JPH09323695A - Hull form for ice breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the ice breaking capability of the side of a rear half hull part in particular during a turning motion. SOLUTION: An inboard slope 1a is formed on the side of a rear half hull part, so as to extend from a position below a water surface of a design draft line to a position above the line, and an upper curved surface 1c is formed to be continuous to the upper end 1b of the slope 1a, thereby forming a recessed curvature 7 to break and overturn a plate type of ice as a whole. According to this construction, the aft hull part can be easily moved outside a turning radius, due to the improvement of an ice breaking function for plate types of ice 5. Also, the hull can be smoothly turned, and maneuverability is also improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an icebreaker, and more particularly, to a hull form which allows the turning action of a hull during navigation in an ice sea to be performed without hindrance.

[0002]

2. Description of the Related Art Generally, when turning a hull by steering, as shown in FIG. 7, the first half of the hull also turns along the inside of a turning locus 2 delineating the center of gravity of the hull, and the inside of the turning turns. The side surface draws the turning inside track 3, but the latter half of the hull is swung to the outside of the turning, and the ship side surface outside the turning turns draws the turning outside track 4.

The turning action of the hull as described above is performed without any problem on normal sea level, but in the case of an icebreaker sailing in an ice sea, the ice plate contacting the ship side in the latter half of the hull on the outside of the turning hinders. As a result, the turning radius is increased. On the other hand, in the conventional hull form of an icebreaker, as shown in FIG. 8, the cross-sectional shape of the rear half of the hull does not take any measures.

[0004]

In an icebreaker having a conventional hull form as described above, if an attempt is made to turn during ice navigation, as shown in FIG. 8, an ice plate contacting the rear half of the hull 1 outside the turn. No. 5 is ruptured as it is pushed downward on the side surface of the second half of the hull, but the ice plate in the ice sea is stiffer on the top side than on the bottom side, so a large load is applied to the hull, and There is a problem that it obstructs turning.

Therefore, in the present invention, when the hull is turned, the side surface of the latter half of the hull acts to push up the ice plate outside the turn, so that the ice plate can be easily broken and broken. It is an object of the present invention to provide an icebreaker hull form that enables efficient removal of ice sheets.

[0006]

In order to solve the above-mentioned problems, the hull form of the icebreaker of the present invention is such that, on the ship side surface of the latter half of the hull of the icebreaker, the ice plate that abuts the ship side surface when the hull is turned up is pushed up. Therefore, an inward sloping surface sloping inward from the lower part of the planned waterline to the upper part is formed, and the edge part of the ice sheet that is pushed up and broken along the inward sloping surface and abuts the side surface of the ship is hulled. An upper curved surface is formed which is connected to the upper end of the inwardly inclined surface and gradually turns outward as it goes upward so as to guide it outwardly and to fall, and the inwardly inclined surface and the upper curved surface are formed. It is characterized in that a concave curved surface for crushing and breaking an ice plate is formed as a whole by and.

In the above-mentioned ship shape of the icebreaker of the present invention, when the hull is turned by steering, the latter half of the hull presses the ice plate in contact with the side of the ship outside the turning, and is formed on the side of the ship. The inwardly sloping surface that acts to push up the ice plate causes the ice plate to break. In that case, since the lower surface side portion of the ice plate below the water surface is softer than the upper surface side portion, the ice plate is easily broken.

The edge of the ice plate thus broken is
The upper curved surface connected to the upper end of the inwardly inclined surface is gradually guided to the outer side, so that the ice plate can be properly removed to the outer side of the hull by falling.

Therefore, due to the action of the ice plate breaking inversion concave curved surface composed of the inwardly inclined surface and the upper curved surface formed on the side surface of the latter half of the hull, the latter half of the hull is outside the turning when the hull is turning. The swinging action of the hull can be performed very smoothly and with a required turning radius.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The hull form of an icebreaker as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of the latter half of the hull of the icebreaker, and FIG. 2 is a sectional view taken along line AA of FIG. 3 is a sectional view taken along line BB in FIG. 1, and FIG. 4 is taken along line CC in FIG.
A sectional view, FIG. 5 is a sectional view taken along the line DD of FIG. 1, and FIG. 6 is an explanatory view showing the principle of the present invention.

As shown in FIGS. 1 to 4, in the hull form of the icebreaker of this embodiment, in the latter half of the hull, on the side surface of the hull 1 near the stern bossing where the propeller shaft projects rearward, the water level of the planned draft line is reached. An inwardly sloping surface 1a inclined inwardly is formed on the inside of the ship from below to above 6 and is connected to an upper end 1b of the same sloping surface 1a and gradually turns outward as it goes upward. The curved surface 1c is formed, and thus the inwardly inclined surface 1a and the upper curved surface 1c form the ice curved surface tumbling concave curved surface 7 as a whole. It should be noted that the concave curved surface 7 is not formed behind the ship side surface shown in FIG.

