Roll reduction water tank device for large container ships and its control method

Abstract

In recent years, there have been many requests for studies on A.R.T. equipment aimed at preventing container falls in huge container ships with a displacement of 150,000 to 200,000 tons. However, based on the concept of the prior art, the basic dimensions of A.R.T., especially the weight of the liquid used, become excessively large at several thousand tons, so reducing the amount of cargo loaded as a merchant ship could not be achieved from the perspective of cost-effectiveness. 【Solution means】 It is an A.R.T. main body 1 with a cross-sectional shape of a mountain character, which is connected by a new concept center tank 3 and left and right liquid passages 6p, 6s to a DW type A.R.T. manufactured by Stabiliro based on a U-tube type. It creates left and right virtual tank functions 1p, 1s with the vertical partition wall 5 below the equipment room as the boundary, lowering the average roll period value of the ship. It is equipped with the virtual tank, the function of the A.R.T. main body, a program for automatic control, and a program for predicting whether or not it will lead to parametric rolling phenomenon. It becomes possible to provide the A.R.T. equipment, which was difficult to install, to a huge container ship with a displacement of 200,000 tons, keeping the weight of the liquid used for the problem within about 1,000 tons and obtaining a more effective roll reduction rate.

Description

[Technical Field]

[0001] The present invention relates to a roll-swing reduction tank system and a control method for parametric roll-swing, which are related to roll-swing reduction for ships that are becoming larger and larger, particularly for huge container ships. In Japan, there is the Maritime Traffic Safety Act, which applies to major sea areas where ship traffic is congested, and defines a "huge vessel" as a vessel with a total length of 200 meters or more. However, vessels with a total length of over 400 meters have now appeared, and huge vessels in the 200 meter class are considered normal size and are swarming the world's oceans. The "huge vessel" defined in the present invention refers to a vessel with a total length of over 300 meters. [Background technology]

[0002] In accordance with the Ship Safety Act and Ship Stability Regulations, Japan has been working hard to popularize motion reduction devices that reduce the roll angle of ships in rough weather to 20 degrees or less. In particular, car ferries that carry "flammable cars and large numbers of passengers" and are equipped with highly flammable fuel have been identified, and two types of devices, "Fin Stabilizers" or "Anti-rolling Tanks (hereinafter referred to as ART)," have been designated as effective motion reduction devices for ships, and their installation has been mandatory since 1973, making them legal equipment.

[0003] There are two types of ART: active and passive. Passive ARTs include the "Flume type," which has a rectangular cross section, and the "Frahm type," which has a U-tube shape (hereinafter simply referred to as the U-tube type or ART). This application employs the "Frahm type." This technology utilizes the natural phenomenon of liquid flowing from higher to lower places, and was invented by Frahm in 1910 to create a system in which the liquid "delays by one beat" in response to the rolling of the ship. This device consists of symmetrical vertical pipes (wing tanks) on both sides of the ship's hull, and a liquid passage (also called a lower duct) that connects the bottoms of these vertical pipes and moves the liquid w in the tanks left and right. The speed at which the liquid moves (also known as the natural period of the tank) can be calculated from the ratio of the longitudinal cross-sectional area of the wing tank and the liquid passage, and it is known that by designing the tank's natural period (Tts) to be approximately equal to the ship's rolling period (STs), a phase delay of 90 degrees occurs between the waves that induce the ship's rolling, the ship's rolling, and the liquid in the tank, resulting in a high roll reduction effect (see Figure 2). In Japan, in 1930, an article entitled "On the Design of Anti-Roll Tanks," which included the Frahm system, was published in the Shipbuilding Council Bulletin No. 46, and the MN system, which was put into practical use in 1963 through a joint effort by industry, government, and academia, is well known.

[0004] However, this U-tube wing tank, including the MN type, is a single tank (single type) and the tank's natural period cannot be changed, making it unsuitable for merchant ships whose load varies greatly. Therefore, the inventors of the present application have used a ``Double Wing (DW type)'' in which the inside of a single tank is divided by a longitudinal bulkhead in the bow-stern direction and the tanks have different natural periods, and a ``Triple Wing (TW type)'' equipped with wing tanks that make up three compartments, to develop an optimal shape and control method that can be used to suit the type, size, and purpose of the ship. The DW-type ART is a device approved by the former Ministry of Transport as the "D·W anti-rolling tank manufactured by Stabilo Corporation," and is described in the following non-patent document 1. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3537785 (Ship motion reduction tank device and its control method) [Patent Document 2] Patent No. 3377782 (Ship motion reduction tank device and its control method) [Patent Document 3] Patent No. 30428865 (Control method for vessel motion reduction tank device) [Patent Document 4] No. 2144338 (Ship rocking tank equipment) [Patent Document 5] Patent No. 4262127 (Parametric Roll Prevention Device) [Patent Document 6] Patent No. 4721169 (Variable period anti-rolling tank device for preventing parametric roll) [Patent Document 7] Patent application 2023-108567 (Rolling reduction tank device for container ships and its control method) [Non-patent literature]

[0006] [Non-Patent Document 1] Marine Inspection No. 115-2 Notice (dated November 18, 1987, Chief Ship Inspector of the Maritime Technical Safety Bureau) [Non-patent document 2] TopTier N2M Paramatric Roll Following Seas V1.1 Notice to Mariners Beware of parametric roll in following seas [Non-patent document 3] Performance Estimation of Anti-Rolling Tank as a Parametric Roll Prevention Device (2nd Report) Journal of the Japan Society of Naval Architects and Ocean Engineers No. 8 December 2008 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention relates to an ART for unprecedentedly large container ships with a beam of 40 to 60 m, a GM of 2.0 m or more, and a displacement of 150,000 to 300,000 tonnes, and to parametric roll prevention.

[0008] (1) Since around 2000, as container ships on international routes have become larger, the number of containers they can carry has increased dramatically, resulting in a number of accidents in which a large number of containers have been lost or damaged during navigation. One of the causes of this is thought to be the occurrence of a large roll angle known as parametric roll. One of the countermeasures is the patent documents 5 and 6, which were filed in 2004, for an "Anti-rolling Tank Device for Preventing Parametric Roll." (2) In the winter of 2020 - 2021, major accidents involving container losses occurred frequently. In response, a joint industry project (The TopTier project) was launched to explore countermeasures to prevent recurrence of such accidents. It became clear that parametric rolling in following seas is particularly dangerous. Non - Patent Document 2 states that advice has been implemented on how the crew and staff involved in the operation of container ships should plan, recognize, and take action to prevent parametric rolling in following seas.

