Maritime Transport Research最新文献

This paper studies the maritime fleet composition problem with uncertain future fuel and carbon prices under the restriction of complying with future greenhouse gas (GHG) emission restrictions. We propose a two-stage stochastic programming model that can be adapted to two different variants of this problem. The first variant considers the Maritime Fleet Renewal Problem where there is an existing initial fleet to be renewed through scrapping and acquisitions, as well as retrofitting of ships in the current fleet. The second variant considers the Maritime Fleet Size and Mix Problem, where also the initial fleet must be determined. When applying the model to a fleet of Supramax bulk carriers as a case study, we find that LNG- and methanol-based power systems are favorable initial choices. Two different scenario sets, with 50% and 90% reduction restrictions by 2045, are investigated. Depending on the ambition level, retrofits towards ammonia can be cost-effective.

This paper aims to provide insight into the stability of solutions to a multi-product maritime inventory routing problem (MIRP) when replanning due to the occurrence of unexpected events. The MIRP determines vessel routes while ensuring that port inventory levels remain within operational thresholds. In today's global economy, supply chains are often vast and complex. Managing inventory and routes for multiple products across international waters is a daunting task. The MIRP provides a framework for optimizing these complex supply chain networks. Four stability metrics are available to evaluate the stability of the adjusted plans. The problem is modeled using a goal programming approach to consider all stability metrics simultaneously. Then, 30 instances from the literature are solved using CPLEX. It is shown that there are significant differences when all stability metrics, as opposed to a single one, are considered simultaneously, which can lead to better agreement between the vendor and the retailer in decision making. A cost analysis is performed to examine the impact of the cost increase on the stability of the other metrics. The key finding is that when all stability metrics are considered simultaneously, a 5 % increase in cost can result in 7.5 % fewer changes to replanned solutions, while this rate is less than half when the stability metrics are considered individually. This highlights the significance of evaluating all metrics simultaneously instead of analyzing each metric separately.

While passenger-only ferries can be an effective instrument in mitigating road congestion in urban areas, they are among the most polluting modes of transportation. This paper studies technical and economic feasibilities of a battery-powered high-speed ferry service in Oslo, Norway. An urban ferry planner problem that minimizes ferry operator and passenger costs and external costs of road transport subject to strategic (fleet selection and infrastructure location), tactical (service frequency) and operational (vessel speed) decisions is proposed. While the results show that zero emission technologies can pass the cost-benefit test for a short-range service, competitiveness hinges on energy costs and capacities and on the performance of the existing service. Counterfactual scenarios show substantial cost reductions from altering the current ferry route. Anticipated increase in external costs of road transport from closing the ferry service is also much smaller than the system costs of maintaining the urban ferry connection.

An energy systems comparison of grid-electricity derived liquid hydrogen (LH2) and liquid ammonia (LNH3) is conducted to assess their relative potential in a low-carbon future. Under various voyage weather conditions, their performance is analysed for use in cargo transport, energy vectors for low-carbon electricity transport, and fuel supply. The analysis relies on literature projections for technological development and grid decarbonisation towards 2050. Various voyages are investigated from regions such as North America (NA), Europe (E), and Latin America (LA), to regions projected to have a higher electricity and fuel grid carbon intensity (CI) (i.e., Asia Pacific, Africa, the Middle-East, and the CIS). In terms of reducing the CI of electricity and fuel at the destination port, use of LH2 is predicted to be favourable relative to LNH3, whereas LNH3 is favourable for low-carbon transport of cargo. As targeted by the International Maritime Organisation, journeys of LNH3 cargo ships originating in NA, E, and LA achieve a reduction in volumetric energy efficiency design index (kg-CO₂/m³-km) of at least 70% relative to 2008 levels. The same targets can be met globally if LH2 is supplied to high CI regions for production of LNH3 for cargo transport. A future shipping system thus benefits from the use of both LH2 and LNH3 for different functions. However, there are additional challenges associated with the use of LH2. Relative to LNH3, 1.6 to 1.7 times the number of LH2 ships are required to deliver the same energy. Even when reliquefaction is employed, their success is reliant on the avoidance of rough sea states (i.e., Beaufort Numbers >= 6) where fuel depletion rates during a voyage are impractical.

With the Yara Birkeland, the world’s first autonomous cargo ship developed for commercial use, nearing regular unmanned operation, it is crucial to assess the availability and readiness of unmanned cargo handling solutions. While there are already fully automated container terminals at large international ports, the purpose of this study is to consider solutions to support autonomous ships for small sized ports with little infrastructure, typical of coastal harbors in Norway. The analysis centers on geared cargo vessels that can navigate such ports with minimal or no crew onboard, and the primary method used involved workshops and interviews with personnel from relevant industries. An important finding is the lack of skilled crane operators that are willing to follow the ship. The study concludes that it is important to address the following 3 key technological gaps: (1) the autonomous connection and release of break-bulk, (2) automatic securing and lashing of onboard cargo, and (3) shipboard cranes that can operate without an onsite crane operator.

