Roll-reduction water tank device for huge container ships and control method for same

Abstract

[Problem] In recent years, many requests have been made for investigations into anti-roll tank (A.R.T.) equipment aimed at preventing containers falling from huge container ships of a class having a displacement of 150,000 to 200,000 tons, but based on the concepts of the conventional technology, the basic dimensions of the A.R.T., in particular the weight of the liquid used, would be excessively large, at several thousand tons, resulting in a reduction in the amount of cargo that could be carried by merchant ships, and thus from a cost-effectiveness perspective, this technology has not been implemented. [Solution] An A.R.T. main body 1 having a W-shaped cross-sectional shape is obtained by using left and right liquid passages 6p, 6s to connect a newly-conceived center tank 3 to a DW type A.R.T. (manufactured by Stabilo Co. Ltd.) based on a U-shaped pipe design, and on the basis of the value of the average rolling period of the ship, left and right virtual tank functions 1p, 1s are created with a longitudinal bulkhead 5 below an equipment room as the boundary therebetween, and by providing the virtual tanks, the function of the A.R.T. main body, an automatic control program, and a program for predicting whether or not the phenomenon of parametric rolling will occur, it is possible to provide A.R.T. equipment that was previously difficult to install, even in huge container ships of a class with a displacement of 200,000 tons, while addressing the above problem of keeping the weight of liquid used to no more than approximately 1,000 tones and yielding an even more effective rolling reduction rate.

Description

Motion reduction tank system for giant container ships and its control method

[0001] The present invention relates to a motion reduction tank device and a control method for parametric rolling, which are related to reducing rolling in evolving, larger vessels, particularly giant container ships. In Japan, there is the "Maritime Traffic Safety Act," which applies to major sea areas where maritime traffic is congested, and defines vessels with a length of 200m or more as "huge vessels." However, vessels exceeding 400m in length have now appeared, and 200m-class huge vessels are now common size and crowded the world's oceans. According to the present invention, a huge vessel refers to a vessel with a length exceeding 300m.

[0002] In accordance with the Ship Safety Act and the Ship Stability Regulations, Japan has made efforts to promote motion reduction devices that reduce the rolling angle of ships in rough weather to 20 degrees or less. In particular, it has identified car ferries that carry "flammable vehicles equipped with highly flammable fuel and a large number of passengers" and designated two types of devices, "FinStablezer" or "Anti-rolling Tank (hereinafter referred to as A.R.T.)", as effective motion reduction devices for ships, and has made them legally required equipment, imposing an obligation to install them in 1973.

[0003] There are two types of A.R.T., namely active type and passive type. The passive type includes the "Flume type" with a rectangular cross-sectional shape and the "Frahm type" of U-tube type (hereinafter simply referred to as U-tube type or A.R.T.). In the present application, the "Frahm type" is adopted. This technology utilizes the natural phenomenon of liquid flowing from a high place to a low place. In 1910, Mr. Frahm devised that the liquid "lags one step behind" the rolling of the ship. This device consists of longitudinally symmetric vertical tubes (wing tanks) on both sides of the hull and a liquid passage (also called a lower duct) that connects the bottoms of these vertical tubes to move the liquid w in the tank in the left-right direction. The moving speed of the liquid (also called the natural period of the water tank or tank) can be calculated from the ratio of the longitudinal cross-sectional areas of the wing tank and the liquid passage. By designing the tank natural period Tts to be approximately equal to the roll period STs of the ship, a 90-degree phase lag occurs between the waves that induce the ship's roll, the ship's roll, and the liquid in the tank, and it is known that a high anti-rolling effect can be obtained. (See Figure 2) In Japan, in 1930, a publication titled "On the Design of Anti-rolling Tanks" including the Frahm type was made in the 46th issue of the Shipbuilding Council Report, and the MN type, which was jointly commercialized by industry, academia, and government in 1963, is known.

[0004] However, this U-tube type wing tank is a single water tank (Single type) including the MN type, and the tank natural period cannot be changed, so it is not suitable for merchant ships with a large change in loading weight. Therefore, the inventor of the present application partitions the inside of the single water tank with a longitudinal bulkhead in the fore-and-aft direction, and uses the "Double Wing (DW type)" with different tank natural periods and the "Triple Wing (TW type)" equipped with a wing tank that constitutes three compartments, and has put into practical use an optimal shape that can correspond to the type, size, and use of the ship and its control method. Incidentally, the DW type A.R.T. is a device approved by the former Ministry of Transport as the "D·W Anti-rolling Tank" manufactured by Stabilo Co., Ltd., and there is the following Non-Patent Document No. 1.

[0005] Japanese Patent No. 3537785 (Ship motion reduction tank device and control method thereof) Japanese Patent No. 3377782 (Ship motion reduction tank device and control method thereof) Japanese Patent No. 30428865 (Control method for ship motion reduction tank device) Utility Model No. 2144338 (Ship motion tank device) Japanese Patent No. 4262127 (Parametric roll prevention device) Japanese Patent No. 4721169 (Variable period type roll reduction tank device for parametric roll prevention) Japanese Patent Application No. 2023-108567 (Ship motion reduction tank device and control method thereof for container ships)

[0006] Notice No. 115-2 (November 18, 1987, Chief Ship Inspector, Maritime Technology and Safety Bureau) TopTier N2M Parametric Roll Following Seas V1.1 Notice to Mariners Attention to Parametric Rolling in Following Seas Estimation of Performance of Anti-Rolling Tanks as Parametric Rolling Prevention Devices (Part 2) Transactions of the Japan Society of Naval Architects and Ocean Engineers, No. 8, December 2008

[0007] The present invention relates to an A.R.T. and parametric roll prevention system 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 tons.

[0008] (1) Since around 2000, as container ships on international routes have grown larger, the number of containers they carry has increased dramatically, leading to a surge in accidents where many containers spill out or are damaged during transit. One of the suspected causes of these accidents is the occurrence of large rolling angles known as parametric rolling. One possible solution is the "roll reduction tank device for preventing parametric rolling," as described in Patent Documents 5 and 6, filed in 2004. (2) In the winter of 2020-2021, there were numerous major accidents involving container losses. In response, a joint industry project (The TopTier project) was launched to explore measures to prevent similar accidents from recurring. It became clear that parametric rolling in following waves is particularly dangerous, and Non-Patent Document 2 provides advice on how container ship crews and operational staff should plan, understand, and act to prevent parametric rolling in following waves.

