Hugh Marney of PSB testifies about his design of Grenfell Tower's smoke control system, defending the 'betterment' approach and explaining why he couldn't install compliant systems due to spatial constraints.
00:00:34 right we're ready to resume after lunch so i'm going to make contact with miss grange to ensure that she's there hello miss grange hello mr chairman can you hear me yes
00:00:46 hello mr chairman can you hear me yes thank you and i take it you can hear and see us
00:00:49 see us yes very clearly good thank you and now we'll check that mr barney's there yes mr chairman i'm here my name is damani good to see you and you can see us i hope and hear us i can indeed thank you very much well
00:01:01 i can indeed thank you very much well then if you're ready we'll ask miss greens to carry on okay when you're ready for the screen yes thank you yes mr manny before we broke for lunch um you were pointing out that there was
00:01:13 um you were pointing out that there was a max fordham document their smoke ventilation analysis revision a of may 2014 which in your view is an important
00:01:21 important document in terms of switching to this betterment approach which you were referring to is that correct yes yes let's have a look at that it's exo
00:01:32 exo 50892.
00:01:35 that changed on the 13th of may i think it was so it's there's a change a week later yes we know there's a revision b as well but i just want to kind of understand what you're saying about
00:01:47 understand what you're saying about the significance of this document generally i think if we look at page two of it
00:01:53 of it that's the front page we can see that it says um under summary this report has been prepared in order to compare the design performance of the existing smoke extract ventilation
00:02:04 existing smoke extract ventilation system in grenfell tower with the design performance of the new system proposed as part of the refurbishment works yes it's been found that the proposed upgrade to the system should result in a considerable performance increase
00:02:16 considerable performance increase existing system 1.1 to 1.2 meters cube per second and the proposed system five meters cube per second yes yep now um had you provided the
00:02:28 yes yep now um had you provided the figure of five meters cube per second in that no that was their figure and i think we'll see it in a moment but this first revision certainly they were still looking at the
00:02:39 certainly they were still looking at the pushed pull system as their proposed system in contrast
00:02:44 contrast that's correct by the wording but incorrect in their proposal i spoke to them about it they got their proposal wrong i think okay but is what is the thrust of what you're saying that when you receive this as part of your
00:02:56 when you receive this as part of your package of documents your your understanding was that the objective had now moved from providing a compliance system
00:03:09 moved from providing a compliance system to providing a system which was merely better than that 1.1 to 1.2 meters cube per second across the stair door is that correct that is correct because you couldn't put a compliance
00:03:20 because you couldn't put a compliance system in
00:03:21 system in right so that's why you thought this document was significant because you were just merely now comparing with the volume of air across the stair door that the existing
00:03:33 across the stair door that the existing system was assessed to be able to produce yes yeah we were issued with this document as part as a tender package yes i understand it's become part of the contract yes
00:03:44 contract yes okay um and just to make good the point that this version of it certainly if you look at page five does appear to be suggesting that it's the push pull system that they're comparing we can see that
00:03:58 that they're comparing we can see that um in the last part of that paragraph it says
00:04:01 says it talks about push pull in the first line and then at the end it says this principle is to be retained but automated
00:04:07 automated in the proposed new system so is that the
00:04:11 the error that you said you drew attention to that's correct i think that paragraph drops out in the next one even though there's still wording in the document this is misleading that particular paragraph i believe drops out
00:04:22 particular paragraph i believe drops out i see and just to be clear even though you thought you were now simply looking at this betterment route of
00:04:30 of i think you said before and i just want to check you still felt that the proposals you were putting forward uh were compliant with the functional objectives of the building regulations yes
00:04:41 yes yes b1 and b5 yes but in a different way to compliant the normal compliance systems because we couldn't put them in let's look now we were going through your second statement and how you
00:04:53 your second statement and how you describe
00:04:54 describe the system in your second statement in contrast to your first statement and we take your second statement again at paragraph 41 on page eight
00:05:08 so at 40 you said that you did not design it
00:05:12 design it to comply with all the requirements of that british standard on pressure differential systems and then you say this at 41. my design reflected a more common type of mechanical extract
00:05:23 mechanical extract depressurization system a performance-based building appropriate solution widely adopted as a type of smoke control system
00:05:33 system and which were often referred often referred to within the industry as depressurization systems and is commonly called the colt shaft mechanical shaft system
00:05:44 mechanical shaft system yes that's correct so this was just to be clear a performance based building appropriate solution yes i don't know whether you can use it with appropriate but yes
00:05:55 appropriate but yes well that's yours
00:05:58 right those are your words but by performance based uh i take it there were some performance criteria for it uh by the designer yes yes
00:06:11 uh by the designer yes yes and can you recall ever saying what you've said in that paragraph including the fact that it's um a system which is commonly called the cold shaft mechanical shaft system did you ever
00:06:22 mechanical shaft system did you ever discuss that with building control no i did not and the reason i put it in there is is valid and that is that when i read the transcript of the smoke control experts evidence to
00:06:33 of the smoke control experts evidence to the panel
00:06:34 the panel in phase one they were asked the question i can't remember the precise wording of is it possible a system that was
00:06:42 was installed was to give an equivalence to a br
00:06:46 a br 79204 system or a cult chef system and the answer given by the expert was they weren't familiar with those system types
00:06:53 types therefore they couldn't answer and give any comment on it all shaft systems are based on those two sort of
00:07:01 sort of system types whether they be natural or powered so i was somewhat taken aback that the expert given evidence to the panel didn't know that so that's the reason that's being put in there to say hey you really need to look at this
00:07:14 hey you really need to look at this right
00:07:16 right that's not quite what you say there though is it your evidence that this system
00:07:21 system was one that's um similar to the colts shaft mechanical shaft system it reflects it it's not the same we cannot put a compliance system in that
00:07:32 cannot put a compliance system in that would have been a compliance system it was impossible to put a compliance system in but it would have given the same
00:07:38 same performance as that system but not by following
00:07:41 following the sea guide for example where the principles that it applied similar to the cult shaft system extraction rate's the same i see and and again why wasn't that
00:07:52 i see and and again why wasn't that communicated to building control at the time
00:07:54 time if that was part of the design uh intent because the building control at that time were aware of betterment they had agreed it and signed it off so they were only looking for the system
00:08:05 they were only looking for the system that delivered the cubic meters per second as in the max folding document so it is what you're saying that one route that building control had suggested was comparing the performance
00:08:17 suggested was comparing the performance of the old system with the performance of the new system and checking that the performance was better
00:08:22 better is that what you're referring to there indeed yes now i'll come on to ask you some more questions about the smoke control association guidance in due course um but mr hansen says in his witness
00:08:35 um but mr hansen says in his witness statement for the transcript that's paragraph 52 of his first statement that the system was designed in accordance with the principles of the sca guide 2012. now is he right about
00:08:47 sca guide 2012. now is he right about that
00:08:49 that principles yeah it delivered the same ventilation rate that's the principle we could not put it in in accordance with the recommendations in that guide i see what about following other
00:09:00 i see what about following other recommendations in that guide for example about setting performance criteria and objectives and documenting the design process was the system meant to be designed in
00:09:12 was the system meant to be designed in accordance with the process set out in the sca guide no because we couldn't follow it why couldn't you follow it because we couldn't put that type of system in i see
00:09:29 now just moving forward with the chronology we know that um you left psb at the end of february 2016 and you were well you were on gardening leave in february 2016 and then you began working
00:09:41 february 2016 and then you began working for colt in march 2016. is that right correct and our understanding is that david harrison of psb took charge of liaising with j s wright is that your understanding he was
00:09:52 is that your understanding he was already doing that he was the project manager for the project in advance of that data yes and we can see that you were involved involved with version five of the technical submission um
00:10:04 technical submission um we have emails that show that you were still involved with that then there's a final revision was revision six dated the 15th of march 2016 and that has david harrison's initials
00:10:16 and that has david harrison's initials on it
00:10:17 on it to what extent were you consulted about the final
00:10:20 the final sixth revision to that technical submission i wasn't consulted you weren't but i think we can agree that
00:10:27 that um the key paragraphs in that technical submission setting out the design intention and the key performance requirements remained unchanged didn't they
00:10:38 remained unchanged didn't they throughout as i understand it yes yeah now i now want to ask you some more detailed questions about the final design of the system and i want to start by looking at some
00:10:50 and i want to start by looking at some diagrams that dr lane presented in phase one of her investigations if we go to blas 5038 at page two
00:11:12 now just to be clear i'm going to show you a series of similar diagrams like this
00:11:16 this now this first diagram is showing a depressurization arrangement if the flat was depressurized rather than the lobby
00:11:25 the lobby yes um can you see that you can see here that
00:11:29 that they've depressurized the flat and therefore smoke and heat is prevented from spreading out through an open door because it's a lower pressure so there'd be an airflow into the flat from the lobby
00:11:40 into the flat from the lobby yes that's what it implies but it wouldn't work in reality but go on yes i know i understand i'm not sure doctor i don't think she's suggesting that i think she's just in a very simple terms looking at
00:11:53 in a very simple terms looking at how how depressurization systems might work
00:11:57 work in principle in different parts of the building
00:12:01 building um so then if we go to um page three of this clip the next page before we move on that would not work in principle it simply would not work yes and
00:12:13 it simply would not work yes and normally when you do a depressurization system like this you do it for say a basement
00:12:17 basement don't you which is entirely enclosed yes where you can depressurize the space a basement would be a smoke clearance system
00:12:27 system okay but it's one of the pressure different differential systems that's mentioned in the british standard 12106 isn't it
00:12:34 isn't it that is correct and it would not work in a block of flats yes no i understand that and i'm not sure dr lane's not suggesting it would work but we're just exploring the principles but it's it's important that the lay
00:12:45 but it's it's important that the lay people listening to this understand that what you're showing there will not work i don't know i therefore don't understand the purpose opponent well you might see at the moment that's your call mr marney perhaps you better
00:12:56 your call mr marney perhaps you better tell us why it wouldn't work then we'll learn that because you cannot create a vacuum when you're sucking air out of a space as in the fire flat
00:13:07 as in the fire flat you must have an air flow path in the flat
00:13:10 flat okay so when the door is closed before the fire brigade arrive that system is supposed to operate it will not operate because there's no airflow path right thank you very much now
00:13:20 now if we go to the next um diagram
00:13:25 diagram three this is the grenfell smoke ventilation system in very simple terms
00:13:32 terms so air is extracted in the yellow arrows but from the lobby air is pulled through the open stair door
00:13:41 door and the lift shot shaft at two meters per second and the flat fire door is assumed not to be open is that correct yeah
00:13:52 not to be open is that correct yeah so the basis for the design is that there's an open stair door but not an open flat
00:13:57 open flat door yes yes there's a butt there but go on yes okay um do you want to say what the butt is you might as well say now
00:14:08 you might as well say now if that fire flat door was then to open we could still protect the stair by the volumetric flow rate from the lobby yes well coming let's look at the next diagram
00:14:20 what dr lane's showing here is that if the stair door and the flat door is open there is the potential
00:14:30 potential for smoke to be pulled from the fire flat through the open flat door and into the lobby now do you accept that there is that potential for that to happen no at that stage uh
00:14:42 for that to happen no at that stage uh because the um there's no make-up air into the flat you're not going to pull it out however the smoke would flow quite naturally out at high level because it's hot assuming
00:14:53 at high level because it's hot assuming it's a hot fire and cold air would come from the lobby in and
00:14:57 in and underneath that smoke flow coming out through the same doorway into the flat therefore feeding the fire and smoke would flow out naturally not pulled out by the system so no i
00:15:08 not pulled out by the system so no i totally disagree right i see but what if there were windows open in the far in the fire flat with their windows open then then the smoke would flow more freely from the flat into the lobby
00:15:19 freely from the flat into the lobby yes well at grenfell tower we know for example that flat 16 the kitchen window was open on the night of the fire it was a hot june night yeah so in those circumstances where you've got windows
00:15:30 circumstances where you've got windows open not necessarily broken in a fire but just
00:15:33 but just open yeah is there the potential for smoke to be drawn from that flat into the lobby
00:15:41 the lobby not drawn no it will be forced out by its own energy
00:15:47 as i said previously it still won't enter the stair because of the volumetric flow rate do you not accept that because the lobby is at a lower pressure that there would be this potential for
00:15:59 that there would be this potential for air to flow from the flat into the lobby of course it would because the fire is the high pressure zone the fire will create its own pressure head so it will flow out naturally whether that door up to the
00:16:10 naturally whether that door up to the stairs open or not it will flow out the purpose of the system is to stop it getting into the stair well that's why i've been asking you and
00:16:21 well that's why i've been asking you and i've
00:16:21 i've asked you twice i think already is that right
00:16:25 right is the purpose of the system merely to stop it getting into the stair or is the intention of the system to provide some protection to the lobby and i think you said this morning that it would and it was designed
00:16:37 it would and it was designed to provide some protection to the lobby is that correct right let's go back a few steps because you're you're conflating two things quite wrongly if we take what the guidance documents tell us that we have
00:16:49 guidance documents tell us that we have to do is that that fire will is occurring in that flat as drawn but all the doors are closed okay then the occupants of the flat will make their escape
00:17:00 the flat will make their escape and some not loads not masses some smoke may travel with them that's what the code says
00:17:06 code says all right at that moment in time there is no ventilation at all in that lobby none whatsoever then if sufficient smoke enters the lobby and triggers the smoke detector
00:17:18 lobby and triggers the smoke detector then the the system will start to operate and go into its operational mode okay so until there's enough smoke there's no ventilation then you get if the door then closes it
00:17:29 then you get if the door then closes it should behind those people there will be low level ventilation b1 and that low level ventilation is created by the minus 25 ba okay it'll be pulling air in from around
00:17:40 okay it'll be pulling air in from around cracks of all doors the lift shafts the stair door all those okay
00:17:44 okay and that will equate to somewhere in the region about one cubic meter a second then once the stair door then is open the system will ramp up to the full speed and extract from the lobby
00:17:55 speed and extract from the lobby at three cubic meters a second yes so there's a sequence of events this is a snapshot in time which therefore is totally out of context
00:18:05 context and can i just ask
