Evidence from Jonathan Croft-Smith (Max Fordham) on smoke control system design development, reviews of AECOM specification, reliance on PSB specialist input, challenges with existing non-compliant shafts, and objective to improve system within hard constraints of the tower.
00:00:25 yes would you ask mr croft smith to come back in please
00:00:41 right mr cross smith ready to carry on i am good thank you very much yes mr strange yes thank you yes thank you mr cross smith what i want to do now in this next phase of the questioning is examine in more detail the design
00:00:53 is examine in more detail the design development process as as it evolved and if we can start in july 2012 if we can go to max 50147
00:01:06 this is going to be some notes yes from we can see meeting number five made by studio e recording a meeting on the 18th of july 2012.
00:01:18 2012. and in paragraph 30 of your statement we don't need to go to it you tell us that it was at this meeting that max fordham was asked to review a specification for the smoke control system prepared for the tmo
00:01:30 system prepared for the tmo in october 2011 by acom is that right uh yes that's correct and we can see this if we go to page three under the third paragraph of that middle
00:01:44 under the third paragraph of that middle section with the heading services we can see it says mf max fordham to review
00:01:50 review upgrade to smoke extract system as per acom
00:01:54 acom specifications circulated previously it is intended this work is included in the scope of this project max fordham x over to review
00:02:04 review and report back do you see that there i do so is that um you explained earlier that this piece of work was effectively added on as the project began to develop
00:02:16 added on as the project began to develop was this the point at which you were asked to first ask to start looking at the smoke control system yes that's correct yeah and if we could go to max403007
00:02:34 we can see this is an email from you
00:02:43 to claire barker of x over copying in mr mcquaid at max fordham and you say afternoon claire you mentioned at the meeting on thursday that you'd like to see a copy of the specification for the smoke
00:02:54 of the specification for the smoke extract system for grenfell tower the specification i've attached below is a previous spec for grenfell from another engineering firm we'll be incorporating it into our spec as part of the refurbishment works
00:03:06 as part of the refurbishment works with the addition of extending it to include the additional residential units that are being created so is this you sending a copy of the acom report to x over is that right that's correct yes
00:03:22 now at this stage what was your understanding of the state of the existing smoke control system within grenfell tower um i don't recall without reference to
00:03:35 um i don't recall without reference to any
00:03:36 any yes any notes as to what my understanding was at this point um
00:03:44 and at this point is it right that what max fordham were doing was reviewing the acom
00:03:49 acom specification with a view to then developing some designs to go forward in its further staged reports on the project
00:04:02 yes i'd note that andrew was leading the leading the design at this point so my involvement was somewhat reduced yeah um but my understanding was that we had been asked to incorporate the
00:04:14 we had been asked to incorporate the improvement works that aecom had previously um designed for and provided a specification for within the works i see yes we of course would be reviewing that as to how it fit
00:04:25 reviewing that as to how it fit within the larger refurbishment works that were now being undertaken versus the previous point in time which was the building was not being refurbished but the smoke control system was yes so
00:04:36 but the smoke control system was yes so the acom's proposal was for a stand-alone alteration to the smoke control system and now what you're saying is the whole building was undergoing a refurbishment yes
00:04:44 yes yes correct yeah now you tell us in your statement this is paragraph 30 again we don't need to turn it up that it was suspected that the current system
00:04:53 system may not operate as required during a fire within the building can you remember why you suspected that had you actually gone into the tower and had a look at it at that point
00:05:05 again i can't recall specifically when i became aware of that but certainly quite early on during our our initial inspection and site visit to the building we noted that the system
00:05:16 the building we noted that the system was a poor state of repair um and again without referring to my notes to get the precise chronology i know that we were circulated a report from the tmo about a previous
00:05:27 report from the tmo about a previous fire where the system hadn't operated as as as required yes exactly i'm just about to take you to that now so if we go to max40315
00:05:43 and if we can start looking at page three of this chain there's an email from mr soon's at the bottom of that page dated the 10th of september 2012.
00:05:54 september 2012. this is to paul dunkerton copying in terry ashton and we can see that there was a query from mr soon's about whether the lfb had raised any concerns about the existing system that might have
00:06:05 system that might have informed the acom proposal and then we can see in reply looking at page two
00:06:14 page two if we go up this we can see that ms ray has said to mr duncan janice ray hi paul as for our conversation just now
00:06:25 hi paul as for our conversation just now i've attached an email i sent to the lfb's fire safety officer following a fire in the common parts of grenfell tower in april 2010 unfortunately as i have outlined the vents did not operate as required during
00:06:36 vents did not operate as required during this fire
00:06:37 this fire which led to pressure on us from the lfb and then she carries on so and you became aware of this uh because this was forwarded on to you i believe okay correct i mean it looks familiar
00:06:48 okay correct i mean it looks familiar yes thank you
00:06:52 um did that knowledge about the fact that the system was in a state of disrepair and hadn't worked
00:07:01 worked correctly during a previous fire including the vents not operating properly
00:07:05 properly did that influence the way you went about developing your design for the project
00:07:14 i don't think necessarily i don't think it influenced how we went about the design of the project um i think what it did was highlight that
00:07:24 that maintenance was not planned maintenance was not being carried out properly at grenfell um but i don't think it would have impacted on our design at all
00:07:35 on our design at all yes now if we could look at another email at max403205 page two
00:07:51 this is an email in september 2012 from mr maquot
00:07:55 mr maquot to kate cooney of x over and here he says attached is a report that was produced by aecom regarding the updating of the existing smoke ventilation system at grenfell tower
00:08:06 at grenfell tower this work was never carried out as the tma thought it would better to do it in conjunction with the regeneration works therefore the tma passed this report on to us for it to be incorporated into our package
00:08:17 package and then you mr mcquatt says we would be interested in any comment you may have before we start to incorporate it into our information now can you help us what role did x over play
00:08:30 what role did x over play in developing the design of the new system
00:08:33 system for this for the smoke control system at the tower
00:08:38 the tower so xova were the fire engineers on the job so their responsibility was the fire strategy
00:08:44 strategy um and with that in mind we would be steered very much by them um in terms of which areas ought to be served by the smoke extracts ultimate control system um
00:08:56 extracts ultimate control system um and also in terms of some of the requirements for flow rates etc for the system we'd be steered by the fire engineer and the fire strategy for the building yes
00:09:07 for the building yes but in practice did you actually get that steer from x over how much guidance did you get from them on the proposals that you subsequently developed um we certainly requested it a number of
00:09:19 we certainly requested it a number of points during the project yes um and i believe we got some guidance from them but i think in the end we
00:09:27 end we i mean we may come through this as you step through the phonology um if that's the intent but i think we began to rely somewhat more on
00:09:36 on psb as a specialist designer rather than on
00:09:40 on x over that's not to say that we didn't include them you know within communication and request comment at certain points yes do you remember ever receiving comments
00:09:49 comments from x over on the acom report um
00:09:57 i have a slight recollection that we did get a very high level yes this looks okay yes um but i think that may have been the extent of it yes thank you
00:10:08 extent of it yes thank you now just looking at that acom proposal for a moment if we could pull it up it's at sea
00:10:13 at sea seven zeros four
00:10:22 this is um that october 2011 document that was prepared for the tmo you can see the date of it at the bottom and if we go on to page six
00:10:37 right at the bottom under you item u14 smoke extract control there is a system description and it describes um the system
00:10:52 and it describes um the system and if we can go over the page let's talk about smoke dampers there it then
00:11:02 in the second paragraph said in order to overcome these issues the following works are required renovation of the dampers
00:11:09 dampers conversion of the control system such that the fans start automatically the addition of micro switches and a monitoring system etc and then it talks about renovation of the dampers
00:11:20 the dampers and then conversion to automatic control of the extract fans do you see that at the bottom of the page i do now just in general what was your understanding of how the existing system
00:11:32 understanding of how the existing system was supposed to work did you have an understanding of that yes um
00:11:38 yes um i believe i mean it may help to turn down to the next section this but i believe my understanding was pretty similar to this actually would you like me to yes just explain in your own words that would help us what
00:11:50 your own words that would help us what how you understood the existing system to work
00:11:53 to work okay so the existing system there was a smoke detector on each of the common lobbies throughout the tower um on detection of smoke from any one of those
00:12:04 smoke from any one of those detectors would activate the dampers on that floor only so all dampers would normally be closed and then on detection of smoke with on that on that particular floor the dampers on that specific floor would
00:12:16 dampers on that specific floor would open
00:12:17 open um there were four shafts two to the north and two to the south i can't recall which was supplying which was
00:12:24 was was extract um but the the supply dampers um would give a natural
00:12:30 natural air path so it's natural ventilation no mechanical assistance um for the air to for supply air to enter the the lobby yeah and then on the other set of dampers across the lobby and that would that was
00:12:41 across the lobby and that would that was the extract route so that would go up to the up to the top of the tower again no mechanical assistance and so there'd be dilution of the smoke and then with the natural stack effect of
00:12:51 of effectively hot air rises there's a simplistic way of thinking about it that the the smoke would exit through the it'll be diluted and some of it would
00:12:59 would exit through the extract shaft yes and did you understand there to be a fireman's override function which could provide some mechanical assistance to that natural ventilation system if the fire
00:13:10 natural ventilation system if the fire brigade chose to operate it yes i did so i would actually our initial
00:13:16 initial view i think actually i should say i think andrew's initial view because i think he did some more in-depth um review of the existing system than i did initially yes um was that it was mechanically
00:13:28 yes um was that it was mechanically assisted for extract only and but then subsequently it was found that it was mechanically extracted for supply
00:13:33 supply as well so there's a set of supply fans um within the podium level which was an area that would previously we haven't been able to get access to when doing our initial inspections which is i think why it took us a while to pick that up
00:13:44 us a while to pick that up yes um and then there was a set of extract fans uh within the rooftop plant room yes and that was activated by the fire brigades upon arrival if they deemed it necessary yes they had no control over opening or
00:13:56 yes they had no control over opening or closing any of the dampers on any of the floors that was all manual it wasn't they weren't actuated in any way but what they could do is is turn the fan set on or off yes thank you
00:14:06 you just while you're speaking try not to speak too quickly just for the benefit of the transcriber but no that's a very helpful explanation thank you um and you said it might help if we scroll down to see this proposal
00:14:18 scroll down to see this proposal just in in in general terms how what did you understand this acom proposal
00:14:24 proposal to be suggesting in terms of improving the system i mean it would help if we could scroll down
00:14:34 down mr operative we could just scroll down the page
00:14:38 the page is that the bit you wanted to look at um yes
00:14:51 okay so my understanding from this specification is the intent was to ensure what was installed
00:15:02 was to ensure what was installed was operating effectively um so some dampers would be somewhat all dampers would be replaced as required um and then the operation of the system
00:15:13 um and then the operation of the system would be
00:15:14 would be automated such that on the detection of smoke in any one of the given lobbies um would also active would not only activate the the dampers to open on that
00:15:27 activate the the dampers to open on that lobby but would also activate the supply and extract fan um with that being a variation from the previous case where the fire brigade would arrive and then decide whether to
00:15:38 would arrive and then decide whether to manually activate it would automatically go into mechanical correct mode and automatically start supplying and extracting correct yes and could you describe that
00:15:50 correct yes and could you describe that as a push-pull system yes yes thank you
00:15:58 now you mentioned a paragraph 33 of your witness statement that um max forder measured the shaft of the existing smoke control system early on in the project um can you remember why were you doing that
00:16:09 can you remember why were you doing that why did you measure the shafts because that's the first thing that you would look at if you were to look at i think as a general point forgive me if i'm not
00:16:20 i'm not particularly great with the building regulations but i've been working within the u.s regulatory environment for the past five years almost exclusively so i'm not as quick to refer to the correct part of
00:16:32 quick to refer to the correct part of building standards so that's forgive me for that um within part b for providing means of escape
00:16:39 escape which is where you would refer to initially for guidance on smoke extracts and for smoke ventilation they have very clear guidance within their around expected shaft areas for
00:16:51 their around expected shaft areas for both
00:16:51 both natural ventilation and mechanical systems yes so as a first point of interest it would be to measure what was there already to see if it was compliant
00:17:01 compliant yes and um did you ever consider um whether that smoke control system was compliant with the standards that it was installed to originally did
00:17:13 that it was installed to originally did that question ever get raised within max fordham yes it did i mean it got raised right from the very beginning yes um but i think we looked at it in detail
00:17:24 um but i think we looked at it in detail later on
00:17:25 later on um i think when we
00:17:28 at the point where we were more involved with building control and proving um proving that the design proposal was an improvement over what was already there
00:17:39 what was already there we looked at it in quite some detail so i personally looked at the building regulations um that were enforced in 1974 um i looked at glc section 20s at
00:17:52 um i looked at glc section 20s at greater
00:17:52 greater london council section 20 and there was a glc
00:17:59 code of practice for means of escape um and then there was a there's there was the the bs code of practice yes for escape as well so i looked at all of those i came to the conclusion that what was
00:18:11 i came to the conclusion that what was installed at grenfell at the point of construction was not compliant at that point yes um uh that was verified to me subsequently by terry ashton at x over who had come to the same conclusion as i
00:18:22 who had come to the same conclusion as i had
00:18:22 had yes um and then beyond that point we then sought to look for the the
00:18:33 the submissions at the time of construction to see how that system was submitted to the equivalent of building control at the time yes um but we found that rbkc had destroyed all records
00:18:44 destroyed all records prior to 1990 so we were unable to find anything else it was a sort of a dead end but on the face of it it was not compliant at the time yes that's very helpful thank you and um as part of your research into the
00:18:55 and um as part of your research into the guidance at that time did you ever look at a guidance document called cp3 1971 yeah that's what i referred to as bs cp3 rather than the glc cp3 yes because as dr lane has explained
00:19:07 cp3 yes because as dr lane has explained in phase one of her work to the inquiry there are certain key features of the tower which are indicative of the fact that it's probably that piece of guidance that was intended to be used in certain respects
00:19:19 certain respects um so so you did no note cp3 1971 yeah yeah and but my conclusion was that it was not compliant with mp3 right and um was one of the key
00:19:31 with mp3 right and um was one of the key reasons it wasn't compliant was because um the aggregate area of the shafts on each side of the lobby is about 0.48 meters squared whereas that guidance for example would
00:19:42 whereas that guidance for example would have required it to be 1.5 meters squared is that the conclusion you came to correct it was about a third of what would typically be required yes thank you that's very helpful
00:19:53 that's very helpful now just moving forward with the chronology and moving on to the stage d report you tell us at paragraph 34 of your witness statement no need to go to it that in
00:20:04 that in november 2012 max fordham's proposals were incorporated in the stage c a stage d report and we can see that report at
00:20:12 report at max 50675
00:20:16 max 50675 page 12.
