Posted By shaun mckeever How would you conduct the evacuation of a 6000 person public assembly/conference/exhibition centre in the event of fire? I am looking for the pros and cons for simultaneously evacuating such a large number of persons and whether it is best to disperse the occupants or try to provide on site assembly points. The site boundaries are very limited but a safe distance from the building can be achieved from where persons can eventually disperse if necessary. I have my own thoughts which conflict with the local fire authority. I would be interested to hear from others who may have ideas or suggestions that may not have occurred to me. Perhaps some lateral thinking. Crowd management, staff/public ratios and potential hazards aside from fire are things that need to be considered.

Posted By shaun mckeever This is not so much a query about fire safety. The building has not been constructed yet. I have established the fire and evacuation strategy for the building with the exception of where to put them once they have left. I have my own plans but these conflict with the local fire authority. This issue is more about crowd control and crowd dynamics rather than fire safety hence me asking for risks other than fire. I am looking to this forum because there are many wise heads here who may be more aware of the risks of dealing with large crowds tha I am.

Posted By D. Hilton Shaun difficult without additional detail, dont know the layout, compartmentation, grouping of individuals, number and degree of training for intended staff etc. I would advocate a two stage alarm in order to initiate a response (verification of alarm & fire condition). Verification of fire would initiate an evacuation and deployment of trained personnel to predetermined points outside of the building. These trained staff should be provided with portable PA equipment in order to attempt to control the crowds in his/her location in oder to have them travel to a safe distance muster point. Final crowd dispersion would then take place by releasing or advising the crowds to disperse from one or two muster points at a time. As you are more than aware, the difficulty is in the behaviour of the evacuating occupants. The main hazards would relate to restriction of crowds against obstructions, barriers etc and the crush injury/asphyxiation hazards associated. I presume you have already reviewed the Green, Purple & Primrose Guides? Further reference could be made to the following: Sime J. Crowd Safety Management and Communications in Disasters. MoSHE. 1992 Available from the Building Research Establishment. Borehamwood or from JSA Research Consultants, Goldalming, Surrey. Ketchell, N, Cole, S. et. al. The EGRESS code for human movement and behaviour in emergency evacuations in Engineering for Crowd Safety 1993 Elsevier. (Ed Smith RA, Dickie J) ISBN 0 444 899200. Kendik, E. Assessment of Escape Routes in Building and a design method for calculating Pedestrian Movement. Society of Fire Protection Engineers Technology Report 85-4 (1985). Hemisphere Pub. Corp Hanna, J. Emergency Preparedness guidelines for mass, crowd-intensive events Emergency Preparedness 614.88 Han Canada. Sept (1995) Helbing, D. A Fluid-dynamic model for the movement of Pedestrians. Complex systems 6 (1992) pages 391-415 Pauls, J. Movement of People. SFPE Handbook of fire Protection Engineering. (1988). National Council of Canada and BUSI Building Safety Institute. Regards D

Posted By D. Hilton Am presuming progressive evacuation has been considered and excluded by you?

Posted By GeoffB4 Mainly out of my remit this one Shaun, but I don't subscribe to the theory that if you ask a question you are incompetent. I'd suggest on the crowd front that they should disperse simply because it will be quicker. Trying to fit people into a restricted space will reduce the speed of evacuation.

Posted By D. Hilton Shaun from your description of the structure (out in the middle east I assume). I would presume that progressive horizontal evacuation is the way forward and that no doubt you have considered and modelled for this. WRT, the holding of the occupants outside the building, the limit advised is below the safe packing density limit for the UK (4 people per Metre squared)and at that speed crowd speed is calculated at 0.4 m/sec. The limiting factor to the holding scenario is that of the chest cavity and restriction of breathing. IMO, I would suggest that it is unlikely for all 6000 people to be outside the building structure at the same time due to fire although it is conceivable due to bomb threat. I do not see a problem in the packing density advised but I would suggest that the holding points are a prime location for secondary terrorist devices and on that basis alone the holding versus dispersion would not be my first choice. However, even the immediate dispersion or large numbers of people would be a target wrt explosive devices. Regards Darren