NL2015113B1

NL2015113B1 - A method for transporting a person from a first position relative to a watercraft to a second position relative to the watercraft, a device for transporting the person, and a system and a watercraft comprising the device.

Info

Publication number: NL2015113B1
Application number: NL2015113A
Authority: NL
Inventors: Rooswinkel Johannes
Original assignee: Coöperatieve Ver Offshore Coop U A
Priority date: 2015-07-07
Filing date: 2015-07-07
Publication date: 2017-02-01
Also published as: ES2736114T3; TR201910030T4; HRP20191183T1; PL3319873T3; WO2017007320A1; DK3319873T3; EP3319873B1; EP3319873A1

Abstract

A method for transporting a person from a first position relative to a watercraft (300) to a second position relative to the watercraft (300), the method using a device comprising: a foundation (11 0) comprising: o a base section (120) fixed to the watercraft (300); o a tilting section (130) hingedly connected to the base section (120); and o a pedestal (140) rotatably connected to the tilting section (130); an arm (150) hingedly connected at a first end (158) to the pedestal (140); a platform (160) hingedly connected to a second end (159) of the arm (150); actuators; and a Control Unit for operating the device (1 00) by driving the actuators; wherein the person is transported by operating the CU and wherein a Motion Reference Unit (360) detects a watercraft-motion and outputs the CU to compensate a platform-motion.

Description

A METHOD FOR TRANSPORTING A PERSON FROM A FIRST POSITION RELATIVE TO A WATERCRAFT TO A SECOND POSITION RELATIVE TO THE WATERCRAFT, A DEVICE FOR TRANSPORTING THE PERSON, AND A SYSTEM AND A WATERCRAFT COMPRISING THE DEVICE

FIELD OF THE INVENTION

The invention relates to a method for transporting a person from a first position relative to a watercraft to a second position relative to the watercraft and more specifically to a device for being fixed to a watercraft.

BACKGROUND OF THE INVENTION

Methods for transporting a person from a first position relative to the watercraft to a second position relative to said watercraft are known. For example, US20110038691 discloses a method wherein an apparatus comprising a robot arm is used for transporting a person from a watercraft to an offshore structure, wherein the robot arm can be moved in at least six degrees of freedom by servomotors. The robot arm is connected to a transfer element, for example a platform or a ladder/footbridge, and to an adjusting device that allows for mounting of said robot arm on the watercraft. The adjusting device allows for adjustment of the robot arm relative to the watercraft vertically, horizontally and lengthwise. The apparatus further comprises a control system for minimizing the relative movement of the platform relative to the offshore structure due to the movement of the watercraft.

There is still room for improvement to get a more flexible method using a structural simpler apparatus capable of providing a better performance.

SUMMARY OF THE INVENTION A first aspect of the invention relates to a method for transporting a person from a first position relative to a watercraft to a second position relative to the watercraft, the method using a device comprising: a foundation comprising: o a base section fixed to the watercraft; o a tilting section hingedly connected to the base section for allowing rotation of said tilting section relative to the base section around a first axis; and o a pedestal rotatably connected to the tilting section for allowing rotation of the pedestal relative to the tilting section around a second axis transverse to the first axis; an arm defining a first end and a second end, the arm hingedly connected at the first end to the pedestal for allowing rotation of said arm relative to the pedestal around a third axis transverse to the first axis and the second axis; a platform for supporting the person, the platform hingedly connected to the second end of the arm for allowing rotation of said platform relative to the arm; actuators for operating the foundation, the arm and the platform; and a Control Unit, CU, for operating the device by driving the actuators; wherein the person is transported by operating the CU to move the platform from the first position to the second position and wherein a Motion Reference Unit, MRU, detects a watercraft-motion and outputs the CU, said CU compensating a platform-motion caused by the watercraft-motion. A second aspect of the invention relates to a device for transferring a person from a first position relative to a watercraft to a second position relative to the watercraft, the device comprising: a foundation comprising o a base section arranged for fixing the foundation to the watercraft; o a tilting section hingedly connected to the base section for allowing rotation of the tilting section relative to the base section around a first axis; and o a pedestal rotatably connected to the tilting section for allowing rotation of the pedestal relative to the tilting section around a second axis transverse to the first axis; an arm defining a first end and a second end, the arm hingedly connected at the first end to the pedestal for allowing rotation of said arm relative to the pedestal around a third axis transverse to the first axis and the second axis; a platform for transporting the person, the platform hingedly connected to the second end of the arm for allowing rotation of said platform relative to the arm; actuators for operating the foundation, the arm and the platform such that when the device is fixed to the watercraft the platform can be moved relative to said watercraft; a Control Unit, CU, for operating the device by driving the actuators, the CU arranged for cooperating with a Motion reference Unit, MRU, for compensating a platform-motion caused by a watercraft-motion when the device is in use. A third aspect of the invention relates to a system comprising a device according to any claims 5 to 9 and a watercraft-MRU for i) measuring a watercraft-motion and ii) outputting the watercraft-motion to the CU of the device for compensating a platform-motion caused by the watercraft-motion when the device is in use.

