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).

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.

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

Det kommer att dröja några år innan vi har autonoma bussar som utan förare kör runt på stadens gator och torg. Däremot borde det tidigt gå att ha autonoma bussar i en depå för att få ett effektivare underhåll av fordonen när de inte är i tjänst, samtidigt som man lär sig hur de ska ingå i den framtida verksamheten. Sådana bussar skulle vara typgodkända för vägtrafik med manuell förare (SAE-nivå 0-2), men inte godkända för autonom drift på väg (SAE-nivå 4 eller 5). Under ett och samma dygn kommer bussen därför att ”hoppa” mellan regelverken för inhägnat område (depå) respektive inte inhägnat område (väg), mellan att vara autonom och inte autonom.Bussen, som tidigare var en juridisk ”statisk helhet”, kommer nu istället att prövas utifrån två regelverk beroende på vilken miljö den befinner sig i och på graden av automation. Detta är en helt ny situation, att en buss blir ”dynamiskt delbar” ur ett regelverksperspektiv, vilket i sin tur får konsekvenser för vem som ska bestämma att fordonet är säkert att använda i en viss miljö.Efter att ha analyserat utmaningen utifrån existerande regelverk, intervjuat berörda myndigheter, anordnat workshops med olika intressenter och arbetsmöten med experter inom certifiering är vår slutsats att bussen ska självcertifieras genom CE-märkning utifrån maskindirektivet för att anses säker i autonomt läge inom depån. Detta är författarnas slutsats och den är inte nödvändigtvis representativ för de andra parter som varit med i arbetet.Vi förutspår att vi kommer att få se mer självcertifiering av autonoma fordon i framtiden. Dels för att det är så den nordamerikanska marknaden arbetar, dels för att det möjliggör en snabbare marknadsintroduktion av dynamiska fordonskoncept. Med dynamiska fordonskoncept syftar vi på fordon som får ett nytt användningsområde genom att byta chassit eller ändra mjukvaruinställningar och därmed går från att vara buss till lastbil eller från personbil till mopedbil. Kanske till och med flera gånger om dagen.Med mer självcertifiering kommer också behovet av standardisering öka, både för processer och produkter. När det gäller processer kan det röra sig om hur man certifierar ett fordon, framförallt hur man gör riskanalysen. För produkter kommer standardiserade beskrivningar av teknikens funktionalitet underlätta den egna självcertifieringen då man vet hur man ska beskriva sin produkt, men också hur man kan bygga sin certifiering utifrån de ingående certifierade komponenterna. Även dagens regelverk kommer behöva uppdateras om fler fordon kan självcertifieras.Avslutningsvis vill vi lyfta den använda metoden bakom slutsatserna. Projektet har genomförts som ett Policy Lab där vi samlat olika aktörer runt en gemensam utmaning. På så sätt har vi förankrat både utmaningen kring autonoma fordon inom inhägnat område och våra slutsatser i konkreta detaljer. Valet av metod har också gett relevanta myndigheter möjlighet att sätta sig in i hur de bör förhålla sig till morgondagens teknik utan att behöva ge ett förhandsbesked om hur de kommer att förhålla sig till ett specifikt fordon eller försök. På så sätt är svenska myndigheter redo att ta sig an tekniska innovationer när de väl introduceras på marknaden.Den här rapporten är strukturerad så att avsnitt 2 redogör för de aktuella regelverken, framförallt gällande distinktionen mellan maskindirektivet och typgodkännande av fordon. I avsnitt 3 redogör vi för affären för autonoma bussar i en depå med konkreta exempel. Avsnitt 4 innehåller författarnas slutsatser utifrån hur regelverken förhåller sig till de konkreta detaljerna som fås från depå-piloten. Den större bilden ges i avsnitt 5 genom att relatera våra slutsatser till vad som händer internationellt och hur den nationella försöksförordningen för autonoma fordon på väg motsvarar de internationella trenderna. Slutligen sammanfattar vi i avsnitt 6 med en resumé och de viktigaste frågorna enligt vår syn att arbeta vidare med.  

Closed ro-ro spaces on maritime vehicle carriers are usually protected by a total-flooding carbon dioxide system. Such systems have many benefits, for example that there are no residues that can adversely affect the protected objects (in this case thousands of vehicles) and the agent is electrically non-conductive. However, there could be a considerable time delay from the start of a fire until the carbon dioxide system is discharged. Experience has shown that this delay time can cause significant fire damage and jeopardize the performance of the system. Within the EU funded LASH FIRE project, design and installation guidelines for supplementary automatic water-based fire sprinkler systems were developed. An important design feature is that the system automatically activates at an early stage of a fire. This would allow more time to fight the fire manually or to safely evacuate the space and discharge the CO2 system when the fire is controlled to one or a few vehicles instead of at a time when it has escalated in size. The work was partly based on a comprehensive literature review that identified relevant standards and information applicable to the design of automatic fire sprinkler and deluge water spray systems. Large-scale fire tests verified that the suggested system designs were able to provide control of realistic vehicle fires, including fires in passenger cars and a freight truck.

