WO1987007876A1 - Procede et appareil pour determiner la charge d'un navire - Google Patents

Procede et appareil pour determiner la charge d'un navire Download PDF

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Publication number
WO1987007876A1
WO1987007876A1 PCT/EP1987/000319 EP8700319W WO8707876A1 WO 1987007876 A1 WO1987007876 A1 WO 1987007876A1 EP 8700319 W EP8700319 W EP 8700319W WO 8707876 A1 WO8707876 A1 WO 8707876A1
Authority
WO
WIPO (PCT)
Prior art keywords
vessel
water
pressure
sensors
keel
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.)
Ceased
Application number
PCT/EP1987/000319
Other languages
English (en)
Inventor
Gustav Rudolph Grob
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.)
INTERCASE HOLDINGS SA
Original Assignee
INTERCASE HOLDINGS SA
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
Priority claimed from GB868615110A external-priority patent/GB8615110D0/en
Application filed by INTERCASE HOLDINGS SA filed Critical INTERCASE HOLDINGS SA
Publication of WO1987007876A1 publication Critical patent/WO1987007876A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • B63B39/12—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude for indicating draught or load

Definitions

  • THE PRESENT INVENTION relates to a method and apparatus for ascertaining details of the load in a ship.
  • the position of the water line relative to the hull of the ship is initially observed, and then the cargo is loaded on to the ship.
  • the level of the water line relative to the hull is again observed, and by perform ⁇ ing a calculation based on the two observed relative ,j- levels of the water line it is possible to calculate the depth by which the ship has sunk in the water, thus enabling the mass of water displaced to be determined.
  • the internal volumetric method can really only be utilised with cargos that are fluid.
  • the cargo is caused to flow into tanks or containers of a known volume.
  • dipsticks or equivalent techniques it is possible to measure the volume of cargo within each tank or container, and by performing an appropriate calculation the weight of the cargo can be calculated.
  • a further problem that exists with a conven ⁇ tional ship is adjusting the trim of the ship.
  • the weight of the ship must be evenly balanced about the mid point of the keel of the ship, both in a port-to- starboard sense and in a for-to-aft sense if the ship is to float evenly in the water. If there is an imbalance in the port-to-starboard sense the ship will list, whereas if there is an imbalance in the for-to-aft sense the stern of the ship will be lower or higher in the water than the bow, and thus in both cases the ship will not be on an even keel.
  • a method of ascertaining details of the incremental change in the load in a vessel comprising the steps of determining the pressure exerted on the hull of the vessel by the water at pre- determined positions on the hull both before and after the loading or unloading of the vessel and calculating, from said pressures, the details relating to the differ ⁇ ential change in the weight or mass of water displaced by the vessel.
  • the method includes the steps of determining the density of the water in which the vessel is floating to faciliate in the performance of the nec ⁇ essary calculation.
  • the method includes the step of determining the atmospheric pressure, and utilising the measured value in the calculation to correct errors caused by fluctuations in atmospheric pressure.
  • the method includes the steps of determining details of any list or for-to-aft inclin ⁇ ation of the vessel.
  • the method may include the add ⁇ itional step of automatically adjusting the ballasting of the vessel in order to place the vessel on a substan ⁇ tially even keel.
  • the method includes the steps of determining the sag or hog of the vessel.
  • a vessel provided with a plurality of pressure sensors adapted to sense the pressure of water acting at predetermined points on the hull of the vessel, the pressure sensors being associated with a calculation means adapted to calculate the differential change in weight of water displaced by the vessel caused by the loading or unloading of the vessel.
  • the pressure sensors comprise force transducers of the oscillating wire or gyroscopic type.
  • Such transducers may have an accuracy or repeat ⁇ ability of better than 0.1/6.
  • At least two sensors are spaced apart in a direction transverse to the axis defined by the keel of the vessel and at least two transducers are spaced apart in a direction parallel to the axis defined by the keel of the vessel.
  • At least four transducers are provided, two transducers being mounted in a region of the stern of the vessel at symmetric positions on opposite sides of the keel of a vessel and two trans ⁇ ducers being located in the region of the bow of the vessel at symmetric positions on opposite sides of the keel of the vessel.
