Rolls-Royce Commercial Marine has secured a contract worth around Nkr300m ($35m), to supply propulsion systems to Italy-based Grimaldi Group’s nine new Roll-on-Roll-off (Ro-Ro) vessels.

The 238m-long vessels, named Grimaldi Green 5th Generation, will be built by Nanjing Jinling Shipyard in China.

Rolls-Royce expects to start delivering the propulsion systems next year to help complete the last vessel in the series in 2021.

Rolls-Royce Commercial Marine Propulsion Sales senior vice-president Ottar Ristesund said: “We are very much looking forward to working together with the customer to deliver this large order in a timely manner.

“So far, the cooperation between the yard, the owner and our involved team members in China, Italy, and the Nordic countries, has been excellent, a pivotal factor in both securing the deal and for the future success of the project.”

Rolls-Royce will deliver steering gears and the Promas system, which is designed to combine the propeller and rudder into a single system to optimise hydrodynamic efficiency.

“The Grimaldi Green 5th Generation vessels will be able to carry over 7,800 linear metres of rolling units.”

Developed at the Rolls-Royce facility in Kristinehamn, Sweden, Promas features a special hubcap that is fitted to the propeller to streamline the flow onto a bulb that is attached to the rudder to minimise flow separation immediately after the propeller.

The process results in an increase in propeller thrust by recovering wasted energy from the flow. The bulb on the rudder also allows streamlining of the flow aft of the rudder, further reducing drag.

Upon completion, the Grimaldi Green 5th Generation vessels will be able to carry over 7,800 linear metres of rolling units, equivalent to nearly 500 trailers.

Denmark’s Knud Hansen is currently designing the vessels, which will use hybrid power to run by combining the use of traditional fossil fuels during operation and battery power when in port.