00:20:31 great and if we that so that's the stage d report and if we look on this is page 12 and this is where we find the smoke extract section it's in the
00:20:41 the the third column on the right under item u14
00:20:45 u14 smoke extract and first of all what we see is a description of the existing system
00:20:51 system yes we see a number of paragraphs and then if we go over the page to page 13
00:21:01 we can see then in that left-hand column top left-hand side of the page new system it says provide a new smoke extract system as shown and there's a series of
00:21:12 as shown and there's a series of drawings referred to in a schematic a smoke extract schematic extend the existing smoke extract system down two floors from the walkway level to the mexican level so because you were
00:21:24 to the mexican level so because you were creating new residential levels one of the consequences was you had to extend the smoke control system downwards
00:21:30 downwards in the tower is that correct that is correct yeah remove the existing fresh air supply fans and replace with new supply fans
00:21:41 fans and replace with new supply fans provide a new run and standby fan etc etc
00:21:44 etc all dampers are power open power closed so that's the new system and again um was that effectively the push-pull system
00:21:55 system mechanically pushing air in and mechanically extracting air out correct yes now um and is it right that this proposal was based on discussions
00:22:08 was based on discussions with somebody called fergus mcgregor at psb
00:22:11 psb is that correct in part yes yes you say in part why do you clarify that in
00:22:17 in in that way so
00:22:22 we were issued with the acom report just prior to
00:22:26 prior to to submitting our stage c report um we weren't given much time basically so we the stage c report is is almost you know is a is a very
00:22:36 very high level summary of the icon we put you know they come spec for inclusion between states c and stage d so river stage c is concept stage and stage stage d is design
00:22:48 stage and stage stage d is design development so we're developing the design
00:22:51 design between those two points um there were a number of conversations primarily andrew was leading the smoke extractor at this point and i was aware
00:23:01 was aware of the conversations but he was talking to psp but he was also speaking to x over at that point terry ashton at xover to ensure that as fire engineer they were also happy
00:23:12 as fire engineer they were also happy with our proposals i see yes and were those telephone calls with mr ashton do you recall or were they email exchanges i would imagine
00:23:22 imagine both yeah from memory terry was more likely to respond over the phone than perhaps on email yes yes thank you and and you say that um psb were partly
00:23:34 and and you say that um psb were partly involved
00:23:35 involved um can you help us just from memory do you remember roughly when were psb first contacted by max fordham um so i think i did obviously review the
00:23:46 um so i think i did obviously review the chronology um of some of the evidence before coming in today
00:23:49 in today i believe it to be around november 2012 yes
00:23:53 yes um and who made the decision to make contact with psb that would be andrew mcquatt yes and can you help us why contact psb do you know what what
00:24:04 why contact psb do you know what what the reason was why psb were chosen to for max fordham to contact
00:24:09 contact um i i don't know that was andrew's decision yes fair enough and um can you help us as to what was discussed with mr mcgregor in these early exchanges can you
00:24:20 in these early exchanges can you remember what advice he gave um again some of this is from reviewing emails in you know shortly prior to this
00:24:31 emails in you know shortly prior to this but yes
00:24:32 but yes and so i can't recall how many of those i was actually cc then on the time but i do know that andrew and i did discuss it generally yes um so it was basically going to psp
00:24:43 yes um so it was basically going to psp as a
00:24:43 as a specialist contractor specialist designer um to review the proposals that we had put together at that point yes um which is not uncommon um to go to a
00:24:53 a to go to a designer before they're contracted yeah um just to get a high level overview as to whether we're on the along the right lines whether there's anything else that we ought to be considering yes that's helpful and can you remember
00:25:05 that's helpful and can you remember broadly what was being recommended by fergus mcgregor at this time so prior to
00:25:11 to the stage d report being prepared it was a
00:25:15 a effectively a refurbishment of the refurbishment and extension of the push-pull system so automating it as outlined within the acom spec which is what we took on as well
00:25:27 what we took on as well um and i i believed there was probably some talk
00:25:30 some talk about improving upon the existing supply and extract rates yes
00:25:38 and and do you know whether in those exchanges mr mcgregor ever expressed any doubts about whether a push-pull
00:25:46 push-pull fully mechanized system would work at the tower was viable do you remember there being ever any doubt expressed about that on psp's behalf
00:25:57 expressed about that on psp's behalf i can only speak to the emails and from conversation between myself and andrew at the time i don't believe i ever spoke to fergus directly at that point
00:26:05 point that's fine um but i don't recall that being no
00:26:08 being no any any negative conversations about it it was
00:26:12 it was yes this looks okay yes [Music]
00:26:16 [Music] and um if we just go to your statement now and i
00:26:19 now and i would like to show you this if we go to paragraph 34 on page 12 of your statement and pick it up in line four
00:26:30 and pick it up in line four you you tell us you say this you say it was
00:26:33 was never the intention to bring it up to the current standards as there were hard constraints including the size of the shafts which were smaller in cross-sectional areas than those required in current standards
00:26:44 standards the chefs were builders work shafts forming part of the structural core of the tower which would be very difficult to make any larger without major structural works our intention was to make the system as
00:26:55 our intention was to make the system as good as we could within the constraints of the tower and then you go on and talk about x over after that and can you just help us when you say as
00:27:07 and can you just help us when you say as good as we could it probably makes sense but what exactly did you mean by that as good as we could so we've previously touched on the
00:27:19 so we've previously touched on the non-worsening principle yes that is not something that was necessarily subscribed to by max fordham as a practice and as certainly within the team working on
00:27:30 certainly within the team working on this we were very much trying to to do the best that we possibly could within within the constraints of the physical building itself and obviously the budget as well does play into it with any
00:27:41 into it with any with any construction project um so we were basically you know accepting yes there are limits but we want to improve it as much as we possibly can yes so just to be clear your objective
00:27:54 yes so just to be clear your objective was not simply to make it the same or a little bit better it was actually to make it as good as it could be
00:28:01 be but given the hard constraints you were facing yes correct and was that to your knowledge and i appreciate you didn't have all the conversations mr mccourt may have had some of them was that communicated to psb that that
00:28:13 was that communicated to psb that that was your objective to try and make it as good as you could i mean i can't speak to the conversations that andrew had but i would say i would be very surprised i
00:28:24 i would say i would be very surprised i mean i'm
00:28:25 mean i'm at the risk of speculation i would be very surprised if if he hadn't have said yes because that's your whole philosophy and the way you work at max fordham yes i mean yes and i think that's reflected
00:28:37 i mean yes and i think that's reflected within the other works that we did in the tower as well yes i understand now a paragraph 35 of your statement in the next page page 13.
00:28:50 you tell us um line if we look at line four i just want to pick up what you say there
00:28:55 there you say we were throughout this time trying to obtain information on the existing system so we could exist x over in demonstrating the improvement of the system to building control and then you refer
00:29:07 to building control and then you refer to various emails
00:29:11 so was your understanding that building control wanted to see some form of demonstration that the existing system was better by comparison with the old one
00:29:24 yes i mean ultimately building control have to approve whatever goes in there so we have to be in a position to provide them with the necessary documentation that they need to see to be comfortable with that
00:29:36 need to see to be comfortable with that yes
00:29:36 yes and was the information that you obtained ever sufficient to be to be able to actually do that comparison in your opinion
00:29:46 i'm not quite sure i understand the question well we'll come to it maybe we'll come to it in due course but it's right isn't it that it proved to be difficult to
00:29:57 it that it proved to be difficult to ascertain um what the performance of the old system was correct i mean i can expand if you'd like as to why
00:30:08 like as to why so our initial point would be to look for original design documentation that wasn't available for grenfell our next step
00:30:18 next step would have been to test the system as it was installed but the system was not in a state to allow us to test that system so beyond that it becomes a calculation
00:30:29 so beyond that it becomes a calculation problem
00:30:30 problem so there are two routes for that one of them would be it's it's feasible that you could do cfd i believe it's not my area of expertise but i know it has been mentioned by others
00:30:41 others yes um or what we what we did you know eventually was we did a we calculated it ourselves based on the known information that we had on the
00:30:52 the known information that we had on the tower yes
00:30:54 tower yes so some calculations were done and we're going to come to the documents where we see this
00:31:00 see this of the flow rate based on the parameters you were working with and simple maths in terms of what you could work out the system might be able to perform if it was working correctly yes
00:31:12 perform if it was working correctly yes correct
00:31:17 yes thank you and um was that a common difficulty in your experience well i guess maybe you didn't have that much experience at that time but
00:31:28 much experience at that time but um are you aware of whether that is a common difficulty in your industry when you're trying to look at non-worsening and comparison comparisons is it often difficult to get
00:31:39 is it often difficult to get reliable information about the system you're comparing with from subsequent experience of working with refurbishment jobs it can be very challenging getting accurate information about
00:31:51 accurate information about systems that have been designed generally with the concept of accurate as-built documentation patient let alone design documentation is a problem yes thank you
00:32:04 is a problem yes thank you now if we move forward now to the employers requirements and so we're moving forward in time but i i have to take these steps in quite big leaps sometimes otherwise we'd be here for too
00:32:15 sometimes otherwise we'd be here for too long
00:32:16 long um and if we go to the employer's requirements now this is psb
00:32:26 50236 these are the employers requirements for mechanical electrical and plumbing services
00:32:35 services correct at grenfell tower and um if we turn to page 35 of this so sorry just to be clear these are dated i don't think the dates on this page but they're dated the 19th of november
00:32:47 they're dated the 19th of november 2013. actually you can see that there's some tiny
00:32:51 some tiny writing in the bottom corner of the document
00:32:55 document on each page which gives that date october 2013.
