JP2001180581A - Ice breaker, and operation method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ice breaker, and an operation method thereof capable of conducting safe navigation and effective ice breaking of the ice breaker in a sea zone where accumulation of snow exists on an ice plate. SOLUTION: A water storage tank 12 which is also capable of regulating the trim of a hull at a higher position than a draft line 17 in a bow part, a drain mechanism 14 connected to its bottom part, a brine lifting pump 11, and a water injecting passage 22 for injecting water into the water storage tank 12 are provided. The drain mechanism 14 is composed of a drain port 13 and a switching valve 15, the drain port 13 is provided at a height of a specifies distance from the draft line 17, and a movable current plate 19 is provided in it, so regulation of a discharge direction and current regulation of discharged water are conducted. The drain port 13 is formed as a slit, and it is disposed along a flat surface form of the bow part. Water is injected into the water storage tank 12 to apply pressure downward to accumulated snow 8 on an ice plate 3, brine 12a is then discharged from the water storage tank 12 by gravitational fall onto the ice plate 3 while it is retracted, and an ice breaker 1 having the bow part on the ice plate 3 is released from the ice plate 3 to retract.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an icebreaker and a method of maneuvering the same, and more particularly to an icebreaker capable of performing effective icebreaking in order for the icebreaker to safely sail. is there.

[0002]

2. Description of the Related Art Conventionally, various types of icebreakers are known, and sail on ice seas.

FIG. 6 shows a conventional ice breaking method for an ice breaking ship.
In a conventional typical ice breaking method for an icebreaker, when the icebreaker 1 moves forward, a force that pushes down the ice plate acts on the contact portion 2a between the ice plate 3 and the bow 2 by the bow angle θ of the ice breaker 1, The ice cube 3 was broken downward. Therefore, when there is snow on the ice plate 3, the force 4 for pushing down the ice plate 3
In order to reduce the increase in frictional force due to the absorption of snow by the compaction of dry snow,
Bows with sliding crushing sides, such as those found in Japanese Patent Publication No. 85, have also been devised.

FIG. 7 is a schematic view of a bow of an icebreaker 1 having a pontoon-shaped bow 5 having sliding crushing sides 6, 7, and FIG. 8 is a schematic front view of the icebreaker of FIG.
On both sides of the lower surface of the pontoon-shaped bow 5, sliding crushing sides 6 and 7 are provided, and even if snow 8 exists on the ice plate 3,
The acting force from the bow 5 to the ice floe 3 is caused by the bow outer plate 9 and the snow cover 8.
The crushed pieces of ice can be concentrated on the sliding crushed sides 6 and 7 without being reduced by contact with the crushed ice. Therefore,
It is stated that a high ice breaking effect can be achieved irrespective of snow cover (hereinafter referred to as prior art 1).

As another means, as shown in FIG. 9, a number of watering nozzles 10 are attached to the bow, and seawater pumped up by a pump 11 is continuously watered from the watering nozzles 10 onto the ice plate 3. A method of lubricating a contact portion between the hull 18 and the ice plate 3 or the snow cover 8 to reduce frictional resistance therebetween (hereinafter, referred to as prior art 2).

[0006]

As described above, according to the prior arts 1 and 2, it seems that there is an effect of reducing the frictional resistance of the contact portion between the hull and the ice plate or snow cover, respectively. However, it is hard to say that the following issues are sufficiently satisfactory.

Conventionally, when the ice thickness is thick and the condition of the ice is severe, the icebreaker repeats the process of approaching and rushing into the ice floe.
Gradually destroy the ice. Such an ice crushing method of repeatedly moving forward and backward to enter the ice floe is hereinafter referred to as charging ice crushing. When the snow depth on the ice plate is deep, even when charging ice is broken, the kinetic energy of the approach is absorbed by the dry snow, and the friction with the snow increases the propulsion resistance of the hull, causing charging ice breaking. Cannot be performed effectively.

[0008] Even in the case of the prior art 1 shown in FIGS. 7 and 8, when the depth of the snow cover 8 is larger than the height of the sliding crushing sides 6 and 7, the bow outer plate 9 and the snow cover 8 are not connected. Contact occurs, and it is not possible to prevent the ice breaking action of the ice plate 3 from being reduced.

