Walk-to-work systems are being asked to do more with a greater level of autonomy, driving innovation and efficiency
In a relatively short period since they were first introduced, offshore access systems have evolved quickly – and the pace of evolution shows little signs of slowing. Leading manufacturers such as Van Aalst (Safeway), Ampelmann, SMST and Uptime agree that clients want greater workability, flexibility and lifting capability, but conventional walk-to-work systems now also have competitors that work in quite different ways.
All of the manufacturers interviewed by OSJ for this article agreed that clients see offshore access systems as a way to save time and reduce operating costs. They want to see efficiency improvements and improved ‘hands on tool time’ when using a vessel with an access system and, as in most industries, sustainability is becoming ever-more important, so the power consumed by walk-to-work equipment has come into focus.
Van Aalst Group managing director Wijnand van Aalst told OSJ: “In the oil and gas market right now, workability is important, as it always has been, but our clients are also asking for height-adjustable systems and for greater flexibility. Safety is always important, of course. Looking to the future, we know they will want greater cargo-lifting capacity, a greater level of autonomy.”
Mr van Aalst said power consumption and energy use is important in the walk-to-work market for two reasons, one being the fact that using less energy ‘helps save the planet’; the second is a more practical issue: if a gangway needs a lot of power, as some do, they can require the installation of additional, diesel-driven hydraulic power units.
Mr van Aalst said clients continue to ask manufacturers if they can provide gangways capable of lifting heavier loads. They routinely request systems capable of handling 400 to 500 kg, but from time-to-time the ability to lift 1,000 kg is required, although manufacturers are cautious that asking for heavier and heavier lifts will start to conflict with the main purpose of a gangway. Mr Van Aalst said “You could arrive at a gangway/crane that is no longer ideally suited to transferring people, and not ideally suited to lifting cargo. Above a certain level, if you want to lift five to 10 tonnes, it makes more sense to use a 3D crane and a separate 3D gangway.”
Inevitably, given its fast pace of growth, developments in the offshore wind market are also affecting the development of gangways and access systems, and this is flowing over into the offshore oil and gas market. SMST sales manager Jelle Dijk said trends in access systems for offshore wind will definitely influence systems used in the offshore oil and gas market – in fact, they already are.
Mr van Aalst said one notable feature of the offshore wind market is the need for speed. “In the offshore wind market you are transferring personnel and cargo to multiple structures,” he explained, “whereas in the oil and gas market transfers usually take place to one offshore structure or vessel. In offshore wind you need to be able to transfer people and cargo in less than 30 minutes and then move to the next structure.”
Asked in which market – offshore wind or offshore oil and gas – clients’ requirements are most demanding, Mr van Aalst said that ultimately, because clients in oil and gas are working with hydrocarbons, safety is, if anything, even more important than it already is in offshore wind. In contrast, he explained, in the offshore wind market, workability needs to be even higher. A soon-to-be-awarded tender from Equinor for a walk-to-work system for the service operation vessels (SOVs) needed for the Dogger Bank offshore windfarm in the North Sea originally specified the ability to transfer personnel in a significant wave height of Hs 3.5m – well above industry norms.
Uptime International director of sales and marketing Svein Ove Haugen agreed that offshore wind and offshore oil and gas “are challenging one another” when it comes to the development of offshore access systems.
Mr Haugen agreed with Mr van Aalst and Mr Dijk that workability and the ability to work at a range of heights are increasingly important. He also cited greater lifting capability and suggested that, in some applications, the lifting capability of a motion-compensated access system could eliminate the need for a crane altogether.
“If you can lift three tonnes at 30 m with full 3D motion compensation and use the same system to lift much more in harbour, maybe you don’t really need a stand-alone crane,” he said. “But we need to ask the question, do you really need to lift more, and how much more do you really need to lift? At what point does greater lifting capability become too expensive?” The more you lift with a gangway, the more it affects the design of the overall system, and the stronger and heavier – and hence more expensive – components need to be.
“Sustainability is becoming more important, so the power consumed by walk-to-work equipment has come into focus”
Another area in which Mr Haugen sees potential for further development, and one on which Uptime has already embarked, is incorporating a much greater level of autonomy into an access system. If you take the ‘human factor’ out of the equation, and you give a gangway a greater level of artificial intelligence, it can ‘learn’ as it operates, offering a potentially more efficient system.
