Maritime Transport Research最新文献

The International Maritime Organization (IMO) has stated an ambition to achieve net-zero GHG emissions by 2050 and new regulations are under development to achieve this. To inform decisions on GHG regulations, this study has modeled the CO₂ emission abatement potentials and costs towards 2050 for all ships above 400 gross tons. We explore CO₂ reduction pathways based on marginal abatement cost curves (MACC) for 2030, 2040 and 2050. MACC is an important tool to assess the potential impact of regulations and can inform current policy debates as well as ship owners that need to develop their decarbonization strategies. Compared to previous work, we provide global MACCs taking into account the latest technologies and cost development, including alternative fuels. The updated MACC is based on more than 50 state-of-the-art abatement measures, 10 fuel systems and 8 fuels. The results indicate that the revised IMO GHG strategy ambition of 20–30 % GHG emission reduction in 2030, relative to 2008, can be reached at a marginal cost of 50–100 USD/tCO₂; 70–80 % emission reduction in 2040 can be achieved at 230–240 USD/tCO₂ and net-zero emissions in 2050 at a marginal cost of 300 USD/tCO₂. The two inputs which have the highest impact on the results are the future cost of carbon-neutral fuels and growth in seaborne trade.

Port safety plays an important role in port operations. Ship size has become larger and the port environment has rapidly changed in recent years. Ship accidents occur in the port area due to the complex environment in the port area. To improve past decision analysis methods on port operation safety fields and reduce fatalities and financial loss for potential accidents, the novelty of this study is to construct a safety index of ports with the application of the Best Worst Method (BWM). Four dimensions and 14 indicators were summarized based on an intensive literature review. The BWM was implemented to prioritize the weights of dimensions and indicators. Based on 21 expert questionnaires, the results indicate that the ranking of dimensions is ‘human’, ‘ship facilities’, ‘port facilities’, and ‘documentation check’. Regarding the ranking of indicators, the top three are ‘fire-fighting and life-saving equipment’, ‘captain’, and ‘pilot’. Safety improvement strategies (e.g. revising inappropriate operational rules and strengthening human safety education and training) based on these research findings are provided. The merits of this paper are presenting a simpler questionnaire-filling method and overcoming the traditional complicated questionnaire survey process and research limitations (e.g. indicator independence problems in the Analytic Hierarchy Process, and the complexation of filling out a questionnaire in the Analytic Network Process). In addition, the findings can help decision-making for port management authorities, port practitioners, and shipping operators (shipowners) regarding policy implementations of port safety.

Many advancements are being made within the domain of autonomous shipping, motivating discussions of corresponding amendments to international safety regulations within the International Maritime Organization. Near-coastal passenger ferries are a form of sea traffic that has been the target of automation trials due to their short voyages and relatively protected waters of operation. This study investigated emergency evacuation from a range of such ships, covering both the current situation (focused on crew tasks, external rescue actors and interactions) and safety aspects that should be considered when automation brings about new work patterns, such as remote supervision and control. The study employed qualitative methods – interviews, field visits and a stakeholder workshop. Results give insight into ferry evacuation processes and challenges in their current form. In addition, results from the application of different automated evacuation scenarios suggest that more detailed studies are needed within the areas of remote operation situation awareness, remote operator and onboard personnel competencies, passenger safety information and communication, simple and robust evacuation equipment, technical means allowing assistance between autonomous and regular ships, and lastly, both procedures and interfaces for collaboration in a changing rescue network.

Seaports are exposed to multiple risks that may affect security and operations. This research aims to develop a framework for identifying, ranking, and prioritizing the risks. Also, this study ranks the 12 major Indian ports based on the identified risk factors. The study follows an extensive literature review, prioritization by Fuzzy TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution), and sensitivity analysis for robustness. Thirty-two risks were identified and classified into five categories: natural disasters, geographical risks, security risks, operational and financial risks, and socio-political risks. The analysis suggests that the most important risk that the ports in India should consider is natural disasters. The risk of cyclones and tsunamis occupied the first two ranks among the global risks. Operational and financial risks, such as complex and lengthy approval procedures and infrastructure risks, are ranked third and fourth. Mumbai is ranked first as the riskiest Indian port, followed by Kolkata, JNPT (Jawaharlal Nehru Port Trust), and Vishakapatnam Port

We present an analysis of the impact of large container ship call sizes on the operational efficiency of container terminals as well as on hinterland modes of transport. We use standard container terminal simulation software, that can represent a realistic terminal operation. We include dynamic crane productivity, arrival time uncertainty, and deepsea vessel prioritisation in our model.

