General Cargo Vessel Research Articles

Artificial Neural Network Approach for Main Engine Power Prediction of General Cargo Vessels

Before the physical constructing of a ship will start, it must first go through a multistage design process. Determining the ship's main engine power is a critical stage in the concept design process. This work established a model to predict for the main engine power of general cargo ships. The model input parameters included ship length overall, breadth, gross tonnage, DWT and ship service speed. In the training stage of the model, Levenberg-Marquardt optimization algorithm was used. After many training attempts with various numbers of hidden neurons, the structure with 22 hidden neurons showed the best performance. R values for the test set were 0.986, 0.988 for validation, and 0.992 for training, according to regression analysis. Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE) values remained consistently low across all normalized datasets, ranging from 0.0128 to 0.0148 for MAE and 0.0178 to 0.0238 for RMSE. These results underscore the model's robust predictive capabilities.

Evaluation of the powering extrapolation of a ship with a gate rudder system, including ageing and fouling effects

This paper is based on the evaluation results of the calm water powering extrapolation of a 90-m general cargo vessel, originally built with a conventional rudder system (CRS) and later retrofitted with an innovative energy-saving device (ESD) known as the Gate Rudder System® (GRS), as part of the EU H2020 Project GATERS. The power estimation of the vessel was conducted using an adapted extrapolation procedure based on the scaled model tests of the vessel in a towing tank, validated by the three sets of sea trials. The first sea trial was performed when the ship was new, while the latter two were conducted during the project timeline, before and after the GRS retrofit. This paper aims to adapt the ITTC-78 power extrapolation method to predict the power performance of a ship retrofitted with the GRS for the first time in the maritime industry. Within this framework, the specific objectives of the paper are to describe and validate the proposed method using relevant power-speed data of the GATERS project target vessel (M/V ERGE) initially equipped with the CRS and later replaced by the retrofit GRS to achieve the project objective. Due to the real-world circumstances of retrofitting a 13-year-old ship with a novel energy-saving device, investigating the effects of ageing, hull roughness, and fouling has also become one of the key objectives of the paper. The findings demonstrate the ageing effect on the target ship's powering performance after retrofitting with GRS, highlighting the need for special consideration of power extrapolation alongside the hull fouling effects. The paper also demonstrates that the GRS is an emerging ESD, as a retrofit beside newly built ships with GRS, which improved the powering performance of the project target vessel, achieving a remarkable 25% power saving based on the comparative full-scale sea trials.

Energy Use and Carbon Footprint Assessment in Retrofitting a Novel Energy Saving Device to a Ship

The Gate rudder system (GRS) was recently introduced as an innovative energy-saving device (ESD) for ships, and it is the most attractive ESD currently used in the market, with double figures of fuel savings in full-scale (>10–35%) compared with a ship with a conventional rudder system (CRS). Although there are few new ship applications of GRS, the recently completed EC-H2020 GATERS project successfully demonstrated its unique energy-saving and manoeuvrability benefits as a “retrofit” solution for an existing general cargo vessel for the first time. The project results suggested that the GRS holds significant potential for retrofitting existing ships to enhance fuel efficiency (~35%) and improve manoeuvrability. Nevertheless, the application was a comprehensive undertaking requiring various work tasks such as component manufacturing, removing existing systems, and modification and upgrading works, with substantial energy consumption and environmental impacts. Therefore, it was insightful to study energy use and environmental impacts in a GRS retrofit process. This study developed and implemented a comprehensive energy consumption and carbon footprint assessment framework for the GRS retrofit in the GATERS project. A detailed assessment of energy consumption and related carbon emissions was performed during the major stages of manufacturing, system removals, and modifications and assembly in the GRS retrofit. Also, the potential savings in energy use and emissions were addressed. The results demonstrated that the manufacturing stage was the most energy-intensive phase, being responsible for 91.4% of total electricity and 46.7% of fuel-based thermal energy use. The system removals accounted for 53.3% of the fuel-based thermal energy, whereas the modification and assembly work accounted for about 7.7% of the total electricity use. Additionally, various measures such as clean electrification, energy efficiency, mould/tool reuse, and component reuse to reduce the energy consumption and related carbon emissions in future GRS retrofit applications were addressed and discussed together with their reduction potentials.

