JP3971190B2 - Ship - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ship, and more particularly, to a ship that is capable of navigating in both the bow direction and the stern direction and that performs ice breaking on an ice breaking surface provided in the stern part.
[0002]
[Prior art]
In recent years, in order to use an ice sea area as a route, development of a ship having an ice breaking ability has been advanced. Generally, since a ship navigates in the bow direction, the conventional ship has made various improvements to the bow shape to improve the ice breaking performance at the bow.
[0003]
However, if the bow shape is determined by focusing only on the ice breaking performance, there is a problem that the water resistance increases in open water without ice, and the propulsion performance in open water decreases.
[0004]
Thus, for example, Japanese Patent Laid-Open No. 5-77784 (Reference 1) discloses a ship intended to achieve both ice breaking performance in ice and propulsion performance in open water. The ship disclosed in Document 1 includes a propulsion device capable of turning at an angle of 360 degrees, and can navigate in both the bow direction and the stern direction. In this ship, the bow has a shape suitable for propulsion in open water, and the stern has a shape suitable for propulsion in ice (ice breaking). As described above, in the ship disclosed in Document 1, both the ice breaking performance in ice and the propulsion performance in open water are achieved by assigning functions to the bow and stern.
[0005]
[Problems to be solved by the invention]
However, since the ship disclosed in the above-mentioned document 1 has not been sufficiently designed with respect to the shape of the stern part, the ice breaking ability at the stern part is not necessarily sufficient when navigating in the stern direction.
[0006]
Then, an object of this invention is to provide the ship provided with the stern part excellent in the ice breaking performance.
[0007]
[Means for Solving the Problems]
The ship according to the present invention can be navigated in both the bow direction and the stern direction, and is a ship that performs ice breaking on the ice breaking surface provided in the stern part. In this ship, in a cross section obtained by cutting the ship by a plane including a center line extending along the longitudinal direction of the ship and including a rear vertical line, a straight line connecting the position of the summer full load water line on the ice breaking surface and the position of the ballast water line. The angle formed by the center line is θ. In addition, in the cross section of the ship cut by a plane perpendicular to the rear vertical line including the summer full load water line, the angle formed by the tangent at the position of the rear vertical line on the ice breaking surface when viewed along the rear vertical line and the center line is Let α be. At this time, θ is 45 degrees or less and α is 50 degrees or less.
[0008]
The inventor has found that the stern profile has a significant effect on ice breaking performance. And as above-mentioned, it discovered that the said ship can show | play the outstanding ice-breaking performance by making angle (theta) 45 degrees or less and making angle (alpha) 50 degrees or less. The inventor has also found that the angle α has a great influence not only on the ice breaking performance but also on the propulsion performance during normal navigation in the bow direction. And as above-mentioned, it discovered that the said ship can show | play the outstanding propulsion performance by making this angle (alpha) 50 degrees or less. Therefore, according to the ship which concerns on this invention, while improving ice-breaking performance, improvement of propulsion performance is achieved.
[0009]
Moreover, the ship which concerns on this invention can be navigated to both a bow direction and a stern direction, and is a ship which performs ice breaking on the ice breaking surface provided in the stern part. In this ship, in a cross section obtained by cutting the ship by a plane including a center line extending along the longitudinal direction of the ship and including a rear vertical line, a straight line connecting the position of the summer full load water line on the ice breaking surface and the position of the ballast water line. The angle formed by the center line is θ. In addition, let β be the angle formed by the tangential line at the position of the summer maximum draft on the ice breaking surface and the rear vertical line in a cross section of the ship cut by a plane perpendicular to the center line including the rear vertical line. At this time, θ is 45 degrees or less and β is 35 degrees or more.
[0010]
The inventor has found that the stern profile has a significant effect on ice breaking performance. And as mentioned above, it discovered that the said ship can show | play the outstanding ice-breaking performance by making angle (theta) into 45 degrees or less and making angle (beta) into 35 degrees or more. Therefore, according to such a ship, the ice breaking performance can be improved.
