Статті в журналах: "Ship draft"

1

Setiawan, Zhein Adhi Mahendra, and Yuichiro Yoshida. "Geographical Condition And Port Development." LIQUIDITY 10, no. 2 (December 31, 2021): 218–35. http://dx.doi.org/10.32546/lq.v10i2.1110.

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The first-time purposely build container ships introduced in 1967 with a draft of 9 meters, and now, newer container ship drafts can reach 16 meters and more. The development of the container ship dimension is rapid. Ports respond to these changes and keep up with the more significant size and a deeper draft of the new container ship design. Ports are developing their infrastructure from installing gantry cranes to dredge their seafloor. This research reviews that phenomenon and studied how ports adapt to the changing container ship dimension, especially for Post Panamax container ships built for efficiency. To do that, we use an exogenous variable of ports' depth from 1972 to 1985 before the ports knew that they would need deeper depth to accommodate such ships. We find that ports with actual depth more or equal to 13.716 meters is significantly affected port to accommodate Post Panamax container ship in this present time. The scope of this research is to show how a port responds to the change of the dimension of a container ship. Nevertheless, this research can be a steppingstone to measure the causality of trade that never has been done correctly before by introducing an exogenous variable that is strong, which port’s depth regarding the Post Panamax container ship draft.

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2

Gu, Hong Wei, Wang Zhang, Wen Hai Xu, and Ying Li. "Digital Measurement System for Ship Draft Survey." Applied Mechanics and Materials 333-335 (July 2013): 312–16. http://dx.doi.org/10.4028/www.scientific.net/amm.333-335.312.

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In order to overcome the limits of visual observation widely used in ship draft survey, a digital measurement system based on image acquisition and processing is presented. The images of drafts are obtained by an image acquisition unit containing a high definition camera extended to the shipboard from the deck. The draft marks are digitalized in use of a multilayer neural network, and the draft lines are detected by means of color image segmentation algorithm. Finally, the ship's trim are identified based on the relative position of the draft line located at the digitalized draft marks, where the artificial influences are eliminated. The influences of wave may also be reduced by calculating the mean value of the ship's trim obtained from different images.

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3

Wu, Jun, Shen Qi Ding, Kui Yu, and Xiao Biao Li. "Real-Time Detection Method on Draft of Inland Departure Ships." Advanced Materials Research 562-564 (August 2012): 1972–76. http://dx.doi.org/10.4028/www.scientific.net/amr.562-564.1972.

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For ensuring the safety of inland river shipping and avoiding super draft, it is of significance to propose a method to detect draft of inland departure ship. The real-time detection method on draft of inland departure ship is proposed, the measurement principle of ship draft is deeply analyzed, and the small scale experiment has been carried out. Experimental results show that as ship speed inicreases, the ship draft is of gradually declining tendency, and the measurement error is of gradually increasing tendency, the minium error is -4.2%, the maximum error is -11.4%. The results prove the possibility of this method , and also indicate that ship speed has large influence on measured ship draft.

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4

Kelareva, Elena, Sebastian Brand, Philip Kilby, Sylvie Thiebaux, and Mark Wallace. "CP and MIP Methods for Ship Scheduling with Time-Varying Draft." Proceedings of the International Conference on Automated Planning and Scheduling 22 (May 14, 2012): 110–18. http://dx.doi.org/10.1609/icaps.v22i1.13494.

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Existing ship scheduling approaches either ignore constraints on ship draft (distance between the waterline and the keel), or model these in very simple ways, such as a constant draft limit that does not change with time. However, in most ports the draft restriction changes over time due to variation in environmental conditions. More accurate consideration of draft constraints would allow more cargo to be scheduled for transport on the same set of ships. We present constraint programming (CP) and mixed integer programming (MIP) models for the problem of scheduling ships at a port with time-varying draft constraints so as to optimise cargo throughput at the port. We also investigate the effect of several variations to the CP model, including a model containing sequence variables, and a model with ordered inputs. Our model allows us to solve realistic instances of the problem to optimality in a very short time, and produces better schedules than both scheduling with constant draft, and manual scheduling approaches used in practice at ports.

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5

Ziha, Kalman. "Displacement of a Deflected Ship Hull." Marine Technology and SNAME News 39, no. 01 (January 1, 2002): 54–61. http://dx.doi.org/10.5957/mt1.2002.39.1.54.

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Relevant approximations based on permanent waterplane characteristics are summarized for a more accurate assessment of the effects of longitudinal deflections of an elastic ship's hull on drafts and displacement during marine surveys of merchant ships. The possibility of a different practice for placement of draft marks on a ship's sides, ensuring the same precision in displacement assessment of a deflected and trimmed hull by only two draft observations, is investigated by employing the waterplane properties. Correction factors for conventional ships, based on the waterline coefficient for changes of hydrostatic load, arising due to hull deflections, are also summarized. Example results are demonstrated on a Croatian-built bulk carrier.

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6

Ivanovsky, A. N., Ye G. Zinchenko, and S. G. Cherny. "Machine learning technologies for automated draft measurements." Transactions of the Krylov State Research Centre S-I, no. 2 (December 21, 2021): 33–39. http://dx.doi.org/10.24937/2542-2324-2021-2-s-i-33-39.

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This paper discusses the process of ship draft measurement known as draft survey. The purpose of the study was to improve the accuracy of draft survey results and the efficiency of this procedure itself. The study relies on video footages of draft marks, as well as clinometer readings, following the methods of digital image processing, machine learning, digital signal processing, linear filtering and applied programming. The tools developed as a result of this work are based on machine-learning algorithms and can perform draft surveys even in bad weather. Accuracy limits depend on camera resolution, lighting and weather conditions. Combined with linear filtering algorithms and ship inclinometers, this technology might offer draft survey tolerances as narrow as several millimeters, thus being well above its existing counterparts. Automated draft survey method suggested in this paper will make cargo weight measurements of bulkers more accurate, thus saving time and money, as well as making survey results independent on human error. Relying on machine-learning and computer-vision technologies, this method is universal and will work with any type of ships. Theoretical value of this study is that it gives a comprehensive review of what ship draft is and how it is measured.

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7

Akbar, Muhammad Sabiqulkhair, Aditya Rio Prabowo, Dominicus Danardono Dwi Prija Tjahjana, and Tuswan Tuswan. "Analysis of plated-hull structure strength against hydrostatic and hydrodynamic loads: A case study of 600 TEU container ships." Journal of the Mechanical Behavior of Materials 30, no. 1 (January 1, 2021): 237–48. http://dx.doi.org/10.1515/jmbm-2021-0025.

