WO2016050324A1

WO2016050324A1 - Offshore mooring line systems and methods

Info

Publication number: WO2016050324A1
Application number: PCT/EP2014/071256
Authority: WO
Inventors: Lars OLAV MYHRVOLD
Original assignee: Verity Offshore
Priority date: 2014-10-03
Filing date: 2014-10-03
Publication date: 2016-04-07

Abstract

An offshore mooring line system comprising a mooring line (1), a floatable element (2) attached to the mooring line, a retaining mechanism (3) configured to retain the floatable element in a submerged retracted position, a receiver (4) configured to receive acoustic signals and a controller (5) configured to act on the retaining mechanism to selectively release the floatable element in response to a receipt of an acoustic signal by the receiver. The disclosure further relates to methods of mooring.

Description

Offshore mooring line systems and methods

The present disclosure relates to offshore mooring line systems and methods for offshore mooring.

BACKGROUND

Stern-on mooring of crafts, is widely used in tourist ports or berths. Such type of mooring is normally achieved by attaching the craft stern-first to a quay or pier by ropes fastened to suitable bitts or other fastening accessories and by attaching the bow to a normally submerged mooring rope. The mooring rope is kept in place by a suitable anchoring system.

The mooring line or rope can be recovered using a recovery line. The first end of the recovery line is attached to a mooring bollard situated and the second end is attached to the mooring line. The recovery line is generally recovered by the crew of the boat using a rod (and a sliding pulley) provided with a hook or simply a hook (either manual or automatic).

A problem with this kind of mooring system may be particularly that the mooring line may carry dirt that it has collected in the seabed (mud, seaweed, and other), and thus the deck of a boat can be soiled and even the person in charge of the operation may be injured.

It is also known to fix the mooring line to a buoy floating on the open water. The mooring rope may then be directly taken from the buoy to the deck of the boat. The development and implementation of offshore mooring line systems is becoming more and more important because ports or marinas can become very crowded. In order to increase the capacity of ports, offshore mooring (i.e. not directly connected to a quay or pier or similar) is encouraged.

A problem of this solution may be that during the mooring operation it is necessary to perform several maneuvers in order to approach the boat to the floating buoy, thus the steering mechanism of the boat may be hooked to the mooring line. This approach can be especially problematic in case of adverse meteorological conditions such a fog, heavy rain, or winds.

It is an object of the present disclosure to provide improved offshore mooring line systems and methods for offshore mooring.

SUMMARY

In a first aspect, an offshore mooring line system is provided. The mooring line system comprises: a mooring line, a floatable element attached to the mooring line, a retaining mechanism configured to retain the floatable element in a submerged retracted position and a receiver configured to receive acoustic signals. Furthermore, a controller configured to act on the retaining mechanism to selectively release the floatable element in response to a receipt of an acoustic signal by the receiver is provided.

Releasing a floatable element situated in a submerged retracted position (and thus a mooring line) using an acoustic signal is advantageous and is particularly suitable for offshore mooring. This way, the floatable element (and thus a mooring line) may be brought to the surface of the sea. Once the floatable element is on the surface of the sea, the mooring line may be easily recovered by simply picking up the floatable element and lifting it on the boat. Soiling of the deck of the ship can be avoided. Furthermore, the floatable element (and thus the mooring line) is retained in a retracted position on or near the seabed until the mooring line attached to the floatable element is actually needed, thus problems of the steering mechanism of the boat getting hooked during the approach to the mooring line or difficult manoeuvers to avoid that problem may be avoided.

In second aspect, a method for offshore mooring by using the mooring line system is provided. The method comprises receiving an acoustic signal at the receiver of the mooring line system and acting on the retaining mechanism using the controller of the mooring line system in response to the receipt of the acoustic signal in order to release the floatable element of the mooring line system. Then, the mooring line attached to the floatable element of the mooring line system may be brought to the surface by lifting the floatable element.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting examples of the present disclosure will be described in the following, with reference to the appended drawings, in which:

Figure 1 a schematically shows an example of a mooring line system according to an implementation;

Figure 1 b schematically shows another example of a mooring line system;

Figure 1 c schematically illustrates yet a further example of a mooring line system;

Figure 1 d shows yet another example of a mooring line system;

Figure 2a schematically shows an example of a mooring line system in a submerged retracted position;

Figure 2b schematically shows the same mooring line system in an extended position.

