Expert Evidence - Prof Purser (29 November 2018 Pt 2 of 2)

Full transcript

00:08:49 you

00:09:52 all right better ready to carry on yes good thank you very much okay yes thank you

00:09:58 you right I know you've got some questions to put to me so I'll try and keep this as brief as I can I would like to reassure this is a somewhat short presentation for anyone this morning so

00:10:09 presentation for anyone this morning so sorry no no thank you so in this one I want to address the possible toxicity performance for materials present at the ground floor tower and in doing this I

00:10:23 ground floor tower and in doing this I want to emphasize that the statements and constant calculations things and the numbers I'm presenting you intended purely to be sort of indicative of the

00:10:34 purely to be sort of indicative of the possible conditions that could be produced and really what I'm trying to address here is essentially a sort of qualitative question which is taking all

00:10:46 qualitative question which is taking all these different individual materials including the cladding the insulation the window structural materials and the contents each of these individually or in combination have they become involved

00:10:58 in combination have they become involved in far outsider if you like a typical or an example sector a two-story two-bedroom flat could they have produced hazard hazardous conditions in

00:11:10 produced hazard hazardous conditions in the flat and a Lobby beyond and particularly here I'm looking at a sort of snapshot in time early in the fire when the fire is breaking into flat six on every floor and then the smoke is

00:11:23 on every floor and then the smoke is going beyond into the lobby and it's this sort of period up to around 8 o 130 hours when the lobbies filled with a dense irritant smoke that was so

00:11:34 dense irritant smoke that was so important in affecting the potential of escape for people who are remain in their flats that time so it's this kind of 130 ish period that's sort of in the back of my mind so what is the

00:11:46 back of my mind so what is the contribution of any burning material to toxic hazards a Grenfell it will depend on the obviously on the extent of their combustion products the expense or the extent to which their combustion

00:11:58 extent to which their combustion products from part of the time concentration curves for toxic smoke and gases inhaled by each at various locations and times in the tower and and this depends upon the mass

00:12:13 tower and and this depends upon the mass burning rate how many kilograms of any particular fuel are consumed each second and then it depends on the yields of smoke and toxic products from those

00:12:24 smoke and toxic products from those fuels when they burn for example how many kilograms of carbon monoxide is produced when each kilogram of material is burned and then it depends on the

00:12:35 is burned and then it depends on the volume into which those products are dispersed such as the interior volume of an enclosed flat and that gives us a term called mass loss concentration kilograms per meter cubed it's a number

00:12:48 kilograms per meter cubed it's a number of products from that material disperse say into the volume of this room now what what can determines the yields of smoke and toxic gases from any burning

00:12:59 smoke and toxic gases from any burning material well firstly it depends upon the elemental composition of that material how much carbon hydrogen oxygen nitrogen chlorine bromine phosphorus and

00:13:10 nitrogen chlorine bromine phosphorus and possibly inert fillers this material is composed of secondly it depends on some to some extent on the organic composition what kind of polymer is it

00:13:21 composition what kind of polymer is it something like polystyrene for example of polyisocyanurate they behave differently in the way they behave polystyrene for example because it's aromatic composition Ezreal produces

00:13:34 aromatic composition Ezreal produces very high yields of smoke particulates when it burns and flame-retardant additives can also have a large effect on the type of combustion and the

00:13:45 on the type of combustion and the products you get but then thirdly and very importantly it depends on the combustion conditions as I explained this morning the flaming fires is the fuel to our equivalence ratio whether

00:13:56 fuel to our equivalence ratio whether it's well-ventilated or under ventilated that can have a big effect on the yields toxic products now for developing in hazards on inner Grenville flat I've

00:14:07 hazards on inner Grenville flat I've identified three main fuel what I call fuel packages of interest the first one is the combustible parts of the rainscreen cladding and the insulation

00:14:19 rainscreen cladding and the insulation basically outside the flat so that's the Reina bond the seller text panels on the spandrels and the panels on the columns secondly you've got the combustible

00:14:31 secondly you've got the combustible parts in the window surround and between the windows so you've got the exterior infill panels which were expanded polystyrene and you have the window

00:14:42 polystyrene and you have the window surround consisting of this nine point five millimeter thick PVC uPVC sills and new exterior bits quite a large amount

00:14:54 new exterior bits quite a large amount of material in that there are lots of other smaller components that dr. Lane for examples and profits are basically have set out in their reports now so far

00:15:05 have set out in their reports now so far I haven't continued consider the contribution for many of those because they're fairly minor ones so for our concentrate on the major fuel packages but I could use that and then of course

00:15:16 but I could use that and then of course once the fire has moved beyond the windows into the flat you've got a very large fuel mass consisting of the contents of any particular flat so just

00:15:27 contents of any particular flat so just to remind you this is from Professor Business Report these are some of these structural materials this is the three millimeter p/e in the cladding this is the PR PIR installation which is two

00:15:40 the PR PIR installation which is two forms 100 millimeter thick single layer on the columns and two 80 millimeter thick layers on the spangles this is the polystyrene which is quite thick but

00:15:53 polystyrene which is quite thick but it's a very light density foam and then you have the very dense very heavy material which is the PVC which is about nine and half millimeters thick but they were quite deep sills so these are

00:16:06 were quite deep sills so these are mainly the main materials are considered other than the contents of the flat just to remind you where they are then so these are these XPS panels between the windows and here is the cladding and of

00:16:19 windows and here is the cladding and of course the insulation is behind it this is a lower part that tower where there's been limited damage but a top of the tower there this is police business report you can see that

00:16:33 report you can see that there's been considerable loss of these materials that will go into way so pretty well all the rainscreen cladding is gone and a considerable amount of the

00:16:44 is gone and a considerable amount of the PIR installation however as you can see here there's quite a bit of charred PIR still left on some of these flats particularly the spandrels although the columns are pretty well bare now this is

00:16:57 columns are pretty well bare now this is adoption when this photograph was taken but of course I'm aware that I certainly when I went to see the tower a year on we're seen at that time and so I can't

00:17:10 we're seen at that time and so I can't say exactly what is there immediately after fire but there may be photographic evidence of that which I haven't yet been shown then inside the inside the

00:17:22 been shown then inside the inside the flat we've got the PVC serenus around and this illustration is from dr. lanes report showing how the fires come in around the window frame and has started

00:17:34 around the window frame and has started to decompose this PVC this is a very small amount of all this was actually in flat 15 but I'm afraid you can't see it Tony well but this is from I think it's

00:17:45 Tony well but this is from I think it's bisby's report which shows or movies Toreros I forget Bo but it shows that over there where some of this PVCs Mudman had a much more destruction now

00:17:58 Mudman had a much more destruction now in order to estimate the potential hazard from these the first thing I needed to know is how much material is there and so I took the dimensions I had to work out the area for all these

00:18:10 to work out the area for all these panels on the exterior and I took the dimensions from professor Bisbee's report to calculate the area and then from a thickness I could work out the

00:18:21 from a thickness I could work out the volume and by using figures for the density the material I could work out the mass so what I'm trying to work out here is what is the mass of these various components in this case of the exterior materials outside a typical one

00:18:36 exterior materials outside a typical one or two bedroom flat now for the flat contents it's much more difficult because every flat is going to have different contents we don't know what was in the Conte seviche individual flat so I haven't

00:18:49 seviche individual flat so I haven't detailed how I've done this but basically I had to come up with a figure for the typical fuel load in a flat and it's sort of average composition so I

00:19:00 it's sort of average composition so I went through an exercise of assessing this typical amount of furniture you'd have in a typical flat terms of mass all the different items cupboards doors

00:19:11 the different items cupboards doors wardrobes beds everything I could think of even appliances to come up with a sort of overall total fuel combustible fuel over flat and from my knowledge of the composition of those materials from

00:19:23 the composition of those materials from work when you've done at VRE and the approximate composition of these materials for example if you have a wooden cupboard it's made of wood if you have a sort of composite one than it

00:19:34 have a sort of composite one than it probably MDF or something like that which I know the composition of so I can work out the mass of carbon in these various items and sumit to form find the total proportion and mass of carbon in a

00:19:46 total proportion and mass of carbon in a typical fuel load and the same for nitrogen and I've also done that for chlorine so having gone through that exercise and I will try to detail how I

00:19:57 exercise and I will try to detail how I arrived these figures more comprehensively my phase to report this is what I've come up with and I'll say what I'm looking for here is not the exact figures it's the sort of relative

00:20:10 exact figures it's the sort of relative amounts have we got a large amount of something or a small amount that might be trivial in comparison for example with the combustible fuel load in the flat and I'm going to focus here on

00:20:21 flat and I'm going to focus here on two-bedroom flats because most people who took refuge were in two-bedroom flats so for a two-bedroom flat then according to my calculations which are

00:20:33 according to my calculations which are very preliminary and subjects of me checking them and looking for more information I'm estimating that there's about 158 kilograms of PIR in the

00:20:45 about 158 kilograms of PIR in the insulation outside each two-bedroom flat or quite a large area the LDPE although it's only three millimeters thick is much denser than the

00:20:56 much denser than the PIR and so actually quite quite a large mass of LDPE the XPS though is that quite a small amount so we would expect that not to contribute too much the PVC

00:21:09 that not to contribute too much the PVC and somebody's queried this and I must admit I'm a little bit surprised according to my calculations and there was a lot of it there and it's very heavy very dense material there's about a hundred and eighty four kilos of PVC

00:21:24 a hundred and eighty four kilos of PVC in the window surrounds all the windows of a typical two-bedroom flat in the tower when we come to the flat contents this of course is by far the largest total item so I would say that the flat

00:21:40 total item so I would say that the flat content is going to be about six hundred and sixty kilos of contents but what this shows is that the PIR on the LDPE and the PVC are quite large significant

00:21:54 and the PVC are quite large significant amounts in the context of for example a total flat fire load and I keep going back to my five to seven kilograms is enough to burning in to a flat is enough

00:22:05 enough to burning in to a flat is enough to cause a hazardous atmosphere right and we're talking about hundreds of kilos here so having got the total

00:22:18 kilos here so having got the total masses of materials I then need to know what they're made of and I've taken data from from our work and this is all in the report but essentially I've identified some

00:22:30 but essentially I've identified some individual materials here that we're interested in and then you see I've got a row for the mixed flat contents and also for comparison cut in plight

00:22:41 also for comparison cut in plight plywood and polyurethane excuse me foam which is in our posted furniture and so what you can see immediately of course is that all these materials have a high

00:22:53 is that all these materials have a high carbon content the lowest being PVC but and so that means that when they burn they will all produce a certain amount of smoke particulates which if based

00:23:06 of smoke particulates which if based carbon based and they will all produce a certain amount of carbon mono side and carbon dioxide but the carbon monoxide will depend a bit on the conditions under which they're combusted

00:23:17 conditions under which they're combusted with regard to fuel nitrogen PIR stands out as having quite a high nitrogen content and the other main item with nitrogen is the upholstered furniture

00:23:28 nitrogen is the upholstered furniture the polyurethane foam and some extents and fabrics and things in upholstered furniture in plywood and MDF things like

00:23:40 furniture in plywood and MDF things like that it's not pure wood you have certain resins and things in but you also have a little bit of nitrogen as you can see there so for the mixed flat contents taking all the sorts of things you'd

00:23:51 taking all the sorts of things you'd find in a flat my estimate is overall about 50% of the mass being carbon and about 3.7 percent nitrogen and little bit of chlorine now the next thing we

00:24:05 bit of chlorine now the next thing we have to consider is the combustion conditions because I've said that will affect the yield of toxic products well the LDPE cladding and the XPS panels are burning mainly in open air on

00:24:18 panels are burning mainly in open air on the building exterior so I've estimated that they will be combusting under reasonably well ventilated combustion conditions the PIR insulation burning in

