Search

This research investigates the effect of waves and hydrodynamic interaction on the ice loads during a glancing impact between an ice floe and a ship advancing at low speed in various sea states. An extended energy-based model is proposed for the ice loads estimation, accounting for hydrodynamic interaction through added mass and wave-induced motions, where the hydrodynamic interaction is fully involved between an advancing ship and a free-floating ice floe. The influence of sea states is investigated by calculating the added mass and motions of a ship and ice floes in six degrees of freedom under different significant wave heights and peak periods. The effect of ice floe size is analyzed by using three ice floes with different diameters. The results reveal that sea waves significantly affect ice loads by altering the relative velocity between the ship and the ice floe right before the impact. Furthermore, the influence of added mass on ice load predictions is not as pronounced as the effect of wave-induced motions. This research underscores the importance of considering hydrodynamic interactions and wave conditions in the accurate assessment of ice loads, which is crucial for the design of ice-strengthened ships and for the selection of safe speed according to sea state in ice-infested waters. • This study explores how waves and hydrodynamic interactions affect ice loads from a ship-ice glancing impact. • The Popov method is improved by incorporating added mass and wave-induced motions. • A potential flow model is employed to capture the hydrodynamic interaction between two bodies moving at different speeds. • Sea waves can significantly increase ice loads for ships sailing in Marginal Ice Zone. • Relative motions exert stronger influence on the ice loads compared to added mass. [ABSTRACT FROM AUTHOR]

Overload response of the stiffening frames in ship side structure due to ice loading is an important design consideration for ships operating in ice infested waters. By overload, we mean loads that are larger than assumed by the rules. Therefore, the response of ice strengthened grillage frames is investigated under a range of idealized rectangular pressure patches and by assuming different boundary conditions for the structural units. A flat, representative grillage of an ice-strengthened ship is considered and analysed using non-linear Finite Element Method. The response of the grillage frames is compared with the isolated frame response. Two frame types are considered: flatbars and L-frames. Finite element simulations revealed that patch length has strong effect on the frame deformation mode. The key characteristic that differentiates the response under shorter and longer patches is the longitudinal membrane stretching of the shell plating. Longer patches tend to suppress this deformation mode that leads to similar frame behaviour observed in isolated frame analysis. It is further shown that overload capacity of grillage frames reduces with increasing patch length to levels observed in isolated frame analysis. Analysis of plastic strain development in the frames and plating revealed that plastic strain localized faster in frames, but shell plating is more sensitive to patch height variations. This renders frames more susceptible to fracture than plating. Finally, the local failure mechanisms of the L-frames tend to diminish the load sharing capability and so negatively affects the overload behaviour. [ABSTRACT FROM AUTHOR]

This paper presents a big data analytics method for the proactive mitigation of grounding risk. The model encompasses the dynamics of ship motion trajectories while accounting for kinematic uncertainties in real operational conditions. The approach combines K-means and DB-SCAN (Density-Based Spatial Clustering of Applications with Noise) big data clustering methods with Principal Component Analysis (PCA) to group environmental factors. A Multiple-Output Gaussian Process Regression (MOGPR) method is consequently used to predict selected ship motion dynamics. Ship sway is defined as the deviation between a ship and her motion trajectory centreline. Surge accelerations are used to idealise the time-varying manoeuvring of ships in various routes. Operational conditions are simulated by Automatic Identification System (AIS), General Bathymetric Chart of the Oceans (GEBCO), and nowcast hydro-meteorological data records. A Dynamic Time Warping (DTW) method is adopted to identify ship centre-line trajectories along selected paths. The machine learning algorithm is applied for ship motion predictions of Ro-Pax ships operating between two ports in the Gulf of Finland. Ship motion dynamics are visualised along the ship's route using a Gaussian Progress Regression (GPR) flow method. Results indicate that the present methodology may assist with predicting the probabilistic distribution of ship dynamics (speed, sway distance, drift angle, and surge accelerations) and grounding risk along selected ship routes. • Machine learning methods can be used to model the kinematics of ship motions. • Results can be used for the predictive mitigation of grounding risk in adverse conditions. • Uncertainties are minimised by application of a five-fold iteration process. • Examples of application are presented for Ro-Pax ships operating in the Gulf of Finland. • The method proposed may be used in intelligent decision support systems. [ABSTRACT FROM AUTHOR]

Due to the complexity of the ice-structure interaction, the knowledge about the ice-induced loads on a ship hull has been gained from full-scale measurements. As the instrumentation of the hull for the measurements is expensive, the extension is concerned at the planning phase. However, a narrow instrumentation can cause an error in the measurements, as the response of the adjacent frames with respect to the observed frame is not known. Thus, this paper studies the differences between loads measured from one or several frames on board S.A. Agulhas II. The difference results from the ability of the structure to transport loading internally. The results show that when the loads affect only an individual frame, the instrumentations give similar results. However, the difference increases with the load length and the loading that is determined can be 15% higher for one frame instrumentation for a structure similar to the aft shoulder of S.A. Agulhas II. Furthermore, the difference in the mean value and standard deviation of the measurement time histories can be up to 10%. The study presents a new efficient method to obtain a rough estimate of the possible difference in the measured results between extensive and narrow instrumentation. [ABSTRACT FROM AUTHOR]

This paper studies the frequency of ice loads of varying lengths and the occurrence probability of their magnitudes in full-scale. In these measurements, the four frames were instrumented with shear strain gauges on the Polar Supply and Research Vessel S.A. Agulhas II. The experiments were carried out on first-year ice in the Baltic Sea. An influence coefficient matrix based on analytical and numerical analyses was used to determine the load length in the horizontal direction. Rayleigh separation was used to define the load amplitudes. The measurements show that the ice loading has to be long in order for the shear-load maximum on a single frame to occur. Furthermore, the statistical study showed that the Weibull distribution gives the best fit to the measured loads on a frame. The probability distribution of the ice loads on a frame is exponential-like for short loads and lognormal-like for long loads. [ABSTRACT FROM AUTHOR]

A method for estimating ship's resistance caused by sea ice ridge keels is revised and used as a part of a method for predicting performance of ships in ridged ice conditions. The resistance method is based on a continuum plasticity model of ridge rubble and is simple to compute. The performance prediction method combines deterministic simulations of ship motion with probabilistic modelling of ridged ice fields. Performance estimates given by the model are distribution of attainable mean speeds for given ice conditions and probability of the ship being able to operate independently. A comprehensive sensitivity analysis was performed to gain insight into the model and identify possible problematic parameters. The sensitivity analysis covered both the ice conditions and modelling assumptions. Two data-sets were used to test the simulation method. One set included the depth profile of sea ice, machinery data and the speed of a ship operating in ridged ice. The resistance method was able to predict the mean speed over 3km well. The second data-set consisted of a history of ship's speeds and positions from AIS data and ice conditions estimated by a numerical ice model HELMI, developed in the Finnish Meteorological Institute. Observed mean speeds were mostly well within the distributions of mean speeds simulated by the transit simulation model. Predictions of independent operation were also promising. [ABSTRACT FROM AUTHOR]

