Section 3 Surveys

301.

1.

General

Units classed with the Society are to be subjected to the following surveys to maintain the classification.

(1) Special Surveys

(2) Annual Surveys

(3) Docking Surveys

(4) Surveys of Propeller Shaft and Stern Tube Shaft, Etc.

(5) Boiler Surveys

(6) Continuous Surveys

(7) Alteration Survey

(8) Occasional Surveys

2. In the Annual Surveys and Special Surveys to hull and equipment of units, the requirements among those in Pt 1, Ch 2 of Rules for the Classification of Steel Ships which are deemed espe- cially difficult to apply in relation to the type and purpose of units may be modified in their appli- cation under the approval of the Society on the occasion of plan approval for Classification Survey, submitting information in relation to the maintenance, corrosion control and inspection.

3. It is the responsibility of the owner/operator of the unit to report to the Society without delay any damage, defect or breakdown, which could invalidate the conditions for which a classification has been assigned so that it may be examined at the earliest opportunity by the Surveyor. All repairs found necessary by the Surveyor are to be carried out to Surveyor's satisfaction.

4. Plan and procedures for Special Surveys, Continuous Surveys, and Docking Surveys(or In-water Survey in lieu of Docking Survey) are to be submitted for review in advance of the survey and made available on board. These should include drawings or forms for identifying the areas to be surveyed, the extent of hull cleaning, non-destructive testing locations(including NDT methods), no- menclature, and for the recording of any damage or deterioration found. Submitted data, after re- view by the Society, will be subject to revision if found to be necessary in light of experience.

302. Annual Survey

1. Due date

The due date of annual surveys is to be in accordance with Pt 1, Ch 2, 201. of Rules for the Classification of Steel Ships.

2. Hull and equipment

At each Annual Survey the exposed parts of the hull, deck, deck house, structures attached to the deck, derrick substructure, including supporting structure, accessible internal spaces, and the appli- cable parts listed below are to be generally examined and placed in satisfactory condition as found necessary. And the Surveyors are to be satisfied at each Annual Survey that no material alterations have been made to the unit, its structural arrangements, subdivision, superstructure, fittings, and closing appliances upon which the stability calculations or the load line assignment is based.

(1) For all units

(A) Accessible hatchways, manholes and other openings.

(B) Machinery casings and covers, companionways, and deck houses protecting openings.

(C) Portlights together with deadcovers, cargo ports and similar openings in hull sides, ends, or in enclosed superstructures.

(D) Ventilators, tank vent pipes together with flame screens, and overboard discharges from en-

closed spaces.

(E) Watertight bulkheads and end bulkheads of enclosed superstructures.

(F) Closing appliances for all the above (A) to (E), including hatch covers, doors check valves, together with their respective securing devices, dogs, sill, coamings and supports.

(G) Freeing ports together with bars, shutters and hinges.

(H) Protection of the crew, guard rails, lifelines, gangways, and deck houses accommodating

crew.

Ch 2 Classification and Surveys Ch 2

(I) Windlass and attachment of anchor racks and anchor cables.

(J) The type, location and extent of corrosion control as well as effectiveness, and repairs or re- newals should be reported and submitted to the Society at each survey.

(K) Documentations on board including the stability data, etc. approved by the Society are to be confirmed to be kept on board.

(L) Where the loading instrument having a stability computation capability is provided on board,

the system is to be tested.

(2) For surface type units

(A) The hull and deck structure in vicinity of any other structural changes in section, slots, steps,

(B) openings in the deck or hull

(C) the back-up structure in way of structural members or sponsons connecting to the hull.

(3) For self-elevating units.

(A) Legs above the waterline

(B) Jack house structures and attachment to upper hull or platform

(C) Jacking or other elevating systems and leg guides, externally

(D) Plating and supporting structure in way of leg wells

(4) For column-stabilized unit

Columns, diagonal and horizontal braces together with any other parts of the upper hull support- ing structure as accessible above the waterline.

