The invention relates to a mast arrangement for handling, particularly for starting, landing, flying, steering and/or rescuing, an aerodynamic wing serving as auxiliary or additional drive of a watercraft, particularly a large-scale watercraft propelled by fossil fuels, the mast arrangement comprising a pole extending from a deck attachment point in a vertical direction, wherein the deck attachment point of the pole is located in a distance in horizontal direction from a deck tow point for attaching a tow rope of the aerodynamic wing transferring the tractive forces exerted by the aerodynamic wing to the watercraft.

A further aspect of the invention relates to a method for handling, particularly for starting, landing, flying, steering and/or rescuing, such an aerodynamic wing serving as auxiliary or additional drive of a watercraft, particularly a large-scale watercraft propelled by fossil fuels.

Aerodynamic wings serving as an auxiliary or additional drive of a watercraft, particularly a large-scale watercraft propelled by fossil fuels, are known from WO 2005100147, WO 2005100148, WO 2005100149, and WO 2008031446. Due to the very large sizes of these aerodynamic wings, that can range from more than 100 up to several thousand square meters, these aerodynamic wings their selves, their handling and their connection to the watercraft differ significantly from sails, parachutes or aerodynamic wings used for watercrafts in the dimension of small-scale or midsize commercial boats, and particularly for non-commercial sail boats or motor boats.

For example, US 5,642,683 and US 6,918,346 deal with configurations particularly for sailing boats or small motor boats. US 5,642,683 proposes to connect a parachute-type sail to a movable location such that the tethered sail can be moved to substantially any desired location on the periphery of the boat. In another embodiment disclosed in US 5,642,683 the tethering cable of the sail is connected to an arm that can pivot on a horizontal axis relative to a mast. The mast can pivot about a vertical axis. US 6,918,346 also discloses a sailing boat with a kite-type canopy that is connected to a spar that is mounted to a mast.

However, the mast arrangements disclosed in US 5,642,683 and US 6,918,346 are not suitable for large-scale applications. First, the problem addressed by these mast arrangements, namely heeling of the boat due to the sail, since traditional sails known in the art are associated with the risk of capsizing due to the heeling resulting from the forces generated by the sail and further require special competence to handle the art of sailing with traditional sailing equipment are no significant or important issue when using such aerodynamic wings for large-scale watercrafts. In contrast, the torque induced by the excentric line of force might adversely affect the deck attachment point of the mast and the deck in the region around the attachment point. The high tractive forces generated by large-scale aerodynamic wings and transferred via a tractive cable or the like to the watercraft might be too high to be transferred to the watercraft via an arm mounted to a mast as described in US 5,642,683 and US 6,918,346. Thus, the solutions shown in US 5,642,683 and US 6,918,346 are not applicable for aerodynamic wings serving as an auxiliary or additional drive of a watercraft, particularly a large-scale watercraft propelled by fossil fuels, as in the present invention.

One problem associated with aerodynamic wings, particularly in large-scale applications, is to transfer extremely high tractive forces exerted by the aerodynamic wing to the watercraft in a safe and reliable manner. This problem has been solved in the solutions described in WO 2005100147, WO 2005100148, WO 2005100149, and WO 2008031446 by connecting the aerodynamic wing via a tow rope or the like to a tow point located directly on the deck, particularly the foredeck, of the watercraft. By this, it is possible to transfer the high tractive forces of large-scale applications directly to the watercraft without the leveraging effect of a mast or - even more disadvantageous - a horizontal arm mounted to a mast as proposed in existing solutions. Further, WO 2005100147, WO 2005100148, WO 2005100149, and WO 2008031446 provide for a single deck tow point capable of transferring these forces to the watercraft in a safe and reliable matter. A connection point that is movable along the periphery of the boat as proposed in US 5,642,683 would not be sufficient to transfer the very high tractive forces occurring in large-scale applications on the one hand and extremely costly and space filling to realize on the other hand.

