What are Anti Fouling Paints and TBT ?

Hull condition for merchant ship is a key factor in deciding the fuel efficiency of the ship. The application of protective coating of anti fouling paints results in a smooth hull devoid of any marine fouling, which decreases the frictional resistance caused by the water flow. The anti-fouling paints decrease the load on the engine and increase fuel efficiency.

With time, marine fouling and sea condition roughens the hull surface of the ship. As the frictional resistance caused by the water flow over the hull increases, the engine has to consume more fuel to overcome this resistance which adds on to the normal fuel consumption of the ship.

What are Anti-fouling Paints?

Anti fouling is the process of removing or preventing the accumulation of marine organisms from the surface of hull and the paint used for this application is called anti fouling paint.

What is TBT and Why was it banned?

Tributyltin or TBT is a biocide which came into being in the 1970s’ because of its brilliant anti fouling properties over ships hull as it prevents the growth of algae, barnacles and other marine organisms.

However, TBT was phased out of use from 1^st Jan 2008 by IMO due to following reasons:

• TBT’s harmful effects causes disruption of endocrine system of marine shell fish which leads to the development of male sex characteristics in female snails.

• It also impairs the immune system of organisms and malformations of the shell of shellfish.

Since then several types of anti-fouling paints have come to the market. As the rules of IMO regarding anti-fouling paints become stringent day after day, the paints have become more environmental friendly with least effect on the marine environment.

You may also like to read-What is Marine Growth Preventive System On a Ship?