BS 7273-4

[westerner]

can they be used for lift return, smoke dampers, air handling, secure door release and all other fire protection systems? fire doors are only a small part of the equation.
I have read that a hospital falls into Category A (based on guidance with a sleeping risk and open to the public) it kind of tells me that this standard has been completely overlooked in the design process.

Colin - what is your interpretation of this standard, why is it so onerous on equipment capability, am i barking up the wrong tree and should I bury my head?

[colin todd]

Westie,  ever since the days of the F P Act, fire officers, due to a lack of knowledge of basic engineering principles, thought that door hold open devices and electronic locks failed safe. They really did not understand the concept of fail safe. The did not think beyond the fact that, if you drop power to a device that needs power to keep it held, of course it releases. What never occurred to most of them (and this is not a rant about fire officers, so if you think that read on) was, in the event of fire, what caused the power to drop.

So, when the poor dears (ok I will not patronise them any more in this thread, I promise) became head hauncho fire officers, writing Home Office guides as long ago as the early 1990s, they wrote in all the guides that held open fire doors and electronic locks would release if there was a fault on the fire alarm system.  YELL OF FRUSTRATION COMING: IT WAS IN EVERYSINGLE BLOODY GUIDE!!!!!!!!!!!

The only problem is that the geezers in the fire alarm world had no need to read guides on certification of premises under the fire precautions act, so they NEVER EVER EVER EVER arranged the systems that way.

So, there was this huge communication failure, such that fire officers thought the damn interfaces worked in one way, and the fire alarm industry did not even know that anyone wanted them to work in that way.  I gave up telling both sides that each misunderstood the position of the other.

We knew all of this in 1990, and, when BS 7273-1 was published it contained a promise that, one day, a further part would deal with doors.

What happened to bring about the realisation of the original promise? I confess Westie to being the cause of all your woes.  I brought it to the attention of the relevant BS committee that:

1. An old lady called Maude died in a care home in the NE of England, because someone operated a master door release control and the closing fire door knocked her to the ground, resulting in her death after an operation the next day for her broken hip. The local authority were fined heavily under HAWA and piad undisclosed damages to Maude's family.

2. A security guard died in a fire in Edinburgh (of a heart attack as it happens), when caught in a situtation in which electronic locks failed to release, so no one could get to him.  The Sherrif concluded that the failure was because the cable from the access control central equipment to the outstation was damaged by fire, something we had warned people about for years (and tried to prevent in BS 7807, which no one ever read either). (Word on the streets was that there was a totally different cause of the failure, but for reasons of libel law, I cannot set them out here.)

3. We had info about various near misses, in which people were trapped because electronic locks failed to release on operation of the fire alarm system, some due to installation wiring errors.

It was agreed that there should be a BS 7273-4 to deal with these things. (As it happens, we were awarded the contract after competitive tender to draft it for the committee).

At one of the first meetings of the committee, CFOA were represented by a fire officer who was a chum of mine.  Realising, in his profession, there was no proper understanding of the engineering issues involved, I asked leave of the committee chairman if I could explain the issues to him, drawing on a flip chart.  As, in my explanation, I was addressing only him, eventually he asked (I was never sure if he was being sarcastic) if he was the only one on the committee who did not understand the issues.  Regretably, everyone had to gently tell him that they all fully understood.

At first, my pal from CFOA would not even believe me that what I was saying was true.  He could not countenance that, for all these years, fire officers had been requiring door hold open devices to "fail safe" in the manner described in Home Office guides, and that the requirement was universally ignored.  I had to ask another chum who was representing BFPSA to tell him if his company had ever in its history arranged for fire doors to release when a fault occurred on the fire alarm system or the CIE processor crashed.  Of course they had not.

This left us with a dilemma. Should the new BS 7273-4 actually recommend what the fire service wanted and thought they had all these years, or should it reflect custom and practice.  Ultimately, it was agreed that, if that was what the enforcing authorities wanted, that is what we would give them, bearing in mind that what they wanted could prove very safety critical in some circumstances.  But first, the committee had a chat with a very large manufacturer and a very small manufacturer.  The large manufacturer advised us not to concern ourselves with what the trade did, but only with how we wanted systems to work.  The small manufacturer concurred that, if that was what we wanted, the manufacturers could provide it.