This paper reviews challenges of relevance to the future development of Arctic sustainable shipping by considering future demands for vessel types, available alternative energy sources, and novel technologies. Results reveal the need to extend existing concept ship design methods to account for the holistic yet sustainable design of Arctic vessels. Accordingly, the paper introduces a decision support framework for holistic and sustainable optimization of the concept design of Arctic ships for different cold regions and purposes of operation. The method presented simultaneously accounts for eco-efficiency, cost-efficiency, and safety. Demonstration for the case of a battery-driven Arctic offshore wind farm service and offshore support vessels shows that optimized designs could outperform their existing environmentally and economically efficient counterparts. • A framework and method for the holistic and sustainable design optimization of Arctic ships is proposed. • Innovative vessels, alternative energy sources, and novel technologies are considered. • The method is demonstrated for battery-driven offshore wind farm and offshore support vessels. • Optimised assets may outperform existing or retrofitted vessels in terms of safety and sustainability. [ABSTRACT FROM AUTHOR]

The coupled dynamics of wave elevation and motions around bodies floating in proximity may be sensitive to radiation and diffraction effects. In this paper, the influence of radiation on wave elevation is examined for two side-by-side boxes subject to forced sway, heave, and roll oscillations in a two-dimensional numerical wave tank. The effects of diffraction on wave elevation and the joint influence of radiation and diffraction are investigated in regular waves assuming free heave motions. Heaving of one or two boxes and single-box sway or roll excites a piston mode of water motions in the proximity gap. Synchronous sway or roll induces sloshing. The close relationship between gap resonance and rapid water exchange in and out of the gap is confirmed. Vortices within the gap drive water exchange and influence the gap wave elevation. Their impact is determined by both spatial and temporal distributions. [ABSTRACT FROM AUTHOR]

With the climate change, polar sea ice is diminishing. This, on one hand, enables the possibility for e.g., Arctic shipping and relevant resource exploitation activities, but on the other hand brings additional risks induced by these activities. Increasing research focuses have been observed on the relevant topics in the complex and harsh polar environment and its fragile ecosystem. However, from risk management perspective, there is still a lack of holistic analysis and understanding towards safe shipping in the ice-covered waters and its available models applicable for managing risks in the system. Therefore, this paper aims to establish a framework and analysis for better understanding of this gap. The paper targets a comprehensive and long-term project specifically focusing on holistic safe shipping in ice-covered waters as the analysis basis. It firstly creates a holistic framework for the shipping system in ice-covered waters and then implements review and analysis of project publications on their overall features. Quantitative prediction models are selected for a structured applicability analysis. Furthermore, an extensive review outside the project following the elements established for the holistic shipping system is conducted so that this paper provides an overview of models for the shipping system in ice-covered waters, addressing the status of the current toolbox. Moreover, it helps to identify the next scientific steps on risk management of shipping in ice-covered waters. • A holistic framework for the shipping system in ice-covered waters is established. • A deep review and structured applicability analysis for a long-term polar project are implemented. • An extensive review outside the project is carried out following the framework. • It forms a toolbox specifically for the ice-covered waters risk management. • It enables to show the potential gaps on the models for relevant topics in the system. [ABSTRACT FROM AUTHOR]

Increasing maritime traffic, combined with the possible warming of the climate, will affect the demand for icebreaking assistance. Accurately predicting the local demand for assistance without an appropriate simulation tool is hard because of the number of variables that must be considered. This report describes a simulation tool built around a deterministic, ice-breaker movement computer model. The tool is still under development, and has not yet been tested with real data. However, preliminary test results based on selfgenerated input data are promising. [ABSTRACT FROM AUTHOR]

• A Machine learning method utilising big data analytics is used to evaluate ship grounding risk. • The analysis is based on an Avoidance Behaviour-based Grounding Detection Model (ABGD). • Results are in good agreement with real accident records available for ship routes between the ports of Tallin (Estonia) and Helsinki (Finland). • The proposed method may assist with identification and operational vulnerability of a ship fleet at risk. • The knowledge developed can support the development of future decision support systems. Ship groundings may often lead to damages resulting in oil spills or ship flooding and subsequent capsizing. Risks can be estimated qualitatively through experts' judgment or quantitatively through the analysis of maritime traffic data. Yet, studies using big data remain limited. In this paper, we present a big data analytics method for the evaluation of grounding risk in real environmental conditions. The method makes use of big data streams from the Automatic Identification System (AIS), nowcast data, and the seafloor depth data from the General Bathymetric Chart of the Oceans (GEBCO). The evasive action of Ro-Pax passenger ships operating in shallow waters is idealized under various traffic patterns that link to side - or forward - grounding scenarios. Consequently, an Avoidance Behaviour-based Grounding Detection Model (ABGD-M) is introduced to identify potential grounding scenarios, and the grounding probabilistic risk is quantified at observation points along ship routes in various voyages. The method is applied on a Ro-Pax ship operating over 2.5 years ice-free period in the Gulf of Finland. Results indicate that grounding probabilistic risk estimation may be extremely diverse and depends on voyage routes, observation points, and operational conditions. It is concluded that the proposed method may assist with (1) better identification of critical grounding scenarios that are underestimated in existing accident databases; (2) improved understanding of grounding avoidance behaviours in real operational conditions; (3) the estimation of grounding probabilistic risk profile over the life cycle of fleet operations and (4) better evaluation of waterway complexity indices and ship operational vulnerability. [ABSTRACT FROM AUTHOR]

