Ship owners can reduce fuel consumption by up to 9% and shave thousands off their fuel bills simply by installing Energopac.
Officially launched during the SMM 2008 exhibition in Hamburg, Germany, Wärtsilä’s Energopac is an easy-to-install rudder/propeller combination that uses a rudder bulb behind the propeller hub mounted on a custom-designed full spade flap rudder.
Finnlines, the Helsinki-based shipping company linking Finland to ports throughout Europe, has ordered Energopac to be fitted on six sister vessels currently being built for delivery in 2009.
The energy saving capacity of Energopac is based on optimizing the interaction between the vessel’s propeller and rudder. In-house Computational Fluid Dynamics (CFD) capabilities have enabled an optimal design for the total system.
Reduces operational costs of vessel
“Energopac will effectively reduce operational costs for any vessel with a considerable share of non-stop sailing in its operational profile, and will work very well for vessels with a relatively large propeller hub. For a vessel using a conventional rudder/ propeller arrangement, hub losses are significant, but these can now be avoided by applying the Energopac system,” says Teus van Beek, Director of R&D, Energy Efficiency, Wärtsilä Ship Power.
“More and more ship owners are looking to invest in technology that improves energy efficiency, and with it fuel consumption and emissions, throughout their fleets, especially with fuel prices at an all-time high.”
A 20,000 dwt cargo vessel with a main engine of 8000 kW and a controllable pitch propeller installation, could benefit from annual fuels savings of USD 45,000 for each percentage point in power reduction. On a 22 knots twin-screw Ropax ferry with an installed power of 25,000 kW, Energopac will generate annual savings of over USD 125,000 per percent. For a 5000TEU-plus containership with 50,000 kW installed on one fixed pitch propeller, Energopac could realise an annual reduction in fuel costs of USD 300,000 per each percentage of improvement.
“Energopac can do this“ says van Beek. “It will improve overall performance by 2-9 %. Energopac will be custom designed for each individual vessel to give maximum fuel savings. And this will be done without compromising on either manoeuvrability or comfort,”
Better Water flow
The leading edge of the rudder is twisted and subsequently more aligned with the propeller’s slipstream, which in turn produces better water inflow angles and improved cavitation behaviour. A fairing hubcap guides the propeller slipstream around an individually designed rudder bulb, thereby substantially decreasing the drag. Vibrations are reduced to a minimum.
This arrangement differs from earlier energy-efficient rudder systems. In the new design, the bulb is fixed to the rudder blade and turns together with the rudder. The Energopac rudder is also equipped with a flap, ensuring superb manoeuvring characteristics with only relatively small steering angles needed to keep the vessel on course. This considerably reduces steering losses whilst in transit.
The rudder part of the Energopac will be made by Becker Marine Systems and an intrinsic component of Energopac is Becker Marine Systems’ patented KSR (King Support Rudder) bearing arrangement, which has been used to provide a slimmer rudder profile, resulting in low resistance. It also allows the Energopac system to be installed on any size of vessel, which is truly unique when it comes to large vessels.
Model tests were performed with both single and twin-screw ships. In both, the Energopac application resulted in significant reductions in required power and fuel consumption. Where the system replaced another sophisticated propeller-rudder arrangement, a 2% power decrease was noted. When the system was used in place of a conventional propeller and semi-spade rudder configuration, an 8% efficiency gain was recorded!
We also welcome your visit to SMM exhibition in Hamburg, Germany, Wärtsilä stand – No. 223 in Hall A4!
Ms Marit Holmlund-Sund
Public Relations Manager
Direct tel: +358 10 709 1439
Direct fax: +358 10 709 1425
Wärtsilä Corporation in brief:
Wärtsilä enhances the business of its customers by providing them with complete lifecycle power solutions. When creating better and environmentally compatible technologies, Wärtsilä focuses on the marine and energy markets with products and solutions as well as services. Through innovative products and services, Wärtsilä sets out to be the most valued business partner of all its customers. This is achieved by the dedication of more than 17,000 professionals manning 160 Wärtsilä locations in 70 countries around the world. Wärtsilä is listed on The Nordic Exchange in Helsinki, Finland.