The prior art 2 shown in FIG. 9 is effective when the snow depth is shallow, but in order to obtain the same lubrication effect even when the snow depth is deep, it is necessary to spray water at a large flow rate. And a pump with a large flow rate is required, or a long time is required for watering to slurify a wide range of snow.

In any of the prior arts, the bow climbs on the ice floe during the process of snow rushing into the deep ice floe,
If it is not easy to reverse, the worst case is that you may be stuck in an ice floe.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem of snow accumulation in the icebreaking operation of an icebreaker, in particular, the escape of the icebreaker from the ice plate when the bow rides on the ice plate during charging ice breaking. The purpose of the present invention is to provide an icebreaker capable of performing safe voyage and effective icebreaking of icebreakers in ice sea areas with severe ice conditions, and a method of maneuvering the icebreakers. To provide.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies from the above-mentioned viewpoints, and have obtained the following findings. That is, at a position higher than the waterline at the bow of the icebreaker and higher than the snow surface, a large-capacity water storage tank having a hull trim adjustment function is provided, and at the bottom of this water storage tank, In addition, a slit-shaped drain port is provided at a position higher than the snow-covered surface along the plane shape of the bow. A watertight door that can be opened and closed is provided in a connection path between the drain port provided at the bottom of the water storage tank and the water storage tank body.
Further, a water supply channel for injecting water from the upper water supply port of the water storage tank into the water storage tank and a pump for pumping seawater and flowing the seawater to the water supply channel are provided. When the bow climbs on an ice plate with a deep snow depth during charging ice breaking and it becomes difficult to move backward, a large amount of seawater is poured into the tank at the bow. Since the water storage tank provided at the bow is provided with a function of adjusting the hull by water injection, the weight of the seawater stored in the tank compacts the snow cover in contact with the bottom of the bow. Next, the watertight door at the bottom of the water storage tank is opened, and a large amount of seawater is dropped and discharged from the drain port onto the snow surface on the ice plate in a short time. At this time, in order to be able to direct the water discharge direction to the contact point between the bow surface and snow cover,
A movable rectifying plate is provided inside the opening to control the water discharge direction.

[0013] By such a water discharging action by the short-time drop of a large amount of seawater in a predetermined direction from the water storage tank at the bow, the frictional resistance between the snow and the hull, particularly the bow outer plate, can be reduced. Furthermore, since the large volume of seawater was injected into the water storage tank at this time and the water storage tank was emptied by the operation of discharging the large amount of seawater, the pressure acting on the snow surface from the bow was reduced. An effect is obtained, in which, despite the pressure reduction, the once compacted snow does not return to the original snow. When such an operation and effect are obtained in combination, it becomes easy for the icebreaker to separate from the ice plate and move backward.

The present invention has been made by focusing on the above findings, and the gist thereof is as follows. The icebreaker according to the first aspect of the present invention has a water storage tank located at a position higher than the waterline and used for trim adjustment of a hull provided at a bow portion, and a drainage water connected to a bottom of the water storage tank. The icebreaker is provided with a mechanism, a pump for pumping seawater, and a water injection passage for injecting the seawater pumped by the pump into the water storage tank. In addition, the drainage mechanism includes a drainage port and an on-off valve, and the drainage port is disposed at a position lower than the waterline by a predetermined distance at the bottom of the bow portion, and the drainage port includes the water reservoir. It is characterized in that a movable rectifying plate is provided for adjusting the outflow direction of discharging the seawater of the tank from the discharge port and rectifying the discharge of the seawater.

In the above description, the arrangement of the drain outlet at a position higher than the waterline by a predetermined distance means that the position of the drain outlet is higher than the surface of snow on the ice plate. Means

The icebreaker according to the second aspect of the present invention is the icebreaker according to the first aspect, wherein the drain port has a slit shape and is located at a position higher than the waterline of the bow by a predetermined distance. It is characterized in that one or a plurality of them are arranged along a plane shape.

