Ship Sailing Research Articles

Extremity Tourniquet Training at High Seas

Future navy officers require unique training for emergency medical response in the isolated maritime environment. The authors issued a workshop on extremity bleeding control, using four different commercial extremity tourniquets onboard a training sail ship. The purposes were to assess participants' perceptions of this educational experience and evaluate self-application simplicity while navigating on high seas. A descriptive observational study was conducted as part of a workshop issued to volunteer training officers. A post-workshop survey collected their perceptions about the workshops' content usefulness and adequacy, tourniquet safety, self-application simplicity, and device preference. Tourniquet preference was measured by frequency count while the rest of the studied variables on a one-to-ten Likert scale. Frequencies and percentages were calculated for the studied variables, and application simplicity means compared using the ANOVA test (p < 0.05). Fifty-one Spanish training naval officers, aged 20 or 21, perceived high sea workshop content's usefulness, adequacy, and safety level at 8.6/10, 8.7/10, and 7.5/10, respectively. As for application simplicity, CAT and SAM-XT were rated equally with a mean of 8.5, followed by SWAT (7.9) and RATS (6.9), this one statistically different from the rest (p < 0.01). Windlass types were preferred by 94%. The training sail ship's extremity bleeding control workshop was perceived as useful and its content adequate by the participating midshipmen. Windlass types were regarded as easier to apply than elastic counterparts. They were also preferred by nine out of every ten participants.

Numerical prediction of ship motion and slamming load characteristics in cross wave

When waves from two weather systems converge at a certain sea area, cross waves can be produced. It is important to have a better understanding of the motion characteristics of ship in cross sea to ensure its navigation safety. In this paper, the motion responses of a S175 container ship hull in cross sea is first analyzed based on CFD technique using RANS method. VOF method is used to model and capture the free surface and overset grid technique is adopted to simulate ship motions in waves. Verifications on ship motion by the numerical method have been conducted for time step- and grid-independent studies. According to the motion results by numerical simulation, typical conditions are chosen for further investigation of slamming pressure on bow area and green water on deck. It is found that vertical motion responses of ship induced by cross waves can be quite large and the ship experienced obvious roll–pitch-coupled motion. Severe bow slamming and green water under cross sea state are also observed. The bow flare slamming pressure on the baseline can be quite large in symmetric cross wave. Asymmetrical slamming impacts occurred when the ship sails in an asymmetric cross wave field.

The Improvement of Local Shipping Safety in Makassar

Traditional Shipping is a traditional business of the people and has its own characteristics to carry out transportation in waters using sailing ships including Pinisi, Motorized Sailing Ships, and/or simple motorized boats of a certain size. Accidents in people's voyages still often occur in the waters of Makassar City. This study aims to analyze the improvement of local shipping safety in Makassar. This research is a qualitative descriptive method using SWOT analysis. The results of this study show 1). Seaworthiness Conditions of Traditional Ships regarding the implementation of procedures, information on weather conditions, seaworthiness conditions were in the very good category 53.3% and good category by 46.7%. 2). safety management and supervision of sea transportation in Makassar City have performed in accordance with applicable regulations and procedures so that the services provided in the excellent category were 50.0%, in the good category at 46.7%, and in the poor category 3.3%. 3). Plans to reduce shipping accidents in Makassar, namely the establishment of the Syandu Program (Syahbandar Education) program and conducting field supervision on 1x vessels are in a good category at 60.0% and in the very good category at 40.0%

Utilization The Ship Main Engine Cooling Water for Micro hydro Power Plants Design

