Ships

Abstract

To provide a ship capable of improving propulsion efficiency while suppressing a windshield height in a vertical direction.SOLUTION: A ship 1 comprises: a wall part 2 installed roughly perpendicularly from a top end of a bulwark 7 and formed roughly in a U-shape in a plan view; and a cover part 3 installed upright from a top end of the wall part 2, formed in a roughly U-shape in a plan view, and the upper side of which tilts toward the inside. The cover part 3 consists of: a first swash plate 3a installed upright from the top end of the wall part 2; and a second swash plate 3b installed upright from a top end of the first swash plate 3a. It is set to a state that an angle θ2 between the second swash plate 3b and a horizontal plane is smaller than an angle θ1 between the first swash plate 3a and the horizontal plane.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a ship equipped with a windshield, and more particularly to a ship that can improve propulsion efficiency while suppressing the height of the windshield in the vertical direction.

Background Art

[0002] The applicant has already proposed a structure of a ship equipped with a windshield (see, for example, Patent Document 1). The ship of Patent Document 1 can reduce the air resistance generated by the container loaded near the bow because the wind received from the front of the ship flows upward and rearward.

[0003] In order to improve the transportation efficiency by the ship, the height of the container loaded on the upper deck may be increased. In particular, the height of the containers in the front row that are directly affected by the wind is generally seven to eight tiers. This means that the containers in the front row form a wall about 20 m high. In this case, in order to suppress the air resistance caused by the containers, it is conceivable to increase the height of the windshield. However, as the height of the windshield increases, the air resistance generated by the windshield also increases. In addition, the wind hitting the windshield is redirected upward and peels off on the way to the upper end of the windshield. There was a possibility that the propulsion efficiency of the ship would decrease as the size of the windshield increased. In addition, an increase in the weight of the windshield and an increase in the manufacturing cost were inevitable as the size of the windshield increased.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a ship that can improve propulsion efficiency while suppressing the height of the windshield in the vertical direction. [Means for solving the problem]

[0006] A vessel for achieving the above objective is a vessel comprising a wall portion erected substantially vertically from the upper end of a bulwark and formed substantially U-shaped in a plan view, and a cover portion erected from the upper end of the wall portion and formed substantially U-shaped in a plan view, with the upper side sloping inward, wherein the cover portion has a first slanted plate erected from the upper end of the wall portion and a second slanted plate erected from the upper end of the first slanted plate, and the angle between the second slanted plate and the horizontal plane is set to be smaller than the angle between the first slanted plate and the horizontal plane. Furthermore, the angle between the first swash plate and the horizontal plane is set to be larger on the aft side of the vessel than on the forward side, and the angle between the second swash plate and the horizontal plane is set to be larger on the aft side of the vessel than on the forward side. It is characterized by the following. [Effects of the Invention]

[0007] According to the present invention, the wind that strikes the cover flows along the second swash plate, which has a smaller angle with respect to the horizontal plane. This suppresses air resistance generated in the cover and reduces wind separation and vortex formation. This is advantageous for improving the propulsion efficiency of a ship while keeping the height of the windshield low. [Brief explanation of the drawing]

[0008] [Figure 1] This is an explanatory diagram showing the general outline of a ship in a side view. [Figure 2] This is an explanatory diagram illustrating the ship in Figure 1 from a plan view. [Figure 3] This is an explanatory diagram illustrating the AA section in Figure 2. [Figure 4] This is an explanatory diagram illustrating the wall and cover sections from an oblique view. [Figure 5] This is an explanatory diagram illustrating a modified example of Figure 1. [Figure 6] This is an explanatory diagram illustrating a modified example of Figure 1. [Figure 7] Figure 6 is an explanatory diagram illustrating a ship in a plan view. [Figure 8] Figure 7 is an explanatory diagram illustrating a cross-section of BB. [Figure 9] Figure 7 is an explanatory diagram illustrating the ship as seen from a frontal view from the bow. [Modes for carrying out the invention]

[0009] The following description of a vessel will be based on the embodiment shown in the figure. In the figure, the width direction of the vessel is indicated by arrow y, the length direction which intersects the width direction y at a right angle is indicated by arrow x, and the vertical direction which is perpendicular to the width direction y and the length direction x is indicated by arrow z.

[0010] As illustrated in Figures 1 and 2, the vessel 1 comprises a wall section 2 and cover sections 3 (3a, 3b) located at the bow. The wall section 2 and cover sections 3 form a windbreak. The vessel 1 is, for example, a container ship. Containers 5 are placed on the upper surface of the upper deck 4 of the vessel 1. In this embodiment, the vessel 1 comprises a forecastle deck 6 formed at the bow and a bulwark 7 formed along the edge of the forecastle deck 6. The bulwark 7 is roughly U-shaped in plan view.

