 14, 16; the exact number will depend on a number of factors including length of the ship. Each boom has at least one reel 100 suspended from it and each reel 100 has a cable 150 attached which is capable of being wound round the reel 100 for storage or prior to deployment or unwound from a reel 100 when deployed. The cable 150 is attached at one end to the reel 100, providing an anchor and giving the option for re-winding the cable 150 onto the reel 100. Ratchets and/or locks are optionally provided on reels to ensure they are not damaged in the event of entanglement of a cable by a propeller of a hostile vessel.

Optionally strain sensors or other sensing means are located on reels or in a manner that signals can be retrieved from cables, so as to provide a signal indicative of an attack. The signals are sensed and processed, as described below with reference to Figure 11.

Optionally reels may have ratchets so as to enable cables to be wound in to a desired length or fully retrieved. Length markers may be placed on cables so as to indicate lengths of cable deployed. Reels may be motor driven and optionally remotely controlled by way of automatic sensing devices, which may be adapted for example to determine the amount of undeployed cable.

When the cable 150 is deployed, it drops via the influence of gravity into the surrounding water. If the ship is in motion, deployed cables tend to lie approximately parallel to and stretching out alongside and behind (if long enough) the ship. To assist deployment, the free end or adjacent part of the cable can be weighted. In a preferred embodiment, the cable actually comprises a number of portions each having a different function.

A first portion of the cable is weighted or made from a relatively dense material. This dense portion is attached to a main part of the cable which is made from a less dense material, (which ideally floats), such as a synthetic plastics material, so that this portion lies on or near the surface of the water.

A weak link can be provided between the main part and first part as well as between the main part and the reel. This weak link enables the cable to be detached in the event of entanglement or snagging of the line, so reducing the risk of damage to the boom and/or reels, whilst ensuring a sufficient length of cable is paid out so as to incapacitate or damage the engine of a hostile craft.

In one embodiment a propeller arrester comprises a 5 stage line or cable deployed from reel 100. The line has a lead line/heavy weighted line 1016 which is attached to the spool providing the anchor for the deployed cable. This allows the line to be weighted when fully deployed and ensures the line drops the height of the freeboard of the ship. The weak link, which is a safety feature, allows the line to break if a vessel is entangled or there is a snag on the line whilst the vessel is underway. This weak link has a lower breaking strain than the main rope, and the lead line. A main rope/cable/line of varied length made from polypropylene rope of varied length but typically 50-300 metres. This polypropylene rope floats on top of the surface whilst the vessel is underway. At the remote (distal) end of the cable/line, there is provided a drag float which is used in the initial deployment and provides the surface drag/friction to both deploy the line to full extent and also keep the line straight in the water whilst being towed.

A lanyard is fitted to the reels that extend from reels located on the boom or hand rail and acts as a release device. This is used so that the reels can be deployed when at full boom extension away from the vessel.

Swinging boom arms used in deployment forms a system that effectively extends the breadth of the vessel to be protected and maintains an extended perimeter. The booms can be made of steel or carbon fibre and they preferably have suspension and retaining stays for deployment and recovery.

It is preferred that cables are rewound onto the reels after deployment, for example when the ship is approaching port or has safely navigated dangerous waters. This could be achieved by hand either by having a person inch along the boom arm and hand turn a reel handle or by moving the reels closer to the ship for rewinding or an automatic system whereby the reels are attached to motors which are activate by an onboard mechanism (such as a button).

Alternatively, (and in the event of an unsuccessful rewinding procedure) the cables can be released into the water however, this is not preferred as the cables become litter and new cables are required to re-defend the ship.

In a particularly preferred embodiment booms are supported on a hinge or swing in then reels are detached, line is manually pulled onto ship, then wound onto reel. Figure 2 shows an alternate arrangement for reels 100 attached to a boom 200. In this example the reels 100 are staggered along the length of adjacent booms. This embodiment enables a higher packing density of cables (number of cables per unit area) to be provided in the water adjacent the ship. It is also understood that booms may be mounted at variable inter-boom spacing so as to achieve this, with cables being released at different staggered locations in adjacent booms so as to interlace the footprint of the cables, thereby achieving a greater packing density of cables.

Figures 3a and 3b show a reel 100 according to the invention. The reel 100 comprises a spool 110, a handle 120 and a retaining bracket 130. The spool 110 has a central spindle 112 with a retaining disc 114 at each end. The cable (not shown) is wound on and off the central spindle 112 and retained in its wound form by the retaining discs 114.

