Getting the best possible accuracy with the lowest possible computational cost is an important factor in the early design stage of ships. Potential flow-based analysis presents such a solution for seakeeping analyses. The accuracy of roll motion in potential flow is however not so good, due to the large influence from vicsous roll damping, which is missing in these calculations. This paper proposes a hybrid method, as a solution to this problem, where the viscous roll damping from Ikeda’s semi-empirical method is injected into an existing 3D unsteady fully nonlinear potential flow (FNPF) method. The hybrid method is investigated using roll decay tests with the KVLCC2 test case. This investigation shows that the accuracy of simulated roll motions is significantly improved and also shows good agreement with the corresponding roll decay model tests.

Having an accurate prediction of ship roll damping is crucial when analysing roll motions. In this paper, the simplified Ikeda method (SI-method) is compared with the original Ikeda method. The methods are compared using results from a database of roll decay tests carried out on modern merchant ships and a smaller set of predictions in which the original Ikeda method was used. It was found that most of the ships in the database had dimensions outside the limits of the SI-method. Thus, the SI-method showed poor agreement with model tests outside its limits but acceptable agreement for ships within limits. It was found that the deviations were caused by extrapolation errors of the wave-damping in the SI-method. Two ways to improve the accuracy of the SI-method were proposed based on regression, which gave about the same accuracy as the original Ikeda method. © 2021 The Author(s).

Identifying the ship's maneuvering dynamics can build models for ship maneuverability predictions with a wide range of useful applications. A majority of the publications in this field are based on simulated data. In this paper model test data is used. The identification process can be decomposed into finding a suitable manoeuvring model for the hydrodynamic forces and to correctly handle errors from the measurement noise. A parameter estimation is proposed to identify the hydrodynamic derivatives. The most suitable manoeuvring model is found using the parameter estimation with cross-validation on a set of competing manoeuvring models. The parameter estimation uses inverse dynamics regression and Extended Kalman filter (EKF) with a Rauch Tung Striebel (RTS) smoother. Two case study vessels, wPCC and KVLCC2, with very different maneuverability characteristics are used to demonstrate and validate the proposed method. Turning circle predictions with the robust manoeuvring models, trained on zigzag model tests, show good agreement with the corresponding model test results for both ships. © 2022 The Author(s)

System identification offers ways to obtain proper models describing a ship’s dynamics in real operational conditions but poses significant challenges, such as the multicollinearity and generality of the identified model. This paper proposes a new physics-informed ship manoeuvring model, where a deterministic semi-empirical rudder model has been added, to guide the identification towards a physically correct hydrodynamic model. This is an essential building block to distinguish the hydrodynamic modelling uncertainties from wind, waves, and currents – in real sea conditions – which is particularly important for ships with wind-assisted propulsion. In the physics-informed manoeuvring modelling framework, a systematical procedure is developed to establish various force/motion components within the manoeuvring system by inverse dynamics regression. The novel test case wind-powered pure car carrier (wPCC) assesses the physical correctness. First, a reference model, assumed to resemble the physically correct kinetics, is established via parameter identification on virtual captive tests. Then, the model tests are used to build both the physics-informed model and a physics-uninformed mathematical model for comparison. All models predicted the zigzag tests with satisfactory agreement. Thus, they can indeed be considered as being mathematically correct. However, introducing a semi-empirical rudder model seems to have guided the identification towards a more physically correct calm water hydrodynamic model, having lower multicollinearity and better generalization.

It is essential to describe a ship’s manoeuvrability for various applications, e.g. optimal control of unmanned surface vehicles (USVs). In this study, the capability of two recognised manoeuvrability models to predict ships’ trajectories is investigated based on both simulation and open-water experiment test data. The parameters of these models are estimated by a statistical learning method. The goodness of the two estimated models for describing a merchant ship’s manoeuvrability is first studied using her manoeuvring simulation data. Then, experimental manoeuvring tests to use a USV in open water with wind and drifting effects are used to check the conventional model identification procedures. Finally, some modifications and adjustments are proposed to improve the conventional procedures. It shows that the proposed procedures can accurately derive the ship’s manoeuvrability based on experimental data. © 2022 The Author(s). 

At the onset of the pandemic in spring 2020, the Swedish shipping sector was first affected by border closures preventing passengers to use RoPax shipping and cruise ferries. There were some blank sailings but in general they kept operating to foster intra-European trade by trucks despite the missing revenues from passengers. Shipping in general was affected by port disrup-tions and complicated crew changes. Eventually, however, it was clear that the most dramatic disruptions on a global scale where experienced in the container segment. General media reported on delayed goods, high freight rates and, however not related to the pandemic, the Ever Given blocking the Suez Canal for a week in March 2021. Currently, there are few reports of supply chains and shipping suffering from disruptions and capacity constraints related to the pandemic. The peak in freight rates was rather replaced by depressed rates and there is a certain risk that some logisticians and supply chain managers regard the pandemic as a once-in-a-lifetime event and just want to get back to a previous be-haviour seeing container shipping as a commodity with indefinite capacity at a reasonable price. Nevertheless, the war in Ukraine, the drought in the Panama Canal and the attacks by the Houthi rebels in the Red Sea create other problems for container shipping. Freight rates increase significantly, but from very low levels. The purpose of the report is to describe and analyse how international container shipping was affected by the Covid-19 pandemic and other disruptions. The analysis takes a Swedish perspective on disruptions and tries to go beyond the anecdotal reporting and capture what happened and why. Container shipping is put into a context of economy, consumption, world trade, supply chains and logistics. The pandemic and more current events affecting container shipping market are described together with how shipping lines responded. A series of interviews with Swedish actors revealed how they perceived the disruptions and what countermeasures the actors have applied to mitigate the effects, their organisational learning and how they prepare for future disruptions

Installing an energy saving device such as a pre-swirl duct (PSD) is a major investment for a ship owner and prior to an order a reliable prediction of the energy savings is required. Currently there is no standard for how such a prediction is to be carried out, possible alternatives are both model-scale tests in towing tanks with associated scaling procedures, as well as methods based on computational fluid dynamics (CFD). This paper summarizes a CFD benchmark study comparing industrial state-of-the-art ship-scale CFD predictions of the power reduction through installation of a PSD, where the objective was to both obtain an indication on the reliability in this kind of prediction and to gain insight into how the computational procedure affects the results. It is a blind study, the KVLCC2, which the PSD is mounted on, has never been built and hence there is no ship-scale data available. The 10 participants conducted in total 22 different predictions of the power reduction with respect to a baseline case without PSD. The predicted power reductions are both positive and negative, on average 0.4%, with a standard deviation of 1.6%-units, when not considering two predictions based on model-scale CFD and two outliers associated with large uncertainties in the results. Among the variations present in computational procedure, two were found to significantly influence the predictions. First, a geometrically resolved propeller model applying sliding mesh interfaces is in average predicting a higher power reduction with the PSD compared to simplified propeller models. The second factor with notable influence on the power reduction prediction is the wake field prediction, which, besides numerical configuration, is affected by how hull roughness is considered. © 2022 The Authors

