Propeller Boss Cap Fins (PBCF) Guidelines

The study on the data led to the conclusion that vessels installing PBCF will be given a 1.5% power reduction to achieve the same speed (Vref) at 75% nameplate MCR without the need to conduct a new sea trial or CFD studies. The new Vref can be derived using the formula:  

New Vref = Vref,original * {(1/0.985)^(1/3)} 

Nevertheless, if an actual sea trial or CFD study is done showing higher improvement, that will be credited upon verification. The above calculation needs to be detailed in Section 4 – Estimation Process of Speed-Power curve, of the EVDI Technical file and the adjusted Speed-Power curve needs to be presented together with the original Speed-Power curve therein at the EEDI draft by the submitter.