FIELD OF THE INVENTION

This invention relates in general to the field of marine mooring equipment and, in particular, to fairleads used for guiding a mooring line.

BACKGROUND OF THE INVENTION

Fairleads are an important tool in marine environments to guide a line, e.g. a rope, cable or chain, around an object, or to prevent lateral movement of the line. Some fairleads, known as moveable fairleads or rotating fairleads, are capable to rotating around a vertical axis to allow for changes in the direction of the line, without having an angle in the line.

Figure 1 is a schematic diagram showing a moveable fairlead 1 according to a prior art implementation. The moveable fairlead 1 is generally attached to the hull of a floating vessel such as, for example, a ship or floating platform. The moveable fairlead comprises a pair of brackets 10, a rotating support shaft 20 and a guide member 30.

The brackets 10 are for attachment to the floating vessel. For example, the brackets 10 may be welded to the hull of the floating vessel. The rotating support shaft 20 is coupled to the one or more brackets and configured to rotate with respect to the brackets 10. In some implementations, a single rotating support shaft 20 may extend vertically between the two brackets 10, or a pair of rotating support shafts may support the guide member 30 between them.

The guide member 30 typically includes a guide wheel 31 or a fixed guide channel for the cable or chain to pass through. The guide member 30 can include connecting plates 32 e.g. to connect the guide wheel with the rotating support shaft 20. The guide member is attached to the rotating support shaft(s) and is configured to rotate with the rotating support shaft(s). In this way, the fairlead 1 can rotate around a vertical axis and can guide the line without having an angle in the line.

A problem with these moveable fairleads arises where an offshore unit or floating vessel is not anchored and is moving or being moved, and one or more fairleads attached to an exterior of the hull are rotating freely. Freely rotating fairleads can often slam against the floating vessel, causing damage to the vessel and/or the fairlead itself due to the waves and movement of the vessel.

The present invention aims to address these problems in the state of the art.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a braking and locking module for a moveable fairlead on a floating vessel according to claim 1 .

According to a second aspect of the present invention, there is provided a method of retrofitting a braking and locking module to a moveable fairlead on a floating vessel according to claim 8.

According to a third aspect of the present invention, there is provided a method of locking a moveable fairlead on a floating vessel according to claim 9.

According to a fourth aspect of the present invention, there is provided a computer- readable medium according to claim 16.

Optional features are as set out in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example only, to the accompanying drawings, in which:

Figure 1 is a schematic diagram showing a moveable fairlead according to a prior art implementation;

Figure 2 is a schematic diagram showing a braking and locking module according to an embodiment;

Figure 3 is a schematic diagram showing a braking and locking module according to an embodiment;

Figure 4 is a schematic diagram showing a control system for a braking and locking module according to an embodiment;

Figure 5 is a side-elevation view showing a braking and locking module according to an embodiment; and

Figure 6 is a flowchart showing a method of locking a moveable fairlead according to an embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a braking and locking module for attachment to a moveable fairlead, and a method of locking the moveable fairlead. In particular, the braking and locking module reduces movement of the fairlead using a braking unit and locks the fairlead in place with a locking unit.

Figure 2 of the accompanying drawings shows a braking and locking module 100 for a moveable fairlead 1 on a floating vessel according to an embodiment. The braking and locking module 100 comprises a stopper plate 110, a braking unit 120, a locking unit 130 and a control unit 140.

The stopper plate 110 is configured for coupling to a rotating support shaft of the moveable fairlead 1. The stopper plate 110 is configured to be coupled in a position where an axis of the rotating support shaft is normal to the stopper plate 110. The stopper plate is of part-disc shape. The braking unit 120 is configured to engage with the stopper plate 110 to reduce a rotation of the moveable fairlead 1. The locking unit 130 is configured to engage with the stopper plate 110 to fix a position of the moveable fairlead 1. The control unit 140 is configured to arrest a rotation of the moveable fairlead 1 by activating the braking unit 120 and then activating the locking unit 130 when the rotation of the moveable fairlead 1 is substantially zero.

In this way, the braking and locking module 100 can stop and prevent swinging of a moveable fairlead 1 which has the potential to cause damage to the floating vessel or the fairlead 1 itself. By activating the braking unit 120 followed by the locking unit 130, the braking and locking module 100 can prevent undue wear on components. For example, by activating the braking unit 120 the module can reduce axial stress applied to the locking unit 130 during locking, and by activating the locking unit 130 the module can deactivate the braking module, reducing wear on braking elements.

The braking and locking module 100 can be provided in a modular form which can be retrofitted to an existing fairlead 1 in situ on a floating vessel. By engaging both of the braking unit 120 and the locking unit 130 with the stopper plate 110, the braking and locking module 100 can be produced with fewer parts, and retrofitted more easily by coupling only the stopper plate 110 to the moveable fairlead 1 . The braking and locking module 100 can be attached or retrofitted to any form of floating vessel, e.g. a ship or floating platform. The braking and locking module 100 can be made compatible with any of the large variety of moveable fairleads used on such floating vessels. For example, the braking and locking module 100 can be attached to a fairlead 1 with a guide wheel or guide channel, with or without connecting side plates, and with a single support shaft or a pair of support shafts supporting a guide member in between. The braking and locking module 100 can be made compatible with any other variation in form or size of moveable fairlead 1 .