At each end of the central spindle 1 2 is provided attachment means 116 for attaching the spool 110 to a retaining bracket 130. In this example the attachment means 116 comprises a metal stub which is partially screwed into the spindle and extends therefrom (see Figure 5 in particular). At one end, the attachment means includes a handle 120 for winding and unwinding a cable from the reel 100.

The spool 110 can be attached to a ship via a retaining bracket 130. The retaining bracket is generally H-shaped with a hole 132a, 132b, 134a, 134b provided at each end of each leg of the H. A cross brace 136 is provided between the two legs of the retaining bracket 130. One set of holes 132a, 132b enables attachment of the retaining bracket 130 to the spool 110 using attachment means 116. The attachment means 116 fits through apertures or holes 32a, 132b and are secured by a conventional technique, for example using a nut 138. The other set of holes 134a, 134b which are at distal ends of the legs of the H of the retaining bracket 130 to the spool attaching holes 132a, 132b, are used to attach the reel 100 to either a ship or a boom. Where the reel 100 is attached directly to the ship (as shown in Figure 1 at the stern) a bracket 20 (Figure 1) is generally used between the ship and the reel 100. The person skilled in the art will appreciate that a number of different brackets can be utilised. In this example a generally U-shaped bracket is used having holes near the end of each upright of the U into which the attachment means 116 of the spool 110 fit.

Where the reel is attached via a boom there are two options, either a bracket can be used between the retaining bracket 130 and the ship or, the boom can be threaded through the retaining bracket 130 and either secured in position with respect to the boom or, as in a preferred embodiment movable with respect to the length of the boom. It is also feasible for a bracket secured reel to be movable along the length of the boom arm.

Figures 4 and 5 show different aspects of a lock and unlock mechanism for a reel 100. This locking mechanism enables remote deployment of the cables using a lanyard 160,172. One retaining disc 114 of the spool 110 is provided with a hole 162 into which the lanyard post 160 is insertable. The corresponding leg 164 of the retaining bracket 130 is also provided with a hole 166 which is positioned such that when the spool 110 and retaining bracket 130 are correctly aligned, the lanyard post may pass through the hole 166 in the leg 164 of the retaining bracket 130 and into or through the hole 162 in the retaining disc 114 of the spool 110. Again it is understood that brackets may be mounted to ships handrails.

These cooperating holes have been depicted as being at the distal end of the spool 110 to the handle 120, for convenience only and may alternatively be provided at the handle end. Indeed it may be advantageous to have the handle and locking mechanism at the same side as one could use the handle to align the holes 162,166 and depending on the size of the reels, it may not be possible for one person to access both ends of the reel and manipulate the lanyard 160,172.

The lanyard post 160 is provided with a hole 170 into which string 172 or other cord is securely attached near one end. It is preferred that the hole 170 is located on the outside of the reel in use, however, it could be located within the spool 110 as long as a tugging action on the string 172 results in removal of the lanyard post from at least one of the holes 162,166 and preferably both of the holes which enables complete removal of the lanyard 160,172 when the spool 110 is unlocked from the retaining bracket 130.

Unlocking of the reel is achieved by pulling the string 172 thus releasing the lanyard post 160 from at least one of the holes 162,164. The pulling can be a manual operation, where one or more strings 172 from different reels are pulled by hand or wound onto a spool which is rotated to tug the lanyard posts out. The rotation of the spool can be a manual or mechanical operation for example, by using a motor driven spool.

Figure 6 shows a boom 200 according to the invention. The boom 200 is shown in its extended position where the cables are able to be deployed and has a boom arm 210 which is essentially horizontal and a boom upright 220 which is substantially perpendicular to the boom arm 210 and provides the main anchor for the boom to the ship 90.

The boom arm 210 and boom upright 220 are attached using a bracket 212 which is preferably welded onto the boom arm 210 and either welded to of crimped around the boom upright 220. In addition a forward stay 220 is provided which links the upper end 234 (when in use) of the boom upright 220 to a point somewhere (not shown) along the length of the boom arm 210. Depending on the boom arm length and expected sea conditions additional stays may be provided to support the weight of the boom arm 210. The boom upright 220 is secured to a railing 230 of the ship. At the base of the boom upright 220, a bracket 228 is attached thereto and this is bolted 232 to an upwardly extending lip 236 on the ships' hull 18. Two back stays 226 are anchored both to the ships' deck 240 and the boom upright 220 providing a counterbalance to the weight of the boom arm 210 and the force exerted on the forward stay 220. The boom upright 220 is attached to the railing 230 using two (or more) U bolts 224 which enable the boom upright 220 to swivel about the railing 230 when moving from a stowed to a deployed or extended position.

