Expert Evidence (Professor Purser) - Thursday 30th June 2022 (2/2)

30 June 2022 · Professor David Purser - Toxicology Expert, Counsel to the Inquiry · 2:56:30
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Professor Purser continues expert toxicology evidence on causes of death. Provides detailed analysis of specific victims including flat 113 occupants (Dennis Murphy, Zab Dean, Jeremiah Dean, Muhammad Al-Hajali), Abdeslam Sebbar in flat 81 bathroom, and the three victims who died in the 10th floor lobby after exiting the lift.

Key moments

Full transcript

00:00:25 too early would you ask Professor P to come back in please

00:00:35 too early too

00:00:45 hot right Professor P you're ready to carry on I thank you very much yes yes thank you Mr chairman uh Professor yes onward uh I now go uh to the occupants

00:00:57 onward uh I now go uh to the occupants of flat 113 on floor 14 where Zab Dean Jeremiah Dean and Dennis Murphy were recovered from and where uh Muhammad alali was uh in occupation

00:01:09 Muhammad alali was uh in occupation before he fell from the tower uh now can I ask you please to go first to page3 of your report at paragraph 836 where we pick it pick up the chronology at

00:01:21 pick it pick up the chronology at 130 and doing a little of what I've done before with other occupants um if we can pick up pick it up please please uh at paragraph 763 on page

00:01:41 142 uh we um well I wonder if it's a simply way of doing this um I can I think summarize this to you um you'll recall from your report that at about

00:01:52 recall from your report that at about 2113 the occupants of flat 113 uh who was Dennis Murphy flat 112 who was Muhammad alali and Omar alali and flat 115 Zab Dean and Jeremiah Dean

00:02:06 and flat 115 Zab Dean and Jeremiah Dean were moved by the firefighters to Flat 1113 where they joined alas tabi Rosemary o o and their daughter that's a combination of different paragraphs in your report 763 753 and

00:02:19 your report 763 753 and 747 uh and I'm summarizing and then to remind you that soon after 2113 further firefighters return to Flat 113 and advise the occupants to remain in the flat

00:02:30 flat um and uh you say if uh in two places in your report paragraphs 765 and 767 which we can turn the page to 43 we'll see 767 that there was some limited

00:02:46 smoke uh yes yes limited smoke and the exterior fire had not reached the flat yet but the hallway had become increasingly filled with smoke from the lobby um and then if we go to 771 on

00:02:58 lobby um and then if we go to 771 on page 143 we can see see that at this time which is two about 239 you get that from

00:03:04 from 770 four occupants left flat 113 namely Muhammad Al jali alhajal Z Dean Jeremiah Dean and Dennis Murphy um stayed behind so four left and

00:03:18 Murphy um stayed behind so four left and those individuals I've just named stayed behind and from calls made to 9999 from Flat 1113 smoke conditions then deteriorated and you're if you go to paragraph 791 on page 14 4 6 you'll see

00:03:31 paragraph 791 on page 14 4 6 you'll see the time marks for that that's 255 to 317 791 do you see that yes you say from three calls made at 255 306 and 317 the

00:03:45 three calls made at 255 306 and 317 the smoke conditions in flat 113 were gradually deteriorating over the half hour period up to approximately 317 yes yes so just to stop you briefly there and put a marker down 317 we still

00:03:59 there and put a marker down 317 we still have hav't yet got the fire spreading to that flat exterior yet exactly and just to make that point Professor let's go back to page 141 paragraph

00:04:13 761 uh and you say yeah there we go there does that help you yes you said the pattern and timing of far exterior fast spread was as follows 317 South face far still outside flat 1112 at 333

00:04:26 face far still outside flat 1112 at 333 the South face fire was outside flat 1113 bedroom rooms the 340 South face fire was outside flat 113 bedrooms and living room and then over the page to 142 352 to 53 South face fire outside

00:04:40 142 352 to 53 South face fire outside flat 1113 bedrooms and living room on the west face the fire was still outside flat 114 and at 425 the West face fire was still outside flat 114 so that's where you sett all those

00:04:51 114 so that's where you sett all those out and then um you if you go to um 793 please on page 146 I'm sorry to Jump Around the story is told in a number of different places

00:05:03 is told in a number of different places 146 paragraph 793 at

00:05:07 793 at 348 to 355 you say that the conditions in the living room were likely to have deteriorated rapidly during that period and then you say and likely to have become unsurvivable within a few further

00:05:21 become unsurvivable within a few further minutes yes so that takes you to get my brain around this yes 355 and you go on however exterior views show no flaming outside the bedrooms after

00:05:32 outside the bedrooms after 3:58 although Flames are visible outside the living room now um we then go to page 147 paragraph

00:05:42 paragraph 798 uh

00:05:45 798 uh and you say Muhammad al-hajar was shouting from the window to fire for far fighters to spray water at the end of the call Muhammad alhajal said the fire had arrived Hashim alali heard crackling

00:05:56 had arrived Hashim alali heard crackling and then the phone cut out he could not reconnect the lasted approximately 30 minutes from hashim's arrival from the witness accounts I estimate that this may have been approximately 350 to 405

00:06:07 may have been approximately 350 to 405 this is the time period when the exterior fire spread around the flat 113 South living room and then if you go to

00:06:19 805 please paragraph 805 uh on page 148 thank you um you say since no precise start time or other time information is a ailable sorry I should just back up a

00:06:32 a ailable sorry I should just back up a little bit um um but this is a you're talking here about a call uh which happens at 803 a long call yes this is a long call um with between

00:06:44 yes this is a long call um with between Zab Deen and Francis Deen lasting more than an hour and 15 minutes uh and you say at 803 throughout this period the call remained connected to Zab Dean at one point she told him

00:06:56 to Zab Dean at one point she told him that Jeremiah Dean had collapsed Francis Dean had passed the phone to cm Christopher bachel door who estimated that he remained on the phone for approximately 1 hour and 15 minutes since the phone log for this call is not available the actual call start time and

00:07:08 available the actual call start time and duration is unknown and then at 8:04 you can see what you say there stayed on the phone for 30 to 35 minutes you could hear the little boy crying from the beginning of the call then coughing and then after

00:07:20 the call then coughing and then after about 30 or 35 minutes he stopped coughing and crying and you can read the rest of that paragraph on the screen there and that's the background to 805 since no precise start time or other

00:07:31 since no precise start time or other time information is available for this call the timing of events during the call is somewhat uncertain from the sequence of events described and by comparison with a call from Omar alhaj Ali I estimate that Jeremiah Dean died at approximately 3:45

00:07:44 Jeremiah Dean died at approximately 3:45 before or around the time the exterior fire spread outside the south side of the living room Christopher Bachelor stated that he then spent another 35 to 40 minutes on the phone to her in total Z abdine

00:07:56 the phone to her in total Z abdine eventually became less responsive with a bit of coffe and spluttering then silence for 5 to 10 minutes with sounds of deteriorating conditions in the

00:08:07 flat and then you at 4 807 you've got a call to Muhammad Al haali at 4:00 a.m. and at 808 on page 149 a call to Flat 1113 but that went through to

00:08:21 voicemail and if you go to 82 paragraph 823 on page 151 please use say there 823 it's rather a

00:08:32 please use say there 823 it's rather a long paragraph but in the fourth line you say it is likely that he fell says Muhammad Al hajali and he fell from the tower sometime between approximately 4: and 4:26

00:08:45 and 4:26 a.m. yes so that that's what we have there I think we should you keep that one flag that yes flag that now two other facts first the concentration of carboxy hemoglobin couldn't be measured in Zab deine and Dennis Murphy's test

00:08:58 in Zab deine and Dennis Murphy's test results um Muhammad Al haar's sample showed a concentration of 50% carboxyhemoglobin but no cyanide detected and you say that at paragraph 829 on p52 if we can have that up

00:09:14 please now um I've I've shown a lot of that to you perhaps not in particular particular order as in the way you've drafted it but hope and chronological order so that you get some idea of it um

00:09:28 order so that you get some idea of it um if you next go please to page 153 and look at paragraphs 836 to 845 836 on page 153 this is these are your

00:09:39 your conclusions uh and just remind yourself of what you say in paragraph 836 to the bottom of page 153 and um just signal when you need to turn the page

00:09:52 please yes um if you can turn the page please and you'll see then um the rest of it and paragraphs 8 42845 just remind yourself please of those we may have to keep coming back to this because there's

00:10:04 keep coming back to this because there's obviously so much detail but yes I know I remember the I've got the basic picture yeah yes I I only have a very few number of questions but you need I think other people outside this room perhaps need to see the detail yes well

00:10:15 perhaps need to see the detail yes well but you need to see it too yeah okay now um if you just read on to the end of paragraph

00:10:27 845 um and tell me when you

00:10:33 finished okay thank you now um since as you have identified it Muhammad al-hajar was alive when he fell from the tower yes and the fact that he had blood

00:10:47 tower yes and the fact that he had blood carboxy hemoglobin levels tested at 50% does that inform the time of death of Dennis Murphy Zab Dean and Jeremiah Dean

00:10:59 Dean it helps us to establish it so unfortunately we don't know the precise time that alhaj Al fell from the

00:11:10 precise time that alhaj Al fell from the tower because nobody observed it so there's a bit of a window of uncertainty on that which we've given us quite wide I think we've said between 0405 and 04 about 0430 yes well you say

00:11:25 0405 and 04 about 0430 yes well you say in 845 between 0400 and 042 6 right oh yeah okay so so that it's some time in that window I think that he he

00:11:38 time in that window I think that he he fell

00:11:39 fell and right from my memory obviously I've put a lot of work into this it was really complex set of data to try and analyze uh because there's so many conflicting not conflicting but so many

00:11:51 conflicting not conflicting but so many telephone conversations going on um but we don't have the logs really for them so it's quite difficult but um am I not right in saying

00:12:02 right in saying that you may have read it out one of his one of alhaj jali's calls he he states that the other four occupants had become

00:12:14 occupants had become unresponsive he observed them to basically at least be comos and if not dead so he saw them close to death

00:12:25 dead so he saw them close to death before he he fell from a tower yes

00:12:33 yes I mean no he couldn't he couldn't I mean he obviously couldn't verify whether they were actually dead but they were they they they I can't remember his exact words

00:12:45 they I can't remember his exact words but I did reproduce them at one point he basically said that they they' become unresponsive um before he before he fell so now they could have still been alive

00:12:58 so now they could have still been alive but com at that point but they were obviously very far gone this is the adults I'm talking about so as far as the child is concerned we have the statement by his mother sometime during

00:13:10 statement by his mother sometime during this process that he had died so from the mother's uh telephone call we can pretty well establish that her son died while she was still able to

00:13:23 her son died while she was still able to converse on the telephone and to fix the time at which she then ceased to be able to converse and um Dennis was it uh we have the

00:13:36 and um Dennis was it uh we have the evidence from Al haali himself where he said that they will become unresponsive yes and just to pause there and take you to the reference that's paragraph 812 on page

00:13:46 page 149 just scroll back to that just so people can see that you see that paragraph 812 812 after yeah during the 30 minute call starting

00:13:57 yeah during the 30 minute call starting at 8:35

00:13:59 at 8:35 yes that's the one I I put quite a bit of store by that yes right I'm so sorry to continue professor and then I'm and then I'm all the time of because I'm trying to jux depose this

00:14:10 of because I'm trying to jux depose this against the fire conditions that we can observe from outside but again they're rather complicated this low down in the tower because they're affected by firefighting activities and of course we have these references to water being

00:14:22 have these references to water being sprayed

00:14:24 sprayed so so um the sort of the sort of time when serious loss of tenability occurs in Flats three all the way out the

00:14:35 in Flats three all the way out the tower uh due to the external spread is is more is easier to distinguish on these upper floors but by the time we get down to this floor uh it's possible that the I mean

00:14:49 floor uh it's possible that the I mean it was burned out there was very bad burning in that living room at some point so about so it's possible it may have been and I would normally based on

00:15:01 have been and I would normally based on the other flats three be looking at somewhere around about 345 for serious loss of tenability in those in those in that

00:15:09 that flat but

00:15:11 flat but I've i' I've given the option if you like somewhere in my text here that because of these firefighting activities it's

00:15:20 it's possible that tenability survivability was prolonged somewhat in that flat until after 4:00 when I first started analyzing this set

00:15:31 when I first started analyzing this set I I found it difficult to believe anybody could have survived much after 4:00 but I think because of these firefighting activities that may have widened that window of survivability

00:15:44 widened that window of survivability somewhat to periods after 4:00 right is it possible that Dennis Murphy Z ABD and jeremi were still alive all they're possibly unconscious at the moment in

00:15:57 possibly unconscious at the moment in the range you've put between four and 426 that Muhammad Al haali fell from the tower is it possible they were unconscious but still alive so just to just to sort of Step

00:16:11 alive so just to just to sort of Step through that so as I've just said I'm putting some store by the fact that before he fell from the tower during that call and we have a time for that call ending roughly don't we uh when he

00:16:24 call ending roughly don't we uh when he said the others are unresponsive what time was that it's a 30- minute call starting at 0335 it looks like it's so about 4:00 yes it ends at about uh 405 yeah so so

00:16:38 yes it ends at about uh 405 yeah so so if we say that 0405 when he came off that call and this is before he fell from the tower obviously at that time the other adults

00:16:50 obviously at that time the other adults the child was presumably already dead but the other adults were unresponsive and therefore comes at that point or even possibly dead right so they were

00:17:01 even possibly dead right so they were close so I think that gives us a window around about 4:00 they were close to death at that time then we have to add on the uncertainty window for their gradual decline to the point of actual

00:17:13 gradual decline to the point of actual death and so you're so so it's quite possible that they were still technically if you like alive up to somewhere about 420 is but

00:17:26 alive up to somewhere about 420 is but in a deep you know deep com stage and is it possible that Z abdine who was on the on the on the telephone to the firefighter Christopher bachel

00:17:38 to the firefighter Christopher bachel door was still alive but unconscious um even after she stopped speaking at least for a period at what time uh now that call um ran on till about 3:45 3:45 oh

00:17:52 call um ran on till about 3:45 3:45 oh yes you could have been live then yes uh I mean one of these calls I I have a pro a problem with that very long call the the sort of timings seem to be

00:18:03 call the the sort of timings seem to be too long to me for and we don't have the call log so it's a bit difficult to be certain exactly when that call finished now given the uncertainties about the exact time of death would you are you

00:18:14 exact time of death would you are you able to record as a window of death time for each of the the three Dennis Murphy Zion abdan and J Jeremiah Dean yes so we we just

00:18:25 we just said I think somewhere so we're saying I'm saying there were comos at certainly com and possibly already dead at

00:18:36 possibly already dead at 0405 yes that's the end of the yes that's the end of the Muhammad Al call so they may have been already dead there so that's one end of your

00:18:47 so that's one end of your window um but it's possible they were alive but in a coma and and gradually sinking so we can C maybe add another 20 minutes or so to that so stretching it to 0430 at the latest I

00:19:02 so stretching it to 0430 at the latest I would say but that's you know if you you do a probability distribution of the time of death I would I would put it at somewhere around about 410 and what's the earliest point in the