According to a third aspect of the present invention, in the process of operating an icebreaker in an ice sea, the icebreaker whose bow has climbed on an ice plate is disengaged from the ice plate. It is a maneuvering method. That is, by injecting water into the predetermined container at the bow, pressure is applied downward from the bow to the ice plate and the snow on the ice plate, and then the water injected into the predetermined container is applied. By performing a reverse operation of the icebreaker while discharging water onto the ice plate by gravity drop from a drain port of the container, thereby reducing the pressure on the ice plate and snow cover from the bow, as well as the snow cover and the bow. It is characterized in that the frictional resistance between the portion and the outer plate is reduced.

[0018]

Next, the present invention will be described with reference to the drawings. 1 to 3 are explanatory views of a main part of a bow of an icebreaker according to one embodiment of the present invention. FIG. 1 is a schematic vertical sectional view taken along the center line of the hull, FIG.
FIG. 3 is a schematic front view.

As shown in FIG. 1, the icebreaker 1 is provided with a water storage tank 12 at the bow 2 at a position higher than the waterline 17 for adjusting the hull.
The seawater pumped in 1 can be injected into the water storage tank 12. A drain 13 is provided at the bottom of the water storage tank 12, and a watertight door 15 is provided at a connection path between the water outlet 13 and the water storage tank 12. A drainage mechanism 14 is provided by the watertight door 15 and the water outlet 13. Is composed. The drainage port 13 is provided at a position higher than the waterline 17 by a predetermined distance h (a position higher than the surface of the snow cover 8 on the ice floe 3), and its form is, as shown in FIG. It is provided by being divided into a plurality of pieces along the plane shape, and has a slit shape. Further, the drain 13 is provided inside the drain 13.
A movable rectifying plate 19 for adjusting the direction of water discharge from 3 between the outward direction and the inward direction of the bow 2 is attached. The movable rectifying plate 19 is controlled by the water discharge direction control panel 21 to discharge water in a desired direction. The movable current plate 19 is connected to the current plate motor 20 and constitutes a water discharge direction control mechanism. Then, the ice breaking auxiliary device described above pumps seawater with the pump 11 and closes the water storage tank 12 with the watertight door 15 closed as shown in FIG.
The watertight door 15 is then opened, and a large amount of seawater can be discharged onto the ice plate 3 in a short period of time while controlling the outflow direction from the drain 13.

The icebreaker 1 of the present invention is equipped with the icebreaker auxiliary device as described above, and according to the state of the snow cover 8 on the ice plate 3,
Appropriate water discharge can be performed. That is, FIG. 4 shows a case where the snow cover 8 is very deep in the course of the charging ice breaking by the icebreaker 1 and the bow 2 riding on the ice plate 3 is difficult to reverse due to friction with the snow cover 8. Like the pump 11
Pumps seawater through the water injection channel 22
The seawater 12a is stored in the water storage tank 12 of the section. Since the water storage tank 12 is located at the bow 2, a force F that pushes the bow 2 downward on the hull 18 due to the weight of the seawater 12 a of the water storage tank 12 acts on the hull 18 by the trim adjustment action, and the bottom of the bow 2 is an ice plate. 3 is compacted.

Next, as shown in FIG.
, The watertight door 15 at the bottom is opened, the seawater 12b is discharged at a stretch onto the snow cover 8 on the ice plate 3, and the seawater 12b is moistened with a large amount of seawater up to the deep portion of the snow cover 8 in a short time. At the same time, the water storage tank 12 at the bow 2 becomes empty, and the pressure acting on the snow cover 8 from the bottom of the bow 2 is reduced. When the icebreaker 1 is moved backward (arrow B) in this process, the icebreaker 1 is driven by the synergistic effect of the reduction of the frictional force G due to the wetting of the snowpack 8 and the reduction of the reaction force H from the snowpack 8 after compaction. Separation from the ice plate 3 and retreat can be performed more easily. In the ship maneuvering method intended to escape from the ice plate 3, if the water discharge direction is directed to the contact portion between the ice plate 3 and the bow 2 by the movable rectifying plate 19, the water discharge is more effective.

[0022]

As described above, according to the present invention,
Drainage outlets are installed at a position higher than the bow waterline and higher than the snow surface on the ice floe so that a large amount of water can be dropped from the bow water storage tank for a short period of time, so that the snow is sufficiently infiltrated. It is possible to reduce the frictional resistance between the snow cover and the outer shell of the bow, thereby effectively breaking the ice on the ice plate.

