WO2020127778A2

WO2020127778A2 - Hull structure for integration with a hull of a ship and a method and a thruster control module for manoeuvring a ship

Info

Publication number: WO2020127778A2
Application number: PCT/EP2019/086370
Authority: WO
Inventors: Sauli SIPILÄ; Oskar Levander
Original assignee: Kongsberg Maritime CM AS
Priority date: 2018-12-21
Filing date: 2019-12-19
Publication date: 2020-06-25
Also published as: EP3898408C0; KR102398851B1; CN113302127A; CN113302127B; WO2020127778A3; EP3898408B1; EP3898408A2; FI128947B; FI20186132A1; KR20210106488A

Abstract

A hull structure (10) for integration with a hull (2) of a ship (1) and a method and thruster control module (1600) for manoeuvring the ship (1) are disclosed. The hull structure (10) comprises a through-hole (14), extending through the hull structure (10) in the transversal direction (34). The hull structure (10) is adapted to accommodate at least one thruster unit (41, 42) in the through-hole (14). The hull structure (10) comprises a front hull part (50) limiting the through-hole (14) in the forward direction (30). The front hull part (50) is tapered, in the aftward direction (32), in a cross-section (60) that is perpendicular to the main plane (20) and that is parallel to the aftward direction (32). Furthermore, the front hull part (50) has a front length (52), in the cross-section (60), in the aftward direction (32) that is greater than one quarter of a widest front width (54) of the front hull part (50) in the cross-section (60). A computer program and a carrier corresponding to the method for manoeuvring the ship are also disclosed.

Description

HULL STRUCTURE FOR INTEGRATION WITH A HULL OF A SHIP AND

A METHOD AND A THRUSTER CONTROL MODULE FOR MANOEUVRING A SHIP

TECHNICAL FIELD

The present invention relates to ship technology. In particular, a hull structure for integration with a hull of a ship as well as a method and a thruster control module for manoeuvring a ship comprising the aforementioned hull structure are disclosed. Furthermore, a computer program and a carrier corresponding to the method for manoeuvring the ship are disclosed.

BACKGROUND

Within ship technology, there exists solutions for improving manoeuvrability of a ship. With improved manoeuvrability, need for e.g. a towboat in harbours may be reduced, or even eliminated. Therefore, a large ship may often be provided with one or more bow thrusters, where each bow thruster is arranged in a respective transversal tunnel through a hull of the ship.

An exemplifying known solution for improving manoeuvrability is disclosed in document DE1113383. In more detail, the document discloses an auxiliary control device for a ship using a bow propeller pivotable about a vertical axis from the ship's longitudinal direction. The propeller and its connected drive motor form a pivotal unit that is arranged in a corresponding opening of a hull of the ship. When the bow propeller is in the center position behind a bow bulb front, the pivotal unit forms part of the hull's shape. A disadvantage with this known solution may be that efficiency of the auxiliary control device may not be sufficient in many cases, possibly due to unfavourable flow dynamics.

Furthermore, some known ships have a so called limp home mode, which allows the ship to be brought to a port by means of a separate emergency engine when a main propulsion engine malfunctions. Some ships may have two or more completely separate propulsion systems to increase reliability.

However, maintenance of and cost of independent propulsion systems are costly. To reduce maintenance and cost, a ship may include only one propulsion engine or propulsion system, which when out of order makes the ship totally incapable. A disadvantage may then be that the only way of safely bringing the ship to a harbour is to get assistance by a towboat. A further disadvantage is that the towboat may be costly and that there may be a substantial waiting time before the towboat arrives at the ship if the ship is far from the nearest towboat, which typically is found in a harbour. During the waiting time, the ship might drift uncontrolled and, in worst case scenario, hit other ships or run aground. SUMMARY

An object of the present invention may be to overcome, or at least alleviate, one or more of the abovementioned disadvantages and/or other disadvantages.

According to an aspect of the invention, this object, or other objects, may be achieved by a hull structure according to the appended independent claim.

Thus, there is provided a hull structure for integration with a hull of a ship. The hull structure has a main plane, perpendicularly to which a transversal direction of the hull structure is defined, and parallelly to which a forward direction and an aftward direction of the hull structure is defined.

The hull structure comprises a through-hole, extending through the hull structure in the transversal direction. The hull structure is adapted to accommodate at least one thruster unit in the through-hole. In some examples, the through-hole is elongated. The hull structure is thus adapted to limit the through-hole to become elongated. Thanks to the elongated through-hole, it may be possible to fit more than one thruster unit in the through-hole.

Furthermore, the hull structure comprises a front hull part limiting the through-hole in the forward direction. The front hull part is tapered, in the aftward direction, in a cross-section that is perpendicular to the main plane and that is parallel to the aftward direction. Additionally, the front hull part has a front length, in the cross-section, in the aftward direction that is greater than one quarter of a widest front width of the front hull part in the cross-section.

Thanks to that the front hull part is tapered, water flowing along the hull structure when the ship travels in the forward direction, may be guided towards said at least one thruster unit. In more detail, the water may be guided into and through the through-hole, thereby allowing said at least one thruster unit to interact with the water. As a consequence, said at least one thruster unit may more efficiently adjust a course of the ship by exhausting the water thus received in a suitable direction. Accordingly, the abovementioned object is thus achieved.

In some embodiments, the hull structure may be at least partially located under a design waterline of the ship when the hull structure is integrated with the ship. It may be that the hull structure comprises a hull portion that is located under the design waterline of the ship.

The front hull part may project a front contour in the cross-section. Tangents of the front contour along at least half of the front contour may present angles to the forward direction in the cross-section that are greater than 5 degrees. In some examples, the angles are less than 90 degrees, less than 60 degrees, less than 45 degrees, less than 30 degrees or the like. Furthermore, the angles may be greater than 10 degrees, 15 degrees, 20 degrees or the like.

Furthermore, the aft hull part may project an aft contour in the cross-section. Tangents of the aft contour along at least half of the aft contour may present angles to the aftward direction in the cross-section that are greater than 5 degrees. In some examples, the angles are less than 90 degrees, less than 60 degrees, less than 45 degrees, less than 30 degrees or the like. Furthermore, the angles may be greater than 10 degrees, 15 degrees, 20 degrees or the like.

In some embodiments, the hull structure comprises an aft hull part limiting the through-hole in the aftward direction. The aft hull part may be tapered, in the forward direction, in the cross-section, wherein the aft hull part has an aft length, in the cross-section, in the forward direction that is greater than one quarter of a widest aft width of the aft hull part in the cross-section. In this manner, flow of water into the through-hole, e.g. towards said at least one thruster unit, may be facilitated when the ship travels in the aftward direction. The aft hull part also improves flow dynamics when the ship travels in the forward direction.

