Evidence from Paul Hanson, RBKC Building Control Officer, regarding approval of the smoke control system at Grenfell Tower. Counsel examines Hanson's decision to approve PSB's technical submissions despite missing critical design documentation.
00:00:40 right well we'll resume now assuming that we've got contact with ms grange
00:00:46 grange hello yes hi hello mr chairman can you hear me
00:00:49 hear me we can and you can hear and see us i hope yes i can thank you good in that case we'll ask mr hansen to come back in would you ask mr hanson to come in please
00:01:12 right mr tansen are you all ready to carry on absolutely good thank you very much yes mr strange when you're ready then yes thank you yes can i just say it at the outset of this afternoon session mr
00:01:23 the outset of this afternoon session mr hansen
00:01:24 hansen um but can you try hard to stick to the answer to the question that i pose
00:01:31 i pose this afternoon just because i know you're trying to be very helpful but we are going to run out of time and not finish your evidence today if you keep on adding additional answers so can you try really
00:01:42 additional answers so can you try really hard to concentrate on the question i've asked you
00:01:44 asked you and to to answer as succinctly as you can
00:01:48 can and that would be great thank you okay so can we go to jsw7
00:01:55 at page three
00:02:10 jsw704 at page three
00:02:18 so this is an email from mr david bradbury of j s wright to mr mahoney of psb on the 11th of june 2015
00:02:27 2015 and he says this he says hugh paul hanson from building control has just called
00:02:32 called can we let him know asap if we mean the statement
00:02:36 statement highlighted in yellow or can it be deleted and resubmitted he wants us to basically delete it as it doesn't tie in with what we have discussed with him if we can respond quickly we can avoid
00:02:49 if we can respond quickly we can avoid him rejecting the ts i think that's technical submission thanks and then what he's done is extracted um part
00:02:57 part of psb's technical proposal technical submission below that from paragraph 1.1.2 and we can see that there is a sentence which
00:03:08 which is highlighted which reads i think it's meant to be it should be noted that as the system is designed to extract
00:03:16 extract air from the lobby via the open stairwell door the system is not designed to comply with all the requirements of the aforementioned code of practice and that aforementioned
00:03:27 code of practice and that aforementioned code of practice we can see is the code of practice bsen 12101 part 6 the specification for pressure differential systems
00:03:38 pressure differential systems and in the paragraph because in the paragraph before that it said that the velocity that's been chosen of two meters per second is in accordance with the recommendation for a class b
00:03:49 with the recommendation for a class b pressure differential system as defined in that code of practice yes yeah now can you recall um telephoning mr bradbury as this email indicates
00:04:00 indicates and asking him to delete that part of the technical submission um the conversation was asking a question
00:04:10 question actually do you want me to relate briefly
00:04:14 briefly um well just answer my question first did you ask him to take out that part of the technical submission to delete those words there
00:04:28 submission to delete those words there um because the the the the the the difficulty i've got is that there's two things mentioned you see and um
00:04:38 the simple answer
00:04:42 did you ask for something to be deleted from the submission
00:04:47 i suppose yes basically that the result of the conversation was that it should be deleted yeah because there's no what was it that you wanted deleted was it that sentence that we can see there that's
00:04:59 sentence that we can see there that's highlighted yeah so yeah do you want me to explain the reason why or yes or no um right so what he's actually saying is that air is going to be extracted
00:05:12 is that air is going to be extracted from the lobby via the stairway yes via the open stair which would imply that you're taking smoke from the lobby into the stairway now that is completely um that will not
00:05:25 now that is completely um that will not that's not what we're looking for so i run him up to say do you really mean what you say because if you oh that that system will not work and he didn't mean that at all it was a it was a mis
00:05:36 all it was a it was a mis wording or whatever so i say symbol then you shouldn't say that because that's not what you're doing and i reconfirmed with him
00:05:42 with him what the proposal was to extract from the lobby and the stair door being used as inlet air from the stairs and i think that was the mis the the the white word was was
00:05:53 mis the the the white word was was um badly worded basically to try and describe that so you didn't read that um it's designed to extract air from the lobby via the open stairwell door as suggesting
00:06:05 the open stairwell door as suggesting that the stairwell door was providing the inlet
00:06:07 the inlet air you read it as the the air would be extracted
00:06:12 extracted through the stairwell door and up yes yeah because it says via the open stairway door means by way off so it's stating that you're extracting
00:06:23 you're extracting smoke from the lobby by way of the open stairway door and that's um you know you don't want smoke in the circus basically if you're extracting that way
00:06:31 that way but that wasn't their intention at all it was just it was worded um not correctly i would say so hence the reason you wouldn't want to put this in the strategy because it's just wrong
00:06:43 strategy because it's just wrong yes i followed that but did you also ask for the second part of that sentence to be removed as well where it says the system is not designed to comply with all the
00:06:54 not designed to comply with all the requirements of the aforementioned code of practice we certainly discussion about that because the problem making a statement like that is that
00:07:03 is that that there are certain elements of that british standard that are referred to in um the sca guide so then becomes vague
00:07:12 vague um what you're talking about so i think your your answer to my question is yes is this right that you did ask
00:07:20 did ask for the words the system is not designed to comply with all the requirements of mentioned code of practice yes basically yes because it was misleading basically yeah why did you think that was
00:07:31 yeah why did you think that was misleading if in fact the system wasn't going to comply with all those requirements in that code of practice
00:07:42 see the thing is it's a confused um it's a confused um sentence um did did you think that the system was supposed to be designed to comply with
00:07:55 supposed to be designed to comply with the requirements of that code of practice
00:08:01 yeah yeah it no it doesn't because no so there are certain elements of that code of practice that is being used in this system um so clearly it doesn't comply with with the
00:08:13 clearly it doesn't comply with with the whole
00:08:14 whole standard but to mention it is too vague to say that it won't comply with the current so which part of it doesn't it comply you know
00:08:20 know you don't really want to say that in the specification because it it could be anything it doesn't comply with the critical requirements of compliance so it's just the wrong way of wording it basically
00:08:31 wording it basically but by taking it out entirely the reader isn't left with a clear impression that it's not been designed to comply with all of those requirements the reader is left with what you see in
00:08:42 the reader is left with what you see in the paragraph above which might suggest to some people that it has been designed in accordance with a class b
00:08:49 a class b pressure differential system do you see that
00:08:58 if i just clearly read the the paragraph
00:09:24 i mean the above paragraph is pretty good at describing what they're doing actually
00:09:28 actually um because it clearly states that it's a mechanical extract system and as we've previously established 12101 is actually a pressure differential system so you're
00:09:40 pressure differential system so you're clearly stating you're you're using a mechanical system and then it clearly states that in this instance you're using the value of the two meters a second in accordance with a class b um
00:09:53 in accordance with a class b um pressure differential system across the staircase
00:09:56 staircase so i felt that captured that paragraph captured very well and to then um add you're not fully complying with it it's pretty obvious this is about industry understanding if
00:10:08 this is about industry understanding if you're saying it's a mechanical electronic system it's not a depressurization system it's not a pressure differential system so that's very clear the focus here is taking the value of the two meters second as a performance criteria that
00:10:20 second as a performance criteria that you're going to prove on site and that was quite important i didn't want to track away from that by the vagueness of the paragraph the wrongness of the first part of it and the vagueness of the second part of that
00:10:31 the vagueness of the second part of that sentence
00:10:32 sentence well you say it's obvious that it wasn't a pressure differential system but what i'm suggesting to you is that because there's reference to that pressure differential system standard that code of practice
00:10:45 system standard that code of practice that if it wasn't going to comply with all of those requirements in that code of practice wasn't it very important not just for the you and psb at this time but for all future readers
00:10:56 at this time but for all future readers of this technical submission to understand clearly that it was not going to meet all the requirements of that code of practice wasn't that very important
00:11:11 he he
00:11:18 i mean if you wanted to say something like that you probably needed to word it differently um why didn't you suggest alternative wording rather than simply deleting it remember i'm building control so it's
00:11:29 remember i'm building control so it's not for me to get involved in how the design specification is written i was pointing out the misleading sentences i see but you've just
00:11:40 sentences i see but you've just suggested that part of it is deleted isn't that in getting involved in the submission
00:11:48 yeah i think we're we're crossing but if you're describing the system is extraction smoke through the stair you you've got to say you've got to not say that because that's not what the system is doing so yes i follow that i follow that mr
00:12:00 so yes i follow that i follow that mr hanson but i'm talking about the second part of that sentence which you have accepted you asked to be deleted because you thought it was unclear and what i'm suggesting to you is that in doing that you are getting involved
00:12:12 in doing that you are getting involved and if in fact it needed to be alternative wording that made clear that not all of that standard was complied with why didn't you do that instead
00:12:29 just to repeat your question is it um are you saying why didn't i suggest alternative text [Music]
00:12:38 [Music] to restate what they intended to state is that what you're yes that's what i'm suggesting is that if you thought it was unclear but the statement nevertheless needed to be
00:12:50 the statement nevertheless needed to be made why didn't you just suggest ultimately it's the desire to write the specification what i was um ringing about is that the two sentences were misleading and
00:13:01 the two sentences were misleading and unclear
00:13:03 unclear so it's not as though i give an instruction to the designer to delete you know they need to look at what they're writing and decide whether they need to write it in a different way right so i wasn't i'm not giving an instruction i can't
00:13:15 i'm not giving an instruction i can't give instructions i'm highlighting that if this was sent to us as a submission which it was then i can't approve it with it you know the wrongness and the vagueness basically
00:13:27 wrongness and the vagueness basically well let's move on and can we look at um now and what mr mahoney has said in his
00:13:33 his statement he's the designer of the system i want to go to his first statement first this is psb401329 at page five
00:13:51 and i want to look at paragraphs 24 and 25.
