E MARITIME SAFETY COMMITTEE 93rd session Agenda item 6 MSC 93/6/6 11 March 2014 Original: ENGLISH PASSENGER SHIP SAFETY Damage stability of cruise passenger ships Submitted by the Cruise Lines International Association (CLIA) SUMMARY Executive summary: The Cruise Ship Safety Forum (CSSF), a tripartite group of cruise ship operators, shipbuilders, and classification societies, is actively working on matters related to damage stability on cruise ships, including solutions for newbuilds and existing ships, and in particular probabilistic damage stability, watertight doors and damage response tools/procedures that represent a comprehensive approach from the design, operation and emergency situation management aspects of the ship. This document provides a summary of tangible outputs from the CSSF that are intended to drive a step change in safety on new and existing cruise passenger ships. Strategic direction: 5.2 High-level action: 5.2.1 Planned output: 5.2.1.13 Action to be taken: Paragraph 28 Related documents: None Background 1 The Cruise Ship Safety Forum (CSSF) is a consortium of cruise ship operators, shipyards, classification societies, and the Cruise Lines International Association (CLIA) that began in 2002 to advance cruise ship safety in a coordinated and focused manner. The purpose of the CSSF is to:.1 develop and promote a unified strategic direction for advancing cruise ship safety, including security, health and environmental matters;
Page 2 Introduction.2 proactively address issues as they relate to the future of the industry, regarding the design, construction and operation of new cruise ships and modification of existing cruise ships;.3 provide a forum to consider regulatory and other safety initiatives and to develop and pursue a coordinated position to external bodies (IMO); and.4 exchange information. 2 The CSSF is actively developing proposals related to damage stability of cruise ships, including solutions for newbuilding and existing ships. The principal aim of this work is to produce tangible outputs to drive a step change in safety on cruise passenger ships, as well as to develop and promote industry-wide measures to enhance damage stability of cruise ships. 3 The CSSF is actively working matters related to damage stability in three key areas:.1 evaluation of probabilistic damage stability for both grounding and collision scenarios, including realistic options for improving stability parameters, potential methods for increasing survivability and cost-benefit analyses of life-cycle costs;.2 development of options for watertight doors that pose operational challenges, including new and innovative concepts, as well as ways to reduce the time that doors remain open and the number of doors that remain open during navigation; and.3 production of uniform damage control plans and operating practices regarding shipboard drills and training for damage stability. 4 The CSSF has developed six outputs related to damage stability of cruise passenger ships for consideration as follows:.1 measures to enhance survivability after flooding (MSC 93/6/7);.2 simplified calculation of the attained subdivision index A (MSC 93/6/8) with results from analysis of this simplified method (MSC 93/INF.11);.3 monitoring and assessing risk from operation of watertight doors (MSC 93/6/9);.4 damage response strategy (MSC 93/6/10);.5 enhanced damage stability training (MSC 93/6/11); and.6 enhanced damage control plans (MSC 93/6/12). 5 Any additional outputs relevant to passenger ship safety will be submitted to MSC 94 and the relevant technical sub-committee, as appropriate. Objective 6 The objective of this document is to inform the Committee about the ongoing work of the CSSF with regard to damage stability on cruise ships as it relates to items on the Committee's agenda, particularly for MSC 93, under agenda item 6.
Page 3 Enhanced survivability after flooding 7 Survivability after flooding is recognized by the industry to be an essential safety issue. In this context, the CSSF has developed measures to improve survivability after flooding of cruise passenger ships. Some of these measures, while not quantifiable in the attained subdivision index A, have been agreed by the relevant experts to improve overall safety. 8 In this regard, document MSC 93/6/7 contains additional details on the various measures that have been developed to enhance survivability after flooding, including the following:.1 double hull in way of main engine rooms;.2 continuous closed double bottom;.3 no open water tight doors;.4 onboard damage stability system;.5 use of fire doors to prevent flooding; and.6 flooding simulations. Probabilistic damage stability 9 With regard to its work on probabilistic damage stability, the CSSF has taken action to drive change in this area including the following:.1 retrospective analysis of ship designs over the last 15 years;.2 identification of what is currently recommended as a step change on safety for newbuilds;.3 qualitative analysis of subparagraphs 9.1 and 9.2 above using expert judgment;.4 rank matrix on a priority basis, taking into account difficulty, costs, and other factors identified by the group;.5 identification of the most effective recommended solution(s) to drive a step change in safety;.6 evaluation of applicability of solution(s) to new and existing ships;.7 recommendation of new or revised policies; and.8 agreement on common terminology. 10 The CSSF work on probabilistic damage stability has focused on three main elements:.1 investigation of sample ships covering a range of the global cruise ship fleet as to how the attained index can be raised within operational constraints including the impact on costs;.2 development of a simplified index calculation suitable for a reasonable judgment of the improvement of the subdivision standard of pre-solas 2009 ships. This method may also be used to assess the impact watertight doors have on ship survivability; and
Page 4.3 development of a voluntary industry standard for enhanced damage stability. Components of such a standard may include an increase in the attained index beyond the SOLAS 2009 requirements, deterministic design elements such as double hulls in way of engine rooms and an appropriate combination of watertight doors and fire doors to minimize the risk of progressive flooding. 11 The fundamental instrument of the subdivision regulations in SOLAS chapter II-1 is the calculation of the attained subdivision index A. Together with explanatory notes, the regulations provide a well-established methodology to verify that attained subdivision index A is equal to or higher than required subdivision index R. 12 Modern cruise ships have complex ship designs thus application of the methodology is also complex requiring well educated naval architects and sophisticated software tools to calculate the large amount of damage cases for the three initial conditions, often consuming more than 24 hours of computing time. 13 Cruise ship owners would like to have a tool to validate survivability in case of flooding onboard, especially in light of the new requirements in SOLAS regulation II-1/8-1 regarding installation of an onboard computer with a damage stability module that entered into force on 1 January 2014. 