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Moving fast by high-speed planing craft (HSPC) is advantageous for some special missions, though it causes severe hull vibrations and shocks that can transfer to the human body and increase health and comfort risks. This study reviews the current safety standards to avoid human safety risks affected by whole-body vibrations (WBVs), as well as the safety status of HSPC occupants. In addition, the efficiency of motion-reduction devices (trim tab and interceptor) and shock/vibration-mitigation devices (shock-mitigation seat) in improving the safety of HSPC occupants is examined according to existing documents. The research methodology was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIS-MA) method, and published papers in the Scholar, Scopus, and Web of Science databases were analyzed. Because most of these publications are academic research, issues of bias in the eligible publications were not of particular interest. During this systematic review, many gaps and challenges in current information on safety improvement devices were found that need to be addressed in future studies, such as a lack of information on motion-reduction devices and shock-mitigation seat performance in reducing lateral and fore-and-aft motions. Referring to these gaps and challenges can be valuable as a suggestion to improve current knowledge in research and reduce safety risks., QC 20240522

Moving fast by high-speed planing craft (HSPC) is advantageous for some special missions, though it causes severe hull vibrations and shocks that can transfer to the human body and increase health and comfort risks. This study reviews the current safety standards to avoid human safety risks affected by whole-body vibrations (WBVs), as well as the safety status of HSPC occupants. In addition, the efficiency of motion-reduction devices (trim tab and interceptor) and shock/vibration-mitigation devices (shock-mitigation seat) in improving the safety of HSPC occupants is examined according to existing documents. The research methodology was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIS-MA) method, and published papers in the Scholar, Scopus, and Web of Science databases were analyzed. Because most of these publications are academic research, issues of bias in the eligible publications were not of particular interest. During this systematic review, many gaps and challenges in current information on safety improvement devices were found that need to be addressed in future studies, such as a lack of information on motion-reduction devices and shock-mitigation seat performance in reducing lateral and fore-and-aft motions. Referring to these gaps and challenges can be valuable as a suggestion to improve current knowledge in research and reduce safety risks., QC 20240522

Moving fast by high-speed planing craft (HSPC) is advantageous for some special missions, though it causes severe hull vibrations and shocks that can transfer to the human body and increase health and comfort risks. This study reviews the current safety standards to avoid human safety risks affected by whole-body vibrations (WBVs), as well as the safety status of HSPC occupants. In addition, the efficiency of motion-reduction devices (trim tab and interceptor) and shock/vibration-mitigation devices (shock-mitigation seat) in improving the safety of HSPC occupants is examined according to existing documents. The research methodology was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIS-MA) method, and published papers in the Scholar, Scopus, and Web of Science databases were analyzed. Because most of these publications are academic research, issues of bias in the eligible publications were not of particular interest. During this systematic review, many gaps and challenges in current information on safety improvement devices were found that need to be addressed in future studies, such as a lack of information on motion-reduction devices and shock-mitigation seat performance in reducing lateral and fore-and-aft motions. Referring to these gaps and challenges can be valuable as a suggestion to improve current knowledge in research and reduce safety risks., QC 20240522

Moving fast by high-speed planing craft (HSPC) is advantageous for some special missions, though it causes severe hull vibrations and shocks that can transfer to the human body and increase health and comfort risks. This study reviews the current safety standards to avoid human safety risks affected by whole-body vibrations (WBVs), as well as the safety status of HSPC occupants. In addition, the efficiency of motion-reduction devices (trim tab and interceptor) and shock/vibration-mitigation devices (shock-mitigation seat) in improving the safety of HSPC occupants is examined according to existing documents. The research methodology was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIS-MA) method, and published papers in the Scholar, Scopus, and Web of Science databases were analyzed. Because most of these publications are academic research, issues of bias in the eligible publications were not of particular interest. During this systematic review, many gaps and challenges in current information on safety improvement devices were found that need to be addressed in future studies, such as a lack of information on motion-reduction devices and shock-mitigation seat performance in reducing lateral and fore-and-aft motions. Referring to these gaps and challenges can be valuable as a suggestion to improve current knowledge in research and reduce safety risks., QC 20240522

Moving fast by high-speed planing craft (HSPC) is advantageous for some special missions, though it causes severe hull vibrations and shocks that can transfer to the human body and increase health and comfort risks. This study reviews the current safety standards to avoid human safety risks affected by whole-body vibrations (WBVs), as well as the safety status of HSPC occupants. In addition, the efficiency of motion-reduction devices (trim tab and interceptor) and shock/vibration-mitigation devices (shock-mitigation seat) in improving the safety of HSPC occupants is examined according to existing documents. The research methodology was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIS-MA) method, and published papers in the Scholar, Scopus, and Web of Science databases were analyzed. Because most of these publications are academic research, issues of bias in the eligible publications were not of particular interest. During this systematic review, many gaps and challenges in current information on safety improvement devices were found that need to be addressed in future studies, such as a lack of information on motion-reduction devices and shock-mitigation seat performance in reducing lateral and fore-and-aft motions. Referring to these gaps and challenges can be valuable as a suggestion to improve current knowledge in research and reduce safety risks., QC 20240522

Analyzing the reliability of autonomous ships has recently attracted attention mainly due to epistemic uncertainty (lack of knowledge) integrated with automatic operations in the maritime sector. The advent of new random failures with unrecognized failure patterns in autonomous ship operations requires a comprehensive reliability assessment specifically aiming at estimating the time in which the ship can be trusted to be left unattended. While the reliability concept is touched upon well through the literature, the operational trustworthiness needs more elaboration to be established for system safety, especially within the maritime sector. Accordingly, in this paper, a probabilistic approach has been established to estimate the trusted operational time of the ship machinery system through different autonomy degrees. The uncertainty associated with ship operation has been quantified using Markov Chain Monte-Carlo simulation from likelihood function in Bayesian inference. To verify the developed framework, a practical example of a machinery plant used in typical short sea merchant ships is taken into account. This study can be exploited by asset managers to estimate the time in which the ship can be left unattended. Keywords: reliability estimation, Bayesian inference, autonomous ship, uncertainty., Ship Design, Production and Operations

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.

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.

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.

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.

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.

This article presents an optimization-based approach for sizing and composition of an Arctic offshore drilling support fleet considering cost-efficiency. The approach studies the main types of duties related to Arctic offshore drillings: supply, towing, anchor handling, standby, oil spill response, firefighting, and ice management. The approach considers the combined effect of the expected costs of accidental events, the versatility of individual support vessels, and ice management. The approach applies an Artificial Bee Colony algorithm-based optimization procedure. As demonstrated through case studies, the approach may help to find a range of cost-efficient fleet compositions. Some of the obtained solutions are similar to corresponding real-life fleets, indicating that the approach works in principle. Sensitivity analyses indicate that the consideration of the expected costs from accidental events significantly impacts the obtained solution, and that investments to reduce these costs may improve the overall cost-efficiency of an Arctic offshore drilling support fleet., Comment: 25 pages

Analyzing the reliability of autonomous ships has recently attracted attention mainly due to epistemic uncertainty (lack of knowledge) integrated with automatic operations in the maritime sector. The advent of new random failures with unrecognized failure patterns in autonomous ship operations requires a comprehensive reliability assessment specifically aiming at estimating the time in which the ship can be trusted to be left unattended. While the reliability concept is touched upon well through the literature, the operational trustworthiness needs more elaboration to be established for system safety, especially within the maritime sector. Accordingly, in this paper, a probabilistic approach has been established to estimate the trusted operational time of the ship machinery system through different autonomy degrees. The uncertainty associated with ship operation has been quantified using Markov Chain Monte-Carlo simulation from likelihood function in Bayesian inference. To verify the developed framework, a practical example of a machinery plant used in typical short sea merchant ships is taken into account. This study can be exploited by asset managers to estimate the time in which the ship can be left unattended. Keywords: reliability estimation, Bayesian inference, autonomous ship, uncertainty., Ship Design, Production and Operations

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.

