With increasing interest in utilizing the inland waterways (IWW) in European countries, the design of IWW vessels gains attention both from a transport efficiency and an emission control point of view. However, unlike in western and central European countries, in Nordic countries, e.g. Sweden, IWW ships must deal with ice on the fairway during every winter. Usually, IWW ships are designed without ice concerns and are structurally weaker compared to ships designed according to ice class notification from the classification societies. Developing such ships requires particular concerns since there is no strict requirements regarding ice class notifications for IWW ships. A primary challenge is to estimate both the global and local ice loads acting on the ship hull structure. To consolidate the design problems for IWW ice-going ships, Lake Mälaren is selected. Ice conditions, i.e. ice type and concentration, and ice data, e.g. ice thickness and ice flexural strength, are extracted and analysed for the ice load estimation. The ice mechanical properties have great influence on the ice load. Ice characteristics are studied based on empirical formulae and properties are calibrated by reference data. The deterministic approach is widely used to predict the ice loads. It is suitable when all variables, i.e. ship geometry and ice properties, are known and refers to rule-based design hereby. For first year light ice conditions in Lake Mälaren, the Finnish Swedish Ice Class Rule (FSICR) is widely used. The thesis uses guidelines from the Finnish Swedish Ice Class Rules as a reference and compare the results with other methods. The probabilistic approach, on contrary, is useful when certain variables are unknow, which are interpreted as random variables, for instance ice breaking pattern. Here the probabilistic method and ice-hull interaction mechanism are studied. The probabilistic method simplifies the ice pressure in relation to the contact area between the ice and the ship hull. It predicts maximum ice pressure acting on the ship hull based on field ice test data and ice exposure conditions. Such semi-empirical method can be used regardless of ship type and size. For this, a numerical model is introduced based on ice-hull collision mechanisms and the essential ice breaking characteristics. The physical mechanism is studied for idealizing ship-ice impact model. The idealization model includes the ice failure process, ice conditions and ship geometry. The ice failure is assumed to be initiated by crushing ice and followed by breaking due to bending failure. Ice properties are set as constant values without any variations. The stochasticity in interact process is represented by randomness in collision location and number of pieces of ice floe formed after breaking. An energy method is used to calculate the ice crushing force, indentation displacement and contact area. The ice bending scenario is simplified as an infinite plate resting on an elastic foundation under a concentrated load. Ice impact load and critical load can be obtained for global and local structural assessment respectively. The structural responses and structural strength of a representative panel at linear and nonlinear contexts are investigated as well. Ship structure is commonly designed with material yield strength as limit. However, the study shows a lighter structure can be achieved if plastic deformation is allowed without causing failure. Therefore, the design can be optimized with regards to ice loading capacity and weight control.

There has been a recent surge in interest in waterborne public transportation (WPT). Publictransport providers (PTP) are seeing its potential in complementing the existing transportnetwork and alleviating urban traffic congestion and pollution. But the adoption of WPTtoday is challenging due to a series of technical and implementation challenges. Thesechallenges include ferry procurement practices, local legislation and policies andenvironmental factors like winter ice. Several of these challenges can be alleviated if efficientferries can be made accessible off-the-shelf with a low manufacturing time and cost. Thethesis focuses on developing such a ferry concept based on modular design whose overalldimensions are standardized and internal arrangement is customizable towards operationalrequirements, with a focus towards sustainable and safe operations in ice.Starting with the characterization of WPT, ferry routes are broadly classified into three types.These routes are described with an operational requirements framework considering allrelevant stakeholder expectations. Then, overall dimensions of vessels representative ofWPT are deduced. Using these dimensions to standardize the overall dimensions, a modularferry concept is developed as an assembly of modules and submodules. The modules arepresented as standardized units having fixed dimensions and interfaces whose internalarrangements can be tailored to meet operational requirements. Design standardizationlowers costs and manufacturing time while internal customization favours tailoring the ferryconcept. One challenge associated with this for the PTP is the difficulty in choosingappropriate modules among multiple alternatives. This is overcome through thedevelopment of a ranking and selection method which benchmarks competing designs andhelps in decision making.In terms of technical challenges for the developed ferry concept, cities like Stockholmexperience freezing of water bodies