page 1 1 Tuesday, 22nd July 2008 2 (10.41 am) 3 MR MARTIN: My Lord, the final witness in the group of 4 witnesses who were ICL directors or employees is 5 Mr Andrew Stott. 6 ANDREW DUGUID STOTT (called) 7 Examined by MR MARTIN 8 Q. Mr Stott, I think you are content that I read through 9 your statement and I shall ask you to look at various 10 documents as I do that. 11 Your full name is Andrew Duguid Stott. I shall read 12 in the first person: 13 "I have a BA honours in Industrial Relations at 14 Strathclyde University. This was a 4-year course. 15 I started it in the summer of 1993 and completed it in 16 the summer of 1997. It is now called Human Resource 17 Management. Basically it was a business type course and 18 consisted of pay, motivation, the relationship between 19 employer and employee, and employer and the state. 20 "I have a Masters in Business and Management at 21 Strathclyde Graduate Business School. I obtained that 22 masters between 1997 and 1998. This was not governed by 23 Strathclyde University and as far as I know was 24 a private enterprise course. 25 "Employment at ICL Tech. page 2 1 "From about 16 years of age I worked every summer, 2 July, August and the beginning of September from 8.00 am 3 until 5.00 pm at ICL Tech." 4 I take it that was when you were at school and 5 a student, Mr Stott; is that correct? 6 A. Yes, that would be correct. 7 Q. Did you have a family connection in the firm which led 8 to the summer job that you have described? 9 A. Yes, I did. 10 Q. Who was that? 11 A. That was Frank Stott, my Dad. 12 Q. I wonder -- forgive me -- could I ask you to keep your 13 voice up, please, because the lady has to hear it on the 14 microphone to transcribe it. 15 Carrying on paragraph 5: 16 "I would go in during the summer and do basic 17 fabrication work such as drilling holes into plastics 18 and I also painted the floors in the fabrication and 19 coating shop. I remember I painted them red and grey. 20 "When I was 18 years of age I went to university. 21 However, I continued to work at ICL Tech during the 22 summers when I was aged 18, 19, 20 and 21 years old. 23 "Risk assessment 1997. 24 "During my time at ICL Tech I carried out a risk 25 assessment exercise. I have been shown a folder of page 3 1 documents." 2 Could I have 11893, please, and 11894. 3 Mr Stott, I think this is a bundle of documents you 4 were shown in the first instance by the Procurator 5 Fiscal. Is that right? 6 This is just the first page. I am going to look at 7 various pages in it. Do you recognise that? 8 A. Yes. 9 Q. I think it is fair to say that as recovered following 10 the disaster, this bundle of documents contains some for 11 which you were perhaps responsible and can identify and 12 others which were obviously created later and when you 13 no longer had any connection with ICL as far as 14 employment is concerned; is that right? 15 A. Yes. Yes, that's right. 16 Q. So we will go through the document, I think with that in 17 mind. 18 Could I have 11894, please. 19 Page 1 is entitled "ICL Technical Plastics Limited, 20 health and safety programme, risk assessment exercise 21 AS/TM/16/07/97." 22 "The risk assessment that I carried out was purely 23 for ICL Tech. The initials AS/TM would be my initials 24 and the initials of the secretary who typed it, Tracey 25 McCafferty. It would have been typed about 16th July page 4 1 1997." 2 Could I have 11962, please. 3 "Page 69" -- is that the page in front of you? 4 A. Yes. 5 Q. -- "are the minutes of our first risk assessment meeting 6 held on 17th October 1996. It is likely that this risk 7 assessment would therefore have been an ongoing piece of 8 work between those dates of 17th October 1996 and 16th 9 July 1997. I did this risk assessment a long time ago 10 and it is difficult to remember. 11 "The report was completed by me with joint input 12 from Bill Masterton and Frank Stott. Bill Masterton was 13 responsible for health and safety and was also the 14 Coating Shop Manager. 15 "At that time I would be in my fourth year at 16 Strathclyde University and I was coming into the factory 17 two mornings a week. 18 "I believe my involvement in the risk assessment 19 exercise ended around the end of January 1997, albeit 20 that the date of the report is 16th July 1997. I never 21 did another risk assessment or anything associated with 22 it again. 23 "I recall that initially Frank Stott had asked me to 24 do a training needs assessment. This had been something 25 that had been part of my degree. I was to carry out the page 5 1 training needs assessment and then answer to Peter 2 Ferguson. Peter Ferguson was a manager. I think he 3 might have been Fabrication Manager and he also 4 had responsibility for training. I then reviewed every 5 process within the fabrication plant, the coating shop. 6 This was essentially listing every process taking place, 7 ie scrapping, drilling, burning, welding and I then drew 8 up a list of the employees and essentially put ticks 9 against their skills in plastics, fabrication and 10 coating. I then compiled a grid to assess how developed 11 people were in particular fields. 12 "It was following on from this that I was asked to 13 do the risk assessment. It is likely that I would have 14 been carrying out the training needs assessment then 15 this risk assessment as well as doing general office 16 filing. 17 "I expect that it was either Bill Masterton or my 18 Dad who asked me to do the risk assessment. 19 "I am not sure if the risk assessment was required 20 through legislation but in my opinion I thought it was 21 being carried out as good practice. This was not 22 a paper exercise. It was a genuine desire to address 23 the problems identified. It was a concern for the 24 workers' welfare. 25 "I had not conducted any previous risk assessments page 6 1 for any other company prior to this one. I had not done 2 anything in my university training that would have 3 assisted me in producing this risk assessment. However, 4 I obviously had experience of working in the factory in 5 all departments (that is office, coating shop, 6 fabrication shop) which helped me. 7 "On the basis of my remit (which was to identify 8 potential hazards, through my own knowledge and through 9 discussion with experienced managers and employees, 10 I did not and do not think that I required any external 11 qualifications to do this. I felt competent in 12 conducting the risk assessment because I knew the 13 building well because I had worked there over an 14 extensive time period. I felt competent to identify 15 potential hazards at the factory through my own 16 knowledge and through discussions with numerous 17 experienced managers and employees. My task was to look 18 for physical type hazards. I was to walk around the 19 building looking to see if something was potentially 20 hazardous or not. 21 "I did not request any training on risk assessments 22 except reading materials which were useful. I was not 23 given any internal training on risk assessments other 24 than I think I discussed with Peter Ferguson because he 25 had done something similar in the past. I did not feel page 7 1 that training was especially beneficial because my remit 2 was not especially complex. Much of it was common 3 sense, for example, a brick lying in a walkway. 4 "At the time of the risk assessment I would have 5 been aware of the Health and Safety at Work Act, 6 probably from reading manuals. I was also probably 7 aware from university studies that risk assessments were 8 a requirement in law. 9 "I would not have been aware of industry standards 10 regarding underground pipework. I may have browsed 11 through them whilst completing preparatory reading but 12 I'm not sure. They were not on my agenda in terms of 13 the scope of the risk assessment I was undertaking. 14 "Prior to commenting this risk assessment I read up 15 on health and safety publications. I remember that one 16 of the health and safety publications had a yellow cover 17 but I cannot remember the names of the HSE publications. 18 They were all official Health and Safety publications. 19 I can't remember whether they were solely on risk 20 assessments but they did contain risk assessment 21 material. I recall one manual from Health and Safety 22 outlined various risks such as people tripping on 23 pallets and other general risks within premises. 24 "I also a few times telephoned the health and safety 25 hotline to ask questions when putting my risk assessment page 8 1 together. I now cannot recall what questions I asked. 2 I can't remember what information I got from the HSE but 3 I seem to recall that I received positive feedback in 4 terms of how I was carrying out my part in the risk 5 assessment exercise. 6 "I think I also looked at a previous risk 7 assessment, which I think came from Peter Ferguson but 8 it could have come from Bill Masterton or the foreman, 9 Laurie Connolly." 10 If I pause at that point, Mr Stott, to say you had 11 referred to the possibility earlier that no evidence has 12 been discovered of there having been a previous risk 13 assessment but of course it may well have been lost in 14 the disaster. 15 It is your recollection that there was such a thing, 16 is it? 17 A. I think that there was. As I say, I mean, it was 18 a long, long time ago so it is difficult to recall but 19 I do remember looking at materials which, thinking back, 20 I think it is possible that they were risk assessment 21 materials. I'm not saying for certain. 22 Q. No, I understand. 23 Is it your recollection that it was a risk 24 assessment or risk assessment material which actually 25 had been prepared by someone in ICL; in other words, it page 9 1 was specific to that actual building or enterprise 2 rather than just general health and safety materials? 3 A. Yes, I think it would have been something specific to 4 ICL. 5 Q. Again, I appreciate this is very difficult for you to 6 answer at this stage but do you think that in any sense, 7 for example, in the layout or in the way it had been 8 done it influenced the way that you did what you did? 9 A. Again, I don't want to sound unhelpful but that's very 10 difficult for me to answer. I followed more than 11 anything what I read in the literature that I read 12 before I started the risk assessment exercise. 13 Q. "I also read some documentation that already existed at 14 ICL Tech regarding risk assessment but I do not know who 15 produced it. It was a list of certain potential hazards 16 within the premises. 17 "I did not consider obtaining advice from an 18 external risk assessment consultant because what I had 19 read in the HSE literature was fairly explanatory and 20 I had consulted numerous experienced members of the ICL 21 workforce who provided me with helpful guidance. 22 "I initially carried out the exercise with 23 supervision from Bill and Frank. I had meetings with 24 Bill and Frank outlining the objects of the risk 25 assessment exercise and how I might go about it. page 10 1 "I then walked the entire premises with a pen and 2 piece of paper and wrote down anything and everything 3 that I thought might be a potential risk. This included 4 the coating shop, fabrication shop and offices on the 5 second floor. It included the ICL Tech staff offices, 6 ICL Group accounts and the offices of Campbell Downie, 7 Lorna Downie and Stewart McColl. It was most of the 8 offices on the second floor apart from the main 9 Stockline open plan offices. I looked at the machinery, 10 storage, trip hazards, lighting, fire hazards and 11 chemical hazards. 12 "I can't remember if I went into the basement when 13 conducting the risk assessment." 14 If I pause there, Mr Stott, given your familiarity 15 with the premises over the years that you have 16 described, aside from what you might have done in 17 relation to your risk assessment, were you aware that 18 there was a basement? 19 A. Was I aware there was a basement in the factory? 20 Q. Yes. 21 A. Yes. 22 Q. You were. That being the case, is it likely or is it 23 possible that you did go into the basement when 24 conducting the risk assessment but there is no note of 25 that and, again, there is no criticism -- page 11 1 A. Yes, it is possible. 