[0011] Vessel 1 is not limited to container ships. Vessel 1 can be any vessel that has cargo or equipment installed on its upper deck 4 and requires a windbreak. Vessel 1 may consist of, for example, bulk carriers that transport coal or grain, chip carriers that have cargo handling equipment on their upper deck 4, passenger ships and ferries, or tankers that transport liquefied natural gas, etc.

[0012] The wall section 2 is erected almost vertically from the upper end of the bulwark 7 and is formed in a roughly U-shape in plan view. The wall section 2 may be formed to slope outward from the bulwark 7 or to slope inward. However, it is desirable that it be formed to be perpendicular to the bulwark 7. As illustrated in Figure 1, the wall section 2 is formed such that the rear side (stern side) is longer in the vertical direction z than the front side (bow side). The wall section 2 is not limited to this configuration and may be formed so that the front side and the rear side are the same length. The wall section 2 is made of, for example, steel plate.

[0013] As illustrated in Figure 2, the cover portion 3 is erected from the upper end of the wall portion 2 and formed in a roughly U-shape. The cover portion 3 is inclined upward toward the inside of the roughly U-shape. The inside of the roughly U-shape refers to the direction away from the bulwark 7 toward the centerline S of the ship 1 in Figure 2. The centerline S is a hypothetical line that passes through the center of the ship 1 in the ship width direction y and extends along the ship length direction x. In Figure 2, a part of the centerline S is shown as a dashed line for explanatory purposes. For example, the front end of the cover portion 3 is inclined toward the rear. The vicinity of the rear end of the cover portion 3 is inclined toward the centerline S. The cover portion 3 is made of, for example, steel plate.

[0014] The cover portion 3 has a first slanted plate 3a erected from the upper end of the wall portion 2, and a second slanted plate 3b erected from the upper end of the first slanted plate 3a. As illustrated in Figure 1, the first slanted plate 3a is fixed to the wall portion 2 at an angle θ1 with respect to the horizontal plane. The horizontal plane is a plane parallel to the ship's length direction x and the ship's width direction y. The angle θ1 related to the first slanted plate 3a is, for example, 60°.

[0015] As illustrated in Figure 1, the second swash plate 3b is fixed to the first swash plate 3a at an angle θ2 with respect to the horizontal plane. The angle θ2 related to the second swash plate 3b is, for example, 45°. As illustrated in Figure 1, the first swash plate 3a and the second swash plate 3b are formed such that the rear side is longer than the front side in the vertical direction z. The configuration is not limited to this, and the first swash plate 3a and the second swash plate 3b may be formed so that the front and rear sides are of the same length, or so that the rear side is shorter than the front side. The wall section 2, the first swash plate 3a, and the second swash plate 3b are fixed to each other, for example, by welding. The rear end faces of the wall section 2 and the cover section 3 are positioned in the ship's length direction x and are formed to be perpendicular to the horizontal plane. The rear end faces of the wall section 2 and the cover section 3 are not limited to the above. It is desirable to form them in a structure that is as perpendicular to the horizontal plane as possible in accordance with the hull structure and fittings.

[0016] The magnitudes of the angle θ1 related to the first inclined plate 3a and the angle θ2 related to the second inclined plate 3b are not limited as described above. The angle θ2 formed between the second inclined plate 3b and the horizontal plane may be set smaller than the angle θ1 formed between the first inclined plate 3a and the horizontal plane. That is, the two angles may be set within a range that satisfies the formula θ2 < θ1. Also, the two angles θ1 and θ2 are set within a range greater than 0° and less than 90°.

[0017] As illustrated in FIG. 3, the first inclined plate 3a forms an angle θ1' with the horizontal plane on the rear side (stern side). Similarly, the second inclined plate 3b forms an angle θ2' with the horizontal plane on the rear side. In this embodiment, the angle θ1' is set to be larger than the angle θ1. That is, the first inclined plate 3a is in a state where the angle θ1 gradually increases from the front side toward the rear side.

[0018] Similarly, the angle θ2' is set to be larger than the angle θ2. That is, the second inclined plate 3b is in a state where the angle θ2 gradually increases from the front side toward the rear side.

[0019] The angle θ1' may be set to be equal to the angle θ1 related to the first inclined plate 3a. At this time, the first inclined plate 3a has a constant angle θ1 with the horizontal plane not only on the front side but also throughout the substantially U-shaped whole. The angle θ1' may be configured to be smaller than the angle θ1. At this time, the first inclined plate 3a is in a state where the angle θ1 gradually decreases from the front side toward the rear side.

