The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
W Mironiuk - One of the best experts on this subject based on the ideXlab platform.
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DETERMINATION OF THE STABILITY PARAMETERS AND THE POSITION OF A SHIP IN THE CONDITION OF FLOODING OF THE WATERTIGHT COMPARTMENT. IN: MARINE TECHNOLOGY V
2020Co-Authors: W Mironiuk, A. Pawlędzio, R. WróbelAbstract:The results of stability calculations in the case of a damaged watertight compartment occurring during flooding are reviewed in this paper. The constant displacement method along with the method of established volume were used in the calculations. These stability parameters have made it possible to analyze the changes of Metacentric Height, angles of heel and angles of trim that occur during the flooding. Both the method developed and computer programs elaborated can be used for a training stability simulator at the Naval University of Gdynia. The calculations can be useful in the training program for midshipmen and other personnel who are responsible for safety in flooding situations.
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Influence of flooding compartments on the stability safety of the training warship
Journal of Konbin, 2017Co-Authors: W MironiukAbstract:Abstract The paper presents computational stability issues with a flooded ship compartment situated on boat deck. As the main criteria for stability of the warship, calculation algorithm of Metacentric Height and righting levers have been defined, with a free surface effect taken into account. Based on the results of the calculations presented in tabular and graphical forms, suitable conclusions have been drawn up.
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Influence of flooding boat deck compartment on the training warship stability safety / Wpływ zatopienia pomieszczenia pokładu łodziowego na stateczność okrętu szkolnego
Journal of Konbin, 2016Co-Authors: W MironiukAbstract:Abstract The paper presents computational stability issues with a flooded ship compartment situated on boat deck. As the main criteria for stability of the warship, calculation algorithm of Metacentric Height and righting levers have been defined, with a free surface effect taken into account. Based on the results of the calculations presented in tabular and graphical forms, suitable conclusions have been drawn up.
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the influence of the flooding damaged compartment on the Metacentric Height ship type 888
TransNav: International Journal on Marine Navigation and Safety of Sea Transportation, 2010Co-Authors: W MironiukAbstract:Research on damage stability and unsinkability is a valuable source of knowledge on ship behavior during compartment flooding. In the paper, a short description of accidents and damages of Polish warships taking place in 1985-2004 is presented. The time when compartments are flooded (tf) and stability parameters are key elements that influence rescue action. The knowledge of the time mentioned and a Metacentric Height (GM) are very important for a commanding officer making decisions while fighting for unsinkability and survival of the ship. To provide the information about the time tf, a new method was designed. The method was tested experimentally and results of the tests are presented in the paper. In the experiments, the flooding process of compartments in a ship of the type 888 was simulated. The results of the experiments can be used as a basis to define general rules for proper decision-making during the process of damage control.
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Determination Of The Stability Parameters And The Position Of A ShipIn The Condition Of Flooding Of The Watertight Compartment
WIT Transactions on the Built Environment, 2003Co-Authors: W Mironiuk, A. Pawl, Dzio, R. WróbelAbstract:This paper presents the results of stability calculations in the case of damaged watertight compartment during flooding. Working out these calculations there have been applied the constant displacement method and the method of established volume. The work has contributed to the analysis of changes of Metacentric Height, angles of heel and angles of trim, which may occur during flooding of the watertight compartment. The method of determination of the position of a ship during the flooding of the watertight compartment and computer programmes elaborated might be exercised on training stability and survivability simulator which is being prepared to be executed at The Naval University of Gdynia. These calculations might be of some help in training midshipmen and functional persons who are responsible for safety of floating.
C.b. Barrass - One of the best experts on this subject based on the ideXlab platform.
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Drydocking and Stability – Procedures and Calculations
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. Barrass, D.r. DerrettAbstract:When a ship enters a dry dock she must have a positive initial GM, be upright, and trimmed slightly, usually by the stern. On entering the dry dock the ship is lined up with her centerline vertically over the centerline of the keel blocks and the shores are placed loosely in position. The dock gates are then closed and pumping out commences. The interval of time between the stern post landing on the blocks and the ship taking the blocks overall is referred to as the critical period. During this period part of the weight of the ship is being borne by the blocks, and this creates an upthrust at the stern that increases as the water level falls in the dry dock. The upthrust causes a virtual loss in Metacentric Height and it is essential that positive effective Metacentric Height be maintained throughout the critical period, or the ship will heel over. The purpose of this chapter is to show the methods by which the effective Metacentric Height may be calculated at any instant during the drydocking process. Worked examples of two methods to find important quantities regarding a ship’s stability in the drydocking process are given.