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Abstract The assessment of a ship's ability to withstand environmental loads is very crucial. This research focuses on the strength assessment of 600 TEU container ship hulls against hydrostatic and hydrodynamic loads using finite element-based software. Parameter changes in the material types, hull thickness, and ship drafts were performed to compare the structural responses using deformation, strain, and von Mises stress criteria. All of the materials tested were acceptable, where the ASTM A131 Grade AH36 and ASTM A131 Grade AH32 materials have the lowest deformation values and strains. The simulation results regarding plate thickness variation, deformation, strain, and von Mises stress values were smaller as the thickness of the ship structure increased. Moreover, from the draft variation, the structural response due to environmental load was better as the draft of the ship increased.

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8

Dong, Yan Qiu, and Weixue Lin. "Hydroelasticity and Wave Loads for a Full-Form Ship with Shallow Draft." Journal of Ship Research 36, no. 03 (September 1, 1992): 280–85. http://dx.doi.org/10.5957/jsr.1992.36.3.280.

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A shallow-draft full-form ship is a particular type of ship with a breadth-to-draft ratio higher than is conventional. To investigate the characteristics of such full forms in response to hull vibrations induced by waves, a special computer program based on the hydroelasticity theory of ships has been developed. In addition, an experimental investigation using a segmented elastic-keel model of the ship has been carried out in order to verify the theoretical calculations. It is found from calculation of the wave loads that the dynamic responses of this specific hull form cannot be accurately predicted by strip theory. It is concluded therefore that hydroelasticity theory should be used in the design of the hull structure.

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9

Noblesse, Francis, Dane Hendrix, Lisa Faul, and Jonathan Slutsky. "Simple Analytical Expressions for the Height, Location, and Steepness of a Ship Bow Wave." Journal of Ship Research 50, no. 04 (December 1, 2006): 360–70. http://dx.doi.org/10.5957/jsr.2006.50.4.360.

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Dimensional analysis and other fundamental theoretical considerations (thin-ship limit, shallow-draft and deep-draft limits) are used, with bow-wave measurements for six wedge-shaped hull forms, to obtain simple analytical expressions that explicitly define the height, location, and steepness of the bow wave generated by a ship in terms of the ship speed, draft, and waterline entrance angle. These simple analytical expressions are in excellent agreement with the available experimental measurements for six wedge-shaped hull forms. Good agreement is also obtained for other ship-bow forms, especially if a simple procedure—illustrated for the Wigley hull and the Series 60 model—is used to define an effective ship draft and an effective waterline entrance angle.

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10

Zhang, Lu Chen, Zhong Qi Yu, Jian Wei Lv, and Shao Ze Luo. "Real Ship Experimental Research on Ship Sailing Resistance in Inland Restricted Channel." Advanced Materials Research 1030-1032 (September 2014): 2082–86. http://dx.doi.org/10.4028/www.scientific.net/amr.1030-1032.2082.

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Ship sailing resistance is an important index of cross section size optimization of restricted channel. Through real ship experiment with one typical ship in inland restricted III channel, the relationship between ship sailing resistance and factors such as water depth to draft ratio, discharge section area and so on is studied. And modified calculation formula of ship sailing resistance is put forward. The results show that as water depth to draft ratio decreases, or discharge section area becomes smaller, ship sailing resistance will increase significantly. By introducing two parameters: section blockage ratio and water depth to draft ratio, the Эиванков formula of ship sailing resistance calculation is modified, and the calculation accuracy which the modified formula applied in restricted channel has greatly improved.

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11

Cole, S. L. "Low-Aspect-Ratio Flat Ship Theory for Moderate Froude Numbers." Journal of Ship Research 35, no. 04 (December 1, 1991): 325–30. http://dx.doi.org/10.5957/jsr.1991.35.4.325.

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Low-aspect-ratio flat ship theory models ships whose dimensions satisfy draft << beam <<length. This paper systematically derives the inner and outer linearized problems for moderate Froude number potential flow past such a ship and their solutions. These solutions are matched through an intermediate region. It is found that the leading-order term for the wave resistance for moderate speed low-aspectratio flat ship theory is the same as found in slender ship theory for ships with equivalent cross-sectional areas. Flat ship theory, however, predicts singularities in the flow along the outside of the ship's leading edge which are not present in slender ship theory. A simple example demonstrating these spurious singularities is worked out.

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12

Galor, Wiesław. "Determination of Dynamic Under Keel Clearance of Maneuvering Ship." Journal of Konbin 8, no. 1 (January 1, 2008): 53–60. http://dx.doi.org/10.2478/v10040-008-0100-0.

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Determination of Dynamic Under Keel Clearance of Maneuvering Ship The safety of navigation of a ship manoeuvring within port waters mainly depends on its under keel clearance (UKC). Mainly UKC depends on water level change, squatting of moving ship and heeling and wave response. The effect of these components will be determined currently than such UKC is called as dynamic under keel clearance. The paper presents an analysis of certain components of UKC to maximise of ship draft and thus to achieve the economic benefit to port and ships owner.

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13

Noblesse, Francis, Gérard Delhommeau, Michel Guilbaud, and Chi Yang. "The Rise of Water at a Ship Stem." Journal of Ship Research 52, no. 02 (June 1, 2008): 89–101. http://dx.doi.org/10.5957/jsr.2008.52.2.89.

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The height of water at the stem of a ship hull—with a nonbulbous wedge-shaped bow—that advances at constant speed in calm water is considered using two distinct methods:a theoretical-experimental approach in which elementary fundamental theoretical considerations (dimensional analysis and rudimentary asymptotic considerations in thin-ship, shallow-draft, and deep-draft limits) are used in conjunction with experimental measurements for simple hull forms and a rectangular flat plate towed at several yaw and heel angles; andthin-ship theory, that is, a fully analytical approach. Both of these two methods yield simple expressions that define the rise of water at a ship stem explicitly—ab initio and without calculations—in terms of the ship speed, draft, and waterline entrance angle. The theoretical-experimental expression and the thin-ship expression are in good agreement except at low Froude numbers and are also in reasonable agreement with experimental measurements.

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14

Yang, Yunfei, Haiwen Tu, Lei Song, Lin Chen, De Xie, and Jianglong Sun. "Research on Accurate Prediction of the Container Ship Resistance by RBFNN and Other Machine Learning Algorithms." Journal of Marine Science and Engineering 9, no. 4 (April 1, 2021): 376. http://dx.doi.org/10.3390/jmse9040376.