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.

This thesis aims to analyze the dynamic response of a semi-submersible floating wind turbine under combined wind and ice loads through a coupled analysis. The importance of the topic is due to the increased interest and investments in the renewable energy and particularly in the wind energy. Lots of cold region have shown great potential in terms of wind energy and therefore the effect of ice loads on wind turbines should be investigated. Among the different types of floating wind turbine concepts, semi-submersible platform are probably the most suitable for operating in cold region due to the high stability, the depth flexibility and the possibility to fit the column with ice-breaking cones without compromising the hydrodynamic performances. The analysis was performed using a aero-servo-hydro-elastic model developed on the software SIMA that was coupled with a semi-empirical ice module developed through a FORTRAN DLL. The loads acting on the platform and on the wind turbine are: ice loads, aerodynamic loads, mooring line loads and hydrodynamic loads. When evaluating the hydrodynamic loads, no waves are considered since they are assumed to be damped out by the ice. First, we analyzed the ice load on a bottom fixed cylinder in order to test the ice load DLL and to understand how the different parameters affected the ice loads. After that, we performed different sets of coupled analysis on the floating wind turbine. For each set, we considered both ice and wind load and we kept one parameter constant while changing the others to understand how the ice characteristics affect the ice load and consequently the platform motion. Our analysis showed that the ice load magnitude increases with both the ice thickness and the ice drifting speed, while the ice load frequency increases with the ice drifting speed and it decreases with increasing ice thickness. It also showed that the wind loads are dominant in wind direction, while the ice loads are dominant in the direction perp

Maritime activities have significantly increased in Polar regions as a result of climate change. Ice covers are fading resulting in new routes which were not accessible before. Due to increased navigational aspects in such regions, the interest of maritime industries and academia has been raised with a common goal to estimate design loads for the development of ice-going vessels. Estimation of design loads has been carried out using full-scale trials and various numerical and analytical models. The Polar research vessel S.A.Agulhas II’s Antarctic expedition took place at the end of the year 2018. The vessel came across numerous ice floe fields ranging from open water to highly concentrated floe fields. Selection of one scenario based on observed variations in ice conditions and ice loads from the entire expedition was carried out. Implementation of modern image processing techniques over visual observations and image data provided geometrical parameters of ice floes. Peak ice loads were filtered from full-scale measurements. Collision-energy-model based on (Popov, 1967) was implemented to estimate ice loads by analysing impact scenarios of the ship with floating ice floes selected from generated ice floe fields (produced based on image processing results of actual floes). Probability analysis to study distribution family was carried out using line load results obtained from the (Popov, 1967) method. Distribution fitting results were analysed using the goodness of fit tests. Simulated line loads measurements were compared with full-scale measurements to predict the validity of implemented model. This research study implemented collision-energy approach for estimation of ice loads deduced from original ice conditions created using image processing methods.

An experiment was carried out to study the ice loads of level ice and ridge on the vertical and slope structures. The prototype of the model is the lighthouse Nordströmsgrund, which is a vertical structure and locates in the north Baltic sea. Nevertheless, a conical part was added to the model to study the ice load on slope structures in addition to the study of the ice loads on vertical structures. Three ice sheets with ridges were targeted to design the ice condition around Nordströmsgrund, including the flexural strength, ice thickness, geometrical cross-sectional profile of ridge, etc. Every ice sheet had a constant thickness, ranging from 0.04m to 0.043m in model-scale, but its flexural strength could be changed by using tempering procedure. Eight tests were successfully conducted and the ice loads were measured and recorded with three components divided according to the Cartesian coordinate system. The effect of ice properties and degrees of consolidation were also observed and analyzed with the measured data. The history curve and its envelope were utilized to study the ice loads on structures. The ice loads were decomposed into rubble loads (loads induced by accumulated rubbles) and level ice/consolidated layer loads (loads induced by breaking the level ice/consolidated layer). The upper envelope was assumed to represent the total ice loads and the lower envelope was assumed to represent the rubble loads. Thus, the difference between the upper and lower envelopes could be considered the level ice/consolidated layer loads. Fast Fourier Transform was applied to study the energy distribution of ice loads. The splitting of level ice was observed in front of the ridge at three tests. The histogram and return period are employed to study the distribution of ice loads and affecting parameters. The most important discovery of this research was that the horizontal range of rubbles moved by the structure had stronger influence on the ice ridge loads than the depth of

As safety regulations for passenger ship design continue to advance, so does the need for evacuation analysis tools to simulate the evacuation process. Currently the IMO requires an evacuation analysis for all new passenger ships in one of two ways: a simplified analysis or an advanced analysis. The simplified analysis takes a macroscopic view of the problem, treating the evacuees as particles in a fluid, flowing to their muster stations through corridors and doors as if they were pipes and valves. On the other hand, the advanced analysis takes a more microscopic approach, treating each evacuee as an individual with their own behaviour and decision making. However, as crowd simulation on passenger ships is a relatively young field of study, there is no clear consensus on the best way to perform this advanced analysis and therefore the guidelines are left more open ended. Consequently, there are several software suites that perform the analysis in different ways. This study aims to evaluate and better understand two different software packages, Evi and Pathfinder, which are capable of performing an advanced evacuation analysis. To do this, the same evacuation scenario on the same Main Vertical Zone (MVZ) of a RoPax ferry was simulated on both software in order to see how the differences in approaching the modelling affected both the numerical results and the user experience, including the time taken to build and run the analysis. These results were further compared with those obtained from a simplified analysis. Despite differences in how the reaction times were distributed, the total completion times measured were very similar, falling within the acceptance criteria set for this study. However, the user experience is where the largest differences between the two software became apparent. While Pathfinder had a more feature-rich toolset to build the geometry, the fact that Evi is purpose built to perform evacuation analyses of passenger ships is apparent in its prese