The ice conditions, together with the physical and mechanical properties of the ice encountered by a ship, can change rapidly. As these affect the ship–ice interaction process, the magnitude of the ice-induced loads changes significantly even in the short term. Therefore the ice-breaking process is known to be a stochastic process, which should be studied statistically. Earlier studies indicate that the exponential, lognormal, and Weibull probability distributions would be the best probability distributions to describe the short-term ice-induced load measurements on the ship's hull. Furthermore, the standard deviation of the measured ice-induced load histograms has been observed to increase in linear fashion as a function of the mean value of the measured ice-induced load histograms. In addition, the inverse coefficient of variation of these histograms has been observed to decrease exponentially as a function of the measured maximum ice-induced loads. The study in this paper focuses on the statistical analysis of ice-induced loads. At first, the effect of the inverse coefficient of variation on the behaviour of the exponential, lognormal, and Weibull probability distributions is presented briefly. Then it is shown that the close-to-linear relation that exists between the mean value and standard deviation of the measured ice-induced load histograms can be explained by analysing the calculation methods for mean values and standard deviations. In addition, it is shown that the exponential-type relation between the inverse coefficient of variation and the measured maximum value can be explained similarly using the defined nature of the standard deviation and mean value. The effect of the threshold used in the full-scale measurements on these values is also studied and discussed in the paper. [ABSTRACT FROM AUTHOR]

Highlights: [•] Reliability and validity of ship–ship collision risk analysis methods investigated. [•] Focus on probability- and risk indicator perspectives. [•] Varying internal reliability and low cross-methodological reliability found. [•] Both accuracy of total system risk and rank order of subsystem risk questioned. [•] More valid definitions of the ship encounter process needed to reduce uncertainty. [ABSTRACT FROM AUTHOR]

Current ice class rules may design a structure that can undergo some plastic deformations during their design life. The amount of allowable plastic deformations is however not clearly defined in these ice class rules so as the critical deformation limit that requires repair. It is possible to increase the scantlings until no plastic deformations occur during the ship's lifetime. This will cause a high investment cost at the construction phase but no repair cost during the design life. Another possibility is to allow some local plasticity requiring repair work at specified nominal frequencies during the ships' lifetime, which causes smaller investments, but higher maintenance costs. The optimum between these two extremes is searched in this paper and the procedure on how to identify such concept will be described. [ABSTRACT FROM AUTHOR]

Abstract: The influences of the variables in a Bayesian belief network model for estimating the role of human factors on ship collision probability in the Gulf of Finland are studied for discovering the variables with the largest influences and for examining the validity of the network. The change in the so-called causation probability is examined while observing each state of the network variables and by utilizing sensitivity and mutual information analyses. Changing course in an encounter situation is the most influential variable in the model, followed by variables such as the Officer of the Watch''s action, situation assessment, danger detection, personal condition and incapacitation. The least influential variables are the other distractions on bridge, the bridge view, maintenance routines and the officer''s fatigue. In general, the methods are found to agree on the order of the model variables although some disagreements arise due to slightly dissimilar approaches to the concept of variable influence. The relative values and the ranking of variables based on the values are discovered to be more valuable than the actual numerical values themselves. Although the most influential variables seem to be plausible, there are some discrepancies between the indicated influences in the model and literature. Thus, improvements are suggested to the network. [Copyright &y& Elsevier]

Abstract: Ice bound shipping is considerably more dangerous than shipping under more favourable water conditions. During winter the Baltic Sea can be covered with ice over an average of about 45% of its surface. The ice mostly reaches its maximum extent in late February or early March. The Bay of Bothnia located in the northern basin of the Gulf of Bothnia is prone to extreme frozen ice conditions. During winter the typical ice thickness in the northernmost areas of the Bay of Bothnia is about 70cm for land-fast sea ice. In this paper the ice crushing pressure on a ship''s hull is analysed statistically. A series of tests took place over four days in the Aalto ice tank and involved two different ship models. The peak pressures caused by ice were calculated from four sensor sheets located at different positions on the hull. In the statistical part, the sum of the forces acting on a section of a ship''s hull was modelled as a Poisson random process. Analysis of the cumulative distribution function (CDF) was modelled for the total force. The full scale comparisons of pressure-area values and line loads as a function of the load width were analysed by comparing the model scale data with full scale measurements onboard MS Arcturus and IB Sisu. Finally a short comparison is also conducted with the load level obtained from damage statistics gathered in the Baltic Sea. [Copyright &y& Elsevier]

Abstract: Maritime traffic poses various risks in terms of human, environmental and economic loss. In a risk analysis of ship collisions, it is important to get a reasonable estimate for the probability of such accidents and the consequences they lead to. In this paper, a method is proposed to assess the probability of vessels colliding with each other. The method is capable of determining the expected number of accidents, the locations where and the time when they are most likely to occur, while providing input for models concerned with the expected consequences. At the basis of the collision detection algorithm lays an extensive time domain micro-simulation of vessel traffic in the given area. The Monte Carlo simulation technique is applied to obtain a meaningful prediction of the relevant factors of the collision events. Data obtained through the Automatic Identification System is analyzed in detail to obtain realistic input data for the traffic simulation: traffic routes, the number of vessels on each route, the ship departure times, main dimensions and sailing speed. The results obtained by the proposed method for the studied case of the Gulf of Finland are presented, showing reasonable agreement with registered accident and near-miss data. [Copyright &y& Elsevier]

Steel sandwich panels welded by laser can offer 30–50 % weight savings compared to the conventional steel structures. Helsinki University of Technology/Ship Laboratory has done active research during the past 10 years on various topics related to the laser welded steel sandwich panels. The work carried out includes development of design formulations for the ultimate and impact strength, analysis of fatigue strength for the joints, and development of solutions to improve the behaviour under fire. A number of research projects both at the national and European level have been ongoing. In the paper, a summary of the marine applications, main benefits and problem areas of the panels as well as available design tools are given. A case study for weight and cost optimisation of a hoistable cardeck is also presented proving some of the described benefits of all steel sandwich panels. [ABSTRACT FROM AUTHOR]

The purpose of this work is to compare the resistance with damage of various types of double bottom structures in a stranding event. The comparative analyses are made by use of a commercial, explicit finite element program. The ship bottom is loaded with a conical indenter with a rounded tip, which is forced laterally into the structures in different positions. The aim is to compare resistance forces, energy absorption and penetration with fracture for four different structures. Those four structures are: a conventional double bottom, a structure (presently protected through a patent) with hat-profiles stiffened bottom plating, a structure where all-steel sandwich panel is used as outer shell and a bottom structure stiffened exclusively with hat-profiles. The paper shows that it is indeed possible to elevate the crashworthiness of side and bottom structures with regards to the loading considered here without increasing the structural weight. [Copyright &y& Elsevier]