[0009] Since the beginning of 2021, there has been an increase in requests for A.R.T. equipment for giant container ships, and one of the conditions presented is: (1) Length 335.0m, width 50.0m, depth 30.0m, displacement 200,000 tons, stability performance from full load to port entry is a GoM value of 4.0 to 2.0m, rolling period of 20 to 30 seconds, and target roll reduction efficiency of 50%. (a) The A.R.T. plan must first provide A.R.T. dimensions that can satisfy the required roll reduction efficiency, based on the stability values ​​presented in the order specifications and the vertical position of the tank installation. (b) Therefore, applying the width of 50m, GoM value of 4.0m, rolling period of 20 seconds etc. presented by the client to conventional technical calculations, the average flow velocity of the liquid is approximately 5.0m / second. Also, when the GoM value is 2.0 m and the oscillation period is 30 seconds, the average flow velocity of the liquid is approximately 3.33 m / second. (c) The oscillation period assumed in the theoretical calculation is 20 to 30 seconds. Considering the head wave (also called the head wave) and the following wave (also called the head wave), the effective oscillation reduction period range required is 18.5 to 34 seconds. (d) In order to obtain the required oscillation reduction efficiency of 50%, considering the large values ​​of the stability coefficient described in paragraph 0023 (1) of this application, which is 800,000 t-m, the required tank length is approximately 15 m, the liquid passage height is approximately 2.5 m, the weight of the liquid used is approximately 2,200 tons, and the required volume is approximately 1.1% of the discharge volume. Incidentally, (Non-Patent Document 3) Performance Estimation of an Anti-Rolling Tank as a Parametric Rolling Prevention Device (Second Report) indicates a displacement of 105,000 tons and a stability coefficient of 111,300 t-m. (See Table 1) (2) The loading of this liquid weight of 2,200 tons would lead to a reduction in the amount of cargo that can be carried, and from the perspective of cost-effectiveness associated with A.R.T. equipment, it is far from practical, and there is a strong desire for new development.

[0010] Summary of prior art relating to a roll-damping water tank device for parametric roll prevention and comparison with the present application. (1) Results of prior art search etc. (a) Search type: Patent search using J-Platpat (b) F1 / IPC: B63B39 / 03 (c) Search scope: Search formula within the "entire text" (d) Search items: F1 (B63B39 / 03): 268 items and IPC (B63B39 / 03): 381 items. (e) Search items: F1 / IPC + keyword (e1): "Giant ship + large container ship + mountain shape" yielded 0 results in both F1 and IPC. (e2) "Anti-rolling tank (74 / 91 cases), ART (21 / 22 cases)." (e3) "Anti-rolling tank (15 / 17 cases), "U-tube type (41 / 44 cases)." (e4) "Parametric rolling + anti-rolling tank device" had FI: 2 cases / IPC: 2 cases. (2) Regarding the contents of the prior art search, (a) We checked prior art for motion reduction tank devices related to giant container ships, but we could not find any disclosure of the "mountain-shaped cross-section" which is a feature of the present invention, so it is considered to have novelty. (b) For parametric rolling + anti-rolling tank devices, there are "Patent Document 5 and Patent Document 6," both of which are by the same inventor and employ a "U-tube type (Single type)," and a comparison with the present invention is shown below. (3) In the parametric roll prevention device described in Patent Document 5, one of the solutions is described in the paragraph (Abstract / Solution) as "by moving the position of the center of gravity of the hull 1 by adding and removing liquid (seawater) in a tank 5 installed in the hull 1, the rolling period of the hull 1 is changed so that the ratio of the rolling period to the pitch period deviates from a predetermined parametric rolling occurrence condition." However, in the case of large vessels, there is no technology that can handle the liquid weight of the A.R.T. (0.6% of the displacement?) by adding and removing the liquid, and in particular, there is no means in the present invention that would eliminate the rolling reduction effect if the liquid of the A.R.T. is drained. (4) In Patent Document 6, (a) paragraph 0014 states, "The weight of the liquid carried in the rolling reduction tank is characterized by being 0.8% to 0.2% of the displacement of the vessel...", but there is no disclosure or suggestion of specific numerical values ​​for "liquid weight used" and "displacement".(b) Paragraph 0015 specifies a U-shaped configuration, stating that it includes a sway-reducing water tank comprising a pair of left and right wing tanks and a connecting water channel connecting the lower parts of the pair of left and right wing tanks, a damper provided in the connecting water channel for adjusting the oscillation period of the liquid in the sway-reducing water tank by opening and closing it, 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 stopping of the liquid in the sway-reducing water tank by opening and closing it. However, in the case of a U-shaped configuration, "a pair of wing tanks," "connecting water channels," "a damper for adjusting the oscillation period of the liquid in the liquid passage," and "an air duct connecting the upper parts and its valve" are all indispensable and known technologies, and there is no specific disclosure or suggestion regarding their specifications or control methods. (c) Paragraph 0016 states, "The air duct is... Thus, the air duct is characterized in that it is provided on the stern side or the bow side of the anti-rolling water tank," but this technology is not used in the present invention, and if it cannot be installed on top, it is possible to do so by the method of Patent Document 4. (d) Paragraph 0020 states, "The amount of moment required to prevent parametric rolling has not been elucidated and is unknown to date, so a design method for a variable-period anti-rolling water tank device for preventing parametric rolling has not been established to date..." However, it is impossible to "prevent parametric rolling" with an A.R.T. that does not have the required anti-rolling moment. (e) The required anti-rolling moment of the A.R.T. 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 (Patent Documents 5 and 6) and the present invention are different in their A.R.T. It can be seen that the shape of the R.T., the specifications of the ancillary equipment, and the control means are significantly different. (5) Incidentally, "Non-Patent Document 3" is a paper on experimental results related to A.R.T. as parametric roll prevention for giant container ships from around 2008, and contains the following description, making it a valuable resource. (a) A comparison of the embodiment of the present application and the main items 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-tube type (Single Wing Type).

[0011] The present invention, which solves the problems of excessive liquid weight used in A.R.T. and parametric lateral oscillation, will be explained clearly by separating the sections on "A.R.T." and "parametric lateral oscillation." (1) A detailed technical description of A.R.T. is given in paragraphs 0012 to 0035. (2) An explanation regarding parametric lateral oscillation is given in paragraphs 0036 to 0039.

[0012] The basic technology related to A.R.T. for giant container ships, as described in paragraph 0007 of the present invention, is based on the achievements of Patent Documents 1 to 4 and Document 7 (technology by the present inventor), as well as improvements thereof. Furthermore, to address parametric rolling, a calculation program that predicts whether or not parametric rolling will occur is added to the program that executes the A.R.T. function, and a controllable technology to prevent parametric rolling is provided. (1) Patent Document 1 is for merchant ships for large vessels and has been well-received with various specifications such as length: 158.0 m, 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 liquid used in the tank is approximately 200 tons. (a) From the calculation of the ship's natural period in paragraph 0003 to the control group in paragraph 0044, A.R. (b) Patent Document 2 describes the comprehensive technology necessary for the design of T, and improvements thereto constitute the technology of the present invention. Incidentally, much of it is reused in paragraphs 0013 to 0035 of the present invention. (b) Patent Document 2 describes the technology of determining whether or not a following wave state is reached based on external information such as wind direction and wind speed, ship speed and period. By improving this technology, a program related to parametric rolling is constructed. (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 also handles parametric rolling, can be obtained. (d) Patent Document 4 describes means for when it is not possible to install an air communication pipe at the top. (2) As mentioned above, the above prior art documents (Patent Documents 1 to 4) are known technologies by the present inventor, and the technical content is well known, but detailed drawings etc. have been omitted in the present invention.

