class renewal survey - hull and additional class notations

Basic requirements

Safety arrangements

The scope of survey must always include the requirements as stated in Part A of the Rules.

Class Renewal Surveys are carried out for renewal of the term of Classification.

Surveyors must be aware of safety arrangements. Refer to the general administrative instructions.

Administrative arrangements

Refer to the general administrative instructions.

The first duty of the Surveyor when commencing any survey is to check all Recognised Organisation (RO) documentation on board.

The importance of this instruction cannot be overlooked and no excuse whatsoever is acceptable for not following it.

Surveyor arrangements

Refer to the general administrative instructions.

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The objective of this instruction is to improve the quality of surveys. This instruction applies to surveys of hull structures and piping systems in way of cargo holds and/or cargo tanks, cofferdams, cargo pump rooms, pipe tunnels, void spaces, within the cargo length area and all ballast tanks. In the case of bulk carriers, selected fuel oil tanks within the cargo length area might be part of the areas to be surveyed according to the applicable provisions of applicable parts of Recognised Organisation (RO) Rules Part A, Ch 4.

Taking into consideration, the size of ships and scope of surveys for ships noted below, it is more effective to have more than one surveyor examine the required spaces, holds or tanks and to provide mutual support and consultation during the surveys in recommending repairs and actions required for conditions of class.

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On ESP ships 20,000 tonnes dwt and above, starting with the third Class renewal survey, at hull Class renewal and intermediate surveys, the survey of hull structure and piping systems to which this instruction applies, is to be carried out by at least two exclusive surveyors being qualified in the survey processes involved, for such surveys commenced on or after the 1st January 2017.

On bulk carriers 100,000 dwt and above of single side skin construction, at the intermediate survey between 10 and 15 years of age, the survey of hull structure and piping systems to which this instruction applies is to be carried out by at least two exclusive surveyors being qualified in the survey processes involved, for such intermediate surveys commenced on or after the 1st January 2017.

See the related procedure.

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This requires that at least two exclusive surveyors attend onboard at the same time to perform the required survey. This also applies to voyage surveys.

For Dual Classed ships, where compatible with relevant laws and regulations, the requirement for two surveyors is to be fulfilled as follows:

1. when Recognised Organisation (RO) is the leading Society and acts as RO (hence responsible for the ESP code) the survey is to be carried out by 2 exclusive Recognised Organisation (RO) surveyors qualified for ESP vessels (as per applicable service notation of the vessel). In cases where this is not feasible, alternatively, this requirement may be fulfilled by having one surveyor attend from each Society. In that case, MO Agreement is to be obtained.

2. When Recognised Organisation (RO) is acting only as second Class Society (not responsible for Statutory Certification of the vessel), the survey may be carried out by a single Recognised Organisation (RO) surveyor appropriately qualified, covering the whole scope. Compliance with the ESP requirements remains the responsibility of the leading Society.

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Though each attending Surveyor is not required to perform all aspects of the required survey, they are required to consult with each other and to do joint overall and close-up surveys to the extent necessary to determine the condition of the ship areas to which this instruction applies. The extent of these surveys should be sufficient for the surveyors to agree on actions required to complete the survey (with respect to renewals, repairs and other conditions of class). Each Surveyor is required to co-sign the survey report or indicate their concurrence in an equivalent manner.

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The following surveys may be witnessed by a single Surveyor:

• Thickness measurements in accordance with para. Requirements for thickness measurements (TMs).

• Tank testing in accordance with the applicable parts of Recognised Organisation (RO) Rules Part A, Ch 4.

• Repairs carried out in association with intermediate and hull class renewal survey, the extent of which have been agreed upon by the required two surveyors during the course of the surveys.

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The on-board attendance of the surveyors is to be documented according to the general administrative instructions.

Class renewal Survey under normal survey system (all ships)

Survey preparation

All items carried out during the preceding 15 months are creditable towards the Class Renewal Survey.

The Surveyor verifies which items were previously surveyed, on the List of Credited Items Towards Hull Renewal Survey and the List of Outstanding Items to be Credited Towards Hull Renewal Survey.

Note : Only the surveys carried out as per full scope of the Rules are considered towards the Class Renewal Survey. For surveys commenced in one Survey Centre and to be continued in other Centre(s), the Surveyor only validates the items fully covered by their surveys (the List of Credited items Towards Hull Renewal Survey is to be issued accordingly). If any items were partially surveyed, he does not credit them and issues the List of Outstanding Items to be Credited Towards Hull Renewal Survey.

When preparing their survey, the Surveyor is to check the presence of substantial corrosion or suspect areas on board the ship to attend by reviewing memoranda and/or previous survey reports.

In case substantial corrosion or suspect areas are identified, corresponding areas have to be re-inspected for assessment as per applicable requirements of Part A. In case the inspection shows any deformation, damage or alteration, actions have to be taken according to applicable requirements of Part A and all necessary informations (location, size, repairs, etc…) have to be included in the final survey report.

A memorandum indicating the presence of substantial corrosion or suspect areas is to be endorsed upon completion of survey.

Survey planning

For ships subject to enhanced survey programme - ESP - a specific survey programme shall be worked out prior to the commencement of any part of the class Renewal Survey (or intermediate survey when relevant, see the related survey procedure), by the owner in co-operation with the Connecting District of the vessel (refer to the Rules, Part A, Ch.4, Sec. 2 [4]. A specific Survey Planning Questionnaire and a Survey Plan have been implemented in this scope.

For detailed instructions, refer to relevant Annexes.

Along with the a.m. Survey Plan and Survey Planning Questionnaire made available to him by the Connecting District, the Surveyor examines the Survey Report File and additional documentation on board (refer to the Rules, Part A) in order to take into account previous surveys findings and ship's past records.

It may anyway be in the owner's interest to make some surveys in advance of the renewal survey, some possibly in conjunction with the 4th annual survey, to allow advance planning of repairs.

In some cases, surveys at sea are contemplated to establish the condition of the hull structure and decide on repair schedules. These surveys are credited towards the renewal survey when attending the full scope of parts of renewal survey, e.g. overall survey and close-up survey of particular tanks.

The ship should be presented, prepared for surveys. The Surveyor informs immediately the owner's representative if the preparation or the time schedule is incompatible with performance of the required surveys.

Holds and similar compartments must be cleaned and cleared, all limber boards and bilge boards removed. Bilges must be cleaned and bilge strainer boxes opened and cleaned. Hold ceilings shall be removed to the extent necessary for examination of the tank top. Plating and associated stiffeners should be free from rust scale, etc.

Engine rooms, boiler rooms and other compartments must be cleaned and cleared. Floor plates lifted to the extent required to permit examination of the hull structure, etc. Bilges shall be emptied and cleaned, strainer boxes opened and cleaned.

Double bottom tanks, deep tanks and other tanks, as required for survey, must be emptied, gas-freed and cleaned. Corroded areas should be de-scaled where required to allow the Surveyor to make a proper inspection.

Casing must be removed to expose pipe runs, where applicable.

External examination

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The Surveyor carries out a general examination as detailed as for annual surveys of hull, machinery and fire-fighting equipment (see the related survey procedure).

See also the general administrative instructions, 4. in Section 2.16.

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Should the Renewal Survey be completed at the end of term with the ship afloat, the Surveyor shall carefully examine the shell plating above the waterline even if the ship was recently subjected to a periodical bottom survey.

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As to deck plating and deck erections, particular attention shall be paid to areas subject to stress concentration due to changes of section or discontinuities such as at the corners of hatch openings, superstructures or deckhouses.

Areas where the scope of annual surveys is less stringent, are now verified and necessary repairs required. Therefore, areas under deck equipment, e.g. winch seatings, behind pipe runs, etc., are hammer-tested, de-scaled, thickness measurements required and the renewal of corroded plates carried out as necessary.

Where a fracture is found in deck plating, such as at a hatch corner, all the similar locations are carefully examined for similar failures, including the deck structure underneath. Permanent repairs are always required in case of:

• materials renewal due to corrosion wastage,

• change of design of a part due to stress concentration, e.g. fitting inserts of increased thickness and increased radius, where practicable. Consult the Local Plan Approval Office for the modifications.

Important points to check for any possible cracks are:

• cross deck at crane post foundations,

• cross deck at the toes of hatch side,

• coaming end brackets and hatch end coaming stay brackets,

• welded joint of manhole coamings,

• bulwark stay connections,

• bulwark stays.

In principle, doubling plates are not definitive repairs, except in defined locations under specific conditions (see the related survey procedure).

Thickness measurements are required by the Rules.

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The Surveyor examines wooden decks or wood-sheathed decks for wear, rotten parts, damages, conditions of caulking, etc.

For wood-sheathed decks, planks are lifted where rust appears between ground bars and planks or any other suspect area. The steel deck under is examined.

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In addition to the examination of hatch covers and coamings required for annual surveys (the related survey procedure), the following also shall be met:

• Examination shall be extended to all covers. Signs of local wastage are verified in detail and the necessary repairs recommended.

• The operation of mechanically operated hatch covers is checked, rolling and hinged types. The Surveyor checks any misalignment of adjacent panels.

• The proper fit and locking of hatches is checked.

• Hose testing or equivalent is carried out for all hatches. For small access hatches, chalk test is acceptable in lieu of hose testing.

Note: Refer to the Rules as concerns the applicable minimum required extent for thickness measurements.

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The survey of the steering gear depends on the type of the gear fitted, as detailed hereafter, where applicable.

Electrical equipment

Electrical motors, starter boxes, panels, wiring and alarm systems are examined. The insulation resistance of motors and wiring is checked and recorded. In case where the driven gear is noisy, motors are run uncoupled to check the bearing noise of the motors themselves. Worn motor bearings should be replaced by new parts. In any case, the condition of motor coupling arrangements is inspected.

Hydraulic equipment

Hydraulic pumps are examined in running condition. The gear is tested in still water. If the time taken from 35 degrees on one side to 30 degrees on the other side is more than 28 seconds, it is required to adjust the pump output. Where 2 pumps are fitted, this is checked for each pump. In cases of excessive noise, loss of performance or other indications, the Surveyor requests dismantling and reconditioning, as necessary.

Hydraulic circuits are carefully examined in operation with a particular attention for any flexible hoses or vibration of steel pipes. Leakages are attended to. Level alarms in oil reservoirs are tested.

Pressure testing to relief valve pressure is usually effected by operating the steering gear against its hard over stops. If necessary, its adjustment is required.

Hydraulic ram type gear

In addition to the preceding, check:

• the condition of cylinders and rams. Leaking seals shall be repaired,

• the condition of flexible joints or sliding bearings in crossheads, etc.. Excessively worn bearings shall be repaired.

• the tiller mechanism with a particular attention for the fit of the tiller to the rudder stock and the key, as well as the running clearances. Excessive wear of the rudder carrier bearing shall be investigated.

Hydraulic rotary vane type gear

In some designs, the rudder carrier bearing is an integral part of the unit and wear of this bearing or problems associated with wear of rudder bearings or misalignment, etc., can only be checked by internal inspection.

The top cover shall be removed. Most types of rotary vane steering gear raise little problem apart from contamination of the hydraulic system which would dirt or grit gain entry. Once open and drained, the contact surfaces are examined for signs of scoring, and the seals checked.

It is always advisable, for unknown designs, to check the manufacturer's instructions for servicing, inspection and testing. If during testing in still water, the pressure is found to be abnormally high and this cannot be attributed to external forces such as damage or misalignment of the rudder arrangement or excessive wear of rudder bearings, then the vane unit shall be opened for examination.

If the rotary vane unit is reported operating satisfactorily provided that it be satisfactorily tested as prescribed above and that the manufacturer's service instructions be followed to the Surveyor's satisfaction, then the vane unit needs not be opened up.

Telemotor and other control linkages

They shall be examined under test for excessive wear or backlash. Parts excessively worn shall be repaired.

Rod and chain equipment

Sometimes found on older design of small ships, this shall be dismantled and cleaned for inspection. Checks are made for cracks and wear, calibrations are recorded. Parts should be repaired or replaced by new certified parts (see Rules on Materials), when damaged, cracked or worn to the maximum limits of wear.

Geared quadrant or screw equipment

This shall be examined for signs of excessive wear or cracks.

Steam-driven gear

The engine is dismantled and reconditioned as necessary, including piston rings, gland packing, crankshaft bearings, valve gear and gearing.

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Anchor, chain cables, windlasses and deck machinery: the windlass and mooring equipment shall be inspected. The condition of the windlass foundations shall be verified.

Cable lifters, gears and brakes shall be examined for excessive worn. Clutches shall be checked under operation.

The prime movers shall be also examined to the Surveyor's satisfaction:

• Steam engines dismantled as deemed necessary,

• Electrical motor inspected and the insulation resistance measured,

• Hydraulic motors examined as deemed necessary,

• Flexible couplings and torque limiters examined with particular care,

• The Surveyor witnesses a running test and also checks the condition of cable stoppers, when fitted.

The chain cables and anchors shall be lowered and ranged. The mean diameter of links, in the most worn part, shall be recorded.

Refer to the related survey procedure for permissible wear of anchor and chains.

The Surveyor examines the anchors and requires replacement of the pins when necessary and also checks that the number of anchors and links of chain cable meets the Rules.

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Masts and standing rigging: the survey bears on the fixed parts of lifting appliances which may be considered as integral parts of the hull such as crane pedestals, masts, king posts, and other structures permanently welded to the hull. The shrouds of masts fixed in the ship structure are also considered as fixed parts.

For the survey of cranes themselves, derrick booms, rigging and loose gear, refer to Guidance Note NI 184, Rule Note NR 526 and the applicable TNS.

The examination includes, for crane pedestals, an internal and external examination of the pedestal and underdeck supporting structure. The connection of masts or derrick posts to decks or deckhouse structure is examined for evidence of failure.

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A bottom survey in dry condition shall be carried out for the Renewal Survey.

It is of great importance, as soon as the ship's bottom cleaning is completed, to perform the external examination of the ship's hull in order to define immediately the required repairs, in case of any bottom damage.

Note: A bottom survey carried out during the last 15 months, which has fully covered the Rules, can be credited towards the Renewal survey.

Refer to the related survey procedure.

Internal examinations

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The extent of the internal examination is defined in the Rules, Part A. As the ship gets older, the extent of the internal examination increases. In general, all dry compartments, holds, peak tanks, water ballast tanks, chain lockers and void spaces are surveyed internally at every Renewal survey. The requirements for fresh water and oil tanks (other than cargo tanks) may be less stringent.

The following gives some guidance for internal examinations of typical spaces. It is assumed, in all cases, that spaces have been cleaned, adequate lighting provided and usual safety precautions taken.

For ballast tanks particularly, the condition of the tank coating shall be checked.

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In way of cargo holds, the underdeck structure shall be examined for cargo damage in way of the hatch and corrosion of underdeck stiffeners. On a tweendeck ship, this inspection is easily made; on a ship without tweendeck, the Surveyor can examine closely the underdeck structure close to the deck access hatches, or ladders or other access are used. The structure is sounded with a hammer. If the condition of this area is doubtful, means of access shall be required for a more detailed inspection.

Apart from cargo damages, the usual problems are corrosion of underdeck stiffeners and their connection to the plating. A representative area must be examined to evaluate actual conditions.

The side shell and framing shall be examined for damage due to vessels contact with quays, etc. from the outside or cargo damage from the inside and corrosion. Frames can be sighted to determine any areas of major deflection due to damage. Deck beam knees are checked for buckling. Stringers are checked and their connection to side plating and bulkheads inspected for corrosion since flat surfaces may be left to accumulate dirt leading to corrosion. Frames, etc. are sounded with a hammer. The same is done to the brackets to tweendecks, where fitted, and the double bottom margin plate or tank top. These lower brackets are most subject to damage and corrosion and shall be carefully inspected for wastage and cracks.

Tweendecks shall be examined for damage and corrosion including underdeck stiffeners.

Where pontoon covers are fitted, their landings and means of securing shall be checked.

Bulkheads shall be examined for damage and corrosion, particularly at lower parts and at sides, and sounded with a hammer.

The inner bottom shall be examined for damage and corrosion and sounded with a hammer. The tank top ceiling is partially removed and when corrosion is found, the complete removal of the ceiling shall be required to allow a thorough inspection of the tank top plating.

Bilge wells shall be inspected for corrosion and bilge strums examined.

Where hold pillars or the centreline bulkhead are fitted, they shall be examined for corrosion particularly at top and bottom.

Sounding pipes, air pipes, scupper pipes and other pipes passing through the hold shall be examined for corrosion and seen under test during tank testing. Scupper pipes shall be flooded with water if their condition is doubtful.

Note: Where applicable, the Surveyor may request thickness measurements of corroded parts. Where required by the Surveyor, corroded or damaged parts must be repaired.

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The forepeak tank shall be examined throughout.

In coated tanks, the condition of the coating is checked. Local coating breakdown usually leads to accelerated local corrosion since the small bare steel areas become anodic to the coated area. Areas of corrosion scaling must be cleaned to allow inspection of the area.

The general structure must be examined for damages from external contacts or fractures particularly in way of breast hooks and stringers. Also in the bottom for pounding damage, particularly if noted during bottom survey.

In unpainted tanks, the extent of corrosion must be assessed either visually and by hammer testing, or supplemented by thickness measurements. The top parts are generally the most corroded, particularly the tank top area. Tanks with a lot of scaling must be descaled to allow an adequate examination.

The sounding pipe shall be hammer-tested, the forepeak bulkhead valve examined and tested. This valve is sometimes neglected and left permanently open, resulting in jamming of the extended spindle.

Where the forepeak tank is divided into upper and lower sections, the means of separation shall be examined.

Note: The limit of wastage in the forepeak tank is 35 % for small local pittings and 15 % generally. Parts worn in excess of this must be repaired using material with the original rule thickness.

Doubling plates are not considered as a permanent repair on forepeak bulkheads.

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Afterpeak tank.

Generally, the preceding applies to the forepeak tank with, in addition, the checking for fractures related to vibrations of the shell due to the propeller, plus inspection and sounding of the stern-tube with a hammer.

Particular care shall be given to the afterpeak bulkhead.

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Double bottom water ballast tanks shall be examined to check for damages or deterioration. The condition of striking plates fitted under sounding pipes or the ends of blind sounding pipes shall be checked as shell plates can become holed by sounding rods due to the lack of a striking plate (this applies to all tanks). Missing striking plates or equivalent shall be fitted. During this examination, any pipe runs passing through the tank shall be examined and hammer-tested. Special attention shall be given to the plate under suction pipes.

In coated tanks, the condition of the coating shall be checked as for the forepeak.

In uncoated tanks, the Surveyor requires de-scaling where scaling prevents a full examination. The Surveyor should hammer-test double bottom internals, tank top, watertight floors and watertight longitudinal divisions. Thickness measurements shall be required where necessary.

Special attention shall be paid to double bottom seawater ballast tank bulkheads which are boundaries of fuel oil double bottom tanks, as due to the fuel oil heating, the corrosion process of the sea waterballast tank bulkheads is accelerated.

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Deep tanks are sometimes found on cargo ships, which may be used either for dry cargo, liquid cargo, ballast, or a combination thereof. The most usual problem in deep tanks used for water ballast is corrosion. Boundaries and stiffeners shall be hammer tested and gauged as necessary.

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Ballast Tank Protection List – Cargo & Ballast Capacities in ship’s status

Note : Void spaces which were previously used as ballast tanks shall be considered as ballast tanks.

All ballast tanks are subject to an overall survey. Their condition or the condition of their protective coating shall be assessed. At each Renewal survey, the Ballast Tank Protection list will be automatically updated in the system after the surveyor has sent it’s NPSS, representing the ship’s actual condition. Any change in this condition is to be reflected by the same way. Refer also to the related survey procedure, Section 19 “Classification survey of coating condition”.

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Double bottom tanks - other than sea water ballast - shall be examined to check damages or deterioration.

• Fresh water tanks: Dedicated fresh water tanks are usually coated, either with paint or cement. The condition of the coating shall be checked.

  Cement coatings or special paint coatings on drinking water tanks are usually repaired on a regular basis. Corroded areas must de-scaled, hammer-tested and thickness measurements required where deemed necessary.

  Cement coatings are not considered as corrosion prevention systems, as defined in Pt A, Ch 2, Sec 2.

• Fuel oil tanks are usually uncoated and not subject to significant corrosion. Pipe runs passing through these tanks, if any, are hammer-tested.

• Lubricating oil tanks may be painted or bare steel. Corrosion is rarely a problem, at least starting from the inside, however corrosion starting on the outside may eventually pierce the tank, e.g. on tank top beneath drain pipes.

• Boiler feed tanks suffer from corrosion, particularly when located under boilers, on older ships.

• Void spaces must be dry and sufficiently ventilated. Inspection is best carried out in conjunction with testing of adjacent tanks since, in most cases, for engine room double bottoms tanks, an internal examination is not required, provided an external examination of the tank boundaries be made. The main engine holding down bolts, when arranged through the tank top, are usually in a void space; these are inspected and hammer-tested to check for slack nuts.

Note 1: Bilge, oil overflow and sludge tanks are treated as oil tanks for the purpose of survey requirements.

Note 2: The tanks not required to be internally examined, shall be examined externally from accessible boundaries.

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Integral tanks other than those mentioned above shall be internally examined as for the types above, depending on the type of tank and the fluid contained. Where internal examination is not required by the Rules, this is subject to a satisfactory external examination of the accessible tank boundaries.

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Independent tanks are usually dedicated to fuel oil, lubricating oil, feed water or fresh water and not subject to excessive corrosion.

Internal examination may be required by the Rules. Where the internal examination is not required, this is subject to a satisfactory external examination of accessible tank boundaries.

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In machinery spaces and boiler rooms, the Surveyor examines the spaces for signs of damage or deterioration, particularly:

• Ships side valves, scupper pipes, etc.,

• Tank tops or plating under boilers including condition of boiler supports and collision chocks,

• Condition of end bulkheads and their penetrations,

• Bilge wells for corrosion. Great care shall be paid as this can be a source of engine room flooding. The bilge well must be presented dry.

