PRELIMINARY HAZARD IDENTIFICATION BALLAST WATER EXCHANGE AT SEA

ANNEX PRELIMINARY HAZARD IDENTIFICATION BALLAST WATER EXCHANGE AT SEA by International Association of Classification Societies 1

PREAMBLE... 4 BALLAST WATER EXCHANGE BY SEQUENTIAL DE AND RE-BALLASTING... 4 HAZARD 1: Deficient Stability... 4 HAZARD 2: Deficient Stability... 5 HAZARD 3: Excessive hull girder bending moments or shear forces... 5 HAZARD 4: Excessive torsional stresses... 5 HAZARD 5: Structural Damage of BW tanks... 6 HAZARD 6: Structural damage of ballast hold(s)... 6 HAZARD 7: Structural damage to flat bottom forward... 6 HAZARD 8: Loss of manoeuvrability and/or ability to make headway... 7 HAZARD 9: Loss of bridge visibility... 7 HAZARD 10: Over-stressing of Cargo Securing Arrangements... 7 HAZARD 11: Structural damage due to under-pressure.... 7 HAZARD 12: Structural damage due to over-pressure... 7 HAZARD 13: Structural strength or stability problems due to incorrect filling levels... 8 HAZARD 14: Personnel Safety... 8 HAZARD 15: Reduced human operator performance during deballasting/ Reballasting... 8 BALLAST WATER EXCHANGE BY THE FLOW THROUGH METHOD... 9 HAZARD 1: Deficient Stability... 9 HAZARD 2: Deficient Stability... 9 HAZARD 3: Excessive hull girder bending and/or shear forces.... 10 HAZARD 4: Excessive torsional stresses... 10 HAZARD 5: Structural Damage of partly filled BW tanks and hold(s)... 10 HAZARD 6: Structural damage due to under-pressure.... 11 HAZARD 7: Structural damage due to over-pressure... 11 HAZARD 8: Structural strength or stability problems due to incorrect filling levels... 11 HAZARD 9: Structural strength or stability problems due to added weight.... 11 HAZARD 10: Personnel Safety... 12 2

HAZARD 11: Personnel Safety... 12 HAZARD 12: Reduced human operator performance during flow through operation... 12 CONCLUSION... 13 THE HAZID TEAM... 14 SHORT CVS... 14 3

PREAMBLE In carrying out the hazard identification it has been assumed that the master and the crew of the ship are fully competent to carry out a ballast water exchange at sea and fully appreciate the relevant operational, for example relating to strength limits, stability limits, and other given design constraints. Also, it has been assumed that the ballast system and associated equipment are fully operational. The hazard identification is carried out to identify hazards presented when ballast water exchange has to be carried out at sea, as suggested in Guidelines for the Control and Management of Ships Ballast Water to Minimise the Transfer of Harmful Aquatic Organisms and Pathogens. (Ref. Resolution A. 868(20).) Requirements for carrying out ballast water exchange at sea is a fairly resent development. Therefore, it should be expected that many new hazards are present. Some of these hazards have been identified in Res. A.868 (20). BALLAST WATER EXCHANGE BY SEQUENTIAL DE and RE-BALLASTING HAZARD 1: Deficient Stability Step in procedure: Deballasting/ reballasting of ballast water tanks Causes: decrease in GM due to free surface effects decrease in GM due rise to in KG of the ship decrease in GM due to trims (long tanks) heeling angle due to un-symmetrical arrangement of tank heeling angle due to un-symmetrical cargo arrangement stability in an intermediate stage misjudged Current requirements: GM/KG limit curve (Intact/ damage stability). (Other draught/ stability related requirements, e.g. minimum tank filling curves versus draught.) Ship Types: All ships where current legislation governs regular loading conditions already, i.e. deck cargo carrying vessels, vessel with tank arrangements that feature large changes in free surfaces. Rule/Procedure Reference: Intact Stability Code, Damage Stability Requirements, and Load Line Convention. procedure within the allowable draught/ stability ranges. 4