00:19:13 410 and what's the earliest point in the window do you think uh that death could have occurred 0405 yeah 0405 not

00:19:22 0405 not earlier even in the case of the child he says they were I'm not talking about the adults right yeah well he said they were unresponsive by that time I don't know what the latest time they were

00:19:35 what the latest time they were responsive um I think I think that's our best window really somewhere around about this is the adults yes yes 0405 0430 puts it very late to me to me that

00:19:46 0430 puts it very late to me to me that they could have surv so the window is essentially overlapping at the same time as the potential time of death for Muhammad it does because as he fell from the tower you mean yes yes yes I'll yes

00:19:57 the tower you mean yes yes yes I'll yes yes I see

00:19:59 yes I see yes thank you um let's then turn please if we may to another occupant on another floor in another flat this is um abdeslam sear on floor 11 in flat 81 and

00:20:12 abdeslam sear on floor 11 in flat 81 and you deal you cover him in U section six of your report at paragraph 15 sorry page 158 if we can go on to that and again I'll take you um through

00:20:24 that and again I'll take you um through the um the the report on this very um success inly he was alone as you say at paragraph 866 in flat 81 on the 14th of June and then conditions in the flat at

00:20:36 June and then conditions in the flat at 867 you say abdeslam sabab was aware of the fire by 0125 when he made a 999 call describing flooding and fire on the 11th floor he made a second call at 13312

00:20:48 floor he made a second call at 13312 stating that the fire was inside the flat so you got two calls there and then at

00:20:53 at 874 if you turn please to page 159 you note that there are no further

00:21:00 calls you turned it to yes thank you uh there are no further calls uh but his grandson called 999 on two occasions to report that abdeslam saah was in his

00:21:13 report that abdeslam saah was in his flat you see that yes uh a and there's a final call at 43933 where his grandson stated that he'd been on the telephone to ABD slam saah who was choking and was then cut

00:21:25 saah who was choking and was then cut off I infer that he was referring to the calls with his Grand father at around 0236 yeah so that was a 999 call made by the grandson wasn't it yes uh and he was

00:21:36 the grandson wasn't it yes uh and he was then referring to I think earlier events it doesn't mean the events are occurring at 0439 you yes the call the call was made at

00:21:48 yes the call the call was made at 0439 but the events he was referring to I believe he was referring to his earlier attempts to contact this yes and when you say 236 do you mean 240 do you

00:22:00 when you say 236 do you mean 240 do you mean do you mean 236 yes you do I think I do yes yes and then um you can see that the first is at 246 there's a call at 246 oh gosh where you

00:22:11 there's a call at 246 oh gosh where you say he's stuck in the toilet of the flat right maybe and then a final call at 439 where he states that he'd been on the telephone to ABD Islam seah who's checking then cut off and sorry we need

00:22:23 checking then cut off and sorry we need step through this again yes all right at approximately 2:30 he stated he was dying

00:22:29 dying and his son could hear he was finding it difficult to breathe shortly after this this is 2:30 I've got yes the connection ended and further calls were unanswered right I see so that is a reference to

00:22:40 right I see so that is a reference to the call yes at about 2, yes thank you yes again we've got a bit of a confusing situation right so that so just just to clarify that then the the and then

00:22:51 clarify that then the the and then that's right and then the grandson made subsequent calls to 999 referring back to these events I believe yes so that's so we not I don't think these two call times mean that

00:23:03 think these two call times mean that he's referring to events that are happening at that moment no he had previously spoken but there's been a development hasn't there well um just just let's just stick

00:23:14 there well um just just let's just stick with this for the moment yes so just to be clear this is this is the this in the last paragraph is a reference back to the call that you identify in 872 yes the 230 call yes yes and then if

00:23:25 872 yes the 230 call yes yes and then if you go to 870 back a page please just to be clearer still you um note there at paragraph 870 that uh an image taken at 248 shows extensive flaming outside flat

00:23:37 248 shows extensive flaming outside flat 81 and some spread across column C5 outside the flat 82 kitchen exterior fire outside flat 81 then subside somewhat with periods of intermittent flaming until approximately

00:23:50 flaming until approximately 3:45 and then you identify large interior fire just H just pause please for a moment so the exterior fire it was complicated at these low levels because there was an initial brief bit of fire

00:24:03 there was an initial brief bit of fire outside which then sort of subsided and then it came back at a later time so the exterior fire outside flat 81 then subsides until approximately

00:24:14 subsides until approximately 0345 so

00:24:18 0345 there then appears to be a large interior flaming fire at the window openings of flat 81 so now we've got evidence from the exterior fire that there's a b far inside that flat at

00:24:32 there's a b far inside that flat at 0345 continuing for some time now then then go to page9 at paragraph

00:24:40 878 just to pick this point up while we're here you

00:24:46 say paragraph 878 you you say that his body consisted of heavily child remains with some preservation of internal organs his lungs were emitus and there

00:24:57 organs his lungs were emitus and there was soot in the air ways with arithma of upper Airways no clear evidence of burns or trauma before death his blood contained an extremely high lethal 90% carboxyhemoglobin now you described the

00:25:09 carboxyhemoglobin now you described the Le lethal dose threshold for carboxyhemoglobin as 50% yes or thereabouts yes are the results for Muhammad sear of 90% carboxy hemoglobin explained in any way by him I think they

00:25:23 explained in any way by him I think they are really yes sorry yes um and uh the paragraph above we know that he was in the bathroom next to the bath so he so if

00:25:35 bath so he so if you do we need to put the flat let's put the picture up of the flat

00:25:42 again sorry what would you the uh uh yes me30 is

00:25:48 me30 is 12593 right yeah thank you um so we're flat we're in a flat one aren't we yes yes so um as you can see so the the scenario we're talking about are that at

00:26:01 scenario we're talking about are that at this time so 0345 we've got a large interior fire in that

00:26:06 that flat um I can't remember what I said the living room which room the living room I think so so the the flat is in a really serious situation by this period but of

00:26:17 serious situation by this period but of course a person uh in the bathroom is to some extent protected by the internal uh compartmentation of the flat and that is

00:26:28 compartmentation of the flat and that is a kind of last Refuge if you like that somebody might shut themselves away in and therefore survive really when in the greater part of the flat the conditions

00:26:39 greater part of the flat the conditions are really pretty extreme they could still survive there for some time until the the uh fire and was smoke and then eventually the fire uh destroyed that part of the building so we have

00:26:53 part of the building so we have conditions where a person could shelter there

00:26:57 there the high concentrations of smoke and toxic gases in the greater flat are going to gradually penetrate into the bathroom Refuge but not so much the heat so you're protected particularly from

00:27:09 so you're protected particularly from the heat you can't avoid the gases but you can delay them to some extent but you could survive in that location for quite a long time while conditions in the flat are very bad and um that I

00:27:22 the flat are very bad and um that I believe is what happened here does that imply that it was likely he fell unconscious at a higher dose than the average 20 to 40% range not particularly no I think he probably became unconscious right not that I would any

00:27:35 unconscious right not that I would any particular reason to think that no right then let's go to page 160 of section six please of your report and I'd like you just to remind yourself of what you say there at paragraphs 879 to

00:27:46 there at paragraphs 879 to 883 under uptake uh and conclusions all on the same page just remind yourself of what you

00:27:55 what you say yeah so I think there a key point here 882 abam sadar seled in the closed bathroom until about 0230 048 when the exterior fire spread outside the living

00:28:07 exterior fire spread outside the living room of flat 81 so this is when conditions start to become extreme during a telephone call with his son at this time he said he was dying and his son could hear he had breathing

00:28:18 son could hear he had breathing difficulties soon after this the connection ended and it's likely that he became unconscious due to ination of gases soon afterwards I've said here and then died from a fix here now on that um

00:28:30 then died from a fix here now on that um uh let me well actually could you just read on to the end just yeah so his very high 90% shows that he was overcome by ination of aient gases the flat interior

00:28:41 ination of aient gases the flat interior was largely burned out sometime later and his remains became Char the exterior view shows a large interior fire 0345 to 0431 now can I show you iws 4's

00:28:55 0345 to 0431 now can I show you iws 4's 2375 um because this is uh a second statement provided by um Muhammad Sabah his son and this was

00:29:06 Muhammad Sabah his son and this was provided to the inquiry on the 20th of May 2022 this year not long ago uh and if we turn please uh to page two paragraph

00:29:19 7 uh he says Under The Heading phone calls with my father on the 14th June 2017 on the night of the fire paragraph 7 on the night of the fire I spoke to my father on three occasions but for long

00:29:31 father on three occasions but for long periods of time as outlined the first was while on my way to the tower shortly after arriving I spoke to my father again at sometime between 1:45 and 2:30 a.m. I was constantly on the phone to

00:29:43 a.m. I was constantly on the phone to him at around 2:46 my son Unice phoned the fire service he told the operator that my father was in flat 81 on floor 11 or 14 and he was and that he was stuck in the

00:29:54 and he was and that he was stuck in the toilet and needed evacuating and paragraph 8 after this I was able to call my father again his landline had stopped working and I was able to reach

00:30:05 stopped working and I was able to reach him on his mobile he was in the toilet and was struggling to breathe I was on the phone with him until about 2:30 3:30 a.m. and I I believe I heard him pass away or fall unconscious I do not want

00:30:17 away or fall unconscious I do not want to describe the events but this was a devastating call after the phone cut out I sat on a bench near the tower in a state of utter shock uh it was horrific at 350 and and then you don't need the

00:30:29 at 350 and and then you don't need the rest but the the key point there is that the telephone call until 3:30 about 3:30 a.m. and believe I heard him pass away or fall

00:30:38 or fall unconscious now it's right I think that you didn't have this evidence um available to you when you were preparing your

00:30:46 your report right yes um the the the I'll come back to that in a moment um but first were you aware of reports that water was being projected onto the exterior of the building at

00:30:58 onto the exterior of the building at around the 11th floor on the east side of the tower I think I mentioned discussed that in my text yeah and might that have slowed the deterioration of conditions inside flat 81 from the

00:31:09 conditions inside flat 81 from the external fire okay what so repeat that time

00:31:13 time again water time well uh I haven't given you a time Oh I thought you did okay well as I said in my text time the spread of fire at that flat was quite complicated because it occurred in sort

00:31:25 complicated because it occurred in sort of two bursts so f remember we had this rapid spread of fire all the way up the tower uh up the east side of Flat 6 right from about 0120 to

00:31:40 right from about 0120 to 0127 the initial Fame spread up of Tower and so of course it had to go as it went up the tower in that very early stage it had to go past uh flat

00:31:51 had to go past uh flat 881 and as it did so there was and if you look at the videos and some of the images you can see that there has been some degree of flaming around the across

00:32:03 some degree of flaming around the across the column and across to part of flat 81 right from Flat 86 to8 81 but that was fairly and I think that

00:32:14 81 but that was fairly and I think that was referred to that's the early flaming that's referred to by the witness by by um in one of these phone calls the from the uh from

00:32:25 the uh from abum um then then the uh the fire outside that flat has has gone out now just on that yeah um you asked me a question yes timing and of course I'm

00:32:37 question yes timing and of course I'm I'm not able to answer from my own knowledge but I might be able to answer from the record yes um uh take this from me that Natasha elcock yes identifies

00:32:48 me that Natasha elcock yes identifies her reference to water being sprayed in 999 calls at 237 and 244 and let me just take you back to your report at1 yes please at 823 in the light of

00:33:02 please at 823 in the light of that take that from from me uh and at 823 I don't think you take into account the application of water except until

00:33:13 the application of water except until the last four lines and you say for from the witness accounts there were some exterior firefighting activities with water sprayed over the flat around this time yes if so it's possible that these

00:33:24 time yes if so it's possible that these provideed some degree of protection enabling Muhammad Al a jarly to remain in the flat for longer than otherwise might have possible otherwise been possible now that's of course about flat 113 as you can see um applying that

00:33:38 113 as you can see um applying that logic at the same time to Flat 81 three floors below oh you see what I'm I'm driving at here is it possible given what Nat

00:33:49 here is it possible given what Nat elcock observed about the application of water between 237 and 244 also and given what's said here by you about application of water uh at at the 11th

00:34:01 application of water uh at at the 11th floor my question do you agree that the application of water could have slowed the deterioration of conditions inside flat 81 yes I do and and as I've said the time at which fire did spread badly

00:34:12 the time at which fire did spread badly past that flat was quite late in this sequence of these things I mean it's much much earlier on higher floors isn't it for flat one uh yes flat 1113 is 14th floor and 81 is the 11th floor

00:34:29 so my question again do you agree that the application of water might be an explanation yes you're speculating but but it's an now given that given that possibility of building the blocks let's

00:34:41 possibility of building the blocks let's go back to paragraph

00:34:46 882 882 please and this is back at flat

00:34:56 81 just showing you that you uh say there Abdus slam Saar sheltered in the closed bathroom until around 2:30 to 48 when the exterior fast bed around the

00:35:07 when the exterior fast bed around the outside the living room of flat 81 during a telephone call with his son at this time he stated that he was dying and his son could hear that he had breathing difficulties shortly after this the connection ended and it's likely that he became unconscious due to

00:35:18 likely that he became unconscious due to inhalation of asphyxiant gases soon afterwards then died from asfixia that's what you say there yes in the light now of everything I've shown you further Evidence from Muhammad seah and the um

00:35:31 Evidence from Muhammad seah and the um possibility based on the evidence I've referred you to and your own findings about water being projected onto flat 81 would you revisit your conclusion about the time of abdes abdeslam seah becoming

00:35:44 the time of abdes abdeslam seah becoming unconscious due to the inhalation of spixi and gases well I haven't given a precise time at which he became unconscious I've implied that it was shortly after 02348 I don't say what

00:35:57 shortly after 02348 I don't say what shortly means I don't find any particular uh conflict with what I've written but obviously in the light of the new information that he was last

00:36:08 the new information that he was last spoken to

00:36:10 spoken to 0330 he was still alive in the bathroom at 0330 and I find that fits quite well with the analysis I've made as I said he's in a protected area

00:36:22 he's in a protected area now I looked at the ex the images of the exterior far spread we can revisit them if you like um there was some flaming exterior flaming spread past the flat at

00:36:35 exterior flaming spread past the flat at that level around the Times uh I've stated I think we went through them earlier didn't we we did uh so those are based on my examination of the exterior flame flaming images from

00:36:46 the exterior flame flaming images from the exterior uh so there was flaming there and it's quite possible that and I said at these lower levels uh even several floors above as we just discussed for for the flat there was

00:36:59 discussed for for the flat there was some uh the fire spread was complicated by the interaction with these suppression activities attempts that were going on so that that may have may

00:37:10 were going on so that that may have may have somewhat prolonged the or delayed the lot lack of survivability in that flat but even so you know the conditions are pretty bad in that flat from the

00:37:21 are pretty bad in that flat from the time I've said but by being as I said by virtue of the fact that he was in the protected bar bathroom that gave him an unspecified longer period of survival

00:37:32 unspecified longer period of survival until the smoke penetrated and the gases penetrated into that bathroom which of course I I have no way of really calculating except to say it would have been after uh the these times here so

00:37:47 been after uh the these times here so um I I'm not I'm not surprised to find that he survived up to o or that he was conscious up to 0330 I think that fits in with with the sort of analysis that I've made and how long after that after