00:24:30 conditions the PIR insulation burning in the cavity is more complicated as I explained this morning and I believe as long as it's in the cavity there's a probability that it will be burning

00:24:42 probability that it will be burning under a somewhat under ventilated combustion condition but when the cladding falls away and exposes the PIR then of course it's open to the air and will transition to a well ventilated

00:24:55 will transition to a well ventilated combustion condition and I we at the moment we don't know what the overall combustion condition was for most of the combustion of PR this could be resolved

00:25:07 combustion of PR this could be resolved potentially by some form of testing specially if we feel it was appropriate to do so but for the purposes of my indicative assessment here I've because we don't know I've used

00:25:19 I've because we don't know I've used both cases so I put in data for if it all was well ventilated and if it was all under ventilating this truth should be somewhere between to the PVC window surround was initially

00:25:32 PVC window surround was initially well-ventilated but the thing about PVC is that unlike other materials where the yield goes up like that with vitiation PVC has a fairly flat yield across the

00:25:45 PVC has a fairly flat yield across the whole of its range so because of the halogens in PVC when it burns it produces high yields of carbon monoxide even under well ventilated air conditions and when it's vitiated it

00:25:57 conditions and when it's vitiated it doesn't really make any difference in all it's more or less the same throughout the road so I've assumed a fairly well ventilated combustion conditions but it doesn't matter when contents become involved by then I've

00:26:11 contents become involved by then I've estimated the conditions would be already under ventilated so I've treated all the flat contents that I've used as being under this under ventilated condition smoke and toxic gases have

00:26:23 condition smoke and toxic gases have derived from the data that are produced at BRE and years ago and the smoke these are for generic materials by the way none of these numbers are for the actual

00:26:34 none of these numbers are for the actual Grenville materials but they're for the same general type of polymer so they should be substantially similar but they're not what so far we haven't done any testing on actual grain Palmateer

00:26:47 right okay so from all this I'm then produce this table so I'm going to talk you through but to start with just go back to the scenario so the first stage

00:26:59 back to the scenario so the first stage of course I said this morning is you've got this dilute smoke plume diluted smoke

00:27:04 smoke flowing up the side of the tower which is not particularly hazardous where things become potentially has this is when the fire arrives at the level of your flat our two bedroom flats I

00:27:16 your flat our two bedroom flats I believe are the most vulnerable because they have a much greater mass of cladding insulation and windows surround material because they go around the corner of the tower so the time to

00:27:28 corner of the tower so the time to untenable conditions then depends on the area of the flat exterior and the windows involved and the timing and extent of Farr involvement of the contents

00:27:38 contents now this table shows potential contributions from materials to toxic hazards in two-bedroom flat and potentially the lobby beyond if the door is open or it's leaking

00:27:49 is open or it's leaking the first Burnie so now we have to consider the order in which these things get involved so the first burning materials generating toxic smoke into the flat are likely to be the LDPE rainscreen

00:28:02 likely to be the LDPE rainscreen cladding and the PIR insulation because the fire is coming up the outside of the building involving these materials first and you remember I was talking this morning about this various routes of ingress of penetration of flame and

00:28:15 ingress of penetration of flame and smoke around the windows and things that dr. Lane has explained to us so the next thing we need to consider is how off

00:28:27 thing we need to consider is how off this burning material on the outside of the tower what proportion of the products from what proportion of the mass comes into the flat and how much

00:28:38 mass comes into the flat and how much goes up the outside of the tower and blows away over London so and we don't know I don't know whether anybody could model this but it's a question now what

00:28:50 model this but it's a question now what the extremes of course are that we could assume that none of it goes into the flat but that's patently not the case because we've lots of descriptions from occupants of smoke actually coming in and we have dr. lanes analysis the other

00:29:03 and we have dr. lanes analysis the other the other extreme we could make is that all of it goes in the flat well that's obviously also ridiculous because we know a lot of the smoke has gone up at the outside so it's somewhere between

00:29:14 the outside so it's somewhere between the two now I've used quite a conservative estimate for these materials and I've assumed that of the mass that's burning the product from

00:29:26 mass that's burning the product from only 5% a twentieth of that mass find their way into the flat a 95 percent of the smoke is going to go up and away not be involved I've also though looked at

00:29:41 be involved I've also though looked at the effects of a case where only 1% goes in and I'll talk a bit about that in a minute

00:29:46 minute but for the moment for the purpose of these calculations I've estimated about five percent and I don't think that's unreasonable

00:29:58 now the other thing is how much of the material is burned during the fire particularly at this stage this early stage now from what I've seen from the

00:30:09 stage now from what I've seen from the other experts and looking at the tower now most of the rainscreen cladding is gone so for the purposes of this calculation I've assumed that a hundred percent of the polyethylene has been

00:30:23 percent of the polyethylene has been burned now of course some of it fell away some of it dripped away so in reality it might be somewhat less slightly less than I'm saying but that's what I've done for the purpose of these

00:30:34 what I've done for the purpose of these calculations however because it's all burning on the outside the tower it's going to produce low yields of CO now when you look at the PIR installations I showed you on the photograph

00:30:46 showed you on the photograph most of the PIR installation on the columns has gone this is a year on of course but it's not there now and most and we've got two layers of PIR on the

00:31:00 and we've got two layers of PIR on the spandrels and from from what I've seen politically when I've been to the tower and some of these flats the at least the outer layer is gone representing about 50% of the spandrel PIR mass so for the

00:31:16 50% of the spandrel PIR mass so for the purposes of these calculations I've assumed or estimated that 50% of the PIR has been burned during this stage of the

00:31:28 has been burned during this stage of the fire so 50% of its burned all of that 50% 5% of the products find their way into the flat over this short period the

00:31:39 into the flat over this short period the next materials to be involved are the other more that's at the same time actually it's the XPS panel but again that's burning under well-ventilated conditions and it's a small mass but

00:31:50 conditions and it's a small mass but I've again I've assumed 5% of those products also find their way into the PVC is all going to be generated into the flat when it because it's inside the flat now but for

00:32:02 because it's inside the flat now but for the purpose of calculation I've taken a sort of point in time where the destruction of these sills her has has burnt 5% of the PVC so sort of early stage of penetration and then the next

00:32:14 stage of penetration and then the next stage is going to be to involve the flat contents and at this early stage I've assumed that 0.5% of the flat contents a

00:32:25 assumed that 0.5% of the flat contents a small amount at this point in time this snapshot of time that I'm analyzing has been burned so that's sort of a quarter of an armchairs worth has got involved now maybe near the window at this stage

00:32:38 now maybe near the window at this stage and that's what I've used to create the numbers in the tables let me just talk you through this table a little bit so the first row in the table represents the yes

00:32:49 the yes the LDPE so I'm assuming it's burning under a well ventilated condition and then the mass must burned or outside

00:33:00 then the mass must burned or outside each fat is 90 kilograms five percent of that is 4.7 kilograms so it's the product from this four point seven that we're worried about dispersing out into

00:33:11 we're worried about dispersing out into the volume of the flat gives us that mass loss concentration and from the yield data I can then calculate what the concentration of carbon dioxide would be in that flat and the numbers I'm coming

00:33:23 in that flat and the numbers I'm coming up with is three and a half percent which is not hazardous there's also some carbon monoxide but it's quite a low concentration and there's no cyanide because there's no nitrogen in PE but

00:33:35 because there's no nitrogen in PE but the bit that is important is that I'm finding count the smoke in terms of visibility and I'm estimating that the visibility in the flat at a time when

00:33:46 visibility in the flat at a time when you burn five kilograms four point seven kilograms of LDPE is 0.25 a meter hands in front of your face so the LDP on its

00:33:57 in front of your face so the LDP on its own could produce dense smoke in the flat and by inference the lobby beyond the flood scientist fixture is calculated using my Fe D equations for these gases and you see it's a long time

00:34:09 these gases and you see it's a long time one hundred and sixty minutes so so the main hazard that we're getting from the LDPE is just the smoke the irritant visibility smoke moving on to the PIR

00:34:21 visibility smoke moving on to the PIR you'll see I've got two rows here and the upper row is assuming that all the PIR so it's oh right sorry I'll talk you through it again so I've got 79 kilograms of PIR so that's the 50% that I'm starting with

00:34:32 that's the 50% that I'm starting with and then 5% of that is coming into the flat and similar concentration as the PE and then you've got two rows of gases

00:34:43 and then you've got two rows of gases and the upper rows for the well ventilated case so this is all burning under well ventilated conditions because the PIR has a significant halogen

00:34:54 the PIR has a significant halogen content it means that it always burns under somewhat inefficient manner and as you can see here we're getting quite high concentrations of CO and cyanide in

00:35:07 high concentrations of CO and cyanide in the flight even under the well ventilated case and also quite a lot of smoke such that if that mass was dispersed into the volume of the flat I'm calculating that somebody would

00:35:18 I'm calculating that somebody would become unconscious after 23 minutes if it was all burning in the under ventilated case then we've got more it's fixing gases and that time comes down to only a couple of minutes now of course

00:35:30 only a couple of minutes now of course if we think of this as a flat six we know that nobody died in a flat 6 or collapsed in a flat 6 and that's because they all had time to get out before

00:35:42 they all had time to get out before these conditions developed so what we know for flat 6 is that although these gases were generating into the flat and particularly after people had left these

00:35:56 particularly after people had left these gases have had no effect on their ability to escape because they all escaped into the lobby at least taking the polystyrene not much coming off that

00:36:07 the polystyrene not much coming off that but a bit of smoke PVC window though on the other hand is quite a significant hazard because it produces very high concentrations of carbon monoxide it doesn't reduce any cyanide but it does

00:36:19 doesn't reduce any cyanide but it does produce a high concentration of hi dear ATandT hydrogen chloride gas and a lot of smoke and it would cause on its own could produce incapacitation it

00:36:32 its own could produce incapacitation it was in about 13 minutes and then you've got the small bit of flat contents that I've assumed has been decomposed up to this point and because of their

00:36:43 this point and because of their furniture in that pod a lot of CO and cyanide typical domestic furniture fire essentially a lot of smoke you could survive that for about 10 minutes if you did if you stayed and breathed it well

00:36:54 did if you stayed and breathed it well you could before you're incapacitated so the breakdown is that the toxic product from each material considered alone the

00:37:06 from each material considered alone the LDP on its own will produce dense smoke but low concentrations of carbon dioxide PA are on its own dense smoke CO and cyanide polystyrene a little bit of smoke PVC a lot of smoke Arjun chloride

00:37:21 smoke PVC a lot of smoke Arjun chloride and carbon monoxide and the flat contents smoke carbon monoxide and cyanide and of course these things aren't decomposing individually they're all decomposing together so all these

00:37:32 all decomposing together so all these effects are summed so because of that I I feel quite strongly that these all these structural materials but you are being involved in the early stages think

00:37:44 being involved in the early stages think I'm thinking again in my mind of a flat-six situation are producing capable of producing rapidly high concentrations of smoke inside a flat 6 and the Lobby

00:37:58 of smoke inside a flat 6 and the Lobby beyond so if we think of the sort of scenario at 1:30 when that Lobby is filling with smoke my feeling is that most of that smoke at that time is

00:38:10 most of that smoke at that time is coming mainly from these structural materials burning outside the flats particularly flat 6 and this is predicted even if there's no involvement up to that time of the flat context well

00:38:23 up to that time of the flat context well that's the end of my presentation yeah well thank you very

00:38:29 yes mr. Allen professor can we deal and would you like to take a seat oh thank

00:38:42 would you like to take a seat oh thank you

00:38:42 you could we start then with with the last part of your presentation part three and can I ask you just pick

00:38:57 part three and can I ask you just pick up on the last point you were saying that you you talked about the stroke contribution from structural components

00:39:08 contribution from structural components which would happen irrespective of flat contents yes in your report and I can take you to the paragraph if you want it but you've mentioned that at some point

