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1001 - Interim Guidelines For A Simplified Evacuation Analysis Of High-Speed Passenger Craft
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MSC/Circ.1001                                                                                                          26 June 2001

 

1 The Maritime Safety Committee, at its seventy-third session (27 November to 6 December 2000), adopted the International Code of Safety for High-Speed Craft, 2000 (2000 HSC Code) by resolution MSC.97(73), which is expected to enter into force on 1 July 2002. This Code requires in section 4.8.2 that an evacuation procedure, including an evacuation analysis carried out taking into account the guidelines developed by the Organization shall be developed for the information of the Administration in connection with the approval of fire insulation plans and for assisting the owners and builders in planning the evacuation demonstration required in 4.8.3 of the Code.

2 The Committee, at its seventy-fourth session (30 May to 8 June 2001), noting that computerized simulation systems are still under development, decided that a simplified evacuation analysis method was needed in the interim and, having considered a proposal by the forty-fifth session of the Sub-Committee on Fire Protection, approved the Interim Guidelines for a simplified evacuation analysis of high-speed passenger craft, together with the worked example appended thereto, as set out in the annex.

3 Member Governments are invited to apply the annexed Interim Guidelines when implementing the requirements of section 4.8.2 of the 2000 HSC Code and submit to the Sub-Committee on Fire Protection information on experience gained in the implementation of the Interim Guidelines and on any progress made in the development of computerized simulation systems.

4 Member Governments are also invited to bring the annexed Interim Guidelines to the attention of craft designers, craft owners and other parties involved in the design, construction and operation of high-speed passenger craft.

***

Annex

INTERIM GUIDELINES FOR A SIMPLIFIED EVACUATION ANALYSIS OF HIGH-SPEED PASSENGER CRAFT

1 General

1.1 In addition to the relevant requirements for means of escape, escape routes in high-speed passenger craft are required to be evaluated by an evacuation analysis early in the design process, under the International Code of Safety for High-Speed Craft, 2000 (2000 HSC Code), section 4.8.2.

1.2 The purpose of the Interim Guidelines is to provide guidance on how to execute a simplified (hydraulic) evacuation analysis and use its results to plan the evacuation demonstration required in section 4.8.5 of the 2000 HSC Code.

2 Definitions

2.1 Ideal deployment time (t M) is the time needed for the preparation and launching of the marine evacuation system (MES) and the first survival craft in calm water.

2.2 Ideal travel time (tI) is the time needed for the slowest group of people to reach the embarkation point in calm water. Unless otherwise stated in the evacuation procedure, the number of people of the slowest group should be assumed equal to the capacity of the largest survival craft onboard. For the purpose of these Interim Guidelines, tI is assumed to run concurrently with tM.

2.3 Ideal embarkation time (t E) is the time needed for all passengers and crew to board the survival craft in calm water.

2.4 Structural fire protection time (SFP) is the protection time for areas of major fire risk as defined in section 4.8.1 of the 2000 HSC Code.

2.5 Slowest group of people is the group of evacuating persons for which the highest travel time is obtained from calculations according to paragraph 3.6.3.3.

3 Method of evaluation

The steps in the evacuation analysis are:

3.1 Description of the system

.1 Identification of assembly stations.

.2 Identification of embarkation stations, MES and survival craft.

.3 Description of the evacuation procedure including the role of the crew.

.4 Identification of groups and their escape route.

3.2 Assumptions

This method for estimating evacuation time is basic in nature and, therefore, common evacuation analysis assumptions should be made as follows:

.1 passengers and crew should carry out the evacuation in a sequence of groups according to the evacuation procedure;

.2 passengers and crew will evacuate via the primary escape route;

.3 walking speed depends on the type of escape facility, assuming that the flow is only

in the direction of the escape route, and that there is no overtaking;

.4 passengers disabilities or medical conditions that will severely hamper their ability to keep up with the flow are neglected (see paragraph 3.2.8.1 below);

.5 passenger load is assumed to be 100% (full load);

.6 full availability of escape arrangements is considered;

.7 people can move unhindered;

.8 the allowable evacuation time as per section 4.8.1 of the 2000 HSC Code is given by SFP - 7(min), where:

                                                                                                           3

.8.1 division by 3 accounts for the safety factor, which includes passengers ages and disabilities, restricted visibility due to smoke, effects of waves and craft motions on deployment, travel and embarkation time and of violations to the evacuation procedure;

.8.2 subtraction of 7 min accounts for initial detection and extinguishing action

(section 4.8.1 of the 2000 HSC Code); and

.8.3 for category B craft, the passenger awareness time, the time needed for passengers to reach assembly stations and the time needed for manning emergency stations is included in the 7 min time (see section 4.8 of the 2000 HSC Code);

.9 as the evacuation procedure is designed to carry out evacuation under controlled conditions (section 4.8.1 of the 2000 HSC Code), no counter flow takes place; and

.10 when using table 3.6 it is assumed that at the beginning of the evacuation, passengers are located at a distance not greater than two decks from the embarkation station.

