Short Sea Research Articles

A ferry route in the Skagerrak optimised via VISIR-2

Abstract Urgent measures are needed for the shipping industry to contribute proportionately to climate change mitigation. To date, the potential of weather routing has not been reproducibly assessed, especially for short sea shipping. We employ the open-source VISIR-2 model on a ferry passage in the Skagerrak (the strait among Norway, Sweden, and Denmark), considering both sea currents and waves. By computing 5,840 least-CO2 optimal routes for 2023, we find promising results, particularly for voyages from Denmark. The savings follow a bi-exponential distribution, with over 10% CO2 emissions savings achievable on about ten days per year. Specifically, the Norwegian coastal current can be harnessed to enhance speed over ground and reduce overall emissions. The vessel performance curve needs to be tailored to specific ships in service, and the optimisation algorithm should be developed to enable just-in-time arrivals.

Analyzing the Blue Economy Potential of Pakistan’s Maritime Sector

The maritime economy is an important contributor to the economies of the countries. Pakistan, with more than 1000 km of coast, has a huge repository of sea resources and is located on a very important trade route. Its geo-sectoral location provides easy and short sea access to China, Afghanistan, and the Central Asian Republics. However, the continuous neglect of the maritime sector has resulted in the depletion of the sector, which was once thriving at a rapid pace. The lack of awareness of the maritime economy, depleting infrastructure, untrained human resources, and lack of effective policies are the contributing factors that have prevented the full potential of this sector from being exploited so far. The development of ports, the shipping industry, fisheries, and coastal tourism are the areas that can significantly contribute to the GDP of the country and provide livelihood to people. There is a dire need for the government to pay full attention to this sector and start investing in this ignored area for its revival, ultimately enabling it to contribute significantly to the economic development of the country.

Toward green container liner shipping: joint optimization of heterogeneous fleet deployment, speed optimization, and fuel bunkering

AbstractContainer liner shipping companies, under the international shipping carbon reduction indicators proposed by the International Maritime Organization, must transform two key aspects: technology and operations. This paper defines a green liner shipping problem (GLSP) that integrates the deployment of a heterogeneous fleet, speed determination, and fuel bunkering. The objective is to achieve low‐carbon operations in liner shipping, taking into consideration the diversification of power systems, the use of alternative fuels in ships, and the continuous improvement of alternative fuel bunkering systems. For this purpose, we present a bi‐objective mixed integer nonlinear programming model and develop two methodologies: an epsilon‐constraint approach and a heuristic‐based multi‐objective genetic algorithm. We validate the effectiveness of our model and methods through a case study involving container ships of various sizes deployed on intra‐Asian short sea routes by SITC International Holdings Co., Ltd. The experimental results highlight the crucial role of dual‐fuel (DF) ships in the pursuit of low‐carbon strategies by liner companies, with liquefied natural gas and ammonia DF ships being the most widely used. Additionally, fuel cell (FC) ships, particularly those powered by ammonia and hydrogen, demonstrate significant carbon reduction potential. Furthermore, ships with larger container capacities have a greater cost advantage. For the GLSP, speed determination is an auxiliary decision, and the lowest speed is not necessarily the optimal choice. Decision‐makers must carefully balance competing economic and carbon emission reduction objectives, as deploying more alternative fuel ships may increase fuel bunkering and fuel consumption, resulting in a higher total operating cost.

Approaching zero emissions in ports: implementation of batteries and supercapacitors with smart energy management in hybrid ships

The urgent need to reduce energy consumption and environmental impact in the shipping industry has prompted research and industry to explore new solutions for minimizing fuel usage. This study examines the potential effects and benefits of integrating electrical energy storage systems, such as lithium-ion batteries and supercapacitors, into short sea shipping ships during port stay. Specifically, a novel dynamic simulation tool is developed to conduct suitable analyses that investigate the feasibility of charging electrical storage systems while at navigation and utilizing them as alternatives to traditional diesel generators while in port. The analysis reveals that lithium-ion batteries and supercapacitors are effective tools for reducing pollutant emissions by minimizing diesel generator usage during port stopovers, resulting in a significant reduction in fuel consumption from 1.148 kt/year to 0.511 kt/year. Moreover, under identical conditions, the use of supercapacitors increases the lifespan of batteries from 10.6 years to 11.9 years. Additionally, there is a 55 % reduction in carbon dioxide emissions during port stays, decreasing from 2.98 kt/year to 1.64 kt/year.

