Ice Breaking Vessel

Abstract

An icebreaking vessel (10) with icebreaking reamers (23a, 23b) at each side and, in connection with the reamers, propellers (24a, 24b) for the propulsion of the vessel. The icebreaking vessel can be formed by attaching a detachable icebreaking bow section (31) equipped with reamers and propellers in connection with them to any such ship (30) which is not an actual icebreaker and which has corresponding joint members for attaching the detachable bow section to the ship.

Claims

1. An icebreaking vessel (10) with reamers (23a, 23b) at each side, characterized in that, in connection with the reamers (23a, 23b) located at each side of the icebreaking vessel (10), there are propellers (24a, 24b) for the propulsion of the vessel.

2. A vessel (10) according to claim 1, characterized in that there are downwards breaking reamers (23a, 23b) at each side of the vessel (10) and the propellers (24a, 24b) in connection with them are located in the midship area of the vessel, or between the midship and the bow of the vessel.

3. A vessel (10) according to claim 1 or 2, characterized in that the propellers (24a, 24b) in connection the reamers (23a, 23b) located at each side of the vessel (10) are attached to propeller shafts (25a, 25b) directed towards the stern of the vessel, the propellers shafts being horizontal or tilted downwards or upwards, and the propellers shafts being parallel as viewed from above or directed slightly outwards, towards the sides of the vessel, or inwards, such that the propeller shafts form an angle relative to one another.

4. A vessel (10) according to claim 1 or 2, characterized in that the propellers (24a, 24b) in connection the reamers (23a, 23b) located at each side of the vessel (10) are attached to either fixed or azimuthing thruster apparatuses (28) which have one or two pulling propellers ahead of the thruster apparatus, or one or two pusher propellers astern of the thruster apparatus, or at least one propeller ahead of the thruster apparatus and at least one propeller astern of the thruster apparatus.

5. A vessel (10) according to any one of claims 1-4, characterized in that the vessel (10) has propellers (24a, 24b) in connection with the reamers (23a, 23b) located at the sides of the vessel (10) only.

6. A vessel (10) according to any one of claims 1-4, characterized in that, in addition to the propellers (24a, 24b) in connection with the reamers (23a, 23b) located at the sides of the vessel (10), the vessel has at least a single propeller (24c) and/or thruster apparatus (27) in the stern.

7. A vessel (10) according to any one of claims 1-6, characterized in that, the inclination of the hull sides relative to the vertical plane in the bow section of the vessel (10) is greater than 10 at the point where the hull sides of the ship come into contact with the ice to be broken.

8. A vessel (10) according to any one of claims 1-7, characterized in that, in the icebreaking vessel (10), the draught of the bow section (20) equipped with reamers (23a, 23b) and propellers (24a, 24b) is equal to or larger or smaller than the draught of the stern section (21) of the vessel.

9. A vessel (10) according to any one of claims 1-8, characterized in that the icebreaking vessel (10) equipped reamers (23a, 23b) located at the sides and propellers (24a, 24b) in connection with them has been arranged by attaching to a ship (30) which is not an actual icebreaker such a detachable icebreaking bow section (31) that has reamers (23a, 23b) at the sides and propellers (24a, 24b) in connection with them.

10. A vessel (10) according to any one of claims 1-9, characterized in that the icebreaking vessel (10) is comprised of a ship (30), such as a merchant ship or a cargo ship, to which can be attached a detachable icebreaking bow section (31) with reamers (23a, 23b) at each side and propellers (24a, 24b) in connection with them.

11. A vessel (10) according to any one of claims 1-10, characterized in that the total engine power of the propellers (24a, 24b) in connection with the reamers (23a, 23b) of a detachable icebreaking bow section (31) is greater than or equal to the engine power of the propeller or propellers of the ship (30) to be attached to the detachable bow section.

