UNCORRECTED TRANSCRIPT OF ORAL EVIDENCE To be published as HC 837-viii

HOUSE OF COMMONS

MINUTES OF EVIDENCE

taken before the

COMMITTEE

on the

CROSSRAIL BILL

 

DAY EIGHT

Wednesday 1 February 2006

Before:

Mr Alan Meale, in the Chair

Ms Katy Clark

Mr Philip Hollobone

Kelvin Hopkins

Mrs Siān C James

Sir Peter Sousby

 

Ordered: that Counsel and Parties be called in.

2168. CHAIRMAN: Before we begin the evidence today, might I read out the following statement in response to the questions put to the Committee by Mr Laurence yesterday: "The Committee has carefully listened to the request by Mr Laurence which he has made to the Committee to offer a judgment on the case before it. The view of the Committee is that it cannot offer such a judgment on this or any other Petitioner's case. The Committee's view is that it must listen to all the evidence before it makes any decisions. Nevertheless, the Promoters should not in any way interpret this decision as indicating that the Committee is rejecting the case that Mr Laurence has actually made. The Committee would encourage the Promoters to continue to negotiate with all Petitioners during the Committee's sittings in an effort to find a suitable compromise between them. The Committee will take a view on all remaining issues before it at the conclusion of the Committee's sittings."

2169. Ms Lieven, do you now want to add something?

2170. MS LIEVEN: Yes, sir. I wanted to deal with the issue of the station's operations room which Sir Peter Sousby raised yesterday for clarification and potentially an undertaking. Can I inform the Committee that the position is that London Underground Ltd have a PPP contract with Metronet which requires an enhanced station refurbishment at Liverpool Street, and that includes the provision of a station control room of proportions which cannot be provided in the existing location. So the PPP contract itself requires that change to take place, and the deadline for completion of that enhanced station refurbishment at Liverpool Street is 1 March 2008. The Committee can take total assurance from that position. If, for whatever reason ‑ and totally unpredictable things can always happen in life ‑ the station's operation room is not relocated by Metronet under the PPC contract, then I am authorised, for the avoidance of doubt, to inform the Committee that, in any event, the nominated undertaking will be required by the Secretary of State to remove the station's operation room from its present location. I hope that closes every potential problem on that.

2171. SIR PETER SOUSBY: I think that is very helpful indeed. Can I take it that we are to understand from that that the space released by the removal of the station control centre would become part of the general circulation area within the station and would not be used for any purpose in the interim?

2172. MS LIEVEN: That is my understanding.

2173. CHAIRMAN: Now can I ask Mr Robert McCracken to make the case for himself and also the Covent Garden Community Association. Mr Laurence?

2174. MR LAURENCE: Sir, you have very kindly shown me a draft of the remarks you have just made. As I understood it, I was invited to have a look at a copy of that draft with a view to assisting you by my initial reaction to it in some way.

2175. CHAIRMAN: Albeit very briefly, Mr Laurence, yes. I thought it was the best way to proceed really.

2176. MR LAURENCE: Sir, let me focus on the paragraph of your comments which immediately strikes me as calling for some further clarification. The paragraph reads as follows: "The Committee would encourage the Promoters to continue to negotiate with all Petitioners during the Committee sittings in an effort to find a suitable compromise between them. The Committee will take a view of all remaining issues before it at the conclusion of the Committee's sittings."

2177. What is not clear about that, Sir, and it may be that it has deliberately been left unclear, is the basis upon which we are entitled to approach the Promoter for the purposes of those continuing negotiations. Are we entitled to say to the Promoter: "You may very well have not succeeded in front of the Committee, although you do not know that yet", or what? What I anticipate is that, when these negotiations get underway, the response of the Promoter will be to say, "You have not had a successful decision in your favour. You may well end up with a complete failure at the end of the day. Why should we negotiate with you on any basis that is at all meaningful?", and in response to your kind invitation to tell you, what strikes me as potentially problematic about the words you have just uttered is that point, and I am being absolutely honest here - it is my first reaction - but I do apprehend that, unless a slightly stronger steer is given to the Promoter, his attitude will be, "We are very busy, we have many other things on our mind and what you are asking for we simply cannot concede", as was made clear before.

2178. CHAIRMAN: I understand the direction you are seeking to take, Mr Laurence, but let me repeat to you the gist of that particular paragraph. As I indicated yesterday, and as I indicated some two weeks ago, we will not interfere in any negotiations which are proceeding, and what we hope, where problems exist, is that all parties will continue to negotiate and not be inhibited by these proceedings themselves. At the end of the day we are charged with the Bill which the House likes and has insisted that it moves forward. Whatever you come up with yourselves and present to the Committee at whatever time, at the beginning, middle or end, we will take a view on all of that at the end rather than during the course, but we expect everybody to continue to do their very best to try and get a solution which the Committee itself will find acceptable but we are not going to interfere in that negotiation before we decide.

