WO2012058145A2

WO2012058145A2 - Marine vessel arresting devices and methods

Info

Publication number: WO2012058145A2
Application number: PCT/US2011/057464
Authority: WO
Inventors: David Williams; Philip Bull
Original assignee: Actuant Corporation
Priority date: 2010-10-29
Filing date: 2011-10-24
Publication date: 2012-05-03
Also published as: WO2012058145A3

Abstract

A marine vessel arresting device includes a vessel arresting guard having an upper rope and a lower rope connected by a plurality of transverse ropes. A towable spreader connects to the upper rope and the lower rope such that the upper rope and the lower rope are spaced apart. The towable spreader is configured to connect to a towing marine vessel such that the spreader tows the vessel arresting guard in an entanglement configuration. In the entanglement configuration, the upper rope is at or near a surface of the body of water and the lower rope is spaced below the surface. The upper rope, the lower rope, and the plurality of transverse ropes are thereby configured to entangle running gear of a hostile marine vessel.

Description

MARINE VESSEL ARRESTING DEVICES AND METHODS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 61/408,024 filed October 29, 2010, the disclosure of which is hereby incorporated by reference in its entirety.

STATEMENT CONCERNING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.

FIELD OF THE INVENTION

[0003] This invention relates to devices and methods for protecting marine assets from hostile vessels. Particularly, this invention relates to devices and methods for arresting hostile marine vessels.

BACKGROUND OF THE INVENTION

[0004] In recent years, several types of marine vessels, such as military combat ships, commercial container ships, cruise liners, and the like, have been targeted in attacks by hostile individuals aboard smaller marine vessels, such as outboard engine fishing boats. In some cases, these individuals have caused damage by approaching the side of the target vessel and triggering explosives. In other cases, the hostile individuals have boarded the target vessel and held passengers captive in an attempt to secure a ransom.

[0005] These situations can be addressed in various manners, one of which includes avoiding the situation altogether by preventing hostile vessels from approaching the target vessel. This can be achieved by positioning a sub-surface and/or super-surface barrier apart from the side of the vessel to create a secured area that smaller vessels cannot enter.

[0006] Unfortunately, such protective barriers have a number of disadvantages. For example, these barriers are typically elongated and heavy and, as such, difficult to deploy. Similarly, protective barriers are typically only used to protect stationary vessels due to the large drag forces caused by towing such devices.

[0007] Furthermore, specific types of protective barriers have specific disadvantages. For example, net-type barriers that attempt to entangle and disable the propeller of a hostile vessel can instead be cut by the propeller, thereby rendering the barrier ineffective. Moreover, even if such a barrier entangles the propeller of a hostile vessel, the hostile vessel may be returned to operation by untangling the barrier, albeit painstakingly, from the propeller.

[0008] As such, a need exists for improved marine security devices and methods that address one or more of the above limitations of previous designs.

SUMMARY OF THE INVENTION

[0009] In one aspect, the present invention provides a marine vessel arresting device for deployment in a body of water. The device comprises a vessel arresting guard including an upper rope and a lower rope connected by a plurality of transverse ropes. A towable spreader connects to the upper rope and the lower rope such that the upper rope and the lower rope are spaced apart. The towable spreader is configured to connect to a towing marine vessel such that the spreader tows the vessel arresting guard in an entanglement configuration. In the entanglement configuration, the upper rope is at or near a surface of the body of water and the lower rope is spaced below the surface. The upper rope, the lower rope, and the plurality of transverse ropes are thereby configured to entangle running gear of a hostile marine vessel.

[0010] In another aspect, the present invention provides a method of using a marine vessel arresting device to protect a marine vessel in a body of water. The marine vessel arresting device includes a vessel arresting guard having an upper rope and a lower rope connected by a plurality of transverse ropes. The method includes deploying the marine vessel arresting device in the body of water. The marine vessel arresting device is then towed apart from a side of the marine vessel in the body of water such that the upper rope and the lower rope are spaced apart with the upper rope at or near a surface of the body of water and the lower rope below the surface. The marine vessel arresting device is thereby configured to entangle running gear of a hostile marine vessel.

