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While society benefits from Arctic shipping, it is necessary to recognize that ship operations in Arctic waters pose significant risks to people, the environment, and property. To support the management of those risks, this article presents a comprehensive approach addressing both short-term operational risks, as well as risks related to long-term extreme ice loads. For the management of short-term operational risks, an extended version of the Polar Operational Limit Assessment Risk Indexing System (POLARIS) considering the magnitude of the consequences of potential adverse events is proposed. For the management of risks related to long-term extreme ice loads, guidelines are provided for using existing analytical, numerical, and semi-empirical methods. In addition, to support the design of ice class ship structures, the article proposes a novel approach that can be used in the conceptual design phase for the determination of preliminary scantlings for primary hull structural members.

openaire: EC/H2020/814753/EU//FLARE 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.

Funding Information: This work was supported by the Academy of Finland, Finland: Towards human centered intelligent ships for winter navigation (Decision number: 351491), and the AI-based simulation grant for intelligent ice navigation (Grant number: W22-1 SIMNAV) funded by Winter Navigation Research Board. The authors also thank Ketki Kulkarni from Aalto University, Jarkko Toivola and Tuomas Taivi from FTIA, and FMI for providing practical knowledge and data. Funding Information: This work was supported by the Academy of Finland, Finland : Towards human centered intelligent ships for winter navigation (Decision number: 351491 ), and the AI-based simulation grant for intelligent ice navigation (Grant number: W22-1 SIMNAV) funded by Winter Navigation Research Board. The authors also thank Ketki Kulkarni from Aalto University, Jarkko Toivola and Tuomas Taivi from FTIA, and FMI for providing practical knowledge and data. Publisher Copyright: © 2022 The Authors Icebreaker assistance is a common but complex operation in ice-infested regions. Currently, the operational decision-making and the decisions regarding the safety indicators are primarily based on expert knowledge, resulting in subjectivity and the ad hoc nature of icebreaker assistance. This can negatively impact both the navigational efficiency of icebreaker services and the productivity of port services. This paper proposes a data mining method to automatically identify icebreaker assistance cases from big data. The identified cases are then used to statistically analyze the safety indicators. The data used in the paper include navigational data obtained from the Automatic Identification System (AIS) and sea ice data in the Baltic Sea area. A multi-step clustering method is adopted to cluster similar trajectories of merchant vessels and icebreakers, identifying assistance events automatically. The results show that the proposed method can automatically identify icebreaker assistance cases with an accuracy of 99.6%, precision of 87%, and recall of 78.3%. The automatic identification along with the statistical analysis can assist in the development of an intelligent decision-making system for safe and efficient winter navigation.

Publisher Copyright: © 2022 The Author(s) Over the past decades, the underlying mechanism of level ice resistance changing with ship speed has not been fully understood, particularly the resistance component due to ship interactions with broken ice pieces. Pre-sawn ice test can negate icebreaking component from the whole resistance of a ship in level ice, providing an effective approach to decompose ship-ice interactions and investigate the speed-dependent resistance from broken ice pieces. This work has built a computational model that can realistically simulate a ship advancing in a pre-sawn ice channel. The model applies Computational Fluid Dynamics (CFD) to solve the flow around an advancing ship, which is coupled with an enhanced Discrete Element Method (DEM) to model pre-sawn ice pieces. Model-scale experiments have also been conducted at the Aalto Ice Tank to validate the simulations, which shows the computational model can provide a reasonable estimation of the pre-sawn ice's resistance and movement around the ship. Upon validation, the dependence of ice resistance on ship speed was analysed. The simulations enable underwater monitoring of the ice motions, indicating that the speed dependence results from the mass of ice submerged underneath the ship and the displacement of broken ice induced by the ship. The identified relationships are more complex than the widely-used assumption that ice resistance linearly changes with ship speed in all cases, which provides a deeper understanding of ice resistance. As such, the findings from this study can potentially facilitate improvements in relevant empirical equations, useful for ship design, operational strategies and maritime management in polar regions.

openaire: EC/H2020/814753/EU//FLARE 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.

openaire: EC/H2020/814753/EU//FLARE SOLAS2020 damage stability regulations are based on probabilistic damage distributions. Those originate from the pooled analysis of collision accidents across a fleet with bias towards cargo ships. This paper introduces a method that accounts for collision-based crashworthiness on ship damage distributions. The method reshapes statistical SOLAS damage distributions for a given ship or structural details for a reference ship section and her reinforced version. Damage reductions may differ depending on ship characteristics and operational scenarios. To mitigate this, a high number of collision scenarios was simulated using the super-element method. It is shown that risk control in terms of damage reduction over the whole range of damages is possible by adding a double hull or by deck reinforcement. Damage reduction is quantified by damage stability analysis of a cruise vessel. It is concluded that installing a double hull on ship vulnerable zones leads to increased A-index.