A first surface of the front hull part may smoothly integrate with an exterior hull surface of the hull structure. The first surface may be referred to as "exterior aft surface" facing aftwards.

Alternatively or additionally, a second surface of the aft hull part may smoothly integrate with an exterior hull surface of the hull structure. The second surface may be referred to as "exterior front surface" facing forwards. Thanks to a smooth integration, streamlining of the hull structure may be improved.

The first surface may form at least one of straight line, convex curve and concave curve in the cross-section. The second surface may form at least one of straight line, convex curve and concave curve in the cross-section. As a result, e.g. by combining one or more of the straight line, the convex curve and the concave curve, the exterior front and/or aft surfaces may be shaped in a streamlined manner, or at least substantially streamlined manner.

Therefore, according to some embodiments, the front hull part is at least partially streamlined to facilitate and/or guide a flow of water towards at least one location where at least one water interacting device of said at least one thruster unit is located. With an improved flow of water towards said at least one location, efficiency of said at least one thruster unit may be improved when the ship travels in the forward direction. Consequently, manoeuvrability of the ship is improved.

Similarly, the aft hull part may be at least partially streamlined to facilitate and/or guide a flow of water towards at least one location where at least one water interacting device of said at least one thruster unit is located. With an improved flow of water towards said at least one location, efficiency of said at least one thruster unit may be improved irrespectively of whether the ship travels in the aftward direction. Consequently, manoeuvrability of the ship is improved.

The through-hole may be elongated in a tilt direction in the main plane, wherein an angle between the tilt direction and the forward direction is greater than zero, preferably upwards relatively the forward direction. The angle may be less than 45 degrees, 25 degrees, 20 degrees depending on shape of the hull structure. Preferably, the through-hole is elongated in a flow direction defined by water flow along the hull structure when integrated with the ship. The water flow does of course occur when the ship travels in water in the forward direction. The flow direction may typically depend on one or more of a speed of the ship, a shape of the hull of the ship or the like.

In preferred embodiments, said at least one thruster unit is rotatable about at least one rotational axis, being perpendicular to the cross-section and being located in the main plane.

In some embodiments, said at least one thruster unit is rotatable about at least one rotational axis, being perpendicular to the cross-section.

Said at least one thruster unit may further comprise a first thruster unit and a second thruster unit. Said at least one rotational axis comprises a first rotational axis and a second rotational axis.

The first and second thruster units are rotatable about the first and second rotational axes, respectively. An advantage is thus that said at least one thruster unit may be directed towards any desired direction, e.g. in the cross-section. An advantage with said at least two thruster units may be that a more fine-tuned manoeuvrability may be achieved as compared to with only one thruster unit.

According to some embodiments, the first thruster unit may be directed in an aft starboard direction between the aftward direction and a first transversal direction in the cross-section, and the second thruster unit may be directed in an aft port direction between the aftward direction and a second transversal direction that is opposite to the first transversal direction. The first and second transversal directions are perpendicular to the main plane of the hull structure. Thanks to that both the first and second thruster units are at least partially directed in the aftward direction, the ship may travel in the forward direction at a limited speed. Accordingly, the first and second thruster units may be used in a limp home mode, e.g. when a main engine of the ship malfunctions.

In some embodiments, said at least one thruster unit and/or the hull structure is/are adapted to ensure that at least one water interacting device of said at least one thruster unit remains within an outer contour of the hull structure during a revolution of said at least one thruster unit about said at least one rotational axis. This means that said at least one thruster unit is adapted to ensure that at least one water interacting device of said at least one thruster unit remains within an outer contour of the hull structure during a revolution of said at least one thruster unit about said at least one rotational axis and/or that the hull structure is adapted to ensure that at least one water interacting device of said at least one thruster unit remains within an outer contour of the hull structure during a revolution of said at least one thruster unit about said at least one rotational axis. Preferably, the entirety of said at least one thruster unit remains within the outer contour of the hull structure.

An advantage may be that flow dynamics may be improved, e.g. due to that no or few parts of said at least thruster unit are located outside the outer contour and thus inhibits water flowing past the through-hole.

A further advantage may be that a risk of damaging said at least one thruster unit is reduced as compared to when a thruster unit is outside a contour of the hull, e.g. when pointing in the transversal direction. Damaging may typically occur due to that the ship runs aground.

Said at least one thruster unit may be capable of being directed in the forward direction or the aftward direction. In this manner, said at least one thruster unit avoids interaction with a flow of water passing by it as the ship runs forward, e.g. at cruising speed, to a greater extent than when said at least one thruster unit is directable towards any other direction than the forward direction or the aftward direction.

Propeller blades of said at least one thruster unit may be capable of being feathered when said at least one thruster unit is directable in the forward direction. In this manner, resistance in the water due to the propeller blades may be reduced.

Alternatively, the propeller blades may be folded aftwards to present reduced cross-section in the forward direction. In this manner, the propeller blades, when not in use, may reduce resistance when said at least one thruster unit travels through the water in the forward direction.

According to another aspect, there is provided a method, performed by a thruster control module, for manoeuvring a ship comprising a hull structure according to any one of the

embodiments herein. Said at least one thruster unit comprises a first thruster unit and a second thruster unit. The first and second thruster units are normally directed in a same direction in the cross-section during operation. Typically, the first and second thruster units are located at a distance from each other along, e.g. parallelly with, the main plane. Further, the first and second thruster units may be located along, e.g. parallelly with, the aforementioned cross-section. Said at least one rotational axis comprises a first rotational axis and a second rotational axis. The first and second thruster units are rotatable about the first and second rotational axes, respectively. The thruster control module directs the first thruster unit in an aft starboard direction between the aftward direction and a first transversal direction in the cross-section. Moreover, the thruster control module directs the second thruster unit in an aft port direction between the aftward direction and a second transversal direction that is opposite to the first transversal direction. The thruster control module further runs the first and second thruster units, whereby the ship may travel in the forward direction in a so called limp home mode.

According to further aspects, a computer program and a computer program carrier

corresponding to the method above are provided.

According a further aspect, there may be provided a hull structure for integration with a hull of a ship. The hull structure has a main plane, perpendicularly to which a transversal direction of the hull structure is defined, and parallelly to which a forward direction and an aftward direction of the hull structure is defined. The hull structure comprises a through-hole, extending through the hull structure in the transversal direction. The hull structure is adapted to accommodate at least one thruster unit in the through-hole. Said at least one thruster unit and/or the hull structure is/are adapted to ensure that at least one water interacting device of said at least one thruster unit remains within an outer contour of the hull structure during a revolution of said at least one thruster unit about said at least one rotational axis.