• Tank top in way of pumps, etc., where leaks from snifting cocks and steam and water drains may have led to local wastage,

• Air pipes and sounding pipes at their lower ends, particularly air pipes of fuel tanks which are sounded with a hammer.

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In ships with engine room amidships, the shaft tunnel is examined for damage caused by cargo handling and watertight integrity including the stuffing box in the forward bulkhead. The stern gland aft is checked. The watertight door is tested both locally and remotely. Hose testing of the tunnel is requested if deemed necessary.

In ships with a pipe duct, duct keel or similar service tunnels, these are examined for watertight integrity. Signs of leakages are investigated and repairs made as necessary. Watertight doors or other watertight closures are examined as applicable.

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Hull pipelines: When surveying the different compartments, the Surveyor sounds with a hammer the ballast and bilge pipes, particularly at bends where thinning is initially most likely to occur. Any temporary repairs found shall be permanently repaired. These inspections include joints, flanges, bolts and pipe fixations, etc.

Bilge suction mud boxes and strums are inspected as well as the various valves for bilge and ballast service.

Pipelines for seawater mains, ballast and bilge mains, may be requested to be pressure-tested if deemed necessary.

At an early stage, the Surveyor must witness a bilge pumping test, at least in the holds, by filling the bilge hat or box or several frame spaces with water, to enable any defects to be repaired in due time.

Tank testing

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Tank testing may be carried out afloat but there are obvious advantages in testing tanks in drydock where the smallest perforation or shell fracture will be apparent, provided that the necessary steps be taken by the owners' representative regarding re-inforcement of blocks.

Testing is carried out as per the requirements of the Rules, Part A. Guidelines for testing and the pressure to be applied are given in Testing of watertight compartments.

During tests, the Surveyor must satisfy himself that there are no air pockets by checking that the water level is constant in the air pipe or sounding pipe as appropriate.

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Tests of heavy fuel oil tanks, using the fuel oil itself, should be made where practicable with hot oil. Particular attention is given to security of tank lids, air sounding pipes and overflow pipes where applicable.

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Testing of deep tanks is required when the compartment is used for water ballast or for a liquid cargo, either continuously or alternating from time to time with any cargo.

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In refrigerated ships/gas carriers, for tanks the boundaries of which cannot be readily seen because of insulation, it is acceptable to test them by filling, isolating, and checking for a constant level in the sounding or air pipe after a suitable period. Any suspected leaks shall be attended to, even if this requires removal of insulation sections.

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As concerns double bottom tanks in machinery spaces, it is sometimes difficult to have tank tops clean and dry for examination during a test; access may also be difficult. When the Surveyor has no doubt about the general condition of the tank top, he may be satisfied with filling and isolating the tank and checking the level in the sounding pipe after a suitable period.

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The Surveyor requires a hose test for cargo doors, watertight bulkheads and watertight doors in watertight bulkheads.

Thickness measurements

Extent

The Surveyor requires thickness measurements at any time, when he has doubts about the thickness of various hull parts. For Renewal survey, the Rules, Part A call for thickness measurements the amount of which increases with the ship's age. This extent is also increased if deemed necessary by the Surveyor, taking into account the findings of their examinations and thickness measurements already taken.

Special consideration

“Special consideration” may be applied to various types and sizes of ships, different areas of ships and part of hull structure which greatly differ among themselves.

Due to this, it is not considered appropriate to determine a minimum quantity of thickness measurements that could be applied equally to all possible structures to which special consideration may apply.

Therefore, it is deemed that the “Minimum quantity of thickness measurements to be taken in case of special consideration” is left to the Surveyor’s professional judgement on a case by case basis.

This common view applies to all surveys where special consideration may be applied to reduce the quantity of the thickness measurements, as authorized in the relevant rules of Part A.

Reduction of the number of measurements

The extent of thickness measurements may also be reduced on basis of the Surveyor's findings, in particular, when the structure is suitably coated and the coating is found in good condition.In any case, selected measurements shall be taken as references, to ensure that the coating was not applied on an already corroded area (see the Rules, Part A Ch 2 App 3 Table 2 for easy reference).It is reminded that soft coating is not considered as an efficient coating and, therefore, is not a justification for reducing thickness measurements.The survey report must contain proper justification about the reason for reducing thickness measurements, including the selected measurements taken.

Means of taking measurements

The thickness measurements shall be carried out by a qualified Company. For certain service notations (ESP ships, liquefied gas carriers, general cargo ships of 500 grt and above, bulk carriers without the additional service feature ESP of 500 grt and above), the Company must be a certified one, see the related survey procedure.

Ultrasonic measurement is a non-destructive method which has replaced drilling.

Three types of thickness gauging equipment exist:

• digital, single echo pulse equipment; this equipment is not able to measure thickness through coating and therefore shall be avoided in such a case, unless coating is removed.

• digital multiple echo pulse equipment; this equipment measures the time between the first echo and the second echo, which eliminates the effect of the coating in the measurement; such an equipment shall be used in case where coating exists and is adherent. In case where coating is not adherent, it still needs to be removed.

• A-scan analogic equipment; this equipment is fitted with a display screen showing the different echoes; by measuring the time between the first and the following echoes, it has the same properties as the digital multiple echo pulse equipment.

The Surveyor shall verify that the equipment is suitable for the measurements to be done (presence of coating or not), and shall get proof of proper accuracy and calibration of the equipment

Requirements of thickness measurements at Renewal Survey (all ships)

Refer to the Rules, Part A. For transverse sections, all items contributing to the longitudinal strength have to be measured, as indicated in the midship section from bottom to top of the ship.

Requirements for thickness measurements (TMs)

Thickness measurements required in the context of hull structural classification surveys are to be witnessed by a Surveyor. This requires the Surveyor to be on board, while the gaugings are taken, to the extent necessary to control the process. This also applies to TMs taken during voyages.

The Surveyor, in addition, shall be certified for the specific ship type/survey.

The attendance of the Surveyor is to be recorded in the applicable ASMS report.

As a consequence:

1. Survey Meeting

   Prior to commencement of the intermediate or class renewal survey, a meeting is to be held between the attending Surveyor(s), the master of the ship or an appropriately qualified representative appointed by the master or Company, the owner's representative(s) in attendance and the TM firm's representative(s) so as to ensure the safe and efficient execution of the surveys and TMs to be carried out onboard.

   Communication with the thickness measurement operator(s) and the owner's representative(s) shall be agreed during the meeting with respect to the following:

   • reporting of thickness measurements on regular basis to the attending surveyor,

   • prompt notification to the Surveyor in case of the following findings:

     • excessive and/or extensive corrosion or pitting/grooving of any significance,

     • structural defects like buckling, fractures and deformed structures,

     • detached and/or holed structure,

     • corrosion of welds.

   When thickness measurements are taken in association with intermediate or class renewal survey, the survey report shall indicate where and when the meeting took place and who attended (the name of the Surveyor(s), the master of the ship or an appropriately qualified representative appointed by the master or Company, the owner's representative(s) and thickness measurement firm's representative(s)).

   It is recommended that TMs are carried out in a single operation, by one TM firm. If, however, TMs are carried out in several operations during the allowable period for the survey and/or by different TM firms, separate survey meetings should be held at each time.

   The followings items shall also be addressed in this meeting:

   • schedule for TMs,

   • provisions for TMs (personal safety, means of access, cleaning and de-scaling as appropriate, illumination, ventilation),

   • planned scope of survey:

     • mandatory extent of TMs, according to Recognised Organisation (RO) Rules,

     • areas subject to close-up surveys and TMs including areas previously identified with substantial corrosion, if applicable.

   • availability onboard of drawings with original scantlings,

   • allowable thickness diminutions (reference is made to NR467 Part A and the related procedure [11.6.5], as appropriate),

   • taking representative readings in general and where uneven corrosion/pitting is found,

   • procedure for additional readings of areas with substantial corrosion, if applicable, according to Recognised Organisation (RO) Rules,

   • information to be provided by the TM firm related to:

     • equipment to be used,

     • personnel records of operators scheduled for TMs onboard.

2. Monitoring of the TM process onboard

   The Surveyor shall decide final extent and location of TMs after overall survey of representative spaces onboard. In case the Owner prefers to commence the TMs prior to the overall survey then the Surveyor shall advise that the planned extent and locations of TMs are subject to confirmation during the overall survey. Based on findings, the Surveyor may require that additional TMs have to be taken.

   • Prior to commencing the TMs, the Surveyor should:

     • check type of equipment and verify that equipment is calibrated according to recognised national/international standards and properly labelled.

     • witness calibration appropriate for size and type of material.

     • be satisfied with operator's skills and competence.

     • ensure that the TM operator will be using instruments using pulsed echo technique (either with oscilloscope or digital instruments using multiple echo). Single-echo instruments may be used on uncoated surfaces, which have been properly cleaned.

   • The Surveyor shall direct the gauging operation by selecting locations such that readings taken represent, on average, the condition of the structure for that area.

   • TMs taken mainly to evaluate the extent of corrosion, which may affect the hull girder strength, shall be carried out in a systematic manner of all longitudinal structural members that are required to be gauged by the relevant part of the Rules. The Surveyor shall be in attendance during this process.

   • TMs of structures in areas where close-up surveys are required shall be carried out simultaneously with the close-up surveys in order to facilitate a meaningful survey.

   • The Surveyor may specially consider the extent of TMs of structures within spaces where the protective coating is found to be in GOOD condition.

   • Where TMs indicate substantial corrosion or wastage in excess of allowable diminution, the Surveyor shall direct locations for additional TMs in order to delineate areas of substantial corrosion and to identify structural members for repairs/renewals.

3. Review and verification

   • Upon completion of the TMs, the Surveyor shall confirm that no further gaugings are needed, or specify additional gaugings.

   • If, where special consideration is allowed by the relevant part of the Rules, the extent of TMs is reduced, the Surveyor's special consideration shall be reported.

   • In case TMs are partly carried out, the extent of remaining TMs shall be reported for the use of the next Surveyor.

   • The Surveyor shall confirm that the proper TM reporting forms were used if the ship is under ESP programme.

   • Upon completion of the TMs onboard, the Surveyor verifies and keeps a copy of the preliminary thickness measurement report signed by the operator.

The Surveyor reviews the TM report issued by the TM firm, performs the analysis as per the applicable TNS and requests the necessary repairs and renewals.

Upon review that the final gauging report is consistent with the preliminary report, the Surveyor is to countersign the cover page of the final report.

The preliminary report shall be kept, as a minimum, until the review is completed.

The following statement is to be added before the Surveyor's signature on the cover page of the final report:

"Report reviewed for consistency, measurements partly attended"

The date and place of review is also to be indicated on the cover page of the report.

When the final thickness measurement report is submitted electronically to Head office, the paper cover page is to be printed, countersigned as detailed above and filed locally in the Survey Centre.

Notes:

In case of ESP ship of 15 years of age and above (starting with the third class renewal survey) of 20 000 dwt and above and in case of bulk carriers of 100 000 dwt and over of single side skin construction, between 10 and 15 years of age, witnessing of thickness measurements only by one Surveyor is acceptable.

Remote inspection techniques (RIT)

For surveys started on or after 01 January 2019, consideration may be given to the attending Surveyor to allow the use of RIT as an alternative means to close-up survey.

For surveys conducted by use of a RIT, one or more of the following means of access, acceptable to the Surveyor, is to be provided:

• Unmanned robot arm

• Remotely operated vehicle (ROV)

• Unmanned aerial vehicle / drones

• Climbers

• Other means acceptable to the Society.

For non-ESP vessels, the use of RIT is to be agreed prior to the survey. The arrangement details are to be part of the inspection plan, which is to be submitted for review and acceptance in advance of the survey.

Reference is made to Pt A, Ch 2, Sec 2 for definition and conditions of use of RIT.

Companies doing surveys using RIT are to be approved according to the related survey procedure and NR533, Rule Note for approval of service suppliers.

Use of RIT is not allowed for close-up surveys on ESP vessels subject to the IMO ESP code (bulk carriers and oil tankers assigned with the additional service feature ESP), unless flag written agreement and appropriate instructions are obtained by the MOC in consultation with the MO.

For ESP vessels, the arrangement details may be part of the ESP planning document.

Repairs and other remedial actions

Any fractures found are repaired by part renewal of material or by veeing and welding. Structural modifications may also be advisable to avoid repetition of fractures.

Any buckling found during the survey is important and is dealt with by stiffening or renewal of material as considered necessary.

Indents in plating between stiffeners are either acceptable or dealt with as deemed necessary. Refer to Mini ISM for limits of plate deformations between stiffeners.

Isolated local corrosion or pitting of shell or bulkheads can lead to penetration. Where these have exceeded the permissible depth they are repaired. Usually pittings, unless widespread, can be built up by welding or ultimately, the element must be renewed. When these pittings are found still within permissible limits, coating systems may be considered as a realistic option to arrest the pitting. Alternatively, the filling of pittings with an epoxy type filler, may be acceptable so long as it is applied according to the manufacturer's instructions. In cases where the corrosion is due to coating breakdown, it may be that the coating is repaired, the area being blasted and re-coated or, local anodes fitted to protect exposed steel.

Welding of pitting corrosion is generally carried out by qualified personnel using qualified welding procedures, in drydock. The practice of welding afloat is to be subject to a specific procedure.

The renewal of plates, internal stiffeners and structure is carried out further to the Surveyor's analysis of the thickness measurements taken.

Reporting

The reports concerning the Hull Renewal Survey shall provide details of the Surveyor's findings and reflect the surveys carried out.

The internal examinations of spaces such as cargo holds, tanks, etc., shall be made in a narrative way and provide details of findings, space by space.

Important items

• bottom plating including suction pipe bell months,

• side shell and frames,

• transverse bulkheads and stiffeners,

• underdeck structures,

• hatchcovers and coamings,

• tweendecks,

• framing systems,

Points to be noted

• scale formation and evidence of general scaling,

• corrosion and need for repairs/further examinations,

• pitting corrosion (depth/diameter/density),

• condition of coating or anodes,

• any global buckling of structure or local buckling of plates or stiffeners,

• any deformations of structure,

• fractures,

• condition of pipings and fittings,

• condition of handrails, ladders and walkways,

• areas not seen due to sludge, water or lack of access.

Additional requirements for "Oil Tanker" Service Notation or for combined Service Notations

Safety considerations

Untitled

Oil tankers are inherently dangerous, not least when empty. The danger is the explosion of inflammable gases, asphyxiation or poisoning by lack of oxygen or toxic gases respectively. The use of inert gas on oil tankers has added another dimension to the dangers of asphyxiation.

When surveying oil tankers, the Surveyor must follow the applicable safety practices and not entering any tank, cargo pump room or other enclosed space likely to contain gas or a foul atmosphere unless that space is certified gas-free and safe to breathe, by a responsible person, and the maintenance measures taken.

The Surveyor must never enter any such spaces unaccompanied and without proper safety measures being taken.

Untitled

For surveys carried out afloat under the authority of the Master, it is recommended, before commencing surveys on an oil tanker, that a safety meeting be held to discuss all aspects of safety, especially the arrangements for gas-testing procedures, ballast modification procedures, tank entry, communication links, and rescue arrangements. All those directly involved with the survey and the back-up must be present at this meeting.

For surveys carried out under the control of a shipyard or ship repairer, the Surveyor must be aware of all local procedures and instructions and always work in close co-operation with the ship manager or other designated person as regards entry into enclosed spaces, etc. The Surveyor verifies gas-free certificates often posted at tank entry positions, to ensure that safety procedures are being followed.

Untitled

As concerns gas-testing for tank entry, the following information is given for guidance and must not be taken as a safety standard.

Tanks must not be entered until testing indicates that the following criteria are met:

• Gas less than 1 % lower explosive limit (LEL) using explosimeter,

• Benzene (C6H6) less than 10 ppm (by draeger tube or similar),

• Hydrogen sulphide (H2S) less than 10 ppm (by draeger tube or similar),

• Oxygen (02) Minimum 21 % by volume (oxygen analyser),

• Hydrocarbons less than "threshold limit value - time weighted average" (TLV-TWA) for the actual mixture encountered (by draeger tube or similar),

• Other limits specific to certain chemical cargoes where applicable.

Note: For gasoline, TLV = 300 ppm corresponding to about 2 % LEL. If the TLV-TWA is unknown, a value of 150 ppm should be used.

Where inert gas is used:

• Carbon monoxide (CO) less than 50 ppm,

• Nitrogen dioxide (NO2) less than 3 ppm,

• Nitric oxide (NO) less than 25 ppm,

• Sulphur dioxide (SO2) less than 2 ppm.

These may be checked using draeger tubes or similar. Normally a steady reading of 21 % of oxygen by volume means that these compounds are sufficiently diluted.

If gas readings in any tank exceed any of these limits, the tank must not be entered and if already entered, it must be vacated.

Note: The explosimeter used must be calibrated with a high sensitivity, i.e. 0 to 10 % LEL full scale.

Tanks must be frequently tested during time of entry, say every 2-3 hours, at several locations. The use of portable hydrocarbon and oxygen level audible alarms must be made where available to detect local pockets of gas.

Untitled

Tanks must be clean and free of any heavy scale, oil, water, residue or debris before being presented for survey. Areas to be gauged shall be specially cleaned. After cleaning, tanks must be gas-freed for entry.

During the tank entry period, continuous forced ventilation must be maintained, using an adequate number of deck fans and ducting to supply fresh air to the bottom of the tank, where possible.

Ventilation must be stopped temporarily during regular checks on the atmosphere.

Note: Inert gas fans must not be used to supply fresh air ventilation because of the danger of introducing contaminants from the inert gas system. If tank entry is required whilst other tanks are inerted or not gas-free, then the tank to be entered must be efficiently isolated from the others by blanks or removable sections of inert gas piping.

All cargo pipelines leading to the tank to be entered are checked for oil content, the valves locked closed and warnings posted. Any oil present in pipelines must be removed.

Adjacent tanks should either be gas-free or fully ballasted. It is acceptable for adjacent tanks to be fully inerted or part ballasted/part inerted, but the pressure must be reduced to a minimum and the inspection team made aware of the potential danger of inert gas leakage through bulkhead fractures or faulty valves.

Untitled

For surveys carried out at a shipyard or repair berth, local safety procedures must include provisions for rescue.

For surveys carried out afloat under the authority of the Master, such as surveys at sea, a safety watch must be maintained at the tank hatch. Rescue equipment must be available on deck, including breathing apparatus, resuscitators, rescue lines, stretchers, etc.

Adequate communication must be maintained between the safety watch and the survey party and the bridge.

Untitled

The Surveyor must not enter any tank or remain in any tank if ballast is being transferred either in or out. Ballast movements in adjacent tanks must also be considered.

Untitled

The Surveyor must not enter nor remain in any tank while the ship is manoeuvring in congested or confined waters.

Untitled

Only safe electric equipment is used in cargo tanks (torches, 2-way radio, etc.). Ultrasonic measuring equipment may not be intrinsically safe and thus used only in tanks certified for "hot work" or with equivalent safe atmosphere. In this case, any surfaces within cargo tanks that are insufficiently cleaned of cargo residues are unacceptable for inspection. If ultrasonic readings are required in such areas, the surface is cleaned for a radius of about 1 m from each point of reading.

Untitled

In general, the Surveyor must not resort to free-climbing in tanks. Where climbing is considered safe, the climbing height is limited to 3m above the bottom or any large platform. Where climbing above this height is necessary, safety lines or the tank partially filling with water are employed. The free climbing height above a water "cushion" must not exceed 6m. When working in tanks containing water, the Surveyor must always wear a buoyancy aid.

Untitled

Surveyors must be aware of the problems of both hyperthermia and heat stroke. Most problems occur in hot temperatures where the problem of fatigue and heat stroke are real. In hot climates, surveys must be scheduled to avoid midday heat, adequate rest periods being taken.

Untitled

Natural lighting must be provided by opening all tank hatches, etc. Suspended safe lighting is also provided to supplement the natural lighting. The Surveyor and each person in the tank must carry a torch or lantern with a high intensity beam. All such equipment must be of safety type, certified for use in cargo tanks.

Untitled

When it is necessary to perform close-up surveys of under deck structure or transverse ring (web frame) structure, some form of access is required.

Untitled

In some cases the provision of manholes, permanent ladders and walkways are adequate to obtain a general assessment of the condition of the structure and identify suspect areas for closer examination.

Untitled

Conventional temporary stagging is employed in repair yards. Surveyors must exercise due care when on stagging. The use of safety harness is advised.

Untitled

Various types of mobile platform exist, most suspended from the deck by various means. These are not recommended for use at sea.

Untitled

The ballast procedure being controlled by the inspection team only, rafting may be used for performing close-up surveys, particularly at sea. The tank is ballasted to the level required for inspection and the survey team embarked usually in an inflatable boat. The safety measures include the wearing of buoyancy aids, the water level must be such that the persons cannot be cut-off from the escape hatch, the water must be oil-free (maximum thin sheen of oil on surface), the ship's motion should be such that there is little motion of the ballast water in the tank (maximum rise and fall 1m).

Performance of the survey

The scope of survey is given in the Rules, Part A. The extent of surveys increases with the age of the ship. The following guidance to Surveyors does not define or limit the scope of surveys but outlines the manner in which surveys are performed and the reasons for such inspections.

Survey planning

Refer to Class renewal Survey under normal survey system (all ships) and Annexes Preamble, Untitled and Untitled.

External examination

Any renewal survey includes the general examination of all the items required for annual survey. Refer to the related survey procedure. In addition, all patent air pipe heads are opened up to check the functioning of the float arrangement and the integrity of the float chamber; likewise, all pressure valves are also opened up for examination and calibration.

Internal examinations

Untitled

The examination of the service spaces, machinery spaces and tanks located in way of machinery spaces shall be carried out for like for all ships (see Class renewal Survey under normal survey system (all ships)).

