Anchor deployment and retrieval system for catamarans

Abstract

Disclosed is an anchor deployment and retrieval system for a catamaran comprising a windlass, an anchor chain connected to an anchor, a chain roller for rolling the anchor chain when operating the windlass for deploying or retrieving the anchor, a plurality of proximity sensors arranged such as to determine whether, at a predetermined height above water line, the anchor chain is within or outside of an allowed range, while the anchor chain is deployed or retrieved, and a controller configured to automatically pause operation of the windlass at least during anchor retrieval if the anchor chain is determined to be outside of the allowed range and to continue or resume operation if the anchor chain is determined to be or to be returned within the allowed range. A respective automated method of deploying and / or retrieving an anchor is also disclosed.

Description

Field of the invention

[0001] The present disclosure relates to an anchor deployment and retrieval system for a catamaran, to a catamaran comprising the anchor deployment and retrieval system and to a method of deploying and / or retrieving an anchor.Background

[0002] Catamarans are marine vessels comprising two hulls spaced apart and a bridge deck connecting the two hulls, including a foredeck. They typically also comprise an anchor deployment and retrieval system comprising a windlass located on the foredeck, an anchor chain connected to an anchor and operatively engaged with the windlass and a chain roller located also on the foredeck for rolling the anchor chain when operating the windlass for deploying or retrieving the anchor. The windlass typically comprises an electric motor operated by means of an electronic command, either wired or wireless, located either on the foredeck, typically within sight of the anchor chain and / or located at the helm station.

[0003] Deploying the anchor typically comprises stopping movement of the vessel on a selected spot with the bow directed upwind, starting deploying the anchor by operating the windlass in one direction and when the anchor reaches the bottom of the sea starting moving slowly in reverse and / or letting the wind cause a reverse movement while continuing deploying the chain and trying to maintain the bow upwind, until a sufficient length of chain has been deployed, typically for a length corresponding to at least three times and up to seven times or more the height between the chain roller and the see bottom at the location where the anchor is dropped. Once an appropriate length of chain has been deployed, the chain is typically engaged with a bridle. A bridle is basically a line having a port-side end fixed to a port-side bow eye-bolt or cleat or the like and a starboard-side end fixed to a starboard-side bow eye-bolt or cleat or the like respectively and a central engagement tool designed to be manually engaged and disengaged with the chain at any desired position. Once the bridle has been engaged with the chain, the chain is further deployed until the tension is transferred from the windlass to the bridle. The bridle serves two main purposes on a catamaran. One purpose is that to prevent tensional strain on the windlass while at anchor thus preventing damaging the windlass and eventually loosing hold on the chain. Another purpose is that to achieve a stabilizing effect while at anchor by preventing the catamaran from excessive swings, which besides being uncomfortable for living onboard may also cause the chain to hit and damage the hulls and the chain roller. The length of the chain being deployed can be determined either visually, e.g. by signs or marks, e.g. color marks at regular chain segments, e.g. every 10 m, and / or by an automatic chain counter. In order to ensure that the anchor has firmly gripped to the sea bottom it is a good practice to apply a sufficient pulling force to the deployed chain by increasing the propulsion power in reverse up to or near to the maximum power. It is recommended to perform this operation after engaging the bridle in order to prevent damage to the windlass. If the anchor has gripped firmly and sufficient length of the chain has been deployed, the vessel will maintain a stationary position even under increased power. If that is not the case, the anchor may have to be retrieved and the entire operation repeated, eventually starting at a different spot.

[0004] Retrieving the anchor typically comprises operating the windlass in the opposite direction while moving the catamaran forward, shortly pausing when the bridle tool is in proximity of the chain roller in order to disengage the bridle from the chain and then continuing retrieving the chain. In doing so, it is important to steer the catamaran such as to maintain the chain as close as possible aligned with the longitudinal axis of the catamaran, in order e.g. to roll smoothly on the chain roller without lateral friction and / or in order to prevent the chain from hitting one of the hulls. It is also important to control the forward speed such as to be about the same as the speed of chain retrieval in order e.g. to prevent running ahead while leaving the chain behind under the foredeck and / or to prevent applying excessive tensional force to the windlass and overloading the windlass motor, and risking damaging the windlass. Also, after prolonged stay and varying wind conditions, the anchor chain can lay with different chain segments at different angles, different from a straight line with the bow of the boat possibly pointing in a direction different from that of the anchor. It is thus not unusual that during retrieval the anchor chain is suddenly at a completely different angle, e.g. aft below the foredeck and / or biased towards one of the hulls. Thus, retrieving the anchor may require continuous steering and propulsion adjustments, while ideally the chain is maintained in an about vertical or upright position during retrieval. Also, operation of the windlass should be stopped immediately as soon as the anchor is fully retrieved in order to prevent abrupt bumping of the anchor into the chain roller, potentially causing damage to both the chain roller and the windlass.

[0005] One way of preventing overloading the windlass is to regulate the clutch of the windlass. This method however, cannot prevent damage to the chain roller and to the hulls, when the anchor chain is biased sideways for example. Also, when the maximum load that the clutch can hold is reached, the anchor chain can run free and control over the length of chain being deployed or retrieved may be at least temporarily lost, eventually reaching the end of the anchor chain.

[0006] Both anchor deployment and retrieval can thus be very challenging for a single person at the helm without sight of the anchor chain, even if the windlass operation command is located at the helm, since the anchor chain is typically not visible from the helm. If the windlass operation command is located on the foredeck, this is even more challenging for a single person. A second person on the foredeck is thus typically required for providing guidance to the person at the helm based on actual chain position relative to the vessel and preferably also for operating the windlass, and for engaging and disengaging the bridle. Communication between the person at the helm and the person on the foredeck is not always simple, e.g. due to noise caused by engines and wind and possibly lack of direct visual contact, thus the result of such communication is not always satisfactory, even because by the time indications are executed, also due to the inertia of the vessel and other environmental factors such as wind, current and waves that result in natural delays, the effect of the execution may be different from that expected by the person who provided the indication, or else the conditions have changed in the meantime. Moreover, a second person may not always be available for providing indications and assistance. Also, in some cases, the chain roller may be located at a position below the foredeck that makes the chain not easily or not at all visible even from the bow or foredeck.

[0007] There is thus a need for improved anchor deployment and retrieval systems that enable proper operation even by a single person.

[0008] US10850809B2 discloses for example a bow-mounted detecting system such as a camera and a display at the helm station for monitoring the position of the anchor chain from the helm during anchor deployment and retrieval. Such a system requires however visual interpretation of the displayed images which may not be reliable with a single camera looking forward. In particular, such a system may provide indication of lateral displacements of the chain either port side or starboard side but can be less reliable in determining the extent of longitudinal displacements. It is thus rather inefficient at preventing overloads of the windlass. Also, visual image interpretation while steering, regulating speed and operating the windlass commands may still be challenging. Moreover, a camera-based system may not be suitable in all conditions, e.g. at night, and might become dirty resulting in obscured or unclear imaging. Also, light reflection by the sun on the sea surface can cause too bright and saturated images making the camera system unsuitable.

[0009] WO2012148525A1 discloses an anchor deployment and retrieval system for catamarans that may also comprise a video camera or a proximity sensor mounted on each hull. In particular, the sensors are mounted forward relative to the chain roller and oriented slightly downwards, such as to provide indication of the position of the chain with respect to the hulls, when this is stretched forward and tensioned during deployment or retrieval. This system is unable to detect the chain as soon as the chain is positioned out, e.g. aft, of the range of detection of the sensors and is thus unable to prevent the chain from hitting the hulls when the chain is out of this detection range and / or to prevent damaging the chain roller. Moreover, this system is unable at preventing overloading the windlass.General description

[0010] In view of the above background, an anchor deployment and retrieval system is herein introduced, the operation of which is greatly facilitated, even by a single person, that is reliable in any situation, and in particular that can prevent damage to the windlass, to the chain roller and to the hulls. Another advantage is that the time for anchor deployment / retrieval can be reduced thereby saving also engine time and reducing power consumption. Other advantages will become apparent from the following description.