12. A vessel (10) according to any one of claims 1-11, characterized in that the detachable icebreaking bow section (31) equipped with reamers (23a, 23b) located at the sides and with propellers (24a, 24b) in connection with the reamers can be attached to the ship (30) when breaking ice is necessary or when the ship is heading to ice-covered water areas, and can be detached from the ship when the ship is used in open water areas.

13. A vessel (10) according to any one of claims 1-12, characterized in that, in the icebreaking vessel (10), the draught of the detachable bow section (31) equipped with reamers (23a, 23b) and propellers (24a, 24b) is equal to or larger or smaller than the draught of the ship (30) to be attached to it.

14. A vessel (10) according to any one of claims 1-13, characterized in that the propulsion system of the detachable icebreaking bow section (31) of the icebreaking vessel (10) includes parts such as an electric motor, generator, diesel engine and the fuel tank of the diesel engine, which are distributed and positioned such that some of the said parts are located in the detachable icebreaking bow section (31) and some in the vessel (30).

15. A vessel (10) according to any one of claims 1-14, characterized in that the detachable icebreaking bow section (31) equipped with reamers (23a, 23b) and propellers (24a, 24b) in connection with them has joint members to attach the detachable bow section to any ship (30), such as a merchant ship or a cargo ship, which has corresponding joint members for attaching the detachable bow section to the ship.

16. A vessel (10) according to any one of claims 1-15, characterized in that the icebreaking vessel (10) is arranged by the detachable icebreaking bow section (31) equipped with reamers (23a, 23b) and propellers (24a, 24b) in connection with them and any ship (30), such as a merchant ship or a cargo ship, that can be selected from a group of one or several such ships where the ships belong to these groups have joint members for attaching the detachable bow section to the ship.

17. A vessel (10) according to any one of claims 1-16, characterized in that the icebreaking vessel (10) is arranged alternatingly by at least two ships (30), such as a merchant ship or a cargo ship, with joint members for alternatingly attaching the detachable icebreaking bow section (31) equipped with reamers (23a, 23b) and propellers (24a, 24b) in connection with them.

Description

LIST OF FIGURES

[0051] FIG. 1A shows a side view of an icebreaking vessel according to the invention.

[0052] FIG. 1B shows a schematic view of the vessel in FIG. 1A as seen from below.

[0053] FIG. 2A shows a side view of a ship to which a detachable bow section can be attached.

[0054] FIG. 2B shows the vessel in FIG. 2A as seen from below.

[0055] FIG. 3A shows a side view of the detachable icebreaking bow section.

[0056] FIG. 3B shows a schematic view of the detachable bow section in FIG. 3A as seen from below.

[0057] FIG. 4A shows a side view of the vessel in FIG. 2A and the detachable bow section in FIG. 3A as attached to one another.

[0058] FIG. 4B shows a schematic view of the vessel in FIG. 2B and the detachable bow section in FIG. 3B as attached to one another and seen from below.

[0059] FIG. 5A corresponds to FIG. 1A and shows another embodiment of the icebreaking vessel.

[0060] FIG. 5B shows the vessel in FIG. 5A as seen from below.

[0061] FIG. 6A shows a side view of a ship to which a detachable bow section can be attached.

[0062] FIG. 6B shows the ship in FIG. 6A as seen from below.

[0063] FIG. 7A shows another embodiment of the detachable icebreaking bow section.

[0064] FIG. 7B shows the detachable bow section in FIG. 7A as seen from below.

[0065] FIG. 8A shows the ship in FIG. 6A and the detachable bow section in FIG. 7A as attached to one another.

[0066] FIG. 8B shows the ship in FIG. 6B and the detachable bow section in FIG. 7B as attached to one another.

[0067] FIG. 9A shows a side view of the vessel in FIG. 8A where the propellers of the detachable bow section are in a pivoted position.

[0068] FIG. 9B shows the vessel in FIG. 9A as seen from below.

[0069] FIG. 10A shows a schematic back view of the vessel in FIG. 8A.

[0070] FIG. 10B shows a schematic back view of the vessel in FIG. 9A.

