Parachute sea anchor

Abstract

This invention relates to a parachute sea anchor system deployable from a payload tube. There is provided a parachute sea anchor system suitable for launch from a vessel comprising at least one payload tube, said payload tube, comprising a payload canister, which comprises a parachute sea anchor, wherein said parachute sea anchor comprises a buoy tethered thereto, wherein said payload canister is attached to said vessel.

Claims

1. A parachute sea anchor system, the parachute sea anchor system being suitable for launch from a vessel, the parachute sea anchor system comprising at least one payload tube, said payload tube comprising a payload canister that includes a parachute sea anchor, wherein said parachute sea anchor comprises a buoy tethered thereto, wherein said parachute sea anchor comprises an anchor tether attached to said vessel, wherein the payload canister comprises an active release mechanism to allow the parachute sea anchor and the buoy to be deployed, the active release mechanism comprising a mechanical, explosive or electrical actuator to cause rupture and/or separation of the payload canister, and wherein the anchor tether comprises an electrical and/or optical conductor to allow transmission of activation commands to the active release mechanism of the payload canister.

2. The parachute sea anchor system according to claim 1, wherein the parachute sea anchor is affixed to the payload tube, or affixable to a structural member of the vessel.

3. The parachute sea anchor system according to claim 1, wherein the parachute sea anchor is attachable to the vessel via a severance device.

4. The parachute sea anchor system according to claim 1, wherein the parachute sea anchor comprises an anchor tether, said anchor tether connectable to said vessel.

5. The parachute sea anchor system according to claim 4, wherein the anchor tether is a rode, chain, line, or combination thereof.

6. The parachute sea anchor system according to claim 1, wherein the parachute sea anchor comprises a buoy tether, to connect the parachute sea anchor to the buoy, said buoy tether including an electrical and/or optical conductor.

7. The parachute sea anchor system according to claim 1, wherein the active release mechanism comprises a mechanical, explosive, or electrical actuator to cause rupture and/or separation of the payload canister.

8. The parachute sea anchor system according to claim 1, wherein the payload canister is ejectable from the payload tube by a positive pressure of fluid from the vessel.

9. The parachute sea anchor system according to claim 1, wherein the payload tube is configured to be a submerged payload tube under a body of water.

10. A method of preventing drift of a vessel, said vessel comprising at least one submerged payload tube under a body of water, the method including: securing the parachute sea anchor system of claim 1 to a structural member of the vessel or payload tube, and locating the payload canister within said payload tube; opening a watertight barrier to allow the payload tube to fill with water; causing a positive pressure of fluid, to eject the payload canister from the payload tube; and causing deployment of the parachute sea anchor from said payload canister.

11. The parachute sea anchor system according to claim 3, wherein the severance device is configured to cut and release the anchor tether, and hence release the parachute sea anchor from attachment to the vessel.

12. The parachute sea anchor system according to claim 11, wherein the severance device includes a cutter, blade, or shear device to cause the anchor tether to be cut.

13. The parachute sea anchor system according to claim 11, including a retraction system having a spool or winder, so as to allow retraction of the parachute sea anchor back into the payload tube.

14. The parachute sea anchor system according to claim 11, in which said anchor tether is also connected to the buoy, thereby tethering the buoy and parachute sea anchor together.

15. The parachute sea anchor system of claim 1, wherein the active release mechanism is configured to be activated responsive to the activation command transmitted via the electrical and/or optical conductor.

Description

(1) An arrangement of the invention will now be described by way of example and with reference to the accompanying drawings of which;

(2) FIG. 1a shows a parachute sea anchor system in a first state.

(3) FIG. 1b shows a parachute sea anchor system in a second deployed state.

(4) FIG. 2 shows a vessel with a parachute sea anchor systems deployed from a submerged payload tube.

(5) FIG. 3 shows a vessel with a parachute sea anchor systems deployed from a payload tube.

(6) Turning to FIG. 1a, there is provided a parachute sea anchor system 100 in a first state, suitable for launch from a vessel (not shown) comprising at least one submerged payload tube 101 below the water line 102. The submerged payload tube 101 comprises at least one watertight barrier 103, to keep the water outside of the payload tube, a fluid ejection system 104 to provide a high pressure fluid to ejection the payload canister 105. The payload canister 105 comprises a parachute sea anchor 106, and a buoy 107 tethered thereto. The payload canister 105 is attached to said vessel, via a severance device 108.