DETAILED DESCRIPTION OF EXAMPLES

The figure 1 a schematically shows a mooring line system according to an example. A mooring line 1 may be provided. The mooring line 1 may have an elongated form. In this particular example, the mooring line 1 is shown in an extended position lying on or near the seabed.

The mooring line 1 may be a mooring rope, but could also be e.g. a mooring chain. A mooring rope may be made of polyethylene although some other materials are possible polypropylene, polyester, nylon, steel wire. The mooring line 1 may fix a boat's position relative to a point on the bottom of a waterway, thus the free movement of the boat on the water may be avoided.

A first end of the mooring line may be attached to the seabed using a seabed anchor base 30. The seabed anchor base 30 may comprise a skirt to penetrate the seabed soil. The seabed anchor base 30 may be filled with a suitable ballast material, such as high density concrete, iron ore or other suitable high density material. The seabed anchor base 30 may be made of e.g. stainless steel.

The mooring line 1 may be attached to a first support part 80a and a second support part 80b of the housing 80.

A recovery line 57 may be provided. The recovery line 57 may have attached a floatable element 2 e.g. a buoy at its first end. In this particular example, the recovery line 57 has been depicted in a rolled up state as it may be stored in the housing. The floatable element 2 is thus indirectly connected to the mooring line (through housing 80).

The floatable element 2 e.g. buoy may have a spherical form. The floatable element 2 may have a nylon reinforcement polyurethane skin, thus the resistance to water, oil, strong sunlight and/or abrasive surfaces may be improved. In an example, the buoy may be an ordinary tennis ball as long as its buoyancy is sufficient or it could even be a football. The floatable element 2 may have bright colours, so that it can easily be found when floated upwards. In this particular example, the floatable element 2 is shown in a retracted position on or near the seabed.

The floatable element 2 could further have lights or marks of different colours to assist the recognition of the floatable element 2, thus the danger of hitting the floatable element 2 especially during the night or bad weather conditions may be avoided or at least limited. Furthermore, such navigational aid systems may in some examples include sounds signals.

A retaining mechanism 3 may be provided. In this particular example, the retaining mechanism 3 may comprise a wrap element 55 e.g. a tie wrap and a cutting mechanism 56. The wrap element 55 may hold together the recovery line 57 attached to the mooring line 1 . The wrap element 55 could e.g. be made of plastic although some other materials are possible e.g. stainless steel coated with rugged plastics. Tie wraps are often used and readily available on e.g. sail boats.

The wrap element 55 may consist of a sturdy tape with an integrated gear rack. The tape may comprise at one end a ratchet within a small open case. Once the pointed tip of the cable tie has been pulled through the case and past the ratchet, it is prevented from being pulled back. Therefore, the loop may only be pulled tighter. This may allow wrapping together the recovery Iine57, thus the floatable element 2 (and thus the mooring line 1 ) may be kept in a retracted position.

As commented above, the retaining mechanism 3 may be provided with a cut mechanism 56. The cut mechanism 56 may be configured to cut the wrap element 55, thus the floatable element 2 (and thus the recovery line 57 and the mooring line 1 ) may be released. In this way, the recovery line may 57 be brought to the surface and it may be easily hooked by the staff of a boat.

The recovery line 57, together with the housing 80 and its components, and also the mooring line 1 connected to the housing may thus be lifted upwards. The crew on a boat may thus easily and securely access the mooring line.

The cut mechanism 56 may be a cutter configured to work underwater although some other cut mechanism are possible e.g. a plier mechanism, a scissor mechanism.

The cut mechanism 56 may be activated by a controller 5. The controller 5 may be enclosed in a casing for the controller e.g. a watertight casing. The housing 80 itself may be closed and watertight. The controller 5 may be provided with a receiver 4 e.g. an antenna situated on the top of the controller 5 although some other locations are possible. The controller may be activated using an emitter (not shown) that may be located on a boat e.g. the hull of a boat or along a pole. The emitter may send an acoustic signal to the controller 5. The controller 5 may receive the signal sent by the emitter using the receiver 4. The controller may activate the retaining mechanism 3, thus the wrap element 55 may be removed using the cut mechanism 56.