DESCRIPTION OF THE FIGURES

[0071] FIGS. 1A and 1B show an icebreaking vessel 10 according to the invention. In this example, the icebreaking vessel 10 was built to primarily function as an icebreaker, as it has a wide bow section 20 to open up a sufficiently wide lane or channel in the ice for the ships to be assisted. The stern section 21 is narrower than the bow section 20, whereby the vessel is suitable, due to its seagoing characteristics, also for use in open water conditions. Between the wide bow section 20 and the narrower stern section 21 of the vessel 10, on each side of the vessel 10 there are downwards breaking reamers 23a and 23b with inclined surfaces rising astern and up, which break up the edges of the ice lane when the icebreaker proceeds stern ahead.

[0072] According to the invention, propellers 24a and 24b are attached in connection with the reamers 23a and 23b at each side of the icebreaking ship 10 shown in FIGS. 1A and 1B. In this example, the propellers 24a and 24b are installed in the conventional manner using propeller shafts 25a and 25b directed towards the stern section of the ship. FIG. 1B is shown schematically such that it also shows the locations of motors 26a and 26b and the directions of the propeller shafts 25a and 25b.

[0073] Most preferably, there is space available for the propellers 24a and 24b in connection with the reamers and their motors 26a and 26b in the bow area, where the hull of the vessel is narrower, but they can also be positioned in the midship section of the vessel if the hull shape of the vessel allows this. If fixed shaft struts are used in connection with the propellers 24a and 24b, they are most preferably tilted 3-10 in the transverse direction of the vessel.

[0074] FIG. 1B shows that the propeller shafts 25a and 25b are not parallel. They are directed slightly outwards, towards the side of the vessel, such that the propeller shafts 25a and 25b together form a small angle. However, the propeller shafts 25a and 25b can also be parallel or tilted inwards, but the arrangement shown in FIG. 1B allows better fitting of the motors 26a and 26b driving the propeller shafts 25a and 25b into the hull of the vessel 10. Such an angle between the propeller shafts 25a and 25b is also preferable in some icebreaking conditions. The propellers 24a and 24b in connection with the reamers of the vessel can also be attached to other types of propulsion equipment, such as azimuthing thruster apparatuses, as described below.

[0075] The vessel 10 shown in FIGS. 1A and 1B has, in its stern, an azimuthing thruster apparatus 27 and a propeller 24c, whereby all three propellers 24a, 24b and 24c can be used for propelling and manoeuvring the vessel 10. A very effective solution for any type of manoeuvring is to enable the thruster apparatus 27 to pivot a full 360 circle and to enable both the propellers 24a and 24b at the sides to be used separately to propulse the ship ahead or astern. Thanks to the bow shape of the vessel 10, inclined side shells in the bow and the propellers 24a and 24b at the sides, rotating in opposing directions, the vessel 10 is capable of making a turn in place even in severe ice conditions.

[0076] FIGS. 2A and 2B show a ship 30 that can be modified into an icebreaking vessel by means of a detachable bow section 31 shown in FIGS. 3A and 3B. In other respects, the ship 30 does not have to be in any way specialised, and it can indeed be a regular merchant or cargo ship. However, the ship must have joint members for attaching the detachable bow section to it. The joint members are not shown in the drawings. The ship can also be ice-reinforced for the most severe conditions.

[0077] When a detachable bow section is used, both the ship and the detachable bow section can be optimised for entirely different conditions. The ship can be shaped and optimised for use in open water, whereby its hull does not necessarily have to be reinforced for ice. The detachable bow section can be shaped and reinforced to operate as an icebreaker. Thus building and operating the vessel and the detachable bow section becomes more economical. Using a reinforced icebreaking vessel in open water would not be economical because an icebreaker has to break up a wide channel. An icebreaker would make a poor cargo vessel.

