Expert witness Rodney Hancox provides technical evidence on gas engineering aspects of the fire, including isolation valve failures and regulatory compliance.
00:00:47 good morning everyone welcome to today's hearing today we're going to hear evidence from mr rodney hancock one of the experts instructed to assist the inquiry yes ms grange yes mr chairman could we
00:00:59 yes ms grange yes mr chairman could we call mr hancox please
00:01:10 good morning mr tancox good morning i understand you're going to make the affirmation and it should be there on the screen in front of you it is good would you read out the words please i do solemnly sincerely and truly declare and affirm
00:01:24 sincerely and truly declare and affirm that the evidence i shall give shall be the truth
00:01:27 the truth the whole truth and nothing but the truth thank you very much please sit down and make yourself
00:01:38 comfortable all right you've got some oh good you've got some water there and yes let's give you a moment to settle in
00:01:55 yes let's give you a moment to settle in right right yes yes thank you yes thank you very much mr hancock for coming to the inquiry today to assist us with our investigations it's very much appreciated
00:02:06 appreciated um if you have any difficulty in understanding any of the questions i'm asking you today please just ask me to repeat the question or put the point in a different way and please try and keep your voice up so that the transcriber who's sitting to
00:02:18 that the transcriber who's sitting to your right can take a nice clear note of your evidence now you've produced two reports for the inquiry if we can go to your main your first main expert report at rhx6012
00:02:34 we can see from this first page that the subject of the report the specialist field is gas engineering and this report is dated the first of october 2019
00:02:45 october 2019 it has 11 appendices and i refer to that as your first report
00:02:52 and can we go to your supplementary report as well please it's at rhx6020
00:03:01 there we have that it's dated the 18th of june
00:03:05 of june 2021 that has seven appendices and i will refer to that as your supplementary report
00:03:11 report now can you confirm that none of the opinions and conclusions in your report have changed since these were produced to the inquiry i can confirm that yes yeah and if we look at page six of your
00:03:23 yeah and if we look at page six of your first report at paragraph 10 you confirm that you've provided this report in the same way that you would have provided it to a court
00:03:32 court and you confirmed the same thing at page three of your supplementary report now can you confirm that any factual matters set out in your reports are true to the best of your knowledge and belief
00:03:44 to the best of your knowledge and belief yes i can confirm that and can you confirm that your reports accurately set out your true and complete professional opinions on the matters addressed within them yes thank you now you've helpfully provided
00:03:56 thank you now you've helpfully provided us with a cv let's have a look at that that's at rhx701
00:04:04 there's your cv and just to summarize you're a chartered engineer in the field of gas
00:04:10 of gas engineering is that correct that's correct and if we look at the bottom of page one under the career history section we can see that you've worked in the field of gas engineering since 1970 is that correct that is correct
00:04:24 1970 is that correct that is correct and can you confirm that you've worked in various engineering positions with what was then called british gas including district engineer area planning engineer and operations engineer
00:04:35 engineer yes i can and is it right that while working for british gas you managed a number of gas incidents in the field
00:04:43 the field including fires on gas mains yes i did yes we can see over at page two of your cv that you then became a senior training advisor for british gas
00:04:54 senior training advisor for british gas hq regional services between 1991 and 1996.
00:04:59 1996. is that correct that is correct that's right at the top of the page there and then in 1996 you became a freelance consultant for the gas industry is that correct that is correct and
00:05:11 is that correct that is correct and between 1999 and october 2007 you were a senior engineering consultant with esoteric gas solutions is that right that's correct and is it right you've worked in various
00:05:22 and is it right you've worked in various organizations including your own as a consultant to the gas industry since that time
00:05:27 that time yes i've had a fair number of clients yes thank you and in your role as a consultant to the gas industry do we understand correctly that you have written and audited a number of gas safety cases
00:05:39 and audited a number of gas safety cases for gas transporters i have written yes i have written uh them for a number of gas transporters and i have audited for one of the independent gas transporters
00:05:52 independent gas transporters over a number of years yes thank you and we'll come back in a moment to what a gas safety case is i'll ask you some more questions about that um actually let's do that sorry let's do
00:06:03 um actually let's do that sorry let's do that now can you just explain what a gas safety case is a gas safety case is meant to the gas transporter
00:06:14 meant to the gas transporter or gas conveyor is meant to state what they do to manage their gas network safely yeah and in so doing they are meant to follow
00:06:25 meant to follow what they do so it's it's not an aspirational document it is a statement of what they actually do
00:06:32 do yes and um it covers the whole range of safety activities regarding the safe flow of gas yes and does it deal with how they will
00:06:43 yes and does it deal with how they will deal with escape and supply emergencies yes standards and procedures in relation to those yes thank you and that's a requirement under the gas safety management regulations 1996
00:06:54 1996 is that correct yes it is yeah and it's produced to the hse and resubmitted every three years is that correct if you produce to the hsc every three years a report has to be done
00:07:07 years a report has to be done yes of a review yes if there are material changes then the safety case has to be resubmitted thank you but if there's no changes or the
00:07:17 the changes are not material uh then just the report is sufficient every three years thank you that's very helpful and as a consultant is it right that you've also designed gas
00:07:28 that you've also designed gas networks yourself that's correct and we can see
00:07:31 can see on page two of you'll see that there's a header october 2007 uh director gas distribution solutions we have that there yes and is that your
00:07:42 we have that there yes and is that your own consultancy yes
00:07:47 and if we look at the third and fourth bullet points on page two under that header it says that you have prepared tender documents relating to the replacement of private gas networks
00:07:59 the replacement of private gas networks conveying gas to multi-occupancy buildings with ones which were adopted by
00:08:03 by a um what does gt stand for there gas transporter yes for a housing trust exactly
00:08:10 exactly that is correct and below that in the next bullet point you say you've also your assignments have also included indicative designs of three replacement gas networks conveying gas to multi-occupancy
00:08:22 conveying gas to multi-occupancy buildings for a london borough for inclusion in tender documents prepared by their lead consultant is that correct that is correct so these assignments show do they not that you have designed gas installations for
00:08:33 have designed gas installations for multi-occupancy buildings yes thank you and just back to the first page of your cv just one page back just under qualifications
00:08:44 qualifications we can see that you're a member of igem is that correct yes and under participation in igem activities we can see you are currently the
00:08:56 we can see you are currently the chairman of some technical panels is that correct that is correct and igem is we've heard it from the other factual witnesses it's the institution of gas engineers and managers
00:09:06 managers is that right that's correct yeah and that's the professional body for gas engineers is that correct that is correct and does it publish technical standards which cover safety
00:09:17 technical standards which cover safety regulation knowledge and best practice and are those igem standards um so far as you're aware highly regarded in the industry
00:09:27 industry i believe so yes and those standards are routinely adopted by the gas industry professionals as the standards to which they work on a day-to-day basis is that correct that is correct yeah and
00:09:39 is that correct that is correct yeah and one of those standards is a standard we've referred to a number of times already in the last few days is igem g5 and we can see on your cv that you are the current chairman of the
00:09:52 that you are the current chairman of the igem
00:09:53 igem g5 third edition is that correct that is correct
00:09:58 correct so is this right the current edition of igem g5 is the second edition which was from 2012
00:10:04 from 2012 correct and do we understand correctly that you're the chairman of the panel that is currently working on the updating of the next edition of that standard that is correct yes
00:10:17 is there a a date when the g3 standard is likely to be uh published is that i am hopeful that it will be published in september yes of this year thank you this year
00:10:30 um so can we take it from all of that that you have extensive experience on the safe supply of gas i believe so and also particular
00:10:41 i believe so and also particular expertise in the supply of gas to multiple
00:10:43 multiple multiple multi-occupancy buildings
00:10:48 i believe so thank you now just a little bit more on um the legislation regulation and standards because you were asked in your expert report to explain the
00:11:00 your expert report to explain the background to the relevant legislation regulation standards guidance governing the gas supply to grenfell tower now i think you tell us in your report
00:11:12 now i think you tell us in your report and i just want you to confirm that before the 1st of december 1972 it was the london gas undertakings regulations as amended in 1954
00:11:22 1954 which applied to the supply of gas in the royal borough of kensington and chelsea is that correct that is correct and you describe those regulations in your first report as very
00:11:33 in your first report as very prescriptive yes can you just explain exactly what you mean by that um it
00:11:42 um it would stipulate um that an inspection interval would be exactly two years it would stipulate that the valve would
00:11:54 it would stipulate that the valve would be of a particular type yes it would give no latitude to the engineer
00:12:00 engineer strictly speaking to uh deviate from that or to get a employer a better product yes yes i understand and
00:12:12 yes yes i understand and um did they also have detailed specifications of for example how pipe work should be constructed to comply with those regulations
00:12:24 with those regulations it's yes it was it would refer to british standards as they were at the time yes
00:12:31 time yes um and um
00:12:35 um and um sometimes a bit more detail as well yes now it's right isn't it that the first of december 1972 was an important date for gas regulation is that right
00:12:46 date for gas regulation is that right yes and um that's the date that some new regulations came into force the gas safety regulations of 1972 is that correct that is correct can you just explain why that was such an important moment in the gas industry
00:13:00 important moment in the gas industry basically the those regulations which were published i think about two to three months before that and came into force on the first of december they changed
00:13:12 december they changed quite a few of the practices that uh the industry was um was following and also extended gas safety
00:13:22 safety regulations across the whole country yes uh not just having regulations for central london the
00:13:30 the key things uh as far as those regulations are concerned in terms of gas supplies in into buildings were the one that the a gas pipe going through a
00:13:43 one that the a gas pipe going through a wall
00:13:43 wall or a floor should be slaved whereas prior to that it was common practice to embed it in the concrete or just cement it into the wall yes and for listeners can you just explain very
00:13:54 listeners can you just explain very briefly what sleeving is a sleeve basically is a larger diameter pipe
00:14:00 pipe through which the um gas service or or network pipeline will be inserted through there would be gap between the pipe and the inner inside of the
00:14:14 pipe and the inner inside of the larger pipe yes it's the annular gap which would be sealed the mastic so give you some flexibility yes that was one major area also they outlawed placing
00:14:25 also they outlawed placing gas pipes in unventilated voids those are the two major ones relating to um
00:14:34 um gas pipework going into buildings there were other changes which affected the gas appliances etc but which
00:14:43 which beyond the scope of the inquiry yes so prior to 1972 there was no requirement to sleeve the gas pipes is that correct that's correct and also there wasn't requirements to have an unventilated void is that
00:14:55 have an unventilated void is that correct
00:14:55 correct that's correct yes and and in terms of ventilation can you just explain what the purpose is of ventilation just in brief
00:15:04 in brief the purpose of ventilation is to if you've got a credible gas leak a leak out of a joint valve stem etc miner a minor gas leak have enough ventilation to
00:15:17 gas leak have enough ventilation to dilute the atmosphere and disperse the gas in air mixture before it gets to the lower flammable limit
00:15:24 limit of the gas yes we define adequate ventilation as being ventilation such that the gas in air mixture will not rise above
00:15:35 gas in air mixture will not rise above 25 percent of the lower flammable limit yes
00:15:38 yes thank you so to prevent there to be a build up that could cause an explosion that's correct yeah
00:15:50 yeah now um in terms of the date that grenfell tower was built
00:15:58 was built um is it right that one of the challenging challenges you had as an expert when looking back at the regime that applied when it was first built is that we're not sure exactly when it was built
00:16:10 we're not sure exactly when it was built i mean we have 1972 to 1974 but is it right that you're not entirely clear whether or not the regulations would have been enforced
00:16:21 have been enforced at the time the gas works would have been completed at the tower that that's correct it's the date when gas was installed in the tower
00:16:32 gas was installed in the tower uh it was unknown yes if it was installed
00:16:36 installed before first of december 72 um then the those regulations would not have applied but if it was after 72 strictly speaking those
00:16:47 strictly speaking those regulations would have applied yes but is it right that it took a little while for those regulations to be fully enforced and appreciated by the gas industry that was my experience yes so there were
00:16:59 that was my experience yes so there were still build buildings after december 1972 that might have been built without sleeves and without proper ventilation highly likely yes and from what you've seen at grenfell tower
00:17:10 from what you've seen at grenfell tower when we'll come on in detail to look at the gas installations there does it appear to you that this this tower was originally built in compliance with
00:17:20 with the 1972 regulations they were not no because you've not seen evidence of sleeving on the old pipes is that correct
00:17:28 correct and you don't believe that originally it would have been ventilated properly that's correct yes thank you now just in terms of other changes to the regulatory um framework
00:17:40 to the regulatory um framework um by 2016 and that's relevant because that's when the new gas riser replacement work was carried out at grenfell as we know there'd been a number of changes to the gas industry is it right that the
00:17:53 gas industry is it right that the industry was deregulated in 1985 um deregulated yes
00:18:04 um deregulated yes were private there was private privatized yes yes um and from then on there was no no longer just one big gas undertaker is that correct
00:18:15 big gas undertaker is that correct and they were by 2016 there were many gas transporters is that right 2016 there were many gas transporters yes yes
00:18:24 yes yes um and is it right there around eight regulated distribution networks and cadent operates four of them
00:18:31 them uh yes distribution using that terminology yes yes thank you um and can you just help us as to who monitors the gas transporters
00:18:43 monitors the gas transporters is it right first of all that the health and safety executive energy division is responsible for the health and safety of onshore gas distribution and supply that's my understanding and is it right
00:18:54 that's my understanding and is it right that the hsc does oversee gas transporters measures for safety