Figure 3 of the accompanying drawings shows an internal view of the braking and locking module 100.

In some embodiments, the braking unit 120 may include one or more braking pads 121 configured to resist a rotational movement of the stopper plate 110 and a braking actuator 122 configured to move the braking pads 121 into a braking position where the braking pads 121 are in contact with the stopper plate 110. The control unit 140 may be configured to activate the braking actuator 122 to reduce the rotation of the moveable fairlead 1. The braking actuator 122 may be configured to reduce a rotation of the stopper plate 110 to zero or substantially zero.

In some embodiments, the locking unit 130 may include a locking pin 131 configured to pass through the stopper plate hole and a locking actuator 132 configured to move the locking pin 131 into a locked position where the locking pin 131 extends through one of one or more locking holes 111 in the stopper plate 110 (shown in Fig. 2). The control unit 140 may be configured to activate the locking actuator 132 to fix a position of the moveable fairlead 1 when the rotation of the moveable fairlead 1 is substantially zero. In some embodiments, the control unit 140 may be implemented by any suitable processor or processing unit.

The term "processor" may refer to a computational element that is operable to respond to and process instructions to perform operations. In an example, the processor may be a microprocessor, a microcontroller, a complex instruction set computing (CISC) microprocessor, a reduced instruction set (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or any other type of processing circuit, for example as aforementioned. The processor may be operated individually or as a part of a computation system.

In some embodiments, the control unit 140 may be remotely operable through a wired and/or wireless connection. For example, the control unit 140 may be operated from a central control point of the floating vessel, e.g. a bridge or cockpit. Alternatively, or in addition, the control unit 140 may be operated from a control point removed from the floating vessel. The control unit 140 may be remotely operable through a connection including any selection or combination of suitable wired connections (e.g. serial, parallel, USB, ethernet etc.) and wireless connections (e.g. Bluetooth, Wi-Fi, cellular network, satellite network etc.).

By remotely operating, the braking and locking module 100 can remove the need to reach the location of the fairlead 1 on an interior or exterior of the hull. In some cases, this can remove the need to raise the floating vessel out of the water, or reach the fairlead 1 underwater to control the braking and locking module 100. Where braking and locking modules 100 are installed on multiple fairleads, the remote operation allows the synchronised operation of some or all of the fairleads. In this way, the braking and locking module 100 can be more responsive, e.g. to changing weather conditions, or the operation can be more effectively synchronised to a mooring/relocating operation of the floating vessel. Alternatively, the control unit 140 may be operated directly, e.g. via a terminal or control panel co-located with the braking and locking module 100.

Figure 4 of the accompanying drawings shows a control system view of the braking and locking module 100 according to an embodiment.

In some embodiments, the braking unit 120 may include a brake pressure sensor 123. The brake pressure sensor 123 may be configured to measure a pressure on the braking pads 121. The brake pressure sensor 123 may be configured to measure a pressure applied between the braking pads 121 and the stopper plate 110. In some examples, the brake pressure sensor 123 may be arranged on a face of the braking pads 121 , or may be integrated with a shoe or shell of the braking pads 121. The brake pressure sensor 123 may be configured to provide a value for the pressure to the control unit 140. In some examples, the control unit 140 may be configured to control the braking actuator 122 to provide a specified level of pressure.

In some embodiments, the locking unit 130 may include a locking position sensor 133. In some examples, the locking position sensor 133 may be configured to detect a position of the locking pin 131 on the axis of travel of the locking pin 131. For example, where the locking pin 131 and locking actuator 132 are arranged vertically, the locking position sensor 133 may be configured to detect a vertical position of the locking pin 131. The locking position sensor 133 may be configured to provide a location of the locking pin 131 to the control unit 140. In some examples, the control unit 140 may be configured to control the locking actuator 132 to control a position of the locking pin 131.

In some embodiments, the locking position sensor 133 may include a pressure sensor configured to detect when the locking pin 131 is in contact with the stopper plate 110. In this way, the locking position sensor 133 can detect when the locking pin 131 is in an incorrect position. That is, the locking position sensor 133 can detect when the locking pin 131 is not in the locked position.

The control unit 140 may be configured to control the locking actuator 132 to stop moving the locking pin 131 in response to detecting that the locking pin 131 is in contact with the stopper plate 110. In this way, the control unit 140 can prevent damage to the locking pin 131. In some examples, the control unit 140 may be configured to automatically stop moving the locking pin 131 in response to detecting that the locking pin 131 is in contact with the stopper plate 110. The control unit 140 may be configured to partially or fully retract the locking pin 131 in response to detecting that the locking pin 131 is in contact with the stopper plate 110.

Alternatively, in some examples, the locking position sensor 133 can detect when the locking pin 131 is in the locked position. For example, the locking position sensor 133 may include a switch or a light gate arranged on a distal side of the stopper plate 110 from the locking actuator 132, or a limit switch installed at any point on the locking actuator 132. In this way, the locking pin 131 may engage with the locking position sensor 133 when the locking pin 131 has passed through the locking hole 111 , i.e. in the locked position.

