IMO ANY OTHER BUSINESS. Alternative arrangements for the inspection of the outside of the passenger ship s bottom (other than ro-ro passenger ships)

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1 INTERNATIONAL MARITIME ORGANIZATION E IMO SUB-COMMITTEE ON SHIP DESIGN AND EQUIPMENT 52nd session DE 52/INF.3 12 December 2008 ENGLISH ONLY ANY OTHER BUSINESS Alternative arrangements for the inspection of the outside of the passenger ship s bottom (other than ro-ro passenger ships) Submitted by the Bahamas, Marshall Islands, the Cruise Lines International Association (CLIA) and the International Chamber of Shipping Executive summary: Strategic direction: 1, 2, 5, 8, 12 High-level action: 1.1, 1.3.5, Planned output: Action to be taken: Paragraph 25 SUMMARY This document provides the information on the practice that exists in the cruise industry pertaining to the inspection of the outside of the ship s bottom. The practice is supported by the classification requirements and approved by a number of flag Administrations as an alternative to the inspection in dry-dock. Related documents: MSC 84/22/10; MSC 84/24, paragraphs and 22.52; MSC 85/26; and DE 52/20/4 1 At its eighty-fourth session, MSC agreed to assign a high-priority work programme item requesting the DE Sub-Committee to develop guidelines to ensure that sound technical judgement is exercised by flag Administrations which allow their passenger ships (other than ro-ro passenger ships) to have an inspection of the outside of the ship s bottom carried out in water, rather than in dry-dock, with one session to complete the work. 2 In anticipation that this work will start sooner rather than later, this document provides the background and technical information that is considered by the cruise industry, classification societies and flag Administrations when proposing and accepting the inspection arrangements as an alternative to the inspection in a dry-dock. It also informs the Sub-Committee of the experience gained with the application of such inspections to a number of cruise ships. For reasons of economy, this document is printed in a limited number. Delegates are kindly asked to bring their copies to meetings and not to request additional copies. I:\DE\52\INF-3.doc

2 - 2-3 It is recalled that the decision of MSC 84 was based on the fact that SOLAS regulation I/7(ii) does not prohibit the use of alternative means of inspection. Statutory background 4 SOLAS requires all passenger ships to have a periodical renewal survey every twelve months that will include an inspection of the structure, boilers and other pressure vessels, machinery and equipment, including the outside of the ship s bottom. The survey shall be such as to ensure that the ship, as regards the structure, boilers and other pressure vessels and their appurtenances, main and auxiliary machinery, electrical installation, radio installations including those used in life-saving appliances, fire protection, fire safety systems and appliances, life-saving appliances and arrangements, shipborne navigational equipment, nautical publications, means of embarkation for pilots and other equipment is in satisfactory condition and fit for the service for which it is intended, and that it complies with the requirements of the present regulations, and of the laws, decrees, orders and regulations promulgated as a result thereof by the Administration. 5 The inspection of the outside of the ship s bottom can be done either in dry-dock or in-water using divers (usually with video/cctv) under the direction of a flag representative or recognized organization. The inspection of the outside of the ship s bottom should normally be carried out within the last three months of the validity of the existing Passenger Ship Safety Certificate, as part of the requirement for certificate renewal. Classification societies rules 6 Most classification societies require that passenger ships are dry-docked twice in each five-year special survey period and the maximum interval between successive docking surveys is not to exceed three years. One of the two docking surveys required in each five-year period is to coincide with the completion of the special survey, as most passenger ships are on continuous machinery and hull survey special survey. Consideration may be given in exceptional circumstances to an extension of this interval not exceeding three months beyond the due date. 7 At the same time, an in-water survey (IWS) may be accepted by class in lieu of the intermediate docking subject to the vessel meeting specific class requirements, such that in a five-year cycle there would be: one docking survey (DS); and one in-water survey (IWS) In addition, the three underwater examinations (UWE) to be held for PSC purpose. 8 Examples of the relevant classification requirements are provided in annex 1 to this document.