00:38:00 I've made and how long after that after 3:30 also did you think that he died from inhalation of axient gases if if he became unconscious at about that time so let's say he became unconscious about 0330 sorry do we have a carbox of

00:38:12 0330 sorry do we have a carbox of hemoglobin for him we uh 90% 90% 90% so that's very very high so 0330 let's assume it well estimate that he he he became unconscious around

00:38:24 became unconscious around 0330 um at a level of round about 40% caroal hemoglobin he's then got to continue up to 90 and he's in this long

00:38:37 continue up to 90 and he's in this long he's in this protected space in this long decline scenario

00:38:42 scenario so we're talking about quite a prolonged period maybe 20 to 30 minutes more to death so

00:38:55 0330 uh for for l Of Consciousness 0350 0400 somewhere around about there for for death and perhaps even a few

00:39:08 for for death and perhaps even a few minutes

00:39:09 minutes later I would I would estimate and that's an estimate of course like all these are very very approximate yeah for for a very indefinite kind of thing we're trying to estimate yes it is and I'm just on that and perhaps for this

00:39:21 I'm just on that and perhaps for this decease but for general in general also you able to give some kind of boundary of error fact I mean does it plus or minus trouble is it depends on the individual

00:39:32 it depends on the individual circumstance and the gas is so very difficult all right fair enough I'd rather not fair enough let's then turn to the final group I want to ask you about which is floor 10 lift Lobby and this is Muhammad n tuu aliar Jafari and

00:39:45 this is Muhammad n tuu aliar Jafari and Kadija khui and you cover this at page 162 section six of your report if we can go to that please now um you've set out the relevant facts here uh and uh and

00:39:58 the relevant facts here uh and uh and the conditions on the floor and uh take taking this in summary all three individuals are believed to have entered the lift together with Nadia Jafari and Ria Rojo yes yes and I think from a

00:40:12 Ria Rojo yes yes and I think from a detailed review of all the available evidence you reach the conclusion doing the best you can that Muhammad Nuku Ali yahwa Jafari and Kadija kifi did not have significant exposure to toxic smoke

00:40:24 have significant exposure to toxic smoke before entering the lift yes and we pick we can pick that that up I think at page 169 if we just um go on to that paragraph

00:40:33 paragraph 927 there it is uh and and that's what you say

00:40:39 you say um uh now we know that and I'll summarize these that the toxicology tests carried out showed that Ali yawa Jafari had carboxyhemoglobin levels of

00:40:51 Jafari had carboxyhemoglobin levels of 47% that's paragraph 719 Kadija Ki had carboxy hemoglobin levels of

00:40:58 levels of 66% that's 919 paragraph 919 and Muhammad Nuku had carboxy hemoglobin levels of 73% and that's paragraph

00:41:09 that's paragraph 921 now um if we then scroll up on page 69 to the figure figure [Music]

00:41:17 [Music] 46 you've got a a diagram there or a chart there which is entitled effects of exposure of lift occupants after arrival at 10th floor and entering 10th Lobby

00:41:28 at 10th floor and entering 10th Lobby um now um just just working through this can you just explain to the panel what this figure show what we get from this yes so what I'm doing here is plotting the uptake of gases in an fed sense and

00:41:41 the uptake of gases in an fed sense and the easiest one to relate to is the calculated carox hemoglobin which is the the pink squares yes so

00:41:52 the the pink squares yes so um

00:41:54 um the I the the the lift uh got that to uh opened on the 10th floor at approximately

00:42:05 0125 uh and at that point I'm saying that the curve starts at zero in other words they had negligible exposure up to that point in time and when the lift

00:42:16 that point in time and when the lift stopped at the 10th floor um the occupants of the lift described before the lift doors opened uh smoke pouring in and filling the lift

00:42:27 uh smoke pouring in and filling the lift very distressing situation people were kicking and banging the doors and the buttons and things and trying to uh get something to happen and

00:42:38 something to happen and um event a very chaotic situation and and eventually the lift doors opened and uh for a short period and these three persons uh I believed to

00:42:49 these three persons uh I believed to have left the lift at that time the lift doors then closed and the lift now containing Nadia and Ria Rojo uh continued down to the ground

00:43:00 continued down to the ground floor and um according to Nadia I believe if I remember rightly she believes the lift did not stop between there and the ground floor where Ria roio felt it may have stopped a number

00:43:12 roio felt it may have stopped a number of times um but when when when they got to the ground floor we have an image which is I think maybe in the Chairman's report but I've certainly seen this image of the lift doors opening on the

00:43:23 image of the lift doors opening on the ground floor and smoke them walking out of the lift and smoke coming Plum whisp out of the top of the of the lift yeah and they said it cleared as they as the lift descended it cleared gradually cleared as they came down so we have

00:43:36 cleared as they came down so we have quite a nice time for when they got to the bottom and we can see that they had that smoke there and we had their their witness descriptions the conditions extreme conditions they encountered in the lift in that short period of time

00:43:48 the lift in that short period of time and they have some estimates of the time for which the lift was there before the doors closed and it descended I I feel those might be slightly long than the reality it's very hard subjectively to

00:43:59 reality it's very hard subjectively to assess these times but there was a period of 30 seconds perhaps to a minute when that lift before the lift carried on down but the people who came out of the lft um then uh collapsed and died in

00:44:13 the lft um then uh collapsed and died in the

00:44:13 the lobby and there um so Ali Jawa Jafari uh his uh body was found quite close to the

00:44:24 his uh body was found quite close to the lift Itself by firefighter sometime later doing a a search under the smoke quite bad conditions in the lobby when the firefighters eventually got there to

00:44:35 the firefighters eventually got there to do this recovery operation so he he he collapsed almost immediately after coming out of the lift I believe the other two uh were found in this well I

00:44:47 other two uh were found in this well I think we should we need the diagram again sorry yes me30 is 12593 Page seven please now this is very help full because it it does show so you can see

00:44:59 because it it does show so you can see here uh the proximity of the lists now I think it's the upper one isn't it that was working on the diet uh right had one but anyway one of these

00:45:10 uh right had one but anyway one of these lists was there one of these lists yes it's that one and um they they came out and it's really quite a short distance of travel to walk from there to the stair door enter the stair and carry on

00:45:22 stair door enter the stair and carry on down the stair uh and if you were prepared for this event um you would think you'd have a game plan and you would be able to do that even if the smoke was very dense uh potentially you could do that

00:45:35 dense uh potentially you could do that without too much difficulty I think but in but the chaotic situation I've described I think these people tumbling out into this Lobby they were very lik to have been very uh disorientated and the the bodies of uh

00:45:48 disorientated and the the bodies of uh KFI and um the other person C tuku were found more or less where it's where the number two is on the diagram I think if I remember right right so they' missed the front they' missed the stair door

00:46:00 the front they' missed the stair door and yeah they're in this sort of short that's why I wanted the image putting up cuz you can see there there's a sort of short stub Corridor that that goes towards the entrance of flat one and two

00:46:11 towards the entrance of flat one and two well two is yeah two at the beginning of it but go towards flat yeah Corridor ends that goes to Flat one at the end and their bodies were found I think somewhere around about where the two is

00:46:22 somewhere around about where the two is on this diagram so I'm estimating that what they probably happened was they they tumbled out into this Lobby the conditions were extreme very very smoky very very high

00:46:35 very very smoky very very high concentrations as I said yesterday of carbon monoxide and quite significantly High concentration of cyanide in this situation and they

00:46:46 situation and they were uh act act acting around in you know blundering around in this very extreme conditions attempting to find presumably attempting to find the stair

00:46:57 presumably attempting to find the stair door but missed it and ended up in that Corridor and it's in irrelevant I think that the pathologist found some physical injuries to these two

00:47:08 injuries to these two persons uh you know skin lesions and other things as if they'd been may have bashed um you know B and foul of various items in that

00:47:19 know B and foul of various items in that area which is sort seems to be consistent with P people in in a struggle situation you know they were attempting to find this door and then they collapsed and died there

00:47:30 and then they collapsed and died there with high blood Caro well well above the lethal levels now just to uh this point Al Al

00:47:40 Al Al alali no sorry Al Ali yawa Jafari yeah he he's got 47% correct which of course is somewhat lower but as we know and I spoke about yesterday he had quite a

00:47:52 spoke about yesterday he had quite a serious heart condition so much so that as they left the flat his daughter was concerned about whether he had his an I think his angina pills with him and this kind of thing so it's not at all

00:48:03 kind of thing so it's not at all surprising to me that in this extreme situation he would have succumbed collapsed very very quickly and um over been overcome and died uh just after

00:48:14 been overcome and died uh just after coming out of the the lift whereas the other two would have been a bit more robust and and carried on for a bit longer yes thank you c c can we please go back to figure 46 on page 40 uh page

00:48:25 go back to figure 46 on page 40 uh page 169 figure 46 so hold on I have a question you see um now you've explained I think what the figure shows uh in but you I think ex

00:48:37 figure shows uh in but you I think ex strayed into other things which is very helpful but and thank you I just want to ask you specifically um how did you calculate the time to collapse yes um so I'm

00:48:51 so in order to time to collapse I have to have a concentration of carbon monoxide in the lobby to put into my calculation and uh I also have to have a

00:49:03 calculation and uh I also have to have a concentration of cyanide which I derive from the Co in the way we've described earlier so from from that uh from those two two concentrations and and for the

00:49:15 two two concentrations and and for the purposes of this calculation and the short period involved I'm assuming a sort of more or less constant estimated average level in the lobby over that period of time a constant constant level

00:49:27 period of time a constant constant level I think this probably on the pre probably figure 45 has the actual gas concentrations I've used but um the the starting point would

00:49:40 um the the starting point would [Music]

00:49:42 [Music] be uh 10,000 PPM of carbon monoxide and I forget the exact figure but

00:49:51 but about 300 PPM of uh hydrogen cyanide it's in the text somewhere so where did I get those figures from those are very rough estimates derived

00:50:02 those are very rough estimates derived from my knowledge of uh the ratios of these gases and the conditions in these sorts of fires we've talked about this yesterday I believe that the concentrations in in these lobbies

00:50:15 concentrations in in these lobbies because people said it was hand in front of the face very very dense smoke therefore this indicates we're talking about very high levels but there's a considerable uncertainty about what

00:50:26 considerable uncertainty about what those levels actually were and so I've given a wide quite a wide range of between about five this is a CO between about 5,000 PPM Co still very high and

00:50:39 about 5,000 PPM Co still very high and 10,000 PPM Co but for this calculation this is the calculation for the 10,000 case right I think saying uh so um

00:50:52 case right I think saying uh so um assuming that the conditions were as were as I've just described how long would it take for somebody to become unconscious under those conditions

00:51:03 unconscious under those conditions otherwise healthy adult and the answer is I'm predicting here for this particular data set uh collapse within uh a couple of minutes so I think I've

00:51:14 uh a couple of minutes so I think I've got

00:51:14 got 02650 there three persons entering the lobby collapse and become unconscious with and that's assuming the lift stopped at

00:51:24 02430 yes so that so very rapid so so it it it really is an illustration of how quickly some can be overcome by these extreme

00:51:34 extreme conditions but I've also considered an alternative case where the levels were about half that but it still gives you a very very short window of a few minutes and I I defend this by partly by saying

00:51:45 and I I defend this by partly by saying well if this was wrong by a factor of five or 10 and we were only talking about say 1800 PPM as in the stair that would have then given those occupants

00:51:57 would have then given those occupants 20 minutes or so or 15 to 20 minutes in order to be able to find the stair and the fact that that they they obviously didn't have that window of time

00:52:08 didn't have that window of time available to them uh they must have collapsed very quickly also uh just to moving on we know they collapsed quickly because it wasn't so long after that that the occupant of flat one came out

00:52:19 that the occupant of flat one came out and tripped over their bodies well I was going to ask you about those two now so it's really quite a narrow we can fix this window quite narrowly I think no um yeah yes uh now that's one that's 933 so that's very helpful just pick

00:52:31 933 so that's very helpful just pick that up please page 170 you say that approximately 131 nagan nugo Nago that's I proy isn't it proy Nago uh found the lobby filled with

00:52:43 Nago uh found the lobby filled with dense smoke she stepped out of her flat into the short dead end Corridor leading from her flat entrance Door into the lobby uh the door to the stair is at the end of this Corridor immediately to the right we've seen it on the map as she

00:52:55 right we've seen it on the map as she attempted to move from her FL into the lobby she fell several times over bodies on the floor the final time she fell her head hit the stair door which opened slightly so she could see some light Etc and then she she managed to get out as

00:53:06 and then she she managed to get out as you as you go on to say uh and then similarly in 934 around 14 minutes later 14439 Clarita gimi left flat

00:53:17 14439 Clarita gimi left flat 75 and she also crossed the lobby to the stern descended exiting at 14909 uh uh now uh my question in relation to to that is and first of all

00:53:30 relation to to that is and first of all that gives you a time marker which you've explained my question is um why was it that those two occupants nagawa Nago and Clarita gimi were able to cross

00:53:41 Nago and Clarita gimi were able to cross the Flor 10 Lobby to this relative safety of the St and Escape whereas Ali y Jafari K kiji Ki and Muhammad Nuku were not yes that's very interesting so

00:53:54 were not yes that's very interesting so if we take the case of Nala quago she she was prepared for this event she was in a flat where she lived she knew where the stair was she if you like she had a game plan she stepped out and and quite

00:54:08 game plan she stepped out and and quite quickly crossed that that short distance although of course she had to fall over and pick herself up a couple of times but we're talking of a very of a short period of maybe a few seconds and less

00:54:19 period of maybe a few seconds and less than a minutes so she had time and she was almost certainly holding her breath as much as she could to avoid inhaling this smoke I think she actually said at one point she tripped and took a breath

00:54:30 one point she tripped and took a breath so because she tripped over as you might imagine uh so uh and she didn't it wasn't with ease that she did this as we said she she she sort of fell over and

00:54:41 said she she she sort of fell over and happened to knock the door open you know so it was a quite extreme situation and it's also very interesting to look at TR Kimi because again this is somebody

00:54:52 Kimi because again this is somebody who's making a deliberate attempt to escape with a game plan but com from Flat five or four was it five Clarita gim flat 75 five yeah flat five so she's

00:55:04 gim flat 75 five yeah flat five so she's got to negotiate this rather complex route that we've been talking about previously she's entering which we know are very hazardous conditions in there an extreme situation and um she didn't just walk

00:55:16 situation and um she didn't just walk across and get out she she she walked across and she was somewhere in the vicinity of the door to the stair in quite a lot of distress when when liui

00:55:27 quite a lot of distress when when liui um and His companion walked down from the floor below and somehow became aware of her struggling I think she was struggling to open the door to get into the stair at that point and they could

00:55:38 the stair at that point and they could have opened the door and went into the lobby and pulled her out uh so she I mean if she had she hadn't had their assistant she might have become another casualty in that Lobby I think Clarita

00:55:50 casualty in that Lobby I think Clarita graini right but are you able to in a sentence account for the differences yeah so so they they had a short exposure they had a game plan and so they were able to make that transition

