Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
  • B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
  • B63H5/125—Arrangements on vessels of propulsion elements directly acting on water of propellers movably mounted with respect to hull, e.g. adjustable in direction, e.g. podded azimuthing thrusters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
  • B63B35/66—Tugs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
  • B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
  • B63H5/14—Arrangements on vessels of propulsion elements directly acting on water of propellers characterised by being mounted in non-rotating ducts or rings, e.g. adjustable for steering purpose
  • B63H5/15—Nozzles, e.g. Kort-type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
  • B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
  • B63H5/125—Arrangements on vessels of propulsion elements directly acting on water of propellers movably mounted with respect to hull, e.g. adjustable in direction, e.g. podded azimuthing thrusters
  • B63H2005/1254—Podded azimuthing thrusters, i.e. podded thruster units arranged inboard for rotation about vertical axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H25/00—Steering; Slowing-down otherwise than by use of propulsive elements; Dynamic anchoring, i.e. positioning vessels by means of main or auxiliary propulsive elements
  • B63H25/42—Steering or dynamic anchoring by propulsive elements; Steering or dynamic anchoring by propellers used therefor only; Steering or dynamic anchoring by rudders carrying propellers

Definitions

• the invention relates to a tugboat having azimuthal propelling units.
• azimuthal propelling unit a propelling unit whose propelling direction in horizontal direction can be varied through 360°.
• azimuthal propelling units are already known per se, for instance in the form of a nozzle having a propeller arranged therein.
• a tugboat cannot only produce hauling power in forward direction, but also in rearward direction, and even in lateral direction, although the hauling power producible in lateral direction will be less than the hauhng power producible in longitudinal direction.
• a tug boat having three azimuthal propelling units. Two azimuthal propelling units are provided at a first longitudinal position, on opposite sides of a mid sectional plane of the tugboat. A third azimuthal propelling unit is positioned at a longitudinal position different from the longitudinal positions of said two azimuthal propelling units.
• each propelling unit has a propeller shaft and a main shaft. The propeller can be rotated around the main shaft over at least 360 degi'ees and the main shafts extend parallel to each other, in a vertical direction when the tug boat is level.
• tug boats especially for use in harbors and waterways with draft limitations and/or harbors and waterways featuring tug pens with draft restrictions, it is important to provide sufficient towing force, for pulling and/or pushing assisted vessels. There is therefore a desire to alternative tug boats having optimal power and draft, while remaining agile and reliable.
• the object of the invention is to provide a tugboat which, in respect of the above-mentioned aspects, performs better than the tugs known thus far.
• An object of the invention is to provide a tugboat which can produce more power than the rotor tug type tugs known thus far, without the draft being increased.
• An object of the invention is to provide a tugboat which can produce similar power as the rotor tug type tugs known thus far, with the draft being decreased.
• an increase of the power producible can be realized by using two stronger propelling units, but a consequence thereof is that the dimensions of the propelling units are increased as well, which has an adverse effect on the draft of the ship.
• a tugboat according to the present invention may have three azimuthal propelling units viewed from the top, lie in a triangular pattern, wherein of at least the main axis of two such propelling units on opposite sides of a mid sectional plane of the tug boat extend at an angle relative to a vertical line when the tug boat is in a level position.
• Such angle preferably is formed by or includes an angle with the mid sectional plane of the tug boat.
• Such angle may be formed by or include an angle in a plane parallel to said mid sectional plane.
• an improved towing behavior can be obtained by the improved arrangement of the thrusters in relation to the towing points.
• Fig. 1 schematically shows a side view of a tug boat according to the prior art
• Fig. 2 schematically shows an azimuthal propelling unit
• Fig 3 schematically shows in top plan view a tugboat according to the present invention, to illustrate the positions of the three propelling units;
• Fig. 4 is a schematic longitudinal section taken on the line II-II in Fig. 3;
• Fig. 5 is a schematic cross section taken on the line V-V in Fig. 3
• Fig. 5 A shows in a view according to fig. 5 part of a tug boat with two juxtaposed propelling units with sideways thrust, showing their main direction of thrust and general wake;
• Fig. 6 shows in front view a tugboat according to the prior art
• Fig. 7 shows in front view a tugboat according to the present invention
• Fig. 8 shows in side view a tugboat according to fig 7 in a first embodiment
• Fig. 9 shows in side view a tug boat according to fig. 7 in a second embodiment
• Fig. 10 shows in side view a tug boat according to fig. 7 in a third embodiment
• Fig. 11 shows in side view a tug boat according to fig. 7 in a fourth embodiment.