This work presents a revision of the structural similarity technique developed for the experimental modeling of marine structures subjected to collision, grounding or similar catastrophic events via miniature models with drastic scale reduction. This revision involved basically the inclusion of combined collapse modes to predict the mechanical behavior of structural members and the redefinition of the flow stress range. The revised technique was validated through numerical simulations of the miniature modeling of nine large-scale marine structures' experiments found in literature and here presented in the form of nine study cases. Each study case evaluates the accumulated effects of scale reduction, thickness distortion and material distortion in the miniature model as part of the similarity technique. In general, a reasonable-to-good correspondence was observed between the force and absorbed energy responses obtained from reference large-scale structures and their miniature models once brought to the same dimensional scale. Discrepancies between structural responses were quantified by evaluating the normalized root mean square error. By these means, most of the study cases presented errors below 12.5% in terms of force response and below 4.5% in terms of absorbed energy response. On the other hand, lower agreement was encountered when reproducing experiments strongly ruled by progressive buckling or crack initiation/propagation together with severe reduction scales. In these cases, better results are achieved when implementing a more accurate material failure model or by moderating the reduction scale. [ABSTRACT FROM AUTHOR]

Ships navigating in ice inevitably encounter different ice conditions. Dynamic ice typically presents severe conditions when it is moving perpendicular towards the parallel midship section, which can lead to ships getting stuck in ice. This can cause delays for ships or even damage to the ship hull. However, there currently is no model to assess ship operability in this dynamic ice. This paper aims to develop a method to assess operability of ships in dynamic ice conditions, which can be used for ship routing to avoid ship stuck. The method is especially useful for emergency response planning purposes, e.g. for marine pollution preparedness and response planning, where an understanding of the operability of response vessels in dynamic ice conditions currently is lacking. First, a transit model is introduced for both independent navigation and escort operations, considering the additional ice resistance by dynamic ice. Then, a ship operability index is proposed based on the modelling of ship's performance. Case studies of independent navigation and escort operations in realistic dynamic ice conditions are investigated to compare with the simulated results. Reasonable agreement is obtained, indicating that the proposed method can be used for ship operability assessment in dynamic ice. • A transit model for both independent navigation and escort operation in dynamic ice is developed. • A ship operability index is proposed based on the modelling of ship's performance. • Case studies show reasonable agreement between the simulated model results and empirical observations. • Model behaviors are tested in a series of sensitivity analyses. • The method is useful for ship routing and emergency response planning to avoid ship stuck in dynamic ice. [ABSTRACT FROM AUTHOR]

Ice bending is a major failure mechanism of level ice when ships and marine structures interact with level ice. This paper aims to investigate the ice bending and ice load when level ice collides on ships and marine structures using numerical simulation method, and compare the numerical results with field test. The fracture of ice is simulated with extended finite element method (XFEM), and cohesive zone concept is used to describe the crack propagation. In order to consider the characteristics of S2 columnar ice, a transversely isotropic elastic material model is used for the ice bulk elements, and a transversely isotropic Tsai-Wu failure criterion is adopted to predict the initiation of cracks. A well-controlled field test of a landing craft bow colliding with level ice in Baltic Sea is simulated to verify the numerical scheme. The ice plate's continuous deformation, crack initiation and crack propagation at different impact velocities and angles are simulated and the results are discussed. In the simulation, the bending crack emerges at the midline of the top surface of ice plate, then propagates towards free boundary, and finally a circumferential crack forms. It is found that with the impact velocity increases, the bending load increases and the fracture size (perpendicular distance from the crack to the contact edge) decreases. And as the angle between the landing craft bow and vertical direction increases, the bending load and the fracture size decrease. The simulated results corresponds well with the field test. The competition between the circumferential crack and radial crack is also found in the simulation and will be discussed in this paper. The results show that this method well simulates the bending of level ice and predict the ice load, and provides a good approach for investigating the mechanism of different forms of level ice fracture. • A numerical method is proposed to simulate the bending failure of level ice. • Numerical results are validated against a full-scale field test. • Bending crack emerges at the midline of top surface then propagates towards free boundaries. • As the collision velocity increases and angle β decreases, the bending load increases. • As the collision velocity and angle β are small, radial crack may emerge at the bottom surface of level ice. [ABSTRACT FROM AUTHOR]

The structural damage of ships in navigational accidents is influenced by the hydrodynamic properties of surrounding water. Fluid structure interactions (FSI) in way of grounding contact can be idealized by combining commercial FEA tools and specialized hydrodynamic solvers. Despite the efficacy of these simulations, the source codes idealizing FSI are not openly available, computationally expensive and subject to limitations in terms of physical assumptions. This paper presents a unified FSI model for the assessment of ship crashworthiness following ship hard grounding. The method uses spring elements for the idealization of hydrostatic restoring forces in 3 DoF (heave, pitch, roll) and distributes the added masses in 6 DoF on the nodal points in way of contact. Comparison of results against the method of Kim et al. (2021) for the case of a barge and a Ro–Ro passenger ship demonstrate excellent idealization of ship dynamics. It is concluded that the method could be useful for rapid assessment of ship grounding scenarios and associated regulatory developments. [ABSTRACT FROM AUTHOR]

In recent years, the European Commission and the International Maritime Organization (IMO) implemented various operational measures and policies to reduce ship fuel consumption and related emissions. The effectiveness of these measures relies upon developing accurate predictive models encompassing the influence of real operational conditions. This paper presents a deep learning method for the prediction of ship fuel consumption. The method utilizes big data analytics from sensors, voyage reporting and hydrometeorological data, comprising of 266 variables made available following sea trials of a Kamsarmax bulk carrier of Laskaridis Shipping Co. Ltd. A variable importance estimation model using a Decision Tree (DT) is used to understand the underlying relationships in the available dataset. Consequently, a deep learning model is developed to understand the influence of sailing speed, heading, displacement/draft, trim, weather, sea conditions, etc. on ship fuel consumption (SFC). This is achieved by incorporating attention mechanism into Bi-directional Long Short-Term Memory (Bi-LSTM) network. The potential of the new method is demonstrated by training data streams corresponding to real ship fuel consumption rates as well as internal and external operational conditions. A comprehensive comparison with existing methods indicates that the Bi-LSTM with attention mechanism presents the best fit when using high frequency data. It is concluded that subject to further testing and validation the method could be used for the development of decision support systems for monitoring environmentally sustainable ship operations. [ABSTRACT FROM AUTHOR]

For ships navigating in ice floe fields, ship-ice-wave interactions may affect ship performance and ice impact forces. This paper presents an approach to evaluate the cross-coupling added mass and hydrodynamic damping between a passing ship and a free-floating small/medium size ice floe based on the boundary element method (BEM). The influences of added mass and hydrodynamic damping are explored for different wave frequencies and headings. Results are presented for a regular waves scenario whereby a tanker progressing at a slow speed is passing by a free-floating ice floe modeled as a round disk. Radiation and diffraction potentials of the interacting floating bodies are linearly superimposed to reflect the influence of hydromechanical coupling on responses. Parametric analysis of response amplitude operators (RAOs) indicates that the cross-coupling terms of added mass and hydrodynamic damping are of the same order of magnitude as those of the ice floe but smaller by one or two orders of magnitude than those of the ship. It is concluded that hydrodynamic interactions primarily influence the motions of the ice floe and are significant attributes in terms of suitably idealizing ship-ice system dynamics. [ABSTRACT FROM AUTHOR]