00:18:58 safety yes yeah and we also know that off gem monitors pricing matters is that correct yes for the gas industry yeah and in terms of the legislation and
00:19:10 yeah and in terms of the legislation and regulations that would have applied in 2016 when the new gas riser the replacement riser was built um by that time the primary legislation was
00:19:21 by that time the primary legislation was the gas act 1986 is that correct as amended yes as amended yes thank you and there were also three other sets of regulations the gas safety
00:19:33 sets of regulations the gas safety management regulations 1996. yes the pipeline safety regulations 1996 yes and also the gas safety installation and use regulations 1998 is that correct
00:19:45 and use regulations 1998 is that correct that's correct and taken together is it right that those replaced the gas safety regulations in 1972. yes yes now in terms of how they apply
00:19:56 yes yes now in terms of how they apply to gas services is it right that the location of the ecv the emergency control valve is a key point in the infrastructure because the gas transporter is
00:20:08 because the gas transporter is responsible for the pipe work upstream of the ecv so the service is going into the building and the rises through it is that correct that's correct a meter asset manager
00:20:19 that's correct a meter asset manager would be responsible for the gas meter itself where the ecv is is that correct that is correct they'd be working on behalf of the usually of the gas supplier yes thank you so the
00:20:31 of the gas supplier yes thank you so the get get
00:20:31 get get the gas responsibilities there ten to four actually come under the gas supplier
00:20:35 supplier yes i understand yes and then is it right that the landlord is responsible for everything else downstream of the outlet of the ecv the emergency control valve is that
00:20:47 the emergency control valve is that correct
00:20:48 correct the landlord or the household owner or the consumer or the consumer yes i understand
00:20:56 now and is it right that in the industry everything upstream is referred to as service pipe work and everything downstream of the ecv is called the installation pipe work is
00:21:07 called the installation pipe work is that right yes yes yes and is it right that that division
00:21:13 division broadly is set out in the regulations yes yeah
00:21:19 and is it right that in terms of caden and trio
00:21:22 and trio trio's work on residential supply 2 ie the new gas riser it was the pipeline safety regulations 1996 was
00:21:30 1996 was that was the most important piece of regulation yes and you described those pipeline safety regulations 1996 as being in functional form or goal setting again
00:21:42 in functional form or goal setting again can you explain exactly what you mean by that it lays out the uh overall principles safety principles you should for example you should be able to inspect and maintain it doesn't tell you how to do
00:21:53 maintain it doesn't tell you how to do it
00:21:53 it yes yes and is that where other pieces of guidance like the igem guidance come into play yes yes i understand yes
00:22:04 and is it right that the hse itself also issues guidance for the gas industry including detailed guidance on regulations yes they do have guidance documents
00:22:15 documents yeah and as we've just mentioned we've got the igem publishing technical standards for the gas industry would you say that in 2016 the industry would have regarded the idem standards
00:22:27 would have regarded the idem standards as the primary or the most important guidance for the gas industry
00:22:37 in this field yes yes yes nonetheless would you have expected gas engineers in 2016 to also be familiar with first of all relevant hse guidance
00:22:51 with first of all relevant hse guidance yes and other relevant standards that might be referred to um such as those from the british standards that are relevant to gas um i would have expected them to be able
00:23:04 um i would have expected them to be able to
00:23:05 to access them if they felt necessary yes i think
00:23:09 think so see where they were relevant and then go to them as as and when required yes yes i understand now just moving on now to discuss the gas
00:23:20 just moving on now to discuss the gas engineers knowledge of the building regulations and the associated practical guidance in the approved documents including approved document b on fire safety
00:23:32 safety you mentioned and you discussed in your report some very specific sections within approved document b which deal specifically with gas piping and ventilation of shafts and we'll come to look at some of those
00:23:43 and we'll come to look at some of those in due course for example sections 8.40 and 8.41
00:23:48 and 8.41 yes now would you have expected a gas engineer in 2016 to be familiar with those particular sections in approved document b so those ones that are directly relevant
00:23:59 so those ones that are directly relevant to gas
00:24:00 to gas installation work or gas ventilation yep those are the specific that you would find on a word search gas and pipe
00:24:08 and pipe yes yes
00:24:11 would you have expected a reasonably competent gas engineer in 2016 to be familiar with all the other guidance in approved document b no no was there a presumption in the gas
00:24:23 no no was there a presumption in the gas industry
00:24:24 industry that what you had to do was comply with the igem standard and that this would mean that you would automatically comply with all other regulations including the building regulations
00:24:35 regulations yes probably yes in your opinion was that
00:24:39 that a reasonable and acceptable approach for a reasonably competent gas engineer to take
00:24:44 take say in 2016 2017 at that time yes yes and you say at that time why do you qualify your answer that way we've learned a lot since yeah and does
00:24:57 we've learned a lot since yeah and does that mean you've learned a lot since the grenfell tower fire yes yes
00:25:06 in 2016 would a gas engineer have expected their work on a replacement riser
00:25:12 riser to be controllable work under the building regulations and subject to building control approval no no now
00:25:20 no no now as we heard in the evidence of mr dolan rbkc building control appeared to think that the works on grenfell were a repair in your experience was that a common position taken by building
00:25:31 common position taken by building control when it came to gas riser replacement work as far as i am aware it was i never had any dealings with building control right yes to be fair yes no thank you
00:25:44 right yes to be fair yes no thank you that's helpful [Applause] now in your first report you were asked to give
00:25:49 to give your opinion about what occurred on the night of
00:25:52 night of the fire the 14th of june during the fire
00:25:56 fire and the chairman heard evidence about this in phase one and made certain findings but just briefly i just want to run through some of the conclusions that you've reached in in your report
00:26:09 now we know that on the night caden identified that there were three mains supplying gas to the tower and all three had to be cut off to shut the gas down completely is that right that's correct yeah
00:26:20 right that's correct yeah and we know they achieved that by manually digging down to the mains and cutting or isolating each of them at three isolation points is that correct
00:26:28 correct that's correct um and the chairman made some findings in his phase one report including the fact that it he didn't he concluded it was not an option to operate the gas governors as they
00:26:41 to operate the gas governors as they were known at the time um in order to try and isolate the gas supply
00:26:47 supply can you just help what are gas governors and can you explain why those would be unsuitable as emergency isolation points basically
00:26:58 isolation points basically the governor installations what was like the pressure reduction installations like the one at latimer road particularly in the middle of summer where there's no heating load highly integrated network if you shut that one down the other
00:27:10 that one down the other uh pressure uh regulating installations in west london would have just taken over supply to the area yeah you'd have had to shut down
00:27:21 down i suggest the whole of west london if you were going to to do that that would have taken out well days
00:27:28 well days yes and restoration would have taken weeks yes
00:27:32 weeks yes now if i think i recall and if i understand it correctly that the the function of the governors was to ensure that if there were a problem in one area the flow was made up from other sources that's pretty rather
00:27:44 from other sources that's pretty rather crudely i'm sure but is that right yes that's good design yes yes now um in the phase one report the chairman also concluded that turning off the gas supply by operating
00:27:56 the gas supply by operating the pipeline isolation valves or pivs on the east side of the tower was not an available option because they were completely inaccessible due to the falling debris
00:28:07 falling debris uh during the fire and we're going to come on nevertheless to to look at pivs and and discuss the fact that
00:28:15 fact that there is this difficulty with pivs being lost so i'll ask you about that in due course
00:28:22 in the phase one report the chairman also concluded that the conditions in the tower made it impossible to turn the valves off in the basement because there were risks to life
00:28:31 to life um and you say in your report do you not that you
00:28:34 that you entirely agree with that that that was a very dangerous situation for a gas engineer and not to be recommended in terms of going into a basement like that
00:28:44 that that's correct yeah
00:28:47 and you say in your report that in your professional opinion the cadent emergency engineers made the appropriate decision about the isolation and you would like to think you would have done the same in the circumstances
00:28:58 have done the same in the circumstances is that an accurate summary of what you've said yes absolutely yes thank you now in the chairman's phase one report um he reached a conclusion i'm just going
00:29:10 he reached a conclusion i'm just going to show us now just so we can place that if we go to inq3014817 and look at page 287
00:29:26 and look at page 287 and if we look at paragraph 34.15 at the bottom
00:29:30 bottom it says that it was thought at one time that the supply of gas to the tower might have played a significant part in the outbreak and development of the fire but as a result of the investigation carried out in phase one it's become
00:29:41 carried out in phase one it's become clear that that was not the case although the supply of gas allowed fires within individ individual flats to continue to burn until it was shut off at 23.40 that day that's the 14th of june 2017. its
00:29:53 that's the 14th of june 2017. its contribution to the fire which consumed the tower appears to have been minimal however some works associated with the installation of the new gas riser were incomplete and may have contributed
00:30:05 were incomplete and may have contributed to the spread of smoke in those circumstances it will be necessary at phase two to consider whether the installation of the gas service is complied with the relevant regulatory regime but the focus of those investigations
00:30:16 but the focus of those investigations can be relatively narrow so that set that set the kind of platform for the work that's been done at phase two and you've assisted us with identifying whether or not the gas
00:30:28 with identifying whether or not the gas services
00:30:29 services complied with the relevant regulatory regime is that correct that's correct and let's move on on to that um now so i'm first going to ask you
00:30:40 now so i'm first going to ask you about some non-compliances that you've identified that are relevant to isolating gas in an emergency even though in this particular incident
00:30:49 incident they didn't play a role and i want to start by asking about the pivs the pipeline isolation valves now in lay terms is a piv a valve that's located outside a building
00:31:01 located outside a building but close to it which can be shut off um to to shut off the service pipeline for gas is that correct that is correct yeah and is it usually an underground
00:31:13 yeah and is it usually an underground valve
00:31:14 valve yes if we can go to your first report at rhx6012 at page 71 we can see at the top
00:31:27 at page 71 we can see at the top you've provided what you describe as an exploded
00:31:31 exploded diagram and parts list for one of these service valves and so what you've done is you've extracted the parts out and separated them so that we can see it and um is it right that there's there'd
00:31:44 and um is it right that there's there'd be a surface box at the very top of this valve yes and and is it right that that should be visible on at ground level is that correct that's true that's correct
00:31:55 that's true that's correct yeah and under that is a a top section into which that surface box sits is that correct that's correct and is it right that below that is a chamber which allows access for the piv
00:32:08 chamber which allows access for the piv without digging up the ground that's correct and that valve is located within that chamber is that correct yes and can you just explain
00:32:18 explain um how you would operate that valve to block the flow of gas well you you would lift the lid of the surface box
00:32:32 assuming there isn't any debris or drugs paraphernalia or whatever in the chamber you'd insert a valve key and i believe a bit later there is a
00:32:44 bit later there is a photograph of somebody doing it just that which would engage with the top of the valve if you look at number five in that drawing and you then
00:32:56 drawing and you then turn the valve yes and certainly uh up to two inches like 50 ml diameter pipes it's a quarter turn valve larger
00:33:09 pipes it's a quarter turn valve larger diameter services like the 10-inch into the
00:33:12 the um for the boilers at granville tower would have been um 13 or 14 turns different type of valve and it being a quarter turn valve what does that mean
00:33:23 quarter turn valve what does that mean that you can only turn it a quarter of a turn at a time only a quarter of a turn to shut it off you only turn it 90 degrees i see it's a ball valve you literally
00:33:34 i see it's a ball valve you literally yes i understand and just beneath that you've given us i think the picture you're referring to um if we look at the bottom of the page so that's that those are pictures of the surface box and what they should look
00:33:45 surface box and what they should look like at ground level is that correct that's correct and is it right that it's a special instrument that's actually used to engage with the valve is that correct um look at yes it's a a simple square
00:33:59 um look at yes it's a a simple square key yes um which would fit over the um the top of the valve yes and are these um pipeline isolation
00:34:10 yes and are these um pipeline isolation valves these pips sometimes called service isolation valves yeah and typically how far beneath the surface
00:34:18 surface or beneath this talk about the valve plate on the top the valve cover how far down is the well the valve cover is at the obviously at the surface the the top box
00:34:29 the top box the valve itself will be um
00:34:36 600 mil i think between 600 and 750 mil so two for two foot six so would someone reaching in with an arm be able to activate that valve
00:34:47 arm be able to activate that valve they'd have to be jolly have very very strong fingers to do that
00:34:51 do that okay um it's i suppose theoretically possible so how does it actually work in practice then um
00:35:02 um well you have the valve key you've got a nice handle i see so you operate the handle at a high level we give you the moment to do it i i rather assume that when we talk about a key what we're
00:35:13 when we talk about a key what we're talking about here is a a rod of about two two four six in length with uh about three two
00:35:20 three two there's the photographs a bit farther on yeah which actually shows a guy uh operating it one yeah so we go to page 67 i think we might be able to see that
00:35:32 yes thank you yes so that's him operating a piv that's correct yes that's right and can you confirm that it was a legal requirement for all
00:35:44 was a legal requirement for all three of the service pipes into grenfell tower so that's the landlord supply residential supply one and residential supply 2 to have a piv installed
00:35:56 yes yes and um just in terms of what the duty was to keep the pivs accessible um if we can go to the pipeline safety
00:36:07 um if we can go to the pipeline safety regulations 1996 now this is inq three zeros one four seven nine zero
00:36:17 this is a copy of those regulations and if we go to page seven we can see regulation 13 there it says the operator shall ensure that a pipeline is maintained in an efficient
00:36:29 pipeline is maintained in an efficient state in efficient working order and in good repair do you see that there yes and is it right that if we go up to regulation three
00:36:40 regulation three on page three