Hur skulle autonoma fordon kunna användas inom kollektivtrafiken på landsbygden? Genom intervjuer, workshops och en RFI (request for information, ett första steg mot upphandling) har vi undersökt frågan utifrån fyra konkreta områden i Sverige – Lund, Gotland, Eskilstuna och Skellefteå. 

Med en definition av landsbygd baserad på individens mobilitet har vi sett att Sveriges landsbygd rymmer mindre orter på väg att avfolkas där äldre, barn och de utan körkort hade kunnat få bättre tillgång till samhällelig service med autonoma fordon. Vi har också sett att flera av landets nya arbetsplatser kommer befinna sig på landsbygden och därmed skapa ett mobilitetsbehov från staden till landet. 

För att kunna realisera de identifierade möjligheterna finns ett behov av att framföra fordonen i högre hastigheter samt att de ska kunna hantera mer komplexa trafiksituationer än vad dagens piloter i städerna visat. På landsbygden finns alltså ett utrymme för nya fordon att visa upp sig. Samtidigt ser vi hur man inte ska förvänta sig att investeringarna i autonoma fordon kommer betala sig på en linje, snarare behöver man lyfta blicken och se systemeffekten när stomlinjetrafiken blir mer attraktiv då bussarna går raka vägen istället för via mindre samhällen. 

Vi har inte sett några belägg på att den digitala infrastrukturen behöver utvecklas för att möjliggöra försök med autonoma fordon på någon av de undersökta rutterna. Dagens 4G-täckning är fullgod och fordonen borde ha tillgång till tillräckligt bra positioneringsdata för att bedriva verksamheten. Däremot ställs flera frågor om hur ersättningstrafiken organiseras när fordonen inte klarar av vädret, vem som står för säkrare hållplatser och hur chaufförens övriga ansvar realiseras när fordonet är förarlöst. 

The Blue Move project aims to generate an increased demand for hydrogen as a fuel and investigate the business potential of heavy machinery in the Öresund-Kattegatt- Skagerrak (ÖKS) region, contributing for renewable energy in the transport sector to increase. The use of heavy machinery generates significant carbon dioxide emissions and local air pollution. By using machines with batteries and/or fuel cells instead of combustion engines, local air pollution and climate impact from the machines can be reduced. Electrification also reduces noise and vibration problems, contributing to an improved local and working environment. Customers' requirements are changing and within the near future some clients will only buy zero-emission vehicles. For example, many municipalities have high environmental targets and aim to be climate neutral and fossil fuel-free by 2030. Setting the requirements for public procurement, municipalities and regions become very important players in the process of converting to fossil fuel-free working machines. Electrification is on the rise and the development is fast, which, in addition to the environmental benefits, allows many benefits such as increased service life and a reduced number of components. The cost and character of the service of the vehicles will also change. The choice between electrical operation with batteries or with fuel cells depends on the cost, weight and space requirement for the current energy need. When operating on fuel cells, the heavy machinery can be quickly fueled, and it has an unchanged performance from full to empty tank. The use of fuel cells is also space-saving compared with fullelectric machines since areas for charging or battery change are not required. Today there are both battery and fuel cell - electric heavy machinery available on the market. This report gives an overview of available equipment, but also prototype and demo machines. Both a continued technical development and an increased market share for emission-free vehicles are required to meet future environmental goals. In order to achieve success, it is important that customers and manufacturers meet.

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 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. 

Residual range estimation plays a crucial role in route selection and the trust of electric vehicles (EVs). With inspiration from longitudinal vehicle dynamics, a simple and computationally efficient model for traction power is presented. Such a model has the advantage of being exclusively based on vehicle exogenous parameters. The model allows for insight into variations in power usage along a transport operation and separation of power losses originating from air drag, rolling resistance, hill climbing, and inertial forces. A model of this structure can handle regenerative braking and estimate service brake usage as an additional feature. Also, it treats the inherent truncation bias resulting from truncating a stochastic process. Evaluation of the performance is presented using Monte Carlo simulations, comparing the estimation error against a simple benchmark model and vehicle log data.

