rss_2.0Sciendo RSS Feed for Polish Maritime Researchhttps://sciendo.com/journal/POMRhttps://www.sciendo.comhttps://sciendo-parsed.s3.eu-central-1.amazonaws.com/6472860f215d2f6c89dcb59f/cover-image.jpghttps://sciendo.com/journal/POMR140216https://sciendo.com/article/10.2478/pomr-2024-0032<abstract> <title style='display:none'>Abstract</title> <p>The assessment of ship manoeuvring properties is a crucial part of the process of ship design and is usually first carried out during the model test phase of the project. According to the International Maritime Organisation (IMO), the manoeuvrability of the ship can be assessed on the basis of the standard trial manoeuvres. In order to do this, free running model tests or captive model tests are used, in conjunction with a mathematical model of ship motion; this is considered to be a reliable prediction method. In recent years, numerical-based methods have also been widely used in ship hydrodynamics and constantly improving computing power and more accurate fluid dynamics models have made the simulation of more complex cases possible. The study presented in this paper focuses on the determination of propeller-rudder-hull interaction coefficients based on the Mathematical Modelling Group (MMG) standard method in ship manoeuvring prediction. The identification of the parameters uses both captive model tests and a simplified numerical method, as well as regression formulas. The results of 35° turning and 10°/10° zig-zag manoeuvres, obtained with the use of each prediction method, are then compared. The test case used in the study is the container type cargo ship equipped with a single propeller and rudder. The model scale, for which the referenced model tests were carried out, is equal to 1:25 and a NACA 0020 rudder profile was used. This research highlights the advantages and disadvantages of each presented prediction method and their potential for future improvement.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00322024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0044<abstract> <title style='display:none'>Abstract</title> <p>Despite technological progress in the maritime industry, navigators are still the final link of the decision-making chain and rely not only on equipment, but also on human senses. Visual observation of the vessel’s surroundings still plays a crucial role in navigation. Four different ships in service were visited to investigate the work of professional navigators and carry out a pilot experiment on real crews to test the methods for future full-scale research. The main objective was to better understand the influence of bridge design on lookout routines of navigators, while the additional goals were to check the presence of navigators in certain parts of the bridge and to determine if it is reasonable to forbid navigators to sit, as the practice is still used on some ships. Considering space limitations and differences in layouts of the wheelhouse, rarely mentioned in this kind of study, the movement of watch-keeping officers was analysed. In total, twenty observations were made to generate the heatmaps of presence during the routine duties. The results of the research indicate that many factors, including bridge design and layout of equipment, might affect lookout routines but it is possible to find similar patterns on the bridges of different shapes and arrangements. The pilot experiment confirms that it is reasonable to carry out a full-scale study, as there is still room for improvement in the area of ergonomic bridge design. Better understanding of modern lookout and movement routines might lead to the development of adequate ergonomic regulations and result in increased work comfort and the well-being of seafarers.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00442024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0038<abstract> <title style='display:none'>Abstract</title> <p>Marine diesel engines work in an environment with multiple excitation sources. Effective feature extraction and fault diagnosis of diesel engine vibration signals have become a hot research topic. Time-domain synchronous averaging (TSA) can effectively handle vibration signals. However, the key phase signal required for TSA is difficult to obtain. During signal processing, it can result in the loss of information on fault features. In addition, frequency multiplication signal waveforms are mixed. To address this problem, a multi-scale time-domain averaging decomposition (MTAD) method is proposed and combined with signal-to-image conversion and a convolutional neural network (CNN), to perform fault diagnosis on a marine diesel engine. Firstly, the vibration signals are decomposed by MTAD. The MTAD method does not require the acquisition of the key phase signal and can effectively overcome signal aliasing. Secondly, the decomposed signal components are converted into 2-D images by signal-to-image conversion. Finally, the 2-D images are input into the CNN for adaptive feature extraction and fault diagnosis. Through experiments, it is verified that the proposed method has certain noise immunity and superiority in marine diesel engine fault diagnosis.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00382024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0035<abstract> <title style='display:none'>Abstract</title> <p>The aim of this study was to assess the feasibility of creating a prototype of a self-sufficient houseboat that is capable of prolonged independence from power grids and freshwater sources. In this design, electricity demand is met by a photovoltaic installation, and the energy is stored in batteries. Fresh water for living needs may be obtained from many sources, depending on the environmental conditions, such as through purifying outboard water, desalinating seawater, and collecting and storing rainwater. No waste production of the vessel can be achieved in two ways: waste can be treated and discharged into a body of water, or processed into fertiliser for later use in agriculture. Four possible locations were analysed: Rome, Lisbon, Gdańsk and Stockholm. The findings reveal that the length of time for which the unit is autonomous and emission-free depends on the geographical location of the facility. In periods when there is overproduction of energy, the system can produce hydrogen, donate energy to the grid, use it for the needs of its own movement, or perform other useful work, e.g. cleaning or aerating the water body on which it is floating.