This article presents a novel simulation tool for the analysis of winter navigation operations in the Baltic Sea in the context of the Finnish–Swedish Winter Navigation System (FSWNS). The aim of the tool is to simulate the performance of the FSWNS under various potential future operating scenarios and thereby support decision making in matters affecting the operation and development of the FSWNS, for instance, in terms of icebreaking resources and ice class regulations. To this end, the tool considers key performance factors and characteristics of the FSWNS, such as the prevailing ice conditions, the ice-going capability and other technical characteristics of the relevant merchant vessels, the availability of icebreaking resources, and the features of specific icebreaking operations (e.g., convoys). The tool would allow testing of several “what-if” scenarios, answering questions related to optimal engine power for safe, efficient, and environmentally friendly navigation and the optimal scheduling of icebreakers for effective and cost-efficient assistance missions.

In winter, shipping activities in the Baltic Sea area involve risks because of the harsh navigational environment. To ensure maritime safety and the efficiency of the transport system, icebreaker assistance is needed when the ship is not able to navigate independently in the prevailing ice condition. The existing ship operation mode determination practices are primarily based on empirical knowledge. To better understand when the assistance operation is needed for various ships operating in real ice conditions from a quantitative perspective, this paper proposes the use of a data-driven assistance operation identification model. The model combines different data types, including Automatic Identification System (AIS) data and ice data that portray the real operational conditions in the Baltic Sea. The aim is to measure temporal-spatial similarities among trajectories of icebreakers and potentially assisted ship(s) using clustering algorithms, automatically identifying assistance scenarios in ice-covered waters. Both the static voyage features (e.g., ship types, departures /destinations, voyage length) and the dynamic navigation features (e.g., speed, course, and ship trajectory spatial distance) are considered in the model. The outcomes of the model would assist in better understanding of ship behaviors and coupled kinematics of ships linking with the following distance and speed under icebreaker assistance in various ice conditions. They would also contribute to data-driven ship operation mode determination, therefore supporting the development of an intelligent decision support system in winter navigation.

Arctic shipping is growing driven by a demand for natural resources, climate change, and technological development, among other factors. While this provides many benefits for society, it also entails risks for people, the environment, and property. The purpose of this article is to assist ship designers, operators, owners, and other stakeholders in managing those risks by defining a comprehensive approach to scenario-based risk management for Arctic waters. The approach covers both the management of short-term operational risks, as well as of risks related to a ship’s long-term extreme (design) ice loads and structural response. For operational risk management, a further developed version of the established Polar Operational Limitations Assessment Risk Indexing System (POLARIS) method is defined. In contrast to the established method, the further developed version considers the consequences of potential accidental events. For managing risks related to a ship’s long-term extreme ice loads and structural response, guidelines are provided for the application of existing methods of assessing ice loads, including analytical, numerical, and semi-empirical methods. In addition, to support the design of ice class ship structures, a new approach based on closed-form expressions is defined that can be used in the conceptual design phase to determine preliminary scantlings of primary hull structural members (e.g., transverse web frames).

Escort and convoy are typical operations when a merchant ship navigates in ice beyond its own ice-going capability. In such scenarios, a safety distance between the front ship and the following ship is maintained. The leading vessel may suddenly decelerate or even come to a halt if it encounters a heavy ridge or thick ice floe. When this happens, the following ship needs to take actions to avoid collision with the leading vessel. An evasive operation for such collision avoidance is to break out of the channel. The safety distance can be defined as the minimum distance which is needed for successful collision avoidance. This depends on various parameters such as ice thickness, ship speed, channel width, the ship’s icebreaking capability and its manoeuvrability in ice. This paper investigates safety distance during escort and convoy by model-scale experiments and numerical simulation of a ship breaking out of ice channel. The experiments are carried out at Aalto Ice Tank and the numerical simulations are conducted via the in-house simulation software package of Aalto University Marine Technology group. The dependencies of the safety distance on ice thickness, channel width and initial speed are identified via multiple experimental and simulation runs. The simulation proves to provide accurate estimation on breakout distance through comparison with model test results, and reveals the influence of ice thickness, channel width and initial speed on the breakout distance.