Shipboard pollution has been regulated by international and regional instruments since the end of World War II. Wastewater and sewage from ships have, however, been one of the less researched aspects of pollution. Typically, rules and regulations are enforced during the initial installation of purification systems, but their performance is not monitored in practice. Development of treatment systems has been largely in the hands of ship system suppliers, main driver being compliance with regulations. As wastewater systems have become increasingly advanced, new need has emerged for evaluation of the purification process in the context of ship design. Starting from the main key parameters required for system selection, wastewater system suppliers and other stakeholders of the ship design process need to work in the early stage ship concept design to decide on a fitting solution. Proper knowledge of wastewater sources and volumes onboard, as well as the ship operational profile act as cornerstones for the design improvements. This study utilizes the resources provided by a wastewater system supplier and a ship design company to evaluate the current state of system design onboard passenger ships and what is expected from early ship concept phase. Based on this, two case vessels with initial parameters are studied in terms of suitable system selection. Optimization and multi-criteria decision making tools have been widely used for ship machinery evaluations and land-based municipal wastewater plant applications. This study utilizes a linear optimization model using a standard product database for initial evaluation of the main parameters and variables for wastewater systems from the perspective of a case study vessel. Main objectives and constraints are fulfilling the hydraulic and organic loading requirements, as well as fitting of the systems in the designated space initially reserved by a ship design company. Main conclusion of the study is that in the concept stage ke, Laivaperäisiä saasteita koskevat säännöt ja määräykset ovat olleet olemassa toisesta maailmansodasta lähtien. Jätevesi on kuitenkin jäänyt vähemmälle tutkimukselle verrattuna muihin laivaperäisiin saasteisiin. Usein jäteveden puhdistussysteemien on määrä täyttää asennusvaiheessa säännöt ja määräykset, mutta käytössä niiden suorituskykyä ei enää seurata. Laitteiston kehitys on ollut pitkälti laitetoimittajien vastuulla, pääajurina juuri sääntöjen ja määräysten tavoitteiden täyttyminen. Samalla kuin puhdistussysteemeistä on tullut edistyksellisempiä, on muodostunut tarve arvioida puhdistusprosessia laivasuunnittelun kontekstin näkökulmasta. Alkaen ensimmäisistä pääparametreistä, joita tarvitaan laitteiden suunnitteluun, jätevesisysteemien toimittajien ja muiden laivasuunnitteluprosessin sidosryhmien on toimittava yhdessä suunnitellakseen ja valitakseen sopivan ratkaisun. Tieto laivan jätevesilähteistä ja volyymeistä, sekä laivan operointiprofiilista toimii suunnitteluprosessin kulmakivenä myöhemmissäkin vaiheissa. Tämä tutkimus hyödyntää jäteveden puhdistussysteemien toimittajan ja laivasuunnittelutoimiston resursseja arvioitakseen systeemisuunnittelun nykytilan matkustaja-aluksissa, sekä mitä odotuksia sille on aikaisessa laivan konseptisuunnitteluvaiheessa. Tämän tiedon pohjalta kaksi esimerkkilaivaa parametreineen ovat tarkemmassa tarkastelussa sopivan systeemin valinnan näkökulmasta. Optimointi ja monikriteerisen päätöksenteon työkalut ovat olleet laajasti käytössä laivojen koneistoratkaisujen ja maissa olevien jätevedenpuhdistamoiden arvioinnissa. Tämä tutkimus hyödyntää lineaarista optimointimallia ja standardituotteiden tietokantaa alkuvaiheen muuttujien ja parametrien arviointiin esimerkkialusten näkökulmasta. Päätavoite on täyttää hydraulisen ja orgaanisen kuorman vaatimukset, sekä sijoittaa systeemit niille suunnittelutoimiston toimesta varattuun tilaan laivassa. Työn pääjohtopäätös on, että konseptivaiheessa on vakiinnutettava jätevesisysteemien tärkeimmät

Improving energy efficiency and reducing greenhouse gas emissions in shipping have been central objectives in the development of sustainable shipping. The way how ships are operated has a noteworthy impact on the overall energy efficiency and produced emissions. Voyage optimization processes aim to improve the operational efficiency of a ship by optimizing route and speed profiles and consequently bring economic benefit to the shipping stakeholders. The central subject of this thesis is a case study where the overall benefits of voyage optimization for a fleet of a specific shipowner are evaluated. The study utilizes the operational Automatic Identification System data of 49 Medium Range tankers between January 2018 and March 2019 in ship performance simulations where different voyage optimization strategies are implemented. The objective in the case study is to assess the potential of improvement in the fleet energy efficiency and how the implementation of voyage optimization processes would affect the overall economics of the shipowner. The results of the case study show that the potential in fuel saving and emission reduction can be 11.5 to 28% depending on the optimization strategy. For the shipowner economics the consequential reduction in fuel cost would result in approximately 7.2 to 17.8% increase in the average daily revenue performance of the fleet. Several stakeholders are typically involved in the shipping process which makes the implementation of voyage optimization difficult. The discussion part of the thesis focuses on the approaches how to share the benefits from voyage optimization in a way that all stakeholders are motivated to change the operational processes. The key factor would be a creation of benefit distribution scheme where the monetary benefits from the voyage optimization are shared between the ship operator and the charterer. Moreover, a successful implementation of voyage optimization would require changes in port operation scheduling, Laivojen energiatehokkuuden parantaminen sekä päästöjen vähentäminen ovat viime vuosina olleet keskeisiä tavoitteita laivaliikenteen kehittämisessä ympäristöä vähemmän kuormittavaksi. Tavalla, jolla laivoja operoidaan on huomattavaa merkitystä laivojen polttoaineenkulutukseen sekä tuotettuihin päästöihin. Laivojen matkaoptimointi pyrkii parantamaan laivojen operointitehokkuutta löytämällä mahdollisimman tehokkaita reittejä ja nopeusprofiileita, joiden seurauksena voidaan lisäksi saavuttaa taloudellista hyötyä merenkulun eri osapuolille. Tämän diplomityön keskeinen teema on tapaustutkimus, jossa arvioitiin matkaoptimoinnin kokonaishyötyjä olemassa olevalle laivanvarustajalle. Tapaustutkimuksessa hyödynnettiin 49:n Medum Range-tuotetankkerin operatiivista Automatic Identification System-dataa tammikuun 2018 ja maaliskuun 2019 väliltä. Operatiivisen datan, säädatan ja digitaalisen laivamallin avulla suoritettiin matkasimulaatioita eri optimointistrategioita hyödyntäen. Tapaustutkimuksen tavoite oli arvioida kuinka paljon matkaoptimointi voi parantaa laivojen energiatehokkuutta ja millaisia vaikutuksia matkaoptimoinnilla on laivanvarustajan talouteen. Tapaustutkimuksen tulokset osoittivat 11.5 - 28% säästöpotentiaalin polttoaineen kulutuksessa ja tuotetuissa päästöissä käytetystä optimointistrategiasta riippuen. Vastaavasti säästöt polttoaineenkulutuksessa voivat kasvattaa laivanvarustajan päivittäistä kokonaistuottoa 7.2 - 17.8%. Tyypillisesti merenkulkuun liittyy useita osapuolia, mikä tekee matkaoptimoinnin käyttöönotosta hankalaa. Tämän diplomityön keskusteluosa käsittelee lähestymistapoja, joiden avulla matkaoptimoinnilla saavutettuja hyötyjä voidaan jakaa eri merenkulun osapuolten kesken. Avaintekijä muutokseen olisi luoda järjestelmä, jonka avulla matkaoptimoinnin tuoma taloudellinen hyöty voidaan jakaa laivan operoijan ja rahtaajan välillä. Lisäksi matkaoptimoinnin kokonaisvaltainen käyttöönotto vaatii muutoksia satamaoperaatioiden aikataulutuksessa, reaaliaikai