But to ensure that devices that could not properly fail safe might be used in less critical situations, we invented the categlories of reliability, with some suggestions as to where each should be used.  It was informally agreed that, if we invented the categories, other codes, including BS 9999, could specify where they wanted the highest category. That never occurred, because no one bothers to read BS 7273-4.  People even ask questions about it on firenet, openly admitting they dont even have a copy.  Yet it is referenced normatively in BS 5839-1.

So, the bottom line is that, far from the BS setting very onerous recommendations for the first time, all it did was reflect the requirements of regulators, as expressed in guidance for 15-20 years!!! And we even relaxed the recommendations for less critical situations.

FOOTNOTE: DONT BLAME THE BS COMMITTEE OR ME FOR THE FACT THAT HALF OF OUR PROFESSION CANT READ AND HALF OF THE OTHER HALF CANT BE BOTHERED TO BUY BRITISH STANDARDS.

[Wiz]

Westerner, I have had a copy of BS7273-4 for a few years, and despite reading it a number of times, I still consider it to be difficult to understand and 
I believe this is why designers and installers generally just ignore it. They just can't 'get their head around it'

My interpretation of some of the recommendations is that it includes such things as having to adjust the siting/spacing of automatic detection contrary to the recommendations of BS5839-1, which many of us find confusing, and also that some control equipment is required to have facilities and functions that are not yet actually generally available from the major equipment manufacturers. I still haven't even seen any fire alarm control panel manufacturer promoting the fact that their equipment can be used to comply in BS7273-4 installations, and if it could, you'd think that they would be shouting about it!

In saying the above, I must also say that I truly believe that the recommendations were written with the best intentions. I have a lot of respect for the important role BS play in the fire safety field, and for those who have the difficult task of devising and then trying to explain the recommendations in the written word. I just don't think BS 7273-4 meets the normally high standards of other BS.

Whilst accepting the instances highlighted by Mr Todd in his previous post, that led to some of the recommendations of BS7273-4, as being very serious, I personally do not agree with the lengths that the BS recommends to make electrically controlled door systems totally 'fail-safe'. I would firstly suggest that the emphasis on recommending that electrically powered equipment is always in the powered state in the system 'normal' condition, misses the fact that something always has to 'turn on' to enable something else to 'turn off'; You could have a whole circuit of supposedly fail-safe relays energised in the normal condition but the 'alarm' condition would still need something to turn on to start with. I would also suggest, that as long as an Emergency Door Release switch (green box) is properly installed as per BS7273-4 then this becomes the real full and final fail-safe component which should always allow someone to be able to release the electromagnetically locked door in an emergency. In fact, in my opinion, if there is a properly installed EDR switch there might not be any real need for the rest of the complicated fail-safe/monitoring circuitry recommended by BS7273-4. Even in the unlikely event of a simple not-fully-fail-safe control circuitry failing, there would always be the simple and reliable EDR to facilitate the releasing of the locked door!

[colin todd]

Sadly, Wiz, while respecting your views, a committee comprising the then BFPSA (two representatives), CFOA, the IFE, the ECA, the then ODPM and other supposedly knowedgabe people totally disagreed with your opinion.  All of us, to a man, thought it quite a good idea not to trap people in a burning building (with a high degree of reliablility), and there is plenty of anecdotal evidence of people not using, or appreciating, the purpose of a green break glass. Thats democracy, and the trade were made well aware long before the standard was published of the major implications on system design.

With regard to the spacings in BS 5839-1, that standard acknowledges that its recommendations can be overriden where there is a need to interface with other things or there are other objectives (e.g. BS 6266, HTM 05-03 etc). The spacings are based on test evidence that showed the potential for doors not to close if there were detectors only in the corridor at normal spacings. Tough that it means a bit of bother for fire alarm engineers, but any form of engineering is not an end in itself but is there to perform an objective, in this case fire safety of building occupants. Happily, fire safety does not revolve around the convenience of contractors.

I have a parable on the matter. One day, Mrs Kurnawhasitski was worried about the Kurnal, as she thought he was becoming delusional about being the grand old man of fire, avuncularly assisting the needy and gently chastising those who fall out of line.