2179. MR LAURENCE: Before my learned friend rises, we will certainly negotiate. I think what you have just said is making it clear what the Committee expects from everybody, and that, of course, includes the Promoter as well.

2180. CHAIRMAN: If they so wish to negotiate, if they so wish to find any problem, I would expect everybody to try to continue to get their case across, but we will not interfere in the negotiations.

2181. MR LAURENCE: By "if they so wish" are you meaning to imply that if that you want to‑‑‑‑

2182. CHAIRMAN: It may be, in the course of any negotiations on anything, maybe one side will say, "We do not agree with that", and that is their prerogative, as, indeed, it is yours.

2183. MS LIEVEN: Can I say something, sir, like Mr Laurence, trying to be as honest and clear as possible? We will continue to talk to all Petitioners in the hope of achieving settlement on their Petition. With many Petitioners and many issues, that can be done by agreement outside the Committee. Where something like the City's Petition raises an issue that from the City's point of view could only be solved by an additional provision - in other words it cannot be settled within the parameters of the Bill at the moment because we cannot provide an additional ticket hall within the grounds of the Bill, and we can negotiate about gateline re-jigging and resigning, all those kinds of things, within the parameters of the Bill, but where there is effectively a request for an additional provision - the Promoter will discuss with the Petitioners whether an additional provision is necessary or not, and we will go on discussing that with the City quite happily; but if, ultimately, the conclusion is reached that there is no need for an additional provision - and this will come out across the room not just with the City - then the point will come when we will say, "We are not going to draw up an additional provision and discuss with you the precise parameters of it in circumstances where our view, based on a great deal of consideration, is that it is not necessary." I am not saying that to say that we will not go on discussing with the City. We will, and we will discuss their capacity figures with them and whether we have got it wrong, but with an issue like that we will ultimately come to the choice: do we promote an additional provision? And the Committee will be aware we have already promoted one series and are in the course of drawing up another series, but Liverpool Street additional ticket hall is not in there because we do not think it is necessary. I do not want anybody to be under a misunderstanding that we are going to go away and draw up detailed engineering drawings for something that at the present time we do not think is necessary. We will go on discussing with the City whether it is necessary, but, if we continue of the view up to the end of this Committee that it is not necessary, then, until the Committee tells us to, we will not draw up that additional provision. I think it is important that the Committee understands that, as it were, there are two different things that can be negotiated over.

2184. CHAIRMAN: Ms Lieven, we are fully aware that you have agreed to agree on what you can agree on, but what we are saying is that the door is left ajar. It is left ajar because it may be found useful to you and both the Petitioners, but it also may be found very, very useful to this Committee because we may want to go through it ourselves at some point. That is where we are. That is the ruling. I hope that clarifies things a little bit more.

2185. MR LAURENCE: You are indicating that the Committee may itself be assisted by being told at the end of the proceedings, "This has been the result of our continuing negotiations in the meantime." I see Sir Peter nods assent to that way of putting it.

2186. SIR PETER SOUSBY: I am sorry; I will do my best to keep my head still in future.

2187. CHAIRMAN: You should take from what I have already said that the door is actually ajar, and it is ajar for a number of reasons and purposes, and we would hope, when we get to the summaries of each of these sections, we will put all of those together and we may revisit them or not, as the case may be, but certainly we want all avenues to remain an opportunity to progress in the course of the sittings towards the Bill.

2188. MR LAURENCE: I am gratified that you have found the time to provide that extra clarification.

2189. CHAIRMAN: I hope that was helpful to both of you.

2190. MS LIEVEN: Thank you very much, sir.

2191. CHAIRMAN: Can I call Robert McCracken to make the case for himself and also the Covent Garden Community Association, for whom he is acting as agent.

 

The Petition of the Covent Garden Community Association.

 

Mr Robert McCracken appeared as Agent.

 

2192. MR McCRACKEN: There are before the Committee two Petitions, my own Petition and that of the Community Association, and I hope that the Committee have copies of those in front of them.

2193. I should say at the outset that I am actually a practising barrister and I specialise in environmental law. Oddly enough, I am co‑author of one of the leading works on statutory nuisance and I have been involved as leading counsel in some of the important cases on environmental assessment law in the Court of Appeal, the House of Lords and the European Court of Justice, oddly enough, often against Mr Elvin, but, obviously, I am not here today professionally. I shall make some submissions on the implication of environmental assessment directly for your Committee's deliberations and Parliament's decision, but what I am going to suggest is that it would be wise for the Committee to take some independent professional advice on that aspect of the matter. Obviously, the Promoters will make their submissions, but, in the nature of things, submissions made by a promoter naturally are coloured by the objectives which they want to achieve.

