The two first Ulstein Twin X-Stern SX216 Construction Service Operation Vessels (CSOVs) with design by Ulstein Design & Solutions have been ordered by Acta Marine. The design contract includes the option for two further SX216 vessels.
Scheduled to be constructed at Tersan Shipyard, the CSOVs for Acta Marine will benefit from a hybrid power solution, with green methanol intended to be used as the main source of energy. The dual-fuel engines are also supported by a battery pack which has been integrated into the vessel to enable the most fuel-efficient modes of operation, reduced maintenance costs and reduced emissions.
Once methanol had been chosen as alternative energy source, Ulstein Design & Solutions adapted the vessel’s design, in addition to implementing the methanol bunkering, tank and system layouts on a conceptual level.
Ulstein’s 89.9m-long vessel design also features the company’s Twin-X-Stern, consisting of two sterns and four main propeller units – two at either end – for a high level of maneuverability, improved fuel efficiency and reduced motions and noise. The Twin-X-Stern also enables a wider choice of propeller types, a bi-symmetric hull shape and a propulsion setup with fewer propulsion units.
“We are pleased to build on our existing relationship with Ulstein Design & Solutions for our next generation CSOV vessels combining Acta Marine’s operational experience and Ulstein’s innovative design capabilities,” commented Rob Boer at Acta Marine.
“Being a leading actor in the renewable energy business, it is paramount to be prepared for a future where zero or low-carbon fuels are available,” commented Erwin Jager of Ulstein Design & Solutions. “Acta Marine has a strong wish to offer their clients the largest possible reduction of emissions straight from delivery of the vessels. Therefore, these vessels required a practical and timely available solution to reduce their carbon footprint from the outset of the design.”
“The carbon footprint of marine gas oil (MGO) makes MGO non-sustainable as the sole choice for the future,” said Jager. “Currently, the decision on what alternative fuel to focus on can be overwhelming as it is affected by many factors internally and externally. Through a decision support process, developed by Ulstein to guide owners in the myriad of choices to be made, a matrix of alternative fuels has been evaluated towards a set of criteria unique to the shipowner and the business case.
“Through this process, methanol came out as the winner for this project, with the best overall score. The energy density and storage of methanol is favorable, it is an accessible energy source, and there are dual fuel engines available in the market that can handle both methanol and diesel.”