00:13:55 25. so he says this the design i developed was for a depressurization system in other words a system which achieves smoke control using depressurization principles achieved by
00:14:07 depressurization principles achieved by mechanical extraction depressurization systems are one of the most common types of smoke control system used in buildings in the uk
00:14:14 uk they are designed to deliver protection to the protected space in this case the stairwell
00:14:19 stairwell by extracting air and combustion products from the common lobby to create a pressure differential and opposing air flows between the stairwell and the common lobby now just pausing there
00:14:30 lobby now just pausing there was that your understanding of how the system was designed right well the the this again we've got a terminology issue here because it's not a depressurization system um
00:14:44 depressurization system um so if we just pausing there you say it's not a depressurization system do you accept that by having mechanical extraction through the lobby vents north and south
00:14:56 through the lobby vents north and south south shafts you would by definition be depressurizing the lobby do you accept that um you are but because the industry has a
00:15:07 you are but because the industry has a specific definition for depressurization in one two and one part six um use of that term would mislead um the reader to believe that it is one of those systems so it's
00:15:19 that it is one of those systems so it's all about terminology but what it is it's an extract system um you almost don't need to say depressurization but but even my question did you
00:15:30 but but even my question did you understand that the consequence of it being a mechanical extract system was that it would depressurize the lobby did you understand that at the time
00:15:41 did you understand that at the time the term depressurization isn't something that entered my mind because the way these systems work is that's not the objective the objective to do something else what is the objective as far as you
00:15:53 what is the objective as far as you understand it is to remove smoke from the lobby to avoid smoke entering the staircase i see and then he says in paragraph 25 the
00:16:05 and then he says in paragraph 25 the system at grenfell tower was designed so that when smoke was detected in a common lobby causing the system to function in smoke control mode extract fans would operate to extract air and combustion products from the
00:16:17 air and combustion products from the affected common lobby via the shafts this would reduce the air pressure in the lobby
00:16:22 the lobby and therefore create a pressure differential between the lobby and the stairwell
00:16:27 stairwell while the door between them remained closed preventing smoke from migrating into the stairwell now is that consistent with how you understood the system was going to work again we're
00:16:38 the system was going to work again we're using terminology the the idea of um the the stegos being kept clear of smoke by airflow being pulled effectively from the stairway
00:16:50 stairway is in fact how the stairway isn't affected
00:16:54 affected and it by pure coincidence both the pressurization principle around the staircase door and the sva
00:17:04 the sva extract system work have the same principles right i see if you see let's look at what he says let's look at what he says in his second statement now if we can go
00:17:15 in his second statement now if we can go to psb
00:17:16 to psb four zeroes one three seven three at page eight
00:17:24 and i want to look at paragraphs forty and forty one so he says he's given us some explanation before he says it follows i did not design a pressure differential system which are
00:17:35 a pressure differential system which are designed to comply with all the requirements of bsen12101 part six and then he says at 41 my design reflected a more common type of mechanical extract
00:17:47 mechanical extract depressurization system a performance based
00:17:50 based building appropriate solution widely adopted as a type of smoke control system
00:17:56 system and which were often referred to within the industry as depressurization systems and is commonly called the colt shaft mechanical shaft system do you see that there i do
00:18:08 shaft system do you see that there i do now um in terms of paragraph 41 did you understand that this was going to be a performance based building appropriate solution
00:18:19 appropriate solution uh yes and did you understand it to be a system that was often referred to within the industry as a depressurization system i wasn't aware that the term
00:18:31 system i wasn't aware that the term depressurization is misused in the industry
00:18:35 and when you were aware that it was commonly called the cold shaft mechanical shaft system um yeah yeah we're aware of the the cold shaft system is actually not
00:18:47 shaft system is actually not um you know it's not a residential system actually it's i didn't regard that as relating that to residential systems to be honest with you so probably the answer is no i suppose did anybody anyone say to you
00:19:00 i suppose did anybody anyone say to you at the time when you were receiving these proposals that it was the system was commonly called the colt shaft mechanical shaft system no no i don't remember that at all
00:19:16 now the technical submission that psb prepared we'll go to revision three of it in a moment that you approved can we agree that it doesn't make clear that psb
00:19:27 that psb are adopting a performance-based building solution
00:19:38 building solution we saw we saw that the key paragraphs from that just a moment ago
00:19:44 oh i see right yeah right you're not going to show me anything else i'll tell you what let's look at revision three so this is psb 50209
00:19:58 this is the 12th this was issued on we can see from the revision history in the table
00:20:04 table it was issued on the 12th of june 2015. yes and it says sorry can i continue it says paragraph removed from 1.1.2 that was the paragraph that we were just
00:20:15 that was the paragraph that we were just looking at and this is revision3 we'll see an email in a moment where we can see that you approved this submission and said it was satisfactory but if we just go to page three
00:20:31 and we look at 1.1.2 where we get the smoke control proposals we can see there that the first paragraph is as per
00:20:43 there that the first paragraph is as per the extract we were just looking at the final splint control system designed to provide the existing stairwell with protection from the ingress of smoke from a fire within a dwelling by means of a mechanical extract system
00:20:55 by means of a mechanical extract system system has been designed to provide an average open door velocity across an open lobby stairwell door of two meters per second this velocity is in accordance with the recommendation for a class b pressure pressure differential system as
00:21:08 pressure pressure differential system as in that code of practice bs 12101 part 6 specification for pressure differential systems and then the next paragraph which said it didn't comply with all of that code
00:21:19 it didn't comply with all of that code has been deleted and it goes on and says the smoke control measures will be implemented in two phases um phase one to reinstate the natural
00:21:30 um phase one to reinstate the natural system and then
00:21:36 and then it goes on at the bottom the plc control system will have links to the new fire alarm system to provide initiating signal once the signal is received over all the
00:21:47 once the signal is received over all the dampers in the smoke affected lobby will open and all dampers on other floors are to remain closed and then if we go over the page
00:21:59 the page we can see that it's talking about what the components of it will be there'll be an hmi human mechanical interface panel will be override switches etc so that's
00:22:11 will be override switches etc so that's what we see in this technical specification about the design basis so just to ask you the question again this does not make clear does it that psp are proposing a
00:22:23 proposing a performance-based building specific solution i think it doesn't say that does it
00:22:30 does it it doesn't use those words but that is what the two meters the second paragraph is describing
00:22:39 i see that's what that conveyed to you did it it does yeah it does not make clear that it was or it equated to the cult shaft system that's not stated anywhere is it
00:22:51 anywhere is it um i'm not quite sure how the cult system is relevant no and it doesn't make clear that it did not comply with all of the requirements of bsen12101 part 6 because that had
00:23:02 of bsen12101 part 6 because that had been deleted yes yes because it is not a pressurization depressurization system the the if we're looking for where the performance criteria is
00:23:13 performance criteria is it's it's the paragraph that states the velocity past the door which is a a test of the building um yeah so let's go back to that what you're i think what you're trying
00:23:24 what you're i think what you're trying to say is that the performance criteria for this system is in that first page we go one page back to the bottom of page three
00:23:36 back to the bottom of page three you're saying that the performance criteria was that single criteria yes providing an average open door velocity across the lobby stairwell door of two meters per second
00:23:47 stairwell door of two meters per second yes
00:23:47 yes yes that's the performance criteria is it
00:23:50 it that's performance criteria yeah yeah and that i see that's what they would need to meet on site in order for the system to achieve the objective of stopping smoke perfecting the staircase and just that
00:24:02 perfecting the staircase and just that yes
00:24:04 yes yes nothing else when you say it depends on the context of your question that this is a um a test that's carried out that show that the objective is achieved
00:24:16 that the objective is achieved um so providing the two meters a second criteria is uh regarded as um suitable and appropriate i we can rely on it then if the system achieves that objective then it achieves
00:24:27 achieves that objective then it achieves the objective of keeping the staircase clear
00:24:30 clear of smoke i see and you say it's a test that's carried out that shows that the objective is achieved was that the only objective of this system to keep the stairs free from smoke
00:24:44 um
00:24:49 i'm not quite sure where are you leading to
00:24:52 to um you talked about that being a performance objective to keep the stare free from smoke and i'm asking you was that the only performance objective you were aware of for this system
00:25:07 there was a consideration of the the lobbies relating to a a prescriptive natural system
00:25:18 a a prescriptive natural system in the you know can you consider
00:25:22 how much smoke ends up being in in a natural system compared with a mechanical system
00:25:30 when you say that there was a this is important
00:25:34 important when you say there was a consideration of the lobbies relating to a prescriptive natural system
00:25:40 system in that you know you consider how much smoke ends up being in a natural system compared with a mechanical system where do we see that anywhere in the technical submissions
00:25:51 technical submissions that you looked at and approved yeah i don't think it is stated no so there's no consideration of what the conditions in the lobbies would be is there
00:26:02 is there more apart from the performance of the system
00:26:06 well you've said the performance objective of the system was to keep the stair clear where do we see the performance objectives for the lobby
00:26:19 well it's not directly mentioned no now if we go on to jsw401747
00:26:37 now if we go on to jsw401747 we can see this should be an email dated the 24th of june 2015 in which um you confirm that the proposals are satisfactory so we can see
00:26:49 proposals are satisfactory so we can see you say
00:26:49 you say hi dave to mr bradbury of jsright please find attached my comments regarding the smoke control system for the stairway lobbies
00:26:57 lobbies the proposals for which are satisfactory so
00:27:00 so you appear to be there confirming that in revision three of the technical submission that we were just looking at the proposal was satisfactory is that correct
00:27:09 correct that's correct yeah and in the accompanying memorandum which we can see at page two of this document
00:27:23 we can see that you also say just before the numbered paragraphs halfway down the proposals outlined in technical submission revision three that's the one we just looked at are satisfactory and then you make
00:27:37 are satisfactory and then you make three points and in the final point you say at point three you say generally the components of the system should confirm form to the guidance on smoke control
00:27:48 smoke control to common escape routes and that's the sca guidance 2012 yes that's great yeah you're saying that the components of the system should comply with that guidance yes
00:27:59 should comply with that guidance yes yeah
00:28:01 yeah did you ever record any additional reasons as to why the proposal was approved
00:28:07 approved in essence this is all we can see in the documents
00:28:11 documents about your your reasoning as to why you were content with this proposal do you remember ever recording anything else in writing no no
00:28:28 now just for completeness if we look at cst four zeros one two three zero we can see a further memorandum from you
00:28:40 we can see a further memorandum from you to mr hoban dated the 26th of january 2016 in which again in which you've approved revision 3 subject to some comments
00:28:51 revision 3 subject to some comments and if we look at the three short points which appear at the top of page 3 on the smoke control system
00:29:02 we can see it's exactly the same three comments we were just looking at
00:29:08 do you see that there so again the same comments repeated in the final one about the components of the system complying with the sca guidance
00:29:21 now you tell us in your witness statement
00:29:24 statement that you approve this submission regarding the smoke control system which you
00:29:29 you say was you agreed was acceptable subject to these three comments when you say it was acceptable do you mean that you considered that the proposed smoke control system was compliant with parts b1 and b5 of the building
00:29:42 parts b1 and b5 of the building regulations functional requirements
00:29:47 is this because of my heading b1 only is that the visual well i i want to understand whether you considered that this system did comply with parts b1
00:29:59 with parts b1 and b5 yes yes the building regulations
00:30:04 now i'm going to come back in a moment to ask you some more detailed questions about the design of the system but just moving forward with the chronology of what occurred on the project for the
00:30:15 of what occurred on the project for the moment
00:30:17 moment if we look at paragraph 62 of your first statement
00:30:20 statement at page 11
00:30:31 you tell us in this paragraph
00:30:35 that um you attended a working demonstration of the system you say although
00:30:40 although commissioning certification had been issued i knew from past experience visiting other sites that there can be problems with inlet air functioning properly i suggested to john hope and
00:30:51 properly i suggested to john hope and the area surveyor that we attend a working demonstration of the system alan white from js wright the smoke control system installers also attended to demonstrate the system on the 4th of may
00:31:01 may 2016. now can you help us what exactly did that demonstration involve it was um a sequence operation so basically it was
00:31:14 operation so basically it was showing that everything happened in the right sequence so therefore set the detector off in the lobby
00:31:21 lobby does it activate the power ventilation system on the floor that the signal was generated are the dampers on the other floors
00:31:29 floors kept closed and any necessary inlet air in this case it was it was permanent would operate but as it was permanent it didn't need to operate
00:31:41 and did you actually go to multiple floors in the building and look at whether the dampers were open or closed in accordance with how the systems would be operating yeah yeah how many how many floors did
00:31:53 yeah yeah how many how many floors did you look at can you recall off the top of me i can't it was a few it was just a random view jumping just playing background i know