[0011]
At this time, β may be 65 degrees or less. The inventor found that the angle β has a great influence not only on the ice breaking performance but also on the propulsion performance during normal navigation in the bow direction. And as above-mentioned, it discovered that the said ship can show | play the outstanding propulsion performance by making this angle (beta) 65 degrees or less. Therefore, according to such a ship, the propulsion performance can be improved.
[0012]
In addition, in the section of the ship cut by a plane perpendicular to the rear vertical line including the summer full load water line, the angle formed by the tangent line at the position of the rear vertical line on the ice breaking surface when viewed along the rear vertical line and the center line When α is α, α may be 50 degrees or less. In this way, the ice breaking performance and propulsion performance can be further improved.
[0013]
The ship according to the present invention may include a pod type propulsion device capable of turning around a rear vertical line. If it does in this way, a big turning force can be obtained by turning a propelling device centering on a rear perpendicular, and orienting a propelling device in arbitrary directions. Therefore, the steering performance can be improved as compared with the rudder method. Further, by reversing the direction of the propelling device, it is possible to reverse the traveling direction of the ship in both the bow direction and the stern direction (DAS: Double Acting Ship).
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.
[0015]
FIG. 1 is a right side view showing a ship according to the present embodiment. FIG. 2 is a plan view showing the ship according to the present embodiment.
[0016]
As shown in FIGS. 1 and 2, the marine vessel 10 includes a hull 12 and a pod-type propulsion device (hereinafter also referred to as “propulsion device”) 14 attached to the hull 12.
[0017]
The hull 12 has a bow portion 16, a hull center portion 18, and a stern portion 20. The bow portion 16 is designed so as to reduce the propulsion resistance in open water. For example, the bow portion 16 has a Barbus bow shape in which a portion below the water surface projects forward.
[0018]
The structure of the hull central portion 18 differs depending on the type of the ship 10. For example, if the ship 10 is a container ship, a plurality of holds are formed inside the hull center portion 18. If the ship 10 is a crude oil tanker, a plurality of oil tanks are formed inside the hull central portion 18.
[0019]
The stern part 20 includes an attachment part 22 for attaching the propulsion device 14 and an overhang part 23. The outer surface of the stern portion 20 functions as an ice breaking surface for performing ice breaking during navigation in the stern direction.
[0020]
The propulsion device 14 includes a propeller 24, a pod portion 26 containing a motor (not shown) for rotating the propeller 24, and a strut 28 for supporting the pod portion 26. As shown in FIG. 1, the propulsion device 14 is attached to a mounting portion 22 of the stern portion 20 via a strut 28 so that the propulsion device 14 can turn in a range of 360 degrees around the rear vertical line Y by a rotating device (not shown). Yes. The propulsion device 14 is a so-called tractor-type propulsion device in which a propeller 24 is attached to the front portion of the pod portion 26, and a propeller wake is ejected toward the strut 28 by the rotation of the propeller 24 to obtain propulsive force. The propulsion device 14 may be a so-called pushing type propulsion device in which the propeller 24 is attached to the rear portion of the pod portion 26. Thus, since the ship 10 which concerns on this embodiment is equipped with this propulsion device 14, turning the propulsion device 14 around the rear perpendicular line Y and directing the propulsion device 14 in an arbitrary direction makes it possible to generate a large turning force. Can be obtained. Therefore, the steering performance can be improved as compared with the rudder method. In addition, by reversing the direction of the propulsion device 14, the traveling direction of the ship 10 can be reversed (DAS: Double Acting Ship) in both the bow direction and the stern direction.
[0021]
Here, the ship 10 according to the present embodiment is characterized by the shape of the stern portion 20. That is, consider a cross section in which the ship 10 is cut by a plane including the center line X extending along the longitudinal direction of the ship 10 and along the rear vertical line Y. As the center line X, as shown in FIGS. 1 and 2, consider a straight line on the upper deck 30 that divides the port side and starboard side symmetrically. Further, the rear vertical line Y usually indicates the central axis of the rudder column or rudder material. In this embodiment, since the propulsion unit 14 also has a rudder function, the rear vertical line Y is used here as the strut of the propulsion unit 14. Consider 28 axes (i.e., the pivot axis of the propulsion unit 14).