[0013] (1) Incomparable to large ships that have previously been equipped with tanks with a width of 30.0 m, the ship's width of 40 to 60 m results in a large stability coefficient, specifically, a GoM value of 4.0 m that corresponds to a ship's rolling period of 20 seconds. When calculated in reverse from the average flow velocity of the liquid moving in the A.R.T., the weight of the liquid used can reach 2,000 to 3,000 tons. (2) Therefore, focusing on the fact that the narrower the overall width of the tank, the smaller the longitudinal cross-sectional area of ​​the liquid passage can be made in a U-tube type A.R.T., as a design means to minimize the weight of the liquid used, the design technology of the DW type A.R.T. and the A.R.T. that reflects its philosophy have been invented, with a cross-sectional shape that is mountain-shaped (hereinafter referred to as mountain-shaped) (Figure 1). (3) Mountain-shaped A.R.T. In T, the means for slowing down the average flow velocity of the moving liquid consists of a center tank 3 that narrows the width of the tank, an independent equipment room 4 within the center tank, a longitudinal bulkhead 5 located at the center of the hull below the equipment room, one pair of liquid passages 6p, 6s on each side, and DW-type wing tanks 2p, 2s. (a) The two virtual tanks 1p, 1s on the left and right sides, separated by the longitudinal bulkhead 5, are as follows: (b) Virtual tank 1p refers to the tank on the port side, separated by the port wing tank 2p, the liquid passage 6p, and the longitudinal bulkhead below the equipment room. (c) Virtual tank 1s refers to the tank on the starboard side, including the starboard side of the center tank, the liquid passage 6s, and the starboard wing tank 2s, separated by the longitudinal bulkhead below the equipment room. (4) Figure 3 shows the state in which the above items (a) and (b) are connected, which can exhibit the mountain-shaped configuration and function.

[0014] Claim 1 of the present invention relates to an A.R.T. main body having a mountain-shaped cross-section, comprising the entire width of the A.R.T. and a center tank capable of forming one set of virtual tanks 1p and 1s on each side, each approximately half the width of the A.R.T., and is characterized by enabling a roll reduction effect and parametric prevention.

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

[0016] The invention of claim 3 relates to the liquid passages 6p and 6s of the A.R.T., and is characterized by comprising a hardware means for obtaining multiple different tank natural periods, as described in claim 1, for a motion reduction water tank device for a giant container ship.

[0017] The invention of claim 4 is a control method for a motion reduction tank device for a giant container ship as described in claim 1, characterized by: (1) means for constructing control groups (CASE 1 to 9) including a plurality of different natural periods of tanks; (2) setting a preset average rolling period value for control (also simply called rolling period) as a threshold (25.5 seconds), and when a value less than the threshold is detected, creating functions for a center tank 3 and a virtual tank that correspond to the effective rolling reduction period range of 18.5 to 26 seconds; (3) deactivating the functions of tank 3 and the virtual tank that correspond to the effective rolling reduction period range of 25.5 to 34 seconds when the rolling period exceeds the threshold; (4) deactivating the A.R.T. when a preset value of 34.5 seconds or more is detected; and (5) controlling the equipment essential for the preceding paragraphs (1) to (4).

[0018] The invention of claim 5 relates to parametric rolling, and is a control method for a motion reduction water tank device for a giant container ship as described in claim 1, characterized in that a calculation program that predicts whether or not parametric rolling will occur is added to the program of claim 4 that executes the A.R.T. function, and the device instantly responds to the rolling conditions of the ship encountered.

[0019] The present invention, which has been difficult to implement in commercial vessels and has not been installed on any large ships until now, incorporates technology cultivated on large ships and, using a mountain-shaped A.R.T., can instantly reduce rolling during rough weather, which frequently occurs on international routes for large container ships, predict whether or not parametric rolling will occur, take preventative measures, and take countermeasures to reduce rolling if parametric rolling occurs. In particular, the equipment used can be the same specifications as that used for conventional large ships, making it a highly effective invention as a motion reduction water tank device for large container ships.

[0020] Figure 3 is a perspective view of the mountain-shaped anti-rolling water tank body 1 relating to the invention. Note that when viewed from the stern (rear) of the ship, the left side of the figure is called the port side and the right side is called the starboard side. This is a table showing the phase lag between the wave (Mt), the ship (FMt), and the moment of the tank (TMt). This is a cross-sectional view showing an example in which the gate 5c that opens and closes the opening 5o of the longitudinal bulkhead 5 is closed and the valve 7v with air ducts 7a and 7b is opened to create the functions of the wing tanks 2p and 2s and the virtual tanks 1p and 1s. Figure 3 is a cross-sectional view showing an example in which the liquid movement state when the ship has rotated 1 / 2 turn is shown. Figure 3 is a cross-sectional view showing an example in which the gate 5c is opened to release the functions of the center tank, the left and right liquid passages 6p and 6s, and the virtual tanks 1p and 1s, and the valve 7v with air duct 7b is closed 7vc to use the outer wing tank 2ot. Figure 5 is a cross-sectional view showing an example of the liquid movement state when the ship has rotated 1 / 2 turn. It is a perspective view showing an example of the center tank and equipment room shape and equipment arrangement on the liquid passage. However, the lower dampers (8d1, 8d2) are installed symmetrically on both sides, but only the starboard side is shown. Figure 7 is a plan view showing an example of the top plate of the liquid passage near the center tank. However, the lower dampers (8d1, 8d2) are installed symmetrically on both sides, but only the starboard side is shown. Figure 7 is a longitudinal cross-sectional view of the centerline position of the center tank.

[0021] The present invention aims to file a PCT international application with a view to overseas expansion, and therefore there are some parts of the explanation that overlap with the present inventor's ideas, including prior art. (1) The most important thing when planning A.R.T is to understand the natural period of rolling of the ship. The formula for estimating the natural period of rolling based on Japan's ship stability regulations is as follows: Ts (natural period of rolling of the ship) = (2.01 x B x k) / √GoM (unit: seconds) B: width of the ship (m), k: radius of rotation (coefficient), GoM: metacenter height (m) From this formula, it can be understood that the larger the GoM value in the denominator, the shorter (faster) the natural period of rolling. Incidentally, assuming the displacement is constant, the larger the GoM value, the larger the required anti-roll moment. (2) The ship's rolling period STs is the same as the ship's natural rolling period Ts when encountering regular wave periods. However, when encountering irregular wave conditions, the ship's rolling period differs depending on the angle and period of the encounter between the wave and the ship. In particular, large rolling motions are induced when the encounter period with the ship and the ship's natural rolling period Ts are synchronized. Note that the explanation regarding wave height is omitted here. (3) The natural rolling period Tts of a tank refers to the time required for the liquid in the tank to complete one round trip. Note that in the case of a passive system, the liquid in the tank moves after the ship is induced by an external force. (4) The phase lag between the wave that induces the ship's rolling motion, the rolling motion, and the movement of the liquid in the tank will be explained. (a) Ship rolling motion is induced with a one-tempo delay when the wave period value and the ship's natural rolling period value are the same. This one-tempo delay is called the phase lag between the wave and the ship. (b) When the rolling period of the ship and the natural period of the tank are approximately the same, the liquid movement occurs with a delay of one beat in response to the ship's movement. This state of ship and liquid movement is also called phase lag. (c) To obtain a high anti-rolling effect, it is essential that the rolling period and the natural period of the tank match. (d) The rolling of a ship is a repetitive motion, and if we replace one roll with one rotation (360 degrees), it can be expressed as horizontal (0 degrees) ⇒ starboard inclination (1 / 4 rotation: 90 degrees) ⇒ horizontal (1 / 2 rotation: 180 degrees) ⇒ port inclination (3 / 4 rotation: 270 degrees) ⇒ horizontal (one rotation: 360 degrees = 0 degrees).Furthermore, the phase lag diagram is shown in (Figure 2). Theoretically, it is a smooth sine curve, but in this figure, in order to emphasize the phase lag between the waves, the ship's rolling, and the liquid in the tank, it is deliberately shown as a straight line, with each peak representing one rolling motion and one period. (e) In A.R.T., the flow is: waves that induce the ship ⇒ ship rolling occurs ⇒ liquid moves in the tank. There is always a 90-degree phase lag between the waves and the ship's rolling, and furthermore, when the rolling period value STs and the tank's natural period value Tts are the same, there is a 90-degree phase lag between the ship's rolling and the liquid movement in the tank. In other words, if the peak of the wave force Mt that induces the ship is on the starboard side, the peak of the tank's anti-rolling force (also called moment) TMt, which has a 180-degree phase lag, will be on the opposite port side. This means that the wave force Mt that causes the ship to rock and the anti-rolling force TMt that tries to suppress the ship's movement are in opposite directions, and therefore, the two forces cancel each other out, resulting in an anti-rolling effect.

