US3322090A - Ship stabilization system - Google Patents

Ship stabilization system Download PDF

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Publication number
US3322090A
US3322090A US525426A US52542666A US3322090A US 3322090 A US3322090 A US 3322090A US 525426 A US525426 A US 525426A US 52542666 A US52542666 A US 52542666A US 3322090 A US3322090 A US 3322090A
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US
United States
Prior art keywords
tank
ship
plate
liquid
stabilizing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US525426A
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English (en)
Inventor
Frans V Pangalila
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
John J Mcmullen Associates Inc
Original Assignee
John J Mcmullen Associates Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by John J Mcmullen Associates Inc filed Critical John J Mcmullen Associates Inc
Priority to US525426A priority Critical patent/US3322090A/en
Priority to BE693325D priority patent/BE693325A/xx
Priority to NO166617A priority patent/NO121376B/no
Priority to GB4831/67A priority patent/GB1165605A/en
Priority to FR93463A priority patent/FR1511755A/fr
Priority to FI670326A priority patent/FI45734C/fi
Priority to SE1636/67A priority patent/SE343025B/xx
Priority to ES336483A priority patent/ES336483A1/es
Priority to DEM72667A priority patent/DE1274909B/de
Priority to NL6701844A priority patent/NL6701844A/xx
Application granted granted Critical
Publication of US3322090A publication Critical patent/US3322090A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
    • B63B39/02—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by displacement of masses
    • B63B39/03—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by displacement of masses by transferring liquids