The demand for wood biofuel for district heating plants and combined heat and power plants (CHPs) has increased, caused by an increase in both the number and size of CHPs. This places large demands on the logistics system supplying these plants with fuel, with a particular interest in the use of alternative modes of transport such as rail and sea. The aim of this paper is to identify the industry actors’ requirements, constraints, and preferences regarding the wood-biofuel supply chain and to identify the logistical challenges this entails, as well as how this impacts the opportunity for an increased use of alternative transport solutions. A survey was sent to all Swedish CHPs, combined with six interviews with transport companies, terminal operators, and forest companies. The study shows that the industry has a local focus that limits potential logistics and sourcing solutions. It is also challenged by urban sprawl, with expanding residential areas close to the CHPs putting further constraints on the operations. Significant variations in fuel demand, depending on unpredictable outside temperature and seasonal variation, is a further challenge. The low density of the fuel has a negative impact on transport costs and introduces a trade-off between chipping close to the forest to increase density versus more efficient chipping at the CHP. Intermodal transport only used by large plants, driven by a shortage of local fuel. © 2020 The Authors

Transportsystemet står inför en enorm utmaning då trycket på genomförandet av hållbara operationer aldrig varit större. Enligt IEA står transportsektorn för 16% av det totala koldioxidutsläppet i världen som med nödvändighet måste minska för att vi ska kunna lämna efter oss en planet med resurser för framtida generationer. Utmaningen kräver att alla delar av transportsystemet gör sitt bidrag, oavsett om det handlar om transportoperatörer, transportnoder, myndigheter på såväl lokal, regional som global nivå och tvärs samtliga transportslag. Det slutar dock inte där, det är lika viktigt att de som konstruerar olika typer av lastbärare och fordon för både gods- och persontransporter också beaktar den energi som förväntas vara tillgänglig i rätt kvantitet och till rätt pris. Energiproducenter behöver också tillgodose att efterfrågade energibärare produceras och finns att tillgå vid rätt plats och i tillräcklig kvantitet då den behövs. Detta är i linje med de behov av insatser som Sveriges regering lyfter inom transporteffektivitet, hållbara förnybara drivmedel samt energieffektiva fordon och fartyg, för att reducera Sveriges territoriella CO2 utsläpp i linje med de globala målen. En viktig del av transportsystemet är hamnar som har fönster mot flera olika transportslag och utgör multimodala noder som förväntas ombesörja en så sömlös övergång mellan olika transportslag som möjligt, såsom till/från sjö, järnväg och väg. Svenska hamnar är inget undantag, utan i Sverige med sin längsta europeiska kustremsa behöver Sveriges hamnar också etablera tillräcklig kapabilitet för att hantera såväl inhemska transportbehov som förväntade transporter för import och export på ett hållbart sätt. Hamnar står inför utmaningen att både bedriva sina operationer på ett så hållbart sätt som möjligt genom nyttjande av fossilfri energi, att förse besökare med fossilfria energibärare, och att balansera sitt nyttjande och distribution av hållbar energi med de behov som omgivningen har. Organisationer med lastbilar, tåg, och fartyg som besöker en transportnod, däribland hamnar, förväntar sig att de kan försörjas med viss energi. Transportnoder kan således inte bara betraktas utifrån att vara en effektiv omlastningspunkt, utan behöver också betraktas utifrån den roll som transportnoden har och kan komma att ta i den del av energisystemet som relaterar till transportsystemet. Hamnar som transportnoder behöver således etablera en förmåga som energinod. I föreliggande projekt har trender beaktats för utvecklingen inom olika transportslag, intervjuer genomförts med svenska hamnar samt en enkätundersökning genomförts riktad till en majoritet av Sveriges hamnar. I projektet identifieras att de viktigaste drivkrafterna för hamnarnas hållbarhets- och omställningsarbete är kundkrav, kostnadsbesparingar, hamnens interna målsättning (ofta baserad på ägarnas krav och vision) samt regelverk. Slutsatsen är att Sveriges hamnar har en stark ambition att utveckla sin förmåga som energinod för olika roller. Samtidigt råder en villrådighet om vilka satsningar som skulle ge störst effekter för hamnens verksamhet. Viktigt att notera är också att olika hamnar har olika förutsättningar och roller i transportsystemet, beroende på dess geografiska placering, storlek och typ av gods / passagerare som hanteras. Samtidigt görs stora investeringar i Sveriges hamnsystem, för att proaktivt utveckla en kapabilitet att möta dagens och morgondagens transportbehov, särskilt i ljuset av den omflyttning som sker från vägbundna transporter till järnväg och sjö. Det är vanligt att hamnar etablerar inlandsterminalskapabilitet, d v s skapar förmåga för omlastning mellan tåg och väg där inte någon sjötransport behöver vara inblandad. Många av Sveriges järnvägsoperatörer ser hamnar som strategiska noder i järnvägssystemet. Dessutom det är tydligt från intervjuerna, vilket även styrks av enkätsvar, att respondenterna anser att otillräckliga finansiella medel, höga kostnader och skatt, omogen teknik, infrastruktur, effekt, standardisering, kompetens, och politisk otydlighet är de största utmaningar som påverkar svenska hamnars roll i hållbarhets- och omställningsarbete. Baserat på genomförd trend- och nulägesanalys föreslås en mognadsmodell som rådgivande för hamnens proaktiva utveckling av sin energinodskapacitet. Denna modell tar utgångspunkt i att hamnen etablerar en energistrategi som tar höjd för nödvändiga samarbeten och investeringar som de både blir tvingade till genom regelverk, påverkade av genom beslut och själva har rådighet över. Hamnarna är tydliga med att huvudverksamheten är att utgöra en transportnod, men att de, för att möjliggöra en omställning mot ett hållbart transportsystem, också behöver ge utrymme för andra aktörer, såsom energiproducenter och energidistributörer att bedriva sin verksamhet relaterat till hamnens geografiska område. Således behöver det kluster av aktörer som ingår i hamnen som nod expanderas till att också innefatta producenter och distributörer av energi. Hamnens energistrategi är rådgivande för att hamnen skall kunna etablera en förmåga som säkerställer att de krav som hamnens operationer, hamnens besökare och hamnens roll med sin geografiska placering, möts. Föreslagen mognadsmodell riktar uppmärksamhet just till dessa nivåer av förmåga och skapar grunder för formuleringen av en proaktiv strategi för den enskilda hamnens roll i transportsystemets energiomställning. En viktig grund blir då att simulera framtida energibehov, såsom inom elförsörjnings- och eldistributionsområdet, men även för andra energibärare, varför detta projekt föreslår ett fortsättningsprojekt där förväntade energibehov kan simuleras och bli rådgivande för strategi, samverkan och investering för Sveriges hamnar. En sådan simuleringsmodell bygger på hamnens digitala förmåga att fånga och använda data från operationer för att säkerställa att hamnen bidrar till transporteffektivitet, användning av hållbara förnybara drivmedel samt energieffektiva fordon och fartyg. Samspelet mellan hamnen som energinod och transportbärares kapabilitet att drivas på hållbar energi samt energiproducenters/energidistributörers förmåga att tillhandahålla fossilfri energi, utgör grunden till fossilfria transporter. Fossilfria väg-, järnvägs- och sjötransporter kan således inte etableras utan att ta hänsyn till alla ingående komponenter. I denna nödvändiga transformation har hamnar och andra transportnoder en nyckelroll.