00:18:08 you're assuming that once the occupants have left the flat the flat door closes thereby preventing smoke from entering the lobby is that correct that is correct that is part of the compartmentation rules for blocks of
00:18:19 compartmentation rules for blocks of flats
00:18:20 flats and what we're told to design for yeah they will come out for a short period of time the door will be open then it will close and if you look at the way we see fd model that is reflected in the modelling
00:18:31 model that is reflected in the modelling yes i see i'm going to come and ask you uh
00:18:34 uh in a little while a bit more about different scenarios and what in fact it was reasonable to assume would occur on a fire floor like this
00:18:43 like this uh in due course but i i just want to stick with the kind of basic point and i want to put this to you that aren't you effectively protecting the staircase from smoke in this system
00:18:55 staircase from smoke in this system at the expense of moving more smoke out of the fire flap and into the lobby if those two doors are open at the same time no
00:19:03 time no and why not because the amount of smoke coming out will be the amount of smoke coming out
00:19:10 it has its own driving forces when the door is open the pressure disappears the differential disappears because the doors open yes so there's no pressure now so that high pressure zone is the fire zone
00:19:22 pressure zone is the fire zone it will create its own pressure head subject to temperature and density changes
00:19:26 changes and it will drive the smoke out there is no differential in the lobby at that stage i see but importantly therefore and particularly given you've just said that
00:19:37 particularly given you've just said that in terms of the stair protection isn't when the door to the fire flap opens isn't the airflow through the stair door likely to be reduced because the
00:19:48 likely to be reduced because the pressure difference will have dropped in the lobby
00:19:51 the lobby yes however as i said before the volumetric flow rate from the lobby will stop that smoke flowing into the stair yes but did you ever calculate at any
00:20:02 yes but did you ever calculate at any time
00:20:03 time as part of your design process the extent
00:20:06 extent to which the the airflow rate through the stair would drop if the flat the flat door was opened at the same time as the stair door no
00:20:18 at the same time as the stair door no because enough modelling has taken place over the years to prove that the case of how the system operates so no so you just assumed based on your knowledge of previous modeling
00:20:29 knowledge of previous modeling that it would be adequate still to protect the stair even though you would lose because you would lose your two meters per second then wouldn't you that's right and the critical number is the three cubic meters a second
00:20:41 the three cubic meters a second yes but you keep saying the three cubic meters per second that's the same as the two meters per second talking about volume and i'm talking about speed if you lose
00:20:53 and i'm talking about speed if you lose the speed
00:20:54 the speed why aren't you losing the volume as well because the fans will still extract the volume
00:21:00 volume but the fan it doesn't matter where it takes takes the air from it takes the air from
00:21:06 air from it it does not stop the fan operating at full speed no the fan will still operate at full speed yes but the fan's got nowhere to go once it's gone up once to full speed has it it can't go up again
00:21:17 it can't go up again does that mean you don't think it needs to it doesn't need it i'm sorry can we make sure we understand why mr man is saying what he's saying mr martin
00:21:29 saying what he's saying mr martin you you objected when council suggested that
00:21:33 that uh you would lose the three meters a second when the stair door was open where would you lose it to it's still taking three cubic meters a second out of the lobby and that will stop the smoke coming from
00:21:44 and that will stop the smoke coming from that flat flowing into the stair but if you've lost your two meters per second uh vol um speed of air through that door aren't you also
00:21:56 of air through that door aren't you also losing volume isn't it a corollary of that let me let me let me go back a few steps if we put a fully compliant system in it would work exactly as we're discussing a compliance
00:22:08 exactly as we're discussing a compliance system
00:22:09 system a mechanical shaft system it extracts three cubic meters a second and when that starter stair does open it will have two meters a second once the fire door opens you still got three cubic meters a second
00:22:20 three cubic meters a second on a standard system and it stops the smoke going into the stairs we know this okay that's what we know in our industry so i'm sorry to keep interrupting you but i think what you're
00:22:31 but i think what you're telling us mr marley is this that the fans will extract uh the the three or three point five cubic meters a second even though the opening of the stair
00:22:42 even though the opening of the stair door
00:22:42 door will uh affect the air flow rate in is that right that's right what you have to remember is at this moment in time looking at that diagram there's no broken wind
00:22:53 diagram there's no broken wind okay so the smoke will come out under its own pressure head okay it will flow cold air will flow in underneath that hot layer coming out and there will be a transfer between the
00:23:04 and there will be a transfer between the two spaces it won't be huge and you're still taking your three kilometers second out and the bulk of the airflow is coming from the stair if a window breaks you have a new airflow path but air will
00:23:17 you have a new airflow path but air will always take the least line of resistance to flow okay and the system will still fulfill its function because the amount of air that you can pull through a doorway is the amount of way you can pull through it away it will be split between the two once a
00:23:29 it will be split between the two once a window breaks before the window breaks you can't create a vacuum in the space so you can't suck out into space because there's no air coming back in i see
00:23:39 see but as i pointed out some air will go in because it'll do that by the natural heat transfer that's going on between the hot smoke being driven out and cold air being driven into the burn process the fire acts like a pump pulls cold air
00:23:51 the fire acts like a pump pulls cold air in and pushes hot smoke out so the transfer will be dictated to by no window being open and a window being open
00:24:00 open yes i see so i think what you're saying is once there is a potential air flow route through the fire flat
00:24:07 fire flat then you're accepting that the position might be different and you might lose your velocity but not the volume flow the volume flow remains constant yes but you lose your velocity through
00:24:18 yes but you lose your velocity through the stairs that's right but as i've said before we're happy with the amount of modelling that's been done that that smoke still would not enter the stair i appreciate you're happy with that but can you explain
00:24:29 that but can you explain why that was never calculated specific to grenfell tower why no one ever did a calculation to say once the flat doors open and there's some kind of airflow path whether that's an open window a broken
00:24:41 whether that's an open window a broken window through that fire flat what the effect would be on your two meters per second and how much would be lost the standard is accepted as a standard you don't do calculations
00:24:54 you can even buy this kit on the shelf it's standard the standard is accepted i'm sorry let mr marley finish his quest finish his answer then right then you come back there are certain
00:25:05 come back there are certain manufacturers of these systems where you can buy the components as a kit off the shelf because the answer is the answer so you don't have to calculate anything because the answer is no you don't do a
00:25:17 because the answer is no you don't do a calculation the three cubic meters a second is almost
00:25:21 almost throughout the industry a universal number that's used because we know through research and our own modeling that it works you don't redo the calculation every time it is the answer if it was a
00:25:33 it is the answer if it was a commercial building with large undivided volume spaces it'd be a different answer because you've got a larger fire load the fire load is dictated to by the compartmentation yes now you say the standard is the standard
00:25:44 standard is the standard but and i'll come on to this in due course if you were uh looking at a a system that was designed to the british standard 12101 part
00:25:54 part six
00:25:57 that standard work yes sorry great can i finish
00:26:01 finish that mr money let council finish her question and then she'll let you finish your answer right if you were designing it to that standard
00:26:09 standard then the standard forces you to confront what would happen to your airflow if different combinations of doors are open doesn't it
00:26:25 open doesn't it i think there's another conflation going on here well maybe let's come back to this because let me let me let me think of what you just said
00:26:33 just said right so if you have certain numbers of doors open certain doors open have no material effect
00:26:40 effect on the ventilation rate for example the fire brigade would arrive at the fire entry point in the open door so there's a door open there you then travel to the firefighting lift
00:26:51 you then travel to the firefighting lift to the floor below the actual uh floor that's on fire and the lift door then opens they come out of the lift they then connect their hose to a dry riser main
00:27:02 hose to a dry riser main sorry sorry mr money i'm going to interrupt you and we'll come on to this in due course so generally the doors being open have no effect no right so you're saying that different combinations of doors being open has no
00:27:14 combinations of doors being open has no effect
00:27:15 effect on the airflow across the stair for the pressure differential system on my system well with the pressure differential system it does doesn't it no i see
00:27:27 it does doesn't it no i see the critical the critical thing with a pressure differ looking at your sketch now let's reverse it around you're blowing air into the stair
00:27:34 stair you're blowing it into the lift and you're blowing out into the lobby and then the windows could be open but in that
00:27:40 in that in this arrangement you couldn't use windows you'd have to put a purpose-made shaft in behind the front door to the flat the air would flow
00:27:49 flow from the stair into the lobby out of the lobby into the flat and out of that shaft
00:27:54 shaft it doesn't matter what other doors are open other than the ground axis level door
00:27:57 door because air bleeds to outside in that application because it's pressurized positively okay we'll come back to that and i'm going to ask you some more questions about that later
00:28:08 later let's just focus now for a moment on the colt's shaft system because you say as we've seen in your witness statement that this uh system is similar to the common the commonly called colt
00:28:19 commonly called colt shaft mechanical shaft system now to what extent did you actually rely upon any uh analysis of the cult shaft system when you were developing your design for grenfell tower
00:28:31 design for grenfell tower i did not as i told you i put that in there because the experts didn't know what they were talking about i see so um it wasn't something that you took into account at the time that this was similar to the
00:28:43 the time that this was similar to the colt
00:28:44 colt shaft system well the reason i put the words cult shaft in there the systems are commonly called i'm sure that's the building i used i didn't say it is they're commonly called cult shaft systems
00:28:55 cult shaft systems because cult with the market leaders in that industry using those type of systems
00:28:59 systems and they become synonymous with their name well you you tell us let's go back to paragraph 41 of your second statement page eight
00:29:10 you say my design reflected a more common type of mechanical extract depressurization system yeah you tell us that it reflected that
00:29:21 yeah you tell us that it reflected that and that that system was a performance-based building appropriate solution and then you go on to say and it's commonly called the cult shaft mechanical shaft it's commonly called yeah yes so
00:29:32 yeah yes so that's why i'm asking to what extent did you draw upon the colt's shaft system
00:29:38 system when you were designing the system at grenfell tower let me try and explain a different way then when i say commonly called
00:29:44 called it doesn't mean cult shaft is the reference point it's a mechanical shaft system but the industry knows it commonly as a culture system but it's a mechanical shaft system
00:29:57 but it's a mechanical shaft system as in the system you installed at grenfell tower is that no it can't be because we can't follow the recommendations it has the same outcome as that
00:30:08 it has the same outcome as that but it can't be put in in the same way which i'm sure we'll come on to
00:30:14 so did your design reflect a system that is commonly called the coltshaft mechanical system it reflects the outcome of it yes right
00:30:25 it reflects the outcome of it yes right now um
00:30:30 in her phase two report dr lane has explained that to aid her understanding of that cult shaft system she has considered two cult technical papers
00:30:41 papers there's a technical paper from 2004 called mechanical ventilation of firefighting shafts performance and design
00:30:48 design and a paper from 2007 called cfd analysis of smoke ventilation in a fire fighting lobby with a 12-megapixel unsprinklered fire now
00:30:58 now can you recall had you read those cult documents
00:31:02 documents when you specified the the when you designed the grenfell system um no but i would question the validity of the second document refer to why why a 12 megawatt firing unsprinkled
00:31:14 why a 12 megawatt firing unsprinkled building it's not relevant to residential buildings fine well let's look at the 2004 technical paper and were you aware that that technical paper and i'll take
00:31:25 that that technical paper and i'll take you to it but in general terms were you aware that that paper expressed concern about the extract tending to draw excess smoke into a lobby through gaps around the closed door to
00:31:36 through gaps around the closed door to the to the accommodation to the flat yes that's why you use -25 pa to stop that
00:31:42 that or to mitigate it so um if we go to bla four zeros five four eight four
00:31:57 this is the paper and i want to look at page three
00:32:04 it's that paragraph that's got the yellow highlighting in it it says in this paper while the door open condition is the most critical the system of course has to deal with conditions with the lobby doors closed
00:32:16 conditions with the lobby doors closed as well
00:32:17 as well and obviously an obvious concern was whether the mechanical extract would tend to draw excess smoke into the lobby through gaps around the closed door to the accommodation do you see that there yes and
00:32:30 do you see that there yes and if you look at page four sorry carry on reading don't stop there because you're taking something out of context again this condition was therefore also modeled
00:32:39 modeled with the addition of a pressure relief damper in the shaft to limit lobby depressurized into 25 pa the model took a worst case condition of a double door okay so that's consideration of the 25 pa
00:32:50 so that's consideration of the 25 pa pressure differential is that where you got your 25 pa pressure differential from i didn't take it from that document no right
00:32:59 right and if you look on page 4 under 3.2
00:33:05 we can see this is for a mechanically ventilated shaft and some of the figures have had to be redacted with a door open condition
00:33:14 condition for this particular configuration you can see it says at the end paragraph the overall extract flow rate is greater than provided by the bre shaft the results show however this increase is not beneficial the system draws more
00:33:26 is not beneficial the system draws more smoke out
00:33:27 smoke out out from the accommodation and makes conditions worse in the lobby with a deeper smoke layer and higher temperatures right yeah and then at page five
00:33:38 yeah and then at page five under discussion
00:33:41 the paper says this it uh we can see in the yellow highlighted paragraph it is important that the mechanically ventilated shaft is not overrated
00:33:50 overrated since an increase in the design extract rate tends to draw excess smoke from the accommodation into the lobby making conditions in the lobby worse yeah now
00:34:02 were you aware that the 2004 paper modeled this condition with the addition of a pressure release relief damper in the shaft to limit the lobby depressurization to 25
00:34:13 depressurization to 25 pascals to alleviate this tendency to suck smoke into the lobby from the fire i wasn't familiar with that paper at that time
00:34:24 was the potential effect of drawing smoke into the lobby from the fire flat something you ever considered yes that's what we that's why we designed for 25 pa i see and i'm not forgetting when you
00:34:37 i see and i'm not forgetting when you when you're extracting at minus 25 pa you're sucking air through and around all doors
00:34:44 all doors not just the fire flat so the amount that would come from the fire flat is reduced by the amount you can draw from other doors so it's not all coming from that one door yes so the ventilation in in the lobby
00:34:56 yes so the ventilation in in the lobby at the minus 25 pa will reflect the amount of air that can be drawn in around the crackage around all those including lifts i see now can we agree that the cold
00:35:08 i see now can we agree that the cold shaft system in comparison to the system that you designed is materially different including in the physical arrangement of the components and their performance specification
00:35:19 no no no you don't think it is different
00:35:27 we're not necessarily using the same components are we because we're a different company but certainly the ventilation rate is the same okay if we can look at blarp2
00:35:38 if we can look at blarp2 5035 at 161.
