Wärtsilä Propeller Solutions Enable Energy Savings Through Slow Steaming
The technology group Wärtsilä will supply its Fixed Pitch Propeller (FPP) and EnergoProFin solutions for two container vessels owned by Yang Ming Lines, the Taiwan-based shipping company. As container ship operators continue to seek energy savings through slow steaming, the necessary engine adjustments need to be matched by the propeller arrangement. The Wärtsilä solutions enable this adjustment, allowing the speed of the two vessels to be reduced from 24 to 18 knots. The order with Wärtsilä was placed in August 2020.
The two vessels, the ‘YM Mobility’ and the ‘YM Milestone’, are the last in a series of four Yang Ming ships to be retrofitted with the Wärtsilä FPP and EnergoProFin solutions. The two earlier retrofit projects have resulted in energy savings in the region of three to five percent. The newly designed Wärtsilä propeller mass is approximately 27 percent lighter than the ships’ existing propellers. The EnergoProFin post-swirl device reduces energy losses from the flow around and behind the propeller.
“The two retrofit propeller projects already completed with the Wärtsilä systems have been very successful, which is why we had no hesitation in taking the option to do the same with these two vessels. Wärtsilä was also able to meet our tight delivery schedule requirements, and we are very happy with the support they have provided,” says Jackie Ho, Chief Technical Officer, Yang Ming Lines.
“Efficiency and cost savings are extremely important in today’s operating environment, and the Wärtsilä propulsion solutions are designed to meet these needs. By enabling the engine power to be reduced, we are also enabling fuel consumption to be lowered, which in turn also leads to fewer exhaust emissions,” says Patrick Van Gorkom, Senior Manager Sales & Sales Support, Wärtsilä Marine Power.
The Wärtsilä equipment is scheduled for delivery in March and June 2021 to the Changhong shipyard in China where the retrofitting will take place.
The Wärtsilä EnergoProFin is an energy-saving propeller cap with fins that rotate together with the propeller. This solution provides average fuel savings of two percent, with a payback time of less than one year. The propeller’s energy losses are among the factors related to the flow phenomena around and behind the propeller boss. Installing the Wärtsilä EnergoProFin helps to reduce these energy losses and increase overall propulsion efficiency.