00:36:45 that we get the definition there of the meaning of a pipeline and it makes clear in section three one the pipeline means a pipe or system of pipes together with any apparatus and
00:36:56 pipes together with any apparatus and works
00:36:57 works of a kind described in paragraph two below
00:37:01 below and that those that paragraph two then makes clear that it includes at sea valves valve chambers and similar works is that correct that's correct so the pipeline includes all all of these valves including
00:37:13 all all of these valves including a piv is that correct that's correct so there's a duty to keep the piv maintained in an efficient state in efficient working order and in good repair yes thank you
00:37:26 and just to be clear does that include the valve chamber and the surface boxes yes yes
00:37:36 yes yes and it's your view is this right that there is an ongoing duty on the gas transporter to maintain the valve the valve chamber and the surface box
00:37:47 valve chamber and the surface box yes yes i'll certainly maintain access to them
00:37:50 to them yes sorry and that that primarily includes making sure that there's access to the valve is that correct yes now you say in your supplementary report that you don't consider that it
00:38:01 report that you don't consider that it should be routine for a gas engineer to actually check that the valve itself is operating yes that's it that is that you don't think any check of the piv needs to include actually
00:38:13 of the piv needs to include actually turning it on and off can you just explain why you say that my view particularly when you may not know whether the valve is a quarter turn valve or not and it's
00:38:25 is a quarter turn valve or not and it's my view that if you just went along to see whether it did operate and if it was a bit stiff and you could see from the photograph using the nice big handles and
00:38:36 using the nice big handles and a good strong chat suddenly making it move they'll turn it up turn off supplies to the block of flats so you've got a lot of supply incident right yes and i don't think that risk is
00:38:47 right yes and i don't think that risk is worth taking yes and in your experience does the valve
00:38:52 valve itself require a lot of maintenance is it likely that it it's going to deteriorate or do these usually work when you need to go to them they usually work yeah even if they're many many years old
00:39:05 yeah even if they're many many years old but they might require a little bit of brute force and ignorance yeah but is it right that a key problem that you and others from the gas industry have spoken about and you discuss it in your report is a phenomenon called lost
00:39:18 report is a phenomenon called lost pivs yes
00:39:21 and can you just explain what you mean by a lost piv well basically local authorities will have
00:39:29 have more resurface roads footpaths they will do other road work such as moving up kerbs and so on and in doing that reinstatement uh
00:39:41 and in doing that reinstatement uh resurfacing work etc the contractor may not replace the valve box uh in their work
00:39:52 box uh in their work um yes especially if there isn't a council
00:39:56 council supervisor on site at the time yes um and in your experience is that a common occurrence in the gas industry it's not uncommon right yes so it's not common but it's
00:40:08 right yes so it's not common but it's also
00:40:09 also you're not surprised when i'm not surprised no when you learn that's happened
00:40:12 happened yes and would a reasonably competent gas transporter have known about this as a problem
00:40:19 problem affecting the industry in 2016 i would have thought so um yes yes and would you expect a reasonably competent gas transporter
00:40:31 competent gas transporter to be checking the accessibility of pips
00:40:36 regularly it's something they should have been doing but i don't think what's being done
00:40:41 done yes yes so in your experience that's not been
00:40:45 been it's always a job that can be put off till tomorrow yes i understand and would you expect a reasonably competent gas transporter to have taken action when they discovered that pivx had been
00:40:56 when they discovered that pivx had been lost or could not be located yes yes
00:41:02 and just to be clear um is this the first line of defense in an emergency is that the first thing that a gas engineer will look to do to turn off the gas in the event of some
00:41:14 to turn off the gas in the event of some incident
00:41:16 incident yes in in terms of rectifying it yes or making it safe now we've already discussed that gas engineers can obviously shut off these pivs in your opinion is
00:41:27 shut off these pivs in your opinion is there any case for allowing other people non-non-gas engineers to shut off pivs for example fire services personnel or building fire wardens or other
00:41:40 building fire wardens or other responsible persons
00:41:43 it's a controversial point but there is a case that to leaving it to the gas engineer to do it who has access
00:41:54 who has access or should have access to plans so they can turn the right valve off yes that's the big fear of letting other people
00:42:01 people really nearly have access to valves yes um but
00:42:10 it's it's why the industry has oscillated over the years between letting emergency services have details of where
00:42:19 of where valves are yes to saying if you want to valve call us out we'll deal with it yes and in your opinion going forward what
00:42:30 and in your opinion going forward what is the correct approach should it be just
00:42:32 just gas engineers that manipulate those valves
00:42:35 valves or should we think about other persons becoming responsible for dealing with them i'd say keep it to the gas engineer but the other pers other people i think
00:42:47 but the other pers other people i think will need to cooperate yes and we'll come back to this um later when we look at the recommendations you've made in your report now in your first report you talk about the hierarchy of options
00:42:59 you talk about the hierarchy of options as to where to put the pivs on services into buildings and you tell us that this is covered by the igem g5 second edition if we can just look at that document now
00:43:10 that document now it's at rhx705
00:43:16 there there we have the igem g5 second edition
00:43:20 edition and if we could go within it to page 65 at the top of the page we can see paragraph 7.3.4 which says the location of the piv shall
00:43:33 which says the location of the piv shall permit access to it in normal circumstances in selecting the location of the piv it shall be cited as near as practicable to the boundary of the property the effect of a building fire on its
00:43:44 the effect of a building fire on its operability shall be considered it shall not be positioned where vehicles are likely to stop or park and if we go down the page
00:43:55 or park and if we go down the page um we can see that there's a figure figure 27
00:43:59 figure 27 which is a diagram and is this right this is showing the hierarchy of preferred locations for where pivx are to be placed is that correct that's correct
00:44:11 correct that's correct and is it right that so what this does is tell you what the what the best locations are and then working outwards what other locations
00:44:23 working outwards what other locations might be
00:44:23 might be is that correct yes location at the end of the day the choice of the location will depend on a number of factors like where
00:44:34 depend on a number of factors like where the gas main is for a start um and how much
00:44:43 land or what's the distance between the main and the block of flats yes yes and is it right that the most preferred placement for pivs as shown in this
00:44:53 this um diagram and in this guidance are points c
00:44:56 points c f j n m and l so we can see c f j there at the top there on the footway is that correct that's correct and then we've got points
00:45:07 that's correct and then we've got points j sorry um n m and l so they are kind of behind the flats is that correct yes not far away from another footway
00:45:19 yes not far away from another footway that we can see at the bottom of the page is that correct yes and then is it right that the next preferred
00:45:26 preferred is inside the property boundary but not in a planted area correct so that would be at points a d and g that's correct
00:45:37 a d and g that's correct so you can see there's the planting area with little black plants um circled there and it's really not a good idea to put these in planted areas is it
00:45:48 these in planted areas is it no but they are right so is it again is it not uncommon to find that someone has planted around a piv and in due course yes that becomes lost because of the
00:45:59 yes that becomes lost because of the planting well you have planting you have enthusiastic gardeners you have weeds yes thank you etc um
00:46:11 yes thank you etc um and then the next preferred location elsewhere in the property boundary um and it's got to be at least five meters from the building is that correct preferably if you've got five meters yeah and so those are points b
00:46:23 yeah and so those are points b e and h yes and then finally the least preferred points are k and l is that correct yes we can see right next to those flats now
00:46:34 we can see right next to those flats now is it right that you think and we know you've been to the tower on is it two occasions you've been to grenfell two years yes that you consider that the pigs at grenfell tower were located under the
00:46:45 grenfell tower were located under the footway
00:46:46 footway within a few meters from the east boundary of the building yes now if that's right were they correctly positioned in accordance with the igm g5
00:46:57 accordance with the igm g5 guidance yes yes in your opinion was there any better position for them to be no the positions were governed by
00:47:09 no the positions were governed by where the building or more specifically the basement wall was yes and where the 15-inch gas main on the eastern side was and the pivots
00:47:21 on the eastern side was and the pivots had to be between those two points yes and is that where any reasonably competent gas engineer would expect them to be
00:47:28 to be yes yes now we heard from mr harrison about how pivs were likely to be have been installed on residential supply
00:47:37 supply one because they were identified in cadence 2008 survey is that your understanding that's my understanding yes but we also know that they could not be found
00:47:48 found in cadence later survey in september 2016. is that correct that's correct and that yeah that matches your observations yes on-site and um
00:48:00 yes on-site and um if we can go to your first report again rhx6012
00:48:04 rhx6012 page one two two this is figure 68 which is a photograph um this is actually a photograph which was taken from mr boy girl's survey when he was surveying for the
00:48:18 riser replacement works and is it right that this shows the footpath on the east side of grenfell tower i believe so yes yes and you've marked this up with
00:48:29 yes yes and you've marked this up with a text box pointing to a manhole cover but that's not the piv surface box is it no it's not no and that surface that we can see
00:48:40 that surface that we can see there immediately adjacent uh did that that appeared to you to be relatively recent landscaping work that was done at the tower
00:48:48 the tower yes it looks it do you agree with mr harrison that the likely cause of the pips
00:48:54 pips being lost at grenfell tower is that they were covered over probably during the primary refurbishment works which completed in july 2016. i think the probability of that is quite
00:49:06 the probability of that is quite quite high yes um
00:49:13 but the reality is we don't know 100 for sure do we because it is possible that they were covered up sometime closer to 2008 is that right
00:49:24 sometime closer to 2008 is that right but the most likely explanation is it was part of the refurbishment works yes i believe that's the as you say the most likely yes explanation
00:49:35 and um
00:49:38 the pivs on residential supply too now they would have been installed after any landscaping works is that correct
00:49:50 because that work was taking place in 2016 and 2017.
00:49:57 the piv for the residential supply number two was um
00:50:05 was um installed i think in february 2017 yes um so that's after practical completion of the refurbishment works in july 2016
00:50:18 the refurbishment works in july 2016 yeah correct yes so is it right that the um the pay for residential supply 2 should have been accessible regardless of whether the other pips
00:50:30 of whether the other pips had been become lost yes now do you think that there was a piv on residential supply too i believe one was installed
00:50:42 supply too i believe one was installed yes uh there is an as installed drawing which i mentioned in the report on the show so i'm confident that one was installed at time of construction
00:50:53 construction yes and um we heard from the witnesses that the suspicion is that it was the metropolitan police concrete pad for
00:51:05 police concrete pad for the lift work that was put in after the fire that may have covered up that piv do you believe that may be correct that is a possibility right yes and just to be clear you
00:51:16 right yes and just to be clear you couldn't find that piv when you went to the tower could you no i
00:51:20 i no i i couldn't i attempted to do so because the measurements from that drawing
00:51:25 drawing i mentioned uh gave the pivot nine meters exactly from the northeast corner
00:51:32 corner yes and in so far as i was able to measure
00:51:35 measure nine meters accurately with a three meter tape uh three times i ended up about
00:51:45 less than half a meter from the edge of the plinth yes so it is possible with measurement error
00:51:52 error on my part on the or on the part of the guy who installed it yes um that the pivot was underneath the um where the the prince was put yes that's
00:52:05 where the the prince was put yes that's the plinth for the lift that was put after the fire yes yes yes and and it's right you that's right yeah no sorry you were obviously looking pretty hard for this yes um valve cover um are you in a position to say in
00:52:18 um are you in a position to say in effect that it must be under the print otherwise you'd have spotted it
00:52:28 i don't know because it is quite possible
00:52:32 possible that something happened in respect of the reinstatement of the area after the gas a residential supply was put in
00:52:44 the gas a residential supply was put in there were some reinstatement defects which were reported
00:52:52 reported um is where the the blocks had been taken up and tarmac had been put in place so it it is possible that
00:53:04 it is possible that it was lost at the permanent reinstatement of that area but i don't know i don't know it's why i can't be i won't say
00:53:17 it's why i can't be i won't say categorically that it's under that plinth right well that's helpful thank you very much yes thank you and just to be clear we we haven't been able to go back and look underneath the concrete print that just hasn't been possible has it
00:53:28 hasn't been possible has it no um now
00:53:34 we know that cake cadent um has no record of any action or any plans of action
00:53:42 of action to reinstate the the piv to residential supply one caden appears to have known about that lost piv and and from at least the first of
00:53:54 piv and and from at least the first of october 2016 to the night of the fire can you help us in your opinion what steps do you think cadence should have taken
00:54:02 taken once it became apparent that there was a lost piv
00:54:06 lost piv on residential supply one um well we lost piv on both residential supply one and also the landlord supply fine we do do both together both
00:54:17 fine we do do both together both together both were missing well in the first instance there should have been dialogue with the tmo yes um
00:54:26 yes um and from that um investigations because and a valve box reinstated there yes and that would have involved effectively
00:54:38 and that would have involved effectively taking out some of the blocks cutting those blocks to fit around the yes new top box yes and in what time frame do you think it was reasonable for
00:54:49 do you think it was reasonable for cadent to be expected to have reinstated those pivs after they were discovered to be missing i i think if he was not done in say six
00:55:01 i i think if he was not done in say six weeks
00:55:01 weeks it wasn't going to be done so uh i would say six weeks two well they made the decision to investigate it before christmas
00:55:13 before christmas so it should have been done january february yes yes so we know this didn't happen on the night of the fire because there was all the falling debris but had someone gone to try and use that piv on the
00:55:25 gone to try and use that piv on the night of the fire the work still hadn't been done by that point that's correct yeah now just briefly now about some other valves that you might find on a service pipeline there's something called a
00:55:38 pipeline there's something called a branch isolation valve is that correct yes and they've been required on service pipe work since uh well before the 1972 regulations is that correct um yes