S3-projektet handlar om att testa delade, elektrifierade och automatiserade skyttelbussar för att demonstrera hur dessa nya transportlösningar kan stimulera och stödja en förtätning av staden.Inom projektet har stadsutvecklare, näringsliv, akademi och offentlig sektor samlats för att gemensamt utforma och prova nya mobilitetskoncept för den första- och sista kilometern av resan. Rapporten beskriver den första fasen av projektet, från maj 2017 till och med december 2019, där skyttelbussarna testats vid Lindholmen Science Park, Chalmers campus Johanneberg samt i Härryda centrum. För att stärka projektet har arbete även utförts kring kompletterande mobilitetstjänster, öppen innovation, utvärdering, affärsmodell, färdplan, molninfrastruktur samt event och kommunikation kopplat till initiativet. Efter utmanande processer av projektering och tillståndsansökan lyckades testerna genomföras på vad som av teknik- och fordonsleverantörerna ansågs vara den mest utmanande rutten i världen som dessa fordon hittills kört på. Samtidigt är mognadsgraden för teknik och helhetstjänst fortfarande relativt låg, och kombinerat med givna säkerhetsprioriteringar lämnas en del att önska vad gäller grundläggande parametrar som hastighet och komfort. Dessutom innebär nuvarande tillståndskrav på säkerhetsoperatör ombord på fordonen begränsningar vad gäller till exempel hållbara affärsmodeller och möjligheten att studera vissa användarförhållanden. Tack till medverkande parter och finansiärer med ett särskilt tack till Vinnova, Drive Sweden och Lindholmen Science Park som gjort detta projekt möjligt. Tack till Transportstyrelsen, Trafikkontoret, Polisen och Chalmersfastigheter för snabba beslutsvägar och till Atrium Ljungberg för lånet av garageplats. Slutligen önskar projektet rikta ett stort tack till samtliga som varit med och testat skyttlarna.

The VAMLAV project is a Vinnova FFI-funded project with the following partners: AstaZero, Zenseact, RISE and AI Sweden. The project set out to create a dataset that includes the computer vision sensors that many Advanced Driver-Assistance System (ADAS) and Automated Driving Systems (ADS) vehicles use and complement them with a high-definition (HD)-map over a known geographic area. The VAMLAV dataset includes sensors such as camera, Light Detection and Ranging (LiDAR), Inertial Measurement Units (IMUs), and Global navigation satellite system (GNSS) sensors. This dataset, publicly available at AI Sweden, offers a corresponding HD-map in OpenDRIVE format covering the Rural Road at AstaZero. The dataset includes adverse weather, multiple maps and drives around the track with emulated traffic work scenarios that can occur. Beyond creating the dataset, the project aimed to validate HD-maps by comparing them to other measurement technologies. It delved deeper into localization for ADS vehicles by comparing various measurement campaigns and designing high-accuracy anchor points. This data was later used to validate and update the HD-map. By comparing different measurement systems and samples on the map, the project hopes to increase the trust in the HD-map over a longer time. This data also makes it possible to experiment more within the field of crowdsourced HD-maps from different systems while having an easier time measuring the accuracy of such maps. Another big part of the project was related to safety therefore some data was collected where the project emulates traffic work at AstaZero. This use case is otherwise difficult to test and evaluate due to the stochastic nature of traffic work in real life. Where the system detected the traffic work with the help of map and sensor data and then distributed the information to other cars in the area.

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 study investigates interactive behaviors and communication cues of heavy goods vehicles (HGVs) and vulnerable road users (VRUs) such as pedestrians and cyclists as a means of informing the interactive capabilities of highly automated HGVs. Following a general framing of road traffic interaction, we conducted a systematic literature review of empirical HGV-VRU studies found through the databases Scopus, ScienceDirect and TRID. We extracted reports of interactive road user behaviors and communication cues from 19 eligible studies and categorized these into two groups: 1) the associated communication channel/mechanism (e.g., nonverbal behavior), and 2) the type of communication cue (implicit/explicit). We found the following interactive behaviors and communication cues: 1) vehicle-centric (e.g., HGV as a larger vehicle, adapting trajectory, position relative to the VRU, timing of acceleration to pass the VRU, displaying information via human-machine interface), 2) driver-centric (e.g., professional driver, present inside/outside the cabin, eye-gaze behavior), and 3) VRU-centric (e.g., racer cyclist, adapting trajectory, position relative to the HGV, proximity to other VRUs, eye-gaze behavior). These cues are predominantly based on road user trajectories and movements (i.e., kinesics/proxemics nonverbal behavior) forming implicit communication, which indicates that this is the primary mechanism for HGV-VRU interactions. However, there are also reports of more explicit cues such as cyclists waving to say thanks, the use of turning indicators, or new types of external human-machine interfaces (eHMI). Compared to corresponding scenarios with light vehicles, HGV-VRU interaction patterns are to a high extent formed by the HGV’s size, shape and weight. For example, this can cause VRUs to feel less safe, drivers to seek to avoid unnecessary decelerations and accelerations, or lead to strategic behaviors due to larger blind-spots. Based on these findings, it is likely that road user trajectories and kinematic behaviors will form the basis for communication also for highly automated HGV-VRU interaction. However, it might also be beneficial to use additional eHMI to compensate for the loss of more social driver-centric cues or to signal other types of information. While controlled experiments can be used to gather such initial insights, deeper understanding of highly automated HGV-VRU interactions will also require naturalistic studies. Copyright © 2022 Fabricius, Habibovic, Rizgary, Andersson and Wärnestål.

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.