[0011] A catamaran comprising such anchor deployment and retrieval system and presenting the same advantages is herein also disclosed.

[0012] A method of deploying and / or retrieving an anchor from a catamaran and presenting the same advantages is herein also disclosed.

[0013] The term "anchor deployment and retrieval system" as used herein refers to an electronically controlled system for facilitating dropping / deployment of an anchor attached to an anchor chain along with a certain length of the chain and hoisting / retrieval of the deployed anchor chain and anchor attached thereto, based on sensors feedback.

[0014] The anchor deployment and retrieval system of the present disclosure is particularly suitable for a catamaran, the catamaran comprising a port-side hull and a starboard-side hull and a bridge deck between the two hulls, including a foredeck, the hulls having inner sides facing each other, the anchor deployment and retrieval system comprising a windlass located on the foredeck, an anchor chain connected to an anchor and operatively engaged with the windlass, and a chain roller on the foredeck for rolling the anchor chain when operating the windlass for deploying or retrieving the anchor. In particular, the anchor deployment and retrieval system further comprises a plurality of proximity sensors arranged either on the inner side of the port-side hull and of the starboard-side hull and / or below the foredeck and / or on a forward side of the foredeck, such as to determine whether, at a predetermined height above water line and below the chain roller, the anchor chain is within an allowed range or outside of the allowed range, while the anchor chain is deployed or retrieved by the windlass.

[0015] The anchor deployment and retrieval system further comprises a controller connected to the proximity sensors and to the windlass and configured to automatically pause operation of the windlass at least during anchor retrieval if the anchor chain is determined to be outside of the allowed range and to continue or resume operation if the anchor chain is determined to be or to be returned within the allowed range.

[0016] A "catamaran" is a multihull marine vessel, designed for navigation on water, such as ocean, sea, lake, river, regardless of its use, e.g. as a leisure vessel, or for commercial or dedicated use, e.g. as a charter yacht, a fishing boat, etc... In particular, the marine vessel of the present disclosure can be a motor and / or sailing catamaran comprising a port-side hull and starboard-side hull connected by a bridge deck including a foredeck. The foredeck may comprise at least in part a rigid structure aft and more typically a light and flexible area forward such as a tensioned net structure, also called trampoline. The foredeck may comprise a longitudinal structural beam located about centrally between the two hulls and / or a cross structural beam or the like located forward at the bow between the two hulls, eventually intersecting with and contributing to hold the longitudinal beam. Alternatively, the foredeck may be entirely rigid and structurally integrated with the hulls.

[0017] A "windlass" can be any suitable type of windlass, including windlass with vertical axis and windlass with horizontal axis, configured to deploy and retrieve any type of anchor chain that is operatively engaged with the windlass. In particular, the windlass may be a gypsy-type windlass including a wheel, also called barboten, with indentations, cavities or protrusions sized to match the size of a corresponding linked anchor chain in order to engage and translate the anchor chain in a forward or reverse direction (up or down) depending on the direction of operation of the windlass. In particular, the windlass typically comprises a windlass motor providing power to the windlass / barboten upon operation. The windlass motor may be an integral part of the windlass or may be externally connected to the windlass and is typically an electric motor, typically powered by DC current, e.g. connected to a 12 V, 24 V or 48 V power source. The power of the windlass motor may be dimensioned according to the size of the windlass and of the anchor-chain / anchor, which is related to the size of the marine vessel, e.g. from as little as 500 W up to several thousand W. The windlass motor may be wirelessly controlled using wireless communication technology. Alternatively, or in addition, the windlass motor may be electronically controlled through a hardwired connection.

[0018] The windlass is typically located on the foredeck about centrally between the hulls.

[0019] The term "on the foredeck" may include parts located above the foredeck and parts inside or below the foredeck or entirely above the foredeck, entirely inside the foredeck or entirely below the foredeck, as long as it is accessible from the foredeck.

[0020] The term "about centrally" includes locations biased more towards one of the hulls, but typically between the two hulls. Also, some vessels may have more than one, e.g. two windlasses, operatively engaged with respective anchor chains and anchors, e.g. one main windlass and anchor chain / anchor and one back-up windlass and anchor chain / anchor.

[0021] The anchor deployment and retrieval system may further comprise a chain counter, that is an electronic device configured to automatically determine the length of the anchor chain being deployed / retrieved, e.g. by counting the rotations of the windlass / barboten after calibration based on the known length of a chain segment / number of chain links translated upon one single rotation.

[0022] The anchor chain is typically deployed from and retrieved into an anchor-chain compartment, typically accessible also from the foredeck.

[0023] A "chain roller" is basically a wheel rotatable about a horizontal axis mounted to a support that can act as a guiding element, preventing the chain to roll or slide out of the wheel. The wheel can be made of rubber, metal, plastics or combinations thereof and typically comprises a concave circumference to facilitate guiding of the chain. The support can comprise a tilting and / or damping mechanism for at least partially reducing friction and the impact of abrupt pull forces on the wheel that could cause damage or deformations to the wheel itself or its axis, as well as to the support and the parts of the vessel that the support is fixed to. The tilting and / or damping mechanism is less effective at reducing the impact of lateral pull forces, which can still cause damage or deformations, especially to the support and guide element. The chain roller is typically located also on the foredeck, typically forward with respect to the windlass and with the axis of the wheel at an angle that results orthogonal to the anchor chain segment stretched between the windlass and the chain roller (when the anchor chain is centered on the chain roller), and at a height that results in the segment of the anchor chain between the windlass and chain roller to be about horizontal. The chain roller is typically but not necessarily about longitudinally in line with the windlass, meaning that the distance of the chain roller on the foredeck from the central longitudinal line of the vessel is about the same or as close as possible to the distance of the windlass from the central longitudinal line of the vessel. Minor deviations are possible according to some designs, e.g. in case of a double anchor deployment / retrieval system with two windlasses and two chain rollers.

[0024] The term "on the foredeck" with respect to the chain roller may include parts located above the foredeck and parts inside or below the foredeck or extending forward from the foredeck or entirely above the foredeck, entirely inside the foredeck, entirely below the foredeck or entirely extending forward from the foredeck.

[0025] A "proximity sensor" is a sensor able to detect the presence of nearby objects without physical contact, by emitting a signal and looking for changes in the field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets may require different sensors. Different types of proximity sensors are known in the art, e.g. inductive sensors, capacitive sensors, ultrasonic sensors, photoelectric sensors, magnetic sensors, to name only some. Any proximity sensor suitable for detecting an anchor chain hanging from a chain roller as a target can in principle be used. The required measurement range (up to a few meters) and the shape of the target object (narrow and long), rather than the material (metal), are the main factors in choosing the type of proximity sensor in this case. Thus, optical and / or acoustic proximity sensors may be more suitable than e.g. inductive, capacitive or magnetic proximity sensors, the acoustic sensors being preferred to the optical sensors because more independent of environmental conditions such as light, dirt, moisture.

[0026] In particular, according to the present disclosure, the proximity sensors are arranged either on the inner side of the port-side hull and of the starboard-side hull and / or below the foredeck and / or on a forward side of the foredeck, such as to determine whether, at a predetermined height above water line and below the chain roller, the anchor chain is within an allowed range or outside of the allowed range, while the anchor chain is deployed or retrieved by the windlass.