[0009] In 2021, there was an increasing number of requests for A.R.T equipment for ultra - large container ships. One of the conditions presented was (1) Length between perpendiculars: 335.0 m, beam: 50.0 m, depth: 30.0 m, displacement: 200,000 tons. The roll - restoring performance in the fully - loaded to in - port state is a GoM value of 4.0 - 2.0 m, roll period: 20 - 30 seconds, and the target roll - damping efficiency: 50%. (a) The A.R.T plan must, based on the roll - restoring numerical values presented in the order specifications and the vertical installation position of the tank, first provide A.R.T dimensions that can satisfy the required roll - damping efficiency. (b) Thus, when applying the beam of 50 m, GoM value of 4.0 m, roll - period value of 20 seconds, etc. presented by the requester to conventional - technology calculations, the average flow velocity of the liquid is approximately 5.0 m / s. Also, when the GoM value is 2.0 m and the roll - period value is 30 seconds, the average flow velocity of the liquid is approximately 3.33 m / s. (c) The roll period assumed in onboard calculations is 20 - 30 seconds. Considering head seas (also called oncoming waves) and following seas (also called trailing waves), the effective roll - damping period range requires 18.5 - 34 seconds. (d) To obtain the ordered roll - damping efficiency of 50%, considering these large values such as the roll - restoring coefficient of 800,000 t - m described in the roll - restoring specifications of paragraph 0023 of this application, the required tank length is approximately 15 m, liquid - passage height: approximately 2.5 m, weight of the liquid used: approximately 2,200 tons, which is approximately 1.1% of the displacement. Incidentally, in "Performance Estimation of Anti-Rolling Tank as Parametric Rolling Prevention Device (Second Report)" in (Non-Patent Document 3), the displacement is 105,000 tons and the restoring coefficient is 111,300 t-m. (See Table 1). (2) The installation of this 2,200-ton use liquid weight leads to a decrease in the amount of loaded cargo, and from the perspective of the cost-effectiveness associated with A.R.T equipment, it is far from practical at present, and there is an urgent need for new development.

[0010] Outline of prior art related to the anti-rolling water tank device for parametric rolling prevention and comparison with the present application. (1) As a result of prior art investigations, etc. (a) Type of investigation: Patent investigation using J-Platpat (b) F1 / IPC: B63B39 / 03 (c) Scope of investigation: Search formula in the "entire text scope" (d) Search items: F1 (B63B39 / 03): 268 cases, and IPC (B63B39 / 03): 381 cases. (e) Search items: F1 / IPC + keyword (e1): "Giant ship + large container ship + mountain shape" is 0 cases for both F1 and IPC. (e2): "Anti-rolling water tank (74 cases / 91 cases), ART (21 cases / 22 cases). (e3): "Anti-rolling tank (15 cases / 17 cases), "U-tube type (41 cases / 44 cases)"" (e4): "Parametric rolling + anti-rolling water tank device" was 2 cases for FI and 2 cases for IPC. (2) Regarding the content of the prior art investigation, (a) Although prior art was confirmed for the anti-rolling water tank device for large container ships, There was no disclosure of the "mountain-shaped cross-sectional shape" which is a feature of the present invention, and it is considered to have novelty. (b) For the parametric rolling + anti-rolling water tank device, there are "Patent Document 5 and Patent Document 6", and these 2 cases are both by the same inventor and adopt the "U-tube type (Single type)", and the comparison with the present invention is shown below. (3) In the parametric rolling prevention device of Patent Document 5, as one of the solution means, in the paragraph of (Summary · Solution Means), it is described that "by taking in and out the liquid (seawater) in the tank 5 installed on the hull 1, the position of the center of gravity of the hull 1 is moved, and the rolling period of the hull 1 is changed, so that the ratio of the rolling period to the pitching period deviates from a certain parametric rolling generation condition set in advance". However, in the case of large ships, there is no technology that can cope with the liquid weight of A.R.T (0.6% of the displacement?) by filling and draining, especially, there is no means in the present invention that the damping effect will be completely lost when the liquid of A.R.T is drained. (4) In Patent Document 6, (a) In its paragraph 0014, it is clearly stated that "the weight of the liquid loaded in the anti-rolling tank is 0.8% to 0.2% of the displacement of the ship...", but there is no disclosure or suggestion of the specific numerical values of "the weight of the liquid used" and "the displacement". (b) In its paragraph 0015, it is specified that "an anti-rolling tank comprising a pair of left and right wing tanks and a connecting waterway connecting the lower parts of the pair of left and right wing tanks, a damper provided in the connecting waterway for adjusting the oscillation period of the liquid in the anti-rolling tank by opening and closing, an air duct connecting the upper parts of the pair of left and right wing tanks, and a valve provided in the air duct for switching the operation or stop of the liquid in the anti-rolling tank by opening and closing" to have a U-shaped tube configuration. However, in the case of the U-shaped tube configuration, "a pair of wing tanks", "a connecting waterway for communication", "a damper for adjusting the oscillation period of the liquid in the liquid passage", "an air duct connecting the upper parts, its valve", etc. are well-known technologies that are indispensable, and there is no disclosure or suggestion regarding any specifications or specific control methods. (c) In its paragraph 0016, it is described that "the air duct is... thus, the air duct is provided on the stern side or the bow side of the anti-rolling tank", but in the present invention, this technology is not used, and when it cannot be installed on the upper part, it is possible to adopt the corresponding solution of Patent Document 4. (d) Paragraph 0020 of the same document clearly states that "The amount of moment required to prevent parametric rolling has not been elucidated or known until now, and therefore no design method for a variable-period anti-rolling tank device for preventing parametric rolling has been established to date..." However, it is impossible for an ART, which does not have the necessary anti-rolling moment, to "prevent parametric rolling." (e) Furthermore, the required anti-rolling moment of the ART can be easily determined from the ship's "displacement," "KG," "GoM," "ship's rolling period," "anti-rolling efficiency," etc. (f) As can be seen from the above comparison, the prior art documents (Patent Documents 5 and 6) and the present invention are significantly different in terms of the shape of the ART, the specifications of the ancillary equipment, and the control means. (5) Incidentally, “Non-Patent Document 3” is a paper on the results of experiments on ART, which was conducted around 2008 to prevent parametric rolling of huge container ships. It contains the following information and is a valuable resource: (a) A comparison of the main points of the examples of the present application with those of the prior art is shown in Table 1 below. (b) The tank type of the non-patented portion in Table 1 below is a U-shaped pipe type (Single Wing Type). [Table 1] [Means for solving the problem]

[0011] The present invention, which solves the problems related to the excessive liquid weight used in the ART and parametric rolling, will be explained in an easy-to-understand manner by dividing it into the sections "ART" and "Parametric Rolling." (1) The detailed technical description of ART is given in paragraphs 0012 to 0035. (2) An explanation of parametric rolling is provided in paragraphs 0036 to 0039.

[0012] The basic technology related to the A.R.T for ultra-large container ships in paragraph 0007 that the present invention aims to solve is based on the achievements of Patent Documents 1 to 4 and Document 7 (the technology by the inventor of the present application), and its improvements. Also, for parametric rolling countermeasures, an arithmetic program for predicting whether parametric rolling will occur is added to the program that executes the A.R.T function, and further, a controllable technology for preventing parametric rolling is provided. (1) Patent Document 1 is for merchant ships for large ships, with the following numerical values: ship length: 158.0 m, ship width 30.2 m, GM value 2.0 m, displacement 16,000 tons, tank length 3.6 m, rolling period: 11 seconds to 24 seconds, liquid passage height 1.5 m, and the weight of the liquid used in the tank is also about 200 tons, and has received favorable reviews. (a) From the calculation of the ship's natural period in paragraph 0003 to the control group in paragraph 0044 of that document, the comprehensive technology required for the design of the A.R.T is described, and its improvement becomes the technology of the present invention. Incidentally, much of it is borrowed from paragraphs 0013 to 0035 of the present invention. (b) Patent Document 2 describes the technology for determining whether a following state will be reached based on external information such as wind direction, wind speed, ship speed, and period. This technology is improved to construct a program related to parametric rolling. (c) Patent Document 3 describes technologies such as moving average period calculation and multiple control groups. By improving this technology, the results described in Table 2 of paragraph 0035 of the present invention, which can also handle parametric rolling, can be obtained. (d) Patent Document 4 describes means when it is impossible to install the upper part of the air communication pipe. (2) As described above, the above prior documents (Patent Documents 1 to 4) are known technologies by the inventor of the present application, and although the technical content is well-known, the detailed drawings, etc. thereof are omitted in the present invention.