00:35:51 i'm looking for table 5.8 i think it might
00:35:55 might possibly be the next page
00:36:00 yes so in this table 5.8 what dr lane has done is compare the cult
00:36:07 cult system with the psb technical proposal and she's identified certain
00:36:15 certain differences between the two systems now for example i just want to put to you if you
00:36:21 you see three three column rows up from the bottom there's a heading floor area of lobby and you can see that for the colt shaft system the floor area
00:36:32 for the colt shaft system the floor area was 12.5 meters squared and it was rectangular 2.5 meters by 5 meters as per the bre report whereas the floor area of the lobby at grenfell tower you
00:36:44 area of the lobby at grenfell tower you can see on the right hand side was 32 meters squared and it was an irregular eye
00:36:49 eye shape with dead end corridors to flat entrances
00:36:53 entrances do you see that i'm not sure i can't it's just so much information on that screen
00:36:57 screen where are we sorry we are three lines up from the bottom three three rows up from the bottom on the left hand side there's a label floor area of lobby do you see
00:37:09 label floor area of lobby do you see that
00:37:10 that three lines up three three three boxes up two drops exactly right now where are we three boxes up from the bottom on the left hand side
00:37:22 from the bottom on the left hand side you should see no that's right floor area of lobby right with you yeah and in the colt system the floor area was 12.5 meters squared and it was a rectangular
00:37:34 and it was a rectangular shape at grenfell tower she's then put the
00:37:38 the configuration of the lobby on the right-hand side and you can see it was 32 meters squared and it was an irregular eye shape with dead-end corridors to flat entrances
00:37:51 entrances right now um doesn't this show us that the cult system for the cult system was a very different type of system from the one you
00:38:04 type of system from the one you installed at grenfell tower in that there were grenfell specific features of the building that made it different from the systems that had been modeled by colt the layout is different but the
00:38:17 by colt the layout is different but the volume
00:38:17 volume of smoke entering the lobby will be different
00:38:21 different i see why don't we see any consideration in your design documentation of the potential dead zones and the eye shape of the lobby and the
00:38:31 the impact that that might have on this system because it's not relevant i don't know where this dead end thing you second time you've asked this question
00:38:41 question that the systems are not designed to deal with dead-end sections of that nature
00:38:47 nature that even even the compliance systems don't do that are you aware that cult supply what's called an extended
00:38:58 supply what's called an extended corridor system designed to complement the cult shaft system
00:39:03 system where there are extended travel distances in a common corridor answered this this morning yes and colt recommends using something called an extended corridor system
00:39:15 extended corridor system not the cult system yeah those increased travel distances yes yeah push pull yeah which we've already discussed and said we couldn't do
00:39:25 so were you aware of that cult extended corridor system at the time you were working on the grenfell tower project is it relevant to cult i was aware of those system types from the sea guide
00:39:37 those system types from the sea guide why wasn't that more appropriate or that the more appropriate cult comparator given the extended travel distances in the grenfell tower lobbies if it's impossible to install something
00:39:48 if it's impossible to install something it's impossible so you cannot do it therefore what am i supposed to say you could not do it you couldn't put that system in and just to be clear why are you saying
00:40:00 and just to be clear why are you saying you couldn't put something in that was like an extended corridor system well to start with it certainly wouldn't have dealt with what you just said about dead end bits because i've explained this morning it's dealt it's dealing with a straight
00:40:12 it's dealt it's dealing with a straight corridor section where the a flows from one end to the other it doesn't flow around corners and then back out again it simply would bypass it so it doesn't deal with that with regard to other aspects of this the
00:40:25 with regard to other aspects of this the system type because of the constraints of the employer's requirements you'd have had the high velocity jetting from the low level grills and in my opinion that would have pushed smoke into the stair but you couldn't use that type of system
00:40:37 but you couldn't use that type of system because we couldn't get the air to enter into that space at the right velocity right now in your second statement you refer to the local authority building
00:40:48 refer to the local authority building control the labc certificate for the colts system can we just go to that certificate it's
00:40:57 inq3014683 i want to look at page two under scope of registration in this labc
00:41:09 under scope of registration in this labc certificate we can see that it says
00:41:16 this registered detail relates to colt's shaft the mechanical ventilation means of escape firefighting systems etcetera and then if we pick it up in the third line it says cult shaft means of escape systems
00:41:28 of escape systems other than the standard shaft approach will be justified by project specific cfd analysis all systems are subject to performance testing and commissioning at project completion
00:41:39 project completion were you aware that the labc certificate provided that systems other than the standard cult shaft approach were required to be justified by a project specific cfd analysis
00:41:53 by a project specific cfd analysis how do i answer that question the answer is no because it's not required but i am aware that it's recommended that if you have extended travel distances that you would cfd model it but it's not required
00:42:04 would cfd model it but it's not required it's not mandatory so you are aware that it's recommended that if you have extended travel distance so that you would cfd model it yes i would myself recommend it cfd model
00:42:15 i would myself recommend it cfd model yes
00:42:16 yes why didn't you recommend a cfd model at grenfell tower given we've agreed that there were extended travel distances because we already know that the system couldn't comply with the requirement for extended travel distances we could not install a system to do that
00:42:29 we could not install a system to do that so you don't see fd something that's going to fail but don't you see couldn't you see fd something to see how it performs right if you're going to cfd something
00:42:40 right if you're going to cfd something normal practices you someone says we need to cfd model this here's an order we'll pay you for doing the modeling so no unless you're being paid to do the modeling you don't do it until such time that you're requested to
00:42:52 until such time that you're requested to do it
00:42:53 do it it's not it's not these things take a long time to do they take they can take up depend on busy your cfd modeling companies it can take anywhere between two and ten weeks to do a model of this
00:43:04 two and ten weeks to do a model of this nature yes but what i'm seeking to get to the bottom of is why not recommend some cfd modeling on the grenfell tower project this was discussed with max fordham partners there was insufficient time to carry out modeling
00:43:18 insufficient time to carry out modeling so modeling was not considered and that was
00:43:21 was also a requirement of why they the decision to go down the betterment route there wasn't time to get any approval for a non-standard system so if you can just wait for the end of my question
00:43:32 just wait for the end of my question each time
00:43:33 each time so when you say to get corrected this was discussed with max fordham and there was insufficient time to carry out modeling
00:43:42 modeling when did you discuss that with max fordham
00:43:45 fordham in our second telephone conversation when we went through the problem with trying to put a compliance system in and then the subject of cfd model was brought up by max fordham and then we responded by
00:43:57 by max fordham and then we responded by saying how long it would take and the fact we would need an order to proceed with that work why didn't you recommend that there should be cfd
00:44:08 should be cfd modelling to check that the system could work in the way you thought it might why didn't we recommend it
00:44:18 we discussed it it was agreed there was no time to do it so there's no there's no point in recommending it if they're not going to do it
00:44:26 just finally on this cult shaft point and we saw that you raised it in your second witness statement and are you aware that the colt
00:44:35 colt shaft system was primarily designed as a system
00:44:39 system for commercial premises office office accommodation which system are you talking about they got more than one and one is for residential apartment buildings
00:44:51 residential apartment buildings so if we can pull up a witness statement now
00:44:54 now col 701
00:45:09 and if we can look at paragraph 1.7 on page two
00:45:17 so he's talking about the shaft system described in the reports those are the two bre reports that i mentioned earlier which are
00:45:24 which are uh referred to in the labc certificate it says the shaft system described in the reports is a mechanical firefighting shaft smoke ventilation system originally designed and intended for
00:45:36 originally designed and intended for buildings over 18 meters in height constructed primarily for office use the two documents in question were prepared to be specifically relevant for commercial projects fire sizes and construction layouts
00:45:47 fire sizes and construction layouts differ significantly for residential applications and neither reports were originally relevant to them and then if we go on at page 3
00:45:58 at 1.8 he then says while applicable to commercial buildings the 2004 cult report has been used as the basis for designing smoke control systems in residential
00:46:09 smoke control systems in residential stairs
00:46:10 stairs but only after publication in 2005 of a second bre study on behalf of the then um opdm now mhclg which concluded that suitably
00:46:21 now mhclg which concluded that suitably designed mechanical ventilation can provide protection to the stairs that is in principle resilient to adverse wind and building stack effect pressures
00:46:29 pressures this can be achieved by either depressurizing the corridor lobby relative to the adjoining stair however as the 2004 report was written before the second bre report it does not make reference to the use of these systems in residential buildings and the
00:46:42 systems in residential buildings and the 2007 report was only ever intended to support
00:46:45 support unsprinklered office applications and then he says further in many cases where colt were contracted to a project where the building design incorporated any non-standard conditions for example
00:46:56 any non-standard conditions for example non-compliant travel distances to approve document b smaller shafts or unusual staff locations
00:47:02 locations project specific modeling and a project specific report would have been prepared and then at two he
00:47:09 he says two point naught below that says as the 2007 report is specifically only applicable for unsprinkled officers it therefore has no relevance to grenfell
00:47:21 grenfell do you see that there oh you indeed and can we agree therefore that the original colt system was developed for commercial office accommodation of course it was that's where they talked about a 12
00:47:32 that's where they talked about a 12 megawatt fire which wouldn't get any residential building and that subsequently although it's been by
00:47:38 by by other studies extended into residential systems cults have said that where they are contracted to a project where for example there are non-compliant travel distances
00:47:49 distances smaller shafts or unusual shaft locations
00:47:52 locations project specific modeling and a project specific report would have been prepared do you see that i do and i said i totally agree with that earlier why don't we see project specific
00:48:03 why don't we see project specific modeling and their project specific report
00:48:06 report for grenfell tower because we were we were we've had the discussion with max fodo and it was decided not to do that
00:48:14 that i can't make people spend their money and make me do a model i see but how strongly did you recommend that that project specific modeling and project specific report ought to be
00:48:25 and project specific report ought to be prepared it didn't become necessary because they went forward on a betterment i see so because you say you were just merely trying to better the airflow rate of the old system it
00:48:37 the airflow rate of the old system it didn't become necessary to do any form of modelling that wasn't my call i was offering advice
00:48:45 advice i see that wasn't my decision to make just moving on then can we go to um look at something in bsen121016 we've
00:48:56 look at something in bsen121016 we've referred to this british standard a number of times and if we can look at it rbk three four
00:49:06 and i want to look at section 9 on page 57
00:49:14 this is at the bottom of the page
00:49:20 you can see it's it states here under general the objective of a depressurization system is to achieve the same protection at the doorway between the depressurized space eg a basement and the protected space eg
00:49:32 eg a basement and the protected space eg a stairwell as would be achieved by pressurizing the protected space it is important to know that there's no protection of any part of an escape route
00:49:42 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 between depressurization and
00:49:53 difference between depressurization and smoke exhaust ventilation to be effective each depressurized space shall be bounded on all sides by fire resisting constructions because any loss of integrity would result in an
00:50:05 any loss of integrity would result in an equalization of pressure between the depressurization zone and external air however in compartmented buildings it may be possible to depressurize individual spaces
00:50:16 individual spaces now would you agree that this section of that british standard is therefore explaining clearly that with a depressurization system there is no smoke protection for the depressurized space itself
00:50:31 in a large and divided volume space yes that's where the fire is that's where the fire is however in compartmented builders it may be possible too and this is this is a compartmented building we're talking about not a large
00:50:43 building we're talking about not a large and divided basement but in the case of grenfell tower doesn't that mean that although the system was designed to prevent smoke-filled air going into the stair it was not providing smoke protection to
00:50:55 it was not providing smoke protection to the lobbies no it doesn't mean that at all i've already explained if you look at 2.25 of adb it's very specific
00:51:05 specific in what he wants the system to do and it was designed to do that you're conflating that again with a a space that's on fire and full of smoke
00:51:16 that's not b1 if the place is in the fire and full of smoke you won't get b1 can we also look at uh bs triple nine one
00:51:26 one twenty eleven that's at bsi five zero six two one
00:51:39 there it is we saw it earlier on this morning
00:51:42 morning and i want to look um at
00:51:47 clause 26.1 of this on page 66
00:51:55 this is the heading smoke control smoke control for means of escape and under the heading general it says in residential buildings designed with a
00:52:07 in residential buildings designed with a stay put strategy additional protection to the staircase should be provided in the form of a smoke control system and then you can see the commentary underneath it says whilst the primary
00:52:18 underneath it says whilst the primary aim of smoke control in residential buildings
00:52:21 buildings is to protect the staircase enclosure it can also
00:52:24 can also provide some protection to the adjacent protected corridor or lobby and then it says this in extended corridors the primary objective of the smoke control system is to protect
00:52:35 smoke control system is to protect both the common corridor and the staircase enclosure for means of escape do you see that there indeed now we know that grenfell tower did have extended travel distances both as
00:52:48 extended travel distances both as defined in approved document b and in this bs triple nine one i over 75.5 meters
00:52:58 yes yes do you agree that as a result according to this guidance a smoke control system needed to be designed to protect both the staircase and the common corridor i.e the lobby
00:53:12 the common corridor i.e the lobby i totally agree however you couldn't put that system in it was impossible so i agree but with that qualification so you did appreciate that at the time i
00:53:23 so you did appreciate that at the time i understand that i've been involved in drawing these standards up so yes i totally understand it and i totally subscribe to it but if you can't do something you can't do it
00:53:34 do it why don't we see a clear statement in the design documentation then saying even though that that is what's said in the british standards and even though we have extended travel
00:53:46 and even though we have extended travel distances here um this is why we're not protecting the lobbies why don't we see any grappling with this in the design documentation because
00:53:58 in the design documentation because it was discounted when we had our discussions of advice with max fordham and partners and we therefore were not involved in that decision making process of where it went from there we