00:33:03 sorry i said november actually there's both dates you've got 16th of october 2013 and then somebody's revised it with 19th of november 2013. do you see that it doesn't matter but it just gives us
00:33:15 it doesn't matter but it just gives us an indication of when in the project this was prepared so then if we go to page 35 here we get the employer's requirements for smoke control
00:33:26 for smoke control and it says this in the first two paragraphs it is not viable to adapt the existing system to comply with the current standards given the physical constraints of exist of the existing building the design approach has therefore been to
00:33:38 design approach has therefore been to retain the existing system and replace all of the existing components with new equivalent or better components there are no design records for the existing system and it has not been possible to establish the fan duties
00:33:51 possible to establish the fan duties as there are no directly applicable standards which can be referred to it is considered that it would be preferable to have a mechanical ventilation system and that it would be reasonable to design the system to provide an air change rate of 15 air changes per
00:34:04 air change rate of 15 air changes per hour and then it lists out the following new work that's to be carried out as a minimum to that system and we've got various pieces of work and
00:34:17 we've got various pieces of work and then a description at the bottom of that page about how the system would work with a fresh air supply and an extract so again um this is what some people have referred to as the the push
00:34:28 have referred to as the the push pull proposal yes or the push-pull design is still in here yes correct yes
00:34:40 now
00:34:46 if we look at the final sentence of the second paragraph i just read it out we can see that um the requirements were basing the new system on an air change rate
00:34:57 system on an air change rate of 15 changes per hour yes yes now is that um was that rate chosen because you were effectively
00:35:08 chosen because you were effectively seeking to impose some kind of criteria by which you might then be able to compare the performance of the new system against what you thought the existing system might be able to deliver
00:35:21 so broadly the design of the smoke event system within max fordham was led by andrew mcquatt from the beginning of the project
00:35:31 project up until stage d yeah at which point the project was transferred down from the edinburgh office where andrew went down to london
00:35:37 to london and then from stage d through to the end of production of the employer's requirements the smoke extract portion of it in terms of establishing performance criteria was predominantly led by duncan
00:35:49 criteria was predominantly led by duncan campbell
00:35:50 campbell the senior partner who i worked beneath on this project i'm not sure where the 15 air changes per hour came from it was a number that i believe duncan
00:36:01 it was a number that i believe duncan arrived at through conversation with x over right
00:36:06 okay thank you that's helpful um now in his oral evidence to the inquiry mr mani
00:36:15 mr mani said that um based on what he was told by mr mcgregor and what mr mcgregor had been told
00:36:22 been told um and and let's just look at this actually because it's easier to have it on the screen if we go to day 155 page 30.
00:36:42 and if we pick it up
00:36:52 no that's not there sorry that must be a wrong reference um what he said is that mr mcgregor was told how many flaws there were and he was asked what kind of system could be put forward
00:37:03 could be put forward he was told what was already there so he decided push pull was the better solution
00:37:08 solution because of the extended travel distances within the lobby area so so mr marnie is saying that mr mcgregor was aware of extended travel
00:37:19 mcgregor was aware of extended travel distances and at that an early stage he was satisfied that push-pull would work now what i want to ask you is do you remember there ever being any mention by psb about there being extended travel
00:37:33 by psb about there being extended travel distances
00:37:33 distances in the lobbies at grenfell tower again i can't speak to conversations that andrew had but it never came up in a
00:37:40 a in a conversation that i was involved in right and all the meetings you attended subsequently and we'll come to some of them later do you ever remember it being mentioned that there were extended travel distances so what i mean
00:37:52 extended travel distances so what i mean by that is travel distances on the lobby in excess of sorry i know you know 7.5 meters which is the the maximum and approved document b and in bs triple nine one you don't remember there ever being any
00:38:04 you don't remember there ever being any discussion about that in any meetings not that i recall
00:38:11 and he said um
00:38:16 he also said that mr mani's understanding was that when they got to see the employers requirements document
00:38:24 document that there were additional restrictions that were
00:38:27 that were spelt out in those employers requirements which psb hadn't been aware of earlier and which rendered in the push-pull system less viable were you aware of psb ever saying well
00:38:40 were you aware of psb ever saying well now we've seen these employers requirements and we see some of the additional restrictions push-pull isn't going to work
00:38:46 work do you remember that being said no i don't and we were very open and collaborative in our design approach with
00:38:55 with all contractors um on the project so had someone come to us and said well actually
00:39:01 actually you know the wording of your ers is preventing us doing something that we think would be beneficial of course we would always review that right
00:39:09 right so it's never said to you well there are such serious restrictions in these employers requirements that um we're going to have to change tack and do something different and we can't do push-pull
00:39:21 and we can't do push-pull no that was never said not to my
00:39:26 recollection now
00:39:34 in paragraph 40 of your witness statement page 14 i don't think we need to bring it up you you explain that whilst duncan campbell that's the partner you were working under
00:39:44 under continued liaising with x over about what you call the building control issues so that's showing to building control that the system's better yes yes your task was to continue to seek information about the existing system
00:39:57 information about the existing system is that correct that's what you say yes yes and you tell us that in january 2014 you contacted a company called rge and you arranged a walkthrough of
00:40:08 rge and you arranged a walkthrough of the existing system on the 22nd of january 2014 do you remember that i do and you tell us that while on site the rge representative told you that as
00:40:20 the rge representative told you that as they did not believe that the system worked
00:40:22 worked they couldn't test it and they also said it hadn't been maintained for a considerable period of time is that correct that is correct did you get any indication about um how long they thought a
00:40:34 about um how long they thought a considerable period of time was that it hadn't been maintained for um i didn't but i i believe i subsequently arrived at the conclusion that that must have been at least
00:40:45 have been at least 2010 having based on documentation that they'd sent me subsequently after that walk through yes okay now i want to look a little bit
00:40:57 okay now i want to look a little bit more
00:40:58 more at some of mr mani's evidence and i want to start with um paragraph 23 of his first witness statement this is a psb four zeros one three two nine
00:41:10 and at page five
00:41:14 now mr marnie we know was mr mcgregor's colleague within psb and i just want to read paragraph 23 to you
00:41:23 you um he said when i looked at these proposals however i could see that that could lead to problems with excessive pressure drop due to the high duct induct velocity
00:41:34 due to the high duct induct velocity within the existing builder's work shafts
00:41:37 shafts which could result in inadequate flow being achieved through the shafts and then he goes on and says as a result i developed an an alternative proposal which still reused the existing ducts and shaft as
00:41:49 reused the existing ducts and shaft as per the employer's requirements but which could achieve the functional objectives set out in the relevant guidance in place at the time now just focusing um
00:42:00 now just focusing um well i'll come to the detail of what he's saying there in a moment but do you remember mr marney ever explaining to you that there were problems
00:42:11 problems with the push-pull design that max fordham had been suggesting up to that point
00:42:20 so my first interaction with with hugh was over the phone
00:42:26 and he did put forward an alternative like he he described a potential alternative design solution um i'm not sure he said i'm not sure he
00:42:37 um i'm not sure he said i'm not sure he put it in the i think we call the full content of the conversation so i don't know whether he said
00:42:41 said there are problems with your design or whether he simply put forward an alternative that he suggested was better so as as you know with him being an expert in
00:42:52 expert in smoke control systems i was very open to hearing his alternative yes i see um and i appreciate that um you can't remember him saying whether there were problems but
00:43:03 there were problems but he's given some detail in this statement he says that he thought it could lead to excessive pressure drop due to the high induct velocity within the existing builder's work shafts could result in inadequate flow being
00:43:15 could result in inadequate flow being achieved did psb ever spell that out to you whether in the conversations you had with mr mani on the phone or at a later stage did that particular problem ever get flagged to you about
00:43:26 problem ever get flagged to you about the push-pull system
00:43:31 i don't recall having that conversation right
00:43:37 but that isn't to say that i don't believe he's correct in his assertion there
00:43:42 there no i'll i'll ask you that in a moment um it just to be clear it is oral evidence mr manny said that the problem was like a bit like the old court caught into a pint pot you're trying to push
00:43:53 pint pot you're trying to push too much air through a small hole and this could create large pressure drops which are difficult to balance out so you don't recall it being explained in those terms to you
00:44:07 explained in those terms to you i mean i don't recall the full content of the conversation yes um did you agree well you kind of agreed it was a problem if you weren't told there was a problem
00:44:18 if you weren't told there was a problem but
00:44:19 but um had that point occurred to you while you were working up these proposals that there could be this problem with excessive pressure drop at the point in time when we when i
00:44:30 at the point in time when we when i first spoke to hugh we didn't actually have
00:44:33 have a design well our design flow rate was substantially less than what was ultimately proposed by psp yes so at the design flow rate that we
00:44:44 yes so at the design flow rate that we had been working to previously pressure drop was not an issue um so you know i think that would be the first point where that could have been raised because at that point psp you know
00:44:56 psp you know perhaps we're talking we're thinking about a much higher flow rate than we were
00:45:00 were i see does that make sense yes yes that's helpful so one one potential answer was at a lower flow rate
00:45:08 flow rate that might have dealt with that difficulty in your opinion a lower flow rate would you wouldn't get an excessive pressure drop but if
00:45:20 drop but if if hugh's point was that that wouldn't comply with the functional requirements of
00:45:25 of b1 then you know obviously that would take precedence yes and can you explain how you came to be dealing with mr mani instead of mr mcgregor
00:45:36 mcgregor um we know that mr mani picks up the project and takes it forward and then we know
00:45:41 know and we'll come to it in a minute he prepares an april 2014 proposal for this alternative solution but what was your understanding about why you weren't dealing with mr mcgregor
00:45:52 why you weren't dealing with mr mcgregor anymore um i can't recall precisely but i don't think i've specifically requested to speak to hugh i think maybe fergus was out of office
00:46:03 out of office right but i i don't recall precisely okay thank you now mr marnie also said um that the wall openings into the lobby could have had what he called velocity jets
00:46:15 have had what he called velocity jets somewhere in the region of 20 to 25 meters per second which would push smoke into the stairwell during firefighting if there was a fire in a flat on the south side
00:46:26 south side of the tower so that's another problem that he described and he said the problem again was the size of the ducks do you ever remember that
00:46:34 that problem being explained to you either during telephone conversations or in any subsequent meetings no
00:46:44 and um if we look at paragraph 29 of his second statement this is psb 401373 page six
00:47:02 he says he says this as well as the this is 29
00:47:05 is 29 as well as the issues raised in paragraph 23 of my first statement and we've just looked at that i was also aware that the lobby layout at grenfell tower was not a typical corridor arrangement
00:47:16 corridor arrangement the two shafts were located on either side of the lobby but there were additional areas coming off the main lobby area which provided access to the flats in each corner of the tower
00:47:25 the tower one shaft had a grill at low level the south side and the other had a grill at high level the north side the location of the door from the lobby to the stair was also an issue as it was not positioned at the end of a corridor
00:47:36 not positioned at the end of a corridor i recognize that the specific orientation of the lobby and the position of the shafts and door to the stair in grenfell tower meant that it would not be possible to adequately mitigate the risk that smoke would enter the stair
00:47:48 would enter the stair using a push-pull system given the size of the lobby and the position of the shafts there would also be dead spot areas in the lobby where there would be no airflow and therefore no mixing of air and smoke
00:47:59 and therefore no mixing of air and smoke to create
00:47:59 to create dilution now again um there are a number of concerns here do you ever recall mr marnie explaining these concerns he had about the
00:48:09 the max ford and push pull system
00:48:14 again i don't recall the exact content of the conversation so i don't feel like i could give an accurate answer either way i understand i think the language of jet of jets
00:48:24 of jets would have stuck in my head yeah his previous point but i can't be sure with this one i understand did you ever have a conversation with him about the unusual shape
