Ship Deck Research Articles

A data-driven, scenario-based human evacuation model for passenger ships addressing hybrid uncertainty

In a disaster at sea, the safe and timely removal of passengers from the ship is paramount. Here, a human evacuation plan enables passengers to be swiftly displaced from a risk area to one less so. Despite existing research on evacuation planning, there is a need for a more comprehensive model that considers various uncertainties and factors. This paper proposes an optimization evacuation model that balances uncertain variables, including passenger walking speed and travel distance, and deterministic factors like deck layout, door capacity, initial density, and corridor traffic flow. The model also accounts for varying starting locations and two levels of awareness—alert and non-alert. The model utilizes a data-driven technique, i.e., the k-means algorithm, to cluster historical data on speeds and generate scenarios. An adjustment scheme is applied to account for the ship's rolling motion, affecting passenger speeds during the evacuation planning period. Travel distance scenarios are produced to capture the impact of different route choices per passenger. A risk-neutral two-stage programming model is constructed to handle uncertainties. The model is tested on multiple problems for a passenger ship deck in day and night modes, revealing valuable managerial insights for the maritime safety sector.

Hierarchical condition-based maintenance planning for corrosion process considering natural environmental impact

Condition-based maintenance (CBM) powered by corrosion inspection is vital to ensure the service safety and availability of equipment structure, especially in harsh natural environments. Preventive repair and coating are two effective measures widely adopted in corrosion-centered CBM implementation, whose collaborative planning, however, is rarely reported in corrosion control models. This paper proposes a hierarchical CBM policy oriented to gradual corrosion deterioration, which quantifies the comprehensive effect of corrosive environment and uncertain coating lifetime. The long-term corrosion is governed by a generalized stochastic process incorporating multiple environmental factors. Inspections are equally spaced to reveal corrosion severity, followed by a combination of recoating, imperfect repair and replacement to restore structure health. In particular, repair is executed if the accumulated corrosion exceeds a safe control limit, and replacement is immediate if (a) the repair number attains a pre-set threshold, and (b) the residual corrosion after repair remains above the limit. The impact of random coating lifetime on CBM performance is also analytically analyzed. The long-run maintenance cost is minimized through the joint optimization of inspection interval, corrosion control limit, and imperfect repair number. The model applicability is demonstrated through numerical experiments conducted on ship deck structures under marine environment.

Investigation of Effect of Wind-Induced Vibration on Typical Frame Structures on the Open Decks of Large Cruise Ships Based on the Subdomain Method

Due to the tall and large superstructures of cruise ships, the wind-induced vibration of frame structure on open decks cannot be neglected. This study investigated the wind-induced vibration of a typical frame structure on a cruise ship by using wind tunnel tests and numerical simulations. Wind tunnel tests were conducted to explore the simulation methods of the fluid–structure interaction (FSI). CFD simulations were performed to obtain the wind field data of the entire ship, which was utilized as an input for the open deck through the subdomain method. Subsequently, wind-induced vibration simulations of the guide rail frame structure on the open deck was carried out under various wind conditions. The results revealed that employing the turbulence model SST k-ω had a good agreement with the experimental data. The entire ship’s CFD results have a significant impact on the subdomain’s wind-induced vibration results. The vibration frequency of the guide rail frame structure was mainly concentrated between 0.8–10.1 Hz. The most unfavorable conditions appear at the wind attack angles of 0° and 120°. This study can provide some instructive insights for the prediction of wind-induced vibration and control of typical structures on the open decks of large cruise ships.

Ultimate Strength Behaviour and Optimization of Laser-Welded Web-Core Sandwich Panels under In-Plane Compression

In pursuit of more efficient load-bearing solutions for ship deck panels of Very Large Crude Carriers exposed to vertical hull girder bending forces, laser-welded web-core sandwich panels are considered as an alternative to conventional stiffened panels. The primary goal is to identify a lighter steel sandwich structure capable of matching the ultimate strength of conventional counterparts. Utilizing non-linear finite element analysis, the ultimate strength of conventional decks subjected to uniaxial compression is assessed. Attention is then shifted to laser-welded sandwich panels, with a detailed examination of how various design parameters influence their performance. Specifically, four key design aspects of unidirectional vertical webs, including face thickness, web thickness, web height, and web spacing, are optimized to strike a balance between weight and strength through structural optimization techniques combined with the response surface method. Ultimately, a comparison is drawn between the ultimate strength of these innovative steel sandwich panels and their conventional, stiffened counterparts. The findings reveal that web-core sandwich panels, when employed as an alternative, result in a notable reduction in hull weight, thereby showcasing the potential for a more efficient and sustainable approach in the maritime industry.