She took Al to Apalling Medics of Matlock Bath, a private practice that she could amply afford from Al's fire service pension. He looks fine to me, said the Dr closely observing Al as he strode purposefully around the surgery looking for alternative means of escape, but I will check him anyway.

He shone his torch in Al's right ear, totally blinding Mrs K as she looked in his left. He shook his head. Dementia, he pronounced. Dementia, repeated Mrs K her lip trembling slightly.  Can you treat it Dr?

Nah said the Dr nonchalantly, putting his feet up on the desk. Why not asked Mrs K with surprise.  Load of bother , that would be, said the Dr. All too complicated.

But, asked mrs k is there no research or known treatments? Wellllll..... said the Dr hesitantly. There was this group of specialists, including the GMC, wrote a guide to treatment 5 years ago. The draft was then reviewed by the GMC and in fact the entire medical profession was invited to comment.

Then what happened asked mrs k with increasing interest. Nothing, said the doctor. Nothing!!!! said mrs k with astonishment. Nothing nadah said the dr again. Nichts, nil nowt, well not at Mike the medic from matlock's practice anyhow. I took a look at it, but it was all too complicated so I SHUT THE BOOK AND PRETENDED IT HAD NEVER BEEN PUBLISHED!!!

mrs k sat speechless (something that had never afflicted her better half). Look said the dr, I do colds, I do sprained wrists, I dish out contraceptive pills. he was now on a roll. See, mrs k, medical science gets too complicated. It moves on all the time. New cures are developed. But it gets too complicated. If people minsist on having complicated illlnesses, and the specialists keep finding cures that are terribly complicated, its not my fault. Im not into all that.

But what about drugs asked mrs k. Well, said the dr, I heard that a couple of pharmaceutical companies developed pills at huge cost. They are supposed to do what was recommended in the book on the subject, and they address all the symptoms though not curing the thing 100%.


WELL WHO ARE THESE COMPANIES AND WHAT ARE THE PILLS DEMANDED MRS K Wwith increasing outrage.  No idea said the dr. Havent a clue. look have you tried the time honoured treatment of slapping him round the head when he goes on about fire safety?  Oh dr said mrs k, if you only had any idea of how many times. But it doesnt seem to work. Course it doesnt said the dr but its what we used to recommend 50 years ago.

Im worried said mrs k. Sometimes he tries to walk on water and im worried he might drown.  Yeah said the dr the specalists book said that could happen and drowning might result.  But hey I dont think it will ever happen. Just scaremongering by people who know what they are talking about.

That did it. Ive heard enough said mrs K. I am going.

COME ON AL, she called out to Al,who by now was standing on a chair trying to read the label on an emergency light fitting.

Where are you going asked the dr.

I AM GOING, said mrs k to see a GENT WHO WILL MAKE MY HONEY WELL.

All Characters in this parable are fictitious. Any resemblance to any person, living or dead,  or to any manufacturer of BS 7273-4 compliant products is purely coincidental.

[Clevelandfire 3]

Sorry Col but I dont quite buy your argument. You are making sweeping statements. Are you seriously telling us that every last installer out there has been doing it wrong all this time?. Im well versed with the contents of bs5839 but it doesnt mean i could install a fire alarm system. The point being no assessor consultant or enforcer can be expected to have the technical nounce to check every last component of a fire alarm system installation has been installed correctly to spec which is what you seem to be suggesting. that includes things like the efds wizz mentions. yes they can be wired up incorrectly with dire consequences. But guess what the same could be said about my new gas boiler.

You place reliance on a professional installer doing the job right and issuing the relevant certification to confirm that. not that certification means the jobs done right. but if the engineer cocks up is that the clients fault?. is it the enforcers or risk assessors faut? What you are seem to be saying is that there is this mass conspiracy amongst installers to throw the standards to the wall and do what they want instead. i cant believe thats the case except for the odd cowboy. You say youre not having a go at enforcers but what exactly do you expect them to do?

It throws up the following questions for me. 1) should clients, enforcers, fire safety consultants be expected to check the work of installers to the degree you seem to suggest ? 2) if the problem with installers is as prolific as you suggest then surely you would agree that that must point to a problem with comprehension of the standard? 3) If the trade were informed well in advance why is there the hardware capability problems that wizz mentioned ? 4) if no one is bothering to read the standards why do you think that is? cost? clarity?