Finally, a fourth aspect of the invention relates to a watercraft comprising a device according to any of claims 5 to 9 or the system according to claim 10, wherein the device is fixed to the watercraft at the base section of the foundation.

DETAILED DESCRIPTION OF THE INVENTION

The first aspect of the invention concerns a method according to claim 1. In this way a more flexible method is achieved for transporting a person from a first position to a second position.

The method can be used for transporting a person from a watercraft, for example a floating vessel, to another structure such as an offshore construction or a second watercraft. The method can also be used for transporting the person from the structure to the watercraft, or even for transporting the person from two different positions relative to the watercraft, for example from a first position of the offshore construction to a second position of said offshore construction. In any case, the method uses a device fixed to the watercraft for transporting the person. Thus, the method is suitable for rescuing purposes.

The device comprises a foundation, an arm, a platform and a Control Unit, CU.

The foundation allows for fixing a base section of the device to a watercraft, preferably to the deck of the watercraft. The foundation comprises a tilting section and a pedestal rotatably connected to the tilting section. The tilting section is arranged for rotating relative to the base section and, consequently, relative to the watercraft around a first axis. The rotating movement can be achieved by an actuator arranged at the foundation of the device. In a different embodiment, the watercraft comprises a further actuator arranged for tilting the tilting. It is preferred that the first axis is transverse to the longitudinal of the watercraft.

The pedestal is arranged for rotating relative to the tilting section about a second axis transverse to the first axis. Thus, as the tilting section rotates around the first axis, so does the pedestal and the second axis. The rotation of the pedestal relative to the tilting section is arranged in general by a pinion and gear system.

The arm defines a first end at which said arm is connected to the foundation and a second end at which it is connected to the platform. The arm is hingedly connected at the first end to the pedestal of the foundation for rotating said arm relative to said pedestal around a third axis transverse to the second axis. Thus, as the pedestal rotates about the second axis, so does the arm and the third axis can be arranged also transverse to the first axis. In general, the arm comprises at least two arm-sections in order to improve the versatility of the arm.

The platform for supporting the person is hingedly connected to the second end of the arm to keep said platform in a horizontal position during movement from the first position to the second position. The platform can be moved with six degrees of freedom relative to the base section by the movement of the tilting section, the pedestal and the arm since the first axis, the second axis and the third axis are transverse relative to each other. In general, the platform is a bucket arranged for accommodating at least one person to be transported from the firs position to the second position.

The device also comprises actuators for actuating the foundation, the arm and the platform such that said platform can be moved relative to the base section and, therefore, from the first position relative to the watercraft to the second position relative to said watercraft. The movement of the platform is operated by the CU, which commands the corresponding actuator to move the platform from the first position to the second position.

During operation, the watercraft is subjected to motion, referred as watercraft-motion, such as heave, sway, surge, yaw, pitch and roll. Since the device has been fixed by the base section to the watercraft, the platform is also subjected to said motions, referred as platform-motion.

In the method a Motion Reference Unit, MRU, is used for detecting the watercraft-motion and for outputting the detected watercraft-motion to the CU. The CU takes into account said watercraft-motion when giving commands to the actuators to move the platform from the first position to the second position such that the platform-motion is compensated. Thus, the person is transported more safely. In general, the MRU is located at the watercraft, generally relatively close to the center of gravity of the watercraft, and this MRU will be referred to as a Watercraft-MRU. The watercraft-MRU and the device forming a system. It is possible that the MRU is located at the device itself, and said MRU will be referred to as a device-MRU. Further, it is also possible that one device-MRU outputs the CU in cooperation with one watercraft-MRU in a master-slave configuration, the watercraft-MRU being the master. Thus the safety of the person being moved is improved.