HAZARD 2: Deficient Stability Step in procedure: Deballasting/reballasting of cargo hold(s)/tanks used for ballast water. Causes: decrease in GM due to free surface effects decrease in GM due to rise in KG of the ship decrease in GM due to trims (long tanks) stability in an intermediate stage misjudged Current requirements: GM/KG limit curve (Intact/ damage stability). (Other draught/stability related requirements, e.g. minimum tank filling curves versus draught.) Ship Types: Bulk Carriers where current legislation governs regular loading conditions already, i.e. draught limits and or deck cargo carrying vessels, vessels with tank arrangements that feature large changes in free surfaces. Rule/Procedure Reference: Intact Stability Code, Damage stability requirements, Load Line Convention. Relevance: Not OK procedure within the allowable stability ranges. HAZARD 3: Excessive hull girder bending moments or shear forces Step in Procedure: Deballasting/reballasting of ballast water tanks/ hold(s). Causes: Intermediate steps not checked against class rules. Current Requirements: Permissible bending moments and shear forces at sea in loading manual, approved by Class Society. UR S1A.3(h) requires that typical sequences for change of ballast at sea for bulk carriers be checked, where applicable. Ship Types: All ships where such rule checks are applicable, in particular Bulk Carriers and Tankers. procedure whose steps have been checked against excessive hull girder bending moments and shear stresses. The loading manual should be extended to include the relevant loading conditions in accordance with the BWE management plan. Class Rules should require explicitly these additional conditions to be considered HAZARD 4: Excessive torsional stresses Step in Procedure: Deballasting/Reballasting of ballast water tanks. Causes: Un-symmetric deballasting/reballasting. 5

Current Requirements: Current Class Rules, actual loading condition for deballasting/ reballasting at sea currently not checked. UR S1A.3(h) requires that typical sequences for change of ballast at sea for bulk carriers be checked, where applicable. Ship Types: Ships with large deck openings. UR S1 procedure whose steps have been checked against excessive torsional stresses. Checks based on the relevant loading conditions in accordance with the BWE management plan have to be included within Class Rules requirements. HAZARD 5: Structural Damage of BW tanks Step in Procedure: Deballasting/Reballasting. Causes: Severe sloshing caused by resonance with ship motion. Current Requirements: Class Rules. Requires calm weather, if tanks are not designed for all intermediate filling levels during deballasting/ reballasting. Ship Types: All ship types. Relevance: Class Rules are OK, the load case is new. procedure whose steps have been checked for resonance effects. HAZARD 6: Structural damage of ballast hold(s) Step in Procedure: Deballasting/ Reballasting. Causes: Severe sloshing caused by resonance with ship motion. Current Requirements: Class Rules. Require calm weather, if holds are not designed for all intermediate levels during deballasting/ reballasting. Ship Types: Bulk Carriers. Relevance: Class Rules are OK, the load case is new. procedure whose steps have been checked for resonance effects. HAZARD 7: Structural damage to flat bottom forward Step in Procedure: Deballasting/ reballasting. Causes: Slamming due to insufficient forward draft, below permissible limits according to class rules. Current Requirements: Class Rules. Ship Types: All ships. procedure whose steps have been checked for forward draft. 6

HAZARD 8: Loss of manoeuvrability and/or ability to make headway Step in Procedure: Deballasting/Reballasting. Causes: Not sufficient draft. Current Requirements: None. Ship Types: Most large ships. Rule/Procedure Reference: None. Remarks and recommendations: Each ship must have a management BWE plan, where draft allowable has been checked. HAZARD 9: Loss of bridge visibility Step in Procedure: Deballasting/Reballasting. Causes: Excessive trim by the stern. Current Requirements: SOLAS Ch 5, Regulation 22. Ship Types: All ships. Rule/Procedure Reference: SOLAS Ch 5, Regulation 22. Remarks and recommendations: Each ship must have a BWE management plan, where trim by the stern has been checked. HAZARD 10: Over-stressing of Cargo Securing Arrangements Step in Procedure: Deballasting/Reballasting. Causes: Large GMs. Current Requirements: Cargo Securing Manual, new load-case. Ship Types: All ships, except ships carrying liquid and bulk cargoes. Rule/Procedure Reference: MSC Circ. 745, A.714 (17). Remarks and recommendations: The Cargo Securing Manual has to be extended to include the relevant conditions in accordance with the BWE management plan. HAZARD 11: Structural damage due to under-pressure. Step in Procedure: Deballasting. Causes: Un-detected blockage of air-pipes, for example due to lack of proper maintenance, ball failure, freezing, and sabotage, un-intentional closure (human error). Current Requirements: None, except for ball failures where tests are required in Class Rules. Rule/Procedure Reference: No routine operating instructions. Relevance: Not OK Remarks and recommendations: Each ship needs to establish strict procedures within the BWE management plan. HAZARD 12: Structural damage due to over-pressure 7

