Ship lifecycle

With growing concerns of marine pollution, the International Maritime Organization (IMO) has recently adopted a new Resolution MEPC.304 (72), presenting a strategy on curbing greenhouse gas emissions (GHGs) from shipping. Along with this, a series of stringent regulations to limit emissions from shipping activities has been produced at both the international and local level. Such ambitious regulatory works urge us to trust that cleaner production and shipping is one of the most urgent issues in the marine industry

Application of solar panel array on a short route ferry : a life cycle and economic assessment

Green technologies are considered to be one of the most significant way to mitigate the severe global warming effect and have been drawing attentions from researchers all over the world. Solar energy is a type of renewable energy and solar panel array can capture and convert solar energy to electricity for domestic and industry uses. This paper considers the application of solar panel array to propulsion system of a short route ferry operating in the Marmara Sea where currently no environment protection policy is active to guide marine activities. The evaluation of the application is carried out using life cycle assessment from the aspect of cost effective and environment friendly. To take the payback time of the system into account, this study investigate the difference due to different average daily sunny hours in the operating area considering three levels of carbon credits. The results indicates both average daily sunny hours and carbon credits have an impact on the payback time. With the highest average daily sunny hours and carbon credits, the payback time of the application is only 2 years

Life cycle and economic assessment of a solar panel array applied to a short route ferry

This paper was to investigate the potential benefits of solar panel systems if applied for obtaining propulsion power of a short route ferry operating in the Marmara Sea. The life cycle assessment was applied to evaluate the long-term environmental impact of the solar power systems on-board in replace of conventional diesel engine systems. The cost and benefit of such systems were evaluated through the economic assessment where the life cycle cost relative to installation, operation and recycling of the solar panels, fuel savings and payback time were considered. Research findings revealed the payback time would be around three years, whereas the accumulative fuel cost saving would be over $300,000 by the end of vessel life. The sensitivity analysis using two varying parameters - energy efficiency and investment cost - implied, that the longer payback time would be positively associated with lower energy efficiencies and higher investment costs. It was also suggested that the marginal cost of the carbon credit should be$ 190 per tonne or higher to make the shipping business successful

Comparative safety analysis of engine room fires with different marine fuels of MGO, LPG and H2

This research project is designed to investigate the behaviour of fires resulting from hydrogen leakage in engine rooms and evaluate the associated fire risks, aiming to compare these risks with those posed by traditional fuels which can be used in the shipping industry today. The study employs a model of the engine room constructed according to the original dimensions of the vessel under study. The primary objective of this research was to determine if the fire risk associated with hydrogen would be higher or lower than that of traditional fuels. To achieve this, a series of simulation scenarios were meticulously executed and subsequently analysed. The outcomes of the simulations indicate that hydrogen fires do not present a higher threat when compared to fires fuelled by marine gas oil or liquefied petroleum gas. Notably, hydrogen exhibits superior fire behaviour, characterized by the absence of smoke development and relatively less harm to machinery and crew, thus outperforming conventional fuel fires. This finding suggests that hydrogen-related fire risks can be brought under control and highlights its potential as a comparatively safe fuel choice in the maritime domain

Evaluation of the lifecycle environmental benefits of full battery powered ships : comparative analysis of marine diesel and electricity

The paper aims to investigate the holistic environmental benefits of using a battery system on a roll on/roll off (ro-ro) passenger ship which was originally fitted with a diesel engine engaged in Korean coastal service. The process of this research has multiple layers. First, the operating profiles of the case ship were collected, such as speed, output, operation time and the configuration of the diesel propulsion system. Second, the full battery propulsion system, in place of the diesel system, was modelled and simulated on a power simulation software (PSIM) platform to verify the adequacy of the proposed battery propulsion system. Then, the life cycle assessment method was applied to comprehensively compare the environmental footprint of the diesel-mechanical and fully battery-powered vessels. A focus was placed on the life cycle of the energy sources consumed by the case ship in consideration of the South Korea’s current energy importation and production status. Three life cycle stages were considered in the analysis: ‘production’, ‘transport’ and ‘use’. With the aid of Sphera GaBi Software Version 2019 and its extensive data library, the environmental impacts at the energy production and transport stages were evaluated, while the same impacts at the use stage were determined based on actual laboratory measurements. The environmental performance of the two scenarios in four impact categories was discussed: global warming potential (GWP), acidification potential (AP), eutrophication potential (EP) and photochemical ozone creation potential (POCP). Results of the comparative analysis are presented based on estimates of the overall reduction in the environmental impact potential, thereby demonstrating the overall benefits of using a battery driven propulsion, with a decrease of the GWP by 35.7%, the AP by 77.6%, the EP by 87.8% and the POCP by 77.2%. A series of sensitivity analyses, however, has delivered the important message that the integration of batteries with marine transportation means may not always be the best solution. The types of energy sources used for electricity generation will be a key factor in determining whether the battery technology can ultimately contribute to cleaner shipping or not. By casting doubts on the benefits of battery propulsion, this paper is believed to offer a meaningful insight into developing a proper road map for electrifying ship propulsion toward zero emission of shipping

Comparative safety assessment of LNG re-liquefaction systems applied on LNG carriers