According a still further aspect, there may be provided a hull structure for integration with a hull of a ship. The hull structure has a main plane, perpendicularly to which a transversal direction of the hull structure is defined, and parallelly to which a forward direction and an aftward direction of the hull structure is defined. The hull structure comprises a through-hole, extending through the hull structure in the transversal direction. The hull structure is adapted to accommodate at least two thruster units in the through-hole.

An advantage may be that manoeuvrability of the ship may be improved thanks to increased power of said at least two thruster units, while at the same time the thruster units form a compact unit that does not engross valuable space and/or area of the hull structure.

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects of embodiments disclosed herein, including particular features and advantages thereof, are explained in the following detailed description and the accompanying drawings.

Figure 1 is a side view, illustrating an exemplifying hull structure. Figures 2-3 are cross-sectional views of exemplifying hull structures, wherein the cross-sections are horizontal and located as indicated by the broken line 60 in Figure 1.

Figures 4 is a cross-sectional view of an exemplifying hull structure, wherein the cross-section is oriented as indicated by the broken line 61 in Figure 1.

Figure 5 is a side view, illustrating another exemplifying hull structure.

Figures 6-13 are cross-sectional views of exemplifying hull structures, wherein the cross-sections are horizontal and located as indicated by the broken line 60 in fig. 1.

Figure 14a is a side view, illustrating a further exemplifying hull structure.

Figure 14b is a transversal cross-sectional view of the hull structure of Figure 14a.

Figure 14c is another transversal cross-sectional view of the hull structure of Figure 1.

Figure 15 is a flowchart, illustrating an exemplifying method.

Figure 16 is a block diagram, illustrating an exemplifying thruster control module.

DETAILED DESCRIPTION

Figure 1 shows a hull structure 10 for integration with a hull 2 of a ship 1. The hull 2 of the ship 1 comprises exterior surfaces, which face downwards, partially downwards, forwards, partially forwards, aftwards, partially aftwards and towards, at or about, both a port side and starboard side of the ship 1.

An imagined main plane 20 of the hull structure 10 may be centrally located in the hull structure, e.g. centrally in a transversal direction as explained below. The imagined main plan 20, or main plane 20 for short, may be vertical when the ship 1 is immersed in calm waters.

A transversal direction 34 of the hull structure 10 is defined perpendicularly the main plane 20. The transversal direction 34 may point towards starboard direction or port direction of the ship 1. This means that the transversal direction may comprise a first transversal direction and a second transversal direction relatively to the ship 1 when the hull structure 10 is integrated with the ship 1. The first transversal direction may be a port transversal direction and the second transversal direction may be a starboard transversal direction relatively to the ship 1 when the hull structure 10 is integrated with the ship 1.

A forward direction 30 and an aftward direction 32 of the hull structure 10 is defined parallelly to the main plane 20. In more detail, the forward and aftward directions 30, 32 may be horizontal when the ship 1 is immersed in calm waters. Flence, the forward and aftward directions 30, 32 may be parallel to a longitudinal direction of the ship 1, or the hull structure 10. The forward direction may refer to a direction of straight forward travel of the ship 1. The forward direction 30 is opposite to the aftward direction 32. To sum up, the main plane 20 of a typical elongated hull structure 10 defines the forward direction 30, the aftward direction 32, the port direction 34, and the starboard direction 36 of the hull structure 10.

The hull structure 10 may be at least partially located under a design waterline 4 of the ship 1 when the hull structure 10 is integrated with the ship 1.

The hull structure 10 may comprise a hull portion 12. The hull portion 12 may be located under the design waterline 4 of the ship 1 when the hull structure is integrated with the ship 1. Expressed differently, the hull portion 12 may be a hull body 12. As is well known in the art, the design waterline, also known as the load waterline, or the summer load line, is the line where, for a specific water type and temperature, the hull meets the surface of the water, when the ship is floating freely at rest in still water and loaded to its designed capacity. The design waterline may be indicated on the hull with a so called Plimsoll line. The Plimsoll line is a reference mark with a horizontal line through a circle. The horizontal line of the Plimsoll mark is at the same level as the design waterline, and indicates the maximum depth to which the ship may be safely immersed when loaded, i.e. the legal limit to which the ship may be loaded, for a specific water type and temperature in order to safely maintain buoyancy.

Moreover, the hull structure 10 comprises a through-hole 14, such as a transversal tunnel, a slot, an aperture, an orifice or the like. Expressed differently, the hull portion 12 comprises the through-hole 14. The through-hole 14 extends through the hull structure 10 in the transversal direction 34. The through-hole 14 may be open-ended in the transversal direction 34 (shown in Figure 2). The hull structure 10 is adapted to accommodate at least one thruster unit 41, 42 in the through-hole 14. Said at least one thruster unit 41, 42 may be a water-jet thruster unit, a propeller thruster unit, a bow thruster or the like. Said at least one thruster unit 41, 42 may comprise a water interacting device 45, such as a propeller, a nozzle for a water-jet or the like.

In some embodiments, said at least one thruster unit 41, 42 may comprise two thruster units, three thruster units, four thruster units etc. These embodiments may of course be combined with any other example or embodiment herein when logically and/or physically possible.

Moreover, Figure 1 shows that the hull structure 10 comprises a front hull part 50 limiting the through-hole 14 in the forward direction 30. This is further illustrated in Figure 2.

The front hull part 50 is tapered, in the aftward direction 32, in a cross-section 60 that is perpendicular to the main plane 20 and that is parallel to the aftward direction 32. The front hull part 50 has a front length 52, in the cross-section 60, in the aftward direction 32 that is greater than one quarter of a widest front width 54 of the front hull part 50 in the cross-section 60. In other examples, the front length 52 may be greater than one third of the widest front width 54, greater than the widest front width 54, greater than twice the widest front width 54 or the like. The ratio of the front length 52 to the widest front width 54 may depend on a desired approximation to streamlined shaped of the front hull part 50.

In some examples, the front hull part 50 may have a streamlined or approximately streamlined shape.

Furthermore, Figure 1 shows a thruster control module 1600, such as a dynamic positioning system or a part thereof. Simply put, the thruster control module 1600 is a computer that operates, e.g. controls speed, direction etc. of, said at least one thruster unit 41, 42.

The through-hole 14 may be elongated in a tilt direction 33 in the main plane 20. Expressed differently, the through-hole 14 may be elongated in a flow direction 33, or tilt direction 33, defined by water flow along the hull structure 10, or the hull portion 12, when integrated with the ship 1. The water flow occurs when the ship 1 travels in water in the forward direction 30. Typically, the through-hole 14 is symmetric with respect to the main plane 20, in order to achieve a consistent behaviour of the ship 1 regarding manoeuvrability towards, at or about, the first and/or second transversal directions 34, 36.