(5) At the 1st Annual Survey after construction, Column-stabilized and Self-elevating Units may be

subject to examination of major structural components including non-destructive testing, as deemed necessary by the Society. If the Society deems such survey to be necessary, the extent should be agreed to by the Society and the Owner or operator prior to commencement of the Survey.

3. Machinery

(1) Propelling machinery of self-propelled units is to be surveyed in accordance with the require- ments specified in Pt 1, Ch 2, 203. and 502. 2 (4), (5), (8), (9) (a), (10) and (12) of Rules for the Classification of Steel Ships.

(2) Machinery of units not provided with propelling machinery is to be complied with the following requirements.

(A) A general examination of machinery is to be carried out.

(B) The inspections and performance tests specified in Pt 1, Ch 2, 203. 14, 20, 24 and 502.

2 (5), (8), (9) (a), (10) and (12) of Rules for the Classification of Steel Ships are car- ried out.

(3) Other tests and inspections considered necessary by the Surveyor are to be carried out.

4. Electrical Equipment

A general examination of electrical machinery, the emergency sources of electrical power, the switchgear, and other electrical equipment, including operation of same. The operation of the emer- gency sources of power, including their automatic operation, is to be confirmed as far as practicable.

5. Shipboard Automatic and Remote-Control Systems

A general examination of the automatic and remote-control system is to be made to the Surveyor's satisfaction. The machinery-space fire-detection and bilge water-level alarms are to be tested to con- firm satisfactory operation.

6. Special Features

A general examination of hazardous areas, remote shutdown arrangements, fire fighting apparatus where included in the Societies' Rules, self-elevating systems, piping systems, and bilge systems is to be made.

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303. Special survey

1. Due range

Special Surveys of hull, structure, equipment, and machinery are to be carried out at 5 year inter- vals to renew the Certificate of Classification.

(1) The first Special Survey is to be completed within 5 years from the date of the initial

Classification Survey and thereafter within 5 years from the credited date of the

previous

Special Survey. However an extension of class of 3 months maximum beyond the 5th year can be granted in exceptional circumstances. In this case the next period of class will start from the expiry date of the Special Survey before the extension was granted.

(2) For survey completed within 3 months before the expiry date of the Special Survey,

the next

period of class will start from the expiry date of the Special Survey. For Survey completed

more than three months before the expiry date of the Special Survey, the period of class will start from the survey completion date.

(3) The Special Survey may be commenced at the 4th Annual Survey and be progressed with a view to completion by the 5th anniversary date.

(4) When considered necessary by the Society the interval between Special Surveys may be reduced.

(5) Special Survey requirements of units of unusual design, in lay-up or in unusual circumstances

will be determined on individual basis.

(6) At the

request of the

Owner, and upon the Society's approval of the proposed arrangements, a

system

of Continuous Survey may be undertaken whereby the Special Survey requirements are

carried

out in regular

rotation in accordance with the Rules of the Society to complete all the

requirements of the particular Special Survey within a five year period. Any defects that may

affect classification found during the survey, are to be reported to the Society and dealt with to the satisfaction of the Surveyor.

2. Kind of Special Survey

The kinds of Special Surveys are to be in accordance with Pt 1, Ch 2, 402. of Rules for the Classification of Steel Ships.

3. Scope

The Special Surveys shall include, in addition to Annual Survey and Docking Survey (or equiv- alent) requirements, the following examinations, tests, and checks of sufficient extent to ensure that the hull, structure, equipment, and machinery are in satisfactory condition and that the unit is fit for its intended purpose for the new period of class of 5 years to be assigned subject to proper maintenance and operation and the Periodical Surveys carried out at the due dates.

4. Special Survey No. 1

In the Special Survey No.1, examinations are to be made in accordance with all the requirements specified in the Annual Survey, Docking Survey and, in addition, the following requirements.

(1) Hull and equipments

(A) For all units

(a) The hull or platform structure including tanks, watertight bulkheads and deck, coffer- dams, void spaces, chain lockers, duck keels, helicopter deck and its supporting struc- ture, machinery spaces, peak spaces, steering gear spaces, and all other internal spaces are to be examined externally and internally. Thickness gauging of plating and framing, non- destructive testing and tightness testing may be required where excessive wastage is evident or suspected.