during winter months. For reliable year-roundoperations that are safe and sustainable in terms of economy and environment, there is aneed for the development of lightweight and robust ice going hulls. This thesis lays thefoundation for the development of such hulls by studying the prevalent ice data and proposesa probabilistic method for estimating the design ice pressures.One must rely on probabilistic methods since most experimental studies are based on seaice whose mechanical properties are different from freshwater ice, which is typical for WPT.Traditionally, classification society rules like the Finnish Swedish Ice Class Rules are usedfor first year light ice conditions which were developed for the Baltic Sea consideringicebreaker vessels. They work well in ensuring a safe design, but their performance forfreshwater ice, applied to commuter ferries have not been tested. Therefore, a probabilisticapproach is adopted where the unknown parameters are incorporated as random variables.The probabilistic method reduces the hull-ice interaction to a pressure and contact-arearelationship. With arctic datasets that closely match WPT conditions as the parent dataset,the probabilistic method is calibrated with exposure conditions for WPT to give the designpressure-area curve. The different uncertainties arising from operations in ice are studied using a statistical tool and the leading source of uncertainty is attributed to ice-loadprediction methods. This establishes the need for more robust methods for prediction of iceloads so that a lightweight, yet robust hull may be designed which is efficient in terms of fueleconomy and emissions.WPT presents a tremendous opportunity in complementing the existing transport network.With careful design and development of the modular ferry concept and its technicalchallenges, it would be easier for PTPs to adopt WPT globally. / De senaste decenniet har intresset ökat för kollektivtrafik på vatten (WPT).Kollektivtrafikleverantörer ser potential att minska trängsel och utsläpp och tillförakapacitet genom att utnyttja de urbana vattenvägarna. Men realiseringen har utmaningar,så väl tekniska som relaterade till regelverk och systempraxis. Dessa omfattar inköp av färjoroch upphandling av vattenburen trafik, lokal lagstiftning och policyer, miljöfaktorer ochdessutom isen vintertid. Flera av dessa utmaningar kan hanteras om effektiva färjor kangöras lättillgängliga med kort tillverkningstid till ett pris i paritet med övrig kollektivtrafik.Avhandlingen fokuserar på att utveckla ett färjekoncept baserat på modulär design medövergripande, standardiserade, dimensioner och med möjlighet att anpassa inredningenefter operativa krav.Efter karaktäriseringen av WPT klassificeras färjerutter i tre kategorier. Dessa rutterbeskrivs i ett operativt ramverk som beaktar relevanta intressenters förväntningar. Därefterbestäms de övergripande dimensionerna för WPT fartyg. Baserat på dessa utvecklas ettmodulärt färjekoncept som en sammansättning av moduler och delmoduler. Modulerna harstandarddimensioner och gränssnitt så att arrangemang kan skräddarsys för att uppfyllaaktuella operativa krav. En utmaning med det modulära färjekonceptet är svårigheten attbedöma vilken kombination av moduler som är bäst när det finns många möjligakombinationer som uppfyller en kravprofil. För att hantera detta utvecklas en rankningsochurvalsmetod för att kunna jämföra konkurrerande lösningar och därmed ge stöd i valetav design.En teknisk utmaning i städer som Stockholm är isen vintertid. För tillförlitlig trafik, åretrunt, som är både säker och hållbar, ekonomiskt och miljömässigt, finns det ett behov avutveckling av lätta och starka skrov som tål att operera i is. Avhandlingen närmar sigutvecklingen av sådana skrov genom att föreslå lämpliga isdata och en sannolikhetsbaseradmetod för att uppskatta dimensionerande isbelastningar.Is för nordiska WPT förhållanden är vanligtvis sötvattensis, vars mekaniska egenskaperskiljer sig från havsis. De flesta studier som beskriver isegenskaper är experimentella ochbaserade på havsis där man måste förlita sig på probabilistiska metoder för att ta hänsyn tillosäkerheter. Traditionellt används regler från klassificeringssällskap, som de finsk-svenskaisklassreglerna FSICR för första års isförhållanden vilket utvecklats för Östersjön ochisbrytande fartyg. Reglerna fungerar för att säkerställa en säker konstruktion men hur välde är anpassade för att dimensionera effektiva pendelfärjor i sötvattenis har inte utretts. Iavhandlingen antas ett probabilistiskt tillvägagångssätt där de okända parametrarna antassom slumpmässiga variabler. Den probabilistiska metoden förenklar interaktionen mellanskrov och is till ett förhållande mellan tryck och kontaktyta. Med publicerad data, som näramatchar WPT-förhållanden, som bas, kalibreras den probabilistiska metoden tillexponeringsförhållanden för WPT för att formulera den dimensionerande tryck-kurvan. Deolika osäkerhetsfaktorerna vid operation i is studeras med statistisk analys som visar att denfrämsta källan till osäkerhet är just förutsägelsen av isbelastningen. Detta fastställer behovet av mer robusta metoder för förutsägelse av isbelastningar så att ett lätt, men ändå starktskrov kan utformas som är effektivt med avseende på bränsleekonomi och utsläpp.WPT ger stora möjligheter att komplettera ett befintligt kollektivtrafik nätverk. Mednoggrann design och tillämpning av det modulära färjekonceptet kan det bli enklare att tatillvara möjligheterna runt om i världen.