In some examples, the locking position sensor 133 can detect a position of the locking pin 131 at any point along the axis of travel. In some examples, the locking position sensor 133 may be integrated with the locking actuator 132 to detect the actual position of the locking pin 131 , e.g. by detecting a pressure level within the locking actuator 132. In some examples, the locking position sensor 133 may include a camera for user confirmation of the locking pin 131 position.

In some embodiments, in response to determining that the locking pin 131 is not in the locked position, the control unit 140 may be configured to perform a repositioning process. The control unit 140 may be configured to control the braking actuator 122 to reduce the pressure on the braking pads 121 and allow the stopper plate 110 to rotate slowly. By reducing the pressure, without fully releasing the braking pads 121 , the stopper plate 110 can be allowed to rotate slowly without swinging freely. In some examples, the control unit 140 may reduce the pressure by a predefined value, to allow the stopper plate 110 to rotate. For example, the braking pressure may be reduced by, e.g. 5% or 10%. Alternatively, in some examples, the braking actuator 122 may be controlled to release the braking pads 121 by a predefined amount (e.g. braking force applied by the braking actuator 122) without measuring the applied pressure. For example, the braking force applied may be reduced by, e.g. 5% or 10%.

In some examples, the stopper plate 110 may be rotated by a natural swing of fairlead 1 in either direction, e.g. by waves, currents, or tension in the line acting on the fairlead 1. Rotation of the stopper plate 110 in either direction can cause the locking pin 131 to align with the next locking hole in that direction.

In some examples, pressure applied by the locking actuator 132 through the locking pin 131 may urge the stopper plate 110 to rotate. For example, a surface of the stopper plate 110 may be sloped towards the locking holes 111 such that pressure between the locking pin 131 and the stopper plate 110 exerts a turning force on the stopper plate 110.

In some embodiments, the braking and locking unit 130 may include a plate actuator 112 configured to rotate the stopper plate 110. In some examples, the control unit 140 may be configured to activate the plate actuator 112 to align the locking pin 131 with one of the locking holes 111 in the stopper plate 110.

In some examples, the plate actuator 112 may include a geared element. In some examples, the geared element may be driven e.g. by an electric motor. An edge of the stopper plate 110 may be formed to engage with the geared element. For example, a plurality of teeth may be formed at the edge of the stopper plate 110, such that rotation of the geared element causes the stopper plate 110 to rotate. Alternatively, in some examples, the plate actuator 112 may include a wheel or belt element configured to engage with the stopper plate 110. In some examples, the plate actuator 112 may be configured to engage with and disengage from the stopper plate 110, as required. In some examples, the plate actuator 112 may be engaged with the stopper plate 110 before reducing the pressure on the braking pads 121 .

The control unit 140 may be configured to reactivate the braking actuator 122 to reduce the rotation of the moveable fairlead 1. The braking actuator 122 may be configured to reduce a rotation of the stopper plate 110 back to zero or substantially zero.

In some embodiments, the braking and locking module 100 may include a plate position sensor 113. The plate position sensor 113 may be configured to provide a position of the stopper plate 110 to the control unit 140. In some examples, the control unit 140 may be configured to control the plate actuator 112 to control a position of the stopper plate 110.

In some examples, the plate position sensor 113 may be configured to detect an angular position of the stopper plate 110. For example, the plate position sensor 113 may include an optical or ultrasonic sensor configured to detect a plurality of 2D or 3D markings on the stopper plate 110. In some examples, a camera may be directed at the stopper plate 110 for confirmation of the plate position by a user. In some examples, the plate position sensor 113 may be configured to detect an alignment between stopper plate 110 and locking pin 131. For example, the plate position sensor 113 may include an optical sensor configured to detect a light source directed through one of the locking holes 111 or, alternatively, a light source reflected from the stopper plate 110 (i.e. when not aligned with the locking holes 111). In this way, the plate position sensor 113 can detect when the locking pin 131 is aligned with one of the locking holes 111.

In some examples, the control unit 140 may be configured to reactivate the braking actuator 122 based on the plate position sensor 113 detecting that the locking pin 131 is substantially aligned with one of the locking holes 111 in the stopper plate 110. In some examples, the control unit 140 may be configured to reactivate the braking actuator 122 based on the plate position sensor 113 detecting a predetermined angular movement of the stopper plate 110. In some examples, the control unit 140 may be configured to reactivate the braking actuator 122 after a predetermined period of time.

In some embodiments, the control unit 140 may be configured to determine that the stopper plate 110 has not moved, e.g. based on the plate position sensor 113, or determine that the locking pin 131 is not in the locked position, e.g. based on the locking position sensor 133. The control unit 140 may be configured to incrementally reduce the pressure on the braking pads 121 or the braking force applied by the actuator, e.g. in steps of 5%, until the control unit 140 determines that the stopper plate 110 has moved or the locking pin 131 has moved into the locked position. In some examples, by incrementally decreasing the pressure in this way, the control unit 140 can find a point at which the pressure applied by the locking actuator 132 through the locking pin 131 is sufficient to urge the stopper plate 110 to rotate.