Renewable energy is non-fossil energy derived from the nature and sustainable, also if properly managed, resources are depleted. The utilization of cooling water disposal on his boat as an energy-producing environment-friendly, by making use of the cooling water flow pressure machine ships as water turbine impeller assembled in such a way so it can generate electricity. Commercial ships usually have large size machines and most use large-capacity cooling system, so the cooling water flow capacity will be even greater as well. This prompted the opportunity to create an instrument for utilizing renewable energy flow of cooling water disposed in vain to rotate the propeller has been drafted into a micro hydro. And expected results can help reduce the workload of the auxiliary engines which will also have an impact on the reduction of fuel consumption. Fluid which flowed by the pump-the pump will rotate the intended water turbine that will generate electrical energy. When the ship sail, the lighting definitely need in each room, by using the electrical energy produced by the auxiliary engine, this water turbine can be applied then the fuel that had been used or consumed by the auxiliary engine can be replaced by the electric energy generated by the water turbines for light ships.

Transmission Path Tracking of Maritime COVID-19 Pandemic via Ship Sailing Pattern Mining

Since the spread of the coronavirus disease 2019 (COVID-19) pandemic, the transportation of cargo by ship has been seriously impacted. In order to prevent and control maritime COVID-19 transmission, it is of great significance to track and predict ship sailing behavior. As the nodes of cargo ship transportation networks, ports of call can reflect the sailing behavior of the cargo ship. Accurate hierarchical division of ports of call can help to clarify the navigation law of ships with different ship types and scales. For typical cargo ships, ships with deadweight over 10,000 tonnages account for 95.77% of total deadweight, and 592,244 berthing ships’ records were mined from automatic identification system (AIS) from January to October 2020. Considering ship type and ship scale, port hierarchy classification models are constructed to divide these ports into three kinds of specialized ports, including bulk, container, and tanker ports. For all types of specialized ports (considering ship scale), port call probability for corresponding ship type is higher than other ships, positively correlated with the ship deadweight if port scale is bigger than ship scale, and negatively correlated with the ship deadweight if port scale is smaller than ship scale. Moreover, port call probability for its corresponding ship type is positively correlated with ship deadweight, while port call probability for other ship types is negatively correlated with ship deadweight. Results indicate that a specialized port hierarchical clustering algorithm can divide the hierarchical structure of typical cargo ship calling ports, and is an effective method to track the maritime transmission path of the COVID-19 pandemic.

Application of surf-riding and broaching mode based on IMO second-generation intact stability criteria for previous ships

International Maritime Organization (IMO) have recently discussed the technical problems related to the second-generation intact stability criteria of ships. The second-generation intact stability criteria refer to five modes of vulnerability when the ship sailing in the ocean. In this study, we described a method to verify the criteria of the surf-riding/broaching. In case that Lv1 (Level 1) vulnerability criteria is not satisfied based on the relatively simple calculation using the Froude number ( Fn ), we presented the calculation procedure for the Lv2 (Level 2) criteria considering the hydrodynamics in waves. The results were reviewed based on the data for given previous ships. In absence of ship-specific data, a similar Lv2 result was confirmed by comparing the result obtained by calculating the added mass with the case where the added mass was 10% of the ship mass. This result will contribute to basic ship design process according to the IMO draft regulation.

A Practical Estimation Method of Inland Ship Speed Under Complex and Changeful Navigation Environment

The complexity and changefulness of inland navigation environment in space and time makes it hard to guarantee the applicability and accuracy of existing ship speed models. In this paper, a novel method for inland ship speed modelling under complex and changeful navigation environment is proposed. Firstly, an unsupervised machine learning algorithm, Density-Based Spatial Clustering of Application with Noise (DBSCAN), is utilized to cluster the environmental data including water level, water speed, wind speed and wind direction, to get the segment division information, which greatly helps reduce the influence of other uncertain environmental factors on the speed model. Then, Generalized Regression Neural Network (GRNN) is tailored and employed to build the ship speed estimation model with multiple input variables. Finally, a detailed case study of a ship sailing in the Yangtze River trunk line is conducted to validate the proposed methods. The results show that the ship speed model established based on machine learning methods works effectively in speed estimation and analysis. Moreover, compared with other regression methods and neural networks, the proposed GRNN model has the best performance in ship speed modelling.