• Fig. 1 schematically shows in side view a tugboat 1.
• the tugboat 1 is afloat in approximately even keel, or - zero trim condition, and the expression 'horizontal' and 'vertical' are meant relative to the water surface.
• Fig 3 schematically shows the contour of a tug boat 1 seen from above, showing the position of propelling units 10, 20, 30. They are shown as positioned at the corners of a triangle, by way of example.
• a tug boat according to the disclosure can for example be but is not limited to a tug boat designed for harbor assistance to vessels, for near shore assistance to vessels and or for open water assistance to vessels.
• a tug boat can be a boat for assistance in fire fighting, such as a fire boat, or for other assistance in harbors, near shore, or off-shore such as ice-breaking, anchor- handling, hose-handling, supply, in-field support, dive support, ROV support and/or other offshore support.
• propelling units in relation to propelling units as will be described, be understood as meaning at least that at least two units are positioned at opposite sides of an intermediate plane, especially an intermediate vertical plane, extending in a longitudinal direction of the tug boat. Such units can be referred to as juxtaposed propelling units.
• the tugboat 1 is substantially symmetric relative to a vertical main plane of symmetry 2 (II - II in fig. 3), extending in the longitudinal direction of the tugboat 1.
• the tugboat 1 has a front extreme point 3 located in the main plane of symmetry 2, and a rear extreme point 4 also located in the main plane of symmetry 2.
• the horizontal distance between the front and rear extreme points 3 and 4 is indicated as the length L of the tugboat 1.
• horizontal length positions will be indicated as measured relative to the rear extreme point 4.
• a vertical plane is indicated in the figures which is perpendicular to the main plane of symmetry 2, and which intersects that main plane of symmetry 2 according to a vertical line precisely halfway the front and rear extreme points 3 and 4. That vertical line M will be referred to as the center of the tugboat 1, and the vertical plane 5 will be referred to as the transverse center plane of the tugboat 1.
• horizontal width positions will be indicated as measured relative to the main plane of symmetry 2.
• the body portion of the tugboat 1 located behind the transverse center plane 5 will be referred to as the stern 6 or stern side, and the body portion of the tugboat 1 located before the transverse center plane 5 will be referred to as the bow 7 or bow side.
• a towing point 8 provided on the stern 6, i.e. a point intended for securing a towing cable or the like thereto, or for guiding, via that point, a towing cable or the like to a towing winch, or towing hook.
• the tugboat 1 can have several towing points; for instance, a towing point 8A can be provided on the bow 7 and a towing point 8B can be provided on the stern 6. If the tugboat 1 has several towing points on the bow 7 and/or stern 6, the towing point 8 is meant to be the last point of physical contact between towing line 100 and tugboat 1.
• a contact point is to be understood as also including a line contact or relatively small area of contact.
• any towing point 8, 8A can be indicated by reference sign L with an indicator, such as 8 or 8A.
• Towing points 8, 8A can for example comprise a winch 101, such as but not limited to a render recovery winch, for winching a towing line 100.
• the tug boat can further be provided with a fendering system, for allowing pushing as well as pulling of a vessel to be assisted, or for operating in close proximity to other vessels and/or structures.
• the tugboat 1 comprises three azimuthal propelling units 10, 20 and 30, whose propelling direction in horizontal direction can be varied through 360° relative to the respective main axis 11, 21, 31 associated with the propelling units 10, 20 and 30.
• Each propelling unit may be driven by a separate driving engine or different propelling units can be driven by the same motor, for example through appropriate gear boxes, or engine-driven generators in combination with electric- driven propelling units, not shown for simplicity's sake.
• Such azimuthal propelling units are known per se, for instance in the form of a screw, a nozzle having a propeller arranged therein, or a so-called Voith Schneider unit.
• An example of such propelling unit is shown in fig. 2, by way of example only, not limiting the scope of this disclosure in any way.
• As the nature and construction of such azimuthal propelling units do not constitute a subject of the present invention, and a skilled person need not have specific knowledge thereof for a proper understanding of the present invention, they will not be further described further than necessary for the disclosure.
• a propelling unit has a propeller 12 mounted on a propeller shaft 13.
• the propeller shaft 13 extends at an astute, for example substantially right angle (90 degrees) to a main axis or main shaft 14, traditionally referred to as a vertical axis 11, 21, 31, though in the present invention for at least one of the propelling units 10, 20, 30 the main shaft 14 may extend non-vertical and may enclose an angle relative to the planes 2 and/or 5.
