Recognition and response to alarm

[boro]

Hi

I am currently writing up a fire strategy for a hi-rise building (20 stories) and using the BS 9999 has a guide I wish to allocate a sufficient time that it would take for some one asleep to be roused by an alarm of which sounds above 75 and above at the head board in each study bedroom. I refer to Fig 2 on page 52  Occupant response and travel time
I would be grateful if any one can advise if there is a given time for the Pre-movement time (recognition and response to alarm) for occupants asleep. I have been told that 90 seconds should be enough.

[afterburner]

Is there a process / protocol to ensure the sleeping occupants can actually 'hear'?

If they're asleep and also suffer from a hearing impairment the audible alarm will not help.

As for the 90 second pre-movement time, the needs and reactive capabilities of the occupants will be a contibutory factor.

The need to wake, recognise and react to the alarm will be further compounded by interpretation of perceived danger,  group dynamics (if there is more than one occupant / sleeping accommodation unit, dressing times and any other specialised needs. 

[Midland Retty]

I appreciate you are using BS9999 but what are the intentions here? What are you trying to achieve

Are you not looking at stay put policies for this block particularly given its size? Or are you looking for a full or staged evac everytime the alarm sounds?

What is the design brief? and I take it that the residents will be students?

[boro]

I am trying to establish using the guide a paper exercise on a Simultaneous evacuation.

[kurnal]

Boro- This topic is covered in PD7974 - 6 -2004. Basically in studies the pre movement time range for sleeping accommodation was  very long- in one study of hotels the lower quartile 3 minutes, third quartile 131 minutes.

It is well explained in 7974 so I wont re-iterate here - heres a short extract. Let me know if you need a fuller attempt at an explanation.

Due to the long periods reported and their extreme variability, very conservative default times should be
used. .....................For sleeping and unfamiliar scenarios such as hotels, it is considered that occupants cannot be relied uponto evacuate efficiently without management intervention. Even for a well-managed occupancy with a
well-designed warning system, it is suggested that default 1st percentile pre-movement time should
be 15 min. For managed occupancies, somewhat shorter times may be appropriate if occupants are well
trained"

[kurnal]

You may also be interested in Research Report Number 45, 1992, Joint Committee on Fire Research by Jonathan D Sime Human Behaviour In Fires
A three year project commissioned by the Fire and Emergency Planning Department of the Home Office, 1985-1988
Jonathan Sime, Chris Creed, Michiharu Kimura and James Powell
ISBN 0-86252-621-3

[boro]

Thanks guys for the advise and links, it is greatly appreciated.

[Tom Sutton]

You may also be interested in Research Report Number 45, 1992, Joint Committee on Fire Research by Jonathan D Sime Human Behaviour In Fires
A three year project commissioned by the Fire and Emergency Planning Department of the Home Office, 1985-1988
Jonathan Sime, Chris Creed, Michiharu Kimura and James Powell
ISBN 0-86252-621-3

You should find a pdf version at http://www.communities.gov.uk/documents/fire/pdf/155997.pdf maybe of use.