The 2012 guidelines on the method of calculation of the attained Energy Efficiency Design Index (EEDI) for new ships (MEPC.212(63)) represent a major step forward in implementing the REGULATIONS ON ENERGY EFFICIENCY OF SHIPS (resolution MEPC.203(62)) through the introduction of a series of specifications for calculating the EEDI for various types of ships. There are, however, serious concerns regarding the sufficiency of propulsion power and of steering devices to maintain the manoeuvrability of ships in adverse conditions, hence the safety of ships, assuming that the ship marginally passes the relevant EEDI criterion. This gave reason for additional considerations and studies at IMO (MEPC 64/4/13 and MEPC 64/INF7). Furthermore, whereas present EEDI regulations concern the limitation of toxic gas emissions by ship operation, what may be understood as a new constraint in ship design and operation, it is urgent to look holistically into integrated ship design and operational environments and implement multi-objective optimization procedures optimising ship’s powering while ensuring safe ship operation, but at the same time looking for the right balance between ship’s efficiency and economy, safety and greenness.
To this end, a consortium was put together representing the whole spectrum of stakeholders in the maritime industry and with superior expertise and scientific know-how in hydrodynamic tools development, validation of software tools, experimental techniques and expertise in ship design and international maritime rule making.
The aim of the proposed research project is to address the above raised issues by:
Further development and refinement of existing high fidelity, hydrodynamic simulation software tools for the efficient analysis of the seakeeping and manoeuvring performance and safety of ships in complex environmental and/or adverse sea/weather conditions (including the consideration of winds and extreme sea events). The efficiency of steering devices and the effect of restricted waterways in port areas will be considered. Extensive use will be made of state-of-the-art numerical simulation tools available to the consortium, which will be adapted to the needs of the project and be supported by a comprehensive model testing programme.
Performing seakeeping/ manoeuvring model tests in combined seaway/wind environment by use of a series of prototypes of different ship types (offshore supply vessel, bulk carrier, tanker, containership, RoRo ferry), to provide the required basis for the validation of employed software tool and the results obtained by numerical simulations. Full scale measurements available to the consortium will be exploited for the validation of tools and scalability of model tests.
Integrating validated software tools for the hydrodynamic/manoeuvrability assessment of ships in adverse seaway/weather conditions into a ship design software platform and set-up of a multiobjective optimization procedure in which ship’s performance is assessed holistically, thus, looking for the minimum powering requirement to ensure safe ship operation in adverse seaway/weather conditions, while keeping the right balance between ship economy, efficiency and safety of the ship and the marine/air environment.
Putting together design teams that comprise designers, shipyards, owners and class societies to conduct investigations on the impact of the proposed new guidelines for the assessment of the minimum propulsion power to maintain manoeuvrability in adverse conditions (MEPC 64/4/13) on the design and operational characteristics of various ship types. To investigate in parallel the impact on EEDI by implementation of the developed integrated/holistic optimisation procedure in a series of case studies. Herein, to assess in addition ship types currently not covered by the EEDI provisions, like tugs and Offshore Support Vessels.
Development of new guidelines for the required minimum propulsion power and steering performance to maintain manoeuvrability in adverse conditions. Establishing minimum propulsion power and likely new EEDI requirements ensuring safe operation for various types of ships. Preparing and submitting to IMO a summary of results and recommendations for further consideration (end of project, year 2016).