[0022] First, a basic explanation of rolling conditions will be given. (1) Regarding rolling conditions in rough weather: (a) The motion of a ship during a voyage is a known phenomenon that occurs when the encounter period of the waves with the ship matches the ship's natural rolling period. (b) The rolling condition of a ship is determined by the course and wave direction. Hereinafter, the bow in the direction of travel is set to (0°), and the port side is directly aft (90°), the stern is (180°), the starboard side is directly aft (270°), and the bow after a full rotation is (360° = 0°). (c) The maximum pitch angle occurs when there are headwinds from the bow (0°) direction and following waves from the stern (180°). (d) The maximum roll angle occurs when there are transverse waves from the side (90° and 270°). (e) The boundaries between pitch and rolling are 45°, 135°, 225°, and 315°. (f) The range in which vertical oscillation occurs is between 0° and ±45°, and between 135° and 225°. (g) The range in which horizontal oscillation occurs is between 45° and 135°, and between 225° and 315°. (2) The means of analyzing the horizontal oscillation period and angle information, which are essential for A.R.T. control, will be explained. (a) For passive A.R.T. control, it is not necessary to use different oscillation values ​​for each oscillation. For example, it is sufficient to average multiple accumulated data during measurement. For example, five data points are analyzed as follows: A simple moving average is sufficient, where the sum of the five data points plus the next new sixth value and the first oldest value is removed is divided by 5. A1 = (n1 + n2 + n3 + n4 + n5) / 5 ⇒ A2 = (n2 + n3 + n4 + n5 + n6) / 5. (b) Moving average rolling period (ATs) = (STs1 + STs2 + STs3 + STs4 + STs5) / 5 STs: Rolling period of the ship (c) Moving average vertical rolling period (APs) = (SPs1 + SPs2 + SPs3 + SPs4 + SPs5) / 5 SPs: Vertical rolling period of the ship (d) Moving average rolling angle (ATθ) = (STθ1 + STθ2 + STθ3 + STθ4 + STθ5) / 5 STθ: Rolling angle of the ship (e) Moving average vertical rolling angle (APθ) = (SPθ1 + SPθ2 + SPθ3 + SPθ4 + SPθ5) / 5 SPθ: Vertical rolling angle of the ship (3) Rolling information used in A.R.T control (a) The inventor of the present invention, A.R. Based on over 50 years of experience and history related to T, we have adopted the moving average calculation method.(b) Based on past experience, the optimal number of accumulated data points used for calculating the moving average is 3 to 5, but it is not necessary to adhere to this. (c) If the number of data points is small, the number of times the device is switched will increase, and conversely, if the number of constantly changing data points is large, the instantaneous prediction accuracy will deteriorate.

[0023] The embodiments of the A.R.T. of the present invention will be described below with reference to the drawings. Figures 1 to 9 are for illustrative purposes only, and the scale of the figures has been ignored. Furthermore, the embodiments can be implemented in a way that suits each vessel according to the order conditions of the client (shipbuilding company, design company, shipowner), and are not limited to the specific examples described in the embodiments below. (1) Ship stability specifications (a) Stabilizing force refers to the force that attempts to return the attitude of a ship that has tilted due to some factor back to its original position. In this embodiment, the stabilizing force coefficient is set to displacement (200,000 t) x GoM (4.0 m) = 800,000 t - m. (b) The ship width and the total width of the tanks are set to 50.00 m. (c) Virtual tanks 1p and 1s are symmetrical and of the same dimensions, with each tank width set to 25.00 m. (d) The tank length is 9.00 m based on the calculation results from the stability specifications provided by the client, but the length is divided into two equal parts of 4.50 m x 2 sets, and one of these sets will be explained. Note that if the tank is made longer, the liquid inside the tank will move in the bow and stern direction due to the effects of the ship's steady longitudinal inclination and pitching, so it is desirable to divide the tank length and shorten it so as not to hinder the liquid movement in the lateral direction necessary for reducing rolling. (e) The A.R.T. bottom plate position is 33.0 m above the ship's bottom plate, and the fore and aft position is near the center of the ship, with a bridge including a living deck room above the A.R.T. The purpose of this is that in container ships, containers are stacked high, so raising the bridge position is a means of improving visibility, and there is no need to newly secure space for the A.R.T. installation, and therefore there is no need to consider a reduction in the number of containers. (f) In ships that have living quarters and bridges in both forward and aft locations, it is possible to install them in both locations as needed, depending on the length of the A.R.T., but this is not something that the designer is obligated to do. (g) It is desirable to avoid placing the A.R.T. near the bow and stern as much as possible. The reason for this is that the larger the ship, the greater the weight of the A.R.T. required and the weight of the fluids used, which will have a negative impact on the trim and longitudinal strength of the hull.

[0024] The embodiments of the present invention will be described in detail below with reference to the drawings, but the present invention can be implemented in many different forms for each vessel depending on the type of ship, size, stability values, and installation position of the A.R.T., and is not limited to the specific examples described in the embodiments below. The basic overall configuration of the A.R.T. to achieve the above objective is as follows: (1) As shown in Figure 1, the A.R.T. body 1 is based on a U-tube shape, with a center tank 3 provided between DW-type wing tanks 2p and 2s of the same dimensions on both sides of the hull, and the inside of the tank consisting of a set of liquid passages 6p and 6s on the left and right sides at the bottom of the tank 3 and the wing tanks 2it is sealed, and its cross-sectional shape is mountain-shaped. (a) The effective rolling period range of the A.R.T. is 18.5 to 34 seconds, taking into account head waves and following waves, and the rolling response threshold for controlling whether or not to use a virtual tank is 25.5 seconds. (b) When the average oscillation period ATs is short and below the threshold, the virtual tank function is activated to handle head-following conditions. (c) When the average oscillation period is long and above the threshold, the virtual tank function is deactivated, and the A.R.T. main unit function is activated to handle following conditions.