Untitled

Before commencing internal examinations of tanks and spaces in the cargo area, the Surveyor consults the Survey Report File kept on board and the following additional documentation:

• Main structural plans of cargo and ballast tanks (pay attention to design features for proper planning of survey and reporting of findings)

• Cargo and ballast history (as corrosion is more prevalent in ballast tanks or tanks used for ballast)

• Documents on board (in order to determinate areas requiring particular attention. Previous repairs may be prone to corrosion. Adjacent parts to the ones previously renewed may need particular attention):

  • Hull condition evaluation report issued further to previous renewal survey

  • Reports of previous surveys

  • Ship's personnel inspection reports

  • Structural deteriorations

  • Leakages in bulkheads & piping

  • Condition of coating or anodes if any

• Records of use of inert gas (corrosion rates may be affected by the use of inert gas. Safety for tank entry to be considered).

Untitled

Overall surveys are applicable to all spaces in the cargo tank area including cargo tanks, pump rooms, pipe tunnels, cofferdams and void spaces bounding cargo tanks, and to all ballast tanks, in and outside the cargo area, therefore including peak tanks.

Overall surveys are best performed to a pre-determined procedure, using prepared note recording procedures including sketches of a typical wing tank, a typical centre tank, etc., to allow easy noting of any fractures, buckling, corrosion, coating failure, ultrasonic readings, etc., during the survey.

For a centre cargo tank or a wing tank, the Surveyor performs:

• Examination of deck longitudinals through openings in deck and from access hatch ladder (looking for deterioration of any coating, fractures, corrosion, especially at connection to deck, buckling)

• Visual inspection of deck girders or transverse rings at deck from access platform, as far as possible (looking for deterioration of any coating, fractures, buckling)

• Condition of access ladders and platforms themselves (looking for corrosion)

• Examination of each stringer (looking for deterioration of any coating, fractures, corrosion)

• Examination of structure adjacent to each stringer: longitudinals, transverse bulkheads, bulkhead stiffeners, centre line bulkhead, swash bulkhead, transverse rings, brackets, etc. (looking for deterioration of any coating, fractures, corrosion, buckling)

• Examination of bottom structure, plating, longitudinals, transverse rings, bilge area (looking for deterioration of any coating, corrosion, particularly on horizontal surfaces and bays of bottom plating and under pipe suction bell-mouths)

• Examination of piping, particularly ballast piping in cargo tanks or cargo piping in ballast tanks (checking tightness and corrosion, particularly underside and in way of bends).

During these inspections, ultrasonic gauging is required for any bulkheads or pipelines as deemed necessary by the Surveyor. The aim of the overall survey is to discover any excessive corrosion, significant deformation, fractures, damages or other structural defects and defines the extent of close-up surveys.

Untitled

Close-up surveys shall be performed in cargo tanks and ballast tanks. The minimum requirements given in the Rules, Part A, depend on the ship's age. They may be extended as deemed necessary by the Surveyor, after consideration of the findings at the overall surveys.

Ships with reduced scantlings, covered by the mark CL, are subject to special consideration. The areas with reduced scantlings must be specially examined, close-up survey being required if any doubt exists.

Special consideration may be given to tanks even where coatings are in good condition. In cases where the scope of surveys is either extended or reduced by the Surveyor, based on their findings, the survey reports must contain proper justifications.

In selecting representative tanks for close-up survey, the cargo/ballast service of the tanks shall be considered. Tanks used solely for cargo are generally not subject to a so severe corrosion, when compared to tanks used for ballast or ballast/cargo. The amount of corrosion control provided must also be considered.

By definition, close-up surveys require access to parts of a tank not normally within reach and thus means access is provided such as:

• permanent stagging and passages through the structure,

• temporary stagging and passages through or around structure,

• lifts and movable platforms,

• boats or rafts with access by ballasting the tank.

As for overall surveys of tanks, notes taken during the survey are best made using pre-prepared sketches of the parts subject to close-up survey. Thickness measurements are also indicated on these sketches as well as the position of the measurements.

Thickness measurements may be reduced where coatings are found satisfactory but additional readings may be necessary where corrosion is significant and near the permissible limits of wastage. Refer to the Rules, Part A for the extending of the measurements for substantial corrosion areas.

There is no point in taking additional measurements on parts of the structure where corrosion is advanced well past acceptable limits and where the renewal is obviously necessary.

Untitled

Typical structural defects are fractures and buckling

Fractures commence at latent defects in welding and usually appear at the beginning or end of a weld pass, or at a contour weld at the end of a stiffener, or at an intersection.

Fractures may also originate from undercut weld in high stress areas.

In general, as fractures may not be readily visible due to lack of cleanliness, difficult access, poor lighting, etc, it is important to identify and closely inspect the areas prone to fractures.

Permanent buckling may arise as a result of overload, overall reduction in thickness due to corrosion or damage due to grounding or other contact. Elastic buckling may be detected by damage to coating, stress lines or shedding of scale.

The following areas deserve special attention during the survey:

• Ends of main girders, stringers and struts with associated brackets. Particular attention must be paid to the toes of brackets, bracket ends of shell, deck and bulkhead stiffeners.

• Connection of shell, deck and bulkhead longitudinals to transverse web frames. Particular attention must be paid to the side shell connections between full load and ballast waterlines and the tie beams at connection to transverse web frames (these areas being subject to cyclic loading of passing waves).

• Any discontinuities in the form of mis-alignment or abrupt change of section.

• Plating in way of cut outs or openings.

• Areas which show signs of damage or buckling.

Untitled

The main types of corrosion encountered are as follows.

Pitting is localised corrosion that usually occurs on the bottom plating internally, on other horizontal surfaces and at structural details that trap water, particularly the aft bays of tanks.

Normally, on coated surfaces, pitting appears as relatively small diameter deep pits which can lead to penetration as the small bare area is anodic to the remainder of the adjacent coated area. Pitting of uncoated tanks may also be presented as scab type pitting which may be relatively shallow but of large area (300 mm diameter) and resembles overall surface corrosion.

General corrosion appears as a non-protective friable rust which can occur uniformly over uncoated tank surfaces. The rust scale formed continuously breaks off exposing fresh steel to corrode. Thickness loss cannot usually be judged visually until excessive loss has occurred. Severe general corrosion is usually characterised by heavy scale.

Grooving is localised corrosion occurring in linear form at structural intersections where water collects or flows, and sometimes, on vertical members and flush sides of bulkheads in way of flexing.

Weld metal corrosion is preferential corrosion of weld metal due to galvanic action. The weld metal becoming anodic to the adjacent steelwork.

Untitled

The factors affecting corrosion are as follows.

Frequent tank washing can increase corrosion. In uncoated tanks, it is often possible to see corrosion pitting in way of direct impingement paths of the crude oil washing machines.

The tank washing means directly influence the importance of the corrosion, for example, hot seawater, ambient temperature sea water and crude oil respectively have decreasing effects on the corrosion.

All washing means can remove protective oily films residual from crude oil carriage. Tank coatings may deteriorate more rapidly in a tank that is regularly crude oil washed.

Carriage of clean or dirty ballast: Although modern tankers operate with (SBT) segregated ballast tanks, some old tankers may have a history of operation with some tanks as cargo/ballast tanks. In these tanks, due to the frequency of tank cleaning and minimal corrosion control systems, higher corrosion rates may be found.

Carriage of crude oil can result in tank surfaces of cargo tanks being covered with "waxy" or "oily" protective films. Cargoes such as gasolene do not leave behind such a film.

The sulphur content of crude oil varies. High sulphur content can lead to high rates of general corrosion and bottom pitting corrosion. The sulphur in the cargo can react with any water to form sulphuric acid which will collect at the lowest point in the tank and be very corrosive.

Carriage of cargoes with high water content can increase corrosion rates, the same occurs with the carriage of cargoes with high oxygen content (e.g. gasolene) and the carriage of acidic cargoes.

For unprotected tanks, corrosion increases with the time in ballast.

For tanks protected by anodes, the corrosion rate can be high initially in ballast until oil dissipates from anodes and they become fully active. Corrosion can be expected when tanks are empty and thus anodes ineffective. Thus segregated ballast tanks protected only by anodes are subject to corrosion during laden voyages due to humidity in tank.

Carriage of heated cargo can lead to increased corrosion at adjacent unladen ballast tank sides.

Intact coatings prevent corrosion of the steel. However, local absence or deterioration of coating can lead to accelerated corrosion of the unprotected part which becomes anodic to the coated areas.

The location and density of anodes product the following effects:

• Anodes immersed in bottom water can afford protection against corrosion of bottom surfaces,

• Anodes are usually ineffective in reducing underdeck corrosion rates,

• Properly designed systems with high current densities may afford greater protection against corrosion,

• Electrical isolation or coating (oily films, etc.) on anodes can make anodes inoperative (indicated by low consumption of anodes),

• Quality of anode material has a great influence on the system performance.

The structural design of tanks products the following effects:

• High velocity drainage effects can lead to increased corrosion in the vicinity of cut-outs, etc. for uncoated surfaces,

• Horizontal internals and other water traps can lead to increased corrosion rates for uncoated surfaces,

• Less rigid designs allowing increased flexing causing shedding of scale or damage to coatings and increased corrosion rates,

• Sloping of tank bottoms or any system for better stripping of water may reduce corrosion in a tank.

The inert gas products the following effects:

• Decreased oxygen in atmosphere in inerted spaces may reduce corrosion,

• Sulphur compounds in flue gas may lead to formation of sulphuric acid and increased corrosion.

The navigational route products the following effects:

• Solar heating on one side of the ship can lead to increased corrosion of affected wing tanks on that side,

• Ships operating on short voyages may be subject to increased corrosion where anode systems are used (see above).

The following areas deserve special attention as regards corrosion:

• Horizontal surfaces such as bottom plating, face plates and stringers, particularly towards the aft end of the structural element. Wastage may take the form of general corrosion or pitting. Accelerated local corrosion often occurs in the aft bays and particularly in way of the suctions which must be requested to be removed for inspection.

• Deck heads and ullage spaces in uncoated ballast or cargo/ballast tanks (where anodes are not effective) or non-inerted cargo tanks.

• Structure in way of lightening holes or cut-outs where accelerated corrosion may be experienced due to erosion caused by local drainage and flow patterns. Grooving may also be found on both horizontal and vertical surfaces.

• Areas in way of stress concentrations such as toes of brackets, ends of stiffeners, etc.

• Surfaces close to high pressure washing units where jets may impinge causing corrosion.

• Bulkhead surfaces in ballast tanks adjacent to heated cargo or bunkers.

• Any areas of local coating breakdown but particularly in way of deck longitudinals.

Untitled

The importance of appropriate surface preparation and correct application of the coating material is vital to the overall success of any coating system.

The two principal types of tank coating system in use today on crude carriers are inorganic zinc and coal tar epoxy. Pure epoxy systems can also find application for product carriers for protection of the cargo tank to avoid and cargo contamination problems.

The inorganic zinc system acts as an anode to protect any pinhole failure in the original coating. However, the zinc is gradually consumed with time, and when failure occurs, it is very rapid.

Inorganic zinc is affected by sulphur components of inert gas and crudes and therefore it is not recommended to be used for cargo tanks. Inorganic zinc is best suited for segregated ballast service. It is not recommended for partial coating systems as the coating will act as an anode and will be consumed rapidly by the unprotected steel. It is also not recommended where recoating is required because of the difficulty in achieving the necessary standard of surface preparation.

Coal tar epoxy is usually the preferred choice for cargo tanks, partial coating systems and ballast tanks. It can also be used for recoating ballast tanks. Coal tar epoxies are not consumed and work by forming a protective barrier. In way of pinholes or other breakdown in the coating, pitting corrosion and grooving can occur, sometimes at a very high rate, particularly on horizontal platforms, bottom shell plating and under bell-mouths. For this reason, it is often advisable that a supplementary anode system is fitted to prevent the rapid penetration of pits in way of localised coating failures.

The fact that corrosion control systems have a limited life means that Owners who have taken the option of reduced scantlings because of the protection system installed, must be prepared to maintain or renew the system as breakdown occurs.

In the past, inert gas has been accepted as a corrosion control medium for deckheads of tanks but particular care is required to ensure that this is giving effective protection, especially if reduced scantlings are adopted.

Untitled

It is reminded that anodes are not covered by classification.

The basic principle of a cathodic protection system is that the anodes are preferentially corroded to save the steelwork. Steel corrosion is not stopped completely but, if a system is designed and installed correctly, the levels of corrosion are kept within tolerable limits. The anodes must, however, be renewed periodically as they waste away.

Anodes are only designed to be effective when immersed in sea water. The wastage rate is also highly dependent upon the position in the tank structure particularly in cargo/ballast tanks where sludge build-up may not be washed off by the washing guns due to shading by the tank structure.

The design of an anode system should be based upon a specific performance requirement such as polarisation of the steel to give a required potential level in a given period of time, typically 2-5 days. This will define a required "initial" current density to achieve polarisation. The current density required after polarisation has been achieved is the "maintenance" current density. The location of anodes must take into account the expected output and throw from the anode.

It should be noted that ballast residence times for segregated and clean ballast tanks should be sufficient to justify installation of an anode system. Due account should be taken of the potentially high corrosion rates in segregated ballast tanks during laden voyages.

Anode material is generally of zinc. Other types of materials, for example aluminium, are limited because of the danger of sparks when dropped or struck, although these materials do offer better current output for the same weight. The use of anodes of aluminium have an installation height restriction in cargo tanks equivalent to a potential energy of 275 Joules which effectively limits their use to bottom structure and requires that falling objects do not strike them.

Magnesium alloy anodes are normally not accepted in cargo tanks. These anodes result in high production of hydrogen when immersed in sea water, thereby introducing an explosion/fire risk. Temporary use of magnesium anodes for descaling purposes should be undertaken with due regard to the risk involved.

Thickness measurements

The requirements for thickness measurements are given in the Rules, Part A, Ch. 4, Sec. 3.

The Surveyor's report shall contain a summary of findings which reflects the scope and extent of the measurements including percentage of thickness reduction and indicating the extent of repairs, etc.

The full measurements report taken by a certified company is also sent to the Head Office, after being stamped. The points which were verified by the Surveyor (at random) are clearly identified on this report.

See Oil tankers of 130 m or more and exceeding 10 years of age. hereafter for oil tankers of 130 m or more and exceeding 10 years of age.

Summary of salt water ballast tanks

Sub-para. Untitled fully applies.

Tank testing

The extent of tank testing is given in the Rules, Part A. See also Annex.

When survey of the bottom leaves no doubt that the plating is watertight, the tank testing may be carried out afloat.

The Surveyor examine the bulkheads under test in the adjacent tanks. Usually any fractures or leakages in cargo or ballast tanks are easily detected by the sound of water leakage.

When repairs have been carried out on the bottom or side plating affecting watertightness, the testing may be approached in 2 stages:

• First in drydock confirming the tightness of the repair by vacuum box technique hose test or by partially filling the tank in question, the bottom being supported to take the additional weight, under responsibility of the owner's representative.

• Full test as per Rules carried out with the ship afloat

With reference to the acceptance by the Surveyor of cargo tank testing carried out by the ship’s crew under the direction of the Master, reference is made to the IMO MSC.1/Circ.1502 “Guidance on Pressure Testing of Boundaries of Cargo Oil Tanks under Direction of the Master” (see attached file “IMO_MSC_1_Circ_1502”). In particular, a tank testing procedure, specifying fill heights, tanks being filled and boundaries being tested is to be submitted by the Owner to the CD for review, before the testing is carried out by the ship’s crew under the direction of the Master. One copy of the procedure shall be kept by the Owner and one copy by the CD. At the time of the overall and close-up survey, the Surveyor verifies that the Owner’s procedure, as accepted by the CD, is available on-board. The Surveyor also verifies that there is no record of leakage, distortion or substantial corrosion affecting the structural integrity of the tanks tested by the crew. The Surveyor further checks, on the Owner’s report, that the testing has been carried out by the crew within the renewal survey window and not more than 3 months prior to the date of the survey on which the overall or close-up survey is completed by the Surveyor. The Surveyor verifies that the satisfactory results of the testing are duly recorded in the ship’s logbook and that a formal Owner’s report on the testing is retained on board (refer to para. 5.3 of MSC.1/Circ.1502 for the Owner’ s reporting). Subject to all the above and to the internal/external condition of tank boundaries and associated structures being found satisfactory by the Surveyor at the time of the overall/close-up survey, then the testing of the boundaries of cargo tanks by the ship’s crew under the direction of the Master may be accepted by the Surveyor. The ASMS survey report is to refer to acceptance of such testing carried out by the ship’s crew under the direction of the Master and to make reference to the Owner’s procedure, to the Owner’s report and to the record in the ship’s logbook.

Essential auxiliaries and piping systems in cargo tank range

Untitled

Cargo, ballast and stripping piping systems are examined externally and opened up as deemed necessary by the Surveyor. The pipelines are submitted to hydraulic test as deemed necessary by the Surveyor, following their external examinations.

Untitled

Cargo pumps, ballast pumps, stripping pumps and their prime movers are generally surveyed as for machinery items. Refer to the related survey procedure.

Untitled

Pressure relief devices on cargo pumps and pipelines shall be examined and tested. Valves shall be opened up for examination at random, adjusted and re-sealed.

Untitled

Venting systems and flame screens shall be examined and opened up as deemed necessary. Missing or damaged flame screens shall be attended to immediately.

Untitled

Tank level gauges are examined and function-tested, where they are fitted.

Where fitted these are examined and function tested.

Untitled

The inert gas system shall be surveyed at the renewal survey as at annual survey and intermediate surveys. Refer to the related survey procedure.

The renewal survey should take place during a technical stop with enough time to perform internal examinations of the main components and for the necessary maintenance and repairs. The system shall be tested at completion of the works.

Untitled

The equipment for oil pollution prevention shall be surveyed as per the Rules, Part A. Where fitted, crude oil washing pumps, piping, valves and deck mounted washing machines shall be examined and leak tested.

Untitled

Electrical cables are examined for signs of deteriorations to outer sheathing or corrosion of metal braid. Circuits are megger tested. Defective wiring shall be renewed. In hazardous areas such as cargo area, splice kits or similar are not acceptable. Cables shall be renewed over full length or junction boxes installed (certified safe for the zone considered). Any repaired cables are megger tested on completion.

Repairs and other remedial actions

Refer to Repairs and other remedial actions.

Reporting

The reports concerning the overall and close-up surveys should be narrative and provide details of findings, tank by tank.

Important items:

• Bottom plating including under suction pipe bell-mouths & longitudinals

• side shell & longitudinals

• transverse bulkheads and stiffeners

• swash bulkheads

• underdeck structure

• girder systems

• web frames & cross-ties

Points to be noted:

• condition of coating or anodes as applicable

• scale formation & evidence of general scaling

• global buckling of structure or local buckling of plates or stiffeners

• fractures

• corrosion and need for repair/further examination

• flexing of local structure

• pitting corrosion (depth/diameter/density)

• condition of piping & fittings

• condition of handrails, ladders and walkways

• areas not seen due to sludge, water or lack of access.

To allow the easy taking of detailed notes during the survey, prepared check-lists and key plans are very useful, using sketches of a typical wing tank, centre tank or other. The Surveyor indicates fractures, buckling, areas of corrosion, coating failure, position of ultrasonic thickness readings, etc.

The Surveyor's report is a conclusion of these findings made in a brief, concise but precise manner, containing relevant details of findings, observations, repairs, and tests carried out.

A condition evaluation report of the survey and results is issued once renewal survey completed and transmitted to the Owner after endorsement by the Society for placing it on board.

Notes:

1. For ships having safety construction certificate issued by the Society, the condition evaluation report is to be issued on behalf of the Flag administration (box to be ticked in ASMS2 Certificate).

2. The Hull Condition Evaluation Report is to be signed by the Surveyor and verified and countersigned by the SSQM. It is then to be placed on board the ship by the Owner for reference at future surveys together with the detailed survey report. The SSQM transmits to the MOC the Hull Condition Evaluation Report for ESP ships and general cargo ships subject to Pt A, Ch 4, Sec 7. For ESP ships and general cargo ships subject to Pt A, Ch 4, Sec 7, the MOC prepares the hull condition evaluation report, if not already prepared by the SSQM, or checks the one issued by the SSQM. For cases where the SSH is performed in parts (mergeable surveys) the MOC will assess if the SSQM will issue the HCER (if all parts of the mergeable surveys performed by the same SC) or the MOC (when multiple SCs are involved). In the latter case, the SCs who performed parts of the survey may be requested to support the MOC for the HCER drafting, with regards to their part of the survey. The hull condition evaluation report is sent through ASMS2 Certificate.

Oil tankers of 130 m or more and exceeding 10 years of age

Untitled

Resolution MSC.105 (73), adopted in December 2000, requires that the residual longitudinal strength remains within acceptable limits, i.e. it shall not be less than 90 % of the value required in the Rules, should the ship be single-hull or double-hull.

The ship length to be considered is that defined in the Loadlines Convention in force.

Untitled

The evaluation of the longitudinal strength of the hull girder shall be performed, starting from 1st July 2002, at Renewal Surveys, by measuring thicknesses of structural members and assessing the diminution of the sectional area of deck and bottom flanges (see Calculation of sectional areas of deck and bottom flanges of hull girder hereafter).

Untitled

No Class certificate may be issued at the completion of the Renewal Survey, if the results of the longitudinal strength evaluation are not satisfactory, and if relevant replacement and/or reinforcement have/has not been completed.

Thickness Measurements

Ship transverse sections shall be thickness measured:

• either at the beginning of the Renewal Survey, if the preliminary measurements indicate that no steel renewal affecting the longitudinal strength is foreseen,

• or after steel renewal (calculation can be made before effective renewal, including in the calculation the structural members to be renewed),

• or after longitudinal reinforcement (calculation can be made before effective renewal, including in the calculation the equivalent thickness due to the straps),

• or after steel renewal and reinforcement (calculation can be made before effective renewal, including in the calculation the structural members to be renewed and the equivalent thickness due to the straps).