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Effect of free surface of liquids on stability
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. Barrass, D.r. DerrettAbstract:When a tank in a ship is completely filled with liquid, the liquid cannot move within the tank when the ship heels. For this reason, as far as stability is concerned, the liquid may be considered as a static weight having its center of gravity at the center of gravity of the liquid within the tank. If free surface be created in a ship with a small initial Metacentric Height (GM), the virtual loss of Metacentric Height due to the free surface may result in a negative Metacentric Height. This causes the ship to take up an angle of loll which may be dangerous and in any case is undesirable. When a ship takes up an angle of loll due to a very small negative GM it should be corrected as soon as possible. The ship cannot roll suddenly over to the other side as there is more water in the low side than in the high side. If sufficient weight of water is loaded to bring center of gravity, G , on the center line below initial metacenter, M , the ship should complete the operation upright.
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Drydocking and grounding
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. Barrass, D.r. DerrettAbstract:This chapter discusses the methods by which the effective Metacentric Height (GM) may be calculated for any instant during the dry-docking process. When a ship enters a drydock, it must have a positive initial GM, be upright and trimmed slightly, by the stern. On entering the drydock, the ship is lined up with her centerline vertically over the centerline of the keel blocks and the shores are placed loosely in position. The dock gates are then closed and pumping out commences. The rate of pumping is reduced as the ship's stern post nears the blocks. As the water level falls in the drydock, there is no effect on the ship's stability, but after the stern lands on the blocks, the draft aft will decrease and the trim will change by the head. The interval of time between the stern post landing on the blocks and the ship taking the blocks overall is referred to as the critical period. This creates an upthrust at the stern that increases as the water level falls in the drydock. The upthrust causes a virtual loss in Metacentric Height and the positive effective Metacentric Height should be maintained throughout the critical period, or the ship will heel over and perhaps slip off the blocks with disastrous results.
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Trim Calculations – Satisfying Prescribed Requirements for End Drafts
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. Barrass, D.r. DerrettAbstract:Trim calculations are given when satisfying prescribed requirements for end drafts. Scenarios of loading a weight to keep the after draft constant and to produce a required draft are considered, with example calculations. An example of using change of trim to find the longitudinal Metacentric Height is also included.
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Chapter 40 – Rolling, pitching and heaving motions
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. BarrassAbstract:Publisher Summary This chapter deals with rolling, pitching, and heaving motions of the ship. When a ship rolls, the axis about which the oscillation takes place cannot be accurately determined, but it would appear to be near to the longitudinal axis through the ship's centre of gravity (G). Hence, the ship rotates or rolls about its G. It is assumed that the amplitude of the roll is small and that the ship has positive initial Metacentric Height. Under these conditions, rolling is considered to be simple harmonic motion. The time period of roll is completely independent of the actual amplitude of the roll so long as it is a small angle. It varies directly as the radius of gyration, and inversely as the square root of the initial Metacentric Height. It changes when weights are loaded, discharged or shifted within a ship. Pitching is the movement of the ship's bow, from the lowest position to the highest position and back down to its lowest position. Heaving motion is the vertical upward or downward movement in the water of the ship's G.
D.r. Derrett - One of the best experts on this subject based on the ideXlab platform.
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Effect of free surface of liquids on stability
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. Barrass, D.r. DerrettAbstract:When a tank in a ship is completely filled with liquid, the liquid cannot move within the tank when the ship heels. For this reason, as far as stability is concerned, the liquid may be considered as a static weight having its center of gravity at the center of gravity of the liquid within the tank. If free surface be created in a ship with a small initial Metacentric Height (GM), the virtual loss of Metacentric Height due to the free surface may result in a negative Metacentric Height. This causes the ship to take up an angle of loll which may be dangerous and in any case is undesirable. When a ship takes up an angle of loll due to a very small negative GM it should be corrected as soon as possible. The ship cannot roll suddenly over to the other side as there is more water in the low side than in the high side. If sufficient weight of water is loaded to bring center of gravity, G , on the center line below initial metacenter, M , the ship should complete the operation upright.