An angle A1 between the tilt direction 33 and the forward direction 30 is greater than zero. Parallelly with the tilt direction 33, there may be a tilted cross-section 62, similar to the cross-section 60. The angle A1 may be less than 45 degrees, 25 degrees, 20 degrees, 15 degrees, 10 degrees, 5 degrees or the like. The angle may depend on shape of the hull structure, possibly in combination with the shape of the hull of the ship. Typically, the angle A1 is in a range from 10 degrees to 40 degrees, preferably the angle A1 is 15 degrees.

The cross-section 60 may be centrally located, e.g. with respect to a vertical direction or a size of the through-hole 14 in the vertical direction, in the through-hole 14. Flowever, the cross-section 60 and/or the cross-section 62 may be slightly offset to such central location. The discussions below, concerning e.g. contours, may typically also apply to these offset versions of the cross-section 60 and the cross-section 62.

In some embodiments, again referring to e.g. Figure 2, the hull structure 10 comprises an aft hull part 70 limiting the through-hole 14 in the aftward direction 32. The aft hull part 70 may then be tapered, in the forward direction 30, in the cross-section 60. Accordingly, the aft hull part 70 has an aft length 72, in the cross-section 60, in the forward direction that is greater than one quarter of a widest aft width 74 of the aft hull part 70 in the cross-section 60. In other examples, the aft length 72 may be greater than one third of the widest aft width 74, greater than the widest aft width 74, greater than twice the widest aft width 74 or the like. The aft length 72 may depend on desired approximation to streamlined shaped of the aft hull part 70.

In this manner, the hull structure 10 may improve flow of water towards said at least one thruster unit 41, 42 when the ship 1 travels through water in the aftward direction 32. Additionally, the aft hull part 70 also improves flow dynamics when the ship 1 travels through the water in the forward direction 30.

In some examples, the aft hull part 70 may have a streamlined or approximately streamlined shape.

In some embodiments, the front hull part 50 projects a front contour in the cross-section 60, wherein tangents of the front contour along at least half of the front contour present angles A2 to the forward direction 30 in the cross-section 60 that are greater than 5 degrees.

In some examples, the angles A2 are less than 90 degrees, less than 60 degrees, less than 45 degrees, less than 30 degrees or the like. Furthermore, the angles A2 may be greater than 10 degrees, 15 degrees, 20 degrees or the like.

The front contour may thus have a streamlined shape, or approximately streamlined shape.

Said at least half of the front contour may be presented as a continuous line along said front contour. As indicated above, said continuous line may have a length than is at least half of a length of the front contour. However, in other examples, the length may be at least two thirds of the length of the front contour or other suitable value. In this manner, desired approximation to streamlined shape may be achieved. The continuous line may preferably begin at an aft most point of the front contour. Though, it may be that the continuous line begins at the widest front width 54 of the front hull part 50.

Alternatively, said at least half of the front contour may be presented as a discontinuous line along said front contour. Said discontinuous line may comprise a set of chucks of lines. As indicated above, the set of chucks of lines has a length than is at least half of the length of the front contour. This merely means that the front contour may be split into one or more lines. The hull itself is of course solid and non-leaking.

In view of the above, it may be seen as that the tangents may be constructed on the basis of a point that runs, continuously or discontinuously, along the front contour. At the aft most portion, one of the angles A2 may be 90 degrees as in e.g. Figure 2, Figure 6 and Figure 9. However, in the example of Figure 8 (see below) said one of the angles A2 may be about 20 degrees, 30 degrees, 45 degrees, 50 degrees, 60 degrees or the like. Preferably, the angles A2 are within 5 degrees and 45 degrees at least in an interval of the front contour, the extension of the interval being from a point which is at a distance, in the forward direction 30, from an aft saddle point 59, which distance is 20%, or about 20%, of the front length 52, to a point which is at a distance, in the forward direction 30, from the location of the widest front width 54, which distance is 30%, or about 30%, of the front length 52.

Accordingly, the angles A2 may continuously change as the point runs along the contour, e.g. the front contour. Thus, the curvature of the contour may change continuously. Thus, in some embodiments, the contour has no edges, or discontinuities. As a preferred example, when the point starts at the aft most portion when observing the front hull part 50, the value of the angles may gradually decrease as the point approaches the widest front width 54. However, as shown in Figure 6, again when the point starts at the aft most portion when observing the front hull part 50, the value of the angles may gradually decrease, then increase and again decrease as the point travels along the front contour towards the widest front width 54.

In some embodiments, the aft hull part 70 projects an aft contour in the cross-section 60, wherein tangents of the aft contour along at least half of the aft contour present angles A3 to the aftward direction 32 in the cross-section 60 that are greater than 5 degrees.

In some examples, the angles are less than 90 degrees, less than 60 degrees, less than 45 degrees, less than 30 degrees or the like. Furthermore, the angles may be greater than 10 degrees,

15 degrees, 20 degrees or the like.

The aft contour may thus have a streamlined shape, or approximately streamlined shape.

Said at least half of the aft contour may be presented as a continuous line along said aft contour. As indicated above, said continuous line may have a length than is at least half of a length of the aft contour. However, in other examples, the length may be at least two thirds of the length of the aft contour or other suitable value. In this manner, desired approximation to streamlined shape may be achieved. The continuous line may preferably begin at a prow most point of the aft contour. Though, it may be that the continuous line begins at the widest aft width 74 of the aft hull part 70.

Alternatively, said at least half of the aft contour may be presented as a discontinuous line along said aft contour. Said discontinuous line may comprise a set of chucks of lines. As indicated above, the set of chucks of lines has a length than is at least half of the length of the aft contour. This merely means that the aft contour may be split into one or more lines. The hull itself is of course solid and non-leaking.

In view of the above, it may be seen as that the tangents may be constructed on the basis of a point that runs, continuously or discontinuously, along the aft contour. At the prow most portion, one of the angles A3 may be 90 degrees as in e.g. Figure 2, Figure 6 and Figure 9 (see below). However, in the example of Figure 8 (see below) said one of the angles A3 may be about 20 degrees, 30 degrees, 45 degrees, 50 degrees, 60 degrees or the like. Preferably, the angles A3 are within 5 degrees and 45 degrees at least in an interval of the aft contour, the extension of the interval being from a point which is at a distance, in the aft direction 32, from a front saddle point 79, which distance is 20%, or about 20%, of the aft length 72, to a point which is at a distance, in the aft direction 32, from the location of the widest aft width 74, which distance is 30%, or about 30%, of the aft length 72.