In an embodiment, the CU is at the platform and the person transported on the platform is operating said CU. In this way, the device can be operated more accurately to move the platform from the first position to the second position by the person being transported on said platform, since said person has a better view when the platform is being moved.

In an embodiment, the platform is in at least one of the first position or second position relatively close to an structure and the platform is anchored to said structure.

In this way, the person can embark/disembark to/from the platform more safely. The structure can be another watercraft or offshore structure. The attachment of the platform can be done for example with a hook or any means for anchoring the platform on the offshore structure.

In an embodiment, the arm of the device is telescopic and in the method the platform is moved by extending said arm along its longitudinal axis. In this way, the device provides for a higher outreach. Further, the platform-motion can be compensated more accurately to compensate movement of the watercraft when said platform is kept at the second position, making the method more safe.

The second aspect of the invention relates to a device according to claim 5. In this way a more cost-effective device is achieved. The device allows for a more simple design, since there is no need for a robot arm comprising articulated joints in order to allow the platform for movement in six degrees of freedom. Further, the device comprises hinges arrangement that can be operated by linear actuators, and there is no need of using servomotors for actuating articulated joints.

The CU of the device according to the invention is arranged for cooperating with a MRU, such as a watercraft-MRU, a device-MRU or both of them.

In an embodiment, the arm comprises at least two arm sections hingedly connected one after the other for rotating each of the arm sections relative to the previous one around an axis substantially parallel to the third axis. Thus, the versatility of the movement of the platform provided by the device is improved. The platform can be moved to a positon in the vertical lower than the base section. In the present invention, an arm section is defined as a section arranged between the pedestal and the platform defined by two consecutive hinge arrangements.

In an embodiment, at least one of the at least two arm sections of the arm is extendible along its longitudinal axis. Thus, the device allows for reaching further distances, improving the versatility of the device.

In an embodiment, the CU is at the platform. Thus, the platform can be operated more accurately since the person being supported controls the platform, said person having a better view.

In an embodiment, the device comprises a device-MRU that outputs the watercraft-motion to the CU. The MRU is a device-MRU. The MRU may output the CU only by itself or in cooperation with a watercraft-MRU in a master-slave configuration, the watercraft-MRU being the master.

The third aspect of the invention relates to a system according to claim 10. Thus, the watercraft-MRU arranged for outputting the CU of the device can be placed on the watercraft in order to obtain more accurate data about the watercraft-motion.

The fourth aspect of the invention relates to a watercraft according to claim 11.

Thus the method can be performed. In general, the base section is fixed to the deck of the watercraft such that the first axis is transverse to the longitudinal of the watercraft. It is preferred that the base section is fixed as close as possible to the edge of the deck so the device is capable of having a better outreach when in use. The arm can be arranged in a non-operational position and in an operational position. In the non-operational position the longitudinal of the arm is parallel to the longitudinal of said watercraft, so the device cannot protrude from said watercraft. In the operational position the longitudinal of the arm is substantially transverse to the longitudinal of the watercraft. This movement from the non-operational position and the operational position is achieved by rotation of the pedestal relative to the base section.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of said invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:

Fig. 1 shows a perspective view of a device according to the invention;

Fig. 2 shows a detail of a foundation used in the device depicted in Fig. 1;

Fig. 3 shows a cross-sectional view of a watercraft comprising the device depicted in Fig. 1;

DETAILED DESCRIPTION OF THE DRAWINGS

It should be noted that items which have the same reference numbers in different figures, have the same structural features and the same functions. Where the function and/or structure of such item has been explained, there is no necessity for repeated explanation thereof in the detailed description.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments.

Figure 1 depicts a perspective view of a device 100 according to an embodiment of the invention. The device 100 comprises a foundation 110, an arm 150 and a platform 160.

As shown in more detail in Figure 2, the foundation 110 comprises a base section 120, a tilting section 130 and a pedestal 140. In the present example, the base section 120 is arranged for being fixed to a watercraft by fixing holes arranged for receiving bolts (not shown). However, said base section 120 can be fixed by other means, for example it can be welded to the watercraft.

