BACKGROUND
Commercial shipping routes on the world's oceans pass through remote areas often with limited support infrastructure and severe met-ocean conditions. One such route, the great circle route between Asia and the North American West Coast, happens to be one of the busiest commercial shipping routes in the world. It passes directly through the Aleutian Archipelago and the southern portion of the Bering Sea. Electrical and mechanical system failures, loss of propulsion, and other issues experienced on large ocean-going vessels can and have resulted in significant marine casualties and oil spills in this area. A need exists for a means of slowing the drift and reducing the motions of disabled ocean-going vessels for the prevention of marine casualties and related oil spills. Given its remoteness and the density of marine traffic in the area, the need is especially pronounced in the offshore waters of Alaska and the Bering Sea.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a vessel attachment system and a retrieving system.
FIG. 2 is a top view of a sea anchor system.
FIG. 3 is a top view of the sea anchor system connected to the vessel attachment system, which is attached to a vessel.
FIG. 4 is a top view of a responding vessel with a line gun cord deployed to a disabled vessel.
FIG. 5 is a top view of the vessel attachment system and the retrieving system operatively connected to the line gun cord on the responding vessel.
FIG. 6 is a top view of the vessel attachment system and the retrieving system connected to the foredeck of the disabled vessel.
FIG. 7 is a detailed perspective view of a bridle line wrapped around a forward bitt on the foredeck of the disabled vessel.
FIG. 8 is a detailed perspective view of the bridle line leading around a fairlead on the foredeck of the disabled vessel.
FIG. 9 is a detailed perspective view of the bridle line belayed on an aft bitt on the foredeck of the disabled vessel.
FIG. 10 is a detailed perspective view of the bridle lines leading through a chock in a forward end of the disabled vessel.
FIG. 11 is a top view of a method of engaging the retrieving line from the responding vessel.
FIG. 12 is a top view of the sea anchor system on the responding vessel.
FIG. 13 is a top view of the sea anchor system deployed with the vessel attachment system on the disabled vessel.
FIG. 14 is a top view of an alternate embodiment of the vessel attachment system and the retrieving system.
FIG. 15 is a perspective view of a hawser bushing of the vessel attachment system shown in FIG. 14.
FIG. 16 is a top view of the hawser bushing.
FIG. 17 is a front view of the hawser bushing.
FIG. 18 is a sectional view of one embodiment of the hawser bushing taken along line A-A in FIG. 17.
FIG. 19 is a sectional view of an alternate embodiment of the hawser bushing taken along line A-A in FIG. 17.
FIG. 20 is a top view of a connection between the vessel attachment system and the retrieving system shown in FIG. 14.
FIG. 21 is a top view of the vessel attachment system shown in FIG. 14 attached to the foredeck of a vessel.
FIG. 22 is a top view of an alternate embodiment of the sea anchor system.
FIG. 23 is a top view of the sea anchor system shown in FIG. 22 connected to the vessel attachment system shown in FIG. 14, which is attached to the foredeck of a disabled vessel.
FIG. 24 is a top view of the connection between the sea anchor system shown in FIG. 22 and the vessel attachment system shown in FIG. 14.
DETAILED DESCRIPTION OF SELECTED EMBODIMENTS
An emergency ship arrest system may be deployed to a disabled vessel to reduce motions and slow the drift of the vessel in a free drift state. Vessel as used herein means any ocean-going ship such as a commercial tank vessel, a container vessel, or a bulk carrier. Ocean as used herein means any ocean, sea, or any other body of water. The system serves dual purposes. First, the system generally aligns the disabled vessel into the direction of wind and waves to reduce vessel motions, thereby rendering vessel repair more feasible and reducing stresses on the vessel and its cargo. Second, the system slows the vessel's rate of drift, thereby increasing the window of opportunity for an appropriate towing vessel to arrive at the vessel's location before grounding occurs.
The emergency ship arrest system may include a vessel attachment system configured to attach to a foredeck of the disabled vessel, a retrieving system configured to connect to the vessel attachment system in a setup position, and a para sea anchor system configured to connect to the vessel attachment system in an anchor position.
