Constant speed versus variable engine speed

A study by MAN Diesel & Turbo compares a diesel mechanical plant with CP propellers operating with constant engine speed with operations at variable engine speed on an offshore vessel. Henrik Segerkrantz explains.

A 170t bollard pull AHTS with 2x2 XL27/38 engines with twin in/single out RENK gearboxes and CP propellers was tested running the engines from idle speed 38Hz to 61Hz; the auxiliary genset provided power for the hotel load: a fuel saving of 41% ...

A study by MAN Diesel & Turbo compares a diesel mechanical plant with CP propellers operating with constant engine speed with operations at variable engine speed on an offshore vessel. Henrik Segerkrantz explains.