With the climate change and the decreasing of Arctic sea ice, Arctic shipping receives increasing attentions from both the industries and academia due to a large amount of uncertainties involved. CEARCTIC (Centre of Excellence for Arctic Shipping and Operations) and CEPOLAR (Centre of Excellence for Scenario-based Risk Management in Polar Waters) projects are therefore established and worked continuously from year 2013 to 2022, focusing on various fields regarding safe Arctic shipping. Extensive research work has been carried out in CEARCTIC and CEPOLAR framework during the multi-year projects towards safe Arctic shipping. The outcomes are mainly published in scientific journal and conference papers, where various subjects, research directions and methods have been focused and applied. Therefore, it is vital to review the research to better understand the status and overall research of Arctic shipping. This paper aims to review and analyze the research papers published in the framework of the projects, from the viewpoint of research topics, research methods, practical purposes, and risk governance so that a general picture of research on the Arctic shipping can be seen from these perspectives. Based on review and analysis, potential gaps and clues for future research directions towards the Arctic shipping can also be identified.

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 sensor instrumentation and an automated process are proposed for sea-ice field analysis using ship mounted machine vision cameras with the help of inertial and satellite positioning sensors. The proposed process enables automated acquisition of sea-ice concentration, floes size and distribution. The process contains pre-processing steps such as sensor calibration, distortion removal, orthorectification of image data, and data extraction steps such as sea-ice floe clustering, detection, and analysis. In addition, we improve the state of the art of floe clustering and detection, by using an enhanced version of the k-means algorithm and the blue colour channel for increased contrast in ice detection. Comparing to manual visual observations, the proposed method gives significantly more detailed and frequent data about the size and distribution of individual floes. Through our initial experiments in pack ice conditions, the proposed system has proved to be able to segment most of the individual floes and estimate their size and area.

Funding Information: The development of approaches for calculating design parameters over the Baltic Sea has provided different estimations through time. The difference in these estimations (more than 10 %) is bigger than the effect from climate change calculated from different climate scenarios (a few percentage points). Climate modelling describes future scenarios and provides a coherent calculation of the whole set of environmental parameters, including wind, temperature, icing, and precipitation. One such output is from the Climate and Energy Systems (CES) research project supported by the Nordic Research Council (Thorsteinsson, 2011). This study features both opportunities and risks within the energy sector associated with climate change up to the mid-21st century. Fifteen combinations of regional and global climate models were used. The results, however, did not portray a consensus on the change in storms and extreme winds in the future over the Scandinavian seas (see also Sect. 2.2.1 and Belusic et al., 2019). Funding Information: Financial support. The contributions of Jari Haapala, Laura Tuomi, and Jani Särkkä have been supported by the Strategic Research Council at the Academy of Finland (SmartSea project; grant no. 292 985). Anna Rutgersson and Erik Nilsson have been supported by FORMAS (grant no. 2018-01784). Xiaoli Guo-Larsen has been supported by the Danish ForskEL/EUDP OffshoreWake project (grant no. PSO-5012521/64017-0017). Irina Danilovich’s studies were conducted as part of the “The Nature Resources and Ecological Safety” sub-programme within the framework of the “The Nature Management and Ecology” state research programme during 2016–2020. The contributions of Taru Olsson and Anna Lu-omaranta have been supported by the National Nuclear Waste Management Fund in Finland, Kirsti Jylhä has been supported by the Academy of Finland HEATCLIM project (grant no. 329307), and Taru Olsson has been supported by the Finnish Cultural Foundation (Satakunta Regional Fund). Publisher Copyright: © 2022 Anna Rutgersson et al. 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.