00:54:09 of where it went from there we immediately followed on from what they then agreed with building control so you wouldn't see anything anywhere
00:54:15 anywhere because it was never done
00:54:18 i appreciate it was never done but but why why
00:54:22 why why it was never done because at that moment in time we were told they were not going down the design route they would go down the betterment route yes but even that's what happened in the contract documents even with the betterment route in trying
00:54:34 even with the betterment route in trying to make the system better than the old one
00:54:36 one wasn't it nevertheless important to grapple
00:54:39 grapple with the fact that grenfell tower contained
00:54:43 contained extended travel distances and therefore there needed to be some protection to the lobby you couldn't give it so you couldn't do it and it was discussed if we can go to
00:54:55 and it was discussed if we can go to clause
00:54:57 clause 0.2.3 of this document on page 11. we can see it says smoke controlling
00:55:08 we can see it says smoke controlling common parts there and if we look in the second paragraph it says smoke can be controlled in the common areas through fitted ventilation systems which are either natural or mechanical
00:55:19 are either natural or mechanical these ventilation systems have two main purposes the first of which is to provide some protection to the stair core
00:55:26 core and the second of which is to aid firefighters when tackling a fire ventilation systems can also be used to compensate for extended travel distances within the common corridor leading to the stairs and thereby help
00:55:38 leading to the stairs and thereby help occupants to escape safely where smoke control is used to provide compensation for extended travel distances
00:55:46 distances it is the responsibility of the designers to demonstrate that the ventilation system can provide tenable conditions for the occupants using the route with extended travel distances
00:55:59 with extended travel distances now just to be clear i think what you're saying is
00:56:02 saying is you didn't ever consider the impact of extended travel distances in your design is that right we couldn't we couldn't put a system in that would deal with it so
00:56:15 deal with it so you didn't attempt to demonstrate how the system could provide tenable conditions for using the lobby escape route is that right
00:56:26 i don't understand what you're trying to say in that question i don't understand if you can't do something you can't do it so i think we agree there's no consideration
00:56:37 consideration of whether the system could provide tenable conditions in the lobbies for those using the lobbies as an escape route is there
00:56:48 i'm not sure how to answer the question i really don't i'm lost if you can't do it you can't do it
00:56:59 do you want to put it to mr marnie as to what he should have done perhaps he'd understand the question uh a little better yes what i'm putting to you is that the design documentation should have
00:57:10 the design documentation should have recorded the fact that there were extended travel distances do you agree right if the design documentation should contain that that was for the design engineers and this fire engineers to do not the
00:57:22 and this fire engineers to do not the smoke control engineer that was not the case it did not happen so that when we were asked to look at it we told them and advise them we couldn't put anything in that formed any form of compliance
00:57:33 compliance therefore took a different view the designers to go down a different route i see so i think you're saying that it was not for you to consider the effect of extended travel distances in the lobby
00:57:44 travel distances in the lobby consider it and i pointed it out can i just intervene again i i think there's a danger of getting it slightly across purposes here mr mani has said in the past that he didn't
00:57:55 has said in the past that he didn't that psp were not designing a system although your question rather assumed that they were um yes well is that right mr marley were
00:58:06 um yes well is that right mr marley were you designing a system we started off by designing a system yes but then that quickly was rejected because we couldn't convince
00:58:16 convince the designers to put a non-compliant system in because it was non-compliant using my language we couldn't get to comply with any guidance or standards however using engineering judgment
00:58:28 however using engineering judgment it was a reasonable approach to try and do it in a different way they then said they didn't have time to go down a route of trying to get a non-compliant system approved or cfd
00:58:40 a non-compliant system approved or cfd model so they went down a route of betterment and would you are you telling us that the betterment route as you've described it
00:58:47 it was not one which involved any design on your part or the part of psb they just use the volumetric flow rate that we gave them yeah all right thank you very much yes
00:58:59 yeah all right thank you very much yes yes
00:59:01 yes yes i mean i think to the extent that you are suggesting mr money that you didn't do any design no no i'd still i i i said earlier i'll put my hands up there i did do design i did look at this and
00:59:13 i did do design i did look at this and offered
00:59:14 offered the best solution that was available given all the restrictions yes we did discuss all of these points including
00:59:22 including we couldn't put a system in that would comply
00:59:25 comply therefore we offered a alternative design solution that alternative design solution was not taken forward by the designers they went forward on betterment
00:59:40 well just to be clear what are you saying are you saying your alternative design solution was the one where the smoke was extracted at both the staff that's correct which didn't comply
00:59:50 comply which did comply you're saying didn't comply
00:59:53 comply didn't comply we'll come to that when we get the sea guidance or any of the documents you want to go through bs double 901 it did not comply with the the suggested
01:00:04 it did not comply with the the suggested formation of a system within those documents
01:00:07 documents yes i understand but then i think you confirmed earlier that you then modified the design so that it was extracting down through the south shaft and you didn't
01:00:18 through the south shaft and you didn't indicate that there was a problem with that design did you
01:00:23 that wasn't nice situation to to question it they had agreed a betterment and that was part of what they were doing but just going back to this betterment even even with betterment are you saying that when you're
01:00:35 you saying that when you're simply trying to better the old system are you saying that you don't need to think about extended travel distances as part of that approach no don't put words in my mouth that's not what i'm
01:00:46 words in my mouth that's not what i'm saying at all i told you i had considered it but there was nothing i could do about it with the constraints that were given by the employer's requirements if you can't do something you can't do
01:00:59 if you can't do something you can't do it so
01:00:59 it so it was then discussed with the responsible party because we weren't the responsible party we were merely offering advice and it wasn't taking what we suggest it wasn't
01:01:10 wasn't taking what we suggest it wasn't taken up
01:01:11 taken up because they didn't believe they would have sufficient time to get a non-compliant system approved it did not comply
01:01:17 comply it didn't give you those aspects of design that you were talking about with regard to safe travel distance yes and one of the things i'm seeking to understand is if you did consider it
01:01:28 understand is if you did consider it as part of your betterment approach you did consider the extended travel distances
01:01:33 distances why don't we see that consideration written down in any of your design submissions in the technical submission or any other proposals why don't we see it recorded that there were extended travel distances
01:01:46 were extended travel distances and an explanation or a mitigation provided as to why that was nevertheless acceptable because what we were suggesting wasn't accepted it didn't go
01:01:57 accepted it didn't go we didn't go beyond that but we were not involved in this contract we were not party to
01:02:02 party to all these conversations all this documentation flow that was going on we had a single conversation which followed up with a single email that said this is what we want you to do we went back against that and said we
01:02:13 we went back against that and said we can't do anything the best we can do is this
01:02:15 this and that was then rejected then we fell up
01:02:19 up as in we were no longer involved until such time
01:02:23 such time the tender documents arrived when we were asked to tender against those documents
01:02:27 documents and that document then existed which said
01:02:30 said we're going forward on a betterment and mr manny in that context the betterment context who if anyone did you think ought to have been considering extended travel
01:02:42 been considering extended travel distances
01:02:44 distances you couldn't consider them oh sorry correction you could not put a system in
01:02:51 system in that complied with current thoughts and smoke control methods to deal with that because of the constraints imposed by the employer's requirements
01:03:02 imposed by the employer's requirements thank you if we can look at the sca guidance now i want to look at the uh the 2015
01:03:10 the 2015 uh version of that guidance rbk402932 page six can i ask why we're looking at this document that doesn't refer to this particular project
01:03:21 particular project uh is that because of the timing of it because of the timing of it yes contracts on a in a contractual status the documents that are relevant to those that were published
01:03:32 that were published and used at the date of planning permission well i appreciate that's your position
01:03:37 position um mr my position as a contractual position well mr molly let's just see what
01:03:42 what council wants to ask you and uh in due course the panel will decide uh what is relevant to what we'd like your help if you're prepared to give it to us on some of these other
01:03:53 to give it to us on some of these other points so off you go miss grange thank you yes and we do know that building control did send this version of this sca guidance uh to the professionals involved in the
01:04:04 the professionals involved in the in the project uh during the course of the
01:04:07 the of the design process so um it it it's not wholly irrelevant um if we can look at
01:04:14 look at this at page six under 2.1 primary objectives in the second paragraph it says where the travel distances are no more than 7.5 meters in distance from the door to
01:04:25 7.5 meters in distance from the door to the staircase or sterile lobby to the most remote apartment entrance door the primary objective of the smoke of smoke control in residential buildings is to protect the staircase enclosure by
01:04:36 is to protect the staircase enclosure by ensuring that the stairways remain relatively free from smoke and heat in the event of a fire within a dwelling and then if we look two paragraphs down from that
01:04:46 from that it then goes on however where corridors are extended the primary objective of the smoke control system is to protect both the common corridor and the staircase
01:04:57 the common corridor and the staircase enclosure
01:04:58 enclosure there are considered to be two forms of extended corridors and then the first form extended corridors it says these typically have no more than 15 meters travel distance from the furthest apartment door
01:05:10 the furthest apartment door to the staircase or sterile lobby the primary objectives of the smoke control system are to protect the common corridor
01:05:16 corridor for means of escape and the staircase enclosure for means of escape and firefighting do you see that there i do
01:05:25 do and were you familiar with this part of the sca guidance while you were working on the grenfell project i was indeed and i can also point out this for extended corridors not lobbies it's quite specific in what they're
01:05:37 it's quite specific in what they're talking to you about so um
01:05:43 you are you are saying are you that where it talks about corridors being extended that doesn't apply to a lobby yes
01:05:51 yes no i've seen what that applies to
01:05:55 i see so are you doing the document the system type will be the system type that flows in at one end of a corridor and out of the other
01:06:03 other not an awkward shaped lobby
01:06:08 but isn't it isn't the thrust of this guidance that where the travel distances are more than 7.5 meters you need to treat the primary objective of the system as to protect both the common
01:06:20 system as to protect both the common corridor
01:06:21 corridor and the staircase enclosure the common corridor yeah i totally agree common code not the common lobby but whether it's no you cannot you you cannot do what you're trying to
01:06:33 you you cannot do what you're trying to make this fit it doesn't fit if you've got a straight corridor or an l-shaped coder you can make it work you can't make an eye shape work on extended travel listen it's simply not possible so are you saying that um
01:06:46 not possible so are you saying that um if you looked at this guidance you don't have to treat the lobby and the stairs as the primary objectives because this is referring just to the common corridor is that your is that
01:06:57 common corridor is that your is that that's not what i'm saying what i'm saying to you is if you read the complete document not isolated parts you'll see that when it comes to how you deal with an extended corridor it is a corridor it's a straight tube or
01:07:08 it is a corridor it's a straight tube or an l-shaped tube it is not funny-shaped lobbies so the objective is the objective this taken out the context doesn't mean
01:07:21 this taken out the context doesn't mean what you're saying it means
01:07:24 i see so when you've got an extended travel distance but an irregular shaped lobby it needs careful consideration yes yes i accept that i've said all
01:07:35 yes yes i accept that i've said all along
01:07:35 along through this conversation yes i accept
01:07:40 that um if we also look at um paragraph um section 5.1 of this guide it states at the bottom if
01:07:53 of this guide it states at the bottom if we look at the bottom of page 11. this is about objectives and performance criteria
01:08:03 it states here it's the response second from paragraph from the bottom it's the responsibility of the assessing engineer to determine which method of investigation should be sorry let's read one paragraph before that
01:08:14 before that as with any alternative solution there are a number of methods which allow the investigation and demonstration of its performance these range from hand calculations through to more sophisticated computer
01:08:25 through to more sophisticated computer models such as zone models and cfd each method often offers different benefits with associated limitations ranging from fast calculations with limited spatial and temporal resolution
01:08:36 limited spatial and temporal resolution to extensive spatial and temporal resolution with extended calculation time
01:08:41 time it is the responsibility of the assessing engineer to determine which method of investigation should be used it is recommended however that the technique to be used be agreed with the relevant approving authorities
01:08:52 relevant approving authorities prior to an assessment being performed do you see that yes now did you understand that those paragraphs applied in terms of the guidance they're giving
01:09:03 in terms of the guidance they're giving about investigation and demonstration of performance to your work at grenfell tower as i said before what we suggested wasn't accepted
01:09:16 well what you ultimately suggested was accepted because the version six of psp's technical submission is in fact the design for grenfell tower isn't it
01:09:27 isn't it i don't know it wasn't there at the time well
01:09:30 well you can take it from me that version six and we know you worked on everything up to version five and i think you've already accepted there weren't any fundamental changes that version was the
01:09:41 fundamental changes that version was the system that was installed at grenfell tower and which was accepted by building control
01:09:45 control and that system was designed to deliver the three cubic meters a second from the document that was produced by max fordham
01:09:53 fordham yes can you explain why we don't see um a determination of what method of investigation you're going to use to assess and demonstrate performance
01:10:04 assess and demonstrate performance and we don't see that being agreed with the relevant approving authorities prior to that assessment being performed it was it was already signed off at that stage this document had gone in from max
01:10:15 stage this document had gone in from max fordham as i understand it and i'm hoping proved wrong my understanding and that it was signed off by building control on that betterment it was already agreed before we become party to the contract
01:10:26 before we become party to the contract yeah can we look at um a figure from dr lane's report if we go to blarp25035
01:10:37 lane's report if we go to blarp25035 at page 73 what dr lane's done in this flow chart
01:10:49 what dr lane's done in this flow chart is attempt to summarize the processes and the assessment methodology that's recommended in both the 2012 and the 2015
01:10:58 the 2015 sca guide so um what you've got at the top is questions to be asked