Abstract In northern sea areas such as the Baltic Sea and the Arctic, especially in winter conditions, the presence of sea ice frequently necessitates icebreaker assistance operations for vessels navigating in these areas. Icebreaker escort operations are important for ensuring the safety of navigation in these harsh environments. While these operations reduce the overall system risk, studies have shown that specific navigational risks are associated also with escort operations, necessitating appropriate training and operational support for ship crew engaged in these. In this paper, the icebreaker escort operations are investigated, and a ship-following model is proposed, drawing on similarities with the car following phenomenon. This ship-following model accounts for the necessity of keeping an appropriate safety distance to avoid collision, as well as for the effects of sea ice on the operation. Its main intended use is for implementation in maritime simulators, providing a realistic environment of operational conditions for training ship crews. As a first approximation, the model accounts for the ice condition by the average ice thickness, while the safety speed constraint is relative to the vessel's ability of navigating in ice. The model parameters are calibrated using empirical data of icebreaker escort operations. Case studies are executed, showing good agreement between the simulation model and real-world operational conditions. Highlights • A ship-following model for icebreaker escort operations is proposed. • Safety distance and the effects of sea ice on the operation are accounted for. • Main intended use of the proposed model is for implementation in maritime simulators. • The model parameters are calibrated using empirical data of icebreaker escort operations. • Case studies show good agreement between the simulation model and real-world operations. [ABSTRACT FROM AUTHOR]

As the initiatives to develop and implement autonomous merchant vessels into the global shipping industry are gaining momentum, their safety remains in the spotlight. It is argued that every effort shall be taken to ensure that the safety of maritime transportation is not reduced in the process, but the question of how to achieve it remains open. Meanwhile, the systemic approach is more widely being used to analyse innovative systems’ safety. We therefore apply a System-Theoretic Process Analysis to develop a model suitable for safety analysis and design recommendations’ elaboration for future autonomous vessels. Furthermore, we introduce a method of evaluating and communicating uncertainties pertaining to the method. The results indicate that the system-theoretic safety analysis’ outcome can be affected by manageable uncertainties despite the fact that the system in question is yet to be implemented. [ABSTRACT FROM AUTHOR]

For the design and transit simulation of ice-going ships, a number of methods have been proposed for the prediction of ship resistance and transit speed in various ice conditions. In this paper, selected methods for ship performance in level ice, ridged ice and channel ice are evaluated based on full-scale measurement data of two ships. Uncertainties are identified and evaluated for a better understanding of the deviations in the results. Ice thickness in full-scale data was measured using multiple methods to minimize the uncertainty. The thickness of level ice was measured by a stereo camera system. The ridge profile was identified through measurement with an electromagnetic device. Visual observation was conducted for the description of encountered ice conditions. For a better estimation of ship net thrust through propulsive data, the net thrust model is revised in this paper to take the effect of power and propeller pitch into consideration. The results show that for transit simulation, the selected methods for level ice give acceptable prediction of ship speed with certain underestimation. For ridged ice, the method seems to underestimate the speed, especially when a ship needs to conduct ramming operation. Data acquisition is the most problematic for the investigation of channel ice. The uncertainties due to the modelling of sub-processes and ice properties lead to certain scatter in applying these methods for speed prediction. Possible improvements are given as the conclusion of this work. [ABSTRACT FROM AUTHOR]

Unmanned merchant vessels' prototypes are expected to come into operation within a few years. This revolutionary shift in the shipping industry is feared to negatively impact the safety of maritime transportation. Therefore, in order to support future designers of remotely operated merchant vessels system, we applied System-Theoretic Process Analysis (STPA), identifying the most likely safety control structure of the analysed system and investigating it. The aim was to suggest potential ways of increasing the system's safety and to assess the effectiveness of such measures. Results indicate that the implementation of remotely-controlled merchant vessels and, in a wider sense, unmanned ships, and ensuring their safety shall consist of executing various controls on regulatory, organisational and technical plains. Potential effectiveness is evaluated and some recommendations are given on how to ensure the safety of such systems. [ABSTRACT FROM AUTHOR]

The prototypes of unmanned merchant vessels are expected to come into service within the coming years. The main line of argument supporting their introduction pertains to the increase in navigational safety, which is expected to be achieved by reducing the frequency of human-related accidents on board ships, by removing the crews. On the other hand, the response of unmanned ship to potential accidents is still uncertain. With enthusiasm on one side and apprehension on the other, the literature lacks an objective study on the effect of unmanned ships on safety of maritime transportation. This paper constitutes an attempt to bridge the aforementioned gap by applying a framework based on what-if analysis to a hundred maritime accident reports. The aim of the analysis is to assess whether the accident would have happened if the ship had been unmanned, and once the accident had happened - would its consequences have been different. The results obtained reveal that the occurrence of navigational accidents (e.g. collision, grounding) can be expected to decrease with the development of unmanned ship. However the extent of consequences resulting particularly from non-navigational accidents (e.g. fire, ship loss due to structural failure) can be expected to be much larger for the unmanned ships when compared to the conventional ones. [ABSTRACT FROM AUTHOR]

Ice management enables offshore and marine activities in Arctic waters in the presence of sea ice or icebergs. The presence of ice introduces additional risks to the activities. This paper discusses the risks in the light of novel risk perspectives, emphasizing uncertainties arising from potentially weak background knowledge in ice management operations. An ice management system is defined and a generic risk picture of an ice management operation is created. Risk theory is connected to the results using discussion and a conceptual example. Ice management operations are complex socio-technical systems requiring expertise in various fields. Available data is scarce and uncertainties are high. Still, the main activities need to trust in the ice management system to operate safely. The risks in ice management operations culminate in decision making and physical ice management. These need to be better understood to manage the operational risks. [ABSTRACT FROM AUTHOR]