[0020] Similarly, the angle θ2' may be set to be equal to the angle θ2 related to the second inclined plate 3b. Also, the angle θ2 may be configured to gradually decrease from the front side toward the rear side. Even when the angles θ1 and θ2 change from the front side toward the rear side, θ2 < θ1 is maintained at their respective corresponding positions. That is, at any cross-section position of the cover portion 3, the angle in that cross-section is θ2 < θ1.

[0021] As illustrated in Figure 4, when wind from the front left (diagonally forward) of vessel 1 collides with the bow of vessel 1, the wind flows towards the rear while changing direction along the wall section 2 and cover section 3. In Figure 4, only the windbreak consisting of wall section 2 and cover section 3 is shown for illustrative purposes. Also, for illustrative purposes, the direction of wind flow is indicated by arrows. In the area shown by the dashed line in Figure 4, the velocity of the wind flow increases, creating negative pressure, and a force is generated in the direction indicated by the white arrow. This force includes a component in the direction of propulsion of vessel 1.

[0022] For example, some of the wind that hits wall 2 changes direction in the ship's width direction y and flows along wall 2 toward the rear (stern side). Also, some of the wind that hits wall 2 changes direction upward and flows toward the rear along the first swash plate 3a to the second swash plate 3b. Wind that hits the first swash plate 3a flows toward the rear along the first swash plate 3a, or flows toward the rear via the first swash plate 3a to the second swash plate 3b.

[0023] The angle θ2 between the second swash plate 3b and the horizontal plane is smaller than the angle θ1 between the first swash plate 3a and the horizontal plane. Therefore, the wind that strikes the first swash plate 3a has its direction changed and flows along the second swash plate 3b toward the rear. The wind that strikes the second swash plate 3b continues to flow along the second swash plate 3b toward the rear. By diverting the wind toward the rear using the second swash plate 3b, the air resistance generated in the cover section 3 can be reduced. The windbreak installed on the ship 1 can improve its effect of reducing air resistance through design improvements. This is advantageous for improving the propulsion efficiency of the ship 1 while suppressing the height of the windbreak in the vertical direction z. In addition, since the windbreak installed on the ship 1 can reduce air resistance without increasing its size, the increase in weight and manufacturing costs due to the windbreak can be suppressed.

[0024] The wind flowing along the cover section 3 moves from the first swash plate 3a to the second swash plate 3b. Since the angle θ2 applied to the second swash plate 3b is smaller than the angle θ1 applied to the first swash plate 3a, wind separation is suppressed at the second swash plate 3b. The wind is smoothly guided along the cover section 3 and flows as if sticking to the cover section 3, thus reducing separation and vortex generation on the leeward side (rear side). This is advantageous for improving the propulsion efficiency of the ship 1 while suppressing the height of the windbreak in the vertical direction z.

[0025] As illustrated in Figure 5, the cover portion 3 may have a third inclined plate 3c erected from the upper end of the second inclined plate 3b. The angle θ3 between the third inclined plate 3c and the horizontal plane is set to be smaller than the angle θ2 between the second inclined plate 3b and the horizontal plane. The angle θ3 related to the third inclined plate 3c is, for example, 30°. The angles in the cover portion 3 satisfy the condition θ3 < θ2 < θ1.

[0026] The more steps (number of swash plates) there are in the cover section 3, the closer the surface of the cover section 3 can be to a clothoid curve. By making the surface of the cover section 3 closer to a clothoid curve, the wind received by the ship 1 during navigation can be smoothly guided along the cover section 3, causing the wind flow to adhere to the cover section 3. This can suppress wind separation and vortex generation on the leeward side in the direction of wind flow. This is advantageous for improving the propulsion efficiency of the ship 1.

[0027] In this embodiment, the cover section 3 is composed of three stages. The cover section 3 may have four or more stages. Increasing the number of stages allows for a shape closer to a clothoid curve, which is advantageous for improving the propulsion efficiency of the ship 1. Reducing the number of stages in the cover section 3 simplifies the shape of the cover section 3, thus reducing manufacturing costs when producing the cover section 3.

[0028] As illustrated in Figure 5, it is desirable that the length L1 of the cover portion 3 be greater than the length L0 of the wall portion 2 in the vertical direction z on the forward side (bow side).

[0029] The cover part 3 is formed larger in the vertical direction z than the wall part 2 erected substantially vertically. Even when wind blows from the obliquely forward direction of the ship 1, for example, it becomes easier to flow this wind along the cover part 3 to the leeward side in the direction in which the wind flows. As illustrated in FIG. 4, the accelerated wind flow generates a negative pressure, which consequently becomes a leading-edge thrust and reduces the resistance of the ship 1. This is advantageous for improving the propulsion efficiency of the ship 1.