openaire: EC/H2020/723526/EU//SEDNA Following the International Code for Ships Operating in Polar Waters (Polar Code), ships operating in ice-covered polar waters must comply with an appropriate Polar Class (PC) or equivalent ice class standard. For the selection of an appropriate Polar Class, ship designers and operators are encouraged to use the Polar Operational Limit Assessment Risk Indexing System (POLARIS). A limitation of POLARIS is that it does not consider the extent to which a ship operates in various ice conditions, and thus also not the probabilistic nature of ice loading. To address this limitation, this article outlines a goal-based approach that is intended to complement POLARIS when selecting a ship's Polar Class. Following the proposed approach, the appropriateness of a ship's minimum required Polar Class as determined using POLARIS is evaluated by assessing the ship's long-term extreme ice loads, and by relating these to the design loads behind the considered Polar Class standard. To account for the probabilistic nature of iceloading, the approach calculates a ship's long-term extreme ice loads considering its intended operating profile and expected ice exposure. This is achieved by synthesising a modified version of the so-called event-maximum method, discrete-event simulations, and satellite ice data. The utility of the proposed approach is demonstrated through a case study, in which it is used as a complement to POLARIS to select an appropriate Polar Class for a double-acting ship intended for year-round independent operations along the northeast coast of Canada.

Funding Information: The work is supported by SIMREC project. The South-East Finland-Russia CBC 2014-2020 programme is the main contributor. Publisher Copyright: © 2021 Elsevier Ltd To ensure the risk level associated with continuously increasing maritime traffic through particularly sensitive sea areas remains at acceptable level, a periodic risk assessment needs to be carried out by the relevant authorities. As a part of such assessment, allowing for proactive countermeasures to mitigate risk, the frequency of accidents is estimated along with the assessment of geographical locations where the accidents are most likely to happen. To this end scientific literature offers a number of approaches, however only a few solutions are recognized by the maritime authorities and applied world-wide. One of such approach is a evidence-based, semi-dynamic, network-based model called IWRAP Mk2. Despite its advantages, the tool lacks the verification procedure of the model development process that governs the reliability of the results. This ultimately may undermine the reliability of the obtained results. This shortcoming seems to be quite common in the field of maritime risk assessment, as revealed by the recent analysis of the risk assessment method and tools. Therefore, this article attempts to close this knowledge gap by providing a novel framework for ship-ship collision probability estimation and identification of the collision-prone locations, encompassing novel verification procedure suitable for network-based maritime risk models such as IWRAP Mk2 tool. As a results this new, wider modeling framework offers more reliable, evidence-based estimates of the probability of ship-ship collision and identifies more accurately the collision-prone locations in a given sea area. To demonstrate the usability of the framework a case study is performed, with the use of 10 months of ship traffic data recorded in the heavily trafficked and enclosed sea area of the Gulf of Finland during ice-free season with the special attention paid to the oil tankers. The updated framework delivers the annual probability of ship-ship collision, where at least one ship is an oil tanker, which is higher by 16% compared to the results obtained from regular IWRAP Mk2 software, that lacks verification procedure. Also the framework identifies the most collision-prone locations in the Gulf of Finland, which are located in the eastern part of the Gulf, explaining over 60% of the total collisions in the whole GoF, for ice-free seasons.

Funding Information: In order to have a holistic perspective and elements for the shipping system, the paper targets a comprehensive and long-term project specifically focusing on holistic safe polar shipping as the analysis basis. The long-term project has coherent focus and involves fundamental elements and holistic views towards safe polar shipping, thus provides a good basis for analysis. The polar project has two stages namely CEARCTIC (Centre of Excellence for Arctic Shipping and Operations) and CEPOLAR (Centre of Excellence for Scenario-based Risk Management in Polar Waters) starting from 2013 to 2022 focusing on different aspects regarding safe shipping in ice-covered waters. It is funded by Lloyd's Register Foundation and combines the research strengths from five universities: Aalto University, Hamburg University of Technology, Memorial University of Newfoundland, Norwegian University of Science and Technology and University of Helsinki. Extensive research work has been carried out in the framework of risk management towards safe shipping and the outcomes are mainly published in scientific journal and conference papers, where various subjects, research directions and methods have been focused and applied.Table 13 shows the toolbox under ecosystem impact topic. The model P3 adopts index-based approach to assess the vulnerability of Arctic biota. The resource and skill level needed are considered as medium and low respectively. The uncertainty is discussed to some extent; therefore, it is considered as a medium level SoE, which gives a M applicability level. The potential limitation is that the model still uses a number of judgements and uniform distribution due to lack of relevant data. In addition, the model does not include the spatial features for both oil spill and Arctic biota, which limits the practical utilization. The model P13 aims to estimate the probability of marine fish cell damages to oil spill. The required resource and skill level are low, and the model considers validation through a general comparison. Therefore, validation level is considered as Medium, and the final applicability level is rated as M as well. The limitation of the model is that the CPT states are limited and the modelling of structure and CPTs lack SoE supports. This project has received funding from the Lloyd's Register Foundation, a charitable foundation, helping to protect life and property by supporting engineering-related education, public engagement and the application of research www.lrfoundation.org.uk. Funding Information: This project has received funding from the Lloyd's Register Foundation , a charitable foundation, helping to protect life and property by supporting engineering-related education, public engagement and the application of research www.lrfoundation.org.uk . Publisher Copyright: © 2022 The Authors 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.

