Using escalators for evacuation.

[Foggy]

Good morning,

Can I ask whether any of you have any experience in relation to allowing or not allowing escalators to be used as a means of evacuation.

The 2 escalators in question, one up, one down which are side by side, lead from a sterile ground floor enclosure that leads directly to open air, up to a first floor circular mall of a small split level covered shopping complex. At present a single escape staircase is provided beside the escalators which acts for general use and of course for means of escape in the event of a fire.The other means of escape from the mall is opposite the staircase and escalators and is a large 5m opening which leads directly to open air at ground level.

The managing company wish to remove the staircase in order to extend a ground floor unit.

The escalators will come to a gradual stop on the activation of the fire alarm or detection and security will manage their use during the evacuation.

I am aware that certain guidance states that they should not be considered as a means of escape other than in certain circumstances although it is accepted that people may in any case use them. However, in this particular instance and especially given that they lead directly to open air,  I feel that it would be reasonable to allow them to be considered as a means of escape for evacuation purposes.

I would be grateful for your thoughts on the matter.

[kurnal]

Hi Foggy
I take it you have seen the following guidance note?

http://www.communities.gov.uk/documents/planningandbuilding/pdf/guidanceemergemcylifts.pdf

[Foggy]

Thanks Kurnal,

I have seen the guidance but understand that this is aimed at the benefits keeping them working as part of an evacuation strategy whereas in this instance the company want to remove the existing staircase and utilise the escalators in the stationary position as escape stairs.

[kurnal]

BS9999 takes a slightly less prescriptive view than the BS 5588 part 10 that preceded it. However it recommends that they should not be counted as means of escape except where a fully fire engineered solution is in place. The obvious issues relate to the speed of evacuation and risk of walking down a stalled escalator as the rise and going are very variable.

[Dinnertime Dave]

Presumably, their position would mean that they can only be classed as an accommodation stair. Whilst it isn`t impossible l haven`t seen many on a protected route.

[AnthonyB]

Hang on - this sounds like ****** **** Shopping Centre in K**********

The original fire strategy & fire certificate included the use of the escalators with a coasting stop in addition to the stair to facilitate evacuation & occupancy calculations were based around this.

The planned alterations should be subject to the Building Control process & so any alterations should be subject to their approval.

The designer will have to decide if they can get a BS9999/Engineered Solution Approved, ultimately the BCO will decide if it gets approved or knocked back.

I would prefer a fixed stair of suitable width and an up escalator in an ideal world.

[Fishy]

The use of escalators as a means of escape has been well-established practice on the railways for yonks.  The HSE document “Railway Safety Principles & Guidance” Part 2, section B, dating from 1996 states “65 (c) – All exit routes may be counted as available for use but any escalators should be regarded as continuing to run in the same direction as before the emergency”.  Automatically stopping the escalators is not common practice, though, because of the risk of falls and the difficulty of managing escape (particularly if you have an escalator full of people that you have to get turned around & moving in the opposite direction – worse if they have luggage, shopping etc).  The CLG guide on ‘Transport premises and facilities’ also gives some relevant guidance.

There are several other issues to be mindful of:

1.   If a fault develops with any of the escalators and they need to be worked on, or if they are being maintained during opening hours then they would normally need to be taken out of service and would not be available for escape purposes (even as a fixed stair).  So, if you had two escalators & kept one available at all time you would still be halving the escape capacity on a fairly regular basis, whereas with a normal staircase you would be very unlikely to have to take it out of service anything like as frequently;

2.   Stopped escalators are not particularly good staircases – the step dimensions are completely different & people often stumble getting on and off (because their brains are expecting them to be moving).  The vertical travel speed is significantly lower than on a normal stair & the risk of slips, trips & falls is greater.