[0027] The "predetermined height" above water line and below the chain roller is not an exact height but rather a height range corresponding to the measurement range of the proximity sensors in the vertical direction, sufficiently high above the water line such that the water line is out of the measurement range of the proximity sensors and sufficiently low below the chain roller such as to have a sufficiently wide measurement range above the water line, e.g. about centrally between the water line and the chain roller or in the first half closer to the water line, although higher in the second half closer to the chain roller is also possible.

[0028] The "allowed range" is defined as the volumetric space in the height range of measurement within which the anchor chain is expected to be during deployment / retrieval because corresponding to an angle bias of the anchor chain from an ideal vertical direction or zero angle that is still acceptable. The allowed range is comprised between a threshold port-side distance and a threshold starboard-side distance from a vertical longitudinal plane passing through the chain line between the windlass and the chain roller and between a threshold forward distance and a threshold aft distance from a vertical lateral plane tangential to a forward side of the chain roller and orthogonal to the longitudinal plane. If the anchor chain is in the allowed range, it implies that the angle or direction of the anchor chain is such that there is no extra-tension and hence no overload on the windlass and on the chain roller, and also that the anchor chain is within a safety distance from the hulls, so there is no risk to damage any of the windlass, the chain roller and the hulls. On the other hand, if the anchor chain is outside of the allowed range, it implies that the angle bias of the anchor chain is too large possibly causing strong tension and overload of the windlass and of the chain roller and / or leading to the collision with one of the hulls.

[0029] In order to re-establish the correct position of the anchor chain, that is in order to bring the anchor chain from outside of the allowed range back into the allowed range it is advantageous to determine at least an approximate position of the anchor chain at the predetermined height, so that an appropriate corrective steering maneuver can be executed. For this purpose, it may be sufficient to determine for example in which quadrant outside of the allowed range the anchor chain is positioned, e.g. forward port side, forward starboard side, aft port side, aft starboard side and eventually a more precise position within each quadrant in order to determine a more precise corrective action.

[0030] Both the predetermined height, the allowed range and the number and arrangement of the proximity sensors can be variable for different catamaran models, designs and sizes and depend especially on the distance between the hulls, the position of the chain roller relative to the hulls and foredeck and the height of the chain roller above the water line.

[0031] The anchor deployment and retrieval system further comprises a controller connected to the proximity sensors and to the windlass and configured to automatically pause operation of the windlass at least during anchor retrieval if the anchor chain is determined to be outside of the allowed range and to continue or resume operation if the anchor chain is determined to be or to be returned within the allowed range.

[0032] The term "controller" as used herein encompasses any physical or virtual processing device and in particular a programmable logic controller running a computer-readable program or software provided with instructions to execute control operations related to the anchor deployment and retrieval system, and in particular automatically pausing and resuming operation of the windlass. Pausing operation may include pausing the current direction of operation and at least temporarily reversing the direction of operation before resuming the previous operation. Automatically pausing the current operation by the controller can contribute to prevent further overloading the windlass and chain roller, while at least temporarily reversing the operation can contribute to release the already accumulated tension in a much quicker manner than that achieved by a corrective steering action or in addition to the effect achieved by the corrective steering action. This automatic action has priority over any manual action meaning that any manual action, e.g. intended to continue the current operation, is overruled by the automatic action, which can be opposite to the intended action, e.g. by reversing the direction of operation of the windlass with respect to intended direction, e.g. down instead of up or vice versa. According to some embodiments, it could be however possible to disable the automatic function, e.g. in emergency situations, and manual control could be reestablished.

[0033] The anchor deployment and retrieval system may comprise electronic command means, e.g. located at the helm station, connected to the controller, wired and / or wireless, for operating the anchor deployment and retrieval system. The electronic command means may comprise for example manual functions for starting anchor deployment or retrieval and an automatic steering mode function.

[0034] According to an embodiment, the anchor deployment and retrieval system comprises at least one proximity sensor arranged in a manner that provides indication or confirmation that the anchor chain is or is returned within the allowed range. Alternatively, indication that the anchor chain is or is returned within the allowed range could be indirectly obtained by lack or loss of signal outside of the allowed range.

[0035] According to an embodiment, the controller is further configured to stop operation of the windlass during retrieval of the anchor as soon as signal loss by all proximity sensors on the inner sides of the hulls is determined indicating that the anchor is above measurement range of all proximity sensors or after a predetermined time from signal loss corresponding to the time needed for the anchor to be fully retrieved from the time signal is lost. This can prevent abrupt bumping of the anchor into the chain roller, potentially causing damage to both the chain roller and the windlass. According to an embodiment, the controller is connected to a chain counter to determine when the anchor has been fully retrieved, which then sends a stop signal to the windlass. However, as the chain counter can be inaccurate, an additional feedback based on the proximity sensors can increase the level of security.

[0036] According to an embodiment, the controller is configured to temporarily reverse direction of operation of the windlass at least during anchor retrieval if the anchor chain is determined to be outside of the allowed range and to resume the previous operation if the anchor chain is determined to be returned within the allowed range.

[0037] According to an embodiment, the anchor deployment and retrieval system comprises a chain-position-indication system, e.g. visual and / or acoustic, connected to the controller for indicating at least an approximate position of the anchor chain. The chain-position-indication system may include for example a display with any visual representation of the relative anchor chain position, at the predetermined height, with respect to a reference point or object representing e.g. the allowed range, a vertical projection of the chain roller, of the bow or the like. The visual representation may include for example a pictogram of the catamaran, with a virtual representation of the position of the anchor chain in any form and color, eventually dynamically changing in order to facilitate monitoring how the position changes over time or during a corrective steering action.

[0038] According to an embodiment, the anchor deployment and retrieval system comprises a steering-indication system connected to the controller for indicating a corrective steering action, determined by the controller, in order to bring the chain position from outside of the allowed range into the allowed range. The steering-indication system can include for example a display and / or one or a combination of visual and / or acoustic signs, including e.g. one or more arrows or signs, which indicate the direction in which to steer the vessel, eventually dynamically changing in order to facilitate monitoring and dynamically adapting the corrective steering action during execution. The steering-indication system can be combined with the chain-position-indication system such as e.g. to indicate the anchor chain position and the corrective steering action simultaneously, e.g. on the same display.

[0039] According to an embodiment, the controller, upon activation of an automatic steering mode, is configured to automatically execute a steering action such as to maintain the anchor chain within the allowed range during at least anchor retrieval and / or to execute a corrective steering action in order to bring the anchor chain from outside of the allowed range into the allowed range.

[0040] According to an embodiment, the controller is connected to a wind-indication system and is further configured to prevent windlass operation for anchor deployment unless the catamaran is oriented upwind and / or to automatically execute a steering action in order to bring and / or to maintain the catamaran oriented upwind before enabling the windlass to deploy the anchor and / or during anchor deployment.