00:48:34 shape of the grenfell tower lobbies and the fact there were these dead ends and what that might mean in terms of the consequences for any smoke control system
00:48:46 i don't recall talking about the shape of the the lobby specifically
00:48:52 i mean we certainly spoke about the fact that it was not a typical arrangement yeah and did you ever discuss the positioning of the vent so as he points out there on the south side
00:49:03 out there on the south side the south shaft vents are at floor level at low level whereas at the north side they're higher up on the wall do you remember ever having a conversation about the effect of that on the smoke control system
00:49:14 of that on the smoke control system and its design i mean we certainly had a conversation about the position of the vents because it was integral to his understanding of the existing conditions of the building yes and i don't recall it being
00:49:26 yes and i don't recall it being mentioned in in relation to the performance of a subsequent design yes i see and and you said before that on the phone
00:49:37 on the phone he started mentioning an alternative solution is that correct that's correct um and and what was he can you remember when he started explaining this to you
00:49:48 when he started explaining this to you what did he say about this alternative solution
00:49:53 i i can't recall exactly i believe it was words to the effect of this would be a better approach yes i see
00:50:02 and well i'll come to in a moment let's go then to psb's design proposals put forward by mr marnie if we go to jsw403474
00:50:25 so this is these are the psb smoke ventilation technical proposal for the stair depressurization systems for the grenfell tower project and we can see that the author was hugh mahoney
00:50:36 see that the author was hugh mahoney from the table prepared 22nd of april 2014 and if we go on to page two of this
00:50:50 it says under the introduction it says having identified possible problems with the proposed push pull system leading to excessive pressure drop due to the high induct velocity within
00:51:01 due to the high induct velocity within the existing builders work shaft an alternative smoke control design solution is required and then after discussions this report provides an alternative approach to designing a lobby smoke control system
00:51:13 designing a lobby smoke control system now pausing there um we can see well first of all do you remember seeing this proposal so this has been made i've been made aware of this only very recently um i didn't see this
00:51:26 only very recently um i didn't see this at the time i don't believe i've been back through records um and i believe that my first conversation with you was actually post dates this right
00:51:37 right so he'd already prepared this when you spoke to him you think i mean it it appears to based on the date but i don't
00:51:49 to based on the date but i don't understand how having seen some of the content yeah some of the the communication at the at the time yes so i think what you're saying is you don't understand how this could have
00:52:00 don't understand how this could have been prepared before you'd had that conversation with him about an alternative system yes um yeah i mean i don't want to speculate but
00:52:09 but but yeah i don't certainly it doesn't it doesn't fit with my understanding of the chain of events and the chronology i see so is it possible that somebody else instructed him to prepare this
00:52:21 else instructed him to prepare this and you were unaware of that at the time i mean i can't that would be speculation i think i understand now um and we can see um in the third
00:52:32 now um and we can see um in the third paragraph it says the proposals have to be firmed up and submitted to building control authority for discussion and agreement
00:52:38 agreement and then it goes on the proposal is to design a depressurization system which will protect the stairwell by providing an airflow from the stairwell to the lobby when the stairwell lobby door is open
00:52:49 stairwell lobby door is open and it goes on the velocity across the open stairwell door should be sufficient to meet the requirements for a class b system within that british standard 12101 part 6 and it says it's proposed to use
00:53:02 6 and it says it's proposed to use all four of the builders work shaft as part of the smoke control system which will result in a much reduced average induct velocity of 5 meters per second
00:53:13 now i appreciate what you've just said you didn't actually get to see this at the time
00:53:19 the time um but um can you just explain to us what your understanding was of what this alternative system would do compared with the max warden proposals
00:53:30 proposals based on the conversation i had with you over the phone yes okay sorry i'll say that i'm talking about it um so i think after the phone call
00:53:41 so i think after the phone call i replied to hugh via email with my understanding of the content of that phone call which was a an email containing
00:53:52 which was a an email containing my my basically repeating back to him my understanding of the description of the system that he had described to me along with a marked up schematic so i i just used a pen and you know overwrote our previous schematic
00:54:03 our previous schematic in order to just just to clarify basically that we were talking about the same thing yes um which generally agrees with this in that we would be extracting from
00:54:14 extracting from all four shafts and the flow rate would be um would be determined in order to meet
00:54:21 to meet a door at an air velocity across the door of two meters a second so that which broadly up broadly that was your understanding yeah which broadly would which broadly reflects
00:54:33 broadly would which broadly reflects this i mean i don't think i'm not sure whether two meters a second is having never seen this until just recently i can't recall whether the two meters per second is described in here there's a there's a duct velocity mentioned in here
00:54:44 duct velocity mentioned in here we didn't discuss a duct velocity on the phone yeah and we just we did but we did discuss a
00:54:49 discuss a velocity across the door yes were you familiar with the distinction between a fully mechanical extract system
00:54:56 system and a mechanical system using pressure differentials
00:55:03 so my as we progressed the design at grenfell it got called a lot of different
00:55:11 different things you know i think the the precision of language wasn't particularly great and my you know my understanding of that was because it was a bespoke solution from the beginning so it didn't neatly
00:55:22 from the beginning so it didn't neatly fit you know within any of the prescribed options within for example approved document b and just pausing there did mr mani explain that to you that it didn't fit neatly within any of
00:55:34 that it didn't fit neatly within any of the
00:55:35 the established systems for example as described in approved document b i can't recall whether he put it to me like that but i think it was a general understanding across the project team
00:55:46 understanding across the project team yes that it was it was a bespoke system that was being progressed because of the because of the the limitations of the of the building itself
00:55:57 itself yes and did you understand that that had certain advantages were you ever explained what the advantages of this system were versus the push-pull yes um
00:56:12 i can't recall exactly what was described but i certainly recall coming away from the initial conversation with hugh
00:56:18 hugh thinking that was a neat solution yeah and thinking well i'm glad we had this conversation it seems like a better solution than what we have currently
00:56:27 currently yes and how enthusiastic was he about his
00:56:31 his solution when you spoke to him about it
00:56:36 he put it across as if this was this was the way to do it yeah yes
00:56:43 and to what extent did you understand that psb
00:56:47 that psb would be aiming to comply with some aspects
00:56:51 aspects of the code of practice that we see outlined there did was it said to you that they would attempt
00:56:57 attempt to take some performance criteria from some of the recognized british standards i can't recall precisely um but i think having come away with a positive experience from the phone call i'm sure
00:57:09 experience from the phone call i'm sure he
00:57:10 he he may have outlined exactly the benefits of it yeah for what reasons was it ever subsequently explained to you why those performance criteria were selected
00:57:21 were selected and not other performance criteria was that ever explained during the time you were involved
00:57:31 i recall there been conversations around yes certainly as it led up to commissioning when we were talking about when i was requesting information from psp as to
00:57:42 psp as to their commissioning sheets so i could be sure that the system was operating correctly
00:57:47 correctly there was talk at that point certainly around um
00:57:51 around um bs 12 and that was arrived at yeah they clearly stated it within their technical submissions and also i had read i had read the
00:58:02 and also i had read i had read the relevant regulations and also asked internally within max fordham as to what this system ought to be commissioned commissioned to and the recommendation internally within max fordham was that bs 12 101-6 seemed to be the most
00:58:14 bs 12 101-6 seemed to be the most relevant
00:58:15 relevant so you know having made that this decision amongst a number of different people it seemed like the right way to go
00:58:20 go yes so it's going to ask that question i mean you've explained you were quite inexperienced with these systems were there other people in max fordham that you did speak to about this alternative design once you
00:58:31 about this alternative design once you understood it to check whether they thought it was a sensible proposal
00:58:36 proposal yeah i mean i do recall talk it's very common within you know it was i can't speak for now i haven't been there for five years but it was certainly very common within the practice to to ask around for the more ask the more
00:58:48 to ask around for the more ask the more experienced engineers and there are certain specialists you know within the practice on certain areas
00:58:52 areas not necessarily smoke ventilation but certainly on mechanical ventilation systems
00:58:57 systems yes so yes i would have spoken to yes were there any specialists on smoke ventilation within max fordham that you could speak to it wasn't a service that was offered that's that's why we would work with a
00:59:09 that's that's why we would work with a fire engineer and you know in this instance a smoke ventilation specialist as well
00:59:13 as well yes thank you now just looking at this proposal we can see in the fourth paragraph
00:59:18 paragraph it says that the proposal is to design a depressurization system which will protect the stairwell now can you recall to the extent you actually thought about it
00:59:29 actually thought about it did you understand psb's design would be protecting the staircase alone or the staircase and the lobby
00:59:37 the lobby i understood that the staircase was was the most important with it being a high-rise building yes and i don't know whether it was spelled out to me or whether i had assumed that there would be a small measure of of protection afforded to the lobby as
00:59:49 of protection afforded to the lobby as well just by think that there is an extract right there yes after the smoke detector has been activated yes and again did you ever ask the question uh whether the system provided protection in the means of escape
01:00:01 protection in the means of escape phase and also the firefighting phase was that something that ever you ever thought about or that ever got discussed it's a little hard to unpick this one
01:00:12 it's a little hard to unpick this one just because obviously there's been so much talk about it subsequently
01:00:20 i certainly understood
01:00:24 at a high level the reason for the different extract rates in the different conditions with the with the um the door to the staircase open and with the door to the staircase closed and how
01:00:35 the door to the staircase closed and how important
01:00:35 important that was and why they were relevant yes um i'm not sure whether i would have whether
01:00:42 whether at the time i would have referred to them of the means of escape and the firefighting phases yes in that language
01:00:49 language yes and did you ever think beyond that one door
01:00:53 one door and think about scenarios where flat doors were open or doors on other stair doors on other floors were open did you ever think about that and consider whether
01:01:04 think about that and consider whether the design was intended to meet different scenarios as well as just the stair door being open
01:01:12 um certainly not all of those scenarios personally in all those scenarios um we were as is often the case relying on other specialist input so
01:01:23 specialist input so xo as fire engineers and psp but having read you know having read around
01:01:30 around around this at the time the building regulations the guidance documents i was certainly aware of the fact that the fire brigade would likely connect their hose on the floor below and then you know therefore be two doors
01:01:42 and then you know therefore be two doors open
01:01:43 open yes um my understanding of the system was such that the you know the extract they would still be able to maintain two meters per second across the door was my understanding yeah within that condition you mentioned
01:01:55 yeah within that condition you mentioned x over just then do you ever remember discussing this alternative proposal with x over and if so what was their response
01:02:05 response so the revision after this one which is the one that i received um was
01:02:12 um was i i received that i immediately sent it on to terry aston at x over for review and i think stating in there worst the effect of this is somewhat outside of our area of
01:02:23 somewhat outside of our area of expertise can you review this for me and let me know if this is
01:02:28 this is acceptable for you and did you ever get a response back i've been back through and i don't i don't recall getting one no it may have been a phone call but yeah i'm usually quite good at yeah
01:02:39 yeah i'm usually quite good at yeah responding to phone calls over email i think i've got coming up in my notes i can show you that email in fact where you send
01:02:46 you send that request to x over but i just wanted to check at this stage whether you remember
01:02:49 remember ever getting a response from x over about the alternative design proposal i don't recall gain one and you don't remember chasing x over for that
01:03:00 um i don't know i can't recall if there's if if there isn't an email chasing then yeah i wish you didn't do it over email so yeah um