01:11:10 the top is questions to be asked whether there's a demonstration of system performance required yes is the building designed fully compliant with adb no establish what type of system it is
01:11:21 no establish what type of system it is then define the assessment methodology and then it splits into deterministic and comparative um methodologies deterministic
01:11:34 um methodologies deterministic involves setting design criteria conditions and performance criteria and to be determined on a case-by-case basis
01:11:43 basis comparative is the more traditional route and involves proving equivalence to one of the prescriptive systems in adb after setting design conditions and then there's lots
01:11:55 design conditions and then there's lots of
01:11:55 of stages that the sca guide recommends and what the sca guide starts off by saying is that it's acceptable to have alternative solutions to those
01:12:07 solutions to those set out in adb provided you follow this kind of
01:12:11 kind of methodical design process do you see that yes now can you explain why we don't see
01:12:22 now can you explain why we don't see anything like this in any of the design documentation that was prepared by psb even though you are someone who is intimately familiar with the 2012 and the 2015 sca guide
01:12:35 the 2012 and the 2015 sca guide because we were responsible putting the design forward to building control that was done by others so are you suggesting that somebody else should have gone through this step-by-step
01:12:46 this step-by-step process no i'm not suggesting that at all that's not for me to suggest what i'm saying to you is we didn't put the design document forward for approval to building control that was done by
01:12:57 to building control that was done by others and it was done on a betterment basis
01:13:00 basis which normally would not cover any of these
01:13:03 these that's my understanding
01:13:07 i see so is your understanding that where you're just doing this betterment approach
01:13:13 approach even though that's an alternative system not not not a system that's set out in any
01:13:18 any british standard or other guidance that you don't need to follow a logical step-by-step approach as part of the design process not on an existing building which is being refurbished no
01:13:29 being refurbished no if it's gone down a betterment route that's all you need do and i'm sure that building control would have
01:13:36 have asked for a lot more information if they felt it wasn't a betterment route
01:13:44 and they did they set off on that basis so
01:13:47 so so we go back to your point that because you thought all you were doing was bettering
01:13:52 bettering the old system you didn't need to provide any of this documentation relevant to your design i was following the requirements of a contract the documents that are issued
01:14:03 documents that are issued and i'm sure you're aware when you have a contract you have express terms and you have implied terms the implied terms of axa parliaments etc that you do know about such as the health and safety workout but the express terms are written down
01:14:15 but the express terms are written down and that's what you follow as part of the contractual agreements that you reach and that was a document of betterment that said
01:14:23 that said we have to design a system that delivered three cubic meters a second that's all i see mr chairman i think that's a good moment yes we'll have a break i think that would be a good idea um
01:14:35 a good idea um mr marley we'll have a bit of a break now we'll stop and resume at 25 to 4 please and again as as before please don't talk to anyone about your evidence
01:14:46 about your evidence while you're away from the uh from the monitor all right okay thank you very much see you at 25 okay thank you thank you very much thank you ms grange 25 to 4. thank you
01:34:28 right well we're now ready to resume so oh well there's mr marley first up hello mr manny you're obviously ready to continue rich well done uh i better check miss
01:34:39 rich well done uh i better check miss grange is there as well hey ms grange you there
01:34:42 you there yes i am oh hello good right well mr marley is already logged in so to speak so when you're ready thank you yes thank you yes now this morning we looked at part of your witness statement
01:34:53 looked at part of your witness statement where you explained that the services that psb provided were provided pursuant to a number of purchase orders by js wright can we just look at one of those purchase orders at jsw403835
01:35:18 we can see that this is from js wright the contract is for grenfell tower refurbishment and under subcontract order details it says design only for aov system
01:35:32 it says design only for aov system unit price 9450 pounds do you see that there
01:35:35 there i do and was that the uh purchase order for uh psb providing the design but design only not installation but design
01:35:46 installation but design of the smoke control system
01:35:51 not in the sense i think you mean no what do you mean by that that when we take on a project when we get an order to do it what we're looking to do is extend the
01:36:02 what we're looking to do is extend the known design into a complete working system so the design
01:36:07 design involves the preparation of cause and effect statements drawings technical submission and all those aspects in support of the design requirements i see so what you're saying is the
01:36:18 i see so what you're saying is the design requirements were set before you did your detailed design work is that right that's correct as i can't remember because item two of our technical submission tells you
01:36:30 of our technical submission tells you what the base documents were one of which was
01:36:32 which was that betterment document so what we were then setting up is how we would put our system in to meet that betterment document do you accept that you were contracted
01:36:43 do you accept that you were contracted to do and carry out the detailed design of the smoke control system pursuant to the employers requirements documents you were provided with by max fordham
01:36:56 what documents are they well the ones you've talked about that were referred to in your technical submission all right that's the drawing and the um betterment well what you're calling the
01:37:09 betterment well what you're calling the betterment document yes that's right yes and just to be absolutely clear if we look at your second witness statement page 14 paragraph 74
01:37:28 you say conclusions for the reasons outlined above i believe the basis of my design and the performance criteria i specified for the system were sufficient to meet the requirements of the building
01:37:39 to meet the requirements of the building regulations does that remain your evidence
01:37:41 evidence it does thank you now if we could look at an email psb 50725 at page nine
01:37:57 so beginning with the 16th of july 2015 email from mr david bradley to you that we see there um in his email
01:38:09 that we see there um in his email um mr bradbury sends on to you a series of questions from matt cross smith of max
01:38:14 max fordham we can see those questions below at page 10.
01:38:22 and is it right that the answers in red were your answers that you provided yes that's correct and um looking at page 10 in answer to the
01:38:34 um looking at page 10 in answer to the first query about the low level point of smoke discharge you address that specific point and you also say picking it up in the second line down in red this system will not be extracting smoke
01:38:46 this system will not be extracting smoke during the evacuation phase as air will be drawn through the open stairwell door and it will pull in clean air from the stairwell during firefighting operations air will again
01:38:57 firefighting operations air will again be pulled in from the stairwell should a window in the fire affected flat break then some smoke may be extracted during firefighting operations i.e the flat door is open and the
01:39:08 i.e the flat door is open and the stairwell door is open that's correct now we've discussed that earlier and that's consistent with what you were telling us earlier but can you just explain
01:39:18 explain the answer to this why don't we see the scenarios that you're discussing here for example flat door open window open in the flat why don't we see
01:39:29 in the flat why don't we see any of those discussed and set out in the design documentation and an explanation provided about what the system
01:39:36 system was and wasn't designed to do
01:39:43 in my documents yes your documents you're answering this question here and you're providing this scenario and you're explaining what would happen in this scenario why don't we see a discussion like that
01:39:56 why don't we see a discussion like that in any of your design documents my document was to show confirmation with the contract document
01:40:06 so therefore there is no need for me to write all this up
01:40:11 the fact the fact it will occur is the fact it will occur
01:40:17 and when you say my document was to show confirmation with the contract document are you trying to say that somehow your contract limited you so that you couldn't actually consider the design scenarios the system was intended
01:40:29 design scenarios the system was intended to address we merely had to comply with a delivery system
01:40:35 system to do three cubic meters a second oh sorry 3.5
01:40:39 sorry 3.5 yes i see now just back for a moment to the
01:40:43 the the point about um well sticking with this this point about scenarios i just want to show you something in the british standard en 12101 part six if we go to rbk3045054
01:40:58 12101 part six if we go to rbk3045054 and look at page 20.
01:41:08 now this is the airflow criterion for a class b pressure differential system according to this british standard and i i understand you didn't design it to comply with all of these criterion but
01:41:20 comply with all of these criterion but what i want to look at is what this british standard would would require and what it says is that the air supply under air flow criterion shall be sufficient
01:41:31 sufficient to maintain a minimum airflow of two meters per second through the open door between the lobby and the accommodation at the fire affected story with all of the following doors
01:41:41 doors open between so the doors are the stair and the lobby on the fire affected story the stare in the lobby on an adjacent story
01:41:49 story the firefighting lift shaft and the lobby on the adjacent story the stare and the external air at the fire service access level and the air release path on the fire floor is open
01:42:01 floor is open so the british standard if if you had designed a system that had complied with this british standard and i appreciate you saying you couldn't have done but it requires that two meters per
01:42:12 but it requires that two meters per second
01:42:13 second to be maintained despite lots of other combinations of doors being open and um so can we agree that that's what
01:42:24 and um so can we agree that that's what the british standard does that's what the british standard says yes and
01:42:30 yes and um dr lane in her report has explained if we look at blarp 2
01:42:38 5035 at page 396.
01:42:46 the paragraph 8.11.33 she's set out the criterion from that british standard that we just looked at and she said this
01:42:57 and she said this the open doors listed above are intended to replicate firefighting operations in a non-residential building where the fire and rescue service use the floor below the fire floor as a bridge head when they exit from the fire fighting
01:43:08 when they exit from the fire fighting lift and attach a hose to the fire main on that floor in the non-residential building yeah yeah
01:43:16 yeah the fire and rescue service then run a hose through the door to the stair firefighting stair on the floor below the fire then back through the door to the lobby on the fire affected door and finally to the door of
01:43:27 affected door and finally to the door of the flat
01:43:29 the flat now do you agree that to be an appropriate system for for installation at grenfell tower the system needed to show that it could operate effectively
01:43:40 operate effectively with this arrangement of doors open in a residential building rather than a non-residential building because that's about non-residential buildings but do you agree at grenfell
01:43:51 buildings but do you agree at grenfell tower
01:43:51 tower that you needed to be able to show that it could operate effectively with this arrangement of doors open it would have done didn't need to show it because they have no material effect
01:44:02 it because they have no material effect on the door where the air is being extracted through and again are you saying that that's simply based on your past experience that you knew it would have done anything of these systems yes
01:44:15 in his evidence to the inquiry last week mr hansen the building control officer said that his expectation was that psb would be testing with other doors open and closed
01:44:26 doors open and closed in accordance with this british standard for a class b system um was that your expectation as well that you would be testing the system with different combinations of doors
01:44:38 with different combinations of doors open and closed
01:44:41 um yes and no at the end analysis go back to your previous question the reason why they're critical is because you're blowing air in not sucking air out when it comes to
01:44:55 not sucking air out when it comes to the system that we put in was sucking out those doors being open would have no material effect on the airflow through the doorway from the stairwell into the fire affected lobby
01:45:07 into the fire affected lobby if anything you'd give an enhancement because you give more air coming in so are you saying there are no circumstances in which other doors being open
01:45:15 open would affect the air flow through the stair door no because if the apartment door is open that would have an effect but those doors no what about if another apartment door
01:45:26 apartment door was opened and that for example had a pathway to the outside wouldn't that potentially affect the air flow through this pathway to the outside be created we're certainly talking about
01:45:37 certainly talking about a scenario where doors that should be closed are now open uh but they should be closed we said earlier compartmentation is the primary function of controlling a fire and spread of smoke in a building not the smoke
01:45:48 smoke in a building not the smoke pressure realization or smoke extract system it is the compartmentation so if a door is open it shouldn't be open no we can't account for that would you agree that not only the
01:45:59 would you agree that not only the british standard but also for example the 2012 sca guide provides recommendations about the need to consider different opening doors when designing the system because any such system needs
01:46:11 the system because any such system needs to address the foreseeable scenarios which will occur when the system is operating they're talking about the doors on the escape route not random flats
01:46:22 not random flats but you do accept that the sca guide requires consideration of other open doors
01:46:29 doors when designing a mechanical smoke ventilation system yes and as i said they would have no material effect on the system in section 12 of her phase two report dr
01:46:40 in section 12 of her phase two report dr lane has concluded that she cannot identify
01:46:43 identify any time period in the early stages of the grenfell tower fire where only the stair door was open as per the system's design condition doesn't that indicate that one single
01:46:55 doesn't that indicate that one single stair door being open and all other doors being closed was an unrealistic design
01:46:59 design assumption to make not a design assumption it's a given it's given in the adb
01:47:06 the adb it says in there that you will get some smoke coming out when the people make that escape for that short period of time when the door is open some smoke will come out not that the door is open and the smoke is pouring out no
01:47:17 is pouring out no that is given to us and that's what we design for that's what all design is designed for it's not unique to grenfell tower to suggest she was wrong
01:47:27 well i i've put the point to you that she her evidence is that it was unrealistic to think that just one single door would be open in a fire scenario and therefore the design
01:47:38 design should have provided for different door opening conditions and and grappled with those conditions as part of the design process and she used to write it with the standards and the approved document
01:47:49 the standards and the approved document be
01:47:49 be the governing body and get them to change the documents i see can we turn to compartmentation now
01:47:56 now a different topic um do you agree that where smoke control systems are comprised of shafts and duct work penetrating internal
01:48:07 work penetrating internal compartmentation their construction is also subject to the functional requirement b3 internal fire spread that's fire engineering i don't tend to get involved with that were you
01:48:18 tend to get involved with that were you aware that the shafts and duct work which connected the lobbies as part of the smoke control system at grenfell tower
01:48:24 tower would be classified as a protected shaft and must be protected to limit fire and smoke spread between compartments that's a given because that's fire engineering so you were aware of it but you say that
01:48:36 so you were aware of it but you say that wasn't part of your because we don't get involved in building we're not construction experts and it's right isn't it that at grenfell tower the builders work shaft and
01:48:47 tower the builders work shaft and subsequent extension of those shafts during the primary refurbishment connected every lobby compartment in grenfell tower from ground level to level 23.
