Due to the increasing impacts of ships pollutants on the environment and the preventive laws that are tightening every day, the utilization of all-electric ships is a recent emerging technology. Being a promising technology, the usage of fuel cells as the main energy resource of marine vessels is an interesting choice. In this article, an all-electric hybrid energy system with zero emission based on fuel cell, battery, and cold-ironing is proposed and analyzed. To this end, actual data of a ferry boat, including load profiles and paths, are considered to assess the feasibility of the proposed energy system. The configuration of the boat and energy resources as well as the problem constraints are modeled and analyzed. Finally, the boat's energy management in hourly form for a one-day period is implemented. The improved sine cosine algorithm is used for the power dispatch optimization, and all models are implemented in MATLAB software. Based on the analysis results, the proposed hybrid system and the energy management method have high performance as an applicable method for the marine vessels. In addition, to be a zero-emission ship, the proposed system has an acceptable energy cost.
A mixed integer linear programming model is presented for the operational level cargo allocation and vessel scheduling problem of a liner shipping company in Turkey, where flow-dependent port-stay lengths, transit times and transshipment synchronizations are considered. The proposed model aims to assign shipments to routes to decrease total tardiness and construct partial vessel schedules for establishing coordination with port authorities to comply with the berthing time windows. In addition to the mathematical model, novel valid inequalities and benders decomposition algorithm are implemented. Performance of the developed algorithm is evaluated on real-life problem instances. The results show that benders decomposition with valid inequalities yields the best performance.
Ship recycling refers to the process of dismantling vessels with the purpose of extracting and recovering materials for reuse, particularly the steel. The aim of this paper is to map the supply chain of ship recycling. This exploratory and qualitative research provides a glimpse on how regulations influence the supply chain management through inter-organizational arrangements. It considers the trade-offs and combinations of financial and sustainable values that, in many ways, determine these inter-organizational arrangements. Preliminary findings show that there are conflicts of interest with the ship recycling stakeholders. Although compliance of regulations should foster better transparency in the supply chain, these regulations have not yet fully embraced social aspects, such as the fact that domestic demand and supply for steel, as well as many jobs, are dependent on this industry. On the contrary, the initiatives to regulate ship recycling might induce negative effects. This paper suggests that transaction costs analysis and the principal agency theory are two complementary theories for analyzing inter-organizational relationships in the supply chain of ship recycling.
This study investigates the appropriate port governance model for implementation of green port management (GPM) practices. Relying on social systems engineering principles, we propose a multi-criteria decision-making (MCDM) framework considering four port governance models and five major GPM practice indicators. We validate the MCDM framework using survey data collected from top management executives of three ports in the Indian Ocean Rim — Bangladesh, Sri Lanka and Tanzania. We compare the Analytic Network Process (ANP) method with more recently developed Best-Worst Method (BWM) in analysis of the MCDM problem of finding the right port governance model for GPM. We collect data using the ANP and BWM survey in January 2019 and August 2019, respectively, from the same respondents. While participating in the study in January 2019, the respondents did not know that they would respond to the same MCDM problem using a different model, which corresponds to a repeated measures experimental design. In both analyses, we find that increasing privatization in port governance would enhance the implementation of GPM practices. Our study furthermore suggests that BWM is a reliable MCDM method with greater applicability than ANP, as it requires significantly lower number of judgement comparisons.
The Maritime Labour Convention, 2006 (MLC2006) entered into force in August 2013 and is a milestone for better working and living conditions (WLC) for seafarers. As of March 2020, 96 countries have ratified the MLC2006, covering more than 90% of the world’s shipping fleet. A system of port state control (PSC) allows ratifying countries to inspect any foreign ship arriving in their ports for compliance with the convention. It is intended as a second safety measure for the identification of substandard ships that sail all over the world. Nine regional agreements, so-called Memoranda of Understanding (MoU), have been signed to coordinate and standardize PSC inspections and to increase efficiency by sharing inspections and information. This paper uses public PSC statistics to evaluate the impact of the MLC2006.
A preliminary analysis using registered tonnage and MLC2006 ratification was conducted and seven MoU were selected for the analysis. The annual reports of these MoU have been viewed in September 2019. Numbers on annual inspections, deficiencies and detentions and in particular data for deficiencies related to living and working conditions and certificates and documents, have been extracted and analyzed for the years 2010 to 2017.
Across the eight-year period analyzed, inspection numbers remained stable among all MoU authorities. Deficiencies overall and deficiencies related to WLC declined, indicating an improvement in conditions overall and an increased focus on seafarers’ conditions on board. After the MLC2006 entered into force, three MoU reported WLC-ratios above 14%, while the numbers didn’t rise above 10% in the other four authorities. Deficiencies related to certificates and documents did not rise significantly between 2010 and 2017. Two European MoU showed the highest ratios for deficiencies in both categories analyzed.