The control unit 140 may be configured to reactivate the locking actuator 132 to fix a position of the moveable fairlead 1 when the rotation of the moveable fairlead 1 is substantially zero. In some examples, the control unit 140 may be configured to recheck the position of the locking pin 131 using the locking position sensor 133. If the locking pin 131 is not in the locked position it may be necessary to repeat the repositioning process.

The control unit 140 may be configured to reactivate the locking actuator 132 when the locking pin 131 is substantially aligned with one of the locking holes 111 in the stopper plate 110, using the plate position sensor 113.

In some examples, the control unit 140 may be configured to activate the locking actuator 132 when the locking pin 131 is substantially aligned with one of the locking holes 111 in the stopper plate 110, as part of the initial locking process, as follows:

The control unit 140 may activate the braking unit 120 to reduce the rotation of the moveable fairlead 1. In some examples, the rotation may be reduced to a slow speed, or, alternatively, reduced to zero and then released to allow the stopper plate 110 to rotate at a slow speed.

In some examples, the control unit 140 may be configured to monitor the rotation using the plate position sensor 113 described above, to detect when the locking pin 131 is aligned with one of the locking holes 111. In some examples, the control unit 140 may be configured to activate the plate actuator 112 described above to align the locking pin 131 with one of the locking holes 111 in the stopper plate 110.

The control unit 140 may be configured to control the braking unit 120 to reduce the rotation of the moveable fairlead 1 to zero when the locking pin 131 is aligned with one of the locking holes 111. The control unit 140 may be configured to activate the locking unit 130 unit when the rotation of the moveable fairlead 1 is substantially zero. In this way, by braking and locking a moveable fairlead 1 , the braking and locking module 100 can stop and prevent swinging of the moveable fairlead 1 which has the potential to cause damage to the floating vessel or the fairlead 1 itself.

In some embodiments, the control unit 140 is configured to control the braking actuator 122 to release the braking pads 121 when the locking pin 131 is in the locked position. In this way, the control unit 140 can prevent excess wear or power consumption by the braking unit 120.

In some embodiments, the control unit 140 may be configured to reposition the fairlead 1. For example, the fairlead 1 may be locked in a first position and it becomes necessary to move one or both of the floating vessel or mooring line. An angle of the mooring line may be changed and it becomes necessary to reposition the fairlead 1 accordingly.

The control unit 140 may be configured to activate the braking actuator 122 to prevent rotation of the moveable fairlead 1. That is, the braking unit 120 is activated before the locking unit 130 is deactivated. In this way, the braking unit 120 can prevent any axial stress which might be applied to the components of the locking unit 130 while unlocking the moveable fairlead 1 .

The control unit 140 may be configured to deactivate the locking unit 130. In some examples, the control unit 140 may control the locking actuator 132 to remove the locking pin 131 from the locking holes 111 in the stopper plate 110.

The control unit 140 may be configured to control the braking actuator 122 to reduce a pressure on the braking pads 121 and allow the stopper plate 110 to rotate slowly into a new position. The control unit 140 may be configured to reactivate the braking actuator 122 to reduce the rotation of the moveable fairlead 1.

The control unit 140 may be configured to reactivate the locking actuator 132 to fix the new position of the moveable fairlead 1 when the rotation of the moveable fairlead 1 is substantially zero.

In this way, the position of the moveable fairlead 1 can be changed in a controlled way. As the fairlead 1 in not fully released at any point during the repositioning process, the braking and locking unit 130 can prevent swinging of a moveable fairlead 1 which has the potential to cause damage to the floating vessel or the fairlead 1 itself.

Figure 5 of the accompanying drawings shows a braking and locking module 100 according to an embodiment. The braking and locking module 100 is shown from an interior of the hull. As shown, the hull comprises a socket 150 and the stopper plate 110 can extend through the socket 150 to the interior of the hull. A portion of the stopper plate 110 furthest from an attachment point of the stopper plate 110 may extend through the socket 150, i.e. a portion of the semicircular edge may be inside the hull of the floating vessel. The locking pin 131 and locking actuator 132 may be arranged below the stopper plate 110, as shown. Alternatively, the locking pin 131 and locking actuator 132 may be arranged above the stopper plate 110.

In some examples the socket 150 may be rectangular, as shown. The size of the socket 150 may be approximately the same as the portion of the stopper plate 110 extending through. In some examples, the socket 150 may be sized such that the full stopper plate 110 will not pass through. Alternatively, the socket 150 may be any shape or size which allows at least a portion of the plate to pass through. In some examples, the socket 150 may be already present on the hull, e.g. a maintenance hatch for the fairlead 1 , or the socket 150 may be cut into the fairlead 1 in order to retrofit the braking and locking module 100.

In some examples, the socket 150 may include a seal, e.g. a rubber seal arranged to fit tightly against the stopper plate 110 and allow rotational movement while preventing water from entering the hull. Alternatively, or in addition, the braking and locking module 100 may be separately sealed to prevent the ingress of water from inside the socket 150.