openaire: EC/H2020/814753/EU//FLARE Collision accidents may lead to significant asset damage and human casualties. This paper introduces a direct analysis methodology that makes use of Automatic Identification System (AIS) data to estimate collision probability and generate scenarios for use in ship damage stability assessment. Potential collision scenarios are detected from AIS data by an avoidance behaviour-based collision detection model (ABCD-M) and the probability of collision is estimated in various routes pertaining to a specific area of operation. Damage extents are idealised by the Super – Element (SE) method accounting for the influence of surrounding water in way of contact. Results are presented for a Ro - Pax ship operating from 2018 to 2019 in the Gulf of Finland. It is confirmed that collision probability is extremely diverse among voyages and the damages obtained correlate well with those adopted by the UN IMO Regulatory Instrument SOLAS (2020). It is concluded that the method is by nature sensitive to traffic features in the selected case study area. Yet, it is useful for the evaluation of flooding risk for ships operating in real hydro-meteorological conditions.

Funding Information: The first author of this work is supported by the China Scholarship Council (Grant Number: 201606950009) and Marine Technology research group in Aalto University (9170094). This work is also supported by the National Science Foundation of China (NSFC) through Grant No. 52001237 and 52001241. The work has further received financial support from the Canada First Research Excellence Fund, through the Ocean Frontier Institute. This financial support is gratefully acknowledged. Besides, we thank the two anonymous reviewers for their very insightful comments, which have been very instrumental to improve an earlier version of this work. Publisher Copyright: © 2021 This paper introduced a new ship domain concept and an analytical framework. The ship domain takes the point of the ship’s first evasive maneuver as a basis and correlates it with the navigator-perceived collision risk level. The first evasive maneuver of a ship is detected based on the ship turning point identification and ship intention estimation. The available maneuvering margin (AMM) is utilized as a proxy to measure the perceived collision risk by the navigator. Interpreting the first evasive maneuver in terms of this AMM over a large sample of vessel encounters taken from automatic identification system (AIS) data finally enables an empirical estimation of the size of this ship domain. The method is applied to AIS data in the Northern Baltic Sea, and separate ship domains are constructed for the give-way and stand-on vessels with different maneuverability characteristics. Compared to the existing proximity-based ship domain, this ship domain explicitly incorporates the dynamic nature of the encounter process and the navigator’s evasive maneuvers. Several advantages of this proposed ship domain concept and limitations of the presented modeling approach are discussed. Finally, possible future applications are explained, including waterway safety assessment and navigational decision support systems to reduce ship-ship collision risk.

Funding Information: This project has been supported by the Open Fund Project of State Key Laboratoty of Ocean Engineering (grant ID: GKZD010084 ). Publisher Copyright: © 2022 Elsevier Ltd This paper investigates the fracture mechanism of level ice based on the extended finite element method by simulating collision scenarios between ice and a rigid ship structure. It is found the collision velocity and structure inclination affect the fracture mode through changing the deformation and stress distribution of the level ice. The overall response of the level ice is simulated with the transversely isotropic material model and cohesive zone model. The numerical model is verified with the data from a field test, which shows that the obtained ice load and size of the broken ices from numerical method are well consistent with the tested data. Two fracture modes of the level ice, bending and splitting, appear in the simulated cases. The bending crack is found to emerge from the top surface of the level ice and expand along the circumferential direction, and the splitting crack initiates at the bottom edge of the level ice and expands along the radial direction. Deformation and multiple stresses of levelice are analyzed, showing that the initial cracks for both fracture modes are related to the local tensile failure, and the location of the maximum tensile hydrostatic stress always coincides with the initial crack.