Location of sampled transverse sections

1. Measurements shall bear, as a minimum, on the number of transverse sections required for the Renewal Survey as stated in Table 3 of 6.5.1, Section 3, Chapter 4, Part A of the Rules. The same transverse sections may be considered in both case

   This means:

   Two transverse sections if the class renewal survey is commenced after the ship reaches 10 years and on or before it reaches 15 years of age. (10<age of ship<=15)

   Three transverse sections if the class renewal survey is commenced after the ship reaches 15 years of age. (age of ship > 15)

   Where a postponement is granted to the class renewal survey between 5 and 10 years of age and the survey is completed after the ship reaches 10 years of age (age of ship > 10), evaluation of the longitudinal strength of the ship's hull girder is required unless the thickness measurements readings were obtained prior to the ship's anniversary date.

2. Transverse sections sampled are those located where the largest thickness reductions are suspected to occur or are revealed from deck plating measurements and clear of areas which have been locally reinforced.

3. Transverse sections sampled are those located where the largest thickness reductions are suspected to occur or are revealed from deck plating measurements and clear of areas which have been locally reinforced.

Points of measurement on transverse sections

1. The hull of a ship can be considered as a girder.

   The deck plating and the under-deck structure being considered as the top flange, and the bottom plating and the associated structure as the bottom flange. These two areas are the main elements participating to the longitudinal strength.

2. For each section, the remaining thickness shall be determined for each longitudinal web, each longitudinal flange plate and each plate panel between longitudinals, for the following structure:

   • Deck, side shell and longitudinal bulkheads: within 0.1xDepth from the deck at side (i.e. top flange area),

   • Bottom shell, side shell and longitudinal bulkheads: within 0.1xDepth from the bottom at side (i.e. bottom flange area).

   Each remaining thickness shall be determined by averaging measurements taken on the component in question.

3. For other structures within a section, the remaining thicknesses shall be determined from measurements taken on each longitudinal web, each longitudinal flange plate and each plate strake.

4. It shall be checked that the connection of the different elements of the structure and the thickness of their welding remains are in a satisfactory condition.

Additional measurements

1. Where one or more sections do not meet the longitudinal strength requirements (stated in Appendix 3, Chapter 2, Part A of the Rules), the number of sampled transverse sections shall be increased to include all tanks within 0.5L amidships.

2. Tank spaces that are partly within 0.5L amidships shall be included. Where it is deemed inappropriate to increase the number of transverse sections, a more extensive repair strategy is required.

3. Additional thickness measurements shall also be performed on sections fore and aft of replacement areas in order to ensure that they also comply with the longitudinal strength requirements.

Calculation of sectional areas of deck and bottom flanges of hull girder

Untitled

The ASMS survey items ref MEP051 and MEP052 are available, in the ASMS survey report, for reporting compliance of the ship with MSC.105 (73) requirements, further to the relevant class renewal survey.

Untitled

In case the actual wastage of a given transverse section which contributes to the hull girder strength is less than 10% for the deck or bottom flanges, the calculation of the area diminution of these deck or bottom flanges as well as the section modulus is not required (Refer to Untitled, Nota).

Untitled

Otherwise, the measured areas and the diminution of areas are to be calculated. This may be done manually or using the software mentioned hereafter.

Untitled

In case the measurements of the actual structure show a diminution of sectional areas of either deck or bottom flange by more than 10 % of their respective as-built areas (i.e. original sectional area when the ship was built), either one of the following measures shall be taken:

1. renew or reinforce the deck or bottom flanges, so that the actual sectional area should not be less than 90% of the as-built area and verify the efficiency of this renewal by a new calculation, or

2. calculate the actual section moduli of transverse sections of the ship hull girder, by using the results of thickness measurements of the existing structure, or of the existing structure with renewed areas, as appropriate, during the Renewal Survey.

Untitled

The software calculations in order to support § 4 shall be asked for, by the SC or the MOC, to DA/DTO/Structure.

DA/DTO/Structure owns a software, which gives automatically the values of transversal sectional areas of deck and bottom flanges of the hull girder and their section moduli, after entering the values of thickness measurements.

Reporting

The results of calculations will be presented as per the tables here below.

Untitled

Table related to the diminution of the transverse sectional areas:

(*) NOTA: In case the transverse section thickness measurement (TM) report shows that loss of area is less than 10%, enter in the "Remarks" column:

"Areas not calculated as compliance checked from TM report"

Untitled

Table related to the section moduli:

The above tables are included in the Annex 3 of the Hull condition evaluation report. The calculation sheets for the calculated section moduli shall be attached to the report.

CSR Oil Tankers

For oil tankers subject to SOLAS Chapter II-1, Part A-1, Regulation 3-10 (goal-based ship construction standards for bulk carriers and oil tankers), reference is made to IACS Rec. N°. 96 (Double Hull Oil Tankers - Guidelines for Surveys, Assessment and Repair of Hull Structures) which provides guidelines for the identification of areas of high stress or fatigue risk or other structural areas and structural design features that require monitoring while in-service.

Additional requirements for "Bulk Carrier", "Ore Carrier" or "Bulk-Ore Carrier" Service Notation

Purpose

For ships with the service notation "Bulk carrier" or "Ore carrier", there are additional features which require special attention on top of the arrangements provided in Class renewal Survey under normal survey system (all ships) concerning general cargo ships. Refer to the Rules, Part A.

The traditional designs of bulk carriers and ore carriers are shown in Typical bulk carrier midship section and Figure respectively.

Unlike general cargo ships which are traditionally built with the transverse framing system, bulk carriers are traditionally built with a combined system involving transverse side frames in the hold (to allow easy cargo trimming) and longitudinal framing in deck, bottom, and in the hopper wing tanks which are a feature of these vessels.

Ore carriers are traditionally built with full depth wing tanks and full longitudinal framing as shown in Figure. These designs look more like a tanker than a cargo ship, except that there is a hatch and a double bottom in the centre and that they are subject to a much different service life, resulting in a lot of wear and tear, due to cargo handling unlike a tanker.

Bulk carriers

Design features

Where the side framing is transverse and the deck, bottom and hopper tank framing is longitudinal the connection between the two systems is made through brackets connecting the side frames to the hopper plating and the longitudinals as highlighted in Typical bulk carrier midship section.

The longitudinal hull bending tensile and compressive stresses are highest at deck and bottom, the shear stresses due to hull bending are highest in the sides and thus there are important hull shear stresses acting in the region of the transverse framed side shell and the bracket connection system.

The cargo holds are bounded by the ship side shell, the double bottom and usually by corrugated transverse bulkheads with supporting stools top and bottom, and having a large cargo hatchway (see Fig.5).

The presence of the large hatchways can lead to problems from torsion of the hull as well as the usual stress concentrations at the hatchway corners.

In addition, the stiffeners of transverse bulkheads may under some conditions produce stress concentrations in the deck structure between hatches.

Where corrugated bulkheads are used, their lack of resistance to transverse loads may result in problems in the deck structure between hatches.

In the case of single hull bulk carriers, the hold side frames are individual pieces of structure which, if rendered ineffective, will place additional load on the adjacent frames providing the possibility of progressive and rapid failure of the hold side panel.

The loadings on the hold side frames and their brackets are complex and are generated in the transverse direction by cargo loading and hydrostatic loads producing rotation of the hopper and topside tanks. Cyclic loadings are induced from these load sources by the passage of waves and the motion of the ship. See Figure.

Factors affecting hull determination

1. Original design and construction

   Some original design features of the hull arrangement overall such as the span of the transverse frames in the hold and thus the depth of the top and bottom hopper sides and the bulkhead arrangement may have some effect on the ability of the hull to withstand operating loads and conditions and thus the life expectancy of the ship.

   Also the design of structural details may affect the local resistance to operating loads and behaviour under adverse conditions, this is particularly important for the side frame brackets mentioned in Section Untitled.

   Coatings applied during construction have an obvious effect on the ability of the structure to withstand corrosion. This is particularly important in wing tanks of bulk carriers where salt water ballast is carried during ballast voyages and the tank remains empty but often in a "humid" condition on the loaded voyages providing an environment for corrosion. The same is valid for the coatings of holds, specially the frames, brackets and shell side.

2. Operating factors

   Several ship operating factors may have particular adverse affects on the hull structure:

   • Maintenance of coatings: When paint coatings start to deteriorate and are not repaired then corrosion commences and may progress very fast in areas of coating breakdown where the uncoated areas become anodic to the area still coated.

   • Discharging: The use of heavy grabs (25 tonnes + unladen weight) and bulldozers as well as hydraulic hammers for cargo trimming can lead to structural damage to hold frames and brackets, tank top, hopper side plating and hold end bulkheads.

   • Cargo: With coal there comes the problems of high sulphur content and high temperature of the cargo coupled with condensation which forms on the comparatively cold ship's side providing an ideal corrosive environment. Because of the trimming of the cargo this corrosion tends to be concentrated by gravity on the outboard portion of the hold frame webs and the lower bracket connection to the hopper side. See Figure. This corrosion can sufficiently weaken the local structure to allow fractures to commence and propagate from the lower bracket to outboard or up the web connection to the side shell (leaving the bracket intact). The same effect may happen at the connection between side shell and transverse hold bulkhead.

     With ore cargoes the problems may be associated with loading and discharging as mentioned above but also the combined effects of corrosion, damage and cyclic loading when carrying ore cargoes is increased because the comparatively small volume of the cargo itself offers no support to the side structure in resisting the hydrostatic loads at maximum draught. The rolling motion, due to a lower centre of gravity is quicker, resulting in increased sea loads.

   • Repair methods: Damages caused by grabs and bulldozers to the hold frames, brackets, hopper sides, etc. will be inspected after cargo discharge by the owner. In some ports, the owner can be faced with a decision to either accept the damages as minor blemishes or to carry out temporary repairs with a view to making permanent repairs later or possibly to sail to a repair port.

   Note: Any significant damages should be dealt with under the attendance of a Surveyor. If a Surveyor ascertains that repairs were carried out without attendance of a Recognised Organisation (RO) Surveyor, he shall re-examine the area and request additional measures to their satisfaction.

Summary - Typical bulk carrier defects

1. Fractures at hatchway corners

   An isolated case may be repaired by veeing and welding after drill stopping the crack. Careful grinding of the hatch corner radius should be carried out to remove any local stress raisers.

   Hatch corner cracking of a systematic nature should be repaired by partial plate renewal (insert) following all usual welding precautions in this high stress area coupled with consideration of structural modifications to reduce stress concentration i.e. additional stiffeners under deck or extensions of underdeck stiffening or hatch coamings or brackets. Welding of incipient cracks is generally not a successful repair.

2. Plate panel buckling and cracks on transverse deck structure between holds

   • Buckling

     Depending on the extent of buckling; repairs may be by partial plate renewal or the stiffening of buckled panels; a combination of plate partial renewals and the addition of extra transverse underdeck stiffeners; extension of hatch coaming tapering bracket in a transverse direction; or a combination of the proposed solutions.

   • Cracks

     Refer to the related survey procedure, Section 3 and Section 4.

3. Fractures in hatch coamings

   Depending on the case, these may be repaired by veeing and welding. The important point for systematic or re-occuring fractures is to remove the stress concentration causing the fractures. Thus each case requires individual consideration.

4. Fractures at connection between tank top and hopper plating

   These may generally be repaired by veeing and welding. However, for systematic fractures, the cause must considered and action taken to re-distribute local stresses by re-alignment of members or fitting addition stiffeners.

5. Grab damage and bulldozer damage to hold side frames and brackets

   Grab damages, etc. are considered as for shell indents and repaired when the depth of indents exceeds acceptable limits. Fractures and splits require immediate repair.

   Damages to hold frames and brackets are to be treated with care as damages to these elements can seriously weaken the ship side structure.

   Surveyors carefully examine the connection of bulkheads to the tank top, which can be sheared by bulldozer action. This type of damage is very important because flooding of adjacent holds may lead to the loss of the ship. Similarly the connection of the bulkhead to the stool and lower wing tank shall be checked.

   The Surveyor should also be aware that cargo handling damages are sometimes repaired without classification survey and even by the crew. Previous repairs are checked for signs of fracture, etc.

6. Grab damage to tank top, hopper sides and stools

   Repairs are always requested when internal stiffeners are buckled. The Surveyor is reminded that in principle repairs by doubling can only be considered as a temporary measure (excepted in specific cases, see the related survey procedure), and therefore are permanently repaired during renewal surveys.

7. Fractures in hold side frames and brackets

   Fractures here may occur in frames without signs of damage or wastage. However damages and wastage serve to weaken the elements and lead to fractures. When fractures are detected, adjacent frames are also carefully examined for similar fractures. See Figure and FigureSystematic fracturing may be best dealt with by reducing frame spans by fitting deeper brackets or by fitting slightly increased scantling frames, etc.

   Fractures resulting from corrosion or damage are dealt with by renewal of wasted parts where fractured and in other similar locations where wastage is detected.

8. Corrosion of frames and brackets (see Figure)

   This should be examined by a close-up inspection. Where wastage is at the limits of acceptability the Owner may be advised to apply some form of coating. Where wastage is passed acceptable limits repairs should be requested.

9. Fractures at forward and aft extremities of topside tank structures

   Fractures in this location in way of longitudinals may be as a result of stress concentrations, corrosion or a combination of both.

10. Corrosion in topside tanks

    Uncoated tanks corrosion may proceed quite quickly and in areas of high stress local corrosion will be accelerated. These tanks when empty may remain damp and warm, due to the heating effect of the sun and are prone to corrosion. On uncoated tanks the effect of anodes is limited to when tanks are full and even then the upper part may not be completely protected.

    When tanks are coated adequately, corrosion only becomes a problem when the coating starts to fail. Unfortunately this coating failure is more likely in areas of high stress reversal thus local corrosion tends to be rapid when the coating starts to fail.

Special areas of interest during survey

Further to the preceding, it follows that surveys of bulk carriers entail checking for these known problems during the usual examinations.

1. Decks

   Particular attention to hatch corners and coamings for fractures and signs of bucklings in transverse deck panels. Grab damages in hatch coamings.

2. Holds, frames and bulkheads

   Particular attention to be paid to the following:

   • tank top for grab damages,

   • lower hopper side and stools for grab damages,

   • corrosion at lower end of the transverse bulkheads (inside/outside stools),

   • fractures at tank top and hopper plating connection,

   • fractures at bottom of bulkheads caused by bulldozers,

   • fractures at connection of corrugations to upper and lower wing tanks,

   • fractures in hopper side plating especially adjacent to bottom bracket toes,

   • fractures in top side tank hopper side plating, staining or actually leakages are investigated,

   • the hold side frames and brackets must be carefully close up inspected, from ladder, staging or mobile platform (cherry-picker) to check for corrosion and fractures and also for damages such as buckling of webs and face flats of frames or brackets, and condition of shedder plates and any tripping brackets.

   For side frames (Figure) these must be inspected along the line A B C D.

   For brackets, the ends A F E D are checked. The frames and brackets are sounded with a hammer and thickness measurements are requested of the frame webs, shell in way and brackets, where significant corrosion is found.

3. Top side tanks

   Particular attention to the condition of the coating, if any, and the extent of any corrosion particularly concerning deck longitudinals and the main transverse brackets and web-frame system. Thickness gaugings is requested where deemed necessary or where required by the Rules.

   The forward and aft extremities of these tanks are carefully examined for fractures.

Ore carriers

Ore carriers of designs similar to that shown in Figure may experience some of those problems experienced by bulk carriers and dealt with in Bulk carriers., i.e. fast loading, stevedore damage, corrosion in wing ballast tanks and cyclic wave loading of the ship side.

When compared to typical bulk carriers, the main differences are the hull frames which are not subject to grab damages or cargo corrosion and the cyclic effect of the waves which produces a different result in these longitudinally framed vessels.

In this case, the result is wastage and fractures in way of the tie beams, in the cross tie beams themselves or in the web frames, initiating at longitudinals of the shell side or longitudinal bulkhead.

The combination of damaged tie beams and fractures in way of the longitudinals serves to multiply the effect and severe damage can result.

This type of problem may be very localised in the beginning and the remainder of the tank may be without signs of any deterioration. Thus it is very important for the Surveyor to specifically examine these areas during each survey.

Performance of the survey

Scope

The scope of survey is given in the Rules, Part A. The extent of survey increases with the age of the ship. This TNS does not define or limit the scope of surveys but outline the manner in which surveys are performed.

Planning

Refer to Section Survey planning. and Annexes Preamble,Untitled and Untitled.

External examination

This includes all the items required for annual surveys for all ships.

Internal examinations

Untitled

The examination of service spaces, machinery spaces and tanks located in way of machinery spaces is carried out as per renewal survey for all ships.

Untitled

An overall survey of all ballast tanks and all spaces within the cargo area is carried out at each renewal survey. Sketches of typical wing tanks, cargo holds, topside tanks, double bottom tanks are used in order to note fractures, bucking, corrosion, coating failures, ultrasonic readings, etc.

The Survey Report File maintained on board and the main drawings are consulted, as well as the hull condition evaluation report issued by the Society after the previous renewal survey.

The aim of the overall survey is to discover any excessive corrosion, significant deformation, fracture or other structural defects, and define the extent of close-up surveys and ultrasonic thickness measurement.

Untitled

Close-up surveys

During each renewal survey, close-up surveys shall be carried out in order to assess the condition of bulkheads, shell frames, their end attachments in cargo holds and salt water ballast tanks.

The minimum requirements for close-up surveys are given in the Rules, Part A. Thickness measurements of local corrosion areas in shell frames and their end attachments shall be carried out in connection with close-up surveys in order to define exactly the actual conditions and required repairs.

Thickness measurements

The requirements for thickness measurements are given in the Part A of the Rules.

Provisions of Section Thickness measurements also apply.

The Surveyor's report must state a summary of findings which reflects the scope and extent of the measurements, including the percentage of thickness reduction and indicate the extent of repairs.

The full measurements report taken by a certified Company shall be also sent to DO-FM, after having been stamped. The points which were verified by the Surveyor (at random) are clearly identified on this report.

Tank testing

Refer to Part A of the Rules and to Testing of watertight compartments.

Hatch covers and coamings

Refer to Section Untitled. In addition, thickness measurements shall be required as per the Rules.

Summary of salt water ballast tanks

Sub-para. Untitled fully applies.

Reporting

Refer to Section Reporting. and Section Reporting.

The particular characteristics of the ship's type shall be taken into account.

CSR Bulk Carriers

For bulk carriers subject to SOLAS Chapter II-1, Part A-1, Regulation 3-10 (goal-based ship construction standards for bulk carriers and oil tankers), reference is made to IACS Rec. N°. 76 (Guidelines for Surveys, Assessment and Repair of Hull Structure – Bulk Carriers) which provides guidelines for the identification of areas of high stress or fatigue risk or other structural areas and structural design features that require monitoring while in-service

Additional requirements for "Chemical Tanker" Service Notation

Purpose

The survey requirements for chemical tankers are given in the Rules, Part A.

Design features

Designs of chemical carriers may vary from the well known oil tanker design as seen in Additional requirements for "Oil Tanker" Service Notation or for combined Service Notations, possibly with special tank coatings in cargo tanks, to double skin designs using either stainless steel or stainless steel clad mild steel for the cargo tanks, or specially coated tanks, or to the use of independent cargo tanks.

Additional requirements

In addition to the requirements of Additional requirements for "Oil Tanker" Service Notation or for combined Service Notations concerning oil tankers, where applicable, the following points should be dealt with.

Untitled

Independent cargo tanks: External examination is required, as well as internal examination of the cargo tanks to check the condition of the tank structure, the tank supports chocks, keys and other connections to the hull and the adjacent hull structure.

This visual inspection aims at checking for signs of deterioration, straining or fracture, etc.

Any repairs to cargo tanks of chemical tankers are treated with care because of the problems of special materials and tank coatings which may either pose welding problems or will be damaged by the heat input of welding.

Untitled

Attention is drawn to the requirements of the Rules for overall and close-up surveys.

Untitled

For thickness measurements of the cargo tanks in chemical tankers, the Surveyor may limit them, when double skin designs are used and both sides of the cargo tank boundaries are completely coated and the coatings are found intact. It may be practicable to take ultrasonic readings through the tank coating.

In all cases, the Surveyor's report must justify any reduction in the scope of the survey.

Untitled

Pitting in cargo tanks of chemical tankers: Where pitting is found in coated cargo tanks, this is usually due to slight imperfection or damages to the coating usually resulting in small diameter deep pitting which, if not dealt with in time, can result in perforation of the plating. When caught in time, these are usually repaired by grinding and filling with a compatible filler material.

Untitled

Special gutters and stripping devices: Because of the nature of some chemical cargoes, ships may be fitted with special gutters and draining devices in pump rooms, and special stripping features for cargo tanks. These must be examined.

Untitled

Any special gas tight seals shall be examined for effectiveness and maintenance, as necessary.

Untitled

Cargo ballast and stripping piping shall be examined, including cargo valves, and opened up as deemed necessary by the Surveyor. Hydraulic or pneumatic testing may also be required but in any case the systems are leak-tested.

Cargo vent piping shall be examined and tested as deemed necessary by the Surveyor.

Cargo heating system shall be examined and tested.

Cargo pumps, ballast pumps, stripping pumps and their prime movers shall be internally inspected. Ballast/stripping pumps and their prime movers shall be externally examined, and opened up if deemed necessary. Refer to the related survey procedure.

Steam/steam generators, oil and water heaters are generally examined externally and internally as deemed necessary by the Surveyor. Particular attention is given to safety and pressure relief devices.

Anti-sparking fans where fitted to pump rooms, etc. are examined as well as flame screens where fitted.

Pressure/vacuum valves shall be opened up for examination, adjusted, function tested and re-sealed.

Pressure relief valves of cargo piping shall be examined and function tested. Adjustments shall be made as necessary. Selected relief valves may be opened up for internal examination.

Where fitted, any automatic closing valves shall be tested.

Untitled

Electrical cables shall be examined for signs of deterioration, i.e. damage to outer sheathing or corrosion of metal braid. Circuits are megger-tested. Defective wiring is renewed.

