Abstract:
A boat capture system for slowing and/or stopping a maritime vessel is provided. The system comprises an inflatable barrier, the barrier being movable and deformable upon impact whereby to slow or arrest movement of a vessel by increasing drag thereon. The barrier may further include at least one entanglement means.

Description:
RELATED APPLICATION 
       [0001]    This application claims priority benefit of U.S. Application No. 61/869,350, filed 23 Aug. 2013, which is incorporated herein for all purposes. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates generally to maritime, and particularly to systems, devices, and methods for stopping, slowing or disabling a seafaring vessel, ship, boat or the like. 
       BACKGROUND 
       [0003]    There are a variety of circumstances in which it may become necessary to stop a maritime vessel such as a boat, including: (a) “Stop and search” for example by military or coastguard personnel in which the intention is to stop the boat for the purpose of boarding; (b) Protection of assets (such as large vessels), which may involve: protection of an asset at anchor (requiring up to 360 degrees coverage), protection of an asset which is tied up alongside (requiring up to 180 degrees coverage). The intention is to prevent progress of a potentially unfriendly boat towards the asset; and (c) Protection of an asset that is underway (requiring up to 360 degrees coverage). Therefore, there remains a need for systems, devices, and methods to facilitate stopping or slowing of a maritime vessel. 
       SUMMARY 
       [0004]    According to an aspect of the present invention there is provided a boat capture system for stopping a maritime vessel, the system comprising an inflatable barrier, the barrier being movable and deformable upon impact whereby to slow or arrest movement of a vessel by increasing drag thereon. 
         [0005]    By “stopping” is meant either completely stopping, or slowing sufficiently to facilitate capture. 
         [0006]    The barrier may be provided with entanglement portion that provides means for catching a vessel following impact. 
         [0007]    According to a further aspect there is provided a boat capture device for stopping a maritime vessel, the device comprising an inflatable barrier, the barrier having an entanglement portion for catching a vessel following impact. 
         [0008]    The barrier may be movable and deformable upon impact whereby to slow or arrest the movement of a vessel by increasing drag thereon. 
         [0009]    The entanglement portion may comprise a meshwork. 
         [0010]    The entanglement portion may comprise webbing. 
         [0011]    The entanglement portion may comprise a net or net-like structure. 
         [0012]    At least part of the entanglement portion may be formed as an integral part of the material from which the barrier is formed. 
         [0013]    At least part of the entanglement portion may be formed as a cover and/or liner on/in the barrier. 
         [0014]    The barrier may be generally linear and may be deformed to be generally U- or V-shaped upon impact. By U- or V-shaped in meant that upon impact the barrier “bends” with the boat creating an apex at some point along the length (it does not have to be the middle) of the barrier. 
         [0015]    The barrier/obstacle/deterrent/hindrance/impediment/encumbrance/obstruction according to the present invention may comprise a temporary inflatable object deployable on to a water surface into the path of the target to slow/stop/arrest/halt/impede/deter it. 
         [0016]    The barrier may be elongate. 
         [0017]    According to a further aspect of the present invention there is provided a boat stopping device comprising an inflatable barrier. 
         [0018]    By deploying an inflatable barrier onto the surface of the water, it can be used to slow or arrest the progress of a target boat. The device may not cause complete arrest of the target but could slow it sufficiently to allow stopping using other methods subsequently. 
         [0019]    The barrier may be portable. For example, it may be possible to carry one or more barriers on a boat in an inflated, partially inflated or deflated state ready for deployment. 
         [0020]    The barrier may find use, for example, with navies, coastguards, border agencies, police and private security forces. 
         [0021]    In some aspects and embodiments, the barrier is intended to be temporary and deployed only when required. In other embodiments, semi-permanent or permanent structures may be provided. 
         [0022]    According to a further aspect, there is provided an on-move deployable boat stopping device comprising an inflatable barrier. 
         [0023]    The barrier can be deployed from a moving vessel, such as a rigid hull inflatable boat (RHIB) or a fast rescue craft (FRC). In such cases, it may be necessary for the barrier to be stowed in an uninflated condition and to be inflated only at the time of use. In some embodiments inflation occurs during deployment. 
         [0024]    According to a further aspect, there is provided a rapidly deployable hull capture system for arresting a maritime target comprising a temporary inflatable obstacle deployable on to a water surface into the path of the target. 