Effect of fuel prices on sailing speeds in short-sea shipping

ABSTRACT In this paper, we estimate fuel price elasticities of sailing speed for general cargo vessels using data covering the Baltic Sea and Norwegian coastal areas during the years 2007–2018. To disentangle the correlation between fuel prices and freight rates arising from changes in global demand, we instrument fuel prices on price changes triggered by supply shocks. The shocks are derived from the structural vector autoregressive (SVAR) model proposed by Kilian (2009). In a sensitivity analysis, we use unanticipated oil supply shocks derived from oil supply outages as an alternative instrument for fuel prices. We find that disregarding the correlation between fuel prices and freight rates yields biased parameter estimates, which can partly explain the mixed results in the previous literature. Our preferred estimate for the fuel price elasticity of speed is −0.08.

Model-based Parametric Study for Comparison of System Configurations and Control of a Hydrogen Hybrid Cargo Vessel

The current state of research in marine energy systems has concentrated on conventional diesel systems, while limited literature is available on the configuration and control of alternative energy sources such as hydrogen hybrid systems, which have attracted increasing interest recently owing to the energy transition. This paper presents a modelling and control study for conceptual retrofitting of a general cargo vessel to a hydrogen-hybrid version. Generic fuel cell, battery, and converter models are used, enabling easy adaptation to various powerplant sizes and ship types. A robustly coordinated Energy Management Strategy (EMS), which can be implemented for different vessel’s power profiles, was developed for power sharing, DC bus voltage control, and battery State of Charge (SoC) regulation. The total installed fuel cell power and battery capacity were heuristically selected from a range of power profiles of the ship. A database of fuel cells with stacks from different manufacturers was created to test different combinations in terms of fuel consumption, cost, and weight, based on the framework of the problem. Uncertainties in terms of fuel prices are presented using normal distribution graphs. The system configurations and control results are presented for one power profile of the vessel and the average fuel costs. It is demonstrated that with the proposed control method, the power losses are less than 1%, the DC bus voltage fluctuations are less than 0.5%, and the battery SoC remains between 35-65% for the entire duration of the analysed power profile. The configuration with eight stacks of 150 kW has the lowest total fuel cost (730 $) with an average difference of 7.1% from the other solutions, and the lowest total weight (10.54 tons) with an average difference of 15.4% from the other configurations. Overall, this study demonstrates the efficient configuration and control of hybrid energy systems using parameterized components.

A Geographic Information System (GIS)-Based Investigation of Spatiotemporal Characteristics of Pirate Attacks in the Maritime Industry

Maritime transportation is vital for the movement of cargo between different continents and distant locations but can be disrupted by the frequent occurrence of pirate attacks. Based on the pirate attacks from July 1994 to December 2019, a spatial analysis of pirate attacks using a Geographic Information System (GIS) was conducted in the present study using the data available for tankers, dry bulk carriers, container vessels, general cargo vessels, and tugs. The adoption of the kernel density analysis was intended to identify the spatial pattern of global pirate attacks. The research results demonstrated that the pirate attacks showed a clustering pattern and were mostly associated with areas experiencing economic depression, a high unemployment rate, and social unrest. Accordingly, spatiotemporal hot spot analysis was carried out to recognize the changing directions of cold spots and hot spots over a period of time. The waters off Somalia, the Strait of Malacca, the Philippines, the Bay of Bengal, the Gulf of Guinea, and the northwest of South America were found to be the common locations of pirate attacks. The cold and hot spots of pirate attacks on the three key vessel types, including tankers, dry bulk carriers, and container vessels, were found to be similar. When considering the same area, the trends of cold and hot spots of different vessel types being attacked were substantially different. This study can provide a useful guideline for the International Maritime Organization and other relevant organizations in the world to design and implement targeted strategies to combat and mitigate pirate attacks. Additionally, the introduction of a GIS may help to envision the spatial and temporal distribution of pirate attacks and to explore the characteristics of pirate behaviors at sea and the patterns of piracy.