The boom arm 210 is made from a composite or steel tube and is either of fixed length or can be extendable. The extendable version may be formed from sections or can be telescopic in nature and enables either a smaller ship to have longer boom arms or a larger ship to have longer boom arms and/or smaller storage areas for the boom arms when stowed.

The boom arm 210 is shown as having one reel 100 attached thereto. In this example the retaining bracket 130 of the reel 100 is threaded onto the boom arm 210 using holes 134a, 134b of the retaining bracket. Additional reels can be provided along the length of the boom arm 210. Each additional reel enhances the protection provided to the ship as the footprint or entanglement zone is increased.

The reels may be fixed in position with respect to the boom arm 210 or they could be movable and a pulley system could be used to move the reels when the boom arm 210 is extended (as shown). Depending on how the reels are attached to the boom arm 210, additional reels could be added whilst the boom arm is extended. The movable version is particularly useful when an extendable boom arm is used.

Figure 7 shows a boom arm in the stowed position 300. Boom arm 310 is attached to a boom upright 320 via a bracket 312 and a front stay 322. The boom arm 310 is substantially parallel to the fore/aft axis of the ship 340 and in this example is designed to, at least in part, lie on top of railings 330 when stowed. The boom arm 310 can be lashed to railing 330 to prevent unwanted deployment or extension of the boom arm.

Figure 8 shows attachment of a boom upright 320 to a railing 330 in more detail. Two U shaped brackets 324 are spaced along the length of the boom upright 330 and are secured around the railing 230 using nuts and bolts 350.

Figure 9a and 9b show further example of booms according to the invention. Figure 9a shows an extended or deployed boom 400. The boom 400 comprises a boom upright 420 which is a 2m long round section tube attached via a bracket 412 to a steel base tube 420'. The boom arm 410 is a 10m long composite beam made from five 2m long square sections. The boom arm is attached to the boom upright via steel bracket 412.

Two front stays 422a,422b are provided between the upper end 434 (in use) of the boom upright 420 and two spaced apart locations on the boom arm. A back stay 426 is provided from the upper end 434 of the boom upright to an anchor point 448 on the deck 440 of the ship.

Figure 9b shows the boom moving from its stowed position 450 to an extended position 400. When in the stowed position 450, a side stay 460 is provided between the boom upright 420 and the ships' deck 440. This side stay provided support to the boom arm or beam whilst it is being loaded with reels prior to deployment. When the boom arm is deployed 400 in the example, two side stays 470, 470' are provided between an anchor point 472 on the ships' hull 18 and two spaced apart locations 474, 474' on the boom arm.

The reels can be loaded immediately before deployment of the boom arm or at a convenient time prior to deployment. Both have advantages: immediately before deployment means that the functioning of the deck is not impeded by reels and cables on the railing side; prior to deployment means that rapid deployment of all boom arms can be effected by a few persons enabling quick deployment of the cables into the water and therefore protection of the ship.

The system is deployed from vessels to entangle propellers of high speed pirate boats which are used to attempt to board the vessel and hold the vessel and occupants to ransom. The cables or propeller arresters are designed as a countermeasure for vessels underway hence the ability to stow the booms when not in use. The propeller arresters in effect extend the perimeter of the vessel and are deployable from the bow along the sides of the hull to the stern to increase the breadth of the vessel and from the stern to increase the vessels' footprint to effectively around three times the length of the ship.

Throughout this specification, the use of the term ship refers to and includes any seagoing vessels that could use the ship defence system of the invention.

When deployed, the examples described herein shows stays either deployed from the boom upright or from a point on the hull of the ship. The person skilled in the art will appreciate that a combination of such stays or even stays that attach to other parts of the boom and ship superstructure.

It is possible to utilise the present invention with other ship defence mechanism such as a sonic defence method, barbed wire coils located on the ship side of the ship railings.