  • At least three sensors are provided, spaced apart in a direction defined by the keel. Such sensors enable the sag or hog of the vessel to be determined.
  • the calculation means are assoc ⁇ iated with means for automatically adjusting the ballasting of the vessel.
  • means are provided for deter ⁇ mining the density of the water in which the vessel is situated and to supply the determined value to the calculating means.
  • said density sensing means com- prise two sensors spaced apart vertically, and thus adapted to sense the pressure of water at known differ ⁇ ential depths below the water line.
  • At least one sensor is adapted to measure the force exerted thereon by the water in which the vessel is immersed, the sensor being associated with a float of known volume, means being provided to retain the float out of contact with the sensor, said retaining means being adapted to be released to permit the float subsequently to exert an upthrust on the sensor, so that the weight of water displaced by the float can be calculated, enabling the density of the water to be calculated.
  • the pressure sensors may be directly mounted on the hull of the vessel or may be suspended over the side of the vessel, for example on invar wires.
  • This invention also relates to a pressure sensor for sensing the pressure applied thereto by water, the pressure sensor comprising a transducer, means for applying water pressure to the transducer and a float member which can apply an upthrust to the trans ⁇ ducer, means being provided releasably to retain the float in a position spaced from the transducer.
  • FIGURE 1 is a diagrammatic plan view of a ship provided with pressure sensors in accordance with the invention
  • FIGURE 2 is a rear view of the ship, when unloaded
  • FIGURE 3 is a rear view of the ship when loaded
  • FIGURE is a rear view of the ship when loaded, whilst listing,
  • FIGURE 5 is a side view of the ship with the load unevenly spread in the for-to-aft direction
  • FIGURE 6 is a rear view of another embodiment of a ship in accordance with the invention.
  • FIGURE 7 is a diagrammatic cross sectional view of one embodiment of a pressure sensing transducer.
  • FIGURE 8 is a side view, corresponding to Figure 5, showing an alternative embodiment of the invention.
  • Figure 1 illustrates the hull 1 of a ship.
  • the hull is provided with a plurality of pressure sensors mounted on the undersurface thereof.
  • Two pressure sensors 2, 3 are provided adjacent the stern of the vessel.
  • the two pressure sensors are located at symmetric positions about the line defined by the keel of the hull. Thus the sensors are equi-spaced from the keel, one being on the port side of the vessel and the other being on the starboard side of the vessel.
  • Two further pressure sensors 4, 5 are provided located adjacent the bow of the vessel.
  • Another two pressure sensors 6, 7 are located amid ships of the vessel. In each case the pressure sensors are sym ⁇ metrically located on either side of the keel, the sensors being equi-spaced from the keel.
  • the sensors are adapted to sense the hydro ⁇ static pressure exerted on them by the water in which the vessel is floating. When the pressure is sensed while the ship is in a static condition various items of information can be calculated, as will be described.
  • the sensors should be arranged so that at least two sensors are spaced apart in a direction transversely to the keel of the vessel, to assist in detecting list of the vessel, and also so that at least two sensors are spaced apart in the for-to-aft direction of the vessel.
  • two sensors may be provided adjacent the stern of the vessel, corresponding to the illustrated sensors 2 and 3, and a single further sensor may be provided adjacent the bow of the vessel.
  • Each sensor is a sensor that is able very accurately to measure the pressure applied to the sensor by the water in which the vessel is floating. It is thus possible to utilise, as the sensors, virtually any high precision pressure transducer that will provide an appropriate signal.
  • the first is a pressure transducer of the resonant wire type in which the pressure applied to the transducer causes the tension in a vibrating wire to be varied. As the tension in the wire varies, so the resonant frequency of the wire varies. The wire is caused to vibrate and the transducer senses the changing resonant frequency, and is adapted to provide an appropriate output signal in- dicative of the pressure applied to the transducer.
  • Another type of transducer that may be considered appropriate is a gyroscopic transducer in which the pressure applied to the transducer is caused to move a pivot point of a gyroscope causing the gyroscope to precess. The precession of the transducer is monitored and the transducer provides an appropriate output signal.
