Watercraft Immobilizing Apparatus and System

Abstract

A watercraft immobilizing apparatus and system for a marine vessel to passively defend against an attacking engine-powered watercraft includes a towed array of entanglement lines. The entanglement lines can be provided on and administered from reusable/removable/replaceable storage cartridges mountable on a hull mount or stowed in a watertight chamber in the vessel's hull, and/or deployed via floated booms and/or paravanes to foul and immobilize propellers and engine cooling water intakes of encroaching watercraft.

Claims

1. A watercraft immobilizing apparatus deployable from a marine vessel, the apparatus comprising a plurality of spaced apart lines extendable from and towable by the vessel in water surrounding the vessel, the lines being arranged to stream at least one of at and below the surface of the water about at least one assailable face of the vessel when towed so as to become entangled in and to foul a propulsion system of an approaching watercraft, the lines being stowable on or in a side portion of a hull of the vessel, and constructed to break free of the vessel upon becoming entangled in the propulsion system.

2. The apparatus of claim 1, further comprising at least one floated boom and at least one paravane, wherein the at least one floated boom, the lines, and the at least one paravane are stowed adjacent to or below the surface of the water.

3. The apparatus of claim 2, further comprising at least one submersible cartridge, wherein the lines are stored in the at least one submersible cartridge.

4. The apparatus of claim 3, wherein the at least one submersible cartridge is coupled to the vessel via at least one sub-surface hull mount.

5. The apparatus of claim 3, wherein the at least one submersible cartridge can be opened by the at least one floated boom when the at least one paravane is launched.

6. The apparatus of claim 2, wherein at least one of the at least one floated boom, the at least one paravane, or the lines can be released or jettisoned after deployment.

7. The apparatus of claim 3, wherein the at least one submersible cartridge is at least one of reusable or replaceable.

8. The apparatus of claim 2, wherein the at least one paravane includes at least one main paravane and at least one smaller secondary paravane or otter, and wherein the lines include main entanglement lines fitted with the at least one secondary paravane or otter.

9. The apparatus of claim 2, wherein the at least one paravane is stored and launchable from a surface or sub-surface watertight tube or chamber.

10. The apparatus of claim 9, wherein the at least one floated boom and the lines are stored within the watertight tube or chamber.

11. The apparatus of claim 9, wherein the at least one paravane includes at least one main paravane and at least one smaller secondary paravane or otter, and wherein the lines include main entanglement lines fitted with the at least one secondary paravane or otter.

12. The apparatus of claim 9, wherein the watertight tube or chamber is sealed with at least one door.

13. The apparatus of claim 2, wherein one end of the at least one floated boom is coupled to the side portion of the vessel's hull at or adjacent to the waterline so as to provide a pivot point when the at least one floated boom is deployed.

14. The apparatus of claim 6, wherein the at least one of the at least one floated boom, the at least one paravane, or the lines can be released or jettisoned remotely.

15. The apparatus of claim 2, wherein at least one of the at least one floated boom, the lines, or the at least one paravane is biodegradable.

16. The apparatus of claim 2, wherein the at least one paravane includes collapsible or foldable wings.

17. The apparatus of claim 16, wherein the wings automatically extend when the at least one paravane is launched.

18. The apparatus of claim 2, wherein the at least one paravane is independently powered by at least one of a rocket, a motor, or a propeller.

19. The apparatus of claim 2, wherein the at least one paravane is configured to emit a smoke screen.

20. The apparatus of claim 2, wherein the at least one paravane, the at least one floated boom, and the lines are launchable by an above-surface mortar.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] For a fuller understanding of the present invention, reference is had to the following description taken in connection with the accompanying drawings in which:

[0025] FIG. 1a is a simplified plan view of a marine vessel deploying a watercraft immobilizing apparatus and system in accordance with embodiments of the present invention, illustrating exemplary positioning of a main transom bank of submersible rollers and tendril lines, aft outrigger banks, forward shoulder outrigger banks, and forward outrigger stays;

[0026] FIG. 1b is a port side view of a marine vessel deploying a watercraft immobilizing apparatus and system in accordance with embodiments of the present invention;

[0027] FIG. 1c is a perspective view of a marine vessel deploying a watercraft immobilizing apparatus and system in accordance with embodiments of the present invention;

[0028] FIG. 2 depicts the extremity (fitted with a spreader) of a cartridge's towed array of tendril lines (staggered secondary line sequence) in accordance with an exemplary embodiment of the present invention;