Definitions

  • the present invention relates generally to ship stabilization and more particularly to an improved apparatus for applying a restoring moment to a ship by the movement of fluid within a tank.
  • Ballast tanks connected by piping and the like have been employed in order to transfer water in a manner to generate a restoring moment. Such systems encounter the difficulty of maintaining the proper phasing between the restoring moment and the motion imparted to the ship.
  • Efforts to employ volumes of air above liquid ballast for controlling the ballast have resulted in massive systems which were uncertain as well as excessively noisy in operation.
  • Efforts have also been directed to providing the ship with fixed or movable fin members extending from the hull beneath the waterline and adapted to generate restoring moments from the hydrodynamic forces on the fins accompanying the motion of the ship. In certain applications, controlled fins have been effective in controlling the roll of the ship but only at the expense of coupled-systems employing massive fin members and operating machinery.
  • the present invention is an improvement over the prior art in that it has built-in versatility while maintaining simplicity of design.
  • the ship stabilizing system includes a tank entirely passive in design and containing a quantity of fluid having a free surface.
  • the longitudinal axis of the tank is adapted to extend substantially horizontally and substantially at right angles to the axis about which the ship is to be stabilized.
  • a deflecting plate mounted within the tank so that it converges toward one tank wall while diverging from the oposite wall.
  • the plate is so oriented with respect to the walls parallel to the longitudinal axis of the tank, that an oblique angle is formed therebetween.
  • the fluid moves in part with a gradually decreasing width.
  • the effective longitudinal dimension of the tank is changed and, therefore, the frequency can change.
  • the fluid can flow back immediately without having to first reach one or the other tank ends.
  • the plate may assume a variety of shapes and constructions, all designed to efi'iciently adapt to varying conditions of the sea and best suit the needs of various ships.
  • other embodiments include smoother or hydrodynamically designed tanks, plates and/or the additions of guide plates in the tanks for smoother fiow of the stabilizing liquid.
  • Another embodiment includes pivotally mounting the plate to the tank bottom to adjust the oblique angle thereof.
  • the plate can either be adjusted to a position to provide a tank tuned for optimum stabilizing characteristics for a particular ship or weather condition encountered, or include a powered control and sensing mechanism to automatically adjust the oblique angle and tune the tank as the ship rolls.
  • a further embodiment includes cutting holes in the plate for controlling the tuning and damping effects of the plate.
  • the holes may be of a permanent nature, or their efiect may be controlled by adjusting their total area, or their total number as depicted in still further embodiments.
  • the tank is converted to a semi-active stabilizing system by including in addition to the deflecting plate, a powered water-moving device such as propellers immersed in the liquid driven at a constant speed, or to an active system wherein the speed of the propellers is controlled by a sensing mechanism.
  • a powered water-moving device such as propellers immersed in the liquid driven at a constant speed
  • an active system wherein the speed of the propellers is controlled by a sensing mechanism.
  • Another object of this invention is to provide a ship stabilizer employing essentially one internal component position within an enclosed tank containing a stabilizing liquid having a free surface.
  • a further object of this invention is to provide a passive ship stabilizer that can be converted to a semi-active stabilizing system that is relatively simple in design, and does not require complicated and cumbersome additional structure.
  • a yet further object of the present invention is to provide a passive ship stabilizer that can be converted to an active ship stabilizer of simple design that can automatically adjust and tune itself to ship roll.
  • Yet another object of this invention is to provide a passive ship stabilizer that is controllably tunable for various sea and weather conditions.
  • An even further object of the preseint invention is to provide a ship stabilizer that is self-contained and does not require major alterations in the ships structure for installation.
  • a still more obvious object of this invention is to provide a ship stabilizer which is compact and reasonably light in Weight.
  • FIG. 1 shows a plain view of the invention containing the tank and the oblique plate
  • FIGS. 3a, b and 0 show plan views of various modifications of the embodiment disclosed in FIG. 1;
  • FIGS. 4a, and b show a semi-active system by including an additional mechanism to control directional movement of the stabilizing liquid
  • FIG. 5 shows the plate having holes cut in it and a control mechanism for varying the area of said holes
  • FIG. 6 shows the plate with holes cut in it having a control mechanism for varying the number of holes exposed on said plate
  • FIG. 7 shows an active or semi-active embodiment of the invention.
  • a tank 10 has its longitudinal axis substantially horizontal and at right angles to the axis about which the ship is to be stabilized.
  • a deflecting plate 11 mounted within the tank partially filled with stabilizing liquid is a deflecting plate 11 secured vertically and disposed so that the end portions converge toward opposite tank walls, thereby forming an oblique angle therebetween.
  • the stabilizing liquid is channeled in a converging path formed by the plate and respective side wall and tank 10. In this manner, the liquid moves substantially in a circular path as indicated by the arrows.
  • FIG. 2a a side elevation of FIG. 1, taken along lines 2-2, shows plate 11 running the full height of tank 10. 7
  • the static level of stabilizing liquid 20 is slightly above or higher than the height of plate 11.
  • FIG. 2c shows a compromise between the two heights shown in FIGS. 2a and 2b.
  • plate 11 begins with a height approximately equal to the static level of the liquid at the end portions and gradually rises to the full depth of the tank at its mid-portion. In this way, the plate is tuned to provide spillover of the stabilizing liquid during more violent rolls of the ship, where more rapid cross-transfer of the liquid would most likely be needed.
  • FIGS. 3a and 3b show other configurations in which FIG. 1 may take.
  • the side of tank 10 assume the form of a parallelogram, while plate 11 runs approximately at right angles to the roll axis of the ship.
  • FIG. 3b may be incorporated either singly or in combination with any of the other embodiments disclosed herein.
  • FIG. 30 has oblique plate 11 mounted on a vertically disposed rotatable axle 12 located at its mid-portion for adjustment of the oblique angle.
  • the tuning and dampening effects of plate 11 and thus, the stabilizing effects of tank 10 may be controlled.
  • plate 11 is adjusted to an angle that provides optimum stabilizing characteristics for a particular ship or weather condition encountered.
  • the embodiment shown in FIG. 3c may be converted to a fully active stabilizing system that automatically controls or adjusts the oblique angle of plate 11 as a function of ship roll. This is done by switching in a sensing and control apparatus connected to axle 12 of plate 11.
  • a gyroscope 30 is connected to a transducer 32. Transducer. 32 puts out an electrical signal, the voltage of which is directly proportional to the magnitude of ship roll, to control a motor 36 through an amplifier 33 and switch 34. Switch 34 is used to disconnect or connect the sensing mechanism to the control mechanism.
  • Flap valves 40 and 42 are for-med from a plurality of horizontally mounted pivotal slats that open and close in only one direction. The slats overlap one another in single fashion when the valves are closed, and swing open in response to gravity and liquid force to present a plurality of ladder-like horizontal openings that have a dampening effect on stabilizing liquid 20 flowing therethrough.