Retrofitting the Bow of a General Cargo Vessel Andevaluating Energy Efficiency Operational Index

Abstract This report examines the feasibility and impact of retrofitting the bulbous bow on a general cargo ship, in terms of the energy efficiency operational index (EEOI), in the areas of Western Europe and the Eastern Mediterranean. Three ship forms were developed and analysed: with a bulbous bow, without a bulbous bow, and with a modified bulbous bow. The goal in developing the ship forms and conducting the analysis was to achieve minimal differences in the ship’s characteristics with the same volumetric displacement, aided by PolyCAD software. A route was selected between two ports: Varna and Rotterdam. The labour intensity of the bulbous bow retrofitting process was evaluated and approximate values of labours costs and cost for the task were determined. The results obtained for resistance during ship motion, EEOI, and fuel consumption reductions, or increases, were compared against the retrofitting values. The return cost of retrofitting is evaluated and measured in terms of fuel saved.

Fleet Ownership Model for Mineral Export Products Concerning Indonesia’s Downstream Mineral Policy: A Case Study of Copper Ore Exports

Indonesia’s copper ore has a contribution of 3% in the world’s copper ore needs and has rank of the 5th largest export of mining materials after briquette, kerosene, coal, and crude oil. According to Mineral and Coal Mining Law Number 4 of 2009 that raw materials of mining products have been prohibited to be exported including copper ore due to increasing the value of mineral export products. Thus, it would affect to the current copper ore shipment, which should firstly be processed by smelter to be work-in-process products, namely cathodes. In order to comply with the downstream policy, this study aimed to select the optimum vessel used for delivering copper ores to smelter as well as to define the minimum unit cost for transporting cathodes from smelter to importing countries. The method of non-linear programming was used to produce the minimum unit cost of transport for these three scenarios of fleet ownership model: (1) charter vessel, (2) new shipbuilding vessel, (3) second-hand vessel. The results obtained that the selected domestic ship was a new shipbuilding scenario with the type of bulk carrier, transporting copper ores from site to smelter. Meanwhile, the selected export ship was a voyage charter scenario with the type of general cargo vessel, delivering cathodes from smelter to importing countries.

Cost–Benefit Analysis of a Trans-Arctic Alternative Route to the Suez Canal: A Method Based on High-Fidelity Ship Performance, Weather, and Ice Forecast Models

Climate change in recent years has produced viable shipping routes in the Arctic. However, critical uncertainties related to maritime operations in the Arctic make it difficult to predict ship speeds in ice and, thus, the voyage time and fuel costs. Cost–benefit analysis of alternative Arctic routes based on accurate environmental condition modeling is required. In this context, this paper presents a holistic approach that considers the major voyage-related costs of a trans-Arctic route as an alternative to the conventional routes via the Suez Canal Route (SCR) for existing merchant ships. This tool is based on high-fidelity models of ship performance, metocean forecasting, and a voyage optimization algorithm. Case studies are performed based on a general cargo vessel in operation to quantify realistic expenses inclusive of all the major operational, fuel, and voyage costs of the specific voyages. A comparison is made between the total costs of the trans-Arctic route and SCR for different seasons, which proves the economic feasibility of the trans-Arctic route. Overall, this work can provide valuable insights to help policymakers as well as shipbuilders, owners, and operators to assess the potential cost-effectiveness and sustainability of future Arctic shipping, thereby better developing future strategies.

HYDRODYNAMICS PERFORMANCE PREDICTION OF A FULL-SCALE SHIP

Traditionally, ship hydrodynamic performances are predicted by extrapolating the model scale measurements or numerical results to full scale. Recently, scientific publications have highlighted the importance of ship scale numerical simulation and its validation. CFD may be used to determine the main reasons for the poor performance of vessels in operation and to evaluate the efficiency of energy-saving solutions that enhance the vessel's hydrodynamics and aerodynamics. Lloyd’s Register (LR) held the world's first workshop dedicated to ship full-scale hydrodynamic performance predictions, where the industry has published comprehensive measurements obtained during the sea trials to offer the community the chance to validate the CFD solvers for full-scale computations. This paper focuses on the numerical investigation of the full-scale general cargo vessel REGAL. NUMECA/Fine Marine commercial code based on the RANS-VOF solver has been used to evaluate the flow field around the hull. Four speeds were considered for this investigation: 8, 10, 12, and 14 knots, and the simulation conditions, identical to the sea trials records, were also taken into consideration. The simulation results were compared to the data provided by LR in 2015 in the workshop proceeding.