МАТЕМАТИЧНА МОДЕЛЬ ПРОГНОЗУ ЗНАЧЕНЬ ОСНОВНИХ ХАРАКТЕРИСТИК МОРЕХІДНОГО СТАНУ ТАНКЕРА ПІСЛЯ ЗАВАНТАЖЕННЯ

Transportation of oil cargoes by the world tanker fleet takes place in various climatic zones with significant fluctuations in ambient temperature. When the temperature of the oil cargo increases, its volume will increase, which may lead to increasing the risks of the cargo spilling onto the ship's deck. International conventions and codes that regulate the transportation of crude oil and petroleum products allow the use of only 98% of the cargo capacity of the tanker, the remaining 2% is called the safety factor, i.e. the margin of volume for the unforeseen expansion of the cargo when sailing in different climatic zones. From the other hand, the intensity of cargo operations during the transportation of various types of cargo, including oil cargo, has led to an increase in the role of the "human factor" in ship’s energetic system. Reducing the number of ship crews leads to the accumulation of fatigue, distraction of the attention of ship operators (masters) in the process of increasing the intensity of carrying out cargo operations on the ship. A significant share of tanker fleet accidents occurs as a result of loss of control over the volume of bulk cargo that is accepted in each tank of the vessel. The operator's lack of accurate information about the state of each tank’s filling at the current moment of time leads to the risk of overflowing of a separate tank, which, in turn, can cause the spillage of bulk cargo, for example, petroleum products on the ship's deck and on the water surface of the port's water area. The relevance of these problems determines the direction of this research. For constant dynamic monitoring of the tanker parameters’ conformity during loading operations, considering parameters that maximally satisfy the requirements of maritime safety and taking into account all restrictions, such as the maximum permissible volumes of oil cargo in tanks, the current study proposes to use a mathematical model and create a system for automatic control of tanker loading. Keywords: oil cargo, tanker, level gauges, safety factor, loading control, mathematical model.

Analisis Kelalaian dalam Berdinas Jaga di Kapal MV. Andhika Kanishka pada Pelabuhan Muara Pantai saat Bongkar Muat

Negligence during duty on board has a significant negative impact on loading and unloading activities. Problems in loading and unloading activities often arise due to both internal and external factors such as human error, equipment issues, and natural conditions. This study aims to investigate negligence during duty on the MV. Andhika Kanishka ship at Muara Pantai Port, focusing on the factors, consequences, and strategies for addressing it. The research was conducted using a qualitative approach, involving direct observation, in-depth interviews, and documentary analysis, and data was triangulated for analysis. The subjects for interviews included the ship's captain and crew. The research results indicate that: 1) Factors contributing to negligence are carelessness and psychological factors; 2) Consequences include errors during loading, difficulty in closing hatches and hatch covers, and cross-deck becoming dirty; and 3) Strategies for addressing negligence during duty involve maintaining communication, shifting cargo, and cleaning the ship's deck.

Математическая модель стабилизированной платформы с электрогидроприводом на корабле

Stabilized platforms are used on all types of moving vehicles, from satellites to submarines, and are even used on some portable and terrestrial devices. For example, a stabilized platform on a ship is used to accommodate navigation equipment and antennas of radar communication systems, which improves the efficiency of this equipment under the influence of wave disturbances. There are various kinematic schemes for building ship stabilized platforms. In particular, serial stabilized platforms and parallel stabilized platforms are used. In practical applications, serial stabilized platforms have found wider use. In this paper, we consider a mathematical model of a ship-based stabilized platform with two degrees of freedom, where the angular orientation of the platform is controlled using electric hydraulic drives. The use of electro-hydraulic drives makes it possible to ensure the formation of the required magnitude of the force effect to compensate for disturbances from wave oscillations of the ship's deck. In order to obtain relations for describing the relationship between the angular displacements of the elements of the kinematic scheme of the platform and the displacement of the hydraulic cylinder rod, the apparatus of complex numbers is involved in this work. A mathematical model of an electrohydraulic drive is considered taking into account the dynamics of movement of the electromechanism of a spool servo valve, the flow rates and pressures of the working fluid in the cavities of the hydraulic cylinder. A linearized mathematical model of an electrohydraulic drive is considered, and estimates are obtained for the parameters of the obtained mathematical model for given mass-dimensional characteristics of an electrohydraulic drive. This mathematical model can be used in the synthesis of an electric hydraulic drive control system to provide a given angular orientation of the platform under the action of wave disturbances.