14 A simplified method to calculate attained subdivision index A has been developed to improve survivability of passenger ships and to assess vulnerability of open watertight doors. This simplified method does not replace the full set of calculations in SOLAS chapter II-1, but may be used to compare different conditions of a ship, for example comparing watertight doors open and closed or to evaluate the effects of modifications to the subdivision. 15 In this regard, document MSC 93/6/8 contains a proposal for a simplified calculation of the attained subdivision index A to enhance survivability after flooding, including a methodology for both SOLAS 2009 (new) and pre-solas 2009 (existing) cruise passenger ships with results of analysis presented in document MSC 93/INF.11. Watertight doors 16 With regard to its work on watertight doors (WTD), the CSSF has taken action to drive change in this area including the following:.1 identification of a methodology to assess WTD design and location for existing installations;.2 identification of vulnerable doors (location and consequence of flooding) through calculations:.1 propose a management system to then eliminate or reduce opening hours of WTDs using this quantitative assessment while taking into account; and.2 identification of WTDs that pose operational challenges;.3 identification of preferred logistics (workflow traffic) for new and existing ships;.4 propose revisions to the General Arrangement and operational practices based on results gained through subparagraphs 16.1 through 16.3 above;
Page 5.5 evaluation of designs having no WTDs open while at sea; and.6 evaluation of preventing progressive flooding through unprotected openings. 17 The CSSF work on WTDs has focused on three main elements:.1 procedures for monitoring and assessing maritime risk from operation of WTDs, including monitoring use of WTDs on board, analysing results by applying a simplified index calculation for recorded open door conditions and using analysis as a basis for any recommendations, such as changes in operational procedures, as well as potential physical changes;.2 developing an industry best practice, including cruise ship designs with no open WTDs, as well as recommendations on work flow and ship arrangements to reduce the need for WTDs to remain open; and.3 protection from progressive flooding, including descriptions of means/methods to reduce progressive flooding through openings considered unprotected, as well as effects of fire rated doors on or below the bulkhead deck. 18 Effective use of watertight doors on passenger ships is essential for the safety of the ship, the passengers and the crew on board. Watertight doors have been installed for a purpose and will inevitably be used when the ship is in operation. The purpose of these guidelines is to establish procedures to be followed to assess and reduce risk related to the use of watertight doors on a specific ship or on a class of ships. 19 The procedure for monitoring and assessing risk from operation of watertight doors consist of the following three steps:.1 monitoring use of watertight doors on board;.2 analyse results; and.3 impose corrective actions as found necessary. 20 These steps should be reiterated on a regular basis on board a specific ship. Analyses of results may take place ashore or could be done on board when the precalculated results (value of A for open doors) are available. 21 In this regard, document MSC 93/6/9 contains proposed draft guidelines and detailed steps for monitoring and assessing risk from operation of watertight doors on board cruise ships. Damage control plans and operational practices 22 With regard to its work on damage control plans and operational practices, the CSSF has taken action to drive change in this area including the following:.1 evaluation of what information is essential for a damage control plan;.2 identification and content analysis of additional essential damage stability documentation (damage control manual, damage consequence diagram, advisory cards, stability computer);
Page 6.3 consideration of existing industry best practices for shipboard drills and training for damage response and control;.4 review of operating practices by training and human factors experts;.5 impact assessments of subparagraphs 22.1 through 22.4, above;.6 development of standardized communications; and.7 development of proposed industry guidelines on operating practices regarding shipboard drills and training for damage response and control (common strategy, drill frequency, skill sets, equipment). 23 As an interim measure, the CSSF has developed draft guidance to optimize response to a damage situation based on principles of a fast drilled response to understand the nature and extent of the damage, containment, and parallel preparation for evacuation. On a trial basis, drills are being carried out by some CLIA member lines with the aim to increase awareness and understanding of a specific response to a damage condition. In parallel, work is underway to develop examples of improved damage control plans/manuals that would seamlessly integrate with damage condition information provided by the damage response procedure, leading to enhanced situation management and to provide improved decision support for a master. 24 In this regard, document MSC 93/6/10 contains proposed damage response strategy that includes procedures for damage assessment and control drills. Additionally, document MSC 93/6/11 contains a framework for enhanced damage stability training that represents the culmination of operational damage stability management. Document MSC 93/6/12 contains proposed enhancements to the damage control plan are intended to further positively impact survivability of a cruise passenger ship in the event of flooding. Conclusion 25 The CSSF remains actively engaged on matters related to damage stability on cruise ships, including evaluation of probabilistic damage stability, development of options for watertight doors, and production of uniform damage control plans and operating practices regarding shipboard drills and training for damage stability. This work is ongoing. 26 The CSSF anticipates additional and more robust outputs in the near term to drive a step change in safety on new and existing cruise ships as well as to develop and promote industry-wide measures on damage stability of cruise ships. 27 Additional relevant outputs from the CSSF will be provided to the Organization as appropriate. Action requested of the Committee 28 The Committee is invited to:.1 consider the details provided in this document;.2 instruct the SDC 1 intersessional correspondence group on Subdivision and damage stability to take this information into account; and.3 take action as appropriate.