Maritime accidents have the potential to cause significant financial loss, injury, and damage to the environment. One approach to investigating maritime safety is to focus on near misses, that is, situations which did not lead to an accident but where an accident was narrowly avoided. Based on the principles of the traffic conflict technique, which ranks traffic encounters through a conflict severity hierarchy, this paper proposes a novel model for screening maritime traffic data for near miss ship-ship encounters, particularly for open sea and coastal restricted sea areas. Compared to previous methods, the proposed method has a greater specificity, leaving fewer possible near miss cases to be assessed by navigational experts in a contextualised traffic setting. This is achieved by including the effect of ship size through a ship domain, and by better accounting for the criticality of the encounter direction through the Minimum Distance To Collision concept compared to earlier proposed models. The factors included in the model and their relation are based on expert judgments and using knowledge from previous studies. Model parameters are derived from AIS data points from a reference encounter situation dataset. The developed model has been applied to traffic data from the Northern Baltic Sea. The model is subjected to a number of validity tests, the results of which suggest that the model is adequate for ranking and prioritizing encounters for further assessment in an expert judgment phase to identify near misses. Thus, it establishes a method to enable subsequent research into the validity of near miss information to make statements of maritime safety in relation to collision accidents. [ABSTRACT FROM AUTHOR]

Most of the risk models for ship-grounding accidents do not fully utilize available evidence, since it is based on accident statistics and expert opinions. The major issue with such kinds of models is their limitation in supporting the process of risk-management with respect to grounding accidents, since they do not reflect the reality to the extent required. This paper presents an evidence-based and expert-supported approach to structure a model assessing the probability of ship-grounding accidents, to make it more suitable for risk-management purposes. The approach focuses on using evidential data of ship-grounding accidents extracted from the actual accident and incident reports as well as the judgement elicited from the experts regarding the links and probabilities not supported by the reports. The developed probabilistic model gathers, in a causal fashion, the evidential contributing factors in ship-grounding accidents. The outcome of the model is the probability of a ship-grounding accident given the prior and posterior probabilities of the contributing factors. Moreover, the uncertainties associated with the elements of the model are clearly communicated to the end-user adopting a concept of strength-of-knowledge. The model can be used to suggest proper risk-control-measures to mitigate the risk. By running uncertainty and sensitivity analyses of the model, the areas that need more research for making educated decisions are defined. The model suggests the high-level critical parameters that need proper control measures are complexity of waterways, traffic situations encountered, and off-coursed ships. The critical area that calls for more investigation is the onboard presence of a sea-pilot. [ABSTRACT FROM AUTHOR]

This paper presents an overview of ship traffic volume and accidents in the Baltic Sea with a special focus on the Gulf of Finland. The most common accidents are groundings and collisions, usually reported to be caused by human error. The annual number of Baltic Sea accidents reported to HELCOM varied from 34-54 for collisions and 30-60 for groundings. The number of yearly port calls varied from 468-505 thousand with a peak in 2008. Exact port call data could not be found for all ports and hence had to be estimated. The number of line crossingings in HELCOM AIS data was found to be a good, rough surrogate measure for the total number of port calls and could be used if more precise port call data was not available. By analyzing two separate accident databases, an estimate for accident underreporting was calculated. Different statistical methods yielded an underreporting rate in the range of 40-50%. Lastly, the true number of accidents was estimated, based on the estimated underreporting percentage for the Baltic Sea. Based on these results, the true number of true accidents should be first estimated if accident statistics are used in building or validating maritime risk models. When using such models or accidents statistics in decision-making, the underlying uncertainty in the accident statistics should be taken into account as the underreporting frequency estimates are only approximations of the real number of accidents. [ABSTRACT FROM AUTHOR]

• Review of 20-year maritime fleet risks and accident trends. • Survey of systems driven intelligent decision support methods. • Current static methods are costly and overlook real conditions. • Emerging methods enhance collision and grounding prevention. • Future of maritime safety: AI, big data, and rapid prediction. Despite advancements in science and technology, ship collisions and groundings remain the most prevalent types of maritime accidents. Recent developments in accident prevention and mitigation methods have been bolstered by the rise of autonomous shipping, digital technologies, and Artificial Intelligence (AI). This paper provides an exhaustive review of the characteristics of fleets at risk over the past two decades, emphasizing the societal impacts of preventing collisions and groundings. It also delves into the key components of decision support systems from a ship's perspective and undertakes a systematic literature review on the foundations and applications of systems-driven decision support methods for ship collision and grounding prevention. The study covers risk analysis, damage evaluation, and ship motion prediction methods from 2002 to 2023. The conclusions indicate that modern ship science methods are increasingly valuable in ship design and maritime operations. Emerging multi-physics systems and AI-enabled predictive analytics show potential for future integration into intelligent decision support systems. The strategic research challenges include (1) underestimating the impacts of real operational conditions on ship safety, (2) the inherent limitations of static risk analysis and finite numerical methods, and (3) the need for rapid, probabilistic assessments of damage extents. The demands and trends suggest that leveraging big data analytics and rapid prediction methods, underpinned by digitalization and AI technologies, represents the most feasible way forward. [ABSTRACT FROM AUTHOR]

For safe and efficient exploitation of ice-covered waters, knowledge about ship performance in ice is crucial. The literature describes numerical and semi-empirical models that characterize ship speed in ice. These however often fail to account for the joint effect of the ice conditions on ship's speed. Moreover, they omit the effect of ice compression. The latter, when combined with the presence of ridges, can significantly limit the capabilities of an ice-strengthened ship, and potentially bring her to a halt, even if the actual ice conditions are within the design range for the given ship. This paper introduces two probabilistic, data-driven models that predict a ship's speed and the situations where a ship is likely to get stuck in ice based on the joint effect of ice features such as the thickness and concentration of level ice, ice ridges, rafted ice, moreover ice compression is considered. To develop the models, two full-scale datasets were utilized. First, the dataset about the performance of a selected ship in ice is acquired from the automatic identification system. Second, the dataset containing numerical description of the ice field is obtained from a numerical ice model HELMI, developed in the Finnish Meteorological Institute. The collected datasets describe a single and unassisted trip of an ice-strengthened bulk carrier between two Finnish ports in the presence of challenging ice conditions, which varied in time and space. The relations between ship performance and the ice conditions were established using Bayesian networks and selected learning algorithms. The obtained results show good prediction power of the models. This means, on average 80% for predicting the ship's speed within specified bins, and above 90% for predicting cases where a ship may get stuck in ice. [ABSTRACT FROM AUTHOR]

