Global warming and, correspondingly, reducing CO2 emissions is one of the most challenging tasks the world faces today. The maritime industry contributed to 2.89% of the global anthropogenic CO2 emissions. To decrease this share, the International Maritime Organization (IMO) defined, among others, the goal to reduce the carbon intensity of international shipping by 40% until 2030. In this context, the short-term measures recently adopted, in the form of a technical standard (Energy Efficiency Existing Ship Index, EEXI) and a rating scheme based on an operational indicator (Carbon Intensity Indicator, CII), mark a crucial step to achieving the mentioned goal. In addition, the EU Commission has recently introduced the FuelEU Maritime Initiative limiting the annual greenhouse gas (GHG) intensity of a ship’s energy use incorporating a reduction occurring in a five-year rhythm between 2025 and 2050. The paper investigates the practical options availed to existing containerships of different sizes and technological vintages for meeting the specific EEXI, CII, and GHG intensity reduction requirements imposed by the regulations. The investigation will be based on the actual technical and operational profiles of six sample ships and will consider a set of possible compliance options including, but not limited to, engine power limitation, waste heat recovery system, variable frequency drives, and virtual arrival. The data used originates from noon reports of existing containerships provided by a European industry leader. The ship-specific CO2 emission reduction potentials required for the impact assessment result from either literature or actual data-based calculations. Financial data is used for investigating the economic impact of the reduction requirements. Conclusions drawn include an operational advantage that pre-EEDI ships enjoy when applying engine power limitation (EPL) for EEXI compliance, the occurrence of payback periods exceeding ship lifetimes, and an estimate of the effect that onshore power supply can have on complying with the FuelEU Maritime Initiative.
A practical estimation methodology of the mean added resistance in irregular waves is shown, and the present paper provides statistical analyses of estimates for ships in actual conditions. The study merges telemetry data of more than 200 in-service container vessels with ocean re-analysis data from ERA5. Theoretical estimates relying on spectral calculations of added resistance are made for both long- and short-crested waves and are based on a combination of a parametric expression for the wave spectrum and a semi-empirical formula for the added resistance transfer function. The theoretical estimates are compared to predictions from an indirect calculation of added resistance relying on shaft power measurements and empirical estimates of the remaining resistance components. Overall, the comparison reveals a bias in bow oblique waves and higher sea states of the spectral estimates as well as the large variance of the empirically derived predictions — particularly in beam-to-following waves. One of the study’s main findings, confirming previous studies but based on a much larger dataset than in earlier similar studies, is that added resistance assessment based on in-service data is complex due to significant associated uncertainties.
The sea ice in the Arctic has shrunk significantly in the last decades. The transport pattern has as a result partly changed with more traffic in remote areas. This change may influence on the risk pattern. The critical factors are harsh weather, ice conditions, remoteness and vulnerability of nature. In this paper, we look into the risk of accidents in Atlantic Arctic based on previous ship accidents and the changes in maritime activity. The risk has to be assessed to ensure a proper level of emergency response. The consequences of incidents depend on the incident type, scale and location. As accidents are rare, there are limited statistics available for Arctic maritime accidents. Hence, this study offers a qualitative analysis and an expert-based risk assessment. Implications for the emergency preparedness system of the Arctic region are discussed.
Wind propulsion systems (WPS) for commercial ships can be a key ingredient to achieving the IMO green targets. Most WPS installations will operate in conjunction with propellers and marine engines in a hybrid mode, which will affect their performance. The present paper presents the development of a generic, fast, and easy tool to predict the propeller and engine performance variation, along with the cost, as a function of the wind power installed in two operation conditions: fixed ship speed and constant shaft speed. Specific focus is directed toward showing generic trends and trade-offs that inform economic decision-making. To this end, a key feature of the presented work is the ability to assess the cost–benefit of both controllable pitch propellers and fixed pitch propellers (CPPs and FPPs). This provides advice on when, in terms of WPS installation size, it is worthwhile to install which kind of propeller. CPPs are found to be more suitable for newly built wind-powered ships (>70% wind power), while a conventional FPP is satisfactory for wind-assisted ships (<70% wind power) and retrofitted installations. The results for a 91,373 GT bulk carrier showed that a WPS unloads the propeller and the engine, which leads to an increase in the propulsive efficiency and a detrimental rise of the engine specific fuel oil consumption. However, propeller gains are found to be greater than engine losses, which result in extra savings. Thus, not only does a WPS save fuel and corresponding pollutant emissions, but it also increases the entire propulsive efficiency.
