Class services on WAPS in a nutshell
The DNV rules and standards provide a framework for the verification and certification of wind-assisted propulsion systems (WAPS) and their integration on board vessels, whether retrofitted or as part of a newbuilding.
Certification services for WAPS
The DNV Standard ST-0511 Wind-assisted Propulsion Systems can be used for the purpose of certification. The core of this standard is the definition of structural design loads typical for large sail installations on top of the deck of cargo ships, and the associated safety concepts. The interaction of the WAPS with the ship’s hull infrastructure can be quite complex, and thus combinations of the above-listed loads need to be assessed.
Evidence is requested in this standard of how the WAPS copes with particularly extreme wind conditions, combined with other loads, particularly considering the large areas exposed to wind and possibly also green water on deck. This is the reason why beforehand, particularly for novel concepts, a risk analysis must be carried out, addressing all aspects of structural design, control systems and operation in order to identify detrimental effects in the early design phase.
DNV Standard ST-0511 is intended for the certification of WAPS. It primarily serves WAPS designers and manufacturers for the purpose of having their systems independently assessed and certified.
There are three different certifications offered depending on need:
| Service |
|---|
ServiceAn AIP is an independent assessment of a concept within an agreed framework, led by the society, to confirm that the design is feasible and no significant obstacles exist to prevent the concept from being realized. The basic design and safety concept will be reviewed and approved. The functionality of the system and restrictions of operation will be assessed and approved. The society may, on a case-by-case basis, require an AIP for novel designs before engaging in type approval design or other certification activities. An AIP can be obtained for a WAPS alone or in combination with a generic or specific ship installation. |
| Service |
|---|
ServiceThe TADC is a document validating compliance with all design requirements in all technical disciplines as defined by the standard. It is required to be obtained if a WAPS is installed on a DNV-classed vessel. |
| Service |
|---|
ServiceA TAC is a compliancy document covering the scope of the TADC but amended with DNV production assessment and survey requirements on materials, components and the WAPS, once completed. |
Classification services for WAPS
The installation of a WAPS unit on board an ocean-going ship goes along with a few challenges, both on retrofits (“alterations”) and newbuildings.
The mandatory DNV additional class notation WAPS includes all technical and safety-related aspects of that installation, such as:
- Foundation and structural integration
- Intact stability
- Machinery installations (ship)
- Electrical installations (ship)
- Control systems (ship)
- Equipment number
- Installation in hazardous areas
- Line of sight
- Radar blind sector
- Navigation lights
- Load line
- Manoeuvrability
A risk analysis (HAZID) might be carried out in advance to manage associated risks, particularly for novel systems and/or novel or unusual applications. An AIP can serve the purpose of verifying that a design concept is feasible and that no major obstacles would prevent the concept from being realized.
Related Rules and Standards:
[DNV-ST-0511] Wind assisted propulsion systems
Access the latest status via the Rules and Standards Explorer
[DNV-RU-SHIP Pt.6 Ch.2] Propulsion, power generation and auxiliary systems
Access the latest status via the Rules and Standards Explorer
Approval Finder
Access a list of certified WAPS