Although WO 2005100147, WO 2005100148, WO 2005100149, and WO 2008031446 provide practical solutions for transferring high tractive forces to the watercraft, large- scale aerodynamic wings have proven to be difficult to handle in a number of specific flight conditions. Therefore, in WO 2005100147 it is proposed to veer out or haul in the tractive cable in response to the flight condition of the aerodynamic wing. To further improve control of an aerodynamic wing in difficult wind conditions it is known from WO 2005100148 to couple a steering unit close below the aerodynamic wing via a number of control lines. Further, WO 2005100149 proposes various sensors to improve control of an aerodynamic wing towing a watercraft during different flight conditions. Whereas these solutions can significantly improve the steerability of aerodynamic wings, it remains still a quite challenging task to efficiently steer and control large-scale aerodynamic wings, particularly in challenging control situations like starting and landing maneuvers. To improve steerability during starting and landing maneuvers, WO 2005100150 proposes a telescopic mast erected on the foredeck of a watercraft. The tractive forces exerted by the aerodynamic wing are transferred via a tractive cable directly to the watercraft via a tow point on the foredeck as in the existing solutions. The telescopic mast is located in a distance in horizontal direction behind the deck tow point for transferring the tractive forces to the watercraft. Using such mast, the aerodynamic wing can be directly coupled to a coupling device at the top of the mast for docking and undocking maneuvers during starting and landing. To allow such docking and undocking, WO 2008019700 proposes to provide the aerodynamic wing with a kite stick or central mast adapter to couple the aerodynamic wing to the top of a mast to establish the stability and steerability of the aerodynamic wing during starting and landing maneuvers.

WO 2009026939 discloses an aerodynamic wing with a tow rope transferring the tractive forces exerted by the aerodynamic wing directly to the watercraft via a tow point on the foredeck of the watercraft and an additional guiding line that is connected to the aerody- namic wing at the top of a pole located on the foredeck of the watercraft in a distance in horizontal direction from the tow point for transferring the tractive forces.

While these solutions can improve the stability and steerability of the aerodynamic wing during starting and landing maneuvers, the control and stability of aerodynamic wings during starting and landing maneuvers in large-scale applications still needs to be further improved. Particularly since the aerodynamic wing is operated at low altitudes during starting and landing maneuvers, the strength and direction of the wind often significantly and quickly changes. Sudden changes in conditions may lead to loss of control over the aerodynamic wing that might result in loss of the aerodynamic wing and possibly in addition its steering system or parts thereof. Still further, relative movements between the top of the pole and the wing resulting from rolling, pitching or yawing might hinder the docking or undocking maneuver or even result in failure or breakdown of components involved in the maneuvers. This is particularly disadvantageous due to the large size of the aerodynamic wing of more than 100 up to several thousand square meters, since an aerodynamic wing of these dimensions may also damage other ship equipment, particularly when located on the foredeck of the watercraft, or even influence the maneuverability of the watercraft, e.g. when the aerodynamic wing comes in contact with the water.

It is therefore an object of the present invention to provide an improved device and an improved method for handling an aerodynamic wing serving as auxiliary or additional drive of a watercraft, particularly a large-scale watercraft propelled by fossil fuels, wherein the aerodynamic wing is attached to a deck tow point of the watercraft via a tow rope transferring the tractive forces exerted by the aerodynamic wing to the watercraft, particularly during starting and landing maneuvers.

According to a first aspect of the invention, a mast arrangement as described above in the introductory portion of this description is provided, comprising an arm with a first end and a second end, the first end of the arm being coupled to the pole such that the arm can be rotated about a horizontal axis and wherein the arm is adapted to be rotated about a vertical axis, preferably via a bearing point located in the coupling of the first end of the arm to the pole, wherein the second end of the arm comprises connection means for guiding a guiding line connected to the aerodynamic wing and/or for coupling a central mast adapter of the aerodynamic wing to the mast arrangement.