(b) All tanks, compartments and free-flooding spaces throughout the unit are to be examined externally and internally for excess wastage or damage.

(c)

Internal examinations of spud cans and mats are to be specially considered.

(d) Watertight integrity of tanks, bulkheads, hull, decks and other compartments is to be verified by visual inspection.

(e)

(f)

Suspect areas may be required to be tested for tightness, non-destructive tested or thick- ness gauged.

Tanks and other normally closed compartments are to be ventilated, gas freed and

cleaned as necessary to expose damages and allow meaningful examination and thickness

Ch 2 Classification and Surveys Ch 2

gauged in case of excessive wastage.

(g) Internal examination and testing of void spaces, compartments filled with foam or corro- sion inhibitors, and tanks used only for lube oil, light fuel oil, diesel oil, or other non-corrosive products may be waived provided that upon a general examination the Surveyor considers their condition to be satisfactory. External thickness gauging may be required to confirm corrosion control.

(h) Structures such as derrick substructure and supporting structure, Jack house, deck houses, superstructures, helicopter landing areas, raw water (sea water intake) towers and their respective attachments to the deck or hull.

(i)

(j)

Windlass and attachments of anchor racks and anchor cable fairleads.

Foundations and supporting headers, brackets, and stiffeners for drilling related apparatus, where attached to hull, deck, superstructure or deck house.

(k) Thickness gaugings are to be carried out where wastage is evident or suspect.

(l) Where the loading instrument having a stability computation capability is provided on board, all approved test loading conditions are to be examined.

(B) For surface type units

Structural appendages and ducts for positioning units.

(C) For self-elevating units

(a) All legs including chords, bracings, gussets, racks, joints, together with leg guides.

Tubular or similar type legs are to be examined externally and internally, together with

internal stiffeners and pinholes.

(b) Structure in, around and under Jack house and leg walls. Non-destructive testing of sus- pect areas may be required

(c)

Leg jacking or other elevating systems externally. Non-destructive testing of suspect areas may be required

(d) Leg connections to bottom mats or spud cans, including non-destructive testing of leg connections to mats or spud cans.

(e)

(f)

Jetting piping systems or other external piping, particularly where penetrating mats or

spud cans.

Spud cans or mats. Where the spud cans or mat are partly or entirely obscured below the mud line when the Special Survey is otherwise being completed, consideration will

be given to postponement of these examinations until the next unit move.

(D) For column-stabilized units

Non-destructive examination may be required of

(a) Connections of columns and diagonals to upper hull, structure or platform and lower hull, structure or pontoons.

(b) Joints of supporting structure including diagonals, braces and horizontals, together with

gussets and brackets. Internal continuation or back-up structure for the above.

(c)

Suspect areas.

(2) Machinery

Machinery installations of all types of units are to undergo Special Surveys at intervals similar to those for Special Survey on the hull, in order that both may be recorded at approximately the same time.

(A) Non-self-propelled Units

In addition to the requirements for Annual Surveys, at each Special Survey, special attention is to be given to the following items as applicable:

(a) All openings to the sea, including sanitary and other overboard discharges, together with

cocks and valves connected therewith are to be examined internally and externally while the Unit is in drydock, or at the time of underwater examination in lieu of drydocking,

and the fastenings to the shell plating are to be renewed when considered necessary by

the Surveyor.

(b) Pumps and pumping arrangements, including valves, cocks, pipes and strainers are to be examined. Non-metallic flexible expansion pieces in the main salt water circulating sys- tem are to be examined internally and externally. The Surveyor is to be satisfied with the operation of the bilge and ballast systems. Other systems are to be tested as consid- ered necessary.

(c)

The foundations of machinery are to be examined.