Accordingly, the angles A3 may continuously change as the point runs along the contour, e.g. the aft contour. Thus, the curvature of the contour may change continuously. Thus, in some embodiments, the contour has no edges, or discontinuities. As a preferred example, when the point starts at the prow most portion when observing the aft hull part 70, the value of the angles may gradually decrease as the point approaches the widest aft width 74. However, as shown in Figure 6, again when the point starts at the prow most portion when observing the aft hull part 70, the value of the angles may gradually decrease, then increase and again decrease as the point travels along the aft contour towards the widest aft width 74.

Turning to Figure 3, though applicable to any embodiment herein, the front hull part 50 may have a least front width 56 at an aft most portion thereof, in the cross-section 60, in the transversal direction 34 that is less than half of the widest front width 54. Hence, in some examples, the front length 52 and the least front width 56 may together define an approximation of a streamlined shape of the front hull part 50. In cases where the front hull part 50 smoothly and continuously tapers in the aftward direction 32, the least front width 56 may be zero, or neglectably small, as evident from e.g. Figure 2, Figure 6, Figure 7 and Figure 8, which are further described below.

In a similar manner, the aft hull part 70 may have a least aft width 76 at a prow most portion thereof, in the cross-section 60, in the transversal direction 34 that is less than half of the widest aft width 74.

The front hull part 50 may be at least partially streamlined to facilitate and/or guide a flow of water towards at least one location where at least one water interacting device 45 of said at least one thruster unit 41, 42 is located. The aft hull part 70 may be at least partially streamlined to facilitate and/or guide a flow of water towards at least one location where at least one water interacting device 45 of said at least one thruster unit 41, 42 is located. Said at least one thruster unit 41, 42 is rotatable about at least one rotational axis 47, 48, being perpendicular to the cross-section 60 and being located in the main plane 20. Thus, the at least one thruster unit is preferably substantially vertical when the ship is floating in calm waters.

Figure 4 shows one exemplifying contour of the hull structure 10 as seen in the cross-section 61. In this example, the first surface 58 and/or the second surface 78 is/are concave in the cross-section 61. In other examples, these exterior surfaces of the hull structure 10 may be one or more straight lines, convex curves and as mentioned concave curves or a combination thereof. As the cross-section 61 is moved aftwards, the concavity of the contour shown in Figure 4 will gradually decrease and eventually disappear at a particular point along the aft direction 32. The aft hull part 70 may be considered to extend in the aftward direction 32 to said particular point. Thus, the aft hull part 70 may be considered to end at said particular point.

Figure 5 is a side view, illustrating an example according to which the through-hole 14 is limited by flat surfaces as in Figure 3.

Figure 6 through Figure 9 show exemplifying front contours of the front hull part 50. These examples apply equally well to the aft hull part 70. In the following, the front hull part 50 and/or the aft hull part 70 are therefore referred to as the hull part 50, 70. The exemplifying front contours are seen in the cross-section 60. Since the examples also apply to the aft hull part 70, the front contour is referred to as the contour with reference to Figure 6 through Figure 9.

Figure 6 illustrates that the hull part 50, 70 may be formed by surfaces which when observed in the cross-section 60 form convex curves, concave curves and straight lines, which together constitutes the contour of the hull part 50, 70.

Figure 7 illustrates that the hull part 50, 70 may be formed by surfaces which when observed in the cross-section 60 form convex curves and concave curves, e.g. only convex and concave curves.

Figure 8 illustrates that the hull part 50, 70 may be formed by surfaces which when observed in the cross-section 60 form straight lines, e.g. only straight lines. As seen in Figure 8, the hull part 50,

70 forms a peak towards a center of the through-hole 14.

Figure 9 illustrates that the hull part 50, 70 may be formed by surfaces which when observed in the cross-section 60 form straight lines, e.g. only straight lines. As seen in Figure 9, the hull part 50,

70 presents a flat surface 90 towards a center of the through-hole 14.

According to Figure 7 through Figure 9, these curves and/or lines do also together constitute the contour of the hull part 50, 70. The front contour 65 may thus be built up by these curves and/or lines. The examples of the hull part 50, 70 according to Figure 2 and Figure 6 to Figure 9 may render a side view as the one illustrated in Figure 5. Flowever, it may be preferred that the exterior surfaces, limiting the through-hole 14 in the forward and aft directions 30, 32 smoothly integrate with exterior surfaces of the hull structure 10. In this manner, exterior surfaces of the hull structure 10 seamlessly transitions into exterior surfaces that limits the through-hole 14 in the forward and aft directions 30, 32. The through-hole 14 may typically also be at least partially limited in the upward direction and the downward direction, which are perpendicular to the cross-section 60.

In view of the above, the first surface 58 may form at least one of straight line, convex curve and concave curve in the cross-section 60. Similarly, the second surface 78 may form at least one of straight line, convex curve and concave curve in the cross-section 60.

Figure 10 to Figure 13 illustrate a set of embodiments, in which said at least one thruster unit 41, 42 comprises a first thruster unit 41 and a second thruster unit 42, i.e. there are two thruster units. Moreover, said at least one rotational axis 47, 48 comprises a first rotational axis 47 and a second rotational axis 48. The first and second thruster units 41, 42 are rotatable about the first and second rotational axes 47, 48, respectively. The Figures illustrate some examples of how the first and second thruster units 41, 42 may be arranged to manoeuvre the ship 1 with which the hull structure 10 may be integrated. In further examples, not illustrated below, the first and second thruster units 41, 42 may be directed in the port direction or the starboard direction.

As shown in Figure 10, the first thruster unit 41 is directable in an aft starboard direction 37 between the aftward direction 32 and the starboard transversal direction 34 in the cross-section 60, and wherein the second thruster unit 42 is also directed in the aft starboard direction 37.

As shown in Figure 11, the first thruster unit 41 is directable in an aft port direction 38 between the aftward direction 32 and the port transversal direction 34 in the cross-section 60, and wherein the second thruster unit 42 is also directed in the aft port direction 38.

As shown in Figure 12, the first thruster unit 41 is directable in an aft starboard direction 37 between the aftward direction 32 and the first transversal direction 34 in the cross-section 60, and wherein the second thruster unit 42 is directable in an aft port direction 38 between the aftward direction 32 and the second transversal direction 36 that is opposite to the first transversal direction

34. As shown in Figure 13, said at least one thruster unit 41, 42, e.g. the first and second thruster units 41, 42 are capable of being directed in the forward direction 30. This may be beneficial when the ship 1 runs forwards, e.g. at cruising speed. The thruster units may be inactive during cruising speed.

Propeller blades 45 of said at least one thruster unit 41, 42 are capable of being feathered when said at least one thruster unit 41, 42 is directable in the forward direction 30.

Alternatively, the propeller blades 45 may be folded aftwards to present reduced cross-section in the forward direction 30. In this manner, the propeller blades 45, when not in use, may reduce resistance when said at least one thruster unit 41, 42 travels through the water in the forward direction 30.