[0078] Attaching a detachable bow section to a vessel designed for open water does not pose a problem because the mechanical joint members can be made reliable using relatively simple structures. The joint members can also be made such that they allow variation in the draught of the vessel even if there is no change in the draught of the detachable bow section. Such a solution can be preferable when a vessel equipped with a detachable bow section visits a port to unload cargo and returns with the detachable bow section without any cargo.

[0079] When any merchant ships or cargo ships have joint members for attaching a detachable bow section to the ship, any merchant ship or cargo ship can chosen from a group of two or several ships, and a detachable icebreaking bow section can be attached to it. In such a case it can be arranged that at least two merchant ships or cargo ships alternate to form an icebreaking vessel, each ship having joint members for attaching a detachable icebreaking bow section equipped with reamers and propellers in connection with them in turns to these ships.

[0080] According to the invention, a ship proceeding through the Northeast Passage or a cargo vessel entering a frozen Bothnian Bay, for example, does not require support from an icebreaker because the detachable icebreaking bow section can be attached to the cargo vessel before the ship departs for the ice-covered area. When the ship arrives in open water the detachable bow section can be detached and attached to another ship departing for an ice-covered area. It is much more preferable to maintain icebreaking bow sections that are available as required than to always provide an icebreaker to assist the ship.

[0081] The detachable bow section 31 attachable to the ship 30 shown in FIGS. 3A and 3B corresponds with the bow section of an icebreaker shown in FIGS. 1A and 1B, which is wide enough to open up a channel in ice. The detachable bow section 31 is also substantially wider than the ship 30 to which it is attached. FIGS. 3A and 3B show that the detachable bow section 31 has reamers 23a and 23b and propellers 24a and 24b in connection with the reamers 23a and 23b, similarly to the vessel 10 shown in FIGS. 1A and 1B.

[0082] FIGS. 4A and 4B show the ship 30 shown in FIGS. 2A and 2B, and the detachable bow section 31 shown in FIGS. 3A and 3B as attached to one another. FIGS. 4A and 4B illustrate that the ship 30 and the detachable bow section 31 form, as attached to one another, an icebreaking vessel 10 corresponding to what is shown in FIGS. 1A and 1B. If the strengths and engine outputs of the ship 30 and the detachable bow section 31 are sufficient, this icebreaking combination vessel 10 is capable of tasks comparable to those of the icebreaking vessel 10 shown in FIGS. 1A and 1B. It can also be equally effective and agile while manoeuvring in ice.

[0083] FIGS. 5A and 5B show an icebreaking vessel 10 corresponding to the vessel in FIGS. 1A and 1B. In the vessel 10 shown in FIGS. 5A and 5B, however, the propellers 24a and 24b in connection with the reamers 23a and 23b are positioned in azimuthing thruster apparatuses 28a and 28b. Even though traditional fixed propeller shafts work very well in a vessel according to the invention, azimuthing thruster apparatuses do have some advantages over fixed shafts.

[0084] An advantage of thruster apparatuses is that they leave a larger space for pieces of ice compared with fixed shafts. In some cases pieces of ice may become wedged between the hull and the strut of a fixed shaft. In a thruster apparatus, the propeller shaft can also be directed upwards, whereby the propeller pushes water and pieces of ice upwards along the side of the hull. If a propeller is positioned ahead of the thruster apparatus, the propeller of such a pulling thruster apparatus operates in a clear water flow with no disturbance due to turbulences from the pod of the thruster apparatus. The propeller of a pulling thruster apparatus also effectively breaks up pieces of ice, whereby they will not become wedged anywhere.

[0085] According to the invention, all possible propeller configurations can be used in the thruster apparatuses positioned in connection with the reamers. There can thus be a single or two pulling propellers ahead of the thruster apparatus, there can a single or two pushing propellers astern of the thruster apparatus, and a single or two propellers both ahead and astern of the thruster apparatus.

