Safinah Head of Marine Consulting, Carl Barnes presents data on factors that influence asset owners and operators in fouling control product selection - and the benefits of independent advice in optimising asset performance and overall longevity.
With over 150 products to choose from, each with their own performance and marketing claims, the decision process facing Owners and Operators for selecting fouling control technology can often be extremely complex and confusing. As such, the decision is often made based on either cost/fleet discounts, perceptions of product performance, marketing claims or the use of previous products.
The criteria used when selecting fouling control products
This was demonstrated during the “Coatings key role in shipping decarbonisation” webinar hosted by Riviera Maritime Media, when 200 participants were asked on a live survey what criteria they use when selecting fouling control products. The responses are shown below:
continued with previous product / supplier
used paint supplier recommendations
selection is based on cost
used third-party advice
45% of the respondents either continued with the previous product/supplier, or the selection was based on cost.
Furthermore, almost 80% did not use independent advice during product selection, which is against the best practice identified in the IMO biofouling management guidelines – there is clearly significant room for improvement when making product selection decisions.
For the optimal solution to be identified, careful consideration needs to be given to a variety of ship-specific factors affecting the suitability of potential technologies. Examples of such factors include typical vessel operational profiles and associated environmental parameters, expected activity and speed patterns, dry dock/new-build locations, season and product availability, biofouling management options, cleaning equipment availability at typical destinations, and others.
The output of such a methodical analysis of these factors is a robust and objective ‘functional’ specification, as opposed to the ‘generic’ specifications that dominate coating selection at present.
Frequency of underwater cleaning conducted during a 5-year dry dock cycle – Trends and Implications
A further poll question at the webinar asked, what is the frequency of underwater cleans conducted during a 5-year dry dock cycle, the results again made for interesting reading.
every 6 months
1 - 2 times during the full 5-year period
every 1 - 2 years
cleaning is not required
With only 11% of respondents indicating that cleaning is not required, 45% of respondents indicating an underwater clean is required every 1-2 years and surprisingly 11% of the responder’s conduct cleaning every 6 months, this is further evidence that fouling control product selection is currently far from optimal.
Furthermore, as underwater cleaning will always deplete antifouling dry film thickness (DFT), multiple underwater cleans during the drydock cycle will have a detrimental effect on the antifouling scheme life, due early polish through of the antifouling scheme prior to the planned end of scheme life.
The hard fouling problem – Insights from Safinah Drydock Data
To complement these opinions from the webinar, Safinah has unique in-house database of coating condition assessments documented from drydock supervision activities during dating back to 2010.
Based on a sample of over 800 drydock hull projects carried out between 2015 – 2024, the data showed that on average there was >1,300m2 per vessel covered in hard macrofouling (based on the vertical sides) and more than half of the ships with > 20% macrofouling on arrival at dry dock opted for the same manufacturer and often the same product.
The observations regarding hard macrofouling were also a theme in a further poll question at the webinar, when participants were asked, “what was the problem of hard fouling including barnacles”.
no problem at all
moderate problem
huge problem
minor problem
significant problem
80% of the participants deemed hard fouling to be either a significant or a huge problem.
As such and despite the wide range of fouling control product available, the results from Safinah’s drydock database and the opinions from the poll questions, raise the question of whether the selected coating technologies were suitable for the specific ships in question, or whether this was a result of a poor specification and selection process.
Common specification issues
Safinah’s data indicates that specification issues are continuing to be a significant problem and examples include:
- Incomplete/inaccurate historical vessel data
- Changes to the vessel operating profile not considered during tendering
- Errors in the tender offers – products, operating profiles, surface preparation, schemes, and surface areas
- Budget considerations
- Planned vs actual surface preparation in dry dock
- Fleet-wide specifications
- Tradition/no diversification
- A lack of a structured test patch program, involving all coating suppliers.
Clearly poor pre-drydock planning, the use of generic specifications and a lack of a systematic review of overall fleet coating performance is having a detrimental effect on fouling control product and vessel performance.
Having independent data on coating performance across all ship types, operating profiles and coating technologies/products is critical for optimal product selection.
Using a systematic approach to fouling control coating selection and specification via, functional specifications and periodic fleet reviews, are key to robust evidence based fouling control strategy.
Find out more about our Product Selection and Specification service, and how Safinah can can help you with fouling control.
To discuss your requirements or other questions, please contact our team at enquiries@safinah.com – or submit a contact request form below.