FIG. 6 shows the principle of operation of an icebreaker in which the above-mentioned inwardly inclined surface 1a and the upper curved surface 1c are provided with the concave curved surface 7 for breaking the ice plate on the side surface of the latter half of the hull. ing.

In the icebreaker having the hull form of the present embodiment, when the hull starts to turn due to steering during navigation in the ice sea, as described with reference to FIG. Although the side surface of the ship tends to be swung outward, as shown in FIGS. 2 to 4, the side surface of the ship is formed with an inwardly inclined surface 1a that inclines inward from below the water surface 6 to above the water surface 6. As is apparent from FIG. 6 schematically showing the inwardly inclined surface 1a, the inwardly inclined surface 1a acts to press the ice plate 5 and push up an edge portion of the ice plate 5 which is in contact with the ship side surface. Thereby, the ice plate 5 is broken. At that time, since the lower surface side portion of the ice plate 5 which is below the water surface is softer than the upper surface side portion above the water surface, the breaking action of the ice plate 5 can be easily performed.

The edge of the ice plate 5 thus fractured rises along the inwardly inclined surface 1a, and then the inclined surface 1a.
Although it is guided by the upper curved surface 1c connected to a, the upper curved surface 1c is formed so as to sequentially turn outward as it goes upward, so that the edge of the ice plate 5 is While being pushed to the outside of the hull 1, it turns over and falls.

Then, another ice plate 5 adjacent to this overturned ice plate 5 is broken by the action of the concave curved surface 7 which is also composed of the inwardly inclined surface 1a on the side surface of the ship and the upper curved surface 1c. The ice plates 5 adjacent to each other are successively broken and fallen.

The above-described operation is such that the shape of each part of the ship side surface in the latter half of the hull of the icebreaker is as shown in FIGS. 2 to 4 from the same inwardly inclined surface 1a and upper curved surface 1c as in FIG. Since the ice plate breaking and inclining concave curved surface 7 is formed, the breaking and overturning action on the above-mentioned ice plate 5 is performed in the entire second half of the hull.

Therefore, the turning action of the hull accompanying the steering operation of the icebreaker in the ice sea can be smoothly and without increasing the turning motion of the latter half of the hull by the ice plate, and the turning radius can be increased. It will be done accurately without accompanying.

In other words, when the icebreaker makes a turn, the icebreaking ability of the ice plate that hits the ship in the latter half of the hull is improved, and the ice load for suppressing the turning moment for turning the hull is reduced. As a result, the turning performance of the icebreaker will be improved, which will improve the safety of maneuvering.

[0019]

As described above in detail, the following effects can be obtained by the hull form of the icebreaker of the present invention. (1) When an icebreaker having the hull form of the present invention makes a turn due to steering during navigation in an ice sea, an ice plate that abuts the side surface of the latter half of the hull on the outside of the turn is a concave curve formed on the side surface of the ship. The sloping surface is pushed upward by the inward sloping surface and is broken, and the edge of the ice plate that comes into contact with the ship's side surface is further guided by the upper curved surface to invert and fall. As a result of the ice plate breaking and inclining concave curved surface including the above-mentioned inwardly inclined surface and the upper curved surface, the ice breaking ability of the latter half of the hull at the time of turning is enhanced, and the turning performance is improved. (2) According to the above item (1), the safety of an icebreaker navigating in an ice sea can be improved.

[Brief description of drawings]

FIG. 1 is a side view of a rear half of a hull of an icebreaker as an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view taken along line CC of FIG.

FIG. 5 is a sectional view taken along line DD of FIG. 1;

6 is an explanatory view schematically showing the ice breaking action on the side surface of the ice breaking ship of FIG. 1 when turning.

FIG. 7 is a plan view showing a trajectory and a wake drawn when the ship turns.

FIG. 8 is an explanatory view schematically showing an ice breaking action on a side surface of a conventional ice breaking ship when turning.

[Explanation of symbols]

 1 Hull 1a Inwardly inclined surface 1b Upper end of inwardly inclined surface 1c Upper curved surface 2 Track of ship's center of gravity when turning 3 Inner track when turning 4 Outer track when turning 5 Ice plate 6 Water surface of planned draft line 7 Ice plate breakage Recessed concave curved surface

Claims (1)

[Claims] 1. On the side surface of the latter half of the hull of an icebreaker,
In order to push up the ice plate that comes into contact with the side of the ship when the hull turns, an inward inclined surface that inclines toward the inside of the ship from below to above the planned waterline was formed, and it was pushed up along the same inward inclined surface and fractured. In order to guide the edge of the ice plate abutting the side of the ship to the outside of the hull and to tip it over, an upper curved surface that is connected to the upper end of the inward inclined surface and gradually turns outward as it goes upward A hull form of an icebreaker, characterized in that an inwardly inclined surface and an upper curved surface are formed as a whole to form a concave curved surface for breaking and crushing ice plates.