[0030] The lengths L0 and L1 also satisfy L0 < L1 at the rear ends of the wall part 2 and the cover part 3. In the embodiment illustrated in FIG. 5, the length L11 of the first inclined plate 3a, the length L12 of the second inclined plate 3b, and the length L13 of the third inclined plate 3c may be the same in the vertical direction z. The length of the cover part 3 in the vertical direction z may also be set as L13 < L12 < L11.

[0031] Similarly, in the embodiment illustrated in FIG. 1, the length L11 of the first inclined plate 3a and the length L12 of the second inclined plate 3b may be the same in the vertical direction z. The length of the cover part 3 in the vertical direction z may also be set as L12 < L11. The inclination of the upper inclined plates of the cover part 3 with respect to the horizontal plane becomes smaller. Therefore, by reducing the height of the upper inclined plates, the amount of members constituting the cover part 3 can be suppressed. This is advantageous for reducing the weight of the cover part 3.

[0032] As illustrated in FIGS. 6 and 7, the ship 1 may be provided with a pair of end members 8 that are respectively arranged at both ends of the cover part 3 formed in a substantially U-shape in plan view and erected from the upper end of the wall part 2. The end member 8 is, for example, composed of a flat steel plate. The end member ⑧ is not limited to a flat shape and may be composed of a steel plate having a shape including a curved surface.

[0033] As illustrated in Figure 6, the end member 8 is set to be 30% of the total length of the windshield in the ship's longitudinal direction x. The total length of the windshield refers to the length from the foremost position of the cover portion 3 to the rearmost position of the end member 8 in the ship's longitudinal direction x. The length of the end member 8 is not limited to this and can be set to, for example, 10% to 50% of the total length of the windshield. The end member 8 has a configuration in which the upper side is inclined toward the inside of the roughly U-shaped cover portion 3.

[0034] As illustrated in Figure 8, it is desirable that the angle θ4 between the end member 8 and the horizontal plane be set to be greater than the angle θ1 between the first swash plate 3a and the horizontal plane. For example, the angle θ4 related to the end member 8 is set to 75°. The angle θ4 is set in the range greater than 0° and less than 90°. The forward end (bow side) of the end member 8 is connected to the rear end (stern side) of the cover portion 3. In this embodiment, the end member 8 and the cover portion 3 are connected without gaps at the connecting portion 8a. The end member 8 and the cover portion 3 are connected, for example, by welding. The connecting portion 8a is connected without gaps by smoothly deforming the cover portion 3 toward the rear in accordance with the position of the forward end of the end member 8. With this configuration, the rear side of the cover portion 3 rises up in accordance with the end member 8. In other words, the angles θ1' and θ2' that the cover portion 3 makes with the horizontal plane increase toward the rear, and at the connecting portion 8a, θ1'=θ2'=θ4.

[0035] As illustrated in Figure 9, the end member 8 expands the area that covers the containers 5 loaded on the ship 1. Even if the number of loaded containers 5 is increased in the ship width direction y or the vertical direction z, they can still be covered by the end member 8. In Figure 9, for illustrative purposes, the edge of the cover portion 3 in the embodiment illustrated in Figure 1 is shown with a dashed line. Also, the area expanded by the end member 8 compared to the embodiment illustrated in Figure 1 is indicated with a diagonal line. Wind that hits the cover portion 3 flows from the cover portion 3 along the end member 8 toward the rear.

[0036] When viewing vessel 1 from bow to stern, the area covered by the windshield is increased, thus reducing air resistance caused by the containers 5 positioned behind the windshield. Air resistance can also be reduced on vessel 1 where the containers 5 are loaded relatively high.

[0037] Because the angle θ4 of the end member 8 with respect to the horizontal plane is larger than the angle θ1 or angle θ2 of the cover portion 3 with respect to the horizontal plane, it becomes easier to cover the front of the containers 5 stacked at both ends in the ship's width direction y. If the end member 8 is not provided, the cover portion 3 will be inclined toward the center in the ship's width direction y (see dashed line in Figure 9), so the corners of the containers 5 may protrude from the cover portion 3. In other words, the cover portion 3 and end member 8 illustrated in Figure 8 are better able to cover the front of the containers 5 over a wider area than the cover portion 3 illustrated in Figure 3. By suppressing the air resistance of the containers 5, the propulsion efficiency of the ship 1 can be easily improved.