00:39:19 but you've mentioned that at some point in this process flat contents will become a predominant source of toxic gases yes just yes that you reminded me of something I should have said so moving on from the point I got up to in

00:39:30 moving on from the point I got up to in my presentation subsequent to that particularly after round about two o'clock the smoke being generated in the flats and coming to the lobbies is going to be dominated by the contribution from

00:39:42 to be dominated by the contribution from the flat contents and subsequently most of the smoke in the lobbies throughout the fire is going to be dominated by in origin by the burning flat contents with

00:39:54 origin by the burning flat contents with some contribution from the cladding of things but so this situation moved on sorry to interrupt is it well and that prompts my question is in your in the answer you've just given you said sometime after 2 o'clock yeah what's the

00:40:08 sometime after 2 o'clock yeah what's the basis for you giving that time right I suppose I'm referring back to my situation this morning there right there are a couple of things going on here one

00:40:20 are a couple of things going on here one is that with the main the main thing is because we we have photographs from the outside of the town around about that time I thought I had one to show

00:40:33 time I thought I had one to show somewhere but I showed it this morning I think I showed you one this morning where with some that thing so we're going to see the outline of the windows bright with with flame inside indicating

00:40:44 bright with with flame inside indicating serious fires inside those flats and if there's a serious fire like that inside the room that that can must be the burning contents was that B that was the

00:40:57 burning contents was that B that was the Luke Bisbee photograph you showed in your second party marked with the timer's closer to 223 a yes the one but

00:41:08 timer's closer to 223 a yes the one but in terms of flat contents playing a role what's the basis for saying that two o'clock applies to all flats no it doesn't sorry one thing that's really

00:41:20 doesn't sorry one thing that's really starting to show up more is more than we look into this there's quite a variation between the extent and timing of penetration of fire to involve the contents of different flats up and

00:41:33 contents of different flats up and around the tower so there's there's a variation but some some flats at around this time quite a lot if you look at the pictures and I think professor torero

00:41:44 pictures and I think professor torero has given us a breakdown of this had gone to full involvement but others hadn't but applying logically and if you

00:41:55 hadn't but applying logically and if you take a flat surface as an example where you've you've spoken about flat six today and talks about and let's take an example of flame and coming in through the kitchen window yeah would if you

00:42:08 the kitchen window yeah would if you have flat contents on on the kitchen counter for example or in the area of the kitchen with flat contents not immediately begin to play a role yes I mean we owe America again going back to

00:42:19 mean we owe America again going back to flat sixth mine because I've looked at this a bit more in detail because I'm interested in this early development if you read the witness statement from various occupants of for example the flat 60s all the way up column the tower

00:42:32 flat 60s all the way up column the tower you'll see that there's quite a variety of I thought I'd said this but anyway I'm gonna say it now it's quite a variety of ways in which smoke and or flame first breaks into those flats so

00:42:46 flame first breaks into those flats so typically these people were alerted at quite an early stage and they went in today their kitchen and then they described what they saw and some people said I saw flames coming

00:42:57 and some people said I saw flames coming around the windows or through the windows

00:43:00 windows some people said I there was a crack in the window fell out some people had a window open some people however quite a lot of people his first experience was of smoke two people I remember reading

00:43:14 of smoke two people I remember reading describe the early stages of involvement of the curtains and blinds around the window one person I forget who it was said they actually pulled these things

00:43:26 said they actually pulled these things down stamp them out another person had some kind of curtain up between the kitchen and the sliding door stir lounge on this curtain caught fire so there were certainly some instances of some

00:43:38 were certainly some instances of some materials in the vicinity of the windows in some cases being involved at quite an early stage so I think we're going to see a variety and would it be fair to

00:43:49 see a variety and would it be fair to say that what we've got to remember is is the point you've made from your bre experience that you just need five to seven kilograms of mitt of a material during that combusted to be getting

00:44:00 during that combusted to be getting gases which are hazardous yes and obviously the kind of gases generated would depend on the material of course but I think you described it in your

00:44:11 but I think you described it in your first presentation as a third of half an armchair so it's a road to a heart to a third to a half of an armchair it would be in a in the enclosed volume of a house or flat and what can I take you

00:44:24 house or flat and what can I take you back just to again we're sticking with what you were just discussing recently but just to kind of again ask you a few more details about the processes you've

00:44:35 more details about the processes you've outlined in that presentation and it might help if we just look at your report can we have please dapr 6 zeros one at page 63

00:44:56 Griet spam paragraphs 204 to 206 please

00:45:04 in these paragraphs professor this is where you're you're setting out your analysis of what you've described as the three fuel packages of interest and we

00:45:15 three fuel packages of interest and we see that in each of them if we look at you you've given an estimated density yes could you explain or can you explain how you come to estimate these densities

00:45:27 how you come to estimate these densities yes I can I slightly apologize for not having really had tying it to set all this out in my report I will put all that there of all the sources of all this information all I'm hoping to find

00:45:39 this information all I'm hoping to find better informations it's all very preliminary but basically what we the main information or the the areas and volumes come from the other expert reports but the density but I in order

00:45:51 reports but the density but I in order to work out the mass I needed a term the density and I came across a data sheet for Celotex which told me the density of

00:46:03 for Celotex which told me the density of the hundred and the eighty millimeter thick foam so many 3.8 kilograms per meter squared or something like that for those panels so that's the source of my

00:46:14 those panels so that's the source of my density data for those okay and that was being provided to me I think it's a met document it's been provided to me with those information in and for the rana

00:46:26 those information in and for the rana bond rainscreen cladding I don't have a figure for that so I I I looked up I think I got it from the BPF website but I can't more exactly but I

00:46:37 website but I can't more exactly but I looked up typical figures for the density of PE it's about density of one because it's smallest floats so I've worked with it a lot myself and I've used that so that's an estimated figure

00:46:48 used that so that's an estimated figure and so what we can if if necessary what we can do of course now we have samples from the tower that we can measure the exact density of all these materials but

00:46:59 exact density of all these materials but I don't have that information as you so I've had to estimate so is this something that you could consider doing for phase 2 yes could I ask you to pick up one one thing in paragraph 206 just

00:47:11 up one one thing in paragraph 206 just can you explain how you come up with a mass of twenty six point two six kilograms per window there's a lot isn't it

00:47:19 it yeah well the it's what I've done is I've worked out the I found a figure not I must admit I've forgotten where I got

00:47:31 I must admit I've forgotten where I got it from now for the I think I measured it off one of the plans for the depth of the silt from memory it's something like 36 centimeters or something anyway so

00:47:43 36 centimeters or something anyway so I've got a figure for the depth I know the perimeter distance so from depth times the perimeter distance that's the area of PVC paneling around each window

00:47:54 area of PVC paneling around each window I know that it's nine and a half millimeters thick from Bisbee and then I needed a density so again I've looked up to find out you know what I cannot I've

00:48:06 to find out you know what I cannot I've used a figure I think of 1.5 grams per centimeter cubed but that's unless that's what I've used so far it could be

00:48:17 that's what I've used so far it could be slightly less but I think that's the reason to figure it's very heavy stuff previously because all the chlorine in it so and then when I multiply that up by the number of windows and the area that's the mass that I'm getting I did

00:48:29 that's the mass that I'm getting I did try and check it last night I'm still at the moment I'm still sticking to that figure but arithmetic is always a weakness can always be a witness until I will be thoroughly checking all this

00:48:41 will be thoroughly checking all this obviously please - could we go to pages ahead in your report please to page 65 and look at Table two

00:48:58 as we can see it's headed composition of test materials and you've explained it in your report the explanation you've

00:49:10 in your report the explanation you've given is a paragraph 2 1 3 which is on previous page yeah but you explained that it shows net heat of combustion yeah and this stereo stereo key metric oxygen demand and hello.mat composition

00:49:23 oxygen demand and hello.mat composition of 14 common polymeric polymeric materials used in furnishing building products I think what you've done is taken materials that were would have appeared or been in use at the tower and

00:49:34 appeared or been in use at the tower and also would appear in flat contents well actually this yeah I've selected from that list but that list is the list of tools that we tested at BRE where we measured all these Parmenides they

00:49:47 measured all these Parmenides they measured and can you explain the term state stereo it's the amount of oxygen you need to burn each gram of material

00:49:58 you need to burn each gram of material to completion and why is that important to the calculation that you were doing not it's not it's important and it just happened to be in the table and it's used for other purposes in our calculations if we could have the whole

00:50:12 calculations if we could have the whole page and I draw your attention to what you've said in paragraph 215 and you're you're speaking there to the two most important combustible polymers any

00:50:25 important combustible polymers any experiment the two you give are the low density polyethylene and the polyisocyanurate why are they the most

00:50:36 polyisocyanurate why are they the most important combustible polymers in terms of smoke toxicity their most important because there's so much of them there's a large mess

00:50:47 the most important as an input to the toxicity calculation because there's so much to consider as I've described in other words the XPS for example as I said is a small amount of material

00:50:59 said is a small amount of material therefore less significant what you've said your report is that the main relevance of the data that you've set out in table two is one one's reading is

00:51:11 out in table two is one one's reading is firstly and I touched on this in your presentation is carbon content yes because that affects generation of smoke particulates and carbon oxides including carbon monoxide yep during combustion

00:51:22 carbon monoxide yep during combustion yeah second thing is nitrogen content which affects generation of hydrogen cyanide yeah and then halogen content which is chlorine and bromine yeah which

00:51:33 chlorine and bromine yeah which determines the potential to generate irritant acidic gases and affects the combustion of the other part and what you've done if we look at table three on the next page yes is you've summarized I

00:51:52 the next page yes is you've summarized I think is extracted from the other table but yes you summarized the percentages of these elements carbon nitrogen and chlorine here yes in the materials found and this relates materials found at

00:52:03 and this relates materials found at groennfell but also mixed flats contents yeah does it follow that the percentages you give here are the percentages of these elements that will be produced

00:52:15 these elements that will be produced when a sample of that combustible material is burnt completely if yes so basically what that means is that this

00:52:26 basically what that means is that this is the these are the percentages in the pedigree material before it's burned all right if it's all burned and 100 percent is burned then all of those masses of

00:52:38 is burned then all of those masses of elements or percentage of elements per unit mass will come off as Boston products I think that was a yes well and what you need the proportions will

00:52:51 and what you need the proportions will remain constant it's very part of it that's right well then right honest yes the good point not necessarily so if that's if a hundred percent is burned then of course it all goes but if

00:53:02 then of course it all goes but if there's any char remainder or partial decomposition then the proportions can change so inch are falling materials for example it locks

00:53:13 falling materials for example it locks up some of the carbon which means it's the carbon then goes up into the atmosphere it's somewhat less than it would be if you had 100 percent combustion and the same for the other

00:53:25 combustion and the same for the other lots of carbon major yeah can I come back to the question of charring yeah of course the one of the points you make

00:53:40 course the one of the points you make and it's a point you've reiterated here but you've used the term indicative analysis for the world which you've you've done in a set out in part three of your presentation but you also

00:53:52 of your presentation but you also explained in your report that estimates of the contributions of combustion products from specific materials to the concentrations of toxic smoke products in any particular locations within the

00:54:04 in any particular locations within the tower at different times is like these people only within quite wide ranges of uncertainty of course yes absolutely and if we look at Table four which is where

00:54:19 if we look at Table four which is where you're looking at level four is yeah that's these are these are these are the yields of all the products that we measured in our GRE experiments using

00:54:30 measured in our GRE experiments using our tube furnace and Method yeah well the first question was going to be can you explain the reference to tube furnace as I've explained the yields of

00:54:44 furnace as I've explained the yields of toxic products are very dependent upon the combustion conditions this fuel-air ratio

00:54:53 and for this project that we were doing we're particularly concerned to try and produce some data for youth for engineers to use on the yields they

