Extract of thickness measurements
Reference is made to the thickness measurement report:
|
Position of substantially corroded tanks/areas1 or areas with
deep pitting3
|
Thickness
diminution [%]
|
Corrosion
pattern2
|
Remarks:
(e.g. reference to
attached
sketches)
|
|
|
|
|
Notes:
1 Substantial corrosion, i.e. 75 to 100 per cent of acceptable margins
wasted.
2 P = pitting
3 Any bottom plating with a pitting intensity of 20% or more, with
wastage in the substantial corrosion range or having an average depth of pitting of ⅓ or
more of actual plate thickness shall be noted.
Tank corrosion prevention system
|
Tank Nos.1
|
Tank corrosion
prevention system2
|
Coating condition3
|
Remarks
|
|
|
|
|
Notes:
1 All segregated ballast tanks and combined cargo/ballast tanks shall be
listed.
2 C = Coating
3 Coating condition according to the following standard:
| 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.
|
If coating condition less than GOOD is given, extended annual surveys shall
be introduced. This shall be noted in part 9 of the Contents of the condition evaluation
report (executive hull summary report).
Evaluation result of longitudinal strength of the hull girder of oil tankers of
130 m in length and upwards and of over 10 years of age
(of sections 1, 2 and 3 below, only one applicable section shall
be completed)
1 This section applies to ships regardless of the date of
construction: Transverse sectional areas of deck flange (deck plating and deck
longitudinals) and bottom flange (bottom shell plating and bottom longitudinals) of the
ship's hull girder have been calculated by using the thickness measured, renewed or
reinforced, as appropriate, during the renewal survey of the Cargo Ship Safety
Construction Certificate or the Cargo Ship Safety Certificate (SC renewal survey) most
recently conducted after the ship reached 10 years of age, and found that the diminution
of the transverse sectional area does not exceed 10% of the as-built area, as shown in
the following table:
Table 1 – Transverse sectional
area of hull girder flange
|
|
Measured
|
As-built
|
Diminution
|
| Transverse section 1
|
Deck flange
|
cm2
|
cm2
|
cm2 (%)
|
| Bottom flange
|
cm2
|
cm2
|
cm2 (%)
|
| Transverse section 2
|
Deck flange
|
cm2
|
cm2
|
cm2 (%)
|
| Bottom flange
|
cm2
|
cm2
|
cm2 (%)
|
| Transverse section 3
|
Deck flange
|
cm2
|
cm2
|
cm2 (%)
|
| Bottom flange
|
cm2
|
cm2
|
cm2 (%)
|
2 This section applies to ships constructed on or after 1
July 2002: Section moduli of transverse section of the ship's hull girder have been
calculated by using the thickness of structural members measured, renewed or reinforced,
as appropriate, during the SC renewal survey most recently conducted after the ship
reached 10 years of age in accordance with the provisions of paragraph 2.2.1.1 of annex 12, and are
found to be within their diminution limits determined by the Administration, taking into
account the recommended diminution limit adopted by IMO resolution MSC.108(73): 90% of
the required section modulus for new buildings specified in IACS' Unified Requirements
S7 (C=1.0Cn shall be used for the purpose of this calculation) or S11, whichever is the
greater, as shown in the following table:
Table 2 – Transverse section
modulus of hull girder
|
|
Zact (cm3)1
|
Zreq (cm3)2
|
Remarks
|
| Transverse section 1
|
Upper deck
|
|
|
|
| Bottom
|
|
|
|
| Transverse section 2
|
Upper deck
|
|
|
|
| Bottom
|
|
|
|
| Transverse section 3
|
Upper deck
|
|
|
|
| Bottom
|
|
|
|
Notes:
1 Zact means the actual section moduli of the
transverse section of the ship's hull girder calculated by using the thickness of
structural members measured, renewed or reinforced, as appropriate, during the SC
renewal survey, in accordance with the provisions of paragraph 2.2.1.1 of annex 12.
2 Zreq means the diminution limit of the
longitudinal bending strength of ships, as calculated in accordance with the provisions
of paragraph 2.2.1.1 of annex 12.
The calculation sheets for Zact should be attached to this
report.
3 This section applies to ships constructed before 1 July
2002: Section moduli of transverse sections of the ship's hull girder have been
calculated by using the thickness of structural members measured, renewed or reinforced,
as appropriate, during the SC renewal survey most recently conducted after the ship
reached 10 years of age in accordance with the provisions of paragraph 2.2.1.2 of annex 12, and
found to meet the criteria required by the Administration and that Zact is
not less than Zmc (defined in note 2 below) as specified in appendix 2 to
annex 12,
as shown in the following table.
Describe the criteria for acceptance of the minimum section moduli of the
ship's hull girder for ships in service required by the Administration.
Table 3 – Transverse section
modulus of hull girder
|
|
Zact (cm3)1
|
Zmc (cm3)2
|
Remarks
|
| Transverse section 1
|
Upper deck
|
|
|
|
| Bottom
|
|
|
|
| Transverse section 2
|
Upper deck
|
|
|
|
| Bottom
|
|
|
|
| Transverse section 3
|
Upper deck
|
|
|
|
| Bottom
|
|
|
|
Notes:
1 As defined in note 1 of table 2.
2 Zmc means the diminution limit of minimum
section modulus calculated in accordance with the provisions of paragraph 2.2.1.2 of
annex 12.