Arctic shipping is increasingly in focus due to the diminishing ice cover due to the effects of climate change. With new shipping routes opening up, navigation in ice-covered waters receives increasing attention in industry and academia. One of the key issues in the design of ice-going vessels is the required plate thickness to withstand the ice loads. Several regulations have been developed, containing formulae for determining the place thickness for different ice classes. On the other hand, various engineering tools have been developed for simulating the ship performance in ice, with several of these tools explicitly aiming to determine the ice loads on the hull. Such tools in principle provide alternative means to determine the safety level of the hull elements based on first-principle modeling. In this report, a risk-based design approach is taken as a starting point for contextualizing the determination of the required plate thickness based on a structural reliability analysis. The focus of the work is to analyze the importance of the uncertainties in the ice loads resulting from a ship performance in ice simulation model, in relation to the structural reliability as calculated based on the simulated ice load time series. The study centered on the influence of the applied empirical parameters in the model design on the predicted ice loads with respect to the long-term safety and reliability analysis of the ship. The various assumptions in the simulation model for ship performance in ice are systematically varied to quantify the uncertainty about the safety index and failure probability of a plate under ice loading. The results showed that the predicted loads from the simulation model lead to some about of uncertainties across the investigated parameters, indicating the limited usefulness of the simulation model in a risk-based design context. The estimated uncertainties were however based on the relative variations of the simulated ice loads and the estimated s

Azimuthing propulsors offer an efficient and environmentally friendly solution in today’s cruise industry. With an increasing growth in its customer base, cruise companies seek maintenance serviceability as important as the design of the product itself to raise their reliability. Therefore, cruise companies’ suppliers must have a proper inventory for spare parts in order to react on unexpected failures. In this thesis, an applicable spare parts availability model is evaluated by combining the inventory theories with the ship maintenance theories as well as ABB’s spare part engineers’ experiences. The model considers whether a component should be stored in the storage of a supplier in case of any emergency need as well as the optimal quantity of stocking. The designed model is then applied to an imaginary case in which a ferry is equipped with an actual product, Azipod D propulsor. The component chosen to be examined in this example case is thrust bearing which is one of the most critical components in Azipod propulsors. The total installed base and the cost of this chosen component are fictional. Applied tool has proposed that the chosen thrust bearing should be stored in supplier’s storage based on its criticality, installed base, cost and impacts on supplier’s image due to failure. However, verification of the operability of the model requires further applications in practice. It could be presumed that the presented availability tool can applied to other product types with minor adjustments., Azimuth-propulsiolaitteiden käyttö on yleistynyt viime vuosina, sillä ne tarjoavat entistä energiatehokkaamman ja ympäristöystävällisemmän ratkaisun merenkulkuun. Kasvavalla risteilyalalla toimiva huoltopalvelu on noussut tärkeäksi tekijäksi, sillä huoltotehokkuudella on välitön yhteys laivan operoijan toiminnan varmuuteen. Näin ollen operoijien toimittajilla pitää olla kokonaisvaltainen suunnitelma varaosien varastoinnille odottamattomien tapahtumien varalta. Tässä työssä kehitetään tehokas varaosien saatavuusmalli, jossa hyödynnetään varastonhallinnan, laivan kunnostuksen ja kunnonvalvonnan perusteorioita ABB:n varaosainsinöörien kokemuksia huomioiden. Malli arvioi yksittäisen varaosan saatavuuden perusteella, kannattaako kyseistä varaosaa säilyttää toimittajan varastossa, ja ilmoittaa mahdollisesti optimaalisen varastointilukumäärän kyseiselle varaosalle. Muodostettu malli sovelletaan kuvitteelliseen esimerkkilaivaan, joka käyttää Azipod D -propulsoria. Esimerkissä sovelletut numeeriset arvot, kuten komponentin asennettu kanta ja hinta sekä laivan operointiprofiili, ovat kuvitteellisia. Tarkastelukohteeksi valitaan painelaakeri, joka on Azipod-tyyppisten propulsiolaitteiden yksi kriittisimmistä komponenteista. Sovelletun mallin tulokset osoittavat, että painelaakereita tulisi varastoida odottamattomien laiterikkojen varalta. Mallissa on huomioitu komponentin kriittisyys, asennettu kanta, hinta ja laiterikosta seuraama vaikutus yrityksen julkisuuskuvaan. Varaosamallin toimivuus vaatii kuitenkin käytännönsovellusta, sillä malli perustuu yksinomaan teoriaan ja saatavilla olevaan tietoon. Malli voidaan soveltaa muihin erikokoluokkien Azipod-propulsoreihin pienillä muokkauksilla.

Fire is one of the most common threatening accidents onboard a cruise ship. As cruise ship sizes are growing, as well as the number of passengers onboard, so does the risk in catastrophic accidents. It is widely believed, that larger cruise ships oppose bigger risks. On the other hand, a larger ship has a greater potential to survive accidents and to perform its duty as the best lifeboat itself. Another aspect of growing cruise ship size is that the perception of the overall fire safety level of the ship becomes difficult to assess, and the perception of the risks involved diminishes. From previous points, a need for a tool, which could be used for assessing and comparing holistic fire safety levels of cruise ships, was recognized. In this master’s thesis, a model was developed to quantify the overall fire safety level of a cruise ship in a manner that enables comparison between fire safety levels of other cruise ships. The model is based on the fire risk indexing method. The model consists of three modules: fire safety, evacuation and resilience, which are evaluated and scored independently. These scores are then weighted, and the overall fire safety score of the ship is obtained. Fire safety and the resilience modules function as intended. Finalizing of the evacuation module was left out for future work due to difficulty in assessing embarkation reliably with a method suitable for the model. Some parts of the model should be reassessed and looked into in more depth., Yksi yleisimpiä koko risteilylaivaa uhkaavia onnettomuuksia on tulipalo. Uusien risteilylaivojen koko jatkaa kasvuaan. Kun risteilylaivojen koko kasvaa, niin kasvaa laivalla olevien matkustajien lukumääräkin. Suurempi ihmismäärä laivalla johtaa suurempaan riskiin katastrofaalisessa onnettomuudessa. Yleisesti hyväksytty kanta on, että suurempi risteilylaiva tarkoittaa suurempaa riskiä. Toisaalta suuremmalla risteilylaivalla on suurempi mahdollisuus selviytyä onnettomuudesta ja toimia itsessään parhaana pelastusveneenä, niin kuin on tarkoituskin. Toinen huomionarvoinen asia on, että risteilylaivan koon kasvaessa sen kokonaisvaltaisen palotuvallisuuden käsitteleminen hankaloituu ja siihen liittyvien riskien käsitys hämärtyy. Edellisiin kohtiin perustuen havaittiin tarve työkalulle, jolla voitaisiin arvioida ja verrata risteilylaivojen kokonaisvaltaista paloturvallisuutta. Tämän diplomityön aikana kehitettiin työkalu, jolla voidaan qvantifioida risteilylaivan kokonaisvaltainen paloturvallisuustaso niin, että sitä voidaan verrata muiden vastaavien risteilylaivojen paloturvallisuustasoon. Malli perustuu paloriski-indeksiin. Malli sisältää kolme moduulia, jotka arvioidaan erikseen; paloturvallisuus-, evakuointi- ja selviytymismoduuli. Moduuleista saadut pistemäärät painotetaan merkitsevyyskertoimella ja tuloksena on kokonaisvaltainen paloturvallisuusindeksi. Paloturvallisuus- ja selviytymismoduulit toimivat suunnitellusti. Pelastusveneisiin siirtymisen mallintaminen mallille sopivalla tavalla osoittautui haastavaksi, minkä takia evakuointimoduulin viimeisteleminen jätettiin työn seuraavaan vaiheeseen. Joitakin mallin osia tarvitsee käsitellä tulevaisuudessa tarkemmin uudelleen.