01:48:56 level 23. yes and can we agree that the horizontal metal duct work at level two of grenfell tower the new duct work for the system was also connected to the south shafts and kent
01:49:07 south shafts and kent also became part of the protected shaft as well i believe so yes
01:49:13 and where you were aware that in approved document b it makes clear that any system of mechanical ventilation should be designed to ensure that in a fire the ductwork doesn't assist
01:49:24 ductwork doesn't assist in transferring fire and smoke through the building and put at risk the protected means of escape from the accommodation areas
01:49:35 to what extent uh was uh were those considerations um uppermost in your mind when you were designing the the system at grenfell tower which what are we talking about the one
01:49:48 which what are we talking about the one i've just mentioned that any system of mechanical ventilation should be designed to ensure that the ductwork doesn't exist in transferring fire and smoke through the building was that a consideration that you paid
01:49:59 was that a consideration that you paid attention to when you were designing the system we discussed this with matt about the connections in the rooftop plant room to connect the north and south together to form one system
01:50:10 to form one system would be in fire rated ductwork because it's in an unused plant room it wouldn't be nothing insulated to be fire rated let's focus on dampers for a moment installed as part of the smoke control
01:50:22 installed as part of the smoke control system um
01:50:24 system um let's just have a look at some useful images of those if we can look at dr lane smoke control report blarp 2 5 0 35 at page 181
01:50:45 there we can see they're the north dampers
01:50:48 dampers and if we go over the page we can see there the north dampers on level four so on the right hand side we can see the grill that was in front of
01:50:59 can see the grill that was in front of the dampers and then on the right hand side
01:51:01 side it's not a brilliant photo we can see some of the dampers themselves do you agree
01:51:06 agree i agree uh and if we look at
01:51:11 blarp25037 at page 34
01:51:16 we can see in one of the storyboards that dr lane has produced in her reports and perhaps some better photos there you can see on the left hand side say at level six you can see some of the dampers
01:51:27 dampers open at level six can you see that yes and there's a useful little sketch above that
01:51:34 that that's taken i think from professor stek's report where you can actually see the dampers themselves in those sketches right and can we agree that it is
01:51:45 right and can we agree that it is critical that those dampers are up to the task not only of opening and closing when required but also delivering a high level of performance in preventing smoke permeating them while they're closed
01:51:56 while they're closed yes i agree and can we agree that in the standards in the british standards and other guidance documents dampers are divided into three categories fire dampers
01:52:07 categories fire dampers fire and smoke dampers and then smoke control
01:52:11 control dampers were you aware of that i'm aware of that and can you explain in simple terms what the difference is between them a fire damper is one which has uh a
01:52:22 a fire damper is one which has uh a thermal device which allows the damper to close
01:52:25 to close and has a given fire resistance so that if it gets up to a certain temperature it will automatically shut a fire in smoke damper again is one that controls
01:52:34 controls smoke and fire i.e in the final analysis if the temperature gets too great the fire back or some of it will dominate and shut the ventilator and a smoke control
01:52:46 shut the ventilator and a smoke control damper
01:52:46 damper is one that is a high seal damper for controlling the flow of smoke in mechanical systems generally yes so the smoke control damper is the highest level of performance of damper isn't it
01:52:57 level of performance of damper isn't it yes
01:53:00 now um as the lobby damp has protected an escape route if we look at um bsen12106
01:53:07 bsen12106 part six uh um if we can pull this up at rbk
01:53:11 rbk zeros page 71
01:53:22 and if we look at clause 11.8.2 point it's kind of just beyond halfway down that page
01:53:31 that page we can see it says there if different pressurized or depressurized zones are connected to the same fan or set of fans by a common system of work and or shafts smoke control
01:53:42 work and or shafts smoke control dampers shall be used do you see that see that
01:53:45 see that we weren't working with this document but yeah i can see that were you aware of this guidance at the time you designed the grenfell system i was and it's right isn't it um that smoke control dampers have to
01:53:58 um that smoke control dampers have to satisfy more onerous testing requirements than fire dampers or fire and smoke dampers i agree however these were not smoker dampers they were automatic opening ventilators
01:54:10 they were automatic opening ventilators but i know where we're going to go but go on but they're not a damper in their own
01:54:14 own right i see well um let's keep going um do you agree that the permitted leakage limit for smoke control dampers is
01:54:25 limit for smoke control dampers is stricter than for fire dampers the leakage rate has to be less than 200 meters cubed per meter squared per hour according to the british the relevant british standards
01:54:37 british standards i thought it was no greater than 200. yeah less than i see yeah um now it's right isn't it that psv's design documentation did not specify
01:54:49 design documentation did not specify that the system had to use smoke controlled dampers meeting the the prescribed leakage requirements for smoke controlled dampers
01:54:57 dampers can you just explain why that was why we didn't specify them yes because there were no dampers on the market at that time that could be used
01:55:09 market at that time that could be used there were smoke control numbers i see so you're saying that because that product
01:55:17 product wasn't so what there were no products on the on the market at that time that had been tested to those more onerous requirements no what i'm saying is those dampers that
01:55:29 no what i'm saying is those dampers that were available wouldn't could not be fitted into grenville tower do you want me to clarify that yes please yes i think we need to understand why you didn't use smoke control dampers at grenfell tower
01:55:42 control dampers at grenfell tower all smoke control danvers at that time and i think most of this date actually but at that time none had been tested for use in walls they've only been tested
01:55:53 they've only been tested for use in ducks and the man in which they're secured is part of the test requirement so we had on our working groups at sea we had actually experts from the manufacturing association
01:56:04 association as members of that working group and they advised us that you could not use those dampers in a wall because they weren't tested to be used in that way right so they were not certified for
01:56:15 right so they were not certified for that particular application another reason was the size of the framing of the damper would have made the hole materially smaller
01:56:24 smaller exacerbating our problem to trying to get the system to deliver the volume flow rates and the third reason was smoke control dampers have a spindle that pokes out of the side of the damper
01:56:35 that pokes out of the side of the damper construction um to which a motor is fitted therefore that would have clashed with the wall it would not have gone into the opening so we couldn't use those products i see if we look to um
01:56:47 i see if we look to um your first version naught of the technical submission for the smoke control system this is at psb 50207 at page six
01:57:03 we can see this is in the technical specification that you wrote yes that you've actually selected gilbert's 54 series dampers yes so my
01:57:15 gilbert's 54 series dampers yes so my automatic lobby ventilators yeah for use in this application so you you yourself selected those products for use in this system yes it indeed what information or documents
01:57:26 it indeed what information or documents did you have about that those dampers before specifying them in this version of the technical submission sales brochures yes now
01:57:37 sales brochures yes now we can see that you had access to the october 2011 gilbert's product brochure for series 54 dampers as you attached it to an email of the 13th of november 2014 to david
01:57:49 of the 13th of november 2014 to david bradbury when sending version naught of the technical submission that's at psb 50207 now if we look at that product brochure it's a psb
01:58:04 50201
01:58:08 there's the product brochure and if we can look at the second page of this blow up the text at the top
01:58:20 of this blow up the text at the top and the introduction
01:58:23 there it says um in the second paragraph um a multi-parallel linked blade smoke damper the series 54 is manufactured from robust 1.5 millimeter galvanized
01:58:35 from robust 1.5 millimeter galvanized steel and is fully tested to the requirements of en1366 part 2 for one hour now did you notice when you looked at that product brochure that it was saying it was fully tested
01:58:46 that it was saying it was fully tested to those requirements for one hour yes and what impact did that have on your decision to specify these dampers the fact that it gave me the one hour
01:58:58 the fact that it gave me the one hour fire resistance i was looking for was good it was a low leakage damper and it actually fitted the hole in the wall if we go then to the quotation um
01:59:11 then to the quotation um for these dampers that was provided by gilberts
01:59:14 gilberts that's at psb four zeros one two four zero
01:59:22 now in his evidence to the inquiry mr jones of gilbert's who we're going to hear from later this week says that you contacted gilberts for a quote in relation to dampers first speaking to
01:59:34 in relation to dampers first speaking to mark griffiths at gilbert's over the telephone is that correct i don't recall but yes and then on the 22nd of january 2015
01:59:46 and then on the 22nd of january 2015 you can see at the top uh that date that mr griffiths provides you with a written quote for the dampers in this written quote and we can see your name the contact is hugh mahoney
01:59:58 your name the contact is hugh mahoney marnie i beg your pardon in that quotation
02:00:03 quotation thank you um
02:00:10 so this is this is the quote do you remember is this does this help jog your memory do you remember receiving this quotation
02:00:16 quotation i honestly don't but i yes i would have received it and before you asked yes i would have read it thank you and if we look at page two
02:00:30 of this quotation there are some additional notes after the item descriptions there are some additional notes
02:00:37 notes and i want to look at item three under that
02:00:41 that it says this the series 54 damper is designed to be used for natural and mechanical smoke extract applications by means of a vertical shaft
02:00:50 shaft the damper has undergone an en1366 part 2 test started from the closed position and lasted over 60 minutes for both fire integrity and smoke leakage
02:01:02 integrity and smoke leakage es60 but has no formal certification now did you know that that information differed
02:01:12 differed from what the 2011 product brochure said about the dampers testing um i i didn't take cognizance of it then but i can see what you're saying in it
02:01:23 but i can see what you're saying in it it was tested from the closed position whereas the other document says it was tested fully in accordance with exactly and also this says it's got no formal certification did you notice that
02:01:37 formal certification did you notice that at the time i was aware of that because of well do you mind if i explain how i'm aware of it um go on it go back
02:01:46 go back in was coming in under the products regulations that were active parliament i spoke to quite a number
02:01:54 number of damper manufacturers including the people on the committees that we were working with or working groups and a lot of the damper manufacturers were saying that they were not going to test the latest standards and
02:02:06 to test the latest standards and therefore they were not ce marking their products
02:02:09 products in accordance with the latest standards however they were prepared to market them under the old standards and ce mark to them which made life very difficult for the likes of us in the small control industry
02:02:20 industry uh because we couldn't then comply with an act of parliament and uh the series 54 was one of those dampers
02:02:27 dampers where they had no intentions of testing to the
02:02:30 to the bsem went to 100-8 standard and then actual fact no one at that time was testing to that standard
02:02:37 standard i see but do you accept that there was an explicit statement here from mr griffiths to you in this quotation that the product was not certified to bs en1366 part
02:02:48 not certified to bs en1366 part 2 which is the key test for fire dampers and fire and smoke dampers yes
02:02:54 yes doesn't actually say that it says no formal certification it was tested and if it was fully tested to bsem1366 part 2
02:03:05 to bsem1366 part 2 it would have failed the test the reason for that
02:03:09 for that is that that is a test for a fire damper a fire damper has a thermal device and the first part of the test is to test with it commencing in the open position
02:03:18 position and then you ignite the furnace and you then record how long it takes for that damper to close from the open to the fully closed position
02:03:30 position thermal device going off well these dampers do not have thermal devices thus is tested from the closed position it would have failed
02:03:41 now um if we can look at dr lane's report at this point if we go to
02:03:47 blarp25035 page 92.
