JP2014073815A - Twin rudder system and ship equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a twin rudder system that improves propulsion performance by generating a rudder thrust by a rudder plate, and a ship equipped with the same.SOLUTION: A twin rudder system includes a propeller 20 that is attached to a back end 12 of a stern tube 11 of a hull 10, two rudder plates 30, and driving means 50 for driving the two rudder plates 30 via a drive shaft 40. The two rudder plates 30 are arranged ahead of the propeller 20 or on a lateral side thereof, and a camber is formed inside the two rudder plates 30.

Description

  The present invention relates to a dual rudder system and a dual rudder provided with a propeller attached to the rear end of a stern tube of a hull, two rudder plates, and drive means for driving the two rudder plates via a drive shaft. It relates to ships equipped with the system.

The rudder is generally arranged behind the propeller for the purpose of increasing the steering force and using the acceleration flow of the propeller.
However, in a wide enlarged ship, the stern flow becomes unstable, and the course stability is extremely deteriorated. In order to further improve maneuverability, the rudder has been enlarged, but the propeller and rudder storage space at the stern has become insufficient, and the propeller has come extremely close to the hull, deteriorating propulsion performance.
From the ship's history, the means of propelling the ship has been replaced by the propeller era in which the main engine drives the propeller from the past sailing ship sailing era, but the shape and position of the rudder has not changed from the sailing ship era. . In today's era when global warming prevention measures are required, it is necessary to pursue the use of rudder as an energy-saving device in addition to the original rudder.

Patent document 1 and patent document 2 are the ships which have arrange | positioned the rudder behind the propeller.
Patent Document 3 proposes a configuration in which two rudder plates are arranged on the side of a propeller (FIG. 8 and paragraph number (0019)).
In Patent Document 4, the rudder is located in front of the propeller.

JP 2012-131475 A JP 50-55094 A JP 2010-13087 A JP 2003-11893 A

In Patent Document 1 and Patent Document 2, the rudder thrust is not generated because the rudder is disposed behind the propeller.
Patent Document 3 arranges two rudder plates on the side of the propeller, but the two rudder plates form a curved surface on the outside and do not form a camber with the inside as a flat surface, Rectification of the wake of the propeller that flows between the two rudder blades is planned.
That is, in Patent Document 3, the outer flow becomes faster due to the outer curve of the rudder plate, and a flow from the inner side to the outer side is generated at the front edge of the rudder plate. As a result, the inner flow is decelerated. Therefore, lift is generated in the direction outside the rudder plate, but the direction is directed to the stern direction as a drag, not the bow direction, because the flow entering the rudder plate is toward the center of the hull. Therefore, in Patent Document 3, the propeller thrust is improved, but the rudder thrust is not generated.
Note that Patent Document 4 relates to an azimuth propulsion device, which is merely that the rudder is in front of the propeller, and the basic configuration of the rudder system is different in the first place.

  An object of the present invention is to provide a twin rudder system that generates rudder thrust by a rudder plate and enhances propulsion performance, and a ship equipped with the dual rudder system.

  In the two-rudder system corresponding to the present invention according to claim 1, two rudder plates are arranged in front or side of the propeller and a camber is formed inside the two rudder plates. . According to the first aspect of the present invention, the rudder plate can generate a stern flow rectification effect and reduce the flow to generate rudder thrust.

  According to a second aspect of the present invention, in the dual rudder system according to the first aspect, the two rudder plates generate thrust for propelling the hull forward by the effect of the camber due to the contraction of the stern portion of the hull. It is characterized by its shape. According to the second aspect of the present invention, the hull is propelled forward by arranging the two rudder plates as a rudder plate with a camber formed inside in the flow toward the hull center direction at the stern part. Thrust can be generated. For example, by increasing the front width of the two rudder plates with respect to the rear width and tilting them between 0 degrees and 10 degrees with respect to the hull center line, it becomes an optimum rudder plate with little resistance to increase in lift, A large rudder thrust can be obtained.

  According to a third aspect of the present invention, in the two-shelter system according to the first or second aspect, the two rudder plates are coupled by the coupling means, and the two rudder plates are connected at the same angle by the driving unit. It is characterized by operating. According to the third aspect of the present invention, for example, the operation of the rudder plate can be stably performed with a single drive means.

  According to a fourth aspect of the present invention, in the dual rudder system according to the third aspect, the drive shaft is arranged in front of the center in the front-rear direction of the rudder plate. According to the fourth aspect of the present invention, the steering plate can be operated with a small driving load.