The International Maritime Organization (IMO) has recently adopted short-term measures introducing technical standards for existing ships and a labeling system reflecting their operational carbon intensity. This paper investigates the relevant techno-economic implications from a shipowner's perspective and estimates the effect of six compliance options on six sample containerships. The study applies a new evidence-based bottom-up approach, and the results show that compliance, when possible, is not straightforward and costly. Engine power limitation is the most cost-effective option, but low power limits can lead to substantially increased sailing times (up to 793.92 h/year), which can be prohibitive. The option favors older ships with oversized engines as its effectiveness is mainly determined by the main engine load profile. In general, the effectiveness of the measures is not without limits, particularly concerning older ships and those that have already installed several options. Solutions such as market-based measures and alternative fuels, classed by IMO as medium- and long-term measures, must be considered soon.
The International Maritime Organization (IMO) has recently adopted short-term measures introducing technical standards for existing ships and a labeling system reflecting their operational carbon intensity. This paper investigates the relevant techno-economic implications from a shipowner's perspective and estimates the effect of six compliance options on six sample containerships. The study applies a new evidence-based bottom-up approach, and the results show that compliance, when possible, is not straightforward and costly. Engine power limitation is the most cost-effective option, but low power limits can lead to substantially increased sailing times (up to 793.92 h/year), which can be prohibitive. The option favors older ships with oversized engines as its effectiveness is mainly determined by the main engine load profile. In general, the effectiveness of the measures is not without limits, particularly concerning older ships and those that have already installed several options. Solutions such as market-based measures and alternative fuels, classed by IMO as medium- and long-term measures, must be considered soon.
Containerfartens historiske udvikling bliver i litteraturen beskrevet som en revolution og en transformation af den internationale shippingbranche. De teknologiske og organisatoriske forandringer af livet til søs som fulgte med containerfarten har tilsvarende medført en forandring af maritime kulturer og en udfordring af de søfarendes identiteter.
Denne afhandling handler om danske containersøfolks erindringer, fortidsbrug og identitetskonstruktioner og undersøger, hvordan søfolkene fortæller sig selv i relation til deres levede erfaringer i containerfarten. Jeg analyserer i afhandlingen søfolkenes retrospektive fortidsfortolkninger som en måde at nærme mig en forståelse af de forandrede sømandsidentiteter.
Analytisk anlægger afhandlingen et subjektperspektiv, som anser fortiden for nærværende og åben i de mundtlige fortællingers fortolkninger og meningsforhandlinger af fortidens erfaringer. Jeg anskuer den narrative konstruktion af den personlige, autobiografiske, historie som identitetsdannende fortidsbrug, der udtrykker fortællerens subjektivitet. Med en erindringshistorisk tilgang til søfolkenes mundtlige fortællinger undersøger jeg, hvordan vi mennesker forstår os selv gennem de historier, vi fortæller om os selv.
Afhandlingen bygger empirisk på en række dybdegående oral history interviews med danske søfolk, der alle har erfaring inden for den internationale containerfart.
I afhandlingens analyser, viser jeg, hvordan søfolkene retfærdiggør og legitimerer deres valg om i første omgang at blive søfolk og senere at arbejde ombord på containerskibe. Jeg viser, hvordan søfolkene narrativt forhandler forskellige former for erfaret meningstab og aktivt tilskriver arbejdet og fællesskabet ombord på skibene en ny og brugbar mening. Jeg viser samtidig, hvordan den personlige historie konstrueres i dialog med kulturelt dominerende forestillinger og fortællinger. Sådanne forestillinger og fortællinger tilbyder den enkelte fortæller et tilgængeligt sprog at udtrykke sine personlige erfaringer i, men kan også virke begrænsende, hvis fortællerens erfaringer og forståelser ikke passer ind i de dominerende billeder. I sådanne tilfælde kan der opstå, hvad afhandlingen kalder en form for narrativt ubehag (discomposure), der kommer til udtryk som frustration og brud i fortællingens narrative sammenhæng.
Som en gennemgående metodisk pointe viser afhandlingen, hvordan interviewets intersubjektivitet er med til at forme den historie, som fortælles. Det personlige møde mellem fortæller og historiker og interviewets kulturelle kontekster indvirker på forskellig vis på den konstruerede historie. Fremfor at hævde en neutral og objektiv interviewsituation, tager afhandlingen i stedet konsekvensen af denne intersubjektivitet og skriver det konkrete møde mellem søfolkene som fortællere og mig som interviewer ind som en integreret del af den historiske fremstilling. Dette er både et narrativt greb og et metodisk valg, der skal sikre transparens ved at give læseren indblik i, hvordan historierne og mine tolkninger er blevet til.