[0029] FIG. 3 is a stern (transom) view (including below the water line) of a vessel deploying a watercraft immobilizing apparatus and system in accordance with embodiments of the present invention, illustrating exemplary positioning of a main transom tendril line bank with six cartridges, cartridge mounts/bearings, main bank electric drive motor, submersible weighted dual rollers, supporting winch/motor, stern outrigger assembly, deep fin, and towed array lines (shown administered from a single cartridge);

[0030] FIG. 4 depicts weighted sub-surface dual rollers of a main transom tendril line bank and a stern outrigger bank (portside), cross connection, main support wires, deep-finned side and stern towed arrays, and portside fore stay in accordance with an exemplary embodiment of the present invention;

[0031] FIG. 5 is an aft view of a portside shoulder outrigger assembly with submersible weighted rollers in accordance with an exemplary embodiment of the present invention;

[0032] FIG. 6 is a side view of a portside shoulder outrigger assembly with submersible weighted rollers in accordance with an exemplary embodiment of the present invention;

[0033] FIG. 7 is a cross-sectional (portside) view through a main transom tendril line bank and submersible weighted rollers in accordance with an exemplary embodiment of the present invention;

[0034] FIG. 8 is a cross-sectional view through a line cartridge in accordance with an exemplary embodiment of the present invention;

[0035] FIG. 9 depicts a loaded cartridge administering primary lines, with secondary and tertiary lines, in accordance with an exemplary embodiment of the present invention;

[0036] FIG. 10 depicts a traveling block arrangement in accordance with an exemplary embodiment of the present invention;

[0037] FIG. 11 is a plan view of the forward starboard side of a marine vessel deploying a watercraft immobilizing apparatus and system including a paravane in accordance with embodiments of the present invention;

[0038] FIG. 12 depicts a floated paravane and bridle assembly in accordance with an exemplary embodiment of the present invention;

[0039] FIG. 13 is a partial side view of a marine vessel deploying a watercraft immobilizing apparatus and system in accordance with embodiments of the present invention

[0040] FIG. 14 is a simplified top plan view of a marine vessel deploying a watercraft immobilizing apparatus and system in accordance with embodiments of the present invention including one or more paravanes;

[0041] FIG. 15 is a starboard view of a marine vessel deploying a watercraft immobilizing apparatus and system in accordance with embodiments of the present invention including a hard connection of a boom to the hull of the vessel;

[0042] FIG. 16 is a starboard view of a marine vessel deploying the watercraft immobilizing apparatus and system shown in FIG. 15, with a paravane in a deployed position;

[0043] FIG. 17 shows the shape of a paravane including a single rudder blade in accordance with embodiments of the present invention;

[0044] FIG. 18 shows a cross-sectional profile that provides a lift of a paravane in accordance with embodiments of the present invention;

[0045] FIG. 19 illustrates forces taken into account when determining induced drag of a paravane in accordance with embodiments of the present invention;

[0046] FIG. 20 illustrates forces involving tendril lines, a vessel, and a paravane in accordance with embodiments of the present invention;

[0047] FIG. 21 shows a relation between an angle of attack and a lift/drag coefficient for a paravane in accordance with embodiments of the present invention; and

[0048] FIG. 22 shows a dimension of a paravane blade in accordance with embodiments of the present invention;

[0049] FIG. 23 is a perspective view of the starboard side of a marine vessel having a watercraft immobilizing system in which a floated boom, entanglement lines, a cartridge, and paravanes are mounted to the hull of the vessel via a hull mount disposed at or below the vessel's waterline, in accordance with an exemplary embodiment of the present invention;

[0050] FIG. 24 is a partial perspective view of a portion of the watercraft immobilizing system shown in FIG. 23;

[0051] FIG. 25 is a view of the transom of the vessel shown in FIG. 23;

[0052] FIG. 26 is a partial cross-sectional view of the vessel shown in FIG. 23, illustrating an exemplary floated boom release system;

[0053] FIG. 27 is a top view of a paravane having collapsible/foldable wings, in accordance with an exemplary embodiment of the present invention;

[0054] FIG. 28 is a partial cross-sectional view of the hull of a vessel, illustrating an alternative watercraft immobilizing system that includes a sub-surface watertight tube/chamber and a paravane, cartridge, floated boom, and entanglement lines stored therein, in accordance with an exemplary embodiment of the present invention; and

[0055] FIG. 29 is a plan view of a marine vessel, illustrating deployment of a watercraft immobilizing system, in accordance with various embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0056] In accordance with embodiments of the present invention, a passive, non-lethal marine vessel piracy defense apparatus and system are provided that can be deployed about the assailable faces of the vessel to repel attacking watercraft by fouling and thus immobilizing their propellers and engine intakes. Generally speaking, this is accomplished by a towed (at or below the water surface) array of entanglement tendril lines.