00:55:51 um yes they they've been referred to one way or another with in british standards yes yes and if we just look at a photograph this is in mr harrison's exhibit it's at
00:56:04 kcad402993
00:56:07 these are photographs of the four bibs the branch isolation valves and is that for each of the four branches up into the four corners at
00:56:18 branches up into the four corners at grenfell tower of the gas pipes for residential supply one yes yes and is it right that these are turned by activating a yellow wheel that we can see on some of these
00:56:29 that we can see on some of these drawings yes yeah
00:56:36 and there's also something called an inlet
00:56:39 inlet isolation valve is that right yes can you just help us as to what the inlet isolation valve or iiv what is that and what does it do its a valve that is fitted immediately
00:56:51 its a valve that is fitted immediately on the inside of the outside wall where the pipe goes into the building it would allow a competent person
00:57:03 it would allow a competent person to shut off supply to the rise any risers
00:57:09 if they could get to it quickly probably quicker than if you got to the pipeline isolation valve
00:57:18 so it is a secondary
00:57:22 point for emergencies but more specifically for maintenance if you needed to shut down the system for maintenance purposes yes thank you let's look at a a photograph of one of those
00:57:34 look at a a photograph of one of those in your first report this is rhx6012 page 29. it's figure 21 there there we have it is that an
00:57:42 that an um that was the inlet isolation valve on residential gas supply number two yes yes thank you and are these iivs a more recent
00:57:53 and are these iivs a more recent requirement than bibs and pivs yes yes um and is it right that there should not have been
00:58:02 have been you wouldn't expect to see an iiv on residential supply one is that right because there are more recent requirements yes
00:58:15 now the role you've made clear that the role of a beer is primarily for maintenance that's right isn't it yes um and is it right for that reason that
00:58:26 um and is it right for that reason that they're meant to be relatively inaccessible that you don't want
00:58:32 day-to-day access by people in the building today that's correct you don't want valves the only valve that you want the consumers the residents
00:58:43 the consumers the residents to have access to is the emergency control valve yes um and can the same be said for ivs that
00:58:53 that because they're really intended primarily for maintenance um that you don't want to make them readily accessible that's correct yeah
00:59:04 readily accessible that's correct yeah yeah sorry carry on i'll try and explain yes please do the um if it was readily accessible to
00:59:15 if it was readily accessible to someone with mischief in mind they could go
00:59:19 go turn the valve off and knock off supplies to all the consumers on that riser yeah so that would be all the flat twos all of that too the danger then comes
00:59:30 all of that too the danger then comes that if they've not knocked them off for say five minutes and then turn the supply back on and somebody is cooking away in their kitchen
00:59:40 kitchen and their cooker does not have a flame supervision device on it yes then the you could then fill the kitchen up with gas yes i see
00:59:52 fill the kitchen up with gas yes i see uh and uh consequence that could be yes thank you now you've noted in your first report that there wasn't a ladder built into the basement which gave
01:00:03 built into the basement which gave access to the iiv on residential supply 2 which gave access to this valve yep
01:00:13 if we can go to page 199 of this report a paragraph 4-1-1
01:00:22 so you say there um it's noted that in the absence of a ladder the valve was not accessible either to cadent gas or the emergency services or a tmo competent person in an emergency
01:00:33 competent person in an emergency given that an iiv is not an emergency control as defined in the pipeline safety regulations i do not believe its relative inaccessibility constitutes a regulatory non-compliance on the other hand i believe the
01:00:44 on the other hand i believe the inaccessibility constitutes poor practice
01:00:47 practice and non-compliance with the third bullet point of and then you've quoted from 7.4.2 of
01:00:53 7.4.2 of igm or you refer to that of igem g5 um is that right and
01:01:01 what you're saying i think is that not providing a ladder to it was poor practice and not compliant with that part of igem d5 is that correct that's correct yeah
01:01:13 and that part of igem g5 just to be clear says that the iiv shall be accessible for maintenance purposes is that correct
01:01:22 yes now would you accept though that working at the height the iv was would probably more properly require scaffolding
01:01:33 scaffolding not a ladder what i had in mind when i wrote that was something like the the ladder that's actually up on the
01:01:44 ladder that's actually up on the 24th floor on the outside to get onto the roof
01:01:47 the roof there was a ladder with uh still uh banned around it or having a ladder within the plant room that could be picked up and and used but yes
01:01:59 picked up and and used but yes um it's
01:02:06 um it's scaffolding to operate a valve in order to turn a handle one hand um even following hse advice of
01:02:19 um even following hse advice of two feet one hand on the ladder at all times it's yes that's taking yes hsc or health and safety guidance to its extreme right so you maintain your view
01:02:31 extreme right so you maintain your view do you that it's reasonable to expect a ladder to have been put there for me yeah or
01:02:35 yeah or to be available yes yes thank you um
01:02:40 just to finalize this point at page 211 of your first report paragraph 447 you have said in your first bullet point there that you think the latter lack of a
01:02:51 that you think the latter lack of a ladder providing access to the iv and associated signage was relevant to the events of the 14th of june 2017. can you just explain why you've said
01:03:02 can you just explain why you've said that in that part of your report um
01:03:08 it's a factor to consider you could argue
01:03:13 argue that um
01:03:21 well some something that one can debate about but having said that if the ladder was there and if they'd been able to get in
01:03:27 in to the basement early yes then they could have operated it yes but it's right isn't it that that would have only isolated residential supply to not residential supply one
01:03:38 residential supply one is that correct yes so it's a pretty minor
01:03:42 minor it is a minor point if at all would you agree with that yes thank you now i want to turn now to the topic of inaccurate maps in your first report you discuss
01:03:56 maps in your first report you discuss some inaccuracies with the maps of the gas network and i'm going to ask you about that now if we can go to cad 402174
01:04:09 now we understand this is cadence record plan of the network as it was on the 14th of june 2017. we can see grenfell tower is marked in the middle in the great square the pipelines are in
01:04:21 in the great square the pipelines are in red
01:04:23 red and we can see that only one is marked as entering the building is that correct that's correct is that the landlord supply that's marked i believe so yes and we can also see images
01:04:34 yes and we can also see images of what the cadent personnel could see on the night of the fire on their handheld devices they're called go books or hand-held electronic devices if we can look at cad-402241
01:04:49 there we can see a picture of what they could see on their handheld devices and in the top third of the map we can see grenfell tower again and again is it right that we see only
01:05:01 and again is it right that we see only one pipeline recorded as entering into the building that's correct and from that do you understand that the network plan was not up to date on the night of the fire that is correct
01:05:12 that is correct and um you tell us in your report that the pipeline safety regulations 1996 are relevant to this if we can go to three zeros one four seven nine zero
01:05:25 one four seven nine zero and look at page nine
01:05:30 in the middle of the page we can see regulation sixteen that's called prevention of damage to pipelines and it says for the purpose of ensuring that no damage is caused to a pipeline
01:05:41 pipeline the operator shall take such steps to inform persons of its existence and whereabouts as are reasonable and was it understood in the industry that it was implicit
01:05:53 that it was implicit in this regulation that there was a duty to keep accurate maps of gas pipelines so that the operator is in a position to inform persons of their existence and whereabouts who otherwise might cause damage to those pipes yes
01:06:05 might cause damage to those pipes yes i'll say reasonably accurate plans yes i'll come on to that in a moment i think i think you you accept that it it it would be council of perfection to expect
01:06:16 council of perfection to expect all maps to be absolutely perfect and i'll come on to that in a moment um just thinking about regulation 16 what is your understanding about what type of
01:06:27 is your understanding about what type of situation it's envisaging um basically other utilities contractors working in the vicinity of
01:06:38 contractors working in the vicinity of the
01:06:39 the pipeline particularly with a mechanical excavator um a risk of damage and if they hit the gas pipe and also
01:06:52 if they hit the gas pipe and also shall we say electricity cable at the same time you have a fire and possibly casualties yes um so that's your danger
01:07:03 yes um so that's your danger that's your hazard that's your risk um essentially there is a
01:07:10 hse guidance um h g47 about the use of plans the use of tracing equipment and safe digging
01:07:23 tracing equipment and safe digging practice
01:07:24 practice to locate other utilities plant so the first instance if you've got a plan that says there's a pipe somewhere here yes then you
01:07:35 somewhere here yes then you look for it carefully expose it and you work carefully around it yes um that's the as i see it the that's the the process
01:07:46 the process in terms of preventing damage yes yes and um can we also look while we're here at regulation 12 on page seven this is titled arrangements for incidents and
01:07:58 is titled arrangements for incidents and emergencies and it says that the operator shall ensure that no fluid is conveyed in a pipeline unless adequate arrangements have been made for dealing with an accidental loss of fluid from
01:08:09 of fluid from discovery of a defect in or damage to or other emergency affecting the pipeline now the pipelines directly into grenfell we know
01:08:20 we know would have had pivs on them those pivs would have been part of the arrangements for incidents and emergencies is that right um you one could argue that yeah
01:08:32 um you one could argue that yeah i believe this regulation is more focused on the setting up of an emergency response i see yes because um
01:08:43 the point i i want to put to you is um does it follow that the duty to keep an accurate map of these accessible in an emergency might also be a regulation 12 duty
01:08:58 i think you could make an argument out to that effect right but that's not how you've commonly understood it in the industry thank you
01:09:08 and just to be clear do you say that in any event and regardless of these regulations it's a matter of good practice
01:09:14 practice for a transport grass transporter to have
01:09:17 have up-to-date plans of its gas network yes um now we heard the uh in the evidence of mr harrison that in 2008 surveyor appears to have recorded the
01:09:29 surveyor appears to have recorded the residential supply one pipeline by just marking it in hand on the map do you remember that evidence yes
01:09:36 yes and we know from cadence survey in september 2016 that the map that those surveyors had only recorded one pipeline in
01:09:47 only recorded one pipeline in now if we could go to your first report on what you say about this situation at um rhx
01:09:54 at um rhx 6012 at page 74
01:10:00 and if we look at paragraph 174 you say in the light of this that it appears to me that national grid gas limited as it then was did not initiate its dr4
01:10:10 its dr4 asset management error management process on receipt of the above survey information from the field can you just explain briefly what the dr4 asset management error management
01:10:21 asset management error management process was my understanding is is that somebody like
01:10:26 like those surveyors who went out in 2008 have spotted a mistake on the records they would fill up a form
01:10:38 they would fill up a form mark up a drawing with the the arrow or the
01:10:42 the missing pipe whatever and the measurements and put it into the
01:10:49 into the office for that information to be then
01:10:54 be then transposed onto the digital records and the
01:10:57 the the plans that are used by um by national grid yes and would you have expected the network plan to have been updated to show all three pipelines into
01:11:08 updated to show all three pipelines into grenfell tower by the 14th of june 2017. oh yes definitely yes and is that so even though residential supply too um all the works associated with that
01:11:20 um all the works associated with that hadn't been completed by the 14th of june would you have nevertheless expected there to have been an accurate plan
01:11:26 plan showing that pipeline physically going into the building given it was there by that time it was there a record trio had written up a
01:11:38 trio had written up a or produced an as installed drawing which i believe they had submitted to cadent uh early march so in my opinion
01:11:50 early march so in my opinion that drawing or the details of that drawing
01:11:54 drawing should have been put onto their records certainly within 30 days of that
01:12:02 record be passed over yes now it's been pointed out that in fact
01:12:10 the the operatives who isolated grenfell tower on the night did get provided with information from other sources so we know that simon boigel
01:12:21 boigel sent an email to cadent uh in the on the morning of the 14th of june 2017
01:12:28 june 2017 describing the services and we can see that mr
01:12:31 that mr alde all day got that information so um is it right that in fact the cadent operatives did get the correct information
01:12:42 the correct information about the supplies to grenfell tower when it mattered yes but um in your opinion is that how it should be
01:12:53 in your opinion is that how it should be done in practice it's not how it should be done but i wouldn't discourage it no so helpful that it is done but the map should have been accurate in the first place
01:13:02 place thank you mr chairman i think that's a good moment for our uh break all right yes well as i think your name is tan cox we have a break during the course of the morning
01:13:13 the course of the morning this is obviously a good time at which to take it so we'll stop there we'll resume at half past 11 please and as with all the other witnesses i'm going to ask you not to talk about your evidence or anything relating to it
01:13:24 your evidence or anything relating to it while you're out of the room thank you very much would you like to give the usher them please
01:13:40 thank you very much how fast you're level please
01:31:13 would you ask mr hancocks to come back
01:31:31 my name is ted cox are you ready to keep going yes certainly good thank you very much yes it's grange yes thank you just before we go back um to the topic of inaccurate maps i just want to ask you a discreet question
01:31:42 just want to ask you a discreet question about the color of pipes are there any relevant regulations and guidance about what color the pipes had to be inside the building once they're inside either the basement or in any of the
01:31:54 either the basement or in any of the rises
01:31:55 rises and is that something that you considered into grenfell tower yeah the there is guidance that says gas pipe should be painted yellow yes in practice that's fine in a boiler
01:32:07 yes in practice that's fine in a boiler room
01:32:08 room the moment you get or in a duct but once you get outside of a boiler room or or duct where people can see pipes they object to bright yellow
01:32:20 they object to bright yellow pipes being attached to buildings or running where they can be seen yes so the practice is to probably paint them black or whatever
01:32:31 them black or whatever color the building owner wants yes and put a discrete but obvious um tape that says gas pipe
01:32:42 um tape that says gas pipe right on the pipe so that it's it can be recognized i see so at grenfell tower the fact we saw black pipes going through the stairwell that was not uncommon in the gas industry that
01:32:54 gas industry that is very very common yeah because as i say it's
01:32:57 say it's invisible where people will see yes i see
01:33:00 see thank you now just back to inaccuracies and maps
01:33:04 and maps and now i want to talk about the station walk maine if you remember one of the questions that was raised in phase one was a begat about the diameter of the main at station walk