Step in Procedure: Reballasting. Causes: Blockage (see Hazard 11), or unintentional use of excessive pumping capacity relative to design of ballast system. Current Requirements: Class Rules. Remarks and recommendations: Class Rules may have to be updated. Each ship needs to establish strict procedures within the context of the BWE management plan. HAZARD 13: Structural strength or stability problems due to incorrect filling levels Step in Procedure: Reballasting. Causes: Inadequate/erroneous soundings due to ship motion. Current Requirements: Existing sounding arrangement may be inadequate. Remarks and recommendations: Each ship needs to establish strict procedures within the context of the BWE management plan. Reassessment of existing requirements for sounding arrangements may be required. HAZARD 14: Personnel Safety Step in Procedure: Deballasting/Reballasting. Causes: Working on deck and accessibility (sounding, checking of air-pipes, manual starting of forward pumps) in heavy weather and/or ice conditions. Current Requirements: No written requirements. Rule/Procedure Reference: None. Remarks and recommendations: Each ship needs to establish strict procedures to be included in the BWE management plan. HAZARD 15: Reduced human operator performance during deballasting/ Reballasting Step in Procedure: Deballasting/Reballasting. Causes: More complicated operations, poor working conditions, heavy weather. Current Requirements: STCW, ISM. Rule/Procedure Reference: STCW, ISM. Relevance: Not OK, additional duties. Remarks and recommendations: Special training and familiarisation for ship staff is required for BWE practices, and/or improved ship system design may be required. 8

BALLAST WATER EXCHANGE BY THE FLOW THROUGH METHOD Note: Using existing arrangements may be less efficient as a method for ballast water exchange for those systems which would short-circuit the flow-through, thereby preventing effective exchange of ballast water. The flow through method would not generally work for partially filled tanks, because the partially filled tanks would need to be filled completely before they can overflow. In such cases the effects of the extra loading need to be checked. HAZARD 1: Deficient Stability Step in procedure: Flow through method for partially filled tank. Causes: possible decrease in GM due to rise in KG of the ship decrease in GM due to trims (long tanks) heeling angle due to un-symmetrical arrangement of tank heeling angle due to un-symmetrical cargo arrangement freeboard is decreased more than acceptable Current requirements: GM/KG limit curve (Intact/ damage stability). Load Line Draught (other draught stability related requirements, e.g. minimum tank filling curves versus draught.) Ship Types: All ships where current legislation governs regular loading conditions already, i.e. draught limits and or deck cargo carrying vessels, vessel with tank arrangements that feature large changes in free surfaces. Rule/Procedure Reference: Intact Stability Code, Damage Stability Code, and Load Line Convention. procedure within the allowable draught/stability ranges. HAZARD 2: Deficient Stability Step in procedure: Flow through method for partially filled holds. Causes: Decrease in GM due to rise in KG of the ship Decrease in GM due to trims (long tanks) Stability in an intermediate stage misjudged Freeboard is decreased more than acceptable Current requirements: GM/KG limit curve (Intact/ damage stability). Load Line Draught (other draught stability related requirements, e.g. minimum tank filling curves versus draught.) 9

Ship Types: Bulk Carriers where current legislation governs regular loading conditions already, i.e. draught limits and or deck cargo carrying vessels, vessel with tank arrangements that feature large changes in free surfaces. Rule/Procedure Reference: Intact Stability Code, Damage Stability Code, and Load Line Convention. procedure within the allowable stability margins. HAZARD 3: Excessive hull girder bending and/or shear forces. Step in Procedure: Flow through method for partially filled holds. Causes: Intermediate steps not checked against permissible limits. Current Requirements: Class rules. New loading condition. Ship Types: All ships where such Rule Checks are applicable, in particular for Bulk Carriers and tankers. UR S1A.3(h) requires that typical sequences for change of ballast at sea for bulk carriers be checked, where applicable. procedure whose steps have been checked against excessive hull girder bending moments and shear stresses. The loading manual should be extended to include the relevant loading conditions in accordance with the BWE management plan, Class Rules should require explicitly these additional conditions to be considered. HAZARD 4: Excessive torsional stresses Step in Procedure: Filling of partially filled tanks. Causes: Un-symmetric loading. Current Requirements: Class Rules. New loading condition. Ship Types: Ships with large deck openings. UR S1. UR S1A.3(h) requires that typical sequences for change of ballast at sea for bulk carriers be checked, where applicable procedure whose steps have been checked against excessive torsional stresses. Checks based on the relevant loading conditions in accordance with the BWE management plan have to be included within Class Rules requirements. HAZARD 5: Structural Damage of partly filled BW tanks and hold(s) Step in Procedure: Filling of partially filled tanks and reducing filling levels back to original level. Causes: Severe sloshing caused by resonance with ship motion. Water not back to original level due to inaccurate sounding. Current Requirements: Class Rules. Requires calm weather, if tanks/hold(s) are not designed for all intermediate filling levels. 10