The tilting section 130 is a hinging construction having a hinge 131 hingedly connected to the base section 120 by means of a shaft 132 (see Fig. 2). Consequently, said hinge 131 can rotate relative to the base section 120 about a first axis 191 defined by the centerline of the shaft 132. For allowing said rotational movement, the foundation 110 further comprises a hydraulic linear actuator 180.

The pedestal 140 is rotatably connected to the hinge 131 of the tilting section 130 by an axial bearing 141. More specifically, the pedestal 140 is connected to an outer race ring 142 of the bearing 141, and the hinge 131 to an inner race ring 143 of said bearing 141. The outer race ring 142 is provided with an annular gearwheel (not shown) and the tilting section 130 comprises a motor (not shown) having a pinion that drives the annular gearwheel. Thus, the pedestal 140 can rotate about a second axis 192 transverse to the first axis 191.

The arm 150 depicted in Fig. 1 comprises a first arm section 151, a second arm section 152, a third arm section 153 and a fourth arm section 154. Each arm section is connected one after the other to define the arm 150, said arm having thus a first end 158 and a second end 159.

The first arm section 151 is connected to the pedestal 140 by a hinge arrangement 171 as shown in Fig. 2. The first arm section 151 defines thus the first end 158 of the arm 150 and allows the first arm-section 151 for rotation around a third axis 193 (see also Fig. 2) transverse relative to the first axis 191 and the second axis 192, in this example by means of a hydraulic linear actuator 181a.

The first arm section 151 comprises an outer first sub-section 151a and an inner first sub-section 151b. The inner first sub-section 151b is arranged within the outer first sub-section 151a and in this example connected to it by for example a hydraulic linear actuator 181b (see Fig. 3), allowing for extension along its longitudinal relative to said outer first sub-section 151a. Thus, the first section 151 is telescopic.

The second arm section 152 is connected to the distal end of inner first subsection 151b by a hinge arrangement 172. Thus, the second arm section 152 can rotate relative to the first arm section 151 by an hydraulic linear actuator (not shown) to allow said second arm section 152 for rotation around a fourth axis 194 substantially parallel to the third axis 193.

The third arm section 153 is connected to the second arm section 152 by a hinge arrangement 173. Thus, the hinge arrangement 173 allows the third arm section 153 for rotation around a fifth axis 195 substantially parallel to the third axis 193 for example by means of for example a hydraulic linear actuator (not shown).

The fourth arm section 154 is connected to the third arm section 153 by a hinge arrangement 174 for allowing said fourth arm section 154 for rotation around a sixth axis 196 substantially parallel to the third axis 193 by means of a hydraulic linear actuator (not shown). Said fourth arm section 154 defines the second end 159 of the arm 150.

In the present example the platform 160 is a bucket 160. The bucket 160 is connected by a two directional swivel 175 comprising two actuators, such as two hydraulic linear actuators for respectively allowing said bucket 160 for rotation around a seventh axis 197 substantially parallel to the third axis 193 and also around an eight axis 198 substantially parallel to the second axis 192. In a different embodiment, the platform 160 may be a cabin or a gondola fixed to the arm.

In the present example, the total length of the arm 150 after extending the first arm-section 151 and the second arm-section is 25m. The bucket may support for example up to three people and lift up to 300 kg.

The device 100 further comprises a CU for moving the bucket 160 from a first position to a second position relative to said base section 120. The CU outputs the actuators that actuates the tilting section 130, the pedestal 140, the arm 150 and the bucket 160. In the present example, the CU is located at the bucket 160.

Figure 3 discloses a cross-sectional view of a watercraft 300 along its longitudinal, the watercraft 300 comprising the device 100 depicted in Figure 1 fixed to a deck 301 of said watercraft 300.

The device 100 is in a operational position, wherein the longitudinal of the arm 150 is transverse to the longitudinal of the watercraft 300. In the operational position the first axis 191, the second axis 192 and the third axis 193 are substantially transverse relative to each other. The device 100 can also be positioned in a non-operational position (not shown), wherein the longitudinal of the arm 150 is aligned with the longitudinal of the watercraft 300. In the non-operational position the arm 150 does not protrude from the deck 301. The device can be moved from the non-operational position to the operational position by rotation of the pedestal about the second axis 192.