  According to a fifth aspect of the present invention, in the two-rudder system according to the first or second aspect, the two rudder plates are independently driven by the driving means. According to the fifth aspect of the present invention, for example, after one rudder plate is brought close to the hull, the other rudder plate can be further driven to generate a large lateral force on the hull. improves. Also, the braking distance of the ship can be shortened by opening and closing the two rudder plates in opposite directions.

  According to a sixth aspect of the present invention, in the dual rudder system according to the first to fifth aspects, one end of the drive shaft is supported by a propeller guard extending from the hull and disposed below the propeller. To do. According to the sixth aspect of the present invention, the strength against the load from the steering plate can be increased by supporting the drive shaft at both ends. It is also possible to connect the lower ends of the rudder plates and use that portion as a propeller guard so that the propeller does not come into contact with the seabed or drifting objects.

  In a ship equipped with a dual rudder system corresponding to the present invention according to claim 7, the dual rudder system according to any one of claims 1 to 6 is equipped on a ship. According to the seventh aspect of the present invention, a low fuel consumption ship using rudder thrust can be realized.

  The present invention according to claim 8 is a ship equipped with the dual rudder system according to claim 7, wherein the ship is enlarged with a square coefficient of 0.7 or more or a length-width ratio (L / B) of 5 or less. It is a ship. According to the present invention as set forth in claim 8, propulsion performance can be improved and fuel consumption can be reduced by rudder thrust in an enlarged ship with unstable stern flow.

  The present invention according to claim 9 is a ship equipped with the dual rudder system according to claim 7 or claim 8, wherein the stern portion located below the upper end of the rudder plate is substantially the same as the width from the hull center line. It is characterized by the same two-dimensional shape. According to the ninth aspect of the present invention, at the time of steering with one rudder plate close to the hull, the gap between the rudder plate and the hull is made as small as possible to enhance the flap effect, and the other rudder plate is further steered. The turning force can be improved by taking a large angle and acting like a guide vane.

  According to a tenth aspect of the present invention, in the ship equipped with the dual rudder system according to the seventh to ninth aspects, the distance from the rear end of the stern tube to the rear end of the stern of the hull It is characterized by being 3% or less. According to the present invention as set forth in claim 10, the propeller can be positioned rearward, the water line shape can be made longer than that of the conventional ship, and the stern part can be formed into a stern shape with less resistance, or the capacity of the stern part. Can be increased.

  According to the present invention, the rudder plate can generate a stern flow rectification effect, improve the propeller efficiency by reducing the flow, and generate a rudder thrust. It can function as an energy saving device.

  In addition, when the two rudder plates are shaped to generate thrust to propel the hull forward due to the camber effect due to the contraction of the stern part of the hull, for example, the front width of the two rudder plates is set to the rear width. And tilting from 0 degree to 10 degrees with respect to the hull center line, an optimum rudder plate with less resistance to an increase in lift can be obtained, and a large rudder thrust can be obtained.

  In addition, when two rudder plates are connected by a coupling means and the two rudder plates are operated at the same angle by the driving means, for example, the operation of the rudder plate is stably performed by one driving means. be able to.

  Moreover, when arrange | positioning a drive shaft ahead rather than the center of the front-back direction of a steering plate, a steering plate can be operated with a small drive load.

  In addition, when the two rudder plates are driven independently by the driving means, for example, after one rudder plate is brought close to the hull, the other rudder plate is further driven to generate a large lateral force on the hull. The turning performance can be improved. Also, the braking distance of the ship can be shortened by opening and closing the two rudder plates in opposite directions.

  Further, when one end of the drive shaft is supported by a propeller guard extending from the hull and disposed below the propeller, the strength against load from the rudder can be increased by supporting the drive shaft at both ends.

  In addition, according to the present invention, when a two-steer rudder system is equipped on a ship, a low fuel consumption ship using rudder thrust can be realized.

  In addition, when the ship is an enlarged ship having a square coefficient of 0.7 or more or a length-width ratio (L / B) of 5 or less, in the enlarged ship where the stern flow is unstable, the propulsion performance is improved. Fuel consumption can be reduced by rudder thrust.

  In addition, when the stern part located below the upper end of the plate has a two-dimensional shape with the same width from the hull centerline, when steering with one rudder plate close to the hull, The gap between the rudder plate and the hull can be made as small as possible to enhance the flap effect, and the turning force can be improved by making the other rudder plate have a larger rudder angle and act like a guide vane.