According to the invention, the tow rope is to be understood as a tractive line connecting the deck two point to an attachment point of the aerodynamic wing which is close to the aerodynamic wing and lies in or close to the center of lifting forces of the wing to transfer these lifting forces via the deck two point to the ship. Preferably, tensional forces in the two rope shall not have any effect on the guiding and steering of the wing. In contrast hereto, the guiding line is to be understood to be attached in a distance from the center of the lifting forces and to thus have a significant effect on the guiding and steering of the wing, if a tension is applied to the guiding line. Preferably, tractive forces resulting from the lifting forces exerted by the aerodynamic profile of the aerodynamic wing are not, at least not primarily, transmitted via the guiding line, allowing the use of a guiding line having a much smaller cross-section than the tow rope. The invention is based on the finding that the problems associated with the stability and steerability of the aerodynamic wing during starting and landing maneuvers are at least partly related to the connection of the aerodynamic wing to a rigid mast or pole via a guiding line and/or a central mast adapter, for example a kite stick. Using a rigid mast or pole for guiding the aerodynamic wing during starting and landing maneuvers has the side effect, that movements of the watercraft are transferred via the mast and the guiding line and/or the central mast adapter to the aerodynamic wing. These movements of the watercraft can result for example from pitching, rolling and/or yawing and might lead to a change in inclination, altitude, acceleration and/or position of the watercraft and therefore also of the mast or pole or a mast arrangement or parts thereof. Although large-scale watercrafts propelled by fossil fuels are less prone to heeling resulting from forces exerted by a sail - as opposed to small-scale sailing boats for example - these large-scale watercrafts are for example exposed to rough seas and thus a variety of movements of the body of the watercraft may occur independent from the aerodynamic wing. If these movements are transferred to the aerodynamic wing via the mast arrangement during the sensible phase of starting and landing the aerodynamic wing, this may result in a loss of control of the aerodynamic wing and thus might result in a partial or complete loss of the aerodynamic wing and/or further parts of an aerodynamic wind propulsion device.

Therefore, the present invention provides for a mast arrangement that comprises an arm that can be moved in order to compensate for relative movements between the ship and the wing during starting and landing and thus prevent movements of the docking components of the watercraft in relation to the aerodynamic wing or at least to reduce these movements. The present invention is particularly useful for an aerodynamic wing serving as auxiliary or additional drive of a large-scale watercraft propelled by fossil fuels, such as for example commercial container vessels.

The mast arrangement according to the present invention and its components are prefer- ably arranged in the following manner.

The vertical pole is fixed to the deck of the watercraft at the deck attachment point and the aerodynamic wing is connected via a tow rope to the deck tow point. The deck attachment point of the pole and the deck tow point for attaching the aerodynamic wing are preferably located at two separate, laterally distant points on the foredeck of the water- craft. Preferably, the deck tow point for attaching the aerodynamic wing is located closer to the bow of the watercraft than the deck attachment point of the pole.

The aerodynamic wing preferably has an aerodynamic profile that generates an uplift force in the direction of the tow rope when the airflow direction is about perpendicular to the tow rope. The tractive forces generated by the aerodynamic profile of the aerodynam- ic wing are transferred via the tow rope and the deck tow point to the watercraft. Since the deck tow point is located on the deck of the watercraft, only very little, mostly negligible, heeling forces are generated by the aerodynamic wing.

In order to improve the control, stability and/or steerability of the aerodynamic wing particularly during starting and/or landing maneuvers, the mast arrangement comprises an arm, for example a cantilever, boom or jib. This arm is coupled to the pole such that it can rotate about a horizontal as well as a vertical axis. The arm does not necessarily have to be rotatable about a full circle, i.e. 360°, about the horizontal and/or vertical axis, but rather about a section of the circle about the horizontal axis as well as about the vertical axis. For the rotation about the vertical axis a section of the circle about which the arm can be rotated preferably has an upper limit of 300°, 310°, 300°, 290°, 280°, 270°, 260°, 250°, 240°, 230°, 220°, 210°, 200°, 190°, 180°, 170°, 160°, 150°, 140° or 130° and a lower limit of 40°, 50°, 60°, 70°, 80°, 90°, 100°, 1 10°, 120°, 130°, 140°, 150°, 160°, 170°, 180°, 190°, 200°, 210°, 220° or 230°, wherein an angle of 0° shall be defined as the backward longitudinal direction of the ship and the bow of the watercraft preferably is located in the direction of 180°. For the rotation about the horizontal axis a section of the circle about which the arm can be rotated preferably has an upper limit of 180°, 170°, 160°, 150°, 140°, 130°, 120°, 1 10°, 100°, 90°, 80°, 70°, 60°, 50°, 40° or 30°, and a lower limit of preferably 0°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 1 10°, 120°, 130° or 140°, wherein the direction of 0° points towards the top of the pole and the direction of 180° points towards the deck attachment point of the pole.