[0086] FIGS. 6A, 6B, 7A and 7B show a ship 30 to which can be attached a detachable bow section 31 according to the invention. The detachable bow section 31 has in connection with reamers 23a and 23b azimuthing thruster apparatuses 28a and 28b. FIGS. 8A and 8B show the ship 30 and the detachable bow section 31 as attached to one another, which creates an effective icebreaking vessel 10 according to the invention.

[0087] FIGS. 9A and 9B show a schematic view of an icebreaking vessel 10 according to the invention where both thruster apparatuses 28a and 28b in connection with reamers 23a and 23b are pivoted outwards, i.e. to the sides. As the vessel 10 proceeds ahead and breaks ice, the pulling thruster apparatuses 28a and 28b at the sides of the vessel 10 can be pivoted slightly outwards. Thereby the flow of water created by propellers 24a and 24b is directed to the edge of ice at the sides of the vessel 10, breaking it up, as a consequence of which the ice channel broken by the vessel 10 becomes wider. In such a situation, the pivot angle required for the thruster apparatuses 28a and 28b does not necessarily have to be large. Due to the characteristics of the thruster apparatuses 28a and 28b, however, both propellers 24a and 24b can be directed, either simultaneously or independently of each other, also directly to the side and even ahead as required. By using various angles and power settings of the thruster apparatuses 28a and 28b, it is possible to have the vessel either widen up the ice channel, proceed in any required direction or turn around in place.

[0088] FIG. 10A shows a schematic back view of the icebreaking vessel 10 in FIG. 8A wherein a detachable bow 31 according to the invention is attached to a ship 30. In connection with the reamers 24a and 24b at the sides of the detachable bow 31, there are azimuthing thruster apparatuses 28a and 28b equipped with propellers 24a and 24b. FIG. 10A clearly illustrates that, thanks to the detachable bow 31, the bow section of the vessel 10 becomes relatively wide, whereby the vessel 10 is capable of breaking up a wide ice channel. FIG. 10A furthermore shows that the distance between the propellers 24a and 24b in connection with the reamers 23a and 23b located at the sides of the detachable bow 31 on the transverse direction of the vessel 10 is large. As a consequence of this, the thruster apparatuses 28a and 28b located far apart from each other form a large torque axis, by means of which it is possible to create a very large torque resulting in a turning action on the vessel 10. When the power settings of the thruster apparatuses 28a and 28b or corresponding fixed propellers are adjusted independently of each other, or the propellers 24a and 24b are rotated in different directions, the vessel 10 will easily turn as required, thanks to the large torque, or proceed in the required direction.

[0089] FIG. 10B shows a situation where the thruster apparatuses 28a and 28b of the vessel in FIG. 10A are pivoted towards the sides of the vessel 10. Even a small pivot angle of the thruster apparatuses 28a and 28b will direct the flow of water towards the edges of ice on the sides, whereby the ice channel widens up. A further advantage of the thruster apparatuses 28a and 28b, in addition to easily manoeuvring turns, is that the thruster apparatuses 28a and 28b can be tilted both in the longitudinal and transverse direction of the vessel 10, whereby the flow of water under the hull is directed along the hull shape. A preferred tilt of 3-10 relative to the vertical plane of the thruster apparatuses 28a and 28b, for example, will pivot the propeller shafts for an equal distance, whereby the propellers 24a and 24b will direct the flow of water upwards along the hull shell. This has an advantageous effect on an icebreaking vessel because, in addition to the widening of the ice channel, the flow of water will push away the pieces of ice from under the hull and the sides.

LIST OF REFERENCE NUMBERS

[0090] 10 Icebreaking vessel [0091] 20 Bow section [0092] 21 Stern section [0093] 23a Reamer [0094] 23b Reamer [0095] 24a Propeller [0096] 24b Propeller [0097] 24c Propeller [0098] 25a Propeller shaft [0099] 25b Propeller shaft [0100] 26a Motor [0101] 26b Motor [0102] 27 Thruster apparatus [0103] 28a Thruster apparatus [0104] 28b Thruster apparatus [0105] 30 Ship [0106] 31 Detachable bow section