01:03:11 so yeah um mr marnie has described his proposal in this way he said it was an alternative design solution that met the spirit of the requirements because we couldn't meet the requirements again just to be clear was that your understanding from the outset
01:03:24 that your understanding from the outset yeah my understanding was it was a bespoke system there were very specific constraints within the tower and that we were doing the best that we could within those constraints
01:03:37 could within those constraints yes now just look at an email chain now so this is psb 6025 page
01:03:44 6025 page two
01:03:51 there's an email at 11 a.m on the second of may sorry psb 6025 page two
01:04:09 yes so here is an email from you to mr mcgregor of psb copying in mr marney of psb on the 2nd of may 2014
01:04:21 and in your email you say morning fergus i understand you're the person to speak to
01:04:27 to regarding residential smoke extract system in hughes absence and then you say spoke to hugh yesterday about refurbishment job in london which i believe a colleague of mine in our edinburgh office has previously
01:04:39 edinburgh office has previously previously discussed with jim shields we're looking to bring the existing non-compliant push-pull system up to scratch and after speaking with hugh
01:04:46 with hugh it seems the pressure differential system would be the way to go so does that help us in terms of timing when that conversation was that mr mani first mentioned his or you first
01:04:58 mani first mentioned his or you first spoke to him and he mentioned this alternative design yes
01:05:06 now in his oral evidence the inquiry mr mani said that in that conversation he was told what the employer's requirements were the size of the shafts and the wall openings etc
01:05:17 and the wall openings etc and the restrictions which that would place on any proposals and it was in that conversation that he mentioned that push pull wouldn't work with that arrangement now i i know i'm keep coming around this from
01:05:29 i know i'm keep coming around this from different angles but do you recall um him saying that during that conversation that you had in may 14. so again i don't recall the exact content of the conversation
01:05:40 conversation all i recall is coming away from it thinking that that hugh's solution seemed a neater solution than ours so he may have used words of that effect
01:05:51 so he may have used words of that effect i'm unsure he also said in his oral evidence this week
01:05:55 week that at some point after the first of may 2014 telephone call you had a second conversation in which he told you that it was absolutely impossible to install a compliance system
01:06:07 compliance system i.e a system which which complied with any of the current codes of practice regulations or guidance given the restrictions in the employer's requirements do you recall a second conversation
01:06:18 do you recall a second conversation where he said that to you i mean i certainly don't recall any conversation where it was the employee's requirements that were causing a restriction you know we certainly had conversations
01:06:29 you know we certainly had conversations about
01:06:30 about the physical limitations of the building itself perhaps yes am i right in understanding it was part of the employer's requirements to retain and reuse the existing builders
01:06:43 retain and reuse the existing builders work shafts yes i think from very early conversation with x over and structural engineers and architects that was deemed the only viable
01:06:53 viable solution i asked the question because i sensed from his evidence that that was the key restriction all right within the employer's requirements that really affected
01:07:05 requirements that really affected uh the identification of any solution yeah i mean i could see how we could how we could take that view and it was you know the fundamental restriction
01:07:16 restriction if you like yeah all right thank you yes i'm sorry yes no thank you um mr mani also said in his oral evidence
01:07:24 evidence that that max fordham and partners decided that they could not go with a system that didn't comply with anything
01:07:31 anything that they could refer to so they went forward on a what he called went forward on a betterment now first of all was that phrase ever used during the time of the project that
01:07:42 used during the time of the project that you were going forward on a betterment
01:07:46 so i don't recall the phrase being used um and i think it might be helpful just to separate two issues
01:07:56 issues somewhat here so there's the design of the smoke
01:08:00 the smoke control system where we were very much seeking
01:08:05 seeking to get the best performance that we could within the restrictions and as close as possible to current standards but with with recognition that that we couldn't meet you know we're unlikely to meet
01:08:18 meet you know we're unlikely to meet current standards if it was a new build because of the physical restrictions so that's one element and then the other element was building control approval yes so
01:08:29 building control approval yes so you know from a building control perspective we just needed to give them the information that they needed to see in order to approve the system
01:08:40 in order to approve the system so i suppose in hindsight there may have been two ways of doing that one would be a fully fire engineered solution to show that
01:08:49 that that it that it met all of the the requirements within the proof document be
01:08:53 be yes be it not that prescribed yes um and the other one being to show that it was an improvement over what was already there yes but i think it's important to
01:09:04 yes but i think it's important to separate the two issues because it's not they're not one and the same the design wasn't progressed on the basis that all we had to do was squeak it past building control yes and
01:09:16 yes and overall that's the impression we got from some of mr mani's evidence on monday was that that was the design intent was just show it's better than the old one and and that's satisfactory
01:09:28 and that's satisfactory are you saying that that's certainly not your recollection of how the design was proceeding no i mean that might have been viewed as the strategy to get it to pass building control if you like yeah um as being the path of least
01:09:41 yeah um as being the path of least resistance to to get building control approval yeah but there were two very much separate issues
01:09:46 issues yeah certainly in my mind throughout the design process for the tower yes thank you um and if we just have a look again at the transcript
01:09:57 transcript um go back to if we go to day one five five
01:10:01 five page sixty five mr mani's evidence
01:10:16 page sixty five mr mani's evidence and looking from um line two so he said no it wasn't necessary as i said before because the project didn't go ahead based on the design it went forward on the betterment on the
01:10:28 it went forward on the betterment on the ventilation rate and i say question so why was it not necessary to set out the functional requirements and then he says because the design was not accepted
01:10:39 not accepted and then questioned and when you say because the design was not accepted which design are you saying was not accepted
01:10:44 accepted he says answer the psb design we put forward a design proposal to fulfill those functions max fordham and partners decided that they couldn't go with a system that didn't comply with anything
01:10:56 didn't comply with anything that they could refer to so they went forward on a betterment they used the ventilation rate that we gave them to prove the betterment so it wasn't a design that went forward it was a betterment that went forward
01:11:09 it was a betterment that went forward and then question i see when was that agreed with max fordham answer that wasn't when you say agree with max ford and maxwell agreed it with building control question i see and what you were just
01:11:21 question i see and what you were just told that's what's happened yes when we tended the job a document was placed before us which said that that was the case and that document was adopted and placed in our technical
01:11:32 adopted and placed in our technical submission now we'll come on in a moment to the document that the max fordham document that mr mani was referring to which he was relying on as saying that
01:11:43 relying on as saying that the objective was simply to beat the rate of the old system um but i just wanted to put that to you and ask you whether that was consistent with your understanding of how the project progressed now i think your
01:11:55 project progressed now i think your answer is going to be the same as the one you just gave where you you're separating out two things is that correct
01:12:02 correct yeah i mean that's yeah that is that's correct um up until the point where the ers were produced
01:12:10 produced then what we are saying within the ers is that we're improving the system by automating it and by increasing the extract rate over what was currently there
01:12:20 there as an improvement to the existing and then
01:12:24 then subsequent to that we've had discussions with psp where hugh has proposed what he's what he views as an expert
01:12:31 an expert as a an improvement over what we have had in our ers and we've basically accepted that because it appeared to be a better solution so
01:12:42 solution so and yes there was also separately some discussion with building control over what they needed to see in order to to to be satisfied
01:12:53 to to be satisfied and to pass it but i wasn't directly involved in all of those in all of those conversations and meetings with building control i was often
01:13:00 often requested to produce something that could be given to building control i see does that make sense that does make sense would it be right to understand that as far as building control are concerned
01:13:12 far as building control are concerned there were two possibilities one is that you show compliance with the existing guidance and the other is because it's refurbishment you satisfy them that it's no worse than
01:13:23 you satisfy them that it's no worse than it was
01:13:25 it was yes and in one sense betterment could cover both of those approaches i i mean i'm unfamiliar with hugh's term of betterment i i i
01:13:36 betterment i i i i read it as the second of those approaches which is to show that it's an improvement over what was already there i think betterment is a slightly strange term to use for compliant with government regulations
01:13:49 compliant with government regulations well isis
01:13:50 well isis i understood him to have in mind something better than the existing system
01:13:55 system though not as good as current full current
01:13:58 current compliance with current regulations and from the point of view of building control
01:14:04 control that would do would it not it would it would yeah it would be that it would be an improvement over what was there so from a building regulations perspective it would follow the no worsening principle yeah all right thank you
01:14:15 principle yeah all right thank you yes thank you yes thank you and i've just finished one further question on this topic of what you discussed with mr manny and then we're going to come on to look at some different documents so perhaps we can break then
01:14:28 perhaps we can break then mr marney also referred to having a conversation with max fordham about cfd modelling of the proposed system at grenfell do you recall that ever being discussed
01:14:43 do you recall that ever being discussed i don't recall it in connection with psp i do recall there was a conversation about cfd
01:14:51 about cfd between ourselves the tmo and x over at one point um in order to satisfy building control because i think building control
01:15:03 building control i can't recall exactly they may or may not have raised it as one particular one particular route in order to satisfy them i don't recall talking about it with psp right thank you
01:15:15 right thank you what mr mani said was he said this was discussed with max fordham and partners there was insufficient time to carry out modelling so modelling was not considered and that was also a requirement of why
01:15:26 requirement of why the decision to go down the betterment route there wasn't time to get any approval
01:15:31 approval for a non-standard system now first of all
01:15:35 all do you remember a discussion between max fordham you or anyone else at max fordham and mr marney in which it was agreed that there was insufficient time to carry out cfd
01:15:50 modelling i mean i don't it was a long time ago now so i don't i'm not entirely sure one thing that did just occur to me then is that
01:16:01 just occur to me then is that it at the initial the initial point of the conversation with well it was supposed to be fergus initially but was it turned out to be you
01:16:10 you was in order to to get some more information from them for to include within a a report or an analysis that i was preparing
01:16:22 preparing to put in front of for the tmo to put in front of building control effectively to show our calculated flow rate
01:16:30 rate for the existing system versus what our proposed
01:16:34 proposed system would have so the original purpose of the call was to speak to psp to understand what their proposed supply and extract rate because at that point it was on the push-pull system yes now i may
01:16:47 yes now i may potentially like cfd could have been floated within there yeah i can't recall exactly um but then subsequent to that there was a after the email exchange that we spoke
01:16:58 after the email exchange that we spoke about where i clarified with a a marked up schematic there was another phone call with fergus at psp so i was hoping to talk to hugh again i got fergus this time um
01:17:09 i got fergus this time um and fergus was very much in favor of the push-pull system so at that point because i had to get this
01:17:17 this maybe there's an understanding in timing in that i was trying to prepare this analysis by probably the end of the week which is when i've been told to do it by fergus was very much in favor of the pushball system saying
01:17:28 pushball system saying he didn't think differential would be feasible um so he gave me some gave me some flow rates for a push-bull system which subsequently made its way into my analysis which then went to the tmo
01:17:39 analysis which then went to the tmo whether or not it went to building control i have no idea but it went to the tmo
01:17:42 the tmo yes so if that helps to have a little bit of context behind that yes and can you remember fergus mcgregor ever explaining to you why he didn't think the differential would be feasible
01:17:56 not precisely but i think complexity i think i think he thought he was overkill you know in a way yeah okay mr chairman thank you i think that's a good name is that a good point
01:18:08 that's a good name is that a good point yes yes all right well we do we won't have a break during the afternoon session uh and uh we're going to take it now mr crossfit so we'll uh come back please at 25 to 4.