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Resistance is one of the important performance indicators of ships. In this paper, a prediction method based on the Radial Basis Function neural network (RBFNN) is proposed to predict the resistance of a 13500 transmission extension unit (13500TEU) container ship at different drafts. The predicted draft state in the known range is called interpolation prediction; otherwise, it is extrapolation prediction. First, ship features are extracted to make the resistance Rt prediction. The resistance prediction results show that the performance of the RBFNN is significantly better than the other four machine learning models, backpropagation neural network (BPNN), support vector machine (SVM), random forest (RF), and extreme gradient boosting (XGBoost). Then, the ship data is processed in a dimensionless manner, and the models mentioned above are used to predict the total resistance coefficient Ct of the container ship. The prediction results show that the RBFNN prediction model still performs well. Good results can be obtained by RBFNN in interpolation prediction, even when using part of dimensionless features. Finally, the accuracy of the prediction method based on RBFNN is greatly improved compared with the modified admiralty coefficient.

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15

Lu, Ping. "Case Study on Berthing and Disembarking of Ships and Traffic Organization in Rugao Port of Nantong." Mobile Information Systems 2022 (August 9, 2022): 1–9. http://dx.doi.org/10.1155/2022/4261240.

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In order to meet the needs of a 12.5 m deep-water channel, Rugao port of Nantong plans to normally berth ship with a draft of 12.0 m. Based on the study of the current situation and development trend of restricted ships entering and leaving Rugao port in Nantong, taking the navigation environment as the boundary condition, and based on the case study of berthing and disembarking of real ships, this paper objectively analyzes and deals with various risks in the process of docking and berthing of restricted ships. The results show that under the smooth and orderly traffic organization, Rugao port in Nantong has the ability to normally berth ships with a draft of 12.0 meters.

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16

Zhang, Jinfen, Han Zhang, Jiongjiong Liu, Da Wu, and Carlos Guedes Soares. "A Two-Stage Path Planning Algorithm Based on Rapid-Exploring Random Tree for Ships Navigating in Multi-Obstacle Water Areas Considering COLREGs." Journal of Marine Science and Engineering 10, no. 10 (October 6, 2022): 1441. http://dx.doi.org/10.3390/jmse10101441.

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A two-stage ship path planning method is proposed, based on the Rapid-exploring Random Tree (RRT) algorithm, which is composed of global path planning and local path planning, addressing the important problem of finding an economical and safe path from start to destination for ships under dynamic environment, especially in waters with multiple obstacles and multiple target ships. The global path planning takes into consideration the ship draft and Under Keel Clearance to find navigable water using RRT, and reduces the path length and waypoints based on elliptic sampling and smoothing. In the local path planning, a dynamic collision risk detection model is constructed by introducing the Quaternion Ship Domain under a dynamic environment, and the restrictions of ship manoeuvrability and COLREGs are also involved. The simulation results show that the proposed model can find a satisfactory path within a few iterations, and keep clear of both static obstacles and dynamic ships. The research can be used to make and verify planned ship routes before sailing and to guide officers to make decisions regarding collision avoidance.

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17

Liu, Shukui, and Apostolos Papanikolaou. "Approximation of the added resistance of ships with small draft or in ballast condition by empirical formula." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 233, no. 1 (June 17, 2017): 27–40. http://dx.doi.org/10.1177/1475090217710099.

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An attempt was made to extend and further tune the existing formula for approximating the added resistance in head seas to cover a wider range of speed and to account the impact of loading conditions; a new parameter based on B/ T was introduced after conducting extensive parametric study to capture the influence of draft on the added resistance; the trim effect has also been investigated; Furthermore, the draft effect on the added resistance due to diffraction is further tuned and simplified. The derived formula uses only a few input, including only some ship dimensions to yield an estimation of the added resistance of ships in regular waves. Numerical results show that the added resistance of various ships in head seas at low speeds, as well as the added resistance of tankers in ballast condition and cruise ships, can be properly captured by the new formula. Hence, it meets the demand of fast examination of the minimum power; it can also be used in the early design stage of a ship for power estimation.

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18

Son, Woo-Ju, and Ik-Soon Cho. "Analysis of Trends in Mega-Sized Container Ships Using the K-Means Clustering Algorithm." Applied Sciences 12, no. 4 (February 17, 2022): 2115. http://dx.doi.org/10.3390/app12042115.

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The size of ships is increasing rapidly, and over 400 m length overall mega-sized container ships are predicted to appear in the near future. Consequently, studies on large container ships have been conducted; however, based on the 30,000-TEU (twenty-foot equivalent unit) class container ship’s length overall, the deviation of the predicted range showed an 83.9 m difference from 453.0 m to 536.9 m. This is because simple linear regression analysis does not consider trends according to the type of cargo or the size of the cargo. In this study, 5497 container ships up to 20 years of age with an International Maritime Organization (IMO) number registered were clustered according to the change in ship dimensions by k-means clustering algorithm. Based on the clustered data, deadweight tonnage, TEU, length overall, length between perpendiculars, breadth, and maximum draft of container ships with a coverage rate of 75% were analyzed to predict the change in the main dimensions. The results indicated that for a 30,000-TEU container ship, the predicted length overall is 428.4 m, breadth is 67.6 m, and draft is 17.0 m. This study can help minimize the social costs of designing ports in consideration of future mega-sized container ships.

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19

Șerban, Petru Sergiu. "Case Study of Ship Squat in Sulina Channel Using NTPRO 5000 Navigational Simulator." Applied Mechanics and Materials 809-810 (November 2015): 1193–98. http://dx.doi.org/10.4028/www.scientific.net/amm.809-810.1193.

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paper presents a case study of ships passing through shallow and narrow waters in Sulina Channel. The method used in this research was simulation using NTPRO 5000 navigational simulator and it was studied the variation of ship squat, draft and under keel clearance for several military ships similar to Romanian Navy vessels, sailing with different speeds. The purpose of this research was to find out which ship types could navigate through Sulina Channel and what is the maximum speed they could pass without grounding due to ship squat. The integration of the trials results showed what the safe speed for each vessel was and it was concluded that the maximum speeds were 8, 12, and 16 knots. Also, a difference between desired and real speed was observed, caused by the restrictive navigation condition. Numerous researches are being done in ship squat domain and Sulina Channel is one of the canals where this phenomenon is studied, but squat simulation on military ships has never been done before in this canal.

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20

Nedelcu, A. "Ship Maneuvering Prediction based Pivot Point Estimation." Scientific Bulletin of Naval Academy XXI, no. 2 (December 15, 2018): 81–86. http://dx.doi.org/10.21279/1454-864x-18-i2-008.

