Ship designer: ABS’ Approval in Principle for Onboard DC Grid boosts confidence

Henrique Pestana, head ship designer at ABB, says the American Bureau of Shipping's Approval in Principle helps reduce perceived risks of new technology

The Platform Support Vessel Dina Star, delivered to Norwegian offshore owner Myklebusthaug Offshore by Kleven Yard last year, is the first vessel powered with ABB’s Onboard DC grid, the new electricity distribution system aimed at providing the most flexible and efficient marine power and propulsion while eliminating AC switchboards and transformers.

Since then, testing on Dina Star has identified up to 27 percent reduction of specific fuel oil consumption, with a 14 percent fuel savings during dynamic positioning operations. That means even in challenging weather conditions where the Dina Star must maintain its position precisely, the Onboard DC Grid is helping make it one of the most fuel efficient vessels on the seas.

This past January, the Houston-based American Bureau of Shipping classification society extended Approval in Principle for the Onboard DC Grid. Such a distinction is used by most classification societies to review and approve innovative and novel concepts not covered by traditional classification rules, including the Onboard DC Grid. Additionally, ABB has received approval from Det Norske Veritas and is in discussions with Lloyd’s Register in the U.K. and Bureau Veritas in France.

Reaching these milestones helps bolster confidence for prospective ship owners that ABB’s fuel-saving, emission-reducing electrification solution can be applied successfully to their next project.

The American Bureau of Shipping’s approval process is rigorous, for a reason. Since its initial charter 152 years ago to certify ship captains, the society’s mission includes the development and improvement of standards aimed at making life at sea as safe as possible, while also preserving the environment.

Here, Henrique Pestana, a naval architect and ABB’s head of ship design, talks about what the American Bureau of Shipping’s Approval in Principle means for the Onboard DC Grid as this technology gains traction in a marine industry where ship owners are increasingly focused on improving the flexiblity, fuel efficiency and cost effectiveness of their fleets.

ABB: ABB has gained initial approval for its Onboard DC Grid from important classification societies including Det Norske Veritas and the American Bureau of Shipping and is currently working with Lloyd’s Register and Bureau Veritas. What significance do classification societies have for new technology like the Onboard DC Grid?

Henrique Pestana: Classification Societies have sets of rules that cover most of existing technology. New technologies not covered by existing classification rules are accepted but subject to a case-by-case verification which often requires more time and increased uncertainty. By gaining Approval in Principle  from a leading classification society as the American Bureau of Shipping, it is possible to execute projects with the Onboard DC Grid with the same level of predictability and consistency as we would when using technology covered by existing class rules.

ABB: How does that change ABB’s ability to work with ship owners, to help them understand the merits of this new approach to vessel electrification?

HP: Although ABB is already perceived by most ship owners as a solid and leading electric power brand, the Approval in Principle by a classification society signifies the technology has also been checked by an independent body and has been determined suitable for marine application. Therefore, it reduces dramatically the ship owners’ perceived risks associated with new technologies.

ABB: Can you briefly describe the process ABB went through, how long it took and what were some of the challenges of gaining ABS approval?

HP: The Approval in Principle process involves an evaluation of the technology by senior experts from the classification society in order to assess the risks and corresponding safety nets. Different approaches are used, from very systematic risk analysis tools like hazard identification studies, or HAZIDs, to more holistic approaches based on expert experience. In addition, the Onboard DC Grid system was thoroughly tested in a laboratory specifically built for the purpose where the system behavior was confronted with the projected response.

ABB: How will this impact ABB’s work with additional classification societies?

HP: Approval in Principle is an efficient tool to get other classification societies familiarized with the technology and consequently streamline the approval process and provide consistent support to site surveyors that inspect the installation and tests during the ship building process. Consequently, it is important to seek approval from other key classification societies. That will benefit all the parties involved: ship-owner, classification society and shipyard.

ABB: ABB already has the Onboard DC grid aboard the Dina Star, a Platform Support Vessel where tests demonstrate its fuel efficiency performance is even better than the original estimates. What are the next steps?

HP: In the wake of that report, we’ve seen an increased interest in this technology and consequently there are already discussions underway with different ship owners who are interested in the Onboard DC Grid.

ABB: In addition to Platform Support Vessels like Myklebusthaug’s Dina Star, what other types of vessels would profit from the Onboard DC Grid?

HP: The biggest advantage of the DG grid is related to improved responsiveness and efficiency at low loads. Therefore, those vessels that operate often in low load will definitely benefit from DC Grid. This is definitely the case with most of the off-shore fleet, but also very common in other types of vessels including ferries, dredgers and many other ships.