01:18:19 we'll uh come back please at 25 to 4. okay and uh while you're out of the room please don't talk to anyone about your evidence or anything relating to it again okay thanks thank you you'd like to go to the usher please
01:18:38 good 25 to 4 please thank you
01:36:24 would you ask mr croft smith to come back in please
01:36:40 all right mr cross smith yeah when you're ready mr green thank you yes thank you yes before we broke um you were explaining this distinction that you think is important between perhaps what max fordham were
01:36:51 between perhaps what max fordham were trying to do with the system but then and then strictly what non-worsening might mean and what building
01:36:57 building control wanted to see in terms of non-worsening can you just help us what was max fordham's baseline for the existing system was it looking at what the existing
01:37:09 was it looking at what the existing system could do if it was working was that the baseline so are you going to go on and off for another option i will in a minute but let me just find out if it was that option
01:37:20 out if it was that option so were you asking yourself the question for non-worsening purposes what is the existing system capable of doing assuming it's operational is that the question you're answering correct but to what extent did it factor
01:37:32 correct but to what extent did it factor into your thinking that well that's one question but actually we know that the existing system
01:37:40 system was non-compliant with the standards when it was built so is it any part of your thinking that when you look at non-worsening you should look at what a compliance system ought to have
01:37:52 what a compliance system ought to have been at the time
01:37:58 no is the short answer yes okay no that's helpful thank you now at paragraph 47 of your statement
01:38:07 statement page 16 you say that um psb and i think you've referred to this gave you a target
01:38:13 target of five meters cube per second for the system
01:38:17 system that they were designing is that correct that is correct and you say that you'd ask them where that figure came from and they said it was the number that they always used so you adopted that as the target for
01:38:29 so you adopted that as the target for the proposed system is that correct that is correct yes um it was also i think on the same email as well as saying it was a number they also used i think they mentioned that it was proven by cfd
01:38:40 was proven by cfd or a number of cfd yes now let's go to the document you were referring to earlier which i think you say is the document that you were preparing to assist building control in its analysis
01:38:51 its analysis this is max402335
01:39:02 this is um revision b dated the 13th of may 2014 of something called the smoke ventilation analysis and if we look onto page two
01:39:13 and if we look onto page two we can see that what this document does in summary is it says this report has been prepared in order to compare the design performance of the existing smoke extract ventilation system in grenfell tower
01:39:23 tower with the design performance of the new system proposed as part of the refurbishment works and then you go on part of the existing system and now approximately 40 years old etcetera
01:39:34 old etcetera and then below that in bold it says it's been found that the proposed upgrade to the system should result in a considerable performance increase flow rate of existing system 1.1 to 1.2 meters cubed per second
01:39:46 1.1 to 1.2 meters cubed per second flow rate of proposed system 5 meters cubed per second yes yes now can you just explain to us but in your own ways the background to how this document came to be created
01:39:59 how this document came to be created the reason for the document yes so
01:40:05 we've been having some conversation with building control from much earlier on in the project we knew that the smoke the smoke control system by nature of it being
01:40:16 being you know very limited in what we could do with it it would we would have to be to make sure building control were kept up to date with our design as it progressed to make sure that they were happy with it
01:40:27 happy with it effectively um so we've been having a series of conversations with them we so between i think i said before up to stage c we were using um the acom report the
01:40:40 we were using um the acom report the acom spec
01:40:41 acom spec um between stages c and d we circulated the acom spec to both x over and psp to get their view on whether that was a suitable proposal um
01:40:53 proposal um we may not have sent so we may not have sent psp the acorn spec but we we sent them our design and then from stage d until the ers were
01:41:04 from stage d until the ers were produced we were then duncan was dealing with x over trying to get x over to give us a proposed supply rate effective extract rate if you like
01:41:16 effective extract rate if you like supply an extra rate for the building and we were struggling i think i recall to get a number out of them for that so i think the er has progressed on using the 15 air changes per hour
01:41:26 per hour yeah which is uh and again i don't recall where that when we came from i think
01:41:31 think duncan it was duncan's number and it may or may not have come from conversation with xover and then beyond and then building control i think was sent either the employer's requirements that had the
01:41:42 the employer's requirements that had the 15 changes per hour stated in it or there was a separate document prior to this one that i think duncan produced which was called smoke control proposal um which either had the 15 air changes
01:41:53 um which either had the 15 air changes per hour or it had no supply or extracting it wasn't a rate
01:41:58 a rate attributed to it it was described as mechanical no rate um so building controls subsequently came back
01:42:05 came back and said we don't think that you are adequately proving that your proposal is an improvement yes and they laid out
01:42:16 yes and they laid out what they would like to see in order to satisfy
01:42:19 satisfy them that it was an improvement so the outcome of that was well we could go away we could do either we turned
01:42:27 we turned hand calculation it's you know it's an excel spreadsheet effectively in a design um or cfd yeah um and it was decided that the hand
01:42:38 yeah um and it was decided that the hand calculation route would be the way that we would go and that's where this document comes from yes and did you draft this document yes yes um and if we look on page um seven we can see a little bit more
01:42:51 um seven we can see a little bit more about the comparison that was being done here we can see it says the new fans will be sized to provide the minimum of five meters cubed square
01:43:02 five meters cubed square per second flow rate at the furthest point from the fans this is in line with the current best practice for balanced pull push push pull sorry tight smoke ventilation systems
01:43:13 systems with the figure arising from a 3.5 meters cubed per second flow rate through an open door to prevent smoking grass from the lobby to the escape stair during the escape plus an additional 1.5 meters
01:43:24 escape plus an additional 1.5 meters cube per second allowance for leakage from the existing online builders works shaft and remaining dampers and then you set out in the table those figures and below it says from the table above it can
01:43:35 it says from the table above it can clearly be seen that the performance of the smoke ventilation system in grenfell tower will be considerably improved as part of the refurbishment works in addition a new system will also be significantly more reliable and
01:43:46 be significantly more reliable and easier to maintain than the current system so so this document
01:43:52 document just to be clear was still based on the push
01:43:55 push pull type smoke control system is that correct
01:43:59 correct yep that's correct i think just before the break i explained i spoke to hugh he proposed a pressure differential he was then out of office suspected fergus fergus reverted to push-pull and
01:44:10 fergus reverted to push-pull and recommended that one and gave me the numbers
01:44:13 numbers and those are the numbers that i've used here so it's still push-pull at this point
01:44:16 point yes because mr marnie said on monday that it was an error to have push-pull in this document but what you're now saying is that you'd got that figure of five meters
01:44:27 of five meters per key per second from mr mcgregor at psb
01:44:31 psb correct and and that's why that appears in here is that correct correct yes
01:44:38 was there ever any similar analysis done for
01:44:41 for the psb alternative proposal
01:44:46 bios yes no did you ever see one from psb
01:44:53 no but it was fundamentally different at that point and also the five meter cube per second remained so you on face value you could say well you could compare the two values and already there's a much higher
01:45:05 and already there's a much higher extract rate than was previously in the building
01:45:08 building yes i see
01:45:13 now if we just look at an email from you now max405634 this is an email date of the 19th of october 2015.
01:45:32 so it's from you to artelia copying in a number of others and picking it up in the third paragraph you say subsequent to the tender may 14
01:45:44 say subsequent to the tender may 14 we were instructed to produce a report for building control by the tmo this was to show the fire brigade that work was progressing on the system in order to respond to an enforcement notice
01:45:53 notice we again went to psb for advice and at this point they suggested that their recommendation would be to increase the air flow in order to bring it closer to current regulations they also advised that building control
01:46:04 they also advised that building control would be more likely to accept the proposal
01:46:06 proposal if a larger flow rate was specified hence the five meters cube per second figure
01:46:12 figure now those discussions that you're talking about there with psb were they with mr mcgregor or mr marnie
01:46:19 just give me a moment to read this sorry
01:46:48 yes this is yeah it's the same conversations yes that you're referring to yes yes andy in in this email you then refer to
01:46:59 andy in in this email you then refer to a change of strategy in the next paragraph
01:47:02 paragraph you say further design development by js wright with psb eventually resulted in a technical submittal whereby the design system retained the five meters cube per second figure but change strategy from supply and
01:47:13 but change strategy from supply and extract system to an extract only type system
01:47:16 system based on further advice from psb this is what was presented to building control for approval and was subsequently accepted
01:47:23 accepted yes
01:47:26 sorry i missed the question within that no i'm sorry i'm just trying to kind of
01:47:34 recall that that's consistent isn't it but actually what you've just been telling us in terms of what subsequently happened um
01:47:44 can you recall whether the document that you prepared that ventilation analysis do you know i think you may have touched on this earlier whether it was ever actually sent to
01:47:55 whether it was ever actually sent to building control um i don't know i sent it directly there's
01:47:59 there's two revisions of it vision a went to the tmo
01:48:04 tmo and then revision b went to the tmo and potentially xover yes we've checked and revision a was still based on the push-pull system as was revision b and there are some minor amendments to
01:48:16 and there are some minor amendments to the text but it's predominantly the same document is that your recollection yes now js wright's appointment now if we go to paragraph 48 of your statement on page 16
01:48:31 here you're describing a change in max fordham's role um so you say at the kickoff meeting with ryden and js wright in august 2014 we sought an
01:48:43 wright in august 2014 we sought an update on the status of the smoke ventilation system design proposals and building control approval and were informed subsequently by claire williams from the tmo that it was being left for ryden
01:48:54 ryden to deal with in their application to building control the design of the smoke ventilation system was now in the hands of j s wright who were taking the lead with building control as confirmed by js
01:49:05 building control as confirmed by js wright's email to building control of the 17th of october 2014. our involvement was reduced to answering queries on the employer's requirements such as our email to ryden of the 23rd
01:49:17 such as our email to ryden of the 23rd of october 2014 confirming that a dial-up connection to a remote monitoring service or the london fire brigade from the central control panel was required and in
01:49:28 control panel was required and in relation to queries was raised by js wright about the schedules in the employer's requirements which needed updating following the air flow rate increased proposed in the smoke ventilation analysis prepared in may 2014
01:49:40 analysis prepared in may 2014 at this stage the design of the smoke ventilation system was still an upgrade of the existing system and not the psb design that was eventually installed so you're explaining that once ryden are
01:49:51 so you're explaining that once ryden are appointed
01:49:52 appointed and j.s wright are appointed as ryden's m e
01:49:55 m e subcontractor your role changed is that correct that's correct and um you've explained that is this right your role was then limited to responding to queries about the
01:50:08 to responding to queries about the employer's requirements that you'd written
01:50:10 written correct we were retained directly by the tmo in an advisory role to ensure that
01:50:18 that um that the the contractors didn't deviate too much from our
01:50:25 from our employees requirements from a satisfactory performance perspective
01:50:37 yes i see so you're advising the tm tmo
01:50:42 to ensure that whatever system's put in still
01:50:45 still effectively meets your employer's requirements yeah correct across all parts of the project yeah and does that mean that um you didn't consider the alternative design in detail but just looked at the
01:50:58 design in detail but just looked at the general
01:50:59 general principles behind it and whether they were consistent with your employer's requirements
01:51:05 i mean i i believe i did look at this particular design in detail because it was
01:51:09 was somewhat critical to the building yeah um and i think i think we touched on it earlier that on receiving the technical submission i reviewed it and then forwarded it to x over
01:51:19 over more expertise than me in order to go through it as it stood relative to the strategy yes would you accept that max fordham was also
01:51:30 fordham was also involved with some ongoing discussions with building control thereafter including attending a meeting at which building control were present we attended the meeting but very much in a in a
01:51:42 a in a reduced capacity we i sat and listened in effectively the meeting was driven entirely by psb and js wright i see yes i'm coming to that meeting in a moment um but also you did witness
01:51:54 a moment um but also you did witness some of the um a demonstration of the system didn't you
01:51:59 you yeah we were within our contracts we were down to witness certain major elements of plan wait or equipment yes now let's go to that meeting
01:52:10 that meeting um if we go um to an email to remind you it's at max max404665
01:52:26 this is an email from you to claire williams at the tmo copying in your superior duncan campbell and you and it's on the 24th of november 2014. so this is sometime after ryden's
01:52:39 2014. so this is sometime after ryden's appointment and you say evening claire we had a meeting this morning with building control
01:52:45 control regarding the proposed smoke extract system with ryden j s wright studio e and the smoke extract system supplier psb
01:52:53 psb js wright have developed a slightly updated proposal with psb which would eliminate the need for the fresh air inlet which was previously at the top of the glazed foyer