2 Q. "I then returned to Bill and Frank with an exhaustive 3 list of what I had found. Also included were risks that 4 I had used from the health and safety publications such 5 as someone tripping over pallets and from me sitting at 6 my desk thinking about potential risks such as a bad 7 back from lifting things. We discussed what was to 8 happen next, which was to develop a basic matrix of the 9 risks in terms of low, medium and high risks. 10 "I initially scored the risks in terms of low, 11 medium or high. Bill, Frank and I then reassessed every 12 risk. We would have discussed the gradings that I had 13 given the risks, the likelihood of it happening and the 14 actions that should be taken, ie guards, goggles, 15 training, et cetera. I think they changed one or two. 16 Bill and Frank had more experience than most. 17 I understand Bill had knowledge in health and safety 18 together with chemicals. 19 "Anything identified as high or medium was made 20 a priority and had to be dealt with. Also noted was 21 what action was to be taken if an action had not already 22 been taken. 23 "A high risk was a risk that could possibly cause 24 serious injury or kill someone, even if it was unlikely. 25 It had to be dealt with immediately, an example being page 12 1 the motor powered generator which was situated in a 2 brick room on its own off the coating shop. The 3 potential, albeit very unlikely danger of that was that 4 it could explode. The action for that could be that 5 no-one was to go into the power generation room. 6 "Medium risk was a risk that could possibly cause 7 serious injury but was not likely to kill someone. An 8 example being a saw could cause a serious injury. The 9 action for that could be putting a guard on the saw 10 machine or training on how to work the equipment 11 safely." 12 Could I have page 11895, please. 13 "Page 2 is titled 'contents'. Listed on this page 14 is (1) safety policy, (2) methodology, (3) introduction 15 to risk assessment and (4) hazard rating, method and 16 results appendix. This page looks familiar and could 17 have been prepared by me." 18 Mr Stott, I am going to ask as I go through your 19 evidence for the pages referred to to be put up on the 20 screen. Some of them you clearly indicate you are not 21 aware of. So far as the ones that your evidence does 22 relate to I am not going to ask you every time to 23 confirm that the document is as you remember it but, 24 please, if at any stage you do not recognise a document, 25 please interrupt me and make that clear. page 13 1 "Page 3 is a page-divider." 2 Could I have 11897, please. 3 "Page 4 is titled, 'Safety policy' which is category 4 (1) in the above mentioned contents page. On page 4 it 5 is noted that: 6 "'The board of ICL Tech Limited with the 7 participation of employees pursues a policy aimed at 8 ensuring our places of work can be regarded as safe and 9 non-injurious to health. To this end we will control 10 risks to health and safety by positive action, ongoing 11 assessment, communication and awareness. Safety is 12 everybody's business.' 13 "This looks familiar and may have been completed by 14 me. However, I note at the bottom of this page it is 15 dated updated October 2001. I was not involved in any 16 way at ICL Tech in October 2001." 17 A. Sorry, I would point out I think it's less likely rather 18 than more likely that particular page was prepared by 19 me. 20 Q. So the last sentence which I was about to read, "I think 21 perhaps they have either re-used or updated this page 22 which was possibly prepared by me", is subject to that 23 qualification that it is less likely than likely that 24 you did prepare the original page? 25 A. Yes. page 14 1 Q. Thank you. 2 "5-page is a page-divider." 3 Could I have 11899, please. 4 "Page 6 is titled 'Methodology' which is category 5 (2) in the above mentioned contents page. This is 6 a summary of how the report was compiled. 7 "Paragraph 1 details: 8 "'In compiling this report all hazards at ICL Tech 9 were identified. This was achieved through an initial 10 inspection of all work places, equipment and 11 information. The inspection was followed up by 12 interviews with post holders and their 13 bosses supplemented as required by observing the 14 workplace and persons carrying out specific tasks.' 15 "Paragraph 2 details: 16 "'The hazards were then discussed by the risk 17 assessment team, F Stott, B Masterton and A Stott, and 18 a rating given to each one in accordance with the rating 19 system recommended by the Royal Society for the 20 Prevention of Accidents. When the hazard rating stage 21 was completed a course of risk reduction was discussed 22 and agreed upon by the risk assessment team for each 23 hazard. These courses of risk reduction have either 24 been implemented or are in the process of being so.' 25 "I know that we use the rating system recommended by page 15 1 the Royal Society for the Prevention of Accidents but we 2 have not noted the reference for that publication. This 3 page looks familiar and could have been completed by me. 4 "Page 7 a page-divider." 5 Could I have 11910, please. 6 "Page 8 is entitled 'The Royal Society for the 7 Prevention of Accidents risk assessment introduction', 8 which is a category (3) in the above-mentioned contents 9 page. This page looks familiar and could have been 10 completed by me. 11 "It provides the definitions of hazard and risk. It 12 also details the process of hazard identification, the 13 estimation of the associated risk followed by an 14 evaluation of the tolerability of these risks." 15 1192, please. 16 "Page 9 is titled 'Hazard rating method and 17 results', which is category (4) in the above-mentioned 18 contents page. This categorises the risk in terms of 19 injury, namely minor, significant, major or 20 catastrophic. This looks familiar and could have been 21 completed by me. The definitions of the 4 categories 22 are listed as catastrophic probability of multiple 23 deaths, major injury or catastrophic process 24 interruption. 25 "It is not noted but in my opinion this would page 16 1 include any injury resulting in death or injury 2 resulting in the use of a wheelchair. 3 "Major probability of death, major injury or major 4 process interruption. 5 "It is not noted but in my opinion this would 6 include an injury resulting in broken bones or a finger 7 being taken off by a saw. 8 "Significant probability of injury resulting in loss 9 of three or more working days or serious process 10 interruption. 11 "It is not noted but in my opinion this would 12 include an injury resulting in a nasty cut from a saw. 13 "Minor probability of minor injury that would cause 14 no time or process interruption. 15 "It is not noted but in my opinion this would 16 include an injury resulting in a minor injury such as 17 tripping." 18 11903, please. 19 "Page 10 is a matrix that I used to score the risk. 20 The risk was scored in terms of severity of outcome, 21 namely minor would score 1 point, significant would 22 score 2 points, major would score 3 points and 23 catastrophic would score 4 points. This is then 24 multiplied by the likelihood of outcome, namely 25 improbable would score 1, remote would score 2, page 17 1 occasional would score 3, likely would score 4 and 2 certain would score 5. The total is then given 3 a priority category, namely a total scoring P1 was 4 categorised as a low priority risk insignificant, 5 a total scoring P2 was categorised as a medium priority 6 risk, important action within days and a total scoring 7 P3 was categorised as a high priority, action 8 immediately. 9 "To explain the ratings, you would consider the two 10 risk metrics beings (1) severity of outcome and (2) 11 likelihood of outcome and develop a risk priority rating 12 on the basis of these. Anything that was a catastrophic 13 or major injury outcome in terms of severity would score 14 a P3 meaning high priority action immediately regardless 15 of the likelihood of the outcome. Those risks regarded 16 as minor or significant in terms of severity would 17 either be P1, P2 or P3, depending on the likelihood of 18 the outcome. 19 "This page finally details that the hazards found at 20 ICL Tech have been grouped under size headings, namely 21 buildings, compressed air, electricity, gas, fire, 22 machinery and miscellaneous. 23 "Page 11 a page-divider." 24 Could I have 11905 and 6 on the screen together, 25 please. page 18 1 "Pages 12 and 13 are horizontal tables entitled 2 'Risk assessment building'. This table does not look 3 familiar to me. I note that this risk assessment is 4 horizontal but I am unsure as to whether mine would have 5 been horizontal or vertical. I observe that there is 6 handwriting in the last column. This is not my 7 handwriting. It is not Frank Stott's handwriting. The 8 content of this table is probably similar to what 9 I prepared in my risk assessment. Someone may have 10 prepared this table based on what I did previously. 11 I note that the table is dated October 2001. At that 12 time I had no involvement at all at ICL Tech." 13 I think, Mr Stott, we can see the date October 2001 14 is at the bottom left-hand corner of each of those 15 pages; is that right? 16 A. Yes. 17 Q. We have also had evidence that the handwriting is that 18 of the late Mr McColl. 19 Is that possible or do you not recognise his 20 handwriting? 21 A. I wouldn't know his handwriting. 22 Q. Could I have 11907, 8 and 9, please. 23 "Page 14 [that is the first of the pages] is 24 a horizontal table titled 'Fork lift movements'. Page 15 25 is a horizontal table titled 'Risk assessment coating page 19 1 department' dated October 2001. Page 16 is a horizontal 2 table titled 'Risk assessment compressed air' dated 3 October 2001. Again, these were not prepared by me." 4 Could I have 011910, please. 5 "Page 17 is a horizontal table which is entitled 6 'Electricity and gas'. It is dated October 2001 and 7 therefore would not have been completed by me. I think 8 it is similar in terms of frequency potential and 9 severity potential to the risk assessment that I carried 10 out." 11 These are the columns, Mr Stott -- and I know you 12 are not responsible for this document -- headed F which 13 is frequency potential and S which is severity 14 potential. Is that right? 15 A. Yes. 16 Q. When you are referring to the similarity, the frequency 17 potential in respect of a hazard propane gas pipes, 18 potential harm leakage and explosion, the figure is 19 2 and so far as severity potential the figure is 6 which 20 is death (several). 21 Are you saying that, as far as you can recall, in 22 what you did the equivalent of that page, the 23 assessments would have been similar? 24 A. Yes. Obviously the metrics were different. I mean, the 25 frequency potential here shows from 1 to 6 and severity page 20 1 goes from 1 to 6 as well. In the assessment I carried 2 out the -- as I say, the metrics were slightly different 3 but it is pretty much -- 4 Q. But in principle the level of frequency and severity 5 potential is what you recall was in the one that you 6 prepared? 7 A. Yes. 8 Q. Could I have 011911 to 13, please. 9 "Page 18 is a horizontal table titled 'Risk 10 assessment fire' dated October 2001. Page 19 is 11 a horizontal table titled 'Risk assessment machinery' 12 dated October 2001. Page 20 is a horizontal table 13 titled 'Risk assessment miscellaneous' dated October 14 2001. Again, I did not prepare these." 15 Could I have 11914, please. 16 "Page 21 is a list titled 'ICL Technical Plastics 17 Limited health and safety, electricity, gas'. This 18 looks familiar and could have been completed by me. 19 This appears to be a list of the potential risks that 20 I identified when I walked around the factory looking 21 for potential risks. I would have noted these risks and 22 then discussed these with Bill and my Dad prior to 23 putting them into a matrix table indicating the score in 24 terms of severity and likelihood. I would also have put 25 an action beside the score. page 21 1 "I note that the first item on this list is titled 2 'Gas pipes in coating shop are old'. This could have 3 been one of my observations. In a matrix I would have 4 noted that risk as catastrophic. That is because 5 propane gas is flammable and could be lit with a match 6 or from the ovens or from the click of a light switch. 