[0013] (1) It is not comparable to large ships that have previously had the achievement of mounting a tank width of 30.0 m. Due to the ship width being 40 - 60 m, there is a large metacentric coefficient. Specifically, when calculating inversely from the average flow velocity value of the moving liquid of A.R.T. etc. that can correspond to the rolling period of the ship of 20 seconds with a GoM value of 4.0 m, the weight of the liquid used reaches 2,000 - 3,000 tons. (2) Therefore, regarding the U - shaped A.R.T., focusing on the fact that the smaller the total width of the tank, the smaller the longitudinal cross - sectional area of the liquid passage can be, as a design means to minimize the weight of the liquid used, in the design technology of the DW - type A.R.T. and the A.R.T. that reflects its concept, an invention was made of a shape whose cross - sectional shape is mountain - shaped (hereinafter referred to as mountain - shaped) (Figure 1). (3) In the mountain - shaped A.R.T., the means to slow down the average flow velocity value of the moving liquid consists of a center tank 3 that narrows the tank width, an independent equipment room 4 inside the center tank, a longitudinal partition 5 provided at the center position of the hull below the equipment room, a set of left and right liquid passages 6p, 6s, and DW - type wing tanks 2p, 2s. (a) The two virtual tanks 1p, 1s on the left and right with the longitudinal partition 5 as the boundary are as follows in (b) and (c). (b) The virtual tank 1p refers to the tank on the starboard side with the starboard wing tank 2p, the liquid passage 6p, and the longitudinal partition below the equipment room as the boundary. (c) The virtual tank 1s refers to the tank on the port side that includes the port side of the center tank with the longitudinal partition below the equipment room as the boundary, the liquid passage 6s, and the port wing tank 2s. (4) The state of connecting the above - mentioned (a) and (b) that can exhibit the mountain - shaped configuration and function is shown in (Figure 3).

[0014] Claim 1 of the present invention relates to an A.R.T. main body whose cross - sectional shape is mountain - shaped, with a center tank that can form a set of left and right virtual tanks 1p, 1s with a width approximately half of the total width of the A.R.T., and is characterized by enabling a roll - damping effect and parametric prevention, which is a motion - reducing water tank device for a huge container ship.

[0015] The invention of claim 2 relates to a center tank 3 that is essential for creating the virtual tanks 1p and 1s, and an equipment room 4 that is provided within the center tank, and is characterized in that the motion reduction tank device for a huge container ship described in claim 1 is equipped with these.

[0016] The invention of claim 3 relates to the liquid passages 6p, 6s of the ART, and is the motion reduction tank device for a huge container ship described in claim 1, characterized in that it is equipped with a single hardware means for obtaining a plurality of different tank natural periods.

[0017] The invention of claim 4 is as follows: (1) A means for constructing a control group (CASE 1 to 9) including multiple different tank natural periods; (2) The preset average roll period value (also simply called the roll period) for control is set as a threshold value (25.5 seconds), and when a value below this threshold is detected, it is made to correspond to the effective roll reduction period range of 18.5 to 26 seconds. This creates the functions of a center tank 3 and a virtual tank. (3) When the roll period exceeds the threshold, the functions of Tank 3 and the virtual tank are released, which correspond to the effective roll reduction period range of 25.5 to 34 seconds. (4) ART will be deactivated when a preset period of 34.5 seconds or more is detected. (5) A control method for a motion reduction tank system for a huge container ship according to claim 1, characterized in that the control method controls the equipment essential for the above items (1) to (4).

[0018] The invention of claim 5 relates to parametric rolling, and is a control method for a motion reduction tank device for a huge container ship as described in claim 1, characterized in that a calculation program for predicting whether or not parametric rolling will occur is added to the program of claim 4 that executes the ART function, and the method responds instantly to the rolling conditions of the ship that it encounters. [Effects of the Invention]

[0019] The invention described above applies the technology cultivated for large ships to gigantic vessels that are difficult to put into practical use on commercial ships and have not been installed before, and the mountain-shaped ART can reduce rolling during rough weather, which is a frequent occurrence on international routes for gigantic container ships, predict whether or not the phenomenon of parametric rolling will occur, avoid it before it happens, and instantly take measures to reduce rolling if a parametric rolling state does occur.In particular, the equipment used can be of the same specifications as that used for conventional large ships, making this an invention that is highly effective as a rolling reduction tank device for gigantic container ships. [Brief explanation of the drawings]

[0020]

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[0021] The present invention is aimed at filing a PCT international application with a view to expanding overseas, and therefore there are some overlapping explanations based on the inventor's ideas, including publicly known technologies. (1) The most important thing when planning ART is to understand the ship's natural rolling period. The formula for estimating the natural rolling period based on Japan's ship stability regulations is as follows: Ts (ship's natural rolling period) = (2.01 x B x k) / √GoM (unit: seconds) B: ship width (m), k: radius of gyration (coefficient), GoM: metacentric height (m) From this equation, we can see that the larger the GoM value in the denominator, the shorter (faster) the roll natural period. Incidentally, if the displacement is constant, the larger the GoM value, the larger the required roll damping moment. (2) When a ship encounters regular wave periods, the ship's rolling period STs is the same as the ship's natural rolling period Ts. However, when the ship encounters irregular waves, the ship's rolling period differs depending on the angle and period of the encounter between the waves and the ship. In particular, when the encounter period with the ship and the ship's natural rolling period Ts are synchronized, large rolling is induced. Note that we will not go into details about wave height here. (3) The natural period of a tank, Tts, is the time required for the liquid in the tank to make one round trip. In the case of a passive type, the liquid in the tank moves after the ship is induced by an external force. (4) Explain the phase lag between the waves that induce ship motion, rolling, and liquid movement in the tank. (a) The swaying of a ship is induced with a delay of one beat when the wave period and the ship's natural rolling period are the same. This delay of one beat is called the phase lag between the waves and the ship. (b) When the roll period value of the ship and the natural period value of the tank become approximately the same value, liquid movement occurs with a one-beat delay with respect to the ship's roll. The state of this ship and the liquid movement is also referred to as a phase delay. (c) To obtain a high roll damping effect, it is essential that the roll period and the natural period of the tank coincide. (d) The ship's roll is a repetitive motion. If one roll is replaced by one rotation (360 degrees), it can be expressed as horizontal (0 degrees) ⇒ starboard tilt (1 / 4 rotation: 90 degrees) ⇒ horizontal (1 / 2 rotation: 180 degrees) ⇒ port tilt (3 / 4 rotation: 270 degrees) ⇒ horizontal (one rotation: 360 degrees = 0 degrees). The configuration of the phase delay is shown in (Figure 2). Although it is theoretically a smooth Sin curve, in this figure, for the purpose of emphasizing the wave, the ship's roll, and the phase delay of the liquid in the tank, it is deliberately shown as a straight line. The interval between each vertex is one roll and one cycle. (e) In A.R.T., the flow is as follows: the wave that induces the ship ⇒ the ship's roll occurs ⇒ the liquid movement in the tank. There is always a 90-degree phase delay between the wave and the ship's roll. Furthermore, when the roll period value STs and the tank natural period value Tts are in the same state, a 90-degree phase delay occurs between the ship's roll and the liquid movement in the tank. In other words, if the vertex of the wave force Mt that induces the ship is on the starboard side, the vertex of the roll damping force (also called moment) TMt of the tank, which has a 180-degree phase delay, is on the opposite port side. This means that the positions of the wave force Mt that attempts to rock the ship and the roll damping force TMt that attempts to suppress the ship's roll are in exactly opposite directions. Therefore, the two forces cancel each other out and a roll damping effect is obtained.