At least a person on the bucket 160 can be moved relative from said watercraft 300 from a first position to a second position. Thus, the invention can be used to rescue at least said person, for example by moving said person to different points of an offshore structure.

The watercraft 300 is subjected to motions (watercraft-motion) defined by 6 degrees of freedom: heave, sway, surge, yaw, pitch and roll. Since the device 100 has been fixed by its base section 120 to the deck 301 of the watercraft 300, the bucket 160 is also subjected to said motions.

In the present example, the device 100 has been fixed such that the first axis 191 is transverse relative to the longitudinal of the watercraft 300. Further in the present example, the hinge 131 of the tilting section 130 can rotate around the first axis 191 for example by the hydraulic linear actuator 180. Thus, the motion of the bucket 160 (platform-motion) caused by the pitch motion of the watercraft 300 can be compensated by the tilting section 130 in cooperation with the actuator 180.

The pedestal 140 is rotatable connected to the hinge 131 of the tilting section 130 by the bearing 141 as shown in Fig. 2. Thus, the pedestal 140 can rotate about the second axis 192, and so can the arm 150 and the bucket 160. Thus, the motion of the bucket 160 caused by the surge motion and the yaw motion of the watercraft 300 can be compensated by rotation of the pedestal 140 relative to the base section 120.

The arm 150 is capable of rotating around the third axis 193, in this example by the hydraulic linear actuator 181a. Thus, the motion of the bucket 160 caused by the heave motion of the watercraft 300 can be compensated by the hydraulic linear actuator 181a. Further, the first arm section 151 can extend respectively along its longitudinal, said arm section 151 allowing thus for compensation of the sway motion of the bucket 160 caused by the sway motion of the watercraft 300. Also, the third arm section 153 and the fourth arm section 154 are respectively capable of rotation around the firth axis 195 and the sixth axis 196 by the linear hydraulic actuator 183 and 184. Thus, said linear hydraulic actuators 183 and 184 can compensate for the roll motion of the bucket 160 caused by the roll motion of the watercraft 300.

The bucket 160 is connected to the second end 159 of the arm 150 via the two directional swivel 175, said bucket 160 being capable of rotating around the eight axis 198 substantially parallel to the second axis 192. Thus, the yaw motion of the bucket 160 caused by the yaw motion of the watercraft 300 can also be compensated.

The first arm section 151, the second arm section 152, the third arm section 153 and the fourth arm section 154 can move relative to each other within a plane comprising said arm 150. Thus, said sub-sections allow for lifting the bucket 160 in a vertical position relative to the pedestal 140 while said bucket 160 is kept in an horizontal orientation for the safety of the person. Further, the bucket 160 may be lowered in high relative to the base section, improving the versatility of the device 100. The combination of the rotation provided by the tilting section 130 and the pedestal 140 allows the bucket 160 to be moved from the first position to the second position relative to the base section 110. Consequently, the device 100 can be used for transferring people from the watercraft 300 to an offshore structure by moving the bucket 160 via de CU.

In the present example, the watercraft 300 comprises a watercraft-MRU 360 arranged close to the center of gravity of the watercraft 300. The watercraft-MRU 360 detects the watercraft-motion in order to get better data relative to the watercraft-motion. The watercraft-MRU 360 outputs the date to the CU of the device 100.

The CU calculates the compensation required to reduce the platform-motion and gives the pertinent commands to the actuators to compensate said platform-motion when said bucket 160 is moved from the first position to the second position and also when the movement of said bucket 160 is stopped, for example when said bucket 160 is in the second position and the person is descending to the offshore structure.

The invention can be easily varied within the scope of the appending claims.

For example, the number of arm sections can vary depending on the use of the device. Further, the arm may have two telescopic arm-sections. The actuators may be electric linear actuators. Also, the device may comprise a device-MRU that cooperates with the watercraft-MRU in a master-slave configuration when outputting the CU.