Afhandlingen yder med sin tilgang og sine analyser flere bidrag til den eksisterende litteratur. Gennem de personlige fortællinger får vi større indsigt i søfolkenes levede liv og deres erfaringer med containerfartens historiske udvikling. Afhandlingen giver et menneskeligt perspektiv på historien om den internationale containerfart, der bidrager til vores viden om udviklingens identitetsmæssige betydning for de mænd og kvinder, som gennemlevede de historiske forandringer ude ombord på skibene.
Afhandlingen er en virksomhedshistorie, der tager oral history alvorligt både som forskningsfelt, metode og genre. Afhandlingen bidrager med sin erindringshistoriske tilgang til oral history til den fornyede samtale mellem forskningsfelterne oral history og virksomhedshistorie. Afhandlingen bringer metodiske og teoretiske indsigter fra den erindringshistoriske tradition ind i virksomhedshistorie og viser gennem sin egen narrative stil potentialet i en historieformidling, der sætter subjektivitet og erindring i centrum af sin analyse. Dermed bidrager afhandlingen også til den narrative vending inden for virksomhedshistorie ved ikke kun at anlægge et narrativt blik på de danske søfolks fortællinger men ved også at tage sig selv alvorligt som narrativ konstruktion.
The liner shipping industry is undergoing an extensive decarbonization process to reduce its 275 million tons of CO2 emissions as of 2018. In this process, the long-term solution is the introduction of new alternative maritime fuels. The introduction of alternative fuels presents a great set of unknowns. Among these are the strategic concerns regarding sourcing of alternative fuels and, operationally, how the new fuels might affect the network of shipping routes. We propose a problem formulation that integrates fuel supply/demand into the liner shipping network design problem. Here, we present a model to determine the production sites and distribution of new alternative fuels-we consider methanol and ammonia. For the network design problem, we apply an adaptive large neighborhood search combined with a delayed column generation process. In addition, we wish to test the effect of designing a robust network under uncertain demand conditions because of the problem's strategic nature and importance. Therefore, our proposed solution method will have a deterministic and stochastic setup when we apply it to the second-largest multihub instance, WorldSmall, known from LINER-LIB. In the deterministic setting, our proposed solution method finds a new best solution to three instances from LINER-LIB. For the main considered WorldSmall instance, we even noticed a new best solution in all our tested fuel settings. In addition, we note a profit drop of 7.2% between a bunker-powered and pure alternative fuel-powered network. The selected alternative fuel production sites favor a proximity to European ports and have a heavy reliance on wind turbines. The stochastic results clearly showed that the found networks were much more resilient to the demand changes. Neglecting the perspective of uncertain demand leads to highly fluctuating profits.
GreenHopper is the first Danish zero-emission ferry developed as a test platform for autonomous waterborne navigation technologies. The paper presents technology development within the innovation project ShippingLab Autonomy, which led to the commissioning of GreenHopper at Limfjorden (DK) in December 2022. The technology research resulted in a holistic system architecture for surface vessel autonomy, based on distribution of functionality and responsibility on software modules, similar to the structure observed in the International Maritime Organization (IMO) Seafarers Training Certification and Watch-keeping (STCW) regulatory framework. The paper shows how this approach results in an architecture that supports safe behaviours of individual modules and of autonomous navigation at a system level. The paper presents the individual modules, specific features and benefits. Elements of the regulatory framework are highlighted to poise technology approval by maritime authorities. The paper reflects on lessons learned, discusses continued technology validation in dedicated operational scenarios.
Decisions regarding investments in capacity expansion/renewal require taking into account both the operating fitness and the financial performance of the investment. While several operating requirements have been considered in the operations research literature, the corresponding financial aspects have not received as much attention. We introduce a model for the renewal of shipping capacity which maximizes the Average Internal Rate of Return (AIRR). Maximizing the AIRR sets stricter return requirements on money expenditures than classic profit maximization models and may describe more closely shipping investors׳ preferences. The resulting nonlinear model is linearized to ease computation. Based on data from a shipping company we compare a profit maximization model with an AIRR maximization model. Results show that while maximizing profits results in aggressive expansions of the fleet, maximizing the return provides more balanced renewal strategies which may be preferable to most shipping investors.