3 - 3 - DE 52/INF.3 Review by Lloyd s Register of the sample of inspections of cruise ship s bottom carried out under the scheme approved by a flag Administration 9 The purpose of this review was to gauge the effectiveness of the underwater examinations carried out on the cruise ships in LR-classed fleet, by looking at a sample of ships. Results are provided in annex 2 to this document. 10 Each report for examination of a ship s bottom, whether in-water or in dry-dock, was reviewed for issues raised at survey and problems found. 11 For each ship, reports were reviewed over the last six or seven years, during which time two dockings, or one docking and an in-water survey (at which clearances were taken) were completed, in addition to a number of underwater examinations for passenger ship safety certification. 12 From the review it can be seen that satisfactory maintenance of underwater aspects was possible. 13 One ship underwent a period of four years seven months between dry-dockings, with three underwater examinations and an in-water survey at which clearances were taken in between. At the ensuing docking, repairs to minor defects noted during examinations in-water were carried out. 14 The review indicates that the proposed five years between dry-dockings for passenger ships of under 15 years of age is feasible. Statutory and class conclusion 15 All the major classification societies accept the principle of one in five year dry-dockings being applied to passenger ships, which was also agreed by a number of the flag Administrations. These flag Administrations will allow extending docking intervals to three years on a continuous basis (min. two in six years). 16 As noted in the opening paragraphs of this document, the recent debate at MSC 84 resulted in the principle being accepted. DE and FSI Sub-Committees were instructed to prepare the necessary amendments and circulars. Technical measures and their typical examples 17 When considering implementing extended dry-docking intervals some new technologies and hull maintenance methods are needed. These can be specified as follows: shell coating: coating systems designed for five years service interval, for example, silicon-based foul release system, self-polishing antifouling system or other; shafting: use of water lubricated bearings, upgrading conventional seals with air seals, monitoring of oil quality for water content, improved pod bearings; bow/stern thrusters and stabilizers: overhaul all units after five years of operation; rudders: complete overhauling of rudders every five years; anodes and cathodic protection: anode replacement and general overhauling of cathodic protection system every five years.

4 An example of the measures taken by one Company to assure that extended dry-docking was possible is provided in annex 3 to this document. It should be noted that alternatives to silicone paints, the use of water lubricated bearings or bio-degradable oils and other equally acceptable arrangements may also be employed and that the discussion is based on one particular approach. Conclusion 19 Approval for extended dry-docking intervals is only granted after careful consideration by both the classification society recognized by the flag Administration and the flag Administration. The approval requires ships to comply with specific additional requirements. 20 Ships bottoms will be examined every year either in dry-dock, afloat by an underwater examination or by a more demanding in-water survey that is considered by class to have equivalency to a dry-docking. 21 To facilitate in-water surveys, features such as underwater markings are included, access to sea chests and arrangements for taking rudder stock pintle clearances are provided. 22 The overhaul of rudders, propeller shaft bearings and seals, thrusters and stabilizers is always in accordance with maker s recommendations. 23 Method of applying advanced coating systems, renewing sacrificial anodes and servicing cathodic protection systems allows five-year periods between dry-docking. Action requested of the Sub-Committee 24 The Sub-Committee is invited to take note of the above and review this document in detail when addressing the work programme item. ***