The Container Thinks It’s Upside Down, and Other Stories of Automation

A container cannot speak, but thanks to digitization and automation, it can now complain. The COVID pandemic and the pressures leveraged by its consequences on the global economy have brought sudden attention to the supply chain and the transport industry which powers it. While shortages and delays drew attention, industry players accelerated the digitization and automation of the industry. From the staging grounds of rail yards to warehouse floors, from the decks of massive container ships to the cubicles of office buildings, a concerted push for the automation of work is underway. Drawing on industry experience and interlocutors from a wide breadth of the logistics industry, we discuss the pressures and motivating factors that underpin this effort.

Dynamic Evacuation Routes Navigation for Passenger Ship Fire Based on Intelligence Algorithms

AbstractTo explore fire hazards and provide real‐time path navigation services for passenger ships, this study proposes an improved artificial fish swarm algorithm (IAFSA) to give the optimal evacuation route for evacuees when a passenger ship is on fire. First, the PyroSim software is used to simulate the fire scene on the sixth deck of the passenger ship. Through which the real‐time temperature, carbon monoxide (CO) concentration, and visibility of each exit are obtained, and the spread speed of the fire hazard area is determined. Then, the artificial fish swarm algorithm is improved by using the dynamic Visual and step, and the optimal path planning for the evacuation of passenger ships is achieved. The Visualized Evacuation Guidance System (VEGS) is developed to provide the optimal route for evacuees on the passenger ship. Finally, VEGS is applied to the fire evacuation of passenger ships. The results show that VEGS can provide the optimal evacuation path for evacuees and avoid detours in fire hazard areas compared with other algorithms. Seventy‐five percent of the evacuees who used VEGS in the event of a passenger ship can escape in a time shortened by up to 40.8%.

Sustainable Perforated Acoustic Wooden Panels Designed Using Third-Degree-of-Freedom Bezier Curves with Broadband Sound Absorption Coefficients.

The current interior design scope places high demands on acoustic treatment manufacturers. The state of the art does not provide satisfactory material proposals for architects to satisfy design needs. There is a need for a novel approach concerning decorative, recognized materials that adapts them to the acoustic surface properties. The final design proposed in this study presents a modern functional solution with high acoustic properties, which can be produced with sustainable materials such as FSC wood and has a low environmental impact because of its low waste production. This research presents the complete design process of a novel type of wooden acoustic panel. A comprehensive explanation of the scientific development is covered, including basic material testing in an impedance tube, FEM simulations of the initial designs, and final measurements in a reverberation chamber. The solution's novelty is based on the optimized placement of the perforation holes on the surface of a wooden overlay using a ship deck optimization algorithm. The methods used cover the original solution of mixing FEM modeling of the surface impedance with the application of the Jeong-Thomasson correction for random incidence sound absorption coefficient simulation. The contribution of this research is the development of wooden perforated panels with Class A sound absorption and an overall depth of 90 mm, including the 50 mm depth of the backing material. The discussion will explain the difficulties of working with this material and the need for a combination of the aesthetic and acoustic sides of the project.

