The Economics of a Long Term Coating

Abstract

An important challenge during ship construction is the protection against corrosion of the ballast tanks. These tanks have many compartments, contain multiple structural elements and play a critical role in the seaworthiness. The majority of the ballast tanks are prepared and coated according to IMO Performance Standard for Protective Coating regulations (PSPC), using a light colored epoxy coating that, when maintenance is being performed by the crew, must remain in a “good” condition for 15 years. This method is set next to a protection system applied by a given owner who keeps its ships in an excellent condition for their complete lifetime using a long term coating. More attention is paid to the preparation and application of the coating and consequently it protects the ballast tanks for more than 25 years. These coating strategies are compared in an economic analysis, supplemented with a sensitivity analysis to evaluate the outcomes due to variable parameters. The results indicate that a long term coating only pays off for owners willing to keep the ballast tanks of their vessels in a good condition for the complete lifetime. The decisive factor is that a long term coating entails no recoating in dry dock. The latter results in less toxic components in the atmosphere.

Accelerated Ballast Tank Corrosion Simulation Protocols: A Critical Assessment

“…We emphasize the importance of realistically simulating the process environment. Seeing that ballast tanks typically remain in good condition for an average period of 18.5 years [2], employing a realistic test simulation could entail a significant waiting period. We need a test environment that correlates with the realistic environment and that shortens the test time so that an early evaluation can be performed.…”

“…However, to what extent? Verstraelen et al [22], De Baere et al [23] and Willemen et al [2] inspected the ballast tanks of 172 randomly chosen ships between 2007 and 2019. The ships were visited as the opportunity arose.…”

“…These severe in-service conditions make water ballast tanks more vulnerable to corrosion when compared to other areas of the ship [1]. Another reason in promoting the study of the service environment of a ship's ballast tank is that extending the coating life span of a ballast tank reduces costs for the ship owner [2].…”