SEE INTERPRETATION 45
1 Every oil tanker
of 5,000 tonnes deadweight and above delivered on or after 1 February
2002, as defined in regulation 1.28.7, shall
comply with the intact stability criteria specified in paragraphs
1.1 and 1.2 of this regulation, as appropriate, for any operating
draught under the worst possible conditions of cargo and ballast
loading, consistent with good operational practice, including intermediate
stages of liquid transfer operations. Under all conditions the ballast
tanks shall be assumed slack.
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.1 |
In port, the initial metacentric
height GMo, corrected for the free surface measured
at 0° heel, shall be not less than 0.15 m; |
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.2 |
At sea, the following
criteria shall be applicable: |
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|
.2.1 |
the area under the righting lever curve (GZ
curve) shall be not less than 0.055 m·rad up to θ
= 30° angle of heel and not less than 0.09 m·rad
up to θ = 40° or
other angle of flooding θf*
if this angle is less than 40°. Additionally, the area under
the righting lever curve (GZ curve) between the angles of heel
of 308 and 40° or between 30° and θf,
if this angle is less than 40°, shall be not less than 0.03
m·rad; |
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|
.2.2 |
the righting lever GZ shall be at least 0.20
m at an angle of heel equal to or greater than 30°; |
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|
.2.3 |
the maximum righting arm shall occur at an
angle of heel preferably exceeding 30° but not less than
25°; and |
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|
.2.4 |
the initial metacentric height GMo,
corrected for free surface measured at 0° heel, shall be
not less than 0.15 m. |
2 The requirements
of paragraph 1 of this regulation shall be met through design measures.
For combination carriers simple supplementary operational procedures
may be allowed.
3 Simple supplementary
operational procedures for liquid transfer operations referred to
in paragraph 2 of this regulation shall mean written procedures
made available to the master which:
| |
.1 |
are approved by the Administration; |
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.2 |
indicate those cargo and ballast tanks which
may, under any specific condition of liquid transfer and possible
range of cargo densities, be slack and still allow the stability
criteria to be met. The slack tanks may vary during the liquid
transfer operations and be of any combination provided they
satisfy the criteria; |
| |
.3 |
will be readily understandable to the officer-in-charge
of liquid transfer operations; |
| |
.4 |
provide for planned sequences of cargo/ballast
transfer operations; |
| |
.5 |
allow comparisons of attained and required
stability using stability performance criteria in graphical
or tabular form; |
| |
.6 |
require no extensive mathematical calculations
by the officer-incharge; |
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.7 |
provide for corrective actions to be taken
by the officer-incharge in case of departure from recommended
values and in case of emergency situations; and |
| |
.8 |
are prominently displayed in the approved
trim and stability booklet and at the cargo/ballast transfer
control station and in any computer software by which stability
calculations are performed. |
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