         [0025]    This aspect may be based on an inflatable obstacle, barrier, or the like, configured to absorb a target&#39;s energy over a period of time and to slow it through a loss of propulsive efficiency and drag. This may, for example, be achieved by: the boat coming off the plane; increased hull resistance; blocking flow to jets/propellers; drag due to pulling a large inflated barrier through the water; or a combination of these. 
         [0026]    In some aspects and embodiments, the device of the present invention may be predeployed, for example as part of a passive protection system. In other embodiments the device may be non-predeployed, i.e., deployed only at the time of imminent need in an active system. 
         [0027]    In some embodiments, the device may be a flexible obstacle, i.e., not a rigid and/or static barrier. In some embodiments, the intention is for the obstacle to be impacted and then pulled or dragged by the target (i.e. it is movable/dynamic) to hinder and/or arrest its progress. 
         [0028]    Aspects and embodiments of the present invention may be conceived to provide a non-lethal means of stopping or slowing a target boat with minimal or no harm being caused to the target boat occupants. 
         [0029]    Some aspects and embodiments may be regarded as the maritime equivalent of a “stinger” (a long metal strip with sharp spikes that police sometimes put in the road in order to puncture the tires of a car that is being chased and refuses to stop). 
         [0030]    In some embodiments the barrier deflates over time following impact, and this may be used to increase drag and may help the barrier to wrap around the hull of the target boat. 
         [0031]    The barrier may be elongate or may elongate upon inflation. For example, the barrier may be generally tubular, with a generally circular, oval or polygonal (for example square or pentagonal) section. The section may be generally constant. 
         [0032]    In some aspects and embodiments the barrier is of a length in the range of about 10 meters to 100 meters; for example 30 meters to 60 meters. 
         [0033]    The barrier may be convertible from a stowed, transport configuration to an inflated configuration achievable before, during, or after deployment. 
         [0034]    Different mechanisms for inflating the barrier are envisaged. For example, forced fluid flow may be used, such as compressed gas (e.g., air) and/or fan-assisted air entry. Alternatively or additionally, “ram air” may be used in on-move systems, i.e., the dynamic air pressure created by vehicle motion, is used to inflate the barrier. 
         [0035]    The barrier may be inflated using any suitable materials, such as fluid, gas, liquid or gel, or a combination of these. 
         [0036]    Inflation of the barrier structure may be automatic upon deployment. The system may incorporate a sealing system, such as a self-sealing mechanism so that the deployed barrier will remain inflated for a period of time after deployment. 
         [0037]    In some embodiments the barrier may be substantially fully inflated. In other embodiments, however, the barrier may be only partially inflated. For example the barrier may be partially inflated to between 50% and 90% of maximum. Partial inflation may be particularly useful in embodiments where the intention is not to cause an immediate stop but rather to cause impairment to the continued progress of the target and to slow it down or stop it eventually. 
         [0038]    The barrier may be at least partially deflated upon impact from a target. The barrier may therefore be configured to deliberately deflate upon impact, for example to increase drag on a target over time. 
         [0039]    The deployed barrier may have the capability to foul the target&#39;s propulsion system as an alternative or addition to hull capture capability. 
         [0040]    The barrier may be formed from flexible material. In some embodiments material of the type used to construct sails, such as spinnakers, may be used. A lightweight, waterproof material may be used. In some embodiments the material is selected so as to be breakable upon impact, for example by tearing, ripping or shearing. The material may be formed from an opaque, transparent or translucent material. 
         [0041]    The barrier may be launchable from a boat, for example a main ship (e.g., a warship) and/or a smaller auxiliary boat such as a RHIB or a FRC. 
         [0042]    The barrier may be held onto the surface of the water and its drift minimised by using stabilising/anchoring features. Such features may also have benefits in providing additional retarding drag force for target hull capture. 
         [0043]    The barrier may comprise stabilising devices or components, for example anchoring means, a floodable chamber, or one or more weights which could be provided on a skirt. 
         [0044]    The barrier may be deformable, which may be achieved by a combination of the material from which the barrier is formed, the inflatant and the level of inflation. In some embodiments, therefore, the barrier is formed as a deliberately non-rigid/non-solid structure. 
         [0045]    The barrier may comprise or includes a mesh. The mesh may be in the form of a net or net like structure. 