Does the clear english campaign ever get invited to proof read draft standards?

[colin todd]

Clevers!!!! read my post again and you will see that its cock up not conspiracy.  I can guarantee that when you were doing your wee FP Act inspections none of the MDHs  did what was specified in the Home Office guides because why would fire alarm equipment manufacturers read those. It was by far the biggest misunderstanding ever in our industry. its nothing to do with cowboys. its just that what the guides recommended and what the fire officers thought they were getting was not the practice in the fire alarm industry. it it had been do you think that 5 years after the standard was published asking for systems to perform as specified in government guides since the 1990s people in the fire alarm industry would be kicking up this fuss???

Re your questions, answers enumerated as per the questions:

1. Its not difficult to check that when you take unplug a detector head certain doors should close.  But if you cant be arsed to do that, ask for a BS 7273-4 certificate.

2. They comprehend the standard perfectly well when they bother to read it. But they cant be arsed to do what it says, partly because the products they choose to use cant often do what the standard says and what you thought you had been getting for years.

3. The problem is that its difficult to pass a lot of current down a loop to continuously energise a load of relay coils, so that on total power failure the relay changes state and doors close.  But this was all discussed with the trade well ahead of publication.

4.Inertia, lack of cpd, too difficult to do....

the reference to clear english is irrelevant. the recommendation is clear as day, its just too horrible to take in for some people. Old scottish proverb: there is nane sae deef as those that dinnae want to hear.

[kurnal]

1. Its not difficult to check that when you take unplug a detector head certain doors should close.  But if you cant be arsed to do that, ask for a BS 7273-4 certificate.

2. They comprehend the standard perfectly well when they bother to read it. But they cant be arsed to do what it says, partly because the products they choose to use cant often do what the standard says and what you thought you had been getting for years.

4.Inertia, lack of cpd, too difficult to do....

During a fire risk assessment how far should the diligent fire risk assessor in checking the level of compliance in respect of BS7273-4?

Is it reasonable to take Colin's advice and start unplugging detectors during a fire risk assssment? If we do and the doors close is that enough evidence of compliance?

If instead we ask for evidence of compliance and its not forthcoming where do we go then? Start testing every element of the system?

What about door locks? 

I must admit I have never unplugged a detector during a fire risk assessment. Seen behind the scenes too often to be brave enough to do it.  What if it breaks? What if the fault condition will not re-set?

As Colin often reminds me I do not have and am not expected to have sufficient technical knowledge to spot all the undeclared variations in respect of BS 5839-1 let alone variations to BS7273-4.  As for simulating main processor failure....

And despite my acknowledged lack of expertise in respect of BS 5839 et al every day ( I drive them I dont try to fix them)  I find that I probably know more than the "engineers" who specced, designed, installed and "commissioned" the alarm system or the emergency lighting or the electronic locks etc. In the real world  I often ask the questions and end up educating them as to why its important to say install a green emergency release unit on an exit door or to use something more than tower clips to secure the cables and not to connect the hold open devices to the sounder circuits etc etc 

I am not saying its right. I am not trying to defend the current position. I am suggesting that to move forward it would be good if we could come up with some kind of benchmark checklist for the fire risk assessor, who wishes to be seen to be diligent, to  look for in respect of BS7273-4 apart from asking for a certificate because usually there isnt one. Or an audit template as part of the BS. BS5266 makes it easy with the audit template in BS 5266-10. We could do with some similar provision that if in doubt we could refer to.

[Midland Retty]

Couldn't agree more Kurnal.

I am not sure however if an audit template would be of any benefit. What would it ask for?

The likes of you or I or anyone lacking in depth technical knowledge can't start taking fire alarm panels to bits, or opening call points or EDRs to check they are wired correctly.

That leaves us with making some form of cursory surface / visual inspections, or quizzing fire alarm engineers about the installation, which still isn't going to tell us if the installation is correct.