3.3 Scenarios to be considered

3.3.1 For the purpose of calculating the evacuation time in category A craft, passengers should be assumed to be distributed in a normal voyage configuration (section 4.8.4.1 of the 2000 HSC Code).

3.3.2 For the purpose of calculating the evacuation time in category B craft, passengers and the crew should be assumed to be distributed among assembly stations and be ready for embarkation

(section 4.8.4.2 of the 2000 HSC Code).

3.4 Performance standards

3.4.1 The following two performance standards should be complied with for calculating the overall evacuation time:

tM  +tE < SFP-7                                 (3.4.1.1)

3      

tI +tE < SFP-7                                   (3.4.1.2)

3

3.4.2 Both performance standards are derived from section 4.8.1 of the 2000 HSC Code.

3.5 Calculation of t E and t M

3.5.1 The values tE and tM should be calculated separately based on:

.1 the results of full scale trials on similar craft and evacuation systems; or

.2 data provided by the manufacturers; however, in this case, the method of calculation should be documented.

3.5.2 Safety factors on tE and tM are accounted for by dividing by 3 in performance standards formulae (3.4.1.1) and (3.4.1.2).

3.6 Calculation of t I

3.6.1 Parameters to be considered:

.1 clear width, Wc , is:

.1 measured off the handrail(s) for corridors and stairways;

.2 the actual passage width of a door in its fully open position;

.3 the space between the fixed seats for aisles in public spaces; and

.4 the space between the most intruding portions of the seats (when unoccupied) in a row of seats in public spaces;

.2 speed of persons, S (m/s) is the speed of evacuees along the escape route (table 3.6

provides the values of S which should be used for the analysis);

.3 specific flow of persons, Fs (p/(m/s)), is the number of evacuating persons past a

point in the escape route per unit time per unit of clear width Wc (table 3.6 provides

the values of Fs which should be used for the analysis)

Table 3.6*

Type of Facility

Speed of persons S

(m/s)

Specific

Flow Fs

(p/(m/s))

Stairs (down)

0.55

1.1

Stairs (up)

0.44

0.88

Corridors, doorways

0.67

1.3

.4 calculated flow of persons, Fc (p/s), is the predicted number of persons passing a

particular point in an escape route per unit time. It is obtained from:

Fc = Fs · Wc (3.6.1.4)

.5 flow time, tF (s), is the total time needed for a group of N persons to move past a point in the egress system. It is calculated as:

tF = N / Fc (3.6.1.5)

.6 walking time, tw (s), is the total time needed for a person to cover the distance between the assembly station and the embarkation station.

3.6.2 Transitions

Transitions are those points in the egress system where the type of a route changes (e.g. from a corridor to a stairway) where routes merge or branch out.

3.6.3 Procedure for calculation of tI is as follows:

.1         Groups of people:

 

Forthepurposesofevacuation,thetotalnumberofpersonsonboardisbrokendown intooneormore groupsofpeople.  Itshouldbeassumedthatallpersonsinagroup carryouttheevacuationatthesametime,alongthesamerouteandtowardsthesame embarkationstation.  Thenumberofpersonsineachgroup,thenumberofgroupsand theembarkationstationassignedtoeachgroupshouldbeinaccordancewiththe evacuation procedure.

 

.2         Schematic representation:

 

Theescaperoutesfromassemblystationstoembarkationstationsarerepresentedasa hydraulicnetwork,wherethepipesarethecorridorsandstairways,thevalvesarethe doors and restrictions in general.

 

 

 

 

.3 For each foreseen group of people:

.1 The walking time, tw, is calculated by using the speed of persons specified in table 3.6 and the distance between the pertinent assembly and embarkation stations.

.2 The flow time, tF, of each portion of the escape route is calculated using the specific flow Fs from table 3.6 and the appropriate clear width of that portion

of escape route. The total flow time is the largest value obtained.