         [0046]    The mesh may be formed as an integral part of the material from which the barrier is formed. Alternatively or additionally the mesh may be formed as a cover and/or liner. 
         [0047]    In some embodiments, the net is the primary slowing/stopping component of the barrier/obstacle. For example the net may be used to entangle a target&#39;s propulsion system. In such embodiments the primary function of the inflatable part of the barrier may be to provide structure and to hold the net in position. 
         [0048]    The barrier may be provided with a network of rope/cord which may be exposed on the exterior of the barrier. The rope may be polyester rope is made from continuous filament polyester. 
         [0049]    The net may be used to help provide structural integrity to the barrier. 
         [0050]    In some embodiments the barrier is formed from a brightly coloured (such as orange, yellow or red) material. For example, the barrier may be formed from a fluorescent and/or luminescent material. 
         [0051]    The barrier may include impact-detection means. In many cases, it would be an advantage to know when and where the target boat has encountered the barrier. 
         [0052]    In some embodiments, the barrier is formed from a fabric material, for example material of the type used to make sails. Various types of sail cloth material may be suitable, with a thickness dependent on the intended purpose of the barrier e.g. the types of vessel to be stopped. In some embodiments ripstop fabrics used. These are woven fabrics, often made of nylon, using a special reinforcing technique that makes them resistant to tearing and ripping. During weaving, reinforcement threads are interwoven at regular intervals in a crosshatch pattern. 
         [0053]    Some aspects and embodiments of the present invention may consist of, comprise, or include one or more of the following properties:
       1. Lightweight (system&lt;120 kg)   2. Stowable Package, deployed and used as and when required; flexibility   3. Deployed from a RIB   4. Deployed at speed, parallel to asset, perpendicular to target   5. Inflatable, appears fast&lt;1 min   6. Psychological deterrent   7. Boat Stopping—
           i) Primary—Captures the hull of the target ‘envelops’ and provides drag   ii) Secondary—Prop entanglement if impact when not fully inflated   
           8. Uses water ballast   9. Is a 1.5 m-2 m diameter—fabric, low pressure tube   10. Stops most of the boats, most of the time up to F5-6       
 
         [0066]    According to a further aspect there is provided a method for arresting a maritime target comprising the steps of: (a) providing an inflatable barrier; (b) inflating the barrier; and (c) deploying the barrier in the path of a target. 
         [0067]    In some embodiments the method is required in “real time,” i.e., the requirement for stopping a boat is immediate. Such a stopping concept may require a chase boat/defensive boat to have speed and/or positional advantage in order to deploy a barrier in front of a target. 
         [0068]    The method may, therefore, benefit from the use of multiple deployment craft to allow two or more barriers to be deployed so as to surround a target. This can reduce the speed and positional advantage requirement and also the length of the barrier required. 
         [0069]    Deploying the barrier directly in front of the target makes it more difficult to avoid. 
         [0070]    Different aspects of the present invention may be used separately or together. 
         [0071]    Further particular and preferred aspects of the present invention are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with the features of the independent claims as appropriate, and in combination other than those explicitly set out in the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0072]    The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: 
           [0073]      FIG. 1  is a side view of a maritime arrest barrier formed according to an embodiment of the present invention. 
           [0074]      FIG. 2  is an end view of the barrier of  FIG. 1  shown prior to deployment. 
           [0075]      FIG. 3  is an end view of the barrier of  FIG. 2  during deployment. 
           [0076]      FIG. 4 ,  FIG. 5  and  FIG. 6  illustrate a deployment process for a barrier of the type shown in  FIG. 1  to  FIG. 3 . 
           [0077]      FIG. 7 ,  FIG. 8  and  FIG. 9  illustrate a method of arresting a maritime target in accordance with the present invention. 
           [0078]      FIG. 10 ,  FIG. 11 ,  FIG. 12  and  FIG. 13  illustrate progressively the impact of a boat into the barrier of  FIG. 1  to  FIG. 9 . 
           [0079]      FIG. 14  is a side view of a barrier formed according to a further embodiment. 
           [0080]      FIG. 15  is a side view of the barrier of  FIG. 14  shown with a forced air inflation device. 
           [0081]      FIG. 16  is a side view of a barrier formed according to a further embodiment. 