In hazardous areas such as the cargo area, splice kits or similar are not acceptable. Cables shall be renewed over full length or between junction boxes, which are certified safe for the zone considered. Any repaired cables are megger tested on completion.

Untitled

Equipment for pollution prevention: requirements are given in the latest edition of the Rules, Part A.

Survey planning and performance

The scope of the survey is given in Part A.

For survey planning requirements, refer to Section Survey planning. and Annexes Preamble, Untitled and Untitled.

Summary of salt water ballast tanks

Sub-para. Untitled fully applies.

Repairs and other remedial actions

Refer to Section Repairs and other remedial actions.

The particular characteristics of the ship's design are taken into account.

Stainless steel tanks and coating characteristics compatible with the chemical products listed on the Hull Class Certificates shall be observed.

Reporting

Refer to Section Reporting. and Section Reporting.

Additional requirements and recommendations for "Liquefied Gas Carrier" Service Notation

Purpose

The renewal survey requirements are given in the Rules, Part A. In general, the renewal survey of the hull shall be carried out as for a cargo ship as described in Class renewal Survey under normal survey system (all ships) with the relevant parts of Additional requirements for "Oil Tanker" Service Notation or for combined Service Notations concerning ballast tanks. Additional surveys are required concerning the liquefied gas plant and special features.

The survey obviously varies depending on the type of ship. This Section provides some general guidance therefore. Refer also to the related survey procedure for details of annual and intermediate surveys.

Survey preparation and planning

The renewal Survey, by its nature, requires that the ship be presented for survey in a clean and completely gas-free condition.

The safety precautions are similar to those for oil tankers as described in detail in Additional requirements for "Oil Tanker" Service Notation or for combined Service Notations The Surveyor must be aware not only of the danger of gas but also of the potential problem of lack of oxygen due to the use of inert gas or nitrogen for inerting. This may apply to spaces other than cargo tanks, such as void spaces surrounding cargo tanks, and the Surveyor must also remember that lack of oxygen in the atmosphere may also be encountered in poorly ventilated ballast or void spaces due to the consumption of oxygen in the corrosion process.

The Surveyor must follow all usual safety routines but, in any case, he must leave immediately any enclosed space if he has any feeling of "dizziness".

Recommendation (Recognised Organisation (RO) Rules, Part A, Chapter 4, Section 5, [6.2]): As for any renewal survey, it is recommended to work out a specific survey programme in advance, with the owner's representative, specially concerning the gas tanks and special requirements for non-destructive testing and removal of insulation, etc.

Since the survey involves internal examinations and also some operational testing, it is probable that the renewal survey will not be completed until the ship loads the first cargo after the survey.

During this preparation stage, the Surveyor makes himself familiar with the general design of the ship and with any special features, and adapt their survey requirements accordingly.

Reference to log books and discussions with the crew may also reveal important information on any problems recently experienced by the ship, which may require some particular attention during the survey.

In order to ensure that the above requirement related to tightness test of the secondary barrier for membrane containment systems is duly implemented, the following instruction is applied:

For the Membrane system type “GTT-MKIII Membrane Type Cargo Containment System”, Inspection and Testing are to be carried out in accordance with programmes specially prepared in accordance with an approved method for the actual tank system.

Cargo containment system - Overall surveys and examinations

Membrane type containment system

Membrane type containment systems: The renewal survey is generally made up of an internal examination of each tank to check the general condition of the membrane structure itself as regards any signs of damage or deformations in the panels, outside the limits set by the builders. Damage may be caused by falling objects. Whilst, in the tanks, the pump support structure is examined for signs of deterioration, loose components, etc. The cargo pumps usually shall be withdrawn from the tanks for overhaul and inspection.

Usually at each renewal survey the primary and secondary membranes are leak tested to a procedure developed by the Makers and accepted by the Society.(Refer to Recognised Organisation (RO) Rules Pt A, Ch 4, Sec 5, [6.7.10] for the tightness test of the secondary barrier and to para. 6 below "Cargo Containment System - testing")

Since only the inside membrane surface and the inner hull of the ship are visible the visual inspection of these areas should be carefully carried out. The inner hull of the ship will usually form ballast tank bulkheads and double bottom tank top. Inspections in these tanks are carefully carried out particularly with regard to checking for breakdown of coatings and subsequent corrosion and fractures in the structure. It should be noted that repairs to the hull on these types of vessels may require special consideration concerning the transmission of heat through the double hull to the insulation.

In order to ensure that the above requirement related to tightness test of the secondary barrier for membrane containment systems is duly implemented, the following instruction is applied:

For the Membrane system type “GTT-MKIII Membrane Type Cargo Containment System”, Inspection and Testing are to be carried out in accordance with programmes specially prepared in accordance with an approved method for the actual tank system.

A tightness test of the primary and secondary barrier is to be carried out in accordance with the system designer’s procedures, and acceptance criteria, as approved by the Society.

The proposed inspection and testing program is to comply with the procedures set out in the below two GTT documents, which have been approved by Recognised Organisation (RO):

1.GTT MK III Low Differential Pressure Test LDPT (Global) Procedure Op Doc OP-MTD-000001 Rev 01 03-06-2013 (see attached file “GTT MK III LDPT.pdf”) and

2.GTT MK III SBTT Procedure GTT Ext Doc 1136 Rev 04 13-06-2013 (see attached file “GTT MK III SBTT.pdf”)

(The documents currently in force are stamped by Recognised Organisation (RO) Section ACM258/1/6. VU avec observations dated 30-jul-2013)

3. TAMI (Thermal Assessment of Membrane Integrity) test procedure OPSS-MTD-000034 Rev.4 17-10-2014 (see attached file “GTT - TAMI.pdf”)

(The document currently in force is stamped by Recognised Organisation (RO) Section ACM258/1/6. VU avec observations dated 23-Oct-2014)

4. QUALIFICATION OF MARK III SECONDARY BARRIER method OP-MTD-000011 Rev 01 22 Jan 2015 (see attached file “GTT - Qualification MKIII secondary barrier.pdf”)

(The document currently in force is stamped by Recognised Organisation (RO) Section ACM258/1/6. VU avec observations dated 22-May-2015)

5. ACOUSTIC TEST PROCEDURE FOR DETECTION AND LOCALIZATION OF LEAKS GTT External document n 3122 Rev 0 Feb 2007 (see attached file “GTT - Acoustic Emission.pdf”).

(This document, which is not stamped, is accepted by Recognised Organisation (RO)).

The tests as set out within the procedures are to be performed by Recognised Organisation (RO) approved service supplier (any deviation to be reported to MO for instructions) and witnessed by the Surveyor. A copy of the proposed test procedures should be sent to the MO on receipt of these from the approved service suppliers. This is for MO’s information purposes and should not delay the tests in any way.

The preliminary draft results of the Secondary Barrier Tightness Test (SBTT) are to be sent to the MO immediately on receipt. The MO will review the results and/or pass to the technical department for review (DA-SAFE), against the acceptance criteria. Acceptance of the SBTT results by the attending Surveyor cannot be made prior to MO agreement on acceptance.

Note: The Low Differential Pressure Tests (LDPT) may be used for monitoring the cargo containment system performance, but are not considered an acceptable test for the tightness of the secondary barrier. Secondary Barrier Tightness Test (SBTT) for glued secondary barriers: if the designer’s threshold values are exceeded, an investigation is to be carried out and additional testing such as thermographic and/or acoustic emissions testing should be carried out.

The relevant ships are being put under monitoring. ASMS items CIC130A and CIC140A have been made mandatory in the ASMS reporting system. Surveyors are requested to enter the references of the inspection and testing programme and of the system designers procedures in these items.

Self-supporting spherical tanks (type B)

The cargo tank is a spherical shape supported by a skirt.

Tank material may be in Nickel rich alloy steels (9 % +) or aluminium alloy.

Usually, the designs feature a plain surface internally with a central pipe support tower extending from the bottom to the dome. The pumps are also housed in this central tower. Externally, the support skirt and the sphere itself are insulated. Access is available to the skirt and under the tank where a drip tray is fitted.

Internal examination will consist mainly of a visual examination of the internal surfaces of the spheres with particular attention to welds.

The central support tower and attached pipes, etc. shall be examined particularly for loose components. The discovery of nuts or bolt at the bottom of the tank usually means something is loose somewhere. The cargo pumps shall be usually removed for overhaul and survey.

Where required, non-destructive testing may be carried out on some welds of the tank internal structure. This is usually realised by dye penetrant methods.

Externally, the visual examinations cover the insulation usually applied directly to the tank external surface, including the support skirt. The Surveyor checks for damaged or missing insulation which should be repaired.

The support skirt and surrounding hull steelwork shall be examined for signs of deterioration or cracks. Where required by the Rules or deemed necessary by the Surveyor, sections of insulation shall be removed for visual inspection and non-destructive testing of the structure. The most important area externally is the zone where the skirt joins the sphere.

Insulation are replaced after the inspections and the vapour barrier re-instated.

Should any fractures or corrosion problems be detected, proposed repairs should be agreed to by DO-FM. Surveyors are reminded that no welding shall be attempted on liquefied gas carrier containment systems prior to the DO-FM agreement.

Independent tanks (type C)

For this type of tanks, no secondary barrier is necessary. Tanks are usually cylindrical with domed ends or bi-lobe designs. In some cases, there are deck tanks. The materials used are usually steel or aluminium.

Usually these tanks are pressure vessels with internal stiffening in the form of web frame rings.

Externally the tanks are usually supported either in saddles or on support stools. These supports are positioned in way of the internal stiffening rings. For the types supported in saddles the anti-flotation devices usually consist of a steel strap over the top of the tank or some other blocking device at the top of the tank.

On other designs brackets may be found welded to the tank to house loose fitting bolts attaching the tank to the ships structure. Insulation is usually attached to the external surfaces of the tank and covered with sheet metal cladding acting as a vapour barrier to prevent the insulation becoming wet.

Internal inspection of these tanks types usually consists of a detailed visually inspection.

The tanks must be cleaned for inspection and lighting provided. This visually inspection includes the tank shell generally and its construction welds, the connection of the dome and pump sump, the connection and structure of the stiffening rings, connections of shell plates and longitudinal bulkhead of bi-lobe tanks, and foundations for pumps, towers etc.

Generally internal corrosion is not a problem and the inspection is generally for cracks which may be found in welds. The most likely location of cracks is in fillet welds of stiffening ring cut-outs where the welds are returned or in bi-lobe designs in areas where the bi-lobe connection is made.

Since welding of gas tanks is not usually practicable because of problems associated with stress relief, any minor fractures found should be carefully recorded and Head Office advice sought. Surveyors are reminded that no welding should be attempted on liquefied gas tanks without Head Office agreement.

Cargo pumps, deep well or submerged type are usually removed from the tanks for overhaul and survey.

Non-destructive testing may be required by the Rules or requested by the Surveyor following visual inspection. On steel tanks this is best carried out using the magnetic particle method whereas dye penetrant is used on aluminium tanks.

The areas to be checked should always include stiffening rings, "Y" connections, swash bulkhead connections, connections to shell for pumps, pipes, ladders etc., dome and sump connections. The non-destructive testing is done in a systematic way, the Surveyor selecting the areas to be checked or agreeing a programme proposed by the owner.

Detailed records are kept and the Surveyor makes a brief but precise technical report concerning this.

External inspections include the whole surface of the insulated tanks so far as practicable. The condition of tank supports and anti-flotation devices and their connection to the tanks should be checked by visual inspection and non-destructive testing where required by the Rules or requested by the Surveyor.

Insulation may be required to be removed locally to allow inspection of these tank attachments. After inspection the insulation is replaced and the vapour barrier resealed in way.

Whilst in the hold spaces surrounding the cargo tanks the Surveyor looks for signs of water leakage through the dome seals or other locations which are attended to.

Also in these spaces will be located bilge eductors, bilge alarms, gas detection points and piping etc. which should all be examined as should the hull steelwork.

Because of the sometimes limited accessibility of some of the hull structure, particularly the double bottom tank top, maintenance in these areas is often difficult and the Surveyor should pay particular attention to the condition of these parts which should be visited during testing of the tanks in these spaces (water ballast, fuel, etc.).

Miscellaneous types of containment

These should be surveyed according to the Rules, Part A. Parts of the preceding Sections should apply as far as possible.

Close-up survey

The minimum requirements for close-up surveys are defined in the Rules.

The Surveyor may extend or reduce the close-up survey as deemed necessary, taking into account the maintenance of the tanks under survey, the conditions of the tanks (overall survey), the areas where the coating is found in good condition or due to the defects found, in similar tanks.

Cargo containment system - Thickness measurements

Thickness measurements are required by the Rules and/or the Surveyor. Thickness measurements are made by ultrasonic means.

There is no need to make these on membrane tanks or aluminium tanks which are not subject to thickness wear due to corrosion. Aluminium may suffer from corrosion when in contact with seawater but usually this is pitting corrosion not easily detectable by ultrasonic methods. Areas likely to be subject to seawater attack must be visually inspected.

Steel tanks are subject to corrosion, but problems usually occur on outside surfaces due to the seawater action on the steel.

Internally corrosion will be general in nature and very limited due to the lack of oxygen and water in the normal environment.

Externally the areas likely to be affected are those where water ingress is possible, i.e. around the domes. At any signs of such leakages or at areas of damaged insulation, the Surveyor examines visually for signs of corrosion followed up by thickness measurements as considered necessary. Random thickness measurements then must include the dome section, the pump sump section and random plates to bottom, sides, ends and top. These are usually taken from the inside as this does not involve removal of insulation.

Cargo containment system - Testing

For systems other than membrane type system, tightness may be verified by examination of the log books concerning particularly gas detection and verification of the correct functioning of the gas detection system in the spaces surrounding the cargo containment system.

A tightness test may also be carried out using air or other gas such as nitrogen, usually at the maximum working pressure of the tank.

In fact, cargo containment systems are continuously monitored for gas tightness whilst carrying cargo by the gas detection system with sensors in the hold spaces.

Hydraulic testing of cargo containment systems may also be required by the Rules, Part A, to verify the structural strength of the tank. This testing, where performed, should be made with water or by applying air pressure on top of the water. It could be dangerous to use air for testing at pressures greater than the relief valve settings.

After using water in the cargo system, efficient drying is necessary to prevent later problems due to ice forming when the system is cooled down.

Note: For ships under CS, a specific CS item is to be created for the tightness test of the secondary barrier of a membrane containment system, as required by Recognised Organisation (RO) Rules Pt A, Ch 4, Sec 5, [6.7.10].

Cargo containment system - Relief valves

These are opened up for examination, adjustment and testing. This is usually done by specialists or the Makers themselves and, in some cases, the valves may be sent to a factory.

The Surveyor verifies that this work is satisfactorily completed and that the valves are re-sealed to prevent tampering.

Inter-barrier and hold space relief devices

Pressure/vacuum valves and other pressure relief devices, rupture discs, etc. are examined as required by the Rules.

These items may be opened up for examination and resetting, testing, etc. as deemed necessary.

Cargo handling system

Untitled

Cargo piping systems shall be examined externally including valves, actuators, relief valves, etc. Insulation should be removed as deemed necessary to allow close examination of piping surfaces. This is particularly important where piping is made of steel or aluminium and the insulation is either damaged or has the appearance of previous water penetration. Corroded piping is subject to thickness measurement and hydraulic test where deemed necessary. With stainless steel piping corrosion is normally not a problem.

Piping, valves, actuators, etc. may be opened for internal examination. It is advisable to test the actuator operation on the vessels arrival to determine which actuators and valves require overhaul, rather than wait until final testing.

On completion of maintenance works the complete piping system is leak tested using air or nitrogen.

Untitled

Pressure relief valves shall be function tested. A random selection of valves is opened up for examination and adjustment. Where seals are provided to prevent tampering, these should be re-sealed.

Untitled

The survey of cargo process plant (cargo pumps, compressors, heat exchangers, etc.) is, in general, carried out as for the renewal survey of machinery. See the related survey procedure and the Rules, Part A.

The main special point to remember is the operating temperatures involved, and the materials used in relation to this. Any repairs to cargo piping or process plant should use the materials as stipulated in the Rules, or their equivalent.

Materials and the requirements for weld procedure qualification tests, welder qualification, non- destructive testing, hydraulic testing etc. should be fulfilled in all cases.

Untitled

Systems for removal of water from inter-barrier and hold spaces shall be examined and tested as deemed necessary. For systems using pumps, the pump shall be tested under running conditions and opened up as necessary. For eductor systems using high pressure seawater passing through a nozzle, the system shall be tested in operation by putting some water in the bilge suction box.

The gas-tight bulkheads shall visually examined, specially the sealing arrangements fitted to drive shafts passing through the bulkhead between electric motor rooms and pump/compressor rooms. Generally, these may be checked for air leaks with the shaft stopped and the electric motor room pressurised.

Where fitted, special heating arrangements for hull structure should be examined and tested as deemed necessary.

Where applicable, loose hoses and spool pieces used for segregation of cargo piping systems, inert gas and bilge systems shall be examined.

The electrical bonding of cargo tanks and cargo piping shall be checked and repaired as necessary.

Safety electrical equipment shall be visually examined. Any defective parts are repaired to the standards applicable to the certified type in question.

The Surveyor may require opening up and overhaul of the electrical equipment.

The electrical wiring is also examined for damage or deterioration and megger test carried out.

Defective wiring is renewed in its entirety or if junction boxes are used these should be of the required safety type appropriate to the zone. Splicing kits are not accepted in gas dangerous zones.

The renewal survey of the inert gas plant where fitted should be carried out according to the Rules, Part A, and is generally the same as for intermediate survey.

Summary of sea water ballast tanks

Sub-para .Untitled fully applies.

Repairs and other remedial actions

The particular characteristics of ship design shall be taken into account.

Consult the MOs for any welding repairs on the cargo containment system.

Reporting

Refer to Section Reporting. and Section Reporting.

The particular characteristics of ship design shall be taken into account.

Additional requirements for "General Cargo Ship" Service Notation

Untitled

IACS Unified Requirement UR Z 7.1, (previously referred to as UR Z 10.6) provides requirements for hull surveys of general dry cargo ships.

These requirements are included in the Rules, Part A, Ch 4, Sec 7 "General Cargo Ships", May 2003, applicable to surveys commenced on or after the 1st July 2003.

Untitled

Ships of 500 GT and above carrying solid cargoes and with the following current service notations (or equivalent former notations) are subject to the above referenced requirements:

• general cargo ship, including timber carriers and log carriers,

• bulk carrier (without the ESP additional service feature).

The above do not apply to general dry cargo ships of double side-skin construction, with double side-skin extending over the entire length of the cargo area, and over the entire height of the cargo hold to the upper deck.

Untitled

The above referenced requirements are not applicable to the following ship types:

• ships with service notation "bulk carrier ESP" or "ore carrier ESP",

• ships with service notation "container ship",

• ships with service notation "ro-ro cargo ship",

• ships with service notation "refrigerated cargo ship",

• ships with service notation "livestock carrier",

• ships with service notation "deck ship" without any access for cargo below deck,

  or equivalent former notations.

• dedicated cement carriers,

• dedicated wood chip carriers,

• general dry cargo ships of double side-skin construction as referred to in above Untitled.

Untitled

Ships having been assigned the dual service notation general cargo ship - container ship are excluded from the scope of these requirements, provided the loading manual and stability file of such ships is specially intended for the carriage of containers.

The same principle also applies to ships having been assigned the dual service notation general cargo ship - ro-ro cargo ship.

Untitled

Requirements for overall and close-up surveys of cargo holds, ballast tanks and other areas, for thickness measurements and for tank testing are detailed in the Rules, Part A, Ch 4, Sec 7, [4].

Note 1 Thickness measurements shall be taken by a "certified" TM company. Refer to the related survey procedure for details of the certification process.

Note 2 Since ships subject to the requirements of Part A, Ch 4, Sec 7 of the Rules are not ESP ships, they are not subject to the "ESP survey programme" but the hull condition evaluation report, the ship's survey and thickness measurement reports are mandatory.

Note 3 General dry cargo ships of double side-skin construction as referred to in above Untitled are excluded from the requirements of Pt A, Ch 4, Sec 7 and Note 2 above.

Additional requirements for "Container Ship" Service Notation

Purpose

The renewal survey requirements are given in the Rules, Part A. In general, the renewal survey of the hull shall be carried out as for a general cargo ship as described in Class renewal Survey under normal survey system (all ships).above.

There follows some information concerning special design features of typical purpose built container ships.

Design considerations

Figure shows a typical design of container ship.

This design consists basically of a double skin ship with large cargo hatches. The cargo hatches are the full size of the holds themselves, leaving only a narrow strip of deck structure down each side of the ship and with narrow transverse box girders between the hatches.

Additionally, the hatches are divided by transverse screen bulkheads and longitudinal girders to which all guides or similar are fitted to locate containers.

Hatch covers are usually pontoon type and designed to support several layers of containers.

In some ships, the hatch covers may not be of weathertight construction and, in some designs, hatch covers are not fitted; then, spillways and special pumping arrangements are fitted. These arrangements are possible because of the low permeability of the holds when full of containers.

Due to this design arrangement, the longitudinal forces in the deck are carried by the narrow deck strips and longitudinal girders. The upper deck section is usually a box girder design which forms a passageway and pipe tunnel.

Because of the large deck openings, the hull may be subject to torsion and the Surveyor should always pay particular attention to the areas of stress concentrations such as hatchcorners, hatchcoaming corners, the ends of hatchcoaming brackets and the underdeck brackets, etc., in the side box girders.

Hatch covers

Due to the fact that containerships generally are always either loading or unloading during annual surveys, it is always difficult to have good access to the covers. This is not true at the renewal survey, when the ship is in drydock, and the Surveyor must take this opportunity to make a thorough inspection of the hatch coamings, covers and fastenings, etc. as required by the Rules.

Additional requirements for "Passenger Ship" Service Notation

Purpose

In general, passenger ships should be treated in the same way as cargo ships for Classification surveys. See Class renewal Survey under normal survey system (all ships).

The survey requirements are given in the Rules, Part A.