[0011] In yet another aspect, the present invention provides a marine vessel arresting device for deployment in a body of water. The device comprises a vessel arresting guard including an upper rope, a lower rope, and a plurality of transverse ropes connecting the upper rope and the lower rope. The upper rope, the lower rope, and the plurality of transverse ropes each comprises braided polyethylene fibers. In addition, the plurality of transverse ropes are spaced apart to define a guard mesh in a range of four ropes/meter to seven ropes/meter. [0012] The foregoing and other aspects of the invention will appear in the detailed description which follows. In the description, reference is made to the accompanying drawings which illustrate a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:

[0014] FIG. 1 is a perspective view of a vessel arresting device according to the present invention deployed in the path of a hostile vessel;

[0015] FIG. 2 is a perspective view of the vessel arresting device of FIG. 1 entangled with the propeller of the hostile vessel;

[0016] FIG. 3 is a perspective view of the vessel arresting device of FIG. 1 being towed along the starboard side of a marine vessel to protect the marine vessel from hostile vessels;

[0017] FIG. 4 is a top view of multiple vessel arresting devices according to the present invention being towed along the sides of the marine vessel of FIG. 3;

[0018] FIG. 5 is a perspective view of a guard and floats of the vessel arresting device of FIG. 1 connected to guides for towing along the port side of a marine vessel;

[0019] FIG. 6 is a side view of the vessel arresting guard and floats of FIG. 4;

[0020] FIG. 7 is a perspective view of the guide of FIG. 4;

[0021] FIG. 8 is a front view of the guide of FIG. 4;

[0022] FIG. 9 is a side view of the guide of FIG. 4;

[0023] FIG. 10 is a side view of a float of FIG. 4;

[0024] FIG. 11 is a side view of the vessel arresting device of FIG. 1 connected to an anchored buoy; and

[0025] FIG. 12 is a side view of an alternative embodiment of the vessel arresting guard including three rows of generally rectangular openings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Referring now to the figures and particularly FIGS. 1 and 2, the present invention provides a rope-type marine vessel arresting device 50 that is deployable in a body of water 10. The device 50 floats at and beneath the surface of the body of water 10 in order to arrest one or more hostile marine vessels 12 (e.g., marine vessels operated by terrorists, pirates, or the like) by entangling the running gear of the vessel 12 (e.g. , the propeller 14). Unlike previous devices, the present marine vessel arresting device 50 is not likely to be cut by the propeller 14 of a vessel 12 having a size that hostile individuals are likely to obtain (e.g. , vessels having a power output up to about 350hp and possibly having multiple outboard motors). Moreover, when entangling the propeller 14, the marine vessel arresting device 50 causes failure of one or more engine components of the vessel 12 (e.g. , propeller bushings). As such, the vessel 12 cannot be returned to operation by untangling the marine vessel arresting device 50 from the propeller 14. Even further still, the marine vessel arresting device 50 has a relatively low-weight structure and causes relatively little drag when moving through the body of water 10.

[0027] The marine vessel arresting device 50 may be deployed in various manners. For example and as generally shown in FIG. 3, the device 50 may be towed along one side, e.g. , the starboard side, of a marine vessel 20 to protect the vessel 20 during travel (of course, a second device 50, such as that shown in FIG. 5, may be simultaneously towed along the other side, e.g. , the port side, of the marine vessel 20). As will be described in further detail below, the device 50 may be towed at various standoff distances from the marine vessel 20 and at various angles relative to the vessel's direction of travel, and the standoff distance and angle may be adjustable. Such a device 50 could be deployed at all times or only when the vessel 20 passes through dangerous waters. As another example and as generally shown in FIG. 11 , the device 50 may be anchored to protect a moored vessel or other types of marine assets that are vulnerable to water-borne threats (e.g. , shipyards, docks, etc.). In the following paragraphs, the towed configuration of the device is described first followed by the anchored configuration.

