Section 7 Special Survey - Oil tankers (including ore/oil ships and ore/bulk/oil ships) - Hull requirements

7.1.1 The requirements of Pt 1, Ch 3, 2 Annual Surveys - Hull and machinery requirements, Pt 1, Ch 3, 4 Bottom Surveys – In Dry-Dock and In-Water - Hull and machinery requirements and Pt 1, Ch 3, 5 Special Survey - General - Hull requirements are to be complied with as applicable.

7.1.2 In order to maintain and/or assign the ESP notation, the following requirements apply to the surveys of the hull structure and piping systems in way of the cargo tanks/cargo holds, pump rooms, cofferdam, pipe tunnels, void spaces, double bottom tanks, etc. in way of the cargo tank area and all salt-water ballast tanks.

7.2.1 Prior to survey, the Surveyor is to examine the completeness of the documentation on board as detailed in Pt 1, Ch 3, 1.10 Documentation and its contents as a basis for the survey.

7.2.2 For CSR oil tankers subject to SOLAS - International Convention for the Safety of Life at Sea Chapter II-1 - Construction - Structure, subdivision and stability, machinery and electrical installations Part A-1 - Structure of ships Regulation 3-10 – Goal-based ship construction standards for bulk carriers and oil tankers the Surveyor is to examine the information held in the Goal Based Standard (GBS) Ship Construction File (SCF) stored on board the ship. On completion of the survey, in the case of any major event, including, but not limited to, substantial repair, conversion or any modification to the ship structure, the Surveyor is to verify that the information stored on board of the ship has been updated and is to verify any addition and/or renewal of materials used for the construction of the hull structure are documented within the GBS SCF list of materials.

7.2.3 For CSR oil tankers subject to SOLAS - International Convention for the Safety of Life at Sea Chapter II-1 - Construction - Structure, subdivision and stability, machinery and electrical installations Part A-1 - Structure of ships Regulation 3-10 – Goal-based ship construction standards for bulk carriers and oil tankers for the GBS SCF Supplement Ashore, the Surveyor is to verify the information stored in the Archive Centre by examining the list of information included in the Supplement Ashore. In addition, the Surveyor is to confirm that the service contract with the Archive Centre remains valid. In the case of any major event, including, but not limited to, substantial repair, conversion or modification to the ship’s structure, the Surveyor is to verify that the information stored in the Archive Centre has been updated by examining the list of updated information included in the Supplement Ashore.

7.3.1 A Survey Programme is to be submitted by the Owner and is to include the proposals for survey, including the means of providing access for Close-up Survey, thickness measurement and tank testing and should take account of the information detailed in Pt 1, Ch 3, 7.2 Review of documentation on board 7.2.1.

7.3.2 Prior to the development of the Survey Programme a Survey Planning Questionnaire is to be completed and submitted by the Owner, see Pt 1, Ch 3, 1.6 Preparation for survey and means of access 1.6.16.

7.4.1 All cargo tanks/cargo holds, and salt-water ballast tanks including double bottom tanks, pump rooms, pipe tunnels, cofferdams and void spaces bounding cargo tanks/cargo holds, deck and outer hull are to be examined, and this examination is to be supplemented by Close-up Survey, thickness measurement and testing as applicable, to ensure that the structural integrity remains effective.

7.4.2 The examination is to be sufficient to ascertain substantial corrosion, significant deformation, fractures, damages or other structural deterioration and, if deemed necessary by the Surveyor, suitable non-destructive examination may be required.

7.4.3 Where substantial corrosion, as defined in Pt 1, Ch 3, 1.5 Definitions, is identified and is not rectified, this will be subject to re-examination at Annual and/or Intermediate Surveys. In the case of salt-water ballast tanks and combined tanks for the carriage of salt-water ballast and cargo oil, the examination will be required at Annual Survey and Intermediate Survey. In the case of cargo oil tanks the examination will be required at Intermediate Surveys.

7.4.4 All cargo piping on deck, including Crude Oil Washing (COW) piping, and cargo and ballast piping within those spaces indicated in Pt 1, Ch 3, 7.4 Overall Survey 7.4.1 are to be examined and tested under working conditions to ensure that tightness and condition remain satisfactory. Special attention is to be given to ballast piping in cargo tanks and any cargo piping in ballast tanks and void spaces. The Surveyor should be advised on all occasions when this piping, including valves and fittings, is open and degasified during repair periods and may be examined internally.

7.4.5 Where salt-water ballast tanks have been converted to void spaces the survey extent is to be based upon salt-water ballast tank requirements.

7.4.6 Where provided, in association with a corrosion control CC special features notation, as defined in the Register Book, the condition of the protective coating or corrosion prevention system of cargo tanks is to be examined.

7.4.7 The attachment to the structure and condition of anodes in tanks is to be examined.

7.4.8 Where fitted, the strums of the cargo suction pipes are to be removed or lifted to facilitate examination of the shell plating and bulkheads in the vicinity, unless other means for visual inspection of these parts are provided.

7.5.1 The minimum ballast tank testing requirements are given in Table 3.7.1 Tank testing requirements - Single hull and double hull oil tankers, ore/oil ships and ore/bulk/oil ships and, where required, the Surveyor may extend the tank testing if deemed necessary. The remaining requirements for tank testing, as applicable, are given in Pt 1, Ch 3, 5.3 Examination and testing 5.3.6.

7.5.2 The minimum cargo tank testing requirements are given in Table 3.7.1 Tank testing requirements - Single hull and double hull oil tankers, ore/oil ships and ore/bulk/oil ships; boundaries of cargo tanks are to be tested to the highest point that liquid will rise to under service conditions.
Cargo tank testing carried out by the ship’s crew under the direction of the Master may be accepted by the Surveyor provided the following conditions are complied with:

1. A tank testing procedure specifying fill heights, tanks being filled and bulkheads being tested has been submitted by the Owner and reviewed by LR prior to the testing being carried out.