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In the last years, the size and the number of ships has grown remarkably. At the same time, the size of harbors and ports remain constantly. Asa result, the ship maneuvering in harbors has become more problematic and harder to execute. This is the reason that many sailors affirm that it is an art than a science to execute some maneuverings. Ship maneuvers represented a complex vessel motions influenced most of the time by external environmental conditions in the navigation area (i.e. ocean and tidal current conditions, water depth, wind and waves). Navigator`s knowledge and experiences overcome to control the ship speed, course and heading in some close encounter situations. For example, combinations of different environmental conditions (draft variations in a passage from fresh to sea water with other ships near the same navigation area), create not only additional navigation difficulties, but also could compromise and threatens the navigation.

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21

Liu, Yingfei, and Ruru Deng. "Ship Wakes in Optical Images." Journal of Atmospheric and Oceanic Technology 35, no. 8 (August 2018): 1633–48. http://dx.doi.org/10.1175/jtech-d-18-0021.1.

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AbstractShip wakes are more distinct than the hulls and can be visually observed in optical images. In this paper the wakes of 2836 ships in 32 optical images with different resolutions are observed and summarized. The ships are divided into four types according to the hull and wake features: fishing vessels, motorboats, cargo ships, and warships. The results show that each ship type has characteristic wakes, and there are significant differences among the categories. The probabilities of occurrence of different types of wakes and their components are shown. Turbulent wakes are inevitable. The probability of occurrence of Kelvin wakes is small and less than 40%. The visibilities of internal waves that are generated by only cargo ships are very low as a result of the harsh formation conditions. Turbulent wakes should be preferentially detected. Low-resolution images are more suitable for the detection and positioning of hulls and wakes, while high-resolution images with more details are convenient for further analysis of the size, velocity, and draft of ships. The study on the cause of the formation of the features of ship wakes in optical images proves that the classification of the wakes is reasonable and that the features of wakes can be used to initially identify the type of ship.

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22

Ivče, Renato, Irena Jurdana, and Robert Mohović. "Determining Weight of Cargo Onboard Ship by Means of Optical Fibre Technology Draft Reading." PROMET - Traffic&Transportation 23, no. 6 (February 21, 2012): 421–29. http://dx.doi.org/10.7307/ptt.v23i6.177.

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The accuracy of measuring mass of loaded or discharged cargo by draft survey mass measuring method varies due to both systematic and accidental errors. The paper analyzes an error of draft readings on the calculated quarter mean draft, displacement based on the calculated quarter mean draft and the final displacement. By analyzing this problem, the authors have reached the conclusion that the influence of an error made in draft readings can be significant, especially on the draft marks amidships. Optical fibre technology has been suggested as a new option for draft readings. In this paper, the authors propose a liquid level optical sensor for measuring the sea level in the sounding pipe. Draft readings obtained by optical sensors will be entered into ships’ navigational system and load master. KEY WORDS: ship’s draft, error of draft readings, optical fibre technology, liquid level optical sensors.

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23

Elkady, Hesham, Duan Feng Han, and Liang Gao Gao. "The Resistance Performance Influences from Hull Line Variation of V-Shaped Non-Ballast Ship (NoBS)." Advanced Materials Research 936 (June 2014): 2109–13. http://dx.doi.org/10.4028/www.scientific.net/amr.936.2109.

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As a New Concept in Ship Design to be Alternative of Ballast Water System, to Emerge that Remedy the Introduction of Invasive Marine Species and the Disadvantages of Ballast Water Treatment Systems. the Non-Ballast Ship has been Studied Abroad, but it is Rarely Mentioned in China. in this Paper, the Hydrodynamic Influences due to Hull Line Variation of this Kind of Ships were Studied, Using the Method of Invariant Cross-Section Area Curve under the Design Draft to Change the Rise Angle at Bottom. then by Using Numerical Calculation, get the Resistance and Effective Power at each Angle.

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24

Cao, Liang, Xinjian Wang, Wenjun Zhang, Ligang Gao, Si Xie, and Zhengjiang Liu. "Research on Intelligent Detection Algorithm of the Single Anchored Mooring Area for Maritime Autonomous Surface Ships." Applied Sciences 12, no. 12 (June 13, 2022): 6009. http://dx.doi.org/10.3390/app12126009.

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Mooring area detection represents one of the key technological problems that must be solved in the development of Maritime Autonomous Surface Ships (MASS). In view of the lack of research on the current detection methods for ship mooring area, a new intelligent detection algorithm of the single anchored mooring area for MASS was proposed in this study, aiming at improving the detection ability and accuracy of the MASS mooring area. Firstly, the laws of short period swinging motion, long period circumferential motion and reciprocating motion in the radial direction of an anchoring ship were summarized. Secondly, an anchorage circle radius model and safety distance model between the anchor positions were established and various constrains were considered including ship type, ship particulars, draft, safety impact caused by other ships passing through the anchoring ship. Thirdly, the Monte-Carlo stochastic simulation method was used to measure the mooring area, which can detect the anchor position intelligently. Finally, a case study on MATLAB demonstrated that the proposed intelligent detection algorithm for MASS is effective under various marine scenarios. The results enrich the theory of MASS mooring area detection; therefore, the algorithm has great potential to be equipped on MASS in the future.

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25

Clausen, H. B., M. Lu¨tzen, A. Friis-Hansen, and N. Bjørneboe. "Bayesian and Neural Networks for Preliminary Ship Design." Marine Technology and SNAME News 38, no. 04 (October 1, 2001): 268–77. http://dx.doi.org/10.5957/mt1.2001.38.4.268.

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To ease the determination of the main particulars of a ship at the initial design stage it is convenient to have tools which, given the type of ship and a few other parameters, output estimations of the remaining dimensions. To establish such a tool, a database of the characteristics of about 87 000 ships is acquired and various methods for derivation of empirical relations are employed. A regression analysis is carried out to fit functions to the data. Further, the data are used to learn Bayesian and neural networks to encode the relations between the characteristics. On the basis of examples, the three methods are evaluated in terms of accuracy and limitations of use. For different types of ships, the methods provide information on the relations between length, breadth, height, draft, speed, displacement, block coefficient and loading capacity. Thus, useful tools are available to the designer when he chooses the preliminary main characteristics of a ship.

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26

Qiang, Li, Yang Bing-Dong, and Hong Bi-Guang. "Calculation and Measurement of Tide Height for the Navigation of Ship at High Tide Using Artificial Neural Network." Polish Maritime Research 25, s3 (December 1, 2018): 99–110. http://dx.doi.org/10.2478/pomr-2018-0118.