00:56:02 they were able to make that transition whereas those in the lift found themselves if you like deposited suddenly out there in a chaotic situation and they unfortunately made a wrong turn and ended up in that blind

00:56:13 wrong turn and ended up in that blind Corridor yeah now one more one more question about floor 10 given the timing that you've entered into that you uh and the time marks that you put into um figure 46 in particular are you able to

00:56:25 figure 46 in particular are you able to tell with any degree of confidence what the source of the smoke in the lobby in floor 10 was right so we're talking about period um P should put the diagram back up 46

00:56:40 um P should put the diagram back up 46 yes 46 please page uh 169 I put some times on there you do yeah so we're talking about this very short time window from sort of 0124 30ish to 01

00:56:53 window from sort of 0124 30ish to 01 sort of

00:56:55 sort of 25ish 25 26 sorry no sorry uh o what um three collapsing at 02650 so just before 0127 for example with this particular

00:57:07 0127 for example with this particular set of uh estimated concentrations so it's this very early stage so uh and the time of fire

00:57:20 arrival outside flat six

00:57:29 so I think 120 from your 120 yes so this is this is uh within about 5 minutes of the arrival of the fly out fire outside flat 6 on

00:57:40 of the fly out fire outside flat 6 on that

00:57:41 that level and uh so this is a time when where uh essentially the burning fuels available to produce this smoke were the exterior cladding and insulation and

00:57:54 exterior cladding and insulation and window surround Structural Materials mainly

00:57:56 mainly outside the 10th floor was the main that was the main fuels that were involved in combustion around that time then you got to add on a couple of minutes for their smoke to penetrate into the lobby so I

00:58:09 smoke to penetrate into the lobby so I would say that it's likely that most of that Source material that was burning to produce that smoke was the exterior cladding insulation and

00:58:21 the exterior cladding insulation and window surround complex fuel packages one and two because there hadn't really been time for significant involvement of Flat 6 contents up to that period of

00:58:35 time thank you very much um thank you Professor for that now um I'd like to turn to a different uh aspect of your report which is Section

00:58:47 aspect of your report which is Section Five and can we please have up DPR 501 which is entitled uh extent of EX

00:58:58 501 which is entitled uh extent of EX section five extent to which different materials are likely to have contributed to the effects of toxic smoke on grenfell Tower occupants now is it right to say just summarizing the purpose and the findings

00:59:10 summarizing the purpose and the findings of this section of your report that uh in Broad terms it was an attempt by you to establish three things and correct me if this is wrong first what materials were likely to have contributed to the

00:59:21 were likely to have contributed to the toxic smoke and gases that the grandell occupants were exposed to yes yes second how that changed over time in different locations and dependent upon what was burning yes and third the concentrations

00:59:34 burning yes and third the concentrations of smoke particulates and toxic gases in the smoke that the occupants were exposed to yes yes now can I ask you to start page 12 piece

00:59:45 now can I ask you to start page 12 piece paragraph

00:59:49 37 uh at the bottom of the page and you say this um an important consideration with respect to the exposure osure of occupants to axient gases is the concentration ratio of carbon monoxide

01:00:00 concentration ratio of carbon monoxide to hydrogen cyanide the yields of car of Co and hcn depend on the carbon and nitrogen content of the burning fuel the fuel load masses composition and decomposition are described in section

01:00:12 decomposition are described in section 2.7 based on the estimated masses of PE and P burned outside of flat as the fire burned past it and from the carbon contents of these materials I've estimated that they both contributed

01:00:24 estimated that they both contributed equal amounts of carbon monoxide to the exterior smoke plume so the total concentrations of Co in the Smoke would have been derived more or less 50 to 50 from these two

01:00:36 more or less 50 to 50 from these two materials estimating 100% combustion of the polyethylene mass and 50% of the P Mass from the carbon 53 563 sorry

01:00:47 563 sorry 63.5% and nitrogen content p 6.15% n and experimental data on combustion of P foam the carbon monoxide stroke hydrogen cyanide concentration

01:00:59 stroke hydrogen cyanide concentration ratio in the Smoke released during combustion is about 17 to1 therefore including the carbon monoxide contribution from the polyethylene when both are burning simultaneously the

01:01:11 both are burning simultaneously the nitrogen content of the mixed fuels is about

01:01:14 about 3.1% and the carbon monoxide hydrogen cyanide concentration ratio in the mixed smoke is approximately 27 to1 similarly P contains 3.65% chlorine so the

01:01:26 P contains 3.65% chlorine so the chlorine content of the burning cladding and insulation mixed fuel is about 1.8% chlorine now the 27 to1 ratio you've discussed

01:01:37 discussed yesterday um and I think at times today you've said that it's 26 or 27 yeah it's sort between the what's the what's the plus or minus what's the mar what's the error

01:01:47 error Factor on in that

01:01:52 ratio I I would say that's quite small right yeah um you say quite small are you able to put a number I should have been prepared for this question shouldn't I um I did think about

01:02:05 um I did think about this if we go back to the to the uh percentage uh concentrations in the fuel themselves they're pretty well exactly established

01:02:22 so I'd like to say something like 20 5 to 30 to one for that mixture right that's a range so lowest 25 to 1

01:02:34 that's a range so lowest 25 to 1 something something around that region thank you now how much how much hydrogen cyanide did the polyethylene contribute and how much did the P contribute so the polyethylene didn't constitute any cyanide whatsoever it's a very simple

01:02:45 cyanide whatsoever it's a very simple thing not it's all come from the only source right is the P right and were you able to distinguish the the contribution of hydrogen cyanide as between the p and the phenolic insulation no I did not I

01:02:58 the phenolic insulation no I did not I did not con consider the phenolic Insulation at all the reason for that was because we understood that it was a very small uh percentage component of

01:03:10 very small uh percentage component of what was on the tower particularly on the upper levels where most of the burning occurred we didn't have any real information about exactly how much there was or where it was when Professor St and her colleagues did uh ex uh you know

01:03:23 and her colleagues did uh ex uh you know surveys they did find some evidence for occasional pieces of identifiable kingspan and various locations but not a

01:03:34 kingspan and various locations but not a large amount so I wasn't able to really consider its its contribution um from the work of Professor Ste on small samples of these materials obviously there was some

01:03:48 materials obviously there was some nitrogen in the king span U so it it would have produced a small and did in fact when she burned it produced small amounts of Cyanide and I've commented on

01:04:00 amounts of Cyanide and I've commented on this in this section somewhere and from memory it's uh about a 30th I think it was of the of the contribution of cyanide from an equivalent mass of P so

01:04:12 cyanide from an equivalent mass of P so a much smaller contribution of cyanide from the kingspan hardly very small really uh yes and I think and there wasn't much of it there anyway yeah uh uh now in paragraph 45 on page 11 on

01:04:24 uh now in paragraph 45 on page 11 on page 14

01:04:26 page 14 paragraph 45 you've um uh considered you say the implications of the results of Professor st's work on specific building materials at grenfell did her work cause

01:04:37 materials at grenfell did her work cause you to revisit the 27:1 ratio that you've you previously no well I mean no I didn't feel the need to modify it given the levels of General uncertainties about the whole thing you

01:04:49 uncertainties about the whole thing you know now um if we go back uh and we'll come back to this part of your report in a moment but if we go back please to to DPR

01:05:00 605 page 21 paragraph

01:05:05 31 DPR 65 page 21 paragraph 31 you say this during the early stages of far spread up the east side of the tower the cladding

01:05:17 the east side of the tower the cladding and insulation was the main fuel burning as the source of smoke yeah now I don't need more than that is it fair to say that you consider fuel package one have been the main contributor to the smoke in the early

01:05:28 contributor to the smoke in the early stages of the fire yes after a certain time yes and what is and what do you mean by or how would you bound the early stages of the fire right so I'm focusing

01:05:40 stages of the fire right so I'm focusing particularly here on the period during which the fire spread up the outside of Flat 6 from approximately

01:05:52 approximately 015 stroke 20 when it started to come up the fifth floor up to uh 01 2728 when it reached the crown of the Tower so that's

01:06:05 reached the crown of the Tower so that's the

01:06:06 the [Music]

01:06:07 [Music] starting that's when that's the window of time between which it starts on each floor successively obviously in sequence up the

01:06:16 up the tower so that's the beginning of that period and obviously what I'm having in my mind is at what point does the transition occur

01:06:29 at what point does the transition occur to fuel package three which is the contents of the various Flats yes now that is uh where we have a great difficulty because whereas we can observe the fire going up the outside we

01:06:42 observe the fire going up the outside we can't observe what's actually happening inside those Flats now I'm I'm quite clear that I felt from so this is why where I went with great detail and we discussed this yesterday on the

01:06:54 discussed this yesterday on the observations of the ENT we're talking really here about Flat 6 at the moment aren't we so I um I I I studied in great detail what the occupant of Flat 6 said about what they observed and how they

01:07:06 about what they observed and how they saw the fire develop as it came up past past their Flats in order to assess this you remember I was saying that they didn't in general uh observe they they

01:07:18 didn't in general uh observe they they observed the far confined to the sort of window area and and from from all this I was unable to really distinguish any time lag between involvement of the

01:07:31 time lag between involvement of the exterior uh platon uh insulation and the structural window surround PVC and other materials of the windows so to me we

01:07:42 materials of the windows so to me we really can't distinguish in terms of burning time and smoke generation between the combustion of fuel package one which is the exterior materials and fuel package two which is the window

01:07:54 fuel package two which is the window surround materials or less simultaneous but where where we have uh a difficulty is at what point do we bring in fuel package three the the flat contents yes

01:08:06 package three the the flat contents yes and that's what I've been trying to address now so the occupants of flat six during the short period before they left and they all left in a hurry as we discussed yesterday uh did not observe

01:08:18 discussed yesterday uh did not observe significant fire spread within the contents of their Flats so the fire the observations that were reported were almost entirely still confined to the

01:08:29 almost entirely still confined to the window Structural Materials so that those early stages uh the and this is this really relates to the time that the lobbies were filling with smoke which we

01:08:41 lobbies were filling with smoke which we discussed yesterday which was depending on what level you were in the tower uh it was the time of arrival of the exterior Fire Plus 3 to 5 minutes at each floor level so you sort of add that

01:08:54 each floor level so you sort of add that to the spread R timings during that period uh the main fuel package that was involved was fuel packages one and two one and two now then to so then

01:09:05 one and two now then to so then when because eventually all these Flats were completely burned out so we had full total involvement of all the contents there was huge contents fires and it's a question of when did those

01:09:16 and it's a question of when did those fires internal contents fires become of significant size and I think that would have varied from Flat to flat and the uh objective the only objective evidence we

01:09:28 objective the only objective evidence we really have on this is the exterior view which I reproduced in a in a figure which I've put in here where you can observe the first uh first signs of

01:09:41 observe the first uh first signs of large fully involved compartment fires in some of the flat six on certain floors and the first uh external image which appears to show that was at about

01:09:52 which appears to show that was at about 149 I think it is we can look it up in a minute so there's a there seems to be so the picture I'm projecting here is that that it wasn't that the fire arrived at

01:10:04 that it wasn't that the fire arrived at the windows of Flat 6 and instantly ignited everything inside those Flats it's a picture of of the arriving at Flat 6 igniting all the window surround materials and then over quite an

01:10:17 materials and then over quite an extended period of time VAR varying between floors and individual Flats eventually it started to involve in a significant way way the contents and at some point um fires tend to grow in a

01:10:30 some point um fires tend to grow in a very uncertain way when they're small and then when when a fire eventually reaches a certain size about I think it's about 5 kilow then it starts it can

01:10:41 it's about 5 kilow then it starts it can start to take off in a very dramatic and exponential way so that would suggest that when one of those Flats suddenly brightly lights up

01:10:52 those Flats suddenly brightly lights up with a large interior fire that the the transition from a small interior fire to the large one almost certainly occurred over a period of a very few

01:11:04 occurred over a period of a very few minutes just before that time and previous to that we're talking about relatively small fires existing in those Flats we do have one or two witness observations but very few of flaming

01:11:18 observations but very few of flaming fire Behavior inside rooms in different Flats there's one example of an occupant who described the Moses basket of his child Catching Fire and his bed and I

01:11:32 child Catching Fire and his bed and I estimated that was about 10 minutes or so after the exterior fire arrived outside his flat it wasn't a flat six there's one or two examples of that I've obviously been looking into the witness evidence to see what I can find to give

01:11:44 evidence to see what I can find to give me some guidance on this point but I think it's still you know a very uncertain area we're talking about now Professor I'm going to ask you some detailed questions and I it would be useful I think great if you could try

01:11:55 useful I think great if you could try and keep the answers a little little bit more short and focused um can we start with table six please DPR 605 page

01:12:09 47 uh if we look at this table these are estimated yields and volume concentrations of smoke and toxic gases from mixed flat contents compared to that of clading and insulation yes yes

01:12:22 that of clading and insulation yes yes and is it right that your assumptions as we've seen before 100% of the polyethlene in the in the clading burned and 50% of the P correct yes and is it right that the 50% for the combustion of the insulation comes from Professor st's

01:12:34 the insulation comes from Professor st's report and particular her survey of the extent of the burned facade 50% was my original estimate in 2018 and then was then confirmed by the later much more detailed study yeah thank you now um I

01:12:46 detailed study yeah thank you now um I think if you go please to De uh back to page 44 same part of the report you've also I think updated table four with respect to the respective densities for

01:12:57 respect to the respective densities for PVC as measured by Professor St and also for um XPS now we're in one to four here aren't we oh so which which which report are we in here we're table four this of

01:13:09 are we in here we're table four this of report this is your second report this is your sorry of section which section this is Section Five yes so that's correct yes yes yes so you've updated those yes yes thank

01:13:20 so you've updated those yes yes thank you uh we're still in section five and uh if we turn on please to p page 45 paragraph

01:13:27 paragraph 157 you

01:13:29 157 you say 157 you say in the third line based on the finding that almost all the PE cladding was burned but only about 50% of the P insulation the burning exterior

01:13:40 of the P insulation the burning exterior fuel Mass was approximately 50% PE and 50% P yes yes now H can you explain how you arrive at 50% PE burned if almost

01:13:51 you arrive at 50% PE burned if almost all of the PE clading was burned no yes so the the the total fuel Mass outside a flat of P was about twice that

01:14:03 outside a flat of P was about twice that of the PE I see so if all the PE Burns and half P which we and the half is based upon these residues that were left for p whereas no residues were left for

01:14:16 for p whereas no residues were left for PE so that gives us a 50/50 mix right does that explain how very approximately does that explain how the 50% PE burning exterior fuel Mass Ned in this paragraph relates to your calculations based on

01:14:27 relates to your calculations based on 100% Mass loss of PE yes that's correct thank you if we go to page 46 then paragraph

01:14:35 paragraph 160 and I think the answer tell me if this is wrong I think the answer you've just given us feeds through you say I've calculated using the data from the BR tests for

01:14:45 tests for polyethylene ldp and poly is sinate f p I've calculated the yields and concentration ratios for the exterior Fire based on on 100% Mass loss for the for the

01:14:56 100% Mass loss for the for the rainscreen ACM cladding polyethylene and 50% Mass loss for the P insulation outside of flat um and maybe the answer is the same but how does the 50% burning