Short Sea Shipping as a Sustainable Modal Alternative: Qualitative and Quantitative Perspectives

This study investigated the possibility of using short sea shipping (SSS) as a sustainable freight modal alternative by analyzing data collected from shippers in the New York State Capital Region. To this end, qualitative and quantitative approaches were jointly used. The qualitative analysis focused on exploring in-depth interviews with the decision makers regarding the drivers and the barriers to firms shifting to SSS. The quantitative efforts included estimating discrete choice (ordinal logit) models to assess the influence of four key governing aspects (leadership buy-in, emergency logistics, public policy, and sustainability) on the probabilities of shifting to SSS supported by the findings from the qualitative part. This paper also includes a comprehensive description of various variables, factors influencing the current mode choice, shippers’ perceptions, and willingness to use SSS. The results showed that firms with higher truck shares had fewer chances to switch to SSS unless in emergencies. Unfortunately, sustainability was the least valued by most of the participants in choosing SSS. Hence, lower costs and better service were essential. The ordinal logit models provide a potential tool for policymakers and freight planners to estimate the probability of firms choosing SSS over the current mode.

Simulation-based evaluation of concepts for short sea shipping of green hydrogen

In this study, a simulation-based approach is applied to develop concepts for short sea shipping of green hydrogen and to assess their overall energy efficiency. The study is conducted as a case study involving production of green hydrogen at an offshore site in the North Sea. Hydrogen produced at the site is first transported by pipeline to a port-based intermediate storage facility, from where it is transported onwards by ship. For the onward transport, four different hydrogen carriers are considered, namely compressed hydrogen, liquid hydrogen, ammonia, and a liquid organic hydrogen carrier.

Solving a short sea inventory routing problem in the oil industry

We address an optimization problem related to the minimization of the distribution costs associated with product delivery in the oil industry. Particularly, the problem consists of determining a schedule of shipments from production ports to satisfy demand and desired inventory limits at consumptions ports. Products are transported in vessels, which can be viewed as a set of shared resources. The complexity of the problem derives from the problem structure and the number of decisions that need to be made throughout a planning horizon. The context that we studied belongs to the family of short sea inventory routing problems for which the ports are in the same geographical area. We formulate a mixed-integer programming model that captures the most relevant features of the real system. The main decisions include the selection of the vessels that will be used, the paths that each vessel will follow, and the quantities of each product loaded and unloaded at each port visited during the planning horizon. We test the limits of our mathematical programming formulation and develop a heuristic approach for tackling problem sizes that exceed the capabilities of a commercial solver.

Short Sea Shipping in the Age of Sustainability, Autonomous Navigation and Digitalization

This paper presents the comprehensive state-of-the-art on the challenges that short sea shipping currently faces across the world. The concept and its relationship with coastal shipping are introduced, followed by a review of the EU policies for short sea shipping and its practical impacts in modal split. A survey of the literature on the strong and weak points of this form of transportation is carried out, aimed at explaining the difficulties in achieving relevant modal shifts from road to sea. The experience with short sea shipping across the world is described and discussed, providing a global perspective. The paper then discusses the main challenges and opportunities in this field, namely decarbonisation, autonomous navigation, and digitalization. Conclusions are drawn on the possible impact of these game changing developments in this segment of the shipping industry.