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00352024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0041<abstract> <title style='display:none'>Abstract</title> <p>This article details the development and evaluation of a novel wave energy converter (WEC) aimed at efficiently capturing wave energy for electricity production. The study employs Computational Fluid Dynamics (CFD) techniques, specifically the URANS method and the k-ω SST turbulence model, to solve the Navier-Stokes equations and capture the free surface using the Volume of Fluid (VOF) model. The CFD results are validated against experimental data to ensure accuracy. Various design parameters of the proposed device were tested, revealing that the arms and bottom angle significantly affect its performance. Unlike the floating Wave Dragon (WD) device, which utilises potential energy and is set in deep water, the new fixed-seabed device is positioned in the transitional wave region near the shore, where waves retain 80% of their energy. It can be constructed from environmentally friendly cement, making it resistant to hurricanes and suitable for any wave turbine in the open sea. The MP687 turbine was used to capture the wave energy in the proposed device, testing its performance in three positions: in the open sea, in the middle of the device, and at the device’s outlet. The results show that the device significantly enhances wave energy concentration, especially when the turbine is placed at the outlet. The proposed device offers numerous advantages, including its fixed position in a high-energy wave zone, the efficient use of turbulent kinetic energy, and robust construction that can withstand storms.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00412024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0033<abstract> <title style='display:none'>Abstract</title> <p>A semi-planing catamaran is a type of marine craft that benefits from high speed, in conjunction with the its inherent characteristics such as a large deck and high transverse stability. The aspect ratio, length over the beam of a demi-hull, significantly affects the hydrodynamic performance of this vessel. In this study, the effects of the aspect ratio on the hydrodynamic performance of a semi-planing catamaran in calm water and waves are investigated using numerical simulations. The numerical simulation of the AUT-SEM00 model itself is validated by its model test results. The results show that increasing the aspect ratio significantly increases the wetted surface, and that the increase in resistance in calm water is negligible. In addition, increasing the aspect ratio radically reduces the amplitude of vertical acceleration in waves at the center of gravity by up to 85%. Consequently, the seakeeping performance is considerably improved, and the risk to crew and equipment is reduced.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00332024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0036<abstract> <title style='display:none'>Abstract</title> <p>During the operation of jack-up offshore platforms, the complex and variable seabed geological conditions involved can lead to serious accidents, such as pile leg punctures and platform tilt. The aim of this study is to introduce an early warning method for punctures that ensures the operational safety of these platforms. To accomplish this, a real-time monitoring and controlling system is designed using a programmable logic controller that shares data from sensors measuring displacement, tilt, and pressure. In addition, an experimental device is constructed to simulate a jack-up offshore platform in order to assess the safety response of the control system. The working state of the platform under different working conditions (puncture of one independent pile, same side or diagonal piles, and three-pile linkage) is evaluated by analysing the structural motion response, including platform tilt and foundation pressure. The findings reveal that the system developed in this study accurately detects the tilt condition of the offshore platform, and can ensure the operational safety of jack-up offshore platforms.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00362024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0031<abstract> <title style='display:none'>Abstract</title> <p>The roll damping coefficient is essential when considering the viscous effect in the potential-based hydrodynamic analysis of fishing vessels; it is an important factor in the roll motion response. The present study performs free roll decay simulations, altering weight variables using Computational Fluid Dynamics (CFD) to investigate the correlation between the roll damping coefficient and the weight variation of a fishing vessel. The time series of roll amplitude and roll damping coefficient are compared, for varying vertical and longitudinal centres of gravity and radii of gyration in roll motion. As the vertical centre of gravity increases, both the roll decay period and the roll damping coefficient also increase. The roll decay period tends to increase with the increase in the radius of gyration during roll motion, while the roll damping coefficient exhibits a decrease. A longitudinal centre of gravity has a limited effect on free roll decay characteristics. The roll damping coefficients between the maximum and minimum combinations of weight variables show significant differences. The findings of the present study could enhance the understanding of the safety of fishing vessels based on their loading conditions. Consequently, future research could further improve the results obtained in the present study by considering various hull shapes and speeds.