By extending the stopper plate 110 through the hull, and arranging the braking and locking module 100 in the interior of the hull, the braking and locking module 100 can be protected from seawater. For example, where the socket 150 and/or braking and locking module 100 is sealed or substantially sealed, the braking and locking module 100 can be isolated from seawater. In this way moving/mechanical parts of the braking and locking module 100 can be protected from corrosion. In addition, the braking and locking module 100 can be accessed more easily from the interior of the floating vessel, to maintain or repair components of the braking and locking module 100.

Alternatively, the braking and locking module 100 may be positioned on an exterior of the floating vessel e.g. where it is not possible to provide a socket 150 in the hull of the floating vessel. Individual components of the braking and locking module 100, e.g. the locking actuator 132 may be individually sealed to isolate them from seawater.

The stopper plate 110 includes one or more locking holes 111 extending through the stopper plate 110. The locking pin 131 is configured to pass through one of the locking holes 111 in the stopper plate 110. The locking actuator 132 is configured to move the locking pin 131 into a locked position where the locking pin 131 extends through one of the locking holes 111 in the stopper plate 110. In some examples, the stopper plate 110 may be configured to directly attach to the rotating support shaft. In some examples, the stopper plate 110 may be configured to attach to a guide member which is attached to the rotating support shaft and configured to rotate with the rotating support shaft. For example, the stopper plate 110 may be configured to attach to a connecting side plate which is coupled to the rotating support shaft, or supported between two rotating support shafts, and supports a guide wheel.

In some examples, the stopper plate 110 may be shaped for attachment to the moveable fairlead 1. For example, the stopper plate 110 may include a notch configured to fit around the rotating support shaft or any other rotating element of the moveable fairlead 1. The stopper plate 110 may be formed from steel, or any material suitable for marine construction.

In some embodiments, the stopper plate 110 may have a semi-circular form with a straight edge and a semi-circular edge. The stopper plate 110 may be configured to be coupled to the rotating support shaft at a mid-point of the straight edge. In some examples, the stopper plate 110 may be formed from any sector of a circle e.g. subtending an angle of more or less than 180, and configured to be attached at the centre point. In some examples, the stopper plate 110 may include a curved edge passing substantially through the central point.

In this way, the stopper plate 110 can be directly attached at a central point of rotation to a rotating element of the moveable fairlead 1. As the stopper plate 110 is rotated by movement of the moveable fairlead 1 , the stopper plate 110 can pass the locking pin 131 in a semi-circular arc. In some embodiments, the stopper plate 110 may include a plurality of locking holes 111. The locking holes 111 may be spaced along a circular arc of the stopper plate 110 arranged to be centred on the axis of the rotating support shaft. In this way, as the stopper plate 110 is rotated by movement of the moveable fairlead 1 , locking pin 131 will pass over each of the locking holes 111 in the circular arc.

In some examples, the semi-circular edge may be smooth or may be formed or shaped as required. For example, the semi-circular edge may be formed as an actuating surface, e.g. by forming a plurality of teeth, to allow the stopper plate 110 to be actuated.

In some embodiments, the braking and locking module 100 may further include a rectangular enclosure 160 attached to the socket 150. The enclosure 160 may be arranged to receive the stopper plate 110 within. The locking pin 131 may be configured to pass through an opening in an upper and/or lower wall of the enclosure 160.

In some examples, as shown, the braking pads 121 may be arranged in pairs above and below the stopper plate 110. The braking pads 121 may be formed from steel, or any material suitable for marine construction. In some examples, the material of the stopper plate 110 and the braking pads 121 may be selected to avoid galvanic pairs, to prevent excess corrosion.

Alternatively, in some embodiments a braking unit 120 of other type may be provided. For example, a braking element such as, for example, brake pads or a braking belt, may be configured to engage with an edge of the stopper plate or engage the rotating support shaft directly.

In some examples, the braking actuator 122 may include one or more hydraulic cylinders for each of the one or more braking pads 121 , or a hydraulic cylinder may be connected to multiple braking pads 121. The braking actuator 122 may include a shoe or shell configured to hold the braking pads 121. The shoe or shell may be connected to the hydraulic cylinder or any other form of actuator. By implementing hydraulic cylinders, the braking unit 120 is capable of exerting a sufficiently large braking force on the stopper plate.

By implementing a hydraulic braking actuator 122, the braking and locking module 100 can allow for electronic control of the braking mechanism through a direct or remote operation, substantially as described above with respect to the locking actuator 132. By using bi-directional hydraulics the braking actuator 122 can be activated or deactivated to control a braking function by moving the braking pads 121 towards or away from the stopper plate 110. Alternatively, a one directional hydraulic cylinder may be used and the braking actuator 122 may be biased to a deactivated position e.g. by one or more springs. In this way, a fail-off mechanism can be provided. If required, a fail-on mechanism can be provided by reversing the bias/actuation direction.