[0028] Referring to FIGS. 3-10, the towed configuration of the marine vessel arresting device 50 generally includes a rope-type entanglement or vessel arresting guard 52 that is led by and trailed by guides 54. The vessel arresting guard 52 optionally supports a plurality of floats 56 that hold the top of the guard 52 proximate the surface of the body of water 10. A plurality of weights 58 are optionally supported at the bottom of the guard 52 to ensure that the guard 52 maintains a generally vertical entanglement configuration as it moves through the body of water 10. These components are described in further detail in the following paragraphs, beginning with the vessel arresting guard 52 and concluding with the weights 58. [0029] Referring specifically to FIGS. 5 and 6, the vessel arresting guard 52 includes a plurality of preferably buoyant ropes that are capable of engaging and entangling the propeller 14 of a hostile vessel 12 as the vessel 12 passes thereover. In particular, the vessel arresting guard 52 includes an upper rope 60, an intermediate rope 62, a lower rope 64, and a plurality of transverse ropes 66 connecting the upper, intermediate, and lower ropes 60, 62, and 64. The transverse ropes 66 are spliced or otherwise connected to the upper, intermediate, and lower ropes 60, 62, and 64 such that they extend generally perpendicularly therefrom. As such, the ropes 60, 62, 64, and 66 define two rows of generally rectangular openings 68 in the vessel arresting guard 52.

[0030] In practice, the ropes 60, 62, 64, and 66 may bow slightly due to their weight and the transverse ropes 66 may bow slightly due to drag, but the openings defined by such ropes are still considered generally rectangular. In either case, rope structures that include generally rectangular openings have been found to more effectively entangle propellers than other shapes (e.g., loops).

[0031] In operation, the vessel arresting fence 52 is able to entangle the propeller 14 of a hostile vessel 12 due to the flexibility of the ropes 60, 62, 64, and 66. That is and as shown in FIG. 2, when the leading surface of the engine (opposite the propeller 14) first contacts the guard 52, the sections of the ropes 60, 62, 64, and 66 that contact the engine move a short distance. This causes adjacent sections of the ropes 60, 62, 64, and 66 to collapse around and thereby entangle the propeller 14.

[0032] The overall dimensions of the vessel arresting guard 52 preferably provide a structure that is capable of protecting relatively large areas without creating an excessively large device. In particular, the upper rope 60, the intermediate rope 62, and the lower rope 64 may each have a length of approximately 30m, although other lengths may alternatively be used. In addition, the transverse ropes 66 preferably have a length (and thereby provide the guard 52 with a height) in the range of 75cm to 125cm and more preferably approximately 92cm, although other lengths may alternatively be used.

[0033] Similarly, the transverse ropes 66 are preferably spaced apart to provide a guard mesh (i.e., number of ropes per unit distance) in the range of four ropes/meter to seven ropes/meter and more preferably five ropes/meter. Such a mesh has been found to permit several of the transverse ropes 66 to entangle the propeller 14 of a hostile vessel 12 and thereby distribute propeller contact forces to several ropes. The guard mesh could be increased to distribute these forces to even more ropes, although such a modification would increase the weight of the vessel arresting guard 52.

[0034] The structure of the individual ropes 60, 62, 64, and 66 provides the underwater rope fence 52 with relatively high strength (i.e., the capability to arrest vessels having a power output of up to about 350hp and possibly having multiple outboard motors), relatively low weight, and relatively low drag when towed in the body of water 10. In particular, each of the ropes 60, 62, 64, and 66 preferably comprises braided polyethylene fibers having a breaking tension greater than 19,000 kgf. As such, the ropes 60, 62, 64, and 66 may be 12x12 Plasma® rope available from Cortland Puget Sound Rope, Anacortes, WA. The upper rope 60 and the lower rope 64 each preferably have a diameter in the range of 20mm to 25mm and more preferably 22mm. The intermediate rope 62 and the transverse ropes 66 each preferably have a diameter in the range of 9mm to 14mm and more preferably 11mm.