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Drydocking and Stability – Procedures and Calculations
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. Barrass, D.r. DerrettAbstract:When a ship enters a dry dock she must have a positive initial GM, be upright, and trimmed slightly, usually by the stern. On entering the dry dock the ship is lined up with her centerline vertically over the centerline of the keel blocks and the shores are placed loosely in position. The dock gates are then closed and pumping out commences. The interval of time between the stern post landing on the blocks and the ship taking the blocks overall is referred to as the critical period. During this period part of the weight of the ship is being borne by the blocks, and this creates an upthrust at the stern that increases as the water level falls in the dry dock. The upthrust causes a virtual loss in Metacentric Height and it is essential that positive effective Metacentric Height be maintained throughout the critical period, or the ship will heel over. The purpose of this chapter is to show the methods by which the effective Metacentric Height may be calculated at any instant during the drydocking process. Worked examples of two methods to find important quantities regarding a ship’s stability in the drydocking process are given.
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Drydocking and grounding
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. Barrass, D.r. DerrettAbstract:This chapter discusses the methods by which the effective Metacentric Height (GM) may be calculated for any instant during the dry-docking process. When a ship enters a drydock, it must have a positive initial GM, be upright and trimmed slightly, by the stern. On entering the drydock, the ship is lined up with her centerline vertically over the centerline of the keel blocks and the shores are placed loosely in position. The dock gates are then closed and pumping out commences. The rate of pumping is reduced as the ship's stern post nears the blocks. As the water level falls in the drydock, there is no effect on the ship's stability, but after the stern lands on the blocks, the draft aft will decrease and the trim will change by the head. The interval of time between the stern post landing on the blocks and the ship taking the blocks overall is referred to as the critical period. This creates an upthrust at the stern that increases as the water level falls in the drydock. The upthrust causes a virtual loss in Metacentric Height and the positive effective Metacentric Height should be maintained throughout the critical period, or the ship will heel over and perhaps slip off the blocks with disastrous results.
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Trim Calculations – Satisfying Prescribed Requirements for End Drafts
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. Barrass, D.r. DerrettAbstract:Trim calculations are given when satisfying prescribed requirements for end drafts. Scenarios of loading a weight to keep the after draft constant and to produce a required draft are considered, with example calculations. An example of using change of trim to find the longitudinal Metacentric Height is also included.
-
Rolling, pitching and heaving motions
Ship Stability for Masters and Mates, 2020Co-Authors: C.b. Barrass, D.r. DerrettAbstract:This chapter deals with rolling, pitching, and heaving motions of the ship. When a ship rolls, the axis about which the oscillation takes place cannot be accurately determined, but it would appear to be near to the longitudinal axis through the ship's centre of gravity (G). Hence, the ship rotates or rolls about its G. It is assumed that the amplitude of the roll is small and that the ship has positive initial Metacentric Height. Under these conditions, rolling is considered to be simple harmonic motion. The time period of roll is completely independent of the actual amplitude of the roll so long as it is a small angle. It varies directly as the radius of gyration, and inversely as the square root of the initial Metacentric Height. It changes when weights are loaded, discharged or shifted within a ship. Pitching is the movement of the ship's bow, from the lowest position to the highest position and back down to its lowest position. Heaving motion is the vertical upward or downward movement in the water of the ship's G.
R. Wróbel - One of the best experts on this subject based on the ideXlab platform.
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DETERMINATION OF THE STABILITY PARAMETERS AND THE POSITION OF A SHIP IN THE CONDITION OF FLOODING OF THE WATERTIGHT COMPARTMENT. IN: MARINE TECHNOLOGY V
2020Co-Authors: W Mironiuk, A. Pawlędzio, R. WróbelAbstract:The results of stability calculations in the case of a damaged watertight compartment occurring during flooding are reviewed in this paper. The constant displacement method along with the method of established volume were used in the calculations. These stability parameters have made it possible to analyze the changes of Metacentric Height, angles of heel and angles of trim that occur during the flooding. Both the method developed and computer programs elaborated can be used for a training stability simulator at the Naval University of Gdynia. The calculations can be useful in the training program for midshipmen and other personnel who are responsible for safety in flooding situations.