Environmental-economic sustainability of hydrogen and ammonia fuels for short sea shipping operations

Alternative fuels of low or zero carbon content can decarbonise the shipping operations. This study aims at assessing the lifetime environmental-economic sustainability of ammonia and hydrogen, as alternatives to diesel fuel for short sea shipping cargo vessels. A model is employed to calculate key performance indicators representing the lifetime financial sustainability and environmental footprint of the case ship using a realistic operating profile and considering several scenarios with different diesel substitution rates. Scenarios meeting the carbon emissions reduction targets set by the International Maritime Organisation (IMO) for 2030 are identified, whereas policy measures for their implementation including the emissions taxation are discussed. The derived results demonstrate that the future implementation of carbon emissions taxation in the ranges of 136–965 €/t for hydrogen and 356–2647 €/t for ammonia can support these fuels financial sustainability in shipping. This study provides insights for adopting zero-carbon fuels, and as such impacts the de-risking of shipping decarbonisation.

A numerical simulation tool for a wind-assisted vessel verified with logged data at sea

This paper presents a comprehensive numerical simulation tool for a wind-assisted container ship that is used to evaluate vessel performance on real-world shipping routes. The model includes the dynamics of the ship hull, rudder and a controllable pitch propeller (CPP), as well as fuel consumption characteristics of the main propulsion diesel engine and the force profile generated by a pair of suction sails. The fidelity of this simulation tool is verified by on-board sensor measurements conducted during short sea trials and long-distance real-world vessel routes. Based on the verified model, performance prediction plots (PPP) for different modes of operation with wind assistance are utilized to assess energy efficiency and the potential for additional savings in an integrated wind-hybrid propulsion system. It is expected that this PPP methodology can be exploited for future optimization studies of either retrofit or new builds.

Numerical Modeling of Tidal Phenomena of the Penzhinskaya Bay

In this study, the Delft3D-Flow hydrodynamic model was used to determine the characteristics of the main tidal waves and currents in the Penzhina Bay (Sea of Okhotsk, Russia). The initial and boundary conditions are set according to the TPXO9 model data, the salinity and water temperature for each model layer are set based on the reanalysis data of the HYCOM ocean general circulation model, with a time step of 3 h. E-uropean Center for Medium-Range Weather Forecasts ECMWF (European Center for Medium-Range Weather Forecasts) reanalysis ERA-5 was used as meteoforcing. Modeling was performed for the ice-free period from May to September 2005. Maps of cotidal lines, tidal ellipses, and reversibility coefficient for the main tide waves: semidiurnal wave M2 and diurnal wave K1 were constructed. The model was verified by comparing the published and calculated harmonic components for 9 sea level monitoring points located in the Penzhina Bay. Conformance evaluation generally shows a high degree of consistency between model and reference data. The values of the coefficient of determination R2 between the series formed by the model and published harmonic components are in the range of 0.96–0.99. According to the magnitude of relative errors, the simulation results are divided into two consistency categories – high (1.48–2.14%) and satisfactory (2.93–4.27%). Spatial patterns of distribution for the values of relative errors were not found. A certain inconsistency in the results is presumably due to the time discretization of the observation time support and the short sea level monitoring data series used to calculate the published harmonic components at the Penzhina Bay.

Solar photovoltaic systems for the Short Sea Shipping’s compliance with decarbonization regulations in the European Union

Carbon Intensity Indicator (CII) regulation came into force In January 2023 as one of the main International Maritime Organization’s measures to reduce Greenhouse Gas (GHG). Short Sea Shipping (SSS) demand significant electricity supply by reaching up to 30% of total on-board power. This paper addresses SSS-fleet compliance with CII regulation, Market and Goal-Based Measures imposed by the European Union (EU) through solar photovoltaic systems (PV) for on-board electricity production. The paper analyses the techno-economic feasibility of this solution from the shipowners’ standpoint in the medium-term. To meet this aim, a SSS Car-carrier between Canary Islands and Iberian Peninsula is assessed by simulating PV performance, vessel’s technical implications, and economic consequences of GHG mitigation in the context of the EU. The results reveal that PV reduces fuel consumption for electricity generation by 15.5% by reducing the total CO2 emissions by 3.38%. Although this improvement is not substantial enough to change the CII score of the vessel, the Internal Rate of Return of the PV investment achieved 55% for 10 years with three years as payback period. This fact along with the robustness of the results achieved suggest PV system is a promising mitigation option for SSS vessels.