The analysis confirmed that an increasing attention is being paid to the inspection of working and living conditions, especially in European countries. However, a clear positive impact of the MLC2006 could not be determined from the PSC statistics in this analysis. A large variation still exists among the MoU, a fact that demands increased efforts for harmonization of PSC procedures.
The existence of a sense of common or community interests is a prerequisite to establishing an order in a society, national or international. In this connection, it is notable that the protection of community interests is increasingly important in international law and the law of the sea is no exception. The increasing need for protecting community interests necessitates a new paradigm in the law of the sea. The legal issues regarding the marine Arctic should also be considered in the context of changing paradigms in the law of the sea. Thus this article seeks to overview principal issues of the international law governing the marine Arctic from the viewpoints of a dual paradigm, that is, the law of divided oceans (paradigm I) and the law of our common ocean (paradigm II).
A conceptual design framework for collision and grounding analysis is proposed to evaluate the crashworthiness of double-hull structures. This work attempts to simplify the input parameters needed for the analysis, which can be considered as a step towards a design-oriented procedure against collision and grounding. Four typical collision and grounding scenarios are considered: (1) side structure struck by a bulbous bow, (2) side structure struck by a straight bow, (3) bottom raking, (4) bottom stranding. The analyses of these scenarios are based on statistical data of striking ship dimensions, velocities, collision angles and locations, as well as seabed shapes and sizes, grounding depth and location. The evaluation of the damage extent considers the 50- and 90-percentile values from the statistics of collision and grounding accidents. The external dynamics and internal mechanics are combined to analyse systematically the ship structural damage and energy absorption under accidental loadings.
Due to environmental and economic issues as well as the high performance of marine vessels, efficient energy using has been becoming more demanding. Also, in order to have a zero-emission ship, the utilization of a fuel cell combined with energy storage such as batteries gets more and more attention. In this work, a zero-emission hybrid energy system, including fuel cells, batteries, and cold-ironing, is employed to have an environmentally friendly vessel, and to create condition in which ship operates with high performance, both energy management and components sizing of fuel cells and batteries using real data of ferry boat and intelligent optimization method are done simultaneously. In addition, all constraints related to energy management and component sizing with the topography of the boat and electric power sources are represented and analyzed thoroughly. Ultimately, hourly energy management and component sizing for one specific day are considered in this work, and to optimize this problem, the Improved Sine Cosine Algorithm (ISCA) is utilized. According to obtained results, the proposed energy management and component sizing result in the high-performance ship which could be utilized in the marine industry.
Nowadays, sea traveling is increasing due to its practicality and low-cost. Ferry boats play a significant role in the marine tourism industry to transfer passengers and tourists. Nevertheless, traditional ferry ships consume massive amounts of fossil fuels to generate the required energy for their motors and demanded loads. Also, by consuming fossil fuels, ferries spatter the atmosphere with CO2 emissions and detrimental particles. In order to address these issues, ferry-building industries try to utilize renewable energy sources (RESs) and energy storage systems (ESSs), instead of fossil fuels, to provide the required power in the ferry boats. In general, full-electric ferry (FEF) boats are a new concept to reduce the cost of fossil fuels and air emissions. Hence, FEF can be regarded as a kind of dc stand-alone microgrid with constant power loads (CPLs). This article proposes a new structure of a FEF ship based on RESs and ESSs. In order to solve the negative impedance induced instabilities in dc power electronic based RESs, a new intelligent single input interval type-2 fuzzy logic controller based on sliding mode control is proposed for the dc-dc converters feeding CLPs. The main feature of the suggested technique is that it is mode-free and regulates the plant without requiring the knowledge of converter dynamics. Finally, we conduct a dSPACE-based real-time experiment to examine the effectiveness of the proposed energy management system for FEF vessels.
In 2018 the International Maritime Organization (IMO) agreed to cut the shipping sector’s overall CO2 output by 50% by 2050. One of the key methods in reaching this goal is to improve operations to limit fuel consumption. However, it is difficult to optimize speed for a complete liner shipping network as routes interact with each other, and several business constraints must be respected. This paper presents a unified model for speed optimization of a liner shipping network, satisfying numerous real-life business constraints. The speed optimization is in this research achieved by rescheduling the port call times of a network, thus, the network is not changed. The business constraints are among others related to transit times, port work shifts and emission control areas. Other restrictions are fixed times for canal crossing, speed restrictions in the piracy areas and desire for robust solutions. Vessel sharing agreements and other collaboration between companies must also be included. The modeling of the different restrictions is described in detail and tested on real-life data. The scientific contribution of this paper is threefold: We present a unified model for speed optimization together with numerous business constraints. We present a general framework for handling routes with different frequencies. Moreover, we present a bi-objective model for balancing robustness of schedules against fuel consumption. The tests show that the real-life requirements can be handled by mixed integer programming and that the model finds significant reductions of bunker consumption and cost for large-scale real-life instances.