• the propeller 12 will normally be enclosed by a nozzle 15 extending around it.
• the propeller shaft 13 is driven by the main shaft 14, and can rotate around the main axis 11, 21, 31 over an angle of 360 degrees or more in order to direct the thrust of the propelling unit 10, 20, 30 in any desired direction.
• the main shaft 14 extends through a thruster well 17, which can also be referred to as well 17, which will be fixed in and/or formed by the hull of the tug boat 1, such that connections to the propelling unit 10, 20 , 30, such as to a motor or electrics, controls and the like can be achieved inside said hull 18..
• a thruster well 17 which can also be referred to as well 17, which will be fixed in and/or formed by the hull of the tug boat 1, such that connections to the propelling unit 10, 20 , 30, such as to a motor or electrics, controls and the like can be achieved inside said hull 18.
• the forces acting on the propelling unit 10, 20, 30, for example by the thrust generated by the propeller 12, or forces between the hull 18 and the propelling unit 10, 20, 30 will have to be transferred to the hull 18 and vice versa through the thruster well 17.
• the thruster well 17 will have to be sufficiently strong, for example reinforced by ribs, beams, brackets or the like, again requiring space.
• the three azimuthal propelling units 10, 20 and 30 can be arranged according to an isosceles triangle, the triangle being placed symmetrically relative to the main plane of symmetry 2. It is preferred that two azimuthal propelling units 10 and 20 be located on one side of the transverse center plane 5, and that the third azimuthal propelling unit 30 be located on the other side of the transverse center plane 5, seen in said longitudinal direction L of the boat 1.
• a first azimuthal propelling unit 10 and a second azimuthal propelling unit 20 may be located below the bow 7, symmetrically on both sides of the transverse center plane 5.
• the length position Lno of the main shaft 14 of the first azimuthal propelling unit 10 is equal to the length position L20 of the main shaft 14 of the second azimuthal propelling unit 20.
• These positions are greater than 0.5 L, while the width position B 10 of the main axis 14 of the first azimuthal propelling unit 10 is equal (but opposite) to the width position B20 of the main axis 14 of the second azimuthal propelling unit 20.
• the length positions L10 and L20 they may be greater than 0.65L and preferably greater than 0.7 L. In combination with geometry of hull 18 this further restricts available space, further limiting possible
• the length position thereof is preferably greater than or equal to Lio and L20. If a towing point is provided on the stern 6, the length position thereof is preferably greater than or equal to Lao.
• the main axis 14 of the third azimuthal propelling unit 30 preferably lies in the main plane of symmetry 2, and has a length position L30 smaller than 0.5 , and may be greater than or equal to 0.15 L or less.Lso may be smaller than or equal to 0.4 L, for example smaller than or equal to 0.25 . L3 ⁇ 4o may be greater than or equal to Ls or smaller than Ls for the towing point 8 at the stern.
• the position and especially the length position L or B is defined by the position P in which the main shaft 14 of a propelling unit crosses the hull 18 or an imaginary plane of the hull 18 as a continuation of the hull 18 over the relevant thruster well 17 or opening in which the thruster well 17 is mounted in the hull 18.
• the main shaft 14 extends non-vertical, such that the lower end 14A of the main shaft is not directly below the said position P, contrary to the tug boat according to the prior art, in which the said lower end 14A of each of the main shafts 14 is indeed directly below said position P since the main shaft 14 of each propelling unit 10, 20, 30 extends vertically, said shafts 14 in the prior art hence extending parallel to each other and parallel to the main planes 2 and 5.
• fig. 5 schematically a vertical cross sectional view is shown through the axis 11, 21 of the main shafts 14 of the first and second propeller units 10, 20.
• These axis 11, 21 in this embodiment Lie in a plane V- V parallel to the plane 5, as indicated in fig. 3.
• each of the axis 11, 21 includes an angle a with the mid-sectional plane 2, in fig. 5 represented by the vertical line between the two units 10, 20.
• the angle a can for example be between 1 and 15 degrees, such as for example between 1 and 10 degrees, for example between 2 and 10 degrees, such as but not limited to between 2 and 8 degrees.
• Fig. 6 shows in front view the position of especially the first and second propelling units 10, 20 of a tug boat of the prior art, having the main axis 11, 21 extending vertically, parallel to each other.
• contract fig. 7 shows a tug boat according to the invention, which is shown as substantially identical to that of fig. 6 but having the main axis 11, 21 of the first and second propeller units 10, 20 angled relative to each other and to the plane 2, as shown in fig. 5.