Assessing the emissions of short sea international shipping: a case study of the Mytilini–Ayvalik route

Short sea shipping involves transporting passengers and cargo between European ports and coastal countries bordering Europe on enclosed seas. Challenges include aging fleets and environmental concerns, but efforts to reduce emissions are in progress through the use of low-sulfur fuels, hybrid and electric vessels, and improved energy efficiency. This study focuses on emissions from international short shipping routes between Mytilini and Ayvalik, using standardized emission factors to calculate CO2, SO2, NOx, PM, and HC emissions. The research aims to bridge knowledge gaps and provide insights into these emissions, identifying the main commercial ships on the route, analyzing their emissions, and discussing the findings. Overall, six ships completed the route, consuming an average of 60 L of fuel per hour per 100 HP, depending on factors like speed and total load. Notably, NOx emissions are the highest, followed by sulfur oxides, with values exceeding 12.9 and 3.5 tons, respectively. As anticipated, cruising is the shipping practice with the highest energy footprint, amounting to 695 MWh. An essential discovery is that hoteling plays a significant role in energy consumption and emissions, accounting for 152 MWh out of the total 881 MWh consumed across all shipping practices. The potential adoption of hydrogen as a fuel holds the promise of substantial reductions in greenhouse gas emissions, enhancements in air quality, and noise pollution mitigation.

Evaluation of an autonomous, short sea shipping feeder-loop service through advanced simulations

Traditionally, container-freight being shipped from central Europe to the coast of Norway has been transported either by road, or by larger containerships to central ports. For the past 3 years the AEGIS consortium has worked to develop a new, disruptive short sea shipping feeder-loop service based on mother and daughter ships [1]. The hypothesis is that introducing smaller, autonomous, battery-powered vessels into the fjords of Norway would open new business areas, provide access to remote regions, and allow shipping companies to take on cargo that could not previously be transported by water. Such a transport system has the potential of reducing cost, GHG emissions and external costs, while increasing frequency of service and the waterborne cargo volume in Europe. One of the main challenges of the mother-daughter logistic system is how transshipment affects defined key performance indicators (KPIs), especially in terms of cost. For this purpose, the SIMPACT tool [2] was developed in the H2020 projects AEGIS and AUTOSHIP. The tool allows for rapid iterations of maritime logistic systems through discrete event scheduling, and estimation of energy, fuel, emission, and cost.This paper will present results from a case-study on two different daughter ship concepts. The concepts are evaluated through cost and environmental KPIs presented in [1], in addition to external costs based on the European handbook on the external costs of transport [3].Results from the case-studies indicate that transport systems including green daughter-vessels have the potential of being cost competitive and would lower externalities compared to the baseline truck transportation system.

An ALNS-based matheuristic algorithm for a multi-product many-to-many maritime inventory routing problem

In this paper, we propose an adaptive large neighborhood search-based matheuristic algorithm to solve a multi-product many-to-many maritime inventory routing problem. The problem addresses a short sea inventory routing problem that aims to find the best route and distribution plan for multiple products with a heterogeneous fleet of vessels through a network including several producers and customers. Each port can be visited a given number of times during the planning horizon, and the stock level for each product should lie within the predefined bound limits. The problem was introduced by Hemmati et al. (Eur J Oper Res 252:775–788, 2016). They developed a mixed integer programming formulation and proposed a matheuristic algorithm to solve the problem. Although their proposed algorithm worked well in terms of running time, it suffers from disregarding a part of the solution space. In this study, we propose a new matheuristic algorithm to find better solutions by exploring the entire solution space for the same problem. In our solution methodology, we split the variables into routing and non-routing variables. Then in an iterative process, we determine the values of the routing variables with an adaptive large neighborhood search algorithm, and we pass them as input to a penalized model which is a relaxed and modified version of the mathematical model introduced in Hemmati et al. (2016). The information from solving the penalized model, including the values of the non-routing variables, is then passed to the adaptive large neighborhood search algorithm for the next iteration. Several problem-dependent operators are defined. The operators use the information they get from the penalized model and focus on decreasing the penalty values. Computational results show up to 26% improvement in the quality of the solutions for the group of instances with a large feasible solution space. We get the optimal value for the remaining instances matched with the reported results.