  • Arrows 8 indicate the direction of roll experienced by tank 10 in FIG. 4a. Thus, when the ship rolls starboard,
  • flap valve 40 opens to allow free passage of the stabilizing liquid, while flap valve 42 located on the reverse side of plate 11 is forced closed by the combination of gravity and the liquid force' against it.
  • valve 42 will open while valve 40 will be held closed.
  • the liquid is forced to flow along one side of tank 10 during roll in one direction and flow along the other side of tank 10 during roll in the opposite direction, resulting in a circular path as indicated by arrows 6.
  • FIGURE 5 shows plate 11 having holes 16 cut therearea of the holes.
  • tuning and damping may be changed according to cargo carried or prolonged sea conditions.
  • FIGURE 6 shows a variation of FIG. 5.
  • control mechansim 18 operatively attached to shutters 16 slide on tracks 19 to block or unblock holes 21.
  • FIGS. 5 and 6 are passive in nature, i.e., the control mechanism preadjusted and tuned for optimum stabilization, they may be easily converted to fully active systems by switching in a sensing mechanism (not shown) similar to the one disclosed in FIG. 3c.
  • FIG. 7 a pair of propellers are inserted between respective side walls of tank 10 and plate 11.
  • the embodiment shown in FIG. 7 forms a semi-active stabilization system when propellers 50 and 52 are driven at a constant rate causing stabilizing liquid 20 to move in a circular path as described with reference to FIG. 4;
  • the embodiment in FIG. 7 may be converted into a fully active system by switching in, via switch 34, the sensing mechanism made up with gyroscope 30, transducer 32, amplifier 33, and similar in operationto the one disclosed in FIG. 3.
  • propellers 50 and 52 rotate as a function of the sensing mechanism which is controlled by the roll motion made by the ship, e.g., the greater the roll of the ship, the greater the speed of the propellers.
  • tank 10 operates by stabilizing liquid 20 in tank 10 moving in part'with'a gradually de-,
  • liquid 20 in tank may impart a stabilizing effect without having to flow to one end or the other of the tank.
  • the height of plate, 11 in tank 10 determines the dampening effect on the liquid which in turn determines the'magnitude of the stabilizing moment produced.
  • FIG. 2a greater dampening takes place which results in the production of a smaller stabilizing moment.
  • FIG. 2b the reverse occurs with a greater stabilizing moment produced because of the decrease in liquid dampening by plate 11, while in FIG. 2c, a combination of the two results.
  • FIG. 2c with more gentle rolls, a stabilizing effect similar to FIG. 2a is produced, while with more violent rolls, greater stabilizing moments similar in efiect to FIG. 2b are produced.
  • the type ship employed or personal preference will determine which plate (FIG. 2a, b or c) is used.
  • FIG. 4, and FIG. 7 with the sensing mechanism disconnected are examples of the ship stabilizing system according to the present invention operated in the semi-active mode.
  • a semi-active system is created when the ship roll in combination with flap valves 40 and 42 cause liquid 20 to be damped and flow in a circular motion in a manner described hereinabove.
  • the liquid can flow in a circular path around the oblique plate (as opposed to merely a to and for movement) without any detrimental eiTect to the systems operation.
  • simple one-way flap valves (40 and 42) can he and are utilized to aid in providing the required dampening effect on the liquid as it flows through the valves nozzle-like horizontal openings.
  • the tuning efiect of the valves in the system is described in the operation description directly below with regard to the semi-active mode of operation for the propellers of FIG. 7.
  • the propellers driven at a constant speed to maintain the liquid in a circular movement around the plate during all phases of ship motion form a semi-active stabilization system.
  • the structure of the present invention allows circular movement of the liquid, simply constructed propellers that operate at a constant speed requiring no speed adjustment mechanisms or reversing mechanisms are used.
  • the same tuning parameters apply that applied to the semi-active mode of operation.
  • the active mode of operation allows the stabilization system according to the present invention to be totally sensitive and responsive to the motions of the ship.
  • any roll motion by the ship is picked up by the sensing mechanism and is automatically reacted to by the respective control mechanisnis shown.
  • the angle of plate 11 is changed; in FIGS. 5 and 6 (sensing mechanism not shown) the area and number of holes in plate 11 are changed respectively; and in FIG. 7, the speed of the propellers changes.
  • the aforementioned changes produce either greater or less dampening on the stabilizing liquid which result in constant tuning of the system to stabilize against the initiating causes.
  • the passive and/or semi-active stabilization systems according to the present invention are easily and efliciently converted to fully active stabilization systems.
  • a passive stabilization system for a ship comprising a tank having a bottom, first and second sides, and two ends and having its longitudinal axis mounted transversely to the roll axis of said ship, said tank partially filled with a predetermined amount of liquid, an elongated upstanding plate means having a first and second end, said plate means mounted in said tank with its longitudinal dimension extending generally longitudinally in said tank and with said ends terminating short of said tank ends, said first end of said plate spaced closer to said first side of said tank than to said second side, and said second end of said plate spaced closer to said second side than to said first side so that an oblique angle is formed between said plate and either of said tank sides.
  • said plate means additionally includes as part of the structure thereof guide plate means hydrodynamically shaped and mounted within said tank for cooperating with said liquid.
  • said unidirectional liquid flow means comprises a plurality vertically spaced and horizontally displaced pivotal slats that swing open and closed in only one direction, said slats being in overlapping configuration in the closed position and forming a plurality of ladder-like horizontal openings in the open position.
  • the apparatus as claimed in claim 10' further i-n eluding means to automatically adjust said oblique angle as a function of ship roll.
  • said plate means includes a plurality of openings at both ends and spaced equidistant from the mid-line of said plate means.
  • the apparatus as claimed in claim 13 further including means for operating said shutter means in response to ship roll.
  • said plate means includes means for controlling the area of said openings.
  • the apparatus as claimed in claim 15 further including means for operating said area controlling means in response to ship roll.
  • the apparatus as claimed in claim 1 further includ! ing powered water-moving means at least partially immersed in said liquid to control the liquid movement in a predetermined manner.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Vibration Prevention Devices (AREA)
  • Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
  • Vehicle Body Suspensions (AREA)
  • Resistance Heating (AREA)
US525426A 1966-02-07 1966-02-07 Ship stabilization system Expired - Lifetime US3322090A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
US525426A US3322090A (en) 1966-02-07 1966-02-07 Ship stabilization system
BE693325D BE693325A (xx) 1966-02-07 1967-01-27
NO166617A NO121376B (xx) 1966-02-07 1967-01-30
GB4831/67A GB1165605A (en) 1966-02-07 1967-02-01 Anti-Roll Stabilizing Tanks for Ships.
FR93463A FR1511755A (fr) 1966-02-07 1967-02-02 Dispositif antiroulis pour navire
FI670326A FI45734C (fi) 1966-02-07 1967-02-04 Laivan stabilointijärjestelmä.
SE1636/67A SE343025B (xx) 1966-02-07 1967-02-06
ES336483A ES336483A1 (es) 1966-02-07 1967-02-06 Perfeccionamientos en la construccion de sistemas de esta- bilizacion para embarcaciones.
DEM72667A DE1274909B (de) 1966-02-07 1967-02-06 Stabilisierungssystem fuer Schiffe
NL6701844A NL6701844A (xx) 1966-02-07 1967-02-07

