Ship inclination test device and working method

Abstract

The invention relates to the technical field of ship production tests, and particularly discloses a ship inclination test device and a working method.The ship inclination test device comprises a test rack and a plumb bob tracking and positioning mechanism, a suspension wire mounting block is mounted at the center of the upper portion of the test rack, a plumb bob is mounted on the suspension wire mounting block, and the plumb bob tracking and positioning mechanism is mounted at the bottom of the test rack; the plummet tracking and positioning mechanism comprises a swing ball and a driving structure, the swing ball is movably mounted on a limiting seat, an electromagnet is mounted on the upper portion of the swing ball and adsorbs and positions the swing ball, and the limiting seat moves through the driving structure to control the swing ball to find the position right opposite to the plummet; a height fine-adjustment frame structure is adopted, the upper swing point of the plumb bob is located on the design center of a ship, the bottom stabilizes the position of the plumb bob through infrared tracking and an electromagnet, reading of data such as distance and angle is more accurate, the technology of initial center stabilizing height is more accurate, and the accuracy and efficiency of a ship inclination test are improved.

Description

Technical Field

[0001] This invention relates to the field of ship production testing technology, specifically to a ship tilting test device and its working method. Background Technology

[0002] A ship inclining test is an analytical method that measures the ship's actual weight and center of gravity height after completion by tilting, used to verify whether the ship's stability meets safety standards. This method is stipulated by the International Maritime Organization and national classification societies, and must be conducted under conditions of empty ship, wind force less than level 2, and calm waters. It is mainly applicable to newly built ships and ships with compromised or questionable stability.

[0003] During the ship design phase, the weight and center of gravity of the empty ship are typically calculated using a distribution calculation method. However, this often differs from the actual weight and center of gravity after the ship is built. Therefore, ship inclining tests are conducted after construction to accurately determine the ship's weight and center of gravity. Existing ship inclining tests suffer from two main problems: firstly, the measuring device cannot be adjusted in height, leading to discrepancies between the designed center of gravity and the actual measurement; secondly, the stability of the plumb bob is insufficient, causing errors in the inclining angle readings and resulting in deviations in later calculations. Therefore, it is necessary to design a ship inclining test device and its operating method to address the problems of deviations in distance and angle measurements and the inability to effectively verify later calculations in existing ship inclining tests. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of this invention is to provide a ship tilting test device and its working method.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a ship tilting test device, including a test frame and a plumb bob tracking and positioning mechanism. A plumb bob is installed at the upper center of the test frame. A plumb bob is installed on the plumb bob mounting block. A plumb bob tracking and positioning mechanism is installed at the bottom of the test frame. The plumb bob tracking and positioning mechanism includes a swing ball and a drive structure. The swing ball is movably mounted on a limiting seat. An electromagnet block is installed on the upper part of the swing ball. The electromagnet block attracts and positions the swing ball. The limiting seat moves through the drive structure to control the swing ball to find the position directly opposite the plumb bob.

[0006] Specifically, the test frame includes a top plate, adjusting rods, adjusting sleeves, and a base. Four adjusting rods are installed at the four corners of the bottom of the top plate. A level is installed on the top plate. A plumb line mounting block is installed at the center of the top plate. The plumb line is mounted on the plumb line mounting block via a plumb line. An angle scale plate is installed at the bottom of the top plate to observe the swing angle of the plumb line and the plumb line.

[0007] Specifically, the adjusting rod is inserted into the adjusting sleeve. The lower part of the adjusting rod has a through spring hole. A partition is fixedly installed in the middle of the spring hole. Springs are installed on both sides of the partition. The other end of the spring is fixedly connected to a baffle. The baffle blocks the spring from being located inside the spring hole. A locking pin is fixedly connected to the outer side of the baffle. The locking pin passes through the spring hole under the action of the spring force. Multiple locking holes are evenly and symmetrically arranged on the adjusting sleeve. The locking pin passes through the locking holes to connect the adjusting rod and the adjusting sleeve to each other.

[0008] Specifically, the bottom of the adjusting sleeve is fixedly connected to the base, which adopts a box structure with an open top. A distance scale plate is fixedly installed on the upper part of the base, and the distance scale plate is used to observe the movement distance of the suspension line and the plumb line.

