4.2.1.1 Recognizing that different areas in the
tank experience different coating breakdown and corrosion patterns
or erosion, the intent of this section is to subdivide the planar
boundaries of the tank for evaluation of coating into areas small
enough to be readily examined and evaluated by the surveyor. However,
the areas subdivided should not be so small as to be structurally
insignificant or too numerous to practically report on. Coating condition
in each area should be reported using current practice and terminology
(frame numbers, longitudinal numbers and/or strakes numbers, etc.).
Each area is then rated "GOOD", "FAIR" or "POOR" and the tank rating
should not be higher than the rating of its "area under consideration"
having the lowest ratingfootnote.
4.2.1.2 Special attention should be given to coating
in critical structural areas which are definedfootnote as "locations which have been identified
from calculations to require monitoring as indicated in the CTF from
new building stage or from the service history of the subject ship
or from similar or sister ships (if available) to be sensitive to
cracking, buckling corrosion or erosion which would impair the structural
integrity of the ship". Each critical structural area is rated "GOOD",
"FAIR" or "POOR", applying table 1 and the rating of each "area under
consideration" should then not be higher than the rating of its critical
structural area (if present) having the lowest rating.
4.2.1.3 The ship specific guidelines should include,
as an appendix, the actual details of the coated areas in each tank
together with other details as specified in paragraph 7.2.2 of these
Guidelines.
4.2.2
Coated areas of
crude oil cargo tanks in oil tankers
4.2.2.1 Deck head with upper transverses and longitudinal
bulkheads
Areas of under deck and bulkhead plating with attached structure
(one area to consider for deck head and one area to consider for each
bulkhead upper part with any structure and access platforms or stringers).
4.2.2.2 Bottom plating with transverse and longitudinal
lower bulkheads
Areas of tank bottom, side and longitudinal bulkheads (hoppers)
with attached structure (if any), in the lower coated areas.
The upper and lower parts of all swash bulkheads located
in cargo tanks together with any frames, brackets, and access outfittings
in way.
Stringers located outside the prescribed upper and lower
coating areas are not required to be coated. However, in the case
that shipowners have voluntarily coated the upper surfaces of such
stringers then these coated surfaces should be included in reports
solely for shipowner's benefit and choice of any action.
4.2.2.5 Transverse bulkheads (forward and aft)
Areas of transverse bulkheads and attached stiffeners and
access outfittings in upper forward and aft transverse bulkheads.