[0022] First, a basic explanation of the roll state will be given. (1) Regarding the rolling situation in rough weather, (a) The swaying of a ship during navigation is a well-known phenomenon that occurs when the encounter period between the wave and the ship and the ship's natural roll period coincide. (b) The ship's roll situation is determined by the course and the wave direction. Therefore, the bow of the ship in the direction of travel is set as (0°), port beam (90°), stern (180°), starboard beam (270°), and the bow after one full circle (360° = 0°). (c) The maximum vertical rolling angle occurs when the oncoming waves are in the bow (0°) direction and the following waves are from the stern (180°). (d) The maximum roll angle occurs when the beam waves are from the true beam (90° and 270°) directions. (e) The boundaries between vertical rolling and roll are 45°, 135°, 225°, and 315°. (f) The range in which vertical rolling occurs is between 0° and ±45°, and between 135° and 225°. (g) The range in which roll occurs is between 45° and 135°, and between 225° and 315°. (2) Explain the means for analyzing the roll period and angle information essential for A.R.T control. (a) For passive A.R.T control, it is not necessary to use different motion values for each roll. For example, it is sufficient to average a plurality of accumulated data during measurement. For example, analyze 5 data as follows. It is sufficient to use a simple moving average value obtained by adding the next new sixth value to the 5 data and dividing the total value after deleting the oldest first value by 5. A1 = (n1 + n2 + n3 + n4 + n5) / 5 ⇒ A2 = (n2 + n3 + n4 + n5 + n6) / 5. (b) The moving average roll period (ATs) = (STs1 + STs2 + STs3 + STs4 + STs5) / 5 STs: The roll period of the ship (c) The moving average pitch period (APs) = (SPs1 + SPs2 + SPs3 + SPs4 + SPs5) / 5 SPs: The pitch period of the ship (d) The moving average roll angle (ATθ) = (STθ1 + STθ2 + STθ3 + STθ4 + STθ5) / 5 STθ: The roll angle of the ship (e) The moving average pitch angle (APθ) = (SPθ1 + SPθ2 + SPθ3 + SPθ4 + SPθ5) / 5 SPθ: The pitch angle of the ship (3) Roll information used for A.R.T control (a) The inventor of the present application has adopted a moving average calculation method based on more than 50 years of achievements and history related to A.R.T. (b) The number of accumulated data used for moving average calculation is optimally 3 to 5 based on past performance, but there is no need to be restricted to this. (c) Note that if the number of data is small, the switching drive frequency of the device will increase. Conversely, if the number of data that changes moment by moment increases, the instantaneous prediction accuracy will deteriorate.

[0023] Hereinafter, embodiments of the A.R.T of the present invention will be described with reference to the drawings. Note that FIGS. 1 to 9 are descriptions of the forms, and the scales of the figures are ignored. In addition, the embodiments can be implemented in different forms for each ship according to the order conditions of the orderer (shipbuilding yard, design company, shipowner, etc.), and are not limited only to the specific examples described in the embodiments shown below. (1) Hydrostatic particulars of the ship (a) The restoring force refers to the force that attempts to return the attitude of the ship tilted due to some factor. In this embodiment, as the restoring force coefficient, displacement (200,000 t) x GoM (4.0 m) = 800,000 t-m. (b) The ship width and the total tank width are 50.00 m. (c) The virtual tanks 1p and 1s are of the same size and symmetric about the centerline, and each tank width is 25.00 m. (d) The tank length is 9.00 m based on the calculation results according to the hydrostatic particulars presented by the client. The length is divided into two equal parts, 4.50 m x 2 sets, and one of the sets will be described. Note that if the tank is made longer, it will be affected by the steady longitudinal inclination and pitching of the hull, and the liquid in the tank will also move in the fore-and-aft direction. Therefore, in order not to interfere with the left-right liquid movement required for anti-rolling, it is desirable to divide and shorten the tank length. (e) The position of the A.R.T bottom plate is from the bottom plate of this ship to 33.0 m, and the position in the fore-and-aft direction is near the center of the hull. A bridge including a living deckhouse is provided on the upper part of the A.R.T. The purpose is that in a container ship, in order to stack containers high, as a means to improve visibility, the bridge position is raised, and there is no need to newly secure space for mounting the A.R.T. Therefore, it is not necessary to consider a decrease in the number of containers. (f) In ships with accommodation deckhouses or bridges provided in two locations, fore and aft, it is possible to install them in two locations as required due to the length of the A.R.T, but this is not mandatory and is at the discretion of the designer. (g) The longitudinal position of the A.R.T should preferably avoid the bow and stern areas as much as possible. The reason is that as the ship becomes larger, the deadweight and the weight of the liquid used by the A.R.T increase, which will have an adverse impact on the trim and longitudinal strength of the ship.

Embodiment

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention can be implemented in many different forms depending on the type, size, stability parameters of the ship, and the installation position of the A.R.T, etc., for each ship, and is not limited only to the specific examples described in the embodiments shown below. The overall configuration of the basic A.R.T for achieving the above object is (1) As shown in Fig. 1, based on a U-tube type, between DW type wing tanks 2p and 2s of the same size on both sides of the hull, a center tank 3 is provided, and within the tank formed by a set of left and right liquid passages 6p and 6s for moving liquid w left and right at the bottom of tank 3 and wing tank 2it, the inside of the tank is sealed, and the cross-sectional shape of the A.R.T main body 1 is mountain-shaped. (a) The effective roll damping period range of the A.R.T is set to 18.5 - 34 seconds considering head waves and following waves, and the roll response threshold for controlling whether to use a virtual tank is set to 25.5 seconds. (b) When the average roll period ATs is short and less than the threshold value, the function of the virtual tank that can also handle head wave conditions is exerted. (c) When the average roll period is long and exceeds the threshold value, the function of the virtual tank is released, and the function of the A.R.T main body that can also handle following wave conditions is exerted.

[0025] The DW type wing tanks 2p and 2s each have one longitudinal partition 2bh in the fore-and-aft direction in each tank, and the wing tank is divided into left and right tanks 2it and 2ot by the longitudinal partition. (1) The longitudinal partition is set at an appropriate distance from the top plate of the inner and outer plates 2b that form the tanks 2p and 2s. Taking this position as a reference point, a plate inclined downward in the wing tank is connected to the longitudinal partition 2bh. (a) Its purpose is one of the measures to increase the volume at the upper part of the tank 2ot and prevent the moving liquid w from hitting the wing tank top plate violently during large rolling. (b) The position of the lower end of the longitudinal partition is set at the same height as the inner dimension of the top plate height of the liquid passages 6p and 6s. (2) The height of the wing tank is set at 10.00 m. (a) Assuming that the tank width of the A.R.T main body is 50.00 m and the roll angle is 15°, the upward movement height of the liquid in the wing tank is about 6.7 m. Adding the water level of the tank main body (here 1.80 m) to this value gives 8.50 m. Considering factors such as acceleration, it is desirable to make it higher. (b) In particular, to obtain the roll damping effect during parametric rolling, which can be about 1.5 times that of the roll angle in rough weather, it is necessary to have a sufficient height of the wing tank.