5 ANNEX 1 EXAMPLES OF CLASSIFICATION RULES REQUIREMENTS 1. Classification Society A Ship Rules: No requirements to bottom survey on passenger vessels beyond what is required for cargo ships. The annual bottom survey is considered to be entirely a statutory matter, as is the interval between the dry-dockings of 36 months. For in-water bottom surveys it is a pre-requisite that ships are arranged and equipped in accordance with notation BIS. This notation indicates that the ship is prepared for in-water survey. In order to have the BIS notation the tailshaft should be designed and accepted by class for minimum five year survey interval. This implies stern tube bearings must be oil lubricated or in case of water lubricated systems the shafting must be of corrosion resistant material ( stainless ). 2. Classification Society B Ship Rules: For seagoing ships carrying the Character of Class 100A5 there is to be a minimum of two examinations of the outside of the ship s bottom and related items during each five-year Class Renewal Survey period. One such examination is to be carried out in conjunction with the Class Renewal Survey. In all cases the interval between any two such examinations is not to exceed 36 months. In exceptional circumstances, an extension of examination of the ship s bottom of three months beyond the due date can be granted. Seagoing ships with accommodations for more than 12 passengers are to be presented for bottom survey at intervals of one year. For ships assigned the Class Notation IW, an in-water survey performed with the assistance of an approved diving firm may be recognized as a substitute for every second periodical dry-docking survey. The in-water survey is to provide the information normally obtained from a docking survey. Special consideration shall be given to ascertaining rudder bearing clearances and stern bush clearances of oil stern bearings based on a review of the operating history, onboard testing and stern oil sample reports. These considerations are to be included in the proposals for the in-water survey which are to be submitted in advance of the survey so that satisfactory arrangements can be agreed. In general, bottom survey for seagoing ships with accommodation for more than 12 passengers shall be carried out in dry-dock. The final permission for substitution with an in-water survey is subject to the Head Office approval and is valid for one substitution only. More extensive Flag State Requirements regarding the substitution of the bottom survey in dry-dock shall be observed. I:\DE\52\INF-3.doc

6 ANNEX 1 Page 2 The diving firm assisting in in-water surveys shall be approved for this purpose. Unless accessible from outside with the aid of the vessel s trim and/or heel, underwater parts are to be surveyed and/or relevant maintenance work is to be carried out with assistance by a diver whose performance is controlled by a Surveyor, using an underwater camera with monitor, communication and recording systems. Surveys of the underwater body are to be carried out in sufficiently clear and calm waters. The ship should be in light ship condition. If during the in-water survey damages are found which can be assessed reliably only in dry-dock or require immediate repair, the vessel is to be dry-docked. If the coating of the underwater body is in a condition which may cause corrosion damages affecting vessel s class to occur before the next dry-docking, the vessel is to be dry-docked. 3. Classification Society C Ship Rules: The Society will accept an in-water survey in lieu of the intermediate docking between Special Surveys required in a five-year period on certain ships and where an *IWS notation is assigned, where suitable protection is applied to the underwater portion of the hull. If requested, an *IWS notation may be assigned on satisfactory completion of the Survey, provided that the applicable requirements of the Rules and Regulations are complied with. The in-water survey is to provide the information normally obtained from the Docking Survey. Special consideration shall be given to ascertaining rudder bearing clearances and sternbush clearances based on a review of the operating history, onboard testing and stern bearing oil analysis. These considerations are to be included in the proposals. In-water surveys which are to be submitted in advance of the survey being required, so that satisfactory arrangements can be agreed. The in-water survey is to be carried out at an agreed geographical location under the surveillance of a Surveyor, with the ship at a suitable draught in sheltered waters and with weak tidal streams and currents. The in-water visibility is to be good and the hull below the waterline is to be clean. The Surveyor is to be satisfied that the method of pictorial presentation is satisfactory. There is to be good two-way communication between the Surveyor and the diver. Prior to commencing the in-water survey, the equipment and procedures for both observing and reporting the survey are to be agreed between the Owners, the Surveyor and the diving firm. The in-water survey is to be carried out by a qualified diver employed by a firm approved as a Service Supplier. If the in-water survey reveals damage or deterioration that requires early attention, the Surveyor may require that the ship be dry-docked in order that a fuller survey can be undertaken and the necessary work carried out. Where a vessel has an *IWS notation, the conditions of the high resistant paint is to be confirmed at each dry-docking in order that the *IWS notation can be maintained. National Administrations may have additional requirements. ***