[0035] Referring now to FIGS. 3, 4, 5, and 7, the leading and trailing guides 54 tow the vessel arresting guard 52 apart from the side of the marine vessel 20 to create a secured area or "exclusion zone" between the guard 52 and the side of the vessel 20. To tow the vessel arresting guard 52 in such a manner, the guides 54 each include one or more diverter vanes 70 that are disposed at an angle relative to other guide components. That is, the angled vanes 70 partially face the direction of travel and are thereby forced apart from the side of the vessel 20 as the guides 54 move through the body of water 10.

[0036] It should be noted that the structure of the leading and trailing guides 54 is generally similar. In the following paragraphs, only the structure of the leading guide 54 is described for simplicity.

[0037] The vanes 70 support various other components of the guide 54 that together permit the vessel arresting guard 52 to be towed by the marine vessel 20. For example, the leading vane 70 supports an eyelet 72 approximately midway along its height. The eyelet 72 connects to a hawser or tow rope 74 to connect the guide 54 to the marine vessel 20 (see FIG. 3). The vanes 70 also mount one or more elongated rods 76 (FIG. 7) that support an intermediate shackle 78 approximately midway along the height of the vanes 70. The intermediate shackle 78 connects to an eyelet 80 of the intermediate rope 62 to tow the rope 62 there behind. [0038] The upper ends of the vanes 70 support an elongated chamber 82 that floats at the surface of the body of water 10 to position the guide 54 and the vessel arresting guard 52 at and beneath the surface. The float chamber 82 supports an upper shackle 84 (FIG. 7) that connects to an eyelet 86 of the upper rope 60 to tow the rope 60 therebehind. The float chamber 82 also supports out riggers 88 on opposite sides to further provide buoyancy for the guide 54 and to prevent the guide 54 from tipping from a generally vertical configuration. The float chamber 82 and the out riggers 88 may each be hollow metal containers or other buoyant materials. In addition, the float chamber 82 and the out riggers 88 may each include a conical tip to provide a more streamlined shape.

[0039] The lower ends of the vanes 70 support a generally flat skeg plate 90 that stabilizes the guide 54 as it moves through the body of water 10. The skeg plate 90 is angled downward relative to the float chamber 82 to provide the guide 54 with a "diving" tendency as it moves. This ensures that portions of the guide 54 below the float chamber 82 and the out riggers 88 are not towed above the surface. However, the float chamber 82 counteracts this effect of the skeg plate 90 to some extent and prevents the guide 54 from diving completely underwater. The skeg plate 90 also supports a lower shackle 92 that connects to an eyelet 94 of the lower rope 64 to tow the rope 64 there behind.

[0040] From the previous paragraphs, it should be appreciated that the leading and trailing guides 54 also acts as spreaders that provide vertical spacing between the upper, intermediate, and lower ropes 60, 62, and 64. As such, the guides 54 position the vessel arresting guard 52 in a generally vertical entanglement configuration in which the ropes 60, 62, 64, and 66 are capable of entangling the propeller 14 of a hostile vessel 12. As used herein, the term "entanglement configuration" means a configuration in which the upper, intermediate, and lower ropes 60, 62, and 64 define a generally planar arresting guard 52. Such a configuration has been found to be particularly effective for entangling propellers 14 compared to those in which the intermediate and lower ropes 62, 64 are permitted to move freely.

[0041] Referring now to FIGS. 5, 6, and 10, the floats 56, if included, are supported by the upper rope 60 and spaced along its length. The floats 56 are preferably spaced apart at a pitch (i.e., number of floats per unit distance) in the range of 0.6 floats/meter to 0.8 floats/meter and more preferably 0.7 floats/meter. Such a pitch has been found to adequately support the upper rope 60 at the surface but is not so great that the propeller 14 of a hostile vessel 12 contacts multiple floats 56 instead of multiple transverse ropes 66. Furthermore, additional floats 56 would increase drag as the device 50 moves through the body of water 10. In any case, the floats 56 are preferably generally spherical foam components having a diameter of approximately 20cm. Each float 56 also preferably has perpendicular internal passageways 96, one of which receives the upper rope 60 and the other of which may receive a transverse rope 66 (see, e.g., the intermediate float 56 in FIG. 6).

