Expert insights: How Dynamic Positioning (DP) Systems are evolving in offshore operations
Interview with Aleks Karlsen, Senior Principal on Dynamic Positioning Systems, DNV
Could you tell a bit about your background and experience in dynamic positioning (DP) systems?
I joined DNV early in my career and soon took responsibility for DP notation rules and requirements, a role I’ve held ever since.
What inspires me is collaborating with the industry to influence and develop guidelines for safe DP operations, including DNV DP rules and standards, international guidelines from IMO (International Maritime Organization), IMCA (International Marine Contractors Association), and MTS (Marine Technology Society).
Before DNV, I worked as a seaman in my family’s fishing business and owned a 90-foot fishing vessel. While these vessels lacked DP systems, the experience gave me hands-on knowledge of vessel operations and technical systems including engines, control systems, power distribution and various auxiliary systems, which proved invaluable when I first encountered DP control systems over 25 years ago at DNV.
How has the DP market grown in recent years? Which vessel types and offshore operations are currently driving the demand for DP technology?
The DP market has grown tremendously over the years, with more marine and offshore operations now relying on DP vessels. A key driver for this demand is the offshore wind industry, though many other segments are also increasingly adopting this technology.
What in your opinion are the most challenging DP applications currently?
I will not point to any specific application of DP, but to a general challenge that applies to most segments. This is the speed of technological development and the challenge that lies in enabling safe operations at the same time as new technologies are introduced to optimize operations and safety margins. Typical examples are ability to operate with connected power systems (usually referred to as closed bus-ties), battery hybrid power systems and new types of fuels, to reduce fuel consumption and GHG emissions. The industry is now taking this new technology in to use at a large scale, changing the way we design, build and operate systems, all at the same time. To me this is a fundamental and big challenge.
How does weather—especially wind, waves, and currents—affect the performance and reliability of DP systems?
To simplify you could almost say that this is what it is all about. DP systems are designed to counteract environmental forces like wind, waves, and currents to maintain its position and heading and enable safe operations, such as keeping a gangway connected to a wind turbine so that equipment and maintenance personnel can be safely transported. These systems must be robust and single-fault tolerant, meaning that in case of a (one) failure onboard any system on the DP vessel, the vessel shall not lose automatic station keeping ability so that the operations can be terminated in a controlled and safe manner. This also mean that the operability of the DP system is not determined by the intact capabilities, but by the post single failure capabilities. However, operability often depends not just on the DP system but also on industrial equipment, like gangway systems, which must function safely amid vessel motion.
Why is accurate and reliable wind data crucial for maintaining station-keeping capabilities in DP operations?
For the system to be able to handle the environmental forces and maintain safe position both in intact and post failure situations accurate and reliable measurements of wind is very important as wind may change abruptly. There has been experienced several cases in the industry where actual wind-gust or failures to wind measurements have caused unacceptable position and/or heading keeping excursions during operations. Due to this the industry is striving for reliable wind measurements, while also developing capabilities to predict and detect gusting winds before they impact the DP vessel. Similarly, efforts are underway to observe and predict wave forces, as sudden increases from multiple large waves can also challenge DP vessel position keeping ability.
What are the biggest challenges DP operators face in extreme weather conditions, and how in your opinion they could be mitigated?
While I’m not a DP operator, from my position I see challenges arising from increasingly complex DP systems and the changing way of operating these systems, like shift toward optimizing fuel consumption over safety margins. To mitigate risks in extreme weather, the industry must provide DPOs with clear situational awareness, including real-time wind and wave data, DP system intact and post failure capabilities, safety margins and the potential transient behavior of the DP vessel in case of failure. Ensuring operators have the necessary technical and operational training is also crucial for safe DP operations, including what is needed for safe termination, e.g., in case of technical failures or unexpected changes in environmental conditions.
How do DNV’s classification rules and verification processes ensure DP system reliability and safety?
With all these technical and operational changes happening at the same time it requires a lot from the industry to be able to correctly and carefully balance the introduction of beneficial developments and changes against the requirements for keeping systems and operations safe. In this setting DNV wants to be an enabler for achieving safe and incident free DP operations by delivering rules, guidelines and assurance that allows the industry to utilize the opportunities that lies within the new technology and new ways of operation, at the same time as the required and wanted safety levels are maintained and ensured.
What best practices can vessel operators follow to ensure their DP systems remain compliant and optimized?
There are several sources. Vessel operators can follow DP standards from IMCA, MTS, DNV, other classification societies, DP control system manufacturers, and major oil/energy companies like OCIMF (Oil Companies International Marine Forum). Many best practices originate from the oil and gas/offshore sector, which has been the frontrunner when it comes to applying DP for many decades. Newer industries, like wind farm services, can learn from this experience while adapting practices to their specific needs.
How do you see technological innovations shaping the future of DP technology in offshore operations over the next decade?
The future of DP technology will to a large degree be shaped by advancements in remote and autonomous operations, with the remote capabilities probably leading autonomous capabilities with many years. To enable these bigger moves, smaller and more incremental changes will be needed including systems for situational awareness, which of course includes sensor technology. Parallel to this I expect to see further development of advisory systems that will guide operators on how to optimize systems and operations in terms of energy use, emissions and efficiency, while maintaining sufficient safety margins. These innovations will pave the way for the automated systems that will be needed for broader remote control and future autonomy in offshore operations.