(7) In the present arrangement, said payload tube 101 and watertight barrier 103 are constructed from a suitable materials capable of withstanding differential pressure. The payload canister 105 comprises two portions 109 110 which together form an elongate cylinder that houses the parachute sea anchor 106 and buoy 107.

(8) The parachute sea anchor 106 may be made from nylon and may be reinforced by nylon tape across the canopy of said parachute sea anchor.

(9) To aid in the recovery of a stricken vessel the buoy 107 may comprise an emergency location beacon in the form of a transponder (not shown). This may alert others to the plight of the stricken vessel. The transponder will only activate on release of the parachute sea anchor and buoy into the water.

(10) The parachute sea anchor comprises an anchor tether 111 typically in the form of a resilient rode connecting to a suitable anchorage point on the vessel, such as the severance device 108. In the present arrangement, the anchor rode is made of a resilient material. The anchor tether 111 comprises a connection to the parachute sea anchor 106, and further must pass through or be detachably linked to at least one of the at least two portion 109 of the payload canister. It is desirable, that both portions 109, 110 become fully detached from the anchor tether, to avoid impeding the operation of the parachute sea anchor 106.

(11) The severance device 108 may be attached to a structural member of the vessel or part of the payload tube 105. In the present arrangement, the severance device is in the form of a mechanical cutter, which had been affixed to a removable anchor point 112 within the payload tube 101. After the use of the parachute sea anchor 106, the severance device 108 is activated to release the rode 111 and hence the parachute sea anchor 106 from connection with the vessel.

(12) The parachute sea anchor 106 also comprises a buoy tether 113, again typically in the form of a resilient rode to connect the parachute sea anchor 106 to the buoy 107. The buoy 107 ensures that the parachute sea anchor remains at the optimum position in the water 102.

(13) The payload canister 105 is formed from two portions 109 110 which together form an elongate cylinder, and in this arrangement are caused to be separated by a release mechanism 114 to allow the parachute sea anchor 106 and buoy 107 to be deployed. In this arrangement the release mechanism is a resistance fit between parts of the two portions 109 110 of the payload canister 105. The release mechanism 114 can include an active release mechanism 120 having a mechanical, electrical, or energetic device to cause rupture and/or separation of the payload canister. The anchor tether 111 includes an electrical and/or optical conductor 122 to allow transmission of activation commands to the active release mechanism 120 of the payload canister.

(14) In use the watertight barrier 103, in the form of a door, will be opened. The fluid ejection system 104, will be caused to function, ejecting the payload canister 105 clear of the payload tube and therefore vessel.

(15) Turning to FIG. 1b, there is provided a parachute sea anchor system 115 in a deployed state. In this arrangement, the parachute sea anchor system 115 has ejected the payload canister 105 from the payload tube 101, through the water watertight barrier 103. The use of a positive pressure of fluid, in the form of a water ram 104, ensures the payload canister is ejected clear of the payload tube 101 and vessel.

(16) In the present arrangement the release mechanism 114 is the resistance fit of portions 109 110 of the payload canister 105; which when overcome allows dispersal of said parachute sea anchor 106 and buoy 107. The force of the ejection from the payload tube and tensile force placed on portion 109, at the fully extension of the anchor tether will overcome the resistance fit. The parachute sea anchor 106 is inflated by the movement of the vessel such that the canopy inflates to provide a drag force on said vessel.

(17) Once the parachute sea anchor system 115 has provided its useful function, the severance device 108 releases the anchor rode 111, parachute sea anchor 106, buoy tether 113 and buoy 107, allowing the water watertight barrier 103 to be closed.

(18) Optionally, the payload tube 101 may be drained such that a second water watertight barrier (not shown) leading to the inside of a vessel may be opened to allow recovery of the removable anchor point 112.

(19) Turning to FIG. 2, there is provided a stricken vessel 201 comprising an underwater payload tube 202 having deployed the parachute sea anchor system 203 of FIG. 1a & 1b, in an underwater environment 204.

(20) Turning to FIG. 3, there is provided a stricken vessel 301 comprising a payload tube 302 that is located substantially above the surface of the sea. The deployed the parachute sea anchor system 303, is launched from the above surface payload tube. The payload canister (not shown) may be caused to open in the same fashion as described earlier, when it enters the underwater environment 304.