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Abstract Accurate tide height is crucial for the safe navigation of large deep-draft ships when they enter and leave the port. We have proposed an accurate forecasting method for the tide heights from the observation data and neural networks, which can easily calculate the tidal window period of large deep-draft ships’ navigation through long channels at high tide. Moreover, an artificial neural network is established for the tide height from the observation of tide heights before their current time node. For an ideal forecast, the neural network was optimized for one year with the tide height data of Huanghua Port. In case of large ships, their tidal characteristics of channels for are complex. A new method is proposed for the observation of multiple stations and artificial neural networks of each observation station. When ships are navigating through the port, the tide height is predicted from the observed data and forecast tide heights of multiple observation stations. Thus, a valid tidal window period is secured when the ships enter the port. Comparative analysis of the ship’s tidal window period with that of the measured one can lead us to conclude that the forecasted data has a strong correlation with the measurement. So, our proposed algorithm can accurately predict the tide height and calculate the node timing when the ship enters and depart the port. Finally, these results can be applied for the safe navigation of large deep-draft ships when the port is at high tide.

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27

Zhan, Wei, Shengbing Hong, Yong Sun, and Chenguang Zhu. "The System Research and Implementation for Autorecognition of the Ship Draft via the UAV." International Journal of Antennas and Propagation 2021 (August 16, 2021): 1–11. http://dx.doi.org/10.1155/2021/4617242.

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The reading of the ship draft is an important step in the process of weighing and pricing. The traditional detection method is time-consuming and labor-consuming, and it is easy to lead to misdetection. In order to solve the above problems, this paper introduces the computer image processing technology based on deep learning, and the specific process is divided into three steps: first, the video sampling is carried out by the UAV to obtain a large number of pictures of the ship draft reading face, and the images are preprocessed; then, the deep learning target detection algorithm of improved YOLOv3 is used to process the images to predict the position of the waterline and identify the draft characters; finally, the prediction results are analyzed and processed to obtain the final reading results. The experimental results show that the ship draft reading method proposed in this paper has obvious effects. The method has a good detection effect on high-quality images, and the accuracy rate can reach 98%. The accuracy rate can also reach 73% for the images with poor quality caused by improper capture, character corrosion, bad weather, etc. This method is a kind of artificial intelligence method with safe measurement process, high measurement effect, and accuracy, providing a new idea for related research.

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28

Miller, Anna, and Szymon Walczak. "Maritime Autonomous Surface Ship’s Path Approximation Using Bézier Curves." Symmetry 12, no. 10 (October 16, 2020): 1704. http://dx.doi.org/10.3390/sym12101704.

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This work is devoted to the second order rational Bézier curve coefficients estimation. We present the methodology of unique coefficients for each type of ship computation. In the presented formulas of ship’s length, a draft and angular path combined with a drift path are used. This approach leads to the simplest and most accurate Maritime Autonomous Surface Ships (MASS) path modeling. Three rational curve control points are waypoints (WPT). Using WPTs as curve control points allows integrating a trajectory intuitive for the navigator with a path predicting model used as a reference in the control system. Research was done based on real-time data originating from the MASS autonomous trajectory tracking system. The presented mathematical modeling tool may be treated as the best way of future trajectory prediction due to low computation power required.

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29

Liu, Ting, Liu Yao, and Chen Zhao. "The Quantitative Model Research of Impact of Water Level Changes on Channel Capacity." Advanced Materials Research 989-994 (July 2014): 1419–23. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.1419.

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Water level determines channel capacity, in order to protect the safety of navigation and give full play to the advantages of shipping, the paper analyzes the relationship between the draft and loading rate of various types of ships, and proposed the quantitative model of impact of water level changes on channel capacity, the results showed: small ships are less affected by water level changes, and large ships are great affected by water level changes, the actual amount of cargo related the ship design parameters, this article has a certain reference value for navigation management and planning.

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30

Johnson, J. W. "SHIP WAVES IN NAVIGATION CHANNELS." Coastal Engineering Proceedings 1, no. 6 (January 29, 2011): 40. http://dx.doi.org/10.9753/icce.v6.40.

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Ships moving through water generate surface waves which in many navigation channels cause severe wave-wash damage to the bank* In some waterways, rather extensive protection works have been constructed to reduce this destructive action to levee faces (Hertzberg, 1954). This action, termed "foreshore erosion", has been described by Lewis (1956) for the lower Mississippi River as follows: "The attack, interestingly enough, takes place at lowwater . It is due largely to the waves created by passing ocean-going ships and is augmented by shallow draft traffic. It may be asked at this point why this attack is new, in view of the fact that ship and barge traffic has long existed on the river in very substantial volume? The answer is that the recent technological advances in ocean-going and river transportation have greatly increased maximum and average speeds, and accordingly, the wave making potentials."

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31

Roseman, Donald P., and Frederick Seibold. "An Introduction to the U.S. Maritime Administration Systematic Series." Marine Technology and SNAME News 22, no. 04 (October 1, 1985): 329–38. http://dx.doi.org/10.5957/mt1.1985.22.4.329.

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Results of an extensive test program of full-form merchant ship models, sponsored by the Maritime Administration, are presented in abstract form as an introduction to the forthcoming publication by SNAME of the complete series data. The systematic series characteristics are oriented toward low length/breadth for economy in construction and high breadth/draft for restricted draft service. Material presented and evaluated includes hull form development, resistance and propulsion data, and directional stability and control data, for deep and shallow water test conditions. The SNAME text, entitled The U.S. Maritime Administration Systematic Series of Full Form Merchant Ship Models will be published in early 1986.

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32

Dharma, Budhi. "PERENCANAAN KONSTRUKSI BETON SLIPWAY - 150 LWT." Gema Teknologi 16, no. 2 (February 6, 2012): 68. http://dx.doi.org/10.14710/gt.v16i2.1627.

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Budhi Dharma, in paper Construction Planning of Slipway - 150 LWT Concrete explain that in shipyard planning major facility types shipyard slipway suitable transverse system was built in the open or closed.To ship with 150 tons LWT according to the register BKI got main dimension vessels = 34 meters LOA,30 meters LP, 6 meters B, the ship draft T = 2,2 meters, and empty vessel draft Tk = 1,18 meters and block coefficient = 0,68.Of the main dimension of the vessel were then long slipway, heavy lorries and heavy lorries transfer launchers after the total weight is obtained the dimensions of the placement of concrete beam rail and lorry.Keyword : Slip way and structure concrete

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33

Li, Fan, Shaohua Jin, Gang Bian, Fumin Xiao, and Xiaodong Ma. "Method to Determinate Surveying Ship Dynamic Draft and Error." IOP Conference Series: Earth and Environmental Science 658 (February 20, 2021): 012024. http://dx.doi.org/10.1088/1755-1315/658/1/012024.