[0057] Marine engines are designed to propel a craft by moving water in various ways, for example through open or enclosed propellers, through jet engines and through cooling systems. It will be appreciated that the towed array according to embodiments of the present invention moves with this water into the attacking vessel's propellers, cooling intakes or jet intakes, hence fouling and stopping the engine(s).

[0058] It will also be appreciated that the towed array according to embodiments of the present invention provides a defense against piracy that can be characterized as passive because the array remains deployed throughout a voyage without unduly interfering with vessel operations. Moreover, when in a deployed state, attacking watercraft need not be detected in order to repel an attack.

[0059] The towed tendril lines can be engineered to break free when the mass of an entangled attacking watercraft is exerted on the towed array, hence releasing the watercraft adrift. Attacking watercraft can entangle very quickly on relatively few lines.

[0060] The tendril lines can be formed from polymer, nylon or SPECTRA lines, or from wires, and can be weighted for neutral buoyancy (e.g., weighted or coated with emulsion). The tendril lines can also advantageously be formed from a biodegradable material. For example, BIOLINE with an active shelf life of six to twelve months, which is purported to be a biodegradable product engineered to protect the environment, can be used. According to its manufacturer, BIOLINE is made from a biodegradable polymer that will completely biodegrade within five years (in its twelve month usable life format); and it can be engineered to biodegrade more rapidly. Regular monofilament or fluorocarbon line takes over six hundred years to biodegrade. Preferably, the lines can have negative buoyancy when cast adrift so that they can sink to the seabed.

[0061] An arrangement of secondary and possibly tertiary lines deployed from the primary tendril lines at or just below the water surface can also be provided. These tendril lines can have varying lengths, and can be staggered at intervals of, for example, five feet, along the primary lines.

[0062] Furthermore, as described in greater detail hereinafter, the towed array of tendril lines can be deployed via floated wire/chain/SPECTRA booms, which can be positioned by a surface tube (e.g., mortar), sub-surface tube or chamber, traveling block, folding bowsprit, floated paravanes (e.g., with or without collapsible or foldable wings), hard connection to the hull of the vessel, outriggers, rollers, and/or spreaders.

[0063] The tendril lines can be administered from reusable/removable/replaceable (and even disposable or refurbishable) cartridges. Each cartridge can administer multiple main lines (which can, for example, be fitted with secondary paravanes) and, possibly, an array of sub-tendril lines, through links or eyes of the floated booms, and/or by way of rollers. The ends of each of the main lines for each cartridge can be held in a submerged pattern by finned floats and/or spreader bars (and/or intermediate spreaders), which can be suitably finned and/or weighted to push the tendril lines away from the side of the vessel. This can also improve stability.

[0064] Damaged sections of the towed array can be replaced by removing and inserting a new or reconditioned cartridge. Cartridges can include the neutrally weighted multiple main lines, secondary and tertiary lines along with secondary paravanes, otters, planer boards, and/or spreaders. Alternatively, the entire watercraft immobilizing apparatus and system, including the floated booms and paravanes, can be released and jettisoned (e.g., when deemed safe to do so).

[0065] Where fitted, banks of the rollers can be configured to feature multiple ones of the removable cartridges and can be easily and rapidly deployed/recovered manually (e.g., gravity deployment from a spring tension device) or automatically (including by remote control, by means of electric/hydraulic motors, for example). Each bank can feature secondary winches at the extremities, which can also be operated manually or remotely by electric/hydraulic motor. These winches can store the line/wire that deploys (suspends) weighted submersible dual rollers for each bank.

[0066] The weighted dual rollers can be used to place and hold the towed array below the water surface beneath the cartridges. These dual rollers can be further secured below the deployment banks to prevent the rollers from riding aft and above the water surface by preventer wires led from the extremities of the rollers to a strong point on deck forward of the roller installation.

[0067] A main bank of rollers can feature multiple removable cartridges and can be mounted off the vessel's transom. Additionally, two transom outriggers, one at each extremity, can deploy further banks of rollers also featuring multiple removable cartridges. The weighted submersible dual rollers in the way of these aft outriggers can be connected to the extremities of the weighted submersible dual rollers of the main transom bank, effectively forming one unit. Deep fins can be provided at the outer extremities of these rollers to prevent the possibility of the lines of the towed side arrays fouling the vessel's own propeller(s). Additional outriggers, which can be deployed at other locations to shield the vessel, can deploy rollers that also feature multiple cartridges. These banks can be similarly fitted with submersible dual rollers. The towed side arrays can also be fitted with independent spreaders appropriately finned.