However, there are certain items which pose problems not necessarily found in cargo ships, which are described hereafter. See also the related survey procedure, Section 6.

Reference is made to the IACS recommendation REC 111 “Guidelines of the preparation of hull structural surveys” in which surveyors can find guidance for preparation of surveys, accessibility to ship structure and tank corrosion.

Linings of ship sides and bulkheads

These ships may be so constructed that such items as air pipe heads, scuppers, etc. are fitted behind linings in passenger cabins, etc. It is important that the Surveyor be aware of the location of these items so that the linings can be removed or inspection panels opened, where fitted, to allow inspection of these items.

Similarly where side-scuttles (port-holes) are fitted and traces of leakage are noted, the panelling is removed, in way of these elements, to check for corrosion of the side plating.

Watertight doors

Passenger ships are well sub-divided with watertight bulkheads through which there are usually watertight doors. These watertight doors are carefully examined along with the watertight bulkheads themselves. The doors are tested in operation both locally and remotely (usually from the wheelhouse) including open/shut indicators. Any defects should be repaired.

Extended spindles/remotely operated valves

Passenger ships, by their design, have various compartments containing machinery and pumps. Usually there are means to operate bilge valves from outside spaces as well as other valves such as inlets and discharges. At renewal survey, these shall be examined and tested in conjunction with bilge and fire pump testing.

Fire protection

Passenger ships contain usually more fire divisions than cargo ships and numerous fire doors and fire dampers. If the ship has a Safety Passenger Certificate issued by the Society, the fire divisions shall be examined for unapproved modifications. The operation of fire doors and fire dampers shall be verified. Particular attention shall be paid to machinery spaces and galley areas, specially to lift shafts.

Ship side doors

These doors shall be examined carefully for corrosion, damage or other deterioration to the structure, hinges and locking arrangements. The seals are inspected and the doors hose-tested. Refer to the related survey procedure, section 6 para 6.1.5.

Additional requirements for "RoRo Passenger Ship" Service Notation

Purpose

RoRo ships are usually fitted with large stern side and/or bow doors, and large open hold spaces on many deck levels usually incorporating also large weathertight flush hatches and internal ramps or lifts between decks.

The survey of these ships is similar to that for cargo ships (Class renewal Survey under normal survey system (all ships)) with special attention to the unusual features of these ships.

Bow doors, side doors, stern doors

These are examined for corrosion, damage or other deterioration including the hinges, locking and sealing arrangements. Hose-testing is carried out to verify the tightness of such doors, as deemed necessary. Refer to the related survey procedure, section 6 para 6.1.5, in particular for the requirements for close-up survey, NDT and thickness measurement of securing, supporting and locking devices, together with welding and at class renewal survey. Refer to Recognised Organisation (RO) rules Pt A, Ch 4, Sec 6.

Drainage of vehicle decks

Vehicle decks may be drained in several ways, either by gravity directly overboard through scuppers and non-return valves or by gravity to double bottom collecting tanks which are then pumped overboard or simply using bilge pumping systems.

The importance of the satisfactory operation of these systems cannot be over-emphasised.

Scuppers with non-return valves should be carefully examined, the valves are opened up for examination. Any extended spindles or remote closing devices are inspected and tested. Bilge alarms, etc. are tested. Where drenching systems are fitted for fire extinction, it is suggested that the efficiency of the deck drainage systems be checked during a test of the drenching system.

Electrical fittings in special category spaces

The Surveyor attention is drawn to the fact that this type of ship may carry motor vehicles with fuel in their tanks. It shall be carefully checked that electrical equipment fitted in cargo spaces has not been unacceptably modified.

Class renewal Survey for "SYS-NEQ", "CL", "LASHING", "DYNAPOS","SPM","STRENGTHBOTTOM", "CLEANSHIP","MON-HULL", "COMF", "VeriSTAR-HULL", "veristar-hull cm", "veristar-hull sis", "star-hull" Class Notations, CYBER MANAGED and CYBER SECURE NOTATIONS.

SYS-NEQ, SY-NEQ-1, SYS COM, SYS-IBS (ex CNCs)

Refer to the Rules, Part A, Ch 5, Sec 5.

For ships having Centralised Navigation Control covered by the additional Class notations:

1. In case the owner does not intend to have the installation classed anymore, a corresponding memorandum is endorsed. The MOC in charge is to be informed for withdrawal of the concerned class notation from the database.

2. When the owner intends to have the installation re-classed in the near future, the notation is suspended. The corresponding memoranda is endorsed, specifying that the required Class surveys must be carried out in order to re-instate the notation. The MOC must be advised accordingly for suspension / re-instatement of the notation in the database.

CL

Notation not attributed for new ship. Maintained for existing ship. Thickness measurements are required for the elements to which scantling reductions have been applied.

Lashing (ACA suppressed by Rules 2000)

Notation ACA is maintained only until renewal of the Classification certificate and will be replaced, at that time, by notation Lashing. No survey for maintenance of the notation is required.

Refer to the Rules, Part A.

DYNAPOS (ex PDY)

The description of the installation is to be recorded in Neptune.

Renewal survey is to be carried out by surveyor having the dedicated 'Dynapos' qualification by selecting the survey code DYNR. It can not be delegated to a subcontractor.

A specific Failure Mode Effects Analysis (FMEA) test program is to be submitted for review to DAelec before the survey, through MOC.

A complete test of all systems and components covered by DYNAPOS notations are to be tested during the renewal survey at sea. For those covered by DYNAPOS notations AM/AT-R and AM/AT-RS, they are to demonstrate that vessel keeps its position and/or heading after a single failure of a system and component, as defined in the approved (FMEA) test program. All sensors and position reference systems are to be calibrated during renewal survey.

During dry dock survey associated with class renewal survey, all thrusters covered by DYNAPOS notation, together with their prime movers, electric installations and power generation are to be examined, clearances taken and oil analysis results reviewed.

In case where the additional notation -DDPS has been granted, any tests from the approved FMEA test program may be conducted by the competent crew and recorded using the Digital Survey System, as defined in Pt F, Ch 11, Sec 6, [11], within the renewal survey window. During a renewal survey, only the tests which have not been recorded during the past period are to be witnessed by the surveyor. The complete (digital) survey is to be concluded within the renewal survey window.

SPM

Refer to the Rules, Part A, Ch 5, Sec 12 [3].

STRENGTHBOTTOM (ex BRG)

At each dry-docking, the reinforced area shall be specially examined. Thickness measurements shall be required as necessary.

Refer to the Rules, Part A, Ch 5, Sec 14 [2].

CLEANSHIP, CLEANSHIP SUPER

Refer to Recognised Organisation (RO) Rules Pt A, Ch 5, Sec 8 and to the related "ASMS items" for the scope of the annual surveys and Class renewal surveys carried out in connection with these notations.

The conditions of class in connection with the additional Class notations CLEANSHIP and CLEANSHIPSUPER are managed through ASMS tools.

MON-HULL

Refer to the Rules, Part A, Ch 5, Sec 6 [2].

“COMF-SIS” notations

When the noise and vibration measurements required during the class renewal survey connected to a “COMF-SIS” notation are carried out by a service supplier, it is to be certified according to the procedure described in the related survey procedure.

The approved service supplier has to prepare the measurements procedures and to submit them to the Surveyor in charge ; those procedures are then to be sent to HO VLM department for validation before starting the surveys.

Once procedures approved, the service supplier can proceed with the measurements.

Upon completion of the surveys, the service supplier issues the report of the measurements and submits it to HO VLM Department for final approval, with copy to the Surveyor.

The conditions of class in connection with the additional Class notations COMF-NOISE-SIS, COMF-VIB-SIS, COMF+-SIS, COMF-NOISE-Pax-SIS, COMF-NOISE-Crew-SIS, COMF-VIB-Pax-SIS and COMF-VIB-Crew-SIS are managed through ASMS tools.

The survey requirements are detailed in Part A, Ch 5, Sec 7.

VeriSTAR-HULL, VeriSTAR-HULL CM, VeriSTAR-HULL SIS and STAR-HULL

When a ship has been assigned a notation « VeriSTAR-HULL, VeriSTAR-HULL CM, VeriSTAR-HULL SIS or STAR-HULL», the full report and conclusions report are issued by LPO, both including possible Hotspot maps (critical structural areas).

When preparing their survey, the Surveyor is to check the last full report and conclusions report issued and verify if such hot spots were identified (the survey items VSH010 and VSH020 have been created for that purpose) ; report is made available in pdf format in veristar website or VPM.

When hot spots are identified, corresponding areas have to be re-inspected during each periodical surveys (annual, as far as practicable, intermediate and renewal surveys) and re-assessed during intermediate and renewal surveys (according to ship’s age and ship’s notations, and in accordance with Rules requirements of Part A) ; in case the inspection shows any deformation, damage or alteration, actions have to be taken according to applicable requirements of Part A and all necessary informations (location, size, repairs, etc…) sent to MOC (item VSH030 has been created for this purpose).

A memorandum indicating the presence or not of critical structural areas is to be endorsed upon completion of survey.

Once surveys completed, as soon as available, the Surveyor sends to the CD, for transmission to the LPO, the following documents:

• close-up survey report,

• thickness measurement report,

• details of repairs carried out.

Updating of documents after completion of surveys:

• "after survey" hot spot map is issued under the responsibility of the Owner and uploaded in VPM by the LPO in charge.

• Inspection and maintenance plan (IMP) is submitted by the Owner to the CD for review ; the CD then follows-up with the Owner the updating of the IMP taken into account the results of the "after survey" hot spot map as necessary.

Additional requirements for VeriSTAR-HULL SIS or STAR-HULL notations are available in the related survey procedure and in TNC_1121.

CYBER MANAGED and CYBER SECURE

For the relevant requirements, refer to Rules, Part A, Ch 5, Sec 17. Detailed scope is defined in NR659.

During periodical surveys, class notation will be withdrawn in case of major deficiency. When there is a minor deficiency accepted by class surveyor with possible mitigation measures, class notation can be maintained providing a condition of class is endorsed for corrective actions to be implemented within a defined dead line.

Reference is also made to the related survey procedure.

Lifting Appliances covered by "ALP" or "ALM" Class Notation

Ships having "Pontoon/crane" service notation

Refer to Guidance Note NI 184 "Lifting Appliances", Rule Note NR 526 “Rules for the Certificationof Lifting Appliances onboard Ships and Offshore Units” and to the Rules, Part A.

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The maintenance of Class of the lifting appliances is compulsory.

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If the installation cannot be Class maintained:

1. the ship Class shall be suspended or

2. Notation PONTOON shall be granted in lieu of PONTOON/CRANE, subject to the MO agreement, and a memorandum shall be endorsed accordingly.

The Classification certificate shall be re-issued with service notation PONTOON. The MOC shall be informed accordingly.

Other ships

For other ships having their lifting appliances covered by an additional Class notation, in case this installation cannot be Class maintained:

1. When the owner does not intend any longer to have the installation classed, a corresponding memorandum is endorsed. The MOC shall be informed accordingly for deletion of the concerned Class notation from the database.

2. When the owner intends to have the installation classed in the near future, the "Lifting Appliances" additional Class notation shall be suspended. The corresponding memoranda shall be endorsed, specifying that the required Class surveys must be carried out in order to re-instate the notation. The MOC must be advised for suspension / re-instatement of the notation in the database.

Class Renewal Survey for "WAP", "EWAP", “WPS1” or “WPS2” Class Notation

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Refer to Guidance Note NR 206 and to the Rules, Part A.

In case where the notations cannot be Class maintained, apply to the MO for instructions.

Class Renewal Survey for Inert Gas Installations

Class maintenance of the installation compulsory

Refer to the related survey procedure and to the Rules, Part A.

For ships having specific Service Notation and specific size (e.g. oil tanker of at least 20.000 grt), the maintenance of Class of the inert gas installation is compulsory. If this installation cannot be Class maintained:

1. the ship Class shall be suspended,

2. Service Notation IG shall be re-assigned.

Class maintenance of the installation not compulsory

For ships having inert gas installations for which the maintenance of Class is not compulsory, in case this installation cannot be Class maintained:

1. When the owner does not intend any longer to have the installation classed, a corresponding memorandum is endorsed. The MOC shall be informed accordingly for deletion of notation IG from the database.

2. When the owner intends to have the installation re-classed in the near future, Notation IG shall be suspended. The corresponding memoranda shall be endorsed, specifying that the required Class surveys must be carried out in order to re-assign the inert gas installation additional Class notation. The MOC must be advised for suspension / re-instatement of the notation in the database.

Class Renewal Survey for "Light Ship" Service Notation

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Refer to the applicable arrangements of Class renewal Survey under normal survey system (all ships) and to the Rules, Part A.

Additional requirements for some miscellaneous Service Notations

FLS tanker

These ships are loading chemical products which are not covered by the IBC Code. ESP programme is not applicable to these ships. For survey of cargo containment and handling systems, refer to Section 5 dedicated to chemical tankers and to the Rules, Part A, Ch 4.

Tug

They should be dealt with as cargo ships (Class renewal Survey under normal survey system (all ships)) with special attention to the condition of closing arrangements:

• hatches,

• miscellaneous openings,

• watertight doors,

• skylights,

• side scuttles (post-holes) and deadlights.

In addition, for salvage tugs and escort tugs, attention is drawn to requirements laid down in the Rules, Part A, Ch 4, with regard to specific equipment.

Dredger

The applicable arrangements of Class renewal Survey under normal survey system (all ships) apply, taking into consideration the special features of these ships :

• Bucket wells with grab dredgers .......................damage and wear, particularly

• Deck in vicinity of winches and chutes .............corrosion

• Deck attachments for gantry supports, etc. ......fractures, signs of straining

• Spillways ..........................................................corrosion

• Main inlet of dredge pumps ..............................corrosion, erosion

• Watertight doors fitted ......................................examination and test including alarms

Hopper Unit (ex Hopper barge)

The applicable arrangements of Class renewal Survey under normal survey system (all ships) apply, taking into account the special features of these ships :

• Hopper sides ....................................................damage, corrosion & wear

• Hopper doors and closing arrangements ........wear, condition of chains if fitted test of operation & security

Pontoon and barge

The relevant arrangements of Class renewal Survey under normal survey system (all ships) apply. Particular attention should be paid to the area about the waterline, which is usually fairly constant, for corrosion.Where cranes or derricks are attached, the areas of pontoon structure supporting these should be examined for signs of strain, etc.

If the cranes or derricks are classed, the required surveys for Class renewal shall be carried out.

Fishing vessel

The survey requirements are found in the Rules, Part A. The relevant arrangements of Class renewal Survey under normal survey system (all ships) apply with the following additional guidance.

Fishing vessels may be subject to hard and intensive service and are subject additionally to chafing by the fishing gear.

The following additional points may apply depending on the type of ship:

Anchor handling vessels

Vessels performing anchor handling operations are generally assigned the service notation anchor handling. Survey requirements for those vessels are covered in NR467 Part A Ch 4 Section 8.

Vessels above 500 gross tonnage, performing anchor handling operations, but not assigned the service notation anchor handling are to comply with the requirements of SOLAS Ch II-1 reg. 3-13 at the first renewal survey after 1st January 2026. For the survey requirements for those vessels, reference is made to the related survey procedure.

Other service notations

Refer to specific survey requirements in the Rules, Part A Chap 4.

Class renewal Survey under Continuous or Distributed Survey System

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Refer to the related survey procedure and to the Rules, Part A.

Retroactive measures for bulk carriers and other ship types (UR S 26, S 27, S 30 and S 31)

Strength and securing of small hatches on the exposed fore deck (UR S 26)

Application

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These retroactive requirements apply to ships of 100 m and above in length, contracted for construction prior to 1st January 2004, which are assigned one of the following service notations:

• general cargo ship

• bulk carrier (without ESP)

• refrigerated cargo ship

• livestock carrier

• deck ship

• bulk carrier ESP

• bulk carrier BC-A ESP

• bulk carrier BC-B ESP

• bulk carrier BC-C ESP

• ore carrier ESP

• combination carrier/OBO ESP

• combination carrier/OOC ESP

(including dedicated cement carriers).

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The requirements do not apply to:

• woodchip carriers and ships with service notation container ship or ro-ro cargo ship,

• ships granted with the dual notation "general cargo ship - container ship" or "general cargo ship - ro-ro cargo ship". It is reminded that these ships shall be designed and built to the specific rule requirements applicable to each service notation, i.e. rules for general cargo ship and container ship or rules for general cargo ship and ro-ro cargo ship.

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In the case of a ship complying with the rules for service notation general cargo ship and for which only the fixed arrangements comply with the applicable rule requirements in Part E, Ch 2, only notation "general cargo ship equipped for carriage of containers" may be assigned and dual notation "general cargo ship - container ship" may not. This ship is then subject to the said requirements.

Schedule for compliance

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The schedule for compliance is detailed in the Rules, Part A, Ch 6, Sec 2, [3.2] and Ch 6, Sec 4, [1.2].

How to achieve compliance

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The requirements are applicable to small hatches fitted on the exposed fore decks. Refer to Figure.

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The Connecting District checks whether the drawings are available at DA-HULL or LPO. If not, the following details shall be submitted by the owner to the Connecting District, well in advance of the survey:

• hatch size and cover plate thickness,

• stiffeners size, spacing and thickness.

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When the cover plate gross thickness (as shown on the drawings) is less than 8 mm, the intervention of DA-HULL or the LPO when delegated, is necessary to calculate the equivalent stiffeners arrangement and scantlings, in order to comply with UR S 26.

The minimum acceptable gross thickness of the cover plate to be considered is 6 mm.

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When the cover plate gross thickness (as shown on the drawings) is already greater or equal to 8 mm, then it is sufficient for the Surveyor to require the stiffeners arrangement and scantlings to comply with the Rules, Part B, Ch 9, Sec 7, [9], Table 6 and Figure.

Tables of Annex 6-A of the former Rules NR 413 may be used for searching equivalencies between steel profiles/stiffeners.

Twist tightening handles (dogs) with wedges are not acceptable as primary securing devices of small hatches subject to these requirements.

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During survey, thickness measurements may be taken by the Surveyor on the small hatch covers, if considered necessary. The measured thickness is not to be less than the net thickness, as per the applicable Rules at the ship construction date.

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In case the small hatch cover shall be replaced, then it must be replaced by a new one which fully complies with UR S26.

Other technical requirements

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Stiffeners, where fitted, are to be aligned with the metal-to-metal contact points.

Primary stiffeners are to be continuous. All stiffeners are to be welded to the inner edge stiffener.

The upper edge of the hatchway coamings is to be suitably reinforced by a horizontal section, normally not more than 170 to 190 mm from the upper edge of the coamings.

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Requirements for primary securing:

The hatch cover is to be fitted with a gasket of elastic material.This is to be designed to allow a metal to metal contact at a designed compression and to prevent overcompression of the gasket by green sea forces that may cause the securing devices to be loosened or dislodged. The metal-to-metal contacts are to be arranged close to each securing device and of sufficient capacity to withstand the bearing force.

The primary securing method is to be designed and manufactured such that the design compression pressure is achieved by one person without the need of any tools.

For a primary securing method using butterfly nuts, the forks (clamps) are to be of robust design. They are to be designed to minimize the risk of butterfly nuts being dislodged while in use; by means of curving the forks upwards, a raised surface on the free end, or a similar method. The plate thickness of unstiffened steel forks is not to be less than 16 mm.

For small hatch covers located on the exposed deck forward of the fore-most cargo hatch, the hinges are to be fitted such that the predominant direction of green sea will cause the cover to close, which means that the hinges are normally to be located on the fore edge.

On small hatches located between the main hatches, for example between Nos 1 and 2, the hinges are to be placed on the fore edge or outboard edge, whichever is practicable for protection from green water in beam sea and bow quartering conditions (this requirement is normally applicable to new ships, e.g ships contracted for construction on or after the 1st January 2004).

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Requirements for secondary securing device:

Small hatches on the fore deck are to be fitted with an independent secondary securing device, i.e by means of a sliding bolt, a hasp or a backing bar of slack fit, which is capable of keeping the hatch cover in place, even in the event that the primary securing device became loosened or dislodged. It is to be fitted on the side opposite to the hatch cover hinges.

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Securing devices of hatches designed for emergency escape:

For ships contracted for construction prior to 1st July 2007, the following is to be verified or carried out:

Securing devices of hatches designed for emergency escape are to be of a quick-acting type (e.g one action wheel handles are provided as central locking devices for latching/unlatching of hatch cover) operable from both sides of the hatch cover.

The above is to be verified or carried out by the compliance date specified in 1.2 above or by the due date of the first class renewal survey after 1st July 2007, whichever is later.

Completion prior to 1st July 2007 of a class renewal survey with a due date after 1st July 2007 cannot be used to postpone compliance.

Memoranda

The following memorandum shall be endorsed using ASMS tools, when compliance with these requirements has been completely verified, i.e. both by DA-HULL or LPO and by the Surveyor onboard:

Memorandum: " Compliance with the Rules, Part A, Ch 6, Sec 2, [3] and Ch 6, Sec 4 (UR S 26) has been checked on the........(date)".

Reporting database

Marine Operational Centres (MOCs) have the responsibility to report the entries related to the initial assessment in the follow-up database "Bulk Carriers and other ship types reporting".

Strength requirements for fore deck fittings and equipment (UR S 27)

Application

Refer to Application above.

Schedule for compliance

Refer toSchedule for compliance above.

How to achieve compliance

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The requirements are applicable to air pipes, ventilator pipes and their closing devices, located within the forward quarter length on the exposed fore decks. Refer to Figure.

These requirements do not apply to the cargo tank venting systems and the inert gas systems of tankers.

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The Connecting District checks whether the drawings are available at DA_MACH or LPO. If not, the following details shall be submitted by the owner (for review by DA-HULL or LPO), well in advance of the survey onboard: type, steel grade, thickness, diameter, height of the air pipes and ventilator pipes, position on deck (protected or not).

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The survey is then carried out.

If any additional brackets are required, their position is decided by the Surveyor onboard, having in mind that bracket toes at the deck shall be suitably supported. Assistance from DA-HULL or LPO may be required if needed. Refer to Figure.

