Introduction
During 2009, the partners of Green Ship of the Future decided to work together on a concept study of so-called ‘low emission ships’. The purpose of the study was to investigate the possible overall emission reductions when the various available technologies from the Green Ship of the Future project were implemented already during the design phase of a new ship.
Studies were carried out for two different ship types, an 8,500 TEU container vessel and a 35,000 DWT handy size bulk carrier. The basis for the container vessel was a A-Type vessel from Odense Steel Shipyard, while the basis for the bulk carrier was a Seahorse 35 bulk carrier from Grontmij|CarlBro with a capacity of 35,000 TDW.
In the concept studies, only available and proven ‘green’ technologies were used, which meant that it was possible to build the ships as specified and documented by the two task-leading companies of the concept studies, Odense Steel Shipyard and Grontmij | Carl Bro.
The concept studies were carried out to benchmark the new technologies in relation to the goal of Green Ship of the Future (reduction of exhaust gas emissions) and in relation to the coming international regulations on NOX and SOX emissions and most probably also CO2 emissions by introduction of the Energy Efficiency Design Index (EEDI) for new ships.
Designing a ship is a very complex process because many aspects and constraints have to be taken into account simultaneously. Very often demands interfere with each other in a negative way so that by fulfilling one demand, another demand cannot be fulfilled or is even counteracted.
This interference means that it is not always possible just to accumulate the savings from each individual technology to get the total possible saving or reduction. In the present summary, focus has been on the following technologies:
•Sulphur scrubber system
•Liquefied natural gas as fuel
•Advanced hull paint
•Waste heat recovery (WHR)
•Water in fuel system (WIF)
•Exhaust gas recirculation (EGR)
•Other main engine technologies
•Optimization of pump and cooling water systems
•Advanced rudder and propeller designs
•Speed nozzle
To ensure that the two concept ships fulfil the relevant Class regulations, all calculations and drawings have been approved by Lloyds Register, and each ship has thus been given a Class Notation.