01:15:08 is the same but how does the 50% burning exterior fuel Mass noted in this paragraph relate to your calculations based on 100% Mass loss of PE and the yield of smoke and gases is it the same it should be the same yes yeah um and

01:15:20 it should be the same yes yeah um and now

01:15:21 now um can we then uh go please to um well I can show you Professor st's report Mr chairman we're in a sort of subtopic here um would you like a break before we

01:15:33 here um would you like a break before we Embark yes probably we're going to a different document I think we should then right Professor P we'll have the afternoon break before we embark on Professor St so we'll break now we'll

01:15:44 Professor St so we'll break now we'll resume please at off 3 and usual rules of five please thank you all right thank you very much

01:15:59 thank you I'll full

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01:32:03 would you ask Professor P to come back in please

01:32:24 all right good thank you very much yes Mr yes thank you can we please go to DPR uh five which is where we are at the moment page

01:32:36 47 uh and this is Table Six uh and in Table Six you can see that you've picked um a five

01:32:43 um a five figure yes of 1.3 in one column and 1.5 in the other yes um can you explain why you've selected 1.3 and 1.5

01:32:54 you've selected 1.3 and 1.5 yes there partly the exact figures depend partly on the data available from my data set but essentially this is a a fuel air ratio which is moderately

01:33:05 fuel air ratio which is moderately underventilated right which I felt was the most relevant and why this particular case and why have you Illustrated both

01:33:17 scenarios I think no what what the they're both uh those cases are partly underventilated they're similar so one is for the pr and PE and the other one

01:33:28 is for the pr and PE and the other one is for the contents right contents just help me with this if you would Professor this was a fire in Rel as far as the cladding was concerned which was burning on the outside of a building yes why did

01:33:41 on the outside of a building yes why did you consider a partially underventilated situation to be appropriate right good question so basically depending on what I'm doing I've looked at a number of different cases and for some of the

01:33:53 different cases and for some of the calcul in this section I've used uh I've done calculations for both the underventilated case which is here or the well ventilated case but here I'm

01:34:06 the well ventilated case but here I'm particularly focusing on the ratios on on the yields for for using to calculate the ratios and what I found was that the ratios that between these gasses uh was

01:34:19 ratios that between these gasses uh was very similar irrespective of which equivalence ratio you use although the yields would vary um and well my my question really was why did you choose the underventilated module model

01:34:32 module model sorry I mean I are you a fire scientist yes yes so

01:34:38 I that's the one I've Illustrated here but uh when I when I I looked at the data for both cases um these are these are what I've used

01:34:50 um these are these are what I've used for my fed calculations and they they they depended on the ratios that are derived from these numbers which I think is shown

01:34:58 is shown elsewhere and um the most realistic ratios that I obtained were for this case but they weren't very different for the for the well ventilated

01:35:09 ventilated case um and that's why I've chosen that this particular case here right thank you but later on I discussed the extent to which the uh I understand your

01:35:23 to which the uh I understand your exactly the point you're trying to make you're making which is that what were the conditions of combustion most likely on the exterior stuff and that's addressed in this SE section of my report right let me see if

01:35:35 section of my report right let me see if I can just pursue that a little bit more would you agree Professor first that ACM was burning with freely available oxygen because it was burning in the open atmosphere well yes and no with the answer to that

01:35:48 well yes and no with the answer to that so so yes this the outer surface that's facing to the world uh would be burning under pretty well ventilated conditions but as we saw from Professor bisby's uh

01:36:00 but as we saw from Professor bisby's uh video that he presented last week and as you will see from the BR test video um there was considerable amount of flaming in the cavity um between the clading and

01:36:12 in the cavity um between the clading and insulation involving the melting and dripping PE component on the inace in fact it seemed to be well in that experiment there was a lot of flaming on

01:36:23 experiment there was a lot of flaming on the inside and that inside one of course is in a restricted space and therefore like to be under somewhat underventilated condition right but comparing the two would you accept that the insulation May at least initially

01:36:36 the insulation May at least initially have had less oxygen because it was in a cavity completely or hard up against the concrete curtain wall whereas the PE was at least partially sposed to the air yes I agree right and therefore as the ACM

01:36:48 I agree right and therefore as the ACM burnt away the insulation would have been exposed and the oxygen availability would have risen could have isn't well in fact what's happening there is that the once the um once the PE is more or

01:37:00 the once the um once the PE is more or less Fallen away and finished flaming the P component almost immediately seems to self-extinguish it's a Char foring material that's why of course there's a lot of it left on the on the tower it

01:37:11 lot of it left on the on the tower it didn't continue to flame on its own very much right but why have you used moderate well fixed moderately underventilated conditions for the duration of burning when the conditions clearly varied over time and around the

01:37:24 clearly varied over time and around the building the this this particular set is for the ra is used to derive the ratios that I used for my fed calculations

01:37:37 that I used for my fed calculations so that depended mainly on the ratios and um the ratios were actually quite similar for different the ratios although the yields vary the ratios were

01:37:48 although the yields vary the ratios were very quite similar for different cases and I had to choose one so i' I've chosen chosen this one which I felt was the most relevant case as you'll see from later work but this of course we're

01:37:59 from later work but this of course we're taking into account here not just the cladding and insulation fires but also of course the later uh contents fires and what were the conditions under which the room Burns were burning and again

01:38:10 the room Burns were burning and again and basically also talking I mean I've done a lot of work obviously on the relationship between uh fuel air ra equivalence ratios and combustion yields of for all these materials which are all

01:38:21 of for all these materials which are all shown in detail in the BR report that we talked about earlier

01:38:27 earlier and and uh what we find with that is that the yields are considerably lower under well ventilated conditions and then increase in a sort of curve like

01:38:38 then increase in a sort of curve like that well let me show you paragraph 230 from your Phase 1 report if we can go to that it's a DPR 601 page

01:38:46 601 page 70 and I want to show you paragraph 230 please there uh and you say the ldpe cannot burn while encased in its aluminium skin but does so when it melts

01:38:58 aluminium skin but does so when it melts and drips out from the aluminium outer layers and also when they start to delaminate and expose the ldpe core since these processes occurred in the open air on the outer surface of the tower it is likely that most of the Flaming ldp combustion occurred under

01:39:10 Flaming ldp combustion occurred under well ventilated flaming combustion conditions with relatively low yields of Co and smoke similar to those shown in the upper section of table four yes I agree that that's what I wrote in uh

01:39:21 agree that that's what I wrote in uh phase one but how's your view and to still ex some extent C part of the time that would have also possibly been true but from the results that particularly

01:39:32 but from the results that particularly of the BR experiment I would say that I'm moving to a position where there was somewhat more contribution for these outside systems with more less well

01:39:45 outside systems with more less well ventilated more underventilated conditions so your view changed somewhat somewhat I see and is it is it is it that you've changed your view that the p would be burning under well ventilated

01:39:56 would be burning under well ventilated conditions to underventilated conditions to slightly underventilated right well let's pick that up then phase two report please uh back to SEC back to part um uh well back to DPR 65 page 46

01:40:10 part um uh well back to DPR 65 page 46 paragraph

01:40:15 162 uh you say uh there in the last sentence yes uh for my main calculations of effect on expas occupants I've used data for

01:40:26 expas occupants I've used data for somewhat ventilated combustion conditions do you mean somewhat under un underventilated

01:40:33 well let me pick pick it up four lines up in general it's my fault I should I've gone in too late four lines up in general the combustion conditions for large interior flat contents compartment

01:40:44 large interior flat contents compartment Fires at Grell and for the exterior clading and insulation fire are likely to have been somewhat underventilated yes that's the point I yes yes I that's what I'm saying and that's what you're saying right but I have done quite a few

01:40:55 saying right but I have done quite a few calculations in here for both conditions so and does that change in your view uh affect the general conclusions you were able to draw not materially no right now let's go let's go on then to section

01:41:06 let's go let's go on then to section five of your report at DPR 5 is 11 page 32 paragraph [Music]

01:41:14 [Music] 147 and this relates to V construction now Professor par 147 you say this the uh the Flaming involved the exterior cladding and insulation was

01:41:25 exterior cladding and insulation was intense but relatively shortlived at any specific location so that the Flaming period for the spandrel under the flat 26 equivalent kitchen window was about 5 minutes 23 seconds but and for the right

01:41:37 minutes 23 seconds but and for the right side of the column for initial fire involvement next to Flat 16 equivalent to self-extinguish outside flat 26 equivalent was about 4 minutes 23 seconds that's from this test yes from

01:41:48 seconds that's from this test yes from the test was it your conclusion that the P would have stopped burning after the first first few minutes yes and would you accept that the P was unlikely therefore to have had completely

01:41:59 therefore to have had completely combusted within the first few minutes of the fire but would continue to burn after the ACM had combusted I think most of the P would have

01:42:10 most of the P would have self-extinguish extinguished soon after the all the p p PE had gone but I can't tell exactly well we can look at the data from the graphs but yeah so so I

01:42:23 data from the graphs but yeah so so I mean you know the the the basic fact is that when all this flaming is gone as you can see in those images just above there there's a considerable amount of P that's that's

01:42:34 that's that's left self-extinguish as a Char on the surface there of the of the spandrels in this particular case whereas for the columns it's pretty well all burnt away right shows in those images after the

01:42:45 right shows in those images after the fire test and would there have been any continuing combustion effect from heat and Flames coming from internal fires exiting through broken or missing

01:42:56 exiting through broken or missing Windows when uh later much later on yes yes yeah now can I ask you then to look at Professor bisby's work p u package uh

01:43:07 at Professor bisby's work p u package uh um report for Phase 2 at lb wp2

01:43:15 wp2 61 page 4 paragraph 27

01:43:23 and he says the data presented in this report also suggests that up to the point of local burnout of the ACM in a worst case scenario where wherein all mass lost from the insulation product is

01:43:34 mass lost from the insulation product is assumed to be converted into energy release through combustion stroke oxidation and then turn the page please burning of celex rs5000 insulation is unlikely to have contributed more than

01:43:45 unlikely to have contributed more than 20% of the total energy released by any of the clading system Arrangements tested burning of the kingspan K15 may have cont uted up to 53% of the total energy released by The clouding

01:43:56 total energy released by The clouding system Arrangements tested and he explains why that is do those figures have any relevance to the contribution of toxic products as you've identified in your report just to make sure I understand this is extract from his

01:44:08 understand this is extract from his recent report on the experiments he did at Edinburgh yes yes I I I did have a look at those the other day yes my question do those figures have any relevance to the contribution of toxic

01:44:19 relevance to the contribution of toxic products that you have identified in your report L yes but we can band upon that so so in these small scale experiments that he did there was a certain relative mass

01:44:31 did there was a certain relative mass loss or involvement of energy from the celotex and from the PE um and the energy release depends upon the heat of combustion which I remember him discussing in his work um

01:44:44 remember him discussing in his work um now the heat of combustion of celotex is is about half that of PE so so even if you burnt the same amount of both you would get considerably less heat from

01:44:56 would get considerably less heat from the celotex than he would from the PE also which I don't think he talked about too much and I think there's quite a difference between the way the huge assembly of the tower burnt and his small scale experiment because I noticed

01:45:09 small scale experiment because I noticed his video of his experiment went on for 10 minutes or so but in 10 minutes on the real building it went from all the way up the tower so there a bit there are some differences here but uh essentially the contribution to the

01:45:21 essentially the contribution to the energy of the RS 5000 was as as he said less than that of the PE but the mass loss as we know from the survey that Professor St group did was about the

01:45:34 Professor St group did was about the same from these two components and so in terms of yields of toxic products uh would be about the same right so it doesn't doesn't matter is it are you saying I mean it's consist it's not

01:45:45 saying I mean it's consist it's not inconsistent I mean obviously there are nuances of degree but because there's so much less energy much less energy coming from celotex U you can burn a larger

01:45:57 from celotex U you can burn a larger amount and get less energy out compared to the

01:46:01 to the PE yes but I think in the full scale re actual uh the involvement of the celotex is somewhat greater than in Professor bisby's 1 meter Square Panel test now

01:46:12 bisby's 1 meter Square Panel test now can I then ask you to some questions about the BR reconstruction and go please to DPR 51 page 5 paragraph 9

01:46:25 and you say there these findings for the origins of the smoke filling flat six after the arrival of the exterior fire are supported by the results of the

01:46:36 fire are supported by the results of the BR grenfell fire reconstruction experiment during this test there was significant and Rapid smoke penetration and filling of the equivalent of flat 26 kitchen from the exterior fire when Flames reached outside the kitchen

01:46:47 Flames reached outside the kitchen window this was followed very rapidly By Flames entering through and igniting the kitchen extractor then spreading to the window surround and penetrating through the insulation at the side of the window flaming then subsided after the

01:46:59 window flaming then subsided after the exterior cladding outside the kitchen was consumed and the remains of the insulation self-extinguished toxic gas measurements of the smoke collecting in the flat 26 kitchen indicated an approximately equal contribution from

01:47:11 approximately equal contribution from the burning polyethylene PE cladding and the polyiso cyanurate P insulation with a further contribution from the burning upvc window surround now um on the basis

01:47:23 upvc window surround now um on the basis of that is it fair to say two things first that the origins of the smoke penetrating the flat sixes was composed of fuel loads one and two yes yes and secondly that there was an approximately

01:47:34 secondly that there was an approximately equal contribution from the PE cladding and the P insulation to that toxic smoke yes now in relation to the second of those conclusions would the smoke um not also have had a contribution from fuel

01:47:45 also have had a contribution from fuel package three um namely the contents of flat

01:47:50 flat 16 flat 6D 16 oh 16 sorry well no got it been extinguished by then um and so nil yeah uh now can I ask you then to look

01:48:04 yeah uh now can I ask you then to look at I see um can I ask you just to look very briefly at uh Professor terr's evidence sorry just at the very early stages as it spread up would there could

01:48:15 stages as it spread up would there could have been some I think I mentioned this in my report but during this late stage these these gas gas measurements were made right at the very end of the test so long after the fire in the in the one

01:48:26 so long after the fire in the in the one below had been extinguished now now cutting through the point actually I can take this more shortly do you accept that the BR reconstruction fire was different from the original flat 16 fire at greld because in the Reconstruction

01:48:38 at greld because in the Reconstruction the fire attained flashover whereas at the in the original fly in flat 16 it didn't yes I haven't particularly concern myself with the nature of the obviously the reason for doing this was

01:48:50 obviously the reason for doing this was to replicate the entire scenario concent what was happening in flat 16 but my only interest here is not what's happening in flat 16 it's what's happening on the FL installation so it

01:49:01 happening on the FL installation so it may what you might say may be true but I haven't really examined this issue as relevant to my work right right well would

01:49:07 would you g given the difference between the BR reconstruction and flat 16 namely that in the former there was flashover but in the latter there was not does

01:49:18 but in the latter there was not does that affect the Reliance that you're able to place on the BR reconstruction for the purposes of your toxicology opinion I don't think so no right um let's go to then

01:49:31 let's go to then uh page 26 please in the same part of this report same part of this section of this report paragraph 117 and this is looking into a little bit of detail in the BR construct U reconstruction you