A Newly Proposed Method for Hydrogen Storage in a Metal Hydride Storage Tank Intended for Maritime and Inland Shipping

The utilisation of hydrogen in ships has important potential in terms of achieving the decarbonisation of waterway transport, which produces approximately 3% of the world’s total emissions. However, the utilisation of hydrogen drives in maritime and inland shipping is conditioned by the efficient and safe storage of hydrogen as an energy carrier on ship decks. Regardless of the type, the constructional design and the purpose of the aforesaid vessels, the preferred method for hydrogen storage on ships is currently high-pressure storage, with an operating pressure of the fuel storage tanks amounting to tens of MPa. Alternative methods for hydrogen storage include storing the hydrogen in its liquid form, or in hydrides as adsorbed hydrogen and reformed fuels. In the present article, a method for hydrogen storage in metal hydrides is discussed, particularly in a certified low-pressure metal hydride storage tank—the MNTZV-159. The article also analyses the 2D heat conduction in a transversal cross-section of the MNTZV-159 storage tank, for the purpose of creating a final design of the shape of a heat exchanger (intensifier) that will help to shorten the total time of hydrogen absorption into the alloy, i.e., the filling process. Based on the performed 3D calculations for heat conduction, the optimisation and implementation of the intensifier into the internal volume of a metal hydride alloy will increase the performance efficiency of the shell heat exchanger of the MNTZV-159 storage tank. The optimised design increased the cooling power by 46.1%, which shortened the refuelling time by 41% to 2351 s. During that time, the cooling system, which comprised the newly designed internal heat transfer intensifier, was capable of eliminating the total heat from the surface of the storage tank, thus preventing a pressure increase above the allowable value of 30 bar.

Numerical studies on the aeroelasticity of a shipboard helicopter rotor during engagement and disengagement with ship motions using CFD/CSD coupling approach

When the shipboard helicopter rotor engages and disengages on a ship deck, due to the influence of wind-over-deck environment and ship airwake, the heterogeneity of rotor airload is large. This large heterogeneity leads to the fluctuation of blade deflection which changes the aerodynamic forces and causes danger of over deflection. To investigate the aeroelasticity of a rotor blade and find the rule of deflection and the deformed blade aerodynamic force in the rotor/ship coupling flow field, we establish a loose computational fluid dynamics/computational structural dynamics (CFD/CSD) coupling model. This coupling model simulates the aeroelastic characteristics of the shipboard helicopter rotor during engagement and disengagement with ship motions. In the simulation, the CFD solver is based on Reynolds-averaged Navier-Stokes (RANS) equations and the CSD solver is based on the moderate deflection beam model. We compare the results with the experimental data and verify the effectiveness of the simulation. Through the analysis of the flow field, blade deflection, and aerodynamic forces under various wind-over-deck conditions at different positions, we find in certain cases, that the elastic deflection has a significant impaction the blade aerodynamic force. As the wind direction anglesincrease, the rotor blade is more likely to have a large negative elastic twist deflection, causing drop of aerodynamic forces and danger of over deflection.

Lyapunov-Based Model Predictive Control for Shipboard Boom Cranes Under Input Saturation

A Lyapunov-based model predictive control (MPC) scheme is firstly developed for shipboard boom cranes with ship rolling, while considering optimization and input saturation. By integrating the ship rolling into original state variables, the shipboard boom crane model is transformed to facilitate the successive controller design. A Lyapunov-based MPC framework is then constructed for the new dynamical model, while respecting actuator capability. To ensure the recursive feasibility and stability of the established framework, a contractive constraint with a bounded energy-based controller is further introduced, for which the bounds are intrinsical with the utilization of the arctan function. Stability analysis for the bounded controller is also discussed based on Lyapunov theory and LaSalle&#x2019;s invariance principle. Compared with the bounded controller, optimization is taken into account by the Lyapunov-based MPC. Suboptimal solutions are also accepted to ease the computational burden. Moreover, the conservation existing in the bounded controller can be entirely circumvented by the Lyapunov-based MPC, so the capacity of actuators can be fully exploited while obeying the input saturation. Finally, numerical simulations are elaborately devised and implemented to show the effectiveness of the bounded controller and superiority of the Lyapunov-based MPC controller. <i>Note to Practitioners</i>&#x2014;Shipboard crane is an important industrial equipment in ocean transportation and offshore engineering. Cranes are installed on ship deck, so the movements of ship, such as rolling, and pitching, may introduce difficulties, inefficiency, and unsafety to the manual operation. The conditions mentioned above motivate the study of automation control for shipboard cranes. A Lyapunov-based model predictive control (MPC) framework is constructed in this paper. Based on this framework, the payload can be conveyed to the desired location accurately and eliminate the swing quickly. Simultaneously, optimization is considered, thus, better control performance can be achieved by consuming less energy. Moreover, the physical limits of the actuators can be satisfied all the time. The present research only considers 3 degrees of freedom (DOF) shipboard boom cranes, for which the slew movement of boom and payload tangential swing are not involved. In the future research, the 5-DOF shipboard boom cranes will be studied to promote the application of the method proposed in this paper.