FIG. 1 illustrates vessel attachment system 10 and retrieving system 12 in a setup position. Vessel attachment system 10 may include first bridle 14, second bridle 16, and hawser assembly 18. First and second bridles 14 and 16 may each extend from proximal ends 20 to distal ends 22. In one embodiment, proximal ends 20 may each include proximal eye 23 configured to allow connection to an extension line. For example, an extension line may be connected to the proximal eyes of bridles 14 and 16 to lengthen bridles 14 and 16 to secure vessel attachment system 10 to vessels having foredeck fittings positioned further apart. Distal ends 22 may each include distal eye 24. Bridles 14 and 16 may each have a length between 10 and 150 meters, or any subrange therein. In one embodiment, bridles 14 and 16 may each have a length of between 70 and 85 meters, or any subrange therein. Bridles 14 and 16 may each have an outer diameter in the range of 24 to 152 millimeters, or any subrange therein. Bridles 14 and 16 may be composed of multiple stands of ultra-high-molecular-weight polyethylene or other synthetic fibers. In one embodiment, first and second bridles 14 and 16 may be formed of 68 mm Samson Quantum®-12 line. Bridles 14 and 16 may each include protected sections 22, 26, and 28, which may be coated, painted, reinforced, or jacketed with chafe protection to prevent abrasion of fibers in high stress and high friction areas.
Hawser assembly 18 may include hawser line 30 extending from proximal end 32 to distal end 34. Hawser line 30 may a length in the range of 50 to 300 meters, or any subrange therein, and an outer diameter in the range of 24 to 152 millimeters, or any subrange therein. Hawser line 30 may be formed of a light weight, high-strength material, with high pliability and positive buoyancy in seawater, such a line constructed of ultra-high-molecular-weight polyethylene fibers or other synthetic fibers. For example, hawser line 30 may be formed of 68 mm Samson Amsteel®-Blue. Proximal end 32 may include proximal eye 36 that engages distal eyes 24 of first and second bridles 14 and 16. Proximal eye 36 may include Samson DC Gard to protect against chafing due to friction with distal eyes 24 of distal ends 22 of bridles 14 and 16. Distal end 34 of hawser line 30 may include distal eye 38. Hawser assembly 16 may also include floats 40 and hawser thimble 42. Floats 40 may provide buoyancy and visibility of hawser line 30. Any number of floats 40 may be connected to hawser line 30. For example, between 1 and 10 floats 40 may be connected to hawser line 30. Hawser thimble 42 may include central opening 43. Hawser thimble 42 may be disposed in distal eye 38 of hawser line 30. Hawser thimble 42 may be formed of an Orkot® thimble or any other thimble capable of providing the strength necessary for the described connections.
Retrieving system 12 may include retrieving line 44 extending from proximal end 46 having proximal eye 48 to distal end 50 having distal eye 52. Retrieving system 12 may also include pilot anchor 54 with canopy 56 and a plurality of shrouds 58. A central portion of canopy 56 may be attached to retrieving line 44. Each of the plurality of shrouds 58 may extend from a perimeter of canopy 56 (i.e., outer edge or outer surface of canopy 56) to retrieving line 44. Retrieving system 12 may further include marker buoys 60 attached to retrieving line 44, and strobing buoy 62 attached to distal eye 52. Proximal end 46 of retrieving line 44 may be disposed through central opening 43 of hawser thimble 42 with retrieving shackle 64 engaging proximal eye 48. In this way, retrieving system 12 is connected to vessel attachment system 10 in the setup position. In other embodiments, retrieving system 12 may be connected to vessel attachment system 10 by connecting retrieving shackle 64 to a strap or rope grommet secured to hawser line 30 near distal end 34. Retrieving line 44 may have a length in the range of 10 to 300 meters, or any subrange therein. Retrieving shackle 64 may be formed of any shackle having a load capacity sufficient to allow recovery of retrieving system 12, such as a screw-pin or bolt-type shackle formed of a durable material such as stainless steel. Retrieving shackle 64 may provide a mechanism for quickly disconnecting retrieving system 12 from vessel attachment system 10.