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00312024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0034<abstract> <title style='display:none'>Abstract</title> <p>Computing the power required to meet a ship’s operational needs is one of the most important tasks in naval design. The power required to propel a vessel is directly related to the resistance the hull experiences as it moves through the water. The conventional method of determining a ship’s resistance involves towing tank tests of ship models at a fixed speed; however, for short-range vessels, where constant speed is not the primary mode of operation, a dynamic model is needed. This paper demonstrates a way in which different operational motion profile models can be retrieved from the acceleration stage of towing tank tests. We show that the data from the acceleration stage, often overlooked in towing tank tests, allow us to derive the gliding equations of motion. A dynamic model of a small inland ferry on the Motława River in the city of Gdańsk is developed, which enables optimisation of the required power based on different operation profiles.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00342024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0045<abstract> <title style='display:none'>Abstract</title> <p>Autonomous underwater vehicles are increasingly frequently used in the fields of ocean observation, data collection, and tactical surveillance. Underwater navigation and near real-time communication are the most important factors limiting the performance of these vehicles. In this article, an underwater acoustic communication and positioning system (UACPS) based on heterogeneous gliders is presented. The system consists of an acoustic wave glider and an acoustic underwater glider, and includes an ultrashort baseline and an acoustic modem. The program and communication protocol of the communication and positioning algorithm are independently developed, and the hardware circuit design of the communication and ultra-short baseline positioning, as well as the embedded surface wave gliders and gliders are independently implemented. Sea trial results indicate that the communication distance of the system is more than 3 km and the positioning error is less than 5%. With the further improvement of system performance, the low cost, long time, long distance and near real-time communication characteristics of our UACPS can be used to integrate multiple autonomous unmanned platforms as part of intelligent surveillance robot networks.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00452024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0040<abstract> <title style='display:none'>Abstract</title> <p>When loading liquefied natural gas (LNG) onto a dual-fuel LNG container ship fuelled by LNG, there is a considerable temperature difference between LNG and the fuel tank at room temperature. The current solution is to pre-cool the tank with LNG through a spray line but the cooling process, if not correctly handled, can result in excessive cooling rates and Boil-Off Gas (BOG), which can expose the tank to increased temperature stress and gas pressure. Therefore, this paper takes the Mark III fuel tank of a specific type of LNG container ship as the object and realises a real-time predictive control system by writing a UDF (User Defined Function) to simulate and analyse the influence of LNG spray rate on the change of cooling effect, cooling time and cooling cost under the unidirectional LNG spray cooling mode. Compared with the results of the fuel tank gas experiment, the deviation of numerical model simulation results is less than 5%. Under the same cooling rate, the real-time control scheme can achieve a more uniform cooling rate and reduce the total LNG consumption by 25%. With the increase in LNG cooling rate, the cooling time, LNG usage, and the total BOG exhaust volume all decrease; however, the decreased range gradually decreases as well. The results of this paper provide parameters and suggestions for optimising and improving the LNG fuel tank cooling monitoring and control system.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00402024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0042<abstract> <title style='display:none'>Abstract</title> <p>This paper deals with the key operational problems of wind turbosets, especially offshore, where vibrations are generated by rotor blades, as a consequence of erosive wear or icing. The primary causes of the imbalance of wind turbine rotors have been characterised, the observable symptoms of which include various forms of vibrations, transmitted from the turbine wheel to the bearing nodes of the power train components. Their identification was the result of an active diagnostic experiment, which actually entered the aerodynamic-mass imbalance of a turbine rotor into a wind power train, built as a small scale model. The recording of the observed monitoring parameters (vibration, aerodynamic, mechanical and electrical) made it possible to determine a set of symptoms (syndrome) of the deteriorated (entered) dynamic state of the entire wind turboset. This provides the basis for positive verification of the assumed concept and methodology of diagnostic testing, the constructed laboratory station and the measuring equipment used. For this reason, testing continued, taking into account the known and recognisable faults that most often occur during the operation of offshore wind turbosets. Transferring the results of this type of model research to full-size, real objects makes it possible to detect secondary (fatigue) damage to the elements transmitting torque from the wind turbine rotor to the generator early, especially the thrust bearings or gear wheel teeth.