Nowhere is innovation more prominent than in the shuttle tanker sector, especially in the North Sea, explains DNV’s tanker sector business leader, Catrine Vestereng
The shuttle tanker fleet has increased significantly since 2018; in 2019 eight shuttle tankers were ordered worldwide, with 10 more ordered in 2020. This led to 14 shuttle tankers being delivered in 2020. DNV classified two-thirds of the shuttle tankers globally and all the newbuildings. In terms of trends, safety has been the focus of shuttle tanker development in the last few years. DNV has been working closely with the owners and charterers to develop new rules to support critical operations offshore.
With shuttle tankers, much focus has also been placed on manoeuvrability and positioning in heavy weather and hull and fatigue strength. More recently, environmental considerations have also become more prominent: first, oil pollution and now air emissions. This includes reducing emissions from the cargo and exhaust emissions that impact greenhouse gas. IMO has set targets and other stakeholders have joined in, notably Sea Charter and Poseidon Principles. In addition, the North Sea has stringent local requirements on environmental issues.
The current culmination of these development pressures has resulted in the state-of-the-art shuttle tankers delivered to AET and Altera in 2020 for North Sea operations. On emissions, we at DNV believe that LNG fuel is a very good transitional fuel. It has taken 20 years to create the current mature technology. This has been a stretched project for all the stakeholders involved but one thing is clear, LNG fuel will not bring us to IMO’s 2050 targets.
“One thing is clear, LNG fuel will not bring us to IMO’s 2050 targets”
So we will need to do something else as we move forward and many stakeholders believe in the pathway from LNG to ammonia. DNV has developed safety rules for these kind of fuels. DNV has also developed rules for the recovery of Volatile Organic Compounds (VOC) from cargo and mixing into the LNG fuel. It should be noted we had to develop rules for safety and implementing systems, since IMO is lagging behind the technology development.
Another aspect is hybridisation: introducing batteries to reduce fuel consumption and emissions by peak shaving, preventing blackouts and improving safety during DP operations. The latest innovation is machinery optimisation, through the creation of digital twins to model all the operational aspects and to utilise this for safety, testing and the creation of smart operations. The collection of quality data, coupled with remote witnessing and condition-based maintenance, will reduce downtime and help develop new efficiencies.
These developments in the shuttle tanker sector are likely to trickle down into the long-haul tanker fleet. However, some of the developments appearing in that fleet may not appear in the shuttle tanker fleet. For instance, wind-assisted propulsion. Although the North Sea has a lot of wind, this development might not be as suitable for shuttle tankers as compared to tankers on long-haul voyages. Air lubrication is also showing promising results, but may be difficult to optimise in shuttle tanker operations.