[0022]
At this time, as shown in FIG. 3, the line l connecting the position of the ballast waterline d _b summer load waterline d _s on crushed ice surface, and the center line X as described above, the angle θ of 45 degrees Or less, preferably 40 degrees or less.
[0023]
The inventor has found that the profile of the ice breaking surface at the stern portion 20 has a great influence on the ice breaking performance, and has intensively studied the profile of the ice breaking surface. And as shown in FIG. 4, it discovered that the said ship 10 could show | play the outstanding ice breaking performance by making angle (theta) into 45 degrees or less. In FIG. 4, the ice breaking performance was evaluated based on the ship speed when traveling in the same ice sea with the same horsepower. The vertical axis is represented by an index with the boat speed being 100 when θ is 10 degrees.
[0024]
However, this angle θ is preferably 20 degrees or more, and more preferably 25 degrees or more. This is because if the angle θ is smaller than 20 degrees, the length of the overhang portion 23 of the stern portion 20 becomes extremely long, and the manufacturing cost tends to increase.
[0025]
Further, consider a cross section in which the ship 10 is cut by a plane that includes the summer full load water line d _s and is perpendicular to the rear vertical line Y. At this time, as shown in FIG. 5, the angle α formed by the tangent m at the position of the rear vertical line Y on the ice breaking surface when viewed along the rear vertical line Y and the center line X described above is 50 degrees or less. Yes, preferably 40 degrees or less.
[0026]
The inventor further studied diligently about the profile of the ice breaking surface. And as shown to Fig.6 (a), it discovered that the said ship 10 could show | play the outstanding ice-breaking performance by making angle (alpha) 50 degrees or less. In FIG. 6A, the ice breaking performance was evaluated based on the ship speed when traveling in the same ice sea with the same horsepower. The vertical axis represents an index with the ship speed being 100 when α is 10 degrees.
[0027]
The inventor has also found that the angle α has a great influence not only on the ice breaking performance but also on the propulsion performance during normal navigation in the bow direction. And as shown in FIG.6 (b), it discovered that the said ship 10 could show the outstanding propulsion performance by making this angle (alpha) 50 degrees or less, Preferably it is 35 degrees or less. In addition, in FIG.6 (b), the propulsion performance was evaluated by the ship speed at the time of progressing in normal open water by the same horsepower. The vertical axis represents an index with the ship speed being 100 when α is 10 degrees.
[0028]
FIG. 6C is a graph showing the ice breaking / propulsion performance obtained by adding the ice breaking performance shown in FIG. 6A and the propulsion performance shown in FIG. 6B. As shown in FIG. 6C, it can be seen that high ice breaking / propulsion performance can be achieved by setting the angle α to 50 degrees or less.
[0029]
However, the angle α is preferably 20 degrees or more, and more preferably 25 degrees or more. This is because when the angle α is smaller than 20 degrees, the length of the overhang portion 23 of the stern portion 20 becomes extremely long, and the manufacturing cost tends to increase.
[0030]
Further, a cross section of the ship 10 taken along a plane that includes the rear vertical line Y and is orthogonal to the center line X described above will be considered. At this time, as shown in FIG. 7, an angle β formed between the tangent n at the position of the summer maximum draft line d _s on the ice break surface and the rear vertical line Y (here, a straight line y parallel to the rear vertical line Y for convenience). And the angle formed by the tangent line n) is 35 degrees or more, and preferably 45 degrees or more.
[0031]
The inventor further studied diligently about the profile of the ice breaking surface. And as shown to Fig.8 (a), it discovered that the said ship 10 could show | play the outstanding ice-breaking performance by making angle (beta) 35 degrees or more. In FIG. 8A, the ice breaking performance was evaluated based on the ship speed when traveling in the same ice sea with the same horsepower. The vertical axis represents an index with the boat speed being 100 when β is 10 degrees.