• the horizontal distance D r0 p between the centers of the propellers 12 when the propeller shafts 12 extend parallel to each other, perpendicular to the plane V - V, in the prior art tug boat can be smaller than the said distance D pr0 p in a tug boat according to the invention when the distance D p between the points P where said axis 11 and 21 cross the actual or imaginary surface of the hull 18 is the same.
• This can have the advantage that the moment that each of the propellers can exert by thrust relative to the center M of the tug boat 1 can exert can be larger, with the same propeller 12 or could be the same with a smaller propeller 12.
• each propelling unit 10, 20, 30 has a main direction of thrust Dt, preferably directed perpendicular to the main axis 11, 21, 31.
• the main direction of thrust Dt should be understood as meaning a center line extending from the center of the propeller 12 in a direction parallel to and preferably coinciding with an axis 12A of the propeller shaft 12.
• This hne or main direction of thrust Dt extends as a center line of the substantially cone shaped wake W of water displaced by the relevant propeller. As can be seen in fig.
• the juxtaposed propelling units 10, 20 can be mounted such that when their main directions of thrust Dt seen in top view are directed in the same direction and in said top view parallel to each other or even coinciding, the main direction of thrust Dt of a first 10 of the two juxtaposed propelling units is directed below the main direction of thrust Dt of the second 20 of the two juxtaposed propelling units 10, 20 or vice versa, depending on the said direction of thrust.
• the main direction of thrust Dt of a first 10 of the two juxtaposed propelling units is directed below the main direction of thrust Dt of the second 20 of the two juxtaposed propelling units 10, 20 or vice versa, depending on the said direction of thrust.
• they do not interfere or at least to a lesser extend than in the prior art tug boat.
• the hull 18 interferes less or not with the wake W of the propellers 12 than in the tug boat according to the prior art.
• the hull 18 can have an inclined surface area 18A at and near the respective points P as discussed.
• the nozzle 15 can be brought closer to the said surface, i.e. the distance c between the said area 18A and the nozzle 15 measured at the axis 11, 21 can be shorter than in the prior art, again resulting in a smaller distance T when using the same size propeller 12 or with the same distance T a larger propeller can be used.
• the nozzle 15 can be brought closer to the hull 18 at least since by
• the inclination of the axis 11, 21 of the respective propelling units 10, 20 can have the advantage that they can be placed further from the plane 5 in the tug boat 1, for example closer to the stem or bow 7, at a length position L10 + , L20 + , increasing the distance between the center C of the boat and the respective propellers 12 compared to the prior art tug boat, as can be seen in a comparison between figs. 8 and 9, wherein in fig. 8 a side view is shown with the units 10, 20 in a conventional length position Lio, L20, which may or may not be according to the invention, and in fig. 9 a side view is given in an embodiment of the invention having the units 10, 20 further forward, at length position L10+, L20+.
• the moment that can be exerted through the thrust of each propeller 12 relative to said center C can be increased, when using the same propeller or the same moment when using a smaller propeller. Smaller can in this respect be understood as smaller in size and/or in thrust.
• Fig. 10 shows an alternative embodiment of the present invention, in which the main shafts 14, or at least the main axis 11, 21 of the first and second propeller units 10, 20 are inclined, that is include an angle 6 with a vertical plane V - V parallel to the plane 5.
• the axis 11, 21 are inclined such that the lower ends 14A of the shafts 14 are brought forward relative to the points P.
• This can in embodiments be combined with the angular position as disclosed here before in relation to i.a. fig. 5 and 7, or seen in front view the axis 11, 21 can be parallel to each other and extend vertical. As can be seen in fig. 10 this can bring the propellers 12 of the units 10, 21 further forward, increasing the moment that can be exerted relative to the center C.
• the distance T can be reduced when using the same size propeller or the same distance T can be maintained as in the prior art tug boat when using a larger propeller 12.
• the nozzle and thus the propeller can be positioned closed to the hull 18. In embodiments the wake of the propellers 12 and thus the thrust may interfere less with the hull 18, increasing efficiency.
• Fig. 11 shows a further alternative embodiment, in which the third propelling unit 30 has a main shaft 14 with a main axis 11 extending at an angle ⁇ in the mid sectional plane 2 or a plane parallel to that plane 2, which angle ⁇ can for example be such that the lower end 14A is located behind the relevant point P i.e. behind the upper end 14B of said shaft 14.
