Hull performance remains a key element in understanding fuel performance and this is regardless of vessel type. To fully understand[ds_preview] if a vessel is performing well it is vital that shipowners, operators and managers have clear benchmarks and measurements to work from.
To begin, however, it is important to invest in a good antifouling or fouling defence solution as fouling can significantly affect a vessel’s fuel efficiency and performance. Just moderate fouling for example can cause a speed reduction between 10 and 18%. This leads to increased fuel consumption as the ship works to maintain its desired speed and counter the increased frictional drag caused by the biological growth. By hard fouling fuel consumption can be increased by up to 40%.
Once the most beneficial coating solution has been selected it is important to measure the operational conditions of a vessel, and to verify and benchmark these to get a full understanding of the true performance of a vessel’s hull. This is why worldwide coatings manufacturer Hempel launched a hull performance system called SHAPE (Systems for Hull and Propeller Efficiency). It is founded on the ISO 19030 framework which defines a methodology to measure changes in hull and propeller performance and defines a set of relevant performance indicators for hull and propeller maintenance.
»Shape« combines elements of hull and propeller efficiency optimisation to maximise the quality of performance data analysis, allowing to deliver expert advice and solutions to every ship operator to maximise hull efficiency and return on investment. The system can monitor the long-term trends via in-service key performance indicators (KPIs).
Simply put, »Shape« provides a clear system to accurately compare hull and propeller solutions by referencing simple and transparent data and analytics. This offers owners and interested parties the information they need to make an informed assessment and to take decisions to positively impact their fuel efficiency.
Looking in more detail at the thorough process, there are six key stages. To begin with, the vessel’s individual speed power reference curves are established. This is followed by the collection of in-service data, which is then cleansed and purified to eliminate extreme operating conditions and to subtract the effects of environmental factors.
The next stage is to perform the precise speed loss calculation as this is a critical measure for understanding vessel performance and fuel efficiency as power increase and speed loss are directly related. From this four KPIs are calculated:
• Dry docking performance – calculates the changes in hull and propeller performance over drydocking periods
• In-service performance – calculates the effectiveness of the vessel’s hull and propeller solutions
• Maintenance trigger – calculates the change in hull and propeller performance over a given period between drydocking and in-service use
• Maintenance effect – calculates the change in performance before and after a maintenance event
Following this in-depth process, tangible solutions are needed and best practice with shipowners and operators are shared. It is clear that vessel efficiency can be significantly enhanced not only by applying the correct coating solution in the first place, but also by applying big data intelligence to optimise hull and propeller performance. This arms shipowners and operators with the right tools to compete in the current competitive market and maximises the performance of their vessels.
Andreas Glud