This study examines freight rates in four key areas of the U.S. water freight transportation industry –coastal, Great Lakes/St. Lawrence River, inland waterways, and deep-sea shipping. The data involved in this study includes longitudinal data from 2008 to 2021 on freight rates in all four of these sectors along with data on macroeconomic variables and commodity prices. The purpose of this study is as follows: (A) examine lead/lag relationships between the four freight rates, (B) examine lead/lag relationships between the freight rates and macroeconomic variables, and (C) examine lead/lag relationships between the freight rates and commodity prices. We do find significant predictive power for freight rates both on each other as well as for macroeconomic indicators. In terms of predicting other freight rates, inland freight rates are the only ones to predict all three other freight rates. Both inland and deep-sea freight rates are shown to be strong at predicting macroeconomic indicators in the short run, but deep sea has greater long-term predictive power. Commodity prices on the other hand are only minimally predicted by freight rates but are also strong predictors of inland freight rates. Coastal and Great Lake freight rates are shown only to have minimal predictive power. Differences in competitive conditions, as well as the type of cargo between these four sectors, are proposed as an explanation for these results.

In this paper, we present the scheduling problem on a given route where speed optimization under various weather conditions is to be performed. Different approaches for calculating fuel consumption for vessels are introduced with a discussion of how this might influence the speed optimization strategies on predetermined multi-stop routes in a short sea shipping service within offshore logistics. Due to both spatial and temporal changes in weather conditions, fuel consumption as a function of speed becomes time-dependent as a vessel performs its route in varying weather. In our novel approach, the weather impact on fuel consumption for the considered vessels is modeled with a higher level of detail than in previously conducted studies, including both wave direction and wave period as input together with the wave height. We test our approach for optimizing schedules on a large set of routes of different lengths and number of stops, as well as for a set of different weather samples based on historical observations. When comparing the new approach to current industry practice, the computational study reveals on average a 4.5% reduction in fuel consumption across the different routes and weather scenarios. The magnitude of the reduction potential increases for worsening weather conditions. Furthermore, it is demonstrated how the approach commonly used for modeling weather impacts in the literature tends to greatly miscalculate the true cost of performing a voyage in realistic weather conditions. Finally, we discuss how the model fidelity is likely to affect the outcome of the routing decisions at a higher planning level, representing a potential for even further reductions of fuel consumption in various weather conditions.

Seasonality is a unique characteristic of the cruise industry. Cruise lines move their ship deployment areas seasonally to meet tourism needs. Taking advantage of the climatic differences between the Northern and Southern Hemispheres could allow greater growth in the global cruise industry. This study aims to provide basic findings for governments and ports to consider ways to encourage growth by capitalizing on the seasonality of the global cruise industry. Automatic identification system data for all ocean-going cruise ships worldwide in 2019 were compiled and categorized into three travel groups (short, middle, and long) based on the latitudinal distance traveled. Differences between these three groups were analyzed in terms of deployment area/port, vessel size, and itinerary design. As a result, we found that the long travel group had the following characteristics. Cruise ships were deployed to Alaska and Northern Europe in summer and dispersed to the equator and Southern Hemisphere in winter. The vessel size was standard and neither too large nor too small. Specifically, long travel of cruise ships was limited by the maximum gross tonnage, length, and breadth of the ship, but there was no draught restriction. Although the number of nodes and edges, and the average degree comprising the itineraries were high, hub ports appeared only in the summer. Furthermore, despite the long distances traveled by season, the number of communities tended to be small, reflecting the design of their itineraries. In conclusion, the development of several ports in the Southern Hemisphere that can accommodate mega-sized cruise ships with standard draught, while considering overtourism, would allow cruise ships to take advantage of the seasonality and, thereby, grow the cruise industry.

The European Union (EU) transport policy recognizes the importance of the waterborne transport systems as key elements for sustainable growth in Europe. By 2030, 30% of total road freight over 300 km should shift to rail or waterborne transport, and more than 50% by 2050. Thus far, this ambition has failed but there have been several project initiatives within the EU to address these issues. In one of these projects, we consider a new waterborne transport system for Europe that is green, robust, flexible, more automated and autonomous, and able to connect both rural and urban terminals. The purpose of this paper is to describe work and preliminary results from this project. To that effect, and in order to assess any solutions contemplated, a comprehensive set of Key Performance Indicators (KPIs) has been defined, and three specific use cases within Europe are examined and evaluated according to these KPIs. KPIs represent the criteria under which the set of solutions developed are evaluated, and also compared to non-autonomous solutions. They are grouped under economic, environmental and social KPIs. KPIs have been selected after a consultation process involving project partners and external Advisory Group members. Links to EU transport and other regulatory action are also discussed.

We investigate the potential for greenhouse gas (GHG) emission cuts for the Norwegian short-sea (domestic) maritime segments of express boats, offshore support vessels, and aquaculture support vessels in comparison to ferries in Norway. Public procurement conditional on climate-friendly operation is catalyzing a transition to battery-electric operation, where most ferries will be battery-electric or fueled by hydrogen by 2030. The comparison to ferries is performed with the help of a methodology inspired by the multi-attribute utility method, which contains 11 features related to technology, operation, and acceptance. This score is used to adjust the 70% CO₂ emission reduction achieved by ferries. Based on this methodology, the CO₂ emission reduction potential for express boats, offshore support vessels, and aquaculture support vessels is estimated to be 46%. Consequently, these short-sea shipping segments could reduce CO₂ emissions by 0.8 million tonnes from 2017 to 2030, which is equivalent to 1.5% of Norwegian emissions in 2017. Norway's experience indicates that there is a sizable potential for reducing CO₂ emissions for public procurement conditional on climate-friendly solutions for short-sea shipping in other shipping nations.