One advantage of the invention is that the propeller arresters can be readily modified to fit different sized ships. By way of an example Figures 10a - 10d show diagrammatical views of an alternative embodiment of the invention which has been suitably modified. Figure 10a is a plan view showing how lines are deployed from reels 1000, mounted on handrails 1002 on a ship 1004 of boom 1006. Figure 10b is a head on view of ship 1004 and shows the boom 1006 extending outwards on the left (port) side of the ship 1004 and illustrates how cables 1010 pass from the boom 1006 to the surface of the sea.

A tensioning cable 1012 passes from the ship to the end of the boom 1006 in order to support the boom 1006 and to compensate for bending and loading arising form sea swell and viscous drag forces due to the cables 1010 being pulled along in the water.

Figure 10c is an elevation view of a reel 1000 showing how cable is disposed from the reel to a distribution point such as a cable guide 1014 mounted on the boom 1006 (Figure 10d) and how a lead line 1016, which is typically formed form a heavy gauge, dense cable, ensures the cable is presented to a point just above the water surface.

It is to be appreciated that these Figures are for illustration purposes only and other configurations are possible. For example strain gauges 500 may be incorporated in the cables 150, to detect excessive forces which may arise from entrapping a propeller or when ensnaring an obstacle. Alternative sensing means might be included in the cables so as to detect cutting. Such sensing means might for example include an optical fibre which when cut triggers an alarm as a result of a detector sensing a shortening in length of the optical path.

In an alternative embodiment, depicted diagrammatically in Figure 11 , a system includes a hostile attack detection device and remote alert facility. Optionally strain sensors 500 or other sensing means are located on reels 100 or in a manner so that signals can be retrieved from cables 150, so as to provide a signal indicative of an attack. Alert or alarm signals may arise as a result of strain applied to cables 150 or as a result of cutting cables, for example by virtue of a variation in an electrical characteristic or loss of an optical signal that is provided by a laser light emitting diode (LED) 610 which may be located at the end of a cable 150 in a self contained, waterproof housing 650. Alarm or alert signals are sensed and processed, as described below with reference to Figure 11.

The embodiment shown in Figure 11 is optional and may be retrofitted for use with existing defence systems and operates so that when an attack is sensed an alarm is triggered by way of an alert signal. Transmitter 700 sends an alert signal to a central control unit 750, identifying the location of the, or each, triggered sensor(s) 500. Central control unit 750 in turn alerts one or more devices, such as sirens 800 and/or flood lights 810 and/or mobile devices, such as pagers 860 worn by crew members.

An advantage with this feature is that crew members are alerted as to the location of an approaching hostile vessel - ie an imminent attack - which may be important in view of the size of some of the larger vessels, so enabling rapid defensive action to be taken at the location where boarding is being attempted.

Additionally a 'Mayday' signal or distress call can be transmitted automatically to alert remote protection vessels (government authorities, naval or coastguard) of the fact of imminent (likely) or immediate (actual) distress of the vessel. Optionally vessel identification information can be included in the distress call or early warning signal, as well as other information, for example identifying its location via, for example, a 'GPS' beacon.

Ideally the transmitter 700 is a radio frequency (RF) transmitter which sends an alert signal to one or more mobile devices, such as personal alarms, that are worn by crew, such as pagers 860, and these include a message as to the location of the suspected attack. In view of the fact that crew members are often from different nationalities/states, the signal may be a pictorial indication of a vessel, as shown in Figure 11a, indicating graphically the location of the attack.

An alternative sensing means that is able to detect cutting or severing might include a resistive path with an electric current passing therethrough, the restive characteristics of which vary when the path is cut; or a strain gauge adapted to sense inordinate or unusual or sudden changes in load; or indeed any combination of the aforementioned sensing systems.

Other variations may be made to the invention, and one such variation is a system that senses an attack and coordinates the detection of the attack with a communication system, an example of which is shown in Figure 11 , that alerts crew to the fact that an attack is taking place on a particular location (port or starboard side of a ship) as well 'fore', 'midships' or 'aft' and the automatic Optical; strain Bluetooth pager

The invention has been described by way of several embodiments, with modifications and alternatives, but having read and understood this description, further embodiments and modifications will be apparent to those skilled in the art.

Another embodiment of a system is a kit, which is adapted to be retrofitted to existing ships

All such embodiments and modifications are intended to fall within the scope of the present invention as defined in the accompanying claims.