Analisys of Hull Shape Art, Speed, Resistance, Power Using Holtrop Method On A Vessel With DWT 12,335 Ton

A general cargo vessel carries various kinds of cargo in the form of goods. The goods transported are usually packaged goods. General cargo vessels are equipped with cargo cranes to facilitate the loading and unloading of cargo. This study aims to determine the relation between speed, resistance, and power using the Holtrop method on vessels with a DWT of 12,335 Tons. The ship was modelled using shipping software, and then validated the results with Holtrop mathematical calculations. Holtrop method for calculating tankers, general cargo, fishing vessels, tugs, passengers, containers, and frigates By using the main dimensions of the ship with Length Over All (LOA) 129.8 m, Length Between Perpendicular (LBP) 110 m, Length On Load Waterline (LWL) 112.75 m, Breadth (B) 18 m. height (H) 9 m, Draft (H) 7.2 m, Speed (V) 12.5 Knots. Tests were carried out on Maxsurf Software by calculating resistance and obtaining a graph that displays the relationship between power and speed and resistance and speed.

Photovoltaic Potential of the Dutch Inland Shipping Fleet: An Experimentally Validated Method to Simulate the Power Series from Vessel‐Integrated Photovoltaics

The surface of the vessels, as moving tiny islands, can be utilized to implement vehicle‐integrated photovoltaics (VIPV). Herein, a methodology is reported to calculate the power generated by a fleet of urban vessels as a function of time. Then, the result is shown for the largest European shipping fleet, using sailing data of 2746 Dutch general cargo vessels. Results show that the studied fleet can produce ≈ 226 GWh of energy per year, which corresponds to ≈ 6.5% of the whole fleet's energy demand. Next, this research validates the model with three week experimental data gathered by a test vessel sailing through the Netherlands. The validation phase reveals that the model can predict within a 4% error range. Finally, as an interesting finding, it is experimentally shown that the energy production profile of a fleet of urban vessels follows a Weibull distribution, quantified by scale (λ) and shape (k) parameters: λ = 880 Wh Wp−1 and k = 27 for the Dutch fleet. A sensitivity analysis shows that the parameters of the Weibull distribution are a function of urban fabric roughness and the climate. Such probability distribution can be extended to other urban fleets, such as solar cars, and help estimate the financial feasibility of integrating PV into vehicles.

Analisys of Hull Shape Art, Speed, Resistance, Power Using Holtrop Method On A Vessel With DWT 12,335 Ton

A general cargo vessel carries various kinds of cargo in the form of goods. The goods transported are usually packaged goods. General cargo vessels are equipped with cargo cranes to facilitate the loading and unloading of cargo. This study aims to determine the relation between speed, resistance, and power using the Holtrop method on vessels with a DWT of 12,335 Tons. The ship was modelled using shipping software, and then validated the results with Holtrop mathematical calculations. Holtrop method for calculating tankers, general cargo, fishing vessels, tugs, passengers, containers, and frigates By using the main dimensions of the ship with Length Over All (LOA) 129.8 m, Length Between Perpendicular (LBP) 110 m, Length On Load Waterline (LWL) 112.75 m, Breadth (B) 18 m. height (H) 9 m, Draft (H) 7.2 m, Speed (V) 12.5 Knots. Tests were carried out on Maxsurf Software by calculating resistance and obtaining a graph that displays the relationship between power and speed and resistance and speed.

A novel tool for cost and emission reduction related to ship underwater hull maintenance

International shipping plays a vital role in the world's transport system and economy. However, shipping faces challenges in terms of reducing its environmental and health impact, namely emission of greenhouse gases, air pollutants, and chemical substances to the marine environment. In particular, the roughness condition of underwater surfaces of a ship hull affects the ship's energy efficiency, with marine growth (biofouling) and mechanical roughness leading to propulsion powering penalties. Measures to control biofouling, using antifouling coatings and in-water hull cleaning, may also be associated with significant impacts to the marine environment. In the current study, a new tool is presented, HullMASTER (Hull MAintenance STrategies for Emission Reduction), which aims at enabling the shipping industry and authorities in the Baltic Sea region to make evidence-based decisions on hull maintenance strategies. HullMASTER simulates emissions to air and water, to calculate the differences in economic cost for operators, as well as health- and environmental damage costs between different hull maintenance scenarios. Validation of HullMASTER predictions against 40 vessel-years of in-service performance data on propulsive performance, with operations in the Baltic Sea region, shows good agreement, averaging within 5 percentage-point difference in propulsion penalty. Further, a scenario-based demonstration of HullMASTER on a general cargo vessel shows that, in the comparison between a silicone foul-release coating and business-as-usual scenario of a biocidal coating, retrofitting the coating to a foul-release coating can result in significant savings for society, i.e., along with marginal savings in cost for ship operators. Results for such comparisons and analysis will however be dependent on specific vessel cases and operational profiles, thence the value of an interactive tool such as HullMASTER.

