Insights: Getting Ahead with EEDI: BV Provides Guidance
IMO’s Energy Efficiency Design Index is intended to improve energy efficiency of ships at the design stage. It will be mandatory for new ships contracted for construction or major modifications after 1 January, 2013 or delivered after 1 July, 2015. Forward looking shipyards need to gear up for that change now and have designs ready which will give ships a competitive edge in a market where energy efficiency will matter more than it has for a long time. Bernard Anne, managing director of Bureau Veritas (4BV.F)’ Marine Division, weighed in recently with MarPro on the best way forward.
Anne reported to MarPro in July, “The better yards and owners are looking beyond today’s difficult times and preparing for the next generation of vessels. They will be defined by two issues; the implementation of the Harmonized Common Structural Rules and energy saving. That is why it is important for class to be fully up to speed with all the changes that harmonizing the common structural rules will bring in, and also to be able to advise yards now on the EEDI of new designs. Our attestation of the EEDI performance of new designs will help give yards and owners confidence in ordering new tonnage.”
Timelines and Deadlines
The interim guidelines for voluntary certification of the EEDI (MEPC 1. Circ. 682) allow new designs of ships contracted before the above date to be verified against the EEDI, provided that all rules and criteria of MARPOL Annex VI are strictly and fully verified. These include model tank test, sea trial measurements and results, light weight and displacement checks and the correct calculation methodology.
Earlier this year Bureau Veritas issued its first attestation of compliance with EEDI to the ultramax geared bulk carrier JS Amazon; the lead ship in a new generation of CROWN63 vessels developed by China’s Sinopacific Shipbuilding Group with the bulk carrier expert Setaf-Saget.
The 63,300 dwt vessel is designed for the carriage of bulk cargoes, including coal, iron ore, grain and cement, as well as a range of dangerous cargoes. Its GHG (Green House Gas) performance when measured in accordance with IMO’s Energy Efficiency Design Index is twenty percent better than the requirement under MARPOL Annex VI and already reaches the Phase II requirement set for the years 2020/2024. Its deadweight was achieved as a result of an advanced design fully compliant with the Common Structural Rules. The vessel can carry 5.2 per cent more cargo than other bulk carriers of comparable size.
Says Anne, “This vessel marks the start of a new series of ships which will be exemplary contributors to a greener and cleaner world; shaping the future image of shipping. It also represents a celebration of the achievement of outstanding new design concepts and the re-enforcement of strong and successful, long-established levels of cooperation. Bureau Veritas, Sinopacific Shipbuilding Group and bulk carrier expert Setaf-Saget have been working together for many years in the best kind of partnership – one built on trust and a long-term commitment to shipbuilding quality and innovation. BV has been delighted to work with Greenseas, the in-house design office of the Sinopacific Group, which has a proven ability to deliver high-quality designs for energy-efficient ships.”
Energy saving in the Crown 63 design was achieved by introducing an enhanced hull form, fitting an electronically controlled main engine driving a larger and slower running propeller and the fitting a rudder with an advanced profile. A rudder bulb is also fitted, studied together with a propeller cap to produce the most effective aft water flow.
The hull form was developed in close cooperation with the German HSVA model basin and five test campaigns were performed over eighteen months to achieve the final lines. Particular attention was paid to the bow and stern lines to achieve good flow lines and minimum wake. Particular attention was also given to the manufacturing tolerances of the propeller. Built by Nakashima in Japan, it was manufactured to the strictest of tolerances to ensure it delivered the specified performance.
The MAN B & W 5S60ME-C8.1 Tier II x 1set ME electronically controlled engine was selected because it delivers lower specific fuel consumption over a wider range of operating parameters (bed test value at NCR (NCR): 161.6 g/Kw) and improved emission characteristics with lower NOx and smokeless operation. It runs easily at lower RPM for maneuvering and gives better acceleration, astern and crash stop performance. The NCR (normal continuous running) is fixed at 80 per cent MCR, which gives the master an important power reserve available to face deteriorating weather conditions. Full rated continuous running delivers 8,300 kW at 91.0 r/min. Normal operational continuous running delivers 6,640 kW at 84.5 r/min, giving a service speed of 14.5 kt consuming 28.5 tpd.
Compared to typical similar size ultramax designs the combination of increased deadweight and increased fuel efficiency reduces the loaded fuel consumption per ton mile per day by almost 20 per cent. But that is not at the expense of safety.
“The power reserve is crucial,” says Anne. “It would be easy to design ships which give a good EEDI figure but which are underpowered and so unsafe. We have to ensure that ships have the power they need to stay out of trouble in high winds, so this arrangement is the way forward, giving the master some back-up power for times when he really needs it.”
EEDI is More Than Possible: It is here
According to Anne, “EEDI is aimed at producing ships which are ahead of industry standards, with optimized fuel consumption and the highest standards of quality and safety to meet the demanding criteria for bulk carriers engaged in worldwide service today. The CROWN63 series demonstrates to the shipping industry, and to the world, that the shipping and shipbuilding industries can bring to the market an exemplary generation of new ships which are safeguarding the future of our planet.”
The vessel’s deadweight of 63,200 tons on summer draft - the maximum possible achievable deadweight compatible with the requirements of the CSR rules, within the length and draft - was obtained thanks to refined steel structure calculations. Anne says that BV has invested heavily in leading the IACS project to harmonize the Common Structural Rules and invested internally to update its VeriSTAR Hull and MARS structural analysis tools to be ahead of the new implementation. “That gives us both the understanding we need to guide yards in how the rules will work, and the tools to verify quickly and clearly that proposed new designs will meet the rules. It is crucial that yards don’t get carried away with efficiency and forget safety and rule compliance. We have to make the vessels are efficient, but first we have to make sure they will be safe and future proof for the harmonized rules,” he emphasized.
(As published in the 3Q edition of Maritime Professional - www.marinelink.com)