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00422024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0037<abstract> <title style='display:none'>Abstract</title> <p>Using modern high-performance microcontrollers with wireless interfaces, built-in ADCs and low overall consumption, we develop a portable, real-time parametric diagnostic system for marine engines. The system is based on the use of modern Android/iOS gadgets that receive information from sensors via Bluetooth and then carry out the necessary calculations and display charts and data in real time. The system developed here uses a combination of a gas pressure sensor in the working cylinder and a vibroacoustic sensor, which expands the diagnostic capabilities of marine diesel engines under operating conditions. This solution allows for diagnosis of the fuel injection system, the valve train mechanism, and several other engine systems. In order to develop a portable diagnostic system for marine diesel engines, it is first necessary to solve the problem of analytically determining top dead centre (TDC), since such a system does not use special sensors for this. An algorithm for determining TDC is proposed here, based on an analysis of the measured pressure diagram rather than its derivative, which minimises the influence of digital and analogue noise. Our algorithm for determining TDC and subsequent data synchronisation is applicable in the absence of information about the actual compression ratio in the cylinder, which is a typical scenario for modern engines with variable valve timing. The algorithm also works under conditions of only approximate data on the charge air pressure, which are refined during the iteration process. A formula is proposed for determining the initial TDC position. Parameters for irregular operation of the engine are considered, and can be calculated in real time using time diagrams of pressure and vibration. Methods for expressly assessing the stability of the functioning of the main engine systems by monitoring and analysing a number of successive operating cycles are considered. To assess the unevenness of operation of the engine, a dispersion estimate of the deviations in the main parameters is used. To enable a comprehensive assessment of the engine stability in real time, the CII (cycle irregularity index) criterion is developed. The data processing methods described in this article provide an accurate estimate of the indicated power, due to the precise determination of TDC, thereby enabling an analysis of the stability of the operating cycles, optimal tuning of the engine systems, and monitoring of the results during operation.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00372024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0039<abstract> <title style='display:none'>Abstract</title> <p>Heat recovery of exhaust gases from main and auxiliary marine diesel engines is an effective way to improve the technical and economic parameters of marine power plants. Improvements in engine efficiency necessitate an increase in the weight-size parameters of the waste heat boilers, which makes it difficult to recover heat. Intensification of the heat transfer process is considered to be an effective way to reduce these indicators. By utilising mathematical modelling, this paper shows the effectiveness of using profiled heating surfaces of waste heat boilers for this purpose. The use of elliptical heating surfaces with a mechanism of controlled flow separation, in the form of a triangular notch, is proposed. This will reduce surface drag and increase the overall thermal-hydraulic efficiency of the heat transfer processes. It is shown that the use of such surfaces in waste heat boilers makes it possible to increase the efficiency of marine power plants in tankers with a deadweight of about 45,500 tons up to 1.5% absolute and container ships with a deadweight of about 122,000 tons up to 2.5% absolute.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00392024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0043<abstract> <title style='display:none'>Abstract</title> <p>This article analyses the effects of deformation on the structure of CMnSi steel at various deformation levels. After hot forging, the structure of CMnSi steel comprises coarse-sized alpha and pearlite particles. The average grain size of steel after forging was 100 μm. After hot rolling, the grain size gradually decreases, with the average size of the ferrite and pearlite grains measured as 60 μm. After that, CMnSi steel was subjected to cold deformation at levels of 40%, 60%, and 80%. The grain size of the CMnSi steel sample after 80% cold deformation reached level 7, corresponding to about 25 μm. For a deformation level of 40%, the grain size was level 5, corresponding to 40 μm, while a deformation level of 60% produced a grain size of 35 μm, corresponding to level 6. In addition, scanning electron microscopy showed that after 80% deformation, smaller particles with a size of about 5 μm appear inside the parent particles. Moreover, energy-dispersive X-ray spectroscopy analysis revealed the carbide appearance in the form M23C6, with M being a mixture of Fe and Mn. These carbides have a fine size of about 1–2 μm and contribute to the prevention of particle growth during subsequent heat treatments.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00432024-08-21T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0030<abstract> <title style='display:none'>Abstract</title> <p>Maritime transport forms the backbone of international logistics, as it allows for the transfer of bulk and long-haul products. The sophisticated planning required for this form of transportation frequently involves challenges such as unpredictable weather, diverse types of cargo kinds, and changes in port conditions, all of which can raise operational expenses. As a result, the accurate projection of a ship’s total time spent in port, and the anticipation of potential delays, have become critical for effective port activity planning and management. In this work, we aim to develop a port management system based on enhanced prediction and classification algorithms that are capable of precisely forecasting the lengths of ship stays and delays. On both the training and testing datasets, the XGBoost model was found to consistently outperform the alternative approaches in terms of RMSE, MAE, and R2 values for both the turnaround time and waiting period models. When used in the turnaround time model, the XGBoost model had the lowest RMSE of 1.29 during training and 0.5019 during testing, and also achieved the lowest MAE of 0.802 for training and 0.391 for testing. It also had the highest R2 values of 0.9788 during training and 0.9933 during testing. Similarly, in the waiting period model, the XGBoost model outperformed the random forest and decision tree models, with the lowest RMSE, MAE, and greatest R2 values in both the training and testing phases.