The ability of the arm to be rotated in these circle sections is particularly preferred, since in order to save fossil fuels and to use the aerodynamic wing as auxiliary or additional drive of the watercraft, the aerodynamic wing will usually be in a position for which said circle sections are particularly advantageous for those maneuvers addressed by the invention.

To increase the control, steerability and/or stability of the aerodynamic wing particularly during starting and/or landing maneuvers, the second end of the arm comprises connec- tion means for a guiding mechanism of the aerodynamic wing. This guiding mechanism is preferably a guiding line connected to the aerodynamic wing that can be guided via the second end of the arm and/or a central mast adapter of the aerodynamic wing that can be coupled to the second end of the arm. Thus, the second end of the arm provides a guiding point for the aerodynamic wing that preferably can be moved essentially along a section of the surface of a sphere, defined by the rotation of the arm about the horizontal and/or vertical axis.

The movability of the arm according to the present invention has the advantage that it is possible to prevent or reduce the transfer of a movement of the watercraft to the aerodynamic wing by moving the arm into a direction opposite of the direction of the movement of the watercraft. By this, a partial or complete compensation of the effects of rolling, pitching or yawing of the ship to the second end may be achieved. Thus a loss of control, stability and/or steerability of the aerodynamic wing due to movements of the watercraft that are transferred to the aerodynamic wing can be reduced or prevented. For example, when conducting starting and/or landing maneuvers in rough sea conditions with abrupt movements of the watercraft, the aerodynamic wing can be guided via the arm of the mast arrangement within a stable manner without transferring the abrupt movements of the watercraft to the guiding point at the second end of the arm and thus to the aerodynamic wing.

It is to be understood that a movement of the watercraft, the mast arrangement or parts thereof, particularly the arm and/or the pole, may comprise a rotational movement and/or a translational movement and/or a combination of both.

Further it is preferred, that the arm is a telescopic arm, such that the length of the arm can be varied and thus the second end of the arm can also be moved along the longitu- dinal axis of the arm. This provides further degrees of freedom for the movement of the guiding point at the second end of the arm in relation to the ship hull.

According to a preferred embodiment of the invention, the mast arrangement is characterized by actuation means that are capable, particularly during starting and/or landing maneuvers, to move the arm from a first position to a second position and vice versa, wherein the second end of the arm is located in the first position in a lower altitude than in the second position.

When the aerodynamic wing is not in use, it is preferably stowed away somewhere close to the deck tow point on the watercraft. When the aerodynamic wing is supposed to be started, it is preferred that the second end of the arm is located in a position close to the deck of the watercraft and further preferably close to the deck tow point for attaching the tow rope of the aerodynamic wing. During starting maneuvers, the tow rope is usually hauled in at the beginning and veered out successively during starting of the aerodynamic wing, i.e. while the aerodynamic wing gains altitude. Preferably, the second end of the mast also starts guiding the aerodynamic wing close to the deck tow point in a first position and is raised, preferably parallel or simultaneous with the aerodynamic wing, to the second position with the second end of the arm in a higher altitude than in the first position, in order to bring the aerodynamic wing from a lower to a higher altitude in a stable and controlled manner. Vice versa, during landing maneuvers, the aerodynamic wing preferably is brought from its flying altitude close to the second end of the arm in its second position, wherein the guiding line is hauled in close and/or the central mast adapter of the aerodynamic wing is coupled to the second end of the arm. For landing the aerodynamic wing, i.e. bringing the aerodynamic wing down on the deck of the watercraft, the second end of the arm is then brought from its second position in its first position, wherein this first position has a lower altitude than the second position, and is preferably located close to the deck tow point on the deck of the watercraft. Preferably, the tow rope is hauled in parallel to bringing the second end of the arm from its second position to its first position.

The second position is further particularly used for flying the aerodynamic wing in its flying altitude, with the second end of the arm being in a high altitude and thus being closer to the aerodynamic wing than it its first position. This is particularly preferred, in order to be able to bring the aerodynamic wing quickly close to the second end of the arm and provide guiding of the aerodynamic wing via the second end of the arm in case the aerodynamic wing needs to be landed or rescued.