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US525426A US3322090A (en) 1966-02-07 1966-02-07 Ship stabilization system

Publications (1)

Publication Number Publication Date
US3322090A true US3322090A (en) 1967-05-30

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ID=24093206

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Application Number Title Priority Date Filing Date
US525426A Expired - Lifetime US3322090A (en) 1966-02-07 1966-02-07 Ship stabilization system

Country Status (10)

Country Link
US (1) US3322090A (xx)
BE (1) BE693325A (xx)
DE (1) DE1274909B (xx)
ES (1) ES336483A1 (xx)
FI (1) FI45734C (xx)
FR (1) FR1511755A (xx)
GB (1) GB1165605A (xx)
NL (1) NL6701844A (xx)
NO (1) NO121376B (xx)
SE (1) SE343025B (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3559946A (en) * 1968-11-19 1971-02-02 Bell Aerospace Corp Bond for metal to metal joints
US4084534A (en) * 1974-05-28 1978-04-18 Hydroconic Limited Roll damping tanks for ships and like vehicles
WO2016042235A1 (fr) * 2014-09-18 2016-03-24 Geps Techno Dispositif et procede pour structure soumise a oscillations

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111976911B (zh) * 2020-07-15 2021-04-06 上海海事大学 航海船体平衡装置及其安装方法
CN112249254B (zh) * 2020-10-22 2022-05-27 青岛科技大学 一种用于液货舱减少自由液面并回收机械能的装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3054373A (en) * 1960-02-16 1962-09-18 Mcmullen Ass John J Flume type heeling tank stabilizer

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3559946A (en) * 1968-11-19 1971-02-02 Bell Aerospace Corp Bond for metal to metal joints
US4084534A (en) * 1974-05-28 1978-04-18 Hydroconic Limited Roll damping tanks for ships and like vehicles
WO2016042235A1 (fr) * 2014-09-18 2016-03-24 Geps Techno Dispositif et procede pour structure soumise a oscillations
CN107002629A (zh) * 2014-09-18 2017-08-01 Geps泰克诺公司 用于经受摆动运动的结构的装置和方法
RU2689640C2 (ru) * 2014-09-18 2019-05-28 Джепс Текно Способ и устройство для конструкции, подверженной качке
US10414471B2 (en) * 2014-09-18 2019-09-17 Geps Techno Device and method for a structure subject to oscillating movements
CN107002629B (zh) * 2014-09-18 2019-11-05 Geps泰克诺公司 用于经受摆动运动的结构的装置和方法

Also Published As

Publication number Publication date
FI45734B (xx) 1972-05-31
NO121376B (xx) 1971-02-15
SE343025B (xx) 1972-02-28
NL6701844A (xx) 1967-08-08
BE693325A (xx) 1967-07-27
DE1274909B (de) 1968-08-08
GB1165605A (en) 1969-10-01
ES336483A1 (es) 1968-04-01
FR1511755A (fr) 1968-02-02
FI45734C (fi) 1972-09-11

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