00:32:04 jumping just playing background i know you don't want to go on but don't explain the background about why i did this
00:32:07 this test briefly right yes so we we didn't have a mechanical ventilation engineer um who had been made redundant so we
00:32:18 um who had been made redundant so we were relying on the commissioning report um this was the first job we'd ever done
00:32:23 ever done without a mechanical ventilation engine and i felt uncomfortable um walking away from the job without seeing that the system worked in its basic function so it
00:32:34 worked in its basic function so it wasn't the intention here to do to repeat the commissioning which already had so the simple test is making sure everything works in the order it's meant to work
00:32:46 order it's meant to work and that was the intention of that of that test
00:32:49 that test and it really was going outside of management guidance because with the loss of the brag engineer we weren't um [Music]
00:32:57 [Music] expected to go down and witness commissioning or any kind of inspection but i just felt myself that i should um to be comfortable to see it working so i suggested it to the areas area
00:33:11 what were any measurements taken on this occasion
00:33:15 occasion no no measurements no it was purely a secret testing basically yeah did you at this stage or any other point confirm or witness the physical path of the air movement away from the
00:33:26 path of the air movement away from the stair
00:33:28 stair no well why not so the air path away from the stair um i mean when you're in the lobby you can feel the extract um blowing um are you referring to the
00:33:40 um blowing um are you referring to the smoke test that barrel menzies suggests well i'm coming to that yes i want to know whether there was any attempt to confirm the physical path of air movement away from the stair during this
00:33:53 movement away from the stair during this test and it sounds like there wasn't because it was just a sequence test is that right yeah absolutely i i mean with an extract system um in that building you had two shafts
00:34:04 um in that building you had two shafts um
00:34:05 um with an air puff extractor of both showers so it's pretty obvious that the air path is going to be away from the staircase there wasn't an issue with maybe one of the one of the extract points was near
00:34:17 the one of the extract points was near the staircase there could be a problem with
00:34:20 with [Music]
00:34:21 [Music] the flow going in the wrong direction there wasn't a reason to and it isn't contracted to do such a test anyway did you confirm that there was no significant inflow from other leakage
00:34:33 significant inflow from other leakage paths such as from the fire flat
00:34:37 it was a sequence yeah so to understand this it's a secret yes yes or no did you confirm that there was no
00:34:44 was no significant inflow from other leakage paths such as the fireplace for a sequence test you wouldn't need to do that so i i i didn't you know it's not needed for what i was doing i was doing a simple
00:34:56 what i was doing i was doing a simple yeah okay i understand that did you speak with the commissioning engineer at any stage
00:35:02 any stage yes the what commissioning engineer yes mr brownville partlow of psb did you actually speak to him no i didn't no no and the chap who come down
00:35:13 down and showed the um or carried out the sequence testing um he if he was a different person from memory i can't recall um but i spoke to that chap
00:35:26 recall um but i spoke to that chap but not necessarily at least the do you actually see the operation of the dampers
00:35:34 dampers during that test did you actually see them operate to move yeah we did yeah yeah were you showing any aspect of the hmi human mechanical interface panel
00:35:45 hmi human mechanical interface panel in the lobby that operates the system
00:35:49 i mean i was not doing a breg what we would call the cat electrical engineer check
00:35:55 check at all so i i wouldn't have um that's not the purpose of that simple check
00:36:03 check yeah um can we look at clause 9 of the sca guidance at this point this is rbk402932 at page 56. this is the 2015
00:36:16 at page 56. this is the 2015 sca guide
00:36:28 so um this is under the head in commissioning and acceptance testing and in the second paragraph it says as smoke control systems are primarily life safety systems and or for the
00:36:39 life safety systems and or for the assistance for assistance to the fire and rescue service it is imperative that the smoke control system is tested by the installer and then offered for witness testing to
00:36:50 and then offered for witness testing to the appro to the authority having jurisdiction to prove its compliance with the project specification and the approved design criteria do you see that there i do yeah and were
00:37:03 do you see that there i do yeah and were you aware of that part of the sca guide when you did your visit on the 4th of may 2016
00:37:12 um the the yeah the question this is a a particularly important element in the normal practice would have been for the mechanical electrical engineer employed
00:37:23 mechanical electrical engineer employed by building trial to go down and carry out that function so what happened is as as bunch of department had made the mechanical electrical engineer redundant
00:37:35 redundant that function was no longer possible so the management arrangement was that we accept
00:37:39 accept the commission civic without going down there and witnessing the test so to go back to your question i chose to go down there to satisfy myself that everything worked
00:37:50 to satisfy myself that everything worked in sequence but not to witness um was described in that paragraph yes i see so i think what you're saying is because you didn't have a mechanical electrical engineer
00:38:02 electrical engineer this part of the sci guidance wasn't followed is that correct
00:38:07 yes yes yes you're correct yeah because because no one actually went down there i was doing uh something different to this basically my simple simple witnessing of
00:38:19 basically my simple simple witnessing of the
00:38:20 the sequence yes so if if we were to look at the detailed list of um checks that have to be carried out under this guidance for either a pressure differential system
00:38:31 pressure differential system or a mechanical extract system those tests were not carried out in your presence where they're you're correct there weren't no
00:38:42 were you aware that carrying out a cold smoke test is important in any system where there is extended
00:38:49 extended travel distances i'm no i'm not aware of that
00:38:53 that i mean it can be a useful guide if there are concerns about particular circumstances in the job but the cold smoke test isn't as far as i'm aware of standard procedure but it's a tool that can be used where
00:39:05 but it's a tool that can be used where um i i mean i have used it on some jobs where there is some concern but it isn't a standard um a standard thing you do well if we look at miss menzies report
00:39:16 well if we look at miss menzies report um
00:39:17 um at um bmer 607
00:39:23 607 page seven paragraph 31
00:39:30 she says paragraph 31 in my experience systems installations that have not been subject to modeling are generally demonstrated on site using a cold smoke test to illustrate the directional flow of
00:39:41 to illustrate the directional flow of smoke the speed of dispersal and level of
00:39:43 of visibility and then she said whilst this will not
00:39:47 will not fully and if we go over the page replicate an actual fire situation it will be indicative as far as i can ascertain this was not undertaken suggested so she's saying in her experience this
00:39:59 so she's saying in her experience this kind of cold smoke testing is carried out but you're saying that's not your experience is that right yeah i agree yeah
00:40:12 do you agree that using a cold smoke machine can help evaluate the system's efficiency and identify any dead spots in the system in terms of ventilation
00:40:25 system in terms of ventilation it can do but it's it's a very incomplete type of test um you know because wouldn't that have been appropriate at grenfell tower
00:40:36 grenfell tower given first the extended travel distances in the lobbies
00:40:52 distances in the lobbies i'm not quite sure how to praise the answer um
00:40:57 answer um so what you're really saying is that the there's a belief that the the extract system
00:41:04 system might not have performed adequately compared to what we expected a prescriptive um natural vent system no that's not quite that's not quite what i'm saying can we look at a diagram this might help
00:41:15 can we look at a diagram this might help me
00:41:15 me put these points to you if we go to a diagram at blas 5037 page 25. this is from dr lane's phase one
00:41:28 this is from dr lane's phase one supplemental report and there's a figure there
00:41:31 there 15.5 b
00:41:35 15.5 b so if we can zoom in on the figure that she's included there here we can see the arrangement of the lobbies from levels 3 to 23 at grenfell tower
00:41:46 tower we can see the flats around the outside and we can see dr lane's travel distances
00:41:51 distances are marked in blue and blue lines do you see those yup and you can see that to go from flat four
00:41:58 four in the middle on the left she's measured a 10.3 meter travel distance do you see that
00:42:05 that yeah now in fairness to you the bre report following their survey at the tower for the transcript that's met 3039807
00:42:16 3039807 page 24 paragraph 32 they measured 9.3 meters
00:42:21 meters not 10.3 but whether it's 9.3 or 10.3 that was an extended travel distance wasn't it compared with the 7.5 maximum
00:42:32 wasn't it compared with the 7.5 maximum in
00:42:32 in adb yes yeah it was and it was an existing situation here yes but mr hansen did you actually ever think about that extended travel distance
00:42:44 extended travel distance at grenfell tower were you aware of it did you have it in mind when you approved the proposals for the smoke control system i mean i was aware there were distances
00:42:55 i mean i was aware there were distances in the building that wouldn't follow the guidance of today
00:42:59 today definitely yeah you were aware did you ever measure the distance yourself so you knew exactly what the travel distances were yeah i did yeah yeah you did
00:43:10 yeah i did yeah yeah you did did you ever record that in a document um we're talking about the distances which level are we speaking about well this is
00:43:20 this is all levels levels 3 to 23 can we have the diagram back up perhaps this is this is the lobby arrangement for all of those levels
00:43:33 did you ever did you ever get a tape measure out and actually measure the travel distances i wouldn't say i did on the upper floors the the lower floor was really replicating the same sort of layout so
00:43:45 replicating the same sort of layout so you had
00:43:46 you had um distances in that order right did you ever ask anybody what the travel distance was for the upper floors between levels 3 and 23 of the tower
00:43:57 between levels 3 and 23 of the tower i didn't know did you note the geometrical configuration of this lobby we can see that it's an eye shape so you've got a kind of narrow corridor down the middle where you've
00:44:09 corridor down the middle where you've got the stair door and the lifts and then you've got corridors off uh off that so it's like a it's like an eye do you see that i mean what's significant about this
00:44:21 i mean what's significant about this layout is that you have the the ventilation at either end of the corridor
00:44:26 corridor well you have it at either end of the middle of the corridor it's not down the end is it it's down the middle it's at the top and the bottom
00:44:35 bottom yeah if you were to compare that to a natural system um where you have um 7.5 meter corridors the vent can be positioned um
00:44:46 corridors the vent can be positioned um in fact it's encouraged to be positioned near the staircase so you do end up with in the prescriptive case with corridors that effectively um you will get some smoke logging at the end
00:44:58 logging at the end and this is just how systems of how the the design of smoke control systems have or not smoke addresses natural system have evolved yes i understand that but i'm really
00:45:09 yes i understand that but i'm really interested and and i wanted to try and focus your answers on what you appreciated at the time you were signing off on this smoke control system
00:45:17 system and saying it was acceptable did you think about the layout of these lobbies including the eye configuration and in particular whether that might mean there could be dead ends or dead yeah i did yeah
00:45:29 dead ends or dead yeah i did yeah absolutely yeah yeah because it's all did think about that it's obvious yeah and did you ever write down any assessment of why you thought despite that it was still acceptable i i i didn't write it down no no
00:45:41 i i i didn't write it down no no it's not really the normal process to analyze every single thought process um
00:45:49 that's all i could but but where you've got an extended travel distance mr hansen
00:45:54 hansen shouldn't there be a clear record of why the system is nevertheless satisfactory in terms of conditions in the lobby
00:46:10 no so perhaps added information would have been would have been helpful um yes if we go to an email um jsw402945
00:46:24 um jsw402945 and we look at an email second email down from the top from you to mr hughes at ryden copy to mr white
00:46:33 mr white at jsright and you say hi david the figures you've sent do not appear to be extract readings they should be in meters per cube per second the readings you've sent are
00:46:45 per second the readings you've sent are velocity readings we'll come back to that in a moment and then you say after that remember that the testing of the powered vent system we are witnessing tomorrow should be in accordance with section 9 and item
00:46:57 accordance with section 9 and item and then there's no item specified of the attached sca guide do you see that there yeah
00:47:05 and by this stage were you working from the 2015 sca guide can you help us on that no um the the way um the date of documents
00:47:17 the the way um the date of documents works is this the date of the application of the um the proposal which was 2014. so so we wouldn't have been able to say you should then use the
00:47:28 you should then use the a guide that come out after the date of application there's a general principle of in bullet trail i think barrel menses mentions this yes i see we'll come back to a couple of
00:47:39 yes i see we'll come back to a couple of specific
00:47:39 specific parts of that sca guide in a moment when we're when i'm asking you some more detailed questions about the design of the system but just finishing off now with with what happened in terms of
00:47:50 what happened in terms of the actual process during the project if we go to psb 50214 this is the final version of the psv technical submission
00:48:02 technical submission which was revision 6 dated the 15th of march
00:48:07 march 2016 we can see that in the revision history
00:48:10 history table and if we go to the bottom of page three
00:48:15 three the description of the system remains identical to the description we had before
00:48:27 the description we had before so that there was no change in terms of the basic description of the system there was no change and we can see if we go to rbk403778
00:48:38 and we can see if we go to rbk403778 that this revision 6 was sent to you by mr hughes of ryden on the 3rd of may 2016 ahead of the demonstration that you then witnessed on the fourth of
00:48:50 that you then witnessed on the fourth of may
00:48:52 may so technical submission that was we know that that was revision six you can see that in the subject heading do you remember ever considering and reading carefully that version of
00:49:03 and reading carefully that version of the technical submission yeah i did yeah it was basically accompanying the commissioning report so it was kind of supporting the commissioning report but i i did note that there were some changes that um
00:49:15 that there were some changes that um yeah
00:49:16 yeah there were changes in that weren't really significant to the right if we go to psb 50224 this is the commissioning report you were just referring to
00:49:27 were just referring to dated the 28th of april 2016.