[0042] Referring now to FIGS. 5 and 6, the weights 58, if included, are supported by the lower rope 64 and spaced along its length. Each weight 58 may be positioned directly below a single float 56; that is, the weights 58 may be spaced apart at a pitch equal to that of the floats 56. In any case, the weights 58 are sufficiently heavy to maintain the vertical spacing between the upper, intermediate, and lower ropes 60, 62, and 64 {i.e., to prevent portions of the intermediate and lower ropes 62, 64 spaced apart from the guide 54 from moving toward the surface of the body of water 10). As such, the weights 58 maintain the vessel arresting guard 52 in the generally vertical entanglement configuration provided by the guide 54.

[0043] In safe waters, the vessel arresting device 50 may be reeled in by the protected marine vessel 20, a separate escort vessel (not shown), or the like. The guide 54 may be detached from the vessel arresting guard 52, and the vessel arresting guard 52 may be folded or wrapped around a drum (not shown) for storage.

[0044] The structure of the towed configuration of the device 50 may differ from the above description. For example, multiple vessel arresting guards 52 may be connected to one another to create a guard 52 that is long enough to protect an entire side of a cruise liner, such as that shown in FIG. 3. In this case, a guide 54 could be positioned between each vessel arresting guard 52. As another example, at least some of the guides 54 may have adjustable guide vanes 70 so that the standoff distance between the vessel arresting device 50 and the side of the towing vessel 20 may be varied. The vanes 70 of the trailing guides 54 may be adjusted such that two vessel arresting devices 50 form a V-shaped protective configuration, such as that shown in FIG. 4. Similarly, the vanes 70 of each guide 54 may be oriented parallel to the travel direction (i.e. , not angled) and towed behind an escort vessel (not shown) to protect an adjacent marine vessel 20. As yet another example, the guides 54 may take the form of any common diverter or paravane. [0045] Referring now to FIG. 11 and as described briefly above, the vessel arresting guard 52 may also be deployed in a manner that protects stationary marine assets (e.g., moored vessels, shipyards, docks, etc.). In this configuration, the vessel arresting guard 52 generally has a structure and supports the floats 56 and the weights 58 as described above. However, the guard eyelets 80, 86, and 94 connect to a stationary buoy 98 instead of a guide. The stationary buoy 98 is chained to an anchor 100 seated on the sea bed.

[0046] Both the stationary and towed configurations of the vessel arresting device 50 may be modified in other manners not explicitly described above. For example, the vessel arresting guard 52 may have a different number of rows of generally rectangular openings 68. The vessel arresting guard 152 shown in FIG. 12 includes two intermediate ropes 62 and, as such, includes three rows of generally rectangular openings 68. As yet another example, the sizes (i.e., length and diameter) of the ropes may differ from those described above based on specifications of potential hostile marine vessels (e.g., size, power output, and the like).

[0047] From the above description, it should be apparent that the present invention provides improved devices and methods for arresting hostile marine vessels. In particular, the present marine vessel arresting device is not likely to be cut by the propellers of vessels that hostile individuals are likely to use. Furthermore, when entangling a propeller, the present device causes failure of one or more engine components of the hostile vessel. As such, the vessel cannot be returned to operation by untangling the device from the propeller. Even further still, the marine vessel arresting device has a relatively low-weight structure and causes relatively little drag when moving through a body of water.

[0048] Preferred embodiments of the invention have been described in considerable detail. Many other modifications and variations to the preferred embodiments will be apparent to a person of ordinary skill in the art. Therefore, the invention should not be limited to the embodiments described, but should be defined by the claims that follow.

Claims

CLAIMS I/We claim:

1. A marine vessel arresting device for deployment in a body of water, comprising:

a vessel arresting guard including an upper rope and a lower rope connected by a plurality of transverse ropes;

a towable spreader connected to the upper rope and the lower rope such that the upper rope and the lower rope are spaced apart; and

wherein the towable spreader is configured to connect to a towing marine vessel such that the spreader tows the vessel arresting guard in an entanglement configuration in which the upper rope is at or near a surface of the body of water and the lower rope is spaced below the surface and the upper rope, the lower rope, and the plurality of transverse ropes are thereby configured to entangle running gear of a hostile marine vessel.