Metal matrix composites (MMC) are materials which combine a metallic matrix with ceramic reinforcements in the form of fibers, particulates or flakes. There is one supplier of MMC castings in Sweden providing brake discs in aluminium for automotive industry. The material has the potential of replacing other heavier metals and thereby contributing to lower emissions in vehicles. The MACS project has aimed towards understanding the material and its imperfections, as well as finding other viable casting methods and examine the machining parameters since the particles aggravates cutting operations.

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.

SEEL Swedish Electric Transport Laboratory is being established as a new independent test centre for research and development in the field of electromobility including batteries. The aim is to enhance knowledge development and to improve collaboration between enterprises and researchers. Electrification of the transport sector is to be speeded up at SEEL’s facilities in Borås, Gothenburg and Nykvarn in Sweden. SEEL works together with companies from Belgium, Finland, France, Germany, Italy and Poland in an important project of common European interest for batteries, IPCEI Batteries.

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)

Due to the development of new radar technology for advanced driver-assistance systems (ADAS) and automated driving (AD) applications, testing radars for real world conditions is highly desirable. However, testing autonomous driving functions on public roads can be dangerous and the tests results are not always reproducible. In this paper, we present a novel Over-the-Air (OTA) Hardware-In-the-Loop (HIL) radar target simulator for testing radar systems. The complete simulation setup including hardware and software implementations will be presented in this article. We illustrate a test procedure by creating Euro NCAP scenarios, and explain the benefits and importance of realtime HIL testing of automotive radars.

den här rapporten utvärderas alternativa tekniker till elanslutningar av fartyg vid kaj, huvudsakligen vessel emission control system (VECS). Rapporten behandlar de luftkvalitetutmaningar som uppstår i hamnar som är integrerade i stadsmiljö. Hamnverksamheten, och då främst fartygen, ger upphov till utsläpp vilka har en negativ påverkan på den lokala omgivningen. Att ansluta fartygen till elnätet är en befintlig lösning men en åtgärd som i många fall inte är tekniskt eller ekonomiskt möjlig. Ett alternativ till landströmsanslutning är VECS d.v.s. externa reningssystem för fartygsutsläpp. VECS består av mobila plattformar som är utrustade med rökgasrening vilka sedan kopplas direkt till fartygens skorstenar då de ligger vid kaj. En sådan lösning skulle kunna användas när landström inte är möjligt eller otillräcklig och på så vis förhindra utsläpp av partiklar (PM10 och PM2.5), kväveoxider (NOx) och svaveldioxid (SO2) men även koldioxid (CO2) i Svenska hamnstäder.

A wider use of composites in larger, commercial vessels has been limited by initial costs and fire regulations, but both of these obstacles are diminishing. Increasing fuel costs and more stringent emission requirements have heightened the value of lightweight structures. Due to the higher acquisition costs and other entry barriers, composite designs must be as cost efficient as possible in order to compete with traditional steel or aluminium designs. The purpose of this article is to investigate which fibre-reinforced polymer materials and types of structures are most suitable for different parts of a ship design in order to minimize weight or cost. This is done by designing and comparing individual composite panels while varying a wide range of input parameters and strictly following the ‘Det Norske Veritas (DNV) Rules for Classification of High Speed, Light Craft and Naval Surface Craft’. The results are presented as weight and cost comparisons between materials and structures and also degree of utilization for the different design criteria; carbon fibre structures are on the average 20%–30% lighter than glass fibre structures but are consistently more expensive. The results also indicate that sandwich panels in most cases are lighter than single-skin panels, and that for sandwich structures, the mechanical properties of the core material are commonly the critical design criterion. The minimum amount of reinforcement stipulated by the rules is also found to be a critical factor.

The study presents a methodology that uses AIS data and a ship manoeuvring simulator to simulate and analyse marine traffic schemes with regard to risks for accidents. An event identification method is presented, which is needed for the accident scenario part of the methodology. This is based on AIS data, where the Great Belt VTS area was used to verify the methodology. Three events that could result in ship-bridge allisions were modelled and simulated in the simulator: drifting ship, sharp turning ship and miss of turning point. The Monte Carlo method was used to perform large number of simulator runs, including a parameter sensitivity analysis. The probability of a ship allision against the Great Belt Bridge was calculated to be 0.007. Analysis of the ship-bridge allision cases was shown to be dominated by the event drifting ship. This event has a relatively low kinetic energy at the impact, and the expected allision energy for a 1,000-year allision corresponds to a 178 m tanker with 57,870 DWT and ship speed 14.6 knots. Finally, this study presents a mitigation analysis, which shows how the probability of allisions can be reduced by reducing the ship speed or altering the traffic separation scheme. © 2021 The Authors

Gaussian models are frequently used for road elevations. However, these models are often only valid for short sections of the road. Here we present a comprehensive approach to describe various aspects of road surface/elevation by using extensions of Gaussian models arising from random gamma distributed variances. These random variances result in the Laplace distribution and thus we refer to the so defined models as Laplace models. The approach is shown to perform well in modelling road topography, road roughness and multi-valued responses of forces and bending moments containing transients. The different Laplace models are presented together with numerical examples and Matlab code for simulation.