The Baltic Sea is a unique and sensitive brackish-water ecosystem vulnerable to damage from shipping activities. Despite high levels of maritime safety in the area, there is a continued risk of oil spills and associated harmful environmental impacts. Achieving common situational awareness between oil spill response decision makers and other actors, such as merchant vessel and Vessel Traffic Service center operators, is an important step to minimizing detrimental effects. This paper presents the Next-Generation Smart Response Web (NG-SRW), a web-based application to aid decision making concerning oil spill response. This tool aims to provide, dynamically and interactively, relevant information on oil spills. By integrating the analysis and visualization of dynamic spill features with the sensitivity of environmental elements and value of human uses, the benefits of potential response actions can be compared, helping to develop an appropriate response strategy. The oil spill process simulation enables the response authorities to judge better the complexity and dynamic behavior of the systems and processes behind the potential environmental impact assessment and thereby better control the oil combat action.

The increased activity in the Arctic involves hazards such as a harsh environment, especially the ice cover and cold temperature, remoteness and lack of infrastructure, and lack of information about bathymetry, among others [...]

Most vessels cannot safely sail in areas with sea ice. In the Northern Baltic Sea area, the presence of sea ice often requires icebreaking ships to open up ice-covered areas so merchant vessels can proceed to their destinations. In this environment there is an increasing number of ships. With growing transport volumes in sea ice environments, icebreaker operations such as convoys have become increasingly important to ensure navigation safety. This paper proposes a model of multi-ship following for icebreaker convoy operations in continuous icebreaking conditions, using modelling principles from earlier proposed car following models combined with considerations of safe distance and safe speed in ship convoy operations in ice conditions. The model parameters are calibrated with empirical data from actual icebreaker convoy operations, using data from the Automatic Identification System (AIS) and sea ice model data. The model determines ice resistance according to ice thickness, type, and bending strength, and the main dimensions of the icebreaker leading the convoy. The maximum safe navigable speed is used to assess the following ships’ ability to sail in sea ice. The multi-ship following simulation results were found to be in good agreement with empirical data. The new proposed model can provide a theoretical reference for icebreaker convoy operations, can have practical use in ship simulators to improve training, and could be useful for traffic modelling and planning purposes.

In geographical regions with sub-zero temperatures, natural freezing can potentially be used as an energy-efficient purification technique for industrial wastewaters. The utilization of this technique requires knowledge of the effect of impurities on the strength of the ice to enable the effective harvesting of produced ice. Previous studies of the mechanical properties of model-scale ice have tended to focus on the initial solution, and little consideration has been given to the amount of impurities trapped inside the ice. The aim of this research is to evaluate the separation efficiency during the natural freezing process by quantifying the impurities trapped inside the ice formed from known concentrations of aqueous solutions and to investigate the effect of impurities on the bulk mechanical properties of the ice. In this study, twenty similar size ice beams were prepared in freezing boxes in a temperature-controlled cold room from five different aqueous solutions – tap water, and ethanol and sodium chloride aqueous solutions of two different molalities, i.e. 0.1 mol/kg and 0.3 mol/kg. The bending strength and natural frequencies of the ice samples were measured in the freezing conditions, and the concentrations of impurities in melted ice samples were determined. The research shows that with the ethanol and sodium chloride solutions, the concentration of impurities inside the ice clearly decreased in comparison to the initial solution. The structure of the ice from the different solutions differed significantly; as the tap water formed columnar ice, ethanol ice grew through large platelets, while the structure of the sodium chloride ice was a mixture of the two forms. The tap water yielded the highest strength ice and the ice formed from the ethanol aqueous solutions the weakest ice. The measurements indicated that the concentration of impurity in the ice reduces the mechanical strength and the magnitude of the effect varies with the chemical characteristic of impurity.

The growing interest for Arctic and Antarctic shipping activities due to the decreasing ice cover will also increase the risks of accidents on these waters. The design of ships for ice has traditionally been based on the practical experience without a clear link to the physics of the ship-ice interaction. The rules are, however, getting more towards the goal based approach, which require good knowledge of all the various element important for design. Risk based ship design (RBSD) is also widely applied e.g. for the passengers ships. Therefore, the scope of this paper is the review of the knowledge necessary for RBSD for Arctic conditions. The main focus is on ice loads and ship structures. Accident prevention and environmental consequences of oil spills are also discussed, but more briefly. In risk analysis, there is a recent focus on the treatment of uncertainty, or conversely, the strength of knowledge underlying the risk quantification. In light of this, the review is performed with specific focus on the strength of evidence of the different fields of knowledge needed to perform RBSD in ice conditions. The results indicate that the risk based design for Arctic operations is challenging as the ice environment, together with all the possible ship-ice contact scenarios, are complicated to define properly, especially on proper probabilistic terms, The main challenges are still related how to describe the ship-ice interaction parameters such as ship-ice contact characteristics, pressure distributions, and load levels in all the various ice conditions. In addition, the possible environmental consequences of the accidents need further research. Finally, human factors need to be incorporated in risk analysis techniques.

