The Van Aalst Group with his headquarters in Dordrecht, the Netherlands, can look back on a very successful debut in the North Sea wind sector with the implementation of the project using the unique SafeWay motion compensated offshore access system.
This follows the earlier operations in the oil and gas sector with successful transfers done at offshore platforms of Total E&P Netherlands BV and Oranje Nassau Energy (ONE). The design for transferring personnel and cargo safely and efficiently from an offshore vessel to a structure is so revolutionary that SafeWay believes the gangway will be a ‘game changer’ in the offshore oil, gas, wind and renewables industries. The unique 28 metre long walk-to-work Seagull-type is able to compensate for significant wave heights of up to 3,5 metre on a standard 75-metre long PSV hull, resulting in an operating window that can be significantly higher than other available systems in the market.
This first SafeWay gangway is currently installed on the 95-metre long OCV ‘Olympic Intervention IV’, owned by Olympic Subsea ASA, Norway. The DP2 vessel, having excellent seagoing properties, offers accommodation and workspace to 100 passengers (POB) and is chartered by the German wind turbine manufacturer Adwen GmbH for maintenance activities and trouble shooting at three different wind parks located in the German sector of the North Sea. Under sometimes challenging weather conditions, with significant wave heights above 2.8 meter, 851 people transfers were carried out during 173 landings without any problem in 29 days, including an additional 301 cargo transfers. The gangway incorporates a 3D compensated crane capability, for which the design includes a separate winch to transfer up to 400 (or optional 1000) kilos. This efficient transfer of equipment helps expedite the operational work flow as well.
Ralf Schuckert, site manager of Adwen, is enthusiastic about the smooth and high performance of the SafeWay gangway, designed to tailor to the needs of different market segments, weather conditions, sea states, cargo and crew loads. Adwen, part of Siemens Gamesa, has experience with other gangways as well, but especially points out two major advantages of SafeWay. Firstly, the 10 meter vertical lifting possibility of the SafeWay is praised by him.
Schuckert: “Secondly, the hovering above bulwark with stairs to a safe area on the turbine deck has great advantages as a 360 degree landing can be realised without any special preparation. That is why Adwen very consciously chose for using this gangway having a unique active ‘free-float’ mode, the so-called Zero Impact Bumpering mode, enabling the access system to ‘float’ just above the entry point onto a platform or monopile, without actually touching it. Not only does the vessel get more freedom in heading, it also gives the access system greater workability compared to other systems. Moreover the hovering system exclude people from climbing over bulwark, thus increasing their safety.”
Adwen used the SafeWay access system for the first time during the maintenance campaign at the Trianel Windpark Borkum, where 40 turbines had to be inspected. After this project the ‘Olympic Intervention IV’ was directed to the Wikinger wind park, 35 km off the German Island of Rügen and Germany’s first offshore wind farm Alpha Ventus, located 45 km off the coast of Borkum.
Morten Endre Stakvik, captain of the ‘Olympic Intervention IV’ confirms the encouraging comment from client Adwen. “I had never worked before with a walk-to-work system that can be lifted vertically and my experience is quite positive. This gangway is behaving perfectly and it was amazing to witness the speed of the personal transfers as well as the cargo transfers. The cooperation with the SafeWay operators is great. They are very professional and what is more important, they explain the system to the maintenance technicians who make the crossing for the first time, in a very understandable way. And what I understand from these technicians it feels quite natural and comfortable walking 20 metres above sea level from our accommodation vessel to the structure. From the vessel you can walk straight to work in a totally covered construction. Just like walking in a jet bridge to a plane.”
Wijnand van Aalst, managing director of SafeWay, is excited about the excellent feedback. “With the development of the SafeWay we aimed to revolutionize the walk-to-work market, introducing a product which surpasses competition. We learned already from the first crossings earlier this year for Total E&P Nederland and Oranje-Nassau Energie (ONE) that our smart and innovative approach is a big step forward in technology and safety, the latter being undeniable our number one priority. The system is 100% redundant with in total 440 alarm notifications, so a single-component technical failure will never cause hazardous situations. But in the eyes of the world we now had to prove what we were claiming since we unveiled the distinctive features of this motion compensated gangway in 2015. And that’s why we are so grateful to companies like Olympic Subsea and Adwen that they rewarded our innovative system with this contract and trust our capabilities.”
The Bureau Veritas approved SafeWay motion compensated gangway system incorporates three main features which are unique in the walk-to-work market:
- Roll compensation: the SafeWay technology is based on a unique roll cylinder, enabling the system to keep the mast in a vertical position at all times.
- Height adjustment: the possibility of a stepless 10-meter vertical height adjustment enables the access arm to maintain a nearly horizontal position in all tidal conditions. This rules out unsafe uphill or downhill walking, further enhancing safety.
- Zero Impact Bumpering: active free floating allowing maximum freedom in vessel heading and zero preparation at the landing point.
Van Aalst offers all different types of the SafeWay gangway for purchase as well as rental. Based on the positive feedback and market potential, Van Aalst has commenced building a second unit which will be available in Q1 of 2018.
The SafeWay team on board the ‘Olympic Intervention IV’. From left to right: Frank de Vries, Simon Louwerman, Sander Bögemann and Wijnand van Aalst.