Ship Types: All ship types. procedure whose steps have been checked for resonance effects. HAZARD 6: Structural damage due to under-pressure. Step in Procedure: Deballasting to original level. Causes: Un-detected blockage of air-pipes, for example due to lack of proper maintenance, ball failure, freezing, and sabotage, un-intentional closure (human error). Current Requirements: None, except for ball failures where tests are required in Class Rules. Rule/Procedure Reference: No routine operating instructions. Remarks and recommendations: Each ship needs to establish strict procedures within the BWE management plan. HAZARD 7: Structural damage due to over-pressure Step in Procedure: Filling partially filled tanks. Causes: Blockage (see Hazard 6), or unintentional use of excessive pumping capacity relative to design of ballast system. Current Requirements: Class Rules. Remarks and recommendations: Each ship needs to establish strict procedures within the context of the BWE plan. HAZARD 8: Structural strength or stability problems due to incorrect filling levels Step in Procedure: Deballasting to original level for partly filled tanks. Causes: Inadequate soundings due to ship motion. Current Requirements: Existing sounding arrangement may be inadequate. Remarks and recommendations: Each ship needs to establish strict procedures within the context of the BWE management plan. Reassessment of existing requirements for sounding arrangements may be required. HAZARD 9: Structural strength or stability problems due to added weight. Step in Procedure: Flow through in progress. Causes: Added weight caused by accumulation of water on deck and/or ice. 11

Current Requirements: Class Rules. New loading case needs to be covered. Rule/Procedure Reference: None procedure whose steps have been checked against the effects of possible added weight in terms of both reduced stability and/or structural strength. The loading manual should be extended to include the relevant loading conditions in accordance with the BWE management plan.. HAZARD 10: Personnel Safety Step in Procedure: Deballasting/Reballasting. Causes: Working on deck and accessibility (sounding, checking of air-pipes, manual starting of forward pumps) in heavy weather or ice conditions. Current Requirements: ILO, ISM, and National Legislation. Rule/Procedure Reference: ILO, ISM, and National Legislation. Remarks and recommendations: Each ship needs to establish strict procedures to be included in the BWE management plan. HAZARD 11: Personnel Safety Step in Procedure: Overflow in progress. Causes: Working on deck and accessibility (sounding, checking of air-pipes, manual starting of forward pumps) in heavy weather, wet deck, or with ice on deck. Current Requirements: ILO, ISM, and National Legislation. Rule/Procedure Reference: ILO, ISM, and National Legislation. Remarks and recommendations: Each ship needs to establish strict procedures to be included in the BWE management plan. HAZARD 12: Reduced human operator performance during flow through operation Step in Procedure: Flow Through in progress. Causes: More complicated operations, poor working conditions, heavy weather. Current Requirements: STCW, ISM. Rule/Procedure Reference: STCW, ISM. Relevance: Not OK, additional duties. Remarks and recommendations: Special training and familiarisation for ship staff is required for BWE practices and/or improved ship system design may be required. 12

CONCLUSION As a result of the hazard identification the following general findings should be observed: Requiring ballast water exchange at sea introduces a number of hazards to the ship and its crew. Ballast water exchange in harbour conditions and calm weather is a routine operation today. A Ballast Water Exchange plan is a prerequisite for safe exchange of ballast water Where ballast water exchange is carried out for partly loaded conditions, it has to be verified that, in no case, design limits specific for the ship and loading condition are exceeded. For example, for bulk carriers the weight of cargo in cargo hold(s) and water ballast in the double bottom and hopper tanks is not to exceed the permissible limits for seagoing conditions Since such Ballast Water Exchange plans are specific to each ship the format and content should be standardised as soon as possible to ease safe implementation. A number of existing ships cannot perform the sequential procedure safely. (This procedure will be preferred due to the lower costs.) For these ships the flow through method may be a viable option. Some ships cannot perform ballast water exchange by the flow through method. For the ships that cannot perform safe ballast water exchange, alternative risk reduction strategies could be considered e.g. change in trade, reduce loading, structural modifications, or operational limitations (This way ballast water exchange at sea turns into a cost issue for the ship owner.) 13