2. The marine vessel arresting device of claim 1 , wherein the vessel arresting guard further includes a plurality of floats supported by the upper rope, and the plurality of floats are configured to float at the surface to thereby position the upper rope at or near the surface.

3. The marine vessel arresting device of claim 1 , wherein the spreader includes a diverter vane configured to position the vessel arresting guard apart from a side of the towing marine vessel as the towing marine vessel tows the vessel arresting guard.

4. The marine vessel arresting device of claim 3, wherein the spreader includes:

an upper shackle proximate a first end of the spreader and connected to the upper rope; and

a lower shackle proximate a second end opposite the first end and connected to the lower rope.

5. The marine vessel arresting device of claim 4, wherein the spreader further includes:

a float chamber supporting the upper shackle;

a skeg plate opposite the float chamber and supporting the lower shackle; and wherein the float chamber is configured to float at the surface of the body of water to thereby position the upper rope at or near the surface.

6. The marine vessel arresting device of claim 5, wherein the vessel arresting guard further includes an intermediate rope connected to the plurality of transverse ropes between the upper rope and the lower rope.

7. The marine vessel arresting device of claim 6, wherein the diverter vane connects the float chamber to the skeg plate and supports an intermediate shackle connected to the intermediate rope.

8. The marine vessel arresting device of claim 1 , wherein each of the plurality of transverse ropes is perpendicular to both the upper rope and the lower rope to provide the vessel arresting guard with a plurality of rectangular openings.

9. The marine vessel arresting device of claim 8, wherein each of the plurality of transverse ropes, the upper rope, and the lower rope comprises braided polyethylene fibers.

10. The marine vessel arresting device of claim 1 , further comprising a plurality of weights supported by the lower rope, wherein the plurality of weights are configured to position the lower rope beneath the surface of the body of water.

11. A method of using a marine vessel arresting device to protect a marine vessel in a body of water, the marine vessel arresting device including a vessel arresting guard having an upper rope and a lower rope connected by a plurality of transverse ropes, the method comprising the steps of:

deploying the marine vessel arresting device in the body of water; and towing the marine vessel arresting device apart from a side of the marine vessel in the body of water such that the upper rope and the lower rope are spaced apart with the upper rope at or near a surface of the body of water and the lower rope below the surface such that the marine vessel arresting device is thereby configured to entangle running gear of a hostile marine vessel.

12. The method of claim 11 , wherein the step of towing the marine vessel arresting device includes maintaining the vessel arresting guard in a generally vertical orientation.

13. The method of claim 11 , wherein the step of towing the marine vessel arresting device includes towing the marine vessel arresting device by using the marine vessel.

14. The method of claim 11 , wherein the step of towing the marine vessel arresting device includes towing the marine vessel arresting device by using a separate escort vessel.

15. A marine vessel arresting device for deployment in a body of water, comprising:

a vessel arresting guard including:

an upper rope;

a lower rope;

a plurality of transverse ropes connecting the upper rope and the lower rope; and

wherein the upper rope, the lower rope, and the plurality of transverse ropes each comprises braided polyethylene fibers, and the plurality of transverse ropes are spaced apart to define a guard mesh in a range of 4 ropes/meter to 7 ropes/meter.

16. The marine vessel arresting device of claim 5, wherein the upper rope and the lower rope have respective diameters in a range of 20mm to 25mm.

17. The marine vessel arresting device of claim 15, wherein each of the transverse ropes has a diameter in a range of 9mm to 14mm.

18. The marine vessel arresting device of claim 15, wherein the vessel arresting guard further includes an intermediate rope connected to the plurality of transverse ropes between the upper rope and the lower rope.

19. The marine vessel arresting device of claim 18, wherein the intermediate rope has a diameter in a range of 9mm to 14mm.

20. The marine vessel arresting device of claim 15, wherein the upper rope and the lower rope are spaced apart to define a guard height in a range of 75cm to 125cm.