(d) Heat exchangers and other unfired pressure vessels within the scope of classification are

Ch 2 Classification and Surveys Ch 2

to be examined, opened out or thickness gauged and pressure tested as considered nec- essary, and associated relief valves proved operable. Evaporators that operate with a vac- uum on the shell need not be opened, but may be accepted on basis of satisfactory ex- ternal examination and operational test or review of operating records.

(B) Self-propelled Units

In addition to the requirements for non-propelled units, the main and auxiliary propulsion

machinery, including associated pressure vessels should be surveyed. In addition, of the steering machinery is to be carried out, including an operational test and

examination checking or

relief-valve settings. The machinery may be required

as considered necessary by the Surveyor.

(C) Units with Propulsion - Assist or Dynamic Position

to be opened for further

examination

Propulsion-assist and dynamic positioning equipment

should be surveyed on the basis of

Special Survey-Machinery in accordance with Pt 1, Ch 2, Sec 5 of Rules Classification of Steel Ships.

(3) Other equipments

(A) Electrical Equipment

In addition to the requirements for Annual Surveys, at each Special Survey, special is to be given to the following items as applicable:

for the

attention

(a) Fittings and connections on main switchboards and distribution panels are to be exam- ined, and care is to be taken to see that no circuits are overfused.

(b) Cables are to be examined as far as practicable without undue disturbance of fixtures.

(c)

(d)

(e)

All generators are to be run under load, either separately or in parallel. Switches and circuit breakers are to be tested.

All equipment and circuits are to be inspected for possible development of physical

changes or deterioration. The insulation resistance of the circuits is to be measured be- tween conductors and between conductors and ground and these values compared with those previously measured.

Electrical auxiliaries installed for vital purposes, generators and motors are to be exam- ined and their prime movers opened for inspection. The insulation resistance of each generator and motor is to be measured.

(f) The windings of main propulsion generators and motors are to be thoroughly examined and found or made dry and clean. Particular attention is to be paid to the ends of all

windings of stators and rotors.

(B) Shipboard Automatic and Remote-Control Systems

In addition to the requirements of Annual Surveys the following parts are to be examined:

(a) Control Actuators: All mechanical, hydraulic, and pneumatic control actuators and their power systems are to be examined and tested as considered necessary.

(b)

(c)

Electrical equipments: The insulation resistance of the windings of electrical control mo-

tors or actuators is to be measured, with all circuits of different voltages above ground being tested separately to the Surveyor's satisfaction.

Unattended Plants: Control systems for unattended machinery spaces are to be subjected to dock trials at reduced power on the propulsion engine to ensure the proper perform- ance of all automatic functions, alarms, and safety systems.

(C) Special Features (All Types)

Units may have many items of machinery and electrical equipment not found on conven- tional vessels. Certain of these items are required for classification even if the unit is with- out propulsion machinery. Items to be especially examined and reported upon at all Special Surveys are as follows:

(a) Hazardous Areas

(i) Electric lighting, electrical fixtures, and instrumentation are to be examined, proven satisfactory and verified as explosion-proof or intrinsically safe.

(ii) Ventilating systems including ductwork, fans, intake and exhaust locations for closed restricted areas are to be examined, tested and proven satisfactory.

(iii)Ventilating-air alarm systems to be proven satisfactory.

(iv)Electrical motors are to be examined including closed-loop ventilating systems large d-c motors.

(v) Automatic power disconnect to motors for ventilating to be proved satisfactory.

(b) Remote shutdown arrangements

(i) Remote shutdown for fuel-oil transfer service pumps and ventilating equipment

en-

for

are

Ch 2 Classification and Surveys Ch 2

to be proved satisfactory.

(ii) Oil tank outlet valves where required to be capable of being remotely closed are to be proved satisfactory.

(iii)Emergency switches for all electrical equipment including main and emergency gen- erators, except alarm and communication systems and lighting in vital areas such as

escape routes and landing platforms, are to be proved satisfactory.

(c) Fire fighting apparatus

A general examination of the fire detection and extinguishing apparatus is to be made in order that the Surveyor may be satisfied with its efficient state. The following items are to be especially examined.

(i) Fire hoses, nozzles, and spanners at each fire station.