7 I can't remember this being discussed or the proposed 8 action but as it has been listed, it is likely that it 9 would have been discussed. Underneath this I have noted 10 smoking, which again would have been a risk to propane 11 gas. 12 "A possible action that I might have put against 13 that risk could have been for the pipe to be reviewed. 14 "In my opinion, old pipes are potentially not as 15 safe as new pipes but this does not mean old pipes are 16 necessarily dangerous. There is a potential danger with 17 old pipes in that they can burst or leak but equally so 18 can new pipes which is dangerous when there is a naked 19 flame. However, I would reiterate that old does not 20 necessarily equate to danger." 21 You then deal with pages 22 to 41 and I do not 22 think -- do not put them up at the moment. 23 "Page 22 is a list titled 'Miscellaneous'. Page 23 24 is a list titled 'Buildings'. Page 24 is a list titled 25 'Machinery'. Page 25 is a list titled 'Fire'. Page 26 page 22 1 is a list titled 'Compressed air'. Pages 27 to 30 are 2 list titled 'Machinery and plant'. Pages 31 to 37 are 3 lists titled 'Coating shop hazard list'. Pages 38 to 41 4 are lists titled 'Non-task-related hazards'. These all 5 look familiar and are in my style, wording and could 6 have been prepared by me. These look like the lists 7 that I prepared when I walked around the factory looking 8 for risks." 9 I wonder then if you could put up on the screen, 10 please, beginning at 011915 just the various stages. 11 Please, Mr Stott, if you want to stop at any point 12 and make any comment, please do so but I just want to be 13 sure that you are clear that these are the pages for 14 which you might have been responsible. 15 Just a little bit more slowly, please, so Mr Stott 16 can see them. 17 I hope you can read them. If you want them to be 18 blown up individually, we can. 19 A. That's fine. 20 (Flicking through documents on screen) 21 Q. Can we just stop at 11931, please. 22 This is the one under the heading of 23 'Non-task-related hazards'. 24 Can we see as item 4 under the heading 'Electricity 25 and gas', Mr Stott, that again what has been said is: page 23 1 "Propane gas pipes in coating shop are old." 2 I think they are the same words on the page that we 3 looked at previously. Is that right? 4 A. Yes. 5 Q. Just carry on then, please, 922. 6 (Flicking through documents on screen) 7 Thank you. That is the sequence. 8 "Page 42 is a divider page. 9 "Pages 43 to 45 are lists titled 'ICL Technical 10 Plastics Limited, factory plant'. It is a list of the 11 plant, in other words where the machines are and what 12 they are. This does not look familiar. In my opinion 13 I did not prepare this." 14 Could I have 111936, please. 15 That is the first of the pages you are referring to, 16 Mr Stott? You do not recognise that one? 17 A. No. 18 Q. Thank you. 19 Could I have 11939, please. 20 This is page 46. 21 "Pages 46 to 53 appear to be 'Maintenance plan 22 weekly requirement sheets'. The terminology in these 23 sees familiar to me. However this was not done by me 24 and was not one of my tasks." 25 Could I have 11947, please. page 24 1 "Page 54 is a matrix table and it looks like the 2 matrix table that I used for my risk assessment. It is 3 a vertical table. It is titled 'Risk assessment form, 4 miscellaneous'. The first hazard noted is provision of 5 soap/barrier creams. The assessment rating is 1/3, P1. 6 This would probably have been based on the matrix table 7 on page 10. 1 would be based on the severity of outcome 8 as being minor and 3 would be based on the likelihood of 9 outcome being occasional. After considering these 10 metrics a priority rating of P1, low priority risk, 11 insignificant, would have been allocated to this 12 particular risk. Noted in the action column beside this 13 hazard is 'Make barrier cream available' and noted in 14 the follow up column beside this hazard is 'Barrier 15 cream is now available'. This was the methodology 16 recommended by the Royal Society for the Prevention of 17 Accidents. This would have been done during my time 18 there. Some of the follow up would have been completed 19 while I was there and preparing this table, such as the 20 barrier cream had been purchased by the time this table 21 was typed. I observe that this document that I am shown 22 only contains one page showing our matrix table in use. 23 However, there would have been several pages of matrix 24 table detailing the numerous risks that I helped to 25 collate and their assessment ratings." page 25 1 Do you consider, Mr Stott, that this page was part 2 of the risk assessment which you carried out concluding 3 in January 1997? 4 A. Yes. 5 Q. Is what you are saying that there would be equivalent 6 pages for the other hazards, the risks that you had 7 identified elsewhere, but for whatever reason these have 8 simply not been found after the disaster? 9 A. I would expect so, yes. 10 Q. I will just read the next paragraph. 11 "Pages 55 and 56 are lists titled 'Fabrication tasks 12 hazard list'. Pages 57 and 58 are lists titled 'Coating 13 shop tasks hazard list'. Pages 59 and 60 contain lists 14 titled 'Building maintenance tasks hazard list'. Page 15 60 contains a list titled 'Despatch tasks hazard list'. 16 Page 61 contains a list titled 'Sales tasks hazard list 17 and inspection task hazard list'. Page 62 contains 18 a list titled 'Vehicles hazard list'. Page 63 contains 19 a list titled 'Office hazard list'. These look familiar 20 and could have been completed by me. These look like 21 the lists that I prepared when I walked around the 22 factory looking for risks." 23 Again, could I ask, please, that that sequence of 24 documents beginning at 11948 be put up on screen just to 25 give Mr Stott an opportunity to look at each and make page 26 1 any comment. 2 (Flicking through documents on screen) 3 Thank you very much. Could I now have the next 4 page, 11957, please. 5 "Page 64 are minutes dated 23rd January 1997. These 6 detail those present at that meeting were Frank Stott, 7 Bill Masterton and myself. I don't remember this 8 meeting but the likelihood is that it would have 9 happened. 10 "Paragraph 1 details that completed risk assessment 11 forms were studied and discussed. 12 "Paragraph 2 details risk assessments forms for 13 general hazards non-task-related to be completed by 30th 14 January 1997. 15 "Paragraph 3 details a meeting to be held with C 16 Brown, P Ferguson, J McGoldrick and L Connolly on Friday 17 31st January 1997 to explain and distribute assessments 18 for evaluation. 19 "Paragraph 4 details reaction meeting to item 3 on 20 7th February 1997. 21 "Paragraph 5 details 'after meeting on 7th begin 22 implementation of agreed recommendations'." 23 Could I have 11958 and 9, please. 24 "Pages 65 and 66 are titled 'Hazardous substances 25 safety data sheets'. I think these would have been page 27 1 prepared by Bill Masterton because this is where he had 2 knowledge. The bulk of the input would be his regarding 3 hazardous substances. 4 "Page 67 is a page-divider." 5 Could I have 11961, please. 6 "Page 68 is an appendix detailing that meetings were 7 held on 17th October and 8th November 1996 and 23rd 8 January 1997." 9 11962. 10 "Page 69 are minutes of a meeting held on 17th 11 October 1996. These detail that on that date I attended 12 a meeting with my Dad, Frank Stott and Bill Masterton. 13 "I do not recall that meeting but I believe I would 14 have attended it. 15 "Paragraph 1 details that the purpose of 'this first 16 meeting was to establish terms of reference on how to 17 tackle the problem of establishing a risk assessment 18 programme at ICL Tech.' 19 "Paragraph 2 details, 'The first item of business 20 discussed was the main objective of the exercise -- to 21 create a safety policy and then to implement it. It was 22 noted that this aim should be undertaken with regard to 23 any health and safety regulations that may be 24 applicable. The safety policy already in place was 25 acknowledged as insufficient and as being required to be page 28 1 redefined.' 2 "Paragraph 3 details, 'Secondly, it was concluded 3 that our first priority must be to develop an exhaustive 4 list of any hazards that exist at ICL Tech. This, it is 5 hoped, shall be completed by October 1996.' 6 "Paragraph 4 details, 'Finally, it was proposed that 7 the development of plant maintenance hazard booklets 8 should be continued. These booklets are to come under 9 the heading of fire, machinery, compressed air, 10 electricity/gas and buildings'. It is not noted but 11 I don't recall much about those hazard booklets. 12 "As I have described earlier, about that time 13 I started the risk assessment." 14 Could I have the next page 1963, please. 15 "Page 70 are minutes titled 'Health and Safety 16 meeting -- 8th November 1996'. It details those present 17 as Frank Stott, Bill Masterton and myself. I do recall 18 being at that meeting. 19 "Paragraph 1 details, 'The first priority of this 20 meeting was to check that the aims ensuing from meeting 21 1 had been achieved. It was agreed that they had.' 22 "Paragraph 2 details, 'An exhaustive list of hazards 23 within the factory, drawn up by Andrew Stott, was then 24 analysed. It was then decided that this list should be 25 refined as discussed and then retyped and produced for page 29 1 further analysis.' 2 "Paragraph 3 details, 'It was proposed that Jim 3 McGoldrick and Laurie Connelly should become more 4 involved in the risk assessment programme, perhaps 5 sitting in on the next meeting.'" 6 Mr Stott, you said in your evidence that you do 7 recall being at this meeting and it took place in 8 November 1996 and, of course, the pages that we have 9 been looking at previously which you recognised as 10 having been responsible for were dated July 1997. Is it 11 your recollection that there was an earlier version of 12 the risk assessment document that we have looked at in 13 evidence which was in existence by the time of this 14 meeting of 8th November 1996 but, for whatever reason, 15 simply has not been found? 16 A. It's possible. Again, I'm sorry, I couldn't ... I could 17 not recall specifically. However, what I would point 18 out, and I think it's a bit of an inconsistency, is that 19 the report is dated July '97. As I recall, and on 20 reviewing my statement after I had discussions with the 21 Fiscal, I think my involvement in the risk assessment 22 exercise ended at the end of January '97. So it may be 23 that it was typed-up then and then typed-up again in 24 July. I don't know. But, as I say, I think that my 25 involvement ended January '97. page 30 1 Q. I do understand that -- I think you said it earlier -- 2 and, for whatever reason, the date put on the ultimately 3 typed document was July, by which time your involvement 4 had been ended for several months? 5 A. Mmm. 6 Q. But is it reasonable to infer from this minute that 7 there was a document physically in existence on 8 8th November 1996? 9 A. Yes. 10 Q. Which obviously, if the typing date is correct, cannot 11 be the one ultimately dated July 1997 but, although you 12 can recall being at this meeting, is it your evidence to 13 the Inquiry that you simply cannot recall what, if any, 14 document was before the meeting for which you might have 15 been responsible? 16 A. Yes. 17 Q. Thank you. Could I have the next page, please, 11964. 18 "Page 71 is the same minutes of 23rd January 1997 as 19 per page 64 but in a different font. 20 "This folder is incomplete and does not contain all 21 my matrix tables on the risks identified. This folder 22 is a mismatch of documents. 