2. There is no record of leakage, distortion or substantial corrosion that would affect the structural integrity of the tank.

3. The tank testing has been satisfactorily carried out within the special survey window not more than 3 months prior to the date of the survey on which the overall or close-up survey is completed.

4. The satisfactory results of the testing are recorded in the ship’s logbook.

5. The internal and external condition of the tanks and associated structure is found satisfactory by the Surveyor at the time of the overall and close-up survey.

7.5.3 Notwithstanding the provisions of Pt 1, Ch 3, 7.5 Testing 7.5.2, permitting cargo tank testing to be carried out by the ship’s crew under the direction of the Master, the testing of water ballast tanks is to be witnessed by an attending Surveyor, during which the attending Surveyor is to examine all boundaries, including the boundaries facing the cargo oil tanks.

7.5.4 Where the outcome of cargo tank testing reveals structural damage or leakage, the Owner is to advise LR immediately in order to arrange the attendance of a Surveyor.

7.6.1 The minimum requirements for Close-up Survey are given in Table 3.7.2 Minimum requirements for Close-up Survey - Single hull oil tankers (Single hull oil tankers), Table 3.7.3 Minimum requirements for Close-up Survey - Double hull oil tankers (Double hull oil tankers), Table 3.7.4 Minimum requirements for Close-up Survey - Ore/oil ships (Ore/oil ships) and Table 3.7.5 Minimum requirements for Close-up Survey - Ore/bulk/oil ships (Ore/bulk/oil ships).

7.6.2 The Surveyor may extend the Close-up Survey, if deemed necessary, taking into account the maintenance of the tanks under survey, the condition of the corrosion prevention system, and the following:

1. Structural arrangements or details which have suffered defects in similar spaces or on similar ships.

2. Spaces which have structures approved with reduced scantlings in association with an approved corrosion control system.

7.6.3 For areas in tanks where coatings are found to be in GOOD condition, as defined in Pt 1, Ch 3, 1.5 Definitions, the extent of Close-up Surveys may be specially considered.

7.7.1 The minimum requirements for thickness measurements are given in Table 3.7.6 Minimum requirements for thickness measurement - Single hull and double hull oil tankers, ore/oil ships and ore/bulk/oil ships (Single and double hull oil tankers, including ore/oil ships and ore/bulk/oil ships), see also Pt 1, Ch 3, 5.6 Thickness measurement. For ships built in accordance with the IACS Common Structural Rules (CSR), refer to the LR document Thickness Measurement and Close-Up Survey Guidance.

7.7.2 In areas where substantial corrosion, as defined in Pt 1, Ch 3, 1.5 Definitions, has been noted then additional measurements are to be carried out, as applicable, in accordance with Table 3.7.7 Thickness measurement - Single hull oil tankers, ore/oil ships and ore/bulk/oil ships - Bottom structure with substantial corrosion, Table 3.7.8 Thickness measurement - Single hull oil tankers, ore/oil ships and ore/bulk/oil ships - Deck structure with substantial corrosion, Table 3.7.9 Thickness measurement - Single hull oil tankers, ore/oil ships and ore/bulk/oil ships - Shell and longitudinal bulkheads with substantial corrosion, Table 3.7.9 Thickness measurement - Single hull oil tankers, ore/oil ships and ore/bulk/oil ships - Shell and longitudinal bulkheads with substantial corrosion, Table 3.7.11 Thickness measurement - Double hull oil tankers - Bottom, inner bottom and hopper structure with substantial corrosion, Table 3.7.12 Thickness measurement - Double hull oil tankers - Deck structure with substantial corrosion, Table 3.7.13 Thickness measurement - Double hull oil tankers - Wing ballast tank structure with substantial corrosion, Table 3.7.14 Thickness measurement - Double hull oil tankers - Longitudinal bulkhead structure in cargo tanks with substantial corrosion and Table 3.7.15 Thickness measurement - Double hull oil tankers - Transverse watertight and swash bulkhead structure in cargo tanks with substantial corrosion to determine the full extent of the corrosion pattern. The survey will not be considered complete until these additional thickness measurements have been carried out. For double hull oil tankers built in accordance with the IACS Common Structural Rules (CSR), the identified substantial corrosion areas are required to be examined and additional thickness measurements are to be carried out at Annual and Intermediate Surveys.

7.7.3 For oil tankers (including ore/oil and ore/bulk/oil ships) of 130 m in length and upwards (as defined by the International Convention on Load Lines in force), the ship's longitudinal strength is to be evaluated by using the thickness of structural members measured, renewed and reinforced as appropriate, during the Special Surveys carried out after the ship reaches 10 years of age.

7.7.4 Steel renewal evaluation of hatch covers and hatch coamings of cargo holds on combination carriers with contract for construction on or after 1 January 2004 is to be in accordance with IACS UR S21. These requirements are not applicable to ships built in accordance with the IACS Common Structural Rules (CSR). Further information is provided in the LR document Thickness Measurement and Close-Up Survey Guidance.

7.7.5 Steel renewal is required where the gauged thickness is less than t _net + 0,5 mm. For definition of t _net, see Pt 4, Ch 7, 12.1 General 12.1.2.

7.7.6 Where the gauged thickness is within the range t _net + 0,5 mm and t _net + 1,0 mm, a coating (applied in accordance with coating manufacturer’s requirements) or annual gauging may be adopted as an alternative to steel renewal.