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Cables and reaction to fire

lyledunn
Why do you suppose that the MHCLG did not feel it necessary to mandate levels of performance for cables with respect to their reaction to fire as was their prerogative under CPR?

Clearly the current non-prescriptive approach is either working or there is no significant evidence that cables and wiring systems have unduly contributed to the propagation of a fire or resulted in emissions that made a situation untenable when it would not have otherwise been. 

Further, what does it actually mean in the note in 422.2.1 that cables need to satisfy the requirements of the CPR in terms of their reaction to fire? I can find nothing specific in the CPR other than the need for CE marking and the requirements placed on the manufacturers for technical information.
  • Former Community Member
    0 Former Community Member
    BS 5839 covers the issue of unwanted fire signals in some detail - along with appropriate methods of filtering (eg, use detectors with variable sensitivity by time - high sensitivity ant night during sleeping risk and low sensitivity by day when people are awake, alert and aware of their surroundings). Staff intervention can be a useful tool, as can "quiet alarms" for staff only - eg, no point ringing the bells in a high dependency medical unit, as the persons present probably can't move let alone follow an evacuation plan - the staff will do that for them if, and only if required.


    For me, the advice is quite simple:


    For Fire: Get out and Stay Out


    For CTM - Run, Hide, Tell


    Regards


    OMS
  • 0
    And the most common case, for false alarms, you may as well remain in place.


    You have to accept for any sensor, be it detecting fires, navigating autonomous vehicles round a school entrance at leaving time, or for medical diagnosis of tumors, that some real dangerous events will be missed, and some false alarms will occur - but having multiple sensor technologies voting, and careful placement should make this risk balance acceptable - or at least better than a skilled  person. If not, it is not really fit for purpose.

  • Former Community Member
    0 Former Community Member

    mapj1:

    And the most common case, for false alarms, you may as well remain in place.



     



    I disagree - for life safety you should be encouraged to leave, every time (Get out, Stay Out) - as I alluded to above, if your expectation is that it's a false alarm, you engender an attitude that will inevitably result in real risk, because people don't leave when they should.


    I've put people on disciplinary warnings before now for adopting a "cavalier approach" to drills or false alarms - and I'm deadly serious about it. I accept that most people don't like being told what to do, but need telling for their own good. If nothing else, it shows that people understand risk and demonstrates the correct behaviours in a safety culture. For me, a guy who can't react sensibly to a warning system, is probably not safe to be acting as a designer.


    I fully accept that we also have to design appropriately to minimise the unwanted fire signals - but this can be done in a collaborative approach with clients and users (the improvements in FRS call outs in the NHS estate are an example of this)


    regards


    OMS





  • 0

    OMS:

    I've put people on disciplinary warnings before now for adopting a "cavalier approach" to drills or false alarms - and I'm deadly serious about it. I accept that most people don't like being told what to do, but need telling for their own good. If nothing else, it shows that people understand risk and demonstrates the correct behaviours in a safety culture. For me, a guy who can't react sensibly to a warning system, is probably not safe to be acting as a designer. 




    Ignoring an alarm wouldn't have gone down well in a military establishment where we had role calls so nobody could pretend not to have heard.


    One slight snag was the sound-proofed audiology enclosures which were so good that the alarms could not be heard. That simply required somebody else to go and open the door - no use knocking! ?


    To be honest I don't know what the routine is in classified areas - you wouldn't normally even leave your desk if highly sensitive materials were in use. But there will be a risk analysis somewhere.

  • Former Community Member
    0 Former Community Member

    Chris Pearson:




     




    Ignoring an alarm wouldn't have gone down well in a military establishment where we had role calls so nobody could pretend not to have heard.

    Sure - you have a well trained population used to giving (and receiving) instruction and a structure that can enforce and reinforce procedures - bit like a school or hospital. It's the ill disciplined civpop that cause the problems


    One slight snag was the sound-proofed audiology enclosures which were so good that the alarms could not be heard. That simply required somebody else to go and open the door - no use knocking! ?