Seeking new strategic options for promotion of intermodal transport in perishables: The use of short sea shipping

The objective of this study is to find new options for the promotion of intermodality, based on short sea shipping, as applied to perishable products. At present, most of the transport is carried out by refrigerated trucks. In theory, this change would have positive effects on the environment and could even reduce transit costs, but companies are still hesitant to implement this practice. In this context, the present study aims to determine whether there are aspects other than operational considerations (e.g., time, cost, quality or environmental concerns) that condition modal shift. First, a literature review is conducted which attempts to identify both the strengths and weaknesses of intermodality in perishable transport. This review serves as the basis for the elaboration of a questionnaire targeting transport actors within the fruit and vegetable supply chain in southeastern Spain – the area taken as an application example. Next, the survey is used to determine the possible drivers that would favor a modal shift applying a structural equation analysis, corroborated with a traditional econometric model. As a result, the design of an overall strategy based on the creation of redistribution hubs at destination (i.e., located at ports), whose operations could be optimized through the digitization of the supply chain, appears to be a promising approach.

Changes in external costs and infrastructure costs due to modal shift in freight transport in North-western Europe

Modal shift in freight transport entails moving freight from road to rail, inland waterways, and short sea shipping. In current Dutch and European freight transport policy, modal shift is foreseen to play an important role to mitigate external effects of freight transport. Policy efforts on modal shift are legitimate because the size of the external costs of freight transport are considerable. But can modal shift policies also be effective? In other words, can policy efforts on modal shift result in a decrease of external costs and infrastructure costs due to freight transport? Our research approach falls apart into three steps. In the first step we analyse the transported weight by road on four international freight corridors in North-western Europe that could be transported against at least 10% lower private costs by rail or inland waterways. The share of road transport (transported weight) on the corridors in total road transport in the Netherlands is about 10%. The weight of the cargo that could potentially be shifted on the basis of the transport cost criterium is called the modal shift potential (MSP). We estimate the MSP for the base year 2018 and for the future year 2050. Also in this step, we translate the MSP into changes in transport performance per transport mode. In the second step we determine differences in external costs and user dependent infrastructure costs per unit of transport performance (tonkm) between the transport modes road, rail, and inland waterways. The following external effects are included: greenhouse gas emissions (tank-to-wheel), air pollutant emissions (tank-to-wheel), noise, traffic accidents, congestion, and emissions from fuel and electricity production (well-to-tank) for freight vehicles. Including all these effects, we take a more integral approach than existing studies on the effect of modal shift on the external costs of freight transport. In the third step, we combine the results of steps 1 and 2 and calculate the changes in external costs and infrastructure costs that result from the MSP’s. We find MSP’s of between 35 and 55%, depending on the market segment (container, or non-container transport, and year). These percentages may seem substantial, but we emphasize that on the freight transport corridors rail and inland waterways are (very) competitive to road. Estimates for the decrease in external- and user dependent infrastructure costs if the MSP’s are fully realized point to reductions of €67 million to €150 million for the Netherlands, and €87 million to €136 million abroad for 2018 (considering all countries through which the corridors pass). We emphasize that these are maximum annual savings which can only be achieved if all non-transport cost obstacles for modal shift can be removed. For 2050 estimating a maximum and minimum for the change in external- and infrastructure costs is impossible due to uncertainties in the development of the transport costs and the external costs of freight transport. Because for the year 2018 the MSP’s result in a decrease of external costs and infrastructure costs from freight transport on the corridors, we conclude that in the coming years policy efforts on modal shift can be effective. We can however not conclude anything about the efficiency: are the benefits of policy efforts on modal shift larger than the costs? If that is not the case, taking modal shift measures can eventually not be justified from an economic welfare point of view.