 

[Wiz]

Mr C.T., I enjoyed your story and I can re-assure you that I picked up the 'hidden' information! When I last checked this particular source I found that their offerings did not meet my interpretation of what it should do to meet the recommendation. They seemed quite shocked at my interpretation and went somewhat quiet. Obviously my interpretation may be over and above the intent of the recommendation, but they couldn't say I was wrong! I will check this source again, because things might have changed in the two years that I have been walking around sorrowfully mumbling "it's just not possible!"  I also discussed the situation at the time with..., now let me also do things your way... last night I went to an Italian restaurant and fancied chicken so I asked them for "a pollo"....... and their technical guys agreed with my interpretation and were considering how they could meet it. I don't want to try and explain my interpretation in detail right now, although I recollect that I did so in a post on here a couple of years ago, because I haven't worried my little head about it for a while, and I may have forgotten the fine details of my deviously fiendish thought process at the time! however, I hope to report back with new considerations after I find time to do some new research.

I accept your point about how most equipment/wiring systems for electromagnetically locked doors were not as fail-safe as some people in authority assumed in the past. They were hearing about the 50% of the overall control system/wiring which could properly be described as fail-safe, and not understanding that the rest of it wasn't. But has BS7273-4 made it totally fail-safe? I would suggest not. As I've said before, in my experience, all systemes rely on at least on thing  to 'turn on' to enable everything else to 'fail safe'. This failure to be able to achieve a 100% fail-safe system is the crux of my argument. Has the difficult-to-achieve from  difficult-to-understand recommendations increased the reliability of the whole set-up to a degree that has made the whole thing worthwhile? I suggest not, and particularly, because a far more reliable and cost-effective solution is provided solely by the EDR switch. Properly installed to BS7273-4, this provides such a cost-effective and reliable component in the control of electromagnetically locked escape door that it makes the rest of the recommended control circuitry seem superflous and expensive. I take your point that some people have not been able to locate an EDR in an emergency, but maybe it is this aspect that should have improved, rather than worrying about making it impossible for any failure of the fire alarm system would stop the locked door from releasing on a fire alarm condition. A bigger EDR? a brighter EDR? Better signage and marking of EDR?

I totally accept that many intelligent and well-intentioned people from the fire alarm industry worked on BS7273-4 and I would never disrespect them for their efforts. However, my personal opinion is that BS7273-4 is complicated to understand due to it's efforts to make these systems as reliable as possible, and to some extent possibly recommending systems that are more complicated than they might have needed to be. That is, of course, only my own opinion, unless others agree with me.

[colin todd]

Big Al, I wasnt suggesting you check this in an FRA. I was explaining to Clevey that, if anyone wanted to check it, then it is not rocket science.

[Clevelandfire 3]

Well no it isnt rocket science Col. But it aint as easy as you make out either. How would you check Col give us a breakdown of what youd look for.

[colin todd]

Clevey, Check what exactly.  BS 7273-4 is a code of practice. It is like saying what would I look for in checking that a fire alarm system complies with BS 5839-1, or that a sprinkler system complies with the sprinkler EN. We do a good course on it if you want to fully understand it. And the course doesnt even take a whole day- we do it in half a day because there really isnt that much to understand.  If you read the code you will know what to check and how. Have you even looked at it.

[Wiz]

Wouldn't it be true to say that someone who is generally just 'inspecting' an existing installation, should mostly be concerned with inspecting any written certification that the original designer, installer, commissioner should have produced confirming that the installtion met the required recommendations?

Obviously, it would be a bonus if a simple test of the overall system could also be carried out by recreating the initial required 'start' process and checking that the 'end' result, but surely only someone who is fully conversant with all the recommendations can check that every aspect of an installation is correct?

[colin todd]

Thank you Wiz. I am glad somebody can understand simple principles.  Now all you have to do is get your head into BS 7273-4 and you are home and dry.

[Wiz]

Yes, Mr C.T. it is amazing that someone who is obviously as perceptive and intelligent as I am, cannot 'get his head into BS7273-4'. 

But it makes me understand why others struggle even more than I do. 


I am surprised that none of the 'assessors' responded to the point that they didn't really have to know the fine details of Standards such as BS7273-4. Surely, it was a weight off their shoulders?

None of us us can know everything about everything, but it is good to know which things are really important.