Swedish Shipping Policy Lab

Smart ships, or Maritime Autonomous Surface Ships as they are also known, have a great potential to advance shipping and sustainable development through optimisation of operations and maintenance. In situations that pose a risk to humans or where humans tend to lose their concentration, smart ships can also contribute to increased safety onboard and for the environment. In short, smart ships are suitable for operations that are dirty, dull and dangerous. The Swedish Shipping Policy Lab was an initiative to support on-going projects within smart shipping with policy-developing activities with the ambition to strengthen Swedish competitiveness. The project has actively strived for a systematic approach to how shipowners, technology developers and authorities among others can foster policy development and innovation in relation to smart ships. As an outcome the project has identified three policies related to the investigated cases (see Appendix G for more details): 1. Navigational assistance from land – A shared statement by the Swedish Maritime Administration and the Swedish Transport Agency on the role of navigational assistance from land and the need to further investigate the service before it can be regulated in more detail. 2. The Ljusterö Ferry – Certification of ferries is commonly done in relation to an established and consistent set of technical requirements. For smart ships such as the new road ferries procured for the Ljusterö-connection it is reasonable to complement traditional certification with a safety case to ensure that the ship is seaworthy. 3. Smart maritime drones – Ships less than five meters long that do not carry passengers are excluded from national rules regulating the supervision performed by the Swedish Transport Agency. As long as there is no explicit need to inspect a specific ship, the probability of a supervision is low. If an inspection were to incur, it is necessary to show how the smart ship and its operation complies to applicable regulation in terms of laws and collision avoidance. Despite the maritime sector having a long tradition of international governance there are still no international instruments explicitly for smart ships. A conclusion from the policy lab is that while such work is ongoing, there is room for the flag states and their authorities to develop and operate smart ships in accordance with national policies. Or, to paraphrase, smart ships seem suitable for operations that are dirty, dull, dangerous and domestic.

The Swedish policy lab for maritime autonomous surface ships, or smart ships, explored three use cases for developing policy in practice. The policies regard smart ships on national waters: one short-term written policy identifying the next shared step for two authorities to position remote navigational assistance as a new service, giving the maritime ecosystem one official position to relate to; one informal policy relying on a mutual trust, where information sharing between an operator of small, unmanned ships and the supervisory authority enables critical competence building; and one evolving policy on the process of certifying autonomous or remote operated functions using non-standardized technology. In conclusion, despite shipping being explicitly regulated internationally we found that there is substantial leeway for national policies regarding smart ships on national waters.

The Swedish policy lab for maritime autonomous surface ships, or smart ships, explored three use cases for developing policy in practice. The policies regard smart ships on national waters: one short-term written policy identifying the next shared step for two authorities to position remote navigational assistance as a new service, giving the maritime ecosystem one official position to relate to; one informal policy relying on a mutual trust, where information sharing between an operator of small, unmanned ships and the supervisory authority enables critical competence building; and one evolving policy on the process of certifying autonomous or remote operated functions using non-standardized technology. In conclusion, despite shipping being explicitly regulated internationally we found that there is substantial leeway for national policies regarding smart ships on national waters.

Large investments are being made by energy companies to provide hydrogen production, distribution, and refuelling infrastructure. It is hence critical to find hydrogen pathways that are efficient and feasible. This means deciding between the usage of liquid hydrogen (LH2) or compressed hydrogen (CGH2) value-chains from production to storage onboard vehicles in some transport segments such as heavy-duty trucks. During the project the as yet unestablished concept of cryo-compressed hydrogen (CcH2) was also considered. The project aimed at identifying the critical challenges and current limitations that impact the widespread use of hydrogen as a fuel for transport applications. It has focused on increasing the knowledge about technologies that can make LH2 or CGH2 infrastructure and vehicle usage more efficient and safer, by assessing the current state of technology as well as maturity and potential of new technologies. Included in this was also a segment focused on the safety of the different alternatives along the later parts of the value-chain. The project as a whole was conducted as a literature study. For the technology maturity in different parts of the value-chain the project has summarized the results in a very high-level categorisation system, see table below The definitions are mainly qualitatively and show where the technologies are in these categories: • Established (Used on a larger scale, ~TRL 9-10) • Proven concept (Demonstrators or soon reaching this stage, ~TRL 7-8) • Initial design (No public demonstrators available, ~TRL 3-6) • Uncertain applicability (Applicability was not established in this work) • Not applicable (Cannot be used for this state of hydrogen) Technological maturity in the hydrogen value-chain The table above also gives an overview of the segments included in the report. In combination with the technological evaluation a qualitative cost analysis of the different hydrogen storage states was also done. Here it is indicated that though LH2 has a higher cost in the initial part of the value-chain, it has lower costs in the end segments. Therefore, it is possible that the end-price for the user will be similar for both LH2 and CGH2. The full cost can be compared first when LH2 refuelling stations and vehicles are publicly built, and cost information is available. The same is true for CcH2. During the safety, regulations and standards pre-study the following was concluded. From a safety perspective, there are no insurmountable barriers with respect to the use of LH2 on-board heavy-duty road vehicles in the medium term, however, there are several challenges to overcome, not least in the short term. Within the EU there are regulations which allow the type-approval of heavy-duty road vehicles with LH2 storage systems. However, these are based on work undertaken 15 - 20 years ago and are widely acknowledged as in need of being updated and validated in the same way that CGH2 road vehicle regulations have been. Similarly, there is a lack of up-to-date industry standards for road vehicle LH2 storage systems. A particular gap is the absence of an up-to-date standard that can be referenced in regulations for the refuelling receptacle geometry. Additionally, for LH2 refilling stations as a whole there are no suitable, up to date international standards, so there is a risk that individual countries set their own requirements. Overall, the project concluded that there are no show-stoppers for the implementation of LH2. It is a feasible value-chain from both the technology, cost and safety perspective. It could also in the future become comparable with the more proven CGH2 value-chain, but some initial hurdles and investments need to be overcome.

Trade imbalances and global disturbances generate mismatches in the supply and demand of empty containers (ECs) that elevate the need for empty container repositioning (ECR). This research investigated dry ports as a potential means to minimize EC movements, and thus reduce costs and emissions. We assessed the environmental and economic effects of two ECR strategies via dry ports—street turns and extended free temporary storage—considering different scenarios of collaboration between shipping lines with different levels of container substitution. A multi-paradigm simulation combined agent-based and discrete-event modelling to represent flows and estimate kilometers travelled, CO2 emissions, and costs resulting from combinations of ECR strategies and scenarios. Full ownership container substitution combined with extended free temporary storage at the dry port (FTDP) most improved ECR metrics, despite implementation challenges. Our results may be instrumental in increasing shipping lines’ collaboration while reducing environmental impacts in up to 32 % of the inland ECR emissions. © 2023 The Author(s)

In this paper, a fully nonlinear unsteady potential flow method is used to predict added resistance, heave and pitch for the KVLCC2 hull in regular head waves at design speed. The method presents a nonlinear decomposition of the velocity potential and the wave field and an adaptive grid refinement. A formulation for the acceleration potential is used to obtain the pressure. To improve computational efficiency, a Barnes-Hut algorithm is introduced. A grid dependency study and a study on the impact of different time steps on the solution are performed. Numerical results have been compared with experimental data for the design speed. A general good agreement is found for added resistance, especially for longer waves. Heave and pitch are properly computed for all wave lengths in the range λ/Lpp=0.4 to 1.4. © 2021 The Author(s)

This document reports the methods used and results obtained for the tasks established between SSPA and the FAMOS Odin project, as follows:Baseline analysis of traffic in the Baltic Sea, using collected AlS dataa.Analysis of safe Under-Keel Clearance (UKC) used in today’s trafficb.Analysis to which extent transport capacity is currently limited by UKCc.Calculation of the added fuel consumption caused by the squat effectSimulation of traffic based on improved bathymetry and UKC controla.Present energy efficient routing options with regards to distance, UKC and squatb.Calculate the benefits of optimized UKC for increased cargo capacityc.Use and test S-102 data as a basis for these analyses.This document reports as well the active partner’s budget outcomes, milestones and gains accomplished within the project timeframe.Analyses based on bathymetric and Automatic Identification System (AIS) data evidenced, for a chosen area of interest in the Baltic Sea, that tankers may be limited by UKC and as a result carry less cargo, which could amount to 1% more of the total cargo transported through the Baltic Sea, according to the model used. The results also show the linear relationship between the increase of speed and squat effect with the subsequent increase of water resistance and need of energy to propel the ship, signifying a direct increase in fuel consumption. Finally, the results emphasize certain regions of the Baltic Sea where routes could especially benefit from optimization for reduced fuel consumption, yet optimization results may depend on different route parameters prioritized by the mariner (e.g, speed vs. Estimated Time of Arrival (ETA)).Some recommendations for futures stages of this project include access to higher-fidelity depth data for Swedish waters to refine the studies described in this report, as well as the inclusion of a qualitative research component to investigate how UKC is perceived by the mariners or what reasons they may have for keeping a certain UKC or loading cargo to a certain weight.

