PEOPLE & CARGO TRANSFER
Safeway unveils new gangway DESIGNED FOR GROWING SOV MARKET
T A rendering of the Safeway Gannet.
SAFEWAY, THE OFFSHORE ACCESS SYSTEM COMPANY IN THE VAN AALST GROUP IN THE NETHERLANDS, HAS ADDED NEW FEATURES TO ITS RANGE OF MOTION COMPENSATED GANGWAYS. ALL IMAGES COURTESY OF SAFEWAY.
Van Aalst Group CEO Wijnand van Aalst.
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he company has incorporated the features into a new gangway, Safeway Gannet, for next-generation requirements, such as the service operation vessels (SOVs) being sought for offshore windfarms on the Dogger Bank in the North Sea. “The Safeway Gannet 3D motion compensated offshore access system was developed in response to evolving requirements for walk-to-work systems,” explains Van Aalst Group CEO Wijnand van Aalst, “such as those being sought by Equinor and its partners for the massive offshore windfarms they plan to build on Dogger Bank. However, it is equally well suited to emerging requirements elsewhere, such as in Taiwan.” Equinor has issued a tender for a new class of SOV for its Dogger Bank projects, a tender that is particularly demanding for several reasons. The first is that the access systems installed on the vessels will need to be able to connect and transfer personnel and equipment in a significant wave height of 3.5m Hs, compared to the industry norm of 2.5m Hs. The second reason is that the SOVs on which the motion compensated gangways will be installed will be somewhat smaller than those operating in the North Sea. SOVs built to date for operation in the North Sea are in the order of 80-90m in length. Those for Dogger Bank will be 70-80m long. Smaller vessels will be less expensive to build and operate but, given that a vessel’s stability usually increases in relation to size, opting for smaller ships will make motion
compensated access harder to achieve without adopting walk-to-work systems that are more capable than existing equipment.
Hover mode and roll compensation
Safeway’s motion compensated gangway has various unique features, including its well-known ‘hover mode’ and its roll compensation capability. Hover mode means that the gangway does not physically push against the landing point on a turbine or offshore structure, so you can land at your preferred location. The freedom of landing point that you get with hover mode is a big advantage because it means you can select the best heading for the vessel towards the waves, regardless of the conditions, and maximise workability. Roll compensation has become an increasingly important capability, as the height above sea level at which windfarm technicians need to be transferred has grown. Any vessel, however well designed, will experience some rolling motion, but its effect on a gangway when extended increases as the height at which transfers take place grows. A lot of existing equipment was designed with a transfer height of 20-21m in mind, but as wind turbines have grown and more windfarms are built in areas with significant variation in conditions and water depth, so gangways need to be able to safely transfer personnel at 28-30m or more above sea level. At that kind of height, even a small
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