01:53:03 foyer it would instead take the make-up air from a vent at the head of the stair core we have yet to receive a technical submittal for this but in principle it appears to be a neat solution
01:53:15 appears to be a neat solution which also satisfies building control
01:53:19 and then if we just look down and then you go on to talk about other topics now you say at the end of that paragraph that in principle
01:53:29 principle um building control accepted the proposed design well you say that they it satisfied building control yes yes was that your understanding of what happened at the meeting
01:53:40 happened at the meeting when you were present at it my my understanding was that building control gave a tacit approval that if this was progressed then it would be something that they would be comfortable with
01:53:51 that they would be comfortable with yes and can you remember from the meeting how much detail did psb and js write go into about the alternative design the mechanical extract using
01:54:02 the mechanical extract using depressurization principles um i believe that went into some detail yes and um did you get the impression that the building control officer mr
01:54:13 that the building control officer mr hansen fully understood the system that they were proposing at that meeting yes it was quite a detailed conversation yeah were any concerns voiced at that meeting by anyone as far as you
01:54:25 at that meeting by anyone as far as you can remember about that alternative system no i think it was generally well received did you make any comments on behalf of max warden
01:54:36 max warden i can't recall he's the short answer again i came away from the meeting thinking it had been a successful meeting
01:54:42 meeting yes and can we look now at the email you just referred to where you seek some some more advice from mr ashton this is a max404795
01:55:01 this is an email dated the 6th of january 2015 from you to mr ashton and we can see you've attached a number of
01:55:11 of documents nine attachments in total and then if we look down at the text of your email you say afternoon terry can you look over and provide comment on the smoke extract
01:55:22 and provide comment on the smoke extract proposal put forward by psb on behalf of jsright
01:55:26 jsright it looks acceptable and i believe the principle of it has been verbally accepted by building control but it may be wise to get your view as it falls slightly outside our area of expertise it's fundamentally
01:55:38 our area of expertise it's fundamentally different to what we specified in that it's now
01:55:40 it's now a pressure differential system rather than simple smoke clearance details can be found below if you have any questions then please give me a call now you've already explained that you
01:55:51 now you've already explained that you you didn't get a response to this email from x over is that correct i don't recall getting a response did you advise your client um the tmo that you'd tried to seek some advice
01:56:02 that you'd tried to seek some advice from x over on this question and uh hadn't managed to receive any advice in return um i don't recall i certainly had a conversation with
01:56:14 conversation with my superior duncan campbell about this we were
01:56:17 we were having quite a bit of difficulty with getting information out of x over it had been a common thing throughout the project um i don't recall how it was resolved in this case it may have been that duncan
01:56:29 this case it may have been that duncan had spoken to terry sorry slightly losing my voice that's okay do you want to have some water
01:56:39 and you can't recall mr campbell raising it with the tmo that you had sought some advice on this specialist proposal put forward by psb from x over
01:56:50 proposal put forward by psb from x over but you hadn't had a response um i i don't recall now in paragraph 5150 and 51
01:57:01 now in paragraph 5150 and 51 of your statement you you explain after js wright sent you the psb technical submission on the 12th of january 2015 you asked for a schematic to make sure
01:57:12 you asked for a schematic to make sure js wright and psb had properly considered the complexities of grenfell tower
01:57:16 tower and this was provided in the next round of drawings from jsri on the 30th of january 2015. do you remember that i do and what do you mean by um to make sure that they had properly considered the complexities
01:57:28 had properly considered the complexities of the tower can you be more specific about that
01:57:32 so just in our relationship with the tmo at that point as an advisor i wanted to ensure that psb obviously max fordham as a as a company had been
01:57:44 max fordham as a as a company had been involved in this project far longer than js wright had and yes we'd had conversations with psb and we shared design documentation with them but i wanted to be
01:57:55 them but i wanted to be satisfied that js wright and psp fully understood the building you know because it was you know as we've established a non-standard system and it was quite
01:58:06 a non-standard system and it was quite there was some complexity to it that that had all been adequately taken care of in my capacity in my capacity as an advisor to the client yeah and in terms of the information that came back and the quality of it were you satisfied
01:58:18 and the quality of it were you satisfied that js wright and psb had sufficiently understood the complexities of grenfell tower in putting together their proposal yes
01:58:28 and then if we go to rbk3033900
01:58:51 no i don't think that's um actually yes page two of that sorry let's go to page two of that yes this
01:58:58 this is um a memo from paul hanson to john hoban dated the 24th of june 2015. and this is where mr hansen who was the
01:59:09 and this is where mr hansen who was the specialist dealing with means of escape says to mr hogan that the proposals set out in psb's technical submission were satisfactory you can see that under the
01:59:20 you can see that under the the bold lines before just before the numbered paragraphs and he says at the bottom generally the components of the system should conform to the guidance on smoke control to common escape routes revision one june
01:59:33 common escape routes revision one june 2012. now that's the sca guidance and did building control ever mention the sca guidance to you um during any of your meetings with them
01:59:44 um during any of your meetings with them i don't
01:59:45 i don't recall it being referenced to me personally
01:59:49 and um you tell us in your statement this is paragraph 52 but we'll keep this document up you say building control was aware from the various discussions that the whole
02:00:00 various discussions that the whole system could not be compliant with the current guidance on these systems included within adb due to the size of the shafts i therefore took his comment at point three so that's the comment the comment
02:00:12 three so that's the comment the comment about components to mean that whilst the system as a whole could not follow the current guidance the components of the system should still comply with the requirements within the stated list of regulations and that's why the phrase components is used
02:00:25 why the phrase components is used at point three
02:00:30 now um
02:00:34 did you i think it follows did you ever check whether the proposal that was being put forward was more generally compliant with that guidance
02:00:42 guidance not just in terms of the components but in terms of other aspects of the guidance that was being put forward
02:00:52 [Music]
02:00:55 i mean i my belief at this point in the project that everyone was fully aware of of the complexities and what we were and weren't seeking to to meet
02:01:06 weren't seeking to to meet um so i think when i read this i you know it was with the understanding that they were fully under they were fully aware of where we were in the design process
02:01:18 were in the design process what wasn't and how we were how we were approaching it and that's why i came to the conclusion in my witness statement that they were talking specifically about the components and by that i mean the dumpers and the fans
02:01:31 i mean the dumpers and the fans yes yes i understand um now in terms of the final design and how it how it's set we know and i'll take you to the document in a moment that that was set out in psb's technical submission revision
02:01:43 technical submission revision six um do you remember seeing that final revision six of the technical submission um i mean i remember seeing quite a few revisions and commenting back and forth
02:01:54 revisions and commenting back and forth from memory i can't remember which one was the last one okay did anyone ever say at any time that the system was designed to reflect something called the colt shaft system
02:02:06 something called the colt shaft system was that ever discussed not to my recollection
02:02:13 now earlier this week mr marnie said in his evidence that the decision to design the new system so that the south shaft extracted smoke downwards and out at lower levels
02:02:26 downwards and out at lower levels he said it became incorporated by the instruction of others and he said that the final that the final design which was to extract down at south level
02:02:37 which was to extract down at south level and up at north level would still work but it wasn't as clean a design
02:02:42 a design as i'd proposed now captioning not
02:02:59 that i made available but i don't recall i was interested enough i remember it as being a development of the design yeah at some point the design changed yes and
02:03:09 yes and i could see benefits to that in some ways and that you know there was some complexity with joining those those shafts within the plant movement at the top yes but i don't certainly know we call it coming from us to say hey why don't we
02:03:20 coming from us to say hey why don't we do this instead yes so you do clearly recall that originally if they were going to extract both
02:03:26 both upwards join the two shafts together extract upwards and then there was a change to extracting downwards on the south shaft yeah and so much as i remember the the
02:03:39 yeah and so much as i remember the the marked up schematic that i sent back to hugh after i tell you after our initial telephone call i marked that up to join the two shots together at the top which i think would have reflected the conversation we'd had um and i can't
02:03:52 the conversation we'd had um and i can't remember exactly at what point we moved away from that and for what reason but i don't remember it being directed by us because we were not actually involved in the design at this point we were very much
02:04:03 much in an advisory capacity yes if we could just look at mr mani's witness statement on this point if we go to psb four zeros one three two nine
02:04:14 nine and look at page eleven
02:04:21 at little three mr mani is um explaining in this part of his statement he's explaining a number of changes that happened to the design during the course of those technical submission revisions
02:04:34 submission revisions um and he says here that um as well as the configuration of the extended smoke shafts another detail which was finalized after the initial design work recorded in revision one was the specification and location of
02:04:45 was the specification and location of the fan sets used in the system initially it was envisioned that north and south smoke shafts would be connected at the top of the building and they would feed to a single smoke extract fan located at roof level now pausing there was that your
02:04:57 now pausing there was that your understanding of his original design that there'd be a single fan extracting at reef level well there would be two because there'd be a backup fan as well but it would be a single fan set yeah but yeah i believe
02:05:09 a single fan set yeah but yeah i believe that was what i mean only so much as was was discussed over the phone in one phone call and then with a you know a pen markup yeah i understand presented i understand
02:05:21 yeah i understand presented i understand thank you
02:05:22 thank you and then he goes on and he says however given that an environmental fan needed to be installed at low level and given the space limitations at grenfell tower the design was changed to incorporate one smoke extract fan set
02:05:33 to incorporate one smoke extract fan set in the rooftop plant room which was used to extract via the north shafts in both environmental and smoke control mode another smoke extract fan set at walkway level which was used to extract by the south shaft and smoke control mode
02:05:45 south shaft and smoke control mode and an environmental supply fan at walkway level which was used to supply makeup air via the south shaft in environmental mode and he explains that this arrangement is reflected in revision five of the technical submission onwards
02:05:58 five of the technical submission onwards and he says he also confirmed in an email exchange that the duct work housing the smoke extract found at walkway level needed to be far-rated now um if we could just go to
02:06:10 now um if we could just go to his oral evidence on this point and if we can go to day one five five and look at page seventy five
02:06:32 and if we pick it up in line 21
02:06:36 he says this is a later design which design are we talking about originally everything was extracted from the top of the building the two shafts were joined together in the rooftop plant room with one extract fan set
02:06:49 plant room with one extract fan set and then yes if we go over the page he says this is a much later development no question i see so i think this is the design as it was finally intended to be is that correct
02:07:00 finally intended to be is that correct that's correct but it's not our design and then i say when you say it's not your design why do you say that our design was to connect two shafts together the south and north side in the
02:07:11 together the south and north side in the rooftop plant room with a single fan set the design evolved through the course of the contract by other parties i see so are you saying it wasn't part of your design intent for the smoke to
02:07:22 of your design intent for the smoke to be extracted downwards as we can see on the bottom left-hand side of that drawing initially no question but did it become part of your design that it was extracting downwards we can see the flow
02:07:33 extracting downwards we can see the flow path going through the duct work at the lower levels and then out to the outside and then answer it became incorporated at the instruction of others it sounds from what you're saying like you were not happy with that instruction
02:07:44 you were not happy with that instruction by others is that the case well not i'm not happy with it my preference would have been the original design
02:07:49 design it was a much cleaner simpler design than what then evolved during the course of the construction work on site now can you help us were you ever party to any meetings or discussions with mr marney
02:08:01 with mr marney where this re revision to the design was discussed
02:08:06 discussed this particular revision um my last interaction with psb i believe was at the meeting with building control from that point onwards all communication related to psp came through js right
02:08:19 related to psp came through js right because they were psp with js rights subcontractor yes um and i believe i only interacted via the receipt of tech submittals and commenting on them yes were you ever did you ever
02:08:31 yes were you ever did you ever pick up that psb were saying that the second design either wasn't theirs or that they were not happy with it no that was never said and and just to be absolutely clear
02:08:43 be absolutely clear who was the specialist designer of the system so far as you were concerned um i don't know whether i necessarily had it in mind as an individual i had it in mind as psb yes a specialist
02:08:57 i had it in mind as psb yes a specialist designer
02:09:06 now um we know that the technical submission revision six was the final version let's just bring that up psb five zeros two one four
02:09:25 and we can see that the revision six was actually
02:09:29 actually finalized by david harrison it was hugh marney who had done all the earlier versions