[0025] The DW-type wing tanks 2p and 2s each consist of tanks 2it and 2ot, which are divided into left and right sections by a longitudinal bulkhead 2bh running in the bow-stern direction within each tank. (1) The longitudinal bulkhead is located at an appropriate distance from the top plate of the inner outer plate 2b that constitutes tanks 2p and 2s, and a plate sloping downwards within the wing tank is connected to the longitudinal bulkhead 2bh, using this position as a base point. (a) The purpose is to increase the volume of the upper part of tank 2ot and to prevent the moving liquid w from colliding with the top plate of the wing tank during severe rolling. (b) The lower end of the longitudinal bulkhead is 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 10.00 m. (a) A. R. Assuming the tank width of the main body is 50.00 m and the roll angle is 15°, the upward movement height of the liquid in the wing tank will be approximately 6.7 m. Adding the water level in the main tank (1.80 m in this case) to this value gives 8.50 m. Considering factors such as acceleration, it is desirable to make it even higher. (b) In particular, in order to obtain the roll reduction effect during parametric roll, which can be as much as 1.5 times the roll angle during rough weather, it is necessary to make the wing tank sufficiently high.

[0026] The installation of the center tank 3 and the equipment room within the center tank is one of the essential devices when the A.R.T. width exceeds 30m, but its width, height, and length only need to be sufficient to accommodate the amount of water in the DW-type wing tanks 2p and 2s on one side during oscillations, satisfying the design conditions of the client, and its dimensions depend on the design philosophy. (1) The purpose of installing the center tank is to create two sets of virtual tanks 1p and 1s. (2) The equipment room within the center tank is provided for the purpose of creating virtual tanks and deactivating their functions. (3) The height dimension of the equipment room is to be higher than the average water level of the tank body, and its upper end is lower than the top plate of the center tank at an arbitrary distance. (a) The purpose is that when the oscillation angle is large and the liquid w flowing in from the liquid passages 6p and 6s exceeds the top of the equipment room, it is allowed to overflow from its upper end and flow into the adjacent virtual tank. (4) At the center of the hull below the equipment room, a longitudinal bulkhead 5 is provided between the bottom plate and top plate of the liquid passage, running in the bow-stern direction, with the necessary opening area in the longitudinal bulkhead 5 and a remotely driven gate 5c for opening and closing the opening 5o. (a) The purpose of the gate 5c is that when the opening is closed, the functions of the center tank and virtual tanks 1p and 1s are performed, and when the gate is opened, the functions of the center tank and virtual tanks are deactivated. (b) Since the moving liquid reverses direction every 1 / 2 of a pitch at a preset speed (period), it is not necessary to make the gate a watertight structure from a cost-effectiveness standpoint. (c) It is desirable that the width dimension of the equipment room in the left-right direction be wider than the width of the gate 5c. (d) In addition, an entrance / exit is provided in the equipment room for inserting equipment, maintenance, inspection and repair, lifting pieces for work, and other necessary locations.

[0027] The liquid passages 6p and 6s connect the left and right outer plates 3p and 3s of the center tank 3 to the inner outer plate 2b of the wing tank, with one set 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 height of the liquid passages determines the total liquid level (water level) Wh of the tank and the basic height of the wing tank. (b) Also, the volume of liquid occupied by the volume of the liquid passages (longitudinal cross-sectional area x width of the liquid passages) is about 60-70% of the total amount of liquid needed, so the goal is to reduce the amount of liquid used by keeping the liquid passages low. (c) Incidentally, it is desirable that the minimum height of the liquid passages be about 0.70 m or more to facilitate welding and maintenance work, but it is not necessary to adhere to this value depending on the design philosophy. (d) It is especially important to note that it is desirable that the bottom plate and the top plate of the liquid passages be parallel. (2) It is desirable that the length of the liquid passage in the bow-stern 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, it is possible to make the length of the passage shorter than the length of the wing tank as a means of making the height dimension of the liquid passage larger and securing the required longitudinal cross-sectional area of ​​the liquid passage. (3) Within the liquid passage, at any point in the bow-stern direction, there shall be at least three sets of passages partitioned by ribs or the like, and the required number of lower dampers 8d1, 8d2 shall be provided in pairs of the same size on the left and right, and at the points where the dampers are stopped, a pair of flow straightening plates shall be provided around the damper axis as a means of preventing turbulence of the liquid passing around the dampers. (4) The damper 8d shall be a hydraulically remote-driven type that has an opening degree of 0 to 90 degrees clockwise around the vertical axis and stops at least one point in between, and a sensor for confirming the stop position shall be attached, and a means shall be provided to transmit the fully closed, partially stopped, and fully open positions of the damper to the control unit by electrical signals. (a) The purpose of using a hydraulic drive source is the inventor's design philosophy that instantaneous operation is required to respond to rapidly changing lateral oscillation periods, especially parametric lateral oscillation, and other drive systems are also possible. (b) The technology related to dampers is publicly known, and therefore a detailed description is omitted in this application.

[0028] The air ducts 7 (also called air ducts 7a and 7b) are means for controlling the liquid braking (activation or deactivation) of the A.R.T. and the variable nature of the tank Tts. They are directly connected to the divided left and right symmetrical positions of the DW-type wing tank via a remotely driven closing device 7v near the top of the wing tank. (1) In this embodiment, two sets of air ducts 7a and 7b are provided via a hydraulically driven valve 7v. (a) The inside of the tank is sealed, and when the valve 7v with the air duct is closed, the flow of air between the left and right tanks is cut off and the movement of liquid stops. This state is called A.R.T. non-operation. (b) When both air ducts 7a and 7b are opened, 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 shortened and the wing tank width is widened, functionally resulting in a long tank natural period Tts and a large anti-rolling force. Incidentally, the wider the wing tank, the greater the reducing force (anti-rolling moment). (c) When air duct 7a is opened and air duct 7b is closed (○X7vc in the figure), liquid can only move in the two-part outer tank 2ot within the wing tank. In this state, the liquid passage is lengthened and the wing tank width is shortened, functionally resulting in a short tank natural period Tts. The purpose of this embodiment is to provide a special control means that lowers the height of the liquid passage to correspond to a slow rolling period range of 25.5 to 34 seconds. (As shown in Figure 5) (d) You may feel that there is a contradiction between the description of the tank natural period in item (b) above and (c), but when item (b) above is selected, the tank width is 25.0 m and the liquid transfer distance is short, and when item (c) above is selected, the tank width is 50.0 m and the liquid transfer distance is long. In these different liquid passages, making the liquid passage height the same for item (b) above and (c) above is a novel method not found in prior art. (2) The shape of the air duct 7 may be round (pipe) or rectangular, and its cross-sectional area (also called the diameter) is determined by calculating the air flow velocity value from the liquid flow velocity value and appropriately determining a diameter that does not generate noise. (a) When one diameter is large, taking into consideration the cost and the structure of the wing tank, if the required cross-sectional area can be secured, multiple air ducts with small diameters may be used.(b) A straight pipe type air duct is preferable as shown in (Figure 1), but if this is difficult due to the surrounding environment, a U-shaped type (Patent Document 4) is also possible. (c) An open-to-the-atmosphere air pipe may also be used, but in this case, the liquid in the tank will spill out as a spray, so water will need to be added as needed. (3) It has been found that the center tank 3 is part of the liquid passage, and no particular effect can be obtained by connecting the center tank and the left and right wing tanks with an air communication pipe.