Currently, real-time ship manoeuvring simulations are confined to static environments e.g., desktop/full-mission bridge simulators. Seaman Online™ is a novel web-based ship manoeuvring training tool allowing students and professional mariners to practice manoeuvres in ports and confined waters from their personal computers. This paper describes the tool’s first-time implementation in a Master Mariner university programme. The students were asked to complete a post-questionnaire regarding their use experience and the results were discussed between the course instructors and the toolproviding organization at two debriefings. The aim was to obtain feedback about (a) the usefulness of the tool in manoeuvring training; (b) further design improvements and usability; and (c) how to best incorporate it into the programme curriculum in coming academic years for improved user experience. Results revealed usability and maturity issues and the need for further guidance on simulation-based training objectives and limitations. Overall, the tool’s usefulness and potential in individual manoeuvring training were demonstrated.

The purpose of the KAJ-EL project was to offer decision support to ports and shipping companies about the implementation and use of shoreside electricity in Swedish ports. More specifically, this project investigated the following, among other questions related to shore power: • the driving forces and barriers among ports and shipping companies to offer or use shore power; • the decision making, steps and actors involved in the process of adopting shore power; • the costs and business arrangements for installing and operating shore power; • the challenges in the installation and operation of shore power; • the different shore power equipment used in Swedish ports and on board vessels; • the actions and condition to realise OPS adoption to a larger extent. The project group included researchers and experts in shipping, transport, logistics, economics, and human factors from SSPA and the University of Gothenburg, and included industry partners Svensk Sjöfart (Swedish Ship Owners’ Association) and Sveriges Hamnar (Ports of Sweden). In addition, industry and authorities were involved in a reference group with representatives from shipping companies, ports and electricity providers. Interviews were performed with various ports in Sweden, a port in Norway (Kristiansand) as well as the US ports of Long Beach and Seattle to compare the perspectives. Shipping companies were interviewed, as were a number of OPS equipment manufacturers, national grid operators and electricity providers. Two workshops and a final seminar were also conducted. This report presents an overview of the OPS situation in Sweden and provides principles for business models as well as recommendations for ports’ and shipping companies’ OPS work. It can be noted that Sweden is at the European forefront of OPS in the sense that it currently has nine cities offering OPS, with main focus so far on the ro-pax and ferry segment. Actors, in particular ports, perceive that the regulatory pressure to offer OPS is increasing and the knowledge about OPS, especially among non-experienced ports, is still limited. Further guidance on OPS installations and operations is therefore needed, in terms of the financial, business, technical and operational issues that the actors must deal with. One major question is how to secure the electricity supply to the ports. Collaboration between actors is key to successful OPS implementation and a higher level of standardisation can facilitate technical choices. Several areas in need of further research are highlighted in this report, such as investigating possible future power demand scenarios from using OPS, and supply strategies for ports. The project received funding from Trafikverket (The Swedish Transport Administration).

The amount of battery electrical vehicles (BEVs) carried as cargo on ro-ro ships is increasing. The possibility of thermal runaway in a lithium-ion battery makes BEVs a different fire risk compared to internal combustion engine vehicles (ICEV). One of the challenges that arise is how to detect a thermal runaway early. Current detection systems in ro-ro spaces generally consist of smoke and/or heat detection. To identify potential techniques and challenges for detection of a thermal runaway, as early as possible, tests with batteries and detectors are needed. Tests with one battery cell were performed inside an ISO container (with almost negligible ventilation) as well as in an open room with moderate ventilation (14 air changes per hour). Point-type detectors (two smoke and heat detectors, one CO detector, and one LEL detector), thermal imaging, video analytics, and light detection and ranging (LIDAR) were evaluated in the tests. A total of 14 tests were conducted. The detectors were evaluated in different positions relative to the battery cell and comparative tests with wood-sticks were performed to investigate the detectors’ ability to detect a more conventional source of fire. Based on the results, it can be concluded that early detection of thermal runaway in batteries is possible in principle. However, detection is a matter of circumstances e.g., ventilation, gas/smoke production and the location of the detector(s). The result indicates that detection in a small and confined space is relatively manageable, but detection in a large and open space could be more of a challenge. If the gas/smoke is cooled down it may sink and spread along the floor/deck, instead of rising and spreading along the ceiling. This would be a challenge with current smoke detectors installed in the ceiling. Shielding may be a problem, especially with LIDAR and thermal imaging. Future research should address full-scale tests, and it is recommended to include Optical Gas Imaging (OGI) as a mean of detection.

Ships can be operated more efficiently by utilizing intelligent decision support integrated with onboard data collection systems. In this study, a Bayesian optimization-based decision support system, which utilizes ship performance models built by machine learning methods, is proposed to help determine the operational set-points of two engines for double-ended ferries. By optimizing the ferries’ power allocation between the stern and bow engines, the Decision Support System (DSS) will simultaneously attempt to keep the ETA of the ferry fixed under a set of operational constraints using the Bayesian optimization. Its objective is to minimize fuel consumption along individual trips. Based on simulation environment, the DSS can reduce at maximum 40 % fuel consumption with no significant change of the ETA. Final full-scale experiments of a double-ended ferry demonstrated an average of 15 %, where at least half of this saving was achieved by the optimized power allocation between bow and stern engines. 

The scientific investigation into the viability of employing kidney-belt-mounted accelerometers to quantify shock and vibration exposure in the lumbar spine region of occupants in high-speed marine craft, and their concordance with prevailing standards, has been heretofore unexplored. Addressing this research gap, a series of meticulously designed laboratory and field experiments were undertaken. In the laboratory setting, two test subjects were engaged in predefined body movements, with accelerations recorded using both body-mounted and kidney-beltmounted accelerometers. This controlled environment allowed for a comparative analysis of the efficacy of the two accelerometer configurations in capturing lumbar spine accelerations. Field experiments expanded upon these findings, involving the recording of acceleration exposures during a high-speed marine craft exercise. The kidney-beltmounted accelerometers were utilized alongside seat-mounted accelerometers to assess their applicability in real-world dynamic conditions. The results revealed that kidney-belt-mounted accelerometers effectively captured lumbar spine accelerations during basic body movements, particularly when the torso was maintained in an upright position. However, the translation of these measurements into a framework aligned with existing international standards encountered substantial challenges during the field experiment. This study underscores the potential utility of kidney-belt-mounted accelerometers for lumbar spine acceleration measurement in controlled environments. Nevertheless, the complexities associated with aligning these measurements with established international standards were evident, highlighting the need for further consideration and refinement. The implications of this research extend to the recognition that current standards may not fully address the intricacies of shock and vibration exposure in the lumbar spine region within the dynamic context of high-speed marine craft environments. Consequently, there is a clear call for the development of standards specifically tailored to these operational conditions to ensure a comprehensive and accurate assessment of lumbar spine health in marine craft occupants.