  • Other pressure transducers may be found to be appropriate.
  • the ship floats in the water with the water line W at a distance h above the level of the keel of the vessel.
  • the pressure transducers 2, 3 thus sense a pressure determined by the height h and the density of the water.
  • the pressure can be con ⁇ sidered to be proportional to the weight of water dis- placed which will, of course, be equal to the total weight of the vessel.
  • the vessel When the cargo is placed in the vessel the vessel will effectively sink in the water, as illus- trated in Figure 3.
  • the water line W will thus be much further from the keel of the vessel, and the pressure sensors 2, 3 will be a depth hi beneath the water line W.
  • the pressure sensors will thus sense a greater pressure which again can be considered to be propor- tional to the weight of water displaced by the vessel, which is now equivalent to the weight of the vessel added to the weight of the cargo. It is thus possible to determine the weight of the cargo by recording the pressures experienced under the two conditions described above and performing an appropriate calculation.
  • FIG. 4 illustrates the position that exists when the cargo has been unevenly loaded about the keel of the vessel.
  • the whole vessel is leaning or listing to one side.
  • the pressure sensor 2 is a distance h3 beneath the water line W whereas the pressure sensor 3 is a distance h4 beneath the water line.
  • each pressure sensor will provide a pressure reading effectively indicative of the depth of that pressure sensor beneath the water line W.
  • Figure 5 illustrates the vessel with the cargo unevenly distributed in a fore-to-aft direction and it can be seen that the pressure sensor 2 provided adjacent the stern of the vessel is much lower in the water than the pressure sensor k located adjacent the bow of the vessel.
  • the computer would, of course, be programmed to take into account the effect of the precise configur ⁇ ation of the submerged part of the hull since, in a real
  • the precise configuration of the hull can readily perform the necessary calculations to provide extremely accurate information, especially if any "sag” or "hog” is taken into account.
  • the memory of the computer will contain a calibration chart for the
  • the computer may be c adapted to operate an automatic ballasting system, the computer thus controlling the pumping of ballast into and out of ballast tanks present in the vessel, to provide the vessel with perfect trim.
  • the sensors used measure pressure very accurately.
  • the pressure under the surface of water does vary with variations in atmospheric pressure over the water.
  • a further transducer 8 may be provided
  • the pressure sensor 10 is mounted in an aperture formed in the hull 11 of the vessel.
  • the pressure sensor consists of a housing 12 defining flanges 13, 14 that are secured to the vessel and defining an inlet 15 to permit water to enter the housing 12 from the exterior of the vessel.
  • a flexible membrane 16 is provided which extends across the housing 12 and a connecting rod 17 connected to the centre of the membrane extends upwardly into contact with a force. transducer 18 of the type described above. Water entering the housing through the inlet 15 will apply an upthrust P (as indicated by the arrows 19) to 5 the membrane 16, resulting in a force Fo exerted in an upward direction on the force transducer.
  • the force transducer can thus generate a signal which is represen ⁇ tative of the pressure applied to the membrane by the water.
  • a buoyant float member 20 is provided which is located beneath the membrane.
  • the float has a volume
  • Vb Depending from the float is a metallic arm 21 which is located within the coils of an electromagnet 22.
  • the differences between the two pressures being indicative of the upthrust provided by the float member 20. Since the float member 20 is of a known volume V. it is thus possible to calculate the density of the water in which the vessel is floating.
  • FIG 8 is a view corresponding to Figure 5 illustrating an alternative embodiment of the invention.
  • the transducers are firmly fixed to the hull of a vessel 1
  • the vessel 1 is provided with a plurality of pressure sensors 32, 34, 36 which are suspended from the side of the vessel by means of wires 37 which may be made of INVAR, or some other material which does not expand and contract due to changes of temperature.
  • wires 37 which may be made of INVAR, or some other material which does not expand and contract due to changes of temperature.
  • at least one of the wires may be provided with two pressure sensors, such as the pressure sensors 32, 39» to enable the density of the water to be determined, as described above.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