[0009] Specifically, a drive structure is installed on the bottom inner side of the base's housing structure. The drive structure includes a drive motor and a drive box. Both the drive motor and the drive box are installed at the bottom of the base. The motor shaft of the drive motor is connected to a lead screw. The lead screw is installed in the drive box through a bearing seat. A limiting groove is provided on the top of the drive box. A limiting seat slides through the limiting groove. A threaded nut is fixedly connected to the bottom of the limiting seat. A threaded hole is provided in the middle of the threaded nut. The threaded nut is threadedly connected to the lead screw through the threaded hole. The drive motor controls the limiting seat to move along the limiting groove.

[0010] Specifically, the upper part of the limiting seat is hemispherical, and a swing ball is rotatably installed on the limiting seat via a swing shaft. The swing shaft is installed facing the front and rear directions of the ship. The swing ball tilts with the left and right tilt of the ship. A spherical counterweight is set at the bottom of the inner side of the swing ball. An infrared receiver is installed at the center of the top of the swing ball. An infrared transmitter is set at the bottom of the plumb bob. Both the infrared receiver and the infrared transmitter are powered by built-in batteries and have wireless transmission modules.

[0011] A method for operating a ship tilting test device includes the following steps:

[0012] S1. The movable weight used in the tilt test is a cast iron block. The cast iron blocks are divided into four groups and stacked in designated positions on the deck. Each group has an equal weight.

[0013] S2. Before the test begins, install the test frame and record the data. Pour water into the box structure of the base to ensure the stability of the test frame. Adjust the height of the top plate by locking pins so that the height of the top plate is at the design center height of the ship. Observe the horizontal center of the level on the test frame. Control the length of the plumb line so that the plumb bob is 5-10cm away from the swing ball. Turn on the electromagnet and the electromagnet will attract the plumb bob to control its stability. Then turn off the electromagnet.

[0014] S3. The position of the moving weight is adjusted, causing the plumb bob to swing. The drive motor controls the swing ball to locate the plumb bob. After the infrared transmitter on the plumb bob pairs and identifies with the infrared receiver on the swing ball, the drive motor stops, and the electromagnet is energized again to maintain the stability of the plumb bob. The swing angle of the plumb bob is then read from the angle scale and recorded as the tilt angle α generated by the ship. The ship's heel moment M is then calculated. Q : and the restoring moment M of the ship after heeling at an angle α. h : ;

[0015] S4. Since the ship is in equilibrium when it heels to angle a, according to the principle of moment balance, M Q =M h ,but ,Right now The initial metacenter height is calculated as follows: or .

[0016] Specifically, the cast iron blocks in step S1 are arranged to generate a sufficient tilting moment to cause the ship to have a heel angle of 2° to 4°. The total amount of cast iron blocks is 1 to 2% of the ship's displacement, and the moving distance L is 3 / 4 of the ship's beam.

[0017] Specifically, the recorded data in step S2 includes:

[0018] 1) Ship draft: Read the draft at the bow, midships and stern of the ship according to the draft gauge, and calculate the average value.

[0019] 2) The ship's insufficient weight, excess weight, and center of gravity coordinates when the ship is empty;

[0020] 3) The weight and placement of the moving objects, and the moving distance L for each group of moving objects;

[0021] 4) The position of the plumb bob, the length of the suspension line, and the initial reading;

[0022] 5) The specific gravity of water is used to calculate the amount of water discharged.

[0023] Specifically, P is the weight of the moving object; L is the lateral movement distance of the moving object; D is the ship's displacement; h is the initial metacenter height; k is the distance the plumb bob moves as read from the distance scale; and l is the vertical distance from the suspension point M of the plumb bob to the distance scale.

[0024] The present invention has the following beneficial effects:

[0025] The ship tilting test device and working method designed in this invention adopts a highly fine-tuning frame structure, so that the upper swing point of the plumb bob is located on the ship's designed center of gravity. The bottom of the plumb bob is stabilized by infrared tracking and electromagnets, which makes the reading of data such as distance and angle more accurate and the initial center of gravity height more accurate, thereby improving the accuracy and efficiency of ship tilting tests. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a ship tilting test device.

[0027] Figure 2 This is a schematic diagram of the connection structure between the adjusting rod and the adjusting sleeve.

[0028] Figure 3 This is a schematic diagram of the structure of a swing ball mounted on a limiting seat.

