IMO MSC.215 Performance Requirements for Protective Coatings for Double Hull Areas of Special Seawater Ballast Tanks and Bulk Cargo Carriers on Ships of All Types

The International Maritime Organization (IMO) standard “IMO MSC.215 Performance standard for protective coatings for double-sided outer surface areas of special seawater ballast tanks of all types of ships and bulk carriers” describes the technical requirements for protective coatings in the double-sided outer surface areas of special seawater ballast tanks of all types of ships of at least 500 gross tonnage and bulk carriers of 150 m and over in length.

For the purpose of this standard, the following definitions apply:

• Ballast tanks are as defined in the Guidelines for the selection, application and maintenance of corrosion prevention systems for special seawater ballast tanks and in the Guidelines on the enhanced inspection program during inspections of bulk carriers and oil tankers.
• Dew point is the temperature at which air is saturated with moisture.
• DFT is the abbreviation for dry film thickness.
• Dust is loose particulate matter found on a surface prepared for painting, resulting from blast cleaning or other surface preparation operations or from environmental influences.
• Edge grinding is the machining of edges prior to secondary surface preparation.
• “Good” condition is one with minor spot rust.
• A hard coating is a coating that is chemically transformed during the curing process or a non-convertible air drying coating that can be used for maintenance purposes. It can be inorganic or organic.
• NDFT is the abbreviation for nominal dry film thickness. A 90/10 application means that 90 percent of all thickness measurements are greater than or equal to the nominal dry film thickness, and none of the remaining 10 percent of measurements are less than 0,9 x nominal dry film thickness.
• The primer coat is the first coat of the coating system applied after the workshop primer application in the shipyard.
• Shop primer is a pre-production primer coat applied to steel sheets, usually in automated facilities (and prior to the first coat of a coating system).
• Stripe coating is the painting of edges, welds, and hard-to-reach areas to ensure good paint adhesion and proper paint thickness in critical areas.
• Target useful life is the target value in years of durability for which the coating system is designed.
• A technical data sheet is a paint manufacturers product data sheet that contains detailed technical instructions and information regarding the coating and its application.

The ability of the coating system to achieve its target useful life depends on the type of coating system, steel preparation, application, and coating inspection and maintenance. All of these aspects contribute to good coating system performance.

The inspection of the surface preparation and coating processes will be agreed upon between the shipowner, the shipyard and the coating manufacturer and submitted to the administration for review. The administration may participate in the agreement process if it wishes. Clear evidence of these inspections will be reported and added to the coating technical file.

When evaluating this standard, the following should be taken into account:

• It is essential that the specifications, procedures and various different steps in the coating application process (including but not limited to surface preparation) are strictly followed by the shipbuilder to prevent premature decay or failure of the coating system.
• Coating performance can be improved by taking measures at the ship design stage, such as reducing combs, using rolled profiles, avoiding complex geometric configurations and ensuring that the structural configuration allows easy access for tools and facilitates cleaning, drainage and drying of the area to be coated.
• The coating performance standard is based on the experience of manufacturers, shipyards and ship operators. It is not intended to incorporate suitable alternative coating systems. Performance at least equivalent to that specified in this standard has been demonstrated.

The characteristics of the coating system applied to special seawater ballast tanks and double-sided coating areas, the record of coating works of the shipyard and the ship owner, detailed criteria for coating selection, job specifications, inspection, maintenance and repair are documented in the coating technical file, and the coating technical file is reviewed by the administration.

This standard is based on specifications and requirements intended to provide a target useful coating life of 15 years from initial application when the coating system is intended to remain in “Good” condition. Actual useful life will vary depending on a number of variables, including actual conditions encountered in service.

Standard practice is as follows: protective coatings for special seawater ballast tanks of all types of ships and for external double-sided surface areas arranged on bulk carriers of 150 m and above in length shall comply with at least the requirements of this standard.

This standard specifies the protective coating requirements for the steel structure of a ship. It is noted that other independent elements are also installed inside tanks where coatings are applied to provide protection against corrosion.

It is recommended that this standard be applied wherever possible to those parts of the ship's structure that are not integral to the permanent access means provided for inspection (e.g. rails, independent platforms, ladders). Other equivalent methods of providing corrosion protection for non-integrated items may be used provided they do not degrade the performance of the coatings of the surrounding structure. Access arrangements that are integral to the ship's structure, such as increased stiffener depths for walkways, girders etc., should fully comply with this standard.

It is also recommended that supports for piping, measuring instruments and the like be coated in accordance with the non-integrated elements mentioned above.

Base coat requirements:

• The requirements for protective coating systems to be applied in shipbuilding for special seawater ballast tanks of all ship types and double-sided external surface areas arranged on bulk carriers of 150 m and over in length are listed in the table that meet the performance standard specified above.
• Coating manufacturers must provide a specification for the protective coating system that will meet the requirements in the table.
• The administration must verify the technical data sheet and the declaration of conformity or type approval certificate for the protective coating system.
• The shipyard applies the protective coating in accordance with the validated technical data sheet and its own validated application procedures.

The results obtained from the preliminary qualification tests of the coating system are documented and, if found satisfactory by a third party independent of the coating manufacturer, a declaration of conformity or type approval certificate is issued.

Our organization has a strong staff that closely follows the developments in science and technology in the world and constantly improves itself. Among the numerous test, measurement, analysis and evaluation studies provided for businesses in various sectors, there are also test services in accordance with the standard “IMO MSC.215 Performance of protective coatings for special seawater ballast tanks on all types of ships and double-sided wall areas of bulk carriers”.