The commercial impact of Covid-19 on the shipping industry has been immense, and it has taken its toll on biofouling, writes I-Tech AB marketing director Catherine Austin.
A common feature across our industry is that there are significantly more ships sat still than this time last year. Shipowners have looked to put ships in hot or warm lay up as an interim solution to weather the dismal market conditions brought about by decreased consumer goods demand and halted passenger cruising and short-sea ferry trips due to travel restrictions.
Not since the global crisis of 2008 and 2009 has such a large proportion of the industry sat still. This is bad for business and also bad for biofouling.
Biofouling has been a perennial headache for the shipping industry for centuries. However, it now looks like it is going to get far worse, particularly for those vessels sat idle in warmer waters. Marine organisms love a static submerged surface and ship hulls below the waterline are prime real estate.
Since biofouling causes increased frictional resistance when water flows across the hull, ships with heavy-fouled hulls have to burn more fuel to maintain the same speed through the water. If a ship is operating on fixed shaft power, speed penalties will ensue.
Barnacles and their volcano-shaped hard shells that stick out into the water column are a particularly damaging contributor to frictional resistance. Once they attach head-first onto a hull using their super strong glue, they are very tricky to get rid of. If water-based cleaning techniques will not shift them, more abrasive scrubbing methods are required.
“Marine organisms love a static submerged surface and ship hulls below the waterline are prime real estate”
A new research study commissioned by I-Tech AB, undertaken by the Safinah Group, has revealed the extent to which barnacle fouling impacts the global fleet.
For the research study, the Safinah Group analysed underwater hull fouling conditions on a sample of 249 ships which drydocked over a four-year period between 2015-2019. It was discovered that over 40% of vessels surveyed had a barnacle fouling coverage on the hull of over 10%.
Anything above 10% coverage is deemed to cause an ‘unacceptable’ impact on vessel performance.
On many of the vessels surveyed, fouling levels were even worse: approximately 15% of vessels had between 10-20% of hard fouling coverage on the hull; 10% of vessels had 20-30% of hard fouling coverage; and the remaining 10% of vessels had between 40-80% of hard fouling coverage.
“This level of hard fouling could be responsible for at least 110M tonnes of excess carbon emissions”
Extrapolating from published data taken from a 2011 study by Michael P. Schultz, this level of hard fouling (assuming a 10% coverage of hard fouling on 40% of the fleet) could be responsible for at least 110M tonnes of excess carbon emissions, and an additional US$6Bn spent on fuel per year for the global commercial fleet. The true figure is likely to be higher, as this is a conservative calculation based on today’s relatively low fuel prices.
This data analysis was carried out before the Covid-19 pandemic; therefore, it can be anticipated that in recent months, the extent of barnacle fouling coverage across the global fleet will have increased significantly, chiefly due to the huge proportion of vessels that have lain idle. We can assume that if this data collection exercise was repeated, we would see a significant spike in the extent of fouling coverage.
This means that when the thousands of vessels that have barnacles on their hulls set sail again, the impact will be immediately noticeable on the fuel bill. Those ships that were protected against extended idling periods by antifouling coatings that have I-Tech’s Selektope technology inside, will reap the immediate benefits of a barnacle-free hull.
For most antifouling coatings, protection guarantees range between 14 and 21 idle days, with the most premium antifouling coatings coming with up to 30-days idle guarantee. However, under tough market conditions such as those encountered during the current pandemic, ships need longer protection guarantees. For many antifouling coatings on the market this is made possible by the inclusion of Selektope.
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