  In addition, if the distance from the rear end of the stern tube to the stern rear end of the hull is 3% or less with respect to the length of the hull, the propeller can be positioned rearward, compared to the conventional ship. Thus, the waterline shape can be lengthened, and the stern shape with less resistance can be obtained, or the hold capacity of the stern portion can be increased.

The principal part side surface block diagram which shows the ship equipped with the two-rudder system by one Embodiment of this invention Plan view of the main part of the ship FIG. 2 is a main part plan view showing a state during steering. A graph showing the results of an aquarium experiment using a model ship equipped with a twin rudder system according to this embodiment as a large-sized enlarged ship A graph showing the horsepower reduction rate of a model ship equipped with the same two-rudder system versus a model ship equipped with a normal rudder Explanatory drawing showing the improvement of the hull when equipped with the two-rudder system Principal configuration diagram showing other improvements to the hull when equipped with the two-rudder system Explanatory drawing showing further improvements of the hull when equipped with the two-rudder system The principal part side surface block diagram which shows the ship equipped with the two-rudder system by other embodiment of this invention The principal part plane block diagram which shows the ship equipped with the two-rudder system by further embodiment of this invention. The principal part plane block diagram which shows the state at the time of steering in FIG. The principal part plane block diagram which shows the ship equipped with the two-rudder system by further embodiment of this invention. The principal part plane block diagram which shows the state at the time of steering in FIG. The principal part block diagram which shows the ship equipped with the two-rudder system by other embodiment of this invention. Flow chart showing the design method for applying the dual rudder system to existing ships

Below, the ship equipped with the two-rudder system by embodiment of this invention is demonstrated.
1 is a side view of a main part of a ship equipped with a twin rudder system according to the embodiment, FIG. 2 is a plan view of a main part of the ship, and FIG. 3 is a main part of FIG. FIG.

A ship according to an embodiment of the present invention drives a propeller 20 attached to the rear end 12 of the stern tube 11 of the hull 10, two rudder plates 30, and two rudder plates 30 via a drive shaft 40. Means 50 are provided.
The two rudder plates 30 are arranged on the side of the propeller 20 and a camber (difference between the chord and the center line) 31 is formed inside the two rudder plates 30. The two rudder plates 30 may be disposed in front of the propeller 20 as will be described later.

  The drive shaft 40 is disposed ahead of the center of the rudder plate 30 in the front-rear direction. As shown in FIG. 2, when the length in the front-rear direction of the rudder plate 30 is E, the drive shaft 40 is located at a position from the front end of the rudder plate 30 to 1 / 2E, more preferably 1 from the front end of the rudder plate 30. / 3E up to 3E. Thus, the steering plate 30 can be operated with a small driving load by disposing the drive shaft 40 ahead of the center of the steering plate 30 in the front-rear direction.

According to the present embodiment, the two rudder plates 30 are arranged on the side of the propeller 20 and the camber 31 is formed on the inner side of the two rudder plates 30, so that the stern flow is controlled by the rudder plate 30. A rectifying effect can be produced and the flow can be reduced to generate rudder thrust.
The two rudder plates 30 have a shape that generates thrust to propel the hull 10 forward by the effect of the camber 31 that reduces the flow of the stern portion of the hull 10. The shape for generating the thrust for propelling the hull 10 forward is, for example, that the front width A of the two rudder plates 30 is made larger than the rear width B, and is tilted from 0 degrees to 10 degrees with respect to the center line of the hull 10. Thus, an arrangement having an appropriate angle of attack with respect to the flow of the stern portion of the hull 10 can be secured, the propeller efficiency is increased, and the optimum rudder plate 30 with less resistance to the increase in lift is obtained, and a large rudder thrust is obtained. Can be obtained.

The distance D from the rear end 12 of the stern tube 11 to the stern rear end 13 of the hull 10 is usually more than 3.5% with respect to the length (Lpp) of the hull 10. The steering plate 30 is arranged in front of or on the side of the propeller 20 and the camber 31 is formed inside the two steering plates 30 to increase the size of the steering plate 30 in order to improve the steering force. Because there is no need
It can be 3% or less. For this reason, the stern portion of the hull 10 can be shifted rearward, and the stern portion can be formed into an elongated shape with little resistance, or the volume of the hold of the stern portion can be increased.

As shown in FIG. 3, the two rudder plates 30 are connected by the connecting means 32, and the two rudder plates 30 are operated at the same angle by the driving means 50 via the drive shaft 40. By operating the two rudder plates 30 at the same angle by the driving means 50, the rudder plate 30 can be operated stably, and can be driven by one driving means 50.
At the time of steering, it is preferable that one rudder plate 30 is brought into contact with the hull 10 to eliminate a gap between the front end of the rudder plate 30 and the hull 10.