FIG. 2 illustrates para sea anchor system 80 (also referred to as anchor system 80), which may be attached to vessel attachment system 10 in an anchor position. Anchor system 80 may include main rode 82, para sea anchor 84, and recovery line 86. Main rode 82 may extend from proximal end 88 having proximal eye 90 to distal end 92 having distal eye 94. In one embodiment, main rode 82 may have a length between 100 and 400 meters, or any subrange therein. For example, main rode 82 may have a length of about 250 meters or more. In one embodiment, main rode 82 may have an outer diameter in the range of 24 to 152 mm, or any subrange therein. Main rode 82 may be formed of the same material as hawser line 30. Recovery line 86 may have a length in the range of 30 to 300 meters, or any subrange therein. Anchor system 80 may also include anchor thimble 96 having central opening 97. Anchor thimble 96 may be formed of an Orkot® thimble or any other thimble capable of providing the strength necessary for the described connections. Anchor thimble 96 may be disposed in proximal eye 90 of main rode 82.
Anchor system 80 may also include first anchor shackle 98 and second anchor shackle 100. First anchor shackle 98 may engage central opening 97 of anchor thimble 96 and second anchor shackle 100. Second anchor shackle 100 may be attached to central opening 43 of hawser thimble 42 of vessel attachment system 10 to detachably secure anchor system 80 to vessel attachment system 10. In one embodiment, each of shackles 98 and 100 may be formed of a bolt-type shackle having a load capacity of 278 MT or less. Use of shackles with a lower load capacity would provide a greater margin of safety. For example, shackles 98 and 100 may be formed of 2″ Marquip No. 211 anchor pattern shackles, each having a minimum breaking strength of 239 MT, sold by Washington Chain and Supply. Shackles 98 and 100 may be painted safety orange or another color that is highly visible in sea water. Shackles 98 and 100 may provide a mechanism for quickly disconnecting anchor system 80 from vessel attachment system 10. Floats 102 may be connected to main rode 82 for buoyancy and visibility of main rode 82. Any number of floats 102 may be connected to main rode 82. For example, 1-10 floats 102 may be connected to main rode 82.
Para sea anchor 84 may include canopy 104 with a plurality of shrouds 106 each extending from distal eye 94 of main rode 82 to perimeter 108 of canopy 104 (i.e., outer edge of canopy 104). In one embodiment, plurality of shrouds 106 may be attached to a grommet secured to the distal end 92 of main rode 82. Canopy 104 may have a diameter between 10 and 51 meters, or any subrange therein. In one embodiment, canopy 104 may have a diameter of between 30 and 40 meters, such as about 36 meters. Canopy 104 may be formed of any durable material such as high-strength nylon or ultra-high-molecular-weight polyethylene fibers. Canopy 104 may include a central aperture, or throat, that allows water flow therethrough. A plurality of stabilizer lines 118 may extend from a perimeter of the central aperture of canopy 104. Proximal end 110 of recovery line 86 may be secured to a distal end of each of the plurality of stabilizer lines 118, such as with a grommet or other connection mechanism. In one embodiment, each of the shrouds 106 extends along canopy 104 and forms one of the stabilizer lines 118. Distal end 112 of recovery line 86 may include distal eye 114.
Any number of floats or buoys 120 may be attached to recovery line 86 to provide positive system buoyancy and visibility. Distal buoy 122 may be attached near distal eye 114 of recovery line 86 to provide visibility to distal end 112.
With reference to FIG. 3, anchor system 80 may be attached to vessel attachment system 10, which is secured to foredeck 124 of disabled vessel 126 in the anchor position. Para sea anchor 84 will inflate upon deployment and work with vessel attachment system 10 to slow the drift rate of disabled vessel 126. Vessel attachment system 10 and para sea anchor 84 may also align disabled vessel 126 with wind direction 128 and the direction of waves.
FIGS. 4-13 illustrate the method of deploying the emergency ship arrest system that includes vessel attachment system 10, retrieving system 12, and anchor system 80. Vessel attachment system 10 and retrieving system 12 may be delivered to disabled vessel 126 by fixed-wing aircraft, helicopter, or boat using a line-throwing appliance. For example, responding vessel 130 may travel to the location of disabled vessel 126 at sea and position itself alongside disabled vessel 126 as shown in FIG. 4. After taking appropriate safety measures, a line gun may be fired to drape line gun cord 132 across the deck or mid-body of disabled vessel 126. Referring now to FIG. 5, an end of line gun cord 132 may be attached to a first end of messenger line 134 held on responding vessel 130. Messenger line 134 may have a length between 100 and 300 meters, or any subrange therein. For example, messenger line 134 may have a length between 130 and 170 meters. A second end of messenger line 134 may be attached with messenger shackle 136 to distal eye 52 of retrieving system 12, which is in turn connected to vessel attachment system 10 with retrieving shackle 64 and hawser thimble 42. Line gun cord 132, messenger line 134, retrieving system 12, and vessel attachment system 10 may be sequentially pulled onboard disabled vessel 126. Thereafter, messenger shackle 136 may be disconnected from distal eye 52 of retrieving system 12. In some embodiments, proximal eyes 23 of first and second bridles 14, 16 may be used to secure distal ends 20 of bridles 14, 16 together for transfer.