THE HAZID TEAM The hazard identification has been carried out in accordance with the IMO INTERIM GUIDELINES FOR THE APPLICATION OF FORMAL SAFETY ASSESSMENT (FSA) TO THE IMO RULE MAKING PROCESS The members of the hazard identification team have been selected to represent all competence areas relevant to the hazards presented during ballast water exchange at sea. The members are: Dr. R. Skjong, Det Norske Veritas, Chairman/Reporting, Hazid Facilitator, Day 3 Prof. E. Aall Dahle, Det Norske Veritas, Hazid Facilitator, Days 1 and 2 Mr. D. Beghin, Bureau Veritas, Structures Mrs. A. Jost, Germanischer Lloyd, Stability Mr. M. Mahmood, American Bureau of Shipping, Piping & Systems Mr. G.J. Greensmith, Lloyd s Register, Operation Mr. S. Gaarder, Det Norske Veritas, Human element Mr. O. M. Nesvåg, Det Norske Veritas, Machinery SHORT CVs Dr. Rolf Skjong: Chief Scientist, Structures and Systems Reliability, DNV, Strategic Research Department. Experience: 15+ years in risk and reliability analysis, specialist in structural reliability theory, Norwegian specialist in FSA at IMO/MSC (66, 67, and 68), member of the /AD HOC Group on FSA, the Norwegian specialist on FSA in the EU Concerted Action on FESA. Responsible for, carried out a number of FSA/QRA and similar projects on e.g. QRA of Passenger Ro-Ro Ships, FSA of HSC, Cost Benefit Analysis of Safety Measures for Bulk Carriers, Risk Analysis of Solo Watch-keeping during periods of darkness, Formal Safety Assessment of Helicopter Landing Areas, etc. Project manager and project responsible of a number of international joint industry projects, including structural reliability projects, for the ships, offshore, and process industries. Published about 40 papers in technical journals and conference proceedings. Prof. E. Aall Dahle: Senior Principal Engineer in DNV, Master of Science in Naval Architecture and Marine Engineering, Ph.D. in Marine Hydrodynamic, Deck Officer Exam, Master Mariner Exam, Professor in Marine Design at the Technical University of Norway. Worked for DNV 14 years. Main experience: Safety assessment and risk analysis of offshore structures, Safety assessment for shipping, Special Safety Advisor for the Norwegian Maritime Directorate, System for approbation of computer programs, Mechanical Engineering Expert at FAO, Rome. Mr. D.Beghin: Scientific Director of the Marine Division, Bureau Veritas. 20 years of experience in ship structural design in Chantiers de l Atlantique, Saint-Nazaire, and 16 years in Bureau Veritas as responsible for rule development and research. Member of WG on Strength of Ships. 1994-1997: Chairman of ISSC Committee design Principle and Criteria. Member of the steering Committee of the Tanker Structure Co-operative Forum. Many publications in conference proceedings. Mrs. A. E. Jost: Dipl. Ing, Naval Architect. Expert on stability and Load Line matters at Germanischer Lloyd. Experience: 12 + years in approval of stability and load line related matters; German Expert in the Joint North West European Research Project on Ro-Ro Ferry Safety; Chairman of WP/SSLL. 14

Mr. M. Mahmood: Manager of Technology Development, ABS Europe. Graduate of Surrey University in Mechanical Engineering. Prior to that he sailed on various types of merchant marine vessels upto the rank of Chief Engineer. Since graduating from Surrey, he worked with P&O as Senior Project Engineer on their new building program. He has been with ABS since 1975, in various capacities including Manager of the Engineering Services. He has been involved with the Offshore Safety Case regime and has participated in Hazop analysis for systems on offshore units and ships systems. Capt. G.J. Greensmith: Senior Examiner in Lloyd s Registers, Construction Services Department, Statutory Approval Services. Holds a UK Deck Class 1 (Master Mariners) Certificate of Competence, 14 years in the UK Merchant Navy serving with major oil companies, 5 years in Senior Officers positions. 19 years with Lloyd s Register, involved in MARPOL and International Chemical and Gas Code statutory certification work including approval of operations manuals required by the conventions. Member of the AHG BLG/WP, technical adviser at MEPC to a signatory delegation. Mr. Stein Gaarder: 22 years of professional practice in research, counselling and implementation of individual and organisational development, of which 16 years in DNV. Magister Artium Degree in educational psychology. Accredited Specialist in Work and Organisational Psychology. Contemporary position: principal research engineer in Department for Safety Management Systems and Competence Building. Several years of assignments in each of the following industries: maritime, offshore, space and land-based industry. Mr. O.M. Nesvåg: M. Sc. in electrical engineering from the University of Trondheim, Norway. Working area: Det Norske Veritas, Division Technology and Products, Electrical Systems. Two years experience. 15