Mr Dijk agreed that greater autonomy is the way to go. He sees the introduction of autonomy as a step-by-step process towards what could, one day, be completely autonomous operation and automatic connections. An access system SMST is supplying to Rem Offshore for its newbuild construction/service operation vessel Rem Energy will have a level of autonomy designed into it, should the owner want to use it at a future date.
Mr Van Aalst said that in two to three years’ time, he expects clients will still be looking for access systems with even higher lifting capacity, a greater level of autonomy, and further integration of gangways with the dynamic positioning systems on vessels. Mr Dijk highlighted clients’ requirements for systems that can be adjusted to work at different heights. “The more flexible you can be, the better it is for the operator because they can use the same system to access a number of different platforms,” he explained.
Height-adjustable systems are also important for projects with significant tidal variation, Mr Dijk explained. The system SMST will provide for Rem Offshore’s newbuild construction/service operation vessel is able to operate on the starboard or port side of the vessel and can provide access to platforms at a range of heights up to 12 m above sea level.
SMST is also providing an innovative gangway to DEME that can transfer cargo from an SOV to crew transfer vessels. “We have introduced new functionality into the gangway by adding a cargo transfer system that runs underneath it,” Mr Dijk explained. “A winch is installed at the tip of the gangway to provide motion-compensated lifting. The winch is designed to move beneath the gangway, along its entire length. The lifting capacity is fully 3D motion-compensated, and in addition to lifting loads onto a wind turbine, also enables us to undertake ship-to-ship lifts to CTVs.”
Ampelmann UK and Norway business development manager Lorenz Nehring echoed other manufacturers’ comments when he said walk-to-work is all about increasing operational efficiency, ‘value addition’ and safely getting as much work done as possible, in the shortest period of time. “Requirements used to focus on lifting up to one tonne, but we are seeing a growing number of requirements for five-tonne lifts,” he explained. “Sustainability is a driver, as is using less power,” he said. Mr Nehring also agreed that there would be some ‘cross fertilisation’ between walk-to-work systems for the offshore wind and offshore oil and gas markets.
As he told OSJ, the company expects to bring a new version of the Ampelmann, the E5000, to market later in 2021. The E5000 is based on the proven E1000 and will have the capacity to transfer people and cargo of up to five tonnes.
Ampelmann is also working on a walk-to-work system for the SOV segment in the offshore wind industry. Here, the focus of development is what Ampelmann describes as the “increasingly specific” needs of offshore wind operators. This includes a high level of operational efficiency and safe working at a range of heights.
But not all offshore access systems are walk-to-work systems. A new system from Z-Bridge in the Netherlands is a ‘bring-to-work’ system. Originally aimed at the offshore wind market, it also has potential applications in the offshore oil and gas market.
Windfarm technicians transported to offshore windfarms on a crew transfer vessel (CTV) are used to having to step off the deck of a vessel and undertake an arduous climb to the platform on the transition piece, before climbing further up the turbine. In contrast, the bring-to-work system lifts them straight to the platform. Having been successfully demonstrated at sea on MHO-Co’s CTV Esbjerg late in 2020, the innovative system has been ordered for a trio CTVs that will work on Ørsted’s Hornsea Two offshore windfarm, supporting the construction phase of the project.
The bring-to-work system is fully motion-compensated and allows teams of four technicians to transfer in a trolley direct from the deck of a CTV to the platform. Weighing only 25 tonnes, it is suitable for operation from small vessels and can be mobilised at any port using a standard telescopic crane.
Z-Bridge general manager Bastiaan Spruit told OSJ that the company is already working on some oil and gas projects, including fast vessels with a bring-to-work solution. “We see it as a good alternative to helicopters,” he said, “especially since we can access structures 22 m above a vessel’s deck without needing a heavy substructure like some offshore access systems.”
Mr Spruit believes the bring-to-work system could also be used for cargo runs to unmanned platforms. It also has potential applications for projects such as well services, maintenance, inspection and pigging. “Another thing in our favour is that our mobilisation costs are low compared to conventional walk-to-work systems,” he told OSJ. Working with an oil major, Z-bridge has developed a quick response system based around the use of a fast vessel carrying up to 40 offshore technicians. Offshore personnel would be transferred from it using a Z-Bridge bring-to-work system.