The study of icebreaking patterns has been sparsely studied over the course of the past half century. Various methods have been developed primarily to approximate the size of the resultant cusps and general inferences from the observations of the cusps and relating properties. The objective of this work aims to compile the current state of the art in this field and perform model tests focusing on icebreaking pattern. The resultant cusps of the tests were recorded, measured, compiled, statistically fit, and analyzed in works with comparing to currently available approximation methods as well as revisit any current theories regarding the nature of icebreaking pattern and its scalability. The cusps and patterns formed from model tests from the Azipod-version model of the MT Uikku at slow speeds were used for the comparison and analysis. The tests show primarily the confirmation of most current theories with an exception to one criterion regarding elasticity, promoted potential prospects for scaling, and found greater accuracy from theoretical and full-scale based approximation methods as opposed to model scale prediction methods.

Autonomous vessels have become a topic of high interest for the maritime transport industry. Recent progress in the development of technologies enabling autonomous systems has fostered the idea that autonomous vessels will soon be a reality. However, before the first autonomous vessel can be released into her actual context of operation, it is necessary to ensure that it is safe. This is a major challenge as the experience of autonomous ships is very limited. This study highlights the need for elaborating a systemic and systematic hazard analysis since the earliest design phase of an autonomous vessel. In particular, it proposes a process for elaborating an initial hazard analysis and management that provides coherent, transparent and traceable safety input information for the design of an autonomous vessel. The process is applied to analyse the hazards of two autonomous vessel concepts for urban transport in the city of Turku, Finland., Safety and Security Science

Autonomous vessels have become a topic of high interest for the maritime transport industry. Recent progress in the development of technologies enabling autonomous systems has fostered the idea that autonomous vessels will soon be a reality. However, before the first autonomous vessel can be released into her actual context of operation, it is necessary to ensure that it is safe. This is a major challenge as the experience of autonomous ships is very limited. This study highlights the need for elaborating a systemic and systematic hazard analysis since the earliest design phase of an autonomous vessel. In particular, it proposes a process for elaborating an initial hazard analysis and management that provides coherent, transparent and traceable safety input information for the design of an autonomous vessel. The process is applied to analyse the hazards of two autonomous vessel concepts for urban transport in the city of Turku, Finland., Safety and Security Science

Several decision support systems have been developed during the last about ten years to assists crews of both naval and passenger ships in the decision making process during a flooding incident. NAPA Emergency Computer is a decision support system developed by Napa Ltd. for passenger ships to monitor the vulnerability of the ship and conduct a flooding prediction and a survivability assessment if ingress water is detected by the ship’s flooding sensors, and to which this thesis focuses on. There is not yet a system which would reliably combine risk assessment and flooding prediction features to a countermeasure advice to improve the situation on board. Thus, the objective of this thesis is to identify the most feasible counteractions on a cruise ship to combat a flooding situation enhancing the survivability of the ship and to be able to present these in a prototype graphical user interface of NAPA Emergency Computer. Feasible counteractions are identified from the reviewed accidents and the scientific literature. The most promising countermeasure to prevent progressive flooding and especially up-flooding after closing of watertight doors is closing of certain fire doors. The effect of that on the development of a flooding case is studied with simulations in NAPA ship design software through four probable extensive damage cases a cruise ship can encounter and with different fire door statuses. The simulations showed that closing of fire doors on the bulkhead deck above the damaged compartments between staircases and the service corridor has a very significant effect on increasing the time-to-capsize, in the best case with several hours by closing only one fire door in the SHOULDER 1 case. A logic for suggesting the right fire doors to be closed is formed in the end of the thesis and the countermeasure advice is sketched to a prototype graphical user interface of NAPA Emergency Computer., Useita sotalaivoille ja risteilijöille suunnattuja päätöksenteon tukijärjestelmiä on kehitetty viimeisen noin kymmenen vuoden aikana avustamaan laivojen miehistöjä vauriotilanteessa. NAPA Emergency Computer, johon tämä diplomityö keskittyy, on Napa Oy:n kehittämä matkustajalaivoille suunnattu päätöksenteon tukijärjestelmä laivan haavoittuvuuden monitorointiin ja vuoto- sekä selviytymisarvion tekemiseen, mikäli laivan vuotovesisensorit havaitsevat vettä. Päätöksenteon tukijärjestelmää, joka luotettavasti yhdistäisi riskiarvio- ja vuotoennustusominaisuudet ohjeistukseen hyödyllisistä vastatoimenpiteistä vauriotilanteen parantamiseen ei vielä ole kehitetty. Täten diplomityön tavoitteena on selvittää hyödyllisimmät vastatoimenpiteet risteilylaivalla, jotka tähtäävät laivan selviytyvyyden parantamiseen, sekä muodostaa prototyyppi NAPA Emergency Computerin graafisesta käyttöliittymästä, jossa nämä vastatoimenpiteet esitetään. Eri vastatoimenpitedien kannattavuutta arvioitiin tutkittujen onnettomuusraporttien sekä tieteellisten julkaisujen perusteella. Lupaavimmaksi vastatoimenpiteeksi estämään veden leviäminen laivan sisällä vesitiiviiden ovien sulkemisen jälkeen osoittautui palo-ovien sulkeminen. Sen vaikutusta vuototilanteen etenemiseen tutkittiin simulaatioilla NAPA-laivasuunnitteluohjelmistossa neljän risteilijälle todennäköisen laajan vaurion sekä erilaisten palo-ovien sulkemisten kombinaatioilla. Simulaatiot osoittivat, että palo-ovien sulkemisella laipiokannella vaurioituneiden osastojen yläpuolella portaikkojen ja pääkäytävän välillä on erittäin merkittävä laivan uppoamiseen kuluvaa aikaa pitkittävä vaikutus. Parhaassa tapauksessa laivan uppoamiseen kuluva aika pitkittyi useilla tunneilla sulkemalla ainoastaan yksi palo-ovi SHOULDER 1 –tapauksessa. Diplomityön lopussa muodostetaan logiikka, jolla suljettavia palo-ovia ehdotetaan. Vastatoimenpideneuvo esitellään prototyypissä NAPA Emergency Computerin graafisesta käyttöliittymästä.