.3 The travel time is obtained as the sum of the walking time and the total flow time.

3.6.4 Ideal travel time tI

Calculations as per paragraph 3.6.3.3 should be repeated for each foreseen group of people. The highest resulting travel time is then taken as the ideal travel time for use in performance standard in paragraph 3.4.

4 Corrective actions

If the performance standards under paragraph 3.4 are not fulfilled, corrective actions should be considered at the design stage by either modifying one or more components in the evacuation system

(e.g., escape routes, life-saving appliances, passengers load, etc.) or by modifying the evacuation procedure.

5 Documentation

The documentation of the analysis should report the following items:

.1 the basic assumptions for the analysis;

.2 a schematic representation of the layout of the craft;

.3 position and role of the crew during the evacuation, according to the evacuation procedure;

.4 the method for the analysis, if different from these Interim Guidelines;

.5 details of the calculation; and

.6 the resulting overall evacuation time.


 

___________________________

*  Dataderivedfromland-basedstairs,corridorsanddoorsincivilbuildings,andareextractedfromthepublication

“SFPEFireProtectionEngineeringHandbook,2nd  editionNFPA1995”.

Appendix

EXAMPLE OF APPLICATION

1 General

The example provides an illustration on the application of the Interim Guidelines. Therefore it should not be viewed as a comprehensive and complete analysis nor as an indication of the data to be used. More specifically, the short description of the evacuation procedure provided in paragraph 3.3 is only an outline, for the purpose of the evacuation analysis, of the complete evacuation procedure the embarkation time and the deployment time used in paragraph 4 below are purely illustrative.

2 Craft characteristics

The high-speed craft considered is a Category B craft with a total capacity of 800 persons (784 passengers and 16 crew members). As shown in figure 1, when the order to abandon the craft is given, passengers are distributed in the public spaces on two decks (210 on the upper deck and 574 on the lower deck), the lower deck is equipped with 4 MES. The structural fire protection time (SPF) is 60 min.

 

                     Figure 1 : Sketchofthe considered high-speedcraft

3          Descriptionofthe system

 

.1         Identification of assemblystations  Assemblystations coincide with the publicspaces where passengers are located

(seated).  Passengers are wearinglife jackets.

 

.2         Identification of embarkation stations, MESand liferafts

 

.1         Embarkation stations (4, one for each MES)are located at the lower deck.

 

.2         Each MESconsists of an inflatableslide with an attached platform.

 

.3         Liferafts(8),135personscapacityeach,arestowedinracksonthelower decks,intheproximityoftheMES.  Theaggregatecapacityofliferaftsis therefore1080  persons,orof810personsifone embarkation station is not available in accordance with the 2000 HSC Code.

 

.4         Two rescueboats are available formarshallingtheliferafts.

 

 

.3         Description of the evacuation procedure

 

.1         When the order to abandon the craft is given, crew members startoperating theMES(total6crewmembers),therescueboats(1crewmemberperboat) andtodirectthepassengers(asshowninfigure1:twocrewmembersonthe upper  deck  and  6  crew  members  on  the  lower  deck);  all  these  activities progress in parallel.

 

.2                   PHASE1:ForeachMES,theslideisinflatedandthefirstliferaftlaunched, inflatedandconnectedtotheslide'splatform.Inthemeantimethefirst4 groupsofpassengersareformedanddirectedtothe4MES,eachgroupis assisted  by  1  crew  member,  for  a  total  of  400  persons,  as  follows

(see figure 2):

 

·          164passengers,marshalledby1crewmember,movefromupper deck  through  stair  1  down  to  the  lower  deck  and  join  with  34 passengersand1crewmembercomingfromlounge2.   Theythen movealongthecentralaisleoflounge1(corridor2);attheendof corridor2twogroupsareformed,eachcomposedby99passengers and1crewmember,andmovetoMES3and4throughdoors2Aand

2B respectively;

 

·          46passengersmarshalledby1crewmembermovefromupperdeck, through  stair  2,  down  to  lower  deck,  where  theymerge  with  152 passengersand1crewmember;twogroupsarethenformed,each composedby99passengersand1crewmember,andmovetoMES1 and 2 respectively;

 

·           in  the  meantime  the  remaining  passengers  stayin  lounges  1  to  4

assisted by4 crew members.