Hull surface condition plays an important role for ships performances for new-built ships as well as ships in operation since the drag penalties due to hull roughness are substantial. It is a standard practice that ship design is based on performance evaluation by model testing of ship models with hydrodynamically smooth surface and the increase of resistance for new build condition is added by roughness correlation allowance based on empirical formula. Surface roughness effects beyond the new build condition are seldom considered in the design process. The question is whether hull roughness affects the flow characteristics to such extend that it influence with the resulting design. This is especially important for propellers or energy saving devices which are operating around the stern of the ship where the roughness effects on flow characteristics are most pronounced. This paper will discuss some practical questions related to the effect of hull roughness, both in terms flow characteristics, power increase and impact on ship design and operational practice. 

In this paper, we present an approach to integer factorization using distributed representations formed with Vector Symbolic Architectures. The approach formulates integer factorization in a manner such that it can be solved using neural networks and potentially implemented on parallel neuromorphic hardware. We introduce a method for encoding numbers in distributed vector spaces and explain how the resonator network can solve the integer factorization problem. We evaluate the approach on factorization of semiprimes by measuring the factorization accuracy versus the scale of the problem. We also demonstrate how the proposed approach generalizes beyond the factorization of semiprimes; in principle, it can be used for factorization of any composite number. This work demonstrates how a well-known combinatorial search problem may be formulated and solved within the framework of Vector Symbolic Architectures, and it opens the door to solving similarly difficult problems in other domains.

Predicting the propulsive power of ships with high accuracy still remains a challenge. Well established practices in the 1978 ITTC Power Prediction method have been questioned such as the form factor approach and its determination method. This paper investigates the possibility to improve the power predictions by the introduction of a combined CFD/EFD Method where the experimental determination of form factor is replaced by double body RANS computations. Following the Quality Assurance Procedure proposed by ITTC, a best practice guideline has been derived for the CFD based form factor determination method by applying systematic variations to the CFD set-ups. Following the verification and validation of the CFD based form factor method in model scale, the full scale speed-power-rpm relations between large number of speed trials and full scale predictions using the CFD based form factors in combination with ITTC-57 line and numerical friction lines are investigated. It is observed that the usage of CFD based form factors improves the predictions in general and no deterioration is noted within the limits of this study. Therefore, the combination of EFD and CFD is expected to provide immediate improvements to the 1978 ITTC Performance Prediction Method. © 2021 by the authors. 

The 1978 ITTC Power Prediction method is used to predict the propulsive power of ships through towing tank testing. The form factor approach and its determination in this method have been questioned. This paper investigates the possibility to improve the power predictions by introducing Combined CFD/EFD Method where the experimental determination of form factor is replaced by double body RANS computations applied for open cases KVLCC2 and KCS, including first-time published towing tank tests of KVLCC2 at ballast condition including an experimental uncertainty analysis specifically derived for the form factor. Computations from nine organisations and seven CFD codes are compared to the experiments. The form factor predictions for both hulls in design loading condition compared well with the experimental results in general. For the KVLCC2 ballast condition, majority of the form factors were under-predicted while staying within the experimental uncertainty. Speed dependency is observed with the application of ITTC57 line but it is reduced with the Katsui line and nearly eliminated by numerical friction lines. Comparison of the full-scale viscous resistance predictions obtained by the extrapolations from model scale and direct full-scale computations show that the Combined CFD/EFD Method show significantly less scatter and may thus be a preferred approach.

This paper presents a comparative study of wave-induced motion responses and the added resistance of a ship. Four representative types of ships are adopted as test models: LNG carrier, tanker, containership, and bulk carrier. Two experimental techniques—captive and free-running model tests—are conducted under regular head and oblique wave conditions to create benchmark data. Several numerical computation methods (asymptotic formula, 2D strip theory, 3D panel method, and CFD) are applied to perform the seakeeping analysis. The comparison results indicate that the accuracy and reliability of each analysis technique are validated, and its characteristics and limitations are investigated with respect to the physical aspects of the added resistance caused by a wave. The analysis results are compared based on how steady flow-induced coupling effects are considered. Further, the sensitivities of seakeeping quantities with respect to wave steepness were examined based on the results of linear and fully nonlinear computations. The overall tendency of the added resistance in accordance with the incident direction of a wave is discussed. © 2021 The Author(s)

In 2016, EMSA initiated the first FIRESAFE study in order to investigate cost-efficient measures for reducing the risk from fires on ro-ro spaces with a focus on Electrical Fire as ignition source as well as Fire Extinguishing Failure. In 2017, EMSA initiated the FIRESAFE II study to investigate risk control options in relation to Detection and Decision as well as Containment and Evacuation, following a ro-ro space fire incident on any ro-ro passenger ship.The main objective of FIRESAFE and FIRESAFE II was to improve the fire safety of ro-ro passenger ships by cost-efficient safety measures reducing the risk of ro-ro space fire, with an aim to discuss specific proposals for rule making.This report presents the results of the combined assessment of cost effectiveness based on the results from the different parts previously considered separately in FIRESAFE and FIRESAFE II.The combined cost-effectiveness assessment was performed on 21 Risk Control Options (RCOs) for three generic ships representing the world fleet of RoPax ships (Cargo, Standard and Ferry RoPax), taking into account potential differences between Newbuildings and Existing ships.Recommendations for decision making were provided based on the results of the combined cost-effectiveness assessment.