Claims

A method of transporting a person from a first position relative to a vessel (300) to a second position relative to the vessel (300), the method utilizing a device (100) comprising: - a foundation (110) comprising: * a base portion (120) adapted to be attached to the vessel (300); * a tilting portion (130) pivotally connected to the base portion (120) so that the tilting portion (130) can rotate relative to the base portion (120) about a first axis (191); and * a rotary head (140) rotatably connected to the tilting portion (130) so that the rotary head (140) can rotate relative to the tilting portion (130) about a second axis (192) that is transverse to the first ash (191); and - an arm (150) defining a first end (158) and a second end (159), the arm (150) at the first end (158) being hingedly connected to the rotary head (140) so that the arm (150) ) can rotate relative to the rotary head (140) about a third axis (193) that is transverse to the first axis (191) and the second axis (192); - a platform (160) for transporting the person, the platform (160) being hingedly connected to the second end (159) of the arm (150) so that the platform (160) can be positioned relative to the arm (150) rotate; - actuators for operating the foundation (110), the arm (150) and the platform (160); and - a control unit, CU, for operating the device (100) by driving the actuators; wherein the device (100) is attached to the vessel (300), and wherein the person is transported by operating the CU to move the platform (160) from the first position to the second position and wherein a movement reference unit, MRU , (360) detects a movement of a vessel and sends it to the CU, the CU compensating for a movement of a platform caused by a movement of the vessel.

The method of claim 1, wherein the CU is on the platform (160) and the person being transported through the platform (160) serves the CU.

The method of any one of the preceding claims, wherein the platform (160) is at least in one of the first or second position relatively close to a structure and the platform (160) is anchored to the structure.

The method of any one of the preceding claims, wherein the arm (150) of the device (100) is telescopic and the platform (160) in the method is moved by extending the arm (150) along its longitudinal axis.

Device (100) for transporting a person from a first position relative to a vessel (300) to a second position relative to the vessel (300), the device (100) comprising: - a foundation (110) comprising: * a base portion (120) adapted to attach the foundation (110) to the vessel (300); * a tilting portion (130) pivotally connected to the base portion (120) so that the tilting portion (130) can rotate relative to the base portion (120) about a first axis (191); and * a rotary head (140) rotatably connected to the tilting portion (130) so that the rotary head (140) can rotate relative to the tilting portion (130) about a second axis (192) that is transverse to the first ash (191); and - an arm (150) defining a first end (158) and a second end (159), the arm (150) at the first end (158) being hingedly connected to the rotary head (140) so that the arm (150) ) can rotate relative to the rotary head (140) about a third axis (193) that is transverse to the first axis (191) and the second axis (192); - a platform (160) for transporting the person, the platform (160) being hingedly connected to the second end (159) of the arm (150) so that the platform (160) can be positioned relative to the arm (150) rotate; - actuators for operating the foundation (110), the arm (150) and the platform (160) such that when the device (100) is attached to the vessel (300), the platform (160) with respect to the vessel (300) can be moved; - a control unit, CU, for operating the device (100) by driving the actuators, the CU being adapted to cooperate with a movement reference unit, MRU, (360) for compensating for a movement of a platform caused by movement of a vessel when the device (100) is in use.

The device (100) of claim 5, wherein the arm (150) comprises at least two arm portions (151, 152, 153, 154) hingedly connected to each other for rotating each arm portion (151) relative to the previous arm portion. , 152, 153, 154) about an axis that is substantially parallel to the third axis (193).

The device (100) of claim 6, wherein at least one of the at least two arm portions (151) of the arm (150) is extendable along its longitudinal axis.

The device (100) of any one of claims 5-7, wherein the CU is on the platform (160).

The device (100) according to any of claims 5-8, wherein the device (100) comprises a device MRU (361) that controls the movement of the vessel to the CU.

A system comprising a device (100) according to any one of claims 5 - 9 and a vessel MRU (360) for i) measuring a movement of a vessel and ii) transmitting the movement of the vessel to the CU of the device (100) for compensating a movement of the platform caused by the movement of the vessel when the device (100) is in use.

A vessel (300) comprising a device (100) as claimed in any one of claims 5 to 9 or the system as claimed in claim 10, wherein the device (100) is attached to the vessel (300) at the base portion (120) of the foundation (110).

The vessel (300) of claim 11, wherein the tilting portion (130) of the foundation (110) is adapted to be rotatable about the first axis (191) by means of a further actuator mounted on the vessel (300), wherein the further actuator has a first end hinged on the vessel (300) and a second end hinged on the tilting portion (130).