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On exposed decks subject to UR S 27, rotating type mushroom ventilator heads are not authorised and consequently shall be replaced by another suitable type.

Memoranda

The following memorandum shall be endorsed using ASMS tools, when compliance with these requirements has been completely verified, i.e. both by DA-HULL or LPO and by the Surveyor onboard:

Memorandum: " Compliance with the Rules, Part A, Ch 6, Sec 2, [3] and Ch 6, Sec 4 (UR S 27) has been checked on the........(date)".

Reporting database

Refer to Memoranda above.

Cargo hatch cover securing arrangements (UR S 30)

Application

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These retroactive requirements apply to ships which are assigned one of the service notations bulk carrier ESP, bulk carrier BC-A ESP, bulk carrier BC-B ESP, bulk carrier BC-C ESP not built in accordance with the Rules, Part B, Ch 9, Sec 7, [1] to [7] (November 2003 edition applicable from the 1st January 2004).

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The requirements do not apply to ships with pontoon-type hatch covers (pontoon-type hatch cover is defined as being a steel cover, either double plate or single plate, secured by battening devices and fitted with tarpaulins).

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Any other steel cover fitted with gaskets and clamping devices shall comply with the above requirements.

Schedule for compliance

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The schedule for compliance is detailed in the Rules, Part A, Ch 6, Sec 2, [4.2].

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Completion, prior to 1st January 2004, of an intermediate or Class renewal survey with a due date after 1st January 2004 cannot be used to postpone compliance.

However, completion prior to 1st January 2004 of an intermediate survey the window of which straddles 1st January 2004 can be accepted (i.e. compliance with the requirements may be postponed to the next Class renewal survey).

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In case where the intermediate survey is the required date for compliance, then the full window (i.e. at latest, the 3-month upper window after the 3rd annual survey) may be used to complete the intermediate survey and the compliance with these requirements.

How to achieve compliance

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The requirements apply to steel hatch cover securing devices and stoppers for cargo hold hatchways Nos. 1 and 2 which are wholly or partially within 0,25 L of the fore perpendicular.

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The Connecting District checks whether the drawings are available at DA-HULL or LPO. If not, the detail drawings of the securing devices and stoppers shall be submitted by the owner (for review by DA-HULL or LPO), well in advance of the survey.

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The survey is then carried out.

Memoranda

The following memorandum shall be endorsed using ASMS tools, when compliance with these requirements has been completely verified, i.e. both by DA-HULL or LPO and by the Surveyor onboard:

Memorandum: " Compliance with the Rules, Part A, Ch 6, Sec 2, [4] and Ch 6, App1, [6] (UR S 30) has been checked on the........(date)".

Reporting database

Refer to Memoranda above.

Renewal criteria for side shell frames and brackets (UR S 31)

Application

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These retroactive requirements apply to ships with service notation bulk carrier ESP or combination carrier/OBO ESP, of single side skin, not built to the applicable requirements of the Rules, Part II, Ch 8, Sec 8-03 (1st April 1998 edition or subsequent editions).

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The requirements do not apply to double side skin bulk carriers.

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Where the finite element or other numerical analysis or direct calculation procedures are allowed (i.e. in cases of unusual side structure arrangements or framing; Recognised Organisation (RO) Rules Pt A, Ch 6, Sec 2, [5.1.2]),the analysis criteria and the strength check criteria are to be in accordance with Recognised Organisation (RO) Rules.

Schedule for compliance

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The schedule for compliance is detailed in the Rules, Part A, Ch 6, Sec 2, [5.2].

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For ships with service notation bulk carrier ESP, completion, prior to 1st January 2004, of an intermediate or Class renewal survey with a due date after 1st January 2004 cannot be used to postpone compliance.

However, completion prior to 1st January 2004 of an intermediate survey the window of which straddles 1st January 2004 can be accepted (i.e. compliance with the requirements may be postponed to the next Class renewal survey).

For ships with service notation combination carrier/OBO ESP, completion, prior to 1st July 2005, of an intermediate or Class renewal survey with a due date after 1st July 2005 cannot be used to postpone compliance.

However, completion prior to 1st July 2005 of an intermediate survey the window of which straddles 1st July 2005 can be accepted (i.e. compliance with the requirements may be postponed to the next Class renewal survey).

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In case where the intermediate survey is the required date for compliance, then the full window (i.e. at latest, the 3-month upper window after the 3rd annual survey) may be used to complete the intermediate survey and the compliance with these requirements.

Note: The continued compliance is also required at subsequent Class Intermediate and Renewal surveys, after the initial compliance survey.

How to achieve compliance

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The minimum required thicknesses are calculated by DA-HULL or LPO, well in advance of the survey.

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For this purpose, a new version of "BULK32" software has been released in the LPOs.

This "BULK32" version allows DA-HULL and LPO to determine, in advance of the survey and upon request from the Connecting District, the required thicknesses as detailed in UR S 31. These required thicknesses are then sent to the owner in advance of the survey.

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During the survey, the Surveyor is provided with a print-out of these required thicknesses, per hold and per relevant side frames. This allows him to compare immediately the measured thicknesses to the required thicknesses and take appropriate actions for each frame zone (no action, renewal, reinforcement by tripping brackets, stiffeners, other measures).

Gauging methodology

Requirements for the gauging of side shell frames and brackets are given in the Rules, Part A, Ch 6, Sec 2, [5.3].

Notes :

a) The thickness measurements of flanges and side shell plating not covered in the Rules, as mentioned above, shall be carried out in accordance with the gauging requirements of the Rules, Part A, Ch 2, App.3 Figure 7 and the measured thicknesses assessed against the criteria stipulated by the Rules, Part A, Ch 2, App.3, Table 6.

b) The same applies to the intermediate frames which are fitted for re-inforcement in order to comply with ice Class notations. This additional structure required to meet ice strengthening notation, is not included in the scope of UR S 31, and the thickness measurements and assessment of this additional structure shall consequently be carried out according to the Rules, Part A, Ch 2, App. 3.

Instructions for use of calculation sheets (provided by the LPO) by the Surveyor onboard

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Pre-calculations by DA-HULL or by LPO when delegated

1. Before the scheduled survey date, a pre-calculation of the required thicknesses is carried out by DA-HULL/LPO, upon request from the Connecting District.

   This pre-calculation is carried out with software “Bulk 32” specifically redesigned for the purpose of:

   • calculating the minimum required thicknesses before the survey is started,

   • allowing the Surveyor to take appropriate actions during the survey, with respect to steel renewal or repairs or re-inforcements of the frames and brackets, by comparing the measured thicknesses to the pre-calculated thicknesses.

2. To this end, after the calculations have been carried out, DA-HULL/LPO sends the relevant datasheets and calculation sheets “Survey S31” to the Connecting District.

   The Connecting District shall send these datasheets and calculation sheets to the owner and to the Survey Centre when known, in advance of the survey.

   A model of letter to the owner is given in Annex 11.

3. One calculation sheet is available for each pre-calculated frame. Each pre-calculated frame is representative of a group of frames in each hold, as established by DA-HULL/LPO. The group of frames to which the pre-calculated frame belongs is then indicated on the calculation sheet.

   The calculation sheet also indicates the concerned hold No. for each pre-calculated frame.

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How to read calculation sheets “Survey S31”

An example of calculation sheet is given in Annex Untitled.

1. Headings

   The hold No. is indicated on top of the page (Ex: Hold 3).

   The frame No. is also indicated, as well as the group of frames it represents (Ex.: “frame No. 15 for group [10;20]” means that the calculation sheet is related to frame No. 15, and that these calculations are also relevant to frames Nos. 10 to 20 inclusive.

2. 1st Table: “web thickness criteria”

   This table indicates the different nominal thicknesses involved, the action to be taken depending on the value of the measured thicknesses and the replacement thickness required in case of renewal.

   1st Column: indicates the zone A or B or C or D:

   • Zone A is the “lower bracket”,

   • Zone D is the “upper bracket”,

   • Zones B and C are the “frame” itself,

   • Zones A and B are the “lower part of frame” and are considered to be the most critical zones.

   Refer to drawing 1 in Figure 13.(note: lower brackets are to be flanged or face plate is to be fitted)

   2nd column, tasB: as-built thickness, for each zone.

   3rd column, tCoat: thickness as defined in Pt A, Ch 6, App 1, [5.1.2], for each zone.

   4th column, tRend/t: thickness as defined in Pt A, Ch 6, App 1, [5.3.2], applicable to zone A and B only

   5th column, tabd: the greatest of (tCoat-tC) - (0.75 tasB) - t rens ; where tC is defined as per the Rules, Part A, Ch 6, App 1, [5], Table 1. and t rens as per App 1, [5.3.3] (t rens being only applicable in zones A and B)

   6th and 7th columns: indicate the actions to be taken, depending on the value of the measured thickness of the web, for each zone.

   tMweb: measured thickness on the web, for each zone (Refer also to 3.).

   Examples:

   “If tMweb between [9.75, 99.00 [No action required” means that if the average of the measured thicknesses is greater or equal to 9.75 mm, then no action is required on the concerned zone of the subject frame.

   “If tMweb between [0.00, 7.75 [renewal” means that if the average of the measured thicknesses is less than 7.75 mm, then steel renewal is required on the concerned zone of the subject frame.

   “If tMweb between [7.75, 9.75 [other measures” means that if the average of the measured thicknesses is less than 9.75 mm and greater or equal to 7.75 mm, then “other measures”, as defined in Part A, Ch 6, App 1, [5.3.5], are required on the concerned zone of the subject frame.

   Refer also to para. 4.) for the details of the different actions that can be taken.

   8th column, TRepl: minimum replacement thickness required for renewal of webs, in case where such webs shall be renewed.

3. 2nd Table: “Bending strength check of lower bracket”

   This table is used when the lower bracket (zone A) length or depth does not meet the requirements in Part E, Ch 4, Sec 3, [3.2.6] (corresponding to UR S 12, rev. 3). In this case, a modulus calculation is carried out by DA-HULL/LPO. Refer to drawing 2 in Figure 13.

   1st Column: indicates the zone A or B.

   2nd Column, Za(or Zb): is the modulus calculated at section a) or section b). Refer to drawing 3 in Figure 13.

   3rd Column, Zcorr: is the modulus calculated with the maximum acceptable corrosion, for each zone A and B.

   4th Column, Results: indicates the different kind of actions to be taken, for each zone. Refer also to para. 4.) for the details of the different actions that can be taken.

   5th Column, ZRepl: minimum replacement modulus required in case of renewal or re-inforcements are needed.

4. 3rd Table: “Web thickness criteria”

   This table indicates the overall extent of renewal and of sand blasting and coating, when required in connection with the 1st Table.

   It takes into account whether the frame is of integral type or separate type.

   In case of integral brackets, if renewal is required on zone A, then it shall be carried out on zones A+B.

   In case of separate brackets, if renewal is required on zone A, then it shall be carried out on zone A.

   In case of integral brackets, if renewal is required on zone B, then it shall be carried out on zones A+B.

   In case of separate brackets, if renewal is required on zone B, then it shall be carried out on zone B.

   If renewal is required on zone C, then it shall be carried out on zones B+C.

   If renewal is required on zone D, then it shall be carried out on zone D.

   Note 1: When renewal is to be carried out, surface preparation and coating are required for the renewed structures as given in IACS UR Z9 for cargo holds of newbuildings.

   Note 2: when zone B is made up of different plate thicknesses, the lesser thickness is to be used for the application of the requirements in UR S31.

   Note 3: In case of renewal of a damaged frame already complying with S 31, the following requirements apply:

   • The conditions accepted in compliance with S31 are to be restored as a minimum.

   • For localised damages, the extension of the renewal is to be carried out as per Recognised Organisation (RO)'s standard practice, as the frame already complies with S31.

   • Replacements of rolled profile are preferably to be made of the same rolled section. Built-up profiles are allowed in exceptional cases only. A repair made of an inserted built-up profile in a rolled profile could be acceptable provided some precautions are taken. The flange of the built-up profile is to overlap the repair area with sniped shape to smoothly allow the stresses to pass from the rolled profile to the built-up profile and vice-versa.

   Note 4: In case of renewal of a damaged frame before S31 implementation date for the considered ship, as-built scantlings may be applied. For practical reason, it is up to the Owner whether to renew according to S31 or not.

   In case of integral brackets, if sand blasting and coating is required on zone A, then it shall be carried out on zones A+B.

   In case of separate brackets, if sand blasting and coating is required on zone A, then it shall be carried out on zone A.

   In case of integral brackets, if sand blasting and coating is required on zone B, then it shall be carried out on zones A+B.

   In case of separate brackets, if sand blasting and coating is required on zone B, then it shall be carried out on zone B.

   If sand blasting and coating is required on zone C, then it shall be carried out on zones B+C+D.

   If sand blasting and coating is required on zone D, then it shall be carried out on zones C+ D.

5. 4th Table: “Bending strength check of lower bracket”

   The fourth table indicates the overall extent of renewal or of flange re-inforcement, when required in connection with the 2nd Table, as follows:

   If renewal or flange re-inforcement is required on zone A, then it shall be carried out on zones A+B.

   If renewal or flange re-inforcement is required on zone B, then it shall be carried out on zones A+B.

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How to gauge on-board the ship, during the survey

1. The gauging methodology is given in Annex V of IACS Unified Requirement UR Z 10.2, rev. 15, as detailed in the December 2003 edition of the Rules, Part A, Ch 6, Sec 2, [6.3].

   The number of side frames to be measured shall be the same as the number required for the intermediate survey or Class renewal survey corresponding to the ship’s age (refer to the Rules, Part A, Ch 4, Sec 2).

2. When the structural members show no thickness diminution with respect to the as-built thickness (tasB) and when the coating is found in “as-new” condition (i.e. without break-down or rusting), the extent of thickness measurements may be reduced.

3. When the thickness measurements show readings close to the acceptable criteria, the extent of thickness measurements shall be increased.

4. If steel renewal or repairs/re-inforcements are applied on one or more frames in a hold, then all frames in that hold shall be gauged.

5. For a given calculation sheet, i.e. for a given pre-calculated frame representative of a group of frames in a hold, the frames of this group can be subject to different possible actions, due to the different gauging readings from one gauged frame to another gauged frame.

6. Thickness measurements shall be taken for each zone, as follows:

   • Web of Zone A

     5 points to be measured, over the depth of the web and height of zone A. The average of these 5 points is tMweb, which shall be compared to the required thicknesses on the calculation sheet, i.e. on 1st Table.

   • Web of Zone B

     5 points to be measured, over the depth of the web and a vertical distance equal to the frame web depth. The average of these 5 points is tMweb, which shall be compared to the required thicknesses on the calculation sheet, i.e. on 1st Table.

   • Web of Zone C

     3 points to be measured over the length of Zone C. The average of these 3 points is tMweb, which shall be compared to the required thicknesses on the calculation sheet, i.e. on 1st Table.

     This 3-point pattern may be extended to a 5-point pattern when considered necessary by the Surveyor.

   • Web of Zone D

     Same as Zone A.

When the lower bracket (zone A) length or depth does not meet the requirements in Part E, Ch 4, Sec 3, [3.2.6] (corresponding to UR S 12, rev. 3), the bending strength check of the lower bracket is required. The bending check needs not to be carried out in the case the bracket geometry is modified so as to comply with requirements of Part II, Chapter 8, Section 8-03 of the 1st April 1998 edition of the Rules or subsequent editions.

Gaugings shall be taken as follows, in order to calculate the actual section modulus in sections a) and b) :

• at least 2 points shall be measured on the flange, in way of each section a) and b),

• at least one point shall be measured on the attached shell plating on each side of the frame, i.e. fore and aft of the frame, in way of each section a) and b).

Refer to drawing 3 in Figure.

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How to renew, repair or re-inforce

4.6.4.1 The different possibilities of action, listed in 1st Table, are as follows:

1. “No action required” means that no specific action is needed on the subject zone of the frame.

2. “Renewal” means that steel renewal of the web is required. The replacement thickness is given by TRepl.

   The associated flange is normally renewed at the same time, according to the as-built conditions.

3. “Other measures” means that the 3 following actions are required:

   • sand blasting and coating and

   • fitting tripping brackets and

   • maintaining the coating in as-new condition (without break-down or rusting) at subsequent Class renewal and intermediate surveys.

     However, these “other measures” may be waived if the structural members show no thickness diminution with respect to the as-built thickness (tasB) and coating is in “as-new” condition (i.e without breakdown or rusting)

     When the coating is in Good condition, sand blasting and coating may be waived even if not found in "as new" condition, provided that tripping brackets are fitted and the coating damaged in way of the tripping bracket welding is repaired.

     Note related to tripping brackets not welded to frame flange: tripping brackets not connected to flanges are acceptable, provided that they have soft toe and the distance between the bracket toe and the frame flange is not greater than about 50 mm.

4. “stiffeners” means that fitting of stiffeners on the lower bracket (zone A) is required.

5. “tripping brackets” means that fitting of tripping brackets is required.

4.6.4.2 The different possibilities of action, listed in 2st Table, on the column “results”, are as follows, for each zone A or B:

1. “Bending strength not required” means that the verification of the section modulus is not required, as the lower bracket length and depth meet the requirements in Part E, Ch 4, Sec 3, [3.2.6] (UR S 12, rev.3).

2. “Bending strength successful for max. acceptable corrosion” means that, as Zcorr is greater or equal to Za (or Zb), no further action is required with respect to the bending strength check, which is considered satisfactory in this case.

3. “If (tMweb >= xx.xx) and (tMfl>= yy.yy) No action required” means that if the average of the gauged thicknesses on the web (tMweb) is greater or equal to xx.xx and the average of the gauged thicknesses on the flange (tMfl) is greater or equal to yy.yy, then no further action is required for the corresponding zone.

4. “If (tMweb <xx.xx) or (tMfl<yy.yy) Renewal or Flange re-inforcement or Section modulus to be checked with measured thicknesses” means that if the average of the gauged thicknesses on the web (tMweb) is less than xx.xx or the average of the gauged thicknesses on the flange (tMfl) is less than yy.yy, then there are 3 alternatives :

   • a flange re-inforcement shall be carried out on zones A+B in order to obtain ZRepl or

   • a renewal shall be carried out on zones A+B in order to obtain ZRepl or

   • the actual section modulus shall be calculated with the actual average of the gauged thicknesses and compared with Za (or Zb).

     If the actual section modulus is greater or equal to Za (or Zb), then no further action is required.

     If the actual section modulus is less than Za (or Zb), then flange re-inforcement or renewal in zones A+B shall be carried out as mentioned above.

     Note: another solution is to carry out a renewal according to the length and depth criteria for the lower bracket as detailed in Part E, Ch 4, Sec 3, [3.2.6] and with ZRepl as section modulus. The advantage of this solution is that the bending strength check is not required anymore at subsequent verifications on this renewed lower bracket.

5. “As built modulus not OK; Renewal or Flange re-inforcement” means that the as-built modulus is not satisfactory. In this case, there are 2 alternatives:

   • a flange re-inforcement shall be carried out in zones A+B in order to obtain ZRepl or

   • a renewal shall be carried out on zones A+B in order to obtain ZRepl.

Note: another solution is to carry out a renewal according to the length and depth criteria for the lower bracket as detailed in Part E, Ch 4, Sec 3, [3.2.6] and with ZRepl as section modulus. The advantage of this solution is that the bending strength check isnot required anymore at subsequent verifications on this renewed lower bracket.

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Requirements for fitting tripping brackets, when required

4.6.5.1 Refer to drawing 4 of Figure of this document.4.6.5.2 When tripping brackets are required, always two tripping brackets are to be fitted: one at lower part and one at mid-span of the side frames.4.6.5.3 Tripping brackets may be located at every two frames, but lower and midspan brackets are to be fitted in line between alternate pair of frames.4.6.5.4 The thickness of the tripping brackets is to be greater or equal to the as-built thickness (tasB) of the frame webs to which they are connected.4.6.5.5 The tripping brackets are to be connected to the frames and plating by double continuous welding.

4.6.5.6 Tripping brackets for Higher Strength Steel side frames and side shell:

Where side frames and side shell are made of Higher Strength Steel (HSS), Normal Strength Steel (NSS) tripping brackets may be accepted, provided the electrodes used for welding are those required for the particular HSS grade, and the thickness of the tripping brackets is equal to the frame web thicknesses, regardless of the frame web material.

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Requirements for coating, when required

4.6.6.1 Sand blasting, or equivalent, shall be carried out before coating. Epoxy coating, or equivalent, shall be applied.

4.6.6.2 The part to be coated includes:

• the web and the face plate of the frames and brackets,

• the hold surface of side shell, hopper tank and topside tank plating, as applicable over a width not less than 100 mm from the web of the side frame.

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Renewal of all frames in one or more cargo holds

When all frames in one or more holds are required to be renewed according to the requirements of UR S 31, the compliance with the requirements of Recognised Organisation (RO) Rules, Part II, Ch 8, Sec 8-03 (1st April 1998 edition) may be accepted in lieu of the compliance with the requirements in URS31, provided that:

• It is applied at least to all the frames of the holds

• The coating requirements for side frames of "new ships" are complied with.

• The section modulus of side frames is calculated according to the Recognised Organisation (RO) Rules.

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Other Requirements

UR S 31 does not cover all ESP requirements. In this respect:

• The thickness measurements of flanges and side shell plating not covered in 4.6.3 above shall be carried out in accordance with the gauging requirements of the Rules, Part A, Ch 2, App.3, Figure 7 and the measured thicknesses assessed against the criteria stipulated by the Rules, Part A, Ch 2, App 3, Table 6.

• The same applies to the intermediate frames which are fitted for re-inforcement in order to comply with Ice Class notations. This additional structure required to meet ice strengthening notation, is not included in the scope of UR S 31, and the thickness measurements and assessment of this additional structure shall consequently be carried out according to the Rules, Part A, Ch 2, App 3.