23 "When I was walking around the factory, I was 24 looking for dangers such as cutting yourself, burning 25 yourself, lifting something or tripping. I was not page 31 1 qualified to complete a detailed inspection of the 2 pipework. However, I did feel competent to identify the 3 gas pipework as potentially hazardous which is what 4 I was asked to do (and which I understand is normal risk 5 assessment protocol). 6 "I do think that pipework should have been part of 7 the risk assessment and I identified the gas pipework as 8 a potential hazard. However, if it was necessary to 9 carry out a particularly detailed inspection of the 10 pipework at any time, I would not have felt qualified to 11 do this. I would point out that in helping to complete 12 the risk assessment according to the health and safety 13 guidelines that were followed, such a detailed 14 inspection was not highlighted as necessary. I think 15 there may have been another risk assessment other than 16 the one that I was doing. Mine was more a general 17 assessment of potential hazards within the building or 18 premises. 19 "I would have noted anything that looked like it was 20 worn (if I could see it) and therefore was going to be 21 a danger regarding pipework. 22 "If I were to score pipework, I would score it as 23 being '4', this being catastrophic because potentially 24 people could die. I would also rate it as 25 'improbable' because it is not something that happens page 32 1 very often, thankfully. 2 "I am not sure who owned the LPG pipework. I am not 3 sure whether it was the company or the gas company. 4 When I say 'company', I am unsure whether it would be 5 ICL Plastics, ICL Tech or Stockline Plastics. I think 6 if it were the company then it would probably be 'Group' 7 (ICL Plastics) because I think they were top of the 8 companies, although I have never looked at the corporate 9 situation. 10 "I do not know who was responsible for the pipework 11 or the tank. 12 "I have no knowledge of anyone being asked to 13 examine the underground pipework. I am not aware of the 14 company or anyone within the company having any dealings 15 with HSE regarding the underground pipework. I am also 16 not aware of any HSE issues regarding underground 17 pipework. 18 "I remember going into the basement on the odd 19 occasion. I remember there being a cage partition in 20 there together with old tables and there was a workshop 21 for the painter/builder/tradesman Andy Galloway. 22 "I can't remember if the basement was part of my 23 risk assessment. I can't recall any pipework in the 24 basement. 25 "I do not know the route of the LPG pipework. page 33 1 "I do not know the differences between LPG and 2 natural gas. I think LPG is more dangerous because it 3 is liquid petroleum but I do not know why." 4 If I may just pause there, Mr Stott, you have there 5 referred to your having identified, as you say in 6 paragraph 96, that you had identified the gas pipework 7 as a potential hazard and that is quite correct. You 8 identified it both in relation to gas and electricity 9 and in relation to non-work related tasks. 10 Given that we do not have the matrix that relates to 11 those topics of assessment, for whatever reason, do you 12 have any recollection of creating or discussing with 13 Mr Masterton and your late father a matrix assessment 14 for the hazard of gas pipework and of any steps which 15 might have been taken, as it were, in the final column 16 to address that? 17 A. I don't have any specific recollection. I can only 18 imagine that a potential action, if you like, following 19 on this meeting, of the gas pipework would have been 20 something along the lines of inspect the pipework, 21 maintain the pipework and that kind of thing. But it 22 is -- I mean, as I said initially, I don't recall 23 a specific -- discussing it specifically, although 24 I suspect it probably was a (inaudible due to 25 overspeaking) -- page 34 1 Q. -- the logic of the way the process would have been 2 carried out and fact that we do have a matrix at least 3 for one category of risks, the logic is that there 4 probably was such a matrix for this particular risk and 5 that it was discussed with your late father and 6 Mr Masterton at the meeting and action may have been 7 identified but we simply have no document now to confirm 8 it? 9 A. That would be true. Just to elaborate slightly it may 10 well have been discussed with others as well. It 11 wasn't ... the risk assessment exercise or, sorry, as 12 part of it, pretty much everybody in the factory was 13 consulted so you're talking about employees at all 14 levels up through management. So, I suppose what I'm 15 saying is that other people would have had input as well 16 on all risks, including the pipework. 17 Q. But obviously I'm sure, having thought about it since 18 the disaster, you have no actual recollection of the 19 particular events which happened in relation to your 20 identification of pipework as a potential risk? 21 A. No. 22 Q. Thank you. 23 Returning to your Inquiry statement paragraph 106: 24 "I have been shown guides to practices in corrosion 25 control." page 35 1 Could I have document 0763, please. 2 That is the first, Mr Stott. I wonder if we could 3 just have the second page 0764. That is not very 4 helpful. Can we have the next one. That is the 5 contents. If that may be blown up. Thank you very 6 much. 7 You have been shown these documents presumably by 8 the Fiscal. 9 "These documents are not immediately familiar with 10 me but it is possible that I have seen similar types of 11 documentation either in the office or in the testing 12 area. I expect they must have been there given that 13 they were recovered from the locus. 14 "If I had recognised the underground pipework and 15 its entry into the building when conducting the risk 16 assessment I would have brought this to either Bill 17 Masterton or Frank's attention. The reason why I would 18 have brought it to their attention was because I would 19 not have known what to look for when assessing the risks 20 from underground pipework given that I had no experience 21 with underground pipework. 22 "I would not have made any suggestions to ICL as to 23 what they should have done with regard to the risks from 24 underground pipework because I was not qualified to 25 comment on underground pipework. I would have left this page 36 1 to Bill Masterton or Frank Stott to decide as to what to 2 do next. 3 "I would not have contacted an outside company for 4 advice regarding the underground pipework because that 5 was not part of my remit. If I had recognised that the 6 buried pipework required to be risk assessed I would 7 probably have thought about the original installation of 8 pipework. It was not something that I would have 9 thought too deeply about. 10 "I have no knowledge as to how long the underground 11 pipework had been in place or its history. 12 "I am aware that there are probably standards 13 required for the installation of pipework but I would 14 not have known these. 15 "From common sense I would have been aware that 16 there would be guidance available in relation to LPG 17 issues but I would not have been aware of the content of 18 these guidelines. It was not part of my remit to find 19 out if the installation complied with current guidance 20 or to seek outside advice on this. 21 "I do know that buried steel and iron corrode. 22 "I did not know if the underground pipework was 23 corrosion protected because I never saw the pipework or 24 thought about it. 25 "However, I do know that protective plastic coatings page 37 1 are placed on metals to protect metals. I know that 2 because that was ICL's business. ICL stood for 3 Industrial Coatings and Linings. I do not know if 4 protective plastic coatings can be placed on underground 5 pipework. 6 "I confirm that the contents of this statement are 7 true." 8 I think, Mr Stott, just in fairness to you if we go 9 back to paragraph 116 you say: 10 "I did not know if the underground pipework was 11 corrosion protected because I never saw the pipework or 12 thought about it." 13 Of course as we know you did identify in your risk 14 assessment pipework as a potential hazard. 15 Perhaps I could have page 11931 up again, please. 16 If you could put beside it 11914. 17 You say in 116 that you never saw the pipework or 18 thought about it. Clearly you did see the pipework in 19 the coating shop because in each of these passages under 20 "Electricity and gas" and under "non-task-related 21 hazards" you in your assessment have said, "Propane gas 22 pipes in coating shops are old". 23 Is what you are saying in your Inquiry statement 24 that as far as the existence of the pipework potentially 25 underground was concerned, you did not think about it in page 38 1 that regard? 2 A. Yes. 3 MR MARTIN: Thank you very much indeed. If you would 4 remain, please, Mr Stott, his Lordship or others may 5 have questions for you. 6 Thank you, my Lord. 7 THE CHAIRMAN: Mr Stott, does it just come to this really 8 that so far as you recall when you carried out the risk 9 assessment in the 1996/97 period that although the 10 pipework was spotted as a potential hazard so far as it 11 was visible in the coating shop the issue of underground 12 pipework was simply never considered? 13 A. It wasn't considered by me. 14 THE CHAIRMAN: Now you have seen those tables and the matrix 15 that was prepared is it your recollection that you 16 probably prepared something of that sort yourself as 17 a forerunner to the one that we have been -- to the ones 18 that we have been looking at on the screen? 19 A. Yes. 20 THE CHAIRMAN: You, I think that is quite probable? 21 A. Yes. 22 THE CHAIRMAN: Thank you very much. 23 Mr McBride, I think the questions you sought to 24 raise have been dealt with. 25 MR MCBRIDE: Yes, they have been dealt with by counsel and page 39 1 your Lordship. 2 THE CHAIRMAN: There is no need to ask any questions then. 3 Thank you very much for your evidence, Mr Stott. 4 (The witness withdrew) 5 MR MARTIN: My Lord, in the case of the next three witnesses 6 it has been agreed that their Inquiry statements should 7 be taken as read. Those are witnesses Mr George McLean, 8 Jean McGoldrick -- I do not know if it is Miss or 9 Mrs McGoldrick -- and Francis Anthony Mellor. 10 In the case of Mr Mellor, he in his Inquiry 11 statement refers to three reports and the page numbers 12 are given. Perhaps it would be helpful if I were simply 13 to indicate the document numbers. 14 In the case of the report entitled "Examination of 15 LPG tank external surface pipework and natural gas 16 supply", that is document EX024, and the subsequent 17 pages the report entitled "Gas investigation of 18 appliances from ICL Plastics Limited" and entitled 19 "Pressure test of pipe samples from ICL Plastics 20 Limited", these are succeeding pages in the same 21 document which is EX024. So Mr Mellor's evidence should 22 be read with regard to these reports. 23 The final witness on investigation and explanation 24 for the disaster is Dr Stuart Hawksworth. 25 THE CHAIRMAN: Perhaps this would be a convenient point to page 40 1 give the LiveNote writers a break, Mr Martin. We will 2 resume at 11.55. 3 (11.40 am) 4 (A short break) 5 (12.00 pm) 6 MR MARTIN: My Lord, the final witness in Phase 1 of the 7 Inquiry is Dr Stuart Hawksworth. 8 DR STUART HAWKSWORTH (called) 9 Examined by MR MARTIN 10 Q. Dr Hawksworth, I hope you have a copy of your final 11 Inquiry statement? 12 A. I do, yes. 13 Q. I think you are content if I read through it and I shall 14 pause from time to time in particular to look at a 15 number of documents that I would like you to look at. 16 As far as the introduction is concerned, I hope that 17 we can take it as read, save to note that you work in 18 the Health and Safety Laboratory (HSL) as head of the 19 Explosions Safety Unit, which is a team of professional 20 engineers and scientists providing research and support 21 on a range of safety issues, including investigation of 22 industrial incidents and accidents including explosives 23 and explosive atmospheres. 