Coatings and Corrosion

Software and standards to aid cost saving

Malcolm Latarche
Malcolm Latarche

18 December 2018

Software and standards to aid cost saving

There is one particular area where coatings manufacturers’ claims are not only used for boosting sales but are often taken literally by regulators and potentially used in formulating regulation that can affect operators. That area is the potential fuel savings and consequent reduction in exhaust emissions claimed for anti-fouling and foul-release products.

Shipping is often perceived wrongly as a dirty industry and the idea that operators could reduce emissions by 5-10% just by applying a coat of paint has been used by some campaigners to highlight the disregard they believe shipping has for the environment. That idea is of course highly flawed but arguments refuting it would likely not be understood by those that make the claim. The shipping industry is fully aware that coatings – or lack of them – can have significant effects on fuel consumption but determining exactly how much is an extremely difficult task.

Developments such as the Energy Efficiency Design Index (EEDI) have caused shipowners and designers as well as regulators to take a new look at how coatings can impact efficiency for good and ill. Although the early stages of the EEDI formula looked only at the design and power of the ship for calculating its CO2 emission score, refinements to it allow for the effect of new and innovative technologies. Included in these are the potential of low friction coatings.

Performance of a ship tends to deteriorate between drydockings as fouling occurs and shows a marked improvement on leaving drydock. Some of that improvement will doubtless be due to the new coating although engine, turbocharger and propeller overhaul and repair could also be much more significant factors.

Changes in operating strategies and working in different geographical regions also make comparison of a ship’s overall performance overtime difficult, meaning the effect attributable to the coatings may be impossible to determine. Even so, some manufacturers have attempted to quantify the savings using software developed by third parties. International Paint and BMT ARGOSS use the BMT SMARTSERVICES system to verify the contribution to vessel performance made by its products and Jotun has similar arrangements with Kyma and Marorka. There are also independent software providers such as Propulsion Dynamics with its CASPER software and Eniram among others.

Propulsion Dynamics’ software was one of the first offerings to be developed in this specialised area and it compares ship performance from hull and propeller fouling with a clean, smooth hull and propeller from sea trials. This generates accurate figures for speed and fuel consumption due to basic roughness and fouling. This initial product has been supplemented with a tool to provide ideal trim based on speed, weather, and loading that does not require installation or calibration of sensors as it is based on a physical model of the vessel. All of the latest generation of software programs are designed to measure key parameters such as those mentioned above and their developers say that once sufficient data has been collected it is possible to strip out factors alone or in combination to determine the actual effect that one or other has on performance.

Now that coatings manufacturers have developed a means for testing the effectiveness of coatings by way of ISO 19030, the potential for putting quantifiable figures on the energy-saving potential of different types of coatings could impact of the EEDI rating of vessels coated with different products.

The fact that shipowners planning to validate individual manufacturers’ claims for products requires them to install sensors and employ approved software products to record and analyse performance may slow the acceptance of the standard and incorporation into the EEDI formulae for different ship types.