[0029] Figure 4 for Figure 3 Sectional view along the AA direction.

[0030] Figure 5 This is a schematic diagram of the tilting test device for ships in tilting mode.

[0031] Figure 6 Model calculation structure for ship inclining test apparatus Figure 1 .

[0032] Figure 7 Model calculation structure for ship inclining test apparatus Figure 2 .

[0033] Figure 8 This is a diagram showing the arrangement of four sets of moving weights on the ship's deck during a ship tilting test.

[0034] In the diagram: 1-Plumb bob; 2-Suspension line; 3-Suspension line mounting block; 4-Test frame; 4.1-Top plate; 4.2-Adjusting rod; 4.3-Adjusting sleeve; 4.4-Base; 4.5-Locking pin; 4.6-Locking hole; 4.7-Spring; 4.8-Baffle; 4.9-Baffle; 4.10-Level; 4.11-Distance scale plate; 5-Plumb bob tracking and positioning mechanism; 5.1-Swing ball; 5.2-Swing shaft; 5.3-Limit seat; 5.4-Threaded nut seat; 5.5-Threaded hole; 5.6-Electromagnet block; 5.7-Infrared receiver; 5.8-Drive motor; 5.9-Drive box; 5.10-Spherical counterweight; 6-Angle scale plate. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] like Figures 1-5 As shown, a ship tilting test device includes a plumb bob 1, a test frame 4, and a plumb bob tracking and positioning mechanism 5. A plumb bob 1 is installed on the upper center position of the test frame 4. The test frame 4 includes a top plate 4.1, adjusting rods 4.2, adjusting sleeves 4.3, and a base 4.4. Four adjusting rods 4.2 are installed at the four corners of the bottom of the top plate 4.1. A level 4.10 is installed on the top plate 4.1. The plumb bob 1 is installed on the plumb bob 3 at the center position of the top plate 4.1. The plumb bob 1 is installed on the plumb bob 3 via a plumb line 2. An angle scale plate 6 is installed at the bottom of the top plate 4.1. The angle scale plate 6 observes the swing angle of the plumb line 2 and the plumb bob 1.

[0037] The adjusting rod is inserted into the adjusting sleeve. The lower part of the adjusting rod has a through spring hole. A partition is fixedly installed in the middle of the spring hole. Springs are installed on both sides of the partition. The other end of the spring is fixedly connected to a baffle. The baffle prevents the spring from being located inside the spring hole. A locking pin is fixedly connected to the outer side of the baffle. The locking pin passes through the spring hole under the action of the spring force. Multiple locking holes are evenly and symmetrically arranged on the adjusting sleeve. The locking pin passes through the locking holes to connect the adjusting rod and the adjusting sleeve.

[0038] The bottom of the adjusting sleeve 4.3 is fixedly connected to the base 4.4. The base 4.4 adopts a box structure with an open top. A distance scale plate 4.11 is fixedly installed on the upper part of the base 4.4. The distance scale plate 4.11 is used to observe the movement distance of the suspension line 2 and the plumb bob 1.

[0039] The bottom of the test frame 4 is equipped with a plumb bob tracking and positioning mechanism 5. The plumb bob tracking and positioning mechanism 5 includes a swing ball 5.1 and a drive structure. The swing ball 5.1 is movably mounted on the limit seat 5.3. An electromagnet block 5.6 is installed on the upper part of the swing ball 5.1. The electromagnet block 5.6 attracts and positions the swing ball 5.1. The limit seat 5.3 moves and controls the swing ball 5.1 to find the position directly opposite the plumb bob 1 through the movement of the drive structure.

[0040] The drive structure is installed on the bottom inner side of the housing structure of the base 4.4. The drive structure includes a drive motor 5.8 and a drive box 5.9. Both the drive motor 5.8 and the drive box 5.9 are installed at the bottom of the base 4.4. The motor shaft of the drive motor 5.8 is connected to a lead screw. The lead screw is installed in the drive box 5.9 through a bearing seat. The top of the drive box 5.9 is provided with a limiting groove. The limiting seat 5.3 slides through the limiting groove. The bottom of the limiting seat 5.3 is fixedly connected to a threaded nut 5.4. The threaded nut 5.4 is provided with a threaded hole 5.5 in the middle. The threaded nut 5.4 is threadedly connected to the lead screw through the threaded hole 5.5. The drive motor 5.8 controls the limiting seat 5.3 to move along the limiting groove.