FIG. 4 is a graph showing the results of an aquarium experiment using a model ship equipped with a twin rudder system according to the present embodiment as a large enlarged ship.
In FIG. 4, a model ship equipped with the two-rudder system according to the present embodiment and a model ship equipped with a normal rudder are compared with the propeller thrust (kg) on the horizontal axis and the rudder thrust (kg) on the vertical axis. Yes.
The model ship used here has a vertical length (Lpp) of 225 m, a ship width (B) of 48.8 m, a square factor (Cb) of 0.8, and a draft depth (d) of 13.4 m. did.

In the model ship equipped with the twin rudder system according to the present embodiment, a thrust of 7 to 8% of the propeller thrust is generated when the propeller thrust is in the range of 1.300 to 1.500 kg. On the other hand, a model ship equipped with a normal rudder has a hull resistance of about 6%.
Therefore, the model ship equipped with the two-rudder system according to this embodiment has a horsepower saving of 15% or more compared to the model ship equipped with the normal rudder.

FIG. 5 compares the model ship equipped with the same two-rudder system as in FIG. 4 with the model ship equipped with the normal rudder, and the horsepower reduction of the model ship equipped with the two-rudder system with respect to the model ship equipped with the normal rudder. In this graph, the horizontal axis represents boat speed (knots), the left vertical axis represents horsepower (kw), and the right vertical axis represents horsepower reduction rate (%).
As the boat speed increases, the horsepower reduction rate of the model ship equipped with the two-rudder system for the model ship equipped with the normal rudder increases. If the ship speed during actual navigation is 14.5 knots, the horsepower reduction rate is about 12%. If the ship speed during actual navigation is 16.5 knots, the horsepower reduction rate is about 15%.

  As shown in FIG.4 and FIG.5, when a two-steer rudder system is equipped on a ship, a low fuel consumption ship using rudder thrust can be realized.

FIG. 6 is an explanatory view showing an improvement of the hull in the case where the two-slewing system according to the embodiment of the present invention is equipped.
In FIG. 6, the propeller axis line of the hull 10 of the present embodiment, the rudder plate upper end line of the hull 10 of the present embodiment, the propeller axis line of the hull of the normal rudder ship, and the rudder plate of the hull of the normal rudder ship The top line is shown. In addition, the rudder plate upper end line of the hull of a normal rudder ship is set to the same height as the rudder plate upper end line of the hull 10 of the present embodiment.

  When equipped with the two-wheel rudder according to the present embodiment, the propeller 20 can be moved to the rudder position of the normal rudder ship. Therefore, compared with a normal rudder ship, the stern can be elongated and the hull resistance can be reduced and the performance can be greatly improved.

FIG. 7 is a main part configuration diagram showing another improvement of the hull in the case of being equipped with a twin rudder system according to an embodiment of the present invention. In FIG. 7, only a part of the rudder plate 30 and the stern part 14 are shown, and other configurations are omitted for convenience of explanation.
In the present embodiment, the stern portion 14 positioned below the upper end of the rudder plate 30 has a two-dimensional shape with substantially the same width from the hull center line. That is, the stern part line 14a in the upper end line of the rudder plate 30 and the stern part line 14b in the lower end line of the rudder plate 30 have a hull shape that is substantially matched in plan view.

  In this way, the stern portion 14 positioned below the upper end of the rudder plate 30 has a two-dimensional hull shape that does not have an angle in the vertical direction or has a small angle, so that one rudder plate At the time of steering with 30 close to the hull 10, the rudder between one rudder plate 30 and the hull 10 (stern part 14) is eliminated, and one rudder plate 30 acts like a flap, thereby further increasing rudder thrust. be able to.

FIG. 8 is an explanatory view showing still another improvement of the hull in the case where the two-rudder system according to the embodiment of the present invention is installed.
The ship shown in FIG. 8 shows the hull 10 having a vertical length (Lpp) of 300 m, a ship width (B) of 65 m, and a draft depth (d) of 17.9 m.
In a normal rudder ship, the distance Da from the rear end 12a of the stern tube 11 to the stern rear end 13 of the hull 10 is 14 m or more, which is 4.7% with respect to the length of the hull 10 (Lpp = 300 m). is there.

