4 - Coating standard
4.1 Performance standard
This Standard is based
on specifications and requirements which intend to provide a target useful coating
life of 15 years, which is considered to be the time period, from initial
application, over which the coating system is intended to remain in “GOOD”
condition. The actual useful life will vary, depending on numerous variables
including actual conditions encountered in service.
4.2 Standard application
4.2.1 Protective coatings for the following void spaces should
comply with the requirements in this Standard:
- in bulk carriers:
- double bottom pipe passages / pipe tunnels;
- small void spaces located behind gusset or shedder plates at the bottom
of corrugation bulkheads with the exception of totally enclosed spaces;
- other small void spaces in cargo spaces, with the exception of totally
enclosed spaces;
- lower transverse stool of transverse bulkheads, with the exception of
totally enclosed spaces2; and
- upper transverse stool of transverse bulkheads, with the exception of
totally enclosed spaces2; and
- in oil tankers:
- forward cofferdam/cofferdam separating cargo from forepeak;
- cofferdam in cargo area/cofferdam separating incompatible cargoes;
- aft cofferdam;
- duct keel/pipe tunnels;
- lower bulkhead stools; and
- upper bulkhead stools.
4.2.2 Protective coatings for the following void spaces should
comply with the requirements in the Performance standard for protective coatings for
dedicated seawater ballast tanks in all types of ships and double-side skin spaces
of bulk carriers (resolution MSC.215(82)):
- in bulk carriers:
- double-side skin spaces in ships of less than 150 m in length; and
- upper and lower side void spaces and double bottoms void spaces in
cargo area; and
- in oil tankers:
double-side skin (DSS) voids including
sides, bottoms/double hull voids spaces protecting cargo oil tanks.
4.2.3 No requirements are contained in this Standard for
protective coatings for the following void spaces in bulk carriers and oil
tankers:
- totally enclosed spaces located behind gusset or shedder plates at the bottom
of corrugation bulkheads and other small totally enclosed spaces in cargo
tanks;
- lower transverse stool of transverse bulkheads that are totally enclosed
spaces;
- upper transverse stool of transverse bulkheads that are totally enclosed
spaces;
- transducer voids; and
- any spaces not specifically mentioned in paragraphs 4.2.1 and 4.2.2.
4.3 Special application
4.3.1 This Standard covers protective coating requirements for the
ship steel structure. It is noted that other independent items are fitted within the
tanks to which coatings are applied to provide protection against corrosion.
4.3.2 It is recommended that this Standard be applied, to the
extent possible, to those portions of permanent means of access provided for
inspection, not integral to the ship structure, such as rails, independent
platforms, ladders, etc. Other equivalent methods of providing corrosion protection
for non-integral items may also be used, provided they do not impair the performance
of the coatings of the surrounding structure. Access arrangements that are integral
to the ship structure, such as increased stiffener depths for walkways, stringers,
etc., should fully comply with this Standard.
4.3.3 It is also recommended that supports for piping, measuring
devices, etc., be coated in accordance with the provisions for non-integral items
indicated in paragraph 4.3.2.
4.4 Basic coating requirements
4.4.1 The requirements for protective coating systems, which
should be applied at ship construction to void spaces in bulk carriers and oil
tankers meeting the standard specified in paragraph 4.1, are listed in table 1.
4.4.2 Coating manufacturers should provide a specification of the
protective coating system to satisfy the requirements of table 1.
4.4.3 The Administration or an organization recognized by the
Administration should verify the Technical Data Sheet and Statement of Compliance or
Type Approval Certificate for the protective coating system.
4.4.4 The shipyard should apply the protective coating in
accordance with the verified Technical Data Sheet and its own verified application
procedures.
2 Noting, inter alia, the mandatory provisions of
resolution A.744(18), as amended, regarding the requirement to undertake close-up
surveys of the internal structure of upper and lower stools, where
fitted.