[0041] According to an embodiment, the controller is configured to determine, after anchor deployment and bridle engagement, if the bridle has accidentally disengaged from the anchor chain, by determining if the anchor chain at the predetermined height becomes out of range, and to generate an alarm. Once the bridle has been engaged with the chain and extra chain is deployed in order to transfer the tension from the windlass to the bridle, the anchor chain at the predetermined height is supposed to stay within the allowed range, the segment of chain between the chain roller and the bridle being subject to the effect of gravity only. Sometimes it may however happen that the bridle is inadvertently disengaged from the anchor chain, e.g. as a consequence of improper engagement. If that occurs, tensional strain is again transferred to the anchor chain segment connected to the windlass, which in case of strong winds and tension, it can cause damage to the windlass and if the clutch of the windlass is regulated such as to prevent overload at increased tension, the anchor chain can inadvertently run free, possibly resulting in accidental collisions, e.g. with reefs or other boats, or grounding. Also, as the stabilizing effect of the bridle is lost, the catamaran may undergo excessive swings, which besides being uncomfortable for living onboard it may also cause the chain to hit and damage the hulls and also damage the chain roller. It can thus be very advantageous to determine if the bridle has been inadvertently disengaged as soon as it occurs. Since tensional strain is again transferred to the anchor chain in that case and the anchor chain is stretched, at least in case of sustained winds, its position at the predetermined height falls out of the allowed range and can be determined at once by the anchor deployment and retrieval system of the present disclosure according to an embodiment.

[0042] According to an embodiment, the proximity sensors are ultrasonic proximity sensors.

[0043] The basic physical principle of ultrasonic sensing is that the sensor sends out an ultrasonic pulse and receives a pulse back. Using the time difference between the sent and received signal, the distance of a target object can be determined. A common design is to build both the transmitter and the receiver into the same physical housing, although they can also be housed in separate units like certain photoelectric sensors with separate emitters and detectors. Housing the transmitter and receiver in the same unit simplifies installation and cabling. The ultrasonic pulse or sound wave is typically in the frequency range of 25 to 50 kHz, which is higher than the audible limit of human hearing (around 20 kHz). Ultrasonic sensors can be designed or configurable with different output beam, sensitivity and measurement range (from a few millimeters up to several meters) according to the specific application. They are robust and can be temperature-compensated making them usable in virtually all weather and environment conditions while still providing reliable measurement results. The results can be output as analog or switching signals. Various operating modes allow sensor adjustment for the specific application. They can offer functions like synchronization, multiplexing, measurement filters and adjustable output beam (sound cone) and are therefore flexible in usage. Synchronization and multiplexing can avoid mutual interference if wide fields are monitored with a plurality of sensors, like in this case. For this purpose, the sensors can be interconnected. In synchronization mode, the interconnected sensors can send and receive their respective ultrasonic pulses simultaneously to detect any objects in the covered area. With multiplexing, the interconnected sensors send and receive their respective ultrasonic pulses one after another in a defined sequence, hence the sensors cannot unintentionally receive an echo sent from a nearby sensor. This can be helpful in order to have an additional position determination of the target object, in this case of the anchor chain at the predetermined height.

[0044] According to an embodiment, the proximity sensors are arranged with an orientation and are configured with a measurement range and output beam such that are unable to come in detection of the water line and of any other part of the catamaran other than the anchor chain and / or anchor.

[0045] According to an embodiment, the measurement range and the output beam are adjustable (on location upon installation) or pre-configured depending on the catamaran design and especially on the distance between the hulls, the position of the chain roller relative to the hulls and foredeck, the height of the chain roller above the water line and the particular installation position of each individual sensor.

[0046] According to an embodiment, the anchor deployment and retrieval system comprises a plurality of ultrasonic proximity sensors interconnected in multiplexing mode, e.g. at least some or all ultrasonic proximity sensors covering a measurement range outside of the allowed range, or all proximity sensors.

[0047] According to an embodiment, the anchor deployment and retrieval system comprises a plurality of ultrasonic proximity sensors interconnected in synchronization mode, e.g. at least some or all ultrasonic proximity sensors, if any, covering the allowed range as measurement range, if more than one ultrasonic proximity sensor is used.

[0048] Depending on the total number of ultrasonic proximity sensors, the plurality of ultrasonic proximity sensors can be divided in smaller groups of fewer ultrasonic proximity sensors interconnected within the same group in either synchronization or multiplexing mode, each group covering a specific measurement range.

[0049] The present disclosure refers also to an automated method of deploying and / or retrieving an anchor from a catamaran, the catamaran comprising a port-side hull and starboard-side hull and a bridge deck between the two hulls, including a foredeck, the hulls having inner sides facing each other, a windlass located on the foredeck, an anchor chain connected to an anchor and operatively engaged with the windlass, a chain roller on the foredeck for rolling the anchor chain when operating the windlass for deploying or retrieving the anchor, a plurality of proximity sensors arranged either on the inner side of the port-side hull and of the starboard-side hull and / or below the foredeck and / or on a forward side of the foredeck, such as to determine whether, at a predetermined height above water line and below the chain roller, the anchor chain is within an allowed range or outside of the allowed range, while the anchor chain is deployed or retrieved by the windlass, the method comprising automatically pausing operation of the windlass at least during anchor retrieval if the anchor chain is determined to be outside of the allowed range and continuing or resuming operation if the anchor chain is determined to be or to be returned within the allowed range, by a controller connected to the proximity sensors and to the windlass.

[0050] According to an embodiment, the method comprises automatically stopping operation of the windlass during retrieval of the anchor as soon as signal loss by all proximity sensors on the inner sides of the hulls is determined indicating that the anchor is above measurement range of the proximity sensors or after a predetermined time from signal loss corresponding to the time needed for the anchor to be fully retrieved from the time signal is lost.

[0051] According to an embodiment, the method comprises temporarily and automatically reversing direction of operation of the windlass at least during anchor retrieval if the anchor chain is determined to be outside of the allowed range and resuming the previous operation if the anchor chain is determined to be returned within the allowed range.

[0052] According to an embodiment, the method comprises indicating, e.g. visually and / or acoustically, at least an approximate position of the anchor chain by a chain-position-indication system connected to the controller.

[0053] According to an embodiment, the method comprises indicating a corrective steering action, determined by the controller, in order to bring the chain position from outside of the allowed range into the allowed range by a steering-indication system connected to the controller.

[0054] According to an embodiment, the method comprises automatically executing a steering action such as to maintain the anchor chain within the allowed range during at least anchor retrieval and / or automatically executing a corrective steering action in order to bring the anchor chain from outside of the allowed range into the allowed range by the controller, upon activation of an automatic steering mode.

[0055] According to an embodiment, the method comprises automatically preventing windlass operation for anchor deployment unless the catamaran is oriented upwind and / or automatically executing a steering action in order to bring and / or to maintain the catamaran oriented upwind before enabling the windlass to deploy the anchor and / or during anchor deployment, by the controller connected to a wind-indication system.

[0056] According to an embodiment, the method comprises determining, after anchor deployment and bridle engagement, if the bridle has accidentally disengaged from the anchor chain, by determining if the anchor chain at the predetermined height becomes out of range, and generating an alarm.

[0057] Other and further objects, features and advantages will appear from the following description of exemplary embodiments and accompanying drawings, which serve to explain the principles more in detail.Brief description of the drawings