It is further preferred that during starting and/or landing maneuvers the arm does not only move from a lower to a higher altitude and vice versa in order to bring the aerodynamic wing up or down, but also that the arm is moved in such a way that other movements of the hull of the watercraft are not transferred to the aerodynamic wing. It is rather preferred that the aerodynamic wing is kept free from accelerations resulting from rolling, pitching or yawing of the hull of the watercraft and/or path of the aerodynamic wing remains essentially a vertical rising or lowering movement. Preferably the actuation means are capable to move the arm from the first position to the second position and vice versa by rotating the arm about a vertical axis and/or about a horizontal axis.

According to a further preferred embodiment of the invention, the first end of the arm is coupled to the pole in the pole's upper half, particularly in the pole's upper third. This mast arrangement is particularly preferred since it allows a high flexibility in the movement of the arm and provides for a good control and steerability of the aerodynamic wing in lower altitudes close to the deck of the watercraft as well as in higher altitudes on the way to bring the aerodynamic wing to its flying altitude.

According to a further preferred embodiment of the invention, the first end of the arm is coupled to an upper section of the pole wherein at least the upper section of the pole, preferably the whole pole, is coupled to the deck such that it can rotate about a vertical axis and/or such that it can rotate about a horizontal axis, preferably via a journal bearing.

In this preferred embodiment, for example, the upper section of the pole with the first end of the arm coupled to it, can be rotated about a vertical axis in relation to the lower sec- tion of the pole. Thus, the bearing point coupling the first end of the arm to the upper section of the pole does not need to provide for a rotation of the arm about a vertical axis in relation to the upper section of the pole, since the first end of the arm is able to rotate about the vertical axis with the upper section of the pole in relation to the lower section of the pole. Analogous, the whole pole can be mounted to the deck such that it can rotate about a vertical axis. This construction can be advantageous concerning the construction of the pole and particularly the bearing point coupling the first end of the arm to the pole, and further concerning the control mechanism of the movement of the arm and/or the pole.

Additionally or alternatively, the upper section of the pole, preferably the whole pole, can be coupled to the deck via a journal bearing such that it can rotate about a horizontal axis. In this case the bearing point coupling the first end of the arm to the upper section of the pole may not provide for a rotation of the arm about a horizontal axis, since this rotation is provided by the upper section or the whole pole if the horizontal axis is oriented perpendicular to the longitudinal axis of the watercraft. This may compensate for a pitching movement of the hull. Further the horizontal axis or a further horizontal axis may be oriented in the longitudinal direction of the hull to compensate for a rolling motion. Again, this embodiment is advantageous concerning the construction of the pole and particularly the bearing point coupling the first end of the arm to the pole, and further concerning the control mechanism of the movement of the arm and/or the pole.

According to a further preferred embodiment of the invention having actuation means for moving the arm from a first to a second position, said actuation means comprise at least two actuators, preferably at least two hydraulic cylinders, wherein either of the actuators is connected to the pole in a first distance from a longitudinal axis of the pole and connected to the arm in a second distance from a longitudinal axis of the arm, wherein the first distance is larger than the second distance. Preferably, the actuation means are at least two actuators, since the control of the movement of the arm can be realized in a particularly efficient way using two actuators. For the present application, it is particularly useful to use hydraulic cylinders as actuation means since they are reliable and efficient means to provide actuation of the arm. In the preferred arrangement of the current embodiment, either of the actuators is connected to the pole in a first distance from a longitudinal axis of the pole, i.e. at the periphery of the pole having a certain diameter. Further, either of the actuators is connected to the arm in a second distance from a longitudinal axis of the arm, i.e. at the periphery of the arm having another certain diameter. In this embodiment, the first distance is larger than the second distance, i.e. for example, the diameter of the arm is smaller than the diameter of the pole.

With the diameter of the pole being larger than the diameter of the arm, for example the diameter of the pole being twice the diameter of the arm, this arrangement resembles a form of tripod, with the two first ends of the actuators being spaced apart on either side of the pole and the two other ends of the actuators being located close together on either side of the arm. This preferred arrangement provides for a very efficient way to actuate the arm in the desired directions.

According to a further preferred embodiment of the invention, either of the actuators is connected to a lower section of the pole such that either of the actuators can rotate about a horizontal axis and that either of the actuators is connected to the arm such that the arm can rotate about an axis perpendicular to a longitudinal axis of each of the actuators.