Vessel attachment system 10 may be secured to the foredeck of a disabled vessel. Ship foredeck arrangements vary, but generally include a pair of forward and aft bitts, each pair including one port bitt and one starboard bitt. Foredeck arrangements may also include roller or pedestal type fairleads and other fittings that may be used to align bridles 14 and 16 with the orientation of bitts. First and second bridles 14 and 16 may be secured to any fittings on the foredeck of a disabled vessel, preferably with first bridle 14 engaging two or more fittings on the port side and with second bridle 16 engaging two or more fittings on the starboard side of the disabled vessel.
FIG. 6-10 illustrate one arrangement in which vessel attachment system 10 is secured to foredeck 138 of disabled vessel 126. Foredeck 138 may include forward port bitt 140, forward starboard bitt 142, aft port bitt 144, and aft starboard bitt 146. Foredeck 138 may also include port fairlead 148 and starboard fairlead 150. First bridle 14 may be wrapped once around first post 152 of forward port bitt 140 (shown in FIG. 7), run around post 154 of port fairlead 148 (shown in FIG. 8), and fully belayed around posts 156 and 158 of aft port bitt 144 (shown in FIG. 9). Similarly, second bridle 16 may be wrapped once around a first post of forward starboard bitt 142, run around a post of starboard fairlead 150, and fully belayed around the posts of aft starboard bitt 146.
After first and second bridles 14 and 16 are connected to foredeck 138, retrieving system 12 and hawser assembly 18 in the setup position may be routed through one or more chocks of disabled vessel 126 and into the water, beginning with distal end 50 of retrieving system 12. In one embodiment, retrieving system 12 and hawser assembly 18 may be routed through chock 160 in bow 162 of disabled vessel 126 and into the water (as shown in FIG. 10), beginning with distal end 50 of retrieving system 12. In another embodiment, retrieving system 12 may be routed through one chock located on a port side or a starboard side of disabled vessel 126. Alternatively, retrieving system 12 may be routed through two chocks, one on a port side and one on a starboard side of disabled vessel 126.
As shown in FIG. 10, protected section 26 of first bridle 14 and protected section 26 of second bridle 16 may be positioned through chock 160 of disabled vessel 126 when fully extended. Protected sections 26 may prevent wear or chafing of bridles 14 and 16 that may be caused by movement of bridles 14 and 16 within chock 160. Protected sections 26 may also be positioned around forward port bitt 140 and forward starboard bitt 142, as this may be another high stress and high friction area of bridles 14 and 16.
It should be understood that the specific arrangement illustrated in FIGS. 6-10 is only one embodiment of the method of securing vessel attachment system 10 to foredeck 138, with many other arrangements within the scope of the invention understood by those of skill in the art. Vessel attachment system 10 is a universal system designed to be secured to the foredeck of virtually any ship.
In one embodiment, bridles 14 and 16, hawser line 30, and retrieving system 12 may be configured to position distal end 50 or strobing buoy 62 some distance from disabled vessel 126 to allow safe recovery of distal end 50. In one embodiment, hawser thimble 42 is positioned a distance from disabled vessel 126 that is about one half the length of the disabled vessel when hawser line 30 is completely extended. For example, if disabled vessel 126 has a length of about 300 meters, bridles 14 and 16 may extend about 4 meters beyond chock 160 and hawser line 30 may have a length of about 146 meters.
As shown in FIG. 11, with vessel attachment system 10 and retrieving system 12 attached in the setup position, responding vessel 130 may be positioned near buoys 60 and 62 of retrieving system 12. Retrieving system 12 may be recovered on responding vessel 130 by any known methods, such as with grapple hook 164. After retrieving system 12 is pulled from the water onto responding vessel 130, retrieving shackle 64 may be disconnected from hawser thimble 42.