This research was aimed to evaluate the safety of the LNG cargo compressor room against unwanted gas leakage from two different re-liquefaction systems applicable for an LNG carrier: 1) the Partial (Full) Re-liquefaction System (P(F)RS) and 2) the combination of Partial Re-liquefaction System and Mixed Refrigerant Re-liquefaction system (PRS+MRS). To achieve this goal, quantitative risk assessment was carried out with the integration of system hierarchical modelling, statistical analysis, and CFD simulation. The frequency of initial leakages, occurring to each component of the re-liquefaction systems, was analysed, whereas for the consequence analysis, a CFD program of PyroSim was employed to simulate the gas dispersion in the confined room fitted with mechanical ventilation systems. In addition, various ventilation capacities were investigated with changes in their allocations in the room in order to determine these parametric influences on the results. The risk level of re-liquefaction systems was determined in a quantitative way. Research results clearly presented the importance of the proper arrangement of the ventilation systems. The risk levels were estimated at 5.6 E-3/year for P(F)RS whereas about 9.6 E-3/year for the PRS+MRS in consideration of current regulations. However, the increase in the ventilation capacity was found to reduce the risk levels. The research findings are highly believed to offer meaningful guidance into future safety regulatory frameworks

Investigation on toxicity of ammonia releasing from storage tank onboard through CFD simulations

This study investigates potential risks associated with ammonia releases from a case ship to be constructed in a Korean Shipyard and operated in Korean coastal areas. The focus is on understanding how ammonia disperses from the onboard storage tank's Vent Master and the associated toxic zones. Numerical simulations using CFD tools (Pyrosim and Starccm++) were employed to model ammonia gas dispersion scenarios. The study revealed that if the safety valve opens, the high internal pressure of the ammonia tank could release a significant amount of ammonia (100%) through the vent mast. Thus, determining the position and height of the vent mast is crucial for safety design. Simulations showed that even if ammonia is released at sea through the vent mast, it poses minimal risk to nearby residential areas. The vent mast, positioned at least 4 meters above the ship's deck, ensured rapid gas dispersion, reducing the chance of human exposure. However, the study suggests that safety analyses should be more extensive for larger ships with larger ammonia tanks and vent mast releases. The findings aim to enhance the safety design and operation of ships, providing valuable reference material for policymakers, regulators, engine manufacturers, and ammonia suppliers, ultimately contributing to the establishment of safe ship design and construction practices in the future

Investigation on marine LNG propulsion systems for LNG carriers through an enhanced hybrid decision making model

Since the use of LNG as an alternative fuel has drawn increasing attention from the marine industry, this paper aimed to evaluate three competitive LNG fuelled engine systems: ultra-steam turbine, four-stroke medium speed engine, and two-stroke low-speed engine systems. To achieve this goal, the paper developed an enhanced hybrid decision-making model which was applied to integrate the economic, environmental and technical performance of these systems. This model can be represented as a semi-quantitative multi-criteria decision making process in combination of several novel techniques, particularly ‘life cycle cost assessment’ for economic analysis, ‘life cycle assessments’ for environmental analysis, ‘fuzzy order preference by similarity to ideal solution’ for technical analysis and ‘fuzzy analytic hierarchy process’ for multi-criteria decision making. A case study with a 174K LNG carrier has revealed that the two-stroke low-speed engine system is the most effective overall and suggested that this type of engine system will hold the lead over the other candidates in the large LNG carrier market. It has also demonstrated the effectiveness of the proposed model to improve the inherent subjectivity in existing qualitative multi-criteria decision-making processes by guiding the overall process in a more objective direction. Finally, this paper has revealed an underlying novelty of the proposed model to enhance the level of confidence level in the decision by expanding our short-term perspective to the holistic one

Decision-making for cable routing at detailed ship design through life cycle and cost assessment

This paper was to establish a practical approach to evaluating economic and ecofriendly designs for cable arrangement on the deck-side of offshore vessels. Three credible options were identified: acableway arrangement on the main deck alone; the arrangement using both the main deck and passageways; and the arrangement using passageway alone. Each design option was investigated, and their economic and environmental impacts were quantified in aholistic view by Life Cycle and Cost Assessment. The economic and environmental impacts were normalized into monetary values to evaluate the best design option overall. Results revealed that the cableway arrangement using only passageways was the best solution, showing that the total cost of the design was estimated at 308,573 USD, which was 130,010 USD less than the cost of the worst option using only the main deck. The case study proved the effectiveness of the proposed approach to determine an optimal design from avariety of choices, which offers insight into current problems that have underestimated the influence of ship designs on environmental impact. In order to enhance the cleaner production, the proposed approach can be widely applied to every part of shipbuilding such as designing of hull, piping and outfitting

Life cycle cost analysis for Scotland short sea ferries

The pathway to zero carbon emissions passing through carbon emissions reduction is mandatory in the shipping industry. Regarding the various methodologies and technologies reviewed for this purpose, Life Cycle Cost Analysis (LCCA) has been used as an excellent tool to determine economic feasibility and sustainability and to present directions. However, insufficient commercial applications cause a conflict of opinion on which fuel is the key to decarbonisation. Many LCCA comparison studies about eco-friendly ship propulsion claim different results. In order to overcome this and discover the key factors that affect the overall comparative analysis and results of the maritime field, it is necessary to conduct the comparative analysis considering more diverse case ships, case routes, and various types that combine each system. This study aims to analyse which greener fuels are most economically beneficial for the shipping sector and prove the factors influencing different results to LCCA. This study was conducted on hydrogen, ammonia, and electric energy, which are carbon-free fuels among various alternative fuels that are currently in the limelight. As the power source, PEMFC and Battery were used as the main power source, and the solar PV system was installed as an auxiliary power source to compare economic feasibility. Several cost data for LCCA were selected from various feasible case studies. As the difficulty caused by the storage and transportation of hydrogen and ammonia should not be underestimated, in this study, LCCA considers not only the CapEx and OpEx but also fuel transport costs. As a result, fuel cell propulsion systems with hydrogen as fuel proved financial effectiveness for short-distance ferries as more inexpensive than ammonia-fuelled PEMFC and batteries. The fuel cost takes around half of the total life cycle cost during the lifetime span