Figure 14a shows a further example of the hull structure 10 in which streamlining may be further improved. Accordingly, a first surface 58 of the front hull part 50 may smoothly integrate with an exterior hull surface 13 of the hull structure 10. Likewise, a second surface 78 of the aft hull part 70 may smoothly integrate with an exterior hull surface 13 of the hull structure 10. This may also apply to the hull structure of Figure 1.

Notably, the front hull part 50 and the aft hull part 70 are in the example of Figure 14a shown as ovals, but their shapes may be more complex in reality. The ovals are merely used for purposes of providing a simple illustration. The shading is meant to illustrate that the front/aft hull parts 50, 70 smoothly integrates with the exterior surface of the hull structure. Flence, in many cases, there is no visible border that shows where the front/aft hull parts 50, 70 begin and/or end.Flowever, unlike the hull structure 10 of Figure 1, in this example as shown in Figure 14a, the exterior hull surface 13 is smoothly integrated along and a lower longitudinal edge 1401 and an upper longitudinal edge (not indicated) of the through-hole 14. In the cross-sectional view of Figure 14b as seen in the cross- section 1405 indicated in Figure 14a, the through-hole 14 may thus expand towards the exterior surfaces of the hull structure 10.

With the hull structure 10 of Figure 1, a longitudinal edge 1410 of the through-hole 14 may be sharper as shown in Figure 14c. In the example of Figure 1 and Figure 2, the first surface 58 comprises an aft saddle point 59 located in the tilted cross-section 62 when the tilted cross-section is central in the through-hole 14. Likewise, the second surface 78 comprises a forward saddle point 79 located in the tilted cross-section 62 when being central in the through-hole 14. The saddle points 59, 79 are illustrated in Figure 14a.

Also, with reference to Figure 14a though applicable to any embodiment herein, it may be that the aft length 72 may be at least one quarter of a through-hole length in a transversal cross-section, along the line 1405, being central in the through-hole 14 with respect to a longitudinal direction of the through-hole 14.

Still referring to Figure 14b and/or Figure 14c, in some examples, said at least one thruster unit

41, 42 and/or the hull structure 10 is/are adapted to ensure that at least one water interacting device 45 of said at least one thruster unit 41, 42 remains within an outer contour 1420, 1422 of the hull structure 10 during a revolution of said at least one thruster unit 41, 42 about at least one rotational axis 47, 48 (shown in Figure 2).

It may be that some portion of said at least one thruster unit 41, 42 extend out of the outer contour 1420, 1422 when said at least one thruster unit 41, 42 is directed in certain directions, e.g. during a revolution. Flowever, in some examples, the entirety of said at least one thruster unit 41, 42 remains within the outer contour 1420, 1422 of the hull structure 10.

The outer contour 1420, 1422 of the hull structure 10 may coincide with imaginary exterior surfaces of the hull structure 10 as imagined when there is no through-hole 14 in the hull structure 10. As an example, the outer contour 1420, 1422 of the hull structure 10 may preferably present a continuous curvature, which may typically mostly present an angle to the aft direction 32 of at least 5 degrees, 10 degrees or the like. The continuous curvature may be convex with a continuously increasing curvature in the aftward direction 32.

In Figure 15, a schematic flowchart of exemplifying methods in the thruster control module 1600 is shown. Accordingly, the thruster control module 1600 performs a method for manoeuvring a ship 1 comprising the hull structure 10 according to any one of the embodiments herein.

Said at least one thruster unit 41, 42 comprises a first thruster unit 41 and a second thruster unit

42, wherein said at least one rotational axis 47, 48 comprises a first rotational axis 47 and a second rotational axis 48, wherein the first and second thruster units 41, 42 are individually rotatable about the first and second rotational axes 47, 48, respectively.

One or more of the following actions may be performed in any suitable order.

Action 1510

The thruster control module 1600 directs the first thruster unit 41 in an aft starboard direction 37 between the aftward direction 32 and a first transversal direction 34 in the cross-section 60.

Action 1520

The thruster control module 1600 directs the second thruster unit 42 in an aft port direction 38 between the aftward direction 32 and a second transversal direction 36 that is opposite to the first transversal direction 34. Actions 1510 and 1520 may be performed simultaneously. However, as a result of these actions, the first and second thruster units 41, 42 are directed towards the aft starboard direction 37 and the aft port direction 38 simultaneously.

Action 1530

The thruster control module 1600 runs the first and second thruster units 41, 42. In this manner, the thruster control module 1600 may activate a limp home mode for providing emergency manoeuvrability of the ship 1. The limp home mode requires that said at least one thruster unit 41,

42 comprises at least two thruster units 41, 42. It may be preferred that the number of thruster units is even, but it is also possible to realize the limp home mode with an odd number of thruster units.

In one example, there may be three thruster units. Then, one thruster unit may be inactivated in the limp home mode and the other two may contribute equally to propulsion of the ship 1.

Alternatively, a pair of thruster units of the three thruster units may together contribute to propulsion as much as the one thruster unit (remaining among the three thruster units).

With reference to Figure 16, a schematic block diagram of embodiments of the thruster control module 1600 of Figure 1 is shown. The thruster control module 1600, such as a computer, a processing device, an automation control unit etc., may be comprised in the ship 1, the hull structure 10, the hull portion 12 or the like.

The thruster control module 1600 may comprise a processing module 1601, such as a means for performing the methods described herein. The means may be embodied in the form of one or more hardware modules and/or one or more software modules. The term "module" may thus refer to a circuit, a software block or the like according to various embodiments as described below.

The thruster control module 1600 may further comprise a memory 1602. The memory may comprise, such as contain or store, instructions, e.g. in the form of a computer program 1603, which may comprise computer readable code units.

According to some embodiments herein, the thruster control module 1600 and/or the processing module 1601 comprises a processing circuit 1604 as an exemplifying hardware module. Accordingly, the processing module 1601 may be embodied in the form of, or 'realized by', the processing circuit 1604. The instructions may be executable by the processing circuit 1604, whereby the thruster control module 1600 is operative to perform the method of Figure 15. As another example, the instructions, when executed by the thruster control module 1600 and/or the processing circuit 1604, may cause the thruster control module 1600 to perform the method according to Figure 15.