The feasibility of using kidney-belt-mounted accelerometers for measuring the shock and vibration exposure in the lumbar spine region of high-speed marine craft occupants and evaluating them on a par with the current standards remain largely unexplored in scientific literature. To address this gap a series of laboratory and field experiments were conducted. In the laboratory experiments, two test subjects performed predefined body movements while accelerations were measured using body-mounted and kidney-belt-mounted accelerometers. Field experiments involved recording acceleration exposures of two test subjects using the kidney belt arrangement and seat-mounted accelerometers during a high-speed marine craft exercise. Results suggest that kidney-belt-mounted accelerometers effectively measure lumbar spine accelerations during basic body movements with an upright torso. However, evaluating vibration exposures measured with the kidney belt arrangement using existing international standards proved challenging in the field experiment. 

Background: The urban freight transportation (UFT) system is an essential facilitator for the smooth functioning of city logistics. It also contributes significantly to transportation-related issues, such as vehicular congestion, pollution, accidents, infrastructure damage and other related problems. Objectives: This study aimed to understand and compare the urban freight traffic characteristics and their impact in two cities: Gothenburg, Sweden and Delhi, India, having high socio-economic differences. The findings of this study will be helpful for practitioners and policymakers in the development and successful implementation of UFT management policies. Method: Using the cordon count (traffic data), retailers’ interviews (receivers’ data) and freight vehicle drivers’ interviews, UFT characteristics such as sector-specific contribution, trip characteristics, vehicular characteristics and negative impacts in terms of external cost to society are evaluated. This study also discusses the prediction of attracted trips in the study zone using freight trip attraction (models. Results: About 75% of the trips in Gothenburg and 92% of the trips in Delhi are made by light commercial and other small-sized vehicles. Gothenburg has formally organised sectors involved in freight vehicle movement; however, Delhi has informally organised sectors. Conclusion: The results revealed substantial differences in characteristics of freight trip operations in both the cities, compared with few similarities. Measures taken considering the specific local attributes of freight traffic and stakeholders’ requirement may lead to a sustainable transportation system in cities. © 2022. The Authors.

Denna rapport är ett arbetsdokument som har efterfrågats i arbetet inom Gothenburg Green City Zone (GGCZ), där det pågår en process för att ta fram en mer detaljerad planering för en övergång till helt fossilfria transporter i Göteborg. Rapporten resonerar först kring zonbegreppet, vilken forskning som tidigare gjorts, vilka slags zoner som redan finns och som implementerats i Sverige och Europa. Rapporten föreslår sedan en metodik för hur zoner kan definieras och hur en generell zonindelning skulle kunna upprättas som skulle kunna användas som mall för både Göteborg och andra städer. Arbetet är inte färdigt utan kommer att fortsätta under kommande år både inom RISE och tillsammans med övriga samarbetspartners. Det som kvarstår är att definiera i detalj vilka parametrar och egenskaper som gör en viss zon unik, exempelvis genom mätetal som stadsdelars täthet, demografi, socioekonomiska förhållanden, infrastruktur samt befintlig framkomlighet. Målet med arbetet har varit att utveckla och förbättra kunskapen om zonmetodiken, visa på dess möjliga fördelar och utveckla ett verktyg för att användas i omställningen och att hjälpa Göteborg och andra städer att lyckas med omställningen mot klimatneutrala transporter till år 2030.

Denna rapport är ett resultat av en förstudie kring en logistik- och transportlösning (som kan realiseras i form av en gemensam hubb) för aktörer som är placerade i evenemangsstråket i Göteborg. Rapporten svarar på frågor kring nulägesanalys av aktörernas logistiklösningar, leveranstrafik inom evenemangsstråket, samt hur leveranstrafik kan se ut under 2030+ om inga förändringar i leverans/logistikupplägget görs. En viktig slutsats som framgår är att det krävs åtgärder som minskar leveranstrafiken, eftersom elektrifiering av fordon inte kan eliminera trängsel och buller som står för den största delen av de samhällsekonomiska kostnaderna. Utan förändringar i logistikupplägget och fordonsflottan förväntas de samhällsekonomiska kostnaderna öka med cirka 30%. Förändringar i logistikupplägget kan nås genom ett optimerad trafikflöde, vilket i sin tur kan realiseras genom en gemensam samlastningshubb för små och fragmenterade flöden som kan minska antalet anlöp och fordonstrafiken i området. Baserat på intervjuer med aktörerna, studiebesök, studerande av underlag, workshops och analys av logistikbehoven, kan det sammanfattas att verksamheterna, utmaningar och logistikbehoven i stort sett är ganska lika. En gemensam extern hubb kan frigöra yta hos verksamheterna som kan användas för att skapa nya affärsmöjligheter. En möjlighet för att upphandla en tredjeparts logistik- och transportlösning är att bygga ett konsortium där alla aktörer delar på kostnaden för terminalhantering samt samlastning/samkörning. Det finns stora möjligheter att hitta lösningar för logistikhubb som uppfyller kraven på geografisk närhet och säkra leveranser i trafiksystemet – och det är klokt att anpassa leveranstider för att undvika trängsel. Det finns en vilja hos aktörerna att minska transporterna, anpassa sin verksamhet för effektivisering vid mottagning och förvaring, ställa om mot fossilfrihet och på det sättet bidra till transporteffektivitet som krävs för att nå mål inom klimatneutralitet 2030. Det finns stora behov för förändring i trafikflödet inom GGCZ och det finns en stor potential att optimera det genom att konsolidera och styra leveranser.

This work focuses on the validation of the two-phase Navier-Stokes model interFoam, part of the OpenFOAM finite volume framework, applied to the case of a fixed oscillating water column. The model is validated against experimental results from the Technical University of Denmark. Both twoand one-way absorption, i.e. only the upor downstroke is used to drive the flow through the orifice, are investigated. For the one-way absorption cases a numerical one-way valve is employed. The results show a good fit to the experimental values for the two-way absorption, but for the one-way absorption the pressure, and subsequently power generation, is off. The reason is unresolved problems with the numerical one-way valve. Further, for the two-way absorption a formal solution verification was performed, showing the simulations had less than 7% numerical uncertainty arising from the spatial discretization

We numerically simulate the hydrodynamic response of a floating offshore wind turbine (FOWT) using computational fluid dynamics. The FOWT under consideration is a slack-moored 1:70 scale model of the UMaine VolturnUS-S semi-submersible platform. The test cases under consideration are (i) static equilibrium load cases, (ii) free decay tests, and (iii) two focused wave cases of different wave steepness. The FOWT is modelled using a two-phase Navier-Stokes solver inside the OpenFOAM-v2006 framework. The catenary mooring is computed by dynamically solving the equations of motion for an elastic cable using the MoodyCore solver. The results are shown to be in good agreement with measurements.