(ii) Servicing of all portable soda-acid and foam extinguishers.

(iii)Fire pumps and piping including operation and capacity. (iv)Alarm system.

(d) Self-elevating Systems

On self-elevating type units, the elevating systems are to be examined and reported on. Pinions and gears of the climbing pinion gear train of rack and pinion systems are to be examined, as far as practicable, to the Surveyor's satisfaction by an effective crack detection method.

(e) Miscellaneous - Bilge alarm systems, if fitted, to be tested.

5. Special Survey No. 2 and Subsequent Special Surveys

In addition to the requirements for Special Survey No.1, following items should be surveyed.

(1) These Surveys are to be at least as comprehensive as Special Survey No. 1, with special atten- tion being given to the condition and thickness of material in high corrosion areas.

(2) Representative gaugings will be required. These gaugings will be specified in advance by the

Society.

(3) Special attention should be paid to splash zones on structure, legs or related structure, and in ballast tanks, pre-load tanks, free-flooding spaces, spud cans and mats.

304. Docking Surveys

1. Due range

(1) The outside of the unit's bottom and related items are to be examined two times in any five year period, with an interval not exceeding three years between examinations. For units operat- ing in salt water for less than six months each year, the survey interval may be increased by the Society.

(2) Consideration may be given at the discretion of the Society, to any special circumstances justi- fying an extension of the interval.

(3) Proposals for alternative means of examining the unit's bottom and related items while afloat may be considered, provided they are in general agreement with 309. In-water Survey.

2. Parts to be Examined

(1) Surface type units (ship or barge type units)

(A) External surfaces of the hull, keel, stem, stern frame, rudder, nozzles, and sea strainers are to be selectively cleaned to the satisfaction of the attending Surveyor and examined together with appendages, the propeller, exposed parts of stern bearing assembly, rudder pintle and gudgeon securing arrangements, sea chest and strainers, and their fastenings.

(B) Propeller shaft bearing, rudder bearing, and steering nozzle clearances are to be ascertained and reported upon.

(2) For self-elevating units

(A) External surfaces of the upper hull or platform, spud cans, mat, underwater areas of legs, together with their connections as applicable, are to be selectively cleaned to the satisfaction

of the attending Surveyor and examined.

(B) At each

satisfied nections

Docking Survey or equivalent, after Special Survey No. 2, the Surveyor is to be

with the condition of the internal structure of the mat or spud cans. Leg con- to mat and spud cans are to be examined at each Docking Survey or equivalent.

Non-destructive testing may be required of areas considered to be critical by the Society or

Ch 2 Classification and Surveys Ch 2

found to be suspect by the Surveyor.

(3) Column-stabilized units

(A) External surfaces of the upper hull or platform, footings, pontoons or lower hulls, under-

water areas of columns, bracing and their connections, sea chests, and propulsion units as applicable, are to be selectively cleaned and examined to the satisfaction of the attending Surveyor.

(B) Non-destructive testing may be required of areas considered to be critical by the Society or found to be suspect by the Surveyor.

3. Ballast Spaces

In conjunction with Docking Surveys (or equivalent) after Special Survey No. 1 and between sub- sequent Special Surveys, the following ballast spaces are to be internally examined, thickness gauged, placed in satisfactory condition as found necessary, and reported upon. If such examination reveals no visible structural defects, the examination may be limited to a verification that the corro- sion control arrangements remain effective.

(1) All units

Particular attention is to be given to corrosion control systems in ballast spaces, free-flooding areas and other locations subjected to sea water from both sides.

(2) Surface type units (identical)

For surface type units, one peak tank and at least two other representative ballast tanks between the peak bulkheads used primarily for water ballast.

(3) Self-elevating units

Representative ballast tanks or free-flooding compartments in mat or spud cans, if accessible, and at least two representative hull pre-load tanks.

(4) Column-stabilized units

Representative ballast tanks in footings, lower hulls, or free-flooding compartments as accessible, and at least two ballast tanks in columns or upper hull, if applicable.