[0029] Although not shown in the A.R.T. main body 1, the tank is equipped with the necessary equipment such as a liquid filling and draining system, a depth sounding pipe (liquid level gauge), a water level adjustment pipe, and an air vent pipe, and all pipes leading to the outside are provided with closing mechanisms to enable a sealed state inside the tank.

[0030] Here, in order to make it easier to understand the technical supplements for lowering the height of the liquid passages 6p and 6s of the present invention, we will explain them again, including the parts that overlap. (1) Distance traveled by the liquid (a) The distance traveled is the distance between the centers of gravity of the liquid movement, but in this embodiment, it is simply the distance traveled by making one round trip across the entire width of the tank. (b) In the A.R.T. main body 1, it is 50.0m x 2 = 100.0m. (c) In the virtual tanks 1p and 1s, it is 25.0m x 2 each = 50.0m. (2) Time required for liquid movement (a) One rolling motion refers to a situation in which, for example, the ship moves from horizontal to a downward tilt to the port side, returns to the original horizontal position due to the righting force, and then, with the addition of acceleration, moves to an upward tilt to the starboard side, and returns to the original horizontal position, repeating this motion. (b) Passive A.R.T. In T, since the natural phenomenon of flow from high to low is utilized, in the process of the liquid movement reversing, for example, the flow velocity gradually slows down from the maximum, the liquid movement stops, then gradually speeds up in the direction of reversal, and the time required for one oscillation to reach the maximum flow velocity is one cycle, and this becomes the time required 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 50m) is set to 100 / 20 = 5.0 m / sec. (c) If a virtual tank (width 25m) is used, the average flow velocity value is set to 50 / 20 = 2.5 m / sec. (4) Height of the liquid passage (a) The liquid passage height required for the flow velocity value of 5.0 m / sec in the previous item (b) is approximately 2.5 m. (b) The liquid passage height required for the flow velocity value of 2.5 m / sec in the previous item (c) is approximately 0.9 m. (c) In this embodiment, a virtual tank (liquid passage height approximately 0.9 m) is used. (5) Functional tank selection criteria are long rolling period ≥ threshold (25.5 seconds) ≥ short rolling period. (a) The virtual tank is used when threshold (25.5 seconds) ≥ average period of the ship. (b) The A.R.T. main body is used when average period of the ship ≥ threshold (25.5 seconds). (6) Effective rolling period range of the tank (also simply called the effective rolling period range) (a) The effective rolling period range of the virtual tank is 18.5 to 26 seconds. (b) The effective rolling period range of the tank body is 25.5 to 34 seconds.

[0031] The basic control method for creating a virtual tank is as follows: (1) Example of virtual tank shape (a) The shape of virtual tank 1p is the port wing tank 2p, the liquid passage 6p, and the longitudinal bulkhead 5 inside the center tank 3, and is also called the port side tank. (b) The shape of virtual tank 1s is the starboard side of the longitudinal bulkhead inside the center tank, the liquid passage 6s, and the starboard wing tank 2s, and is also called the starboard side tank. (c) When (d) to (f) below are executed, a virtual tank is constructed, and its shape is shown in (Figure 3). (d) Close the opening closing device 5c of the longitudinal bulkhead located below the equipment room inside the center tank. (e) Close the left and right dampers 8d1 inside the liquid passage 6s, and open the left and right dampers 8d2 inside the liquid passage 6s. (f) Open the valves 7v of the air ducts 7a and 7b. (2) Function of the virtual tank (a) The effective rolling period range for the virtual tank is 18.5 to 26.0 seconds. (b) A control group (CASE 1 to 4) is constructed that includes the tank's natural period Tts. (c) The reason the rolling period STs shortens during navigation is when encountering headwind conditions, and the apparent GoM value also increases. To address this, the tank's rolling force TMt needs to be increased, so the wide wing tanks 2p and 2s are used for this purpose. (d) Short periods that occur when facing waves (including parametric rolling) are addressed in CASE 1 to 2. (3) As an example of the situation of liquid movement in the virtual tank, when the hull is rolling (tilting) to the starboard side, (a) In the virtual tank 1p, the liquid w in the port side wing tank 2p flows into the center tank 3 via the liquid passage 6p. (b) In the virtual tank 1s, the liquid in the center tank moves into the starboard wing tank 2s via the liquid passage 4s. (c) Figure 4 shows the state of the liquid when the ship becomes horizontal (half a turn) after listing to starboard. (4) In Figures 3 and 4, wing tanks 2it and 2ot are used as a single wing tank 2p, 2s, so the longitudinal bulkhead 2bh inside the DW-type wing tank is represented by a virtual line.

[0032] The basic control method for the A.R.T. main unit 1 is as follows: (1) Shape of the A.R.T. main unit (a) Open the gate 5c with a vertical bulkhead 5 at the bottom of 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 steps (a) to (c) above are performed, the shape of the A.R.T. main unit is constructed. (e) Figure 5 shows the state in step (d) above, but since it constitutes the divided outer wing tank 2ot, the inner outer plate 2b of the DW type wing tank is shown as a virtual line. (f) If the set lateral oscillation period is a long period of, for example, 36 seconds, it is also possible to open the air duct 7b from the state in step (c) above to correspond to this. (2) Functions of the A.R.T. main unit (a) A.R. The effective rolling period range for the T main body is 25.5 to 34.0 seconds. (b) Construct a control group (CASE 5 to 9) that includes the natural period of the tank. (c) The reason why the rolling period STs lengthens during navigation is when encountering following waves, the apparent GoM value becomes smaller, and the rolling reduction force required to match this is small, so the wing tank 2ot is used for this. (d) Long periods during following waves (including parametric rolling) are addressed in CASE 8 to 9. (3) A.R. Situation of liquid movement in the T main body (a) When the gate 5c with the longitudinal bulkhead 5 that deactivates the center tank function is opened, the liquid passages 6p and 6s become liquid passage 4, so the liquid w in the port wing tank moves directly to the starboard wing tank. (b) Figure 6 shows the state of the liquid when the ship becomes horizontal (1 / 2 turn) after listing to starboard.

[0033] The configuration of the control device is broadly divided into an information analysis unit including a tilt sensor, a control unit that issues pre-set drive commands for the equipment, and a switching equipment unit, etc. However, these are known technologies in A.R.T. (paragraphs 0013 to 0034 of cited patent 1), and individual illustrations and their details are omitted. (1) Grasping ship motion information in the embodiment Data related to motion (vertical pitch, horizontal pitch, wind direction and speed, ship speed, etc.) are collected in an analog manner (continuous flow). This technology is described in detail in Patent Document 3 by the inventor of this application. (2) Means for analyzing ship motion information From the collected continuous flow data, a calculation decoding circuit using a moving average method calculates half of one oscillation, the angle and period of one oscillation, and prediction information for the next oscillation. Incidentally, the point in time when the ongoing oscillation reverses is defined as half of one oscillation. (3) A control unit, which includes a control execution circuit for the equipment and a circuit that performs optimal processing based on feedback information of the execution results of the equipment, outputs a control signal. (4) By combining the variable nature of the tank Tts in the DW type A.R.T. with the closing device 7v with an air duct for liquid braking equipment, the opening closing device 5c for the longitudinal bulkhead, and the opening and closing of the lower damper 8d for adjusting the liquid movement speed, it is possible to vary the natural period of the tank Tts and perform liquid braking as needed, which is usually done by automatic control. (5) Construction of each control group When a predetermined control execution program is executed, control groups CASE 1 to 9 are constructed, and the CASE that is optimal for the moving average rolling period value ATs of the ship encountered is selected and executed from among them.