00:55:04 engineers to use on the yields they might expect over a range of conditions now I put in in this table a snapshot of well-ventilated and under ventilators now I did actually at one point has some slides showing me so I've spared you but

00:55:18 slides showing me so I've spared you but in fact you get us on a sigmoid curve of the old in relationship to equivalence ratio so in order to to measure these amounts I developed this tube furnace

00:55:33 amounts I developed this tube furnace method which involves putting a strip of material into a tube furnace under a stream of air and because it's designed in that way you can dial up if you like

00:55:44 in that way you can dial up if you like choose specific fuel air ratio ensure that the material burns under the defined condition and then measure the yield that you get now one thing you

00:55:56 yield that you get now one thing you have to be aware of with any bench scale test is that you have to be careful that the results you're getting in your small-scale test and supplies to a whole

00:56:07 small-scale test and supplies to a whole range of standard and quasi standard tests that the yields and things that you're getting to what extent they're representing fundamental properties of the material who are testing and to what

00:56:19 the material who are testing and to what extent there are kind of byproduct of the apparatus that you are using and this apparatus were designed specifically to have complete knowledge

00:56:30 specifically to have complete knowledge and control of the exact combustion as far as it's possible to do so in a practical apparatus but when we were developing this in getting data for it we're very anxious to validate it against large scale compartment fire

00:56:43 against large scale compartment fire which is what we're talking about here and so we conducted now the cost large scale far very expensive to do so we're going to do a limited number but we conducted a number of large-scale fires

00:56:54 conducted a number of large-scale fires using the same materials to look at the yields we got in these more realistic large volumes to compare with the yields were getting in our small-scale operate and we found good agreement when I rip

00:57:08 and we found good agreement when I rip fighter recently published a paper on this about 9 2016 addressing this very issue so I'm fairly confident that the results that we've got are predictive of

00:57:19 results that we've got are predictive of the kind of yields you might get under the if you if these if and when these prisoners are produced in the compartment fire if we go then to the

00:57:30 compartment fire if we go then to the next page in your report and page 17 please sorry yes it's 70 so could we

00:57:43 please sorry yes it's 70 so could we expand paragraphs to 30 and to 3-1 please and this is where your your your touching on ventilated and under ventilated conditions professor because

00:57:54 ventilated conditions professor because you say yeah at our graph 230 the LDP cannot burn while encased in its aluminium skin but it does so when it melts and drips out from aluminium outer layers and also when they start to

00:58:05 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 Tau it's likely that most of the flaming LDP combustion occurred under well

00:58:16 combustion occurred under well ventilated flaming combustion conditions and so as you explained in your presentation well ventilated conditions will result in low yields of irritant

00:58:27 will result in low yields of irritant and toxic smoke yes there would be some smoke but not quite as much if we look at paragraph 231 you say the combustion conditions for the PIR insulation are

00:58:39 conditions for the PIR insulation are more complex because at least initially it's believed to have been burning in the enclosed cavity behind the rainscreen cladding on the columns and spandrels

00:58:49 spandrels and also in cavities associated with the window surrounds because it can I just be clear that you're making are you making a distinction between PIR insulation that's in either three or two places it's either PIR installation

00:59:01 places it's either PIR installation behind the cladding on the columns behind the cladding on the spandrels and also in the cavities associated with the window surround right all right let me just think and talk through that basically the mother to main

00:59:14 basically the mother to main Asians are on the columns and on the spandrels where the bulk of the PIR is there are also one of some smaller inserts and things in the window surround but I'm not considering those

00:59:26 surround but I'm not considering those at the moment well I think I'm really getting at here is that and this goes back to dr. lanes kind of analysis but when you have the PIR burning on the

00:59:40 when you have the PIR burning on the columns particularly next to a kitchen window

00:59:43 window the gasified thermal decomposition products are finding their way through these gaps Italy where the edpm strip is

00:59:54 these gaps Italy where the edpm strip is or has been lost into the area around the windows and so some of the combustion from the column PIR product the gases produced but is occurring in

01:00:06 the gases produced but is occurring in these kind of areas and I'm saying that where it's burning in the cavity actually on the column and where the column generated material is burning in

01:00:19 column generated material is burning in these kind of gaps and cavities and things around the windows under both those situations it's likely to have an element of under ventilated combustion I

01:00:30 element of under ventilated combustion I think that's really what I'm saying but I mean there is a bit of PIR there as well right when you were making reaching

01:00:44 well right when you were making reaching this view about the degree of ventilation of the PIR installation did you take into account the fact that the rain screen for sada ground-floor Tower

01:00:56 rain screen for sada ground-floor Tower was a ventilated rainscreen cladding system

01:01:01 right I'm not quite sure exactly what's meant by that but obviously what you the way I'm looking at this is that you have the PIR on the concrete and then you've

01:01:13 the PIR on the concrete and then you've got a a cavity going up but you stopped across in places oh that's that's another much a dispute of course crime but there's there's a column going up

01:01:24 but there's there's a column going up which at least is allows air to flow initially and then you've got the rain screen cladding so the basic sort of situation is that the pr is in a

01:01:36 situation is that the pr is in a enclosure a pipe almost and as i described this morning once that you've got a fire in there it's likely for that to become under

01:01:47 it's likely for that to become under ventilating now if there are various locations where there are gaps to let the bit more air in if that's what's meant by this question and it was any air that gets in is going to assist

01:01:58 air that gets in is going to assist combustion and may shift that phi value in one direction or the other if however some of that PE which i've said is well ventilated because i meant

01:02:09 said is well ventilated because i meant i'm envisioning it pouring down the outside if some of that PE is actually dripping on the inside of the cavity burning in the inside a company that will make the conditions it's adding fuel and therefore making it even more

01:02:21 fuel and therefore making it even more officiated on the ventilator but in terms of i didn't specifically consider other than the fact that air goes up the inside the column i didn't give any other i think maybe the point that

01:02:34 other i think maybe the point that you're being asked to consider it is this that we know that the rain screen planning ahead gaps right designedly right probably not very large franseninge perhaps two inches between

01:02:46 franseninge perhaps two inches between the sort of segments between the segment's i didn't consider that but i did assume that there would be some airflow

01:02:55 as I said we don't know what the condition actually was and that's why I put in both cases well just to break that down a little bit more I mean so

01:03:06 that down a little bit more I mean so firstly in terms of your conclusion that the LDPE was well ventilated what the assumption you made was that it would seep out on the outside in terms of PIR

01:03:19 seep out on the outside in terms of PIR insulation being under ventilated you've not taken into account gaps

01:03:25 did you take into account the gaps that would have existed between the insulation panels and the and the the cladding itself yes that's indeed taken yes and to the

01:03:40 yes that's indeed taken yes and to the extent that is there and did you take into account that they would have been air present okay because that's what supports the initial combustion you've I

01:03:55 supports the initial combustion you've I think responded to this already in that you you you said that there would have been airflow up yeah in looking at the

01:04:11 ventilation of the or the reigns of the cladding system did you consider that the response to heat might be the creation of an updraft I mean I haven't

01:04:25 creation of an updraft I mean I haven't gone to this level of detail but I'm assuming that there is air flowing up and that they was a flame an elongated flame in fact remember this thing of diagrams so I'm assuming an air too low

01:04:37 diagrams so I'm assuming an air too low up yes but I haven't eivin term I don't have any figures for any of these flows or los tres I haven't done anything like that all I've done is addressed the mass

01:04:48 that all I've done is addressed the mass and estimated a mass that's been burned and then assumed either one or the other condition is that factors like that that

01:05:01 condition is that factors like that that that you might get flow up or that there are gaps in the cladding matter you could take into account if you were to review these calculations my present

01:05:14 to review these calculations my present I mean this is something we might be able to go into further in phase two but really to settle these kind of issues the only way that I would know to do

01:05:25 the only way that I would know to do that is to build a rig with these features and have a fire in it and measure these so I don't have any way of calculating this other than to say the

01:05:39 calculating this other than to say the product you're going to get will depend on this fuel-air ratio that you end up with in practice I don't have any way of calculating that for this particular situation

01:05:51 situation professor Bisbee's has noted that in terms of the LDPE it was exposed at the edges yes I think he talked about drips and things but are you able to say what

01:06:05 and things but are you able to say what what impact that would have on the process of combustion well I was a little bit puzzled by this question so I I mean my picture of this is that if you do have an aged and as a flame impinging

01:06:17 do have an aged and as a flame impinging upon that edge this is the 3 millimeter gap between the two sheets of aluminium then being a thermoplastic material that LDP is going to melt and drip and you'll have these sort of burning stream of

01:06:29 have these sort of burning stream of droplets dropping from below this so we're not talking about a vertical panel so it's flowing out dripping down and burning that's the what I would I would anticipate happening and so it's the

01:06:41 anticipate happening and so it's the extent that those drips are on the outside and in air I would expect them to burn quite efficiently and then at some point mom would expect the whole thing to delaminate as it loses its

01:06:54 thing to delaminate as it loses its structural integrity and then of course all the Pease exposed to the air so at the moment I'm I'm basing this on a model of that it's all well ventilated

01:07:05 model of that it's all well ventilated but I'm not so terribly - totally wedded to this I mean should have other information appear can I show you a page from dr. lanes report

01:07:18 I show you a page from dr. lanes report could I have please be la s five zeros ten and then double zero twenty could we

01:07:34 ten and then double zero twenty could we expand just the top diagram please if you can you see miracle if you see

01:07:47 you can you see miracle if you see doctor professor purser that there's a sort of red and yellow arrow yeah hang up

01:07:52 up yeah that's but I think represents the LDP core core so you have you have a P

01:08:03 LDP core core so you have you have a P of a polyethylene core with two aluminium faces yes

01:08:10 could you get flaming up this three millimeter okay with no delamination of the aluminium sides you could do for a period but I

01:08:23 sides you could do for a period but I mean not this is getting a bit out my expertise your area no but let's assume for the moment that you do right does that helps to answer the question so what we would have is a situation where

01:08:34 what we would have is a situation where initially the flavors in pitting upon this age and they're dripping down and burning below as I'll describe if that starts to flow out say up to this sort of level here then you're going to have

01:08:48 of level here then you're going to have this sort of melting PE sort of running inside this sort of space but of course if it's going to burn it's got to get air up there as well which isn't going to be that easy so I

01:08:59 which isn't going to be that easy so I would still expect the main there could be a bit of combustion in there which may assist the delamination process of course we're just getting a bit out of

01:09:10 course we're just getting a bit out of mine well I think I press our last if you can go back to you can go and pick it

01:09:17 it and let's go back to your own the same page on your report and paragraph 2 3 1 again fees you refer to rainscreen

01:09:34 again fees you refer to rainscreen cladding falling away yeah would you agree that there would have been variability as to the time when this occurred of course yeah and with that

01:09:45 occurred of course yeah and with that then you have a consequence for the combustion conditions for adding for the PIR Edwards elation you know in relation to the analysis you've done and I think

01:09:57 to the analysis you've done and I think I know the answer to this but is this something that could be taken into account and if so how right well assuming that the moment for

01:10:09 right well assuming that the moment for the same mass as decomposes in the one case with the cladding intact and the other case with it having fallen away something like that then of course if it

01:10:22 something like that then of course if it remained intact then it preserves this cavity which tends to lead to or more likely to lead to under ventilator combustion so if it stays if the right

01:10:34 combustion so if it stays if the right wing cladding remains in place for a longer period you would can theoretically prolong the period of under Mendota combustion of the pol if the if the cladding falls away at a very

01:10:46 the if the cladding falls away at a very early stage then you move to the more well-ventilated regime at an earlier stage for the PR and that that could be yeah we could do we could do example

01:10:57 yeah we could do we could do example calculations of this should it be relevant as far as we're concerned at least at the moment are your calculations based on what you was

01:11:08 calculations based on what you was considered to be a reasonable average condition exactly along for one extreme or the other yes I mean the most extreme thing in this table is that I've assumed