[0068] Each storage bank of rollers can deploy a suitable amount (length) of towed tendril lines supporting multiple sub-tendril lines in a varying pattern to give practical full, all-round protection and to maximize the arresting effect of an attacking watercraft's propeller or intake system.

[0069] Referring now to the drawing figures, FIG. 1a illustrates an exemplary coverage pattern of the towed tendril line array and positioning of main and davit/outrigger tendril line banks relative to the protected vessel. There can be five banks of rollers (transom, port quarter, starboard quarter, port shoulder or bow and starboard shoulder or bow). FIGS. 1b and 1c show a port side view and a perspective view of the exemplary coverage pattern, respectively.

[0070] It should be understood that the only locations on the vessel that may not need to be protected by towed arrays are the bow areas, where the bow wave creates a highly dangerous position for smaller boats to attack. However, some embodiments described hereinafter in greater detail provide protection for the bow areas as well.

[0071] Where fitted, each bank of rollers (e.g., FIG. 3) can be configured to deploy the cartridges (FIG. 9), which can include multiple main tendril lines suitably spaced to achieve maximum efficiency whilst minimizing the quantity of lines required for deployment (e.g., approximately, four inches apart, or desirably 12 to 24 inches apart). The multiple main tendril lines administered from each cartridge can be weighted/floated for neutral buoyancy and can be fitted with finned end floats and/or spreaders (FIG. 2). The spreaders can be finned for increased underwater stability and/or interlinked to adjacent spreaders. The tendril lines can be provided with the secondary and/or tertiary sub-tendril lines of similar or smaller diameter, with varying lengths and staggered placement of intervals (preferably, of not more than five feet) along the main lines of the towed array.

[0072] Where fitted, the submersible rollers need not be heavy, bulky pieces of equipment, and can be deployed from separate electric/hydraulic motors and winches. The submersible rollers can be lowered directly from the storage banks.

[0073] The main transom bank of rollers can be fitted by steel brackets to the vessel's existing structures, such as the aft bulwark (FIG. 7). The roller bodies can support multiple flanges that incorporate intermediate (preferably, stainless steel) shafts and bearings. The intermediate shaft ends can be notched to receive the removable cartridge shafts (FIG. 8). These shafts can then be locked into place (e.g., by rotatable locking rings (FIG. 8, element 8F) positioned at each end in the way of the flanges. The cartridge shafts can have splines or key ways (FIG. 8, element 8D) or like elements to prevent the cartridges from rotating on the shaft. The complete shaft assembly can then be driven by a centrally mounted electric/hydraulic motor (FIG. 3, element 3C) that can be remotely controlled (e.g., from the vessel's bridge). This shaft assembly can also be fitted with a locking device to prevent forced rotation when the array is deployed.

[0074] The main storage bank (FIGS. 1a, 3) can be configured to span the complete width of the vessel's transom. Due to the different breadths of vessels, the aft roller system at the transom can be expandable to cover the full transom (e.g., via segment extensions to the cartridges).

[0075] For example, two stern quarter outriggers/davits (FIG. 1a) can each be fitted adjacent to the main transom bank on one or more of the port and starboard sides of the vessel. The stern outriggers and banks can be situated aft of the vessel's rudder and propeller to prevent fouling. The stern outriggers (FIG. 3) can deploy parallel extensions of the main transom towed array to the full width of the protected vessel's body. Ideally, the length of the quarter outriggers is proportional to the difference between the length of the main transom bank and the overall beam of the vessel being protected. The stern outriggers can be smaller than the forward outriggers, which can be also be fitted. The towed stern array can spread out by the forward movement of the vessel and extend aft of the vessel to any desirable length.

[0076] Where fitted and deployed, the stern quarter outriggers can be in a generally perpendicular position, but the outriggers can also be rotated parallel to the vessel's main axis and removed when not in use and locked in stowed or deployed positions. The body of the outrigger can similarly support multiple flanges that incorporate intermediate (preferably, stainless steel) shafts and bearings. The intermediate shaft ends can be similarly notched to receive the removable cartridge shafts that are similarly locked in place. The complete quarter outrigger shaft assemblies can then be driven by inboard mounted electric/hydraulic motors, which can be remotely controlled. These quarter outrigger shaft assemblies can also be fitted with locking devices to prevent forced rotation when the tendril array is deployed.