305. Surveys of Propeller shaft and Stern Tube Shaft, Etc.

1. Due range

Refer to the schedule in Pt 1, Ch 2, Sec 7 of Rules for the Classification of Steel Ships

for tailshaft surveys.

2. Extension of Intervals of Tailshaft Surveys

Surveys are to be carried out in accordance with the Rules of the Society, except that in the case of Mobile Offshore Drilling unit, due to low running hours on tailshafts, extended intervals between tailshaft surveys may be considered based on:

(1) Satisfactory diver's external examination of stern bearing and outboard seal area down check as far as is possible.

(2) Internal examination of the shaft area (inboard seals) in propulsion room(s).

(3) Confirmation of satisfactory lubricating oil records (oil loss rate, contamination).

including wear-

(4) Shaft seal elements are examined/replaced in accordance with seal manufacturer's recommendations.

Ch 2 Classification and Surveys Ch 2

306. Boiler surveys

1. Survey Interval

(1) Water-Tube boiler for propulsion

(A) For units fitted with more than one boiler the interval between surveys is, in general, to be

2.5 years.

(B) For units fitted with one boiler, the interval between survey is, in general, to be 2.5 years for the first 7.5 years; thereafter the boiler is to be surveyed within 3 months before or af-

ter every year.

(2) Waste-heat or fired auxiliary boilers used for the operation of the vessel, within the scope of classification, are to be surveyed at intervals, in general, of 2.5 years.

2. Extension of survey

The boiler surveys may be extended upon the request of an Owner within 6 months except for the boilers which are to be surveyed annually.

3. Survey items

The survey items in accordance with Pt 1, Ch 2, Sec 8, 802. of Rules for the Classification of Steel Ships.

307. Survey Preplanning and Record Keeping

1. A specific Survey Program for Special Surveys and Continuous Surveys must be worked out in ad- vance of the Special Survey by the Owner in cooperation with the Society. The Survey Program shall be in written format.

2. Plans and procedures for Docking Surveys (or In-water Survey in lieu of Docking Survey) are to be submitted for review in advance of the survey and made available on board. These should in- clude drawings or forms for identifying the areas to be surveyed, the extent of hull cleaning, non- destructive testing locations (including NDT methods), nomenclature, and for the recording of any damage or deterioration found. Submitted data, after review by the Society, will be subject to revision if found to be necessary in light of experience.

308. Occasional Surveys

1. Damage Survey

(1) It is the responsibility of the Owner/operator of the unit to report to the Society without delay any damage, defect or breakdown, which could invalidate the conditions for which a classi- fication has been assigned so that it may be examined at the earliest opportunity by the Society's Surveyor(s). All repairs found necessary by the Surveyor are to be carried out to his satisfaction.

2. Repairs

(1) Where repairs to hull, legs, columns or other structures, machinery or equipment, which affect or may affect classification, are planned in advance to be carried out, a complete repair proce- dure including the extend to proposed repair and the need for Surveyors attendance is to be submitted to and agreed upon by the Society reasonably in advance. Failure to notify the Society, in advance of the repairs, may result in suspension of the unit's classification until such time as the repair is redone or evidence submitted to satisfy the Surveyor that the repair was properly carried out. This applies also to repairs during voyage or on site.

(2) The above is not intended to include maintenance and overhaul to hull, other structures, machi- nery and equipment in accordance with recommended manufacturers procedures and established marine practice and which does not require Society approval; however, any repair as a result of such maintenance and overhauls which affects or may affect classification is to be noted in the ships log and submitted to the Surveyor.

Ch 2 Classification and Surveys Ch 2

3. Reactivation Surveys

In the case of units which have been out of service for an extended period, the requirements for reactivation surveys will be specially considered in each case with due regard given to the status of surveys at the time of the commencement of the lay-up period, the length of the period, and con- ditions under which the unit had been maintained during that period.

4. Alterations

No alterations which may affect classification are to be made to the hull or machinery of a classed unit unless plans of proposed alterations are submitted and approved by the Society before the work of alterations is commenced. Such work is to be carried out in accordance with approved plans and tested on completion as required by the Society and to the satisfaction of the Surveyor.

