IMO Guidelines for Maintenance and Repair of Protective...
Transcript of IMO Guidelines for Maintenance and Repair of Protective...
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