This embodiment is particularly preferred in combination with the previously described embodiment. Further it is preferred, that the hydraulic cylinders can be lengthened or shortened in their longitudinal direction, i.e. along their longitudinal axis. This arrangement provides for a very flexible actuation arrangement and thus a highly flexible mova- bility of the arm with respect to the watercraft.

According to a further preferred embodiment for at least one position of the arm the at least two actuators are located symmetrically in relation to a symmetry plane, wherein the symmetry plane comprises a longitudinal axis of the pole, a longitudinal axis of the arm, and preferably a longitudinal axis of the watercraft.

This embodiment is particularly preferred with one or both of the two previously described embodiments. A symmetric location of the two actuators in relation to a symmetry plane along the longitudinal axis of the watercraft, i.e. essentially the symmetry axis of the watercraft, is particularly preferred, since the possible movements of the watercraft in relation to the aerodynamic wing can also occur on either side of this symmetry plane.

According to a further preferred embodiment the length of the arm is about 30 to 200 percent of the length of the pole. The upper limit of the arm can be preferably 190, 180, 170, 160, 150, 140, 130, 120, 1 10, 100, 90, 80, 70, 60 or 50 percent of the length of the pole, the lower limit of the length of the arm can be preferably about 40, 50, 60, 70, 80, 90, 100, 1 10, 120, 130, 140, 150, 160, 170 or 180 percent of the length of the pole. This preferred ratio of the length of the arm to the length of the pole provides for a particularly flexible mast arrangement that allows for movements of the arm necessary to compensate for movements of the watercraft and/or to bring the arm in a preferred first and/or second position particularly for starting and landing the aerodynamic wing.

According to a further preferred embodiment at least one navigation light is located at the pole. This embodiment is particularly preferred, if the pole of the mast arrangement according to the present invention is a pole that is used on the watercraft also for different purposes, particularly as a platform for signal means or sensor means. This is particularly advantageous, since it is not necessary to erect a further pole on the foredeck of the watercraft, but to use an existing pole for the mast arrangement according to the present invention and to couple an arm to this existing pole to provide a mast arrangement according to the present invention when equipping a watercraft with an aerodynamic wing.

According to a further preferred embodiment the pole can be pivoted about a pivoting axis perpendicular to a longitudinal axis of the pole, wherein preferably the pivoting axis of the pole is a longitudinal axis of the watercraft. This embodiment is particularly advantageous since the pivoting of the pole can be used in addition to the movement of the arm in order to compensate for a movement of the watercraft, particularly a movement resulting from pitching, rolling and/or yawing. In that the pole can be pivoted about a pivoting axis perpendicular to a longitudinal axis of the pole, movements of the watercraft can be even better and easier compensated for than with a movement of the arm alone. It is particularly preferred, that the pivoting axis of the pole is a longitudinal axis of the watercraft, since especially movements of the watercraft due to heeling and/or rolling often result in significant accelerations at the top of the pole. If, however, the pole can be pivoted about the same axis in an opposite direction this may directly compensate for such movements of the watercraft. According to a further preferred embodiment of the present invention the mast arrangement is characterized by at least one pivoting actuator that is capable to pivot the pole about the pivoting axis.

In order to provide a controlled pivoting movement of the pole about its pivoting axis it is preferred to have at least one pivoting actuator in order to initiate and control a pivoting movement of the pole about the pivoting axis.

According to a further preferred embodiment of the present invention the mast arrangement is characterized by sensor means that are capable to detect, particularly during starting and/or landing maneuvers, a movement of the watercraft and/or the mast arrangement or parts thereof resulting from, pitching, rolling and/or yawing, and/or inclina- tion, altitude, acceleration and/or position of the watercraft and/or the mast arrangement or parts thereof, and/or changes in inclination, altitude, acceleration and/or position of the watercraft and/or the mast arrangement or parts thereof, and/or wind direction, particularly changes in wind direction. In order to compensate for the previously mentioned conditions of the watercraft and/or the mast arrangement or parts thereof, it is necessary to identify these conditions. Therefore respective sensor means are preferred according to the present embodiment. These sensor means can be located on the mast arrangement, on the foredeck of the water- craft, but also in any other location of the watercraft, particularly on the bridge of the watercraft.