[0026] The installation of the center tank 3 and the equipment room in the center tank becomes one of the essential devices when the A.R.T width exceeds 30 m. However, its lateral width, height, length, etc. only need to ensure that it can accept the amount of water in one-sided DW type wing tanks 2p and 2s on one side during shaking to satisfy the design conditions of the orderer, and its dimensions depend on the design concept. (1) The purpose of installing the center tank is to create two sets of virtual tanks 1p and 1s. (2) The equipment room in the center tank is provided for the purpose of creating virtual tanks and releasing their functions. (3) The height dimension of the equipment room is made higher than the average water level of the tank main body, and its upper end is made lower at an arbitrary interval from the center tank top plate. (a) Its purpose is that when the roll angle is large and the liquid w flowing in from the liquid passages 6p and 6s exceeds the upper part of the equipment room, it overflows from its upper end and flows into the adjacent virtual tank. (4) At the center position of the hull below the machinery space, provide a longitudinal bulkhead 5 in the fore-and-aft direction between the bottom plate and the top plate of the liquid passage, the opening area required for the longitudinal bulkhead 5, and a drive-remote type gate 5c for opening and closing the opening 5o. (a) The purpose of the gate 5c is a means to enable the functions of the center tank and the virtual tanks 1p and 1s to be exerted when the opening is closed, and to cancel the functions of the center tank and the virtual tanks when the gate is opened. (b) In addition, since the moving liquid repeats inversion every half of a sloshing cycle at a preset speed (period), there is no need to make the gate watertight from the perspective of cost-effectiveness. (c) It is desirable that the width dimension of the machinery space in the left-right direction be wider than the width of the gate 5c. (d) In addition, provide insertion, maintenance, inspection, repair, working suspension pieces, and entrances and exits at necessary locations for the equipment installed in the machinery space.

[0027] The liquid passages 6p and 6s connect the left and right outer plates 3p and 3s of the center tank 3 and the inner outer plates 2b of the wing tanks, and one set is provided on each side. (1) It is desirable to plan the height of the liquid passages 6p and 6s to be as low as possible. (a) The purpose is that the liquid level height (water level) Wh of the entire tank and the basic height of the wing tank are determined by the height of the liquid passage. (b) Also, the liquid volume occupied by the volume of the liquid passage (longitudinal cross-sectional area x width of the liquid passage) is about 60 - 70% of the total required usage amount. Therefore, the goal is to make the liquid passage low and reduce the amount of liquid used. (c) Incidentally, it is desirable that the minimum height of the liquid passage be 0.70 m or more to facilitate welding and work during maintenance, inspection, and repair. However, there is no need to be restricted by this value according to the design concept. (d) It should be particularly noted that it is desirable that the bottom plate and the top plate of the liquid passage be parallel. (2) It is desirable that the length of the liquid passage in the fore-and-aft direction be the same as the length of the wing tank. (a) Depending on the conditions, the calculated height of the liquid passage may be 0.50 m or less. (b) In this case, as a means of increasing the liquid passage height dimension and ensuring the required longitudinal sectional area of the liquid passage, it is also possible to make the length of the passage shorter than the length of the wing tank. (3) Inside the liquid passage, at any location in the fore-and-aft direction, at least three sets of passages partitioned by diaphragms or the like, and a necessary number of lower dampers 8d1 and 8d2 are provided in a pair of the same dimension on the left and right. As a means of preventing the turbulent flow of the liquid passing around the damper at the location where the damper is stopped, a pair of fairing plates is provided around the damper shaft. (4) The damper 8d adopts a hydraulically remotely driven type with an opening degree of 0 to 90 degrees clockwise around the vertical axis, and stops at least at one or more locations in the middle. A sensor for confirming the stop position or the like is attached, and means for transmitting the fully closed, mid-stop, and fully open positions of the damper to the control unit by an electric signal is provided. (a) The purpose of using a hydraulic drive source is in line with the design concept of the inventor of the present invention that requires instantaneous operation to cope with rapidly changing rolling periods, particularly parametric rolling, and it is also possible to use other drive types. (b) Note that the technology related to the damper is well-known, and detailed description in this application is omitted.

[0028] The air duct 7 (also referred to as air ducts 7a and 7b) is a variable means for the liquid braking (operation or stop) of A.R.T and the natural period Tts of the tank. It is directly connected to the divided left and right target positions of the DW type wing tank near the upper part of the wing tank via a remotely driven closing device 7v. (1) In the embodiment, two sets of air ducts 7a and 7b via a hydraulically driven valve 7v are provided. (a) The inside of the tank is airtight. When the valve 7v with the air duct is closed, the air flow between the left and right tanks is blocked and the liquid movement stops. Note that this state is called non-operation of A.R.T. (b) When both of the air ducts 7a and 7b are opened, the 2it and 2ot in the DW type wing tank become one tank 2p and 2s on each side. In this state, the apparent liquid passage width is short and the wing tank width is wide. Functionally, a long natural period Tts of the tank can be obtained, and at the same time, a large anti-rolling force can be obtained. Incidentally, the wider the wing tank, the greater the damping force (rolling moment). (c) When the air duct 7a is opened and the air duct 7b is closed (indicated by ○X7vc in the figure), only the two divided outer tanks 2ot in the wing tank can have liquid movement. In this state, the liquid passage is long and the width of the wing tank is short. Functionally, a short tank natural period Tts can be obtained. The purpose is a special control means for lowering the height of the liquid passage to correspond to the slow roll period range of 25.5 to 34 seconds in this embodiment. (Shown in (Fig. 5)) (d) Although there may seem to be a contradiction in the description of the tank natural period in the previous items (b) and (c), when selecting the previous item (b), the tank width is 25.0 m and the liquid movement distance is short. Also, in the previous item (c), the tank width is 50.0 m and the liquid movement distance is long. In different liquid passages, this is a novel means that does not exist in the prior art where the liquid passage heights in the previous items (b) and (c) are made the same. (2) The shape of the air duct 7 can be round (pipe) or rectangular. Its cross-sectional area (also referred to as the diameter) is appropriately determined by calculating the air flow velocity value from the liquid flow velocity value so that no noise is generated. (a) When one diameter becomes large, considering its cost and the structure of the wing tank, etc., if the required cross-sectional area can be ensured, a plurality of air ducts with small diameters may be used. (b) The air duct is preferably a straight pipe type as shown in (Fig. 1), but if it is difficult due to the surrounding environment, a U-shaped type (Patent Document 4) is also possible. (c) Incidentally, an open-air type air pipe may be adopted, but in this case, the liquid in the tank will flow out as droplets, so water injection will be required as necessary. (3) Incidentally, it has been found that connecting the center tank 3, which is a part of the liquid passage, and the left and right wing tanks with an air communication pipe does not provide any particular effect.

[0029] Although not shown in the A.R.T. main body 1, fitting necessary for a tank such as a filling and draining facility for the liquid to be used, a sounding pipe (liquid level gauge), a water level adjusting pipe, an air vent pipe, etc. is provided, and closing means is provided for all pipes leading to the outside to enable a sealed state inside the tank.