00:49:33 this is the psb above ground commissioning report we can see at page seven it's signed by mr partlow and mr white for j.s
00:49:44 by mr partlow and mr white for j.s wright we can see that at the bottom
00:49:48 and it appears to have been accepted by building control because we know that a completion certificate for the entire works was then subsequently issued now what i want to ask you is
00:50:01 issued now what i want to ask you is that after this report was produced so this report we can see has been signed off in april 2016. building control then recommended
00:50:12 2016. building control then recommended changes to the system on the 2nd of june 2016. we can see the letter requesting the changes to the system at rbk if we bring this up
00:50:25 two two rbk3013224
00:50:34 it's dated the second of june 2016
00:50:39 and if we can look at point five of this letter
00:50:42 letter it's sent to ryden it says this various openable windows within the main entrance lobby to grenfell tower area required to be linked to the main powered ventilation system for the
00:50:53 powered ventilation system for the building
00:50:54 building so that such windows open on operation of the system and provide makeup air at the bottom shaft for the system so that's what's being requested by building control is it's an adjustment
00:51:05 building control is it's an adjustment to the bottom of the smoke control system
00:51:08 system or the configuration of it so that there's more make up air at the bottom shaft now
00:51:16 shaft now um do you want me to clarify what that means
00:51:19 means because you mentioned the term shaft sorry
00:51:22 sorry maybe that i apologize that may have been inaccurate please do well it says bottom shaft for the system provide makeup air at the bottom shaft of the system i think that's why i said that but you wanted to clarify exactly what was
00:51:35 you wanted to clarify exactly what was being requested by building control okay so after our um witnessing of the what i call the sequence testing you know detector damper opens inlet air
00:51:47 detector damper opens inlet air opens or is available when we got down to the ground floor there was a lobby there that as existing
00:51:54 existing didn't have any ventilation at all so just a little bit of background to this generally speaking if i see something that could have been improved in the
00:52:05 that could have been improved in the building i mentioned it to the design teams i think it was the architect at the time we went around the building early on i noted there was no ventilation to this lobby on the ground floor
00:52:13 floor and i think it was to a piece of plant so i suggested well part of the the process of the work you're doing on the building you could take your ventilation shafts down
00:52:24 shafts down to serve this lobby and then you would have a ventilated lobby at that point so this isn't something we couldn't ask for under the building rigs but it was an improvement so anyway they did they did do that so
00:52:36 so anyway they did they did do that so when we went down and witnessed the sequence testing i noted there was no inlet air path from the stairway to this ground floor lobby because the configuration the stairway was such there was a
00:52:47 there was a a door and screen between the normal steering net path i think so therefore thank you so what we're really saying then is that in order for the lobbyists do you understand i think yeah i think
00:52:59 do you understand i think yeah i think we understand um but the point i'm getting at is this well first of all perhaps you can confirm
00:53:05 confirm who was it within building control that was responsible for considering the commissioning report and then issuing the final building control completion certificate
00:53:16 completion certificate we see that certificate at max four zeros two six five five right okay so um so who was it first of all that considered the commissioning
00:53:27 considered the commissioning commission the systems commissioning report and thought that that was acceptable yeah so i looked at the commissioning report within the limitations of not having a break engineer to support me on that then
00:53:39 to support me on that then i then informed the areas of r that that's
00:53:43 that's acceptable under a new scheme um and then the areas of that would then have
00:53:49 have um did you say the completion certificate
00:53:54 yes then issued the final completion certificate if we look at that max can we bring it up max four zero two six five
00:54:01 six five five it's signed by john allen we can see at the bottom yeah so the completion certificate is um issued by the area surveyor um the john allen's signature is is
00:54:12 um the john allen's signature is is basically a department signature that goes on all the letters so who was responsible for in fact issuing this certificate if not john allen was it mr hogan yes you're correct yeah
00:54:23 you're correct yeah right so does it amount to this you approved the commissioning report but mr allen
00:54:30 allen issued the final building control completion certificate sorry mr hobin the final building control
00:54:36 control completion certificate yes the latter of what you said yeah yeah yeah so but back to back to this point about changes being asked for in the system
00:54:47 system the commissioning report is dated april 2016
00:54:51 2016 that you asked for changes to be made to the system at the lower levels on the 2nd of june 2016 why wasn't there a commissioning report requested for the final system
00:55:03 requested for the final system right i see right okay so the take the aov
00:55:07 aov that was added to the staircase on the ground level um that there's two angles to this the the airflow
00:55:15 airflow values that were produced for the commissioning showed that the lobby did in fact achieve the two meters a second at that level
00:55:24 level i think it was more than 2.9 or something
00:55:27 something so what i was actually saying is you despite that you've actually got no inlet air path to the staircase to sustain that so what we were saying is you if you add the in
00:55:38 we were saying is you if you add the in the aov it would sustain the inlet air path
00:55:42 path so you thought it would make it better so you didn't insist on a further commissioning certificate is that correct
00:55:47 correct exactly yeah so there seemed to be little point there's another reason as well actually there seemed little point in getting to recommission the whole system because it would not have made it worse it would have made it better but the second point is remember that as
00:55:59 but the second point is remember that as i mentioned just now the this lobby at ground level is not something we could have asked for the system to be extended down to serve because it was existing so they were adding to the system
00:56:10 adding to the system so um that basically was the reason yeah um were you notified that the necessarily the necessary
00:56:21 that the necessarily the necessary regulation 38 fire safety information had been passed to the responsible person about the control the the smoke control system
00:56:30 system um i mean it's not my role to deal with regulation 38. so you never thought about regulation 38 i wouldn't have thought about it because it's not my
00:56:41 it's not my in my consultancy role if yeah in the consulting role doesn't involve giving advice on regulation 38. yes i say and just back to the com the
00:56:52 yes i say and just back to the com the commissioning certificate just one point of clarification what does that commissioning certificate actually demonstrate can we agree in particular that it wouldn't cover for example the fire resistance of the dampers to
00:57:05 the fire resistance of the dampers to maintain compartmentation absolutely yeah it wouldn't cover that at all no basically the commissioning is showing that um the system operates as it's meant to do but it's not a
00:57:18 as it's meant to do but it's not a qualification of equipment um or construction standards at all yes i understand
00:57:27 now um i'm going to ask you some more questions now more detailed questions about the final design of the smoke control system and what aspects of the system you actually thought about and checked prior
00:57:40 actually thought about and checked prior to approving that system as satisfactory
00:57:45 now we've seen that um the technical submission that you approved states that the system was to provide the existing stairwell with smoke protection from fire in a dwelling now just to be
00:57:57 from fire in a dwelling now just to be absolutely clear did you understand that the sole function of this system was to protect the stairs from smoke entering from fire in a flat
00:58:18 i'm just trying to equate the question so you're talking about a performance standard for the for the door but was there anything else you you're you're saying
00:58:29 you're saying yes was there any performance standards for anything other than the door to the stairs that was the yeah that was the only performance center for the door to the stair i see if we can look at the sca guidance
00:58:42 i see if we can look at the sca guidance now so we know that your evidence is that the system should have been designed in accordance with this guidance and we can see we've seen emails where you sent this sca guidance to professionals on the
00:58:53 sca guidance to professionals on the project
00:58:54 project if we can look at the 2015 version at
00:58:59 rbk402932
00:59:03 i want to look at page six clause 2.1
00:59:19 i want to look at page six clause 2.1 so this is under a section at the beginning of this guidance that's called primary objectives and we can see in the second paragraph it says where the travel distances are no more than 7.5 meters in distance
00:59:31 no more than 7.5 meters in distance from the door to the staircase or sterile lobby to the most remote apartment entrance door so at grenfell tower to the flat 4 the primary
00:59:42 grenfell tower to the flat 4 the primary objective of smoke control in residential buildings is to protect the staircase enclosure by ensuring that the stairway remain relatively free from smoke and heat in the event of a fire within a
00:59:53 heat in the event of a fire within a dwelling
00:59:55 dwelling do you see that yes and then if we go two paragraphs down from that it we can see it says however where corridors are extended the primary objective of the smoke
01:00:07 the primary objective of the smoke control system is to protect both the common corridor and the staircase enclosure
01:00:14 enclosure there are considered to be two forms of extended corridors and there's extended typically no more than 15 meters and then significantly extended which have more than 15 meters travel distance
01:00:27 than 15 meters travel distance were you aware of this part of the 2015 sca guidance when you worked on the grenfell tower project yes i was yeah
01:00:37 and i've asked you what you were aware of in terms of travel distance before we've looked at the layout of the lobbies in grenfell town we've seen that they are
01:00:46 they are somewhere between 9.3 and 10.3 meters is the is the longest distance to the stairs from the furthest flat do you accept looking at this guidance
01:00:59 do you accept looking at this guidance that as the travel distance was more than 7.5 meters it was not permissible to treat protection of the stair as the primary objective
01:01:08 objective and instead the primary objective should have been protection of both the common corridor in this case the lobby
01:01:16 the lobby and the staircase
01:01:20 um effectively it should take consideration of both cases yes
01:01:26 cases yes that's the yeah yes if we're following this part of the sca guide yes yeah and can we agree that nowhere within the design documentation or
01:01:38 within the design documentation or nowhere within any of your notes do we see any consideration of the objective
01:01:44 objective of protecting the common corridor as distinct from the staircase not in documentation no i mean there was that something that you
01:01:55 i mean there was that something that you was that something that you actually thought about at the time you were approving the grenfell tower system basically you is what we regard as a qualitative decision not based on
01:02:08 qualitative decision not based on any kind of modeling or anything in that nature what you had is a building that was existing that had an existing a very old smoke control system
01:02:19 smoke control system and the objective was to replace it with a system
01:02:22 a system reasonably bearing in mind the limitations of the size of the shafts etc etc
01:02:27 etc etc to provide a system that
01:02:31 at least achieved what the building did have and actually in some cases improved it
01:02:36 it so it's one a point that will make it quite clear is that where you have a natural system so the natural 1.5 ventilator to the lobby
01:02:47 lobby you get a lot of smoke in the lobby basically
01:02:50 basically and therefore um they there's no requirement for tenable conditions um this is just has the case exists and generally speaking smoke would spread from the lobby into the staircase
01:03:01 spread from the lobby into the staircase as well
01:03:03 as well so here we're actually having a system that has
01:03:06 that has effectively a better level of protection to the staircase because we're using the objective of the two meters a second to stop smoke affecting the staircase we're in a natural system it would affect the stair in relation to
01:03:18 it would affect the stair in relation to the
01:03:19 the means of escape you have existing corridors
01:03:22 corridors and your positioning of your ventilation at the end of those corridors will be significant compared to a natural system whereby maybe the ventilator is located elsewhere so it's really a case of when
01:03:35 elsewhere so it's really a case of when you have an existing building it's it to actually apply new standards though it's a new building becomes unreasonable um so that was really the the decision
01:03:48 the thing is it's difficult to quantify something like this um because you're looking for a quantifying element to it basically i'm not looking for that mr hanson
01:03:59 for that mr hanson i'm looking to understand why we don't see anything like what you just said set out in any of the design documentation to explain what the thought process was about
01:04:10 what the thought process was about protecting the stair and protecting the lobby
01:04:14 lobby yeah maybe it's it's a criticism that that he should have if we look um at for just for a moment clause
01:04:23 clause um something in bs triple nine one two thousand and eleven this is at bsi five zero six two one page eleven clause naught point two point three
01:04:52 if we look so under 0.2.3 this is smoke control in common parts i want to look right at the end of that section in the last five lines we can see it says where smoke control is used to
01:05:04 says where smoke control is used to provide compensation for extended travel distances it is the responsibility of the designers to demonstrate that the ventilation system can provide tenable conditions for the
01:05:15 can provide tenable conditions for the occupants using the route with extended travel distances do you see that there i do yeah were you aware of that part of that british standard when you were approving the system
01:05:28 approving the system i was aware of it but it doesn't apply to the cases that you're speaking about the i can explain if you wish me to elaborate
01:05:36 elaborate can you explain why we don't see any consideration in the design documentation about the need to maintain
01:05:43 maintain tenable conditions in the extended travel distance lobby why is that not even considered addressed because the criteria that's used in the sca guide is you need to achieve tenable
01:05:54 sca guide is you need to achieve tenable conditions for long extended corridors so corridor is between
01:05:58 between 15 and 30 meters that's your criteria then for tenable conditions um
01:06:06 well that's that's not what this is saying is it saying where smoke controls used to provide compensation for extended travel distances it doesn't talk about particular extended travel distances it's the responsibility of the
01:06:17 distances it's the responsibility of the designers to demonstrate that the ventilation system can provide tenable conditions yeah the only question again why do we not see any consideration in the design documentation about maintaining tenable conditions in
01:06:29 about maintaining tenable conditions in the lobby
01:06:31 the lobby because it isn't it isn't the practice of the industry to achieve tenable conditions in um corridors unless they're really extended
01:06:42 extended between 15 and 30 meters mr hanson doesn't leave yes i'm sorry ms granger i'm just going to cover you said a moment ago that um you didn't think this applied
01:06:53 um you didn't think this applied to the case we're considering is that did i understand in the context of the question um because what the question has been put to me is the um the suggestion is these corridors
01:07:04 um the suggestion is these corridors should have had tenable conditions and that should have been part of the design so we've only looked you're shaking your head
01:07:11 head but we've only looked at terrible conditions in long extended corridors between 15 and 30 meters and there is direct requirement for those cars to have tenable conditions
01:07:22 tenable conditions right but i think that the passage we were looking at can we have it back on the screen do you think it is um which ms grange put to you yeah um you said at one point
01:07:35 yeah um you said at one point you started an answer by saying this doesn't apply and i and then you um uh went off to deal with some other point
01:07:46 point yes it's um page one five two line yeah i'm talking about the case you said i was aware of that passage
01:07:57 you said i was aware of that passage but it doesn't apply to the cases that you're speaking about and i just wanted to make sure why you said that because you didn't actually give an extra okay right okay so let's let's give the explanation um
01:08:10 explanation um so longer corridors it tells a bit of history here um we've had to try not to get into too much history yeah it does it does help though because otherwise you don't know the context is is important all right so
01:08:24 the context is is important all right so so we've had existing system um the old standards
01:08:27 standards included a ventilated lobby um that was regarded
01:08:31 regarded at the time as being suitable not tenable conditions at all this is just what we had we've now started seeing the need that
01:08:42 we've now started seeing the need that the
01:08:43 the designers extending corridors quite substantially so the decision was made where you're going for a substantial extended corridors
01:08:51 corridors 15 to 30 meters you're now looking at we've got to have a new criteria boom on these codes were written years and years ago
01:08:59 ago which is that a natural event now we said actually if you're going to extend the corridors this long we need to have a definite standard for tenable conditions so that's what we do with these extended corridors you've got a situation here
01:09:11 corridors you've got a situation here that
01:09:11 that is an older job that was designed under the guidance at the time was natural vent they went for an experimental mechanical system i i call it
01:09:23 system i i call it um and achieved a certain level of of acceptance they felt was acceptable can i just ask you to think about this in paragraph 0.2.3 and miss grange read this sentence to
01:09:36 and miss grange read this sentence to you it says where smoke control is used to provide compensation for extended travel distances are you saying that that expression extended travel distances only applies
01:09:48 extended travel distances only applies to corridors of 15 meters or longer yes it does yeah yeah yeah right well what i'm really saying in the context of just wanted to understand that that's why you say it doesn't apply to this
01:10:00 why you say it doesn't apply to this case
01:10:01 case yeah yeah so the criteria the the the tenability criteria that we would apply to a long
01:10:06 to a long if that's clear then i think i understand why now why you say this didn't apply maybe that miss grange would like to follow that up though because there is no reference at least in that
01:10:17 reference at least in that sentence to 15 meters or longer right strange i'm sorry i've broken into your line of questioning no no it's fine um perhaps if i can move on to
01:10:28 on to say with the same theme about tenability criteria
01:10:31 criteria if we can look at the sca guide again um rbk402932 page 15.