01:49:45 the BR construct U reconstruction you say in page on page 26 can we go to page 26

01:49:57 uh paragraph

01:50:00 117 the BR Team constructed a hood to enclose a headp space under the kitchen ceiling area with a half meter downstand so that a temporary smoke layer could form before spilling out and Rising above the experimental rig to the

01:50:12 above the experimental rig to the extract Hood above sampling probes were placed in this head space to enable sampling of toxic gases yes yes uh now um I don't know whether

01:50:23 yes uh now um I don't know whether you're qualified to give this opinion but if you are if you're not say so but if you are are you able to tell us how long might smoke stay in that temporary

01:50:35 long might smoke stay in that temporary Hood does it fall within your area of expertise at all well yes I suppose so I mean seconds to minutes I mean it's it's it's spining out yes right now if we go on to paragraph 119 and

01:50:47 on to paragraph 119 and 120 um it is said that there were two points for the sampling of smoke and gases during the test one for from the calorimeter hood and another specific specifically for gases collecting in the flat 26 headspace yes unfortunately both

01:50:59 flat 26 headspace yes unfortunately both these measurements failed during the test so that no calorimeter gas and smoke data were obtained and flat 26 headspace samples were obtained only for a short period near the end of the experiment that's correct a and if you

01:51:10 experiment that's correct a and if you go please to page 38 in your this section of your report page 38 figure 511 you can see that the failure happened around 99 minutes into the test and restarted about 26 minutes in you

01:51:21 and restarted about 26 minutes in you see that there's a gap yes yes would you are you able to agree with this proposition given that it's in your report all right that uh the data about

01:51:32 report all right that uh the data about the concentration of toxic gases irritants and smoke were not collected at a time when their quantities would have been at their most um dangerous yes yes does that affect your opinions and

01:51:43 yes does that affect your opinions and conclusions in any way I mean I I can only work with with the obviously the evidence I've got but I i' I've I've commented on this in my report and I've said that uh they could have been

01:51:55 said that uh they could have been somewhat higher during this missing period um but that's all we can say I mean sadly it was lost very good now let's turn on then to page 37 well sorry back to page 37 paragraphs paragraph 168

01:52:08 back to page 37 paragraphs paragraph 168 and you say there these temperature readings indicate temperatures at the face of the P capable of decomposing the aluminium foil covering and igniting the surface of the P since the p surface forms a protective Char and exposed to

01:52:20 forms a protective Char and exposed to Flame yeah and since the Flames are partly derived from the burning polyethylene of the cladding at this time these high temperatures although indicative of at least some surface combustion of the P which occurs above

01:52:31 combustion of the P which occurs above about 650 to 700° Centigrade do not establish the depth of burning penetration of the P Fame surface now um what did You observe yourself from the V

01:52:42 what did You observe yourself from the V reconstruction about the burning of the PE well it basically all was burned away do you know when it ignited view about timing well yeah it's

01:52:53 ignited view about timing well yeah it's discussed in my I think it's shown in my um tables and uh and the images from the fire were you able to formally view about its contribution to the

01:53:05 Smoke well yes it was the smoke the smoke penetration into the kitchen was the time when all these materials were burning and there's a difference between the with part of the P there's a

01:53:17 the with part of the P there's a difference between the performance of the on the on the spandrel and and the column which I talk about in the text but I'm just really reporting observing

01:53:28 but I'm just really reporting observing that the minute by minute results of this test right what and obviously up front I've said this is just one example of the way things can go I mean we have to emphasize

01:53:39 emphasize this

01:53:41 this yes I mean I'm just trying to get a feel for the extent to which you relied on the BR uh reconstruction and the features of it I won't call them defects because that would would not be neutral

01:53:53 because that would would not be neutral but the features of it I think what I think I put in my report up front was I've made the best of the information that's available to me and interpret it as far as I'm able to do so you know I

01:54:04 as far as I'm able to do so you know I obviously we would we would there's a lot of uncertainty about a lot of this whole subject area uh and unfortunately we don't have the information to make really definitive remarks but this is I

01:54:18 really definitive remarks but this is I think there's some quite useful stuff that's come out of this test and I've interpreted it as I as I found it right um go to 182 on page 39 let's see if I can speed up with this then in the light

01:54:30 can speed up with this then in the light of those answers you say at 182 that from the different gases measured and the elemental composition of these fuels it is possible to determine which contributed the to to the total mixed smoke under the kitchen headp space

01:54:41 smoke under the kitchen headp space during the sampling period is and is that how you were able to calculate the output of carbon monoxide in table 5.3 yes and this is why I uh I mean again we just

01:54:52 just shown how this data has got some issues but as far as it as far as it goes at face value this interpretation demonstrates that the conditions of combustion were to more toward for the

01:55:05 combustion were to more toward for the whole system both the P plus the p in particularly the PE were somewhat towards the UN slightly underventilated

01:55:16 and uh G given that well if you look at page uh

01:55:24 page uh 40 please um and Par 185 you say there that the only field producing hcn on the BR Rec reconstruction test was the P correct and that and that's consistent with your

01:55:35 and that and that's consistent with your view that the P produced none correct now given that the measurement Hood only collected gases for a temporary period towards the end of the Reconstruction have you adjusted your calculations to account for that no this this only

01:55:47 account for that no this this only addresses that period when we were collecting the data would it be fair to say that you've assumed that that your well your calculations based on that 10-minute period between 25.5

01:55:58 on that 10-minute period between 25.5 and 35.5 minutes appli throughout all the stages of the fire right I these calculations are based on the data that was collected during that period uh I haven't really commented on on the rest

01:56:10 haven't really commented on on the rest of it but I would have I would expect it to have been somewhat similar but all I can all I can report is what's happened in practice at this point certainly but would you consider it a reasonable um approach or yes for the period for that

01:56:21 approach or yes for the period for that five minutes or so when the whole of that face was burning as you can see those images these are the sorts of conditions that we're getting my question to finish it off if I can but would you consider it a reasonable

01:56:32 would you consider it a reasonable approach or assumption to extrapolate from that 10-minute period uh uh throughout all the stages of the fire throughout the through all the period that the all that exterior material was burning yes you do yes and

01:56:44 material was burning yes you do yes and why is that well because it was it was burning progressively so the same package if you like was coming up and burning past the window at that time and does that I mean there would have been

01:56:55 does that I mean there would have been more involvement of the PVC at the somewhat later stages that's that's certainly true right I the point is really this because the measurement had only collected gases for a temporary period and and at the terminal stage of

01:57:08 period and and at the terminal stage of the BR reconstruction would it not be fair to say that your calculations based on this latter stage assume that they apply to the earlier stages of the fire when no actual measurements were performed yeah so the simple fact is we

01:57:19 performed yeah so the simple fact is we can say nothing about the gas ratios that would have been measured in that time because they weren't obtained no and would you accept thegg I could accept that I think it's unlike to have been radically different but without the

01:57:31 been radically different but without the data we can't really say can we no and would you accept therefore that there's no robust evidence to support your assumption I think there's evidence support I don't made any assumptions there's no the evidence I'm presenting

01:57:43 there's no the evidence I'm presenting is the evidence from what the from the data that were gathered at that time under those conditions when those fuels were burning during the those few minutes of test would you accept that there's no evidence to reliably to

01:57:55 there's no evidence to reliably to assess which component PE or p is contributing the most to carbon monoxide concentrations when during this test during the time that we made the measurements it was there was yeah but I

01:58:08 measurements it was there was yeah but I obviously haven't got the data to AR to answer that question about the earlier stages but looking at the burning Behavior I think once once we have a a big external fire established in the

01:58:20 big external fire established in the cladding insulation system moving up up outside between the 16 and 26 kitens we've got reasonably stable conditions and of course what we do have and I've

01:58:31 and of course what we do have and I've analyzed in some detail is all the thermac couple data during that time and I've looked very much at the temperature profiles of the surface of the PE and

01:58:42 profiles of the surface of the PE and the p uh in the various locations in the cladding and in the spandrels and the columns over that period so I think we can make some some assertions on this

01:58:53 can make some some assertions on this point right well in the light of that answer can I just ask you three more questions on this can I ask you first M I'm sorry I'm not sure I've quite understood this so do you mind if I asked my question before you do that um

01:59:04 asked my question before you do that um I'd understood Professor from what you told us earlier that there were roughly equal contributions to the toxic to the generation of toxic gases made by the PE and the

01:59:15 and the insulation yes for carbon monoxide yes carbon monoxide yes I'm concern cide are you suggesting now that it's possible to determine um different

01:59:29 possible to determine um different proportions the different proportions of carbon monoxide were generated by the burning of the different constituents of the

01:59:37 the cladding if so I'd like to understand let me just try and go through this again During the period of gas sampling

01:59:48 again During the period of gas sampling that we're looking at here in this particular test I I'm able to establish that the when those when those gases were collected from that hood in the

01:59:59 were collected from that hood in the then that at that time uh the data we've obtained are consistent with a 50/50 contribution from both the PE and the p and that's based upon the relative

02:00:11 and that's based upon the relative concentrations of all these different gases enabling to me to make that calculation and also by looking at the oxygen depletion during that period I'm able to demonstrate that we get a better fit to the data for a slightly

02:00:24 fit to the data for a slightly underventilated condition for for all that fuel including the PE than for a more well ventilated condition but I could only speak for that period of time once you get a fully developed fire on

02:00:36 once you get a fully developed fire on the outside in the cladding yes I had understood it to be your view that the uh the PE and the insulation made roughly equal contributions to the total

02:00:48 roughly equal contributions to the total volume of carbon monoxide produced as as here as was the case here as yes so that's the basis on which I proceeded yes yes so it's not possible I would it sounds to me it's not possible to say uh

02:01:01 sounds to me it's not possible to say uh when a person inhaled carbon monoxide that it was generated by one or the other no the carbon monoxide obviously I I I I established

02:01:13 monoxide obviously I I I I established quite well what the car amount of carbon monoxide they inhal was yes most of the time as far as the person who's inhaling ex they don't it doesn't matter where it's come from no and and

02:01:25 it's come from no and and um and that's that's if you like what we've been talking about the last couple of days now we're talking now we're focusing very much on on yields and relative contributions of different fuels I think we're in a much more

02:01:37 fuels I think we're in a much more difficult area I I accept that and I said that upfront in my in this part of my report that we have somewhat limited information all right I think that's that I think that's help me quite a lot

02:01:49 that I think that's help me quite a lot thank you very much yeah yes thank you I'm I'm I'm afraid I do still I consider that I need to I need just to ask these questions if it just

02:02:02 ask these questions if it just to um finish the point can we go please to page 41 table

02:02:10 5.4 this is calculated contributions of each fuel material to smoke and gases in flat 26 equivalent during BR reconstruction fire test and you share the estimated contribution to carbon

02:02:23 the estimated contribution to carbon monoxide there at some eight times greater for p than for PE do you see you've got 304 over 36 304 for the p and then 36 for the PE under under under 51

02:02:36 then 36 for the PE under under under 51 under 51 yes exactly and underventilated at five 1.4 to 1.5 you've got 358 uh 361 considerably more yeah considerably more

02:02:47 considerably more yeah considerably more yes almost equal in underventilated conditions yes yes and that fits better with the and as you can see that fits better with what was actually total flat that were actually actually measured so

02:03:00 that were actually actually measured so the the data the data fits much better for the more underventilated case it doesn't fit very well for the fal one case right so that's That's the basis of

02:03:12 case right so that's That's the basis of my belief that the in this Li very limited uh experiment is supporting a more underventilated Cas

02:03:24 Cas well question how do you know that the fire in the BR reconstruction was burning underventilated for the 9 to 25.5 minute interval for which there's no data I don't know I don't know when

02:03:37 no data I don't know I don't know when it's not there's no data obviously no I can't say for certain is it therefore possible that the fire in the Reconstruction was well ventilated and that therefore the P was contributing

02:03:49 that therefore the P was contributing more to the carbon monoxide concentrations in flat 26 during during the test during the period when the gases are measured we have the situation as I've reported it are you are you

02:04:01 as I've reported it are you are you referring to an earlier period no I'm referring to the period of where you don't have any data is it possible that during the period for which there's no data uh the fire was burning well ventilated and that therefore the P was

02:04:12 ventilated and that therefore the P was contributing more by way of carbon monoxide than the PE I can't see that the conditions from the thermac couple data and the and the and the burning conditions as shown by all the thermac

02:04:23 conditions as shown by all the thermac couple data and the videos that there was a big change evident in the way all this was burning there may have been a period uh there may have been a period when things was there's going to be some

02:04:34 when things was there's going to be some variation with time and between cases here you know we don't want it's not very it's not going to be absolutely hard but uh I I don't really see any evidence of what you're suggesting but

02:04:47 evidence of what you're suggesting but the bottom line is there's no data so I can't really say look at this can I now um while we're on this topic uh I think we can ask this

02:04:58 topic uh I think we can ask this question at this point can I ask you to go to section six of your report please uh at da section six yeah section six at DPR uh

02:05:12 65 go to page 169

02:05:21 now you you let's pick this up

02:05:35 here yes figure 46 um uh now um you can see that when the FED equals 1 fedal 1 a hydrogen cyanide makes a

02:05:48 1 fedal 1 a hydrogen cyanide makes a bigger contribution than the carbon monoxide doesn't it to the collapse of an individual who's breathing in toxic fumes uh is that right hang let let me get my brain around this uh when the yes

02:05:59 get my brain around this uh when the yes you see when is the blue the blue curve is the F or the dark blue curve the dark blue curve is a total the dark blue is a total from all sources yeah yes when it equals one

02:06:13 sources yeah yes when it equals one yes the yeah carry on yeah thank you hydrogen cyanide makes a bigger contribution than carbon monoxide to the of an individual breathing in toxic fumes I think you accept that yes it has

02:06:26 fumes I think you accept that yes it has yes at that point it has yes because the F sorry the FED Co sum for Co is the red line and the cyanide is the blue line yes no uh exactly now talk about this

02:06:38 yes no uh exactly now talk about this earlier didn't we given that the acmp as you've told us a number of times gave off no hydrogen cyanide yes and your own figures make it clear that the FED did equal at least one are you able to

02:06:50 equal at least one are you able to confirm that in those cases in this chart 10th Lobby the cause of collapse and death was from fuels other than the acmpe both are contributing because both

02:07:02 acmpe both are contributing because both are contributing to the co but as we discussed because of the peculiarities of toxicity of Cyanide and the high concentrations of both gases in this particular situation the cyanide is

02:07:15 particular situation the cyanide is kicking in here as a a bigger initial cause of incapacitation yes is a bigger cause of initial incapacitation it's showing up as a bigger term in this what about death no

02:07:28 bigger term in this what about death no death once once you become unconscious and as I mentioned and you your breathing drops right down this this peculiar stimulatory effect of cyanide then

02:07:38 then disappears and um and also because the Dynamics of spread of of Co of cyanide throughout the body water entire body water it drops out to become a less

02:07:49 water it drops out to become a less significant term and so death is more like to be and and as we can see from the chbs in the deant was mainly driven the death was mainly driven by Co and

02:08:00 the death was mainly driven by Co and that as you say even in respect of these uh is this right in respect of these uh deceased came 50/50 in your opinion from the PE and the P yes yeah and and and

02:08:14 the PE and the P yes yeah and and and well no sorry and with a contribution from the from the window surround materials as well the upvc yeah which gives a very high yield of C because of the chlorine content which which affects the combustion of all these materials

02:08:25 the combustion of all these materials and makes it makes the burning of all of them more under like more underventilated burning where where the chlorine from the PVC goes into the flame Zone that's another another

02:08:36 flame Zone that's another another complicating fact here by the way is yes now um let's then turn back to DPR 605 please

02:08:59 yeah and Page

02:09:02 38 uh and at page 38 paragraph 126 uh you

02:09:07 you say uh six lines down from the start of the paragraph you say for the specific cladding insulation and window materials present at grenfell samples have since been obtained for which further testing has been carried out by Professor Ana as

02:09:19 has been carried out by Professor Ana as part of phase two of the inquiry although there are minor differences in the composition and toxic product yields between these specific materials and those from the samples of the same generic polymers I've used for my assessment the differences due to

02:09:31 assessment the differences due to specific polymer formulations have been found to be small in comparison to the uncertainties in other aspects of the assessment the data for these generic materials is compared with those tested by Professor St in section five of my

02:09:43 by Professor St in section five of my report so in essence is it right that the work that Professor St did broadly supported the assumptions that you made about the ele compositions in your phase one work yes and therefore you were able

02:09:54 one work yes and therefore you were able confidently to rely on your previous phase one work yes can I ask you then to look at Professor St appendix 15 um this is at a a Sr

02:10:06 Sr 5025 page

02:10:11 two I'm going to throw up some data at you this is the pi celex RS 5000 which she measures gram for gram I think and if you look at the row which has temperatures of 825 towards the foot of

02:10:23 temperatures of 825 towards the foot of the chart you see that she's got a range of temperatures there sorry she she's done she's done these experiments at different temperatures yes well it's she has and 825 is the highest is the

02:10:35 has and 825 is the highest is the highest yes correct that's right and she's got a range gram for gram of between um .12 to.