[0030] Here, to make it easier to understand the technical supplement for reducing the heights of the liquid passages 6p and 6s of the present invention, the description will be given including overlapping parts. (1) Liquid movement distance (a) The movement distance is the distance between the centers of gravity of the liquid movement. However, in the embodiment, it is simply set as the movement distance for one round trip of the full width of the tank. (b) In the A.R.T main body 1, it is 50.0 m x 2 = 100.0 m. (c) In the virtual tanks 1p and 1s, it is 25.0 m x 2 = 50.0 m for each. (2) Required time for liquid movement (a) One swing refers to a situation where, for example, it repeats the repetitive operation of horizontal ⇒ inclined downward to the port side ⇒ returns to the original horizontal by the restoring force, and further, acceleration is applied ⇒ passes through the inclined upward to the starboard side ⇒ returns to the original horizontal. (b) In the passive A.R.T, since it utilizes the natural phenomenon of flowing from a high place to a low place, during the process where the liquid movement reverses, for example, it gradually slows down from the maximum flow rate, passes through the liquid movement stop, and then gradually speeds up in the reverse direction and reaches the maximum flow rate. The time required for one swing is one cycle, which becomes the required time for liquid movement. (3) Average flow velocity value (a) The shortest tank natural period value required in this embodiment is 20 seconds. Based on this (b) The average flow velocity value of the A.R.T main body (width 50 m) is 100 / 20 = 5.0 m / s. (c) For the virtual tank (width 25 m), the average flow velocity value is 50 / 20 = 2.5 m / s. (4) Height of the liquid passage (a) The height of the liquid passage required for the flow velocity value of 5.0 m / s in the previous item (b) is approximately 2.5 m. (b) The height of the liquid passage required for the flow velocity value of 2.5 m / s in the previous item (c) is approximately 0.9 m. (c) Therefore, in this embodiment, a virtual tank (liquid passage height approximately 0.9 m) is adopted. (5) The functional tank selection criterion is set as long roll period ≧ threshold value (25.5 seconds) ≧ short roll period (a) The virtual tank is used when the threshold value (25.5 seconds) ≥ the average period of the ship. (b) The A.R.T. main body is used when the average period of the ship ≥ the threshold value (25.5 seconds). (6) The anti-rolling effective roll period range of the tank (also simply referred to as the effective roll period range) (a) The anti-rolling effective roll period range of the virtual tank shall be 18.5 to 26 seconds. (b) The anti-rolling effective roll period range of the tank main body shall be 25.5 to 34 seconds.

[0031] The basic control method for creating a virtual tank is as follows. (1) The shape of an example of the virtual tank (a) The shape of the virtual tank 1p is formed by the port wing tank 2p, the liquid passage 6p, and up to the longitudinal bulkhead 5 in the center tank, and is also referred to as the port side tank. (b) The shape of the virtual tank 1s is formed by the starboard side of the longitudinal bulkhead in the center tank, the liquid passage 6s, and up to the starboard wing tank 2s, and is also referred to as the starboard side tank. (c) When the following (d) to (f) are executed, a virtual tank is configured, and its shape is shown in (Figure 3). (d) Close the opening / closing device 5c of the longitudinal bulkhead provided below the equipment room in the center tank. (e) Close the left and right dampers 8d1 in the liquid passage 6s, and also open the left and right dampers 8d2. (f) Open the valves 7v of the air ducts 7a, 7b. (2) The function of the virtual tank (a) The anti-rolling effective roll period range of the virtual tank is between 18.5 and 26.0 seconds. (b) Construct a control loop (CASE1 to 4) including the tank natural period Tts. (c) The factor for the roll period STs to become short during navigation is when encountering the head wave state, and the apparent GoM value also increases. To cope with this, it is necessary to increase the anti-rolling force TMt of the tank, so the wide wing tanks 2p, 2s are applied to this. (d) For the short periods generated during head waves (including parametric rolling), they are dealt with in CASE1 to 2. (3) The situation of liquid movement in the virtual tank As an example, when the hull sways (tilts) in the starboard direction, (a) In the virtual tank 1p, the liquid w in the port-side wing tank 2p flows into the center tank 3 through the liquid passage 6p. (b) In the virtual tank 1s, the liquid in the center tank moves into the starboard-side wing tank 2s through the liquid passage 4s. (c) The state of the liquid when it becomes horizontal (half rotation) after starboard tilt is shown in (Figure 4). (4) In addition, in (Figure 3) and (Figure 4), since the wing tanks 2it and 2ot are used as one wing tank 2p, 2s, the longitudinal partition 2bh in the DW type wing tank is shown as a virtual line.

[0032] The basic control method of the A.R.T main body 1 is as follows. (1) Shape of the A.R.T main body (a) Open the gate 5c with the longitudinal partition 5 below the equipment room in the center tank 3. (b) Open the left and right dampers 8d1 and 8d2 in the liquid passage 6s. (c) Open the air duct 7a and close the air duct 7b. (d) When the above items (a) to (c) are executed, the shape of the A.R.T main body is constructed. (e) The state of the above item (d) is shown in (Figure 5). Since the divided outer wing tank 2ot is constructed, the inner outer plate 2b of the DW type wing tank is shown as a virtual line. (f) In addition, when the set roll period is a long period of, for example, 36 seconds, it is also possible to open the air duct 7b from the state of the above item (c) and make corresponding adjustments. (2) Function of the A.R.T main body (a) The effective roll damping period range of the A.R.T main body is between 25.5 and 34.0 seconds. (b) Construct a control loop (CASE5 - 9) including the tank natural period. (c) The factor for the roll period STs to become long during navigation is when encountering a following sea state, the apparent GoM value becomes small, and the roll damping force corresponding to this can be small. So, the wing tank 2ot is applied to this. (d) For long periods during wave chasing (including parametric rolling), it is handled in CASE8 - 9. (3) Liquid movement status of the A.R.T main body (a) When the gate 5c with the vertical partition 5 that releases the center tank function is opened, the liquid passages 6p and 6s become the liquid passage 4. Therefore, the liquid w in the starboard wing tank directly moves to the port wing tank. (b) The state of the liquid when it becomes horizontal (half - rotation) after starboard inclination is shown in (Figure 6).

[0033] The configuration of the control device is roughly divided into information analysis including an inclination sensor, etc., a control unit that issues drive commands for the devices set in advance, and an opening - closing device unit, etc. These are known technologies in A.R.T (paragraphs 0013 - 0034 of the cited patent 1), and individual illustrations and their details are omitted. (1) Grasping the ship's motion information in the embodiment Data related to motion (vertical roll, lateral roll, wind direction · wind speed, ship speed, etc.) is collected in an analog (flow - through) manner. There is Patent Document 3 in which the inventor of this application described it in detail. (2) Analysis means for the ship's motion information of this ship From the collected flow - through data, using the moving average method in an arithmetic decoding circuit, half of a roll, the angle and period of a roll, and further, prediction information of the roll end are calculated. Incidentally, the point when the ongoing roll reverses is taken as half of a roll. (3) Control of the device A control signal is output from a control unit including an execution circuit and a circuit that executes optimal processing based on the feedback information of the execution result of the device. (4) Variation of the tank natural period Tts and liquid braking equipment in the DW - type A.R.T By combining the opening and closing of the air duct - attached closing device 7v, the opening - closing device 5c of the vertical partition, and the lower damper 8d that adjusts the liquid movement speed, the variation of the tank natural period Tts and liquid braking can be carried out as needed, and it is usually implemented by automatic control. (5) Construction of each control group When a predetermined control execution program is executed, control groups CASE1 to CASE9 are constructed, and the optimal CASE is selected and executed from among them based on the moving average roll period value ATs of the encountered ship.