7 ANNEX 2 A REVIEW OF SHIP S BOTTOM EXAMINATIONS SAMPLE OF CRUISE SHIPS IN LR-CLASSED FLEET Ship A Date Survey Remarks 10/02 Docking One shell repair plating 10/03 Underwater Exam Small leakage of sterntube discovered Cracked rivet heads in way of seal, Memoranda imposed 11/04 Underwater Exam Satisfactory 10/05 In-water Survey Clearances taken One 120 mm crack found in propeller blade Condition of Class added 05/06 Docking Sterntube seals replaced Propeller blade replaced 10/06 Underwater Exam Satisfactory 10/07 Underwater Exam Satisfactory Ship B Date Survey Remarks 05/02 Built 04/03 Underwater Exam Bolted cover plate missing Condition of Class imposed (re-fitted 05/03) 04/04 Underwater Exam Satisfactory 11/04 Docking Minor plate repairs 04/05 Underwater Exam Locally paint scored and scratched, Bilge keel distorted, Memorandum imposed 07/05 Grounding Inspection Condition of Class added 04/06 Underwater Exam Grounding damage from 07/05 re-examined and remaining efficient, otherwise satisfactory 05/07 Docking Repairs from grounding 07/05 Hull alterations Ship C Date Survey Remarks 11/02 Underwater Exam Satisfactory 12/03 Docking Minor repairs 11/04 Underwater Exam Satisfactory 11/05 Underwater Exam Some propeller damage, Condition of Class imposed and further UWE required in better visibility 12/05 Underwater Exam Repeated satisfactory Propellers repaired 11/06 Docking Satisfactory 11/07 Underwater Exam Satisfactory I:\DE\52\INF-3.doc

8 ANNEX 2 Page 2 Ship D Date Survey Remarks 04/02 Docking Satisfactory 03/03 Docking Pod repairs, otherwise satisfactory 01/04 Underwater Exam Satisfactory 04/04 Docking Pod repairs, otherwise satisfactory 01/05 Underwater Exam Satisfactory 04/05 Docking Pod repairs, otherwise satisfactory 01/06 Underwater Exam Satisfactory 04/06 Docking Minor repairs on thruster propeller, coating repairs 09/06 Docking Change of pod, otherwise satisfactory 02/07 Underwater Exam Satisfactory Ship E Date Survey Remarks 09/01 Underwater Exam Satisfactory 09/02 Docking Repairs to propeller blades and eroded welds in thruster tunnels 09/03 Underwater Exam Satisfactory 10/04 Underwater Exam Satisfactory 09/05 In-water Survey Clearances taken. Found erosion on thruster tunnels and small crack on rudder access cover. Conditions of Class imposed. 09/06 Underwater Exam Erosion on thruster tunnels and crack on rudder access cover re-examined, Conditions of Class revised 04/07 Docking Repairs to Conditions of Class to thruster tunnels and rudder access cover. 09/07 Underwater Exam Further erosion found on thruster tunnel welds. Condition of Class imposed. Ship F Date Survey Remarks 11/02 Docking Satisfactory 07/03 Docking Pod repaired 06/04 Underwater Exam Satisfactory 06/05 Underwater Exam Satisfactory 11/05 Docking Satisfactory 12/06 Underwater Exam Minor pod repair carried out in water 04/07 Docking Pod repairs, alterations and minor hull repairs Ship G Date Survey Remarks 04/02 Docking Pod repairs. Not credited for Class 07/03 Underwater Exam Satisfactory 07/04 Underwater Exam Satisfactory 02/05 Docking Satisfactory 05/06 Docking Pod repairs. Not credited for Class 08/07 In-water Survey Clearances taken. Minor Underwater repairs carried out ***

9 ANNEX 3 MEASURES TAKEN BY ONE COMPANY TO ACHIEVE EXTENSION TO A FIVE-YEAR DRY-DOCK CYCLE The measures taken by one company to achieve extension to a five-year dry-dock cycle are discussed below in detail. Shell Coating 1 In order to ensure complete protection of the hull during the extended dry-docking period, many cruise lines use silicon-based paints. This is a revolutionary approach to biocide-free fouling control. Unlike other conventional fouling protection technology, silicon-based paint uses no biocides. It produces a slick, slippery hull surface to which macro and algae fouling have difficulty adhering. This fouling may settle, but once the vessel moves, water motion will cause the fouling to detach. 2 The expected life time of this application is 20 years. The only normal maintenance required is low pressure washing in dry-dock every five years. One full coat is applied every 10 years. Laser topographical scan of surface of a tin-free antifouling paint after two (2) years of service reveals an irregular surface profile The same magnification of a silicon-based paint surface after two (2) years in service shows a smoother profile. Picture 1. Tin-free Anti-fouling vs. Silicon-based Paint I:\DE\52\INF-3.doc