Referring to FIG. 12, anchor system 80 may be positioned on responding vessel 130. After disconnecting retrieving shackle 64 from hawser thimble 42, second shackle 100 of anchor system 80 may be attached to hawser thimble 42.
With reference to FIG. 13, anchor system 80 may then be dragged or deployed overboard into the anchor position, beginning with proximal end 88 of main rode 82. As disabled vessel 126 drifts downwind, it pulls on hawser line 30, main rode 82, and para sea anchor 84, thereby expanding canopy 104. In its open position, canopy 104 orients disabled vessel 126 into the direction of the wind and waves as shown in FIG. 3. Canopy 104 then slows the drift of disabled vessel 126. Responding vessel 130 may navigate away from the area, if necessary.
First and second bridles 14 and 16 of vessel attachment system 10 distribute the line load from hawser line 30 to foredeck fittings, such as bitts 140, 142, 144, 146, fairleads 148, 150, and chock 160. Each of bridles 14 and 16 may attach to two sets of bitts or similar foredeck fittings to effectively distribute the line load from para sea anchor 84 to disabled vessel 126. This configuration provides for improved load sharing over conventional methods and systems for emergency towing.
Numerical modeling demonstrated that wrapping each of bridles 14 and 16 once around forward bitts 140 and 142, respectively, and fully belaying each of bridles 14 and 16 on aft bitts 144 and 146, respectively, distributes 50-75% of the line load to forward bitts 140 and 142 and 25-50% of the line load to the aft bitts 144 and 146. This distribution is dependent upon the coefficient of friction of the bridle material and other factors. With bridles 14 and 16 formed of Samson Rope Quantum®-12 having a coefficient of friction of 0.13, about 69% of the line load was distributed to forward bitts 140 and 142 and about 31% of the line load was distributed to aft bitts 144 and 146.
Shackles 98 and 100 may be designed as a weak link intended to fail before failure of the vessel foredeck structure or other system components. As designed, a failure of shackle 98 or 100 would leave hawser line 30 intact and connected to the vessel, thus recoverable for a towing vessel.
The para sea anchor is used to generate sufficient drag force to turn a large ocean-going vessel adrift to within about 20 degrees of the direction of the wind and to slow the free drift velocity of the vessel by about 50%. For example, the para sea anchor may generate a drag force of at least 473 kN (or 48 metric tons) while being towed at a continuous speed of 1.5 knots, representing about 50% of the free drift velocity of certain vessels. The main rode may be rated for a minimum breaking strength of 2,900 kN (296 metric tons). The para sea anchor maintains system integrity for extended periods of time such that the exerted drag force does not diminish over time.
FIG. 14 illustrates an alternate embodiment of the vessel attachment system disclosed herein with retrieving system 12. Vessel attachment system 200 may include continuous bridle 202 and hawser assembly 204. Except as otherwise described, vessel attachment system 200 and hawser assembly 204 may include the same features and materials as vessel attachment system 10 and hawser assembly 18, respectively. These components may be used in connection with retrieving system 12 as described above with reference to FIGS. 1-13.
Continuous bridle 202 may extend from first end 206 to second end 208 (sometimes referred to as proximal ends 206, 208). First and second ends 206, 208 may each include an eye configured to allow connection to an extension line. Continuous bridle 202 may have a length between 20 and 300 meters, or any subrange therein. In one embodiment, continuous bridle 202 may have a length between 140 and 170 meters, or any subrange therein. Continuous bridle 202 may include protected sections in high stress and high friction areas, such as first and second ends 206, 208.
Hawser assembly 204 may include hawser line 30 extending from proximal end 32 to distal end 34. Hawser assembly 204 may also include hawser bushing 210 disposed in proximal eye 36 of hawser line 30. Continuous bridle 202 may be slidingly disposed through central opening 212 of hawser bushing 210 to detachably secure continuous bridle 202 to hawser assembly 204. Continuous bridle 202 may include chafe protection on the section disposed through central opening 212 of hawser bushing 210.