In view of the above, in one example, there is provided a thruster control module 1600 for manoeuvring a ship 1 comprising a hull structure 10 according to any one of the embodiments herein. As mentioned, said at least one thruster unit 41, 42 comprises a first thruster unit 41 and a second thruster unit 42, wherein said at least one rotational axis 47, 48 comprises a first rotational axis 47 and a second rotational axis 48, wherein the first and second thruster units 41, 42 are rotatable about the first and second rotational axes 47, 48, respectively. Again, the memory 1602 contains the instructions executable by said processing circuit 1604 whereby the thruster control module 1600 is operative for:

directing the first thruster unit 41 in an aft starboard direction 37 between the aftward direction 32 and a first transversal direction 34 in the cross-section 60,

directing the second thruster unit 42 in an aft port direction 38 between the aftward direction 32 and a second transversal direction 36 that is opposite to the first transversal direction 34, and running the first and second thruster units 41, 42.

Figure 16 further illustrates a carrier 1605, or program carrier, which provides, such as comprises, mediates, supplies and the like, the computer program 1603 as described directly above. The carrier 1605 may be one of an electronic signal, an optical signal, a radio signal and a computer readable medium.

In further embodiments, the thruster control module 1600 and/or the processing module 1601 may comprise one or more of a directing module 1610 and a running module 1620 as exemplifying hardware modules. The term "module" may refer to a circuit when the term "module" refers to a hardware module. In other examples, one or more of the aforementioned exemplifying hardware modules may be implemented as one or more software modules.

Moreover, the thruster control module 1600 and/or the processing module 1601 may comprise an Input/Output module 1606, which may be exemplified by a receiving module and/or a sending module when applicable. The receiving module may receive commands and/or information from various entities, such as said at least one thruster unit 41, 42 or the like, and the sending module may send commands and/or information to various entities, such as said at least one thruster unit 41, 42 or the like. Accordingly, the thruster control module 1600 is configured for manoeuvring a ship 1 comprising a hull structure 10 according to any one of the embodiments herein. As mentioned, said at least one thruster unit 41, 42 comprises a first thruster unit 41 and a second thruster unit 42, wherein said at least one rotational axis 47, 48 comprises a first rotational axis 47 and a second rotational axis 48, wherein the first and second thruster units 41, 42 are rotatable about the first and second rotational axes 47, 48, respectively.

Therefore, according to the various embodiments described above, the thruster control module 1600 and/or the processing module 1601 and/or the directing module 1610 is configured for directing the first thruster unit 41 in an aft starboard direction 37 between the aftward direction 32 and a first transversal direction 34 in the cross-section 60.

The thruster control module 1600 and/or the processing module 1601 and/or the directing module 1610, or another directing module (not shown) is further configured for directing the second thruster unit 42 in an aft port direction 38 between the aftward direction 32 and a second transversal direction 36 that is opposite to the first transversal direction 34.

Moreover, the thruster control module 1600 and/or the processing module 1601 and/or the running module 1620 is configured for running the first and second thruster units 41, 42.

As used herein, the term "rotate", "rotatable" or the like may be interchanged with "turn", "turnable" of the like. A rotation, or turn, may be a portion of a complete revolution, one revolution, greater than one revolution, an integer, irrational or real multiple of one revolution.

As used herein, the term "module" may refer to one or more functional units, each of which may be implemented as one or more hardware modules and/or one or more software modules and/or a combined software/hardware module. In some examples, the module may represent a functional unit realized as software and/or hardware.

As used herein, the term "computer program carrier", "program carrier", or "carrier", may refer to one of an electronic signal, an optical signal, a radio signal, and a computer readable medium. In some examples, the computer program carrier may exclude transitory, propagating signals, such as the electronic, optical and/or radio signal. Thus, in these examples, the computer program carrier may be a non-transitory carrier, such as a non-transitory computer readable medium.

As used herein, the term "processing module" may include one or more hardware modules, one or more software modules or a combination thereof. Any such module, be it a hardware, software or a combined hardware-software module, may be a determining means, estimating means, capturing means, associating means, comparing means, identification means, selecting means, receiving means, sending means or the like as disclosed herein. As an example, the expression "means" may be a module corresponding to the modules listed above in conjunction with the Figures. As used herein, the term "software module" may refer to a software application, a Dynamic Link Library (DLL), a software component, a software object, an object according to Component Object Model (COM), a software function, a software engine, an executable binary software file or the like.

The terms "processing module" or "processing circuit" may herein encompass a processing module, comprising e.g. one or more processors, an Application Specific integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA) or the like. The processing circuit or the like may comprise one or more processor kernels.

As used herein, the expression "configured to/for" may mean that a processing circuit is configured to, such as adapted to or operative to, by means of software configuration and/or hardware configuration, perform one or more of the actions described herein.

As used herein, the term "action" may refer to an action, a step, an operation, a response, a reaction, an activity or the like. It shall be noted that an action herein may be split into two or more sub-actions as applicable. Moreover, also as applicable, it shall be noted that two or more of the actions described herein may be merged into a single action.

As used herein, the term "memory" may refer to a hard disk, a magnetic storage medium, a portable computer diskette or disc, flash memory, random access memory (RAM) or the like.

Furthermore, the term "memory" may refer to an internal register memory of a processor or the like.

As used herein, the term "computer readable medium" may be a Universal Serial Bus (USB) memory, a Digital Versatile Disc (DVD), a Blu-ray disc, a software module that is received as a stream of data, a Flash memory, a hard drive, a memory card, such as a Multimedia Card (MMC), Secure Digital (SD) card, etc. One or more of the aforementioned examples of computer readable medium may be provided as one or more computer program products.

As used herein, the term "computer readable code units" may be text of a computer program, parts of or an entire binary file representing a computer program in a compiled format or anything there between.

As used herein, the terms "number" and/or "value" may be any kind of digit, such as binary, real, imaginary or rational number or the like. Moreover, "number" and/or "value" may be one or more characters, such as a letter or a string of letters. "Number" and/or "value" may also be represented by a string of bits, i.e. zeros and/or ones.

As used herein, the terms "first", "second", "third" etc. may have been used merely to distinguish features, apparatuses, elements, units, or the like from one another unless otherwise evident from the context.

As used herein, the term "subsequent action" may refer to that one action is performed after a preceding action, while additional actions may or may not be performed before said one action, but after the preceding action. As used herein, the term "set of" may refer to one or more of something. E.g. a set of devices may refer to one or more devices, a set of parameters may refer to one or more parameters or the like according to the embodiments herein.

As used herein, the expression "in some embodiments" has been used to indicate that the features of the embodiment described may be combined with any other embodiment disclosed herein.

Each embodiment, example or feature disclosed herein may, when physically possible, be combined with one or more other embodiments, examples, or features disclosed herein.

Furthermore, many different alterations, modifications and the like of the embodiments herein may be become apparent for those skilled in the art. The described embodiments are therefore not intended to limit the scope of the present disclosure.