    If they are anything like the audiology booths in medical facilities, we used a flashing red light inside the booth. Similar for soundproofed and or EMC screened enclosures so our lady in Beijing can chat to Whitehall (or they have a window from which you can see the beacon outside, if you want to avoid taking what is potentially a black probe into the red (or blue) zone.


    To be honest I don't know what the routine is in classified areas - you wouldn't normally even leave your desk if highly sensitive materials were in use. But there will be a risk analysis somewhere.

    Sure - alarms don't usually mean automatic immediate evac - there will be investigation delays, zoned or phased evacuation depending on the location within the establishment or displacement to secure and fire sterile refuge areas (just remember to "Windows" and L on the PC ? - or more probably remove the brick and stick it in a Manifoil Mark IV) - but as you say, it will be a well developed procedure adopted by trained and disciplined people - if you don't follow the rules, it will be an interview without coffee


     




     

    regards


    OMS
  • 0

    Chris Pearson:



    To be honest I don't know what the routine is in classified areas - you wouldn't normally even leave your desk if highly sensitive materials were in use. 



    Classified areas will generally have access control, normally through a card swipe or keypad to open the door (to get in at least). All doors are automatically unlocked when the fire alarm sounds so that people can escape rapidly (which means if you want to get in, just set off the fire alarm or wait for the weekly test - I know it works as I have tried it, but only with rooms I had access to anyway and only with the weekly test). This does mean that when the fire brigade turn up, assuming the alarm has been silenced as everyone is out, somebody else will need to open the doors to let them in to put the fire out (or they could use their normal method of breaking down all the doors and then apologising as they leave...).

    The only instructions might be to lock the highly sensitive material in a drawer before leaving the room. As only documents in use will be in the open, it should only take a second or two, and with the way things are going the majority of documents nowadays will be on secure computers rather than on paper (secure as in not connected to the internet and encrypted), so locking the computer will be sufficient and only takes a second.

    Having said all this, I realise that we are suffering from a bit of topic creep here. I am not sure what this has to do with cable fire performance. Any comments to bring it back will no doubt be welcomed by Lisa.

    Alasdair

  • Former Community Member
    0 Former Community Member

    Alasdair Anderson:




     



    Classified areas will generally have access control, normally through a card swipe or keypad to open the door (to get in at least). All doors are automatically unlocked when the fire alarm sounds so that people can escape rapidly (which means if you want to get in, just set off the fire alarm or wait for the weekly test - I know it works as I have tried it, but only with rooms I had access to anyway and only with the weekly test).

    Not necessarily true - there are all sorts of establishments where doors do not unlock in the event of a fire - but you absolutely need adequate procedures in place to manage the risk of people effectively locked in a building (or sector of a building) - you need to think prisons, hospitals, cash handling and other banking facilities along with a whole host of other secure facilities.


    Having said all this, I realise that we are suffering from a bit of topic creep here. I am not sure what this has to do with cable fire performance. Any comments to bring it back will no doubt be welcomed by Lisa.

    LoL - teachers pet ?



    Alasdair


     




     

  • 0

    Alasdair Anderson:

    Having said all this, I realise that we are suffering from a bit of topic creep here. I am not sure what this has to do with cable fire performance. Any comments to bring it back will no doubt be welcomed by Lisa.



    I would class this as acceptable topic creep though as it's still loosely related to fire protection etc. albeit not specifically cables now... ?


    Where a conversation goes completely away from the original subject then I'd say that was definitely #offtopic
  • 0

    Not necessarily true - there are all sorts of establishments where doors do not unlock in the event of a fire -




    seconded. Either for security to stop unauthourised folk getting in to see something, or because what is in the room is dangerous, and should never be let out.

    There are also systems for places  where you do not go in to rescue someone, because  it is a waste of time, and would involve the loss of additional lives.


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