This paper presents a model of maritime safety management and its subareas. Furthermore, the paper links the safety management to the maritime traffic safety indicated by accident involvement, incidents reported by Vessel Traffic Service and the results from Port State Control inspections. Bayesian belief networks are applied as the modeling technique and the model parameters are based on expert elicitation and learning from historical data. The results from this new application domain of a Bayesian network based expert system suggest that, although several its subareas are functioning properly, the current status of the safety management on vessels navigating in the Finnish waters has room for improvement; the probability of zero poor safety management subareas is only 0.13. Furthermore, according to the model a good IT system for the safety management is the strongest safety-management related signal of an adequate overall safety management level. If no deficiencies have been discovered during a Port State Control inspection, the adequacy of the safety management is almost twice as probable as without knowledge on the inspection history. The resulted model could be applied to performing several safety management related queries and it thus provides support for maritime safety related decision making. [ABSTRACT FROM AUTHOR]

The importance of including knowledge about human behaviour into the safety design for passenger ships has increasingly been taken into account. The interaction between passengers and the passenger ship is critical for human behaviour in terms of passengers’ perceptions of the environment. The way people perceive the environment and the various features of the environment has been studied quite extensively in design research, but little research has been done on the specific issues that shape people’s perceptions, such as safety. This paper discusses how people perceive safety within the context of passenger ships. Having conducted user studies in authentic environments, this paper identifies five safety perception themes. The results indicate that passengers perceive safety via the architecture of the passenger ship, the life-saving appliances, communication, emotions and other people. The outcomes were compared with the SOLAS regulations. The article contributes to safety research on passenger ship design, where human perceptions and reactions to the surrounding environment significantly affect behaviour and should be studied in parallel with technical progress. [ABSTRACT FROM AUTHOR]

Abstract: In the maritime domain, risk is evaluated within the framework of the Formal Safety Assessment (FSA), introduced by the International Maritime Organization in 2002. Although the FSA has become an internationally recognized and recommended method, the definition, which is adopted there, to describe the risk, seems to be too narrow to reflect the actual content of the FSA. Therefore this article discusses methodological requirements for the risk perspective, which is appropriate for risk management in the maritime domain with special attention to maritime transportation systems. A perspective that is proposed here considers risk as a set encompassing the following: a set of plausible scenarios leading to an accident, the likelihoods of unwanted events within the scenarios, the consequences of the events and description of uncertainty. All these elements are conditional upon the available knowledge (K) about the analyzed system and understanding (N) of the system behavior. Therefore, the quality of K and the level of N of a risk model should be reflected in the uncertainty description. For this purpose we introduce a qualitative scoring system, and we show its applicability on an exemplary risk model for a RoPax ship. [Copyright &y& Elsevier]

Abstract: This paper is presenting novel model-scale ice property measurements for grain size, elastic strain-modulus, compressive and tensile specimen tests. The testing and analyzing procedure is targeted to define the basic material behavior accurately to understand the material behavior for the future development of a numerical material model. Additionally, the model-scale ice thickness and the bending strength (following ITTC) are determined to classify the ice properties. The experiments consist of systematic in-situ tests to identify the model-scale ice properties in a format suitable for numerical simulations. The elastic strain-modulus is determined on the intact level ice sheet based on the load displacement relationship of the infinite plate deflection. All specimens are cut with a template to minimize dimensional variations. The specimens are loaded with a linear drive at constant speed while displacement and force are recorded. The resulting load–displacement curves indicate good repeatability. The experiments are conducted over a time of 4h–5h in the keeping phase, where the cooling system is adjusted to maintain the mechanical ice properties, and the obtained results do not show a dependency on the time of testing. A linear-elastic finite element model is used to reproduce the plate bending measurements for the elastic strain-modulus determination. Therewith, it is found that the actual elastic strain-modulus is 27% larger than in plain stress theory due to stresses in thickness direction. Additionally, the approximate yield strength of the model-scale ice is investigated and is found to be significantly lower than the determined maximum stresses in compression, tension and bending. Consequently, this paper contributes to a deeper understanding of the mechanics of model-scale ice, and a procedure is shown how the mechanical parameters can be determined by systematic experiments and analyses. [Copyright &y& Elsevier]

Abstract: An important element in assessing the consequences in a tanker collision is the probability of breaching an oil cargo tank. It is well recognized that the dynamic parameters at the moment of impact significantly affect the deformation energy. Assumptions regarding dynamic parameters at the moment of impact are nevertheless little discussed in context of collision risk analysis. The available impact scenario models are analyzed using a system risk approach. Comparison of impact scenario models from literature is performed with a risk analysis algorithm emphasizing on oil tanker collisions. Monte Carlo simulation is applied in the risk analysis algorithm for each impact scenario model. Only the impact scenario module is changed while other modules of the algorithm (encounter scenario generation, determination of deformation energy and structural hull capacity) are kept the same. Analysis reveals important differences in results of risk analysis when performed with different assumptions for the impact scenario. Moreover, in the discussion inherent conceptual limitations of the impact scenario models in the system risk framework are revealed. It is concluded that using more accurate collision energy and/or structural capacity models for purposes of maritime traffic risk analysis is currently not worthwhile, as the uncertainty regarding impact scenario is overwhelming. [Copyright &y& Elsevier]

Abstract: In this paper, a study leading towards a new definition of a ship–ship collision criterion, allowing further estimation of the probability of maritime accidents is conducted. The criterion is called the minimum distance to collision (MDTC) and reflects the shortest distance between two ships at which they must take evasive actions to avoid a collision. The new criterion is evaluated by means of a series of simulations using a ship motion model for a range of ship types, courses and speeds and thus its dynamic nature is recognised. It addresses the crossing type of ship–ship encounter. Additionally, this study defines a causation factor, which quantifies the proportions of cases in which two ships meeting each other end up having a collision. The causation factor is obtained in the course of maritime traffic analysis and accidents statistics. A comparative method is applied and the causation factors are determined for three different meeting types (head-on, crossing and overtaking). The causation factors obtained are valid for the MDTC model, chosen location and prevailing traffic conditions. The major factors affecting the MDTC criterion and relevant steps in the evaluation of the causation factors are described and discussed in the paper. [Copyright &y& Elsevier]

Abstract: Among engineers, risk is defined as a product of probability of the occurrence of an undesired event and the expected consequences in terms of human, economic, and environmental loss. These two components are equally important; therefore, the appropriate estimation of these values is a matter of great significance. This paper deals with one of these two components—the assessment of the probability of vessels colliding, presenting a new approach for the geometrical probability of collision estimation on the basis of maritime and aviation experience. The geometrical model that is being introduced in this paper takes into account registered vessel traffic data and generalised vessel dynamics and uses advanced statistical and optimisation methods (Monte Carlo and genetic algorithms). The results obtained from the model are compared with registered data for maritime traffic in the Gulf of Finland and a good agreement is found. [Copyright &y& Elsevier]