02:10:45 .12 to. 3174 well uh uh for co co I'm sorry Co gr for GR yes depending on the equivalence ratio depending on the equivalence ratio now um if we can also have at the same time side by side your

02:10:57 have at the same time side by side your table three and we find that at dapr 65 page

02:11:06 39 you have that at the same time your table three there it is Table Three toxic gas yields effective heat of combustion etc etc now that am I right

02:11:18 combustion etc etc now that am I right that your table three is drawn from the BR study and not Professor st's data my table is from the BR study yes yeah now can I ask you to think about the yield of carbon monoxide in Professor St table

02:11:30 of carbon monoxide in Professor St table with at Burning temperatures of 825

02:11:33 825 Centigrade uh and you can see the range I've shown you for carbon monooxide there yeah 0.12 down to 0. 3174 right now on that

02:11:45 0.12 down to 0. 3174 right now on that um you can consider that and compare it with your figure uh for an underventilated ated fire fuel Rich got

02:11:56 Rich got three 33 exactly and she's got 329 so that's pretty close is it you say that's very close so they relate to each other yeah but I mean not but we we

02:12:07 each other yeah but I mean not but we we did ours at 700 I think well so in fact there's a table in my appendix in my report where I've comparing the nearest which is the her 750 data set with our

02:12:18 which is the her 750 data set with our with our um 700 degre Centigrade data set I see but if we then turn to page five in her appendix we at the moment we're at page

02:12:30 appendix we at the moment we're at page uh two but if we go please to page five in her appendix left hand side of the screen um you can see her results for um

02:12:41 screen um you can see her results for um acmp yes uh where at 825 degre for carbon

02:12:47 carbon monoxide she's got gram for gram of not .

02:12:52 . 2245 uh and not 2124 equivalence ratios of 1.9 and 2 yes yes yes uh are you able to read across

02:13:03 yes yes uh are you able to read across those and explain how those relate to your figures in table three well I compar six I compared the results of our our test directly in the appendix of my report and our results of PE are very

02:13:16 my report and our results of PE are very close to hers I found so I mean this this is for particular runs but uh we we did lots of different runs at different equivalence ratios and I I've compared

02:13:29 equivalence ratios and I I've compared these the more relevant ones in my in my report but anyway just to to follow up on your reasoning so we want polyethylene but we we're trying to compare your ldp entry for carbon

02:13:43 compare your ldp entry for carbon monoxide in the lower top sorry just Professor let Mr can I just can I just I want everyone to understand this so they they can understand your answer to my question right I'm asking you to compare

02:13:55 question right I'm asking you to compare your figure on page 39 right hand side of the screen lower part of the chart fuel Rich ldp yes figure for carbon monoxide of 196 yes and I I want to know

02:14:09 monoxide of 196 yes and I I want to know how that relates to Professor st's number on the left hand side where for um acmpe bottom box temperature at

02:14:22 for um acmpe bottom box temperature at 650 with the equivalence ratio she's identified right carbon monoxide gram for gam uh range is uh um n um is

02:14:34 for gam uh range is uh um n um is 02245 and

02:14:36 02245 and 02124 they're the 825 temperatures right so I just sorry I've got to pick I mean we should be better if we were looking at the actual comparison in my report but anyway uh so this particular example

02:14:49 but anyway uh so this particular example here I've got an equivalence ratio the run I've put in here in this table is equiv ratio of 1.71 yes yes and the co yield was uh 196

02:15:03 1.71 yes yes and the co yield was uh 196 G per gam so just about2 and this is done at a temperature of

02:15:09 of 600°

02:15:11 600° Centigrade so the nearest equivalent would be her 650 experiments but she doesn't have one done out of five 1 .7 so we can't make a direct comparison the

02:15:23 so we can't make a direct comparison the nearest equivalent in hers although it's at a much higher temperature and therefore would give a different result is a an equiv ratio of 1.9 Which is higher than mine and she's got. 22 and

02:15:34 higher than mine and she's got. 22 and I've got 196 I would say given the difference in the test conditions that's a very close approximation right um I I see the reason I ask you is because it

02:15:46 see the reason I ask you is because it might be suggested that there is a discrepancy between these figures depending on whether you rely on the BR e work or STS work but you say there isn't and I didn't say there isn't I said well there isn't but it was in the

02:15:57 said well there isn't but it was in the context of the of the uncertainties over the whole system this that what such differences there are and and we really should be looking at my comparison tables right well should we do that it's

02:16:08 tables right well should we do that it's a DPR

02:16:10 a DPR 611 uh page 60 it's an appendix I think isn't it yeah is that what you're after that's the the elemental composition so we want

02:16:22 the the elemental composition so we want the

02:16:23 the yields uh that probably L next page so if we go down ldp we are page 61 ldpe uh those are the comparisons of the

02:16:37 ldpe uh those are the comparisons of the co yields but as you can see hers were done at a higher temperature 825 and we do find the yields increase somewhat with temperature so I would say those are pretty close and certainly well

02:16:49 are pretty close and certainly well within the sort of uncertainties of all the work and therefore not sufficient for me to need to redo my calculations right you say they're pretty close I mean on the stack data I've shown you

02:17:00 mean on the stack data I've shown you the carbon monoxide produced by the p is 2.3 times more than that produced by the PE whereas on the BR data the difference is only 1.6 more produced by the pr p over the

02:17:13 more produced by the pr p over the PE I we could do that we can show you the the figures again which what just what are you comparing uh Co

02:17:22 uh Co yield at at an equivalence ratio of 1.88 for example yes uh I haven't got one uh what 1 Point um we

02:17:36 what 1 Point um we 1.67 she's getting

02:17:40 .4

02:17:43 87 and um the PE

02:17:52 at 1.89 is point well the two two are given quite rather different there's one one case is 0.12 one the BR sorry it's. 212 and 0 224 yes

02:18:08 one the BR sorry it's. 212 and 0 224 yes yeah and you're comparing that with I'm comparing that with the BR dat with the the BR data so the pi the B at 650 the

02:18:20 the BR data so the pi the B at 650 the the uh Co yield at 1.7 there is 1

02:18:30 is 1 96 and for p it's about 33. 35 so those are the comparisons yes yeah

02:18:44 35 so those are the comparisons yes yeah so so we're saying about. 2 about. 2 to about 0.5 and about 35 that particular run that's a particular individual run but they do vary somewhat right the

02:18:55 but they do vary somewhat right the difference is

02:19:01 significant in the context of what we're doing I would say the the uncertainties of the whole whole thing I don't think they're so so so big no well let's just

02:19:12 they're so so so big no well let's just try the but there are they are obviously some differences yes yes they are let let's just try try this slightly slightly differently uh uh if we go back to the I'm afraid I'm

02:19:23 uh if we go back to the I'm afraid I'm I've worked from the stack figures rather than this index but can we go to her appendix please aasr um 5025 page five

02:19:35 aasr um 5025 page five acmp um and there I just want to compare that again with your table three if I can D

02:19:42 can D APR which which material are we talking about the the the um just a second Table Three DPR

02:19:51 Three DPR 65 page 39 lower part dealing with underventilated

02:19:58 now I'm on the I'm on the the P P yes right and I just want to be clear about this in Professor St data at

02:20:10 this in Professor St data at 825 now we need different temperature yeah sorry we need I'm so sorry we need page two not page five in the left hand side that's it thank you very much now

02:20:22 side that's it thank you very much now there under ventilated conditions 825 she says carbon monoxide produced by P and corrected to mass burnt is some 2.33 more than produced by

02:20:34 ldp

02:20:37 um sorry which one are you pointing at well

02:20:41 well um well I'm afraid I've conflated this into into a conclusion let's try something slightly different in your table three we look across table three lower part dealing with underventilated shows us the BR data indicates P

02:20:55 shows us the BR data indicates P produces 1.66 more carbon monoxide than ldpe that's that's 333 over 196 you see that no I don't know where you are I can do that one easily enough um the

02:21:08 do that one easily enough um the p in your fuel Rich you've got P at um 333 yes where as ldp is 196 ldp is. 196 for these particular

02:21:20 196 ldp is. 196 for these particular runs yeah yes so ldp is 196 and PIR is 333 right but Professor STC and you have to go to two different places for this

02:21:32 to go to two different places for this um gives you um different ratios and I'm telling I'll take it from me it's 2.33 more from from from P than ldpe are you

02:21:43 more from from from P than ldpe are you able to account for the

02:21:47 difference there are what we what we're looking at at here is specific test results and and they vary consider between run and run and the

02:22:00 consider between run and run and the conditions of the run of the individual run within a range so the I would say that what we're looking at is is is there a

02:22:09 there a substantial uh yield of uh Co and cyanide from these materials under these conditions and and and the answer is yes there is now the obviously the there are

02:22:21 there is now the obviously the there are there are some differences here and and it also depends upon the exact formulations these aren't the identical formulations but in the context of the work that I've done I feel that

02:22:34 work that I've done I feel that the uh St

02:22:38 the uh St work substantially valid validates the data that we obtained from BR and and that was legitimate to use that right there are there are differences in there there are minor differences yes but I'm seeking to I'm really just seeking to

02:22:49 seeking to I'm really just seeking to establish whether the differences that I've um rather hedly tried to point out to you are are significant do you think they are in the in the overall context of what we're doing I would say not right obviously if I'd had these data at

02:23:02 right obviously if I'd had these data at the beginning of this exercise I might have used used these numbers right I see and I don't think would make any substantially difference to my conclusions that's if that's the way we looking at now let me just let me just stick just one more go at something

02:23:14 stick just one more go at something slightly different but sticking with table three in your report and This I Promise will be easier um under well ventilated I conditions at five .4 we just have yes we have the hole of the

02:23:25 just have yes we have the hole of the right hand side please sorry we need to see the hole of the thank you yes so you got a five there of 0.4 to 0.8 right so that's well ventilated you've got a yield for carbon monoxide

02:23:37 you've got a yield for carbon monoxide for ldp of 15 yes yes and a yield for car for p of 48 which is three times more yes yes and

02:23:48 which is three times more yes yes and for underventilated flaming of 51 .5 to2 a yield for carbon monoxide for ldpe of 90 196 and for p 33 as we've seen 1.7

02:23:59 90 196 and for p 33 as we've seen 1.7 times greater um there there yes go on does that suggest that the PE will contribute less carbon monoxide than P insulation foam on a weight for weight

02:24:10 insulation foam on a weight for weight basis on a gram for gram basis yes and we what we need to look at is the page five of my mixed um

02:24:23 the page five of my mixed um figures which puts this all into some context which is the phase one report page

02:24:30 page 67

02:24:36 right phase one report page 67

02:24:58 no that's not going to be it let me try something 66 yes yeah uh well what we can find it from this well um the time is getting on we're fishing well anyway there just a point you got it you got it so what that

02:25:10 point you got it you got it so what that show one one at once please let me let's take this in stages um can we please go to page 66 of your phase one report Table Three Mass percentages of carbon

02:25:22 Table Three Mass percentages of carbon nitrogen and chlorine is that what you were after Professor no I was looking I wanted to show you the way the yields vary with the combustion conditions in the those graphs right uh let's then go

02:25:35 the those graphs right uh let's then go to the next page or two pages on 68 yes that's that's what so this is a plot from the BR data set for all these different polymers uh of the

02:25:47 different polymers uh of the relationship between carbon monoxide yield

02:25:51 yield uh on the top one and the uh equivalence ratio and what you can see here is I mean it looks very busy because we put lots of materials on here the yields obviously vary to some extent depending

02:26:02 obviously vary to some extent depending upon the elemental composition of the material the percentages of carbon in the material but the point is that if you have something particularly like PE simple polymer like PE as you can see at

02:26:13 simple polymer like PE as you can see at very very low Ultra efficient combustion conditions sort of thing you might have in your gas boiler at home the yield uh the uh it burns effectively

02:26:24 the yield uh the uh it burns effectively to carbon dioxide water and heat and there's very little carbon oxide produced that's perfect combustion conditions but as as the combustion becomes more um less well ventilated up

02:26:39 becomes more um less well ventilated up to the one which is the stoom metric mixture then you start to see this sort of sigmoid curve of increase in yield and so we have to think about the operating conditions that like to have

02:26:50 operating conditions that like to have occurred at various times during the Grenville fire which of course we don't know precisely because we haven't got the experimental data but I I think you'll find there's a paragraph in my report where I try to address this and I

02:27:03 report where I try to address this and I said well we're not going to have absolutely ideal perfect combustion conditions in something as messy as the grandall fire so I think we can reasonably rule out the equivalent ratio

02:27:15 reasonably rule out the equivalent ratio of 0.5 sort of scenario um on the other hand um particularly for the clouding insulation which is on as we discussed on the outside of the building we're not

02:27:26 outside of the building we're not talking about the right hand end the sort of equivalence ratios are around two or so there where there's only half as much air to burn the fuel as the fuel

02:27:37 as much air to burn the fuel as the fuel so we're somewhere we're operating somewhere in that middle region um and that's why i' I've put in in various points in my report various comparisons at equivalent ratios around one which I

02:27:50 at equivalent ratios around one which I I think is a a reasonable assessment of where some of this Burning may have occurred and somewhat more vitiated somewhere around about 1.3 up to a maximum about 1.5 so I think