With growing need to cut emissions related to transportation, new methods to reduce aero/hydrodynamical drag are being developed constantly. Drag can be divided into friction and pressure drag. One promising branch of approaches to reduce friction drag are the active methods. This thesis focuses on the active drag reduction by means of traveling transversal surface waves. Previously, this method has been shown to yield friction drag reduction of order several percentages in experimental conditions. So far, the research has focused on studying near-wall changes of flow statistics in connection with the surface actuation. Present thesis analyses and compares the large-scale tur-bulent structures above actuated and non-actuated surface. Structures of interest are the uniform momentum zones(UMZ). The experimental data comprises of a large dataset of high resolution particle image velocimetry (PIV) measurements and a micro-particle tracking velocimetry (µ-PTV) measurements. The PIV is used to study the large-scale turbulent structures and the µ-PTV to obtain information on drag reduction. Contrary to previous research on uniform momentum zones, clear dependency on the detection window size and the number of detected zones is observed. This is explained by the ability to detect smaller structures due to the high resolution experimental data. Results show that the number of UMZs is decreased due to the surface actuation. Additionally, these structures seem to be pushed away from the wall during the upward motion and pulled back during the downward motion. No significant changes in the average speed of the zones under surface actuation are noticed. Using conditional averaging, it is noticed that the speed and the location of the UMZ are correlated with the streamwise averaged velocity close to the viscous sub-layer. This is interpreted to be in-line with the superposition of logarithmic layer large-scale motions on the near-wall velocity fluctuations., Kasvava tarve pienentää liikenteestä johtuvia päästöjä on johtaa kasvavaan tarpeeseen kehittää uusia menetelmiä pienentää aero-ja hydrodynaamista vastusta. Tämä vastus voidaan jakaa kitka-ja painevastukseen. Eräs lupaava kehityshaara vastuksen vähentämisessä ovat niin kutsututut aktiiviset menetelmät. Tässä diplomityössä keskitytään tutkimaan aktiviivista menetelmää, jossa kitkavastusta pienennetään aaltomaisella, virtauksen suuntaan nähden poikittain etenevällä pinnan muodonmuutoksella. Aiemmin menetelmän on havaittu pienentävän kitkavastusta useilla prosenteilla. Tähän asti kyseiseen menetelmään liittyen vain lähellä seinämää oleva virtauskenttä on ollut tutkimuksen kohteena. Tässä diplomityössä analysoidaan ja vertaillaan turbulentteja virtausrakenteita tavallisen ja aktuoidun pinnan yläpuolella olevassa rajakerroksessa. Erityisesti tutkimuksen kohteena ovat yhtenäisen liikemäärän alueet (UMZ). Kokeellinen aineisto koostuu suuresta, korkean resoluution PIV mittauksesta sekä mikro-PTV mittauksesta. Työssä PIV:tä käytetään selvittämään rajakerroksessa esiintyvät suuren skaalan turbulentit virtausrakenteet kun taas µ-PTV menetelmällä todennetaan kirtavastuksen vähentyminen. Vastoin aiempia tutkimuksia liittyen UMZ:hin selvä riippuvuus havainnointi-ikkunan ja keskimääräisen havaittujen alueiden lukumäärän välillä on nähtävissä. Tämä selittyy korkean mittausresoluution mahdollistamalla kyvyllä havaita aiempaa pienempiä rakenteita. Tulokset osoittavat, että keskimääräinen UMZ lukumäärä rajakerroksessa pienenee aktuaation seurauksena, tämän lisäksi rakenteiden havaitaan liikkuvan seinämän liikkeiden mukana. Rakenteiden nopeuden ei havaita merkittävästi muuttuvan aktuaatiosta johtuen. Ehdollisia keskiarvoja käyttämällä havaitaan että UMZ:jen nopeus ja sijainti korreloivat viskoosin alikerroksen hetkellisten nopeuksien kanssa. Tämän tulkitaan olevan yhteensopiva aiempien havaintojen suurten ja pienten turbulenttien rakenteiden keksinäsen vuorovaikutuksen, erityisesti supe

Marine industry is leaning towards autonomous vessels with companies such as Rolls-Royce and Kongsberg leading the development. However, this rapid technological change invites greater risks and responsibilities for marine professionals. Ship systems are getting more complex with time as the interactions between components are increasing and software are getting embedded. As a result, the nature of risks in modern systems can be different than in the traditional systems, where the risks were mostly limited to human errors and component failures. However, for identifying risks in modern complex systems, it is first important to understand the structural composition of the system, and the component’s behavior, functions and interactions. Although, modern systems are quite different than traditional systems, traditional system-safety engineering techniques developed are still widely used. This thesis aims to review a modern modeling approach known as Systems Modeling Language (SysML) and a risk analysis method known as Systems-Theoretical Process Analysis (STPA); and compare them against widely used traditional methods known as the Tree structure method and Fault Tree Analysis (FTA). SysML, developed in 2006, is a graphical modeling language which presents structural composition, component functions, behavior, constraints and requirements of a system. SysML aims to support the analysis, specification, design, verification and validation of complex systems. STPA, developed in 2011, is a risk analysis method which aims to identify and mitigate risks in a complex system. Unlike traditional methods such as Fault Tree analysis (FTA), STPA focuses on risks due to the unsafe control actions and component interactions. Furthermore, STPA can be also used during the early phases of the system development process to generate safety constraints and requirements for a safer design of the system. This thesis also includes a workshop with Rolls-Royce where FTA, STPA, SysML and the Tr

Damage stability regulations for ships are constantly evolving. Changing operational profiles and results from new research, amongst others, force International Maritime Organization IMO to develop new regulations for damage stability. After a research project conducted by European Maritime Safety Agency EMSA in 2008 found SOLAS 2009 damage stability rules lacking, IMO started a development process to improve the damage stability regulations. Several proposals on how to improve the regulations were presented. In 2017, a new set of damage stability regulations known as SOLAS 2020 was adopted and will enter into force in 2020. The main difference in the regulations is new formulas for calculating required subdivision index R. The increased amount of marine traffic in polar waters has caused a need for regulations, which focus on ships operating in these areas. Taking ice damages into account in these regulations is important for survivability. Polar Code, adopted in 2014, entered into force in 2017. It sets additional requirements for ships operating in polar waters, including damage stability regulations for new-built ships. This thesis studies the combined effect of the damage stability regulations of Polar Code and SOLAS 2020 in the design of cruise ships. The aim of this thesis is to explain the background of these regulations and analyse the effect of them with an example case. The purpose is to find, what design choices are required to design a small cruise ship, which can comply with both sets of regulations. As a result, it was found that utilizing cross-flooding pipes is the best solution in regards to the new damage stability regulations. In addition to that, slight addition of subdivision works at the solving of local stability problems. It was also noticed that SOLAS 2020 damage stability regulations are more restrictive for design than those of Polar Code., Vauriovakavuussäännöt laivoille kehittyvät jatkuvasti. Muun muassa muuttuvat operointiprofiilit ja uudet tutkimustulokset pakottavat Kansainvälisen merenkulkujärjestön IMO:n kehittämään uusia vauriovakavuussääntöjä. Euroopan meriturvallisuusviranomainen EMSA totesi vuoden 2008 tutkimusprojektissaan SOLAS 2009 vauriovakavuussäännöt puutteellisiksi, jonka johdosta IMO aloitti kehitysprosessin näiden sääntöjen parantamiseksi. Useita ehdotuksia sääntöjen kehittämiseksi esitettiin. Vuonna 2017 SOLAS 2020:nä tunnettu sääntömuutos vauriovakavuuteen hyväksyttiin, ja se astuu voimaan vuonna 2020. Päämuutos säännöissä on uusi laskutapa vaaditulle osastointi-indeksi R:lle. Lisääntynyt merenkulku polaarisissa vesissä on aiheuttanut tarpeen näillä alueilla operoiviin laivoihin keskittyvään säännöstöön. Onnettomuuksista selviämisen kannalta tärkeitä ovat vauriovakavuussäännöt, jotka ottavat jäävauriot huomioon. Vuonna 2014 hyväksytty Polarkoodi astui voimaan vuonna 2017. Polarkoodi asettaa lisävaatimuksia polaarisissa vesissä operoiville aluksille, mukaan lukien vauriovakavuussäännöt uusille laivoille. Tämä diplomityö tutkii Polarkoodin ja SOLAS 2020:n vauriovakavuussääntöjen yhteisvaikutuksia pienten risteilijäalusten suunnittelussa. Tarkoituksena on selittää näiden sääntöjen taustaa sekä analysoida niiden vaikutuksia esimerkkilaivan avulla. Tavoitteena on selvittää, mitä valintoja tulee tehdä suunniteltaessa pientä risteilijäalusta, joka noudattaa molempia säännöstöjä. Työn tuloksena selvisi, että paras ratkaisu uusien vauriovakavuussääntöjen kannalta on cross-flooding -putkien hyödyntäminen. Tämän lisäksi vähäinen osastoinnin lisääminen toimii paikallisten vakavuusongelmien ratkaisussa. Huomattiin myös, että SOLAS 2020 vauriovakavuussäännöt ovat rajoittavampia suunnittelun kannalta kuin Polarkoodin säännöt.