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34

Liu, Xiaoyu, Jianxiong Wu, Yinghao Liao, and Xiaotong Tu. "Column-Based Waterline Detection for Lightweight Ship Draft Reading." IEEE Transactions on Instrumentation and Measurement 71 (2022): 1–10. http://dx.doi.org/10.1109/tim.2022.3154840.

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35

Briggs, Michael J., Paul J. Kopp, Vladimir K. Ankudinov, and Andrew L. Silver. "Comparison of Measured Ship Squat with Numerical and Empirical Methods." Journal of Ship Research 57, no. 02 (June 1, 2013): 73–85. http://dx.doi.org/10.5957/jsr.2013.57.2.73.

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The Beck, Newman and Tuck (BNT) numerical predictions are used in the Coastal and Hydraulics Laboratory (CHL) Channel Analysis and Design Evaluation Tool (CADET) model for predicting underkeel clearance (UKC) resulting from ship motions and squat. The Ankudinov empirical squat prediction formula has been used in the CHL ship simulator and was recently updated. The World Association for Waterborne Transport Infrastructure (formerly The Permanent International Association of Navigation Congresses, PIANC) has recommended several empirical and physics-based formulas for the prediction of ship squat. Some of the most widely used formulas include those of Barrass, Eryuzlu, Huuska, ICORELS, Romisch, Tuck, and Yoshimura. The purpose of this article is to compare BNT, Ankudinov, and PIANC predictions with measured DGPS squat data from the Panama Canal for four ships. These comparisons demonstrate that the BNT, Ankudinov, and PIANC predictions fall within the range of squat measurements and can be used with confidence in deep draft channel design.

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36

Worby, A. P., G. M. Bush, and I. Allison. "Seasonal development of the sea-ice thickness distribution in East Antarctica: measurements from upward-looking sonar." Annals of Glaciology 33 (2001): 177–80. http://dx.doi.org/10.3189/172756401781818167.

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AbstractUpward-looking sonar (ULS) data are presented from a prototype instrument deployed at 63° 18’ S, 107°49’ E in 1994. These data show the seasonal evolution of the ice-draft distribution from May when predominantly thin ice is present, through October when substantially thicker ice has been formed by deformation. The mean ice draft reaches a maximum in August at 1.21 m, the same month in which ship-based observations from the same region show a peak in ice thickness. The observed distribution from ULS data is only for drafts > 0.3 m due to data losses caused by the low acoustic reflectivity of actively forming ice. The spring distributions show very little development of drafts > 3.0 m, and it is hypothesized that this is due to the cyclical nature of deformation in the East Antarctic pack-ice zone, and that periods of sustained pressure required to form very thick ice are uncommon in this region

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37

Şahin, Volkan, and Nurten Vardar. "Determination of Wastewater Behavior of Large Passenger Ships Based on Their Main Parameters in the Pre-Design Stage." Journal of Marine Science and Engineering 8, no. 8 (July 22, 2020): 546. http://dx.doi.org/10.3390/jmse8080546.

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Wastewater formed on ships is divided into blackwater and graywater. While blackwater refers to wastewater from toilets, graywater defines wastewater from sinks, laundry and restaurants. Even though some treatments are applied onboard before discharge, wastewater contains significant amounts of fecal bacteria, heavy metals, etc., in excess of water quality standards. Dilution is a secondary natural treatment in the ship-wake region, which occurs after wastewater discharging. According to the Environmental Protection Agency (EPA), the natural treatment process is quantified by dilution factor, which is strongly dependent on vessel width, draft, speed and wastewater discharge rate. In this study, an Artificial Neural Network (ANN) model linked with the main ship parameters was developed to estimate the dilution factors while the ship is in the preliminary design stage. Gross ton, deadweight ton, passenger number, freeboard, engine power, propeller number and block coefficient values of 1041 large cruise ships were used to estimate the likely dilution factors. The best ANN estimation model was determined by Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) methods. A decision tree was created for the results and the most important parameters affecting the dilution factors were determined. The main ship dimensions are needed for the dilution factor formulation of EPA whereas in the model created in this study only the gross ton or engine power of the ship is sufficient to estimate the dilution. Moreover, this new model is also usable for the estimation of dilution factors even if the main dimensions of the ship are not known.

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38

Parsons, Michael G., and Miltiadis Kotinis. "Trim and Draft Control Capability of the Variable Buoyancy Ship." Journal of Ship Production and Design 27, no. 03 (August 1, 2011): 118–26. http://dx.doi.org/10.5957/jspd.2011.27.3.118.

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The Variable Buoyancy Ship concept has been developed to address the problem of the introduction of nonindigenous aquatic species (NIS) into coastal waters. While this ship design concept essentially eliminates the transport of NIS across the globe, it presents special problems for operators with respect to their control of trim and draft. An investigation was, therefore, undertaken to assess this capability and ensure that adequate capability would be provided. To better visualize this issue, the equilibrium polygon used in early submarine design has been adapted to provide an effective way to characterize the trim and draft control capability of surface vessels. The results of this investigation and resulting design concept modifications are presented.

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39

ILLES, Ladislav, Martin JURKOVIC, Tomas KALINA, Piotr GORZELANCZYK, and Vladimir LUPTAK. "Methodology for optimising the hull shape of a vessel with restricted draft." Scientific Journal of Silesian University of Technology. Series Transport 110 (March 1, 2021): 59–71. http://dx.doi.org/10.20858/sjsutst.2021.110.5.

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Increasing transport volumes on Europe's inland waterways is a major reason for improving the quality and reliability of internationally important waterways. Continued navigation restrictions due to restricted draft (draught) led to the search for new design solutions. Such solutions enable navigation even under critical navigation conditions. Restricted draft is one of the most important limitations that hinder navigation, especially in the summer. The main objective of the construction of an inland vessel is to obtain a shape that will achieve optimum performance with as little resistance as possible. A shape that will be able to navigate at a limited depth. Presently, there is no clearly defined methodology as a procedure for optimising the hull. When solving theoretical problems of shipbuilding character and ship calculations, it is necessary to consider the basic theory of the ship with special regard to the latest methodological procedures of related scientific disciplines. This paper presents a methodology that considers all the basic aspects of optimisation tasks in ship design and construction.

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40

Salmat, Salmat, Arya Zulhendrik, Muhammad Iqbal Iski, Arifin Adli, and Aulia Zulkanain Nasty. "Design of Hybrid Hull Ship by B-NINE TEAM to The National Unmanned Fast Boat Contest 2019." Teknomekanik 3, no. 1 (May 25, 2020): 17–21. http://dx.doi.org/10.24036/tm.v3i1.5772.