Claims

1. A hull structure (10) for integration with a hull (2) of a ship (1), wherein the hull structure (10) has a main plane (20), perpendicularly to which a transversal direction (34) of the hull structure (10) is defined, and parallelly to which a forward direction (30) and an aftward direction (32) of the hull structure (10) is defined, wherein the hull structure (10) comprises:

a through-hole (14), extending through the hull structure (10) in the transversal direction (34), wherein the hull structure (10) is adapted to accommodate at least one thruster unit (41, 42) in the through-hole (14),

characterized in that

the hull structure (10) comprises a front hull part (50) limiting the through-hole (14) in the forward direction (30),

wherein the front hull part (50) is tapered, in the aftward direction (32), in a cross- section (60) that is perpendicular to the main plane (20) and that is parallel to the aftward direction (32), wherein the front hull part (50) has a front length (52), in the cross-section (60), in the aftward direction (32) that is greater than one quarter of a widest front width (54) of the front hull part (50) in the cross-section (60).

2. The hull structure (10) according to claim 1, wherein the front hull part (50) projects a front contour in the cross-section (60), wherein tangents of the front contour along at least half of the front contour present angles to the forward direction (30) in the cross-section (60) that are greater than 5 degrees.

3. The hull structure (10) according to any one of the preceding claims, wherein the hull structure (10) comprises an aft hull part (70) limiting the through-hole (14) in the aftward direction (32), wherein the aft hull part (70) is tapered, in the forward direction (30), in the cross-section (60), wherein the aft hull part (70) has an aft length (72), in the cross-section (60), in the forward direction that is greater than one quarter of a widest aft width (74) of the aft hull part (70) in the cross-section (60).

4. The hull structure (10) according to claim 3, wherein the aft hull part (70) projects an aft contour in the cross-section (60), wherein tangents of the aft contour along at least half of the aft contour present angles to the aftward direction (32) in the cross-section (60) that are greater than 5 degrees.

5. The hull structure (10) according to any one of the preceding claims, wherein a first surface (58) of the front hull part (50) smoothly integrates with an exterior hull surface (13) of the hull structure (10), and/or

wherein a second surface (78) of the aft hull part (70) smoothly integrates with an exterior hull surface (13) of the hull structure (10).

6. The hull structure (10) according to claim 5, wherein the first surface (58) forms at least one of straight line, convex curve and concave curve in the cross-section (60).

7. The hull structure (10) according to claim 5 or 6, wherein the second surface (78) forms at least one of straight line, convex curve and concave curve in the cross-section (60).

8. The hull structure (10) according to any one of the preceding claims, wherein the front hull part (50) is at least partially streamlined to facilitate and/or guide a flow of water towards at least one location where at least one water interacting device (45) of said at least one thruster unit (41, 42) is located.

9. The hull structure (10) according to any one of claims 3-8, when dependent on claim 3, wherein the aft hull part (70) is at least partially streamlined to facilitate and/or guide a flow of water towards at least one location where at least one water interacting device (45) of said at least one thruster unit (41, 42) is located.

10. The hull structure (10) according to any one of claims 1-9, wherein the through-hole (14) is

elongated in a tilt direction (33) in the main plane (20), wherein an angle (Al) between the tilt direction (33) and the forward direction (30) is greater than zero.

11. The hull structure (10) according to any one of claims 1-10, wherein said at least one thruster unit (41, 42) is rotatable about at least one rotational axis (47, 48), being perpendicular to the cross-section (60).

12. The hull structure (10) according to claim 11, wherein said at least one thruster unit (41, 42) comprises a first thruster unit (41) and a second thruster unit (42), wherein said at least one rotational axis (47, 48) comprises a first rotational axis (47) and a second rotational axis (48), wherein the first and second thruster units (41, 42) are rotatable about the first and second rotational axes (47, 48), respectively.

13. The hull structure (10) according to claim 12, wherein the first thruster unit (41) is directable in an aft starboard direction (37) between the aftward direction (32) and a first transversal direction (34) in the cross-section (60), and wherein the second thruster unit (42) is directable in an aft port direction (38) between the aftward direction (32) and a second transversal direction (36) that is opposite to the first transversal direction (34).

14. The hull structure (10) according to any one of claims 11-13, wherein said at least one thruster unit (41, 42) and/or the hull structure (10) is/are adapted to ensure that at least one water interacting device (45) of said at least one thruster unit (41, 42) remains within an outer contour (1420, 1422) of the hull structure (10) during a revolution of said at least one thruster unit (41,

42) about said at least one rotational axis (47, 48).

15. The hull structure (10) according to any one of claims 1-14, wherein said at least one thruster unit (41, 42) is capable of being directed in the forward direction (30).

16. The hull structure (10) according to claims 15, wherein propeller blades (45) of said at least one thruster unit (41, 42) are capable of being feathered when said at least one thruster unit (41, 42) is directable in the forward direction (30).

17. A method, performed by a thruster control module (1600), for manoeuvring a ship (1) comprising a hull structure (10) according to any one of claims 1-16, wherein said at least one thruster unit (41, 42) comprises a first thruster unit (41) and a second thruster unit (42), wherein said at least one rotational axis (47, 48) comprises a first rotational axis (47) and a second rotational axis (48), wherein the first and second thruster units (41, 42) are rotatable about the first and second rotational axes (47, 48), respectively, wherein the method comprises:

directing (1510) the first thruster unit (41) in an aft starboard direction (37) between the aftward direction (32) and a first transversal direction (34) in the cross-section (60),

directing (1520) the second thruster unit (42) in an aft port direction (38) between the aftward direction (32) and a second transversal direction (36) that is opposite to the first transversal direction (34), and

running (1530) the first and second thruster units (41, 42).

18. A computer program (1603), comprising computer readable code units which when executed on a thruster control module (1600) causes the thruster control module (1600) to perform the method according to claim 17.

19. A carrier (1605) comprising the computer program according to the preceding claim, wherein the carrier (1605) is one of an electronic signal, an optical signal, a radio signal and a computer readable medium.

20. A thruster control module (1600) configured for manoeuvring a ship (1) comprising a hull

structure (10) according to any one of claims 1-16, wherein said at least one thruster unit (41, 42) comprises a first thruster unit (41) and a second thruster unit (42), wherein said at least one rotational axis (47, 48) comprises a first rotational axis (47) and a second rotational axis (48), wherein the first and second thruster units (41, 42) are rotatable about the first and second rotational axes (47, 48), respectively, wherein the thruster control module (1600) is configured for:

directing the first thruster unit (41) in an aft starboard direction (37) between the aftward direction (32) and a first transversal direction (34) in the cross-section (60),

directing the second thruster unit (42) in an aft port direction (38) between the aftward direction (32) and a second transversal direction (36) that is opposite to the first transversal direction (34), and

running the first and second thruster units (41, 42).