 

 

         .3         PHASE2:Oncethefirstliferaftisreadyforboarding,thefirstgroupforeach

MESdescendstotheliferaftusingtheslideandplatform.  Whenboardingis completed,theliferaftisdetachedfromtheslideandfloatedawaybythe rescueboat.  Inthemeantime,thesecondliferaftislaunched,inflatedand connectedtotheplatformandthesecond4groupsofpersonsmovetothe embarkation stations.

 

.4         PHASE3:Oncethesecondliferaftisreadyforboarding,thesecondgroupfor eachMESdescentstotheliferaftthroughtheslideandplatform.  Finally,the

6crewmembersoperatingtheMESboard.  Whenboardingiscompleted,the liferaft is detached from theslide.  The evacuation is now completed.

 

.4         Identification of groups and their escape routes

 

Intotal8groups,eachcomposedof100persons,areconsidered.  Their(primary) escaperoutesareshowninfigure2forthefirst4groupsandinfigure3forthe second 4 groups.

 

     

Figure 2 : First 4 groups ofpersons

 

Figure 3 : Second 4 groups ofpersons

 

4          Calculation oftE and oftM

 

.1         Embarkation timetE

 

Accordingtotheevacuationprocedure,eachMESisusedby200persons,ifallfour MESareavailable.Basedonfullscaletrialsoncrafthavingsimilararrangementsand usingthesameMESandsamenumberofcrew,thetotaltimeneededtodeploy, inflateandmooringtheliferaftandtoembark100personsis330s(5minand30s). Accordingly, the total embarkation time is 660 s (11 min).

 

.2         Deployment timetM

 

Based  on  full  scale  trials  on  craft  having  similar  arrangements  and  using  the same MES,thetotaltimeneededtodeployandinflateanMESis150s(2min and 30 s).

 

5          Calculation oftI

 

.1         Forthepurposesofthisexample,itisassumedthatcalculationshavebeencarriedout forallthe8groupsofpeopleintowhichtheevacuationisorganized,accordingtothe evacuationproceduredescribedinparagraph3.3above.Itisfurtherassumedthatthe highesttraveltimeisobtainedforthegroupofpeoplemoving(phase1)fromthe afterwardpassengerareaintheupperdeckdowntoMES3and4respectivelyonthe lower deck.

 

.2         Theschematisationoftheescaperouteisshowninfigure4.Asitmaybe seen, the elements composingthe escape path are 2 doors, 2 corridors and 1 stairway.

.3         The characteristics of the escape path's elements are as follows:

 

                                                                       

                                       

Table 5.3

 

Element

L(m)

Wc (m)

Fs

S(m/s)

Fc (p/s)

N

people

Door 1

N.A.

1.4

1.3

N.A.

1.82

165

Corridor 1

14

4.2

1.3

0.67

5.46

165

Stairway1

4.7

3.5

1.1

0.55

3.85

165

Corridor 2

14

3.0

1.3

0.67

3.90

200

Door 2A

N.A

1.4

1.3

N.A

1.82

100

Door 2B

N.A

1.4

1.3

N.A

1.82

100

 

 

The  values  of  specific  flow  (Fs)  and  speed  (S)  are  taken  from  table  3.6  of theguidelines;  the  value  of  calculated  flow  (Fc)  is  obtained  by  Fc   =  Fs   Wc

(see paragraph 3.6.1.4 of the guidelines).

 

.4         The  resulting  walking  time  (tw)  and  flow  time  (tF),  calculated  according  to paragraphs 3.6.1.5 and 3.6.1.6 of the guidelines are as follows:

                          

                                   

Table 5.4

 

Element

L(m)

Wc (m)

N

people

tw (s)

tF (s)

Door 1

N.A.

1.4

165

N.A.

91

Corridor 1

14

4.2

165

21

30

Stairway1

4.7

3.5

165

9

43

Corridor 2

14

3.0

200

21

51

Door 2A

N.A

1.4

100

N.A

55

Door 2B

N.A

1.4

100

N.A

55

 

Theresultingtotalwalkingtimeisthesumofthewalkingtimeofeachelementintheescape

pathandtotals51s.  Theflowtimeisthehighestamongalltheelementsintheescapepath and corresponds to 91 s.

 

 

Accordingly, theideal travel timeis where, tI   = 142 s.

 

 

 

 

 

 

 

6          Performance standard

 

The calculated overall evacuation time:              tM  +tE   = 150 + 660 <  SFP - 7 min = 1059 s

3

 

 

                                                                                                

                                                                                                                            tI +tE    = 142 + 660 <  SFP - 7 min = 1059 s

                                                                                                                                                                       3


The requirements are fulfilled.


 


 

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