01:10:54 there's a whole section of this guide called tenability criteria for means of escape and there's detailed guidance given about um determining performance
01:11:06 about um determining performance criteria to be set for maintaining tenability and there's all different ways in which you can set performance criteria
01:11:13 criteria you can set them um according to time dependent things based on a timeline of physical events you can set them based on likely but challenging fire conditions in a steady state
01:11:24 in a steady state way that i mean i don't think we need to get into the complexities my basic question is why don't we see in any of the design documentation any consideration
01:11:35 consideration of tenability in the lobbies and what the performance criteria was it may have been the performance criteria may have been
01:11:42 been something which you would describe as you know not very good in the lobbies but why do we not see any performance criteria which set says this is what we are anticipating
01:11:54 anticipating will be the conditions in the lobbies and this is why it's acceptable it might say well because the the travel distances aren't that great compared to 7.5 meters there might be
01:12:05 compared to 7.5 meters there might be all sorts of mitigation
01:12:10 but but why don't we do see any consideration of performance criteria for tenability including in the lobbies and indeed in the stairs
01:12:21 the stairs right okay so going back to what i was saying this tenability criteria for means of escape is about our extended corridors between 15 and 30 meters this was set up in order to
01:12:34 this was set up in order to be able to consider these extended corridors as being acceptable but we're speaking about an existing building that had slightly longer lobbies
01:12:43 lobbies that would have been acceptable with a natural system that had no tenability criteria
01:12:48 criteria what we've done with this job effectively is provided a smoke ventilation system that has ventilation to each end of the corridors and you'll likely get a better result than a natural system
01:12:59 than a natural system there's going to smoke log you stare and a layer of smoke in the natural corridor um yes but we don't see
01:13:06 don't see any of that do you think there's a certain point that's a fair point sorry let me finish what you've just said we don't see any of that written down
01:13:15 down by the designers or by you as building control when accepting the system do we that is a fair point i suppose maybe that there should have been an explanation for that yeah and if we look um at page um
01:13:27 yeah and if we look um at page um 16 the page on from this there should have also been consideration of tenability criteria for fire fighting so what it says in this first paragraph is while it's
01:13:38 this first paragraph is while it's acknowledged that it's extremely challenging to design smoke ventilation systems
01:13:42 systems to maintain terrible conditions for occupant means of escape in common corridor and lobby areas once the door to the flat of fire origin has been opened for fire service intervention considerations should be given to what
01:13:55 considerations should be given to what additional protection these smoke ventilation systems can offer firefighters during firefighter operations do you see that
01:14:02 that i do see that yeah and again we see no consideration whatsoever do we in any of the design documentation about what consideration was being given to
01:14:12 to the protection that the system would provide to firefighters during firefighting operations when the flat door was open
01:14:21 right okay so once again the the whole idea of this section in the sca guide is about the long extended corridors beyond 15 meters if i can refer you to paragraph the third paragraph under 533
01:14:33 third paragraph under 533 this explains that area well underneath it says therefore for common escape routes where smoke ventilation systems are being proposed to justify extended single direction
01:14:45 to justify extended single direction travel distances of more than 7.5 meters in length well that's what where we are here specific assessment of the conditions within these spaces should be completed by the system designer to demonstrate
01:14:56 by the system designer to demonstrate that effective fire service intervention can actually be achieved so it's not talking about beyond 15 meters is it it's talking about more than 7.5 meters yes
01:15:22 so
01:15:36 this
01:15:41 i can see your point the way it's written
01:15:45 okay that's it so i the point i would make though is that the the i just repeating what i said really that we had an existing situation there whereby the intention was to
01:15:57 whereby the intention was to um you know provide a new mechanical ventilation system in existing situations that this is basically
01:16:06 basically designed for new buildings yes i see um mr chairman that would be a good moment i think for the afternoon breaks i'm about to move
01:16:17 the afternoon breaks i'm about to move to a related but slightly separate topic well that sounds like would be a good moment then to have a break from this handsome we'll take the afternoon break now we'll come back at half past three please okay thank you
01:16:29 half past three please okay thank you please don't talk to anyone about your evidence while you're out of the room
01:16:41 thank you strange hot first three please
01:33:05 right we're ready to resume so i'm just going to ensure that we've got contact with miss grange hello can you hear me hello yes we can see you and i think you can see us can
01:33:16 see you and i think you can see us can you
01:33:17 you yes i can thank you and i'll ask mr hansen to come back in
01:33:37 all right ms tansen ready to carry on thank you well and thank you very much yes ms grange yes thank you i now want to look at something in british standard uh en12101.6
01:33:51 british standard uh en12101.6 if we go to rbk3045054
01:33:57 and i want to look at page 57. so this is the british standard and we know that the the two meters per second was taken from this british standard
01:34:09 this british standard as per the design documentation but i want to look within section 9.1 at the bottom of this page there's a section on depressurization within this
01:34:20 section on depressurization within this standard
01:34:21 standard and it says this it says the objective of a depressurization system is to achieve the same project protection at the doorway between the depressurized space eg a basement and the protected space
01:34:34 eg a basement and the protected space egs stairwell as would be achieved by pressurizing the protected space and then it goes on it is important to note that there is no protection of any part of an escape
01:34:45 protection of any part of an escape route
01:34:46 route within the depressurized space itself which may be entirely filled with smoke or may even be fully involved in a fire this constitutes a fundamental difference
01:34:58 constitutes a fundamental difference between depressurization and smoke exhaust
01:35:01 exhaust ventilation do you see that
01:35:07 now if we can look at a helpful diagram that dr lane produced in phase one at blas 5038 page four
01:35:25 in this diagram that was presented in her phase one evidence what dr lane is attempting to do is explain how this system the psb design system would work at
01:35:37 the psb design system would work at grenfell tower and what we can see first of all in the yellow
01:35:42 yellow arrows is that smoke or air is extracted by fans from the lobby at the north and the south shafts we can see that so you've got extraction on both sides
01:35:55 you've got extraction on both sides and then in the blue air is being pulled through the open stair door and the lift shafts to the lobby at less than two meters per second due to the open flat door
01:36:09 due to the open flat door and then lobby extract pull smoke from the fire flap through the open door now just to be clear what this is showing is that when you open the door to the fire flat because the
01:36:21 to the fire flat because the lobby space is the depressurized space as well as having the effect of protecting the stair or trying to protect the stair you're pulling smoke from the fire flat into the lobby
01:36:35 smoke from the fire flat into the lobby do you see that
01:36:46 i wouldn't say you're pulling it from the fire flat i mean the smoke coming from the fire flap will
01:36:53 flap will naturally um have momentum along the corridor what you're actually in this system where you have depressurized the lobby you've lowered
01:37:04 depressurized the lobby you've lowered the pressure in the lobby by extracting air from it when you open the fire flat door do you accept that the low air pressure in the lobby would then mean that smoke was drawn out
01:37:16 that smoke was drawn out into the lobby not not for the reasons you say so let me just
01:37:23 me just you showed me in the standard text about a depressurization system which is a different system that's where you're extracting from the floor area and they they qualify that by
01:37:34 floor area and they they qualify that by saying that the it could be fully involved in a fire so that's something different so i wouldn't connect the two together so looking at the fire flat when someone opens the flat door there
01:37:45 when someone opens the flat door there is the expectation without any question that smoke will flow from the flat um out of the flat door and it will fly out by its own momentum
01:37:56 increase the propensity of that to happen because the pressure is lower in the lobby well if i did discontinue my my my analysis so we've got smoke
01:38:07 we've got smoke with its momentum flowing across the corridor what you're then doing is interrupting the flow of this momentum by your extract system in both locations extracting away
01:38:20 in both locations extracting away it this this question of depressurization i think it needs to be separated because it's a different system you're extracting smoke from the fire room
01:38:31 room you're extracting is here smoke from the um
01:38:34 um the lobby i mean this is the fundamental principle of this type of system you're you're stopping the smoke
01:38:42 approaching the stairway and you're extracting it but it doesn't um basically the fire doesn't need this system to make it flow into the quality it will naturally do it
01:38:55 quality it will naturally do it so are you saying that it will make no difference to the extent of smoke flowing into the lobby that you've depressurized the lobby by extracting air at both sides
01:39:06 lobby by extracting air at both sides it should actually make the conditions better because you what you're doing you're interrupting the flow so when the smoke is flowing across the corner you're actually now saying we're sucking it out the system you'd have to have a very
01:39:17 the system you'd have to have a very powerful system to actually cause your your normal smoke momentum to be pulled further um you haven't got that um powerful a system in this this this
01:39:28 powerful a system in this this this building to do that i would suggest um this comes from um we look at 3d models for new jobs and you get a great idea of how smoke
01:39:39 and you get a great idea of how smoke flows and
01:39:40 flows and you see this all the time smoke flows in the corridor it it it flows along the corridor and then you see the extract system kicking and it pulls it and stops it affecting the staircase and when you see it visually it really
01:39:53 and when you see it visually it really paints the picture so i'm afraid i can't accept that the system this system would have made the conditions worse by pulling it it's actually improving it that's the whole idea of it and it's the whole concept of the way
01:40:04 and it's the whole concept of the way these systems work just to be clear when the flat floor gets opened you're saying you don't think this system makes it any worse than when the flat door is closed
01:40:15 flat door is closed is that what you're saying
01:40:18 uh just repeat the question when the flat door is opened are you saying that it doesn't make uh
01:40:25 make uh conditions worse compared with when the flat door was closed is that what you're saying
01:40:31 saying i think you're talking about something different about no i'm trying to focus on
01:40:36 on on what would happen at the point of the flat door being opened smoke will flow out if we if you didn't
01:40:44 didn't the best example i think will help is say we didn't have the x-ray system at all
01:40:50 all so we purely had a lobby without any ventilation what will happen is smoke will flow naturally
01:40:57 naturally into the corridor and what's going through the closed door no through the open door because someone's the picture you're painting is the door is open so the person can escape
01:41:06 escape from the flat yeah yeah so when the they open the flat door smoke will flow into the corridor and it will do that by its own natural momentum until it finds something else
01:41:17 momentum until it finds something else that will interfere with it and allow it to go somewhere else which is likely to be the stairway it will flow up the the lift shafts but if we interrupt that flow and say
01:41:28 but if we interrupt that flow and say actually now the momentum of smoke is being interrupted by an extract system here this will then you'll still get lots of smoke flowing but it will start pulling it away and you'll get better conditions than if
01:41:40 and you'll get better conditions than if you you had a non-ventilated lobby sorry can i just interrupt i think the point that you're being asked to consider is whether the rate of flow of the smoke from the fire flat into the lobby
01:41:52 fire flat into the lobby will be increased by the effect of the fans drawing air out of the lobby yeah i i i did pick up on that earlier and yeah i mean he probably did what what's your my
01:42:04 he probably did what what's your my general view is that um it shouldn't affect it but i thought there's a possibility that if you have a very powerful system and the system that the extract is is
01:42:16 and the system that the extract is is right near a flat door for example that it could happen but you tend to have these very powerful systems on our extended corridor cases that i've explained earlier
01:42:27 cases that i've explained earlier because you do need an extra rate quite powerful um but i've noticed from 3d modelling i've not seen and bear in mind 3d modeling is a version of reality it's not reality so we have to bear that in mind but
01:42:39 so we have to bear that in mind but they're the best tools we've got to look at things sometimes so from my experience i wouldn't have thought that smoke would be not when the thought i could almost say that that is not the case you know that it won't it won't
01:42:52 that it won't it won't pull the smoke you'd have to have extremely high extract rate and there would be closer to the flat door for that to happen in my view i understand thank you very much sorry does that suggest
01:43:03 suggest that um did you actually think about this risk
01:43:06 this risk at the time you were approving the system did you actually think about the risk that it might pull a greater rate of smoke into the lobby when the door the flat door was opened
01:43:18 was opened well i didn't think about it because it's it's not a known phenomenon i recognise
01:43:23 recognise and bearing in mind that you know i'm not
01:43:26 not as building control i'm following um expect
01:43:30 expect practice in the industry so what you're almost criticizing to be quite frank is that the sca guide is incorrect um because that's that what the process
01:43:42 because that's that what the process i've described is the way that extract system works i see but also and importantly wouldn't another consequence of opening the flat door be that the
01:43:54 opening the flat door be that the airflow across the stair door would be reduced and the protection to the stair would be reduced did you ever consider that absolutely absolutely because that's part of the test
01:44:05 test that so as we we've established on this job
01:44:08 job that we're taking a an on-site test to use as demonstration the system achieves the objective so part of that test involves um a process whereby you have certain number of doors open
01:44:20 number of doors open while you're performing this two meters a second test so you've actually taken that into account
01:44:26 the new helpers then as to why this the technical submission that you approved didn't make clear the design scenarios on which its performance criteria were
01:44:37 on which its performance criteria were based
01:44:38 based for example it doesn't refer to the two meters per second extract rate being appropriate for both means of escape and firefighting phases can you help us as to why that's the
01:44:50 can you help us as to why that's the case
01:45:00 um you know i i i think i may need you to repeat the question
01:45:09 let me approach it a different way let's look at the sca guide because you keep referring to that and we'll go back to it now the 2015 guide rbk402932
01:45:20 to it now the 2015 guide rbk402932 and i want to look at page 23.