Hawser assembly 204 may further include strap 214. A first end of strap 214 may be attached to hawser line 30 near distal end 34. A second end of strap 214 may include strap eye 216. Strap 214 may be formed of a small synthetic strap or loop, spliced or otherwise attached to hawser line 30 at the base of distal eye 38. In one embodiment, hawser assembly 204 includes a rope grommet instead of strap 214. The rope grommet may be attached to hawser line 30 near distal end 34 by tucking a bight of the rope grommet through the body (braid) of hawser line 30, and passing it over the standing part, effectively choking the rope grommet onto hawser line 30. The rope grommet may be formed of a high strength synthetic material, such as high strength polyethylene fibers.
With reference to FIGS. 15-19, hawser bushing 210 may be formed of a cylindrical-shaped thimble or bushing. Circumferential surface 222 of hawser bushing 210 may include recessed channel 224 for securing hawser bushing 210 in proximal eye 36 of hawser line 30 (as shown in FIG. 14). Central opening 212 may include flared surface profile 227, which may facilitate a movement of hawser bushing 210 along continuous bridle 202. Central opening 212 may include a smooth surface to facilitate the movement of continuous bridle 202 therethrough. In use, continuous bridle 202 engages central opening 212 and flared surface profile 227, while proximal eye 36 of hawser line 30 engages recessed channel 224. Hawser bushing 210 may have a width between 4 and 8 inches, or any subrange therein, and an outer diameter between 9 and 14 inches, or any subrange therein.
FIG. 18 is a sectional view of one embodiment of hawser bushing 210, which includes perimeter section 228 and core section 229 disposed within a central bore in perimeter section 228. In one embodiment, flared surface profile 227 is formed by core section 229 and perimeter section 228 as shown in FIG. 18. Alternatively, flared surface profile 227 may be formed by core section 229 alone. In either embodiment, core section 229 provides a smooth surface to facilitate the movement of continuous bridle 202 therethrough. In one embodiment, core section 229 is formed of a high-strength metal (e.g., aluminum, stainless steel, or titanium), and perimeter section 228 is formed of a composite or other high-strength material (e.g., CIP Marine™). In another embodiment, both core section 229 and perimeter section 228 are formed of a solid metal. In use, continuous bridle 202 engages core section 229 and may also engage a portion of perimeter section 228 (i.e., flared surface profile 227), while proximal eye 36 of hawser line 30 engages perimeter section 228 (i.e., recessed channel 224 therein).
FIG. 19 illustrates an alternate embodiment of hawser bushing 210. In this embodiment, hawser bushing 210 is formed of a single integrally formed unit. In one embodiment, hawser bushing 210 is formed of a solid metal (e.g., aluminum, stainless steel, or titanium). In another embodiment, hawser bushing 210 is formed of a composite or other high strength material (e.g., CIP Marine™.
With reference to FIG. 20, proximal end 46 of retrieving line 44 may be attached to strap eye 216 (or the rope grommet in the alternate embodiment) of hawser assembly 204 with retrieving shackle 64 or other hardware. This configuration allows distal end 34 of hawser line 30 to be hauled aboard and temporarily secured on a responding vessel without obstructing the central opening of hawser thimble 42. Thus, the central opening of hawser thimble 42 remains free of interferences and can be immediately connected to the proximal end of the para sea anchor main rode, or to the towline of a suitable towing vessel.
Referring now to FIG. 21, continuous bridle 202 may be secured on two sets of bitts on each side (port and starboard) of foredeck 230 of a disabled vessel such that first and second ends 206, 208 of continuous bridle 202 are disposed on each side of foredeck 230. Hawser bushing 210 is free to slide along continuous bridle 202 to ensure proximal end 32 of hawser line 30 is always balanced in the bight, such that there is near-equal load sharing between the port and starboard bitts, regardless of how evenly continuous bridle 202 was apportioned on each side of foredeck 230, and regardless of the angle of hawser line 30 relative to the heading of the disabled vessel. In other words, this arrangement equalizes the load distribution across foredeck 230 regardless of the exact points of attachment of each end of continuous bridle 202 to the bitts on either side of foredeck 230.