Our experiments investigate the impact of introducing larger call sizes of container ships, increasing the uncertainty in arrival times of deepsea ships, and the impact of the phenomenon of split calls that are employed by the largest container ships in certain regions in the world. We differentiate between the impact on terminal operations, land-based hinterland traffic, and hinterland traffic over water, through barges and feeder vessels.

Our results show that introducing large ships with large container call sizes comes with benefits and drawbacks. Benefits can be found in planning advantages for both the deepsea ships and barges and feeders handled in the terminal. Drawbacks occur as a result of operational peaks in subsystems such as the quay cranes, the stack and the land side gates. Higher uncertainty deteriorates the performance of the terminal, but the impact on the hinterland modes of transport is greater than on the large deepsea vessels. The impact of the split call is that it brings all the disadvantages of large vessels, but none of the benefits.

Our analysis shows the operational impact of large call sizes on terminal operations and hinterland transport operations, based on container terminal simulations with a higher degree of realism than previous work. In addition, we offer, for the first time, insights in the impact of split calls of container ships at container terminals.

This study explores the influence of uncertain waiting times together with uncertain fuel prices, in the selection of bunker fuel stops for a shipowner engaged in tramp shipping. We analyze the stochastic bunkering waiting times in the bunkering optimization problem using scenarios constructed from vessels' Automatic Information System (AIS) records and test their relevance to the bunkering decision. Our findings highlight the tradeoff between port efficiency, as characterized by waiting times, and the economic advantages of purchasing bunkers from cheaper port options and finishing the voyage in higher-priced bunker regions. Although the absence of waiting time would have produced similar results in our empirical setup, introducing waiting times altered the dynamics, making a price-attractive port like Piraeus not as attractive when risk-aversion is modeled, particularly given the risk of prolonged waiting.

Expert judgment has been widely utilized in ship risk assessment. The traditional method is believed to be capable of processing only designated linguistic variables, which fails to capture the degree of expert hesitation in assessing a complex system. A novel model, the bi-independent hesitant fuzzy linguistic term set (BHFLTS), based on the hesitant fuzzy linguistic term set (HFLTS), is proposed to incorporate this hesitation. This paper also identifies ten navigational hazards to maritime autonomous surface ship (MASS) operation based on a literature review. In addition, the BHFLTS approach combined with the technique for order preference by similarity to an ideal solution (TOPSIS) is utilized for hazard assessment and ranking, and with this method, “Collision avoidance decision algorithm malfunction”, “Ship situation awareness system failure” and “Command transmission system failure” are rated as the top three navigational hazards that threaten MASS operation.

Vessel losses of command (e.g., propulsion, electrical power, or steering failure) can serve as the initiating event for significant maritime accidents, such as grounding. It is therefore important to estimate the frequency of such events for navigational risk assessments. Despite the existence of previous studies, new data have become available that may reveal more precise and useful information for risk estimations and accident prevention. This paper analyzes two databases of vessel losses of command within Norway’s economic exclusive area over a five year period. The study utilizes a novel database of incidents observed by the Norwegian Coastal Administration’s (NCA) Vessel Traffic Services (VTS), in addition to incidents reported to IHS Markit over the same five year period. Automatic identification system (AIS) data is used to construct activity metrics of vessel activity, which are used to compute vessel loss of command incidence rates for ship types. To account for under-reporting, capture–recapture methods are used to calculate adjusted incidence-rates. The duration of each incident is recorded and used to construct distributions of repair times. Probabilities of towing and anchoring are computed for ship types and incident location. The results indicate that previous studies may have underestimated the incidence of vessel loss of command. Using the best-case scenario, cargo ships and tankers suffer losses of command more frequently than other ship types. Significant under-reporting of losses of command was observed in the IHS Markit database.

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.