The illustrated cutting mechanism 56 may be battery operated. A user / proprietor would just have to ensure to occasionally replace the batteries.

In order to store the floatable element and the mooring line, a tie wrap may be reattached around the recovery line 57. Tie wraps are generally "lying around" on boats anyway, so that users would normally have easy access to tie wraps. Once the recovery line has been rolled up and put back in the housing, it can sink to the bottom of the sea. In this way, the housing 80 can be situated on the surface of the sea bed again and, due to the mass of the housing 80, the mooring line system may be sunk, thus the mooring line system may be re- situated on the seabed, ready for a new use.

Figure 1 b schematically illustrates another example of a mooring line system. The system works generally the same as described with reference to figure 1 a. The same or similar items have been denoted using the same reference signs.

In the example of figure 1 b, a different retaining mechanism is provided. The retaining mechanism in this example may be a housing 9 located on the seabed. The housing 9 may comprise a first support element 9a and a second support element 9b configured to be located on the seabed. The mooring line 1 is shown attached to the first support element 9a and the second support element 9b although the mooring line 1 may only be attached to the first support element 9a or the second support element 9b.

The housing 9 may also comprise an inner cavity 14 configured to enclose at least in part the floatable element 2. The housing may comprise one opening 10 and a cover 1 1 covering the opening 10. The cover 1 1 may be configured to be moved between an open position and a closed position. In this way, when the cover 1 1 is situated in an open position, the floatable element 2 (and thus the recovery Iine57 and the mooring line 1 ) may reach the surface of the sea. When the opening 10 is closed, the floatable element cannot float to the surface. The mooring line is thus maintained in a retracted position. In this situation, a watertight condition of the housing may be achieved.

The weight of the mooring line, the housing and its components is such that it remains on the sea bed.

A receiver as described before (not shown) may be provided. Upon receipt of an acoustic signal by the receiver, the cover 1 1 may be moved to an open position. The floatable element 2 may thus reach the surface of the water where it may be easily picked up. The floatable element 2 and the recovery line 57, together with the housing 9 and the mooring line 1 attached to it can thus be lifted to the boat.

When a boat wants to leave a mooring station again, the floatable element 2 may simply be stored inside the housing 9 and the housing can be closed. The combination of housing 9 and mooring line 1 may thus be heavy enough in order to sink the mooring line system to the bottom.

Figure 1 c illustrates yet a further example. In this case, an anchoring element 6 may be provided, which serves as a retaining mechanism. The anchoring element 6 may be configured to sink the floatable element 2 in a retracted position. The anchoring element 6 may be provided with a rope 31 and a winch mechanism (not shown). Upon receipt of an acoustic signal, the winch may unwind the rope 31 . The floatable element 2 may thus float to the surface and again be picked up.

In order to store the floatable element, a further acoustic signal could be sent in order to wind the up the winch and thus retract the floatable element. Contrary to the previously illustrated examples, the floatable element 2 in this case is directly connected to the mooring line (rather than indirectly through a housing).

The figure 1 d schematically shows a mooring line system according to further examples. Same reference numbers again denote the same elements as before. The structure and operation of the navigational aid 12, the housing 9, the controller 5, the receiver 4 and the mooring line 1 may be the same as described in the figure 1 a.

The floatable element 2 may have an inlet 7 configured to be connected to the retaining mechanism 4. The retaining mechanism 3 may comprise a pump 8, thus the floatable element 2 may be inflated and deflated using the pump mechanism 8. The pump 8 may be a submersible pump. The pump 8 may have a hermetically sealed motor housing coupled to the body of the pump, thus the pump 8 can work in underwater conditions.

The pump mechanism 8 may be situated on the seabed. This way, the floatable element 2 may be provided with buoyancy, and thus the mooring line 1 attached to the floatable element 2 can be brought to the surface of the sea in an easy way.

In this particular example, the pump mechanism 8 is shown in combination with a housing 9 with opening 10 and cover 1 1 as previously explained. Upon receipt of an acoustic signal, the floatable element may be inflated and at the same time, the housing may be opened.

In further examples, the pump mechanism 8 may by itself serve as a retaining mechanism by maintaining the floatable element deflated, i.e. in a state in which it does not have sufficient buoyancy to float to the surface.