02:09:33 versions and then david harrison because humani had then left and was on gardening leave hugh marley um finalized this and if we look on
02:09:42 look on page three of this section 1.12
02:09:49 at the bottom of the page this is where we get paragraphs which we in this inquiry we've looked at a number of times now which set out the the intent of the the final system
02:10:02 and i think you mentioned earlier that you did ask yourself the question because you felt you had to because of the duties to your client whether you were satisfied that this was an adequate system is that correct that
02:10:13 an adequate system is that correct that is correct
02:10:16 did you ever notice that this submission didn't detail the specific scenarios that had been investigated and how the design would respond in different
02:10:27 design would respond in different scenarios
02:10:28 scenarios so different door opening scenarios different means of escape scenarios different fire fighting scenarios did you ever notice that um i did not and
02:10:40 um i did not and i think to some degree we were relying on x over
02:10:43 on x over as the fire engineer on the project um and also on the the knowledge assumed by psp as a specialist designer for that level of detail and again we
02:10:54 for that level of detail and again we were advising the client at this point we were not signing off or approving designs that that was js right in this instance
02:11:04 instance yes i understand
02:11:09 um
02:11:12 did it concern you that psb's technical submission didn't contain a detailed analysis of the system either comparatively with the existing system or a deterministic analysis showing the
02:11:23 or a deterministic analysis showing the system's ability to meet certain functional requirements did you ever express any concern about that
02:11:36 that was i think that was in part my reason for originally from the first tech submittal that i received revision one
02:11:42 one that was the reason why i forwarded that on to x over at that point because as i stated in the email to terry it's slightly outside of my
02:11:50 my area of expertise and with them being fire engineers that's entirely within their area of expertise um and then i think from
02:12:01 um and then i think from basically i would expect between xover and building control they ought to understand yes the full requirements of this system yes i understand did it ever occur to
02:12:12 yes i understand did it ever occur to you that there might be a risk that if a flat was on fire and the lobby was depressurized that that might pull smoke from the fire flat into the lobby because the lobby was at a lower pressure
02:12:24 was at a lower pressure whether with the door shut or with the door open did that risk of pulling smoke into the lobby did that ever get considered by max fordham i mean that was in part my understanding of
02:12:35 of to some degree the function of the system and that's just how it would behave in that in that specific scenario i see and was that was that explained to you by
02:12:46 you by psb the designers or was that something you just gleaned looking at how the system was written in the documents
02:12:54 documents i think that was my interpretation of from the documentation received from them
02:12:59 them and from my interpretation of the reading i had done around smoke extract systems during my time on the project was there ever any discussion about that risk and and the magnitude of that risk
02:13:11 risk and and the magnitude of that risk in for example the meeting with building control on the 24th of uh september 2014. um i don't recall but you know i think it was sorry sorry
02:13:22 but you know i think it was sorry sorry 24th of november 2014. um i don't recall all the discussions that were taking place there but i just remember that the staircal was the primary
02:13:31 primary you know the primary thing to protect building
02:13:35 building was there any discussion about um the extent to which conditions in the lobby would be tenable based on this system i don't
02:13:46 based on this system i don't believe so but again it's hard to unpack some of this just because i've been exposed to so much of it you know yes since my time working on the project i understand was there ever any discussion including
02:13:58 was there ever any discussion including with building control about whether there were extended travel distances
02:14:03 distances and the extent to which the system was a suitable system in those circumstances all talk of travel distances was handled between x over as fire engineers and studio e as architects and building
02:14:16 and studio e as architects and building control
02:14:17 control so to some extent whenever travel distances were were raised it was clearly outside of our
02:14:24 our area of expertise and and input to this project
02:14:28 project unless it was unless it's over informed us that it in some way affected the design
02:14:32 design yes and i think just final point but i think your answer may be the same was there ever any discussion about whether different opening door scenarios could lead to the stairs
02:14:43 door scenarios could lead to the stairs becoming
02:14:44 becoming compromised for example if the flat door and the stair door were open at the same time yeah similar answer
02:14:51 answer um i don't recall having that conversation but that again is why i wanted to why i was keen to loop linux over at all steps throughout this as fire engineers because it's clearly
02:15:02 as fire engineers because it's clearly within their expertise yes thank you now just some brief questions on um commissioning and the commission the commissioning risk assessment and method statement which i believe you were sent
02:15:14 statement which i believe you were sent we just look at an email that you sent on this
02:15:20 max406726
02:15:32 this is an email on the 5th of february 2016
02:15:36 2016 you sent to david hughes of ryden copying in a number of others including your client clients at the tmo and the subject is psb commissioning
02:15:47 and the subject is psb commissioning rams risk assessment method statement is that correct that's what it refers to yep and you say tony forwarded on the rams document from psb the system description within section 4
02:15:58 the system description within section 4 is not particularly clear to me for example there's no mention of extracting from both shafts simultaneously or of the operation of the dampers between the smoke rated fans and general ventilation fans
02:16:10 ventilation fans the commissioning test also does not mention the additional dampers between fans all take into account that some of the extract dampers in the lift lobbies may already be open could you request that psb
02:16:21 could you request that psb revise it to more accurately reflect the system installed at grenfell now can you help us in the light of this email was that risk assessment and method statement ever revised so far
02:16:32 and method statement ever revised so far as you were aware to reflect the as installed system
02:16:41 i genuinely can't remember yes did you ever notice that the figures uh quoted in that method
02:16:52 figures uh quoted in that method statement referred to a maximum pressure differential of 50 pascals
02:16:58 pascals and nowhere was it mentioned that the pressure differential between the stair and the lobby would be at 25 pascals did you ever notice that discrepancy i think i followed up in another email
02:17:09 i think i followed up in another email actually about the pressure differential and asked for a calculator ask for their reasoning behind how they arrived at the pressure differential yes which may or may not have been triggered by the fact that it wasn't a number i was expecting to see
02:17:21 number i was expecting to see right so you did spot that did you ever have any concerns about the commissioning process based on uh the demonstration that you witnessed
02:17:34 so okay i asked for an i'd ask for a certain amount of documentation ahead of the commissioning i asked for a number of times and it wasn't provided so i wasn't when i went into the
02:17:47 so i wasn't when i went into the commissioning i was already a little bit you know i was going into it a little bit cold if you like um but you know and also prior to going to the commit to the commissioning i had both read the
02:18:01 to the commissioning i had both read the british standard around i can't remember the number whatever it is dash six around press pressure differential system so i understood what sort of things should be request should be required
02:18:10 required and i'd also spoke it asked around the office as well so excuse me
02:18:18 so and i took away from that that it was that the velocity across the door the flow rate and then and then a satisfactory demonstration of the system operating between a number of different events um so i
02:18:31 a number of different events um so i came away from it being reasonably happy from a demonstration perspective yeah the system was working but you know as to whether as to whether the system had been fully commissioned
02:18:42 the system had been fully commissioned or not i hadn't seen enough information at that point and did you ever see enough information to satisfy yourself that the system had been commissioned absolutely and properly i'm trying to remember what i did and didn't see at
02:18:53 remember what i did and didn't see at the time i think on the day i was probably shown a commissioning sheet
02:18:59 sheet by i think it was granville the engineer mr partly
02:19:03 mr partly yeah um with a number of flow rates on it and velocities um yeah i can't remember yeah i think i think i saw that on the day
02:19:15 think i saw that on the day and was when he was reasonably happy by the fact that he'd actually been and taken these measurements i see yes you say in your statement that you you don't think the data was ever sent to you but you you said you record seeing something on
02:19:27 you said you record seeing something on site during the demonstration of the smoke ventilation system so you were seeing his his annotations on on schedules and drawings
02:19:37 drawings and that satisfied you that it was being commissioned properly yes yeah i mean i wouldn't say i was 100 you know it wasn't necessarily what i was expecting to see
02:19:48 was expecting to see as a full commissioning yes um again we were advising the client at that point we were not signing the system off that was just right and ryden and ultimately building control being happy
02:19:59 ultimately building control being happy about it
02:20:00 about it and but from a demonstration perspective i walked away from it being comfortable that the system operated as it should and did you go back and advise your client that you hadn't seen what you would have expected to see for a full commissioning process
02:20:13 for a full commissioning process i don't recall i think the client was cc'd or certainly the client's representative the employer's agent i'll tell you was it cc'd on our requests to
02:20:24 requests to psp for the commissioning data ahead of the head of the the demonstration yes finally were you ever sent any information about the
02:20:35 information about the type of dampers that they were proposing to use
02:20:39 to use for the system the gilbert series 54 dampers which we used at levels three to twenty three are those the ones in the lobby itself yes
02:20:47 yes uh yeah they were within the technical submittals they're mentioned there but were you ever sent any technical the database the data sheet is within the technical submittal pack and did you look at those at those data
02:20:58 and did you look at those at those data sheets yeah and did you ask yourself the question whether they were certified to the correct
02:21:03 correct standards um i recall the on the on the data sheet itself it says suitable for smoke ventilation systems for high-rise buildings are words to that effect basically and
02:21:15 words to that effect basically and mentions at least one british standard one relative one relevant british standard on there so i think i looked at it read that statement saw that it referred to a british standard that i
02:21:26 to a british standard that i you know would have would have assumed to see on there and then was comfortable with it okay thank you so chairman i've come to the end of my pre-prepare prepared questions we could therefore have um a break
02:21:39 we could therefore have um a break i think 10 minutes sought to do it all did sounds like 10 minutes we think yeah yeah based on what we've received so far we think 10 minutes will be fine good thank you um mr cross smith when
02:21:51 good thank you um mr cross smith when council gets the end of her questions we have to have a short pause to enable her to check that she hasn't left anything out and there are other people following the proceedings who may want to suggest questions that ought to be put to you
02:22:03 questions that ought to be put to you so we'll break now we'll come back at 25 to 5
02:22:07 to 5 and at that point we'll decide whether we'll find out rather whether there are any more questions for you okay and uh with any there won't be too many we'll see all right would you like to go with the usher then please thanks
02:22:25 thank you all right 25 to 5 then please
02:35:49 yes would you ask mr cross smith to come back in cheers
02:36:03 right mr crossfit we'll see if there any more questions for you okay maybe not many
02:36:07 many yes just one thank you um can i ask you this
02:36:11 this did you understand that when psb was sent
02:36:14 sent your technical ventilation analysis um there were two revisions written in a or b dated may 2014 the document we looked at earlier with the different flow rates in
02:36:25 earlier with the different flow rates in did you understand that in sending that to psb it was an instruction only to focus on flow rate and bettering the flow rate from the old system
02:36:36 system rather than not trying to make the system as good as possible
02:36:44 in the first instance i'm not sure whether we sent that to psp so that would be my first point i'd have to check naturally but they certainly wouldn't have been on my list of who i would send that document
02:36:55 list of who i would send that document to
02:36:56 to i don't think i don't think they were actually contracted at that point i understand that but we know they got it because it's it's cited at the top of each technical submission it's one of the documents that they refer to as well as the employers
02:37:08 refer to as well as the employers requirements okay so we do know it entered into their hands
02:37:12 hands but i accept and that's why i phrased the question the way i did um it's not clear that max fordham sent it to them yeah um sorry can you just repeat the question again well
02:37:24 question again well did you understand that to be an instruction to the designers of the system simply to focus on flow rate and bettering the flow rate
02:37:31 flow rate of the old system rather than trying to make the system as good as possible no i don't agree with that we yeah just to go back two separate two separate things
02:37:45 two separate two separate things of the system and um and approval by building control i certainly wouldn't have presented that document to psb and said
02:37:56 presented that document to psb and said do this yes thank you that's helpful thank you very much all right um it just goes to thank mr matt crosmus for coming and giving your evidence today and assisting us with our
02:38:08 evidence today and assisting us with our inquiries we're very grateful thanks i hope i've been helpful yes well it certainly has cross-smith and it's right that i should thank you on behalf of all the members of the panel for coming here today and giving us your evidence and taking up your time to do
02:38:20 evidence and taking up your time to do so it is very helpful to us to hear from uh people who've had direct involvement in these matters so we are very grateful to you for coming thanks thank you very much and now of course you're free to go
02:38:40 thanks thank you ms grange well that's the point at which we close for the day i think it is and we have one more smoke witness tomorrow mr white of just right good thank you very much 10 o'clock tomorrow then please
02:39:02 you