Abstract
The application of coatings in ballast water tanks is critical for the safety of cargo ships. International Maritime Organization (IMO) has delivered a standard for the protection of water ballast tanks in which new built cargo vessels have to comply with {resolution MSC.215(82)}. In case the procedure of applying coatings differs from the IMO standard, the Performance standard for protective coatings (PSPC) gives an alternative method for approval; in this case equivalence of the protective properties has to be proved. The aim of this work is to investigate the coating performance in ballast water tanks that have serviced for more than 5 years. In this work, three different types of coating systems have been investigated by visual inspection and in situ electrochemical impedance measurements in ballast water tanks. All coating systems include shop primer plus one or two layer epoxy coatings. The results show that the impedance decreases with service time. However, all of them are in high impedance level, which means that they are in good shape to protect the ballast water tank from corrosion.