[0058] [Fig.1A] is a schematic top view of a catamaran comprising an anchor deployment and retrieval system according to the present disclosure, with the anchor chain in an allowed range during anchor deployment or retrieval. [Fig.1B] shows the same catamaran and anchor deployment and retrieval system of [Fig.1A], but with the anchor chain out of the allowed range during anchor deployment or retrieval. [Fig.2] shows schematically examples of possible positions of proximity sensors. [Fig.3A] is a schematic perspective front view of the same embodiment of [Fig.1A], with the anchor chain in the allowed range during anchor deployment or retrieval. [Fig.3B] is a schematic perspective front view of the same embodiment of [Fig.1B], with the anchor chain out of the allowed range during anchor deployment or retrieval. [Fig.4] shows schematically the same perspective front view of [Fig.3A]-3B with the anchor nearly fully retrieved. [Fig.5A] shows schematically an example of chain-position-indication system indicating the approximate position of the anchor chain in the allowed range during anchor retrieval. [Fig.5B] shows schematically the same example of chain-position-indication system of [Fig.5A] indicating the approximate position of the anchor chain outside of the allowed range. [Fig.6A] shows schematically another example of chain-position-indication system indicating a more precise position of the anchor chain in the allowed range during anchor retrieval. [Fig.6B] shows schematically the same example of chain-position-indication system of [Fig.6A] indicating a more precise position of the anchor chain outside of the allowed range. [Fig.7] shows schematically an example of steering-indication system indicating a corrective steering action in order to bring the chain position from outside of the allowed range into the allowed range. [Fig.8] shows schematically an example of steering-indication system overlayed to a chain-position-indication system. [Fig.9A] shows schematically an automatic steering mode automatically executing a steering action such as to maintain the anchor chain within the allowed range during anchor retrieval. [Fig.9B] shows schematically the same automatic steering mode of [Fig.9A] automatically executing a corrective steering action in order to bring the anchor chain from outside of the allowed range into the allowed range. [Fig.10A] shows schematically a wind-indication system in connection to the anchor deployment and retrieval system preventing windlass operation for anchor deployment if the catamaran is not oriented upwind. [Fig.10B] shows schematically the same embodiment of [Fig.9A] in automatic mode while maintaining the catamaran oriented upwind during anchor deployment. [Fig.11A] shows schematically a bridle correctly engaged with the anchor chain after anchor deployment and the anchor chain in the allowed range at measurement height. [Fig.11B] shows schematically a possible application of the anchor deployment and retrieval system for determining if the bridle has accidentally disengaged from the anchor chain, by determining if the anchor chain at the measurement height becomes out of the allowed range, and generating an alarm.

[0059] Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements whereas other elements may have been left out or represented in a reduced number in order to enhance clarity and improve understanding of the embodiments of the present disclosure.Detailed description

[0060] [Fig.1A] and [Fig.1B] taken together show schematically a top view of an exemplary catamaran 200 comprising a port-side hull 201 and a starboard-side hull 202, and a foredeck 205 located forward between the hulls 201, 202, the hulls 201, 202 having inner sides 203, 204 facing each other. The foredeck 205 comprises a rigid structure 206 aft and a light and flexible area forward such as a tensioned net structure, also called trampoline 207. The foredeck 205 also comprises a longitudinal structural beam 208 located about centrally, more towards port side in this example, between the two hulls 201, 202 and a cross structural beam 209 located forward at the bow between the two hulls 201, 202 intersecting with and contributing to hold the longitudinal beam 208. Many other designs are possible, e.g. the foredeck may be entirely rigid and structurally integrated with the hulls.

[0061] The catamaran 200 further comprises an anchor deployment and retrieval system 100 comprising a windlass 101 located on the foredeck 205 about centrally between the hulls 201, 202 (in fact biased more towards one of the hulls 201 in this example), an anchor chain 102 connected to an anchor (not shown in [Fig.1A]-1B) and operatively engaged with the windlass 101 and a chain roller 103 also on the foredeck 205, located forward at the bow in this example, for rolling the anchor chain 102 when operating the windlass 101 in order to deploy or retrieve the anchor. The windlass 101 comprises an electric motor 101' providing power to the windlass upon operation. The chain roller 103 is basically a wheel with a horizontal axis of rotation 104 mounted to a support 105 that can act as a guiding element, preventing the chain 102 to roll or slide out of the wheel. The wheel comprises a concave circumference to facilitate guiding of the chain 102. The chain roller 103 is located forward and longitudinally in line with respect to the windlass 101 and with the axis of rotation 104 orthogonal to the anchor chain segment stretched between the windlass 101 and the chain roller 103 (when the anchor chain 102 is centered on the chain roller 103), and at a height that results in the segment of the anchor chain 102 between the windlass 101 and chain roller 103 to be about horizontal. The anchor chain 102 is deployed from and retrieved into an anchor-chain compartment 210, accessible also from the foredeck 205.

[0062] The anchor deployment and retrieval system 100 further comprises a plurality of proximity sensors 111, 112 arranged on the inner side 203 of the port-side hull 201 and on the inner side 204 of the starboard-side hull 202 respectively, such as to determine whether, at a predetermined height 301-302 above water line 300 and below the chain roller 103, the anchor chain 102 is within an allowed range 120 or outside of the allowed range 120, while the anchor chain 102 is deployed or retrieved by the windlass 101. The proximity sensors 111, 112 are ultrasonic proximity sensors interconnected in multiplexing mode, in this example. With multiplexing, the interconnected sensors 111, 112 send and receive their respective ultrasonic pulses 111', 111", 112', 112" one after another in a defined sequence, hence the sensors 111, 112 cannot unintentionally receive an echo sent from a nearby sensor. This can be helpful in order to have a more precise position determination of the anchor chain 102 at the predetermined height 301-302.

[0063] The proximity sensors 111, 112 are arranged with an orientation and are configured with a measurement range and output beam such that are unable to come in detection of the water line 300 and of any other part of the catamaran 200 other than the anchor chain 102 and / or anchor.

[0064] The measurement range and the output beam may vary for each individual sensor 111, 112 based especially on the distance between the hulls 201, 202, the position of the chain roller 103 relative to the hulls 201 and foredeck 205, the height of the chain roller 103 above the water line 300 and the particular installation position of each individual sensor 111, 112.

[0065] The anchor deployment and retrieval system 100 further comprises a controller 150 connected to the proximity sensors 111, 112 and to the windlass 101 and configured to automatically pause operation of the windlass 101 at least during anchor retrieval if the anchor chain 102 is determined to be outside of the allowed range 120 and to continue or resume operation if the anchor chain 102 is determined to be or to be returned within the allowed range 120.

[0066] The allowed range 120 is comprised between a threshold port-side distance 121 and a threshold starboard-side distance 122 from a vertical longitudinal plane 125 passing through the chain line between the windlass 101 and the chain roller 103 (when the anchor chain 102 is centered on the chain roller 103) and between a threshold forward distance 123 and a threshold aft distance 124 from a vertical lateral plane 126 tangential to a forward side of the chain roller 103 and orthogonal to the longitudinal plane 125.

[0067] The anchor deployment and retrieval system 100 of this embodiment further comprises electronic command means 151, located at a helm station 250, connected to the controller 150 for operating the anchor deployment and retrieval system 100. Electronic command means may be located additionally or in alternative on the foredeck 205 and / or may be portable and connected wireless to the controller 150 (not shown). The electronic command means 151 may comprise for example manual functions for starting anchor deployment 153 or retrieval 152 and an automatic steering mode function 154. The anchor deployment and retrieval system 100 further comprises a chain-position-indication system 155 for indicating at least an approximate position of the anchor chain 102 and / or a steering-indication system 156 for indicating a corrective steering action, determined by the controller, in order to bring the chain position from outside of the allowed range 120 into the allowed range 120 connected to the controller 150.

[0068] The anchor deployment and retrieval system 100 of this embodiment further comprises a wind-indication system 157 based on feedback from a wind indicator 159, connected to the controller 150, configured to prevent windlass operation for anchor deployment unless the catamaran 200 is oriented upwind and / or to automatically execute a steering action in order to bring and / or to maintain the catamaran 200 oriented upwind before enabling the windlass 101 to deploy the anchor and / or during anchor deployment 153.