Further, since a water storage tank for discharging a large amount of seawater for trim adjustment of the hull is provided at the bow, snow can be compacted by a large amount of seawater stored in the water storage tank. Then, the seawater in the water storage tank is discharged, so that the pressure acting on snow from the bow bottom can be reduced. Through this series of processes, the effect that the bow bottom easily separates from the snow surface can be obtained together with the effect of reducing the frictional force on the snow surface due to the release of a large amount of seawater. It is extremely effective in escaping when the ship gets on the bow. Therefore, it is possible to greatly contribute to avoiding the greatest danger in the operation of the icebreaker, in which the icebreaker cannot climb on the ice plate during charging ice breaking and cannot move. According to the present invention, it is possible to provide an icebreaker and a method for maneuvering the icebreaker, which can provide such effects, and bring an industrially useful effect.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view of a bow of an icebreaker according to an embodiment of the present invention, taken along a hull center line.

FIG. 2 is a schematic plan view of the icebreaker of FIG. 1;

FIG. 3 is a schematic front view of the icebreaker of FIG. 1;

FIG. 4 is a schematic longitudinal sectional view illustrating a state in which seawater is injected into a water storage tank when the icebreaker according to an embodiment of the present invention separates from an onboard ice board and escapes from the ice tray.

FIG. 5 is a schematic vertical sectional view illustrating a state of seawater being discharged from the water storage tank onto the ice plate during departure from the ice plate on which the icebreaker according to one embodiment of the present invention has been boarded and escape operation of the ship;

FIG. 6 is an explanatory view of a conventional ice breaking method using an ice breaking ship.

FIG. 7 is an overall view of a bow of an icebreaker having a sliding crushing side conventionally designed to reduce the influence of snow on the icebreaking action.

FIG. 8 is a schematic front view of the ice breaking unit of FIG. 7;

FIG. 9 is an explanatory view of a watering method conventionally devised for providing lubrication to a contact portion between a hull and an ice plate or snow.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Icebreaker 2 Bow 2a Contact part between ice plate and bow 3 Ice plate 4 Force to push down ice plate 5 Pontoon-shaped bow 6, 7, Sliding crushing side 8 Snow cover 9 Bow outer plate 10 Watering nozzle 11 Pump 12 Water storage tank 12a, 12b Seawater 13 Drainage port 14 Drainage mechanism 15 Watertight door 16 Opening / closing valve 17 Waterline 18 Hull 19 Movable rectifying plate 20 Rectifying plate motor 21 Water discharge direction control panel 22 Injection flow path θ Bow angle h Required distance F Bow pushing force G Friction force H Reaction from snow to bow

Claims (3)

[Claims] 1. A water storage tank located at a position higher than a waterline and provided for a hull provided at a bow portion and also for adjusting a hull, and a drainage mechanism provided in connection with a bottom portion of the water storage tank.
An icebreaker provided with a pump for pumping seawater, and a water injection flow path for injecting the seawater pumped by the pump into the water storage tank, wherein the drainage mechanism includes a drainage port and an on-off valve. The drain port is disposed at a position lower than the waterline by a predetermined distance at the bottom of the bow, and the discharge port discharges the seawater from the water storage tank from the drain port to the drain port. An icebreaker characterized by being provided with a movable rectifying plate for adjusting water discharge and rectifying the discharge of the seawater. 2. The drain port has a slit shape, and one or a plurality of drain ports are disposed along a bow plane shape at a position higher than a waterline of the bow by a predetermined distance. The icebreaker of claim 1, wherein: 3. A ship maneuvering method for moving an icebreaker on an ice plate with its bow disengaged from the ice plate during the process of moving the icebreaker forward or backward in an icy sea. By applying pressure downwardly from the bow to the ice plate and the snow cover on the ice plate, and then the water poured into the predetermined container is gravity-drained from the drain port of the container. By performing the reverse operation of the icebreaker while discharging water onto the ice floe by falling, the pressure on the ice floe and snow from the bow is reduced, and the frictional resistance between the snow and the outer plate of the bow is reduced. A method for maneuvering an icebreaker, characterized in that it is reduced.