Realising the 2023 IMO GHG Strategy, and reaching the Paris Climate Agreement goal requires a holistic and inclusive approach. This chapter discusses setting up and effectively running partnerships to create economic and societal capital. The authors stress that partnering is a core activity in achieving effective decarbonization.

This report provides an overview of current and upcoming legal frameworks and instruments relevant for automated vehicles (AV) and automated driving (AD). It is the first version of this overview, which will be updated every six months as long as the project ‘Network AD regulation’ runs. Next version of the overview can be expected around June 2024. In this version, legislation as of December 2023 has been considered. Laws and regulations play a vital role in the safe and efficient integration of AVs into our transportation system. They can ensure that we maximise the benefits of the new technology while minimising the downside risks and help to build public trust in the technology. Vehicles are sold on an international market and much of the traffic goes across national borders. Therefore, harmonised rules are needed, at least to some extent. A regulatory development around AD is ongoing at international level and regional level within Europe, and this has already resulted in some new regulations. More will come within the next few years. Knowledge of international and EU regulations as well as ongoing and planned regulatory initiatives that affect the development and use of AVs is important for actors in the AV space to follow. The shift towards AD is disruptive and complex, not least from a regulatory perspective. AVs need partly different requirements than previous vehicles, necessitating the development of new vehicle regulations and traffic rules. AVs must be able to interact safely with other road users (not least unprotected road users) in various traffic situations and driving conditions; anticipate and detect risks and drive with a margin of safety to prevent accidents and injuries; and follow traffic rules. (It is even likely that some traffic rules will have to be written differently than today.) ‘Vehicle regulations’ set requirements for how the vehicles should be designed and function, while ‘traffic rules’ set requirements for how road users should behave in traffic. In AD, it is the vehicle and not the driver that must follow traffic rules. This means that the AV must be designed to comply with traffic rules. This needs to be considered from a regulatory perspective. At the same time, users of AVs may need to have different traffic rules for how they should behave in relation to these vehicles. The legislator also needs to consider this.

Cyclists, pedestrians and elderly people’s specific needs in urban road infrastructures are often neglected. They rarely benefit from safety measures or innovations. Inspired by playgrounds and aiming to reduce vulnerable road users (VRUs) injuries, the development of the rubber-based Impact-Absorbing Pavements (IAP) offers a possibility to rethink the design of urban pavements and address safety on roads, which constitutes a major challenge in terms of attaining more sustain-able, resilient, and safe cities. Therefore, bituminous mixtures with four different crumb rubber con-tents, 0%, 14%, 28%, and 33% (in total weight), were produced by partial aggregates substitution using the dry process. After the assessment of the geometrical and volumetric properties, the mechanical performances were evaluated. Finally, the samples were tested to measure the abrasion and impact attenuation with the well-known Head Injury Criterion (HIC), at different temperatures from −10 to 40 °C, to obtain a wide range of values referring to possible weather conditions. A significant effect of the rubber percentage and layer thickness on impact attenuation was observed. All observations and results confirm the feasibility of the IAP concept and its positive effect on future injury-prevention applications. © 2021 by the authors.

Assessing the manoeuvring performances of a ship early in the design stage is becoming ever more important, especially now that wind-assisted propulsion is radically increasing in popularity as a measure to reduce fuel consumption. For conventionally propelled vessels most of the forces are in the longitudinal direction. Some, relatively small, drift angles and rudder angles are encountered in order to compensate for side forces due to environmental conditions. For a wind-propelled vessel on the other hand, side forces are an inevitable consequence of the propulsion choice and it is of utmost importance to balance these side forces with a matching hydrodynamic design to efficiently propel the vessel forward avoiding travelling for longer periods of time. In order to counteract those large side forces, it is necessary to add underwater appendages. Their position along the hull will determine the centre of lateral resistance (CLR) that needs to be related to the aerodynamic centre of effort (CoE) in order to achieve a balanced ship. The research herein described, compares towing tank captive tests with Virtual Captive Tests (VCT) derived from Computational Fluid Dynamics (CFD) simulations and the effects of generated side forces and moments when the inflow angles are varied. Adding a set of diagonal foils to the hull, in the investigated case reduces the leeway angle of approximately 2 degrees in close-hauled conditions.