[0041] The upper part of the limiting seat 5.3 is hemispherical. The swing ball 5.1 is rotatably mounted on the limiting seat 5.3 via the swing shaft 5.2. The swing shaft 5.2 is installed facing the fore-and-aft direction of the ship. The swing ball 5.1 tilts with the ship tilting left and right. A spherical counterweight 5.10 is set on the bottom inner side of the swing ball 5.1. An infrared receiver 5.7 is installed at the top center of the swing ball 5.1. An infrared transmitter is correspondingly set at the bottom of the plumb bob 1. Both the infrared receiver and the infrared transmitter are powered by built-in batteries and have wireless transmission modules.

[0042] A method for operating a ship tilting test device includes the following steps:

[0043] 1. The moving weight used in the inclining test is cast iron blocks, which are divided into four groups and stacked in designated locations on the deck, with each group having an equal weight. The cast iron blocks are arranged to generate a sufficient inclining moment to produce a heel angle of 2° to 4°. The total amount of cast iron blocks is 1 to 2% of the ship's displacement, and the moving distance L is 3 / 4 of the ship's beam.

[0044] 2. Before the test begins, install the test frame 4 and record the data. Pour water into the box structure of the base 4.4 to ensure the stability of the test frame 4. Adjust the height of the top plate 4.1 by using the locking pin 4.5 so that the height of the top plate 4.1 is at the design center height of the ship. Observe that the level 4.10 on the test frame 4 is horizontally centered. Control the length of the suspension line 2 so that the plumb bob 1 is 5~10cm away from the swing ball 5.1. Turn on the electromagnet 5.6 and the electromagnet 5.6 will attract the plumb bob 1 to control its stability. Then turn off the electromagnet 5.6.

[0045] The recorded data includes:

[0046] 1) Ship draft: Read the draft at the bow, midships and stern of the ship according to the draft gauge, and calculate the average value.

[0047] 2) The ship's insufficient weight, excess weight, and center of gravity coordinates when the ship is empty;

[0048] 3) The weight and placement of the moving objects, and the moving distance L for each group of moving objects;

[0049] 4) The position of the plumb bob, the length of the suspension line, and the initial reading;

[0050] 5) The specific gravity of water is used to calculate the amount of water discharged.

[0051] 3. Move the weight to a new position. The plumb bob 1 swings. The drive motor 5.8 controls the swing ball to find the position of the plumb bob 1. After the infrared transmitter on the plumb bob 1 is paired and identified with the infrared receiver on the swing ball 5.1, the drive motor 5.8 stops, the electromagnet block 5.6 is powered on again to keep the plumb bob 1 stable, and then the swing angle of the plumb bob is read through the angle scale plate 6.

[0052] like Figures 6-7 As shown, when the ship is floating upright on the waterline WL, its displacement is D. If the movable weight P at point A on the ship is moved laterally a distance L to A1, the ship will tilt at an angle α and float on the new waterline W1L1, which is recorded as the tilt angle α. Calculate the ship's heeling moment M. Q : and the restoring moment M of the ship after heeling at an angle α. h : ;

[0053] 4. Since the ship is in equilibrium when it heels to angle 'a', according to the principle of moment balance, M Q =M h ,but ,Right now The initial metacenter height is calculated as follows: or .

[0054] In the formula: P is the weight of the moving object; L is the lateral movement distance of the moving object; D is the ship's displacement; h is the initial metacenter height; k is the movement distance of the plumb bob 1 read from the distance scale plate; l is the vertical distance from the suspension point M of the plumb line to the distance scale plate.

[0055] The height of the center of gravity in the experimental state is: ;

[0056] In the formula: Z M The height of point M; Z C Let C be the height of point C, and r be the radius of rotation of plumb bob 1.

[0057] The lateral tilt angle α is generally measured using a plumb bob (1). Figure 7 As shown. A plumb bob 1 is suspended by a thin rope from point M on the top plate 4.1, with a horizontal scale attached to its lower end. When the ship lists, the distance k that the plumb bob 1 has moved can be read from the scale. The ship's list angle is then calculated. In the formula, l is the vertical distance from the suspension point M of the plumb line to the distance scale plate. To reduce measurement errors, l should be as large as possible. Usually, 2 to 3 plumb bobs should be installed on the ship, respectively at the bow, midships and stern.