01:33:15 station walk and you'll recall that the um go books that the
01:33:19 that the gas operatives had showed it to be of 12 inch diameter but when they finally excavated it they discovered it was 15 inch diameter and the caden emergency engineers had
01:33:31 engineers had also not expected the main to be as deep as it was
01:33:34 as it was and they had some trouble locating it now um you tell us in your report that you don't believe it was reasonable for cadence personnel to have known that the main was 15 inches
01:33:46 the main was 15 inches yes and i'll come back to that in a moment um
01:33:50 moment um just before we explore that in your opinion did the map stating that the main on station walk was 12 inches in any way delay the isolation of the gas on the 14th of june
01:34:01 gas on the 14th of june so the fact it was marked as a 12-inch rather than a 15-inch effect what they did in practice in practice not not really not materially yeah but would it be fair to say that
01:34:12 yeah but would it be fair to say that some difficulty in actually locating the main on station walk did did appear from the evidence to delay the isolation uh to some extent yes yes i think
01:34:24 uh to some extent yes yes i think one of them says perhaps for about four hours based on one of the cadence witness statements that's peter hyatt
01:34:32 now in terms of having an accurate map of station walk um would the main at station walk have been considered a pipeline that would be
01:34:43 considered a pipeline that would be relevant in an emergency no because it's too far away from the building yes so are we back into regulation 16 of the gas
01:34:53 gas safety pipeline regulations in terms of the fact that there needed to be accurate maps so that people could inform others or indeed inform themselves
01:35:04 themselves of its existence is that correct i believe so yes yeah
01:35:09 and in your opinion does the obligation to keep an accurate map of the main station walk come from that regulation uh yes yes there's also
01:35:22 uh yes yes there's also arguments that parts of the gas act also apply but
01:35:25 apply but um yes i will leave that to legal teams too
01:35:30 too yes to consider in your opinion was the record of the main station walk sufficiently accurate to inform persons about its whereabouts and to ensure there was no damage done to it
01:35:46 yes it showed that there was a a main in that vicinity
01:35:54 and if we need to consider in detail and yes we can
01:36:01 we can start looking at history yeah and in your opinion was it reasonable to have expected cadent to have updated its maps with the precise location of that main by the time of the fire
01:36:13 main by the time of the fire no and can you just briefly explain why that was
01:36:16 that was well there's it only needed to have updated
01:36:20 updated location details if they've had to have worked on that main in the reason was in the past yes um a 15-inch doctor iron main
01:36:31 yes um a 15-inch doctor iron main was probably laid in the 1950s yes or 60s possibly 1970 but the that diameter imperial size
01:36:43 but the that diameter imperial size ductile iron mains were only laid on a fairly uh brief time period and said the 50s and 60s
01:36:51 60s so probably before the lancaster west estate
01:36:55 estate was developed um it probably and if that is the case it would have been i suspect suspect
01:37:06 been i suspect suspect it would have been laid to lines and levels
01:37:09 levels appropriate at at the time of laying yes and to reference points that were there at the time yes now what then happened with the development of the
01:37:20 development of the lancaster west estate could well have resulted
01:37:24 resulted in the ground above the main being built up
01:37:31 there's a reference in witness statements to a wall being present which
01:37:40 hindered the location of the main now you don't lay a main under a wall the war gets put in afterwards yes so
01:37:51 in afterwards yes so i strongly suspect that the main has always been where it's been laid but the ground
01:37:57 ground landscaping civil engineering works have um
01:38:01 um yes change his position in in respect of plans as of today's date if that makes sense yes it does and and just to be clear for essentially that reason you're not
01:38:12 essentially that reason you're not critical of cadent for not having an entirely accurate map of the location of that main is that correct thank you can i just ask you this um what we heard on the previous occasion
01:38:24 what we heard on the previous occasion was that the team that was sent out to isolate the gas
01:38:31 gas found they had to cap off that main and they didn't expect it to be a 15-inch main they were and they had equipment that was designed to work on a 12-inch main
01:38:44 to work on a 12-inch main now they were able to uh use it effectively so it didn't matter but should they not have known that it was a 15-inch main and had the right equipment no that they would have been equipped
01:38:55 no that they would have been equipped standard bagging off equipment is for up to 12 inch diameter main and they had that available 15-inch is held at a central location
01:39:09 is held at a central location miles and miles away i think they called it pme um and they would have recalled in and and they did eventually turn up
01:39:21 they did eventually turn up to to actually do the banging off but by using the over inflated bags they were able to temp effectively temporarily stop off
01:39:32 temporarily stop off the gas supply one can argue they took a bit of a risk with that but in the circumstances that was justifiable um i suppose they might have wasted
01:39:44 um i suppose they might have wasted well added an extra 15 minutes or so whilst they did a test on the 12-inch bags to see the diameter to which they were
01:39:55 the diameter to which they were expanded over pressurized too um but you're talking minutes not oh yeah i didn't from for a moment um indeed who i think we all felt had done an
01:40:06 i think we all felt had done an excellent job it was just a question of knowing what they were dealing with and finding that instead of dealing with a 12-inch pipe they were dealing with a 15-inch pipe no they would have found they would have
01:40:17 they would have found they would have realized that when they got halfway round
01:40:19 round digging the main yeah and somebody would have said hang on this is a bit bigger than what you're expecting all right thank you very much thank you and just in general are
01:40:31 thank you and just in general are inaccuracies in maps of these types of mains are they a big problem in the gas industry in your experience
01:40:40 big problem it's a problem which is basically kept generally under control but um there'll always be occasions when um
01:40:54 um there'll always be occasions when um you find some inaccurate records the
01:40:59 the important thing is having a record yes
01:41:02 yes if there isn't a record then certainly that can be extremely critical um but if there is a record but there is uh inaccuracy you need to look at is
01:41:14 uh inaccuracy you need to look at is that inaccuracy material yeah really material in terms of safety of life and property and you need to look at it on a case-by-case basis yes thank you in my opinion now um just briefly now i
01:41:28 in my opinion now um just briefly now i want to ask you about the provision of a line diagram of the service pipes in in the building um have we understood correctly from your first report that you would have expected there to be displayed somewhere in the building a
01:41:41 displayed somewhere in the building a system diagram where the pipe supplies for more than one floor was shown and also showing the root of the pipes to the flats within the tower that's the ideal yes
01:41:52 the tower that's the ideal yes yes and i understand that you would have expected this to have been displayed at the location of the inlet isolation valve the iiv that blue valve we looked at earlier the normal position
01:42:04 earlier the normal position or obviously being that high up in the air you
01:42:08 air you probably have it down at uh floor well sort of uh where you can see it from the ground
01:42:16 ground yeah so the valve is kind of five meters up you expect it to be underneath that valve yes at eye level yes and who would you have expected to produce that line diagram in that location um
01:42:29 line diagram in that location um i would have expected the well i would say the gas transporter which would be caden but
01:42:34 caden but it would be trio as everything's been handed to them yes um but i would also expected there would have been dia should have been dialogue with the tmo about fitting it to their wall
01:42:45 about fitting it to their wall yes and in your report you tell us that there's
01:42:48 there's there's no legal requirement to provide this but you point out that in igem g5 in that guidance at 6.1.7 it specifies that consideration shall be given
01:42:59 given to the provision of a line diagram each building entry iiv depicting the dwellings served by the particular network pipeline is that correct
01:43:07 correct yes and you believe it's good practice to provide such a diagram is that correct
01:43:17 and
01:43:23 do you agree with this though that the gas engineer would readily recognize the iiv itself without the need for signage
01:43:32 signage they would recognize it as it was they wouldn't necessarily know what it fed where you've got more than one
01:43:39 than one pipe going into the building yes so do i take it from your evidence that it's not enough just to say well a gas engineer when he gets to site would understand what he was seeing
01:43:52 you're saying it's good practice to provide that line diagram not just for that gas engineer but for other persons working in the building is that correct yes yes thank you
01:44:05 um now you also discuss in in your report um the extent to which gas might have fed fires on the night of
01:44:16 gas might have fed fires on the night of the 14th of june 2017 and i just want to turn briefly to this but before i do i'm going to give a trigger warning to those who may be watching and attending that we may go to
01:44:28 watching and attending that we may go to some images of the building on fire and they may choose not to watch that so i'm going to give that trigger a warning now and i'll also give it immediately before i show any such images now you note in your first
01:44:41 such images now you note in your first report
01:44:42 report that some witnesses saw what they described as blue flames coming from the tower and they thought this might be gas fueling the fire if we go
01:44:51 go in your first report at rhx6012 page 106 we can see that you have provided here some images
01:45:03 that you have provided here some images of two bunsen burners
01:45:07 and we can see that we have blue flame on the left and yellow flame on the right can you just
01:45:13 just explain taking the image on the left first what is needed to achieve that blue flame which we see on the left basically what is happening is you've got gas coming through the
01:45:25 got gas coming through the monsoon burner and primary air is being entrained through the hole at the bottom of the bunsen burner tube yes so you've got a gas in air mixture then
01:45:36 you've got a gas in air mixture then going up the uh the bunsen burner so you've got a primary combustion or reaction zone where in the middle of the flame
01:45:48 where in the middle of the flame and you've got uh some secondary air which is the atmosphere outside the flame also feeding in from from the outside that gives you your nice bluey green
01:46:00 nice bluey green hot flame yes thank you and in contrast to that can you explain what we're seeing on the right with the yellow flame well what you've got with the yellow flame is there is no primary
01:46:11 flame is there is no primary air being drawn in the valve at the bottom of the bunsen burner is closed and so the air to mix with the gas for combustion
01:46:23 air to mix with the gas for combustion is all that is coming from the outside atmosphere yes so you've got uh far less efficient combustion so what you've got almost on on the left hand
01:46:34 you've got almost on on the left hand side you've got a depiction of what somebody who uses a gas cooker will see from their hob yes whereas on the right
01:46:42 the right is where you've got no primary air yes effectively you've got a gas at an open end being burnt
01:46:54 gas at an open end being burnt yes thank you and um just thinking back to the events of the night in your opinion
01:47:00 opinion if escaped gas was burning in the tower and just to be clear that might be burning off a meter end or burning due to say a ruptured riser and we'll come to both of those in a
01:47:11 and we'll come to both of those in a minute
01:47:12 minute what sort of flame in your opinion would it most likely have
01:47:19 yellowy yellow it wouldn't have been blue uh because you've got haven't got the primary air coming in
01:47:27 coming in yes um so where you've got some kind of open-ended gas that's on fire because you haven't got somewhere upstream of that a valve which is pushing in air and
01:47:38 a valve which is pushing in air and creating that nice mix of of air and gas you you wouldn't expect to see the blue flames is that i wouldn't yes now i'm going to give that trigger warning again now
01:47:49 that trigger warning again now because i'm about to go to an image of the tower on fire if we can go to cad402970
01:48:06 this is a powerpoint presentation created by caden after the fire and if we go within this to page nine
01:48:15 we can see a photograph taken within a flat
01:48:20 it says it's believed to be a flat ending with the number three or six with the gas service pipe on fire now can you just describe from a gas
01:48:29 gas safety perspective what you're seeing here
01:48:32 here well over on the right and i i concur it's a flat with either number three or number six yes
01:48:42 yes it's where the meter position is so that means it's a meter position in the kitchen because it hadn't had its meter moved by the front door just to be clear
01:48:53 clear yes yes it's the one of the original meet positions um if that's ending with three or six and effectively gas is coming out of the
01:49:08 effectively gas is coming out of the where that meter is and and he's just generally burned the air for combustion is from the outside there's no entrainment of primary air yes and so you've got a nice
01:49:19 you've got a nice yellowy flame yes and we're not seeing just for the benefit of the transcript we're not seeing any kind of blue flame here are we no we're not yeah
01:49:30 and can we also go and another trigger warning for this image as well to another image this time of the tower on the evening of the 14th of june
01:49:41 on the evening of the 14th of june so if anyone doesn't want to see they should look away now if we can go to page five of this presentation
01:49:49 this shows the tower on the evening of the 14th of june and you've looked at a number of different images like this is that correct
01:49:56 correct yes and is it your professional opinion that the fires we see inside the flats are likely to be gas fires burning um there could be gas involved with those fires
01:50:07 those fires at that time
01:50:10 and is it also your opinion that the most likely cause of the fires burning by this point if it was a gas fire would be at the open ends of the gas meters within the flats
01:50:22 ends of the gas meters within the flats gas meters or where you've got uh cooker connections if the mate if the gas meter was still intact yes but the cooker connections um
01:50:35 but the cooker connections um quite a lot of those were burnt out yes um
01:50:39 um i think they're listed in in the report yes um
01:50:43 yes um and can you just there's a phrase that you use a number of times in your report which is an open end can you just explain what an open end means in the gas industry you've got a pipe it's not capped so
01:50:55 you've got a pipe it's not capped so you've literally got a a full bore
01:51:01 discharge point for the at the at the end of the pipe yes um and is it safer to leave these fires
01:51:12 um and is it safer to leave these fires to continue to burn out until the gas is shut off or is it safer to attempt to put them out before the gases it's generally safer to let them burn
01:51:23 it's generally safer to let them burn until you can turn off the gas supply yes the reason for that is that if you attempt to put out the
01:51:35 that if you attempt to put out the uh the gas fire at the at the point you've still then got unburnt gas getting into the atmosphere and around the building
01:51:46 the building and if you've got other fires around that could ignite and you could have an explosion
01:51:50 explosion yes so i think what you're saying is by by
01:51:53 by by a long way it's safer to just let those burn until you can cut the gas supply to the whole building yes and certainly in the witness statements and the
01:52:05 statements and the fire brigade personnel i think they they were taking that view as well yes now i want to look now at some of the components
01:52:16 components of of a consumer meter installation to understand the different parts of the gas meter because this will become relevant to some of your recommendations if we go within your first report rhx 6012 to page 27.