01:45:36 here in this section of the sca guide it tells you what documentation should be included and we can see in the third paragraph it says the documentation should include
01:45:48 it says the documentation should include at least
01:45:49 at least the following information and we can see it says a description of the residential area and the proposed ventilation system the design criteria and performance objectives of the analysis
01:46:01 objectives of the analysis the scenarios investigated details of the techniques used and related information the results of the analysis a statement as to whether the design criteria and
01:46:12 as to whether the design criteria and objectives have been met and summary input output data for the modeling that's used now can we agree that there was a total
01:46:23 now can we agree that there was a total failure to comply with this aspect of the sca guy because we don't see documentation that tells us at least the majority of those bullets
01:46:34 at least the majority of those bullets doesn't tell us the design criteria the performance objectives it doesn't tell us the scenarios that have been investigated can we agree that that was the case yeah this paragraph is about modeling isn't
01:46:46 this paragraph is about modeling isn't it
01:46:46 it so we're not modeling we're but the way this system has been considered is taking a value that's tested on site
01:46:57 tested on site so you'll see supporting animations et cetera et cetera and i don't think this paragraph is about modeling solely if you look at the second paragraph it says the results of the analysis should be documented and may be
01:47:09 analysis should be documented and may be provided in the form of a report together with any necessary supporting animations from advanced modeling and it's telling you what the documentation should at least
01:47:20 documentation should at least include now can you help us you were intimately familiar with the sca guide 2015 why did you not insist that the documentation that was provided
01:47:32 that the documentation that was provided met all of these requirements
01:47:39 i think i've related it to computer modeling basically um the the the also you you said this is the 15 version and we're we i don't know whether or not
01:47:51 and we're we i don't know whether or not any significant difference but there is in terms of the modeling i think um well let's look at let's look at the 2012 version if that's what you're referring to if we go to lfb five nine two
01:48:04 if we go to lfb five nine two four one page fourteen
01:48:18 four one page fourteen where there we see in this earlier version the 2012 version there's a section 5.4 documentation results should be presented in an appropriate form for each agreed criterion
01:48:29 criterion and then the documentation should include at least the following information a description of the area the design criteria and performance objectives the scenarios investigated the techniques used etcetera so
01:48:40 used etcetera so a very similar list appeared in the 2012 guidance
01:48:45 guidance um did it occur to you at the time to check what documentation ought to be provided
01:48:52 provided for compliance with the sca guide not in that context no i can understand what you're saying um but this really is where your your
01:49:03 but this really is where your your in my view is where you're modeling a scenario
01:49:06 scenario um whereas this is more of a performance based
01:49:10 based criteria well um i would suggest to you that the whole thrust of the sca guy 2012 and 2015 is that you can
01:49:21 2012 and 2015 is that you can come up with an alternative performance based design but you have to carefully document and explain
01:49:28 explain what your design criteria are what your performance objectives are and what your scenarios are that you've investigated as a minimum can we agree on that i i do agree there is a lack of that in
01:49:41 i i do agree there is a lack of that in description in the approach whether or not that's referring to it but the difficulty is how would you know that the system could work without those performance criteria being
01:49:53 without those performance criteria being defined without the objectives being defined
01:49:56 defined without the scenarios being investigated and without confirmation that it meets those
01:50:02 those scenarios how how could you effectively approve the system without that kind of analysis being done of this alternative system
01:50:13 it's merely more more of a qualitative consideration based on the existing building
01:50:22 yes i see i don't disagree though that you've got a point that um this should have been documented better of how the consideration were arrived at so i acknowledge that definitely yes but it's not just a failure of
01:50:34 but it's not just a failure of documentation is it because unless you document these things you can't then assess whether the system is meeting the design criteria and performance
01:50:45 the design criteria and performance objectives you've set because you don't know what the system is designed to be doing do you see yeah yeah if we could look at what dr lane has
01:50:57 if we could look at what dr lane has done in her latest report if we go to blarp
01:51:01 blarp to 5035 at page 148 so blarp 2 5 0 is 35 at page 148
01:51:16 so in this table table 5 four and there are a number of tables in this chapter of her report but this is this is a summary table where what she's done is she's
01:51:27 where what she's done is she's summarized on the left-hand side the information that the the the sca guide requires in that list that we just looked at and she's explained in the right hand
01:51:38 and she's explained in the right hand column whether or not psb's technical submission covered that or not and we can see that she said in amber that there wasn't
01:51:50 that she said in amber that there wasn't a proper description of the residential area it doesn't describe the evacuation strategy it doesn't describe the travel distances
01:51:58 distances the other active and passive fire protection measures we can see below that under performance criteria that the only performance criteria provided was for the open door velocity for a
01:52:11 was for the open door velocity for a maximum pressure difference and the door opening force and she says those don't cover the range of performance and tenability criteria set out in the sca guide then when it comes to scenarios being
01:52:23 then when it comes to scenarios being investigated there are no specific scenarios investigated so it doesn't analyze you know what would happen
01:52:31 happen if there was this escape of occupants from the fire flat or other um flats on that floor it doesn't um indicate what would happen during the
01:52:42 um indicate what would happen during the fire fighting phase so no scenarios are investigated no record of the techniques used to access assess the system performance no comparative or deterministic analysis
01:52:54 no comparative or deterministic analysis so what that means is there's no analysis
01:52:57 analysis comparing it with a prescriptive system and there's no analysis looking at overall performance presented and there's no statement as to
01:53:08 presented and there's no statement as to whether the design criteria and objectives have been met now can we agree that that that was the the picture
01:53:16 picture that we now see presented in the design documentation
01:53:23 yeah i mean we again we are referring to 2015 version that really dealt with extended corridors etc um
01:53:31 um i i don't disagree with you that there should have been a better description of um
01:53:39 how the the the yeah a better description along the lines of this but maybe not
01:53:45 maybe not um as far as you would go to consider an extended corridor case where you're specifically looking for terrible conditions yes
01:53:57 in terms of acceptance tests um if we just look if we could look at section 12 of bsen12101 part 6. this is at rbk3045054
01:54:12 part 6. this is at rbk3045054 on page 72.
01:54:20 so within this british standard there is guidance
01:54:24 guidance on acceptance testing of um pressure differential systems or depressurization systems were you familiar with this series of acceptance test
01:54:36 series of acceptance test stages
01:54:39 no i wouldn't have been because it again it was a matter that would have been covered by our mechanical electrical engineer i see so so what we see is there are a series
01:54:51 so so what we see is there are a series of different acceptance tests that are recommended for these types of systems which require you to very carefully record the results of the system
01:55:03 record the results of the system and can we just look at an example of this
01:55:06 this um so if we go to um clause 12.23 on page 73
01:55:19 clause 12.23 on page 73 we can see at the top of that page there's um acceptance tests here for air velocity 12.23 now there was an air velocity performance criteria we know that was
01:55:31 performance criteria we know that was two meters per second between the lobby and the stair
01:55:36 stair um door now
01:55:43 if we look on within um this testing what it tells you is that you've got to test across
01:55:54 is that you've got to test across a range of doors so if you look at
01:55:58 12.2.3.3 measurement of flow velocity through the relevant doors shall be taken with all other doors open or closed in accordance with the appropriate class of system described in clause 4. the doorway shall
01:56:11 described in clause 4. the doorway shall be clear of obstructions and you've got to see
01:56:13 to see figures two three four five six etcetera and um if we look at page 30 this tells us what all the other doors
01:56:24 this tells us what all the other doors that need to be opened during the test should be
01:56:28 should be so at the bottom of the page we've got the airflow criterion between staircase and lobby
01:56:35 and lobby and it says the air supply should be sufficient to maintain that two meters per second through the open door between the staircase and the lobby at the fire affected story with the air release path on the floor still
01:56:46 the air release path on the floor still open and all of the following doors are open between and then so you've got all the doors between the lobby and the fire
01:56:52 fire affected fire compartment open the stair and the lobby on the story below the fire story open the firefighting lift shaft on the lobby on the story below the fire story open
01:57:03 on the story below the fire story open and and it goes on yeah now in in summary would you agree that this testing is done because you need to be sure that the system is powerful enough to maintain
01:57:15 system is powerful enough to maintain pressure if different scenarios occur during the fire events totally agree with you yeah you're right yeah so opening different doors will
01:57:26 so opening different doors will simulate what might happen in real life where other other occupants escape or where you enter the firefighting phase yes yeah totally agree and can we agree that
01:57:37 totally agree and can we agree that during the firefighting phase you may have a situation whereby you've the fire brigade have set up on the lobby below and have trailed their hose through the stair door below
01:57:48 stair door below up the stairs through the the stair door and then through the flat door so you'd have three doors open at that point yeah absolutely so these are the kind of scenarios um
01:58:01 these are the kind of scenarios um when we talk about scenarios before that we don't see any any analysis of and in the testing that's done we don't see any testing that's done with different doors open to check that
01:58:13 with different doors open to check that the system can still cope in those situations or at least test what the system does in those scenarios do you agree um no basically um but i can see where
01:58:26 no basically um but i can see where you're leading the the technical submittal proposed the two meters a second airflow test in accordance with this standard so my expectation is it would be tested in accordance with this test procedure
01:58:38 in accordance with this test procedure and opening closing the relevant doors to the class b system um so that's clearly stated in the technical submittal um yes now did you ever check that that
01:58:49 um yes now did you ever check that that had been done no going back to my position with the loss of our brag engineer um when we had a break engineer
01:59:00 a break engineer they used to go down there and witness this kind of thing yes let's look at the two sheets of readings which you were provided with in the above ground commissioning report
01:59:11 the above ground commissioning report this is a psb
01:59:14 401152 if we could go to page eight
01:59:19 of that document
01:59:27 so we get two pages of readings there was this page which shows readings in meters per second of the fans at different levels and then over
01:59:39 fans at different levels and then over the page
01:59:41 the page we can see each floor level in the in the second column along open door meters per second we just get one reading per floor
01:59:53 we just get one reading per floor one open door measurement for the 24 floors
01:59:57 floors do you see that yeah i do yeah and in fact there's no record of actually which door this was although we could perhaps assume that it was the door to the stair yes well it has
02:00:08 the door to the stair yes well it has because that's the one you're testing you're testing the door to the stair so there's no record of any testing with other doors open or closed when these measurements were taken yes
02:00:21 when these measurements were taken yes well the expectation is they would test to the standard i mean in any kind of commissioning report i wouldn't expect the testing procedure to be repeated bearing in mind here that um you didn't
02:00:32 bearing in mind here that um you didn't show it but there is actually an illustration so you'd have to reproduce all the texts that you showed about the doors plus the illustration and that's not the kind of thing you would expect to
02:00:42 expect to be including submission report in mind this
02:00:46 this commissioning report was um done to comply with the technical submit of
02:00:54 of yes i see so is what you're saying that you assumed that this was some kind of summary and that you assumed there'd be um more data that was taken behind this
02:01:05 um more data that was taken behind this which did comply with that acceptance okay set of criteria
02:01:09 criteria right right i think i can see where the important
02:01:13 important reading or the reading we're interested in is
02:01:16 in is the flow rate across the door to the staircase
02:01:19 staircase so that's the reading you would take the the second column is the reading you would take the other doors being open you don't take any readings they're open so you've got flow coming from other
02:01:31 so you've got flow coming from other areas and what you're trying to do is make sure that the two meters a second is maintained once you've got other leakage paths but you don't measure those leakage bugs because they're not of of importance for the the value that the
02:01:42 of importance for the the value that the value we're interested is the staircase door value can we agree that if you were doing acceptance testing in accordance with the british standard that's referred to an adb you would do
02:01:54 would do those tests with a range of other doors open
02:01:57 open absolutely yeah yeah and that's the expectation because that's what was proposed
02:02:03 yes otherwise you know you're not proving the system could i just thank you sorry sorry yeah i
02:02:10 i you showed me another section of that guide
02:02:14 guide of the the bs was i aware and um i said i
02:02:18 i i don't think so um i don't know whether all the
02:02:22 all the the tests there are related to a pressurization system or a depressurization symptom i'd just like to make that point um i may have answered wrongly because it may not relate to the
02:02:33 may not relate to the to that type of system that's all
