Annex 1 - Revised Guidelines on Evacuation Analysis for New and Existing Passenger Ships
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Annex 1 - Revised Guidelines on Evacuation Analysis for New and Existing Passenger Ships

Preamble

1 The following information is provided for consideration by, and guidance to, the users of these guidelines:

  • .1 To ensure uniformity of application, typical benchmark scenarios and relevant data are specified in the guidelines. Therefore, the aim of the analysis is to assess the performance of the ship with regard to the benchmark scenarios rather than simulating an actual emergency.

  • .2 Although the approach is, from a theoretical and mathematical point of view, sufficiently developed to deal with realistic simulations of evacuation on board ships, there is still a shortfall in the amount of verification data and practical experience on its application. When suitable information is provided by Member Governments, the Organization should reappraise the figures, parameters, benchmark scenarios and performance standards defined in the interim guidelines.

  • .3 Almost all the data and parameters given in the guidelines are based on well-documented data coming from civil building experience. The data and results from ongoing research and development show the importance of such data for improving the interim guidelines. Nevertheless, the simulation of these benchmark scenarios are expected to improve ship design by identifying inadequate escape arrangements, congestion points and optimizing evacuation arrangements, thereby significantly enhancing safety.

2 For the above considerations, it is recommended that:

  • .1 the evacuation analysis be carried out as indicated in the guidelines, in particular using the scenarios and parameters provided;

  • .2 the objective should be to assess the evacuation process through benchmark cases rather than trying to model the evacuation in real emergency conditions;

  • .3 application of the guidelines to analyse actual events to the greatest extent possible, where passengers were called to assembly stations during a drill or where a passenger ship was actually evacuated under emergency conditions, would be beneficial in validating the guidelines;

  • .4 the aim of the evacuation analysis for existing passenger ships should be to identify congestion points and/or critical areas and to provide recommendations as to where these points and critical areas are located on board; and

  • .5 keeping in mind that it is the company's responsibility to ensure passenger and crew safety by means of operational measures, if the result of an analysis, conducted on an existing passenger ship shows that the maximum allowable evacuation duration has been exceeded, then the company should ensure that suitable operational measures (e.g. updates of the onboard emergency procedures, improved signage, emergency preparedness of the crew, etc.) are implemented.

1 General

The purpose of this part of the guidelines is to present the methodology for conducting an evacuation analysis and, in particular, to:

  • .1 confirm that the performance standards set out in these guidelines can be met;

  • .2 identify and eliminate, as far as practicable, congestion which may develop during an abandonment, due to normal movement of passengers and crew along escape routes, taking into account the possibility that crew may need to move along these routes in a direction opposite the movement of passengers;

  • .3 demonstrate that escape arrangements are sufficiently flexible to provide for the possibility that certain escape routes, assembly stations, embarkation stations or survival craft may be unavailable as a result of a casualty;

  • .4 identify areas of intense counter and cross flows; and

  • .5 provide information gained by the evacuation analysis to the operators.

2 Definitions

2.1 Persons load is the number of persons considered in the means of escape calculations contained in chapter 13 of the International Code for Fire Safety Systems (FSS Code) (resolution MSC.98(73)).

2.2 Response duration (R) is the duration it takes for people to react to the situation. This duration begins upon initial notification (e.g. alarm) of an emergency and ends when the passenger has accepted the situation and begins to move towards an assembly station.

2.3 Individual travel duration is the duration incurred by an individual in moving from its starting location to reach the assembly station.

2.4 Individual assembly duration is the sum of the individual response and the individual travel duration.

2.5 Total assembly duration (tA) is the maximum individual assembly duration.

2.6 Total travel duration (T) is the duration it takes for all persons on board to move from where they are upon notification to the assembly stations.

2.7 Embarkation and launching duration (E+L) is the duration required to provide for abandonment by the total number of persons on board, starting from the time the abandon ship signal is given after all persons have been assembled, with lifejackets donned.

3 Method of evaluation

The steps in the evacuation analysis are specified as below.

3.1 Description of the system:

  • .1 Identification of passenger and crew assembly stations.

  • .2 Identification of escape routes.

3.2 Common assumptions

This method of estimating the evacuation duration is based on several idealized benchmark scenarios and the following assumptions are made:

  • .1 passengers and crew will evacuate via the main escape route towards their assigned assembly station, as referred to in SOLAS regulation II-2/13;

  • .2 passenger load and initial distribution are based on chapter 13 of the FSS Code;

  • .3 full availability of escape arrangements is considered, unless otherwise stated;

  • .4 assisting crew will immediately be at the evacuation duty locations ready to assist the passengers;

  • .5 smoke, heat and toxic fire products are not considered to impact passenger/crew performance;

  • .6 family group behaviour is not considered; and

  • .7 ship motion, heel, and trim are not considered

4 Scenarios to be considered

4.1 As a minimum, four scenarios (cases 1 to 4) should be considered for the analysis as follows. If more detailed data considering the crew distribution is available, it may be used.