01:52:34 if we could zoom in to the picture at the top
01:52:43 and you tell us in your report and can you confirm that this is a typical gas meter installation served by residential supply number one is that correct yes and you've labeled a number of its
01:52:54 yes and you've labeled a number of its component parts if we start on the left you've labeled the ecv is that the emergency control valve
01:53:00 valve yes so that's the valve is it right that a consumer can use and should use if they are concerned that there may be a gas leak within their own flat
01:53:12 a gas leak within their own flat that's correct yes and you say in your first report that you saw some of these that were either partly or fully open
01:53:22 do you mean by that that the ecb hasn't been operated to close the gas supply
01:53:30 they appeared not to have been operated or only partially operated whether that had happened in the cleanup operation or
01:53:44 in the cleanup operation or on the night i don't know you can't tell yes i understand could gas have been escaping and burning from those at any point during the fire only if the meter regulator had
01:53:57 only if the meter regulator had um melted right yes i see now that's the next component moving on to the right we can see marked up the
01:54:08 up the it's the gray kind of disc is the meter regulator next to it and can you just tell us what does a regulator do it's very obvious from its
01:54:19 regulator do it's very obvious from its name but
01:54:20 name but just it regulates the pressure going into the gas meter yes the pressure in the uh in cadence main could be anything
01:54:33 in cadence main could be anything up to 75 millibar
01:54:38 in theory likely to have been in the upper 20s yes that regulator will regulate the pressure down to 21
01:54:49 will regulate the pressure down to 21 millibar
01:54:51 millibar with degree of accuracy so you have a constant pressure going through the gas meter
01:54:58 meter and it's registering the the gas yes thank you
01:55:02 thank you and you tell us that in on your visits to the tower you saw instances where the meter regulators had failed in the fire is that correct that's correct and in your view could gas then have escaped and burn from those
01:55:15 escaped and burn from those yes yes now they aren't marked in this image but is it right that we can also see
01:55:21 see in this photograph something called pliable connectors that's correct yes can you just explain where we see those and what they are well normally they would be between the
01:55:32 well normally they would be between the ecv and the meter regulator
01:55:37 yes there is a photograph in the report that actually shows that i see we'll find we'll find that um and can you just explain what those pliable connectors do do they just connect those two components
01:55:48 connect those two components effectively yes they are a piece of a flexible
01:55:52 flexible or pliable piece of pipe to enable um give some latitude for the fitting of the meter
01:56:00 the meter i think uh in relation to the pipe and the wall and what have you and based on your visit to the tower is it also your view that some of these may have failed and allowed gas to escape
01:56:12 um
01:56:16 not too sure that i that well the pliable connectors tended to be on the more modern uh meters and there certainly were
01:56:28 uh meters and there certainly were some still in existence right yeah um so they
01:56:36 were less likely to have failed i don't recall seeing any because i would say ah that's that's failed
01:56:42 failed yes now just focusing on um meter regulators uh again you discuss in your report the fire resistance of
01:56:53 resistance of the different components of this meter arrangement and you identify a potential problem which as we understand it is this is this right that the meter itself has to be fire resistant to 30 minutes
01:57:05 to be fire resistant to 30 minutes correct reliable connectors also have to be
01:57:09 be of 30 minutes fire resistance is that correct i believe so but this is right that the as far as you understand it the meter regulators do not have to meet any fire resistance
01:57:20 do not have to meet any fire resistance standards
01:57:21 standards that is correct yes and in your opinion does that create a potential weakness in the meter installation in the event that a fire does occur it is
01:57:30 is yes and is it right that none of the regulations or indeed any guidance documents
01:57:37 documents including approved document be on fire safety mention the fire resistance of the regulators themselves that is correct
01:57:51 yes and we'll we'll pick up on this just at the very end of your evidence when we come back to discuss recommendations but that's led to a recommendation that you've made to plug that gap is that correct that is
01:58:03 to plug that gap is that correct that is correct
01:58:04 correct yeah now
01:58:07 yeah now on your inspection at the tower did you see any gas meters that had been entirely burned out entirely i saw some very badly damaged ones
01:58:19 i saw some very badly damaged ones and there's a photograph in the report which um shows that yes a number of gas meters had been removed
01:58:26 removed and one can only assume that that was because they had been entirely um destroyed yes so so and is it right that sometimes
01:58:37 yes so so and is it right that sometimes it's not possible for you to tell if a meat has been removed when that was removed and obviously then you don't know how damaged it was beforehand yes now ruptured riser now if we look at your
01:58:49 ruptured riser now if we look at your first report at page 110 there are two pictures here figures 60 and 61 that you took of a riser
01:58:59 a riser that had ruptured in flat 115 that's flat one of the flat fives on floor 14
01:59:08 floor 14 is that correct that is correct now just looking at these pictures and we see a much more detailed image in the bottom um can you just explain to us exactly where this pipe has split
01:59:19 where this pipe has split in terms of the structure of the pipe it looks if it splits at the
01:59:26 on the threads that the junction where the pipe
01:59:29 the pipe enters the socket of the of the tee yes uh you can also see on the bottom uh photograph a split on the
01:59:40 uh photograph a split on the thread that had been exposed that hadn't got
01:59:43 got into the tree
01:59:48 yes there yes yes and um were you able to form a view about what might have caused the rupture in this riser it's my belief and he's a belief
02:00:02 riser it's my belief and he's a belief that
02:00:02 that you had got building movement because of the fire yes and because the riser was embedded in the concrete
02:00:15 riser was embedded in the concrete of the floors of each floor and ceiling then with the building movement there would have been stresses put on to the uh
02:00:27 stresses put on to the uh the pipe um and i believe that was a weak weak point there possibly because of corrosion you can see
02:00:36 can see some evidence of it um and it snapped yeah yes thank you but it's not possible to tell is it exactly when that would have occurred
02:00:47 exactly when that would have occurred no or what well i don't know exactly and and you mentioned corrosion there um because you i think what you're
02:00:58 um because you i think what you're saying is this was a pipe that would appear to have already been corroded to some extent is that correct
02:01:04 correct um and this just to be clear this is in flat 115
02:01:09 flat 115 um so it's a riser that's part of residential supply number one yes it's the old these are the old pipes yes that fed the building now
02:01:20 yes that fed the building now just a few questions more detailed questions about corrosion um again it sounds like an obvious question but can you just explain to a gas engineer what you mean by corrosion when you talk about it
02:01:32 when you talk about it um
02:01:35 well basically there's a an electrically and an electrolytic action um of that will cause the
02:01:48 that will cause the steel or the ferrous compound if you like to actually revert back to uh iron it eats into the the pipe
02:01:59 eats into the the pipe um and eventually will go through the wall of the of the pipe um and and generally the the strength of
02:02:10 and and generally the the strength of the pipe is deteriorates until such time as it will succumb to stresses on it yes and and does this phenomenon corrosion
02:02:22 and and does this phenomenon corrosion commonly affect uh the steel pipes that are used in the gas industry it is something we're certainly well aware of um and uh is
02:02:33 and uh is um it takes a long time for corrosion to get to a point where it becomes dangerous
02:02:44 where it becomes dangerous yes and
02:02:48 yes and certainly if you spot it early enough you can
02:02:51 you can rub down the get rid of the corrosion deposits etc paint the pipe with appropriate paint um so as to actually get put a
02:03:02 paint um so as to actually get put a protection on the pipe to stop further corrosion yes and is it right that corrosion can be accelerated by a number
02:03:13 number of other factors for example if water were to drip onto the pipe yes um or if conditions are just generally damp within the properties um what if the pipe is embedded directly into the
02:03:25 pipe is embedded directly into the concrete structure of a building i without a sleeve can you tell us is that something that can accelerate corrosion i believe it can
02:03:33 can yes i understand i believe in the concrete industry particularly whether it's reinforced concrete they talk about rebar corrosion as a phenomenon they have to
02:03:45 corrosion as a phenomenon they have to consider
02:03:47 consider and the same effect on unprotected steel pipe
02:03:52 pipe encased in concrete sorry you can get a effect what is it almost a chemical reaction um on the steel
02:04:04 um on the steel yes i understand and we can see that steel pipes are often screwed together meaning they've got the threads
02:04:12 threads around some of the ends what effect can exposed threads have in terms of corrosion
02:04:18 corrosion um it can be a point of weakness because quite often if you've got a pipe that has been painted with such that the paint will
02:04:28 protect the pipe from corrosion where you cut a thread you actually also cut away that that paint that that protection and so unless you
02:04:41 and so unless you paint the the threads which have been exposed
02:04:46 exposed then you
02:04:49 have a weak a point that corrosion can concentrate on yes which way we've already cut into the pipe to start with yeah because of the thread now in your
02:05:00 yeah because of the thread now in your report you identify some regulations that are relevant to the protection of pipes from corrosion and you tell us in your first report that regulation eight of the london gas undertakings
02:05:11 undertakings uh act uh as amended in 1954 and regulation eight of the gas safety regulations 1972 both say that the pipe material must be resistant to corrosion is that correct
02:05:24 resistant to corrosion is that correct yes and how would you have expected pipes to have been protected from corrosion
02:05:30 corrosion at the time grenfell tower was first built
02:05:36 um certainly if you'd been the minimum would have been painting with bituminous paint that's a minimum depends what the old north thames gas board
02:05:49 north thames gas board practice was at the time yes there was certainly in the early 70s well in the 60s certainly you had a bituminous wrap
02:06:01 bituminous wrap uh which was used that was superseded um certainly by 1971 with a plastic covered
02:06:13 by 1971 with a plastic covered uh covering yes and there's a photograph in the report that shows um the service in my house or my garage i should say which with that yellow plastic covering
02:06:25 which with that yellow plastic covering because that was laid 1971 and that gives the corrosion protection to that pipe right and can you tell us based on your inspections of the tower what you observed about the corrosion protection
02:06:37 observed about the corrosion protection of the pipes for residential supply one didn't see any none at all not at all
02:06:46 including painting of the pipes did you see any evidence of that the nearest to it would have been where the
02:06:53 the pipe was actually in the duct um
02:07:03 duct um between the basement and the uh well exiting from the um on the basement i'm thinking um
02:07:15 on the basement i'm thinking um yes but other otherwise you saw no evidence of of painting as a protection
02:07:22 yes so um does it appear then that the installation was non-compliant at the date of installation for that reason
02:07:33 reason in your opinion i couldn't say so so long ago
02:07:38 long ago that the it may well have been painted and considered good enough at that time yes and now and now time's moved on and you can't tell from looking at the pipes is that correct
02:07:49 looking at the pipes is that correct yes now in terms of cadence current duty to maintain materials free from corrosion if we go to the pipeline safety regulations again inq
02:08:00 regulations again inq three zeros one four seven nine zero and look at page five [Applause] we can see regulation eight is there it provides that the operator shall ensure that no fluid is conveyed in a pipeline
02:08:12 that no fluid is conveyed in a pipeline unless it is composed of materials which are suitable now just pausing there um we've seen that there's reference to a fluid in in these regulations
02:08:23 these regulations how does that apply to gas being transported along these pipelines in the context of these regulations gas is deemed a fluid right and that that's provided for somewhere in the
02:08:34 provided for somewhere in the regulations is it um
02:08:38 i don't recall it actually being said that you you're back to
02:08:46 how gas and water hydraulics etc is taught at university these days i see um
02:08:58 i see um and so we can see that it it shouldn't be conveyed in a pipeline unless it's composed of materials which are suitable so that's the func that's effectively the goal setting the functional requirement yes and operator in this uh
02:09:10 yes and operator in this uh instance would mean cadent here is that correct that's correct and so do you understand that this regulation does require cadent to keep the service pipe suitably free from corrosion
02:09:24 yes one can certainly look at that this is where they are assessing the corrosion
02:09:32 corrosion if it's superficial then uh one can argue them it should be rubbed down and repainted that would be sufficient um if it's more severe then
02:09:45 it's more severe then if you like more severe uh more thorough action should be taken yes now we we heard from mr harrison that the way that caden achieves this is through its ongoing
02:09:56 its ongoing rolling survey process is that your understanding yes and is that how the industry more generally tries to keep on top of the problem of corrosion of gas
02:10:07 of the problem of corrosion of gas service pipes
02:10:12 my understanding that it does yes yes
02:10:17 and as i think you've mentioned you can classify
02:10:20 classify corrosion in different ways is it right that it can be classified as superficial moderate severe or extreme yes number of different ways of doing it and some different treatises that
02:10:32 some different treatises that are published yes um i i to be fair to cadence and their predecessors they were looking at a simple grading system
02:10:44 a simple grading system and as to what a normal operative would look at
02:10:48 look at the pipe and say oh that's only superficial or yes that's something we need to yes do something about and helpfully in your report you've given us some examples of of different types of corrosion as it
02:11:01 of of different types of corrosion as it might fall into these definitions so if we go back to your first report rhx 6012 and look at page 127 figure 70a there you've got a riser in a
02:11:13 figure 70a there you've got a riser in a service cupboard and you said it shows superficial corrosion is that correct yes so it's a kind of thin film of what looks kind of rusty yes is that fair that's fair yeah
02:11:26 rusty yes is that fair that's fair yeah and then if we go to page 115 within the report
02:11:29 report figure 66
02:11:34 we can see what you've called more moderate strokes severe corrosion that's from flat 105 do you see that yes and that's the classification that the
02:11:45 the cadence surveyor put on it yes so that's not your label that was his yes yes during their survey process yes so that was during the lc 21 survey is that correct that's correct yes and then if we go
02:11:57 that's correct yes and then if we go over the page um to page 116 figure 67 we can see you this is the water tank in flat 105 with corrosion on the bottom
02:12:08 flat 105 with corrosion on the bottom third of the riser would you describe that
02:12:10 that as moderate or severe i would say that's probably moderate right thank you it could be could be worse yes now we've heard from mr harrison that in the
02:12:22 heard from mr harrison that in the normal course of events cadent would have done a further corrosion survey after their lc-21 survey that they did on the 30th of september and that was because
02:12:34 of september and that was because some severe corrosion was detected at that time is that correct yes yeah and you were asked about that survey process in a supplementary instruction
02:12:46 process in a supplementary instruction which you've dealt with in your first report
02:12:49 report and we know from mr harrison that cadent had a policy at the time called the lc 21 management procedure and by that surveys were to be done at intervals of either one year
02:13:00 intervals of either one year five years or ten years depending on the risk
02:13:03 risk scores of a building is that your understanding that's my understanding yes
02:13:07 yes and in some circumstances that would trigger this separate process for conducting a specialized survey for corrosion called the lc33 management procedure yes again that's
02:13:18 management procedure yes again that's your understanding yes that's my understanding yeah and is it right that had that lc33 corrosion survey been carried out the idea was that
02:13:30 been carried out the idea was that cadent would have then remedied any corrosion they found as part of that process
02:13:36 process if they could have yes yes otherwise it um well they would have certainly made situations safe right now in your experience would a
02:13:47 now in your experience would a reasonably competent gas transporter typically wait until after this specialized corrosion survey
02:13:54 survey to be done before taking any remedial steps
02:14:03 i i think we're talking time scales here yeah
02:14:09 i would have expected that specialist corrosion survey if that was their process to have been done within a matter of a few weeks yes of the first survey after the first
02:14:21 of the first survey after the first survey yes given what they found in the first survey would you have expected some sort of preventative maintenance to have been carried out before the second survey or is it your
02:14:34 before the second survey or is it your evidence that because you expected it to happen within a few weeks you wouldn't expect that i wouldn't have expected that um if it was going to be if the
02:14:46 um if it was going to be if the expectation was it was going to happen within a few weeks i mean a few single certainly single figures and lower single figures at that yes um that
02:15:00 um that that would should be sufficient isn't this all a matter of judgment yes you go and look at the pipe there aren't there's a hard and fast lines between
02:15:09 between a lot of corrosion not much growth i mean it's a matter of assessing what you see and deciding how urgent it is isn't it yes yes yes thank you
02:15:20 yes yes yes thank you now we heard from mr harrison some evidence about what happened and we understand that caden made several attempts to access grenfell tower
02:15:27 tower but did not succeed in completing the lc-33 survey by the night of the fire is that your understanding yes in your opinion was it reasonable
02:15:38 yes in your opinion was it reasonable for caden to have failed to conduct that detailed survey when there were known instances of severe corrosion
02:15:47 could you repeat the question yes um actually i'm going to put the question a different way in your opinion was it reasonable for cadent to have failed to conduct that detailed survey by the night of the fire when we know
02:15:59 by the night of the fire when we know that there were known instances of severe corrosion that were picked up in the september 16 survey not reasonable that should have been done well before then yes
02:16:10 then yes um we know that at the time cayden had something called a work procedure for high-rise building surveys and risk assessment that was called the lc-34 procedure
02:16:22 lc-34 procedure have you looked at that procedure have you considered that i have looked at it yes yes
02:16:26 yes yes and i'm just going to paraphrase it effectively what that says is where there are access problems effectively three attempts should be
02:16:35 should be made to gain access and following this there has to be some record of of what's been recorded and what they could see done is that your understanding
02:16:46 your understanding yes and
02:16:51 yes and where the customer specialist is not able to contact the customer after three attempts and has delivered the appropriate correspondence there should be a network lead that's informed in order for the form to be returned as a no access
02:17:05 be returned as a no access is that correct that's what's written yes yes
02:17:08 yes yes and then this procedure also provides that where a survey can't be completed in its entirety then two additional visits should be made
02:17:18 made [Applause] and if after three visits the survey is not fully complete then the surveyor shall sign the form to confirm that all reasonably practical measures have been undertaken to achieve completion so you were aware
02:17:31 to achieve completion so you were aware of this survey when you of this procedure when you wrote your report is that correct now as far as you've been able to tell did cadence follow the steps outlined in
02:17:42 did cadence follow the steps outlined in its own
02:17:43 its own policy the policy i've just been referring to i don't think i think i say in the report that i don't believe that the inspector for the lc-33 survey was actually provided with the support he could
02:17:54 provided with the support he could reasonably expect to receive and who would that support have come from
02:18:00 from or should that support have come from there's a mention of a customer lead isn't there in their process yes there is one could argue that he didn't get the
02:18:11 one could argue that he didn't get the managerial support he should have had yeah so that's within cadence within codename yes i see
02:18:18 is access a significant challenge in terms of carrying out surveys on multi-occupancy buildings yes and how significant is that problem in your opinion very yes
02:18:39 very yes and we know that the lc-21 survey was completed on first of october 2016 and the fire was on the 14th of june 2017
02:18:50 on the 14th of june 2017 so those actions were outstanding for eight and a half months yes is that correct which you've just said is unacceptable in your view in my view yeah now
02:19:01 in my view yeah now we know that the entire service residential supply one was expected to be replaced in due course by bolting it on to residential supply 2.