2194. CHAIRMAN: Can I assure you, Mr McCracken, that we have got independent advice and it is given to us on a regular basis.

2195. MR McCRACKEN: Excellent.

2196. I have been asked to speak for the Community Association. I have lived in Covent Garden for over ten years, and during the previous 25 years, whenever I was working in my Chambers in London, I probably went into Covent Garden on almost a daily basis. I was a member of the Executive Committee of the Committee Association at the time that it decided to petition against this Bill, and then in September, after three years on the executive, I decided to stand down; so I am reasonably familiar with the thinking of the Community Association about the Crossrail Bill.

2197. There are really two sorts of objectives that we have today. The first is to seek the northern alignment rather than the alignment through Covent Garden, and the second is to seek various conditions or undertakings. Some ought not to be controversial. For example, we seek an undertaking that there should be no freight traffic in the tunnel. That ought not to be controversial because the Promoters say that they have not designed it for freight and do not have any intentions to put freight through the tunnel, so it ought not to be controversial. We also seek an undertaking that during the core night‑time hours there should only be maintenance traffic through the tunnel, and we seek and undertaking that there should be a floating track‑bed through the Covent Garden area. We also seek that the standard for residential noise should not be 40 decibels but 30 decibels, and I will explain all of those in more detail later.

2198. Can I start by just saying something about Covent Garden and the Community Association, and it is really to this effect. It is important always, and I do not suppose the Committee really will be in any doubt about this, to remember that one has to be wary of what experts say and that experts need to be on tap and not on top. I can just give briefly some examples of where experts have got things very wrong and where ordinary people, such as those in the Covent Garden Community Association, have been right.

2199. The experts' predicted traffic‑levels for the M25, for example, were hopeless underestimates because they did not take account of the fact that when you carry out a major infrastructure project you alter the pattern of life, and the critics of the M25 planning were proved to be right. I can think of examples from my own practice up and down the country where the experts, for example, said there was no way that the Albert Dock in Liverpool was going to be saved without filling in the dock; it is the only way to make it a viable scheme for the preservation of the Albert Dock. The commercial enterprise who said that persuaded the Secretary of State to permit him to fill in the dock, but, in fact, he went bankrupt, he was not quite so smart as he thought he was and, in the event, the scheme, which the community had wanted to have, proved to be viable and successful and the Royal Albert Dock is there to be seen today as a great success. This point is illustrated in Covent Garden as well.

2200. When I first used to know Covent Garden - it must be over 30 year ago now - it was obviously quite run down because the market was on the way out. There were lots of empty sites and there were lots of hard to let buildings, and that created a tremendous opportunity, but a lot of the experts simply wanted to replace those buildings with new office developments. The community resisted and, happily, they were successful and Covent Garden has been to a large extent preserved. The low‑rent buildings initially provided opportunities for very creative people ‑ glass blowers and so on ‑ many of the activities which today are quite a draw in Covent Garden. As time has gone on, of course, the area has become very commercially attractive, and that has driven out some of the creative people such as the glass‑blowers but we retain quite a lot of our creative activities, particularly in the media and technology areas, and so we have, for example, quite a lot of art studios and such like here; but one particular example of where the Community Association was right and the experts were wrong is in relation to the Floral Hall.

2201. The Royal Opera House wanted to demolish the Floral Hall and the whole scheme was to demolish it, and the figures, I am sure, were very persuasive, but the Community Association resisted and fought for it, and it has largely been saved as a result of those community efforts, and it is now quite amusing. If one goes to the Royal Opera House, it is astonishing how proud the Royal Opera House now is of the Floral Hall. Had it been left to them it would not be there, but it is there because of the efforts of the community and now is something that is an integral part of their enterprise.

2202. I noted that in opening Mr Elvin referred to the northern route as being promoted by the residents of Mayfair, and I think he may have been trying to imply that it is just rich, privileged people who are interested in the northern route; but certainly Covent Garden is not an area that is exclusively occupied by rich, privileged people. It used to have a rather narrow social mix, and when I first came to London it was mainly social housing. It is now a much more inclusive community. There are quite a number of owner‑occupiers and private tenants but mainly it remains an area of social housing, including some very vulnerable people. The Community Association has to be very active to protect the things that are important, both to the community who live there and work there but also to the wider community who visit the area, because there are inevitably a lot of commercial pressures these days which are focused entirely on short‑term profit and do not have any sense of the long‑term. The long‑term is important to everybody, whether they live or work there.

2203. We have been under a lot of pressure recently from, say, the Licensing Act 2003, which has led to our Chairman, for example, who is a market trader, over the last year probably - she told me last night - spending two to three days a week on dealing with the various applications for licensing, and so on, and our Vice Chairman, who is a mother in the area, has been doing amazing work on that, and it is for those reasons that, since I am here petitioning anyway, I have been asked to speak on behalf of the Association rather than that either the Chair or Vice Chair coming here. There is a limit to what those people, heroic though they were, can do.