[0034] The control groups define an effective period range of about 3 seconds including the individual tank natural period values Tts that exhibit high anti-rolling efficiency as one group (CASE), and are composed of control groups CASE1 to CASE9. (1) Based on the roll period that changes with each encountered roll, a plurality of values are averaged by a moving average method to calculate the average roll period ATs, and an optimal control group is selected. In the embodiment, a duplicate value of 0.5 seconds is set so that chattering of the device does not occur when switching between this group and an adjacent group. However, this duplicate value varies depending on the conditions of each ship and is determined by the designer as appropriate. (2) The opening and closing combination states of the plurality of dampers 8d1, 8d2, the gate 5c, and the valve 7v that form each control group are constructed according to the control specifications for each ship. The means of this embodiment are shown in the following table.

[0035]

Table 2

[0036] From this paragraph, a description related to parametric rolling is given. (1) Non-Patent Document 2 describes the following regarding the danger of parametric rolling and its basis. (a) Container ships are a type of ship that is easily affected by parametric rolling in a following sea state. (b) Depending on the roll period of the ship, the ship's speed, the course, and the encounter angle between the ship and the wave, the roll angle of the ship may suddenly increase to a level that threatens the safety of the ship, crew, and cargo. (c) This phenomenon is known to occur even at relatively moderate wave heights. (2) Parametric rolling may occur in the following situations, and the ship's motion is induced when the natural roll period of the ship during operation coincides with the encounter period with the wave. (a) When the roll period is approximately twice the pitching period or in the vicinity thereof. (b) When the wavelength is within the range of the ship's length. (c) It may also occur in head seas or in a following sea state where the roll period becomes longer.

[0037] Regarding the factors and prediction of parametric rolling (a) In paragraph 0023 of the present application, as the motion information necessary for predicting the occurrence of parametric rolling, the roll period STs, the pitch period APs, the roll angle ATθ, the pitch angle APθ, etc. are constantly grasped. (b) Compare the values of the roll angle ATθ in time series and monitor the increase value of the roll angle. (c) Compare the values of the average roll period ATs in time series and monitor the increase value of the roll period. (d) Monitor the ratio between the pitch and the roll period and monitor the transition situation of the ratio of 1 to 2. (e) From the ship speed during navigation and the rotational speed information of the propeller, monitor whether the ship speed value is slow, indicating head seas, or fast, indicating that it is becoming a following sea state.

[0038] When predicting the possibility of parametric rolling, as avoidance measures (a) Notify the operator by an alarm buzzer, screen display, or voice, etc. (b) As emergency response measures, change the rotational speed of the propeller and the pitch of the variable propeller. (c) Change the course to change the encounter angle with the waves and the encounter period to avoid the occurrence of parametric rolling. (d) The above operations are known means and are manual operations in accordance with a predetermined navigation manual.

[0039] The situation of whether parametric rolling occurs or not is constantly monitored as described in paragraph 0037. (1) The difference between parametric rolling and rolling in rough weather lies in the magnitude of their amplitudes. (a) The parametric roll angle may exceed 1.5 to 2 times the roll angle in rough weather. (b) Parametric rolling and rolling in rough weather each have their respective rolling period values. (c) The parametric rolling period in the head sea state becomes shorter. (d) The parametric rolling period in the following sea state becomes longer. (e) The occurrence of parametric rolling is when encountering the head sea and the following sea states. (2) Countermeasures when reaching the parametric rolling state according to the present application (a) For the short period of parametric rolling occurring during the head sea, it is dealt with in CASE1 - 2. (b) For the long period of parametric rolling occurring during the following sea, it is dealt with in CASE8 - 9. (c) The selective execution of the above items (a) and (b) can be instantaneously executed as described in claim 5. (e) Also, automatic control can be achieved through prior adjustment with the main engine or the steering gear manufacturer. (f) Still, even if the rolling period changes suddenly due to the operations in the above items (b) - (e), the effective anti - rolling period range of A.R.T is set to 18.5 - 34 seconds. From among the applicable control groups (CASE1 - 9), the optimal control group is automatically selected and executed, so there are no problems.

Industrial Applicability

[0040] The invention of the present application is for a motion - reducing water tank device and its control method for ultra - large container ships with a ship width of about 50m, based on the design concept and technological improvement of large ships with proven track records equipped with A.R.T with a ship width of about 30m. It has great industrial applicability in reducing rolling in rough weather, parametric rolling, and further avoiding parametric rolling.

Explanation of Reference Numerals

[0041] 1 A.R.T main body (mountain - shaped anti - rolling water tank) 1p Virtual tank (port side) 1s Virtual tank (starboard side) 2p DW - type wing tank (port side) 2s DW - type wing tank (starboard side) Inner outer plate of 2b DW type wing tank Longitudinal bulkhead in the fore-and-aft direction inside the 2bh DW type wing tank 2it Divided inner wing tank 2ot Divided outer wing tank 3 Center tank 3t Top plate of the center tank 3p Left outer plate of the center tank 3s Right outer plate of the center tank 4 Equipment room inside the center tank 4d Entrance / exit of the equipment room 4t Top plate of the equipment room 4t1 Inclined top plate of the equipment room 4p Longitudinal bulkhead of the equipment room (port side) 4s Longitudinal bulkhead of the equipment room (starboard side) 4b Gap between the top plate of the equipment room and the top plate of the center tank 5 Longitudinal bulkhead between the bottom plate and the top plate of the liquid passage at the center position in the left-right direction below the equipment room 5o Opening of the longitudinal bulkhead applied between the bottom plate and the top plate of the liquid passage 5c Closing device for the longitudinal bulkhead opening (also called a gate) 5g1 No.1 gate 5g2 No.2 gate 5g3 No.3 gate 6 Liquid passage integrating the liquid passages on the port and starboard sides (also called the lower duct) 6t Top plate of the liquid passage 6o Opening of the top plate of the liquid passage 6p Liquid passage (port side) 6s Liquid passage (starboard side) 7 Air communication pipe (also called air duct) 7v Closing device with air duct (also called a valve) 7a No.1 air duct 7b No.2 air duct 7vc State with the valve closed 8d Closing device in the liquid passage for adjusting the liquid movement speed (also called the lower damper) 8d1 No.1 lower damper (applied symmetrically left and right) 8d2 No.2 lower damper (applied symmetrically left and right) Wh liquid level (water level) w liquid Mt wave force inducing rolling of the ship FMt force to restore the ship (also called restoring force) TMt anti-rolling force in the water tank (also called anti-rolling moment) STs rolling period of the ship FTs natural rolling period of the ship ATs average rolling period of the ship Tts natural period of the tank