Оценка технической возможности перевозки плодоовощной продукции морским транспортом между портами Каспийского моря

The modern process of fruit and vegetable transportation between countries depends not only on geographical, but also on political and economic factors, which makes for searching more efficient and shorter routes. The availability of such a transport opportunity as sea transportation between the ports of the Caspian Sea makes it possible to analyze new routes for the product transportation from Iran, Azerbaijan and other countries to Russia using dry cargo vessels that are currently used as the general cargo vessels. There have been analyzed the new routes for transportation of perishable products in refrigerated containers and assessed the possibility of their transportation on the “Volga” type bulk carriers. The routes “Astara (Azerbaijan) - Moscow”, “Astara - port Alat - port Kuryk - Moscow” have been illustrated. A general arrangement drawing of a “Volga” type dry cargo vessel (project 19610) is presented, the photographs of transporting timber and containers on the decks of dry cargo vessels are given. Calculating the load of the dry cargo ship’s power plant has shown a technical possibility of transporting 16 refrigerated containers on deck of the “Volga” type vessel without changes in the design of the ship’s power plant. Conclusions are made about the need to develop effective cargo transportation by waterways in modern conditions of the loss of traditional Russian suppliers of fruit and vegetable products, about the possibility of additional use of dry cargo ships, as well as the feasibility of developing a backup diesel generator for emergency power supply of deck refrigerated containers in connection with a possible increase in the capacity of the ship power plant.

Ship building design of general cargo vessel using comparator ship method in port route of Jakarta-Makassar-Manokwari

Marine-based industrial development includes several sectors including Sea Transportation Services, Ferry Services, Capture Fisheries, Offshore Oil & Gas, Marine Biological Resources, Marine Tourism, and Energy Conversion, which in general both management and operations require supporting facilities, namely ships. with certain types that can serve these interests. During the current economic recovery period, there need to be concrete and more innovative steps that must be pursued by all parties, both government and private, in order to reduce the time needed to improve the state’s economic condition. Hence, the role of marine potential is very vital to be further developed in the future. The optimization results of the comparison ship obtained the main dimensions of the design vessel, namely: Lbp = 81.19 m, B = 15.00 m, T = 5.50 m, H = 7.00 m, Cb = 0.75, Cm = 0.99, Cw = 0.84 Cpv = 0.89, Cph = 0.76, Fb = 1.50 m, Fn = 0.22, Displacement = 5280.91 tons, Volume = 5131.583 m3, GRT = 3910 tons, Vs = 12 knots, Lwl = 83.22 m. This comparator ship method makes it easy for ship designers with accurate results.

Estimation of Vessel Passage Through Bosphorus

The Bosphorus is a heritage from the past to the present with its natural, historical and cultural features. Vessels passing through the Bosphorus, which is a narrow waterway, create a risk in Istanbul Strait. Thousands of vessels carrying dangerous cargoes pass through the Bosphorus every year. In this study, the changes in the cargos carried by these vessels and number of vessels over years are examined. It is seen that approximately 44000 vessels per year have passed through considering the last decade. The data of Ministry of Transport and Infrastructure, General Directorate of Marine between the years 1995 and 2020 has been used to estimate the change of the number of the vessels for five years period. Although the estimation show that the vessels numbers will decrease with an estimation of ~32,250 vessels for the year 2025, the total gross tonnage will increase in the future years. The results show that, while the number of bulk carrier vessels, livestock carriers, passenger ships and refrigerated cargo carriers will increase, the number of general cargo vessels will decrease in the future years.