02:19:12 2. um that's correct isn't it that was the yes that was the would appear to have been the intention was the fact that it was eventually going to be replaced in any event a reason not to deal with the corrosion
02:19:25 a reason not to deal with the corrosion problems before the fire
02:19:30 i don't think that's a question
02:19:40 certainly the where severe corrosion had been
02:19:44 been identified by the first surveyor then it ought to have been assessed properly by the specialist in that field yes um but having said that that
02:19:58 yes um but having said that that um what i don't not an excuse to uh or saying oh we will replace this sometime it's not an excuse not to
02:20:09 it's not an excuse not to have done that no thank you in your experience were these sorts of delays in preventative maintenance about corrosion common in the gas industry in 2016-2017
02:20:24 i rather suspect that they were at well
02:20:29 i i think one has to look at to where the surveys or where the high-rise buildings are
02:20:40 and whether the where in the locations where the high-rise buildings are has the corresponding gas transporter got the resources yes available
02:20:52 got the resources yes available to deal with that cluster where you've got
02:20:57 got the gas transporter in a shall say a more rural area where you're talking about a small number of high-rise buildings far much far easier to manage
02:21:10 far much far easier to manage than where you've got lots yes i understand yes thank you now another feature that you've noticed and we've referred to this is that there were no sleeves around the gas pipes
02:21:21 around the gas pipes for residential supply one when they passed through solid walls and floors yes um
02:21:29 yes um does that mean that it should be it should have been noticed by caden that there was a particular risk of corrosion in this building because of the lack of sleeving they did note on that
02:21:41 note on that uh report cad 31 that there were no slaves that that was reported um so that would have been or should have been
02:21:52 have been or should have been something that was factored into their risk scoring yes now um just some questions about provisions for a thermal expansion for a moment
02:22:03 a thermal expansion for a moment um just thinking back to that ruptured pipe
02:22:07 pipe you note in your report that the ruptured pipe would have been subject to prolonged and extreme heat during the fire
02:22:16 and that might have caused you say that might have caused thermal expansion and contraction as temperature changes
02:22:24 changes during a fire event what sort of features can be incorporated into gas riser
02:22:29 riser designs to allow for thermal expansion and contraction um
02:22:38 you can um
02:22:44 starting from scratch you can have expansion bellows
02:22:52 at intervals and you can pre-determine what they are but but they are mainly designed to deal with normal temperature changes so if it's on the
02:23:03 temperature changes so if it's on the outside of a building you say well what's the minimum temperature we've ever experienced here what's the maximum temperature you've ever experienced and you work on a
02:23:12 plus minus 50 degrees c whatever yes within the building you're probably talking about plus minus 15 degrees c in terms of expand thermal expansion for
02:23:24 in terms of expand thermal expansion for to the effect of a building fire no you don't really take that's not something that's um designed in right yes is there something called
02:23:37 right yes is there something called flexibles
02:23:38 flexibles in laterals which is something yeah you can
02:23:41 can um design particularly on external um
02:23:48 design in that the um if the riser is going to expand and contract and you've got a lateral effect into an individual flat
02:24:00 effect into an individual flat if you have a if you fix the lateral too close to the riser as it expands and contracts you can cause stresses yes so you start talking about what's
02:24:14 yes so you start talking about what's the
02:24:16 the minimum length of unsupported lateral and we've got some diagrams that can help
02:24:25 help right explain that but again in the context of grenfell that's not relevant right yes is it right that at the time grenfell tower was built there was no regulation or other provision requiring
02:24:36 regulation or other provision requiring thermal expansion and contraction to be dealt with no that's
02:24:44 assuming that the
02:24:48 pipeline system from grenfell was installed
02:24:51 installed in 72 or 73 yes um i think the first time that uh thermal expansion was
02:25:02 uh thermal expansion was addressed in igem standards was in the first edition of ign ige td1 a td4 and that just does deals with the
02:25:14 and that just does deals with the superficial level um right and when was that went i think late seven if my members correct now 70 late 73 possibly 74. yes would sleeving of the pipes help
02:25:26 yes would sleeving of the pipes help with thermal expansion and contraction yes yes so that's good in the context of grantality probably would have but yes so that's another reason why sleeving is so important yes
02:25:38 so important yes yeah now
02:25:41 yeah now thinking back to that rupture of the pipe in flat 115. you tell us in your first report that it's not known when the rupture in the pipe happened um is it possible that the pipe could
02:25:54 um is it possible that the pipe could have ruptured because of building movement
02:25:56 movement after the fire in the days after the fire in your opinion on the balance of probabilities i'd say no
02:26:03 no in in my view given that firstly at 15 30 hours the tactical command meeting
02:26:16 the tactical command meeting reported that the fires that were remaining at that point in time were met in the gas-fed fires
02:26:25 secondly you've got the photograph in the report which is marked up with the flat numbers yes let's go to that now i'll take you that right now
02:26:36 that right now so again but before i do i'm going to give another trigger warning that i'm going to go over to a photograph of the tower on fire that night so if anyone would prefer not to
02:26:45 to look at that they should look away now or leave the room um so it's um in your first report rhx6012 at page 111
02:26:59 and it's figure
02:27:04 62 yes if we could just expand that now we can see here's a photograph of the tower during the day time on the 14th of june
02:27:15 during the day time on the 14th of june and as you say you've marked up the flat numbers against the tower and we can see at flat 115 can you explain
02:27:26 you explain what you're seeing at flat 115 well basically
02:27:29 basically i believe this photograph is taken after the tower is almost effectively burnt out so it corresponds with what the tactical command meeting was
02:27:40 what the tactical command meeting was talking about in the afternoon of the 14th
02:27:43 14th and so this is taken uh this is from a cadent exhibit and they have put the
02:27:49 the flat numbers on the photograph you can see at 115 you've actually got a fire raging quite a significant one compared with
02:28:01 a significant one compared with all the other fires which are still a light in the tower and i look at that photograph and i say that
02:28:12 i look at that photograph and i say that the balance of probabilities is that the sheer amount of gas that you would get out of the open end at that rupture is fueling
02:28:23 open end at that rupture is fueling that fire in 115. yes
02:28:28 on the balance of probabilities yes and and just to be clear you've said in your report that you think it's possible that fires were burning at the meter locations in
02:28:39 were burning at the meter locations in the flats
02:28:39 the flats until the point when the gas was isolated
02:28:42 isolated that evening is that right yes but just to be clear you're saying you think that would have happened during the daytime of the 14th yes not earlier when
02:28:53 yes not earlier when the first valid reports of gas fires in the building from the fire brigade was late morning yes thank you
02:29:05 and is it also your view just to be clear that that ruptured riser burning in flat 5
02:29:10 in flat 5 115 may have been burning right up until the time when the gas supply was cut yes it was around half past 11 at night on the 14th is that correct yeah now sorry um
02:29:23 yeah now sorry um oh and flat 115 was the location of the fracture we were looking at all right uh yeah where the rupture was looking at yes thank you now if we go to page 108 of
02:29:34 thank you now if we go to page 108 of your
02:29:35 your report now that in this report you record some of your analysis of what you saw in terms of the state of the meters
02:29:47 the meters and the regulators in this table and you explain in the paragraphs above this table this is a record of the 26 installations where the ecv was
02:29:59 26 installations where the ecv was either fully or partially in the on position there by presenting potentially an open end through which gas could have fed the fire is that correct that's correct yes as seen as recorded by corgi in
02:30:12 yes as seen as recorded by corgi in their
02:30:13 their uh their report yes i was just about to say that was from corgis technical services report for the metropolitan police
02:30:20 police and in table four you've listed those flats with the potential open ends by floor level and by their flat number ending in one to six so it's the floor it's the
02:30:30 it's the so for the top one it's floor five and it's the flat that ended in a six yes yes that's six um and in the third and to seventh columns you've set out where you observed a
02:30:41 you've set out where you observed a meter that had been damaged and you've set out where you saw meters removed
02:30:47 removed and just to be clear you've said it's possible that there might have been more open ends at meters than are shown in this tail in this table but we won't know that because some of the meters may have been removed
02:30:59 the meters may have been removed and in this table you've marked some numbers
02:31:02 numbers in red and is it right that these are the flats in which dr lane noted had their front doors missing their flat doors missing that's quite correct yes and you discuss the significance of
02:31:14 yes and you discuss the significance of this in
02:31:15 this in your report if you go to page 118 paragraph 258
02:31:22 you say this you say i noted in table 4 above that 23 of the 26 dwellings in which there were potential open ends had missing entrance doors the entrance door to flat 115 which contained the
02:31:34 door to flat 115 which contained the ruptured riser was one of those that were missing i've also noted that dr barbara lane in paragraphs 14 69 of her supplementary report concluded that there was no evidence of
02:31:45 that there was no evidence of significant fuel load generally present in the lobbies she also concluded that most of the heat in the lobbies probably originated from within the flats consequently i believe it's possible that flames from the burning gas in some
02:31:56 that flames from the burning gas in some of the dwellings may have traveled as far as the front doors and into the lobbies when gas was fueling the fire from late morning on the 14th of june 2017.