02:28:01 1.3 up to a maximum about 1.5 so I think we're operating somewhere in that it's reasonable to say that we're operating somewhere in that middle region that's all I can say because we haven't really got the data I see understand uh yeah um now on the similar subject and just in

02:28:14 now on the similar subject and just in view of the time I wonder if we can take this as shortly as we can Professor but can I ask you to go to DPR 5 11 which is your phase two report section five paragraph 4 um page 43 table

02:28:29 five and you give there uh the uh two-bedroom flat potential Mass concentrations and gas concentrations from different fuels yes a and here if

02:28:41 from different fuels yes a and here if you look at it you see uh under total mass you have 90 for the ldp eacm yes and 79 9 G sorry kilograms uh for the P

02:28:54 and 79 9 G sorry kilograms uh for the P insulation for two-bedroom flat yeah for two-bedroom flat they kilograms in each case does that just on its own suggest that the carbon monoxide contribution from P would be higher than for

02:29:05 from P would be higher than for acmpe on the Assumption well on the Assumption of 100 com per combustion of both higher from the P yes for a lower Mass would sorry

02:29:19 the P yes for a lower Mass would sorry would it suggest that the contribution from of carbon monoxide from the P right when it's burning if it was burning under under the more well

02:29:31 burning under under the more well ventilated condition then we would expect a lesser a lesser contribution as we discussed from the PE than the P if it's burning under the somewhat more

02:29:43 it's burning under the somewhat more underventilated conditions are about the same I think it was yeah yes what what you're seeing though is the

02:29:55 the co PPM even though the mass is higher at 90 than P at 79 the CP oh yeah sorry I see I see we're getting at now 598 whereas the P insulation is at 2157 yes

02:30:08 whereas the P insulation is at 2157 yes uh and the fire where a fire is um yes un um less than one I well ventilated but where it's more than one I poorly ventilated it's up in the region of 6

02:30:20 ventilated it's up in the region of 6 yes and that's because I assumed in the in these calculations as I said in my phase one report I treated all the PE is burning in a more well ventilated way

02:30:31 burning in a more well ventilated way I've now uh shifted my position somewhat to to feel it could be somewhat more underventilated and therefore the contrib even out somewhat more and is that based on 100% combustion of both no

02:30:44 that based on 100% combustion of both no 100% combustion of the PE but 50% of the p right and that that is that is that is are those numbers taking into account the 100% combustion of the PE but 50% of

02:30:55 the 100% combustion of the PE but 50% of the P yes they do thank you uh right um then let's turn please in the same uh document back two pages to 41 page 41

02:31:06 document back two pages to 41 page 41 the underventilated case where the f is 1.4 to

02:31:11 1.4 to 1.5 and we've seen this before but just to go back to it you can see that for an underventilated case the mass loss concentration for p is 1.9 isn't it yeah

02:31:23 concentration for p is 1.9 isn't it yeah uh whereas for PE it's 3.69 in each case Gams per cubic meter yes can you explain why you concluded that almost twice as much PE burnt compared with the

02:31:35 much PE burnt compared with the p there 2 to 3.6 that is derived from the from the gas concentrations measured so that's a calculated result

02:31:46 measured so that's a calculated result yeah I know why that's come out like that but that's that's what that's way it is yeah does it affect the 50/50 figure that you've come to in terms of total contribution of of carbon monoxide in the

02:31:57 in the smoke so this is we're here talking about the the gases that were measured during that short period in the BR reconstruction test and then back

02:32:08 reconstruction test and then back calculating from the proportions of those gases as to what how much was burned in order to produce them yeah well these figures would suggest that for that

02:32:18 for that particular case we're seeing a somewhat greater predicted Mass loss of the PE compared to the P but not substantially

02:32:30 compared to the P but not substantially but yes we are seeing a slight difference there so that would imply potentially slightly more more involvement for the PE right in terms of amount burn right yeah and would that

02:32:41 amount burn right yeah and would that affect the 50/50 figure that you come to slightly yes right uh tilting in well which way would it tilt more towards the PE and less from the P so it means that it means that under the conditions of

02:32:54 it means that under the conditions of this test if we if we take that exercise that that that analysis that it would imply that they'd been somewhat more PE burnt during that

02:33:07 somewhat more PE burnt during that period of the fire to produce those gases but these are very indicative all these all these numbers now finally Professor you've calculated the mass burn of each element of the facade in

02:33:19 burn of each element of the facade in section five of your report uh we in this section in front of us at page 12 paragraph

02:33:25 paragraph 36 uh as about 50% we can see that yeah uh if we gave to the final sentence of paragraph 36 there you say from the my

02:33:37 paragraph 36 there you say from the my phase one analysis the mass burnt of PE was approximately the same as 50% of the P Mass say that these two materials contributed an approximately equal Mass to the exterior smoke plume can you confirm whether that estimate of the

02:33:48 confirm whether that estimate of the mass takes into account the fact that the Rainer Bond panels were fabricated in a cassette form at Grandfield Tower so that they covered a larger area no I didn't allow that I just based

02:34:01 area no I didn't allow that I just based it on the surface area the sort of the the area of the flat as it were so you're right I think that because the the the insulation is flat against the

02:34:14 the the insulation is flat against the surface of the building correct whereas the the PE is flat over the same surface but then has these bits bent around the sides that's what you're going to against I did not take that into account

02:34:25 against I did not take that into account and that would slightly increase the PE if you took that into account right are you able to measure that have you have you measured that in your no I haven't measured that no but I I I think I I when I looked at Professor bisby's work

02:34:37 when I looked at Professor bisby's work last week I thought about that and I thought well yes maybe that's that's why he he's taking that into account right I didn't no as a as a minor difference un an unknown right thank you very much um

02:34:50 an unknown right thank you very much um of course with the other thing I didn't take into account is that some of the PE has fallen away and dripped away and may not have burnt so you know there are these are all very approximate and there are various ways in which you

02:35:02 are various ways in which you can yes estimate them in different directions yes um Professor thank you very much I've come to the end of my prepared questions and indeed some I haven't prepared but uh uh I'm going to

02:35:13 haven't prepared but uh uh I'm going to ask the chairman to take the usual break with an apology that we've gone beyond the 4:30 Mark um to to you and to the panel that's an apology for me and I'm sorry about that um Mr chairman can we

02:35:24 sorry about that um Mr chairman can we take the usual break now yes I think you you understand D Professor that we have to have a break at this point so that Mr Miller can check that he's not left anything out and also that if anyone

02:35:35 anything out and also that if anyone else wants to suggest questions that we ought to put to you they have a chance to do that so there may be some more questions well there might be a few more questions but we're going to uh rise for 10 minutes right we'll come back at quarter to 5 okay and then if there are

02:35:48 quarter to 5 okay and then if there are any more questions we'll ask them thank you all right yeah thank you very much would you go the aser

02:36:02 please uh thank you Mr mik to five then please thank

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02:45:37 would you ask Professor P to come back in please

02:45:54 all right Professor well we'll see if there are any more questions for you show me yes Mr Mr chairman yes just a couple can I ask you please to be shown a a

02:46:07 sr5010 page 14 this is Professor St report paragraph or page

02:46:16 or page 14 uh and uh she here uh

02:46:21 here uh is uh identifying at paragraph uh

02:46:28 25 the extent of the fire damage to the facade and uh in the third line she says in a few places the outer aluminium composite panel remained intact

02:46:39 composite panel remained intact preventing direct inspection of the insulation uh and and then she goes on in par 26 in the case of the partially burnt in insulation there was a range of

02:46:50 burnt in insulation there was a range of fire damage location surveyed exhibited a a thin layer of chard Fame on the inner board B A thick chard layer with complete loss of the outer board or c a thin or thick CH layer on the outer

02:47:01 thin or thick CH layer on the outer board with the inner board remaining more or less intact yes uh and then paragraph 27 the remains of the facade around the columns was inspected and she explains what she

02:47:12 inspected and she explains what she observed there and then at 28 she says the insulation predominantly celotex rs5000 p but also Kingsman K15 phenolic foam was burnt to different degrees

02:47:23 foam was burnt to different degrees around the tower the P insulation foam boards appear to have responded to the thermal attack from the fire between two extremes of behavior and she identifies them there at a and b a on 14 over the

02:47:35 them there at a and b a on 14 over the page page 15 B thermal decomposition can we turn the page please

02:47:43 uh uh now um although she doesn't say it um

02:47:49 um she doesn't draw a distinction between the top of the tower or other other the places in the tower my question is to you to you is did you attempt to check whether the professor st's data was influenced by particular areas of

02:48:00 influenced by particular areas of significant damage yes I did to some extent she had one particular section where she she looked at what they they classified as uh plats of particular interest where close to the areas where

02:48:12 interest where close to the areas where people had died so really the the upper parts of the tower where there was a lot of Destruction right and um I'm looking in the in the overall so the

02:48:23 I'm looking in the in the overall so the overall figure she got was 51% loss of the insulation but when you look at the individual Flats in certain places there is some variation in this

02:48:35 places there is some variation in this it tended to be greater destruction of the column P than the spandrel p and as you say we've got these two layers and often the there was considerable

02:48:46 often the there was considerable charring of the outer panel of the two panels and the other one remain intact one thing I did notice though was that for the flat six column which I was

02:48:58 for the flat six column which I was particularly interested in the uh and it maybe to do with the way the fire spread rapid fire spread up the East face and then much slower spread around the rest of the tower the the uh P loss was

02:49:13 of the tower the the uh P loss was somewhat less than 50% for that that sort of set I I there some differences there so there was some variation around the tower the overall figure she came up with was about 50% overall right and and

02:49:25 with was about 50% overall right and and what would you agree well um put it this way is it possible that her 50% figure for the mass burnt would incorporate some margin of error or variation to

02:49:36 some margin of error or variation to account for the fact that more or less Pi are burned in different locations on the building depending on uh height and orientation well yes in different places there was different different degrees of

02:49:47 there was different different degrees of burning and she did C she did carefully catalog all that yeah

02:49:53 yeah uh now can I ask you please to go to DPR

02:50:00 to DPR 61 sorry 51 DPR 51 page n paragraph

02:50:09 26 and you say there a particular area of uncertainty is the proportion of fire and smoke

02:50:15 and smoke plume from the exterior fire penetrating the flats at eacho FLW and the proportion that Rose outside and Away above the tower the complexity and inherent variability of the construction and patterns of fire development at

02:50:26 and patterns of fire development at grenfell resulted in such uncertainty variability that the results of any full-scale fire test could not be considered necessarily representative of the conditions occurring in different Flats at grenfell Tower similarly

02:50:38 Flats at grenfell Tower similarly similarly the complexity of the construction and potential patterns of fire development meant that indeterminate variables affecting even sophisticated cfd comp methods would also give uncertain certain results that

02:50:49 also give uncertain certain results that may not adequately represent the variable patterns of fire development and smoke penetration at grandell this applies firstly to the early stages of smoke penetration as the exterior fire spread up the tower outside Flats six

02:51:01 spread up the tower outside Flats six then later to each room in each flat as the exterior fires spread around the tower um is it fair to say looking at that overall that your view is that the results of any modeling work would be

02:51:14 results of any modeling work would be inherently sensitive to the parameters which were inputed yes and that in a far as complex as grandell Tower it would be to put it at its lowest extremely difficult to derive accurate results

02:51:26 difficult to derive accurate results using such a method I mean I think you can do lots of quite interesting work on this and and it's not a complete waste of time to do it but I think the inherent

02:51:36 inherent uncertainties involved in trying to it's not really possible to use any specific approach to definitively say what happened yes uh would it be useful to use any such approach even to give you a

02:51:48 use any such approach even to give you a measure of confidence Beyond which you you you've already used I don't think so no no so doing modeling work would not inhance your your confidence level in the conclusions

02:51:59 your confidence level in the conclusions you've already reached is that is that where we leave it that's the position that was adopted by the inquiry team yes well what's your view

02:52:10 well what's your view uh I think it would be it would be interesting to have done some work of this kind but I respect the decision to regard the

02:52:21 inherent uh variables and things involved that it would not really assist the inquiry to come to a decision so that I respect that point I understand thank you that's very helpful uh well

02:52:32 thank you that's very helpful uh well Professor it only remains for me to thank you very much for your opinions for your uh lengthy reports all of your work and for your in uh unstinting

02:52:43 work and for your in uh unstinting assistance to the inquiry both before the last two days and over the last two days we are extremely grateful to you you've illuminated much which was previously dark to us so I'm extremely

02:52:54 previously dark to us so I'm extremely grateful thank you very much and Professor it's right that I should thank you very much as well on behalf of the panel you've given a great deal of time and effort to assisting the inquiry both in Phase One and even more so in phase

02:53:06 in Phase One and even more so in phase two you've uh given us a lot of your time to explain and elaborate upon your report and as Mr milet says you've supported us in other ways as well so we

02:53:17 supported us in other ways as well so we are truly grateful you for all the uh support you've given us and the time you've given us so thank you very much indeed well I hope it's been been some uh assistance and uh I would like to

02:53:29 uh assistance and uh I would like to thank you for giving me the opportunity to to assist in this way and Mr Millet for managing to get through all the material in front of him in the time available thank you it's been a pleasure thank you very much thank you and now of

02:53:41 thank you very much thank you and now of course you're free to go thank very much I I'll get the car ready for Cornwall oh good we'll have a good time than you thank you right well you'd like to go the much that's it thank

02:53:57 you well thank you Mr mlet that uh concludes the hearing for today uh no I think oh no no it doesn't I'm afraid um I've got one very short duty to perform

02:54:09 I've got one very short duty to perform I'm afraid uh because this is formally the end of module 7 yes and as you as you know at the end of module 7 we have a read in a further witness statement um and um I shall um uh do that very

02:54:23 um and um I shall um uh do that very briefly

02:54:25 briefly um U by reading the um references in um first um me0 389 38 me0

02:54:36 first um me0 389 38 me0 39829 PSB

02:54:40 39829 PSB 41379 me30 39843

02:54:45 39843 DCd which is Dubai civil defense uh 6 70's 1 uh C 70 is1 m30

02:54:58 C 70 is1 m30 13227 lfb 0123 673 lfb1 23795 me30 39844 me30

02:55:09 23795 me30 39844 me30 39932 me01 3116 and me0

02:55:17 me0 39845 uh there's normally an idx number which accompanies that which which would have been shorter but I'm not sure we have it yet and if we do I don't have it well thank you very much and all those

02:55:28 well thank you very much and all those documents will form part of the evidence before the inquiry and will be taken into account in due course thank you good thank you very much well we've sat much later than we usually do uh

02:55:39 much later than we usually do uh particularly at the end of the week and I think I should once again as I say Not For the First Time thank those who support our hearings I'm thinking particular of the stenographer uh

02:55:50 particular of the stenographer uh document manager and those who are responsible for live streaming our work we do rather presume on their good nature when we overrun it this way but it's right to say that we're very grateful to them uh for all that they're

02:56:03 grateful to them uh for all that they're doing for us um at that point we shall rise for today we shall sit again on Monday next week the 4th of July at 10:00 when we shall embark on module 8

02:56:15 10:00 when we shall embark on module 8 thank you Mr thank you very much 10:00 on Monday next week for

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