This article presents a new holistic multi-objective design approach for the optimization of Arctic Offshore Supply Vessels (OSVs) for cost- and eco-efficiency. The approach is intended to be used in the conceptual design phase of an Arctic OSV. It includes (a) a parametric design model of an Arctic OSV, (b) performance assessment models for independently operating and icebreaker-assisted Arctic OSVs, and (c) a novel adaptation of the Artificial Bee Colony (ABC) algorithm for multi-objective optimization of Arctic OSVs. To demonstrate the feasibility and viability of the proposed optimization approach, a series of case studies covering a wide range of operating scenarios are carried out. The results of the case studies indicate that the consideration of icebreaker assistance significantly extends the feasible design space of Arctic OSVs, enabling solutions with improved energy- and cost-efficiency. The results further indicate that the optimal amount of icebreaking assistance and optimal vessel speed differs for different vessels, highlighting the motivation for holistic design optimization. The applied adaptation of the ABC algorithm proved to be well suited and efficient for the multi-objective optimization problem considered.

Funding Information: The work received funding from SIMREC project (CBC 2014?2020), funded by the European Union, the Russian Federation and the Republic of Finland. The work also received funding from the Lloyd's Register Foundation, a charitable foundation, helping to protect life and property by supporting engineering-related education, public engagement and the application of research www.lrfoundation.org.uk. The contributions by the third author were undertaken in context of the project ?Safe Navigation and Environmental Protection?, thanks in part to funding from the Canada First Research Excellence Fund, through the Ocean Frontier Institute. The authors also thank Fang Li and Mikko Suominen for their valuable comments to the paper. Publisher Copyright: © 2021 The Author(s) Copyright: Copyright 2021 Elsevier B.V., All rights reserved. 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.

openaire: EC/H2020/|723526/EU//SEDNA Ships operating in ice-infested Arctic waters are exposed to a range of ship-ice interaction related hazards. One of the most dangerous of these is the possibility of a ship becoming beset in ice, meaning that a ship is surrounded by ice preventing it from maneuvering under its own power. Such a besetting event may not only result in severe operational disruption, but also expose a ship to severe ice loading or cause it to drift towards shallow water. This may cause significant structural damage to a ship and potentially jeopardize its safety. To support safe and sustainable Arctic shipping operations, this article presents a probabilistic approach to assess the probability of a ship becoming beset in ice. To this end, the proposed approach combines different types of data, including Automatic Identification System (AIS) data, satellite ice data, as well as data on real-life ship besetting events. Based on this data, using a hierarchical Bayesian model, the proposed approach calculates the probability of a besetting event as a function of the Polar Ship Category of a ship, sea area, and the distance travelled in the prevailing ice concentration. The utility of the proposed approach, e.g. in supporting spatiotemporal risk assessments of Arctic shipping activities as well as Arctic voyage planning, is demonstrated through a case study in which the approach is applied to ships operating in the Northern Sea Route (NSR) area. The outcomes of the case study indicate that the probability of besetting is strongly dependent on the Polar Ship Category of a ship and that the probability increases significantly with higher ice concentrations. The sea area, on the other hand, does not appear to significantly affect the probability of besetting.

This paper aims to identify the gap between cruise passengers’ expectations and the on-board experience (referred to in the text as ‘the on-board experience gap’) in the context of on-board environmental factors and overall satisfaction. It also investigates the relationship between cruise passengers’ pre-cruise expectations and their post-cruise experience. The study adopts a comparative approach that examines three classes of cruise ships through open-source data (N = 2649). The aim of the comparison was to understand what creates a gap between cruise passengers’ expectations and the on-board experience, and to explain why some cruise ships are more successful than others. The result of this paper concludes that some of the cruise experiences are not aligned with the customers’ expectations, and the on-board experience gap is also clearly observed between the elements. This on-board experience gap concept can be used to provide a dynamic procedure to measure the customers’ cruise experience.