This research aims to provide a feasibility study for an underwater Fluid Structure Interaction (FSI) experimental methodology. The possibility of measuring a structural deflection under fluid load and the flow behaviour around the structure is particularly interesting with the rise of composite materials, due to their inherent flexibility that permits them to be designed to a range of loading conditions. A review study on the experimental methodology available is carried out so that, in the future, a FSI measurement system can be installed in an underwater environment such as a towing tank or a marine basin. A robust and repeatable experimental methodology will also provide researchers with a validation case for numerical FSI simulations. The feasibility study starts with a thorough investigation of the existing measuring systems with an assessment of what could be used in SSPA Sweden underwater facilities (i.e. towing tank and marine dynamics laboratory). Currently there is a lack of FSI experimental methods, especially for underwater environment. The large majority of the current studies does not account for the complexity of the FSI coupled problems, where the structural response affects the flow behaviour and vice-versa. Bringing different techniques together will allow simultaneous measurements to be taken in a dynamic underwater environment. This would be especially important for performance prediction and numerical codes validations of foiling structures to assess the effects of deflections and twist when phenomena like cavitation and ventilation occur.

Differential evolution (DE) is widely used for global optimisation problems due to its simplicity and efficiency. L-SHADE is a state-of-the-art variant of DE algorithm that incorporates external archive, success-history-based parameter adaptation, and linear population size reduction. L-SHADE uses a current-to-pbest/1/bin strategy for mutation operator, while all individuals have the same probability to be selected. In this paper, we propose a novel L-SHADE algorithm, RWS-L-SHADE, based on a roulette wheel selection strategy so that better individuals have a higher priority and worse individuals are less likely to be selected. Our extensive experiments on the CEC-2017 benchmark functions and dimensionalities of 30, 50 and 100 indicate that RWS-L-SHADE outperforms L-SHADE.

Verification and Validation of CFD simulations of delivered power at full-scale are carried out for a single screw cargo vessel. Numerical simulations are performed with a steady-state RANS method coupled with a body force propeller model based on a lifting line theory. There are no significant differences in the uncertainty levels between model and full-scale computations. The finest grid exhibits the numerical uncertainty of 1.40% at full-scale. Computed results are compared with sea trial data for three sister ships. Special attention is paid to the effect of roughness on the hull and propeller. The comparison error for the delivered power is about 1% which is significantly lower than the experimental uncertainty. © 2021 The Authors

Abstract This paper assesses the validity of the Two-Step, One-Way (TSOW) coupled method for computational fluid dynamics, which splits a complicated geometry into an upstream and a downstream part. The problem is solved in two steps: first, the upstream part using approximate downstream boundary conditions, followed by a solution of the downstream flow where the inlet boundary conditions are extracted from the upstream solution. The method is based on two assumptions: first, the solution for the upstream part should be identical in the common domain to a complete solution. Second, the solution for the downstream part should be identical in the common domain to a complete solution. The resulting agreement between the upstream solution and the full solution was excellent, except in the vicinity of the outflow boundary. For the assessment of the second assumption, the downstream flow was simulated with two sets of boundary conditions, one that was extracted from the full simulation, and one that came from the upstream part solution. The two solutions in the downstream geometry with slightly different boundary conditions agreed excellently with each other but exhibited small differences from the full solution. Overall, the difference to the full solution is judged to be acceptable for many engineering design situations. The solution time for the TSOW method was about 23 h faster than the full solution, which took about 85 h on the same hardware. For additional design iterations, where the same upstream geometry can be used, a 30-h gain would be obtained for each step.

Driver behaviour monitoring is a broad area of research, with a variety of methods and approaches. Distraction from the use of electronic devices, such as smartphones for texting or talking on the phone, is one of the leading causes of vehicle accidents. With the increasing number of sensors available in vehicles, there is an abundance of data available to monitor driver behaviour, but it has only been available to vehicle manufacturers and, to a limited extent, through proprietary solutions. Recently, research and practice have shifted the paradigm to the use of smartphones for driver monitoring and have fuelled efforts to support driving safety. This systematic review paper extends a preliminary, previously carried out author-centric literature review on smartphone-based driver monitoring approaches using snowballing search methods to illustrate the opportunities in using smartphones for driver distraction detection. Specifically, the paper reviews smartphone-based approaches to distracted driving behaviour detection, the smartphone sensors and detection methods applied, and the results obtained.

Vibration injuries cause significant costs for society, great personal suffering, and often the relocation of personnel within a company. The project “Zero Vibration Injuries” is a Swedish initiative with the objective of taking a holistic approach to the problem, involving all stakeholders. The project’s vision is “Zero Vibration Injuries”. This is achieved by addressing the source of the problem by reducing the vibration levels in hand-held machines and applying the solutions in industry to the benefit of the users.