[0069] The difference between [Fig.1A] and [Fig.1B] is that [Fig.1A] shows the anchor chain 102 in the allowed range 120 during anchor deployment 153 or retrieval 152 whereas [Fig.1B] shows the anchor chain 102 out of the allowed range 120 during anchor deployment 153 or retrieval 152. In the example shown in [Fig.1B] it can be noted in particular that the anchor chain 102 is biased forwards and towards the port-side hull 201. Also, the anchor chain segment stretched between the windlass 101 and the chain roller 103 is biased towards the port side. Tensional stress is built up both on the windlass 101 and on the chain roller 103. [Fig.1B] also shows the controller 150 automatically pausing operation (STOP) of the windlass 101 upon determining that the anchor chain 102 is outside of the allowed range 120, thus preventing building up even more tension, whereas [Fig.1A] shows the controller 150 continuing operation or resuming operation (GO) of the windlass 101 upon determining that the anchor chain 102 is or is returned within the allowed range 120. The controller 150 may be configured as shown in [Fig.1B] to temporarily reverse direction of operation of the windlass 101, at least during anchor retrieval 152, if the anchor chain 102 is determined to be outside of the allowed range 120 and to resume the previous operation if the anchor chain 102 is determined to be returned within the allowed range 120 ( [Fig.1A]).

[0070] With continued reference to [Fig.1A] and [Fig.1B] an automated method of deploying and / or retrieving an anchor from a catamaran 200 is also shown, the method comprising automatically pausing operation of the windlass 101, at least during anchor retrieval 152, if the anchor chain 102 is determined to be outside of the allowed range 120 and continuing or resuming operation if the anchor chain 102 is determined to be or to be returned within the allowed range 120, by the controller 150 connected to the proximity sensors 111, 112 and to the windlass 101. The method may comprise temporarily and automatically reversing direction of operation of the windlass 101 at least during anchor retrieval 152 if the anchor chain 102 is determined to be outside of the allowed range 120 and resuming the previous operation if the anchor chain 102 is determined to be returned within the allowed range 120.

[0071] [Fig.2] shows schematically examples of additional or alternative possible positions of the proximity sensors on the catamaran 200 connected to the controller 150 of the anchor deployment and retrieval system 100. In particular, the anchor deployment and retrieval system 100 may comprise proximity sensors 111, 112 arranged respectively on the inner side of the port-side hull 201 and of the starboard-side hull 202, proximity sensors 113 arranged on a forward side of the foredeck 205 looking forwards and downwards, proximity sensors 114 arranged below the foredeck 205 looking downwards, and proximity sensors 115 arranged below the foredeck 205 looking at the inner space between the hulls 201, 205, such as to determine whether, at a predetermined height above water line 300 and below the chain roller 103, the anchor chain 102 is within the allowed range 120 or outside of the allowed range 120, while the anchor chain 102 is deployed 152 or retrieved 153 by the windlass 101. The number and arrangement of the proximity sensors 111, 112, 113, 114, 115 can be variable for different catamaran models, designs and sizes and depend especially on the distance between the hulls 201, 202, the position of the chain roller 103 relative to the hulls 201, 205 and foredeck 205 and the height of the chain roller 103 above the water line 300. Also, the particular orientation and configuration, especially with respect to the measurement range and output beam (sound cone) are adjusted such that the proximity sensors 111, 112, 113, 114, 115 are unable to come in detection of the water line 300 and of any other part of the catamaran 200 other than the anchor chain 102 and / or anchor. In particular, the measurement range and the output beam may vary for each individual sensor 111, 112, 113, 114, 115 based especially on the distance between the hulls 201, 202, the position of the chain roller 103 relative to the hulls 201 and foredeck 205, the height of the chain roller 103 above the water line 300 and the particular installation position of each individual sensor 111, 112, 113, 114, 115.

[0072] [Fig.3A] is a schematic perspective front view of the same embodiment of [Fig.1A], with the anchor chain 102 in the allowed range 120 during anchor deployment or retrieval, where like features are given like numbers and for which the description is not repeated. In particular, in [Fig.3A], the three-dimensional nature of the allowed range 120 can be appreciated. Also, it can be better understood how the "predetermined height" above the water line 300 and below the chain roller 103 is not an exact height but rather a height range 301-302 corresponding to the measurement range of the proximity sensors 111, 112 in the vertical direction that is sufficiently high above the water line 300 such that the water line 300 is out of the measurement range of the proximity sensors 111, 112 and sufficiently low below the chain roller 103 such as to have a sufficiently wide measurement range above water line 300, e.g. about centrally between the water line 300 and the chain roller 103 or in the first half closer to the water line 300, although higher in the second half closer to the chain roller 103 is also possible. The arrangement of the proximity sensors 111, 112 can be also better appreciated in this perspective view.

[0073] [Fig.3B] is a schematic perspective front view of the same embodiment of [Fig.1B], with the anchor chain 102 out of the allowed range 120 during anchor deployment or retrieval. Again, like features are given like numbers and their respective description is not repeated here. Compared to [Fig.3A], it can be seen that at the predetermined height 301-302 the anchor chain 102 comes in the measurement range of a different proximity sensor 111 on the port-side, whereas signal is lost or weakened on the starboard-side. Thus, relative position and distance with respect to the allowed range 120 can be at least approximately determined. In particular, based on sensor feedback, the controller 150 is able to determine that the anchor chain 102 is biased forwards and towards the port-side hull 201, out of the allowed range 120, which also causes the anchor chain segment stretched between the windlass 101 and the chain roller 103 to be biased towards the port-side and results in tensional stress to be built up both on the windlass 101 and on the chain roller 103 / mount 105. In particular, as soon as the controller 150 determines that the anchor chain 102 is outside of the allowed range 120, the controller 150 automatically pauses operation (STOP) of the windlass 101, thus preventing building up even more tension, and may even temporarily reverse direction of operation of the windlass 101, at least during anchor retrieval, in order to release the tension that has already been built-up. Operation or the previous operation is then automatically resumed (GO) as soon as it is determined that the anchor chain 102 is returned within the allowed range 120 ([Fig.3A]).

[0074] [Fig.4] shows schematically the same perspective front view of [Fig.3A]-3B with the anchor 106 nearly fully retrieved. In particular, the controller 150 is also configured to stop operation of the windlass 101 during retrieval of the anchor 106 as soon as signal loss by all proximity sensors 111, 112 on the inner sides 203, 204 of the hulls 201, 202 is determined indicating that the anchor 106 is above measurement range of the proximity sensors 111, 112 or after a predetermined time from signal loss corresponding to the time needed for the anchor 106 to be fully retrieved, i.e. with the shank of the anchor 106 partially inserted through the mount 105 of the chain roller 103 and the shank assuming a nearly horizontal position, from the time signal is lost.

[0075] [Fig.5A] and [Fig.5B] taken together show schematically an example of chain-position-indication system 155 connected to the controller 150 for indicating an approximate position of the anchor chain (patterned area). The same electronic command means 151 shown in [Fig.1A][Fig.1B] and [Fig.2] are also shown, comprising manual functions for starting anchor deployment 153 or retrieval 152 and an automatic steering mode function 154, connected to the controller 150. In this example, the function of anchor retrieval 152 is selected, by which the controller 150 starts operation of the windlass (not shown in [Fig.5A] - [Fig.5B]) resulting in the upward movement of the anchor chain. As long as the anchor chain is determined to be anywhere within the allowed range ([Fig.5A]), the controller 150 keeps operating the windlass in the same direction (GO). The area 120' of the chain-position-indication system 155 corresponding to the allowed range is also highlighted (patterned area). As soon as the anchor chain is determined to be outside of the allowed range ([Fig.5B]), the corresponding quadrant 121' (forward port side in this case) is highlighted (patterned area). Also, the controller 150 pauses (STOP) operation of anchor retrieval 152 of the windlass and may optionally temporarily reverse the direction of operation by operating the windlass in the opposite direction 153 resulting in the downward movement of the anchor chain. The chain-position-indication system 155 may comprise an acoustic signal source complementary to the visual representation, e.g. emitting an acoustic alert 158 when the anchor chain is outside of the allowed range.