When equipped with the twin rudder system according to the embodiment of the present invention, the distance Db from the rear end 12b of the stern tube 11 to the stern rear end portion 13 of the hull 10 can be 9 m or less. It can be 3% or less with respect to the length (Lpp = 300 m).
Thus, the propeller 20 is positioned rearward by setting the distance Db from the rear end 12b of the stern tube 11 to the stern rear end 13 of the hull 10 to 3% or less with respect to the length of the hull 10. The water line shape can be made longer than that of conventional ships. Or it becomes possible to increase the volume of the hold of a stern part.

FIG. 9 is a side view of a main part showing a ship equipped with a two-rudder system according to another embodiment of the present invention. The same components as those in FIG.
The ship equipped with the two-rudder system according to the present embodiment supports one end 41 of the drive shaft 40 with a propeller guard 60 that extends from the hull 10 and is disposed below the propeller 20. In this embodiment, the configuration is the same as that shown in FIGS. 2 and 3 except that the propeller guard 60 supports the same operation.

  According to the present embodiment, the strength against the load from the steering plate 30 can be increased by supporting the drive shaft 40 at both ends.

FIG. 10 is a plan view of a principal part showing a ship equipped with a two-rudder system according to still another embodiment of the present invention, and FIG. 11 is a plan view of a relevant part showing the state during steering in FIG. The same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted.
The ship equipped with the two-rudder system according to the present embodiment has the same configuration as FIG. 1 except that the two rudder plates 30 are arranged in front of the propeller 20, and performs the same operation.

  According to the present embodiment, the two rudder plates 30 are arranged in front of the propeller 20 and the camber 31 is formed inside the two rudder plates 30, so that the stern flow is rectified by the rudder plate 30. An effect can be produced and the flow can be reduced to generate rudder thrust.

As shown in FIGS. 1 to 3, when the two rudder plates 30 are arranged on the side of the propeller 20, the rudder thrust increases, and as shown in FIGS. 10 and 11, the two rudder thrusters are used. When the plate 30 is arranged in front of the propeller 20, the propulsion performance (course stability) tends to be further increased.
Depending on whether the rudder thrust or propulsion performance is emphasized, and the necessity of increasing the water line shape or increasing the volume of the hold, the two rudder plates 30 are arranged from the side of the propeller 20. It can be placed at any position in front.

FIG. 12 is a plan view of a principal portion showing a ship equipped with a two-rudder system according to still another embodiment of the present invention, and FIG. 13 is a plan view of a principal portion showing a state during steering in FIG. The same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted.
The ship equipped with the two-rudder system according to the present embodiment has the same configuration as that shown in FIGS. 1 to 3 except that the two rudder plates 30 are provided with driving means 50a and 50b that can operate independently.
In the present embodiment, the two rudder plates 30 can be independently driven by the driving units 50a and 50b. In FIG. 13, the driving unit 50b performs a larger operation on the rudder plate 30 than the driving unit 50a. Shows the case of giving.

According to the present embodiment, for example, after one rudder plate 30 is brought close to the hull 10, the other rudder plate 30 can be further driven to generate a large lateral force on the hull 10, and the turning performance is improved. improves. Moreover, according to this Embodiment, the braking distance of a ship can be shortened by opening and closing the two rudder plates 30 in the opposite direction. Further, the two rudder plates 30 can be arbitrarily driven independently by the driving means 50a and 50b according to the flow state of the stern part and the ship maneuvering situation of the hull 10.
In a ship equipped with a dual rudder system according to the present embodiment, particularly in an enlarged ship having a square coefficient of 0.7 or more or a length-width ratio (L / B) of 5 or less, the propulsion performance is improved and the rudder thrust is used. Low fuel consumption can be achieved.

FIG. 14 is a main part configuration diagram showing a ship equipped with a twin rudder system according to still another embodiment of the present invention. The same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted.
The ship equipped with the two-rudder system according to the present embodiment has two rudder plates 30 that are widened to open outwardly at the rudder plate upper end portion 30a with respect to the rear width, and at the rudder plate lower end portion 30b. The configuration is the same as that shown in FIGS. 1 to 3 except that the front width and the rear width are the same and substantially parallel to the center line of the hull 10.
The two rudder plates 30 are opened outward by making the front width larger than the rear width at the rudder plate upper end portion 30a, and the front width and the rear width are the same at the rudder plate lower end portion 30b with respect to the center line of the hull 10. The configuration is the same as that shown in FIGS.
In the rudder plate upper end portion 30a, the front width is increased with respect to the rear width so that the rudder plate 30 is opened outward. It has the effect of optimizing the angle of attack.
Further, in the rudder plate upper end portion 30a, increasing the front width with respect to the rear width to open outward accelerates the flow of the stern portion that is relatively slower above the central axis of the propeller 20, and further increases the rudder thrust and Propeller thrust can be increased. Further, the rudder plate lower end 30b has the same front width and rear width and is substantially parallel to the center line of the hull 10, thereby accelerating the relatively fast stern portion below the central axis of the propeller 20. Without rubbing, the rudder thrust can be obtained after balancing with the upper side, and can be applied to the propeller.
In a ship equipped with the dual rudder system according to the present embodiment, rudder thrust and propeller efficiency can be further increased.