[0034] The control group is composed of control groups CASE1 to CASE9, with each control group comprising an effective period range of approximately 3 seconds that includes the individual tank natural period value Tts, which exhibits high roll reduction efficiency. (1) Based on the rolling period which changes with each encountered yoke, the average rolling period ATs is calculated using a moving average method with multiple values, and the optimal control group is selected. In this embodiment, an overlap value of 0.5 seconds is set to prevent chattering of the equipment when switching between the group and an adjacent group, but this overlap value will differ depending on the conditions of each ship and will be determined by the designer as appropriate. (2) The state of the open / closed combination of the multiple dampers 8d1, 8d2 that form each control group, the gate 5c, and the valve 7v is determined by constructing the control specifications for each ship, and the means in this embodiment are shown in the following table.

[0035]

[0036] This paragraph will describe parametric rolling. (1) Non-patent document 2 contains the following description of the dangers of parametric rolling and the basis for them: (a) Container ships are a type of ship that is susceptible to the effects of parametric rolling in following wave conditions. (b) Depending on the ship's rolling period, speed, course, and the angle at which the ship meets the wave, the ship's rolling angle can suddenly increase to a level that threatens the safety of the ship, crew, and cargo. (c) This phenomenon is known to occur even in relatively calm wave heights. (2) Parametric rolling can occur in the following situations, and the motion of the ship is induced when the ship's natural rolling period during the operation matches the period at which it meets the wave. (a) When the rolling period is in the vicinity of approximately twice the pitching period. (b) When the wavelength is within the range of the ship's length. (c) It can also occur in headwind conditions in rough weather, or in following wave conditions where the rolling period is long.

[0037] Regarding the causes and prediction of parametric rolling: (a) Paragraph 0023 of this application states that the rolling period STs, longitudinal rolling period APs, rolling angle ATθ, longitudinal rolling angle APθ, etc., are constantly monitored as motion information necessary for predicting the occurrence of parametric rolling. (b) The value of the rolling angle ATθ is compared over time and the increase in the rolling angle is monitored. (c) The value of the average rolling period ATs is compared over time and the increase in the rolling period is monitored. (d) The ratio of longitudinal rolling to rolling period is monitored and the status of the ratio changing to 1:2 is monitored. (e) From the ship speed during navigation and the rotational speed information of the propeller, if the ship speed value decreases, it is monitored whether it is heading towards the waves, and if it increases, it is monitored whether it is following the waves.

[0038] If the possibility of parametric rolling is foreseen, the following measures may be taken to avoid it: (a) The operator shall be notified by an alarm buzzer, screen display, or voice message. (b) As an emergency response, the propeller rotation speed or the pitch of the variable propeller shall be changed. (c) The course shall be changed to alter the angle of encounter with the waves and the encounter period in order to avoid parametric rolling. (d) The above operations shall be known methods and manual operations in accordance with a predetermined ship handling manual.

[0039] The situation regarding whether or not parametric lateral oscillation occurs is constantly monitored as described in paragraph 0037. (1) The difference between parametric lateral oscillation and lateral oscillation during storms lies in the magnitude of their amplitudes. (a) The parametric lateral oscillation angle can be 1.5 to 2 times greater than the lateral oscillation angle during storms. (b) Parametric lateral oscillation and lateral oscillation during storms each have their own lateral oscillation period values. (c) The parametric lateral oscillation period becomes shorter in head-wave conditions. (d) The parametric lateral oscillation period becomes longer in following wave conditions. (e) Parametric lateral oscillation occurs when encountering head-wave or following wave conditions. (2) The response when a parametric lateral oscillation state is reached according to this invention: (a) Short periods of parametric lateral oscillation that occur in head-wave conditions are addressed in Cases 1 to 2. (b) Long periods of parametric lateral oscillation that occur in following wave conditions are addressed in Cases 8 to 9. (c) The selection and execution of items (a) and (b) above can be performed instantaneously as described in claim 5. (e) Furthermore, automatic control is also possible through prior coordination with the main engine or steering gear manufacturer. (f) Even if the rolling period changes abruptly due to the operations of items (b) to (e) above, the effective rolling reduction period range of A.R.T. is set to 18.5 to 34 seconds, and the system automatically selects and executes the optimal control group from among the available control groups (CASE 1 to 9), so no problems arise.

[0040] The present invention, based on the design philosophy and technological improvements of large vessels with a 30m beam and equipped with A.R.T., provides a motion reduction tank device and control method for giant container ships with a 50m beam, which can reduce rolling and parametric rolling in rough weather, and furthermore, avoid parametric rolling, making it highly promising for industrial applications.

[0041] 1 A.R.T. main body (mountain-shaped anti-rolling 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) 2b Inner hull of DW type wing tank 2bh Fore-stern longitudinal bulkhead inside DW type wing tank 2it Divided inner wing tank 2ot Divided outer wing tank 3 Center tank 3t Center tank top plate 3p Left hull of center tank 3s Right hull of center tank 4 Equipment room inside center tank 4d Entrance to equipment room 4t Equipment room top plate 4t1 Inclined top plate of equipment room 4p Equipment room longitudinal bulkhead (port side) 4s Equipment room longitudinal bulkhead (starboard side) 4b Gap between equipment room top plate and center tank top plate 5 5o A longitudinal bulkhead between the bottom plate and top plate of the liquid passage, located at the center in the left-right direction below the equipment room. 5c A closing device (also called a gate) for the longitudinal bulkhead opening between the bottom plate and top plate of the liquid passage. 5g1 No. 1 gate 5g2 No. 2 gate 5g3 No. 3 gate 6 A liquid passage (also called a lower duct) that integrates the liquid passages on both the port and starboard sides. 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 an air duct) 7v Closing device with air duct (also called a valve) 7a No. 1 air duct 7b No. 2 air duct 7vc Valve in closed position 8d Closing device in the liquid passage to adjust the speed of liquid movement (also called a lower damper) 8d1 No. 1. Lower damper (applied symmetrically) 8d2 NO. 2. Lower damper (applied symmetrically) Wh Liquid level w Liquid Mt Wave force that induces rolling of the ship FMt Force that returns the ship to its original position (also called restoring force) TMt Rolling force (also called rolling moment) in the tank STs Rolling period of the ship FTs Natural rolling period of the ship ATs Mean rolling period of the ship Tts Natural tank period