02:03:56 page 92. i want to look at paragraph 4.8.70
02:04:02 she starts that paragraph by saying but it's important to note that the test method for evaluating both integrity e performance and smoke leakage performance that's s is different
02:04:13 is different this is for as between fire dampers and smoke control dampers the key differences are as follows and she goes on if we go over the page
02:04:30 if we can go over the page
02:04:35 and she says there at the top a a smoke controlled damper is subjected to a greater number of open closed cycles prior to testing this is termed the durability of operational
02:04:46 termed the durability of operational reliability a smoke controlled damper intended for a combined smoke and environmental system is subjected to 10 200 open closed cycles prior to fire testing
02:04:57 cycles prior to fire testing a fire damper and fire and smoke damper is subject to just 50 open closed cycles do you see that and then she goes on the ability of a smoke control damper to change from the
02:05:08 smoke control damper to change from the open to the closed position or vice versa
02:05:11 versa at elevated temperatures is tested this is required where a system is designed with a manual intervention function such as the firefighter override switches fire dampers and fire and smoke
02:05:23 switches fire dampers and fire and smoke dampers are not subjected to this tests correct so then she says these key requirements in the test methodology when evaluating the integrity and smoke leaks performance of smoke control dampers
02:05:35 performance of smoke control dampers are more onerous than the conditions applied when testing fire dampers and fire and
02:05:39 fire and smoke dampers do you see that did you ever send the quote with its
02:05:50 did you ever send the quote with its reference to no formal certification on to building control
02:05:55 control no that wasn't my role my role was to send it through to js rights they were my um employers so building control only saw the product
02:06:07 so building control only saw the product literature it would appear is that correct
02:06:09 correct uh no i think we got the test data and sent that through to them i see now if we go to an email now from gilbert's to you if we go to gbl705 at page two
02:06:27 and i want to look at the top of page two
02:06:31 two yeah here we can see gilberts are providing to you a copy of the 48 one page document entitled x over fire resistance test
02:06:42 entitled x over fire resistance test dated the 6th of october 2011 which we'll see in a moment begins on page three of this string and a three-page data sheet from belimo issued in may 2007 which begins on page
02:06:54 issued in may 2007 which begins on page 44 of the string now um can you recall exactly when this information was provided to you there's no
02:07:03 no date on these emails we haven't been able to ascertain that it was following the meet our first meeting with building control i don't know what that date was because they requested the information
02:07:15 because they requested the information yes i see
02:07:16 yes i see and what prompted gilberts and mr griffiths to send this information to you
02:07:22 you we phoned him up and said we needed this information for all onboard transmission to building control because they had questioned had the damper been tested with the motor fitted did you ever ask for example whether the
02:07:34 did you ever ask for example whether the dampers were classified as fire dampers or smoke control dampers i knew that they weren't smoke controlled embers they were smoke exhaust stampers they were automatic opening ventilators i knew
02:07:46 automatic opening ventilators i knew what they were they were not smoke dampers if we go to the fire resistance test
02:07:56 this is at page
02:07:59 42 of this document this is the penultimate page of the x
02:08:10 this is the penultimate page of the x over fire resistance test we can see that the damper was proportionally tested according to the requirements set for fire dampers yes for example they were subject to an
02:08:21 yes for example they were subject to an integrity test of 360 meters cubed per hour
02:08:32 just looking for where we see that yes that's in the second line do you see that there
02:08:41 now given that the british standards required smoke control dampers did that concern you when you saw this test evidence
02:08:49 evidence no
02:08:53 do you accept that these dampers weren't suitable as they were neither fully certified or tested smoke control dampers i don't agree
02:09:06 do you agree with mr jones's evidence to the inquiry to the effect i'm sorry i i feel that that answer leaves us
02:09:14 leaves us begging for more if i may say so why why does
02:09:17 does mr marley not agree with the proposition
02:09:21 they're not smoke dampers they were not purported to be smoke dampers and they told us how they were tested as the other products as i've already mentioned on the marketplace it would not
02:09:32 not fit the application that we had and we had a betterment requirement this was the best that we could offer and that's what we used they were never purported to be smoking us
02:09:43 us thank you do you did you explain that to building control did you say we understand the need in the british standards to have smoke control dampers but this is why we provided these alternative dampers no but they knew
02:09:56 alternative dampers no but they knew what they were getting and if you look at the guidance they asked us to use which is the sea guidance
02:10:02 guidance it says in there that if we want anything greater than what's in that document which is an e30 sa unit uh they have to ask for it but i'm not passing humans onto them anyway it's one of the things i know i did mentioned
02:10:14 one of the things i know i did mentioned at the very front end with matt smith when we did our original appraisal this was the only product
02:10:20 product that would actually fit in the employer's requirements because nothing else would physically fit so was the only thing we could use so did you look around to try and find
02:10:32 did you look around to try and find other
02:10:32 other um smoke control dampers that would work for this configuration did you actually do that exercise yes and there weren't any but as i say i knew most of this anyway through my own
02:10:43 knew most of this anyway through my own um work on at working groups and my own work in trying to find out who was going to comply with the new ce regulations i see and i just want to be absolutely clear what you're saying about the sca
02:10:54 clear what you're saying about the sca guide are you saying that the 2012 sca guide
02:10:58 guide permitted you to use dampers that weren't even certified as fire dampers in this location no that's not what i'm saying what i'm saying in there it identifies that an automatic opening ventilator
02:11:11 that an automatic opening ventilator there is no test standard for it so in such instances they they suggest it should conform to a smoke damper not that it must because they don't exist it recognizes
02:11:23 because they don't exist it recognizes the fact that these standards don't exist for the products or the way in which the products are used so therefore it gives you ways around uh trying to achieve it now the the first one in the heading if my
02:11:35 the the first one in the heading if my memory serves me well is bsen1210 for smoking heat control as smoke dampers and no one was testing to that standard of design
02:11:43 of design um then they gave the next test standard as being smoke damper tests but none of those tested products
02:11:50 products were able to be used in the application that we needed and then they give you the fire test standards
02:11:57 standards so it's an order of of what you can use in there or guidance of what you can use but it also starts off by stipulating that it's they're automatic opening ventilators
02:12:09 they're automatic opening ventilators there is no standard and they have to have a minimum of an e30 essay rating that's the beginning of that particular we'll come to that we'll come to that in just a moment
02:12:20 just a moment um do you agree with mr jones's evidence to the effect that gilbert's was not provided with much if any information about the grenfell tower system for which they supplied the dampers
02:12:32 which they supplied the dampers they knew they were for an aov system
02:12:36 how could you be satisfied that the dampers that you selected wouldn't leak excessively
02:12:44 they would leak as much as they leaked they were what they were what you mean excessively let me let me put some kind of perspective to that the leakage rate is based on a
02:12:55 leakage rate is based on a one meter square damper and it's a maximum permissible if you look at the total area they're less than one square meter so they would leak less because there's less area so it
02:13:06 less because there's less area so it depends what you're actually implying by the statement so i don't quite understand i see you could work out the actual leakage for the size of damper which would be less than the maximum yes
02:13:18 which would be less than the maximum yes if i could just take you at this point to
02:13:20 to something in dr lane's phase 2 smoke control report this is blarp 2 5 0 38 page 19.
02:13:41 this is one of a number of storyboards that dr lane has put together uh explaining um the system performance on the night of the fire
02:13:52 on the night of the fire and and what she's done in box b on the left hand side is actually um put some extracts from the chairman's phase one report um where several residents of
02:14:05 um where several residents of of floors remote from level four where the fire started observed smoke leaking into the lobbies through the dampers so for example we can see at 116
02:14:16 so for example we can see at 116 mr griffin at flat 31 his flat entrances to the southeast corner of the lobby saw smoke coming from the dampers in the south shaft before he evacuated do you see that
02:14:28 before he evacuated do you see that there
02:14:29 there i do indeed and we and we then have below that miss o'connor at 120 whose entrance is to the southeast corner of the lobby adjacent to the south
02:14:40 adjacent to the south dampers noticed smoke coming through those dampers when she was evacuating sorry i should clarify miss o'connor does not confirm if this was from the north or south side of the lobby
02:14:51 north or south side of the lobby now we know that the fire started just before one o'clock in the morning and in fairness to you i just wanted you to give the chance have the chance to consider this
02:15:02 have the chance to consider this um can you explain how that leakage including on the south shaft which should have been extracting downwards occurred so early in the fire
02:15:14 occurred so early in the fire can you help us with that on the south side
02:15:17 side yes well certainly mr griffin that's what he's
02:15:20 what he's recorded as seeing if it was leaking from those dampers it would mean the whole of that shaft would be full of smoke yeah it would then build down to that level um
02:15:34 down to that level um not sure what level it's getting actually into that shaft if it's getting in there
02:15:37 in there and that would suggest something is open for it to fill that quickly if you're going by that timeline and spill out uh and but it also would indicate that the fan wasn't operating
02:15:48 the fan wasn't operating yeah well he's level six so that would be
02:15:52 be on your hypothesis the the chef would have to fill with an awful lot of smoke to get down to level six wouldn't it by that time
02:15:59 that time very quickly yeah and you have to be very hot smoke as well so i think you've said one possibility is that the fan at the south um for the south
02:16:10 um for the south bend might not have been working yes could not have been working if smoke was coming out of those dampers because if it was working smoke can only go in not out of a closed damper because of
02:16:21 not out of a closed damper because of the negative pressure behind it so for it to come out it's a present a positive pressure is built up within that shaft which means the whole shaft is full of smoke to come out at
02:16:32 shaft is full of smoke to come out at level six
02:16:33 level six it has to be full um and the fan can't be working yes can i just look at an email string this is psb
02:16:44 50881 i want to look at the top of the thread this is going to be an email from you to david bradley bradbury at jsri on the 31st of march 2015
02:16:55 2015 relates to a query from building control about the testing of the dampers and whether they were tested with the motors attached and in your email
02:17:04 email you explained that the dampers were tested with the motors and you provide a copy of the bsen1366 part 2 test report for the dampers
02:17:16 now can we take it from this email that you must have reviewed that test report to have answered these questions
02:17:26 yes and if we look at the test report itself at gbl705
02:17:37 but page three
02:17:44 did you notice that the title of the report was a fire resistance test conducted
02:17:49 conducted generally spell spelt wrongly but generally in accordance with bsen 1366 part two
02:17:56 part two 1999 on a multi-blade damper assess assembly did you notice that and did you notice that it says on page four in the summary of the test specimen
02:18:08 four in the summary of the test specimen that at the request of the sponsor the test was started with the damper in the closed position yes and on page eight it says in the introduction
02:18:26 says in there that at the request of the test sponsor the damper was in the closed position at the commencement of the fire test and therefore the test was not conducted fully in accordance with the standard
02:18:38 fully in accordance with the standard i've already given you that reason yeah yeah
02:18:42 yeah and looking at the results on page five did you notice that the dampers failed the smoke leakage criteria and were therefore non-compliant for that reason where is that
02:18:54 that reason where is that smoke leakage box second from the top naught minutes i didn't fail did it that's been filled in because it's a box on a standard test report and that was never tested because of
02:19:07 never tested because of the manner in which they were doing the test so that smoke leakage test is at zero you can't have failure at zero because it hasn't commenced exactly so you're saying i've done that test it wasn't that smoke
02:19:19 i've done that test it wasn't that smoke leakage test was not undertaken therefore they put zero minutes in it
02:19:25 so just to be clear you were not looking for test evidence to bs 1366 part 10 nor classification to bsen135014
02:19:37 10 nor classification to bsen135014 which would be necessary for smoke controlled dampers is that right that's right it's not a smoke controlled for the reasons that you've given that's right
02:19:47 now you've mentioned the sca guide can we just look at that sca guide if we go
02:19:54 go um to lfb three zeros five nine two four one and we look at page 36
02:20:13 i think this is the section you were referring to earlier at 8.2.5 where you were saying that the sca guide makes clear that no formal product standard exists for the use of these products in this
02:20:24 use of these products in this application that's automatic opening vent smoke control damper used for ventilation from corridor or lobby into smoke shaft or smoke control duct yes um
02:20:36 duct yes um and just to be clear if you carry on reading that paragraph it says to ensure the necessary product performance is achieved it is recommended that the aov should be regarded as a smoke control
02:20:47 should be regarded as a smoke control damper
02:20:48 damper and the relevant product standards should be considered do you see that i see that yes it did even though it says no formal product standard exists this is recommending that the aov
02:21:00 this is recommending that the aov should be regarded as a smoke control damper yes
02:21:05 and the next state the next paragraph is important as well that says the damper at the fire smoke source must open to allow the smoke heat to be extracted and therefore have proven ability to maintain its opening
02:21:17 proven ability to maintain its opening adb recommends that dampers on a non-fire floor should be closed and capable of performing to the equivalent of a
02:21:23 of a e 30 s a fire door
02:21:29 has tested to the standards below should satisfy this requirement should be actuated yes and then if we look below that if we look over the page
02:21:45 we can see there are several applicable smoke control standards damper standards and those are listed below yes and that's one two one oh one part eight and part ten of one three six six those
02:21:58 and part ten of one three six six those are the those are the british standards for
02:22:00 for smoke control dampers aren't they yes and then below that i think what you're referring to is that it says any damper tested as fire resisting
02:22:10 resisting supported by an ad hoc operation test at elevated temperature and using a drive open drive door close actuator could also be acceptable these test standards are listed below yes
02:22:24 test standards are listed below yes is that right you're you're referring to that part of the sca guide as well that is the part that the the gilberts have been tested with the first document there 121-8 as i say no one was testing their products
02:22:35 no one was testing their products to that test standard so they didn't even exist but but you say that's the part that gilbert's were tested to and we can see it's one three six six part two
02:22:46 part two but then it says plus if you keep reading
02:22:49 reading along both lines it says fire dampers plus ad hoc test report 300 degrees and or 600 degrees for one hour
02:22:57 hour and the same there's some ad hoc testing that's required as well as testing to bsen 1366
02:23:03 bsen 1366 do you see that the ad hoc is because you couldn't test it as a fire damper as i said before because if you try to testify down it would fail because it doesn't have a thermal device so it becomes an ad hoc test
02:23:17 but even these alternative routes therefore require not just passing tests to bs en1366 part 2 but then ad hoc testing
02:23:30 is it your understanding that that ad hoc testing have been carried out
02:23:35 as i understand it there were two options there one is the first at the 300 degree seat and 600 given one hour or alternatively there's the hot test four hundred to thirty tests for piarian
02:23:47 four hundred to thirty tests for piarian per ten but is it your understanding that the gilbert stampers had undergone that ad hoc testing they had we had that certification sorry that documentation which was forwarded
02:23:58 that documentation which was forwarded on
02:23:59 on i think and it also goes on to say damp is tested in the closed position dbs 476 part 20 could also be suitable so you don't accept that you specified the incorrect
02:24:10 the incorrect dampers for the smoke control system most definitely not and also the fact you have to work with products that are actually available they're not available they're not available i see mr chairman i i've got probably
02:24:24 i see mr chairman i i've got probably about five minutes maximum of questions but i may go slightly over half past four can i carry on and then we break is that acceptable i think
02:24:36 we break is that acceptable i think i think it would be better if we can to finish with this witness today yes i'm sure well let me just have a word with uh mr marley mr marley we normally
02:24:45 normally call the halls at half past four but if council only has five or ten minutes questions left i'm sure you would prefer to finish your evidence today if you can do that would you not
02:24:56 do that would you not i would indeed yes no i just should just warn you though that um when council gets to the end of her questions