Claims

1. A DW type wing tank composed of an inner wing tank (2it) which divides the inside of a single wing tank into two in the left - right direction of the ship by a longitudinal bulkhead (2bh) in the fore - aft direction and an outer wing tank (2ot). A liquid passage (6) for moving the liquid in the DW type wing tank to the left and right is provided below the DW type wing tanks on both sides. A center tank (3) is provided on the top plate of the liquid passage near the center between the DW type wing tanks on both sides. The cross - sectional shape of the structure integrated in this way, when cut at a right angle to the fore - aft direction, is a passive A.R.T. in a mountain - shape, consisting of the DW type wing tank (2p) on the port side, the liquid passage (6), the center tank (3), and the DW type wing tank (2s) on the starboard side. As a means for moving the air in the inner wing tank (2it) and the outer wing tank (2ot) of the DW type wing tank, above the divided inner and outer wing tanks, air communication pipes (7a, 7b) are connected to the opposite inner wing tanks (2it) and outer wing tanks (2ot) on both sides through remotely - driven closing devices (7v) that cut off the air movement in the wing tanks on both sides as required. At the same time, in the liquid passage where the length of the liquid passage in the fore - aft direction is divided into at least three parts, a plurality of remotely - driven lower dampers (8d1, 8d2) for adjusting the moving speed of the liquid are provided. At the center position in the left - right direction of the liquid passage, a longitudinal bulkhead (5) that fixes the top plate (6t) and the bottom plate of the liquid passage is provided with a required opening (5o), and a remotely - driven closing device (5c) for opening and closing the opening (5o) of the longitudinal bulkhead (5) as required. An independent equipment room (4) with the top plate (6t) of the liquid passage as the bottom plate is provided in the center tank (3). Based on the information output from an inclination sensor that detects the instantaneous angles of the ship's roll and pitch, the ship's roll period (STs), the ship's average roll period (ATs), and the ship's roll natural period (FTs) are calculated. Furthermore, a program for predicting the periods and angles of the ship's roll and pitch at the end of a roll, remotely - driven closing devices (7v) for two sets of air communication pipes (7a, 7b), and at least two sets of remotely - driven lower dampers (8d1,Apply left and right to (8d2), and when decoding information output from the remotely driven closing device (5c) for the opening (5o) of the longitudinal partition (5), together with the top plate (6t) of the liquid passage and the longitudinal partition (5) in the bow and stern direction that fixes the bottom plate of the liquid passage. A closing device (5c) for the opening (5o), a closing device (7v) for the air communication pipe, and a control panel for controlling the drive of the lower damper (8d2). ART for super large container ships is characterized by the above.

2. The A.R.T. for a huge container ship according to claim 1, characterized in that the length of the liquid passage is divided into at least three sections by a floor or a partition plate of any width in the left-right direction at any location in the bow-stern direction within the liquid passage, at least two sets of remotely driven lower dampers (8d1, 8d2) with blades fixed to a shaft are provided on either side at any location within the divided liquid passage, the lower dampers are fully open when the blades of the lower dampers are parallel to the left-right direction of the liquid flow, and similarly, the lower dampers are fully closed when the blades of the lower dampers are rotated perpendicular to the direction of the liquid flow, at least one position where the lower dampers stop is provided within the rotation range between fully open and fully closed, and means are provided for driving the lower dampers to a predetermined normal position based on information transmitted from a position sensor that grasps the open / closed positions of the lower dampers (8d1, 8d2) that are driven as needed.

3. The A.R.T. for a huge container ship according to claim 1, characterized in that the center tank (3), which is the key to the present invention, has the same width and length as the DW-type wing tanks (2p, 2s) on one side, the height of which is determined at the discretion of the designer, the width of the equipment room (4) in the center tank (3) may be approximately twice the height of the liquid passage (6) from the width of the center tank, and the height of the equipment room (4) is lower than the center tank top plate (3t) by an arbitrary gap (4b), so that when the ship's roll angle is large, liquid in the DW-type wing tanks (2p, 2s) flows into the center tank (3) through the port (6p) or starboard liquid passage (6s) of the liquid passage, and when the liquid flowing in further exceeds the equipment room top plate (4t), it flows out into the adjacent liquid passage (6p, 6s) through the gap (4b) provided between the equipment room top plate and the center tank.

4. According to the various situations of the rolling and pitching of the ship when encountering rough weather, as a means to obtain the optimal anti-rolling effect of ART, the instantaneous information of the rolling angle and pitching angle of the ship is rearranged in time series, and based on the calculation results of predicting the rolling and pitching periods and angles of one roll of the ship, as well as the rolling periods and angles by moving average, and further the rolling periods and angles at the end of one roll, a closing device (5c) for the opening (5o) of the longitudinal partition (5) in the fore-and-aft direction that fixes the top plate (6t) and the bottom plate of the liquid passage, the inside (2it) of the DW type wing tank, and a closing device (7v) with an air communication pipe for the outside (2ot) are used. At the same time, at least two sets of remotely driven lower dampers (8d1, 8d2) on one side in the liquid passage are made to execute a predetermined drive control specification, and different ART inherent periods are obtained. When the opening (5o) of the longitudinal partition (5) between the bottom plate and the top plate of the liquid passage is closed and the closing device (7v) with the air communication pipes (7a, 7b) for the inside (2it) and the outside (2ot) of the DW type wing tank is opened, two sets of virtual tanks (1p, 1s), namely the center tank (3) and the DW type wing tanks (2it, 2ot) on the left and right sides, are formed. When the lower dampers (8d1, 8d2) in the liquid passage are rotated to a predetermined position in this state, a control group of CASE1 to CASE4 called an anti-rolling effective period range including four short ART inherent periods (Tts) ±1 second corresponding to the rolling period of a short ship including the head sea state is formed. Further, when the opening (5o) of the longitudinal partition (5) between the bottom plate and the top plate of the liquid passage is opened and the closing device (7v) with the air communication pipe (7a) for the inside (2it) of the DW type wing tank is closed, the function of the center tank (3) is released, and the left and right DW type wing tanks (2p, 2s) and the liquid passage (6) are directly connected. In this state, the two sets of lower dampers (8d1,When the 8d2) is driven to a predetermined opening / closing position, a control group of CASE5 to CASE9 is configured, which is called a roll reduction effective period range including the natural periods (Tts) of five types of long A.R.Ts that can correspond to the roll period of a long ship including a following wave state, within ±1 second. Optimal control is automatically selected from the control groups of CASE1 to CASE9 that can correspond to the value of the moving average period (ATs) of the ship's roll that changes moment by moment. Also, when the value of the moving average period (ATs) of the ship's roll exceeds 34.0 seconds, the closing device (7v) with two sets of air communication pipes (7a, 7b) is forcibly closed so that the liquid in the A.R.T does not adversely affect the restoring force of the ship, and the liquid movement in the A.R.T is stopped. The control method of the A.R.T for a large container ship according to claim 1, characterized in that.

5. 5. A method for controlling an A.R.T. for a container ship according to claim 4, characterized in that in the parametric rolling phenomenon, which occurs when the pitching period of the ship is approximately half the rolling period of the ship, the roll angle becomes large, a program is constructed to predict whether or not the parametric rolling phenomenon will occur based on the rolling period of one roll of the ship (STs), the average rolling period of the ship (ATs), and the predicted roll period of the next roll, and when it is predicted that parametric rolling will occur, a predetermined alarm buzzer, visual alarm, or voice alarm is sounded to notify the ship helmsman that parametric rolling will occur, and at the same time, an optimum A.R.T. control group is selected and instantaneously executed for a new rolling period of the ship that will occur when the ship helmsman changes the ship's speed or course to avoid parametric rolling.

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