The retaining mechanism 3 (and thus the pump 8) may be connected to the controller 5. The controller may be enclosed in a casing for the controller e.g. a watertight casing. The controller 5 may be provided with a receiver 4 e.g. an antenna situated on the top of the controller although some other locations are possible. The controller may be activated using a remote control (not shown) that may be located on a boat. The emitter (no shown) may send an acoustic signal to the controller 5. The controller may receive the signal sent by the emitter (no shown) using the receiver 4 and can then activate the retaining mechanism 3 (and thus the pump 8), thus floatable element 2 may be inflated or deflated. The controller may be located in a housing 9. The housing 9 may be watertight, thus the proper work of the controller maybe achieved.

In order to store the floatable element (and mooring line), the floatable element may be deflated and stored in the housing. The housing would thus sink to the sea bed again.

In some alternatives, the pump may be replaced by a gas pressure cylinder. In this particular case, the structure and operation of the system may be the same as described above. After each use, a user may simply replace a gas cylinder and the mooring system is ready for its next use.

In some further non-illustrated alternatives, the retaining mechanism may comprise a magnetic device (not shown) configured to open a fastener e.g. an eyelet or a hook by interrupting the magnetic field of the magnetic device. The fastener may be made of a ferromagnetic material comprising an associated latch magnet or a magnetic piece. Thus, the magnetic device may move the latch magnet operatively from a closed position to an open position. The fixation may be firm and strong in all directions, thus the floatable element 2 may be properly retained in the submerged retracted position.

In further non-illustrated alternatives, various mechanisms as hereinbefore described may be combined. E.g. a housing may be combined with a cutting mechanism for cutting a tie wrap.

In yet further non-illustrated alternatives, the retaining mechanism may be a spring loaded hook. The spring loaded hook may be designed with an interlocking tongue for a safe and secure connection. The spring loaded hook may be made of stainless steel or zinc.

Once again, upon receipt of an acoustic signal the spring loaded hook may be opened or closed by an actuator configured to move the interlocking tongue from a closed position to an open position or vice versa.

Additionally, the spring loaded hook may be provided with two small levers with embedded magnets configured to open the spring loaded hook by interrupting the magnetic field of the embedded magnets. This way, the reliability of the spring loaded hook retaining the floatable element may be improved.

The figure 2a schematically shows a mooring line system in a submerged retracted position. Same numbers denote the same elements as figure 1 a. A boat 40 may be situated offshore at the sea surface. The crew of a boat may need to moor the boat 40. This way, a member 21 of the crew of the boat may use a remote control 20. The remote control may activate an emitter 60 to emit an acoustic signal 22 in order to activate the controller 5 configured to act on the retaining mechanism 3. The emitter may be located at the hull of the boat, thus the acoustic signal may be sent from underwater. Alternatively, the emitter may be located at some other position of the boat or at a pole e.g. a boathook.

The controller 5 may have a receiver 4. The receiver 4 may comprise an underwater acoustic receiver. The underwater receiver may be a single frequency receiver although the underwater receiver may contain multiple receivers for different frequencies.

The recovery line 57 may be rolled up. The recovery line 57 may be kept in the rolled up position using the wrap element 55 of the retaining mechanism 3. The retaining mechanism 3 may comprise a wrap element 55 e.g. a tie wrap and a cut mechanism 56 configured to remove the wrap element 55.

The receiver 4 may receive the acoustic signal 22 emitted by the emitter 20. In response to the receipt of the acoustic signal 22, the controller 5 may act on the retaining mechanism 3, thus the cut mechanism 56 may be activated. The cut mechanism 56 of the retaining mechanism 3 may remove the wrap element and, therefore, the buoy may be released.

The housing 9 may comprise an inner cavity 14 configured to enclose at least in part the floatable element 2. The housing may comprise one opening 10 and a cover 1 1 covering the opening 10. The cover 1 1 may be configured to be moved between an open position and a closed position. In this particular example, the cover 1 1 may be moved to the open position upon receipt of the same acoustic signal, and thus the housing (and the floatable element 2 and the mooring line 1 ) may be properly brought to the surface.