It is particularly preferred to use sensor means that are already existent on the watercraft for this embodiment, since usually a watercraft, particularly a large-scale watercraft, is already equipped with sensor means capable to detect one or more of the above de- scribed conditions. Therefore it is particularly preferred to use one or more of these existing sensors in the mast arrangement of the present invention.

According to a further preferred embodiment of the present invention the mast arrangement is characterized by control means that are capable to control a movement of the mast arrangement or parts thereof, particularly during starting and/or landing maneuvers, in a direction against a movement of the watercraft and/or the mast arrangement or parts thereof resulting from pitching, rolling and/or yawing, and/or in a direction depending on inclination, altitude, acceleration and/or position of the watercraft and/or the mast arrangement or parts thereof, and/or in a direction depending on changes in inclination, altitude, acceleration and/or position of the watercraft and/or the mast arrangement or parts thereof, and/or in a direction depending on wind direction, particularly changes in wind direction.

The control means preferably are capable to control a movement of the mast arrangement or parts thereof, particularly of the arm, wherein the movement can be a rotational movement, a translational movement or a combination thereof. The control means are particularly capable to address the actuators and/or the pivoting actuator in order to control a movement of the mast arrangement or parts thereof. Further, the control means are particularly capable to control the movement depending on the conditions described above that have been detected by one or more sensor means. Therefore it is particularly preferred that the control means are coupled with the sensor means such that the control means receive signals from the sensor means and can react upon analysis of the conditions detected by the sensor means.

According to a further aspect, the invention may be embodied in an aerodynamic wind propulsion device serving as auxiliary or additional drive of a watercraft, particularly a large-scale watercraft propelled by fossil fuels, wherein the mast arrangement is a mast arrangement according to the invention as described above.

Further, the invention may be embodied in a watercraft, particularly a large-scale water- craft propelled by fossil fuels, comprising a mast arrangement according to the invention as described above or an aerodynamic wind propulsion device according to the invention as described above.

Further, the invention may be embodied in the use of a mast arrangement according to the invention as described above to start, land, fly, steer and/or rescue an aerodynamic wing serving as a auxiliary or additional drive of a watercraft, particularly a large-scale watercraft propelled by fossil fuels.

As to the advantages, preferred embodiments and details of these further aspects, reference is made to the corresponding aspects and embodiments described above.

According to a still further aspect of the invention, a method for handling an aerodynamic wing of comprising the steps transferring tractive forces exerted by the aerodynamic wing via a tow rope and a deck tow point to the watercraft, guiding a guiding line connected to the aerodynamic wing and/or coupling the aerodynamic wing via a central mast adapter to a mast arrangement with a pole extending from a deck attachment point in a vertical direction, wherein the deck attachment point of the pole is located in a distance in horizontal direction from the deck tow point on the deck, preferably the foredeck, of the watercraft, and further preferably the deck attachment point of the pole and the deck tow point are located on a longitudinal axis of the watercraft is provided. The method is characterized by the steps of guiding the guiding line connected aerodynamic wing and/or coupling the aerodynamic wing via the central mast adapter to a second end of an arm of the mast arrangement, wherein a first end of the arm is coupled to the pole, rotating the arm about a horizontal axis and/or about a vertical axis.

The method according to the invention can be improved as described in claims 18 - 22. As to the advantages, preferred embodiments and details of the method according to the invention, reference is made to the corresponding aspects and embodiments of the mast arrangement according to the invention described above. The invention will be explained in more detail below with reference to the figures. In the figures, Fig. 1 : is a side-elevational schematical view of a mast arrangement according to the present invention with an aerodynamic wing,

Fig. 2: is a back-elevational schematical view of the mast arrangement shown in Fig. 1 ,

Fig. 3: is a front-elevational schematical view of the mast arrangement shown in Fig. 1 , Fig. 4: is a back-elevational schematical view of the mast arrangement shown in Fig. 1 with the arm in a sideward position, and

Fig. 5: is an enlarged schematical detail of the connection of the first end of the arm and the pole of the mast arrangement shown in Fig. 1 .