02:32:07 on the 14th of june 2017. and just to be clear you're not an expert in fire dynamics that's correct all you're doing is is correlating where there were these open ends or a ruptured riser and where
02:32:18 open ends or a ruptured riser and where there were flat missing flat doors yes now um we know that
02:32:29 now um we know that um some of the meters were moved to quite close to the front doors we'll come back to that that was a part of the rise of replacement but many of the meters remained in the
02:32:41 but many of the meters remained in the kitchen
02:32:42 kitchen as we saw from the photograph we looked at earlier today just thinking about those flats is it still your view that those open ends might have led to a fire such that a
02:32:54 might have led to a fire such that a flat front door would have burnt down later in the fire
02:33:02 i don't know i don't know yes okay but for those where we're talking about the flat twos that had their meter close to the front door do you believe there might well be a
02:33:13 do you believe there might well be a correlation between the meter burning out and the fact that we then saw a missing front door um it's possible but i don't think we've
02:33:24 um it's possible but i don't think we've got recorded that there's a flat two um
02:33:35 flat two um burnt out might have been one or two of them or at least one or two where the meters have been removed i see i'd say i sense this is a question that has to be determined by
02:33:46 a question that has to be determined by reference to a body of evidence and what's really a specialist gas engineering point is it um
02:33:53 yes and it's
02:33:57 yeah i i think obviously you need to pull together what dr laina said
02:34:04 yes you you were just trying to piece together the evidence you've got from the gas side and put it together with what she'd got but you can't draw any firm conclusions can you no let's move on then i want to talk now
02:34:17 no let's move on then i want to talk now about the design non-compliances of resident residential supply number one just briefly first um you give your views on some features of
02:34:29 you give your views on some features of this residential supply one that might have been non-compliant with the regulations and standards of the time and we've talked earlier about ventilation you've identified at least two places where you consider that the
02:34:41 two places where you consider that the residential supply one was deficient in terms of ventilation and you've said in your report that the the rises went through the flats from
02:34:53 the rises went through the flats from kitchen to kitchen is that correct yes and they came into the flats and they were accessed through the kitchen cupboards is that right
02:35:04 for residents yes there's access through through cupboards yes yes um and you've said that at best these were poorly ventilated yes if you um certainly
02:35:16 yes if you um certainly that is also the view of the people who did the lc-21 survey yes they did note that
02:35:28 so would it have been possible to have the riser going up through those kitchens but still have achieved good ventilation in your opinion um
02:35:39 in your opinion um if the ventilators had been in the door but um
02:35:44 but um it's normal uh
02:35:50 if you like from that time it was normal practice just to regard and when we covered door or the gaps around an ornery covered door has been sufficient providing sufficient ventilation but yes but i think as you we discussed earlier
02:36:02 but i think as you we discussed earlier once the 1972 regulations came into force and were being applied yes there were more onerous ventilation requirements that this certainly wouldn't satisfy yes
02:36:14 and are there still buildings in this country built like grenfell with pipes fixed rigidly into the concrete i believe so with unsleeved pipes i believe so and with poor ventilation
02:36:27 i believe so and with poor ventilation i believe so yeah and is it right that the other the basis for your belief sure age of building stock particularly in high-rise
02:36:38 in high-rise blocks um there were a lot i'm sure your your colleagues will know more about when high-rise blocks were built in in this country
02:36:51 blocks were built in in this country i'm certainly aware
02:36:54 from the one i was brought up in of blocks high-rise blocks being built in the middle of the 50s
02:37:01 i knew back to what was the the norm back in the 50s 60s 70s i i work with um a number of housing associations
02:37:13 um a number of housing associations they've got private gas networks and i know the issues that they have got and they've got some very old properties with gas systems in them yeah yes thank you and is it right that
02:37:25 yeah yes thank you and is it right that the other problem with this designer building was that a very substantial portion of the risers go through people's flats so that makes them very difficult to inspect and maintain
02:37:35 maintain is that correct that's correct yeah
02:37:44 now
02:37:53 let's come on to residential supply 2 now we heard from mr harrison and mr dolan about the decisions to replace residential supply one with a new
02:38:04 one with a new riser which went through the stairs and we know that trio created an initial design
02:38:13 design replacement design one and that that design then changed in march 2017 once it had been discovered that flange joints had been installed rather than
02:38:24 joints had been installed rather than screwed or welded joints is that your understanding that's my understanding yeah
02:38:30 now because these the design and construction of the gas riser for residential supply 2 was quite recent there that was governed by these more recent regulations and standards is that
02:38:41 recent regulations and standards is that correct
02:38:42 correct that's correct now just to be absolutely clear in your inspections of the tower did you see any evidence that the fire itself had affected the new riser in the
02:38:55 itself had affected the new riser in the sense of having breached the new riser i saw no evidence of breaching on the new new riser and you inspected it completely from top to bottom top to bottom visual inspection yes yes so there was no leaking of gas
02:39:09 yes so there was no leaking of gas from that pipe no evidence of leaking from gas from that point yes thank you now i want to discuss with you the options that they had for the route of this
02:39:20 that they had for the route of this replacement riser now is it right that igem currently recommends that gas rises to multi-occupancy buildings are positioned if possible on the outside the exterior
02:39:31 if possible on the outside the exterior of the building that is correct so that's the preferred option
02:39:36 option and with with primary meters being emit installed immediately on the inside of the external wall from that external pipe is that correct that's correct
02:39:47 now at grenfell tower can we agree that would have meant that there were a number of pipelines going up outside the cladding piercing it piercing the insulation and going into people's homes
02:39:58 people's homes where their consumer meter would have been relocated is that is that how it in theory could have worked that's in theory how it would work yes
02:40:09 now we've understood that putting the riser on the outside of the building was discounted primarily because of the cladding because it would have affected and invalidated any warranties on the cladding but it would have also affected
02:40:21 cladding but it would have also affected the aesthetics of the exterior in your view was that a reasonable decision to discount putting the riser on the exterior of the building
02:40:32 building well basically if the building owner says no
02:40:36 says no then that is not an option right so for whatever reason the building owner says no yes yes thank you in your view would it have
02:40:47 yes thank you in your view would it have been reasonable to try to put the riser up through the existing route so we know it was the the route serving the flat twos would it have been reasonable to try and
02:40:58 would it have been reasonable to try and effectively repair that riser or replace it in its in its original location i don't believe that that would have been sensible or or possible the
02:41:13 sensible or or possible the first thing is that we're talking about a
02:41:21 a cupboard which if my memory is correct has got a water tank in it so you've got to get would have to get the pipe
02:41:30 the pipe into that space in exactly the same position for every flat
02:41:39 from four fl the fourth floor to the 23rd um
02:41:46 23rd um you'd have had to have drilled through the the floor ceiling exactly the same position you'd have to have made a jointed the pipe fixed it to the wall installed it
02:42:00 fixed it to the wall installed it so if you're going to weld within a somebody's property you've got a fire risk
02:42:05 risk uh you've got um fumes risk from from welding you've got positioning but
02:42:12 but i don't believe there would have been room to actually yes fit the pipe in that compartment yes in that space so in your
02:42:23 compartment yes in that space so in your view that was simply not a practical or viable i don't believe it was no what about putting the new gas riser
02:42:30 riser through the utility shaft that we saw opposite the lift in each lobby whether you inspected to the left of the stair door
02:42:39 door there was a a cupboard that you could open or shaft that you could open which had a number of utilities running up it in your opinion was it an option to put the gas riser through that
02:42:51 the gas riser through that existing i don't believe so because the shaft well it's not really a shaft there were rooms in the sense that you've got a roof
02:43:02 in the sense that you've got a roof ceiling
02:43:03 ceiling yes so what a compartment i see yes um it wasn't and what you've then got is how are you going to ventilate that compartment to outside
02:43:17 that compartment to outside and it's right in the middle of the um the building um there was nowhere you could put docks in or out
02:43:29 so i don't believe that was an option right yes
02:43:33 right yes thank you um and as we know the route that mr boigel the surveyor proposed came um predominantly through the stairwell it had to get
02:43:44 stairwell it had to get up to the stairwell from the basement um and the panel has heard evidence from the tmo and from some residents that there were concerns about that as a route now in principle
02:43:57 as a route now in principle if all other design requirements could be met
02:44:01 be met including adequate ventilation was placing the riser on the stairs an acceptable route under the igem
02:44:08 the igem g5 guidance provided ventilation was available to outside top and bottom
02:44:21 then that would be the suitable route for that part of the pipeline
02:44:28 the issue is how you get the pipeline on a ventilated route
02:44:36 route from the basement yes to that point where it starts going up the stairs yes and we'll come to it in a moment but in short
02:44:46 in short you you have real serious concerns about how you could ever ventilate between
02:44:53 between in that portion of the building yes is that correct that's correct yes now
02:45:00 yes now is it right um and we'll look at it in a moment that approved document b does refer to gas rises being in protected stairs yes let's let's look at it it's at clg
02:45:11 yes let's let's look at it it's at clg 50224 at page 53.
02:45:17 we can see section 4.40 in the right hand column in the middle of the page it tells us their gas service and installation pipes or associated meters should not be incorporated within a
02:45:29 should not be incorporated within a protected stairway unless the gas installation is in accordance with the requirements for installation and connection set out in and then we've got the 1996 pipeline safety regulations
02:45:41 pipeline safety regulations and the 1998 gas safety installation and use regulations yes so um and that was well understood was it
02:45:49 it by a reasonably competent gas engineer in 2016
02:45:54 in 2016 i believe so yeah so you could place it in the protected stairs only if it met those other more specific gas regulation requirements
02:46:04 now i just want to explore um what happens though if it's a fire fighting stare um if we look within approved document be
02:46:15 if we look within approved document be at page 116
02:46:20 this is within the b5 functional requirement part of approved document b so it's about access and facilities for the firefighters and here we have diagram 52 which gives
02:46:33 and here we have diagram 52 which gives components of a firefighting shaft and if we look in the notes at the bottom of the notes item 4 we can see it says this diagram is only
02:46:46 we can see it says this diagram is only to illustrate the basic components and is not meant to represent the only acceptable layout the shaft should be constructed generally in accordance with clauses seven
02:46:55 seven and eight of bs double five double eight part five two thousand and four do you see that
02:47:01 see that i see that
02:47:05 now and then if we go to that british standard which is at bsi 6087
02:47:16 there we have that british standard and if we can go to page 23 actually if we look at page 22 first we can see there's a section 7.1.4
02:47:28 we can see there's a section 7.1.4 that begins at the top of that page layout of firefighting shafts and then if we go over the page to page 23
02:47:37 at the top of the page if we look third paragraph down there's a paragraph beginning goods lifts and service lifts and that reads goods lifts and service
02:47:49 and that reads goods lifts and service lifts should not be located within firefighting shafts only services associated with the firefighting shaft should pass through or be contained within the firefighting shaft
02:48:00 shaft a firefighting shaft should not contain any cupboards or provide access to service shafts serving the remainder of the building now is it right that the practical effect of
02:48:11 is it right that the practical effect of that is that if the stairwell at grenfell tower was a firefighting shaft and we believe it was because it was the only shaft that the firefighters could use to access the tower
02:48:22 use to access the tower there should not have been a gas riser in it is that correct it would appear to be the case yes now in 2016 would a reasonably competent
02:48:33 now in 2016 would a reasonably competent gas engineer have appreciated that there was this provision within this british standard no no no so
02:48:45 no no so it wasn't known within the industry that approved document b had this note referring to this british standard
02:48:52 standard which might be relevant to whether you could put
02:48:55 could put a gas pipe up a firefighting stair is that correct that's correct so if you do a word search on approved document b including the version that was current at the time of
02:49:08 version that was current at the time of 2016
02:49:09 2016 you don't go anywhere near this yes not for gas or for pipes yes and um does it follow from that that a reasonably competent gas engineer
02:49:21 a reasonably competent gas engineer would not have been thinking that there was a distinction to be drawn between a protected stare and what you could put up a protective stair and what you could put up a firefighting stair
02:49:32 you could put up a firefighting stair i doubt if they would unless they were advised of that by the building owner yes
02:49:42 yes so does it follow that you're you're not critical of trio for not appreciating that this british standard might be relevant to that choice of route up the stairs i'm not critical of them in that respect
02:49:54 i'm not critical of them in that respect yes thank you [Applause] now ventilation
02:50:01 um i want to just start with their first design
02:50:06 design and ask you some questions about the ventilation provision in that um if we go back to approved document b clg 50224 at page 81
02:50:18 clg 50224 at page 81 we can see in the bottom left-hand corner
02:50:22 corner it talks about pipes for oil and gas and ventilation ducts in protected shafts and if we look at the second paragraph under that header at the very bottom of the page it says
02:50:33 at the very bottom of the page it says any pipe carrying natural gas or lpg in such a shaft should be of screwed steel or of all welded steel construction installed in accordance with the pipeline safety regulations and the
02:50:45 regulations and the gas safety installation and use regulations so we can see that there and then if we go to the
02:50:52 go to the top of the page in the right hand column there's a note it says a pipe is not contained to be is not considered to be contained within a protected shaft if the pipe is
02:51:03 a protected shaft if the pipe is completely separated from that protected shaft
02:51:07 shaft by fire resisting construction is that correct
02:51:10 correct that's correct yeah and then underneath that there's a heading ventilation of protected shafts conveying gas and it tells us that a protected shaft conveying pipe flammable gas should be adequately ventilated direct
02:51:22 should be adequately ventilated direct to the outside air by ventilation openings at high and low level in the shaft and then it goes on any extension of the story floor into the shaft should not compromise the free movement of air over
02:51:34 compromise the free movement of air over the entire length of the shaft now is it right that you would have expected the trio designers to have been familiar with those parts of approved document b yes
02:51:45 document b yes and the need to ventilate the shaft directly to the outside air by openings at high and low level in the shaft
02:51:55 shaft yes and it's there yeah um there is there was some work done by the health and safety laboratory so some years ago
02:52:08 laboratory so some years ago he said it was like unfortunately i can't find it to come back to you on that which indicated that the if you had half an air change an hour
02:52:19 hour in the shaft that there would be sufficient ventilation uh for a gas pipe yes uh which is why there's some certain notes to clauses in
02:52:32 there's some certain notes to clauses in igem g5 which talks about direct and indirect
02:52:36 indirect ventilation yes i was going to ask you about that so and we heard about this concept of indirect ventilation from mr dolan at trio so is it right that if the pipe
02:52:47 at trio so is it right that if the pipe is
02:52:48 is screwed or welded that igem 5 contemplates that you could have some something that's more indirect ventilation rather than
02:52:59 ventilation rather than ventilation directly to the outside if it's all welded uh if we can yes do you want to um i think i know which bit of igem 5
02:53:10 which bit of igem 5 might be relevant if we go to rhx705
02:53:21 and we go to this is igem g5 second edition page 52.
02:53:30 um and if we look at 6.4.3 yes at the top design is it in this section that we see this concept of direct and indirect being
02:53:42 concept of direct and indirect being discussed yes it is is that correct and do you want to just explain to us what you understand this to be saying in terms of the igem guidance right um six four three three
02:53:55 six four three three any common stairwell or other protected shaft containing a network pipeline that is itself not contained in a sealed duct ventilated direct right side shall
02:54:06 duct ventilated direct right side shall be directly shall be directly to outside air and for the purposes of the standard stairwells or other shafts having well distributed in other words without any stagnant or
02:54:17 in other words without any stagnant or area dead area ventilation above half a air change per hour are normally deemed to be adequately ventilated i believe that came for some work from the health and safety laboratory
02:54:29 the health and safety laboratory a number of years ago yes
02:54:32 we then go on any network pipeline incorporating the screwed flanged or other joint capable of developing a leak yes and we've got the exclusion which doesn't apply to grenville shall be
02:54:43 doesn't apply to grenville shall be ventilated direct to outside air right yes so that requires the riser in the um stairwell at grenfell
02:54:56 um stairwell at grenfell with the screwed joints on the valves as well as the flange well not just the flange but to have been ventilated to outside air top and bottom
02:55:11 we then go five so you could go up just a second yeah you can go down the page a little bit
02:55:21 any network apartment all welded construction network which uh grenfell wasn't so it says any network pipeline of all welded controls all welded yes or continuous steel pipe without
02:55:34 yes or continuous steel pipe without joints
02:55:36 joints shall be ventilated either directly to outside air or indirectly to outside air via an area that is normally occupied so what's envisaged there if you've literally got
02:55:47 literally got just a welded pipe yes no screwed joints no valves there yes then it could be indirectly ventilated in other words where you've got a
02:55:59 in other words where you've got a corridor for example and people are walking through opening doors closing doors and you've got this half an air change now yes i see and that was never the intention was it at grenfell because
02:56:10 the intention was it at grenfell because for the first design it was screwed joints wasn't it for the design
02:56:16 design so i think what you're saying there is that according to igem g5 it wasn't acceptable to say well there's indirect ventilation because that's only applicable where
02:56:28 because that's only applicable where you've got an entirely welded pipe is that correct yes but though you've got the letter out there at the end irrespective of whether ventilation is directly or indirectly to outside air adequate ventilation
02:56:39 to outside air adequate ventilation shall be provided or other areas so in other words prove it
02:56:45 it have you got half an air change now yes i see so even if you can't follow the more prescriptive routes above there might be a way that you could do some calculations for example is that
02:56:57 some calculations for example is that right that shows that you in fact have got adequate ventilation albeit via an alternative route yeah is that how you understand that's how that's the principles behind it yes yes
02:57:08 that's the principles behind it yes yes thank you that's that's very helpful
02:57:16 and you are critical of some aspects of trio's design in terms of its ventilation strategy is that correct
02:57:28 mr chairman i think actually that would be a good moment to break just because i'm going to go into slightly more detail on that topic and i know that might
02:57:36 might rather yes thank you i'd rather do that in one go
02:57:39 in one go well mr hancock's i think the times come for a break for us all to get some lunch so we'll stop there we'll resume please at two o'clock and again please don't talk to anyone about your evidence out of the room all right thank you very much thank you
02:57:51 all right thank you very much thank you all right would you like to go to the usher then please
02:58:06 good thank you two o'clock please