01:11:22 thing in this table is that I've assumed that all the cladding around the flat inquest

01:11:26 inquest is equally affected effective right so if for example you had two bedroom flat and the fire came up only in a column

01:11:38 and the fire came up only in a column near the kitchen so flat six and never spread laterally to evolve any other cladding or information then of course my figures come down in proportion to the area that's been I think I could say

01:11:49 the area that's been I think I could say this that it all depends on the area the area that's been attacked and destroyed by the fire which varies somewhat between flats but I'm taking a case here sort of one of these some very typical

01:12:00 sort of one of these some very typical flats high up in the tower where most of it's gone apart from the Charlie bit that's left behind and so it so that we clear when I'm asking you about Table

01:12:12 clear when I'm asking you about Table five which you put up in your presentation yeah that doesn't what you're not doing is trying to represent varying conditions about the tower only

01:12:23 varying conditions about the tower only what about the progress of the incident so good right no as I said earlier this this sort of analysis I I'm kind of looking at a snapshot of a few minutes

01:12:34 looking at a snapshot of a few minutes during the early stages of fire penetration for example into a flat six well because the same would apply to all the other flats later on that were penetrated and in this particular set of

01:12:48 penetrated and in this particular set of calculations I'm estimating that all the PIR and all the range Green has been affected on both sides of the flat very corner location it's all gone and that

01:13:00 corner location it's all gone and that it's all gone in this short period of time as well I mean would be possible to do with a very set of calculations with various assumptions some of how they might spread but that's essentially what

01:13:13 might spread but that's essentially what I'm doing yeah can I ask you proceeded on the basis that only 5% of the yes-mo generated by a hundred percent combustion yes into the flat yes

01:13:25 combustion yes into the flat yes to what extent would the departure from your assumption yes unlikely to affect the proportion or the volume of smoke getting it yes well

01:13:36 the volume of smoke getting it yes well it would it would be in proportion for these two materials on the outside so 20 percent difference would only result in to one percent no differences I mean I said difference in smoking well I ran a

01:13:48 said difference in smoking well I ran a case for I was soon of five percent twenty fifth twenty percent is going in sorry no five percent Ferguson and I also had a look at the case forty one

01:13:59 also had a look at the case forty one percent going in and what I found with the one percent case for these two materials was that it lowers the concentration obviously of this fixing of gases so prolonged the predicted time

01:14:12 of gases so prolonged the predicted time to collapse not than that happening anymore at six but so much smoke there but even when you do this you still end up with hand in front of the face smoke

01:14:23 up with hand in front of the face smoke and that's just from one each materials and the total thing he's got to be some for the I think I've understood you correctly yeah I think what you're

01:14:34 correctly yeah I think what you're saying is that even if you reduce the volume the quantity of materials consumed by 20% yes it wouldn't make much difference because you're reducing the smoke into the flat by one one

01:14:46 the smoke into the flat by one one percent as well and it doesn't make much no because there are two they're kind of two things here one is the smoke density and has changed like that because it's so dense it won't really affect the

01:14:59 so dense it won't really affect the visibility yeah but it does reduce in proportion the concentrations of a16 gases here and prolongs in proportion the tolerance time for those yeah yep thank you for proximately one of the

01:15:14 thank you for proximately one of the points you make in your in your report and it's a power of two hundred and ten I won't ask to be brought up but it's

01:15:25 what you say is that the components that you've been discussing they were involved in a fire they'd be involved in an order and you put is running from left to right and so then you state the

01:15:37 left to right and so then you state the first smoke - which flat occupants were exposed came from the PIR and LDPE then the PS which is the polystyrene PVC and other minor window components and

01:15:49 other minor window components and finding their flat contents you continue four occupants taken refuge in flats remote from the fire for an hour or more that's exposed to smoke infiltration from the outside and the lobbies or in

01:16:01 from the outside and the lobbies or in the lobbies or stair the source was derived from a mixture of all these sources in varying proportions at different times including the contents so can you clarify or help us further

01:16:14 so can you clarify or help us further with what factors you had in mind when you when you state that any mixture from these sources would vary in proportionate different times well yes so I mean it's not terribly quantitative

01:16:27 so I mean it's not terribly quantitative but what I'm saying is that it's a progression so you start off thinking of flat six again with the exterior and structural materials as the main source

01:16:39 structural materials as the main source during these early minutes up to about oh one thirty thirty-five something like that and that's going into the lobbies and giving you dense smoke in the lobbies and most of that is derived from

01:16:50 lobbies and most of that is derived from the structural materials because the fire hasn't yet started to grow in the flats after that as time goes on we can

01:17:02 flats after that as time goes on we can expect and we can observe fire development inside the flats and so we get and we're getting an increasing involvement of the contents which as I said earlier are a much bigger fire load

01:17:14 said earlier are a much bigger fire load and so once we get on and this is variable of course between floors and flats and times but once we get start to approach Oh 200 hours we can see that a lot of these flat contents are on fire

01:17:26 lot of these flat contents are on fire and they're going to dominate the combustion products that have been formed some of that's going to go up through the whip most of it and they go out through the windows if the windows have failed but of course the proportion

01:17:37 have failed but of course the proportion is going to find its way into the lobby so if you were in another flat taking refuge and you try to open your lobby door to a clock that smoke that confronts you in the lobby is now

01:17:49 confronts you in the lobby is now starting to be more dominated I would say by combustion production from contents of other burning flats again

01:18:06 contents of other burning flats again picking up on that last but anything if we need to take you to the paragraph we will but what you saying it's a paragraph two four eight is that during actual fires the fuel burning rates and

01:18:17 actual fires the fuel burning rates and concentrations of smoke and toxic products are not constant no increase continuously yeah as long as the fire is burning yeah so does that mean that the

01:18:28 burning yeah so does that mean that the the concentration of gases changes would vary throughout the building depending on the on the progress of the fire well this is where it sort of starts to get very complicated so you could consider the situation in an individual flat

01:18:40 the situation in an individual flat because that's all varying with time these these constants these calculations here are a kind of snapshot in in that time and they would have been preceded by some kind of growth curve and then followed by a further growth curve but

01:18:54 followed by a further growth curve but once you get beyond the burning flat into other parts of the tower you have starting to get into more complex questions about smoke leakage through various doors and shafts and I've

01:19:08 various doors and shafts and I've forgotten what your question was but essentially you've got a large generator in all the burning flats and still under fire on the exterior producing smokes some of the exterior smoke is finest way

01:19:20 some of the exterior smoke is finest way into the building and all the building smoke is being produced in the building somebody's going out someone's going out going up and coming in higher levels there's a whole lot of things going on and and then that that smoke is

01:19:31 and and then that that smoke is migrating through the various interior spaces of the building does that answer your question thank you one of the slides that you put up when you were setting out the

01:19:43 up when you were setting out the materials that you you considered as you set out in this part for your report we made the point that what you did not

01:19:55 made the point that what you did not bring into play with other material so if you mentioned specifically lists the pearl board yes and the edpm yes and

01:20:06 pearl board yes and the edpm yes and when you were presenting you said that these are minor can you just expand on why you did not include such combustible materials in in your the short answer is

01:20:18 materials in in your the short answer is because I was trying to do a preliminary figure and so I picked the things that I thought were most significant in terms of mass but I am aware that these other materials are there also it's quite hard

01:20:30 materials are there also it's quite hard to from the information I have to quantify them I don't know necessarily than Barbara exactly what the dimensions are of all these things but I can go on

01:20:42 are of all these things but I can go on to include them in further further work the e d PN is quite a small piece of I mean it's quite important was whether or not it was a barrier but in terms of its

01:20:54 not it was a barrier but in terms of its contribution by mass it's quite a small amount the pearl board might have some signatures and I think there's some wood underneath all this somewhere as well so the short answer is I I could I probably

01:21:05 the short answer is I I could I probably will go on to kind of expand these elements on considering but because they're relatively small in capacitor these are don't they won't make some contribution there's a foil facer to the

01:21:19 contribution there's a foil facer to the PIR insulation isn't this is that material that you you would want to consider if you reviewed this analysis foil folks faces to the PIR insulation

01:21:30 foil folks faces to the PIR insulation well that you mean the aluminium foil that's only that's on all the PIR yeah that with if that would burn it's a PIR any sort of the aluminium itself and I

01:21:43 any sort of the aluminium itself and I don't think that would produce anything very much I mean its main significance is the extent to which it protects the PIR from combustion and some extent it does quite a good job on that up to a point and is

01:21:55 a good job on that up to a point and is that something that you could take into consideration that protective mechanism of the al-amin no not really would it be relevant the sort of calculations you'll know I mean is only

01:22:08 calculations you'll know I mean is only relevant it's relevant to the extent of whether or not the PIR burned and so I'm basing that on what we love you're assuming anything but I'll tell you I I

01:22:19 assuming anything but I'll tell you I I did a series of experiments where I lined a standard rooms with an ISO room without alameen even faced PIR and the purpose was to study the combustion of

01:22:30 purpose was to study the combustion of these materials when they used as wall linings and because I wanted to have the same material only in the room I made

01:22:42 same material only in the room I made what's called a crib which is a standard ignition fire source that experiment is used where by you you saw usually it's wood but he saws the bunch of sticks and you build a kind of Boy Scout and crib

01:22:53 you build a kind of Boy Scout and crib you set fire to that and depending on the crib you can have a standard heat source fire style flame and heat source so because you did some experiments we sawed up PIR a made it into Crimson's

01:23:05 sawed up PIR a made it into Crimson's ignited it and it burned quite fiercely under those re artificial conditions um we calibrated that to get the right heat output and then put it into this ISO room which is now lined with PIR alanine

01:23:17 room which is now lined with PIR alanine and faced paneling and what happened in these experiments is that the standard flame sized flame in the corner of this room never penetrated the aluminium and never involved the PIR so in that

01:23:29 never involved the PIR so in that particular case it performed very well

01:23:35 mr. Allen I'm just wondering whether we should have a break at some point I didn't want to take we can we can suit you we can stop now those who - yes understand I mean I've

01:23:46 those who - yes understand I mean I've got a few more questions on this topic but it's it's

01:23:51 professor I think we'll have a short break now thank you very much ten minutes let's say 25 past three yep and don't talk to anyone about your evidence please as before okay yeah with you sure sure

01:24:04 you sure sure thank you very much thank you thank you

01:24:27 right 25 hours three empties

01:25:58 you

01:34:02 good ready to carry on Flippa good thank you very much yes mr. Rohit could we have Table five up on the screen that's at page 74 of the report please

01:34:16 professor one of the assumptions you made in this as you said as you described it indicative analysis was that not 0.5% of the flat contents

01:34:27 that not 0.5% of the flat contents Woodburn yes a very small amount why did you choose that percentage that's an important question basically because I'm addressing these conditions that have

01:34:39 addressing these conditions that have sort of moment in time of this thing when the fire is just broken in I'm thinking again a flat-six mainly here and coming in around the windows Antasari they're still around the

01:34:52 Antasari they're still around the windows and hasn't involved the contents at all or it's just started say to ignite a chair or something close to the window so we're getting some involvement of the content so so this is a sort of a

01:35:03 of the content so so this is a sort of a snapshot of a situation possibly around 140 150 2 o'clock depending on the flat

01:35:16 140 150 2 o'clock depending on the flat but it's but up but I mean you know obviously after this if we did another snapshot later on I would expect that bottom line to become much much bigger significant as one moves through

01:35:29 significant as one moves through incident in time yes the estimate of different components that burn very very a lot yes yes yes because if for example

01:35:40 a lot yes yes yes because if for example the the cladding had fallen away outside a particular flat and the flat contents were increasing you know every six so one is going down in significance and the other is going on in terms of when