Numerical models used in the design of floating bodies routinely rely on linear hydrodynamics. Extensions for hydrodynamic nonlinearities can be approximated using e.g. Morison type drag and nonlinear Froude-Krylov forces. This paper aims to improve the approximation of nonlinear forces acting on floating bodies by using machine learning (ML). Many ML models are general function approximators and therefore suitable for representing such nonlinear correction terms. A hierarchical modelling approach is used to build mappings between higher-fidelity simulations and the linear method. The ML corrections are built up for FNPF, Euler and RANS simulations. Results for decay tests of a sphere in model scale using recurrent neural networks (RNN) are presented. The RNN algorithm is shown to satisfactory predict the correction terms if the most nonlinear case is used as training data. No difference in the performance of the RNN model is seen for the different hydrodynamic models.

We present a hybrid linear potential flow - machine learning (LPF-ML) model for simulating weakly nonlinear wave-body interaction problems. In this paper we focus on using hierarchical modelling for generating training data to be used with recurrent neural networks (RNNs) in order to derive nonlinear correction forces. Three different approaches are investigated: (i) a baseline method where data from a Reynolds averaged Navier Stokes (RANS) model is directly linked to data from a LPF model to generate nonlinear corrections; (ii) an approach in which we start from high-fidelity RANS simulations and build the nonlinear corrections by stepping down in the fidelity hierarchy; and (iii) a method starting from low-fidelity, successively moving up the fidelity staircase. The three approaches are evaluated for the simple test case of a heaving sphere. The results show that the baseline model performs best, as expected for this simple test case. Stepping up in the fidelity hierarchy very easily introduce errors that propagate through the hierarchical modelling via the correction forces. The baseline method was found to accurately predict the motion of the heaving sphere. The hierarchical approaches struggled with the task, with the approach that steps down in fidelity performing somewhat better of the two.

High-fidelity models become more and more used in the wave energy sector. They offer a fully nonlinear simulation tool that in theory should encompass all linear and nonlinear forces acting on a wave energy converter (WEC). The focus on the studies using are usually dealing with validation. However, a validated model does not necessarily give reliable solutions. Solution verification is the methodology to estimate the numerical uncertainties related to a simulation. In this work we test four different approaches: the classical grid convergence index (GCI); a least-square version (LS-GCI), a simplified version of the least-square method (SLS-GCI) and the ITTC rec- ommended practice. The LS-GCI requires four or more solutions whereas the other three methods only need three solutions. We apply these methods to four different high- fidelity models for the case of a heaving sphere. We tested two parameters in the time-domain and two parameters in the frequency domain. It was found that the GCI and ITTC were hard to use on the frequency domain parameters as they require monotonic convergence which sometimes does not happen due to the differences in the solutions being very small. The SLS-GCI performed almost as well as the SL-GCI method and will be further investigated.

We numerically simulate the hydrodynamic response of a floating offshore wind turbine (FOWT) using CFD. The FOWT under consideration is a slack-moored 1:70 scale model of the UMaine VolturnUS-S semi-submersible platform. This set-up has been experimentally tested in the COAST Laboratory Ocean Basin at the University of Plymouth, UK. The test cases under consideration are (i) static equilibrium load cases, (ii) free decay tests and (iii) two focused wave cases with different wave steepness. The FOWT is modelled using a two-phase Navier-Stokes solver inside the OpenFOAM-v2006 framework. The catenary mooring is computed by dynamically solving the equations of motion for an elastic cable using the MoodyCore solver. The results of the static and decay tests are compared to the experimental values with only minor differences in motions and mooring forces. The focused wave cases are also shown to be in good agreement with measurements. The use of a one-way fluid-mooring coupling results in slightly higher mooring forces, but does not influence the motion response of the FOWT significantly.

A novel idea to reduce the resistance of a transom stern hull in displacement and semi-planing modes is investigated. By placing a spoon-shaped device in the recirculating zone behind the transom, the momentum of the forward-moving water will be absorbed, and a pushing force generated on the device. Numerical and experimental techniques are applied on a transom stern hull to optimize the shape and position of the device and to explore in detail the physics behind the gain. For the towed hull at a Froude number of 0.4, the maximum measured resistance reduction is 11%, while the computed maximum reduction is 17%. In self-propulsion with one propeller, the measured power reduction is 15%. The power cannot be computed with the applied propeller model, which is an axial body-force distribution in the propeller disk, but the reduction in thrust using the device is 11%. More significant gains are possible at smaller Froude numbers, while the effect is reduced at higher Froude numbers. Larger gains are achieved by splitting the thrust on two propellers. © 2021 The Authors

This report demonstrates the qualifications of RISE to carry out CFD for ship self-propulsion, thus predicting the delivered power. The procedures were fully developed at SSPA which became fully integrated into the Maritime Department of RISE by 2023-01-01. An outline is given of the best-practice guidelines used at SSPA/RISE and how they comply with the relevant ITTC recommendations for verification and analysis. In addition, an overview is given of previous validation studies performed for a wide range of ships, including comparison with both model-scale and full-scale data. Complete references are provided to reports and publications in which these SSPA studies and methods are described in detail.

Venue-specific training has, over the years, proven to be a key asset for sailing teams performing at major championships and at the Olympics. A comprehensive understanding of the environmental features and possible weather scenarios in an outdoor sport like sailing can provide athletes with a significant strategic advantage. At the same time, GPS tracking is becoming a readily available technology that athletes use both in training and during races to analyse their own and their competitor’s performance. This work couples environmental and meteorological data with GPS tracks for Olympic sailing classes, linking weather features with strategic decisions on the race track. We propose a greedy algorithm to search for an optimal route based on weather forecasts to present the best strategy prior to the race. Our results show the potential of this approach to provide valuable decision support for athletes in Olympic sailing competitions, demonstrated for the 470 Olympic class.

Sailing is a sport and activity that takes a long time both to learn and to master, as much of its competence-based knowledge is acquired through experience. Experiencebased learning is very important, time-intensive, and the factors for success are often tacit and hidden. Should these success factors become explicit and salient, learning would occur faster and produce obvious competitive advantages. This research was conducted by embedding on-going research results into two competitive sailing teams racing in different classes, one offshore keelboat racing with a crew of eight, and a one-design Star-class racing yacht with a crew of two. The data collection consisted of observations, interviews, and video recordings. The results were also verified with the crews to catch biases in the analysis process. A jibe, a specific but common maneuver was analyzed from the perspective of Common Ground within Joint Activity. Maneuvering a competitive offshore sail racer or a previously Olympic Star-class yacht are tasks that fulfill the requirements for Joint Activity. A high level of Common Ground is required for the effective coordination needed in order to perform at a high level and maintain the safety of the crew and equipment. Breakdowns in the coordination of maneuvers were observed, although they must be recorded on video for higher analysis reliability. To achieve greater validity, more and different maneuvers should be considered within the analysis. By better understanding the factors for success, sail racing teams can more quickly gain competence and thus competitive advantages. The research analyzes the teamwork found in sailing from the perspective of Joint Activity and Common Ground and provides insight into how to achieve performance improvements more efficiently. 

The introduction of the EEDI more than a decade ago, slow steaming, and the wish to reduce bunkering costs have resulted in a trend to install less powerful engines in ships. To avoid vessels becoming underpowered and thus unsafe, the International Maritime Organization (IMO) has published a guideline regarding the “Minimum Propulsion Power to Maintain the Manoeuvrability of Ships in Adverse Conditions”. This report presents a case study that follows the IMO-guideline step by step and works out the minimum engine size for the KVLCC2 tanker. Using a combination of Computational Fluid Dynamics and model tests, the parameters and assumptions behind the guideline are discussed in some detail. Results show that it is particularly important to determine the added resistance in waves correctly because it dominates the power prediction. It becomes clear, that the selection of the propulsive factors, particularly the “thrust deduction factor” has a significant influence on results. The work summarised here is part of a wider project that aims to provide experimental benchmarking data for added resistance predictions. It has been sponsored by the Swedish Transport Administration (Trafikverket) under grant number TRV 2021/53938.