[0032]
The inventor has also found that the angle β has a great influence not only on the ice breaking performance but also on the propulsion performance during normal navigation in the bow direction. And as shown in FIG.8 (b), it discovered that the said ship 10 could show the outstanding propulsion performance by making this angle (beta) 65 degrees or less, Preferably it is 55 degrees or less. In addition, in FIG.8 (b), the propulsion performance was evaluated by the ship speed at the time of progressing in normal open water by the same horsepower. The vertical axis represents an index with the boat speed being 100 when β is 10 degrees.
[0033]
FIG. 8C is a graph showing the ice breaking / propulsion performance obtained by adding the ice breaking performance shown in FIG. 8A and the propulsion performance shown in FIG. 8B. As shown in FIG. 8 (c), it was found that high ice breaking / propulsion performance can be achieved by setting the angle β to 35 degrees or more and 65 degrees or less.
[0034]
FIG. 9 is a perspective view showing the stern portion 20 of the ship 10 having the above-described configuration. FIG. 9 shows a state in which the stern portion 20 is looked up from the starboard side obliquely rearward, and the illustration of the propulsion unit 14 is omitted. In the ship 10 having such a stern part 20, as described above, the angle θ is 45 degrees or less, the angle α is 50 degrees or less, and the angle β is 35 degrees or more. Can be played.
[0035]
Factors that affect ice breaking performance include “ice breaking resistance”, which mainly breaks the ice, and “exclusion resistance”, which removes the crushed ice backward, especially when both of these are low. Can be said to be excellent.
[0036]
With regard to the angle θ and the angle β, as shown in FIGS. 10A and 10B, when the angle θ is small and the angle β is large, the ice can be sufficiently pressed and cracked. It is considered that the removal resistance can be kept low because the ice can be eliminated by letting the broken ice sink under the hull 12. In particular, when the angle θ is set to 45 degrees or less and the angle β is set to 35 degrees or more, excellent ice breaking performance can be achieved.
[0037]
On the other hand, regarding the angle α, the exclusion resistance for removing the cracked ice backward has a greater effect on the ice breaking performance than the ice breaking resistance for breaking the ice by hitting the ice surface of the stern portion 20 with ice. Yes. Therefore, if the angle α is large, the ice breaking resistance increases because the ice is divided by the surface, and it becomes difficult to smoothly remove the broken ice backward, so that the ice breaking performance deteriorates. On the other hand, if the angle α is small, the ice breaking resistance is reduced because the ice is divided by points, and the ice breaking performance is improved because it becomes easy to smoothly remove the broken ice backward. In particular, when the angle α is set to 50 degrees or less, excellent ice breaking performance can be achieved.
[0038]
Further, regarding the angle α, the smaller the angle α, the sharper the hull 12 is, and the propulsion performance during normal navigation in the bow direction is improved. In particular, by setting the angle α to 50 degrees or less, not only excellent ice breaking performance can be achieved as described above, but also excellent propulsion performance can be achieved during normal navigation in the bow direction.
[0039]
As for the angle β, the larger the angle β, the better the ice breaking performance, but the larger the angle β, the larger the stern vibration, and the greater the risk of stern punching due to stormy waves. There is a risk that the propulsion performance during normal navigation will be reduced. At this time, as described above, the reduction in propulsion performance can be suppressed by setting the angle β to 65 degrees or less.
[0040]
The present invention is not limited to the above-described embodiment, and various modifications can be made.
[0041]
For example, in the above-described embodiment, a container ship or a crude oil tanker is exemplified as the type of the ship 10, but the type of the ship 10 is not limited to this.
[0042]
Moreover, in the above-described embodiment, the shape of the bow portion 16 is a Barbus bow shape, but the bow portion 16 may have other shapes. However, it is preferable that the shape of the bow portion 16 is a shape that can improve the propulsion performance during normal navigation in the bow direction.
[0043]
In the above-described embodiment, as shown in FIG. 3, the ice breaking surface of the stern portion 20 includes the center line X extending along the longitudinal direction of the ship 10 and cuts the ship 10 by a plane along the rear vertical line Y. Although the cross section has a linear profile, the present invention is not limited to this, and for example, it may have an upward convex curved profile. Even in this case, the line l connecting the position of the ballast waterline d _b summer load waterline d _s on crushed ice surface, and the center line X as described above, the angle θ is, be 45 degrees or less Preferably, it may be 40 degrees or less.