Numerical evaluation of wind direction effects on the turbulence aerodynamics of a ship airwake

The airwake characteristics around a ship body are an important consideration for helicopter pilots during shipboard operations, as airwake can lead to the formation of massively turbulent flow over the ship deck. Therefore, this study conducted a delayed detached eddy simulation (DDES) to investigate the impact of the bow part of the ship and the wind direction on the turbulent flow characteristics of the ship deck airwake. Numerical simulations were performed for two different ship models (1:12.5) of the Simple Frigate Shape 1 and 2 (SPF1 and SFS2) to analyze the influence of the bow part on the deck flow-field. Seven different orientations of wind direction angle (HW, RW15, RW30, RW45, RW60, RW75, and RW90) were numerically simulated for SFS1. The time-averaged velocity and pressure fields computed by the DDES approach were validated in comparison to those of the experimental data measured by the PIV data and Kulite pressure sensors, respectively, at various locations over the ship deck. The numerical data revealed that, while the deck flow-field is not influenced by the bow of the ship, the airwake flow is significantly affected by the wind direction angle. Specifically, as the wind direction angle is increased, the turbulent kinetic energy is also increased and the flow-field becomes more asymmetric. Moreover, the spectral analysis and time/space assessment of the flow field showed more pressure fluctuations and a higher level of unsteadiness over the ship deck with a larger wind direction angle, which are important parameters in shipboard operations.

Critical aspects of electromagnetic compatibility on board ships

The electromagnetic environment on board a military ship is a bounded space with disturbance sources and receivers. It is defined by the maximum disturbance levels in each interior compartment and on the ship's decks. The electromagnetic environment on board a ship is extremely complex, as it depends to a large extent on the density of equipment on board, the characteristics of the equipment installed (frequency bands, power, modulation types, etc.), the measures to prevent electromagnetic radiation pollution taken by designing the ship in such a way that the electromagnetic field strength inside the ship is as low as possible, with reduced risks to the normal operation of the equipment on board and to the personnel on board. The installation of radars in the on-board electromagnetic environment requires an analysis of the electromagnetic compatibility standards that apply to them. To prevent electromagnetic interference in such systems involves describing the composition of the environment and the interaction between different components. The paper presents a risk-based characterisation of the on-board electromagnetic environment for electromagnetic compatibility analysis.

Numerical analysis on extinguishing of sprinklers in a hydrogen pool fire

Due to the strengthened air pollution regulations, research on hydrogen commercialization is being actively conducted. However, there is a lack of research on the use of hydrogen on ships and the fires. The fire dynamics simulator (FDS, ver. 6.7.8) was used to evaluate optimal sprinkler parameters when the fire broke out after the liquid hydrogen leaked from hydrogen storage tank on the ship's deck using hydrogen fuel cell and formed a pool. It was simulated that simulations were performed to evaluate suitable parameters, droplet size and spray velocity, for extinguishing the hydrogen pool fire and to apprehend the optimal number of sprinklers with suitable parameters. The results indicate that the fire could not be completely extinguished when a low spray velocity of 10 m/s and a large droplet size of 300 μm were set, but the temperature of the fire source could be effectively suppressed when suitable parameters (30 m/s, 30 μm) were selected. However, because one sprinkler with selected conditions was not able to completely extinguish the hydrogen pool fire, it was derived that three or more sprinkler have to be installed. Based on these results, this study presented the minimum extinguishing conditions in the marine system, which is a limited environment.

