3.5.1 Examination of ballast tanks should
be carried out when required as a consequence of the results of the
renewal survey and intermediate survey. When extensive corrosion is
found, thickness measurements should be carried out.
3.5.2 Where substantial corrosion as
defined in 1.2.8 is found, the extent of thickness measurements should
be increased in accordance with the requirements in annex 4.
3.5.3 Double hull oil tankers exceeding 15 years
All ballast tanks adjacent to (i.e. with a common plane boundary)
a cargo or fuel tank with any means of heating should be examined
internally. When considered necessary by the surveyor, thickness measurement
should be carried out and if the results of these thickness measurements
indicate that substantial corrosion is found, the extent of thickness
measurements should be increased in accordance with annex 4.
Ballast tanks which were found, at the previous intermediate
or renewal survey, to have no substantial corrosion within the tank
and which were found in compliance with either of the following conditions:
.1 coating in GOOD condition; or
.2 coating of the common boundary, including adjacent
structures, in GOOD condition and the coating of the remaining parts
of the tank in FAIR condition,
may be specially considered by the Administration.