  It is also possible to obtain thrust and turning force similar to that of the rudder plate 30 by configuring the two rudder plates 30 in the form of two fins or in the form of a duct extending on both sides of the propeller 20. In this case, fins and ducts are included in the broad definition of the two rudder plates 30. It is also possible to increase the thrust and turning force by combining the original two rudder plates 30 with fin-like or duct-like appendages.

Below, the design method of the dual rudder system by this Embodiment with respect to the existing ship is demonstrated.
FIG. 15 is a flowchart showing a design method for applying the dual rudder system to an existing ship.
First, the two rudder plates 30 are moved to the front or side of the propeller 20 (step 1). In step 1, the position of the propeller 20 may be moved together with the two rudder plates 30 in the direction of the stern rear end portion 13 of the hull 10.
Next, if possible, the stern portion 14 positioned below the upper end of the rudder plate 30 is corrected to a two-dimensional hull shape that does not have an angle in the vertical direction (step 2).
After step 1 or after step 2, the two rudder plates 30 are designed in a shape along the contracted flow by the hull 10 (step 3).
After step 3, the camber 31 of the two rudder plates 30 is modified and designed so that the maximum thrust is generated by propeller contraction (step 4).
After step 4, interference between the rudder plate 30 and the hull 10 during steering is confirmed (step 5).
If there is a problem in step 5, the process returns to step 1 to change the position of the rudder plate 30.

With the above design method, the dual rudder system according to the present embodiment can be applied to an existing ship.
As described above, according to the present embodiment, the two rudder plates 30 can produce a flow rectifying effect of the flow of the stern portion 14 and reduce the flow to generate thrust by the rudder plate 30. The rudder plate 30 can be made to function not only as an original rudder function but also as an energy saving device.

  The present invention is suitable for large-sized enlarged ships such as ore carriers and oil tankers, but can also be applied to small ships.

DESCRIPTION OF SYMBOLS 10 Hull 11 Stern tube 12 Rear end 13 Stern rear end 14 Stern 14a Stern line 14b Stern line 20 Propeller 30 Rudder plate 31 Camber 32 Connection means 40 Drive shaft 50 Drive means

Claims (10)

  A dual steering system comprising a propeller attached to the rear end of a stern tube of a hull, two rudder plates, and driving means for driving the two rudder plates via a drive shaft, A dual rudder system in which the rudder plate is disposed in front of or to the side of the propeller and a camber is formed inside the two rudder plates.   2. The two-wheel rudder according to claim 1, wherein the two rudder plates are configured to generate a thrust for propelling the hull forward by the effect of the camber due to the contraction of the stern portion of the hull. system.   3. The two-rudder system according to claim 1, wherein the two rudder plates are coupled by a coupling unit, and the two rudder plates are operated at the same angle by the driving unit.   The two-steering system according to claim 3, wherein the drive shaft is disposed in front of a center in the front-rear direction of the rudder plate.   The two-steering system according to claim 1 or 2, wherein the two steering plates are independently driven by the driving means. 6. The two-wheel steering system according to claim 1, wherein one end of the drive shaft is supported by a propeller guard extending from the hull and disposed below the propeller.   A ship equipped with a dual rudder system, wherein the dual rudder system according to any one of claims 1 to 6 is equipped on a ship.   The ship equipped with a dual rudder system according to claim 7, wherein the ship is an enlarged ship having a square coefficient of 0.7 or more or a length-width ratio (L / B) of 5 or less.   9. The two pieces according to claim 7 or 8, wherein the stern portion positioned below the upper end of the rudder plate has a two-dimensional shape having substantially the same width from the hull center line. A ship equipped with a rudder system.   10. The distance from the rear end of the stern tube to the stern rear end of the hull is set to 3% or less with respect to the length of the hull. 10. A ship equipped with a dual rudder system.