  • .1 case 1 (primary evacuation case, night) and case 2 (primary evacuation case, day) in accordance with chapter 13 of the FSS Code.

  • .2 case 3 (secondary evacuation cases, night) and case 4 (secondary evacuation cases, day). In these cases only the main vertical zone, which generates the longest individual assembly duration, is further investigated. These cases utilize the same population demographics as the primary evacuation cases. The following are two alternatives that should be considered for both cases 3 and 4. For ro-ro passenger ships, alternative 1 should be the preferred option:

    • .1 alternative 1: one complete run of the stairways having largest capacity previously used within the identified main vertical zone is considered unavailable for the simulation; or

    • .2 alternative 2: 50% of the persons in one of the main vertical zones neighbouring the identified main vertical zone are forced to move into the zone and to proceed to the relevant assembly station. The neighbouring zone with the largest population should be selected.

4.2 The following additional scenarios may be considered as appropriate:

  • .1 case 5 (Open Deck): If an open deck is outfitted for use by passengers and its gross deck surface area is larger than 400 m² or accommodates more than 200 persons, the following, additional day case should be analysed: All persons are to be distributed as defined in the primary day case (case 2) considering the open deck as an additional public space with an initial density of 0.5 persons/m², calculated using the gross deck surface area.

  • .2 case 6 (Embarkation): If separate embarkation and assembly stations are employed, an analysis of travel duration from assembly station to the entry point of LSA should be taken into account in the process of determining embarkation and launching duration (E+L). All persons which the ship is certified to carry are initially distributed according to the designated capacities of the assembly stations. The persons will move to the entry point of LSA according to the operator's procedures and designated routes. The time for boarding the LSA is determined during LSA prototype test and thus need not be addressed in detail in the simulation. However, congestion directly in front of the LSA should be considered as part of the simulation. These congestions need to be considered as blockage or obstacle for passenger and crew passing, i.e. generated with a LSA entry flow rate equal to the one observed during the LSA test.

4.3 If the total number of persons on board calculated, as indicated in the above cases, exceeds the maximum number of persons the ship will be certified to carry, the initial distribution of people should be scaled down so that the total number of persons is equal to what the ship will be certified to carry.

5 Performance standards

5.1 The following performance standards, as illustrated in figure 5.1, should be complied with:

  • Calculated total evacuation duration:

    • 1.25 (R+T) + 2/3 (E+L) ≤ n (1)

    • (E+L) ≤ 30 min (2)

5.2 In performance standard (1):

  • .1 for ro-ro passenger ships, n = 60; and

  • .2 for passenger ships other than ro-ro passenger ships, n = 60 if the ship has no more than three main vertical zones; and 80, if the ship has more than three main vertical zones.

5.3 Performance standard (2) complies with SOLAS regulation III/21.1.3.

Figure 5.1

5.4 E + L should be calculated separately based upon:

  • .1 results of full scale trials on similar ships and evacuation systems;

  • .2 results of a simulation based embarkation analysis; or

  • .3 data provided by the manufacturers. However, in this case, the method of calculation should be documented, including the value of correction factor used.

The embarkation and launching duration (E+L) should be clearly documented to be available in case of change of LSA.

5.5 For cases where neither of the three above methods can be used, (E+L) should be assumed equal to 30 min.

6 Documentation

The documentation of the analysis should report on the following items:

  • .1 basic assumptions for the analysis;

  • .2 schematic representation of the layout of the zones subjected to the analysis;

  • .3 initial distribution of persons for each considered scenario;

  • .4 methodology used for the analysis if different from these guidelines;

  • .5 details of the calculations;

  • .6 total evacuation duration;

  • .7 identified congestion points; and

  • .8 identified areas of counter and crossing flows.

7 Corrective actions

7.1 For new ships, if the total evacuation duration calculated is in excess of the allowed total evacuation duration, corrective actions should be considered at the design stage by suitably modifying the arrangements affecting the evacuation system in order to reach an acceptable total evacuation duration.

7.2 For existing ships, if the total evacuation duration calculated is in excess of the allowed total evacuation duration, onboard evacuation procedures should be reviewed with a view toward taking appropriate actions which would reduce congestion which may be experienced in locations as indicated by the analysis.

Parent topic: MSC.1/Circular.1533 – Revised Guidelines on Evacuation Analysis for New and Existing Passenger Ships – (6 June 2016)
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