[0077] Secondary winches, similarly powered by electric/hydraulic motors, can be situated at the extremities of the quarter outrigger storage bank rollers. These winches can store the support wires for the quarter outrigger bank dual submersible weighted rollers (FIGS. 3 and 4). These winches can be similarly locked when the dual submersible rollers are deployed. The submersible rollers can lock into place adjacent to the main transom dual submersible rollers to form a substantially rigid unit (FIG. 4). These units can similarly place the towed array at or below the water surface and, e.g., immediately below the quarter outrigger storage banks. The outboard extremities of these submersible dual rollers can be fitted with deep fins (FIG. 3, element 3G) to prevent the towed side arrays from coming into contact with the protected vessel's own propeller(s). The submersible dual roller extremities can also be fitted with fore stays (FIG. 4) to prevent the assembly from riding aft and away from the vessel's transom.

[0078] Alternatively, or in addition, secondary winches (FIG. 3, element 3E) similarly powered by electric/hydraulic motors can also be provided at the main transom bank. These winches can store the support wires for the main transom bank dual submersible weighted rollers (FIG. 3, element 3D and FIG. 4, element 3D). The winches can be similarly locked when the dual submersible rollers are deployed. The submersible rollers can place the towed array at or below the surface of the water, e.g., immediately below the transom storage bank.

[0079] In some embodiments, forward shoulder outriggers (FIGS. a, 5, and 6) can also be configured to deploy side towed arrays (e.g., not less than twenty feet in width/span) off the port and starboard sides of the vessel. These side towed arrays can extend aft to a desired length and can overlap the stern mounted towed array, outboard of the deep fin positioned at the extremities of the stern quarter dual submersible roller.

[0080] These forward outriggers, which can be situated at the port and starboard shoulders of the protected vessel, can be configured to be the same as or similar to the stern quarter outriggers. In some embodiments, the forward outriggers can be larger than the stern quarter outriggers. These forward outriggers can also be rotated parallel to the vessel's main axis when not in use and locked in stowed or deployed positions. The body of each outrigger can similarly support multiple flanges that incorporate intermediate (preferably, stainless steel) shafts and bearings (FIG. 8). The intermediate shaft ends can be similarly notched to receive the removable cartridge shafts, which can be similarly fixed in place by the rotatable locking ring (FIG. 8, element 8F). The complete shoulder outrigger shaft assemblies can then be driven by inboard mounted electric/hydraulic motors, which can be remotely controlled (e.g., from the vessel's bridge). These shoulder outrigger shaft assemblies can also be fitted with locking devices to prevent forced rotation when the tendril line array is deployed. Like the main transom and stern outrigger assemblies, secondary winches similarly powered by electric/hydraulic motors can also be provided at the extremities of the forward shoulder outrigger storage bank rollers. These winches store the support wires for the forward shoulder outrigger bank dual submersible weighted rollers (FIG. 5, element 5G). The winches can be similarly locked when the dual submersible roller system is deployed. The submersible dual roller extremities can also be fitted with fore stays connected via bridles (FIG. 6, element 6I) to prevent the assembly from riding aft and away from beneath the shoulder outrigger assembly.

[0081] The towed side arrays themselves can cause a vector of force away from the vessel and can help hold the forward submersible rollers off the vessel's side. The rollers can also be fendered on the inboard side. Also, the rollers can be segmented (e.g., cartridge widthevery five feet) and fitted with cutting edges to sever lines entangled between adjacent cartridges to allow more efficient re-spooling. The cartridges themselves can have intermediate flanges to segment tendril line.

[0082] Similar to the towed stern arrays, the trailing spreaders of the towed side arrays can inter-connect (attach between each cartridge) and form a substantially rigid boom. The towed side array spreaders can also be finned to encourage movement out and away from the side of the protected vessel. The towed side arrays can be run out to the approximate turning circle of the vessel.

[0083] Referring now to FIGS. 10-16, alternatively, or in addition to the embodiments described above, the watercraft immobilizing system can include one or more floated booms and respective paravanes for towing the arrays. For example, in some embodiments, the system can include one or more paravanes 1120, each towed by a transverse submersible wire/chain 1180 (e.g., that can also be recoverable) and by a forward floated boom 1110 (e.g., on port and starboard sides) that can deploy side towed arrays 1190 (e.g., of not less than one hundred feet in width/span) off the port and starboard sides. Side towed arrays 1190 can extend aft, e.g., at least 150 feet, and can overlap the stern mounted towed array, outboard of the deep fin positioned at the extremities of the stern quarter submersible wire or chain. Floated boom 1110 can spread out (e.g., 20 to 30 degrees abaft the bow) via towed paravane 1120. In some embodiments, each paravane 1120 and respective floated boom 1110 can mutually hold each other in position.