[0058] The height of the center of gravity under these experimental conditions can be obtained. Then, according to the law of resultant moment, by deducting the excess weight and adding the insufficient weight after completion, the height of the center of gravity of the empty ship can be calculated.

[0059] The movable weights used in the tilting test are generally cast iron blocks, which are divided into four groups and stacked in designated locations on the deck, such as... Figure 8 As shown, each group has the same weight, that is

[0060] P1=P2=P3=P4.

[0061] To improve the accuracy of the test results, the test vessel should be tilted repeatedly several times; that is, the test should be conducted in a specific order. Figure 6-7 The weight on the ship is moved repeatedly several times, with a distance of L. After each lateral movement of the weight, the heeling moments M1, M2, M3...M and the heeling angles a1, a2, a3..., a... are calculated. n , then according to Calculate the h-values ​​for each ranking, then take their arithmetic mean to obtain the stability height under the ship's tilting test conditions. The least squares principle is also commonly used to obtain the h-value, i.e.

[0062] .

[0063] This invention ensures the accuracy of the experiment. When conducting tilt tests, the following should be noted:

[0064] 1. Ship trials should be conducted on a clear day with winds not exceeding force 2. The trials should be conducted in a sheltered location with calm water. If there is a light breeze or current, attention should be paid to the effects of the wind and current, and the bow should be positioned as close to the wind and current as possible to avoid interference from passing vessels. It is better to conduct the trials in a dry dock, in which case the dock gates should be closed tightly to avoid the influence of external currents and waves.

[0065] 2. To avoid hindering the ship's list, the mooring lines should be loosened, extended as far as possible, and tied to the bow end within the ship's longitudinal midsection. During the trial, the ship should be prevented from contacting the dock, riverbed, other vessels, or the dock floor.

[0066] 3. Any objects on board that can move on their own should be secured. The machinery should be stopped, and all personnel except the test personnel should leave the ship. Personnel remaining on board should remain in their positions and not move around unnecessarily to avoid generating additional torque that could affect the accuracy of the test.

[0067] 4. All liquid tanks on board should be emptied or filled to eliminate the influence of free surface. Otherwise, the condition of the free surface should be recorded for correction.

[0068] 5. The loading status of the ship during the test, as well as any missing or excess weight, should be recorded in detail so that the test results can be corrected to reflect the empty ship condition.

[0069] 6. During the test, all tasks should be under unified command, and observation and recording should be carried out carefully and meticulously. While ship inclining tests are generally conducted on a full ship, due to time constraints and budgetary constraints, they are now mostly conducted in test tanks using ship models.

[0070] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.

[0071] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A ship inclining test apparatus, characterized by, The test frame includes a test frame and a line drop tracking positioning mechanism, the upper center of the test frame is provided with a line hanging block, the line drop is installed on the line hanging block, the bottom of the test frame is provided with the line drop tracking positioning mechanism, the line drop tracking positioning mechanism includes a swing ball and a driving structure, the swing ball is movably installed on a limiting seat, an electromagnet block is installed on the upper part of the swing ball, the electromagnet block adsorbs and positions the swing ball, the limiting seat moves through the driving structure to control the swing ball to find a position opposite to the line drop.

2. The ship inclining test apparatus of claim 1, wherein The test frame includes a top plate, an adjusting rod, an adjusting sleeve and a base, four adjusting rods are installed at the bottom of four corners of the top plate, a leveler is installed on the top plate, a line hanging block is installed at the center of the top plate, the line drop is hung on the line hanging block through a line, an angle scale plate is installed at the bottom of the top plate, and the angle scale plate is used for observing the swing angle of the line and the line drop.

3. The ship inclining test apparatus of claim 2 wherein, The adjusting rod is inserted into the adjusting sleeve, the lower part of the adjusting rod is provided with a through spring hole, a partition plate is fixedly arranged in the middle of the spring hole, springs are arranged on both sides of the partition plate, the other end of the spring is fixedly connected with a baffle, the baffle blocks the spring in the inside of the spring hole, the outside of the baffle is fixedly connected with a lock pin, the lock pin is penetrated out of the spring hole under the spring elastic force, a plurality of lock holes are uniformly and symmetrically arranged on the adjusting sleeve, and the lock pin is penetrated into the lock hole to connect the adjusting rod and the adjusting sleeve with each other.

