It is a fact of maritime life that ships’ hulls attract fouling, and there is no coating available that can completely prevent this. When hulls foul, the best solution is to clean that fouling off.
A fouled hull has a far greater resistance in water, needing more power to propel the ship at the desired speed, and thus using more fuel, raising operating costs and increasing exhaust emissions.
Most anti-fouling or foul-release coatings carry risks of damage to the environment or to the coatings themselves during cleaning. However, there is a system – Ecospeed – that lends itself to fast, effective cleaning. Ecospeed offers a hard, glassy surface that is designed to be washed without being damaged, and it contains no toxins that can be released into the water in high concentrations during the cleaning process.
Underwater maintenance of Ecospeed is carried out using specially designed underwater hull cleaning tools that simultaneously remove all fouling and optimize the smoothness of the paint surface. It allows divers to clean the flat areas as well as the harder to reach parts of the hull without damage to the coating. Not only does cleaning not damage Ecospeed, repeated cleaning actually improves the surface, ensuring that it becomes harder for fouling organisms to gain hold.
Because of the potential for toxic contamination, the general trend has been to ban underwater cleaning of ships in port. However, many harbour authorities make an exception for vessels coated with Ecospeed, recognising the advantages of cleaning without release of toxins into sensitive environments. Ecospeed is 100% non-toxic and there is no negative effect on the water quality or the marine environment during either application or maintenance.
As well as underwater cleaning, Ecospeed can be cleaned in drydock with high pressure tools. “Several of our customers use this method to have their vessels cleaned. Their ships are taken out of the water, cleaned with high pressure tools and put back in the water in a matter of hours,” says Manuel Hof, Production Executive at Subsea Industries, the company that produces Ecospeed.
Because no material is lost when cleaning Ecospeed, the coating is always in a brand-new, excellent condition after a high pressure washing. Only the fouling is removed. The coating stays on the ship instead of dispersing in the water and contaminating the shipyard and the surrounding waters. The frequency of underwater cleaning of Ecospeed can be optimised to minimise fouling and prevent any build-up of macrofouling.
Ecospeed coating is well suited for ships undergoing lay-ups or other long stationary periods because it provides an impermeable and impenetrable barrier. This resists corrosion as well as protecting the underwater hull against mechanical damage. Despite the aggressive nature of certain types of fouling, no corrosion or damage to the steel will be present on the underwater hull of the vessel coated with Ecospeed, because hard fouling is unable to penetrate or damage the coating.
According to Boud Van Rompay, Subsea Industries’ founder and coatings innovator, “Ecospeed is an entirely different, more cost-effective and environmentally-acceptable approach to hull protection and anti-fouling. There is no need to re-blast and recoat the hull; no corrosion, no impact on the environment and, if regular hull cleaning is carried out, fuel savings of up to 50% can be achieved. When fouled – just wash it.”
Sea News, April 11