02:02:37 i see okay um can we look at an email now so this is about um opening door force on the door um this happens to be what the fourth
02:02:48 um this happens to be what the fourth acceptance test in bs en 121016 is the opening door force
02:02:54 force tests um now if you go to an email this is psb 401152
02:03:18 so this is an email that mr harrison sends to mr earl uh of js wright dated the 26th of may and i want to look at the third paragraph he says the control system will also
02:03:31 he says the control system will also have
02:03:31 have pressure sensors added into each ventilation lobby to control the speed of the fans to ensure that when the doors on the escape routes are closed that the opening force on the door does not exceed
02:03:42 exceed 100 newtons as detailed in bsen 12106 part
02:03:46 part 6. this was witnessed by your mr alan white
02:03:50 white and the reading which was not recorded in our commissioning sheets but read as 85 newtons on the scale provided by j s wright now
02:04:01 s wright now it follows from that and it's consistent with the commissioning report that there is in fact no record of what the door opening force was in the commissioning reports that's
02:04:12 was in the commissioning reports that's right isn't it you're probably correct
02:04:18 now without
02:04:21 some readings of door opening forces in the commissioning report how could you be satisfied that the system met the requirement that the opening force on the door would not exceed 100 newtons
02:04:34 the door would not exceed 100 newtons as set out in the british standard as identified as a criteria in psv's technical submission
02:04:43 yeah they were using a this pressure sensor device that it was certainly new to me i i took it maybe innocently that the mechanical
02:04:55 it maybe innocently that the mechanical process
02:04:56 process or electrical process um of the of them testing what they did they actually put the word yes at the end of this little section and so i took it as that meaning that they
02:05:08 they carried out the test and the automatic system depressurized the space they tried the door and it was okay now whether that should have been recorded for each door i mean you may have a point um
02:05:21 have a point um shouldn't they at least have been recorded sorry shouldn't it at least have been recorded as a minimum for a representative well now you say i think you've got a fair point um again i'm without a break engineer so
02:05:33 i'm without a break engineer so one of the problems i lacked here is that this was a system an electronic system
02:05:37 system um and it would have been great to have my brake engine there look at it and then decide what he felt or he or she um felt was appropriate on the commissioning
02:05:59 the point you're making it make makes sense but but i looked at it on the basis that that they've used this automatic system and they've regarded as acceptable but they
02:06:08 they but you're right to say they haven't recorded the readings yeah so we're relying on that it goes back to the fact that what we um as a borough when we decided to make
02:06:19 um as a borough when we decided to make a break engineer redundant we're relying on the profession of the installer designer and because i've not been a brag engineer i'm not used to the
02:06:31 engineer i'm not used to the expectation of how the commissioning report should be written um yeah so i did my best in the question you keep referring to the phrase breg engineer b r e g and okay do you explain
02:06:43 engineer b r e g and okay do you explain that right okay so historically back in the glc what does the acronym stand for building regulation engineering group i see and it was that back to the m e engineer not being there
02:06:55 engineer not being there yes yes yes we gave them because they used to be a group in the glc times um we just kept calling even though we had one person we we just kept calling them breg as a
02:07:06 we just kept calling them breg as a colloquialism if you like
02:07:11 um can we um now go to the topic of dampers and um compartmentation associated with smoke control system
02:07:23 smoke control system was anyone at building control responsible for checking on site that important aspects of compartmentation associated with the smoke extract system were complied with right well
02:07:35 were complied with right well any site checking would have been the role of the area surveyor and they would have inspected considered as necessary [Music]
02:07:46 [Music] inspections as they felt necessary during the process were you saying it was mr hoban's responsibility in relation to the smoke control system to check that elements of that system
02:07:59 to check that elements of that system necessary to maintain compartmentation were complied with yes that's right because it basically was a damper so therefore any any fire door damper that kind of thing
02:08:11 that kind of thing was um the area surveyors reference whereas in the old days where we had the mechanical event engine it wouldn't have been the mechanical advantages reference to do the um the dampers
02:08:24 um the dampers right yeah they're on the mechanical side as it were yeah does it follow that you didn't give any consideration at all to for example the fire rating of the dampers
02:08:37 dampers in terms of the technical submittal you mean which is my my role yes i mean the fire so psb actually selected um gilbert's series 54
02:08:48 actually selected um gilbert's series 54 mentioned in the technical submission um was it part of your job to check the fire rating of the dampers that they used yes it was yeah yeah part of the technical symbol there are
02:09:00 technical symbol there are although i don't deal with the mechanical sides then that side of things
02:09:05 things that the basic specification for the dampers would have been my reference yeah and and do you recall actually checking the specification for the dampers to make sure that they were
02:09:16 the dampers to make sure that they were appropriate for the use that they were being put to yes you did how did you how did you carry out that check right so the my recollection was the technical submittal
02:09:27 technical submittal made reference to a particular product yes
02:09:31 yes and they sent the product literature with the technical submittal so therefore i was able to see the product literature and the product literally declared the test
02:09:41 test regime that was used um et cetera so you were able to to determine from the product literature um what the standard of the damper um
02:09:52 um what the standard of the damper um was proposed to be
02:09:55 i see did you specifically consider whether the dampers were certified as fire dampers or as smoke control dampers
02:10:10 i'm not quite sure the context of the question
02:10:15 question do you were you aware at the time that dampers are divided into three categories um fire dampers fire and smoke dampers and smoke control dampers with smoke
02:10:26 and smoke control dampers with smoke control dampers being tested to the most onerous performance standards of the three right it was a smoke control damper because it was being used to control smoke and it did
02:10:41 just answer my question were you aware that there were three categories of dampers fire dampers fire and smoke dampers and smoke control dampers are you aware of that at the time yes and you say it was a smoke
02:10:54 yes and you say it was a smoke controlled damper because it was used in the smoke
02:10:56 the smoke control system but were you aware that to be a smoke control damper it had to achieve certain testing requirements yes i was yeah were you also aware that
02:11:08 yes i was yeah were you also aware that bs1210
02:11:10 bs1210 made clear that if different pressurized or depressurized zones are connected to the same fan or set of fans by a common system of ductwork or shafts that smoke control dampers needed to be
02:11:22 that smoke control dampers needed to be used were you aware of that um yeah but we were using the sca guide on the job not the the the the element of the one two one and one part six was in fact the testing
02:11:35 part six was in fact the testing the two-minute square testing regime that was sort of taken to that guiding used
02:11:39 used um as a criteria for the sca so i would have been looking in the sca guide
02:11:46 guide um their criteria for smoke control dampers
02:11:51 let's look at the sca guide so for example in the 2012 guide at lfb3059241 we go to page 36.
02:12:14 if you look at 8.2.5 this is automatic opening vent smoke control damper and used for ventilation from corridor or lobby into smoke shaft or smoke controlled duct it says there no formal product standard
02:12:27 it says there no formal product standard exists for the use of these products in this application but then it goes on it says to ensure the necessary product performance is achieved
02:12:35 achieved it is recommended that the aov should be regarded as a smoke control damper and the relevant product standards should be considered do you see that i do yeah yeah we're
02:12:46 do you see that i do yeah yeah we're talking about iovs here at the moment though aren't we
02:12:52 yes so it's got to be a smoke controlled damper can we agree on that yes smoke draw damper here yes
02:13:03 yes smoke draw damper here yes and you're saying that you did in fact check
02:13:06 check the fire resistance of the dampers by looking at their product information is that right there is a section in the fca guide that gives a range of different tests appropriate for a smoke control
02:13:17 tests appropriate for a smoke control damper
02:13:18 damper and it followed one of those one of those recommendations well let's look at the information let's look at the information on the dampers if we go to psb
02:13:30 dampers if we go to psb 50201
02:13:34 this is the literature for the dampers that we have available for the series 54 gilbert's dampers and if we go to the second
02:13:44 second page of this you can see if we blow up the top of that page second paragraph down
02:13:55 second paragraph down it says multi-parallel link blade smoke damper
02:13:59 damper series 54 is manufactured from robust 1.5 millimeter galvanized steel and is fully tested to the requirements of en 1366 part 2 for one hour now did you realize that
02:14:12 2 for one hour now did you realize that that's the standard for a natural ventilation system not for a powered pressure differential system
02:14:23 you're mentioning pressure differential systems again i i'm i'm using the sca guide and i believe this sighted standard the 1366 part 2 is one of the
02:14:35 part 2 is one of the um is an acceptable standard um in the sca guide
02:14:44 i see um well we can have a look if you look in order to no i think in order to be smoke controlled dampers there needed to be relevant test evidence to bs en 1366 part
02:14:55 evidence to bs en 1366 part 10 or classification to bsen 13501 part 4. um yeah the the eukaryote
02:15:07 the the eukaryote and and we don't have that that so the en 1366 part two for one hour is is not enough to be a smoke control damper
02:15:16 damper did you realize that at the time
02:15:20 the question put put in me is as though i would have to accept what you say is correct um but i believe the sca guide
02:15:29 guide um cites this as an acceptable standard for the damper we could go to it if you wish
02:15:37 wish well do you know where it is in the sca guide well not off the not off the top of me head but it must be near the area where you were just i'm just putting to you that if it's going to be a smoke control damper
02:15:49 it's going to be a smoke control damper which it needed to be there needed to be relevant test evidence to bsen 1366 part 10 and classification to bsen 13501 part 4. and the dampers didn't demonstrate
02:16:02 4. and the dampers didn't demonstrate that
02:16:04 that um you're including you are referring to two thousand is significant about the seo guide the 2012 version of the sca guide had this standard as an acceptable
02:16:16 had this standard as an acceptable standard he got changed in the 2015 version
02:16:21 version and it's got changed again in the 2020 version
02:16:24 version like what i read to you earlier when it said it needed to be a smoke control damper it was recommended was from the 2012 guide not the 2015 one what they do in that guy they go on to tell you what the
02:16:36 guy they go on to tell you what the acceptable standards are that that's just about generic introduction i i'm virtually certain of this
02:16:44 this so um okay well i'm sure someone can tell me if there's a particular passage in the sca guide that i need to take you to but i think what happened
02:16:55 i think what happened is that there was a consideration of um standards between the 12 the 2012 version and the 2015 version
02:17:06 the 2012 version and the 2015 version and it's possible that was omitted from the 15 version that may be worth worth looking at
02:17:16 right it's certainly cited in there definitely i've got no doubt about it
02:17:24 and did you ever consider the fire resistance of the duct work either the builders work shafts going up the both
02:17:32 the both north and south or the level two duct work
02:17:35 work did you ever make an assessment of that and consider its fire resistance
02:17:41 this was really marked up on the the architect's plans the shafts were as fire resisting shafts so we took that did you just take that at face value did
02:17:52 did you just take that at face value did you ever
02:17:53 you ever actually work out what standard those ducts satisfied when you were approving the system right so what you you have there is um existing shafts
02:18:06 have there is um existing shafts yes made presumably of um concrete form block work etc um so they apart from inspection to see if there's any holes in them um that would have been regarded as um
02:18:19 um that would have been regarded as um suitable in in the case i think barrel menses mentions this that she thought thought that was an acceptable approach
02:18:28 i see so um but did you consider whether the builders the existing builders were ducks had a minimum of 60 minutes fire resistance for each side separately did you ever actually consider that well it's marked up on the plan
02:18:42 that well it's marked up on the plan so therefore you know the expectation is that's the intention um but when they actually look at this this is they would need to do a survey of it and decide if there are any um problems with the shaft there needed
02:18:54 um problems with the shaft there needed to be
02:18:55 to be [Music]
02:18:57 [Music] any holes need to be filled up with fire resistant material etc etc um but we take the plan as an intent to make the shaft for resisting it's got a red or green line around it with
02:19:07 with a note that mentions it for resisting okay um did you ever consider whether those shafts fell within the
02:19:18 whether those shafts fell within the definition of protected shafts within the meaning of approved document b and therefore needed to be treated as protected shafts when the design was being developed
02:19:30 um i mean you're using a particular definition undetected shaft is basically a foreign shaft that achieves the the same standards as the element of construction in the building
02:19:42 building so despite you mentioned earlier about my reference in b1 and b5 um this does kind of cross over actually because you would then have shafts
02:19:53 because you would then have shafts riding out the building so clearly i did because i looked at the plans and they showed the shafts as far as this thing not just the 30 minutes which would have been just the means of escape standard so if you think you realize that that
02:20:05 so if you think you realize that that would also impose a requirement in terms of the dampers they would need to be at least fire and smoke dampers to satisfy that requirement of being a protected chef did you ever think about
02:20:17 protected chef did you ever think about that
02:20:19 that um i'd have to challenge what you said there a protective shaft doesn't require it to have smoke leakage um