24 "The Health and Safety Laboratory is an agency of 25 the Health & Safety Executive. It was established in page 41 1 1995 and provides the majority of HSE science and 2 technology requirements. The services are provided on 3 a customer contractor basis to not only the HSE but also 4 other Government departments, the European Union and 5 other industrial and governmental bodies in the UK and 6 overseas. HSL provides forensic support to not just HSE 7 but also to other regulators including the Environment 8 Agency, the police, the Office of Rail Regulation and 9 the Irish and Northern Ireland Health and Safety 10 Regulators. Support has been given, for example, in 11 relation to the Buncefield explosion, to Strathclyde 12 Police on the Larkhall explosion and otherwise. HSL 13 staff appear as expert witnesses. HSL also undertakes 14 other scientific work for other Government departments 15 on matters related to the environment." 16 In paragraph 2 you set out your own qualifications 17 and experience. You have a first class honours degree 18 in applied physics and you have a PHD in physics. 19 Since joining the health and safety laboratory, as 20 it was previously known, in 1993 you have undertaken 21 research and provided technical advice on various 22 aspects of dust and gas explosions. You have served on 23 national and international committees and you have 24 published a number of scientific papers in this area and 25 have been responsible for UK involvement in a number of page 42 1 major international projects. 2 You have worked as lead investigator or as part of 3 a team on a number of significant incidents, including 4 the Ladbroke Grove rail crash, the Rose Park Care Home 5 fire, the Buncefield oil fire, Cantley sugar explosion 6 and others. If I begin reading from paragraph 7 in 7 relation to your role in the investigation: 8 "At the time of the ICL Plastics incident I was head 9 of a section of approximately ten scientists 10 specialising in gas and dust explosions (Explosions 11 Control Section) and was contacted in this capacity by 12 Mr David Richardson of HSE Edinburgh regarding the 13 incident on 11th May 2004. I subsequently attended the 14 site on 17th May 2004 at his request. I was then 15 I appointed by the HSL board as lead investigator and 16 led HSL's input to this investigation working closely 17 with HSE and with Strathclyde Police to co-ordinate 18 HSL's activities with regard to the investigation both 19 on the ICL Plastics site and at HSL. 20 "During the early stages of the investigation 21 I worked closely with HSE and Strathclyde Police in 22 developing the investigation strategy, including 23 developing the main lines of Inquiry on site with regard 24 to potential sources of explosive atmosphere; developing 25 the approach for identification, recording and transfer page 43 1 of evidence during the extensive operations to clear the 2 site; and developing and managing the programme of 3 on-site and laboratory work to establish the source of 4 explosive atmosphere and the characteristics of the 5 explosion. 6 "Due to the scale and complexity of this 7 investigation, I enlisted a diverse team of staff from 8 across HSL (and outside) to gather evidence on site and 9 carry out subsequent laboratory analyses and testing. 10 The team of HSL staff included explosion and fire 11 specialists, mechanical engineers, metallurgists, video 12 and photographic staff, organic chemists, exposure 13 control scientists, biological monitoring scientists and 14 field support scientists. The on-site investigation 15 involved an almost continuous HSL presence at the 16 ICL Plastics site from 17th May until 6th July 2004." 17 You were personally on site at ICL Plastics from 18 17th to 20th May, 26th to 27th May, 1st to 3rd June, 19 10th to 11th June, 16th to 18th June, 22nd to 25th June, 20 2nd July and 5th to 6th July all 2004 and in daily 21 contact with key HSE/HSL team members when not on-site. 22 "In addition to my co-ordinating role I also played 23 an active part in the on-site work to identify and 24 retain evidence and witness various activities. 25 Specific examples include the emptying and transfer of page 44 1 the liquefied petroleum gas (LPG) tank (20th May 2004), 2 excavation and pressure testing of the buried LPG pipe 3 (10th and 11th June 2004), cutting of the dispatch area 4 steel floor sections (5th July 2004) and subsequent 5 transfer to Buxton (6th July 2004). 6 "Following the on-site investigation I continued to 7 oversee a number of activities at HSL to gather further 8 evidence on the cause of the incident including 9 metallurgical examination and testing, mechanical 10 testing and modelling calculations, explosion testing 11 and analysis, and testing of the LPG and natural gas 12 systems and components. I also organised the testing of 13 specific components at other test houses/laboratories 14 and personally witnessed the testing of the LPG 15 regulator at Intertek on 13th August 2004." 16 I take it that Intertek is a testing enterprise -- 17 A. They are a notified test house, yes. So they have 18 authority to do that testing. 19 Q. "The investigation." 20 Could I have page 8861, please. 21 "The full details of this investigation can be found 22 in HSL report EC/05/15 entitled, 'ICL Plastics incident 23 report part 1, explosion overview and process safety' 24 and accompanying reports and appendices. In this, my 25 statement, I summarise the key findings from the page 45 1 investigation." 2 Clearly, Dr Hawksworth, this is the first page but 3 you recognise that as the first page of the report? 4 A. I know it well. 5 Q. We will look at a number of subsequent pages. 6 "Was there an explosion? 7 "The evidence obtained from the investigation 8 clearly indicates that an explosion occurred resulting 9 from the formation of an explosive atmosphere in the 10 basement area of the ICL building which then ignited. 11 The explosion produced high overpressures which exerted 12 very large forces on the surroundings resulting in 13 failure of an area of steel floor situated above the 14 basement. The high overpressure produced by the 15 explosion acted on the building structure resulting in 16 its collapse. 17 "Damage observed to the steel section of the 18 dispatch floor." 19 Could I have page 8914, please. 20 This is one of a series of photographs, 21 Dr Hawksworth, that I hope you can assist. 22 "Item 1. The damage to the floor at 1 is 23 characteristic of the forces associated with the 24 overpressure generated by a fuel air explosion and not 25 that of a simple building collapse." page 46 1 What is it about this photograph which supports that 2 view? 3 A. If you look at this photograph, the way the dispatch 4 floor area was constructed it is essentially a table and 5 the sections that made up the flat part of the table, if 6 you like, the walking floor area, are the large steel 7 girders you can see at the top of the photograph. What 8 you actually see going out bottom left between the bolts 9 other than -- and you can see the letter A clearly 10 written on there, there is actually one of the supports, 11 the supporting legs of that table top, if you like. 12 What you can see there, it was attached. There were 13 four bolts actually attaching that. The leg and the top 14 of the table, if you like, had been ripped apart with 15 great force bending that top section. There's similar 16 damage which demonstrates the table top was forced 17 upwards with great force which is very characteristic of 18 a gas explosion. 19 Q. So it is indicative of the forces associated with the 20 overpressure acting on the floor from below? 21 A. Yes -- clearly from below. 22 Q. Could I have the next photograph, please. 23 "This clearly indicates that these large forces were 24 acting in an upward direction from within the basement 25 area." page 47 1 Is that again obvious? 2 A. That's just another similar photograph. It's where 3 another leg was attached. This was the plate that we 4 saw in the previous photo which was severely bent where 5 the leg was actually attached -- it's actually pulled 6 away here the welding's broken away -- you can see that 7 it's actually bent. It is bent in the same way. 8 Q. Thank you. 9 I am sorry, Dr Hawksworth, bear in mind this lady 10 has to record everything that you say. Just take your 11 time, please. 12 "Item 3. The damage produced a debris patch with 13 key features elevated position of the floor sections and 14 unique projection of pieces of the concrete ground floor 15 adjacent to steel floor some distance outside the 16 building that are consistent with the explosion 17 preceding the building collapse and not the reverse." 18 Could I have the next photograph, 8916, please. 19 What is it in this photograph? 20 A. That's just more of the same really. This was a section 21 of the concrete floor and that's got a bend in it 22 indicating that the explosion happened from before. 23 Paragraph -- sorry, my point 3 here is actually figure 24 7, so it's probably the next figure that we're coming 25 to, I guess. page 48 1 Q. If I could have -- well, just keep this photograph up. 2 "The exact sequence of events during the explosion 3 is difficult to establish, but HSL's best understanding 4 is (1) the ignition most likely occurred in the basement 5 area that was directly accessed from the stair tower 6 (between the gable end and party wall A in figure 12 of 7 EC/05/15) ..." 8 This is page 8905 but do not bring it up, please, 9 because it has not been copied properly. 10 What you should have, Dr Hawksworth, is a paper copy 11 of this, which is A3 -- 12 A. Yes. 13 Q. -- that is the plan of the basement and I hope all 14 parties have this. It was circulated this morning. 15 Party wall A is identified, I think, if you look at 16 the plan just to the right of the access into the 17 basement area from the stair tower; is that correct? 18 A. Indeed, yes. 19 Q. If you wish to do so immediately to your left -- I know 20 you are familiar with it -- is the model which I think 21 presents the same features. Is that right? 22 A. It does, yes. I mean, essentially this area 23 was obviously where there was access into the cellar 24 from the stair tower. It's also the area where the 25 propane pipe passed through the building and was closest page 49 1 to where the leak actually occurred, which we will come 2 to I guess. 3 Q. Reading from the middle of paragraph 15, sub-paragraph 4 1: 5 "Based on the direction of fall of the basement 6 partition walls. This is also the area where Mr Murie 7 was found, who presumably had just entered the basement. 8 The ignition source could have been the operation of the 9 light switch or the cigarette lighter." 10 Does this photograph to some extent indicate the 11 direction of fall of the basement -- 12 A. There's one of the photographs that we will come to. 13 I have caused a little confusion there, sorry. 14 Q. Could I perhaps have -- sorry, I will just leave that 15 for a moment. 16 2: 17 "The explosive atmosphere in the basement is 18 unlikely to have been well mixed so the duration of the 19 explosion overpressure pulse is likely to have been 20 several seconds. There would have been an initial 21 period of relatively slow pressure rise corresponding to 22 low speed laminar flame propagation. The latter stages 23 of the explosion would have involved interaction between 24 the flame and piers, walls, et cetera, leading to flame 25 acceleration and very rapid rates of increase in page 50 1 pressure." 2 Could I please, if possible put up 8901 and at the 3 same time 8913 and 8903. 4 I do not know if these photographs, Dr Hawksworth, 5 are of any assistance in this matter? 6 A. What they essentially show, the top left photograph 7 8901, this is one of the floor sections which is lifted 8 completely up in the air. The only way to understand 9 how that happened was that there was this explosion in 10 the basement. The damage that I showed earlier where 11 the supports had been attached is actually on the 12 corners of this floor section. If you look in detail 13 you can actually see it. That floor section was lifted 14 high up in the air and clearly it was characteristic of 15 a powerful gas explosion beneath which progressed as 16 described, as you've just said. 17 Initially a laminar burning where you have -- the 18 ignition starts, the explosion in the flammable 19 atmosphere and you more or less get a spherical 20 progression, depending where the ignition was, then as 21 the combustion starts to interfere with structures in 22 the basement it becomes much more turbulent as mixing 23 and things like that start to happen. 