10 ANNEX 3 Page 2 Picture 2. Untreated Disk 2 Years Exposure Picture 3. Rotating disk painted with silicon-based paint after two years of exposure in salt water Picture 4. Same disk after spinning on rotor

11 ANNEX 3 Page 3 Condition of the Galaxy hull after 4.5 years in the water with silicon paint in the vertical sides: note the minimal growth build-up on the hull and the good condition of the silicone coating once the growth is removed. Typically there are approximately 4-5% mechanical damages of the silicon paint. The mechanical damages did not affect the primer or the tie coat layer. Generally only 10% silicon paint touch up is applied. The white portion of the hull is that part which has been washed. Picture 5. Celebrity Galaxy Hull Condition After Five-Year Dry-Dock Shaft Air Seals 3 All conventional shaft seals are replaced with air seals. In addition to the five years warranty the air seals feature: High Reliability: high reliability is realized with the following two measures: small pressure difference on all sealing rings, and the provision of two sealing rings on both sea water side and stern tube oil side. Even if the oil sealing rings are damaged, the leaked oil is completely collected in an air chamber between sealing rings. Easy Maintenance: any draft change is automatically detected and the stern tube pressure changes in accordance with draft changes even on vessels with numerous draft changes due to loading conditions. Various emergency measures: emergency measures include spare sealing rings and air control devices. It is possible to convert from air seal systems to Double Security Type COMPACT Seals with simple valve operations.

12 ANNEX 3 Page 4 Bow Thrusters and Stern Thrusters Picture 6. Air Seal Diagram 4 Every five years, the propeller blade foot seals of the bow thrusters and stern thrusters are replaced. Every 10 years all the bow and stern thrusters are overhauled. Picture 7. Bow thruster units in workshop for overhaul

13 ANNEX 3 Page 5 Picture 8. All thrusters are being overhauled during dry-docking Spurs Rope Cutters Picture 9. Thruster shafts and propeller hubs in the workshop for overhaul 5 In order to avoid any incidents from floating ropes, some Companies are implementing the spurs rope cutters system with excellent results.

14 ANNEX 3 Page 6 Main Propellers for CPP Ships Picture 10. Promotional Material for Rope Cutters 6 Every five years, all the main propeller blade foot seals and the shaft seals are replaced. Every 15 years, the main propeller hub is dismantled for general overhauling. The tails shaft is also dismantled for the installation of the air seals. The life cycle of the liners is expected to be 30 years. Generally Class Screwshaft surveys are due at five-year intervals, unless a Screwshaft Condition Monitoring scheme is in effect. Stabilizers Picture 11. Different stages of shaft and CPP hub overhaul 7 Every five years, all the seals of the stabilizers are replaced. Every 15 years, the stabilizer vanes are overhauled and the fin bushes are replaced.

15 ANNEX 3 Page 7 7 Picture 12. Stabilizer overhaul Rudders 8 Rudder pintles and rudders are inspected at IWS, and pintle clearances taken. The rudders are inspected every five years in dry-dock. Every 10 years, the sliding block and the Becker rudder flap bushes are replaced. The complete rudder and rudder stock is dismantled every 15 years in order to replace the neck bearing bushes. The steering gear is also overhauled. Anodes and Cathodic Protection and Sea Valves Picture 13. Rudder overhaul 9 Sacrificial Anodes are typically replaced when 50% depleted, though this is dependent upon the operator s maintenance regime, e.g., every five years, the cathodic protection anodes are replaced. All the sea valves are inspected at each dry-dock. Based on industry experience, life expectancy of the valves is 15 to 20 years. Every five years, boiler blow down valves are replaced. Hull Thickness Measurements 10 After 15 years, the side shell thickness of M/V Island Star (ex-horizon), the oldest CCI vessel, was measured and the average diminution was found to be less than 0.1 mm.

16 ANNEX 3 Page 8 PODs 11 Every five years, the Drive End and Non-Drive End Bearings on the Port and Stbd PODs are replaced. Seals are inspected and replaced at every five-year interval. 8 Picture 14. Propulsion Pod overhaul and maintenance