Alternatively, the braking actuator 122 may be implemented by other means e.g. an electric motor or pneumatic system. A manual actuator may be provided in addition to any other actuator as a failsafe in the event of a mechanical failure or power outage.

In some embodiments, the locking actuator 132 may include one or more hydraulic cylinders. The hydraulic cylinder allows for electronic control through a direct or remote operation. By using bi-directional hydraulics the locking actuator 132 can be activated or deactivated to control a locking function. Alternatively, a one directional hydraulic cylinder may be used and the locking actuator 132 may be biased to a deactivated position e.g. by one or more springs. In this way, a fail-off mechanism can be provided. If required, a fail-on mechanism can be provided by reversing the bias/actuation direction. In some examples, the hydraulic cylinders can be controlled to position the locking pin 131 at a specified point along an axis of travel. Alternatively, the locking actuator 132 may be implemented by other means e.g. an electric motor or pneumatic system. A manual actuator may be provided in addition to any other actuator as a failsafe in the event of a mechanical failure or power outage.

The enclosure 160 may include one or more pad openings in an upper and/or lower wall of the enclosure 160. Each pad opening may be configured to receive one of the one or more braking pads 121. The pad openings may include seals configured to surround the braking pads 121 or, alternatively, a shoe or shell of each brake pad, to isolate the braking actuator 122 from the interior of the enclosure 160.

The enclosure 160 may include one or more pin openings in an upper and/or lower wall of the enclosure 160. Each pin opening may be configured to allow the locking pin 131 to pass through the opening. In some examples, the enclosure 160 may include a pair of pin openings positioned in opposition on the upper and lower walls, such that the locking can pass fully through the enclosure 160. Alternately, in some examples, only one opening is provided such that the locking pin 131 can pass into the interior of the enclosure 160 to engage with the stopper plate 110.

In some embodiments, at least one of the pin openings includes a shaft seal. The shaft seal is configured to allow movement of the locking pin 131 through the pin opening and prevent water passing through the pin opening.

In this way, the mechanical components of the braking and locking module 100 such as, for example, the braking actuator 122 and locking actuator 132, can be isolated from seawater which may enter the hull through the socket 150.

Also provided is a moveable fairlead 1 , according to an embodiment. The moveable fairlead 1 comprises one or more brackets, a rotating support shaft, a guide member and a braking and locking module 100 substantially as described above.

The brackets are configured for attachment to a floating vessel. For example, the brackets may be welded to the hull of the floating vessel. The moveable fairlead 1 may be attached to any form of floating vessel, e.g. a ship or floating platform.

The rotating support shaft is coupled to the one or more brackets and configured to rotate with respect to the brackets. In some implementations, a single rotating support shaft may extend vertically between the two brackets, or a pair of rotating support shafts may support the guide member between them.

The guide member is attached to the rotating support shaft and is configured to rotate with the rotating support shaft. The guide member may include a guide wheel or a fixed guide channel for a cable or chain to pass through. In some examples, the guide member may include one or more connecting plates e.g. to connect the guide wheel with the rotating support shaft.

As described above, the stopper plate 110 of the braking and locking module 100 is coupled to the rotating support shaft in a position where an axis of the rotating support shaft is normal to the stopper plate 110.

In this way, the braking and locking module 100 can prevent swinging of a moveable fairlead 1 which has the potential to cause damage to the floating vessel or the fairlead 1 itself. The braking and locking module 100 can be provided in a modular unit which can be retrofitted to an existing fairlead 1 in situ on a floating vessel.

Also provided is a method of retrofitting a braking and locking module according to an embodiment. The method includes coupling the stopper plate of the braking and locking module to a rotating support shaft of the moveable fairlead in a position where an axis of the rotating support shaft is normal to the stopper plate.

In some embodiments, the method may include cutting a socket into the hull of a floating vessel. In some examples the socket may be rectangular. The size of the socket may be approximately the same as a portion of the stopper plate of the braking and locking module which is to be passed through the socket. In some examples, the socket may be sized such that the full stopper plate will not pass through. Alternatively, the socket may be any shape or size which allows at least a portion of the plate to pass through.

In some examples, the socket may include a seal, e.g. a rubber seal arranged to fit tightly against the stopper plate and allow rotational movement while preventing water from entering the hull. Alternatively, or in addition, the braking and locking module may be separately sealed to prevent the ingress of water from inside the socket.

Alternatively, in some examples, a socket may be already present on the hull, e.g. a maintenance hatch for the fairlead. Alternatively, in some examples, the braking and locking module may be positioned on an exterior of the floating vessel e.g. where it is not possible to provide a socket in the hull of the floating vessel. Individual components of the braking and locking module, e.g. the braking actuator, locking actuator and control unit may be individually sealed to isolate them from seawater.

In some embodiments, the method may include passing a portion of the stopper plate through a socket in a hull of the floating vessel, and positioning the locking pin and locking actuator adjacent to the portion of the stopper plate within the hull.

By extending the stopper plate through the hull, and arranging the braking and locking module in the interior of the hull, the braking and locking module can be protected from seawater. For example, where the socket and/or braking and locking module is sealed or substantially sealed, the braking and locking module can be isolated from seawater. In this way moving/mechanical parts of the braking and locking module can be protected from corrosion. In addition, the braking and locking module can be accessed more easily from the interior of the floating vessel, to maintain or repair components of the braking and locking module.