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Determination Of The Stability Parameters And The Position Of A ShipIn The Condition Of Flooding Of The Watertight Compartment
WIT Transactions on the Built Environment, 2003Co-Authors: W Mironiuk, A. Pawl, Dzio, R. WróbelAbstract:This paper presents the results of stability calculations in the case of damaged watertight compartment during flooding. Working out these calculations there have been applied the constant displacement method and the method of established volume. The work has contributed to the analysis of changes of Metacentric Height, angles of heel and angles of trim, which may occur during flooding of the watertight compartment. The method of determination of the position of a ship during the flooding of the watertight compartment and computer programmes elaborated might be exercised on training stability and survivability simulator which is being prepared to be executed at The Naval University of Gdynia. These calculations might be of some help in training midshipmen and functional persons who are responsible for safety of floating.
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Computer-aided stability calculations under shipping conditions for the example of chosen ship type
1999Co-Authors: W. Sikorski, R. Szubartowski, R. WróbelAbstract:Information about stability presently used on ship for many reasons is ineffective for functional persons. Stability examples have to make calculation of initial Metacentric Height and progress of curve of righting levers possible. Ship loading states do not overlap often any of typical states. That is the reason why there have been made accurate stability calculations. In this paper there has been presented the computer system of undamaged ship stability calculations which can be used for constant monitoring of ship stability as well without making allowance for over icing as with overicing. The calculations will be helpful to functional persons on a ship, their proper operation, which will increase safety of floating.
Y. Iwasaki - One of the best experts on this subject based on the ideXlab platform.
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DEVELOPMENT OF A NEW STERN FORM FOR OCEAN GOING FINE SHIPS - STABILITY AND PROPULSIVE PERFORMANCE
1996Co-Authors: Y. Iwasaki, Takashi YamanoAbstract:In ocean going fine ships such as container ships with a high power main engine, it seems almost impossible to improve the propulsive performance when the conventional stern form is used. This is because severe design conditions such as a draft restriction, transverse Metacentric Height (TKM) requirement and propeller tip clearance requirement, restrict the propeller diameter and the stern form modification to a narrow range. This paper describes the change of these restrictions and the influence of these restrictions on the propulsive performance, mainly on TKM, and a newly developed stern form.
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SOME METHODS TO REDUCE STERN WAVES
1994Co-Authors: T Yamon, Y. IwasakiAbstract:In model tests, the authors made a detailed observation of stern waves and found that the stern wave breaking in the forward direction occurs just after the stern end in some ships. This phenomena causes large momentum loss in the longitudinal direction, and large hull resistance accordingly. This means that preventing or reducing the stern wave breaking leads to resistance reduction. To prevent or reduce the stern wave breaking, the authors have developed the following three technologies: Kawasaki Stern End Bulb (patented), Kawasaki Stern End Fin (patent pending) and the Kawasaki Sophisticated Concave Stern (patent pending). A characteristic of these technologies is that they can reduce stern waves without decreasing the transverse Metacentric Height. They achieve a higher propulsive performance and a better stability at the same time. The paper describes the development of these technologies.
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DEVELOPMENT OF A NEW STERN FORM FOR OCEAN GOING FINE SHIPS
1994Co-Authors: Takashi Yamano, Y. IwasakiAbstract:In ocean going ships such as new container ships with a high power main engine, it seems almost impossible that the propulsive performance can be further improved if a conventional stern form is used. This is because design conditions such as a draft restriction, a large transverse Metacentric Height requirement and a sufficient propeller tip clearance requirement restrict the propeller diameter and the stern form modification to a narrow range. The authors have tried to overcome this and, as a result, have developed a new stern form, the "Kawasaki SCS (Sophisticated Concave Stern)" (patent pending). This paper describes the development of the stern form.