DNV has released an update to its Wind Assisted Propulsion Systems (WAPS) technical standard.
The major update to WAPS ST-0511 introduces new methods for evaluating WAPS fatigue strength, as well as performance in extreme conditions and follows news that DNV has become a full member of the International Windship Association.
While experience in using the systems is still developing, WAPS have already been implemented on commercial vessels and can enable fuel savings of up to 20%.
“As we continue to build experience on WAP systems, and as new systems come onto the market, the case for owners who are looking at these systems as part of their efficiency and sustainability strategies grows stronger,” said Hasso Hoffmeister, senior principal engineer at DNV Maritime.
“Our customers are extremely focussed on maintaining compliance with the incoming GHG (greenhouse gas) reduction targets and are seeing that WAPS can make a valuable contribution in this respect.”
The interaction of WAPS with the structure of a vessel’s hull can be quite complex, so the update features a comprehensive new section on fatigue strength, including calculations that offer a completely new approach to the derive the load combinations from the wind and inertia forces on WAP systems.
In addition, the standard sets out a new approach to assessing how WAPS perform under extreme wind conditions. Finally, the documentation requirements have been adjusted to streamline the process.
The WAPS ST-0511 standard covers approval in principle, design approval and type approval. These verifications and certifications can also be obtained as part of the integration into a vessel or independently. The ST-0511 technical standard is a complement to the DNV WAPS class notation, which is focussed on the integration of systems onboard vessels, whether retrofitted or as part of a newbuilding.