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The Nastional Unmanned Fast Boat Contest 2019 is an event to discover colleger interests and talents about ships and as an event to hone and develop college competitions.B-NINE TEAM from Universitas Negeri Padang is very interested and interested to participating based on illegal fishing problem that occurs. Ship design through literature study and ship model analysis using computer simulations. Ship comparison methods and trial-error to determine the shape of the hull to be userd and numerical experiments.Dimensions of the ship are Length Overall 0.80 m; Length Waterline 0.79 m; Beam 0.05 m; Depth 0.24 m; Draft 0.05 m. The variable parameter used is the variation of catamaran hull type V asymmetric inner flat. There are two types of modification applied, that is modification hull type U asymmetric and modification hull type U symmetric. Based on result of computer simulation testing, based on result of computer simulation testing, it is found that modification hull type U asymmetric has a low resistance value is 5.31 N at a speed of 4.2 knots with effective is 0.04776 Kw and main engine power of 0.1.70 KW.

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41

Gourlay, T. P., and E. O. Tuck. "The Maximum Sinkage of a Ship." Journal of Ship Research 45, no. 01 (March 1, 2001): 50–58. http://dx.doi.org/10.5957/jsr.2001.45.1.50.

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A ship moving steadily forward in shallow water of constant depth h is usually subject to downward forces and hence squat, which is a potentially dangerous sinkage or increase in draft. Sinkage increases with ship speed, until it reaches a maximum at just below the critical speed Here we use both a linear transcritical shallow-water equation and a fully dispersive finite-depth theory to discuss the flow near that critical speed and to compute the maximum sinkage, trim angle, and stern displacement for some example hulls.

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42

Vasilescu, Mihail-Vlad, Ionut Voicu, Cornel Panait, and Violeta-Vali Ciucur. "Influence of four modern Flettner rotors, used as wind energy capturing system, on container ship stability." E3S Web of Conferences 180 (2020): 02003. http://dx.doi.org/10.1051/e3sconf/202018002003.

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This article is presenting the influence on the stability of a container ship, by connecting four modern Flettner rotors, as wind energy capturing system. Modern Flettner rotors, are energy power generators. They are one of the various equipment used to capture and harness wind energy. By reading the article, the reader can discover what are the forces which influence the modern Flettner rotors and how they influence the ship stability.This article major points are: calculation the influence of the modern Flettner rotors on the ship transverse and longitudinal stability, calculation of the ship new displacement, new draft, new metacentric height and period of rolling.

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43

AlmstrÃ¶m, BjÃ¶rn, Magnus Larson, Lars Granath, and Hans Hanson. "SHIP-GENERATED WAVES OVER A COMPLEX BATHYMETRY." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 35. http://dx.doi.org/10.9753/icce.v36.waves.35.

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Problems related to shipping have increased worldwide during the last decades as a result of more traffic travel-ling at higher speeds and using larger vessels. When ships move in a restricted fairway they generate primary (drawdown) and secondary (transverse and divergent) waves (Bertram 2000) that often cause adverse impact to adjacent shores. An example of this is the Furusund fairway in Sweden, which since the 1980â€™s has experienced increased traffic and larger ships. This has resulted in a loss of natural fine sediment habitats along the shores as well as structural damages to piers and jetties (Granath 2015). Furusund is an important fairway into Stockholm, the capital of Sweden, and is located about 25 km north of the city within the Stockholm archipelago. It is mainly trafficked by large ferries (length/width/draft: 200x30x7m). The wind-wave regime in the fairway can be described as a low-energy environment, due to the short fetches and no swell. Hence, ship waves have a significant impact on the shores in terms of bed and bank erosion. This study aims at determining the primary ship wave characteristics and their relationship to ship properties and bathymetric conditions in the Furusund fairway. Measured water levels were collected for this purpose during three months at three locations. Existing empirical formulas for drawdown are evaluated based on the measurements and compared with a new formula derived for the specific fairway. The results are used for designing nature-based protection against ship-generated waves along the shores and to validate analytical and numerical models that can be employed for ship wave generation and propagation.

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44

Rachmianty, Andi, Suandar Baso, and Syamsul Asri. "The Influences of Lengthening Dimension of Ro-Ro Ferry Toward the Considerations of Hydrodynamics Characteristic and Loading Capacity Aspect." EPI International Journal of Engineering 2, no. 1 (June 27, 2019): 41–45. http://dx.doi.org/10.25042/epi-ije.022019.08.

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The ferry business has become an important business segment for ship designers, builders and operators. Therefore, many ways have been done in order to increase ferry business through the proper design or converting ships by lengthening. This research is focused on the influences of lengthening a Ro-Ro ferry to hydrodynamics characteristic and loading capacity aspects. Moreover, the ships also are fixed in the same width and draft dimensions. The difference of the Ro-Ro ferries length is indicated by the addition of one column of car space where one column car space is given by car size including distance between car columns spaces which is an increment of every 5.88 meter. The total resistances of Ro-Ro ferries are obtained by ship model experiment in towing tank. There are 4 ship models that are made. The lengthening a Ro-Ro ferry is described into non-dimensional parameter by the ratio of ship length and displacement volume (L/V1/3). The hydrodynamics and the loading capacity of carried car aspects could be described into the ratio of resistance and loading capacity of carried car (RT/SUK) with ship speed. The research result shows that the lengthening of a Ro-Ro ferry affects on total resistance, speed, and loading capacity of carried car. The increase of total resistance is caused by higher residual resistance at high speeds and this is experienced by small length size. Therefore by lengthening the Ro-Ro ferry it could reduce total resistance in the same speed especially the residuary resistance but eventhough lengthening Ro-Ro ferry the effective speed should be considered. In additions, the effective speed for actual ships dimension in the same Rt/SUK 0.05 i.e. B5L10 is about 13.85 knot, B5L11 14.33 knot, B5L12 14.94 knot, and B5L13 15.45 knot respectively.

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45

Noblesse, Francis, Gérard Delhommeau, Patrick Queutey, Chi Yang, and Hyun Yul Kim. "Analytical bow waves for fine ship bows with rake and flare." Journal of Ship Research 55, no. 01 (March 1, 2011): 1–18. http://dx.doi.org/10.5957/jsr.2011.55.1.1.