02:25:03 questions we have to have a short break usually about a quarter of an hour to enable her to check that she's not left anything out and also to allow other people who are following the proceedings
02:25:14 the proceedings from elsewhere to suggest questions that perhaps should be put to you so if we carry on in order to finish your evidence we could be here until let's say five o'clock first question does that
02:25:27 five o'clock first question does that bother you no not at all and the second question is would you like a break at this point uh i think i could just manage all right well we'll carry on then if it's five minutes i i'll manage right
02:25:40 if it's five minutes i i'll manage right well um
02:25:41 well um we'll probably have a five or ten minutes and then there'll be a break anyway so
02:25:45 anyway so should we see how we go right okay then thank you very much well miss grange yes let's carry on yes okay i want to ask you now about um the firefighters override that switches
02:25:56 switches that you go to a report um prepared by the metropolitan police for grenfell tower
02:26:04 met3072161
02:26:08 and you just look at the report first
02:26:16 this is a report prepared by reina following some reconstruction and testing of grenfell tower smoke extraction system and if we go to page 17
02:26:32 in the final paragraph at the bottom
02:26:38 sorry let's can we go one page on
02:26:46 maybe no that seems to be an incorrect reference um if we look at page 27
02:27:02 if we look at page 27 yes sorry this is the bit that i need um
02:27:06 if we look at um under conclusions
02:27:12 four paragraphs down five paragraphs down
02:27:15 down there's a paragraph beginning it was identified so it says here it was identified that the firefighters override switches the fos on each floor in the lift lobbies those were the little yellow
02:27:27 lobbies those were the little yellow key switches may have been a weak point in the system in the event of a severe fire the basic construction of these units left them vulnerable to heat damage dust and water ingress
02:27:38 heat damage dust and water ingress from the balance of probability this allowed several of the firefighter override to switch devices in the hottest parts of the fire to short circuits causing the smoke dampers to behave unpredictably
02:27:50 unpredictably and then they say damage from the fire to the smoke damper actuators would have also prevented them from operating correctly
02:27:56 correctly which led to some smoke dampers being unable to either open or close in response to the unintended fos inputs do you see that there yes now do you agree with rina that the
02:28:08 yes now do you agree with rina that the construction of these firefighters override switches left them vulnerable to heat damage dust and water ingress it wouldn't have been the normal way of things but it certainly did a grenville
02:28:20 things but it certainly did a grenville but that was a unique event did you ever consider whether that might be a weak point in the system um i
02:28:30 um i believe i specified them to be in the stairwell but that's another story i don't know why they're in the lobby um but i wouldn't have considered it to be a weak point in that way because
02:28:41 weak point in that way because in the normal a normal firefighting scenario borne out by the research and all the fire cfd modeling that's been done you never got that far intensity in a lobby during firefighting operations
02:28:53 lobby during firefighting operations it occurred at granville uh what can i say okay
02:28:57 say okay i think your design does show these in the stair and not the lobby and we'll be asking
02:29:02 asking others why they ended up in the in the lobby
02:29:06 lobby and was unpredictable operation of the damper system in the event of fire and heat damage to the actuators or the firefighter override switches ever considered in the design stage the
02:29:18 ever considered in the design stage the uh the actuators themselves as per the guidance again the sa uh 300 degrees c tested units that's all they're not they're not there's to be subject as whatever you
02:29:29 there's to be subject as whatever you know 800 degrees or whatever it was in there
02:29:31 there um so it's what it is it's a product again that is used yes i see and just to complete what reena say just going back to that page
02:29:48 27. their conclusion was reena's opinion based on product information the smoke damper actuators and the firefighters override switches were not designed to withstand exposure
02:30:00 were not designed to withstand exposure to the 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 file
02:30:09 file were present in these areas um i think from what you've just said you wouldn't disagree with that but exceptional case because all and the research was booked by bre
02:30:22 all and the research was booked by bre as well
02:30:23 as well not just the trade and all the modeling that's been done we've never experienced those kind of temperatures from a growing fire in a flat
02:30:31 flat in the lobby area it just does not occur it has occurred here and i'd say the trade will need to re-look at itself and now shafts and duct work just
02:30:44 and now shafts and duct work just briefly
02:30:45 briefly um did you ever consider whether the the shafts and the the linings to those shafts um might need uh testing to determine
02:30:57 um might need uh testing to determine the leakage of the shafts no i asked the very first front end about the condition of the shafts um if they'd been inspected etc i was sure they had been looked at by other
02:31:08 sure they had been looked at by other parties and i would send that couple of photographs to show me this constructional detail and it's constructed from an a1 listed material
02:31:16 material um as long as it's again um whoever's been inspecting the system would know whether they were suitable or not
02:31:24 not i see so it you were assured that others had looked at it and that's not something you considered is that right in what way not consider i considered that should be considered to be
02:31:37 that should be considered to be looked at and made sure that it was okay it was an old building if it was a if the all the blocker was falling down it would have been a problem but i was assured it was it was found to be in reasonable order
02:31:48 it was found to be in reasonable order let's just look at one clause in british standard
02:31:51 standard uh one two one oh one part six this is rbk
02:31:54 rbk three four
02:31:58 page 71
02:32:08 if we can look at clause 11.8.2.8
02:32:15 it says that sheet metal ductwork shall be run within either the protected space or in protected shafts brickwork ducts may be used provided that such ducts are used solely for air
02:32:26 that such ducts are used solely for air distribution and the internal surface is rendered to limit air leakage a sheet metal lining is used or it is shown that the leakage is satisfactory
02:32:37 satisfactory did you ever consider whether the shafts were consistent with that part of that british standard yes i asked the question and i was told they were in good order and who were you told that by that would have been coming from max fordham
02:32:49 have been coming from max fordham and i did poke my head in a few of the um
02:32:52 um sections that have been removed when i went to site and and it to my eyes but i'm not a building surveyor
02:33:00 surveyor it looked in good order there was no sign of any cracking no sign of any holes in the areas i
02:33:07 areas i looked it seemed in very good order actually as though it had never been used
02:33:13 used i see and um the sca guide also has a section and 2015 guide on builder's work shafts it says the shaft should be constructed from non-combustible materials and be
02:33:25 from non-combustible materials and be smooth
02:33:26 smooth internally the size of the shaft should be in accordance with the design specification it should maintain fire separation between corridors it should have a maximum leakage rate of 3.8 meters
02:33:37 maximum leakage rate of 3.8 meters square meters cubed per hour per meters at 50 pa were you familiar with that part of the sca guidance indeed did you assess the existing shaft
02:33:48 indeed did you assess the existing shaft against that leakage rate in the sca guide that isn't a requirement for me that's a requirement for me to ask and i ask the questions are they suitable whoever is responsible for this shaft
02:34:00 whoever is responsible for this shaft would be responsible for checking that did you ever document the response that you were provided with no it is documented in the in the email that was sent to me
02:34:11 that was sent to me i see now in her phase two smoke control report dr lane explains that both the extraction duct work and the dampers themselves needed to have a minimum fire resistance of 60 minutes based on
02:34:25 fire resistance of 60 minutes based on the requirements of approved document b did you ever consider that when designing the smoke control system yes and the dampers did have a 60 minute fire
02:34:35 fire resistance i see and finally um the stack effect and the impact of positive pressure on smoke leakage are you familiar with the phenomenon of
02:34:46 are you familiar with the phenomenon of the stack effect as it applies to the movement of air in a high-rise building yes did you consider whether the vertical builder's shafts at grenfell tower
02:34:56 tower are mounted to tall shafts which might increase the impact of this stack effect
02:35:03 uh not in that direct sense no i'm aware of the neutral pressure plane within a
02:35:09 within a building etc and the effect of on systems and i didn't consider it was a particular problem did you ever consider whether the stack effect might drive smoke up the south
02:35:21 effect might drive smoke up the south shaft
02:35:22 shaft as the air in the shaft heated during the fire
02:35:26 the fire no because there should have been a fan sucking out
02:35:31 that's only if there's a failure that we're talking about did you actually consider the stack effect during your design or is your opinion based on
02:35:40 based on what you think subsequently my knowledge and understanding it wouldn't have had a bearing on a mechanical system with the fans operating correctly do you accept that the need to limit smoke spread as a result of this
02:35:51 smoke spread as a result of this phenomenon makes it even more important that the dampers specified for the smoke control system met the smoke leakage limits for smoke-controlled dampers i'm sure if they were available i'd put
02:36:02 i'm sure if they were available i'd put them in
02:36:05 i see and then finally um if we can go to um psv technical submission revision 6 section 3.4 this is at psb
02:36:17 6 section 3.4 this is at psb 50214 at page 21.
02:36:33 so here we can see that psb also specified
02:36:37 specified these bsb s-series bypass dampers and these were installed on level two and they related to the interaction between the environmental function of the system and its smoke control
02:36:49 of the system and its smoke control function do you recall that yes can you tell us why no performance requirement was set out in the technical submission by psb for these bsc sc series dampers
02:37:03 for these bsc sc series dampers no that's obviously an oversight do you agree that because these level two bypass dampers were required to perform while the smoke extract fans were operating they needed to meet the
02:37:14 operating they needed to meet the standards for smoke control dampers ibs en 1366 part 10 and bsen12101 part 8.
02:37:25 and bsen12101 part 8. they were smoke dampers they weren't tested to that standard but they were
02:37:30 tested mr chairman i've come to the end of my prepared questions thank you very much for letting me have a little bit of additional time well done thank you now you we'll lead the usual break at
02:37:43 now you we'll lead the usual break at this stage how long do you think you need 10 minutes or should we say 10 minutes i would hope that 10 minutes would be sufficient we'll say 10. we need more you can let us know exactly
02:37:54 we need more you can let us know exactly mr marley
02:37:55 mr marley as i mentioned to you a moment ago at this point we have to have a short break um we will resume at ten to five unless i get a message that more time is
02:38:07 unless i get a message that more time is needed for dealing with potential questions
02:38:10 questions in which case we'll just have to hold you up a bit but we hope it'll be ten to five and at that stage we'll see whether there are
02:38:16 there are any more questions for you and as before please don't talk to anyone about your evidence
02:38:21 evidence while you're away from the screen all right
02:38:25 right thank you very much ten to five then please thank you
02:50:19 well we're ready to carry on so i'm going to establish contact with miss grange first oh well no i'm not i'm going to establish contact with mr marley first hello mr manny hello i could hear you good here we are
02:50:33 hello i could hear you good here we are back again we'll see if miss grange is there as well and then we can find out whether there are more questions for you ms grange you there yes i'm here and i can hear you clearly hello good thank you very much well now
02:50:45 hello good thank you very much well now um you can tell us are there any more questions for mr marley yes there are just on two topics but they should be quite short
02:50:55 yes off you go then thank you can we go back on the on the topic of dampers and the x over testing document can we bring it back up it's at gbl
02:51:06 it's at gbl 705 and i want to look at page 42
02:51:20 if we look at the bottom of this uh page on performance criterion test results um do you agree under smoke leakage it says
02:51:30 says smoke leakage failure in accordance with the performance criterion of leakage is deemed to occur when leakage through the damper exceeds that amount measures in the first five minutes of the test duration yes
02:51:43 five minutes of the test duration yes and then in the last sentence the specimen did not satisfy this criterion after the first five minutes of the test do you see that that's correct yes because it wasn't started in the open
02:51:54 because it wasn't started in the open position
02:51:56 position well um that's the first five minutes you said before that it didn't actually fail this failure criterion because it wasn't tested for it but it does look from this like it did actually fail that
02:52:07 from this like it did actually fail that criterion do you agree and smoke leakage failure and cause performance because you didn't occur when things
02:52:24 right okay if it's a failure it's a failure i see um if you are unable to find a certified smoke controlled damper can you explain
02:52:35 smoke controlled damper can you explain why did you specify the gilbert's series 54
02:52:38 54 damper which we can see failed the smoke leakage requirement rather than at least find a fire smoke damper which had been shown
02:52:49 fire smoke damper which had been shown to minimize smoke leakage a fire smoke damper would not be suitable for the application because it would shut on temperature none of the smoke damper types that were
02:53:00 none of the smoke damper types that were available have been tested for the application in which we reuse it could not be certified for that and their damper motors would have patched with the wall so we couldn't put any of those in the only thing that actually fitted
02:53:12 the only thing that actually fitted there were two vent types that actually fitted
02:53:14 fitted uh one was an action air damper and this particular unit the action air damper had further problems in it it reduced the area of opening uh i said we already need
02:53:25 already need the maximum size we could get and it also would have required an access door in the wall which were not allowed to put in so the only thing that actually fitted was the this particular unit i see so your
02:53:36 this particular unit i see so your evidence is that you did look for either a smoke controlled damper or a fire smoke damper that fitted that space and you couldn't find one is that correct that is correct and i'm sure somewhere i
02:53:47 that is correct and i'm sure somewhere i wrote that to matt smith to say this is the only particular unit that will fit this application that was my next question if none were available why didn't you flag that for js wright for the tmo for building
02:53:59 js wright for the tmo for building control
02:54:00 control to enable them if necessary to think about risk mitigation given the potential for leakage because of using non-smoke-rated dampers i did raise it with
02:54:14 dampers i did raise it with with matt smith as i say early on and said this was the only unit that was available
02:54:19 available and the documentation was issued i see so you raised it verbally did you ever raise it in writing um i'm sure that was in writing
02:54:30 um i'm sure that was in writing i'm sure in writing we say this is the only particular unit that's available that will fit this application and in relation to betterment as you've been referring to it what information did you
02:54:42 referring to it what information did you have about the existing dampers to make any comparison with their performance and what you were putting in only the the photograph that was issued and what i physically saw when i went to site
02:54:53 site and the virtually identical of gilbert's now just my final short topic today you've described max fordham's may 2014 analysis as this betterment document
02:55:06 analysis as this betterment document which you say was the basis of psb's tender
02:55:09 tender and what psb was contracted to provide by way of design services and as i've already put to you the document looks on its face like it's merely a comparative
02:55:20 its face like it's merely a comparative analysis
02:55:21 analysis setting out proposals for the push pull system proposed by max fordham at the concept design stage following their discussions with mr mcgregor
02:55:30 mcgregor and do you agree with that not the 13th of may 1 no what document or express term of your contract with js wright do you say
02:55:41 contract with js wright do you say gave you a specific instruction to use this may 2014 analysis as your contractual specification that was the specification they issued with their inquiry
02:55:52 with their inquiry why if that document was so central to what you say you were being asked to design
02:55:58 design why don't you mention this in either of your two witness statements
02:56:04 because it wasn't anything to do with me that was that was max fordham and building control i was not party to any of that okay mr chairman thank you very much i've come to the end
02:56:16 come to the end finally to the end of my questions i'd just like to thank mr mani uh for attending today and assisting us with our investigations we're very grateful
02:56:25 grateful thank you very much ms grange well mr mani it's been a longer day than perhaps you or we thought
02:56:33 thought it might be but uh i'm glad that we have been able to finish your evidence today um i can't see you on the screen which is rather a shame
02:56:44 is rather a shame yes i thought you must be it's just i didn't have you on my screen um thank you very much for making yourself available today i think it's taken a little longer than i as i said than i uh we first expected but we have at
02:56:56 uh we first expected but we have at least finished and uh i've i think speaking for all three of us we found it very helpful to hear what you have to tell us on an interesting and rather intricate subject
02:57:06 subject so um thank you very much indeed and and your evidence is really valuable and now that's the end of it and you're free to go make a cup of tea or whatever it is
02:57:14 it is you want to do now good thank you very much and thank you for the opportunity to actually um give you the information thank you very much well we'll
02:57:25 very much well we'll break at that point we shall resume at 10 o'clock tomorrow morning when we have another witness thank you very much 10 o'clock tomorrow
02:58:45 you