[0044]
In the above-described embodiment, the pod type propulsion device has been described as the propulsion device 14. However, as long as the ship 10 can be advanced in both the bow direction and the stern direction, the propulsion device 14 may be another propulsion. It may be a vessel.
[0045]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, a ship provided with the stern part excellent in the ice breaking performance is provided.
[Brief description of the drawings]
FIG. 1 is a right side view showing a ship according to the present embodiment.
FIG. 2 is a plan view showing a ship according to the present embodiment.
FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2 and particularly shows only the stern part.
FIG. 4 is a graph showing the relationship between angle θ and ice breaking performance.
FIG. 5 is a cross-sectional view taken along line VV in FIG. 1, and particularly shows only the stern part.
6A is a graph showing the relationship between the angle α and the ice breaking performance, and FIG. 6B is a graph showing the relationship between the angle α and the propulsion performance. FIG. ) Is a graph showing the relationship between the angle α and ice breaking / propulsion performance.
7 is a cross-sectional view taken along line VII-VII in FIG.
FIG. 8A is a graph showing the relationship between the angle β and the ice breaking performance, and FIG. 8B is a graph showing the relationship between the angle β and the propulsion performance. ) Is a graph showing the relationship between angle β and ice breaking / propulsion performance.
FIG. 9 is a perspective view showing a stern part of the ship according to the present embodiment.
FIG. 10 is a diagram for explaining the principle of ice breaking on the ice breaking surface of the stern.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Ship, 12 ... Hull, 14 ... Pod type propulsion device, 16 ... Bow part, 18 ... Center part of hull, 20 ... Stern part, 22 ... Mounting part, 23 ... Overhang part, 30 ... Upper deck, X ... Center line, Y ... rear perpendicular line, d _s ... summer load waterline, d _b ... ballast waterline.

Claims (2)

A ship capable of navigating in both the bow direction and the stern direction, and performing ice breaking on the ice breaking surface provided in the stern part,
In the cross section including the center line extending along the longitudinal direction of the ship and cutting the ship by a plane along the rear vertical line that is the central axis of the rudder material , The angle between the straight line connecting the position and the center line is θ,
In a cross section of the ship cut by a plane perpendicular to the rear vertical line including the summer full load water line, a tangent at the position of the rear vertical line on the ice breaking surface when viewed along the rear vertical line, the center line, Let α be the angle between
In a cross-section obtained by cutting the ship by a plane that includes the rear perpendicular and is orthogonal to the center line, when the angle between the tangent at the position of the summer maximum water line on the ice breaking surface and the rear perpendicular is β,
The ship wherein the θ is 45 degrees or less, the α is 25 degrees or more and 40 degrees or less, and the β is 35 degrees or more and 65 degrees or less. A ship that is capable of navigating in both the bow direction and the stern direction, and that performs ice breaking on the ice breaking surface provided in the stern part,
It has a pod type propulsor that can swivel around the strut axis,
In the cross section including the center line extending along the longitudinal direction of the ship and cutting the ship by a plane along the rear perpendicular that is the axis of the strut, the position of the summer full load water line and the position of the ballast water line on the ice breaking surface The angle formed by the straight line connecting the center line and the center line is θ,
In a section of the ship cut by a plane perpendicular to the rear vertical line including the summer full load water line, a tangent at the position of the rear vertical line on the ice breaking surface when viewed along the rear vertical line, the center line, Let α be the angle between
In a cross-section obtained by cutting the ship by a plane that includes the rear perpendicular and is orthogonal to the center line, when the angle formed by the tangent at the position of the summer maximum water line on the ice breaking surface and the rear perpendicular is β,
The ship wherein the θ is 45 degrees or less, the α is 25 degrees or more and 40 degrees or less, and the β is 35 degrees or more and 65 degrees or less.

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