The hull of a ship operating in ice might be exposed to significant ice loading, originating from a complex and stochastic interaction between the hull and the ice. In order to analyze such ice loading, taking into account the stochastic nature of the hull-ice interaction, statistical methods might be used. In this context, the estimation of the local ice pressures on various locations of a ship’s hull is required. This thesis aims to analyze a semi-empirical method known as the event-maximum method, which estimates the maximum local pressures as the function of the contact area and the ice condition. To this end, this study uses the full-scale ice load measurements to determine a new set of curves, which describe the relationship between the contact area and the local pressures. The obtained curves are subsequently compared with the previous studies corresponding curves, which had been obtained from different sets of full-scale ice pressure measurements. In addition, the maximum local pressures obtained from this study are compared with the maximum local pressures obtained using the design curve proposed in previous studies. Furthermore, for studying the effect of the variation of the load height on maximum local pressures, a sensitivity analysis is performed for the bow. The results show that the curves obtained in this study are close to the curves obtained in previous study. Furthermore, the sensitivity analysis shows that the variation of the load height causes small changes in maximum local pressures at the bow. The study shows that the event-maximum method is well-suited for the estimation of the maximum local pressures at all the locations of the hull. This research may help naval architects to design safe and efficient hull structures for Arctic ships.

Nowadays, on account of the rapid increase in the global warming, the extent and thickness of sea ice in the Arctic region is diminishing at a very fast pace. It has even been forecasted that the Arctic region will be ice free in the very near future. Owing to this fact, the Arctic waters are increasingly becoming attractive to different classes of society because of its immense reservoirs of oil and gas, short ship routes in the NE and NW region and attractive tourist places. These activities face the major hurdles from harsh environmental conditions like ice loads, insufficient infrastructure in the Arctic regions and the threats from impact of large ice features. The ships or offshore structures need to be sufficiently strengthened to resist the extreme ice impacts. However, very few data or models do exist that can quantify the extreme ice actions, and in addition the reliability of those data is open to question. For instance, the ice going vessels or offshore structures are designed based on pressure-area curves, but most of the P-A curves are based on Ultimate Limit State (ULS) design whereas the P-A curves for Accidental Limit State (ALS) are very rare. The work carried out in this thesis aims to study the response of structures subjected to those accidental ice impacts. The thesis work can be regarded as a continuation of work carried out by Ekaterina Kim in department of Marine technology, NTNU. In addition, considerable improvements and progress have been achieved in quantifying the accidental ice loads in terms of a novel numerical model. Both FEM and coupled FEM-SPH techniques have been efficiently applied in ice modelling and validated against existing Pressure-Area curves. In addition, computationally demanding spatial envelope curves have been plotted using which the existence and spatial variation of high pressure zones most commonly known as HPZs are effectively studied. Moreover, further step has been taken in applying the FEM-SPH ice modelling in

With the opening of more Arctic shipping routes, the motivation to design safe and efficient ice-going ships has increased. Recently, knowledge of ship-ice interactions and the mechanics of icebreaking processes has improved through numerous full-scale studies; however, the understanding of precise ice-induced pressures and load heights requires refinement to improve design methods. This thesis aims to further the development of an inverse engineering method to determine the nature of ice loads experienced by ships. The method uses full-scale strain measurements to estimate local pressures on the ship's structures. The data studied in this thesis was collected on the oblique icebreaker Baltika while operating in the Russian Arctic over a two-year period. The inverse method uses an influence coefficient matrix to relate the measured strain to the input pressure load. Using FEM, strain response functions are fitted at each sensor to generate the terms of the influence coefficient matrix. An optimisation routine is used to solve the inverse force-strain relationship and predict the load patch shape and pressure induced by the ice impact. The hourly maximum strain measurements are identified and analysed to estimate the applied load and contact area during ice impact events. A general analysis of 250 significant impact events reveals that the applied pressure is on the order of 10-25 MPa and the load height is on the order of 1-3 cm. The detailed analysis of 98 individual impact events demonstrates that the load height during impact remains markedly constant for the duration of the contact. Furthermore, the pressure distribution between load carrying structures is investigated. Based on the results, the pressure distribution between structural members is random and independent of the supporting structure.

Marine vessels and offshore structures functioning in Earth's frigid zones requires ice management to continue their routine operations. Icebreakers are the most influential vessel in assisting marine operations. The present study is set to analyze the clearance area of Level-ice using Azimuthing propeller jet in bollard pull condition. Advantages of the current investigation is that propeller jet effect in clearing level ice can be incorporated in designing new icebreaker and to maintain desired channel width. Propeller jets can be used to break level ice, when the ship is stationary or moving, where the amount and capacity of breaking or clearing the ice are based on the thrust of the propeller, angle between the propeller jet axis and free surface, and thickness of the ice as well as propeller running time. This thesis presents a comparison between full-scale experiments data (carry out in Gulf of Bothnia, March 2017) and model scale trials performed in Aker Arctic testing facility on the level ice sheet. These experiments were based on image data from external camera and propeller flow parameters, where the area, as well as coordinate calculation, were within 3% accuracy from the acquired images. Full-scale ice thickness utilized in the experiments were selected and confirmed from surveillance videos. Model-scale images were corrected using Hugin software while ImageJ was used to calculate ice clearance parameters. Propeller thrust and area analysis show 10-22 % of the variation in results of the model and full-scale experiments for 16 mm thick model ice. 16 mm thick model ice results are much closer to full-scale trials than 25 mm thick model ice. Analysis of transversal expansion of open water distance shows random outcomes. Furthermore, time scaling of the propeller operation is not feasible as it does not provide convenient results. Test results at 30-degree and 90-degree pod angles could be extrapolated to design a prototype vessel.