01:35:53 the other is going on in terms of when you made this calculation you and you've touched on this in your presentation but you gave a figure of 50% for the total mass of PIR oh yes and you and this is

01:36:06 mass of PIR oh yes and you and this is something you say in your in your report but you you estimated following a visit on the tower that approximately 50 percent of the pie may have burned on on particular paths

01:36:18 may have burned on on particular paths yes well I'm not shocked you take into account the when half the bottom of the tower is still intact I'm not including that at all in this I'm sort of not I'm thinking of a bit of a sort of stereotypical flat in a certain yeah up

01:36:31 stereotypical flat in a certain yeah up towards the top of the tower sort of thing yeah and was this assumption based purely on the observations that you made during a visual observation during your

01:36:42 during a visual observation during your visits see one of the problems when I went there was that the whole tower was clad in a sort of a membrane so you can't sort of do a survey from the outside without climbing out onto the scaffolding so what I did personally was

01:36:56 scaffolding so what I did personally was I went into various flats and went to the window and looked at the state on the columns and finals around various flats and but I'm also looking at some

01:37:09 flats and but I'm also looking at some of these photographs that you can see if so many of them taken after the fire which I showed in one of my slides where you can see that for example you can see that the columns have got no PIR on most

01:37:20 that the columns have got no PIR on most of them but you still still definitely can see quite I'm in there are substantial amounts of PIR still there even near the top of the tower on some of these on some of these spangles most

01:37:32 of these on some of these spangles most of the column stuff is gone um so is it right to say that you didn't take in making your estimates you didn't take any account of the volume of PIR that may have fallen off during the fire

01:37:44 may have fallen off during the fire no all been removed by firefighting and I will say I'm aware that that may have happened to some extent but I'm purely based in New York on what I can observe

01:37:59 as I understand your your analysis here you're assuming that and let's take the PIR installations example that percentage of it burns and a pretend

01:38:10 percentage of it burns and a pretend percentage of that burnt material then enters the flat yes is it possible that some of the PIR insulation may have been burned as a result of fire break out from compartment fires after the

01:38:22 from compartment fires after the cladding had burnt out yes I saw that question that's an interesting point so I think what we basically what we seem to be seeing is the fire during the

01:38:33 to be seeing is the fire during the early stage of moving rapidly up the tower

01:38:36 tower and that very bright flames that we can see I mean the other experts would comment but I mean I think that's mainly the what are that's the LDPE but it's

01:38:47 the what are that's the LDPE but it's also burning some of the PIR behind it then once the fire has moved on but Poteau I showed you where the fires burning to the left of the original and

01:38:58 burning to the left of the original and you can see the fire inside there's obviously still some PIR left on those okay let's stop burning and stop burning but if you had the fire in the flat then

01:39:09 but if you had the fire in the flat then going to flashover and you had the windows felt falling out and we haven't seen any pictures that show this but you'd had a big flame plume coming out which should happen and that flame plume

01:39:22 which should happen and that flame plume then goes up the outside towards the next level if that's impending on a spandrel above the window level one would expect that to be attacked so I've

01:39:36 would expect that to be attacked so I've not taken that into account and so my assumption which may be no it is that the mass I'm saying has gone during this fairly short window of time that I'm addressing if the in fact it was going

01:39:49 addressing if the in fact it was going over a longer period of time then that would reduce the amount during that window time what one of the the points

01:40:01 window time what one of the the points you mentioned earlier was was the idea of charring yes and as I understand it PIR on its own went and we'll char and selfish think wish

01:40:13 and we'll char and selfish think wish yes that right when you were coming to your approximation of 50% PIR burning did you assume that any child insulation

01:40:24 did you assume that any child insulation had been consumed in the fire hmm what I looked at was the thickness and for this kind of indicative calculation and I'm

01:40:35 kind of indicative calculation and I'm thinking mainly of the spandrels here but as the same logic I've applied to the other is that you've got two aluminium faced layers so so if one of those layers is gone and that's what I

01:40:47 those layers is gone and that's what I observed appeared to have happened then that's 50% of your PIR gone so I've assumed all that's combusted right but behind that is the layer that the windows are setting which is still

01:41:00 windows are setting which is still attached in places to the concrete of the building and and that is all blackened and charred and sort of bulbous and in fact we took some

01:41:12 bulbous and in fact we took some specimens of this and sawed through them and if you look at a cross-section of one of these charred pieces it looks a bit like a loaf of bread that's been burnt in the oven you know so that

01:41:23 burnt in the oven you know so that you've got this kind of charred exterior of a certain thickness which is the way it's designed to happen and then behind that you've got some creamy looking

01:41:34 that you've got some creamy looking apparently intact PIR that's not been decomposed at all but from the bit that's child that has although there is significant carbon still left which is

01:41:45 significant carbon still left which is the char that one have lost a considerable part of its mass and so if for example you had a case where 50% had burned and gone that's your 50% if you

01:41:57 burned and gone that's your 50% if you had 50% left of which 50% of the mass content had gone leaving the child bed then you would end up with 75% of the total mass decompose which would be 50%

01:42:10 total mass decompose which would be 50% more than I've assumed so it can kind of go in either direction depending on I mean one of our plans is to it's a is to look at the density of this charred material

01:42:21 material and estimate how much hatchling has gone from specimens removed in the tower if we look at Table five you give a figure

01:42:33 we look at Table five you give a figure of five hundred and fifty two parts Paju cord for a hydrogen chloride yes and that's from the uPVC windows around yes

01:42:45 that's from the uPVC windows around yes would that hydrogen chloride is produced by the the PVC window have an impact on the efficiency of combustion conditions finally really I've stated that in my

01:42:56 finally really I've stated that in my report

01:42:56 report can you just explain how it has that impact yes so I've only packed light into my calculator I mentioned as a phenomenon but I've only factored it into my calculations here

01:43:08 into my calculations here insofar as it affects the PVC itself all right so PVC when you burn it even when you burn it with the flame which it's quite hard to do it produces as I said a

01:43:20 quite hard to do it produces as I said a very high yield of carbon monoxide and that is because the chlorine content is 50 percent by mass roughly chlorine is all released as hydrogen chloride and and this is a free radical scavenger

01:43:32 and this is a free radical scavenger which means that it it it prevents or limits oxidation flame reactions in the flame zone above it and so instead of all the carbon being burnt occur in the

01:43:44 all the carbon being burnt occur in the carbon gases being burnt to completion you get a high yield of partial combustion which is the carbon monoxide so that's why we get such a high yield of CO from PVC itself okay but if you

01:43:58 of CO from PVC itself okay but if you burn something like wood you know in a well-ventilated condition all the carbon goes to the carbon dioxide if you burn the wood and in next to a piece of PVC

01:44:11 the wood and in next to a piece of PVC so that the product mix in the flame then the clio yield from the wood is increased by these hydrogen chloride in in the flame from that wood with me so

01:44:23 in the flame from that wood with me so in this context what would happen were depend on where where we are in the system right so imagine you've got some polyethylene DPE I've said that's burning underworld

01:44:35 DPE I've said that's burning underworld when Zeta conditions on the exterior that means that most of the products that are finding their way into the flat as I've described a mixing with the flames and smoke from the PVC I've

01:44:48 flames and smoke from the PVC I've already gone more or less to completion co2 so I wouldn't necessarily expect them to be changed very much but if you had another material which had not been

01:45:00 had another material which had not been fully burned and would been under ventilated combustion so you've got unpark leaver and gases coming in through the window mixing with the flame from the PVC then the yield of CO and cyanide from those materials would then

01:45:12 cyanide from those materials would then be increased by the presence of the PVC now to quantify that it's quite challenging but the phenomenon would be there yeah can we look please at page 72 of your report and I just draw yourself

01:45:26 of your report and I just draw yourself first paragraph two four five at the bottom where you say with regard to smoke and fire penetration into individual flats the two bedroom flats

01:45:37 individual flats the two bedroom flats were most vulnerable because the aggregate areas of the windows and of the cladding and insulation outside them was greater than for single flats if we go and look at paragraph two for two

01:45:55 what you say there is that from witness accounts although some smoke was reported as entering the flats from outside the windows the main source of

01:46:06 outside the windows the main source of smoke entering the flats before the fire reached the flats from outside I was likely to have been the lobby lovers yes so what you have is is a statement of flap a 2-bedroom flat is more vulnerable

01:46:18 flap a 2-bedroom flat is more vulnerable because it's got a greater area exposed to the outside yeah but paragraph 2 for to a statement that certainly until I don't think of

01:46:29 that certainly until I don't think of the condition there at all well yeah could you explain why so in the one case we're talking about the vulnerability to exterior fire penetration and in fact I think the two benefits are even more

01:46:41 think the two benefits are even more vulnerable because of their corner situation if you have a fire breaking in through one corner I think somebody described this you can then break out through the next corner you then got two

01:46:52 through the next corner you then got two openings and that's that's a nice condition if you like to develop a quite a big fire in that flat whereas the one-bedroom flats is somewhat more protective which may partly explain the

01:47:04 protective which may partly explain the slower fire growth in flat 201 which is a one-bedroom flat for example so this is all to do with the fire breaking in from outside but this other aspect is of smoke penetration smoke penetration from

01:47:17 smoke penetration smoke penetration from the inside from the lobby and there in fact you could argue in that situation because they all only have one front door that with respect to smoke penetration from the lobby slow smoke

01:47:28 penetration from the lobby slow smoke infiltration from the lobby their one-bedroom flat because the volume is less would actually be more vulnerable in that context than a two-bedroom flat because you're dispersing the same amount of smoke and gases into a smaller

01:47:41 amount of smoke and gases into a smaller or larger volume but they're talking about two two totally different things one is smoke coming from the lobby one is fire and smoke coming from the outside have you for the purpose of you

01:47:53 outside have you for the purpose of you of this phase one report considered the potential impact of the smoke ventilation system to the passage of smoke around the building on the night yes only in very general terms so as

01:48:08 yes only in very general terms so as I've said

01:48:09 I've said there are a number of ways in which smoke could be spread around the building having read the witness statements at the moment I'm coming to the view that the main source of the

01:48:22 the view that the main source of the early dense smoke in the lobbies was via basically flat six on each floor about 1:30 sorry I've forgotten more questions

01:48:35 1:30 sorry I've forgotten more questions it was about the the potential impact of the smoke ventilation sigh yes okay so that's that's that's flow so that's kind of horizontal smoke all right but the

01:48:47 of horizontal smoke all right but the question there is this question of whether if you had smoke filling one lobby on one floor could any of that get up to a lobby on another floor and the answer is of course yes and that there

01:48:59 answer is of course yes and that there are various routes by which that might happen through gaps and penetrations and missing seals and and things like that there's also the lift shaft and I noted

01:49:11 there's also the lift shaft and I noted that this is very early stages the far some people mention seeing smoke emerging from the lift area on the 23rd floor very quiet and another person

01:49:23 floor very quiet and another person talked about smoke emerging from the utility cupboard on the landing that was built as part of renovation what would imply think a lot of pipes going vertically through there so that would imply there's some migration through

01:49:34 imply there's some migration through there there's also the question which is still somewhat unresolved about how exactly the smoke ventilation was performing and what he was doing all the night of the fire

01:49:45 night of the fire I know dr. Lane is trying to look into that in some detail and indeed that I did read an account from somebody that suggested they thought they saw some smoke coming from one of those grills so

01:49:57 smoke coming from one of those grills so there are a number of routes for vertical spread but oh and because the stair shaft is the most obvious one now from my analysis of what I've seen so far in every case I've read of anybody

01:50:10 far in every case I've read of anybody trying to escape they've always said the smoke in the lobby was far worse than the smoke in the stair which means that I don't believe that vertical migration of smoke up the stair

01:50:21 vertical migration of smoke up the stair was looks cause of smoke in a lobby anywhere I think it's the other way although some of the smoking that's there a lot of it most it's I think it's