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The bow wave generated by a steadily advancing ship is considered for a family of fine ruled ship bows with rake and flare. This family of ship bows is defined in terms of four parameters: the ship draft D, the entrance angles a and a' at the top and bottom waterlines, and the rake angle 8. The corresponding bow wave similarly depends on four parameters: the draft-based Froude number F and the three angles a, a', and 8. An extensive parametric study, based on thin-ship theory, is performed to explore the variations of the water height Z0 at the ship stem X = 0, the location X0 (measured from the ship stem) of the intersection of the bow-wave profile with the mean free-surface plane Z = 0, and the bow-wave profile, with respect to the four parameters F, a, a', and 8. This parametric study extends the previously reported similar study of the height Zb of the bow wave and the location Xb of the bow-wave crest. These two complementary parametric studies yield simple analytical relations, which extend relations given previously for wedge-shaped ship bows without rake or flare. In spite of their remarkable simplicity, the analytical relations given here yield bow waves that are comparable to computational fluid dynamics (CFD) waves given by Euler-flow calculations. The analytical relations, which explicitly account for the influence of the four primary parameters F, a, a', and 8, can be used immediately—without hydrodynamic calculations—for ship design, notably at early design stages when the precise hull geometry is not yet known. The study also provides insight for ship bow design. Specifically, it suggests that a bow with positive rake and negative flare may be beneficial, and that a bulb located aft of the stem and integrated with the hull may be an advantageous alternative to a traditional bulb protruding ahead of the bow, in agreement with the results of a hull-form optimization analysis.

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46

Łozowicka, Dorota, Magdalena Kaup, and Dorota Daniłowicz. "Analysis of the Impact of Ship Draft Measurement Results on Shipowners' Decisions About Fleet's Operability." Journal of KONBiN 50, no. 3 (October 1, 2020): 395–416. http://dx.doi.org/10.2478/jok-2020-0068.

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AbstractThe article presents an assessment of the impact of the results of the measurement of the inland ship's draught on the shipowner's decisions regarding incurring financial expenses for maintaining vessels in operability by carrying out repairs and modernization The aim of the article is to present the possible actions taken by shipowners in response to the changing level of reliability of their vessels. The article assesses the impact of ship draught measurement results on shipowner’s decisions, with particular emphasis on operability. The analysis was carried out using data collected during the work of the Technical Inspection Commission in Szczecin in 2017-2018 regarding the draft and load capacity of ships.

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47

Yasukawa, Hironori, Noritaka Hirata, and Yoshiyuki Nakayama. "High-Speed Ship Maneuverability." Journal of Ship Research 60, no. 04 (December 1, 2016): 239–58. http://dx.doi.org/10.5957/jsr.2016.60.4.239.

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In this paper, the effects of changes in hull attitude and the presence of stern append- ages such as rudders, shaft brackets, bossing, and propeller shafts on the maneuver- ability of a high-speed ship are investigated. The study is conducted for a ship operating within a Froude number range of 0.6–1.0. To determine the effect of attitude changes on the hydrodynamic derivatives during maneuvering, the hydrodynamic forces acting on the ship model with/without stern appendages are measured in three conditions: an even keel with the designed draft, and the same setup including hull rise or trim. For each condition, measurements are conducted for oblique motion, steady turning, and straight motion with heel, for various ship speeds. The hydro-dynamic derivatives excluding the attitude change are obtained from the measured results, along with the changes in these derivatives due to hull rise and trim. Using the hydrodynamic derivatives, the maneuverability indexes are calculated.

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48

Baital, Muhammad Sawal Baital, Kusnindar Priohutomo, Jatmika Prajayastanda, and Solichin Djazuli Sa'id. "PENGARUH THRUST DEDUCTION FACTOR DAN WAKE FRACTION TERHADAP EFISIENSI PROPULSI AKIBAT PERUBAHAN DRAFT KAPAL." Wave: Jurnal Ilmiah Teknologi Maritim 15, no. 1 (October 14, 2021): 21–30. http://dx.doi.org/10.29122/jurnalwave.v15i1.4759.

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This study is to investigate propulsion efficiency due to changes in draught of ship using data series and theoretical approach. A hard chain rescue boat with triplet screw was used for the study and to examine the effect of thrust deduction factor and wake fraction due to changes in draught of ship and its relevance to propulsion efficiency by observing hull and propeller interaction based on openwater test by Wageningen Data Series with cavitations analysis has been neglected. The study is done using hydrodynamics analysis for planning hull and using intersection between thrust characteristic curve with openwater test data series for fixed pitch propeller. The result indicated that the changes in ship draught are very influential on the changes in thrust deduction factor and wake fraction value which is one of the contributing factor to change the propulsion efficiency value 1% - 5%.

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49

Elkady, Hesham, Duan Feng Han, and Liang Gao Gao. "The Effect of Rise Angle of V-Hull Non Ballast Ship on Resistance Performance." Applied Mechanics and Materials 619 (August 2014): 110–14. http://dx.doi.org/10.4028/www.scientific.net/amm.619.110.

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In this paper a new concept in ship design was used to be alternative of ballast water system, to emerge that remedy the introduction of invasive marine species and the disadvantages of ballast water treatment systems.Thus, the hydrodynamic influences due to hull line variation of this kind of ships were studied, using the invariant cross-section area curve under the design draft to change the rise angle at bottom. Then numerical calculation was used to get the resistance and effective power at each angle. Two 3D models were constructed for 59000 DWT oil tankers and 35000 DWT bulk carriers, where the result of the bulk carrier was exposed.

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50

Panahi, Roozbeh, Amir Taherkhani, Soheil Radfar, and Ali Ghasemi. "Standardization of the main dimensions of design ships for the Caspian Sea ports." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 233, no. 2 (May 7, 2018): 540–50. http://dx.doi.org/10.1177/1475090218767303.

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Determination of the main dimensions of a nominated design ship is among the most important parameters when planning a port or performing port infrastructure detailed design. In this regard, port designers commonly use standards and handbooks. Inaccurate estimation of ship dimensions can increase the construction cost of a quay for the most-frequent ship of the area or decrease port efficiency. In some cases, main characteristics of the ship are affected by site-specific conditions. Owing to this fact, aforementioned general approach for all regions may not be accurate. In other words, a comprehensive statistical analysis on ship dimensions in such areas could be of great significance, to fill this knowledge gap. Caspian Sea, as the largest lake in the world, has such situation due to restrictions in its water connections as well as limited trade volume among its neighboring countries. So, in this research, a comprehensive statistical analysis has been conducted over a 17-year period data of Iranian port calls, to present more accurate and location-based formulae for general cargo carriers, bulk carriers and tankers at the region. Comparing the results of new formula with those suggested by well-known international guidelines clearly shows the importance of this study. In other words, there is a large difference between the length and the draft of typical ships in the Caspian Sea and those represented by generally accepted standards and handbooks.

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