5. Welding and Replacement of Materials

(1) Welding of steels, including high strength structural steel, is to be to the satisfaction of the Society.

(2) Welding or other fabrication performed on steels of special characteristics or repairs or renewals of such steel or in areas adjacent to such steel is to be accomplished with procedures approved

by the Society considering the special materials involved. Substitution of steels differing from

those originally installed is not to be made without approval by the Society.

309. In-water Survey in lieu of Docking Survey

1. General

Following are the procedures and conditions under which a properly conducted In-water Survey may be credited as equivalent to a Docking Survey.

Where in this case, an examination of the entire unit below the waterline is to be carried out by a suitably qualified diver using closed-circuit television with two-way communication capable of being monitored by the Surveyor.

2. Conditions

(1) Limitations

In-water Survey in lieu of Docking Survey may not be acceptable where there is record of ab- normal deterioration or damage to the underwater structure; or where damage affecting the fit- ness of the unit is found during the course of the survey.

(2) Thickness Gauging and Non-Destructive Testing

Underwater of internal thickness gaugings of suspect areas may be required in conjunction with the In-water Survey. Means for underwater non-destructive testing may also be required for frac- ture detection.

(3) Plans and Data

Plans and procedures for the Docking Survey (In-water Survey) are to be submitted for review

in advance of the survey and made available on board. These should include drawings or forms for identifying the areas to be surveyed, the extent of underwater cleaning, non-destructive test- ing locations (including NDT methods), nomenclature, and for the recording of any damage or deterioration found.

(4) Underwater Conditions

The areas to be surveyed are to be sufficiently clean and the sea water clear enough to permit

meaningful examination and photograph (if necessary) by diver. Overall or spot cleaning may be required.

Ch 2 Classification and Surveys Ch 2

3. Physical Features

The following physical features are to be incorporated into the unit's design in order to facilitate the In-water Survey. When verified they will be noted in the Society for reference at subsequent surveys.

(1) Stern Bearing

For self-propelled units, means are to be provided for ascertaining that the seal assembly on oil- lubricated bearings is intact and for verifying that the clearance or wear-down of the stern bear- ing is not excessive. For use of the wear-down gauges, up-to-date records of the base depths are to be maintained on board. Whenever the stainless-steel seal sleeve is renewed or machined, the base readings for the wear-down gauge are to be re-established and noted in the vessel's re- cords and in the survey report.

(2) Rudder Bearings

For self-propelled units with rudders, means and access are to be provided for determining the condition and clearance of the rudder bearings, and for verifying that all parts of the pintle and gudgeon assemblies are intact secure. This may require bolted access plates and a measuring

arrangement.

(3) Sea Suctions

Means are to be provided to enable the diver to confirm that the sea suction openings are clear. Hinged sea suction grids would facilitate this operation.

(4) Sea Valves

For the Docking Survey (In-water Survey) associated with the Special Survey, means must be provided to examine any sea valve.

4. Procedures

(1) Exposed Areas

An examination of the outside of the structure above the waterline is to be carried out by the Surveyor. Means and access are to be provided to enable the Surveyor to accomplish visual in- spection and non-destructive testing as necessary.

(2) Underwater Areas

An examination of the entire unit below the waterline is to be carried out by an approved serv- ice supplier in accordance with the Guidance relating to the Rules for Classification of Steel Ships Pt 1, Annex 1-11.

(3) Damage Areas

Damage areas are to be photographed. Internal examination, measurements, marking and thick-

ness gauging of such locations may be necessary as determined by the attending Surveyor. Means are to be provided for location, orienting and identifying underwater surfaces in photo- graphs or on video tapes.

5. Alternatives

The Society is prepared to consider alternatives to the above guidelines including remotely operated vehicles, provided means and details for accomplishing results are not less effective.

(1) 309. would be applicable to all unit types due to contents of Par 2 (3) - Plans and Data.

Ch 3 Hull Construction and Equipment Ch 3