Fig. 1 -4 show a mast arrangement 100 according to the present invention located on the foredeck 400 of a watercraft (not shown) and an aerodynamic wing 200. Fig. 1 shows that the aerodynamic wing 200 is connected to a deck tow point 300 on the foredeck 400 of the watercraft (not shown) via a tow rope (not shown) transferring the tractive forces exerted by the aerodynamic wing 200 to the watercraft. As can be seen from Figs. 1 , 2 and 4, the aerodynamic wing 200 is further connected to the mast arrangement 100 for guiding the aerodynamic wing 200, particularly during starting and landing maneuvers.

The mast arrangement 100 comprises a pole 1 10 extending from a deck attachment point 1 13 on the foredeck 400 of the watercraft in a vertical direction. The mast arrangement 100 further comprises an arm 120 with a first end 121 and a second end 122. The first end 121 of the arm 120 is coupled to the upper third of the pole 1 10. The second end 122 of the arm 120 comprises connection means (not shown) for guiding a guiding line (not shown) connected to the aerodynamic wing 200 and/or for coupling a central mast adapter (not shown) of the aerodynamic wing 200 to the mast arrangement 100.

As can be seen particularly from the enlarged detail in Fig. 5, the first end 121 of the arm 120 is coupled to an upper end 1 1 1 of the pole 1 10 via a bearing point 140 such that it can rotate about a horizontal axis. Further, the upper end 1 1 1 of the pole 1 10 can rotate about a vertical axis, such that the arm 120 can be rotated about a horizontal axis as well as about a vertical axis in relation to the lower end 1 12 of the pole 1 10. The lower end 1 12 of the pole 1 10 broadens towards the upper end 1 1 1 of the pole 1 10 to form a platform 1 12a. Two hydraulic cylinders 130a, b function as actuation means in the embodi- ment of the invention depicted in Figs. 1-5. Each of the hydraulic cylinders 130a, b is connected via connection means 131a, b to the platform 1 12a in a first distance 133a, b from a longitudinal axis 1 14 of the pole 1 10 and connected via connection means 132a, b to the arm 120 in a second distance 134a, b from a longitudinal axis 124 of the arm 120, wherein the first distance 133a, b is larger than the second distance 134a, b. Thus, the connection of the arm 120 to the pole 1 10 using the two hydraulic cylinders 130a, b resembles a form of tripod.

The hydraulic cylinders 130a, b are connected via connection means 131a, b to the platform 1 12a such that each of the hydraulic cylinders 130a, b can be rotated about a horizontal axis. Further, the hydraulic cylinders 130a, b are connected via connection means 132a, b to the first end 121 of the arm 120 such that the arm 120 can rotate about an axis perpendicular to a longitudinal axis 135a, b of each of the actuators.

With this mast arrangement 100 according to the present invention it is possible to decouple movements, inclination, altitude, acceleration and/or position of the second end 122 of the arm 120 - and thus the connection means for guiding a guiding line connected to the aerodynamic wing 200 and/or for coupling a central mast adapter of the aerody- namic wing 200 to the mast arrangement 100 - from movements, inclination, altitude, acceleration and/or position of the watercraft and/or the remaining parts of the mast arrangement 100, namely the pole 1 10 and the first end 121 of the arm 120. In this manner, the second end 122 of the arm 120 that is guiding the aerodynamic wing 200 during the particularly sensitive phases of starting and landing can be moved in order to compensate for movements, inclination, altitude, acceleration and/or position of the watercraft and/or remaining parts of the mast arrangement 100 and therefore is not or at least less subjected to uncontrolled and unintentional motions.

In Figs. 1 -5 the second end 122 of the arm 120 is located in its second position. The first position of the second end 122 of the arm 120 would be a position where the second end 122 of the arm 120 is located close to the deck tow point 300 on or near the foredeck 400 of the watercraft. From this first position the second end 122 of the arm 120 can be moved by the two actuators 130a, b to its second position shown in Figs. 1-5 in order to start the aerodynamic wing 200. Vice versa, in order to land the aerodynamic wing 200, the second end 122 of the arm 120 can be brought from its second position depicted in Figs. 1-5 to its first position (not shown) close to the deck tow point 300 close or at the foredeck 400 of the watercraft. This motion of the arm 120 from its first to its second position an vice versa supports the motion of the aerodynamic wing 200 during starting and landing, where the aerodynamic wing 200 itself is moved from a low altitude close to the foredeck 400 of the watercraft to a higher altitude.