• In addition, all other ESP requirements, as per UR Z 10.2 and the Rules, Part A, Ch 4, Sec 2, shall still be applied, when performing the intermediate survey or the Class renewal survey.

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Other clarifications:

• Recognised Organisation (RO) Rules Pt A, Ch 6, App 1, [5.3.6]: lower end bracket flanges

  When lower end brackets were not fitted with flanges at the design stage, flanges are to be fitted so as to meet the bending strength requirements in Pt A, Ch 6, App1, [5.5.5]. The full width of the bracket flange is to extend up beyond the point at which the frame flange reaches full width.

  Adequate back-up structure in the hopper is to be ensured and the bracket is to be aligned with the back-up structure.

• Recognised Organisation (RO) Rules Pt A, Ch 6, App 1, [5.3.2], b): tMweb less than tRend/t at section b of side frame.

  For the comparison with tRend/t at section b, the measured value, tMweb, is to be based on zone B.

• Recognised Organisation (RO) Rules Pt A, Ch 6, App 1, [5.3.2], b): location of tripping brackets not in complete compliance with S31

  Where there are two existing tripping brackets supporting frames but their location is not in complete compliance with S31, i.e one located less than h/3 above zone A and one less than 2h/3 from intersection of the hopper plate with the side shell, this may be accepted as equivalent to the requirements in Pt A, Ch 6, App 1, [5.3.2], b), provided that the tripping bracket thickness is not less than the frame web thickness.

Memoranda

The following memorandum shall be endorsed using ASMS tools, when compliance with these requirements has been completely verified, i.e. both by DA-HULL or LPO and by the Surveyor onboard:

Memorandum: "Compliance with the Rules, Part A, Ch 6, Sec 2, [5] and Ch 6, App 1, [5] (UR S 31) has been checked at first on the........(date).

Compliance with the Rules, Part A, Ch 6, Sec 2, [5] and Ch 6, App 1, [5] (UR S 31) shall be checked at subsequent intermediate and Class renewal surveys".

Reporting database

Refer to Memoranda above

Case of CAC

In case of CAC, it is necessary to verify if, as per the schedule for compliance, the scantlings studies and eventual re-inforcements/renewals:

• are not due. In this case, compliance with the requirements is required at the due date, or

• are due/overdue. In this case, there are 2 alternatives:

  • The Losing Society is an IACS Member. Information can be requested from them and action will be taken according to their answer.

  • The Losing Society is not an IACS Member. Studies and necessary re-inforcements/renewals shall be required at the time of the CAC.

Survey items

The ASMS survey items for the initial verification of compliance with the requirements of UR S 26, S 27, S 30 and S 31 are specifically generated by the "OSBC" survey.

For UR S 31, the ASMS survey items for verification of the continuing compliance with the requirements, at each subsequent intermediate and Class renewal surveys after the initial verification, are automatically generated by the "INT" or "SSH" surveys.

Hull renewal survey on ships in light alloy

Applicability

Subject instructions are applicable to ships with following service notations:

• light ship

• HSC – CAT A

• HSC – CAT B

• HSC – cargo ship

• Other ships in aluminium like offshore Patrol Vessels, Wind farm vessels, crew boats, yachts built according to NI589, NR490, NR500, NR566 and NR600.

Sensitive structure areas

On ships in light alloy, the following sensitive areas are to be close-up surveyed during the renewal survey:

• bottom platings, for search of buckling,

• bilge areas for search of electrolytic corrosion,

• bottom longitudinals, for search of buckling,

• junctions between bottom longitudinal and transverse floors, for search of crack,

• junctions between bottom longitudinal and transverse bulkheads, for search of crack,

• garage decks, for search of buckling and ragging where thickness may be reduced locally,

• pillars in forward areas, for search of buckling,

• superstructure top platings, for search of buckling,

• fixation of main propulsion units on aft areas (bottom and transom).

• Inlet duct for waterjets for search of cracks

• sea water inlet pipes until to the first valve (subject to corrosion)

• structural members of hull i.w.o t-foil (stabilizing systems) connections.

• structure areas around large openings (e.g. doors)

• structural areas around exhaust gas pipes

The following areas may also be subject to close-up survey:

• bi-metal slabs

• compartment with unsufficient or unefficient ventilation,

• reinforcement areas in front of deck equipments,

• shell plating in way of penetrations (side valves, rudder stock, shaft lines …)

Light alloy materials and weldings

On ships in light alloy, the following materials may be found:

• Aluminium 5083, 5383, 5059, 5086, 5754, 5456, 5454

• Aluminium 6005 A, 6060 (6063 in USA/UK), 6061, 6082, 6106. Note : 6060 alloy is not to be used for structural members sustaining dynamic loads (slamming and impact loads). The use of 6106 alloy is recommended in that case.

TIG process will be privileged for manual weldings of thicknesses between 1mm and 6mm.

MIG process will be privileged for automatic weldings of thicknesses above 2,5mm

Welding procedures, welder’s certificates together with proper filler metals are to be verified prior to any repair.

Bevels are required for butt welding when thickness > 6mm and for fillet welding when thickness > 8mm.

Undercuts are not allowed and concave fillet weldings are recommended.

If original material is not available (as per approved drawings), another one may be used subject to LPO approval. Welding Procedure and welder’s certificate should be verified accordingly. In such a case, a memo specifying location of new material used is to be endorsed.

As a general principle, the IACS Rec 47 "Shipbuilding and repair quality standard" is applicable to light alloy materials.

However, due to the Heat Affected Zone, the position of the butt welding inserts is to be extended at least 25 mm away from original butt welding

After the repairs, surveyor is to request non destructive test to the extent considered necessary.

Thickness measurements

Measurements are to be taken by a certified company to the extent detailed in Recognised Organisation (RO) rules part A, ch.3, sec. 3 table 3. Such company is to have knowledge and adequate equipment for thickness measurements on aluminium alloys.

Scope can be reduced by the surveyor upon satisfactory visual examination but the following areas are at least to be measured:

• One transverse section in the midship area with points on all longitudinal structural members,

• Wind and water strakes,

• Exposed, loaded and rolling decks.

Corrosion allowances

Following corrosion allowances are to be used :

where

1. Isolated area is meant as a part of a single structural item. This criterion takes into consideration very local aspects such as grooving of a plate or web, or local severe corrosion; however, it is not to be used for pitting for which separate criteria is considered.

2. Item is meant as an individual element such as a plate, or stiffener, a web, etc. This criterion takes into consideration the average condition of the item, which is assessed by determining its average thickness using the various measurements taken on the same item.

3. a group is meant as a set of elements of the same nature (plates, longitudinals, girders) contributing to the longitudinal global strength.

Nota: For other ships in Aluminium built according to NR600, an additional design corrosion margin of 5% is to be considered

Pitting corrosion

It is usually a localized form of corrosion: formation of cavities (pockets). It occurs in areas where natural oxide film is weakened:

• scoring during fabrication,

• bending

• welding

Once started, reactions inside pitting leads to drop in PH value and rise in chloride concentration enabling reaction to continue

Pitting corrosion can be detected as pits are always covered by white blisters of hydrated corrosion product - Al(OH)₃

Pitting intensity and corresponding maximum average depth of pitting:

Galvanic corrosion

There are three conditions necessary for galvanic corrosion:

• two different metallic materials

• in electrical contact

• in humid and conductive environment (e.g. seawater)

In such a case, corrosion will increase on the least noble material (anode) and decrease on the most noble material (cathode): this is galvanic corrosion.

All materials whose electropotential is above the one of Aluminium, will create galvanic corrosion of aluminium:

Buckling

Buckling is one of the weak point of aluminium structures and should carefully assessed during surveys. It may happen on bottom transverse floors, on bottom & cross deck platings, on transverse bulkheads, on side web frames, on superstuctures.

Fatigue

Fatigue is one of the weak point of aluminium structures and should carefully be assessed during surveys. Quality of working (cutting and welding) is essential. Geometrical concentration factors are to be kept to minimum by smooth design and carefull weld profile. Oxycuting of structure, undercuts and convex weldings are not allowed.

Other HSC sensitive items

Passive fire protection

During hull renewal survey, conditions of fire insulation are to be examined. For bulkheads, both sides insulation conditions are to be checked. Should one part be damaged, missing or spilled, it is to be replaced by same material, same mounting system or another approved material & mounting system.

On HSC, when there is no structural fire protection requirement, divisions are to be smoke-tight. During survey, corresponding integrity is to be carefully checked and immediate actions are to be taken as necessary.

Structural Fire Protection time

On HSC, SFP time is defining the performances of the fire protection. In case of change of furnitures impacting this protection, corresponding characteristics are to be carefully checked accordingly. Eg.: if a table was type approved for an SFP time of 30’, it is to be changed by one of the same type, or with higher performances.

Weather tightness of the datum

During hull renewal survey of HSC, weather tightness of the whole datum is to be examined and tested, as necessary. This includes outer doors, side scuttles, ventilation openings, deck hatches, …

Datum is the envelop including the watertight deck covered by a weathertight structure of adequate strength to maintain the weathertight integrity and fitted with weathertight closing appliances.

Stabilisation systems

On HSC, they are part of the classification if they are associated to the safe operation of the craft. In such a case, their structure and their associated systems are to be carefully examined.

Design acceleration level

On HSC, Gcoll is the collision design acceleration calculated for head-on impact at defined collision speed ( = 60% of maxi speed). Design and location of the public spaces, control stations and crew accommodations are based on calculated Gcoll. Therefore, in case of modification of the fixed furnitures (seats, sofas, tables, paddings, kiosks, bars, baggage compartments, large masses), corresponding design reviews are to be performed. During hull renewal survey, conditions of fixation of furnitures to the decks are to be examined. Any damage is to be immediately repaired. If position have been changed, smoke tightness of decks is also to be ensured.

It is reminded that seats shall be type approved; for any new seat a type approval certificate shall be available.

Memorandum to be attached to classification certificate of HSC and light ships

The operational conditions consistent with hull scantlings are to be annexed to classification certificate through a specific memorandum. Such limitations are provided by the LPO during the NC process. In case of CAC, equivalent document is to be collected and attached to class certificate as well.

Here below is a template for reference:

The limit operational conditions consistent with hull scantlings are given in the attached table.

Refer also to the requirement in NR 467 Pt A, Ch 1, Sec 1 [3.3].

Nota 1: Above limitations apply for a commercial use within agreed design conditions. Other limitations may be accepted for a single voyage without passengers nor cargo on board subject to prior review by the society.

Nota 2: The vessel should not be allowed to sail if weather forecast within the time interval required for the voyage exceeds … m significant wave height. In case of weather worsening during the voyage, leading to significant wave height above … m, particular precautions are to be taken, especially the route to be followed and the speed, including sailing to a place of refuge.

Nota 3: Above limitations always subject to vertical acceleration at COG not exceeding design value (refer to Craft Operating Manual issued by the Shipyard)

Case of ships with glasses on bottom platings

Glasses are to be examined carefully at each survey for search of:

• Deformations. In such a case maximum deflection to be recorded

• Crazing phenomenon (air bubbles in the glass). In such a case, number and size to be recorded.

In case of negative evolution, stiffeners may be fitted in front of the glass so as to reduce the span, or glasses are to be replaced.

Extruded glasses should not be used and material certificate (3.1 minimum) should evidence a minimum Rm = 80 Mpa.

Appendix — Testing of watertight compartments

General conditions of testing

Air tests

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Where an air test is required, the effective air pressure shall not exceed 0.24 bars.

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The staff being protected, the maximum pressure shall be maintained a few minutes at the beginning, then reduced to 0.12 bars during the examination of the non-automatic butt welds. These welds shall be coated with an appropriate liquid (soapy water).

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The air pressure shall be clearly indicated by means of a water-column pressure gauge. Furthermore, an efficient safety system against overpressure shall be provided in the tested compartment.

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Test in a compartment for which a coating is intended shall be performed before application of the coating on the non-automatic butt welds.

Vacuum tests of welds

Particularly for small hull repairs on watertight parts, the portable vacuum box technique can be used to test welded joints. Tests should be carried out with at least 25% vacuum (- 0.25 bars) and soapy water, before application of any coating.

Appendix — Survey Planning Questionnaire and Survey Programme - Instructions

Preamble

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The planning of the Class Renewal Survey of ESP ships had first been introduced on 1 January 1995 for oil tankers and bulk carriers and was then extended to chemical tankers and product carriers on 1 January 1997.

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On 1 July 2001, the scope of the intermediate survey of ESP ships of 15 years old and over was extended to the scope of the previous class renewal survey, and by inference the survey planning was also made applicable to the intermediate surveys of these ships. On 1st January 2003, bulk carriers of 10 years and over shall also be applied these requirements.

On 1st July 2006, single hull oil tankers, double hull oil tankers and chemical tankers shall also be applied these requirements.

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These requirements have been integrated into the Rules for ESP Ships, the Survey programme and Preparation of the hull survey are now requirements of the Rules, Part A, Ch 4, Section 2 par. 4.1, Section 3 par. 6.1 and Section 4 par. 6.1 for the Class renewal surveys and intermediate surveys of the same extent as renewal surveys of bulk carriers, oil tankers/combination carriers and chemical tankers, respectively.

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ESP was also adopted by IMO for bulk carriers and oil tankers, through incorporation into SOLAS and MARPOL Conventions. The ESP practicalities are laid down by Resolution A. 744(18). The principle of renewal survey planning were adopted as well, although no model of survey planning document was imposed at that time.

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In the wake of ERIKA disaster, Regulation 13G of Annex 1 to MARPOL was amended, on the one hand to accelerate the phasing out of single hull oil tankers, and on the other hand to introduce a new concept of surveys, called “Condition Assessment Scheme” or CAS.

Single hull “pre-MARPOL” tankers (so-called category 1 tankers) and single hull “post-MARPOL” tankers (category 2 tankers) intended to continue operation beyond 2005 or 2010 respectively, until the date on which they must either be phased out or made to comply with 13F, must show full compliance with the CAS by these dates.

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CAS requirements are laid down by Resolution MEPC. 94(46). The CAS requirements are to a large extent based on the ESP requirements for renewal surveys, and as such include quite a formalized and precise survey planning procedure which not only involves the class society and the owner, but also the thickness measurement company and the flag administration of the vessel, which in the end has the ultimate responsibility to decide upon whether tanker can continue operation beyond 2005 or 2010.

With these requirements, models of “SURVEY PLANNING QUESTIONNAIRE” and of “SURVEY PROGRAMME” are implemented in the scope of CAS.

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IMO Res. MSC 197(80) "adoption of amendments to the guidelines on the enhanced programme of inspections during surveys of bulk carriers and oil tankers (resolution A.744(18), as amended)" subsequently entered into force on the 1st January 2007.Within the scope of statutory requirements, it includes a model of Survey Programme and Survey Planning Questionnaire, in respectively Annex 4A and 4B for bulk carriers (Annex A), Annex 6A and 6B for double hull oil tankers (Annex B Part A), Annex 6A and 6B for oil tankers other than double hull oil tankers (Annex B Part B).

IACS Unified Requirements Z 10s for bulk carriers and oil tankers have been further amended to include the same models of Survey Programme and Survey Planning Questionnaire (UR Z 10.1 Rev.19 (Jul.2011), Z 10.4 Rev.10 (Jul.2011), Z 10.2 Rev.29 (Jul.2011), Z 10.5 Rev.12 (May.2012)).

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The purpose of the present instructions is to introduce the above statutory (IMO Res. MSC 197(80) and CAS) and classification requirements in the system of survey planning adopted by the Society and to update the applicable documentation for a consistent implementation, whatever the ship or survey types.

The Survey Planning Questionnaire and the Survey Programme have been prepared in a Word format, so that they can be tailored as necessary to the actual ship type and arrangements and survey type.

Content

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Dedicated Survey Planning Questionnaires and Survey Programmes have been prepared in the scope of ESP surveys for the following type of ships:

• oil tankers (refer to Annexes Untitled and Untitled),

• bulk carriers (refer to Annexes Untitled and Untitled),

• chemical tankers (refer to Annexes Untitled and Untitled)

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The documents have been prepared so as to cover, when relevant, both the renewal surveys and the intermediate surveys of same extent as renewal surveys.

For oil tankers the same basic documents additionally cover the planning of CAS surveys.

Therefore, the survey planning questionnaire and survey programme shall be adapted and filled in as required for the relevant type of survey being carried out.

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The ESP planning process is to be managed in the available portal where questionnaire and planning document are sent to the vessel managers through a defined process.

Survey Planning Scheme

The preparation of the renewal survey is composed of three main steps: the survey planning questionnaire, the survey programme and the meeting on board prior to starting the survey.

The questionnaire, the planning document and the accompanying letters are available through the MOVE platform. The accompanying letters are automatically attached to the questionnaire and the planning documents.

The overall process for the ESP survey, including the indication of the responsible parties for each step using the MOVE platform is indicated in ESP survey process.

Survey Planning Questionnaire

Timing

The questionnaire shall be generated in MOVE platform and sent by the Connecting District to the Company according to the following time table, depending on the type of survey:

• In the case of a Class renewal survey, 2 months prior to the opening of SSH survey window (i.e. earliest date when the survey can be started), or

• In the case of a Class intermediate survey, 2 months prior to the opening of the INT survey window (i.e. earliest date when the survey can be started).

The covering letter to the Company, accompanying the questionnaire, as per example in Example of covering letter to owner, shall specify that the document shall be returned to the Society, not less than 1 months prior to the planned commencement of the survey, duly filled in and signed. The letter is automatically generated, in form of email, by the MOVE platform once the CD sends the Questionnaire to the company.

For intermediate surveys of ESP ships of 15 years of age and over, and from 1st January 2003 for bulk carriers of 10 years of age and over and from 1st July 2006 for oil tankers and chemical tankers over 10 years of age, a new questionnaire is also to be established.

This questionnaire shall be attached to the survey programme.

Action requested from the Company

The Company shall fill in the survey planning questionnaire and to sent it back to the Society using the MOVE platform.

Survey Plan

Work-flow

Once the survey Planning Questionnaire is received (in Move) the NS Operations Manager (of the SC linked to the CD) will review and validate. Once validated, the SN Operations Manager shall generate the Survey Planning Document and assign an ESP Qualified Surveyor in Move platform. A letter is auto-matically generated, in form of email, by Move platform once the NS Operation Manager sends the Planning document to the company.

The Survey Planning Document shall be prepared in co-operation between the Company representative and the assigned ESP Qualified Surveyor, using the information contained in the Questionnaire along with other available information.

After validation of the ESP Survey Planning Document, the assigned surveyor records this in ASMS2 where a job is created to record the ESP Planning document (refer to ESP survey process)

The Programme shall be completed and signed by the Company and the assigned ESP Surveyor.

The Programme is automatically saved in the ship’s file as well as in MOVE and ASMS.

If the Company does not co-operate to fill in the ESP Planning, the CD should inform the Company that the Survey will not be commenced until the plan is submitted and approved

The survey programme is to be worked out taking into account any amendments to the survey requirements after the last class renewal survey carried out.

Preparation of the survey programme

The programme shall be worked out in co-operation with the Company. The Survey Planning Questionnaire is to be completed (see Survey Planning Questionnaire) and shall be attached to the plan as an integral part thereof. The information provided by the Questionnaire will be used to prepare the programme.

When filling in the section of the survey programme covering critical and suspect areas, in case of VeriSTAR-HULL, VeriSTAR-HULL CM, VeriSTAR-HULL SIS, STAR-HULL or STAR SIS notation granted to the ship, the hot spot map is to be used.

The survey programme at intermediate survey may consist of the survey programme at the previous class renewal survey supplemented by the hull condition evaluation report of this class renewal survey and later relevant survey reports. The survey programme should be worked out taking into account any amendments to the survey requirements after the last class renewal survey carried out.

Meeting on board

Timing

The meeting shall take place on board prior to the commencement of the survey.

Purpose of the meeting

A survey meeting shall be held between the attending Surveyors, the Company’s representative in attendance, the TM Firm Operator and the Master to ascertain that all the arrangements envisaged in the survey programme are in place, so as to ensure the safe and efficient conduct of the survey work.

In cases where, during the planning meeting, it is noted that modifications are necessary to the planning document, the planning document is to be updated accordingly and signed by all parties. A copy of the updated document is to be attached to the survey report

Appendix — Survey Planning Questionnaire for Oil Tanker

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Attached is the model of Survey Planning Questionnaire in force for Oil Tanker.

Appendix — Survey Programmes/Plan for Oil Tanker

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Attached are the models in force for :

Survey Programme for Renewal Survey of Double Hull Oil Tanker

Survey Programme for Renewal Survey of Single Hull Oil Tanker or Combination Carrier or Survey Plan for CAS of Oil Tanker

Appendix — Survey PLANNING QUESTIONNAIRE for BULK CARRIER / ORE CARRIER

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Attached is the model of Survey Planning Questionnaire in force for Bulk Carrier / Ore Carrier

Appendix — Survey Programme for Bulk Carrier / Ore Carrier

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Attached is the model of Survey Programme in force for Bulk Carrier / Ore Carrier :

Appendix — Survey Planning Questionnaire for chemical tankers

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Attached is the model of Survey Planning Questionnaire in force for chemical tankers

Appendix — Survey Programme for chemical tankers

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Attached is the model of Survey Programme in force for chemical tankers.

Appendix — Example of covering letter to owner

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See attached file

Appendix — Model letter for sending results to the ship owner/manager (UR S 31)

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See attached file

Appendix — Example of "Survey S31" calculation sheet

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See attached file

Appendix — Bulk carrier structural details

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Appendix — Bulk carrier hull deflections - Ore cargo

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Appendix — Typical corrosion pattern of hold frame in bulk carrier

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Appendix — Side frames with brackets

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Appendix — Side frames / Integral brackets

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Appendix — Areas to check during survey - hold frame

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Appendix — Typical ore carrier cross section

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Typical wing internal structure showing areas of special concern.

Appendix — Containership structural details

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Appendix — Frame drawings related to UR S 31

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Appendix — Exposed fore deck

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Appendix — Supporting of brackets for air pipes and ventilator pipes

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Appendix — ESP survey process

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