Figure 2b schematically shows a mooring line system in an extended position. Once the retaining mechanism is operated, the floatable element 2 and thus the recovery line 57 and the mooring line 1 may be brought to the surface 41 of the sea. Consequently, the member 21 of the crew of the boat may use a pickup element e.g. a hook. In this way, the mooring line system (and thus the mooring line system) may be easily recovered.

The member 21 of the crew may attach one end of the mooring line 1 to a bitt (not shown) located on the deck. A tightening mechanism (not shown) may be provided e.g. a capstan. In this sense, the boat may be re-situated in a desired position once the mooring line 1 is attached.

Although only a number of examples have been disclosed herein, other alternatives, modifications, uses and/or equivalents thereof are possible. Furthermore, all possible combinations of the described examples are also covered. Thus, the scope of the present disclosure should not be limited by particular examples, but should be determined only by a fair reading of the claims that follow.

Claims

1 . An offshore mooring line system comprising:

a mooring line;

a floatable element connected to the mooring line;

a retaining mechanism configured to retain the floatable element in a submerged retracted position;

a receiver configured to receive acoustic signals; and

a controller configured to act on the retaining mechanism to selectively release the floatable element in response to a receipt of an acoustic signal by the receiver.

2. A system according to claim 1 , wherein the retaining mechanism comprises one or more anchoring elements configured to sink the floatable element.

3. A system according to any of claims 1 -2, wherein the floatable element comprises an inner part configured to be connected to a pump using an inlet, the pump being configured to inflate or deflate the floatable element.

4. A system according to any of claims 1 -2, wherein the retaining mechanism comprises a gas pressure cylinder connected to the floatable element and configured to inflate the floatable element.

5. A system according to any of claims 1 -4, wherein the retaining mechanism comprises a housing located on the seabed, the housing comprises an inner cavity configured to enclose at least in part the floatable element.

6. A system according to claim 5, wherein the mooring line is connected to the housing.

7. A system according to claim 5 or claim 6, wherein the housing comprises one opening and a cover covering the opening, wherein the cover is configured to be moved between an open position and a closed position.

8. A system according to any of claims 1 -7, wherein the retaining mechanism comprises a wrap element and an underwater cut mechanism configured to cut the wrap element.

9. A system according to any of claims 1 -8, wherein the retaining mechanism comprises a magnetic device configured to open a fastener by interrupting the magnetic field of the magnetic device.

10. A system according to any of claims 1 -9, wherein the retaining mechanism comprises a spring loaded hook.

1 1 . A system according to any of claims 1 - 10, further comprising a recovery line, and wherein the floatable element is connected to the recovery line, and the recovery line is connected to the mooring line.

12. A system according to any of claims 1 -1 1 , wherein the floatable element comprise one or more navigational aids for marine visibility and an electrical power device configured to supply electricity to the navigational aids.

13. A system according to any of claims 1 -12, further comprising a sensing device configured to collect the tensions and length of the mooring line and remotely transmitting the data collected to a processing unit.

14. A system according to any of claims 1 -13, wherein the mooring line is secured at a distal end to the seabed by engaging the mooring line with a stopper controllable by hydraulics.

15. A method for offshore mooring by using the mooring line system according to any of claims 1 -14 comprising: receiving an acoustic signal at the receiver of the mooring line system; acting on the retaining mechanism using the controller of the mooring line system in response to the receipt of the acoustic signal in order to release the floatable element of the mooring line system; and bringing to the surface the mooring line by lifting the floatable element.

16. A method according to claim 15, wherein acting on the retaining mechanism comprises cutting a wrap element using a cutting mechanism configured to work underwater.

17. A method according to any of claims15-16, wherein acting on the retaining mechanism comprises inflating the floatable element using a gas pressure cylinder connected to the floatable element.

18. A method according to any of claims 15-17, wherein acting on the retaining mechanism comprises interrupting the magnetic field of a magnetic device configured to open a fastener.

19. A method according to any of claims 15-18, further comprising after the mooring line is brought in the surface attaching the mooring line to a bitt of the deck of a boat and pulling the boat to a desired position using a tightening mechanism.

20. A method according to any of claims 15-19, further comprising repositioning the floatable element on the seabed using a pump configured to deflate the floatable element.

21 . A method according to any of claims 15-20, further comprising repositioning the floatable element on the seabed using an anchoring element to sink the floatable element.