           [0082]      FIG. 17  is a side view of a barrier formed according to a further embodiment. 
           [0083]      FIG. 18  is a schematic view of an example boat stopping system and method in accordance with the present invention. 
           [0084]      FIG. 19  and  FIG. 20  show the approach and impact of a boat resulting from use of the method of  FIG. 18 . 
           [0085]      FIG. 21  shows an inflated obstacle formed, according to an alternative embodiment, capturing a boat. 
           [0086]      FIG. 22  shows a barrier formed according to an alternative embodiment. 
           [0087]      FIG. 23  illustrates one method for constructing a tubular barrier in accordance with the present invention. 
           [0088]      FIG. 24  shows an example of a towing arrangement. 
           [0089]      FIG. 25  shows an example of a drogue suitable for use in the present invention. 
           [0090]      FIG. 26  shows an end cap and sealing mechanism for use in the present invention. 
           [0091]      FIG. 27  shows steps in a method suitable for constructing a tubular obstacle. 
       
    
    
     DETAILED DESCRIPTION 
       [0092]    As used herein and in the claims, the singular forms include the plural reference and vice versa unless the context clearly indicates otherwise. The term “or” is inclusive unless modified, for example, by “either.” Unless otherwise defined, scientific and technical terms used in connection with the formulations described herein shall have the meanings that are commonly understood by those of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. 
         [0093]    Referring first to  FIG. 1  there is shown a boat stopping device generally indicated  10 . The device  10  comprises a generally tubular body formed from a flexible, lightweight material. 
         [0094]    In  FIG. 2 , the device  10  is shown stored on an A-frame  15  positioned at the stern of a RHIB. 
         [0095]    Referring now also to  FIG. 3 , the device is deployed by throwing a sea anchor  20  into the water. This activates a sealing system which closes that end  12  of the device. In other embodiments, different deployment and/or sealing systems may be used, for example a rip cord or an ejector seat pull handle style sealing method. 
         [0096]    As shown in  FIG. 4  to  FIG. 6 , the device  10  inflates and extends longitudinally from the stern of the RHIB  25  to form an elongate barrier which is laid onto the water surface. In this embodiment inflation is achieved by using the apparent wind created by the RHIB&#39;s forward motion. Very little input from the crew is required. The portable deployment system both inflates and places the barrier in a required position. 
         [0097]    An example of the device in use is illustrated in  FIG. 7  to  FIG. 9 , in which a target boat  30  is being pursued by a chase boat  35 . The chase boat  35  deploys the barrier  10  in front of the target boat  30  so that it impacts the erected structure. 
         [0098]    As shown progressively in  FIG. 10  to  FIG. 13 , the barrier  10  deforms upon impact to partially surround the target boat&#39;s hull, causing sufficient drag to impede the boat and reduce its speed so that the chase boat can capture it. The barrier deployment may comprise placing the barrier in the water and towing it behind the boat  35 ; alternatively the barrier may be released from the boat. 
         [0099]    Referring now to  FIG. 14 , there is shown a maritime arrest barrier  110  formed according to an alternative embodiment. The barrier  110  is similar to the barrier  10 , except that in this embodiment the underside (in use) of the body is provided with three sea anchors  140  which hold the barrier onto the water surface and minimise drift. 
         [0100]    In  FIG. 15 , the barrier  110  of  FIG. 10  is shown with a fan  145  that is used to inflate the body. The fan may be used only during initial inflation on board a deployment boat, or may form part of the device so that there is continual inflation during use. 
         [0101]    In  FIG. 16 , a barrier  210  formed according to an alternative embodiment is shown. The barrier  210  includes a skirt  150  which depends from the underside of the body and extends longitudinally. The skirt is provided with a plurality of mutually spaced weights  155  for stabilising the barrier in use. 
         [0102]    In  FIG. 17 , a barrier  310  formed according to an alternative embodiment is shown. The barrier  310  comprises a main tubular body  305  defining a main chamber  360  and a secondary skirt  365  which defines a secondary chamber  370 . The main chamber is inflated in use and is watertight. The secondary chamber is deliberately floodable to stabilise the barrier when floating in the water; and in this embodiment the skirt  365  also includes a plurality of weights  355  to aid with stability. 