Claims

1. A DW-type wing tank consisting of an inner wing tank (2it) and an outer wing tank (2ot), which are formed by dividing a single wing tank into two sections horizontally along the ship by a longitudinal bulkhead (2bh) running in the bow-stern direction. A liquid passage (6) for moving the liquid from the DW-type wing tank horizontally is located below both DW-type wing tanks, and a center tank (3) is located on the top plate of the liquid passage near the center between the two DW-type wing tanks. The cross-sectional shape of this integrated structure, when cut perpendicular to the bow-stern direction, forms a V-shape from the port DW-type wing tank (2p), liquid passage (6), center tank (3), and starboard DW-type wing tank (2s), indicating a passive A.R. In T, as a means of moving air between the inner wing tank (2it) and the outer wing tank (2ot) of the DW-type wing tank, air communication pipes (7a, 7b) are connected to the opposing inner wing tank (2it) and outer wing tank (2ot) on both sides, above the divided inner and outer wing tanks, via remotely driven closing devices (7v) that, if necessary, block the air movement within the wing tanks on both sides. In addition, within the liquid passage, which is divided into at least three sections in the bow-stern direction, there are multiple remotely driven lower dampers (8d1, 8d2) to adjust the speed of liquid movement, and the top plate (6t) and bottom plate of the liquid passage are located at the center of the liquid passage in the left-right direction. A remote-controlled closing device (5c) is provided in the fixed longitudinal bulkhead (5) in the bow and stern direction, and a required opening (5o) is provided in the longitudinal bulkhead (5), and a separate equipment room (4) is provided in the center tank (3) with the liquid passage top plate (6t) as the bottom plate, and a program is provided that calculates the ship's rolling period (STs), the ship's mean rolling period (ATs), and the ship's natural rolling period (FTs) based on information output from a tilt sensor that detects the instantaneous angle of the ship's rolling and pitching, and further predicts the rolling and pitching period and angle of the ship one rolling motion ahead, a remote-controlled closing device (7v) is provided for two sets of air communication pipes (7a, 7b), and at least two sets of remote-controlled lower dampers (8d1, 8d1, 8d1) are provided in the liquid passageA large container ship A.R.T. is characterized by having 8d2) on both sides, a remotely driven closing device (5c) for the opening (5o) of the longitudinal bulkhead (5) that decodes the information output from the opening (5o) of the longitudinal bulkhead (5), a closing device (5c) for the opening (5o) of the longitudinal bulkhead (5) in the bow-stern direction that fixes the top plate (6t) of the liquid passage to the bottom plate of the liquid passage, a closing device (7v) for the air communication pipe, and a control panel that controls the drive of the lower damper (8d).

2. The A.R.T. for a giant container ship according to claim 1, characterized in that the length of the liquid passage is divided into at least three sections by rib plates at arbitrary locations in the bow-stern direction or partition plates having arbitrary widths in the left-right direction, and at arbitrary locations within the divided liquid passage, at least two sets of remotely driven lower dampers (8d1, 8d2) with blades fixed to an axis are installed on both sides, and when the blades of the lower dampers are parallel to the left-right direction of liquid flow, the lower dampers are called fully open, and when the blades of the lower dampers are rotated perpendicular to the direction of liquid flow, the lower dampers are called fully closed, and at least one position is provided in between the rotation range of fully open and fully closed lower dampers where the lower dampers stop, and means are provided to drive the lower dampers to a preset normal position based on information transmitted from a position sensor that grasps the opening and closing position of the lower dampers (8d1, 8d2) to be driven as needed.

3. The central tank (3), which is the core of the present invention, has the same width and length as the DW-type wing tanks (2p, 2s) on one side, and its height is determined at the discretion of the designer. The width of the equipment room (4) inside the central tank (3) may be approximately the width of the central tank minus twice the height of the liquid passage (6). The height of the equipment room (4) is lower than the top plate (3t) of the central tank by an arbitrary gap (4b). When the ship's rolling angle is large, the liquid in the DW-type wing tanks (2p, 2s) flows into the central tank (3) via the port side (6p) or starboard side liquid passage (6s) of the liquid passage. Furthermore, when the incoming liquid exceeds the top plate (4t) of the equipment room, it is characterized by flowing out into the adjacent liquid passage (6p, 6s) through a gap (4b) provided between the top plate of the equipment room and the central tank, as described in claim 1.

4. In response to the various rolling and pitching conditions encountered by the ship during rough weather, as a means of obtaining the optimal A.R.T. rolling damping effect, instantaneous information of the ship's rolling angle and pitching angle is rearranged in a time series, and based on the calculation results predicting the rolling period and angle of one roll, the rolling period and angle using a moving average, and the rolling period and angle of the next roll, the closing device (5c) for the opening (5o) of the longitudinal bulkhead (5) in the bow-stern direction that fixes the top plate (6t) and bottom plate of the liquid passage, the closing device (7v) with air communication pipes for the inside (2it) and outside (2ot) of the DW type wing tank, and at least two sets of remotely driven lower dampers (8d1, 8d2) on each side of the liquid passage are simultaneously driven according to predetermined drive control specifications, and different A.R.T. In the control method for obtaining the natural period of T, the opening (5o) of the longitudinal bulkhead (5) between the bottom plate and top plate of the liquid passage is closed, and the closing device (7v) with air communication pipes (7a, 7b) on the inside (2it) and outside (2ot) of the DW type wing tank is opened, forming two sets of virtual tanks (1p, 1s) consisting of the center tank (3) and the port and starboard DW type wing tanks (2it, 2ot). In this state, when the lower dampers (8d1, 8d2) in the liquid passage are rotated to predetermined positions, four types of short A.R. cycles are generated that can accommodate short ship rolling periods, including those in head-on wave conditions. Control groups CASE1 to CASE4 are configured, which are called the effective damping period range that includes the natural period of T (Tts) ± 1 second. Furthermore, when the opening (5o) of the longitudinal partition wall (5) between the bottom plate and top plate of the liquid passage is opened and the closing device (7v) with the air communication pipe (7a) 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 8d2) is driven to a predetermined open / closed position, control groups CASE 5 to CASE 9, referred to as the effective anti-roll period range including five types of long A.R.T. natural periods (Tts) ± 1 second, are configured to accommodate the long rolling periods of the ship, including following wave conditions. The optimal control is automatically selected from control groups CASE 1 to CASE 9, which are capable of responding to the constantly changing moving average period (ATs) of the ship. Furthermore, when the value of the ship's moving average period (ATs) exceeds 34.0 seconds, the closing device (7v) with two sets of air communication pipes (7a, 7b) is forcibly closed to stop the movement of liquid in the A.R.T., thereby preventing the liquid in the A.R.T. from adversely affecting the ship's stability. This is the A.R.T. control method for a giant container ship according to claim 1.

5. In the parametric rolling phenomenon, in which the rolling angle increases when the pitching period of a ship becomes approximately half the rolling period of a ship, a program is constructed to predict whether or not the parametric rolling phenomenon will occur based on the rolling period of one oscillation (STs) and the average rolling period of the ship calculated in claim 3, and the predicted rolling period of the next oscillation. When it is predicted that parametric rolling will occur, the program notifies the operator of the occurrence of parametric rolling with a predetermined alarm buzzer, display, or voice message, and simultaneously selects and instantly executes the optimal control group for the A.R.T. for the new rolling period of the ship that occurs when the operator changes the ship's speed or course to avoid parametric rolling. This is the A.R.T. control method for a giant container ship according to claim 4.

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