Road transports are rapidly electrified, and, in a few years, electrified vehicles may represent the majority of all vehicles being sold. This is true for light and heavy vehicles. On the one hand, vehicle electrification is probably necessary to make road transport environmentally sustainable. On the other, electrification is a real challenge to the automotive industry. The automotive industry in Sweden is important and it has since its inception built its business around internal combustion engines. The main question of this pre-study is: To what extent will electrified vehicles have their value added in Sweden and how will the change impact the employment?The core of the pre-study is data from 11 interviews carried out in June 2019. The respondents work with electrification at AB Volvo, Volvo Cars or at a supplier. The inter-views covered among others the speed of change towards electrification, there are people arguing that everything will be electrified within a few years. The vehicle manufacturers argue that the change rate is lower, because it takes time to develop new vehicles and change the vehicle fleet. Another key question is if the consequences of electrification are underestimated. The pre-study indicates that the consequences probably are underestimated by automakers as well as suppliers. A rough estimation tells that internal combustion engine related work employ circa 15,000 people in Sweden. Moreover, the service and maintenance business is expected to diminish substantially, which might impact another 5,000 people. On the positive side, companies like Northvolt may employ 2,000 – 3,000 people in Skellefteå in a few years.

Horizontal T-foils allow for maximum lift generation within a given span. However, for T-foils, the lift force acts in the symmetry plane of the boat, thereby producing no righting moment. It results in a lack of transverse stability during foil-borne sailing. In this project, we propose a system, where the height-regulating flap on the trailing edge of the foil is split into a port and a starboard flap, whose angle is adjusted proportionally to the heel. Such a system generates and scales the righting moment based on the heel angle, making the boat easier to balance. The effectiveness of this system is studied for a custom-made double-handed skiff using a dynamic velocity prediction program (DVPP), especially in the take-off phase. It is shown that the split flap system generates a larger righting moment for the foiling boat than for the non-foiling one at boat speeds above 3 m/s.. The improved stability comes at a cost of additional induced resistance and this effect is computed by CFD. It is shown, using the DVPP, that the increased resistance, slows down the boat at the lowest wind speeds, but above 2.5 m/s true wind, the split flap boat is as fast as the boat with a single flap around the racecourse. Due to the higher stability, less depowering of the sails is required, and that compensates for the increased resistance. 

This chapter discusses the key drivers, challenges, and opportunities for decarbonization. It covers the need for the maritime industry to begin to reduce its greenhouse gas emissions immediately, the fact that a coordinated global approach is required, and that measures are needed to avoid disadvantaging smaller and less developed countries. The chapter authors go on to discuss the role of first-movers in maritime decarbonization, and the need for regulatory mechanisms to underpin decarbonization, and highlight that collaboration across value chains is crucial. 

Shock load caused by underwater explosion in naval battles can lead to malfunction of the equipment on-board naval vessels. It makes the ships vulnerable and they can lose the ability to accomplish their missions. This study presents a shock analysis, using the dynamic design analysis method (DDAM), of a naval ship stern ramp subjected to a non-contact underwater explosion. The objective is to evaluate the performance of the ramp subjected to a shock load, identify areas for structural improvements and recommend design changes. The DDAM in the commercial software ANSYS is used in the evaluation of the ramp. The structural response to the shock load is estimated by combined modal and response spectrum analyses. The shock load is applied in three directions (vertical, fore and aft, athwart ships) and the results show that the vertical direction is the most severe loading direction and critical to the functionality of the ramp. A parametric study is presented which shows which parameters that influence the most the structural response. The results from this study are used to suggest improvements of the ramp structure to make it more resistant to shock loads.

The transport sector, including maritime transport, is facing accelerating electrification, where it is important that charging infrastructure is developed in parallel with electrified vessels. In today's few examples, charging technology is adapted to specific vessels and conditions. The possibility of using standards and standardisation to increase the efficiency of introducing electrified vessels has been the focus of the SeaCharging project. The middle segment of ships, such as waterborne public transport, is facing a rapid increase in electrification.

The project begins with an exploratory analysis of the current situation with charging stations in Sweden. This analysis covers the obstacles, needs and opportunities in different shipping segments and geographical areas. This results in an informative review providing input to standardisation committees, but also ports and shipping companies. Dissemination of the project’s results was achieved via a workshop, a number of seminars and this final report directed at the maritime, energy, technology, and standardisation communities. Together with Lighthouse, we will in early 2023, do a broad workshop for the whole sector, presenting the final project results and putting them into a wider context.

Modal shift to more energy-efficient alternatives, such as from road to rail or sea, is one path to reduce negative environmental effects. Transport providers and shippers have crucial roles in modal choice decisions, and a better understanding of the influence of interorganisational factors on modal shift is needed. The purpose is to increase the understanding of opportunities for modal shifts by exploring the influence of power and trust at the interface between transport providers and shippers. Aspects of power (coercive, reward, legitimate, expert and referent) and trust (con-tractual, competence and goodwill) influencing modal shifts were identified from interviews with shippers and transport providers in Sweden. During the initiation phase of modal shift, power ap-pears more important, while trust is shown essential for the duration. By proactively suggesting modal shift, transport providers can use expert power to create rewards and referent power, through recognition of their expertise. Building trust, particularly goodwill trust, such as time in-vested in understanding the other party, transparency about challenges and jointly seeking solu-tions, is key to establish long-term modal shifts. This paper contributes to modal shift literature with insights on power balances and trust between transport providers and shippers. © 2021 by the authors.