Optionally in this embodiment, a high-strength synthetic line having a small diameter may be used as a safety line for a controlled initial deployment of retrieving system 12 and vessel attachment system 200 from foredeck 230 of the disabled vessel. The safety line features a spliced eye on one end and a bitter end on the other. After securing the eye splice over a cleat or other fitting on the vessel's foredeck, the bitter end may be reeved through central opening 212 of hawser bushing 210 and, after taking up slack, fully belayed on a cleat or deck fitting. This secures the hawser bushing 210 in the bight of the safety line. Upon deployment of retrieving system 12 and vessel attachment system 200 into the water, the safety line takes the initial load and prevents vessel attachment system 200 from being pulled overboard under its own weight. The safety line can then be used to slip hawser bushing 210 to its intended operating position forward of the bow, by removing wraps from the cleat or deck fitting. The ends of continuous bridle 202 can then be secured to the bitts on each side of the foredeck (port and starboard) and the safety line removed.
With reference to FIG. 22, para sea anchor system 232 (also referred to as anchor system 232) may include quick release member 234 at proximal end 88 of main rode 82. In one embodiment, quick release member 234 may be attached to second anchor shackle 100, which is attached to first anchor shackle 98 that is, in turn, secured to anchor thimble 96. Quick release member 234 may be a remotely actuated quick-disconnect device, such as a pelican hook. For example, quick release member 234 may be formed of a disc-type quick release towing hook, such as those commercially available from Mampaey Offshore Industries. Quick release member 234 may be remotely actuated, such as with a pneumatic signal, a hydraulic signal, or an acoustic signal. An acoustic release mechanism may allow quick release member 234 to be remotely actuated without the need for a secondary line required for pneumatic and hydraulic systems.
Referring to FIGS. 23 and 24, anchor system 232 may be secured to vessel attachment system 200. In one embodiment, shackle 236 (shown in FIGS. 22 and 24) may be attached to quick release member 234 of anchor system 232 and to shackle 236 to secure anchor system 232 to vessel attachment system 200. In another embodiment, shackle 236 may be attached directly to hawser thimble 42. In either embodiment, the connection through quick release member 234 allows hawser line 30 to be quickly and remotely disconnected from anchor system 232, leaving distal end 34 of hawser line 30 recoverable in the water, and the connection to foredeck 230 of the disabled vessel intact. The quick-disconnect mechanism may engage anchor shackle 100 on one end and shackle 236 on its opposite end, and may be actuated by acoustic release or other remotely operated mechanism. Except as otherwise described, anchor system 232 may include the same features, specifications, and functions as anchor system 80.
An emergency ship arrest system including vessel attachment system 200 and anchor system 232 may be deployed in generally the same manner as described above in connection with vessel attachment system 10. Vessel attachment system 200 and retrieving system 12 may be delivered to a disabled vessel by aircraft or boat using a line-throwing appliance. First and second ends 206 and 208 of continuous bridle 202 may be attached to the foredeck of a disabled vessel as shown in FIG. 21. With vessel attachment system 200 secured to a disabled vessel and retrieving system 12 attached to hawser thimble 42 in the water, a responding vessel may be positioned near buoys 60 and 62 of retrieving system 12. Retrieving system 12 may be recovered on the responding vessel, and retrieving shackle 64 may be disconnected from strap eye 216 of vessel attachment system 200 (or the grommet in the alternate embodiment). Anchor system 232 may then be attached to hawser line 30. For example, shackle 236 may be attached to hawser thimble 42, and quick release member 234 may be attached to shackle 236.
Referring again to FIG. 23, anchor system 232 may then be deployed overboard into the anchor position, beginning with proximal end 88 of main rode 82. As the disabled vessel drifts downwind, it pulls on hawser line 30, main rode 82, and para sea anchor 84, thereby expanding canopy 104 into its open position to orient the disabled vessel into the direction of the wind and waves. Canopy 104 also slows the drift of the disabled vessel. If a quick disconnection is desired, a remote signal may be sent to quick release member 234 to disconnect main rode 82 from hawser line 30. In one embodiment, the remote signal may be an acoustic signal (i.e., a sound signal).
Each connection disclosed herein may include any combination of thimbles, bushings, grommets, shackles, line eyes, and quick release mechanisms providing the described connection. Each apparatus, system, and assembly described herein may include any combination of the described components, features, and/or functions. Each method described herein may include any combination of the described steps in any order, including the absence of certain described steps. Any range of numeric values disclosed herein shall be construed to include any subrange therein.
While preferred embodiments have been described, it is to be understood that the embodiments are illustrative only and that the scope of the invention is to be defined solely by the appended claims when accorded a full range of equivalents, many variations and modifications naturally occurring to those skilled in the art from a review hereof.
Patent Application
20170361906