Un navire (1) est équipé de capteurs de pression (2, 3, 4, 5, 6, 7) permettant de détecter la pression d'eau exercée en divers points de la coque. A mesure que le navire est chargé ou déchargé, les variations de pression sont notées et un dispositif de calcul, tel qu'un ordinateur, calcule la différence dans le poids total de l'eau déplacée par le navire, c'est-à-dire le poids de la cargaison qui a été chargée ou déchargée.
PCT/EP1987/000319 1986-06-20 1987-06-19 Procede et appareil pour determiner la charge d'un navire Ceased WO1987007876A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8615110 1986-06-20
GB868615110A GB8615110D0 (en) 1985-06-19 1986-06-20 Ships

Publications (1)

Publication Number Publication Date
WO1987007876A1 true WO1987007876A1 (fr) 1987-12-30

Family

ID=10599818

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1987/000319 Ceased WO1987007876A1 (fr) 1986-06-20 1987-06-19 Procede et appareil pour determiner la charge d'un navire

Country Status (1)

Country Link
WO (1) WO1987007876A1 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4226773A1 (de) * 1992-08-13 1994-02-17 Deutsche Aerospace Verfahren zur Ermittlung der Trimmung eines Schiffes
DE4318691C1 (de) * 1993-04-28 1994-04-21 Helmut Dipl Ing Borcherdt Wasserfahrzeug
EP0774409A1 (fr) * 1995-09-01 1997-05-21 Aerometrics, Inc. Méthode et appareil pour déterminer l'inclinaison et le tirant d'eau d'une embarcation flottante pour permettre le chargement automatique de cette embarcation
DE19913165A1 (de) * 1999-03-24 2000-09-28 Ffg Flensburger Fahrzeugbau Gm Meßvorrichtung für die Ladung von Schiffen
ES2160035A1 (es) * 1999-02-23 2001-10-16 Univ Cadiz Procedimiento automatizado para el calculo en tiempo real del peso de la arena transportada en un ganguil o draga autoportante.
CN102530198A (zh) * 2012-02-01 2012-07-04 上海海事大学 基于超声波技术的船舶吃水实时检测系统及其检测方法
ES2406179A1 (es) * 2011-12-01 2013-06-05 Sgs Tecnos, S.A.U. Dispositivo medidor de calados en buques por ultrasonidos.
WO2014067971A1 (fr) * 2012-10-31 2014-05-08 Guian Marc Dispositif de transmission de donnees de geolocalisation et de mesure, procede associe
CN119394404A (zh) * 2025-01-06 2025-02-07 成都兰石低温科技有限公司 一种超低温磁性液位计

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB554435A (en) * 1940-05-20 1943-07-05 Robert Milton Kristal Improvements in method and means for determining hydrostatic data for ships
GB939326A (en) * 1961-07-27 1963-10-09 Takashi Isobe An apparatus for determining the weight of cargo on board a ship
US3110181A (en) * 1958-08-28 1963-11-12 Calamaras George System for measurement of bulk cargo on vessels
GB1105274A (en) * 1965-01-20 1968-03-06 Mineral Technologisch Inst Marine vessel loading rate meter
FR2250668A1 (en) * 1973-11-08 1975-06-06 Cermat Installation for measuring a ship's draught - has water pressure transducers and a digital readout system
FR2569157A1 (fr) * 1984-08-14 1986-02-21 Naidenov Evgeny Systeme de controle automatise de l'assiette et de la stabilite d'un navire

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB554435A (en) * 1940-05-20 1943-07-05 Robert Milton Kristal Improvements in method and means for determining hydrostatic data for ships
US3110181A (en) * 1958-08-28 1963-11-12 Calamaras George System for measurement of bulk cargo on vessels
GB939326A (en) * 1961-07-27 1963-10-09 Takashi Isobe An apparatus for determining the weight of cargo on board a ship
GB1105274A (en) * 1965-01-20 1968-03-06 Mineral Technologisch Inst Marine vessel loading rate meter
FR2250668A1 (en) * 1973-11-08 1975-06-06 Cermat Installation for measuring a ship's draught - has water pressure transducers and a digital readout system
FR2569157A1 (fr) * 1984-08-14 1986-02-21 Naidenov Evgeny Systeme de controle automatise de l'assiette et de la stabilite d'un navire

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4226773A1 (de) * 1992-08-13 1994-02-17 Deutsche Aerospace Verfahren zur Ermittlung der Trimmung eines Schiffes
DE4318691C1 (de) * 1993-04-28 1994-04-21 Helmut Dipl Ing Borcherdt Wasserfahrzeug
EP0774409A1 (fr) * 1995-09-01 1997-05-21 Aerometrics, Inc. Méthode et appareil pour déterminer l'inclinaison et le tirant d'eau d'une embarcation flottante pour permettre le chargement automatique de cette embarcation
ES2160035A1 (es) * 1999-02-23 2001-10-16 Univ Cadiz Procedimiento automatizado para el calculo en tiempo real del peso de la arena transportada en un ganguil o draga autoportante.
DE19913165A1 (de) * 1999-03-24 2000-09-28 Ffg Flensburger Fahrzeugbau Gm Meßvorrichtung für die Ladung von Schiffen
ES2406179A1 (es) * 2011-12-01 2013-06-05 Sgs Tecnos, S.A.U. Dispositivo medidor de calados en buques por ultrasonidos.
CN102530198A (zh) * 2012-02-01 2012-07-04 上海海事大学 基于超声波技术的船舶吃水实时检测系统及其检测方法
WO2014067971A1 (fr) * 2012-10-31 2014-05-08 Guian Marc Dispositif de transmission de donnees de geolocalisation et de mesure, procede associe
CN104838285A (zh) * 2012-10-31 2015-08-12 马克·吉昂 用于传输地理定位和测量数据的设备以及相关联的方法
CN119394404A (zh) * 2025-01-06 2025-02-07 成都兰石低温科技有限公司 一种超低温磁性液位计

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