[0038] The rear end of the end member 8 is preferably positioned close to the front end of the container 5 located behind it in the ship's longitudinal direction x. In the case of a ship 1 without an end member 8, it is preferable that the cover section 3 and the container 5 are positioned close to each other in the ship's longitudinal direction x. The closer the windbreak is to the container 5 in the ship's longitudinal direction x, the less wind resistance the container 5 will experience. Due to the structure of the ship 1, it may not be possible to position the container 5 close to the rear end of the end member 8 in the ship's longitudinal direction x. In this case, the wind resistance the container 5 will experience can be reduced by adjusting the angles θ1 and θ1' related to the first swash plate 3a, the angles θ2 and θ2' related to the second swash plate 3b, and the angle θ4 related to the end member 8, in accordance with the airflow hitting the cover section 3.

[0039] The angle θ4 related to the end member 8 is not limited to a configuration where it is greater than the angle θ1 related to the first slanted plate 3a. The angle θ4 may be set to be equal to the angle θ1, or it may be set to be smaller. The angle θ4 should be set to be greater than the angle related to the uppermost slanted plate of the cover portion 3. If the cover portion 3 has two stages, the angle θ4 should be greater than the angle θ2 related to the second slanted plate 3b, and if the cover portion 3 has three stages, it should be greater than the angle θ3 related to the third slanted plate 3c. With this configuration, the area that the container 5 can be covered by the end member 8 can be expanded.

[0040] The front end of the end member 8 may be partially connected to the cover portion 3. Alternatively, the end member 8 and the cover portion 3 may not be connected. In this case, at least partially, air can pass through the connecting portion 8a. If the end member 8 and the cover portion 3 are connected without any gaps at the connecting portion 8a, air can flow smoothly along the cover portion 3 and the end member 8, making it easier to suppress air resistance.

[0041] If wind passes through the connecting section 8a, the air resistance of the vessel 1 may increase depending on the conditions. On the other hand, since there is no need to process the rear side of the cover section 3 to match the end member 8, the manufacturing of the cover section 3 becomes easier. This is advantageous in suppressing the manufacturing cost of the cover section 3. [Explanation of Symbols]

[0042] 1 ship 2 wall 3. Cover section 3a First swash plate 3b Second swash plate 3c Third swash plate 4 Upper Deck 5 containers 6 Forecastle deck 7 Bulwark 8 End members 8a Connecting part x Captain direction y Width direction z Vertical direction θ1 (angle related to the first inclined plate) θ2 (angle related to the second inclined plate) θ3 (angle related to the third inclined plate) θ4 (angle related to end members)

Claims

1. In a vessel comprising a wall portion erected almost vertically from the upper end of a bulwark and forming a roughly U-shape in plan view, and a cover portion erected from the upper end of this wall portion and forming a roughly U-shape in plan view, with the upper side sloping inward, The cover portion comprises a first inclined plate erected from the upper end of the wall portion and a second inclined plate erected from the upper end of the first inclined plate. The angle between the second swash plate and the horizontal plane is set to be smaller than the angle between the first swash plate and the horizontal plane. A vessel characterized in that the angle between the first swash plate and the horizontal plane is set to be larger on the aft side of the vessel than on the forward side, and the angle between the second swash plate and the horizontal plane is set to be larger on the aft side of the vessel than on the forward side.

2. The cover portion has a third inclined plate erected from the upper end of the second inclined plate, The vessel according to claim 1, wherein the angle between the third swash plate and the horizontal plane is set to be smaller than the angle between the second swash plate and the horizontal plane.

3. The vessel according to claim 1 or 2, wherein the length of the cover portion is set to be greater than the length of the wall portion in the vertical direction.

4. A vessel comprising a wall portion erected substantially vertically from the upper end of a bulwark and formed substantially U-shaped in a plan view, and a cover portion erected from the upper end of the wall portion and formed substantially U-shaped in a plan view, with the upper side inclined inward, The cover portion comprises a first inclined plate erected from the upper end of the wall portion and a second inclined plate erected from the upper end of the first inclined plate. The angle between the second swash plate and the horizontal plane is set to be smaller than the angle between the first swash plate and the horizontal plane. The cover portion, which is formed in a substantially U-shape in plan view, is provided with a pair of end members that are positioned at both ends of the cover portion and are erected from the upper end of the wall portion. The end member is characterized in that its upward side is inclined toward the inside of the substantially U-shaped cover portion.

5. The ship according to claim 4, wherein the angle between the end member and the horizontal plane is set to be greater than the angle between the first slanted plate and the horizontal plane.

6. The ship according to claim 4, wherein the bow end of the end member is connected to the stern end of the cover portion.

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