When a ship runs into an accident, the crew’s awareness of the situation is vital for the sake of a swift execution of possible countermeasures or evacuation. Several decision support systems have been developed to counter this need. A state-of-the-art decision support system, NAPA Emergency Computer, predicts how flooding on board and the floating position of the ship will progress during the next three hours if floodwater is detected on board. This is performed in two parts: first, the size of the breach in the hull is estimated based on how fast water level increases in the damaged room, after which this flooding scenario is simulated on the 3D model of the ship. The floodwater level rate is measured with level sensors that are subject to measurement errors emanating from floodwater surface waves as well as the gauging equipment itself. This thesis aims to quantify the contribution of these errors to breach assessment, as well as proposes a new method for interpreting level sensor data in order to improve the reliability of breach assessment. The physics related to flooding and level gauging was modelled numerically. In addition, two sensor data interpretation methods were established, one simulating the way sensor data is currently treated in Emergency Computer, and the other one minimising the error that follows from the collapse of a door under floodwater pressure. The numerical models were joined with the interpretation methods as a pipeline that takes the actual breach size as input and produces the estimated breach size as output. By varying a set of parameters, the reliability of breach assessment could be evaluated in any flooding scenario. This thesis showed that the gauging equipment commonly used for tank sounding and floodwater detection might not be capable of capturing high level rates that are characteristic of flooding incidents. Larger breaches were generally more difficult to accurately estimate; in addition, floodwater sloshing due to roll moti, Laivan joutuessa hätätilanteeseen miehistön tietoisuus tilanteen vakavuudesta on äärimmäisen tärkeää mahdollisten vastatoimien tai evakuoinnin nopean toimeenpanon kannalta. Useita päätöksenteon tukijärjestelmiä on kehitetty vastaamaan tähän tarpeeseen. Eräs johtava päätöksenteon tukijärjestelmä, NAPA Emergency Computer, arvioi vuodon etenemisen ja kellunta-asennon kehityksen kolmeksi tunniksi eteenpäin, jos vuotovettä on havaittu laivassa. Tämä toteutetaan kahdessa osassa: ensin vuotoaukon koko arvioidaan perustuen havaintoihin vuotoveden pinnankorkeuden noususta, minkä jälkeen vuototapausta simuloidaan käyttäen laivan 3D-mallia. Vuotoveden pinnankorkeuden kasvunopeus mitataan pinnankorkeusantureilla, jotka altistuvat veden pinta-aalloista ja sensoreista itsestään aiheutuville mittausvirheille. Tämä tutkimus pyrkii määrittämään näiden ilmiöiden vaikutuksen vuotoaukon koon arviointiin sekä esittelee uuden tavan tulkita mittadataa, jotta arvioiden luotettavuutta voidaan parantaa. Vuotoon ja vuodon mittaamiseen liittyvät fysikaaliset ilmiöt mallinnettiin numeerisesti. Lisäksi toteutettiin kaksi havaintojen tulkintamenetelmää, joista ensimmäinen jäljittelee nykyisin Emergency Computerin käyttämää menetelmää, ja toinen pyrkii minimoimaan virheen, joka syntyy oven antaessa periksi vuotoveden paineen alla. Numeeriset mallit yhdistettiin putkeksi, joka tuottaa vuotoaukon koon ennusteen todellisesta vuotoaukon koosta mallinnetussa vuototapauksessa. Malleille ominaisia parametreja säätämällä vuotoaukon koonmäärityksen luotettavuutta voitiin arvioida missä tahansa vuototapauksessa. Tämä tutkielma osoitti, että yleisesti tankkien luotaukseen ja vuotoveden havaitsemiseen käytetty mittauslaitteisto ei välttämättä kykene havaitsemaan vuototapauksille tyypillisiä nopeita pinnankorkeuden muutoksia. Suurten vuotoaukkojen koon tarkka arviointi oli yleisesti vaikeampaa kuin pienten; lisäksi keinunnan aiheuttama vuotoveden loiskunnalla oli pieni mutta havaittava vaikutus virheeseen. Nyk

The Polar Code developed by IMO became in to force at the beginning of 2017. It brings more requirements for ships navigating in the polar waters where coldness, floating ice and remoteness to infrastructure poses special risks compared to open waters. The new requirements are focusing to accident prevention and survivability after accident with the means of proper ship design, crew skills and survival equipment. Polar Code requires also methods for the protection of polar environment. Polar Code requires all ships that are intended to navigate at the polar waters to have Polar Water Certificate, which proves that the ship and its crew fulfils the relevant requirements. This study focuses on the chapter four of the Polar Code, concerning ship stability and subdivision. The topic covers two requirements: intact stability due to icing and damage stability due to ice-related damage. The aim of this thesis is to (1) assess the background of these requirements to enlighten where these requirements come from, (2) develop calculation tools for studying these stability scenarios and (3) analyse the effect of the stability requirements with example cases. The interpretation of Polar Code is still somewhat unclear due to ambiguous phrasing and lack of precedent cases. The thesis offers a way for interpreting the damage stability requirement. This selection of interpretation is needed for the calculation tool. In addition, this thesis provides overall view on Polar Code requirements, but focusing mainly on the stability requirements. The risk of accident at polar waters is naturally higher with existing ships that are not in accordance with all Polar Code’s requirements. The damage stability requirement is not mandatory for existing ships, whereas the icing rule is. Thus analysing a pre-Polar Code ship contributes interesting results since the Polar Code’s damage stability case is not taken into account when existing ships are designed and built. However it is possible for exi, IMO:n kehittämä Polarkoodi on tullut voimaan vuoden 2017 alussa. Se tuo mukanaan lisää vaatimuksia, jotka koskevat polaari alueiden aluksia. Arktisilla ja Antarktisilla vesillä liikuttaessa kylmyys, jää ja infrastruktuurin puute lisäävät riskejä. Uudet vaatimukset on tarkoitettu ennaltaehkäisemään riskejä, sekä parantamaan onnettomuudesta selviytymistä lisäämällä vaatimuksia laivan suunnitteluun ja varusteluun. Polarkoodi asettaa myös lisävaatimuksia ympäristön suojeluun. Polarkoodi velvoittaa kaikkia aluksia, joilla operoidaan Arktisilla tai Antarktisilla alueilla, hank-kimaan ’Polar Water Certificate’ -todistuksen joka todistaa laivan ja sen miehistön täyttävän Polarkoodin vaatimukset. Tämä tutkimus keskittyy Polarkoodin neljänteen lukuun, joka koskee laivan vakavuutta ja osastointia. Tutkimuksen aihe kattaa kaksi sääntöä: ehjän laivan vakavuus jään kertymisen seurauksena, sekä vaurioituneen laivan vakavuus jään aiheuttaman vaurion vuoksi. Tutkimuksen tarkoitus on (1) käsitellä molempien sääntöjen taustoja ja historiaa, (2) kehittää laskentatyökalu sääntöjen mukaisten tilanteiden luomiseen ja laskentaan ja (3) analysoida vakavuus sääntöjen vaikutusta tapaustutkimuksen avulla. Jotkin Polarkoodin säännöt ovat monitulkintaisia ja ennakkotapauksia tulkinnoista ei ole julkisesti saatavilla. Tästä syystä tutkimus tarjoaa tulkin-tatavan vauriovakavuus -säännölle, jotta laskentatyökalun kehitys on mahdollista. Työ antaa myös laajemman kuvan Polarkoodin muista vaatimuksista, keskittyen kuitenkin pääasiassa vakavuussääntöihin. Onnettomuuden seuraukset ovat luonnollisesti vakavampia niille laivoille jotka ei ole täysin Polarkoodin mukaisia, kuin niille jotka on suunniteltu täysin sen mukaisesti. Vauriovakavuutta koskeva sääntö ei ole pakollinen olemassa oleville laivoille. Tämän vuoksi vauriovakavuuden tapaustutkimus onkin mielenkiintoinen olemassa oleville laivoille, paljastaen miten tällainen laiva selviäisi Polarkoodin mukaisesta jäävauriosta. Työn tuloksena säännöt ja ni