         [0103]    Referring now to  FIG. 18 , there is shown an asset protection system formed according to the present invention. An asset, in this embodiment a warship  475 , is shown with two target boats  430  approaching. Two protection boats  435  are dispatched and deploy obstacles  410  formed according to the present invention to stop the target boats  430  and prevent them reaching the asset  475 . 
         [0104]      FIG. 19  and  FIG. 20  show impact of a target boat  430  at a lateral, generally perpendicular angle to an obstacle  410  and folding of the obstacle around the front and sides of the hull as the target boat drags the obstacle through the water. 
         [0105]    In  FIG. 21 , a further embodiment is shown in which a target boat  530  impacts a barrier  510  to protect an asset  505 . A pursuit boat  535  is shown in attendance to capture the target boat  530 . 
         [0106]    Referring now to  FIG. 22 , there is shown a barrier  610  formed according to an alternative embodiment. The magnified drawings outline the construction of the tube and the various details that have been considered to provide strength on impact and towing. 
         [0107]    The detail design has been considered with the following four modes of operation: (1) Physiological Barrier—most people will not drive into something if they cannot see the other side and think they might become entangled; (2) Low speed impact, tube envelops the boat and remains intact—boat tries to move forward and drogues resist; (3) High speed impact, tube punctures but the bow of the boat is caught on high strength webbing and cord attached radially and axially around the tube in a lm x lm square pattern (a course pitch net). Force passes through cords to drogues, boat has resistance; (4) Very high speed impact—tube punctures and fabric webbing and cord is severed. Outboard motor and/or propeller fouls on 4 mm steel cable that is used to weigh down skirt. The tube is constructed so that even if it bursts under impact the netting and cords can still entrap a boat. 
         [0108]    In  FIG. 23 , a section of the tubular barrier of  FIG. 22  is shown and illustrates one method of forming such a structure. In this embodiment the tube is formed from three panels which are secured together along seams. 
         [0109]    In  FIG. 24 , a possible towing configuration for a barrier of the type shown in  FIG. 22  and  FIG. 23  is shown. 
         [0110]    In  FIG. 25 , an example of a drogue suitable for use in conjunction with a barrier of the type shown in  FIG. 22  and  FIG. 23  is shown. A weighted collar is used to help the drogue open up quickly to give a drag force more quickly following impact as the barrier is moved through the water by a target boat. 
         [0111]    The construction of the barrier means that the load spreads along the length of the tube, which helps to keep the barrier in use. 
         [0112]    In  FIG. 26 , an example of an end cap (including an air inlet seal with a non-return valve) for a tubular obstacle formed according to the present invention is shown. This allows the tube to be inflated and also allows the tube to be deflated by releasing air. In some embodiments the other end of the tube is closed. 
         [0113]    The end material is gathered and fastened to a cylinder; this distributes the stress fairly evenly through the end cap into the tube length and allows the cylinder to act as an air inlet. A prototype was produced using a fabric (tuftane) sock creating an internal valve that prevents air flowing back. To achieve this neatly the tube will have the ends gathered, then turned inside out to hide the valve and loose material. 
         [0114]    In some embodiments the barrier is deployed into the water uninflated and then inflated; for example it may unfold and/or unroll depending on how it has been stored. 
         [0115]    In  FIG. 27 , the steps in an example of a method of constructing a tubular obstacle in accordance with the present invention is shown. The steps are as follows: (1) Using 25 mm Venture tape, stick four panels together; (2) Triple stitch the roll of webbing along the length of the venture tape seams. Bar tack stitch  60  small hoops at 1 m pitch equidistant from centre; (3) Sew webbing support to skirt panel then sew Ripstop support panels on top. Cutting remaining material at the ends away. Paint on seam coat; (4) Tack the 1st and 4th panels where the material has been cut and use venture tape to seal ends. Leave middle of tube disconnected; (5) Scrumple tube ends around pipe and use jubilee clip to fasten. Then attach tuftane tube to pipe and also fasten with jubilee clip; (6) Turn tube inside out using the middle of the tube that was left disconnected; (7) Seal tube panel to skirt with 25 mm venture tape. Then place 25 mm webbing either side and sew up length; and (8) Punch no.2 eyelets at 1 m pitch (matching small webbing hoops) where ripstop reinforcement patch meets webbing. Feed cord through. 
         [0116]    Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiment shown and that various changes and modifications can be affected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.