Wärtsilä Solutions Enable Slow Steaming
By Jack Burke09 December 2020
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, according to the company. The Wärtsilä solutions enable this adjustment, allowing the speed of the two vessels to be reduced from 24 to 18 knots.
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 Wärtsilä EnergoProFin is an energy saving propeller cap with fins that rotate together with the propeller. This solution provides average fuel savings of 2%, with a payback time of less than one year, the company said. 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.
The two earlier retrofit projects have resulted in energy savings in the region of 3-5%. The newly designed Wärtsilä propeller mass is approximately 27% lighter than the ships’ existing propellers. The EnergoProFin post-swirl device reduces energy losses from the flow around and behind the propeller, the company said.
“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,” said 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.