24 Q. Just carrying on 15, item 3: 25 "The explosion produced in the basement would have page 51 1 started to vent through the doorway to the stairwell. 2 However, this would have had only a small effect on 3 limiting the explosion overpressure as it is 4 a relatively small opening in comparison to the volume 5 of the basement. 6 "At the same time the explosion overpressure would 7 be exerting large forces on the basement walls and 8 ceiling. The weakest parts of the basement would fail 9 initially, for example the basement party walls. This 10 would have effectively created a single space partially 11 obstructed by the stone piers. Any explosive atmosphere 12 in these spaces could then become directly involved in 13 the explosion if not already. Equally, any excess of 14 explosive atmosphere present in the initial space could 15 then mix with the air from these spaces to increase the 16 size of the explosion. 17 "The dispatch floor started to lift and break apart 18 venting the explosion into the ground floor space as 19 gaps began to appear around the edge of the floor. The 20 indications are that the steel sections lifted at an 21 angle, the gable end lifting the highest, pivoting about 22 the other end that was connected to the adjacent 23 concrete floor by Rawl bolts. This would have tended to 24 direct the outflow of high pressure gas from the 25 basement on to the walls at the gable end of the page 52 1 building." 2 Just pausing there, could I have 8901 up again, 3 please. 4 If we look at that photograph, Dr Hawksworth, I 5 think we are aware that it is looking from west to east; 6 that is to say, from the stair tower end that you have 7 referred to earlier because in the background of the 8 photograph we can see the remnants of the building still 9 standing and we know that was at the east end? 10 A. Yes. 11 Q. Does this photograph, given that the basement 12 ceiling/dispatch area floor forced upwards by the force 13 of the explosion seems to some extent to be higher 14 towards the camera than, as it were, at the other end? 15 A. Yes, because I think as we removed the debris, the other 16 end that's still bearing, we found it was Rawl-bolted, 17 as I described, to the adjacent concrete floor. 18 Q. Yes, I am just going to say these were role bolts fitted 19 into the concrete floor. 20 A. Yes. 21 Q. We know as you went to the east of the building there 22 was no longer a basement and the concrete floor of the 23 building came to be pretty much directly on to the 24 ground? 25 A. Yes. page 53 1 Q. Could I then have 8909, please. 2 That is obviously an aerial photograph. Does that 3 help? 4 A. All that's showing is I think to help understand how 5 these floor sections went back together, if you like. 6 We lifted them back in place just to show how the floor 7 would be reconstructed and that is the section that 8 we've just seen up in the air lifted back into roughly 9 where it's original position would have been. 10 Q. To the left -- that is obviously the red coloured 11 framework with pieces in it? 12 A. Yes. 13 Q. To the left of that is the line of the western gable 14 wall building? 15 A. Yes. 16 Q. Underneath it and above it in the photograph is the area 17 where the basement or part of the basement was and to 18 the right of it are the basement steel columns 19 surrounded by brick? 20 A. There's stone piers that the steel columns would have 21 stood on in the basement. 22 Q. Exactly. Then I think there is also basement. We can 23 see that in the model. 24 Could I have 8910, the next one, please? 25 A. This is just the other section lifted into a similar page 54 1 position. 2 Q. So the two sections of floor recovered, that was the one 3 towards the east of the covering over the basement? 4 A. What you can just see on the right-hand side of this 5 photograph is obviously the channel where the LPG pipe 6 had come in, where we'd dug out. 7 Q. That may be just important to find it. I am sorry there 8 is no particular way of -- 9 A. That's the spot just there (indicated). 10 Q. Thank you very much. 11 Could I have the next photograph, please, 8911. 12 A. This is just the central section. The floor broke into 13 three pieces and these were just photographs showing how 14 the pieces were lifted back into place. 15 Q. Thank you, and 8912. 16 That's obviously the crane that we saw the cable of 17 in the previous photograph looking downwards? 18 A. What this shows, this is -- this goes back to the first 19 picture we saw but one of the -- it actually shows you 20 the legs that the floor stood on and you can see the 21 steel section which stood on top of a stone -- well, 22 a brick pier which had been constructed in the basement 23 and that's what actually supported that floor section. 24 So when the explosion occurred, it pushed the steel 25 floor sections up and the weight of these legs is the page 55 1 thing that created the damage that we were able to 2 observe in the wells. 3 THE CHAIRMAN: Mr Martin, forgive me for interrupting but 4 these steel sections, are these the ones that NJ Reid 5 put in? 6 MR MARTIN: Yes, my Lord. This is the steel so-called 7 chequer-plate. It is just simply the markings on the 8 plate floor with the frame that was put in at the 9 beginning of the 1980s, yes, my Lord. 10 Dr Hawksworth, just before I move on, looking at the 11 photograph 08912, is that the line of the gable wall on 12 the right-hand side of the photograph? 13 A. No, at the end of the photograph that's the gable wall. 14 The crane would have been behind the gable wall if it 15 had still been there. 16 Q. Yes, I understand. 17 Item 6 of paragraph 15: 18 "Notwithstanding the venting of the explosion from 19 the basement the overpressure could have continued to 20 increase and start removing the checker plates. By this 21 stage the explosion may have partially expanded into the 22 ground floor or simply could have vented the hot gases 23 into the space. 24 "How powerful was the explosion? 25 "Analysis of the structural damage to the steel page 56 1 floor sections indicates an overpressure of at least 2 0.692-bar (approximately 0.7-bar) in the basement, 3 possibly higher. Further details of how this 4 overpressure estimate was obtained are given in the 5 report by Mr White." 6 My Lord, I can say that that begins at page 7765. 7 I do not think we need to have it but the conclusion 8 expressed is on page 7785. 9 "Based on this overpressure it is possible to make 10 a simple estimate of the minimum volume of explosive 11 atmosphere required. 12 "The maximum pressure that could be produced by 13 a gas explosion under ideal circumstances is of the 14 order of 8 or 9 bar absolute (absolute indicating 15 a pressure relative to total vacuum) if the basement 16 space were completely filled with an ideal ...", and 17 I think that is known as, is it stoichiometric? 18 A. Stoichiometric, yes. 19 Q. "... stoichiometric explosive mixture", that is to say 20 when the balance of explosive gas and oxygen is at the 21 best, the ideal level? 22 A. Ideal, yes. 23 Q. "... was completed enclosed and strong enough to 24 withstand such a pressure. As discussed above the 25 basement was not completely enclosed because of the page 57 1 doorway to the stairwell. However, given the large 2 volume of the basement this area would be relatively 3 ineffective in relieving the explosion and so the 4 basement can be assumed to be totally enclosed. 5 "It is then possible to estimate the minimum size of 6 explosive cloud of liquid propane gas (LPG, the 7 explosive gas in this incident) necessary to produce the 8 overpressures estimated above. Other assumptions that 9 have been made include: first, the explosion process is 10 adiabatic (that is there are no heat losses to the 11 surroundings); ignition of a stoichiometric propane/air 12 mixture, that is 4 per cent volume to volume", I assume 13 that is what "vv" stands for. 14 A. Yes, sorry, 4 per cent -- 15 Q. Volume of the explosive mixture and the volume of the 16 air. 17 "... from a report by Kuchta 1986, in a confined 18 volume will generate an overpressure of 8-bar absolute. 19 The net internal volume of the basement of approximately 20 330 cubic metres. 21 "The minimum quantity of propane required to give 22 this overpressure in a total volume of 330 cubic metres 23 is summarised in table 1. To put this into context the 24 value calculated is the minimum volume of ideally mixed 25 explosive atmosphere required given the assumptions page 58 1 above." 2 Table 1 sets out estimated quantity of propane 3 required to produce the estimated overpressure and in 4 the table we can see for ourselves the overpressure, as 5 you have already indicated, is 0.692-bar, the volume of 6 the stoichiometric cloud in cubic metres is 32.75. 7 By reference to a "stoichiometric cloud" do I assume 8 that is a cloud of the combined volume of the gas and 9 air? 10 A. Yes. 11 Q. The volume of the propane gas in cubic metres is 1.31, 12 which of course is the 4 per cent of the stoichiometric 13 cloud volume, and the volume of liquid propane in litres 14 is 4.81. That is of course because of the conversion, 15 as it were, of propane LPG in a liquid form to a vapour 16 form which is a factor of about 250 to 1? 17 A. Yes. 18 Q. "Where did the explosive atmosphere come from? 19 "In this incident there were a number of 20 possibilities for the source of the explosive 21 atmosphere. However, based on the evidence from the 22 investigation, the source was the leaking buried LPG 23 pipe just outside the basement area. LPG consists 24 mainly of propane gas and is heavier than air. The 25 damage to the basement partition walls supports the page 59 1 presence of an explosive atmosphere and ignition in this 2 area. The propane found in the blood samples taken from 3 the deceased individual found in the basement 4 (Mr Murray) also supports the theory of leakage of LPG 5 into the basement. In addition, I have been advised 6 that Mr Murray was the only victim found to have 7 extensive burns consistent with engulfment in a gas 8 explosion. Analysis of the burn damage to his clothing 9 also confirms this." 10 Without going to the report, Dr Hawksworth, what you 11 are talking about is investigation of samples taken from 12 the body of the late Mr Murray demonstrating a level of 13 LPG consistent with his having breathed in a mixture of 14 LPG with air shortly before he died? 15 A. Indeed. I believe these were blood samples and LPG was 16 found in his blood -- or propane, I should say. 17 Q. I wonder if I could ask you again to look at a number of 18 photographs perhaps just to assist in that paragraph. 19 Could I have 8927, please. That is in effect 20 a demonstration of what we are about to see on a video 21 which will be shown, I hope, in a moment. It is a view 22 of the LPG pipe as discovered in situ. Does that show 23 not very clearly on the photograph, I am afraid, but it 24 shows a mirror reflecting the crack which was found to 25 the underneath of the top screwed union of that page 60 1 right-angled elbow joint; is that right? 2 A. It does, yes. In the mirror hopefully you can see the 3 crack. You're right, it's not terribly clear on the 4 monitor but -- 5 Q. If we blow it up, that is very kind. Just to the sort 6 of left, slightly down below the central line through 7 the circle of the mirror, is that the crack? 8 A. That's the crack that was found, yes. 9 Q. That is a reflection, if we go back to the main 10 photograph, please, that is a reflection obviously of 11 what was there? 12 A. Indeed. 13 Q. The next photograph, please. This is a view of the pipe 14 entering the basement through the mill wall; is that 15 correct? 