• the angle ⁇ can for example be between 1 and 15 degrees, such as for example between 1 and 10 degrees, for example between 2 and 10 degrees, such as but not limited to between 2 and 8 degrees.
• the angles a, 6 and ⁇ may not be to scale and can be represented larger for clarity.
• both the first and second propelling units 10, 20 and the third propelhng unit 30 have main axis 11, 21, 31 which are inchned relative to a vertical plane, seen in side view. It shall be clear that also only the third propelling unit 30 can have such inclination.
• the inclinations of the axis 11 and 21 may differ from that of the third axis 31.
• the axis 11, 21 may be inclined in two directions, i.e.
• angles ⁇ , 6 may both differ from 0 or 180 degrees and may both for example be between 1 and 15 degrees, such as for example between 1 and 10 degrees, for example between 2 and 10 degrees, such as but not hmited to between 2 and 8 degrees, wherein the angles ⁇ , ⁇ may be the same or different for the respective axis 11, 21.
• the three azimuthal propelling units 10, 20 and 30 can be mounted entirely below the bottom 9 of the tugboat 1. However, it is also possible that the azimuthal propelling units 10, 20 and 30 are partly recessed in the bottom 9 of the tugboat 1, so that the tugboat 1 will have a less great draft. This applies in particular to the third azimuthal propelling unit 30, located at the center of the tugboat 1, because, viewed in cross section, the bottom 9 of the tugboat 1 is generally more or less V-shaped, so that in fact, the lowermost point of the third azimuthal propelling unit 30 may determine the draft of the tugboat 1 if propellers of the same size are used.
• the inclination of the axis 11, 21, 31 may be further beneficial since the thrust of the propellers will be less influenced by the sides and edges of such recess, increasing the effective thrust that can be achieved for these units 10, 20, 30.
• the thrust side ways can even further be increased since part of the thrust of a first of the two propelling units 10, 20 which seen in direction of thrust is in front of the second of the two propelling units 20, 10 will pass below said second propelling unit.
• that thrust i.e. the water displaced by the propeller 12 of said second propelling unit will pass below the hull 18 to a greater extend than when the axis 11, 21 would be vertical, further increasing efficiency.
• the third azimuthal propelling unit 30 is located in the main plane of symmetry 2, it is possible in an easy manner to travel straight on utilizing only one or two propelling units, viz. the third propelling unit 30 or propelling units 10 and 20.
• This possibihty which can for instance be used when the tugboat 1 travels in even keel or zero trimcondition, provides a saving of fuel and a reduced wear.
• the three propelling units can jointly develop a thrust greater than the thrust that can be produced by two propelling units at an equal draft. It is even possible to realize a greater total thrust while the three propelling units are individually chosen to be smaller than the individual propelling units of the conventional tugboat, whereby the draft of the tugboat can be reduced as well.
• incorporation tug boat according to the present invention can be provided with another number of propelling units, for example two or four. It is also possible that one or several, for instance the third one, of the propelling units are retractably mounted, enabling a propelling unit that is not being used to be retracted to a position within the profile of the bottom of the boat. As a result, the resistance during travelling will be reduced, which means a saving of fuel.
• the position of the propelling units can be reversed, i.e. one unit at the front and two units at the rear irrespective of the towing points 8 on bow 7 and stern 6.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Selective Calling Equipment (AREA)
• Management, Administration, Business Operations System, And Electronic Commerce (AREA)
• Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
• Road Paving Structures (AREA)

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• 2016
  • 2016-10-05 NL NL2017577A patent/NL2017577B1/nl not_active IP Right Cessation
• 2017
  • 2017-10-05 WO PCT/NL2017/050656 patent/WO2018067008A1/en unknown
  • 2017-10-05 CA CA3039503A patent/CA3039503A1/en not_active Abandoned
  • 2017-10-05 SG SG11201903051PA patent/SG11201903051PA/en unknown
  • 2017-10-05 EP EP17790866.2A patent/EP3523194B1/de active Active
  • 2017-10-05 US US16/339,697 patent/US20190283850A1/en not_active Abandoned
  • 2017-10-05 ES ES17790866T patent/ES2881825T3/es active Active
  • 2017-10-05 AU AU2017338597A patent/AU2017338597A1/en not_active Abandoned
  • 2017-10-05 MX MX2019004028A patent/MX2019004028A/es unknown
• 2019
  • 2019-04-04 CL CL2019000918A patent/CL2019000918A1/es unknown
  • 2019-04-30 CO CONC2019/0004474A patent/CO2019004474A2/es unknown

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