4. The ship inclining test apparatus of claim 2 wherein, The bottom of the adjusting sleeve is fixedly connected with the base, the base adopts a box structure with an upper opening, a distance scale plate is fixedly arranged on the upper part of the base, and the distance scale plate is used for observing the moving distance of the line and the line drop.

5. The ship inclining test apparatus of claim 4 wherein, The inside of the box structure of the base is provided with a driving structure, the driving structure includes a driving motor and a driving box, the driving motor and the driving box are both installed on the bottom of the base, the motor shaft of the driving motor is connected with a lead screw, the lead screw is installed in the driving box through a bearing seat, a limiting strip groove is arranged at the top of the driving box, a limiting seat is slidably penetrated in the limiting strip groove, the bottom of the limiting seat is fixedly connected with a nut seat, a threaded hole is arranged in the middle of the nut seat, the nut seat is threadedly connected with the lead screw through the threaded hole, and the driving motor controls the limiting seat to move along the limiting strip groove.

6. The ship inclining test apparatus of claim 5 wherein, The upper part of the limiting seat is provided with a hemispherical shape, a swing ball is rotatably installed on the limiting seat through a swing shaft, the swing shaft is arranged in the direction of the front and back of the ship, the swing ball tilts with the ship tilting left and right, a ball counterweight is arranged at the bottom of the inside of the swing ball, an infrared receiver is installed at the center of the top of the swing ball, an infrared emitter is correspondingly arranged at the bottom of the line drop, and the infrared receiver and the infrared emitter both adopt a built-in battery power supply and a wireless transmission module.

7. A method of operating a ship inclining test apparatus according to any one of claims 1 to 6, wherein, The method includes the following steps: S1, the moving weight for the inclination test is pig iron block, the pig iron block is divided into four groups and placed on the designated position of the deck, and the weight of each group is equal; S2, before the test, the test frame is installed, data is recorded, water is poured into the box structure of the base to ensure the stability of the test frame, the height of the top plate is adjusted through the lock pin, the height of the top plate is located at the designed metacentric height of the ship, the leveler on the test frame is observed to be horizontally centered, the length of the line is controlled to keep the line drop and the swing ball at a distance of 5-10 cm, the electromagnet block is powered on to adsorb and control the line drop, and then the electromagnet block is powered off. S3, the position of the moving heavy object is transferred, the drop occurs swing, the driving motor controls the swing ball to find the drop position, the infrared transmitter on the drop and the infrared receiver on the swing ball are paired and identified, then the driving motor stops, the electromagnet block is powered again, the stability of the drop is maintained, then the swing angle of the drop is read through the angle scale plate, and recorded as the inclination angle a generated by the ship, the transverse moment M of the ship is calculated Q : and the restoring moment M of the ship after the transverse a angle h : ; S4, Since the ship is in equilibrium when it is heeled to an angle a, according to the principle of moment balance, M Q = M h , then , that is , the initial metacentric height GM0is calculated as or .

8. The method of operating a ship inclining test apparatus according to claim 7, wherein, The setting of the pig iron blocks in the step S1 is to form enough tilting moment to make the ship to have a 2°~4° angle of inclination, the total amount of the pig iron blocks is 1~2% of the ship displacement, and the moving distance L is 3 / 4 of the ship width.

9. The method of operating a ship inclining test apparatus according to claim 7, wherein, The recording data in the step S2 includes: 1) the ship draft, the left and right drafts of the ship bow, middle and stern are read out respectively according to the water gauge, and the average value is calculated; 2) the insufficient weight, the excess weight and the center of gravity coordinates of the ship in the empty ship state; 3) the weight and the placing position of the moving weight, and the moving distance L of each group of the moving weight; 4) the position of the line plummet, the length of the hanging line and the initial reading; 5) the specific gravity of water, which is used to calculate the displacement.

10. The method of operating a ship inclining test apparatus according to claim 7, wherein, The P is the weight of the moving weight; the L is the transverse moving distance of the moving weight; the D is the ship displacement; the h is the initial metacentric height; the k is the moving distance of the line plummet read out from the scale board; and the l is the vertical distance from the hanging point M of the hanging line to the scale board.

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