01:50:33 there a lot of it most it's I think it's coming from lobbies there's people opening doors and things but some of its undoubtedly coming from down below where the fire fighting and things going on that's another is this question the

01:50:45 that's another is this question the potential contribution of this ventilation system something that you want to give further consideration to for your phase 2 report well I would I would like to I don't know how far we're going to get with that but it's

01:50:56 going to get with that but it's obviously a consideration yes I know forget that that was only designed to clear smoke from one floor so the operation as I understand it from dr. lanes report is that is that it was

01:51:09 lanes report is that is that it was designed to be triggered by smoke on us on a certain floor which is which should have been where the first where a fire was and then the dampers are supposed to shut on all the other floors

01:51:20 supposed to shut on all the other floors and then then that smoke is extracted and there is a bit of an indication that some load lower floors don't look as smoke-stained as others but I don't

01:51:31 smoke-stained as others but I don't think we quite know what happened but one thing I did on my second visit to the tower was to look closely at the smoke deposits with Professor step in

01:51:44 smoke deposits with Professor step in the ventilation and in the shafts of those losses on the verse laws we're trying to try and get some weight so we are looking into this a bit but how far we'll get I don't know whatever the

01:51:57 we'll get I don't know whatever the outcome of that you can consider that in your in your face suit yes if we find anything can I take you to page 8 of your statement please

01:52:11 what you've done here is to set out what what might be described dessert as a sort of model of events of the night and

01:52:25 sort of model of events of the night and you and you just you identify three stages and for your second stage which is at the bottom there II you you give that a time period of 127 to at the

01:52:40 that a time period of 127 to at the outside 2 a.m. you see that yes it's a dense smoke filling the lobbies yes and what you're you're identifying and you see it there that the the main source of

01:52:51 see it there that the the main source of smoke entering the lobbies at this time was four flat six on each floor that's my current feeling but well what's what's the sort of evidential basis for that current feeling because because i

01:53:02 that current feeling because because i was i've looked quite closely at what people said they did in flat six and how they described the conditions and

01:53:13 they described the conditions and basically they're saying fire came in i ran around left the flat in a hurry in some cases leaving the door open I

01:53:24 in some cases leaving the door open I know I can't remember the names off hand now but there was one there was some quite graphic descriptions this one person left went down a few floors and then came back up again went back to his

01:53:35 then came back up again went back to his flat and noticed how having left his door open he found that there was a lot more smoke in the lobby other people from other flats looked towards the open door flat six men took him and saw the

01:53:46 door flat six men took him and saw the plume of smoke coming out he's filling filling the lobbies so there quite a lot of descriptions like that for and there were other floors where lower down where people deliberately left the doors open

01:53:57 people deliberately left the doors open for the firefighters to go into the flats building but these doors were open to some peers on other people we don't know what they did so that this based on

01:54:09 know what they did so that this based on that kind of evidence yeah and I want to put now put to you a proposition it's that during that second stage that you've identified that there were internal fires in flats yeah and to do

01:54:22 internal fires in flats yeah and to do that I need to show you a number of pieces of evidence and the first is from dr. Lane's initial report we have BL a are seven zeros to page 19 please and we

01:54:39 are seven zeros to page 19 please and we see there a photograph yes it's timed at 136 and we can see that there are a number of lit flats yes

01:54:53 would that support the conclusion that there were developed internal fires at that at this time between floors 12 and

01:55:04 that at this time between floors 12 and 15

01:55:05 15 yeah we just to sort of clarify I'm basically identifying a period during which little lobbies are filling with smoke now this is a continuous process so it's hard it's varying in different

01:55:18 so it's hard it's varying in different places you know it's hard to get hard numbers in but mostly around about oh 130 that these lobbies are filling with smoke then around about 2 o'clock ish

01:55:31 smoke then around about 2 o'clock ish I'm suggesting that we're now moving to a regime where we may have internal fires now this particular picture here is the fire is main fires are on the

01:55:42 is the fire is main fires are on the east face which we can't see we're seeing the fire coming around the corner onto the north face of the building and so this is the this brightness here I

01:55:53 so this is the this brightness here I believe it's mostly the burning cladding and insulation from the coming around the corner as it were as the fire spreads but I don't see any evidence that there are fires in any of these look like just an ordinary neon lights

01:56:06 look like just an ordinary neon lights so I don't see any fires in there can I show you the second piece of evidence and this is time that oh one third a six

01:56:18 and this is time that oh one third a six so this is sort of after or tours after the period one saying that lobbies were filled with smoke really

01:56:25 really and what was their very end of it could we have LSB s60 source seven zeroes 1 2 5 4 please

01:56:37 5 4 please sorry 6 zeros 1 and then page 204 that's it

01:56:42 it if you go to the bottom there we start at paragraph 1 182 it's yes what it is

01:56:53 at paragraph 1 182 it's yes what it is this is one of the witnesses well I think if we take it in stages for the first thing I need to explain this is a fourth extract from Professor bisby's report yeah and what he's done in this

01:57:04 report yeah and what he's done in this part of it and this is his supplementary report he summarized evidence from a number of BS our witnesses yes so the first person we seized Jose Fierro you have flat 46 stated the first thing

01:57:18 you have flat 46 stated the first thing I saw burning was the extractor if we go to the next page please I think he may have been the man whose curtains caught fire but I can't be sure

01:57:33 hmm that's the one it put the yes states flames came through the found holes where the fan was he gave in it was hanging by the electric wire that

01:57:44 hanging by the electric wire that supported it as I mentioned I mentioned him earlier I mentioned this familiar with well if we look at the others and the first perhaps des if I try and take

01:57:56 the first perhaps des if I try and take it shortly if I summarize the evidence if your foot if you're not familiar with it and you want to read it let me know but if we look at the whole page please what this is in is in effect is summaries of evidence from people who

01:58:08 summaries of evidence from people who were in flat sixes so you don't have after mr. Vieira residence in flat 56 then you have flat 66 at paragraph 1 184

01:58:21 then you have flat 66 at paragraph 1 184 which we knows this is more Hardy who gave evidence some time ago and you then have flat 7 to 6 then flat 86 and the

01:58:32 have flat 7 to 6 then flat 86 and the person who gave evidence flat 86 is referred to a paragraph 1 187 which is an idea Jafari yeah and then the boss and you then go to flat 146 and then

01:58:43 and you then go to flat 146 and then flat 186 I think Einstein when you focus T into the work you've done so far you have paid attention to that crazy a table which is in my draft longer draft

01:58:55 table which is in my draft longer draft report which summarizes all the witnesses for every flat 6 as far as I can and I'm paying particular attention in that section of my longer report to

01:59:06 in that section of my longer report to how they what they observed about the work the penetration of fire is development in their flats and what I found with that I mentioned earlier I did actually have originally a slide

01:59:17 did actually have originally a slide with these names on in various categories but what you find is that some as I said this morning some people had smoke coming in first

01:59:28 some people had smoke coming in first without before the fire came into their flats on more than more than saw flames so as more people said their first experience was this flat filling with smoke other people found the fire coming

01:59:42 smoke other people found the fire coming through the ventilator as described here other people said they had a window open and fly

01:59:47 and fly and smoke came through and two people up I recollect said that they had glazing failure very rapidly after the fire first appeared outside the window but of course all these are still exterior and

02:00:00 course all these are still exterior and structural fires outside and around and involving the window with the two exceptions which I did mention earlier where this is one of them the arrow is one of them where there were some

02:00:11 one of them where there were some curtains that caught fire which even stamped on I think and put out on somebody else as I said earlier had a curtain between the kitchen window and the double doors is the lounge and that

02:00:23 the double doors is the lounge and that curtain caught fire so there's a variety but other people are only mentioning smoke at that stage but if but it's not a contents fire this is a structural form and conclude on it there's nothing

02:00:36 form and conclude on it there's nothing in the witness evidence that you've read in relation to a flat six that leads you to conclude that in the time period for your second stage there was an internal

02:00:47 your second stage there was an internal flat fire I mean the numbers I I think I put up and that particular paragraph he showed me I put up to 147 that might be getting a bit late I mean I know it depends on height in the tower because

02:00:59 depends on height in the tower because it's progression but basically you could all got these two sort of stages and it's hard to it's because there's so much variation it's hard to sort of put it sharp time with any of these

02:01:10 it sharp time with any of these phenomena but basically you've got a period up to somewhere around oh 135 I think I probably now say where there's dense smoke building from about Oh 125

02:01:21 dense smoke building from about Oh 125 to 135 ish in the lobby which precedes any involvement of the content look at your paragraph 21 your first period oh

02:01:35 your paragraph 21 your first period oh yes you're right sit down to about how FAR's one and yeah well second period assumes that they were filled as from about half past one yeah but I mean one

02:01:46 about half past one yeah but I mean one once you start to get closer to two o'clock and this is a continuous process up really operating differently at different places then you have the potential for these interior fires to

02:01:57 potential for these interior fires to start to develop and form up a part of the issue and one of my slides I think shows that quite clearly which was taken it about over 220 by professor he's one of his in his report and then

02:02:09 he's one of his in his report and then that one you can clearly see fires in the windows awesome but that's twenty past

02:02:14 past - I think nearer to 20 past to you well can I show you just a final piece of evidence in relation to this point and it is - again from recipes B's reports from page 207 sorry of the same document

02:02:29 from page 207 sorry of the same document and and what we have there is that's a photograph taken at 140 for an image taken at 144 and which angle is this

02:02:44 taken at 144 and which angle is this which face yes these faces I think yes and and if you if does that help you to decide whether I write developed internal this is 144 now we can see this

02:02:56 internal this is 144 now we can see this brightness here is where the fire has moved left to start involves a sort of 201 flat flat one column this here is where it's moving around onto the North Face and involving the these other face

02:03:10 Face and involving the these other face of flat six all the way up but these brightness here do look as if they could well be internal fires and he said well there may be more than lower down as you

02:03:21 there may be more than lower down as you might expect because that's affected first so there could be some internal fires here although some other shots I've shown don't I showed on my presentation don't seem to really show

02:03:32 presentation don't seem to really show that but these do look like internal fires is taking taking that time period this is long after over 130 your your time period ends at two o'clock for your

02:03:43 time period ends at two o'clock for your second stage to be fair to you give it as 145 to it yeah I mean it's all a bit

02:03:52 but by that time I'm I can't expect him to start to see interior fires yes so would it fair summary be bit towards the end of your second stage is when you

02:04:03 end of your second stage is when you would expect to see internal fire possibly but I mean this needs a lot more work really I mean I'm looking forward to collaborating on looking more into the time the exterior time shots

02:04:17 into the time the exterior time shots from the other experts combined with the observations of people who are in these for us try and pin down some of these aspects well I don't I don't recall much description in the witness statements of

02:04:30 description in the witness statements of large burning furniture fires in flats

02:04:36 and just before we leave I mean as we shown in paragraph 21 of your report where you identified these three stages

02:04:47 where you identified these three stages are the time range that you've given based on your consideration of witness evidence can I just take you back to

02:05:00 evidence can I just take you back to flat-six yes and we can just if we can go take that image off and go back to have you conducted an analysis thus far

02:05:11 have you conducted an analysis thus far of whether the doors to each flat six had a closer when the flat six was vacated and whether the door was left open or is this something that you may consider undertaking the phase two I

02:05:24 consider undertaking the phase two I haven't done a systematic study I'm not sure it would be my place to do that but of course I am extremely interested in the timing and extent of any smoke migration and cause of it through these

02:05:37 migration and cause of it through these doors one of the complications caused is we've got lots of tooth doctor lanes given a breakdown of the different types of doors that were in all the different flats the numbers that there were so

02:05:48 flats the numbers that there were so there's a variety there so far what I've done is to look at the woods the witness statements and without you know