16 A. It is. It's not terribly clear but that's clearly the 17 mill wall, the pipe passing through and then the elbow 18 we were just looking at is where the pipe essentially 19 ends on the left and you can kind of see it bending down 20 and away. I hope that's clear. 21 Q. So to the right of the photograph is what was the inside 22 of the basement: to the left is what was the area 23 outside the basement wall? 24 A. Absolutely, yes. 25 Q. Just where the arrow is -- if you could expand that, page 61 1 please, thank you -- is that actually the corner of 2 the -- 3 A. That is the corner we were just looking at in the 4 previous photo. 5 Q. That is very helpful. Thank you. 8907, please. 6 A. Shall I explain? 7 Q. Yes, please. 8 A. Okay. What this is, I mentioned that obviously the LPG 9 had leaked into the area of the basement which could be 10 accessed from the stairwell and what we're actually 11 looking at here is the door and debris from party wall 12 A. 13 Where this photograph was taken, what actually 14 happened was party wall A was pushed away from the gable 15 end of the wall -- so it was pushed east, I guess -- 16 indicating that the explosive atmosphere and probably 17 the initial explosion was in that area, expanded out, 18 telling us that almost certainly -- well, without 19 any doubt, the explosion happened in that area of the 20 basement initially and then developed out from there. 21 Q. The next photograph 8908, please. 22 A. That is just the same again. I think that's the doors 23 before we moved much of the rubble. That's where they 24 were found. 25 Q. That is the shape of the doors which obviously appear, page 62 1 viewed in that photograph, to have been forced or bent 2 from the other side. 3 A. They appear bowed but the building had fallen down on 4 top of them as well, so ... 5 Q. So you cannot -- 6 A. It would be difficult. You wouldn't want to pin 7 everything on that, obviously. 8 Q. 8920. 9 A. Okay, this is the tank valve. 10 Q. The valve which would have been on the top of the tank? 11 A. Yes, the actual valve running from the top of the 12 propane tank. 13 Q. 8921. 14 A. What we're looking at here is inside the bottom of the 15 valve. What we get to in the next two paragraphs is the 16 discussion about the excess flow valve. The excess flow 17 valve would have been this position in the bottom. If 18 you see the large circular orifice, it would have sat in 19 there. What the photograph shows is the dark green that 20 you can see on the metal, that actually suggests that 21 there was an excess flow valve in there at some point. 22 Q. Yes, you are about to talk about the excess flow valve. 23 Perhaps we are a bit ahead of ourselves in the 24 photographs. Perhaps we could leave that for a moment. 25 Could I just ask you, before we leave the earlier page 63 1 photographs which show the nature of the pipe, 2 Dr Hawksworth, we know that the HSE commissioned a model 3 of the building as a whole. I think it is possible, by 4 looking at the model, to identify the route of the pipe 5 underground from the position of the tank up to the 6 position where it turned, rose vertically and then 7 turned again and went horizontal through the wall into 8 the basement, and thence upwards and into the main 9 ground floor area and ultimately over to the oven which 10 LPG fed to the east of the building. Is that right? 11 A. Right. 12 Q. Is it also the case that a model was commissioned, that 13 we can see on the floor in the centre of the Inquiry 14 room, of the relationship between the basement wall with 15 the pipe passing through it and the pipe on the outside 16 and the right-angled elbow, which was identified as 17 having the crack in it, going at the turn from 18 horizontal to vertical going towards the tank going 19 downwards. 20 A. Yes. 21 Q. On top of that model there is represented a large block. 22 Is that a representation of a block of concrete which 23 was found within the rubble that had been used to bury 24 over and cover the pipe? 25 A. The pipe when it was found, it was buried in loose page 64 1 filling material and -- 2 MR MARTIN: Forgive me, I do no think it is necessary unless 3 the doctor would like to see it. I am sorry, I beg your 4 pardon. 5 THE CHAIRMAN: I am the only person who cannot see it. 6 MR MARTIN: I do apologise, my Lord. 7 A. Yes, it was buried in with loose fill material. The 8 understanding is -- and what we found certainly seemed 9 to support this -- the level of the yard had been raised 10 a number of years after this pipe was installed and, as 11 a result, there was lots of loose building material that 12 was used to backfill that space and a large chunk of 13 concrete was resting against the top of the pipe. 14 MR MARTIN: I wonder, my Lord, those behind me could not see 15 it in either position. I am sorry about that. It can 16 be turned round. You can see it: good. 17 I think also on the floor of the Inquiry room -- 18 I hope it does not need to be lifted up; it is 19 self-explanatory -- is actually after recovery the piece 20 of pipe with the cast iron elbow in it which had the 21 crack and you can identify that. 22 A. Yes. 23 Q. I think also lying down a longer piece of pipe. It is 24 not quite so significant to the cause of the explosion, 25 but that is a piece of pipe actually excavated from the page 65 1 ground all as explained in the relevant report. 2 Returning then to paragraph 22: 3 "There is little doubt therefore that the explosive 4 mixture came from the leaking LPG pipe. The issues then 5 are the size and nature of the leak and the rate at 6 which LPG leaked into the basement and why it wasn't 7 detected. The metallurgical aspects of the leak were 8 investigated in detail by my colleague Dr Parrott ..." 9 I can say, my Lord, for the notes that that is 10 document EX012 commencing at page 7615 and Dr Parrott's 11 conclusion at page 7654. 12 "... which showed that the leak in the pipe was due 13 to a combination of corrosion and mechanical load on the 14 pipe associated with large pieces of concrete resting 15 against it. It was not caused by the building collapse. 16 In his report, he describes the opening/leak in the pipe 17 developing in three stages: initially just corrosion, 18 then a combination of mechanical loading and corrosion 19 accelerating the failure, followed finally by opening of 20 the crack due to its weakened state. He suggests that 21 the rate of LPG release increased during the final 22 period when the pipe was in its most weakened state." 23 At this point could I ask for the video of the flow 24 test to be shown which is described in the report, if 25 you just look at this Dr Hawksworth, please. page 66 1 (Video played) 2 If you can hold this where the video ends, when we 3 come to the end if you just hold the picture on the 4 screen, please. 5 I am sure Dr Hawksworth can help us. This is again 6 a view of the relevant length of pipework actually in 7 situ before it was removed for further testing? 8 A. Yes, absolutely. 9 Q. It is in the position where the mirror reflection 10 examination that we saw in the photograph took place; is 11 that right? 12 A. Yes. 13 Q. We are looking from the position of what was inside the 14 basement with the pipe having come through the wall -- 15 and I am sorry, the smoke makes it a little unclear at 16 this point -- but the pipe on the outside of the 17 building in what was the buried area outside the 18 basement opening was horizontal and then the 19 right-angled bend downwards and then it went down into 20 the ground. 21 We saw at the beginning of this video -- I hope it 22 was clear to all concerned -- initially a small amount 23 of smoke and then a larger amount of smoke coming out of 24 the crack at the bottom of the end of the elbow closest 25 to the wall of the basement. Is that right? page 67 1 A. Yes. What we are actually doing there in that test was 2 feeding smoke in at the tank end of that pipe; so it 3 came all the way along the pipe coming out the crack. 4 Q. Thank you. 5 Could I have, before we move on to the next topic, 6 8880, please. I just want to have your evidence on one 7 specific point, paragraph 3.3.1. In respect of the 8 regulator of the tank, can you confirm that the 9 investigation revealed that, as we see in the final 10 section of this paragraph, the regulator was operating 11 correctly and it had a set outlet pressure of 12 approximately 1.4-bar? 13 A. Yes, indeed. 14 Q. Thank you very much. 15 Paragraph 23: 16 "It was evident during the investigation that outlet 17 valve on the supply tank sited outside the ICL building 18 was not fitted with an excess flow valve. Points to 19 note regarding the absence of this valve are ..." 20 Before we come to these, could you go back to 8920, 21 please. That is the valve which in situ was on the top 22 of the tank and was in effect the valve that the gas or 23 the vapour from the tank passed out of the tank into the 24 pipework and thence towards the building. 25 A. Yes. page 68 1 Q. The next one, 8921, please. That is a view of the 2 underside of that valve; is that correct? 3 A. Correct, yes. 4 Q. It shows that there was a missing excess flow valve 5 spring and in situ, if properly fitted, that would have 6 been a device with a spring acting as a valve screwed 7 into that part of the tank valve; is that correct? 8 A. Indeed, yes. 9 Q. Could I have 8922, please. That is a view across the 10 same orifice at an oblique angle which marks a circlip 11 groove which would have been a clip in the groove 12 holding in the mechanics or the parts of the valve 13 including the spring and -- 14 A. Correct, yes. 15 Q. -- at some stage that has been removed. Is that right? 16 A. At some stage that has been removed. To say when that 17 was is very difficult: whether it was been done before 18 this valve was ever fitted to the tank or after, it is 19 very difficult to say. 20 Q. But it certainly was not removed by the consequences of 21 the explosion? 22 A. No. If it had have been, it would have fallen inside 23 the tank and we did a thorough inspection of the inside 24 of the tank. 25 Q. What you are suggesting is if by any chance there had page 69 1 been a back pressure along the pipe that for some reason 2 it had blown it out, it would have blown it into the 3 tank? 4 A. Into the tank. It would have been collected in the 5 tank. 6 Q. "Points to note regarding the absence of this valve are: 7 "(1) It appears that it probably complies with the 8 LPGA code as such valves are not required if the 9 pipework downstream is 8 mm diameter or less. On the 10 installation at ICL there was a short section of 8.4 11 (8 mm nominal bore) internal diameter pipe immediately 12 downstream of the outlet valve. 13 "Although the leak measured post incident was large, 14 we cannot be sure of its size prior to the explosion and 15 building collapse. In any case, this type of valve is 16 not designed to protect an underground pipe, it is 17 designed to protect against a full pipe break or cleave. 18 "Even if the valve had been fitted, it would have 19 still passed sufficient LPG to give a credible scenario 20 for the explosion based on the flow calculations below." 21 In other words, as I understand it, what you were 22 saying, Dr Hawksworth, is that although one might 23 consider the reasons for and consequences of the absence 24 of this valve in particular circumstances, it does not 25 appear to have had any material effect on the page 70 1 explanation you are about to give regarding the flow of 2 gas? 3 A. No. 4 Q. Thank you. 5 "The question is then at what rate was the LPG 6 released from the leak to find its way into the 7 basement? From on-site measurements made and reported 8 in section 3 and appendix A2 [that is of the report] it 9 was found that: 10 "(1) Tracer gas testing (SF6) ..." 11 What is SF6? 12 A. Sulphurflurahexane(?) I think it's called. It's 13 a standard test gas. It's a neutral buoyancy gas that's 14 used in such situations. 