The Role of Liner Shipping Services in Small and Medium Sized

The Liner services provides regular shipments of goods between ports within the set timeframe. A fixed route, the obligation of receiving cargo and to go to sea with established schedule distinguishes line service from the sea transportation of bulk cargo. Containerization, establishment and improvement of routes and infrastructure helped liner shipping to become the driving force of Global economy, which supports the growth of international trade, development of different business forms such as mainly small and medium sized businesses. The shipment volume of containerized cargo was 37.1 M.TEU in 1994, by 2020 the figure reached up to 143.3 M.TEU. This indicator was growing at a high rate on East-West route during 1990-2016; In terms of North-South, South-South and intraregional route same measure was high between 1990-2004 years. Afterwards, Abovementioned growth has become more stable. Containerization changed the structure of Liner fleet. If general cargo vessels deadweight was growing during 1970-2010 (From 40.5M Dwt to 99.7M Dwt), in the latest 10 years, the tonnage has been decreasing and as for 2020 it was 74.6M Dwt. In exchange for this the number of container ships have been growing consistently and in 2020 it consisted of 274.7M Dwt. Maersk became the largest line operator since 2001 (with a market share of 9.4%) and by 2020 it’s share of the business has grown to 17%. The company owns container terminals worldwide, including the Poti container terminal. MSC is on second place (9.4% market share), COSCO is on third place (12.4%) and CMA CGM takes forth place (11.8%). Keywords: Liner Shipping Services, Containerization, East–West routes, North–South routes, Intraregional routes, General cargo ship, Containership, Liner operator, Container port.

Techno-economic assessment of advanced fuels and propulsion systems in future fossil-free ships

This paper analyses the potential of renewable fuels in different propulsion systems for the maritime sector that can replace fossil fuels by 2030. First, a fuel cost analysis is performed for a range of biofuels, bio-electrofuels, electrofuels plus liquid hydrogen and electricity in 18 fuel production pathways. Next, fuel production costs are combined with different utilisation rates, propulsion cost, on-board fuel storage cost and a cost for reduced cargo space to determine the total cost of ownership for four types of ships: large ferries, general cargo, bulk carriers and container vessels using internal combustion engines, fuel cells or battery-electric propulsion systems and travelling different distances.In large ferries, the battery-electric propulsion is found at a lower cost than all fuel options except biofuels. For the other ship types, cheaper fuels (as biofuels) benefit internal combustion engines, while expensive fuels (as electrofuels) increase the competitiveness of fuel cells due to their higher efficiency. Similarly, low utilisation rates benefit internal combustion engines, while higher utilisation rates tend to support fuel cells. General cargo vessels have a similar total cost of ownership for both four-stroke internal combustion engines and fuel cells. Bulk carriers and container ships use two-stroke engines, with efficiencies closer to fuel cells, but the lowest-cost solution remains internal combustion engines, except when increasing the efficiency or reducing the investment cost of fuel cells. In almost all fuel-propulsion combinations, methanol is the lowest-cost fuel, but dimethyl ether and ammonia show only marginally higher costs.

Simulation strategy of the full-scale ship resistance and propulsion performance

The ship powering performance can be predicted based on model tests or simulations. However, differences exist between the full-scale ship performance and extrapolated model data. Therefore, research on full-scale ship performance simulation has important scientific significance and engineering value. This study used the REGAL general cargo vessel to perform full-scale ship resistance and self-propulsion simulations for various grid numbers, time step sizes, and wall Y+ values and compared the calculation and empirical results. The resistance components, waveform, Courant–Friedrichs Lewy (CFL) number, pressure field, and wake flow field of various resistance simulation conditions were analysed. The wall Y+ value was observed to affect the capture of boundary layer flow, ship pressure field evolution, and waveform, which subsequently affect the ship resistance. A Y+ value within 200 was considered to be appropriate when simulating the powering performance of a full-scale ship. The waveform evolution was significantly affected by the time step size, which should meet the requirement that the CFL number on the free surface is less than 1. When simulating the self-propulsion of a full-scale ship based on sliding mesh, the CFL number on the interface should also be less than 1. Additionally, to obtain the correct propeller excitation force, it was recommended that the time step size be maintained below 1°/step (0.000076 LPP/v).