[0084] Floated boom 1110 can be situated at port and/or starboard sides of the vessel and streamed from a traveling block 1000, a folding bowsprit 1410, and/or a hard connection 1560 to the hull of the vessel. Floated boom 1110 can provide a barrier, hence affording enhanced protection at the bow. It should be understood that a primary purpose of the floated booms (and the submersible rollers of the embodiments described above) is to get the tendril lines into the water directly below or forward of the deployment banks (e.g., FIG. 11).

[0085] Paravanes 1120 can be stored and deployed by davit/outrigger 1140 fitted on port and/or starboard sides of the vessel (e.g., at the extremities and to the vessel's focsle and/or poop deck). Davit/outrigger 1140 can also be operated manually or remotely by electric/hydraulic motor. In some embodiments, each davit/outrigger 1140 can be powered by electric/hydraulic motors to deploy paravane 1120 via an interconnecting transverse submersible wire/chain 1420 (that can support rollers). Each paravane 1120 can also be towed from floated boom 1110 and/or separate recovery wires 1180 streamed from forward positions to prevent the paravane and transverse submersible wire/chain 1420 from trailing aft of the transom. Paravane 1120 can prevent the possibility of the lines of the towed side arrays 1190 from fouling the vessel's own propeller(s). In some embodiments, bridle 1130 can be configured to couple paravane 1120 and recovery wire 1180 and/or transverse submersible wire/chain 1420.

[0086] In some embodiments, tendril lines of the main stern bank can be fed through links of interconnecting submersible wire/chain 1420 (or rollers supported by interconnected wire/chain 1420), which can hold the tendril lines in/on the water below (e.g., immediately below) the transom. Interconnecting submersible transverse wire/chain 1420 can be held tight, due to the tensile force that can be created by the angle of the fins in way of the paravanes.

[0087] In some embodiments (see e.g., FIGS. 10, 11, and 13), the floated boom and paravane assembly can be deployed via winch 1310 and traveling block 1000, which can travel along wire/chain haul 1340 secured to fixed block 1350. For example, winch 1320 can store extension lines, wires, or chains 1360, which can deploy floated boom 1110, and winches 1150 can also be included and configured to store extension lines, wires, or chains 1155, which can also deploy (or assist in deploying) floated boom 1110. In some embodiments, in addition to towed paravane 1120, smaller paravanes 1330 (which can be interconnected) can also be attached to the ends of the wires 1155.

[0088] In some embodiments (see e.g., FIGS. 11 and 14), the floated boom and paravane assembly can be deployed via bowsprit 1410 of the vessel, and traveling block 1000 may not be necessary.

[0089] In some embodiments (see e.g., FIGS. 15 and 16), the floated boom and paravane assembly can include a hard connection 1560 to the hull of the vessel that couples floated boom 1110. Floated boom 1110 can then be deployed and/or stored via one or more of roller 1540, winches 1550, and up-haul winch 1530 (e.g., double drum), such that floated boom 1110 can be stored in a bight, which can be suspended from mast head block 1610 (e.g., coupled to foremast 1510 of the vessel) via wire 1520 coupled to the floating boom via connector 1570. Both port and starboard bights can be deployed from the same double drum winch 1530 at the base of foremast 1510. For example, FIG. 15 is a view of a starboard side of a vessel with a forward paravane 1120 in an elevated and stowed position. Floated boom 1110 can be coupled directly to the hull via hard connection 1560, which can be in alternative to, or in addition to, utilizing traveling block 1000 and/or folding bowsprit 1410.

[0090] Irrespective of whether traveling block 1000, bowsprit 1410, or hard connection 1560 is employed, rollers can be fitted to feed the tendril lines (e.g., of transom and/or focsle storage banks on port and starboard sides) on or into the water.

[0091] Referring to FIGS. 17-22, paravane 1120 can be a part of the system that creates the horizontal force away from the vessel and keeps the forward floated booms 1110 spread out from the side of the hull. Entanglement tendrils can then be fed into the water from eyes/rollers 1160 situated on floated boom 1110. This affords better protection of the vessel's bow and hull sides. Paravane 1120 can include a single rudder blade with the shape as depicted in FIG. 17, where: [0092] Cr=root chord, [0093] Ct=tip chord, and [0094] s=span.

[0095] By definition, the force generated on an airfoil has two components: the drag and the lift. Lift is always perpendicular to the flow. The drag component is also known as induced drag and can be calculated using the following formula:

L=C.sub.D0.5SV.sup.2

Where:

[0096] is the density of the water, [0097] S is the area of the blade, [0098] V is the speed, and [0099] C.sub.D is the coefficient of lift.