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00302024-06-22T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0019<abstract> <title style='display:none'>Abstract</title> <p>The violent swinging motion of a payload imposes significant safety problems for the operation of offshore ship-mounted cranes (offshore cranes). We therefore propose a stable experimental hoisting platform for an offshore crane payload positioning system with a parallel cable-driven method (PP-PCDM), and an adaptive cable-drive anti-swing tension (ACAT) control method based on the PP-PCDM is developed to resolve the problem of swinging of the payload by limiting its spatial position. The PP-PCDM enables synchronous tracking of the movement of the payload when the crane is working. When the payload deviates from a stable state due to an external disturbance, the anti-swing cables are immediately retracted or released based on the feedback signal. The spatial position of the payload is then limited by adjusting the length and tension of the parallel cables until the payload appears stationary from the perspective of the ship’s deck. Operational safety and efficiency is substantially improved, and the proposed PP-PCDM structure and ACAT control method can be applied to a variety of different types of cranes. The results of simulations and physical experiments show that the anti-swing effect exceeds 89.86%. The PP-PCDM enables excellent performance of synchronous tracking and hoisting assistance, and ensures that the rated lifting weight of the offshore crane is not affected.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00192024-06-22T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0025<abstract> <title style='display:none'>Abstract</title> <p>In this paper, we study the control problem of auto-berthing marine surface vessels (MSVs) within a predefined, finite time in the restricted waters of a port, in the face of internal and external uncertain dynamics and actuator faults. We first use radial basis function neural networks to reconstruct the internal uncertainties of the system; then, using the minimum learning parameter method, we transform the weights of the neural networks, the external disturbances of the system, and the bias fault factors into an indirect single-parameter neural learning mode. We also apply a robust depth information adaptation technique to estimate the upper bound on the composite disturbances online. Dynamic surface control technology alleviates the burden of virtual control derivative calculations. Finite-time convergence of the system is guaranteed by a predetermined finite-time function based on a time-based generator (TBG). Based on these methods, we design a finite-time fault-tolerant auto-berthing control scheme based on TBG. The stability of the system is analysed based on Lyapunov stability theory. Finally, we verify the effectiveness of the proposed control scheme through simulation.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00252024-06-22T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0016<abstract> <title style='display:none'>Abstract</title> <p>In this paper, we focus on analysing scale effects on the roll motion of the Italian ship Bettica using a numerical method. First, the roll decay motion of the ship is simulated at both the model scale and full scale, and the predicted results are compared with experimental data to validate the numerical strategy. The results show that there are scale effects that cause the difference in roll amplitudes between the model and the full-scale ship. To investigate the viscous effects on the roll damping components, forced roll simulations are carried out at the model scale and full scale, and the roll damping components (frictional, wave-making, eddy-making, bilge keel and lift components) are obtained. An analysis of these roll damping components indicates that the frictional component is influenced by scale effects, especially in the case of zero or low forward speed. We also show that the bilge keel component is affected by scale effects when the height of the bilge keels is reduced to a certain value below the boundary layer thickness. The velocity fields around the bilge keels are analysed to better understand the scale effects.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00162024-06-22T00:00:00.000+00:00https://sciendo.com/article/10.2478/pomr-2024-0020<abstract> <title style='display:none'>Abstract</title> <p>The current market for the assembly and disassembly of offshore platforms exceeds $100 billion. However, existing methods face limitations that reduce their efficiency. To address these limitations, we propose a dual-vessel collaborative assembly and disassembly system with multiple motion-compensated lifting arms. The compensation system enables the lifting arms to isolate the topside module from the wave-induced loads, and specifically the torque, transmitted from the lifting vessel. Through theoretical derivations based on hydrostatics principles, a mathematical model of the topside module is established. We consider the effects of lifting load, tidal changes and the ballast water system on stability, and develop a stability analysis model for the dual-vessel system. The intact stability and loss-of-load stability under dual-vessel collaborative lifting conditions are analysed to verify compliance with stability requirements for lifting a 30,000 ton topside module. The results conclusively demonstrate that the proposed system with multiple motion-compensated lifting arms meets the stability performance needs for dual-vessel collaborative offshore assembly and disassembly operations.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/pomr-2024-00202024-06-22T00:00:00.000+00:00en-us-1