02:20:30 um do you want me to explain that it might be helpful if i explain the the what i'm asking you to confirm is whether you ever thought about those builders ducts and those shafts as protected shafts
02:20:41 protected shafts and whether you ever thought about what that meant in terms of for example the rating of the dampers uh the leakage requirements yeah the answer is yes yes it is yeah yeah do we see any do we see any
02:20:53 yeah do we see any do we see any documentation or notes that you produce setting out what you concluded about that
02:20:59 that yeah it's not the normal practice when reviewing a job to you know if you look on the plan and you see
02:21:06 you see that the architect's marked it up as far as this thing and you look at the dampers and they follow the guidance there is really no need to have a separate note saying i've looked at the
02:21:17 separate note saying i've looked at the dampers i've looked at so we don't do checks maybe to the um what you're assuming basically what we're looking for is something that's wrong basically so as these dampers if they needed smoke
02:21:28 so as these dampers if they needed smoke resistance then um we'd look at that if it doesn't it doesn't um there was a change between the 2000 i don't want to go on but there was a change between the 2012 version the 2015 version the 2020 version
02:21:41 the 2015 version the 2020 version regarding the standard smoke leakage dampers
02:21:44 dampers so the 2012 version didn't require smoke leakage to the dampers the 2015 version did
02:21:49 did and we've even got a recommendation on the 2020 version to even enhance that one of the things we can think about is that when an extract system is extracting smoke because what we're worried about is
02:22:00 because what we're worried about is smoke leaking from one floor to another up the shaft so if we're extracting smoke and you have a damper on the floor above you're extracting past the damper so therefore the smoke is unlikely to
02:22:11 so therefore the smoke is unlikely to leak back in i don't know if that's a good diagram but i'd like to leak back in because you're extracting that i think was the principle probably on which the 2012 version of the seo guide was based but we get we
02:22:24 of the seo guide was based but we get we get advancements in the industry about quality and standards so when smoke damage are available which have a degree of leakage but they still leak smoke then
02:22:35 still leak smoke then why not use them and i think that's resulted in the the inclusion in the 2015 version yes i see and you mentioned earlier
02:22:46 yes i see and you mentioned earlier that the sca garden you're just referring to it now had the different standards that would apply for the different types of dampers fire dampers smoke control dampers if we just look at that go back to the
02:22:57 if we just look at that go back to the 2012 sca guide lfb 3059241 and i want to look at page 37
02:23:14 can you see at the top there there's it tells you which standards are relevant and you've got one two one oh one part eight smoke and heat exhaustion
02:23:25 eight smoke and heat exhaustion ventilation smoke control dampers one three six six part ten fire resistance tests for service installation smoke control dampers and then the fire classification
02:23:37 classification using that data for smoke control systems is the en 13501 part four and then underneath that in the separate list we can see
02:23:48 that in the separate list we can see that bsen1366 part 2 is the fire resistance test for service insulation fire dampers so that's for the lowest classification type of damper one three
02:24:00 classification type of damper one three six six part two and it's one two one zero one part eight one three six six ten at the top of the page that are relevant to smoke control dampers that's that was the point i was putting
02:24:12 that's that was the point i was putting yeah yeah
02:24:13 yeah yeah so what you've got here is a number of different standards that can be used and without question the lowest the bottom one is by comparison a lower standard than the one above but it is still an
02:24:24 the one above but it is still an acceptable standard well what i'm suggesting to you is that was the standard for fire dampers and the numerous pieces of guidance made clear
02:24:34 clear that the dampers for a system like grenfell tower needed to be smoke control dampers tested to moroner onerous standards as set out at the top of that page and what i want to ask is
02:24:46 what i want to ask is did you notice that at the time did you appreciate that or did you assume that the 1366 part 2 was a satisfactory test well i think it is stating that that is a satisfactory
02:24:58 is stating that that is a satisfactory test
02:25:00 test well it's saying it's satisfactory for fire dampers which are the lowest performance level of damper
02:25:07 of damper but it's not the same as a smoke control damper is it it's not as high as standard that what they're doing they're giving you a list of
02:25:15 of um possible standards that you could use and right at the end they're giving you this older standard that he's is was still regarded as suitable
02:25:26 suitable at the time yeah what happens is you get a lot of
02:25:31 a lot of development of products test standards as well and you've still got a legacy product a legacy standard that exists so they're
02:25:42 legacy standard that exists so they're still allowing you to use that standard below
02:25:46 below but obviously if you went you wanted to go for the modern standard you'd go for the one above generally what happens is these older standards get written out as time goes on and that's just the way
02:25:58 as time goes on and that's just the way standards work one final topic in terms of my pre-prepared questions about the firemen's switches so that we know
02:26:07 know in each lobby there's a little yellow key switch which was a switch which the firemen could use to override the system and make the smoke control system work in a different lobby
02:26:18 different lobby from that which it had first activated on do you recall that um no i didn't know okay can we just look at met three zeroes seven
02:26:29 seven two one six one
02:26:45 can we look um so this is um a report that was done for the metropolitan police
02:26:50 police service by rena about the smoke control system and if we can go to page 27 of the report
02:27:00 and i want to look um four paragraphs down under that section conclusions
02:27:08 so it said there um it was identified that the fireman's override switches the fos on each floor in the lift lobbies may have been a weak point in the system in the event of a severe fire the basic construction of these units
02:27:20 the basic construction of these units left them vulnerable to heat damage dust and water ingress on the balance of probability this allowed several of the firefighter to override switches devices in the hottest parts of the fire
02:27:31 devices in the hottest parts of the fire to short circuit causing the smoke dampers to behave unpredictably damage from the fire to the smoke damper actuators would also have prevented them from operating correctly which led to some smoke control dampers
02:27:43 some smoke control dampers being unable to either open or close in response to the unintended override switch inputs
02:27:50 and then if we can go to the paragraph below
02:27:57 it says in rena's opinion based on product information the smoke damper actuators and the firefighter override switches were not designed to withstand exposure to the heat
02:28:06 heat from an ongoing fire as these units were exposed in the lift lobbies it's likely that the system had not been designed to function reliably in a scenario where significant heat or fire were present in these areas
02:28:18 were present in these areas now did you ever give any consideration to whether the construction of the fireman's
02:28:23 fireman's override switches left them vulnerable to heat damage dust and water ingress in the event of a fire i i didn't and again it goes back to the value of a brag
02:28:34 it goes back to the value of a brag engineer
02:28:38 yes and um in dr lane's report she noted noticed that in psb's technical submission the override switches were to be installed on the stairwell on each level but on
02:28:51 on the stairwell on each level but on the psb
02:28:51 the psb electrical schematic they were shown in the lobbies so there was an inconsistent location on the psb documentation about where those override switches were whether they were in the stairs
02:29:02 stairs or the lobbies was that something that you
02:29:05 you ever noticed again that that kind of
02:29:10 consideration would have been the breg engineer and i explained that the brigade was made redundant and the process was to accept the commissioning certificate so i think it follows that
02:29:23 certificate so i think it follows that you didn't ever give that any consideration you know what it used to be the break role to do that kind of thing so no i didn't
02:29:33 thank you mr chairman i've come to the end of my pre-prepared questions and i'm sorry that i've taken till no that's all right time to do that um
02:29:45 um we need to have the usual break don't we yes we do
02:29:49 yes we do if we can have a break um i mean i'm in your hands i would have thought between 10 and 15 minutes would be
02:29:55 be adequate that's right thank you my name is tansen just to explain what's going on now
02:30:00 on now council's reached the end of the question she had prepared and she thinks therefore that she's asked all the questions she should have done but
02:30:07 done but we always have a pause at this point to enable
02:30:11 enable counsel to check that there's nothing been overlooked and to enable others who are following the proceedings but not in the room to suggest questions that perhaps ought to be put to you yeah now
02:30:22 to be put to you yeah now um what we would do normally is to have a quarter of an hour break and then for you to come back and see whether there are any more questions that will take us later than we would
02:30:33 that will take us later than we would normally sit can i ask you first of all do you mind sitting a bit later to finish your evidence today i don't mind so yeah i thought you probably wouldn't can i just check shorthand writer you're right all right thank you right
02:30:45 you're right all right thank you right well in that case we'll uh break now and come back at quarter to five
02:30:51 five all right right and then we'll see if there are any more questions for you um and while you're out of the room please again don't talk to anyone about your
02:31:00 your evidence or anything relating to it all right so if you'd like to give the usher we'll see you at quarter five
02:31:16 well miss granger i think 15 minutes ought to be long enough but if uh it's thought that more time is required you can send the usher to tell us thank you thank you
02:31:27 thank you so of course to find some please
02:51:22 right well we're ready to resume i'm going to check that miss grange is there and can he's in contact with us yes mr chairman i can hear you clearly oh good hello
02:51:33 oh good hello uh right then we'll ask mrs hanson to come back in
02:51:44 please right mrs hansen sorry we kept you waiting a bit longer than i indicated but
02:51:51 but it does happen sometimes and we'll see if there are more questions for you yes yes we're strange yes just three short questions please um mr hansen we saw in a number of the
02:52:02 um mr hansen we saw in a number of the the the exchanges that you had with the design team you were asking consistently for an extract rate of air through the damper
02:52:11 damper in and meters cubed did you ever actually get that extract rate provided to you i didn't know
02:52:19 um would you would you like me to explain why i asked for that well i think you told us that before i think we understand okay okay thank you yes thank you um second
02:52:31 thank you yes thank you um second question did you ever raise the lack of an m a engineer with your superiors at rbkc did you ever explain that that was creating difficulties yeah yeah i did so what happened was
02:52:44 yeah yeah i did so what happened was when the
02:52:45 when the we'll call it the reshuffle happened um it became clear to me the brag engineer was being made redundant so i asked for a meeting with the head of building control and billy explained my concerns about
02:52:57 and billy explained my concerns about this
02:52:59 this and you know he considered all what i said but
02:53:03 said but the answer was that we need to make these
02:53:08 these budgetary cuts as it were whatever you know the the term they use for it and um so i said well how how then are we going to ensure these systems are
02:53:19 systems are suitable and this is this is then the description of the process whereby we accept the commissioning um but you know we're not going in and checking it so really i i did to be quite frank i did
02:53:30 quite frank i did quite robustly um uh
02:53:35 not agree with that and made my feelings known but it seemed to be it was a fate accompli um i've been so concerned about it since and i and grenfell was the first job i
02:53:47 and i and grenfell was the first job i ever dealt with about a break engineer and i after that job i really felt it was so necessary so since then i've championed the council to
02:53:59 i've championed the council to re-employ or provide access at least to make a mechanical electrical engineer um and i think but when i did that there was there was two management skills
02:54:11 was there was two management skills involved so john allen was the boon trial manager and when i explained it to him my concerns
02:54:18 concerns he supported my thoughts about it very much so
02:54:21 much so um because he had just taken over his building control manager and he tried to establish an exchange with other boroughs um so that kind of started
02:54:32 um so that kind of started um i'm talking about the fusion now but anyway
02:54:36 anyway it's it's a very valuable resource the brag engineer and i think um i i feel that it's very significant when we're dealing with these mechanical ventilation systems i would have felt a lot more confident
02:54:48 i would have felt a lot more confident dealing with this job had i had a brag engineer sitting beside me evaluating the scheme okay thank you and and just finally did you
02:54:56 you ever at the time consider that the lga guide on purpose built blocks of flats was relevant to your consideration of the smoke control system no okay thank you mr chairman
02:55:10 no okay thank you mr chairman thank you very much and those are all our questions for mr hanson it just goes to thank him for attending to assist us today yes thank you mr grange well mr hanson those are all the questions we have for you it's right
02:55:22 questions we have for you it's right that i should thank you very much on behalf of
02:55:25 behalf of all three members of the panel for coming here spending the day here giving us your evidence it's been very interesting and useful to hear what you have to tell us and i'm sorry it's gone on we've kept you much later
02:55:36 it's gone on we've kept you much later than
02:55:37 than i thought we might but at least we finished today and now you're free to go okay thank you very much indeed thank you
02:55:44 you right would you like to give the usher and then she'll look after you thank you
02:55:58 and then she'll look after you thank you very much for strange we've got another witness
02:56:00 witness uh next week on monday is that right yes we have the designer of the system on monday mr
02:56:07 monday mr mahoney and again you're going to take him
02:56:11 him i i will be taking him yes and we shall have the same arrangements for those who are
02:56:16 are interested to know as we have today yes we will and then hopefully i'll be back with you in person on tuesday good we'll look forward to that all right thank you very much well at that point we'll conclude for the day
02:56:27 that point we'll conclude for the day and we shall resume at 10 o'clock on monday morning next week thank you all very much