Numerical Simulation of Ship Sailing In Regular Head Waves Using CFD Method

Numerical Simulation of Ship Sailing In Regular Head Waves Using CFD Method

Nonlinear dynamic characteristics of marine rotor-bearing system under coupled heave and pitch ship motions

The coupled heave and pitch motions of a ship sailing in head waves affect the stability of the marine rotor-bearing system. Based on the theory of analytical mechanics, this study establishes a dynamic model of the rotor-bearing system subjected to the coupled motions of heave and pitch, considering nonlinear oil film moments produced by the tilting of the rotor in the bearings. The nonlinear dynamic behaviours of the system are analysed using numerical methods to obtain Poincaré sections, bifurcation diagrams, and the largest Lyapunov exponents. The results show that dynamic bifurcation characteristics reveal complex quasi-periodic motion of upper and lower branches after the initial instability of the system, and the speed of second instability increase markedly. At high speeds, the amplitude of the rotor system increases sharply, which can cause the rotor to touch the inner wall of the bearings in the quasi-periodic state and a failure to transition to the chaotic state. Additionally, the effects of heave and pitch amplitude variations on the dynamic characteristics of the system are also discussed.

СНИЖЕНИЕ БОКОВОГО СМЕЩЕНИЯ СУДНА ПОСЛЕ МАНЕВРА ВВОДОМ ДОПОЛНИТЕЛЬНОЙ ПОПРАВКИ КУРСА

In work is specified, that navigation safety of sailing to a great extent depends on the errors of the navigation measuring, and also from operating reliability of sensors of navigation information. It is also marked that descriptions of exactness of gyroscopic compass influence on navigation safety. Because sizes of his errors the requirements providing the set exactness of determination of azimuthal directions are produced. At maneuvering of ship there are inertia errors which cause appearance of lateral displacement of ship after his turn, that can lead to the navigation failure of ship. Therefore, there is the problem of decline of lateral relocation bias of ship which appears after his turn, that conduces to the decline of navigation accident rate. The analysis of the last achievements and publications is resulted in work, the decision of the considered problem and selection of parts unsolved before is begun in which. Within the framework of theory endless rapid maneuver, expression for total inertia deviation which depends on character of maneuver and breadth of sailing of ship is resulted in the publication. It is shown that transversal relocation bias of ship is an integral function in relation to the function of deviation and for estimation of its size analytical expression is resulted, which it is visible from, that transversal displacement also depends on speed of ship after a maneuver. It is marked in the publication, that transversal displacement is more complete description of exactness of gyrocompass on the protracted time domains, as it represents the consequences of influencing of maneuvering on a gyrocompass in the «smoothed» kind out. From these positions, obviously, that inertia deviation is the index of instantaneous exactness of gyrocompass. Two methods of decline of transversal displacement of ship are offered, thus for estimation of efficiency of the offered procedure of indemnification of lateral displacement of ship the computer program allowing to produce the calculation of the crooked dependence of total inertia error from time with the subsequent graphic reflection was developed. The program also expects and builds the graphs of dependence of lateral displacement without indemnification, total lateral displacement with partial indemnification and with complete indemnification. The results of computer graphic design are resulted, which it ensues from, that total inertia error and lateral without indemnification is multiplied displacements with growth of breadth, during partial indemnification total lateral displacement diminishes approximately in 5 times, and at the variable additional amendment of course lateral displacement of ship is absent.

Joint Optimization of Ship Sailing Speed and Container Handling Rate for a Near-sea Liner Service Route

This paper jointly designs the optimal ship sailing speeds on shipping legs and the optimal handling rates at ports of a near-sea liner service route operated by a container liner shipping company. A mixed integer linear programming model is developed, which can be solved directly by the commercial solvers to give a global optimal solution. The model is further applied to a real-life case. Results demonstrate that both bunker price and unit inventory cost affect the optimal ship sailing speed and the optimal container handling rate.

