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Efficient Ship additional class notation

RINA SERVICES has designed the additional class notation EFFICIENT SHIP - EEDI (Energy Efficiency Design Index), to identify ships having good energy efficiency performance under a specified operational speed and DWT (Dead Weight Tonnage).
The additional class notation is assigned to ships for which hull, propulsion and electrical power generation efficiency, at specific speed and draft, is verified by a third part society and found beyond the minimum efficiency values established.
Being EEDI a design index, it is not capable to catch the efficiency of the ship in the real operative pattern.


Nowadays the cost of fuel is a very sensitive subject for the marine industry. Fuel saving design and fuel saving techniques are advertised, analyzed, implemented and evaluated by ship-owners and stakeholders, and an instrument to highlight technically sound solutions is needed.
No doubt that, among the most important features a ship must have, there is low fuel consumption and consequently a high energy performance.

The additional class notation EFFICIENT SHIP highlights that a ship has:
  • main and auxiliary engine characterized by high efficiency 
  • a low fuel oil consumptions, that does not preclude the ship from having a good working capability.


New building specifications are reporting daily fuel oil consumption decreasing in these last years: a third party evaluation of the real operative ship efficiency is more and more important.
RINA SERVICES is among the first classification societies to issue an additional class notation, dedicated to energy efficiency of a ship and based on the verification of the ship’s engine efficiency and of the ship’s transport capability at a specified speed and draft.


The process for the assignment of the additional class notation is:
  • examination of required document
  • performance of dedicated sea trials.


Is the additional class notation specific for ship type?
Yes, EFFICIENT SHIP contains different parameters for ship type and for two and four strokes engines.

Is it possible to assign EFFICIENT SHIP to all ships?
Yes, this additional class may be granted to new buildings and ships already classified by RINA SERVICES or not.
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