Wind propulsion systems (WPS) are major investments and the decision to install them requires careful consideration of many complex questions. In this paper we present a systematic, scientific methodology to assess the benefits and drawbacks of such systems at the early concept stage of a vessel. The purpose is to provide guidance for shipowners and operators and help them make informed decisions. The proposed method was developed into a Software tool called ‘SEAMAN Winds’ and has been correlated to full scale results. The program draws on our large database of model tests, and CFD of hulls and wind propulsion technologies. It uses the intended trading routes of the vessel as an important input, typical output data are: a) performance values (ship speed, power requirements etc.) b) environmental parameters (CO2 avoided, EEDI and EEXI reduction, carbon intensity indicator) c) financial metrics (bunker savings, payback time for installation of WPS) Potential applications of the method include making the business case for one particular WPS or investigating in how far certain systems are more suited for a specific route than others.

Wind propulsion systems (WPS) are major investments and the decision to install them requires careful consideration of many complex questions. One of the recurring and challenging issues for ship owners is the choice of a suitable WPS for a specific ship and a specific operational pattern. Today most WPS providers offer on-demand case studies, but obviously the underlying performance prediction methodologies differ from provider to provider. This makes comparing different technologies from competing suppliers next to impossible. In this paper we present a numerical platform to compare different WPS of different makes, sizes, and costs in a fair way. The fundamental idea is to use aerodynamic WPS datasets that are independently verified by SSPA through wind tunnel test, sea trials or extensive CFD. This is combined with a hydrodynamic dataset from SSPAs database of tank tests. The same performance prediction method, identical routes and weather statistics are then used to determine Key Performance Indicators and financial metrics of the competing wind propulsion technologies. The purpose is to provide guidance for shipowners at the early concept stage of a vessel and help them select a system that suits their particular requirements.

Reducing the environmental and climate impact of shipping propelled by liquefied natural gas (LNG) requires the introduction of alternative fuels such as liquid biogas/biomethane (LBG) (Jivén et al., 2022). Today, only a small part of the biomethane produced in Sweden is liquefied into LBG and an even smaller part is used as fuel for shipping. The price and availability of biogas is governed by supply and demand in an international market where shipping, industry and heavy trucks demand biogas. The biogas then needs to be processed into upgraded biogas (biomethane) or LBG quality in order to be transported and used in the respective sectors inside and outside of Sweden. The trend is for a larger proportion of biogas to be liquefied into LBG. The market has thus gone from a local market, where biogas was produced in the city's wastewater treatment plant and the city buses ran on biogas, to an international market where biogas often is transported in the same way as fossil gas and marketed using the fossil gas together with certificates. The project "Renewable liquid biogas (LBG) for shipping in practice" was carried out by IVL Swedish Environmental Research Institute and RISE in 2023 together with stakeholders from the shipping sector, ports and industry organizations for biogas. The project has studied the conditions required to make LBG available to shipping in practice at Swedish ports. The study shows that the major obstacles to an established use of LBG in the shipping sector in Sweden today are pricing/willingness to pay that is affected by international market prices, lack of suitable logistical solutions as well as the absence of the piece of the puzzle that is the business model and cooperation needed to make available the large volumes of biogas that shipping may demand. The stakeholders in the project estimate their total need of biogas to 3 TWh in a short term, and 10 TWh in a longer term. The project has identified a number of conclusions and recommendations for future work, including that the potential for biogas is large and untapped, but that new solutions for the distribution and logistics of LBG are needed. There is a clear interest from maritime actors as they see biogas as a strategic solution and the dialog between actors in the industry remains important. A change in the tax system could be needed so that more actors can use the green gas principle for LBG. In addition, a functioning "marketplace" is needed, which simplifies for sellers and buyers of LBG, and agreements/contracts are needed that are longterm and to a greater extent based on the costs of producing and providing LBG.

Wind-powered ship propulsion (WPSP) is the concept where the wind is the main source of thrust, while the traditional propulsion system operates when needed. This type of propulsion can lead to considerably reduced emissions, something that the shipping community is striving for. A well-known example of WPSP is the Oceanbird with the goal to cut emissions of up to 90%. In this study, the propeller design process for a wind-powered car-carrier (wPCC) such as the Oceanbird is investigated, what the various challenges of WPSP are and therefore how an automated optimisation procedure should be approached. A controllable-pitch propeller was selected as suitable propeller type for the operation of the wPCC, and various functions such as windmilling, feathering and harvesting have been explored. Regarding the optimisation procedure, an essential input is the definition of the operational profile, in order to determine the most important conditions for the route. The main objective of the optimisation is the minimisation of the total energy consumption (TEC), calculated based on a selection of conditions using the potential flow solver MPUF-3A. Cavitation has been evaluated by the blade designer, through an interactive optimisation method. The results showed that designing and optimising for the most highly loaded condition led to solutions with the lowest TEC. © 2022 The Author(s)

Wind-assisted ship propulsion (WASP) has received much attention lately with research focusing on the different sail technologies, ship-hull design optimisation and weather route optimisation. However, the traditional propulsion system is still needed for wind assisted vessels and is associated with several challenges, related to the wide range of operating conditions and propeller loads due to the varying degree of wind-assistance that will occur. In this study we use an interactive design and optimisation methodology applied on propellers of wind-assisted vessels. The methodology involves handling the complete operating profile of the propeller, an optimisation method for interactive cavi-tation evaluation by the blade designer, and the use of a new objective, the total energy consumption (TEC) of the expected operation. We use a case study where the KVLCC2 tanker is retrofitted with six Flettner rotor sails, operating between two fixed destinations at constant speed. The purpose is to investigate to what extent a new propeller design can offer a significantly lower TEC when compared to the existing design. Based on the results of this study, approximately 0.9% further reduction in TEC was achieved with the WASP adapted propeller compared to the existing one.

Projektet har genom demonstration utvärderat nyttan av digitalisering och digital samverkan mellan järnvägssystemets aktörer för att åstadkomma en samlad lägesbild och därmed ge involverade aktörer bättre beslutsunderlag. Projektet har samlat aktörer för att samskapa och utvärdera konceptet StationCDM (Station Collaborative Decision Making). Konceptet bygger på att i realtid utbyta data om aktörers intentioner och faktiska progress i syfte att förbättra koordination och effektivitet i järnvägssystemet. Projektets fokus har varit resandetåg mellan Hagalund - Stockholm – Göteborg. Målet har varit att utvärdera nyttan av digital samverkan genom att analysera olika användningsfall, vilka ska inspirera aktörer att dela överenskommen data i realtid och på ett standardiserat sätt, och se på vilka sätt det åstadkommer högre punktlighet, bättre planeringsförmåga och förbättrad arbetsmiljö. I projektet har metoden LivingLab Approach använts för att utveckla och utvärdera, de av involverade aktörerna identifierade användningsfallen, för digital samverkan. Metod innebär att utvecklat koncept är väl förankrat hos involverade aktörer och visar fördelarna med ett digitaliserat järnvägssystem, vilket ger aktörer möjlighet att växa i digital mognad och innovationsförmåga. Ett exempel på resultat är från användningsfallet PLANKAN, där tågbildningen vid Hagalund sker i samråd mellan aktörerna Trafikverket och SJ. De planerade spåren och tiderna för ankomst samt avgång Hagalund kan genom PLANKAN visas i en gemensam lägesbild och där ändringar görs i realtid. Det har medfört en markant minskning av telefonerande och e-mailande mellan aktörerna då det i snitt görs över 150 ändringar per dygn av spår och tidpunkter. Även råd och riktlinjer för framtida implementation av StationCDM-koncept har utarbetats.