CFD simulations for surf-riding occurrence assessment

Surf-riding phenomenon occurs when a ship sailing in following waves is accelerated to wave celerity. In this paper, surf-riding occurrence is studied for the parent hull of the Systematic Series D by 3 degrees of freedom (DOF) CFD simulations. Simulation cases are chosen following IMO recommendations for a wavelength to ship length range and following IMO criterion for ship speed cases. Initial conditions for simulations are obtained from 1-DOF surge motion equation solved by bifurcation analysis. The aim is to define surf-riding limits for ship operability with a less conservative approach, taking into account force changes in waves compared to the one used in the 1-DOF model, which considers calm water approximations. After defining surf-riding boundaries in terms of wave heights for different wavelengths and ship speeds, calculated forces are analysed to evaluate the magnitude and trend of non-linear effects due to wave elevation and ship-wave interaction. A detailed analysis is conducted on resistance, thrust, and wave forces in surging and surf-riding conditions, comparing the applied methodologies. The introduction of wave velocity field influence in the thrust force and the calculation of Froude-Krylov wave-force up to actual wave profile have been discussed and identified as possible improvements of 1-DOF approach.

Impact of ship operations aided by voyage optimization on a ship\u2019s fatigue assessment

In this study, different operation factors affecting a ship’s wave statistics are studied, such as the slow steaming and voyage optimizations. Especially, the impact of various voyage optimization methods on the long-term wave statistics and corresponding fatigue damage during ship operations is investigated by comparing the encountered waves with the design wave scatter diagram. Three years of full-scale measurements from a container ship sailing in the North Atlantic are employed to study the impact, in addition to noon reports from two fleets of container ships and VLCCs. Furthermore, the benefits of using voyage optimizations for minimum fatigue damage accumulation during operation are discussed. The large difference of wave statistics is found when the ship follows routes generated by various optimization methods and the design diagram. For some westbound voyages, the voyage optimization methods can significantly decrease the ship’s fatigue damage accumulations, leading to longer fatigue life.

A Hybrid Method for Predicting Ship Maneuverability in Regular Waves

Abstract Traditionally, ship maneuvering is analyzed under calm water condition. In a more realistic scenario, such as a ship sailing in waves, the importance of taking the wave effects into account should be stressed. In this context, this paper proposes a hybrid method for predicting ship maneuverability in regular waves by combining a potential flow theory based panel method and a Reynolds-averaged Navier–Stokes (RANS)-based computational fluid dynamics method. The mean wave drift forces are evaluated by applying a three-dimensional time-domain higher-order Rankine panel method, which takes the effects of ship's forward speed and lateral speed into consideration. The hull-related hydrodynamic derivatives in the equations of ship maneuvering motion are determined by using a RANS solver based on the double-body model. Then, the two-time scale method is applied to predict ship maneuvering in regular waves by integrating the seakeeping model in a three degrees-of-freedom MMG model for ship maneuvering motion. The numerical results of a laterally drifting S175 container ship, including the wave-induced motions, wave drift forces, and turning trajectories in regular waves, are presented and compared with the available experimental data in literature. The results show that the proposed hybrid method can be used for qualitatively predicting ship maneuvering behavior in regular waves.

Environmental effects of emission control areas and reduced speed zones on container ship operation

To examine the dual environmental effects of emission control areas (ECAs) and reduced speed zones (RSZs), this study formulates an integrated container ship operation optimization model based on the fundamental facet of liner-service market. Capturing the critical characteristics of container ship operation, the proposed model explicitly incorporates the entire voyage that consists of container ship sailing and port activities as well as nonproductive stay in port. Compared to the separate establishment of ECAs, joint regulations of ECAs and RSZs can lead to more SOx emission reduction within it and less profit loss of the container ship by means of differentiated operation. Meanwhile, the optimal operation speed inside ECAs and RSZs of profit maximization is 10.638 knots, applied to the case study of CSCL Pacific Ocean, the container ship sailing MEX route from Far East (Shanghai, China) to Persian Gulf (Dammam, Saudi Arabia). These findings can provide insights for liner operators in carrying out differentiated operation from the demand side, as well as environmental regulators in adjusting emission reduction regulations dynamically.