02:06:01 statements and without you know categorizing exactly I've come across of a lot of other witnesses were asked this question and many of them said some of them said they'd had to remove the self closes mechanism some of them said we

02:06:14 closes mechanism some of them said we had them but they didn't really work including quite a few of them escaping from flat six and you had to physically close the door if he wanted it to make sure

02:06:22 sure you have to make sure you did eat and so where people fled and left the door open and some of them then went back and conformed this there was smoke coming

02:06:34 conformed this there was smoke coming out seem to becoming work they weren't necessarily shutting for not sure they didn't but some of them may have done I don't know but there's a variety of things going on there and variety of door types I'm not at the moment planning myself to do a systematic sort

02:06:47 planning myself to do a systematic sort of study but I'm very interested in this kind of information yeah thank you and can I move on just a different topic and that's is just about the differences or similarities between

02:06:58 the differences or similarities between hydrogen cyanide and carbon monoxide yes I'm sorry I had two more slides on this morning which I cut out for time reasons yeah what what you've said I mean

02:07:09 yeah what what you've said I mean firstly is it right that hydrogen core cyanide will be more potent than yes but what you've also said in your report is

02:07:20 what you've also said in your report is that they're additive in combination yeah

02:07:23 yeah that's based on an experiment can you explain how that works given this hydrogen cyanide is more potent than carbon monoxide oh yeah because we do it in terms of the FE D so if you've got if

02:07:34 in terms of the FE D so if you've got if you've got an atmosphere and you expose an animal to it in fact with half the concentration of cyanide that would cause incapacitation in a certain time

02:07:47 cause incapacitation in a certain time and that alone and after that sort of time they're not going to be incapacitated if in the same mixture you put half an incapacitating dose of carbon dioxide it could be a much greater amount but half the amount

02:07:59 greater amount but half the amount required 1/2 plus 1/2 equals one they tend to become incapacitated in that additive way it's a fairly rough estimate but that's that that's the way

02:08:10 estimate but that's that that's the way we've retreated it and that seems to be the case and again does hydrogen hydrogen cyanide have a more rapid effect yes and as I said this morning I

02:08:21 effect yes and as I said this morning I really see cyanide much more in terms of incapacitating effects than death I think in most cases there are cases where cyanide fires have killed people

02:08:32 where cyanide fires have killed people in recent papers fires in some prison where the prison mattresses produced a lot of cyanide there was not much carbon up selling the blood of these victims but that's rare normally you find that

02:08:45 but that's rare normally you find that when people are dead in a fire they have a lethal dose of carbon monoxide in their blood as I mentioned earlier so if they have been exposed to side many of them are I feel this is more significant in terms of collapse before you escape

02:08:57 in terms of collapse before you escape rather than whether or not you die one of the points you make in your report is that blood cyanide levels is not are not routinely measured from this ayat' do you know why that is

02:09:09 you know why that is yes no cost I think I mean basically they always measure carbon monoxide and it's fairly straightforward to measure it's very stable as I said it's a very good marker of the extent to which

02:09:22 good marker of the extent to which somebody can be explained as a smoke death and it was not all fires producer cyanide what calm contrast cyanide is very unstable in blood particularly in

02:09:34 very unstable in blood particularly in the blood of fatality so it can lose half of it in 24 hours in a body so if it's three days before you take the blood sample in autopsy you've lost most of the information then once we've got

02:09:45 of the information then once we've got the blood sample whereas the co samples are pretty stable the cyanide will then - - will gradually be lost on storage so and also the interpretation of what the

02:09:59 and also the interpretation of what the significance of a particular cyanide level is in terms of what happened to the people is very complicated I've been developing some models to try and deal with this which I published but it's so it's not an easy thing to deal with but

02:10:11 it's not an easy thing to deal with but it would be very valid if we did it there was a very particular study in France by a professor bode who went out of the French Forest Service and he took blood samples from fire victims in

02:10:24 blood samples from fire victims in dwellings as they were pulled out of the building so very fresh samples there live and he found very high levels of cyanide in those fresh blood samples whereas when there's done at post-mortem

02:10:35 whereas when there's done at post-mortem they're often much lower so it isn't it is a bit of a problem yeah but it would be good I'm disappointed that it's not measured yeah because it would give us more information in the context of the tower is it at all

02:10:52 in the context of the tower is it at all possible that someone could have been exposed to hydrogen cyanide but not carbon monoxide know you always have both but a cost of proportion depend on

02:11:04 both but a cost of proportion depend on the situation and to turn to carbon monoxide if someone was exposed to a level of carbon monoxide sufficient to

02:11:16 level of carbon monoxide sufficient to cause an increase in carboxy hemoglobin levels yes and that person were then able to take shelter somewhere where there was a lower level of carbon oxide or where they could get air oxygen into

02:11:29 or where they could get air oxygen into their system yes would that mean that the carboxy hemoglobin level would reduce decrease yes so if you for example you came down the stair and you were breathing CO and

02:11:40 the stair and you were breathing CO and then he went stood outside and breathed ordinary air over a period of an hour or two you've got a decay curve you'd flush it out if you read oxygen at the same time you flush it out much more quickly

02:11:51 time you flush it out much more quickly because the two things compete in the blood yeah so yes is the answer to that gradually equation is lost and what about hydrogen cyanide if you were able

02:12:02 about hydrogen cyanide if you were able to remove yourself from a source of hydrogen cyanide to somewhere safer would would the levels of - cyanide in the blood been decrease from from my studies the level of cyanide it does

02:12:15 studies the level of cyanide it does decrease but it it so rose quite a long time scale it's comparable to the C over yes it does a decrease this and just one final matter before I ask for a shorter

02:12:28 final matter before I ask for a shorter German but the one of the you've set out in your report at the end we don't need to go to it but you've set out the further work that you're considering yes

02:12:39 further work that you're considering yes for the purpose of your phase 2 report and that includes doesn't it a review of the evidence of firefighters is that right oh yes I haven't really had a chance to do that yes I'm glanced at

02:12:50 chance to do that yes I'm glanced at some of it that I haven't done a systematic study Thank You mr. chairman I've I've

02:12:56 I've I've at the end I think of my questions but if I could ask for a short five-minute break to see if there's anything else I need to briefly say something on this topic party was I missed off on those

02:13:07 topic party was I missed off on those slides I'm asking myself sorry if if syenite the role cyanide may have played have made a difference anywhere at Grenville and I'm talking talked a bit

02:13:19 Grenville and I'm talking talked a bit about the cyanide and the CEO coming into flat-six from the outside as I said this morning nobody was incapacitated in the flat-six they all had time to get away so neither

02:13:30 they all had time to get away so neither CEO nor cyanide played any part had any significant effect on anybody who was in a flat six right then you've got the later phase when people are trapped in

02:13:41 later phase when people are trapped in other flats and trying to get into the lobby that Lobby will be have high concentrations of both CEO and probably cyanide but a lot of that song I will now have been a little after two o'clock

02:13:53 now have been a little after two o'clock generated from the contents as much as the cladding and then when the fire gets around to any flat and breaks in it's a bit like the original flat six situation so the only situation I can see where a

02:14:06 so the only situation I can see where a presence of cyanide may have affected the outcome for people at Grenville if you're trapped in the flat and die there it doesn't make any difference where it just could conceivably have an influence

02:14:18 just could conceivably have an influence is if you stay in for any flat up to say 3:00 a.m. and then you come out into these very smoke-filled Lobby under

02:14:29 these very smoke-filled Lobby under smoke-filled stair and which will contain high concentrations of cyanide and if your flat is on fire that's got some cyanide in then it's conceivable but whether or not you make it to the

02:14:40 but whether or not you make it to the bottom of the stair or not or collapse in the stair might partially be affected by cyanide but the source of that cyanide that you're breathing in the logins there is going to be mainly from

02:14:51 logins there is going to be mainly from the kerning contents it's getting into the lobbies I don't know if that helps all right thank you will yabba short break now so that counts because consider whether there are any further further questions exactly so I

02:15:04 further further questions exactly so I can say cause first four and same as before and they're talking about your evidence and you're out of the room and get me to go in the official copy you

02:15:15 get me to go in the official copy you could be always there if you'd like to because well I yeah I think I'll be all right

02:15:19 right yeah I think that'd be quite safe just whether I need to look anything up but I think okay I'll leave it thank you all right thank you very much right 4:15

02:15:35 right thank you very much right 4:15 please

02:22:48 you

02:23:15 you

02:25:44 that Russ

02:25:57 all right thank you for filling I go there's one matter that counts in these two race okay yes mr. professor person can I ask you this you've in both your report and in

02:26:12 this you've in both your report and in the evidence you've given today you've explained that in terms of the Toxic matters you're concerned with its first this smoke as a toxic product then

02:26:23 this smoke as a toxic product then you've spoken about its fixiak gases and then you've also post spoken about the irritant acidic gases so those in terms of products were will walk somebody in

02:26:36 of products were will walk somebody in in the tower risks being exposed to sorry it's very noisy if a person either in a flat or making their way through a lobby or down the stairs use the face

02:26:48 lobby or down the stairs use the face covering a towel over the mouth would that offer any protection against the toxins that you've spoken up yes it wouldn't and of course many people did do this so the main the main barriers to

02:27:02 do this so the main the main barriers to progress initially down through the lobbies and down the stair of so the optical effects but you can't deal with and the irritancy and so it's the pain

02:27:13 and the irritancy and so it's the pain to the eyes the pain to the nose and the mouth

02:27:16 mouth and the difficulty in breathing and this is partly due to the smoke particles themselves and as I mentioned this morning to the organic irritants and

02:27:27 morning to the organic irritants and acid gases attached to these particles which get down into the Airways and cause distress and partly due to the free gases that's acid gases that you're

02:27:39 free gases that's acid gases that you're breathing by having a towel or a wet towel you can filter those you can't stop the asphyxiated gases though certainly this carbon monoxide by that

02:27:50 certainly this carbon monoxide by that method but you can get some relief from the irritants and people did and what's the benefit of the towel being wet well it's mainly whether it's wet or dry it's

02:28:04 it's mainly whether it's wet or dry it's a filter but I think if it's wet certainly if it's wet it will absorb the acid gases chloride to some extent it's just slightly better filter but it's white or

02:28:15 slightly better filter but it's white or dry anything would help yeah thank you that's all I have can i Thank You professor for coming and giving us today well thank you very much

02:28:26 giving us today well thank you very much indeed could you've given a lot of time and effort to the investigation of this tragedy and you put your undoubted expertise at our disposal which we are

02:28:37 expertise at our disposal which we are very grateful indeed thank you thank you very much and thank you coming on today to give us your evidence and explain what it's all about good well now if you'd like to go with

02:28:49 good well now if you'd like to go with the usher that works yes thank you very much

02:28:53 much [Music]

02:29:07 yes so before we finish for the day there's one short matter that I need to deal with could I please have on the screen inq five zeros five three four

02:29:19 screen inq five zeros five three four please if I could explain that this is a schedule which has already been disclosed all participants and it lists witness evidence of firefighters senior

02:29:33 witness evidence of firefighters senior fire officers firefighters and control room operators and we would ask that the statements listed there are taken as

02:29:44 statements listed there are taken as read into the record today the statements themselves will be published at some point on the inquiry website and everyone has been notified of the plan yes well thank you very much I think

02:29:56 yes well thank you very much I think it's right that we record our gratitude to all those who've made statements even if they haven't been called as witnesses in person their evidence is very valuable and the statements will form

02:30:07 valuable and the statements will form part of the overall evidence before the inquiry good thank you very much so that's all for today it is no we're not

02:30:19 that's all for today it is no we're not sitting tomorrow but we are sitting on Monday we're sitting on Monday just to deal with some evidence from the bereaved residence of survivors yes which is going to be read and admitted

02:30:31 which is going to be read and admitted evidence right thank you very much so we will obviously break now and we'll resume at 10 o'clock on Monday morning thank you very much