In some examples, the stopper plate may be configured to directly attach to the rotating support shaft. In some examples, the stopper plate may be configured to attach to a guide member which is attached to the rotating support shaft and configured to rotate with the rotating support shaft. For example, the stopper plate may be configured to attach to a connecting side plate which is coupled to the rotating support shaft, or supported between two rotating support shafts, and supports a guide wheel.

In some embodiments, the method may include attaching a rectangular enclosure to the socket. The enclosure may be arranged to receive the stopper plate within. The enclosure may be a rectangular box shape which is open at one side. The open side of the enclosure may be configured to attach to an interior side of the hull of the floating vessel, with the socket within the open side. In this way, the interior of the enclosure may be open to the exterior of the floating vessel.

The enclosure may include one or more pin openings in an upper and/or lower wall of the enclosure. The locking pin may be configured to pass through one or more of the pin openings. The pin openings may include seals configured to surround the locking pin, to isolate the locking actuator from the interior of the enclosure.

The enclosure may include one or more pad openings in an upper and/or lower wall of the enclosure. Each pad opening may be configured to receive one of the one or more braking pads. The pad openings may include seals configured to surround the braking pads or, alternatively, a shoe or shell of each brake pad, to isolate the braking actuator from the interior of the enclosure.

In this way, the mechanical components of the braking and locking module such as, for example, the locking actuator and braking actuator, can be isolated from seawater which may enter the hull through the socket.

Figure 6 of the accompanying drawings shows a method of locking a moveable fairlead according to an embodiment. As described above, the moveable fairlead may include a stopper plate coupled to a rotating support shaft in a position where an axis of the rotating support shaft is normal to the stopper plate, wherein the stopper plate includes one or more locking holes extending through the stopper plate; a braking unit comprising one or more braking pads; and a locking unit comprising a locking pin configured to pass through the stopper plate hole.

The method starts at step S11 .

At step S12, the method includes braking the stopper plate. In some embodiments, braking may include activating a braking actuator to reduce the rotation of the moveable fairlead, where the braking actuator is configured to move the braking pads into a braking position where the braking pads are in contact with the stopper plate. The braking actuator may be configured to reduce a rotation of the stopper plate to zero or substantially zero.

At step S13, the method may include attempting to lock the stopper plate. In some embodiments, attempting to lock the stopper plate may include activating a locking actuator to fix a position of the moveable fairlead when the rotation of the moveable fairlead is substantially zero, where the locking actuator is configured to move the locking pin into a locked position where the locking pin extends through one of the locking holes in the stopper plate. At step S14, the method may include repositioning the stopper plate. For example, it may be necessary to reposition the stopper plate in response to a lock pin position sensor determining that the locking pin is not in the locked position. In some examples, a locking position sensor may be configured to detect a position of the locking pin on the axis of travel of the locking pin. For example, where the locking pin and locking actuator are arranged vertically, the locking position sensor may be configured to detect a vertical position of the locking pin. In some examples, the locking actuator may be controlled to control a position of the locking pin.

In some examples, the locking position sensor can detect a position of the locking pin at any point along the axis of travel. In some examples, the locking position sensor may be integrated with the locking actuator to detect the actual position of the locking pin, e.g. by detecting a pressure level within the locking actuator. In some examples, the locking position sensor may include a camera for user confirmation of the locking pin position.

In some examples, the locking position sensor can detect when the locking pin is in the locked position. For example, the locking position sensor may include a switch or a light gate arranged on a distal side of the stopper plate from the locking actuator, or a limit switch installed at any point on the locking actuator. In this way, the locking pin may engage with the locking position sensor when the locking pin has passed through the locking hole, i.e. in the locked position.

In some embodiments, the locking actuator may be controlled to stop moving the locking pin, in response to a pressure sensor detecting that the lock pin is in contact with the stopper plate. For example, the locking position sensor may include a pressure sensor configured to detect when the locking pin is in contact with the stopper plate. In this way, the locking position sensor can detect when the locking pin is in an incorrect position. That is, the locking position sensor can detect when the locking pin is not in the locked position.

In this way, damage to the locking pin can be prevented. In some examples, the locking actuator may be controlled to automatically stop moving the locking pin in response to detecting that the locking pin is in contact with the stopper plate. The locking pin may be partially or fully retracted in response to detecting that the locking pin is in contact with the stopper plate.

In some embodiments, repositioning may include controlling the braking actuator to reduce a pressure on the braking pads and allow the stopper plate to rotate slowly. By reducing the pressure, without fully releasing the braking pads, the stopper plate can be allowed to rotate slowly without swinging freely.