Experimental study of fire containment using water mist curtains in a reduced-scale deck of a ro-ro ship

Experiments have been conducted to evaluate the containment of smoke and heat using water mist curtains in a model setup of a ro-ro ship's cargo deck with a scale of 1:13, providing practical insights into the application of such fire protection systems in the cargo deck as well as valuable data for future numerical simulations. In this regard, the requirements of the international convention of Safety of Life at Sea (SOLAS) are studied for the side openings of so-called ‘open decks’ in comparison with ‘closed decks’, especially to examine the feasibility of using water mist curtains for creating isolated subdivisions in the ro-ro space as a fire management strategy. The water mist curtains are created with one or two rows of water mist nozzles at pressures ranging from 3 to 8 bar, while the source of smoke and heat is a liquid pool fire, and inert cargo items are used in some experiments. Correspondingly, the interaction between the water mist curtain(s) and the fire is evaluated in terms of its heat release rate, and the containment effect is quantified via measurements of smoke flow through the deck and through the windows, concentrations of gaseous species, as well as gas temperatures at various key locations. The study shows that water mist curtains have a strong effect on fire dynamics and smoke propagation, but containment is dependent on the configuration of side openings and the location of fire, among other important factors.

Modelling green water loads on ships using coupled impulse response function and CFD solution

A 3D coupled method is used to model green water and to study numerically the influence of wavelength, wave steepness, and bow rake angle on the green water occurrence and peak pressure on a ship deck. To do that, the global motions of the vessel are obtained in the time domain using an impulse response function. The local hydrodynamic forces of green water load are computed using a commercial CFD solver together with the Volume of Fluid method. The approach is validated using in-house experimental results. Then a systematic parametric study is performed to understand the effect of several geometric and environmental parameters on green water loads. The results indicate that peak pressure due to green water increases significantly with vessel speed for all the wavelengths investigated and decreases with the increase of bow rake angle.

LQR and LQG control of the helicopter during landing on the ship deck

PurposeThe purpose of this study is to test the performance of the designed automatic control system based on the Linear Quadratic Regulator (LQR) and Linear Quadratic Gaussian (LQG) algorithms during landing of the helicopter on the ship deck. This paper is a further development of the series based on Topczewski et al. (2020).Design/methodology/approachThe system consists of two automatic control algorithms based on LQR and the LQG. It is integrated with the ship motion prediction system based on autoregressive algorithm with parameters calculated using Burg’s method. It is assumed that the source of necessary navigation data is integrated Inertial Navigation System with Global Positioning System. Landing of the helicopter on the ship deck is performed in automatic way, based on the preselected procedure. Performance of the control system is analyzed when all necessary navigation data is available for the system and in case when one of the parameters is unavailable during performing the procedure.FindingsIn this paper, description of the designed control system developed for performing the approach and landing of the helicopter using selected procedure is presented. Helicopter dynamic model is validated using the manufacturer data and by test pilots, overview is presented. Necessary information about ship motion model is also included. Tests showing mission performance while using LQR and LQG algorithms applied to the control system are presented and analyzed, taking into account both situations when full navigation data is available/unavailable for the control system.Practical implicationsResults of the system performance analyses can be used for selection of the proper control methodology for prospective helicopters autopilots. Furthermore, the system can be used to analyze the mission safety when information about one of the navigation parameters is identified by the navigation system as unavailable or incorrect and therefore unavailable during landing on the ship deck.Originality/valueIn this paper, control system dedicated for the automatic landing of the helicopter on the ship deck, based on two different control algorithms is presented. Influence of lack of information about one of the navigation parameters on the mission performance is analyzed.

Rotorcraft Robotic Landing Gear With Locking Mechanisms

Abstract Robotic landing gear (RLG) for rotorcraft improves performance in landing on sloped uneven terrain, unprepared areas, and ship decks. The interaction between the feet of the RLG and the landing surface are pivotal to a successful landing event. Slipping or bouncing of the feet can lead to a failed landing and a catastrophic accident. Proposed herein is the use of locking mechanisms on the RLG feet in order to eliminate landing gear slip and bounce during the landing event. Through the use of a comprehensive multibody dynamic simulation, locking mechanisms on the RLG feet are shown to eliminate landing event failures that can occur with nonlocking landing gear configurations, at the expense of a moderate increase in landing gear loads during a landing event. Results indicate that landing event failures are eliminated even in the situation where some feet-locking mechanisms are inoperable or break away. Furthermore, RLG with feet locking mechanisms permit the reduction or elimination of the need for active control of the RLG legs. The results herein give guidance to the development of integrated RLG with locking mechanisms.