o Projektet har bidragit med en samsyn mellan aktörerna av vad som kan och behöver utbytas i form av data i syfte att åstadkomma en samlad lägesbild, uppbyggd av aktörers intentioner, omplaneringar, faktisk status för aktiviteter i och kring Malmö Gods Bangård, MGB. Genom att skapa bättre beslutsunderlag baserat på konceptet YardCDM (Yard Collaborative Decision Making), i realtid bidrar detta till förbättrad samordning och effektivitet på MGB. MGB är en komplex järnvägsnod - dels pga att det är en säckbangård, har en kombiterminal samt att MGB trafikeras av intermodala tåg till och från Danmark. Målet har varit att utvärdera nyttan av digital samverkan genom att analysera olika användningsfall genom demonstratorer, vilket ska inspirera aktörer att dela data i realtid på ett standardiserat sätt, och se på vilka sätt de bidrar till bättre samordning och effektivitet. Metoden LivingLab Approach har använts för att utveckla och testa olika koncept/användningsfall för digital samverkan. Konceptet YardCDM har utvecklats i samverkan med involverade aktörer på MGB, vilket leder till ett väl förankrat koncept som visar fördelarna med ett digitaliserat järnvägssystem, och ger aktörer möjlighet att växa i digital mognad och innovationsförmåga. Ett exempel på resultat är från användningsfallet LOKVÄXLING, där lokväxlaren digitalt via en smartphone erhåller ”sin loklista” och i den kan utföra sina arbetsuppgifter och löpande rapportera arbetsmomenten. På detta sätt blir alla som behöver realtidsinformation kring loken informerade löpande t.ex. personal på MGB men även den centrala lokledningen för de olika operatörerna t. ex. green cargo. Tidigare skrev lokväxlaren ut listan på ett papper i det så kallade ”blå huset” och kunde sedan först efter både en och två timmar vara tillbaka och mata in aktuell status på den datorn. Även råd och riktlinjer för framtida implementation av YardCDM-koncept har utarbetats.

Thermal propagation is one of the major challenges when batteries will be used in dwellings in large scale. It means the exothermic reactions in the cell are out of control and can lead to a fast release of flammable and toxic gases. In a system involving a large number of cells, thermal runaway can rapidly propagate from one battery cell to the whole system, which means substantial fire and explosion risks, an event that is important to mitigate and prevent. Multi-physics simulations together with full-scale testing is a cost-effective method for designing safer batteries. This project aims at simulating thermal runaway initiation and propagation using a multi-physics commercial software GT-Suite. 

A battery thermal runaway model containing 12 prismatic cells based on 3-D Finite Element approach was built using GT-Suite. The computed thermal runaway time instants versus thermal runaway cell number were compared with full-scale experimental data with reasonable agreement. Quantitative sensitivity study on the model input parameters and model space and time resolutions on the computed start time instant and time duration of thermal runaway were performed. The thermal runaway model was then extended with an electric equivalent sub-model to simulate the short circuit. With the electrical model acting as the input to the thermal model, the most interesting output of the simulation is the change in temperature of the cells, dependent on the current in the cells, with respect to time. The current is determined by the value of the external resistance through which the short takes place and the voltage level of the battery pack. The obtained results from the above short circuit simulations can only be used as a starting point and not as absolute values for neither triggering the thermal model nor for accurately simulating a battery under an electrical load. Furthermore, GT-Suite was applied to simulate the gas dispersion inside a room. A comparative study of the dispersion of toxic gases during thermal runaway, utilising an arbitrary release of HCN to represent the battery gases, in a small compartment with natural ventilation was investigated and the results compared the same situation simulated in FDS. The pipe based modelling supported by GT-Suite has limited applicability and overestimated the concentrations close to the ceiling whereas the lateral concentrations where underestimated. 

The multi-physics model for battery thermal runaway process is promising and worth to be applied with care for designing safer batteries in combination with full-scale testing. 

Risk assessment is important both while planning to build new infrastructure and for maintenance of existing structures. The probability of ship-structure allisions could be estimated with IWRAP Mk II, which is a commonly used software for estimating maritime risks. However, the research coverage of the software is limited with regards to groundings and allisions. The aim of this study is to verify how IWRAP Mk II estimates the accident probability. To perform this verification a separate tool is constructed, OMRAT, based on the same theory as IWRAP Mk II. The aim is also to highlight the sensitivity of different parameters in these types of models. It is concluded that IWRAP Mk II estimates the probability of allisions and groundings with the same equations. Another conclusion is that some parameters have a linear effect on the accident probabilities and other parameters are also influenced by the model layout.

Risk assessment is important both while planning to build new infrastructure and for maintenance of existing structures. The probability of ship-structure allisions could be estimated with IWRAP Mk II, which is a commonly used software for estimating maritime risks. However, the research coverage of the software is limited with regards to groundings and allisions. The aim of this study is to verify how IWRAP Mk II estimates the accident probability. To perform this verification a separate tool is constructed, OMRAT, based on the same theory as IWRAP Mk II. The aim is also to highlight the sensitivity of different parameters in these types of models. It is concluded that IWRAP Mk II estimates the probability of allisions and groundings with the same equations. Another conclusion is that some parameters have a linear effect on the accident probabilities and other parameters are also influenced by the model layout.

The demand for maritime transport has increased with the growing demand for worldwide trade.This has led to a major increase in maritime traffic and ship sizes over the last decades, whichraises the probability of accidents. The methods used in maritime risk assessments today arebased on old hypotheses that do not include all data available today. The main objective of thisthesis is to develop numerical models and methods for the analysis of what is considered asnormal navigation behaviour at sea today and improve the analysis of probability for shipbridge allisions.The first part of the thesis describes what is considered as normal meeting distance at sea today.This information is later used while identifying failure events to ensure that the event behaviourwas not caused by other ships. These few cases are excluded from the methodology since thecommunication and situational awareness in the situations are not known. However, whilestudying the probability of ship-bridge accidents, it is also important to understand howwaterway restrictions may affect the probability of ship-ship collisions. Therefore, this thesisalso includes a study of how the improved knowledge concerning meeting distance could beused in a near ship-ship collision identification model. One of the main findings consideringnormal meeting distance is that small and large ships meet each other at a similar distance atsea.In the second part of the thesis, a methodology is proposed to estimate the probability of shipbridge allision. The presented methodology uses Automatic Identification System (AIS) dataand a ship manoeuvring simulator to simulate and analyse marine traffic with regards to risksfor accidents, such as ship-bridge allisions. A failure event identification method is alsopresented, which is needed to determine the frequency, duration and behaviour for the accidentscenarios. The three events that were modelled and simulated in the simulator were: driftingship, sharp turning ship and missing turning point. The probability of the different failure eventscorresponded to previous statistics confirming the AIS-based methodology. This means themethods to obtain the probability and duration of the failure events could be utilised in otherareas. The simulation methodology was confirmed with the probability of grounding in theGreat Belt VTS area.This thesis firstly contributes to a better understanding of the modelling of probability for shipbridge allisions. This will support bridge-building engineers who need to take into accountaccidental loads from ship-bridge allision while designing bridges. Secondly, this thesis alsocontributes to a better representation of normal beha