[0100] The lift created, which should balance the drag generated by the entanglement tendrils and the boom, can be described by the following formula:

L=C.sub.L0.5SV.sup.2

where: [0101] is the density of the water, [0102] S is the area of the blade, [0103] V is the speed, and [0104] C.sub.L is the coefficient of lift.

[0105] The dimension of the blade can be determined by the lift requested. Determination of the lift coefficient can depend primarily on the angle of attack and also on the cross-sectional profile of the blade. The cross-sectional profile giving a suitable (which can be the best) lift is that of the NACA 6712 as illustrated in FIG. 18.

[0106] The forces to be taken into account are illustrated in FIG. 19, where F=force generated on the airfoil; D=drag induced by the airfoil; and L=lift generated by the airfoil.

[0107] In order to balance the tendril drag, the moment (about the bow) of the lift should equal the moment (about the bow) of the total drag, generated by the tendrils and boom; the forces and relative arms with respect to the bow (Point A) are shown in FIG. 20.

[0108] The tendril drag is being considered as concentrated at half length of the boom. In calculating the moments, the arms of drag and lift are:

[0109] Drag: half of the boom length+clearance from the side of the vessel+half of the width of the vessel; and

[0110] Lift: lift between the paravane and the bow of the vessel (point A)=length of the forecastle.

[0111] The relevant data for the chosen profile can be found in the National Advisory Committee for Aeronautics Report No. 460, titled The Characteristics of 78 related airfoils sections from tests in the variable-density wind tunnel published in 1935.

[0112] For the profile NACA 6712, the relation between the angle of attack and the lift/drag coefficient is as shown in FIG. 21. To maximize lift while allowing for a certain movement of the paravane, without causing it to stall, the value of the angle of attack, and therefore C.sub.L and C.sub.D chosen can be as follows:

TABLE-US-00001 20 C.sub.L 1.6 C.sub.D 0.32
With , C.sub.L and C.sub.D set, the remaining values can be calculated as follows:

TABLE-US-00002 PARAVANE NACA 6712 cr 1.80 m ct 1.20 m Span 2.30 m A 3.45 m{circumflex over ()}2 alfa 20.00 deg 0.35 rad C.sub.L 1.60 C.sub.D 0.32 Lift offered 1.85E+05 N Paravane Drag 3.70E+04 N Drag To Win 6.19E+04 N Lift Moment 3.39E+06 N * m Drag Moment 3.35E+06 N * m

[0113] The dimension of the paravane blade can therefore be as set forth in FIG. 22. Multiple blades can be used to reduce size.

[0114] Current naval architecture load requirements mean that lighter systems can be used. Accordingly, a light-weight tubular (even portable) construction can advantageously be used for the outriggers with the motors mounted inboard (to the main pivot point/mounting adjacent to the support) to further reduce overall weight. This can save considerable expense associated with stiffening and shipping. The weight of this equipment will not affect the vessel's cargo carrying capacity at all. Also, the light-weight tubular alloy construction can permit longer outriggers (the outriggers can be up to 20 m in length, for example) with minimum support strengthening. The tubular outrigger construction can also be easily fitted, and require only minimal under-deck reinforcement.

[0115] Required deck space is minimized by the inventive embodiments. The outriggers can stow in line and over the top of the vessel's existing railings.

[0116] Also, the drag effect is minimal (about 40 Kg per cartridge assuming deployment length of the full 3,000 feet). The maximum drag on the forward outriggers is expected to be about 160 Kg (assuming pattern density on 2.5 cm (1 inch) centers). The maximum moment on the forward outriggers (attributable to drag) is expected to be about 600 Kg/m. The drag is a product of the coefficient of friction in water and vessel speed and is not adversely affected by weather/sea state.

[0117] Referring to FIGS. 23-25, an alternate watercraft immobilizing system can be fitted to a smaller, fixed displacement vessel 2350 having a hull 2350h. The system can include a hard terminated floated boom 2302, entanglement lines, and a hull mount 2301 situated at or below the vessel's waterline. Main entanglement lines 2310 and secondary entanglement lines 2312 can be stowed in a cartridge 2303 disposed within and along hull mount 2301. Floated boom 2302 can also be disposed at least partially within cartridge 2303. Each of the starboard and port sides of vessel 2350 can include a set of the floated boom, entanglement lines and hull mount associated with a corresponding one of paravanes 2320 stowed at or adjacent to the transom of vessel 2350. One or more of paravanes 2320 can optionally activate a bank 2314t of entanglement lines 2314, e.g., stowed at the transom in a hull mount and cartridge similar to hull mount 2301 and cartridge 2303. Each paravane 2320 can be coupled to a floated boom 2302, and configured to draw the floated boom, when the paravane is launched, so as to unseal cartridge 2303 at a release portion 2303r (which can, for example, be constructed as a zipped release mechanism) and deploy the floated boom and entanglement lines.