15 Q. You are simply talking about the gas used for the test? 16 A. It's a test gas, yes. 17 Q. "... demonstrated a path from the leak through to the 18 inside of the basement wall. While this is clearly a 19 significant finding, because of the major disturbance of 20 the building collapse the original gas path may have 21 been disturbed or obstructed but nevertheless the 22 principles of a route from the leak into the building 23 was shown." 24 Is it possible to go back to the frozen frame of the 25 video -- that is good enough; if we could just freeze page 71 1 that -- to see actually a much clearer view of what we 2 saw earlier, Dr Hawksworth. 3 When you are talking about a path from the leak to 4 the inside of the basement wall, is it possible to 5 identify where that was from, this particular view from 6 the video? We know that the leak was at the point of 7 the elbow -- that is to the right of the remains of the 8 wall -- and we know that was on the outside buried in 9 the ground. We know that pipe then passed horizontally 10 through the wall. 11 In the paragraph I have just read, are you talking 12 about the path whereby gas, as it were, from the outside 13 of the basement wall buried underground could find its 14 way through the orifice that the pipe passed through and 15 thence into the basement? 16 A. The tests that were done demonstrate -- and what you 17 would have to do for this test is pressurise the pipe 18 with the gas and then use a sensitive instrument to try 19 and pick up where it was coming through the wall. It's 20 one of the appendices in the report, and I can't 21 remember the exact details, but I don't think the gas 22 was necessarily tracking along the side of the pipe and 23 coming out of the hole. But we certainly were able 24 to measure the SF6 gas finding pathways through the 25 ground because clearly there would have been the loose page 72 1 fill and soil material around the pipe and then through 2 the wall. So exactly what the path was is difficult to 3 know but we were able to demonstrate that there was 4 a path. 5 Q. In other words, you were able to demonstrate that there 6 was an explanation for the gas escaping from the leak 7 where it was on the outside of the basement finding its 8 way into the basement? 9 A. Yes. 10 Q. 242: 11 "The leak rate measured using compressed 8 at 0.55 12 bar G ..." 13 What is G? 14 A. Gauge. 15 Q. "... very large at 72 cubic metres per hour. This is 16 equivalent to a leak of 57 cubic metres per hour of 17 propane. 18 "Table 2 below shows the flow required to 19 produce the LPG/air mixture volumes shown in Table 1 to 20 give overpressures of approximately 0.7 bar for 21 different arbitrary time periods. Note these are simple 22 calculations which assume no ventilation in the 23 basement. These calculations are based on the leak rate 24 of propane into the basement to form the explosive 25 atmosphere and not the total leak rate from the pipe, as page 73 1 we must assume that not all of the gas from the leak 2 necessarily found its way into the basement." 3 I think you do know from elsewhere, Dr Hawksworth, 4 that there was a degree of LPG found in the ground -- 5 A. Indeed. 6 Q. -- on a subsequent borehole soil analysis. You set out 7 table 2, estimate of LPG flow rate into basement to 8 produce volume of explosive atmosphere. You give 9 a duration of hours along the top and the volume of 10 propane gas in cubic metres is 1.31. Of course, that is 11 the volume of propane gas from table 1 that you referred 12 to earlier. So that is the next step in your 13 experimental progress; is that right? 14 A. Yes. 15 Q. You can then calculate that the duration of the flow 16 rate into the basement -- and it is self-evident -- if 17 it was the same volume, then it occurred in 1 hour; if 18 it was a 10th of the volume, it occurred in 10 hours and 19 so on for 24 hours and for 100 hours. 20 "The first point to note is that these flow rates 21 are very low compared to the leak rates measured on site 22 of 57 cubic metres per hour of propane. It is clear 23 therefore that the leak could have occurred a matter 24 of minutes, possibly hours, before the explosion. In 25 addition, the efficiency of transfer from the pipe leak page 74 1 into the basement could have been small (for example, 10 2 per cent) and ventilation could have had an effect on 3 the rate of accumulation, although the explosive 4 atmosphere could still have formed within a matter of 5 hours." 6 I take it what you are saying there, Dr Hawksworth, 7 is that it is not now possible to know exactly for how 8 long the gas was entering the basement? 9 A. Unfortunately not. 10 Q. It could be a relatively short period: it could have 11 been a good bit longer. It depends on a combination of 12 factors? 13 A. Yes. 14 Q. "Why wasn't the leak in the LPG pipe protected just 15 prior to the incident? In terms of the leak's effect on 16 the LPG oven, tests carried out at HSL indicate that 17 even a large leak (up to 22 cubic metres per hour) would 18 not have had any effect on the performance of the oven 19 burners and so in this respect would have gone 20 unnoticed." 21 This, I take it, was done because of course the 22 explosion occurred in the middle of the working day when 23 the ovens had been in operation. If, for example, there 24 had been some problem about an inadequate gas supply 25 beforehand over a period, that might have given an page 75 1 indication of the period when the leak was occurring and 2 the gas was going elsewhere? 3 A. Yes. What we found when studied the performance of the 4 burners that they were very insensitive to the leak, 5 really. You have a very large leak and they still 6 operated satisfactorily. 7 Q. "The LPG obviously contained a stenching agent as is 8 normal practice to reveal any leak by way of a strong 9 characteristic smell produced. Unfortunately it would 10 appear that the smell was not observed or if it was, it 11 somehow did not have the desired effect and raise the 12 alarm regarding the leak." 13 If I may just ask you on that, Dr Hawksworth, is 14 there any way in which the smelling agent, the stenching 15 agent, could have either dissipated or reduced because 16 of the circumstances of the gas building up in the 17 basement? I am thinking, for example, of dampness in 18 the basement or any other circumstance related to that 19 particular basement? 20 A. It's not something that I'm an expert on. It's very 21 difficult to say. There may have been an effect, there 22 may have been a masking effect. 23 The other question is the way the stenching agent is 24 used. I was just thinking about this earlier. I assume 25 it has a similar buoyancy to propane gas; so, in this page 76 1 situation, the smell would probably only have been 2 evident in the basement. If a different, more buoyant, 3 stenching agent was used, then maybe that may have been 4 preserved in the factory but it depends on the 5 circumstances. In terms of the process by which it was 6 removed, I couldn't comment. 7 Q. In any event, we can take it the stenching agent is 8 added for the very reason that it is hoped people will 9 smell gas if it has escaped and before damage is done? 10 A. Yes, but maybe in the circumstances of a pit or a cellar 11 the smell remains in that pit or cellar and doesn't get 12 out. 13 Q. Is it likely that it would have been detectable in the 14 cellar itself or would that depend on the level (that is 15 to say, from the ground) in which the gas had 16 accumulated or is it simply impossible to know at this 17 stage? 18 A. Given the amount that we are talking about here, I would 19 have thought you would have been able to smell the 20 stenching agent. I'm familiar with the smell. On-site 21 we all -- just to check that the LPG did have 22 a stenching agent, we checked and it had the 23 characteristic smell and I would have thought it would 24 have been observed. 25 Q. But obviously if it is building up in the basement page 77 1 which, as you described elsewhere, is relatively closed, 2 there is no throughput of people coming and going 3 generally, and no particular ventilation, it might not 4 have been obvious even immediately outside the basement? 5 A. Indeed, yes. 6 Q. Paragraph 29: 7 "Possible ignition sources for propane explosive 8 atmosphere with air include sparks (electrical, 9 electrostatic or mechanical), hot surfaces and flames. 10 The most likely sources of ignition for the propane 11 cloud in this incident include sparks produced when the 12 light was switched on. For a 240 volt mains circuit, 13 the switching of extremely small currents approximately 14 25 mA in a worst case test according to [a particular 15 part of the report] are sufficient to produce incendive 16 sparks. If the fluorescent light consumed 30 watts 17 (conservative value for fluorescent light) then this 18 would give a steady current of 125 mA and a current much 19 higher than this when the light is switched on. There 20 is little question therefore that this would have been 21 incendive. Equally, the operation of the 22 cigarette lighter flint is an ignition source even if 23 the lighter did not light. If the lighter did light 24 then the flame is clearly also a very effective ignition 25 source." page 78 1 I think we know from evidence elsewhere, 2 Dr Hawksworth, that to some extent the lighting circuit 3 in this area of the basement had been constructed from 4 what are known as pyrotenac fittings, which is a type of 5 electrical installation which does not create a spark, 6 it is designed to do that, and therefore on its own is 7 less likely to have produced a spark. But we also know 8 otherwise that later on non-specialised lighting was 9 installed and, as far as we are aware, that at least 10 included a straightforward light switch and a 11 straightforward fluorescent light and that is what you 12 are describing? 13 A. Certainly the fittings I saw were just standard light 14 fittings. 15 Q. Just before we move on, I would like to ask you about 16 two other matters. Following the explosion and the 17 collapse, three witnesses who were present on site heard 18 a hissing noise at the tank before the gas was switched 19 off at the tank. 20 A. Mm-hm. 21 Q. Is that something for which you can provide an 22 explanation, bearing in mind that by that point the 23 explosion had occurred and the building had collapsed 24 but obviously the tank was still connected to the 25 pipework? page 79 1 A. Obviously the tank was hit by debris from the collapse 2 which did move it, but didn't damage it seriously but 3 did move it and did strain some of the joints. 4 I believe my colleague, Mr Mellor, found a small leak on 5 some of the connections at the top of the tank. Also 6 essentially the pipe was completely open. So with an 7 LPG, a liquefied gas, which is liquefied by pressure, as 8 soon as you take that pressure away lots of gas was 9 starting to come off. So there would have been a rapid 10 process of LPG going from a liquid state to the vapour 11 state and that may well have made some noise if that was 12 happening very, very vigorously. 13 Q. So the explanation would simply be because there was no 14 longer any restriction in the outflow of gas at the 15 other end of the pipes, the noise was simply the outflow 16 of -- 17 A. Indeed. Although you see the crack in the pipe, once 18 the building had collapsed, the actual pipe in the 19 cellar was completely clear, it was a fully open pipe. 20 So it was a much bigger leak, very much bigger. 21 Q. So does the existence of hissing at the tank in that 22 circumstance after the disaster have any bearing on 23 a possible cause for the explosion in the first place? 24 A. Not that I could see. 25 Q. The second question I would like to ask you is if the page 80 1 basement had not been used (that is to say, if no-one 2 had ever gone into the basement at the material time) 3 but all of the other circumstances had occurred, the 4 leak, the flow of gas through the wall, the accumulation 5 in the basement, is it possible to say whether or not 6 the absence of people going into the basement would have 7 prevented an explosion occurring with the same or