Naoki Takahashi

Survey Department

IMO Guidelines for

Maintenance and Repair of

Protective Coating

Cause of Hull Damages

Kind of Cause

13.6%

8.2%

3.1%

1.6%

0.4%

0.6%

0.7%

1.4%

70.4%

Corrosion

Design

Vibration

Mishandling

Heavy Weather

Slamming

Workmanship

Loading/Ballasti

ng

Others

Background

SOLAS II-1/3-2.1.4Maintenance of the protective coating system shall be included in the overall ship’s maintenance scheme. The effectiveness of the protective coating system shall be verified during the life of a ship by the Administration or an organization recognized by the Administration, based on the guidelinedeveloped by the Organization.

IMO PSPC 3.4.1Specification of the coating system applied to the dedicated seawater ballast tanks and double-side skin spaces, record of the shipyard’s and shipowner’s coating work, detailed criteria for coating selection, job specifications, inspection, maintenance and repair shall be documented in the Coating Technical File (CTF), and the Coating Technical File shall be reviewed by the Administration.

IMO PSPC 3.4.3In-service maintenance, repair and partial re-coating activities shall be recorded in the Coating Technical File in accordance with the relevant section of the Guidelines for coating maintenance and repair.

Aims of the IMO Guidelines (Draft)

Assisting the Surveyors, Shipowners, Shipyards,

Flag Administrations and other interested parties

involved in the survey, assessment and repair of

protective coatings in ballast tanks.

The Guidelines address a clear definition of

coating condition, Maintenance and Repair.

The basis for developing the Guidelines has been

IACS Recommendation 87

Contents of the IMO Guidelines (Draft)

General

Application

Survey recommendations

Coating conditions

Coating maintenance

Coating repair

Coating Technical File (CTF)

Appendices

Intermediate Surveys for all ships above 500GT

exceeding 5 years of age

Special Survey for all ships above 500GT

The condition of the coating in ballast tanks is

assigned and categorized as GOOD, FAIR or

POOR based on visual inspection

Tanks categorized as FAIR or POOR to be

examined at Annual Interval.

The coating system in ballast tanks is to be

examined in connection with:

Survey recommendations

Coating Condition

Definitions of coating conditions “GOOD”, “FAIR” and

“POOR” in IMO Resolution A.744(18)

GOOD: condition with only minor spot rusting

FAIR: condition with local breakdown of coating at edges

of stiffeners and weld connections and/or light rusting over

20% or more of areas under consideration, but less than

as defined for POOR condition

POOR: condition with general breakdown of coating over

20% or more of areas or hard scale at 10% or more of

areas under consideration

Coating Condition

Coating ConditionArea Under Consideration

SINGLE HULL TANKER- WING BALLAST TANKS

Deck and bottom

one (1) area for deck

one (1) area for bottom

Side shell and longitudinal Bhd

three (3) areas for side shell

three (3) areas for longitudinal bhd.

Transverse bulkheads

(forward and aft)

three (3) areas for forward

transverse bulkhead

three (3) areas for aft transverse

bulkhead

Coating Condition

Area Under Consideration

AFTER PEAK TANKS FORE PEAK TANKSTwo(2) areas to consider Three(3) areas to consider

Coating Condition

In-service Condition Monitoring

Successful maintenance and repair procedure

start with good information.

It is recommended that all ballast tanks, especially

for ships over 6 years of age, are inspected at

least annually by the ship's crew.

The rating (GOOD/FAIR/POOR) gives the Owner's

technical staff an objective report of the condition

so that the urgency of the repairs can be

established and the most cost effective solution

found.

Coating Condition

In-service Condition Monitoring

Successful maintenance and repair procedure

start with good information.

It is recommended that all ballast tanks, especially

for ships over 6 years of age, are inspected at

least annually by the ship's crew.

The rating (GOOD/FAIR/POOR) gives the Owner's

technical staff an objective report of the condition

so that the urgency of the repairs can be

established and the most cost effective solution

found.

Definition of Maintenance and Repair

Maintenance Repair

Purpose Maintain GOOD or FAIRRestore FAIR or POOR

to GOOD

WhenDuring voyage

(ship in service)

During ship’s drydocking

or scheduled repair

period (ship idle)

By Whom Ship’s crewSpecialized manpower

from shore

ToolNormal shipboard means

and tools

Specialized equipment

such as sand blasting

equipment

Recommended Maintenance

Recommended maintenancePreparation Coating system Dry Film Thickness

• Removal of mud, oil, grease, etc.

• Fresh-water hosing

• Drying

• St3 or equivalent according to

manufacturer’s recommendation

• Check ambient condition

•Epoxy-based system

•The same coating

system as was originally

employed or according to

manufacturer’s

recommendation

• according to

manufacturer’s

recommendation

Recommended Repair

Recommended medium and long-term repairPreparation Coating system Dry Film Thickness

• Removal of mud, oil, grease, etc.

• Fresh-water hosing

• Drying

• St3 or Sa2 ½ for FAIR condition

• Sa2 ½ for POOR condition

• Intact coating next to damaged

area should be feathered

• Total soluble salts, calculated as

sodium chloride, according to

manufacturer’s recommendation,

but not more than 80 mg/m2

• Climatic control

• Coating system

approved according to

resolution MSC.215(82)

• The same coating

system as was originally

employed, or a coating

system compatible with

the original system, or

equivalent according to

manufacturer’s

recommendation

• 250 μm DFT

for Medium term

• 320 μm DFT

for Long term

• Minimum two

spray coats with

two stripe coats

Medium term: 10 years’ target life

Long term : More than 10 years’ target life

Library of picturesGOOD COATING CONDITION

Library of picturesFAIR COATING CONDITION

Library of picturesPOOR COATING CONDITION

Development of the IMO Guideline

“Areas under consideration” for ships other

than oil tankers not presented in the draft

Guidelines

IACS invited to further develop this matter

and inform DE52 of the outcome

DE52 further consider the draft Guidelines