[0118] Referring to FIGS. 23 and 26, floated booms 2302 can be releasably coupled to a mounting plate 2330 at fixed termination points 2332 via release/jettison pins 2334. A release solenoid 2336 and control pulleys 2338.

[0119] Referring to FIG. 27, a main paravane 2700 (which can be the same as or similar to paravane 2320 or any of the paravanes disclosed herein) can include a main body 2702, collapsible wings 2704 coupled to the main body at wing pivots 2706, and stabilizer fins 2708. Main body 2702 can be configured with an independent propulsion system, such as a rocket or electric motor/propeller. Main body 2702 can also include a smoke chamber configured to produce surface smoke alongside the protected vessel, which can further confuse or disorientate an attacking watercraft.

[0120] Referring to FIG. 28, an alternate watercraft immobilizing system, which can be suitable for a larger, static displacement vessel, for example, can include a floated boom and entanglement line assembly 2802 coupled to (e.g., via fixed termination) and stowed in a sub-surface, watertight tube or chamber 2875 (e.g., defined in a hull 2850h) along with a self-propelled paravane 2820. A door 2880, which can be composed of a hard (e.g., durable or strong) or soft (e.g., delicate, elastic, or flexible) material, can removably seal chamber 2875. Door 2880 can at least partially open (and, e.g., pivot at a hinge or other suitable coupling point) when pushed upon by paravane 2820 during launching, to allow deployment of the floated boom and entanglement lines. It should be appreciated that both the starboard and port sides of the vessel can include this watercraft immobilizing system embodiment. For example, both sides of the vessel can include watertight tube or chamber 2875.

[0121] FIG. 29 illustrates full deployment of port, starboard, and transom entanglement lines in accordance with one or more of the watercraft immobilizing system embodiments described herein. Deployment (e.g., fanning out) of the transom entanglement lines can be effected as described above, or using one or more secondary paravanes.

[0122] As an alternative to the above-described constructions, only main tendril lines with no secondary, tertiary or other offshoots can be used, and the spacing between lines can be closed (e.g., on 1 inch centers) or otherwise adjusted. In such case, it can be desirable to use intermediate spreaders along the length of the towed arrays. This can enhance recoverability and re-usability and reduce cost. The main long lines can be fitted with swivels to allow rotation.

[0123] Additionally, in various embodiments, it is possible to exclude the aft outriggers and use only the transom mounted bank. It is also possible to use only shoulder outriggers, or to exclude the shoulder outriggers and use only the aft outriggers and/or transom bank.

[0124] Expediently, the deployment banks can hold reserve tendril lines. Also, a rendering device can be provided to manually or automatically play out additional tendril lines as needed in the event that lines are severed. The towed arrays can also be provided with an emergency release.

[0125] In certain embodiments, the outriggers can also be provided with fairing to prevent grappling hooks from hooking on thereto.

[0126] It should be appreciated that it is possible to provide embodiments of a watercraft immobilizing apparatus and system in accordance with the present invention that variously do not employ trailing end spreaders, or finned spreaders. It is even possible to substitute simple weight bars for submersible rollers, or to exclude the submersible rollers and simply deploy the tendril lines on the water surface.

[0127] It should be appreciated that the effectiveness of the watercraft immobilizing apparatus and system according to embodiments of the present invention can be increased by implementing vessel maneuvering practices when an attacking watercraft is detected. By way of example, when an attacking watercraft is in weapons range at the side or quarter of the protected vessel, the vessel can alter course towards the attacker and keep the helm hard over. This will effectively stall the towed side array on the attacker's side of the vessel. The vessel can complete a turn of approximately 270 degrees from its original heading to cross the trailing end of the stalled side array at approximately 90 degrees. If the attacking watercraft attempts to hold station on the vessel then it will be forced to cross the stalled side array.

[0128] Accordingly, the present invention provides embodiments of a marine vessel primary defense apparatus and system, novel characteristics of which, including its optional continuous deployment, in conjunction with recommended maneuvering procedures, provide a non-lethal, passive, cost-effective means to prohibit attacking watercraft from closely approaching a protected vessel whilst it is underway.

[0129] It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0130] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.