Decarbonization of Short Sea Shipping in European Union: Impact of market and goal based measures

In July 2021, the European Union (EU) published a package of measures for the decarbonization of maritime transport: Market Based Measures (MBM) and Goal Based Measures (GBM) that will gradually be phased in over 2023. The measures derive from an EU decision taken independently of the International Maritime Organization. This fragmentation of maritime transport governance leads to new working scenarios in the EU that have given rise to concern in the shipping industry. This paper analyzes the monetary consequences of EU decarbonization regulation on Short Sea Shipping (SSS) by introducing a mathematical model to meet this aim. From the application of this model to SSS container vessel operating between the Canary Islands and the Iberian Peninsula, it is found that, although MBM accurately reflect the pollutant impact of SSS vessels in the aftermath of the 2020 Global Sulphur Cap, only GBM along with non-compliance deterrents can redirect the vessels’ investments towards more sustainable solutions in the medium-term.

A Multi-Objective Tri-Level Algorithm for Hub-and-Spoke Network in Short Sea Shipping Transportation

Hub-and-Spoke (H&S) network modeling is a form of transport topology optimization in which network joins are connected through intermediate hub nodes. The Short Sea Shipping (SSS) problem aims to efficiently disperse passenger flows involving multiple vessel routes and intermediary hubs through which passengers are transferred to their final destination. The problem contains elements of the Hub-and-Spoke and Travelling Salesman, with different levels of passenger flows among islands, making it more demanding than the typical H&S one, as the hub selection within nodes and the shortest routes among islands are internal optimization goals. This work introduces a multi-objective tri-level optimization algorithm for the General Network of Short Sea Shipping (GNSSS) problem to reduce travel distances and transportation costs while improving travel quality and user satisfaction, mainly by minimizing passenger hours spent on board. The analysis is performed at three levels of decisions: (a) the hub node assignment, (b) the island-to-line assignment, and (c) the island service sequence within each line. Due to the magnitude and complexity of the problem, a genetic algorithm is employed for the implementation. The algorithm performance has been tested and evaluated through several real and simulated case studies of different sizes and operational scenarios. The results indicate that the algorithm provides rational solutions in accordance with the desired sub-objectives. The multi-objective consideration leads to solutions that are quite scattered in the solution space, indicating the necessity of employing formal optimization methods. Typical Pareto diagrams present non-dominated solutions varying at a range of 30 percent in terms of the total distance traveled and more than 50 percent in relation to the cumulative passenger hours. Evaluation results further indicate satisfactory algorithm performance in terms of result stability (repeatability) and computational time requirements. In conclusion, the work provides a tool for assisting network operation and transport planning decisions by shipping companies in the directions of cost reduction and traveler service upgrade. In addition, the model can be adapted to other applications in transportation and in the supply chain.

Acoustic telemetry reveals the drivers behind estuary–sea connectivity of an important estuarine-dependent fishery species, Pomadasys commersonnii, in the Breede Estuary, South Africa

The spotted grunter Pomadasys commersonnii is an important estuarine-dependent fishery species known to spawn along the east coast (KwaZulu-Natal Province) of South Africa. However, recent evidence suggests that this species also spawns along the southwest coast in the Western Cape Province (WC), which has necessitated the investigation of estuary–sea movements of adult P. commersonnii in the WC, and their link with spawning season and changing environmental conditions. Seasonal gonad maturation of adult P. commersonnii (n = 112) was investigated using histology and the gonadosomatic index. Seven adult P. commersonnii were acoustically tagged and monitored in the Breede Estuary (WC) between November 2016 and March 2020. Tagged individuals spent more time in the estuary (83.5%) than in the adjacent marine environment. Sea trips (n = 90) lasted on average 3.23 (SD 4.55) days (range 1–37 days), with most sea trips (82.6%) having a duration of less than 5 days. The majority of sea trips (>50%) occurred in austral summer, which coincided with the peak spawning season. Increases in estuary water temperatures in summer and river inflow in winter also influenced the presence of tagged fish in the sea. The high degree of residency of P. commersonnii in the Breede Estuary and short sea trips, along with increased frequency of reproductively ripe fish during summer months, supports the conclusion that regional spawning is occurring along the southwest coast. We suggest that management strategies should be put in place to protect the P. commersonnii population along the South African southwest coast, especially during summer, for the recovery of this population.