Abstract: This paper describes a coupled beam method, which estimates elastic response in the longitudinal bending of a passenger ship with a large multi-deck superstructure. The method can be applied during an early project stage, when detailed three-dimensional finite element modelling is not yet possible. The theory is based on the assumption that each deck in the superstructure and also the main hull can be considered as a thin-walled beam. These beams are coupled to adjacent beams with springs modelling vertical and shear stiffness. The shear effect in the side and deck structures is included with options for large openings. As a result, the method allows for the calculation of the normal stresses and vertical deflections in the arbitrary location of the hull girder. Average longitudinal displacements of deck structures and shear stresses in the side structures can be estimated as well. Simplified structures were analysed in order to validate the coupled beam method against the three-dimensional finite element method. [Copyright &y& Elsevier]

The dynamic response of ships following grounding and collision accidents may be influenced by structural topology as well as operational and environmental conditions. Traditionally, the consequences of such events may be assessed by crude empirical methods or laborious experiments. Computational methods offer a useful alternative in terms of accurately capturing crushing mechanisms also accounting the influence of surrounding water. This paper presents a benchmark study that compares the structural dynamic response by explicit nonlinear FEA approaches and the semi-numerical super-element method. Simulations for typical accident scenarios involving passenger ships confirm that implementing the influence of hydrodynamic restoring forces in way of contact may be useful for either collision or grounding. Yet, for grounding scenarios, the damaged area resulting from analytical simulations appears to be sensitive to the failure strain values adopted to model the rupture of the ship bottom floors. • Explicit nonlinear FSI methods utilising FEA and super element methods are benchmarked for various scenarios. • Structural topology, operational scenarios and environmental conditions influence accidental wave loads uncertainties. • Hydrodynamic restoring forces affect both collision or grounding loads. • In grounding breach sizes are sensitive to failure strain values. • Comparisons demonstrate that the super element method may be used for regulatory development. [ABSTRACT FROM AUTHOR]

During escort and convoy operations, an icebreaker opens a channel while the escorted or convoyed ships follow the path along the channel. If the assisted ship is wider than the channel which the icebreaker creates, the created channel cannot fit the assisted ship. Thus, the assisted ship has to break some ice by itself. This is herein referred to as navigation in 'narrow ice channel'. The performance of ships in narrow ice channel is investigated here. For this aim, model-scale test of a ship going through ice channels with different widths and ice thicknesses is firstly conducted. After that, numerical simulation of the model test scenarios is implemented with an in-house simulation program dedicated for ship operation in ice. The simulation correctly captured the main features of ship resistance change as a function of channel width, which indicates its validity as a simulation tool. Subsequentially, numerical simulations are implemented with several other ships in order to gain general insights into performance of ships in narrow ice channel. Focus is given to the influence of channel width on ships' encountered resistance and attainable speed in ice. The general findings through these simulations are useful for decision making tools. • Performance of ships going through narrow ice channels is investigated. • Model scale tests are carried out with different thicknesses in channels of various width. • Numerical simulations are carried out with multiple ships in channels of various width. • General conclusions on ship performance in narrow ice channel are formulated based on simulation results. [ABSTRACT FROM AUTHOR]

A natural hazard is a naturally occurring extreme event that has a negative effect on people and society or the environment. Natural hazards may have severe implications for human life and can potentially generate economic losses and damage ecosystems. A better understanding of their major causes, probability of occurrence, and consequences enables society to be better prepared to save human lives as well as to invest in adaptation options. Natural hazards related to climate change are identified as one of the Grand Challenges in the Baltic Sea region. Here, we summarize existing knowledge about extreme events in the Baltic Sea region with a focus on the past 200 years as well as on future climate scenarios. The events considered here are the major hydro-meteorological events in the region and include wind storms, extreme waves, high and low sea levels, ice ridging, heavy precipitation, sea-effect snowfall, river floods, heat waves, ice seasons, and drought. We also address some ecological extremes and the implications of extreme events for society (phytoplankton blooms, forest fires, coastal flooding, offshore infrastructure, and shipping). Significant knowledge gaps are identified, including the response of large-scale atmospheric circulation to climate change and also concerning specific events, for example, the occurrence of marine heat waves and small-scale variability in precipitation. Suggestions for future research include the further development of high-resolution Earth system models and the potential use of methodologies for data analysis (statistical methods and machine learning). With respect to the expected impacts of climate change, changes are expected for sea level, extreme precipitation, heat waves and phytoplankton blooms (increase), and cold spells and severe ice winters (decrease). For some extremes (drying, river flooding, and extreme waves), the change depends on the area and time period studied. [ABSTRACT FROM AUTHOR]

Ships and offshore structures operating in ice-covered waters need to be able to break ice. The hulls of ships and offshore structures are often designed to be inclined so that an out-of-plane force can be incurred to initiate flexural failure. During this process, an in-plane force co-exists as the result of the hull inclination, which can affect the bending process and alter the magnitude of interaction force. Additionally, the loading process can be rapid and incur dynamic effect within the ice sheet, resulting in higher peak loads compared to the scenario of quasi-static loading. The effect of in-plane force and loading speed, however, are often neglected in the modelling of the icebreaking process in order to enable simplified solutions of analytical form, which leads to deviations in the estimation of ice loads. This paper aims to investigate the effects of in-plane force and loading speed on the ice bearing capacity during the icebreaking process. This is conducted via the Finite Element Analysis (FEA) with the Cohesive Element Method (CEM). An anisotropic beam analogy concept is proposed to model a 3D ice wedge with a 2D beam which has varying properties along the axial direction. The analogy enables fast and stable simulation of ice crack propagation through its thickness direction, while maintaining properties of the ice wedge in 3D. The analogy is verified with Nevel's closed-form solution for a narrow wedge resting on an elastic foundation. After that, the beam is loaded with a rigid wall with different inclination angles and loading speeds. The results reveal that the in-plane force and loading speed have significant influence on the icebreaking process, resulting in different bearing capacity and overall energy consumption. Based on the numerical results, a regression study is conducted to derive a correction coefficient accounting for the joint effect of in-plane force and loading speed on the bearing capacity, which can be incorporated into ice-structure interaction simulation models. • An anisotropic beam analogy is proposed to model 3D ice wedge with 2D beam to investigate ice wedge bearing capacity. • The joint effect of the in-plane force and the loading speed on the bearing capacity of the ice wedge is investigated. • A strong coupling effect between the in-plane force and the loading speed exists, which jointly affect the bearing capacity. • A regression formula is obtained to account for the joint effect of in-plane force and loading speed on bearing capacity. [ABSTRACT FROM AUTHOR]