[0076] [Fig.6A] and [Fig.6B] taken together show schematically a variant of the chain-position-indication system 155 of [Fig.5A]-5B indicating a more precise position 120", 121" of the anchor chain in the area 120' corresponding to the allowed range ( [Fig.6A]) or outside of the area 120' corresponding to the allowed range ([Fig.6B]), e.g. during anchor retrieval 152. It is also possible to monitor how the position changes over time 120‴, 121"'. The controller 150, the electronic command means 151 and the acoustic signal source work otherwise as already described for [Fig.5A]-5B.

[0077] [Fig.7] shows schematically an example of steering-indication system 156 indicating a corrective steering action 156', determined by the controller 150, in order to bring the chain position from outside of the allowed range into the allowed range, e.g. during anchor retrieval 152. In this example the corrective steering action 156' being indicated has the shape of an arrow pointing in the direction in which the catamaran should be steered. The arrow 156' may dynamically change pointing direction and for example also its length as the corrective action is being executed until eventually disappearing when the anchor chain is determined to be returned into the allowed range. In addition, the acoustic signal 158 may dynamically change intensity and / or frequency as the corrective action is being executed until eventually being turned off when the anchor chain is determined to be returned into the allowed range. While the corrective steering action is manually executed according to the indications of the steering-indication system 156, the controller 150 maintains the retrieval operation 152 paused (STOP) and may optionally temporarily reverse the direction of operation 153 as long as the anchor chain is determined to be outside of the allowed range and automatically resumes the previous operation 152 as soon as the anchor chain is determined to be returned into the allowed range (the resuming step not shown in [Fig.7]).

[0078] [Fig.8] shows schematically another example of steering-indication system 156 overlayed to a chain-position-indication system 155. In this example the chain indication system 155 is the same as that of [Fig.6A]- [Fig.6B], indicating a more precise position 121" of the anchor chain, outside of the allowed range in this case. The steering-indication system 156 is a variant of that shown in [Fig.7], with the difference that instead of an arrow with variable length, a different symbolism, e.g. a line of triangles, e.g. variable in number and / or color and variable pointing direction is used. These are just few examples of numerous possible intuitive representations. Moreover, knowing and being able to monitor the position of the anchor chain in real time by the chain-position-indication system 155 provides per se also a steering indication, making the steering-indication system 156 obsolete if a chain-position-indication system 155 is already implemented. The opposite is also true, i.e. if a steering-indication system 156 is implemented, the chain-position-indication system 155 may become obsolete (as e.g. in [Fig.7]), although the combination of both a chain-position-indication system 155 and a steering-indication system 156, especially if overlayed like in [Fig.8] can provide additional data.

[0079] [Fig.9A] and [Fig.9B] taken together show schematically an automatic steering mode, that upon activation 154, automatically executes a steering action 154' such as to maintain the anchor chain within the allowed range ([Fig.9A]) and / or a corrective steering action 154" in order to bring the anchor chain from outside of the allowed range into the allowed range ([Fig.9B]), during anchor retrieval 152 in this case. The position of the anchor chain 120", 120"', 121" could be monitored in real time by the chain-position-indication system 155, with respect to the area 120' that represents the allowed range, and that in this case is the same as that of [Fig.6A]-6B. Again, the controller 150 maintains the retrieval operation 152 paused (STOP) and may optionally temporarily reverse the direction of operation 153 while the anchor chain is determined to be outside of the allowed range ([Fig.9B]) and automatically resumes (GO) the previous operation 152 as soon as the anchor chain is determined to be returned into the allowed range ([Fig.9A]).

[0080] [Fig.10A] and [Fig.10B] taken together show schematically a wind-indication system 157 also connected to the controller 150, for preventing windlass operation for anchor deployment 153 if the catamaran is not oriented upwind, based on feedback from a wind indicator 159. In particular, the controller 150 is further configured to prevent (STOP) windlass operation for anchor deployment 153 if the catamaran is not oriented upwind ([Fig.10A]), eventually indicating the wind angle 159' relative to the catamaran heading 159" and optionally also the steering action 157' to be performed in order to bring the catamaran upwind, and / or to automatically execute a steering action 154 in order to bring 157'([Fig. 10A]) and / or to maintain 157" ([Fig.10B]) the catamaran oriented upwind before enabling (GO) the windlass to deploy the anchor and / or during anchor deployment 153. The position of the anchor chain 120" can be monitored ([Fig.10B]) during anchor deployment 153, by overlaying the wind-indication system 157 with a chain-position-indication system 155. The automatic steering action 157" aimed at maintaining the catamaran upwind during anchor deployment 153 can be combined as shown in [Fig.10B] with the automatic steering action 154', 154" seen also in [Fig.9A] - [Fig.9B] aimed at maintaining and / or bringing the anchor chain into the allowed range or area 120' in the chain-position-indication system 155.

[0081] Whenever an automatic steering action 154', 154", 157', 157" is executed, indication of the anchor-chain position, wind angle and steering direction may become obsolete, although it provides a way to monitor the automatic execution and eventually to disable the automatic mode and to manually intervene, e.g. in emergency situations.

[0082] [Fig.11A] shows schematically the same catamaran 200 comprising the same anchor deployment and retrieval system 100 as shown e.g. in [Fig.3A] and [Fig.3B]. [Fig.11A] further shows a bridle 211 correctly engaged 212 with the anchor chain 102 after anchor deployment. The anchor chain 102 is in the allowed range 120 at the measurement height 301-302 because after bridle engagement 212 sufficient chain length has been further deployed until the tension has been transferred from the windlass 101 to the bridle 211 and thus the extended segment of anchor chain 102 between the chain roller 103 and the bridle 211 is subject to the effect of gravity only.

[0083] [Fig.11B] in connection to [Fig.11A] shows schematically a possible further application of the anchor deployment and retrieval system 100 for determining if the bridle 211 has inadvertently disengaged 212' from the anchor chain 102, while at anchor. This is possible because in that case tensional strain is again transferred to the anchor chain segment 102 that was previously untensioned (as shown in [Fig.11A]). The anchor chain 102 therefore stretches out, at least in case of sustained winds, and its position at the predetermined height 301-302 gets out of the allowed range 120. The controller 150 can thus be configured to determine at once whether such a situation occurs while at anchor and can promptly generate an alarm. A "bridle watch mode" can be for example added to the electronic commands that can be activated for this purpose (not shown) after anchor deployment and bridle engagement.

[0084] In the preceding specification, numerous specific details have been described in order to provide a thorough understanding of the present disclosure. It will be apparent, however, to one having ordinary skill in the art that the specific details do not need to be implemented in order to practice the present teaching. In other instances, well-known materials or methods have not been described in detail in order to avoid obscuring the present disclosure.

[0085] Particularly, modifications and variations of the disclosed embodiments are certainly possible in light of the above description. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically devised in the above examples.

[0086] Reference throughout the preceding specification to "one embodiment", "an embodiment", "one example" or "an example", "in this case", means that a particular feature, structure or characteristic described in connection with the embodiment or example is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment", "in an embodiment", "one example" or "an example", "in this case" in various places throughout this specification are not necessarily all referring to the same embodiment or example.

[0087] Furthermore, the particular features, structures, or characteristics may be combined in any suitable combinations and / or sub-combinations in one or more embodiments or examples.