Editor's Column: “We are the jury”: Steinbeck's America under Threat

Editor's Column: “We are the jury”: Steinbeck's America under Threat

Connecting to Edward Flanders Ricketts through Mentors and an Iconic Ship Sailing in the Gulf of Alaska

Abstract This essay describes my connections to Edward Flanders Ricketts, fostered because I sailed on the ionic Western Flyer, the ship that Steinbeck and Ricketts chartered for their 1940 trip to the Sea of Cortez. I describe how I initially found out that the vessel was the same ship that I lived and worked on 1962–63 in Alaska. I then outline how my career as a marine researcher involved key mentors who were influenced by their communications with Ricketts or shared common ecological thinking. The Western Flyer is now being rebuilt as a vessel for marine education, and I speculate that Ricketts may have thought his spirit is perhaps imbued on the boat and could influence those who sail on her in the future.

Comparative Economic Analysis on SOx Scrubber Operation for ECA Sailing Vessel

The IMO (International Maritime Organization) has mandated the restriction of SOx emissions to 0.5 % for all international sailing vessels since January 2020. And, a number of countries have designated emission control areas for stricter environmental regulations. Three representative methods have been suggested to cope with these regulations; using low-sulphur oil, installing a scrubber, or using LNG (Liquefied Natural Gas) as fuel. In this paper, economic analysis was performed by comparing the method of installing a scrubber with the method of using low-sulphur oil without installing additional equipment. We suggested plausible layouts and compared the pros and cons of different scrubber types for retrofitting. We selected an international sailing ship as the target vessel and estimated payback time and benefits based on navigation route, fuel consumption, and installation and operation costs. Two case of oil prices were analyzed considering the uncertainty of fuel oil price fluctuation. We found that the expected payback time of investment varies from 1 year to 3.5 years depending on the operation ratio of emission control areas and the fuel oil price change.

Path Following of a Water-Jetted USV Based on Maneuverability Tests

Due to the high propulsive efficiency and better maneuverability under high speed, the water-jetted unmanned surface vehicle (USV) is widely studied and used. This paper presents complete maneuvering tests and control algorithm designed for a twin water-jetted USV model. Firstly, a wireless network control platform is established, and maneuvering tests, for instance, an inertia test, zig-zag test and turning test, are carried out to verify the maneuverability of the USV. In light of the complexity and uncertainty of ship sailing and ship handling, the Human Simulated Intelligent Control (HSIC) method is utilized to optimize the response time, accuracy and robustness of the controller. Finally, for the path following and track rectification part, a Line of Sight (LOS) algorithm is improved and proved practicable with triangle/square path tests. The proposed intelligent navigation algorithm specially designed for matching with the control methods, showing satisfactory improvements on the motion control and path following of the specific USV.

Model Based Robust Predictive Control of Ship Roll/Yaw Motions with Input Constraints

A robust H∞-type state feedback model predictive control (H∞-SFMPC) with input constraints is proposed to optimize the control performance during the ship sailing. Specifically, the approach employed in this paper is able to optimize the closed-loop performance with respect to an H∞-type cost function which predicts the system performance based on the actual model instead of the ideal model. As a result, the effect caused by disturbances is attenuated. The state feedback control gain for the control input of the rudder-fin joint roll/yaw control system is obtained by solving a constrained convex optimization problem in terms of linear matrix inequalities. Simulations are carried out, which reveal that the proposed approach has outstanding control performance. Furthermore, it is found that the approach also has significant robustness with respect to parameter uncertainties.