In some examples, the pressure on the braking pads may be measured by a brake pressure sensor. The brake pressure sensor may be configured to measure a pressure applied between the braking pads and the stopper plate. In some examples, the brake pressure sensor may be arranged on a face of the braking pads, or may be integrated with a shoe or shell of the braking pads. In some examples, the braking actuator may be controlled to provide a specified level of pressure. In some examples, the braking actuator may be controlled to reduce the pressure by a predefined value, to allow the stopper plate to rotate. Alternatively, in some examples, the braking actuator may be controlled to release the braking pads by a predefined amount (e.g. actuator distance) without measuring the applied pressure.

In some examples, the stopper plate may be rotated by a natural swing of fairlead in either direction, e.g. by waves, currents, or tension in the line acting on the fairlead. Rotation of the stopper plate in either direction can cause the locking pin to align with the next locking hole in that direction. In some examples, pressure applied by the locking actuator through the locking pin may urge the stopper plate to rotate. For example, a surface of the stopper plate may be sloped towards the locking holes such that pressure between the locking pin and the stopper plate exerts a turning force on the stopper plate.

In some embodiments, a plate actuator may be activated to rotate the stopper plate to align the locking pin with one of the locking holes in the stopper plate.

In some examples, the plate actuator may include a geared element. In some examples, the geared element may be driven e.g. by an electric motor. An edge of the stopper plate may be formed to engage with the geared element. For example, a plurality of teeth may be formed at the edge of the stopper plate, such that rotation of the geared element causes the stopper plate to rotate. Alternatively, in some examples, the plate actuator may include a wheel or belt element configured to engage with the stopper plate. In some examples, the plate actuator may be configured to engage with and disengage from the stopper plate, as required. In some examples, the plate actuator may be engaged with the stopper plate before reducing the pressure on the braking pads.

Next, the braking actuator may be reactivated to reduce the rotation of the moveable fairlead. The braking actuator may be configured to reduce a rotation of the stopper plate back to zero or substantially zero. In some embodiments, the braking actuator may be reactivated based on a plate position sensor.

In some examples, the plate position sensor may be configured to detect an angular position of the stopper plate. For example, the plate position sensor may include an optical or ultrasonic sensor configured to detect a plurality of 2D or 3D markings on the stopper plate. In some examples, a camera may be directed at the stopper plate for confirmation of the plate position by a user. In some examples, the plate position sensor may be configured to detect an alignment between stopper plate and locking pin. For example, the plate position sensor may include an optical sensor configured to detect a light source directed through one of the locking holes or, alternatively, a light source reflected from the stopper plate (i.e. when not aligned with the locking holes). In this way, the plate position sensor can detect when the locking pin is aligned with one of the locking holes.

In some examples, the braking actuator may be reactivated based on a plate position sensor detecting that the locking pin is substantially aligned with one of the locking holes in the stopper plate. In some examples, the braking actuator may be reactivated based on a plate position sensor detecting a predetermined angular movement of the stopper plate. In some examples, the braking actuator may be reactivated after a predetermined period of time.

At step S15, the method includes locking the stopper plate. In some embodiments, locking the stopper plate may include activating a locking actuator to fix a position of the moveable fairlead when the rotation of the moveable fairlead is substantially zero.

In some embodiments, the locking actuator may be reactivated after an attempt to lock and subsequent repositioning. In some embodiments, the locking actuator may be activated in response to a plate position sensor detecting that the locking pin is substantially aligned with one of the locking holes in the stopper plate. That is, there may be no repositioning required. In some examples, the stopper plate may be positioned to ensure alignment of the locking pin and a locking hole before activating the locking actuator.

In this way, by braking and locking a moveable fairlead, the method can stop and prevent swinging of the moveable fairlead which has the potential to cause damage to the floating vessel or the fairlead itself. In some embodiments, the braking actuator may be controlled to release the braking pads when the locking pin is in the locked position. In this way, excess wear or power consumption by the braking unit can be prevented.

In some embodiments, the method may include repositioning the fairlead. For example, the fairlead may be locked in a first position and it becomes necessary to move one or both of the floating vessel or mooring line. An angle of the mooring line may be changed and it becomes necessary to reposition the fairlead.

Repositioning may include activating the braking actuator to prevent rotation of the moveable fairlead. That is, the braking unit is activated before the locking unit is deactivated. In this way, the braking unit can prevent any axial stress which might be applied to the components of the locking unit while unlocking the moveable fairlead.

The locking unit may be deactivated. In some examples, the locking actuator may remove the locking pin from the locking holes in the stopper plate.

The braking actuator may reduce a pressure on the braking pads and allow the stopper plate to rotate slowly into a new position.

The braking actuator may be reactivated to reduce the rotation of the moveable fairlead.

The locking actuator may be reactivated to fix the new position of the moveable fairlead when the rotation of the moveable fairlead is substantially zero.

In this way, the position of the moveable fairlead can be changed in a controlled way. As the fairlead in not fully released at any point during the repositioning process, the braking and locking unit can prevent swinging of a moveable fairlead which has the potential to cause damage to the floating vessel or the fairlead itself.

The method finishes at step S16.

In some embodiments, the method may be recorded as a set of instructions on a computer-readable medium. The computer-readable medium may include instructions which, when executed by a processor, cause the processor to perform the method.

Although aspects of the invention herein have been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the scope of the invention as defined by the appended claims.