Claims

1. Anchor deployment and retrieval system (100) for a catamaran (200), the catamaran (200) comprising a port-side hull (201) and a starboard-side hull (202) and a bridge deck between the hulls (201, 202), including a foredeck (205), the hulls (201, 202) having inner sides (203, 204) facing each other, the anchor deployment and retrieval system (100) comprising - a windlass (101) located on the foredeck (205), - an anchor chain (102) connected to an anchor (106) and operatively engaged with the windlass (101), - a chain roller (103) on the foredeck (205) for rolling the anchor chain (102) when operating the windlass (101) for deploying (153) or retrieving (152) the anchor (106), - a plurality of proximity sensors (111, 112, 113, 114, 115) arranged either on the inner sides (203, 204) of the port-side hull (201) and of the starboard-side hull (202) and / or below the foredeck (205) and / or on a forward side of the foredeck (205), such as to determine whether, at a predetermined height (301-302) above water line (300) and below the chain roller (103), the anchor chain (102) is within an allowed range (120) or outside of the allowed range (120), while the anchor chain (102) is deployed (153) or retrieved (152) by the windlass (101), characterized in that, the anchor deployment and retrieval system (100) further comprising - a controller (150) connected to the proximity sensors (111, 112, 113, 114, 115) and to the windlass (101) and configured to automatically pause operation of the windlass (101) at least during anchor retrieval (152) if the anchor chain (102) is determined to be outside of the allowed range (120) and to continue or resume operation of the windlass (101) if the anchor chain (102) is determined to be or to be returned within the allowed range (120).

2. The anchor deployment and retrieval system (100) according to claim 1 wherein the controller (150) is further configured to stop operation of the windlass (101) during anchor retrieval (152) as soon as signal loss by all proximity sensors (111, 112) on the inner sides (203, 204) of the hulls (201, 202) is determined indicating that the anchor (106) is above measurement range of the proximity sensors (111, 112) or after a predetermined time from signal loss corresponding to the time needed for the anchor (106) to be fully retrieved from the time signal is lost.

3. The anchor deployment and retrieval system (100) according to any of the preceding claims wherein the controller (150) is configured to temporarily reverse direction of operation of the windlass (101) at least during anchor retrieval (152) if the anchor chain (102) is determined to be outside of the allowed range (120) and to resume the previous operation if the anchor chain (102) is determined to be returned within the allowed range (120).

4. The anchor deployment and retrieval system (100) according to any of the preceding claims comprising a chain-position-indication system (155) connected to the controller (150) for indicating at least an approximate position (120', 121', 120", 120‴, 121", 121‴) of the anchor chain (102).

5. The anchor deployment and retrieval system (100) according to any of the preceding claims further comprising a steering-indication system (156) connected to the controller (150) for indicating a corrective steering action (156', 156"), determined by the controller (150), in order to bring the anchor chain (102) from a position (121") outside of the allowed range (120, 120') into the allowed range (120, 120').

6. The anchor deployment and retrieval system (100) according to any of the preceding claims wherein the controller (150), upon activation of an automatic steering mode (154), is configured to automatically execute a steering action (154') such as to maintain the anchor chain (102) within the allowed range (120, 120') during at least anchor retrieval (152) and / or to execute a corrective steering action (154") in order to bring the anchor chain (102) from outside of the allowed range (120, 120') into the allowed range (120, 120').

7. The anchor deployment and retrieval system (100) according to any of the preceding claims wherein the controller (150) is connected to a wind-indication system (157, 159) and is further configured to prevent windlass operation for anchor deployment (153) unless the catamaran (200) is oriented upwind and / or to automatically execute a steering action (157', 157") in order to bring and / or to maintain the catamaran (200) oriented upwind before enabling the windlass (101) to deploy the anchor (106) and / or during anchor deployment (153).

8. The anchor deployment and retrieval system (100) according to any of the preceding claims wherein the controller (150) is configured to determine, after anchor deployment (153) and bridle engagement (212), if the bridle (211) has accidentally disengaged (212') from the anchor chain (102), by determining if the anchor chain (102) at the predetermined height (301-302) becomes out of the allowed range (120), and to generate an alarm.

9. A catamaran (200) comprising an anchor deployment and retrieval system (100) according to any of the claims 1 to 8.

10. An automated method of deploying and / or retrieving an anchor (106) from a catamaran (200), the catamaran (200) comprising a port-side hull (201) and starboard-side hull (202) and a bridge deck between the hulls (201, 202), including a foredeck (205), the hulls (201, 202) having inner sides (203, 204) facing each other, a windlass (101) located on the foredeck (205), an anchor chain (102) connected to an anchor (106) and operatively engaged with the windlass (101), a chain roller (103) on the foredeck (205) for rolling the anchor chain (102) when operating the windlass (101) for deploying (153) or retrieving (152) the anchor (106), characterized in that the catamaran (200) comprising a plurality of proximity sensors (111, 112, 113, 114, 115) arranged either on the inner sides (203, 204) of the hulls (201, 202) and / or below the foredeck (205) and / or on a forward side of the foredeck (205), such as to determine whether, at a predetermined height (301-302) above water line (300) and below the chain roller (103), the anchor chain (102) is within an allowed range (120) or outside of the allowed range (120), while the anchor chain (102) is deployed (153) or retrieved (152) by the windlass (101), and in that the method comprising automatically pausing operation of the windlass (101) at least during anchor retrieval (152) if the anchor chain (102) is determined to be outside of the allowed range (120) and continuing or resuming operation if the anchor chain (102) is determined to be or to be returned within the allowed range (120), by a controller (150) connected to the proximity sensors (111, 112, 113, 114, 115) and to the windlass (101).

11. The method according to claim 10 comprising automatically stopping operation of the windlass (101) during anchor retrieval (152) as soon as signal loss by all proximity sensors (111, 112) on the inner sides (203, 204) of the hulls (201, 202) is determined indicating that the anchor (106) is above measurement range of the proximity sensors (111, 112) or after a predetermined time from signal loss corresponding to the time needed for the anchor (106) to be fully retrieved from the time signal is lost.

12. The method according to claim 10 or 11 comprising temporarily and automatically reversing direction of operation of the windlass (101) at least during anchor retrieval (152) if the anchor chain (102) is determined to be outside of the allowed range (120) and resuming the previous operation if the anchor chain (102) is determined to be returned within the allowed range (120).

13. The method according to any of the claims 10 to 12 comprising indicating at least an approximate position (120', 121', 120", 120‴, 121", 121‴) of the anchor chain (102) by a chain-position-indication system (155) connected to the controller (150).

14. The method according to any of the claims 10 to 13 comprising indicating a corrective steering action (156', 156"), determined by the controller (150), in order to bring the anchor chain (102) from a position (121") outside of the allowed range (120, 120') into the allowed range (120, 120'), by a steering-indication system (156) connected to the controller (150), and / or automatically executing a steering action (154') such as to maintain the anchor chain within the allowed range (120, 120') during at least anchor retrieval (152) and / or automatically executing a corrective steering action (154") in order to bring the chain position (121") from outside of the allowed range (120, 120') into the allowed range (120, 120') by the controller (150), upon activation of an automatic steering mode (154).

15. The method according to any of the claims 10 to 14 comprising automatically preventing windlass operation for anchor deployment (153) unless the catamaran (200) is oriented upwind and / or automatically executing a steering action (157', 157") in order to bring and / or to maintain the catamaran oriented upwind before enabling the windlass (101) to deploy the anchor (106) and / or during anchor deployment (153), by the controller (150) connected to a wind-indication system (157, 159), and / or determining, after anchor deployment (153) and bridle engagement (212), if the bridle (211) has accidentally disengaged (212') from the anchor chain (102), by determining if the anchor chain (102) at the predetermined height (301-302) becomes out of the allowed range (120), and generating an alarm.

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