2204. I do not know how well the Committee know Covent Garden, because obviously you are here precisely because you are not locals, as it were, but I imagine you probably have from time to time wandered there, and you may be surprised to know that something like 7,000 people live in Covent Garden. I think often when people visit the area they do not appreciate the extent to which there is a vibrant residential community. You may well not have noticed that there are two schools in the area - St Joseph's Roman Catholic School and St Clement James Church of England School ‑ but, although there is a stable residential community, it is under very considerable pressure, and I know quite a number of people with young children, and so on, who have in a sense been driven out of the area in recent years from the relentless commercial activity that has been taking place here. You can imagine some of the pressures that you can have in such an area from bars, from shops and from just literally the amount of rubbish that is in the street and various problems that Central London has, but it is generally recognised that it is a useful thing to have stable communities of people who live in the centre of our cities, and that is something which is worth keeping.

2205. I can think of a couple of examples in my own experience of the value of that in unexpected ways. I can think of an occasion when the commercial premises next to where I lived was smouldering on fire. The commercial company's security people were not interested, and it was only because of those who lived in the area that we were able to get the fire brigade out and stop perhaps what would have been a major conflagration. Again, in recent years I have woken up in the middle of the night, seen somebody carrying out a smash-and-grab opposite my flat and have been able to call the police and give the number of the vehicle as the smash-and-grab was taking place. There are all sorts of ways in which a stable community provides something which is important for society as a whole, including the commercial enterprises.

2206. The borough in which I live, Camden, is, unfortunately, one that feels itself to be under‑resourced, has rather low morale and is therefore very ineffective in providing protection for the people who live in the area. To give an example, Camden environmental health officers will never come out at night to deal with noise nuisance from commercial premises; they simply say, "Sorry, we do not have the environmental health officers to do that." They just will not come. However, the noise team will come out to deal with noise from residential parties, but, as you can imagine, where we live it is likely to be noise from commercial premises rather than noise from residential premises that is of concern to us.

2207. The area of Covent Garden and the West End generally, Oxford Street and so on, has real difficulty in coping with the amount of activity that is currently undertaken there, and that is one of the reasons why both in Westminster and Camden the Licensing Act policies which they have established impose serious restrictions on additional drinking floor space. The Community Association has almost been overwhelmed by the amount of activity it has had to deal with there. In a strange way, although generally speaking retailers judge the attractiveness of their premises by the number of people who walk past ‑ the football count ‑ paradoxically, beyond a certain amount, the more people you get the less trade you do. It just becomes counter‑productive. If you wander round Covent Garden or Oxford Street they are very much at that level: there are so many people wandering around that it has actually become counter‑productive.

2208. There will be minimal benefit to the central area from the provision of Crossrail, but areas both to the north and south would benefit from the boost which Crossrail would provide and the variety of activities that would be provided in the emerging area, for example Kings Cross and to the north, would be considerable. The assessment of the relative merits of the northern alignment and the central alignment has, perhaps inevitably, been based upon rather assuming that things will continue, that present trends will continue, rather than accepting that a major infrastructure actually changes the pattern of the way in which people live; and areas do change over a period of time and something such as Crossrail could make an enormous difference to the northern area. I think if you just wander round the area around Kings Cross you readily see that it is an area that could do with a boost with an injection of activity. It is ironic, in a sense, that London is a world city which is a leader for Europe ‑ we should not be ashamed of being leaders of the European Community ‑ and a city that has a country with a government that is committed to many thoroughly desirable policies relating to sustainability, transport and inclusivity in communities and regeneration should be contemplating having Crossrail going through an area where it can only add to already unacceptable pressures and avoiding areas that would benefit from it. Perhaps one of the things that one reflects on, one of the lost opportunities if the northern line is not taken, is that Eurostar, at enormous expense, has been diverted from Waterloo to King's Cross St Pancras, and it makes no sense for Crossrail, the equivalent of RER (the Paris service) not to go close to the terminal of Eurostar.

2209. We are concerned about the kind of consultation that is taking place and feel that really what has happened has been a series of presentations, but we have had presentations. We have not really been consulted. We have been told what is going to happen and an attempt has been made using crude language to sell it to us, but in terms of what do we think in the sense of a real engagement, the Community Association does not feel that there has been an engagement in that sense, and, as will become apparent when I make some observations about the environmental statement, the information to which we were entitled as a matter of law has not been provided in the form in which the law requires it to be provided, but I will come on to that.

2210. You obviously will have heard a lot about the relative merits of the different alignments. I have no idea what view you are going to take about that in the light of the ruling that you made to Mr Laurence's request earlier. I guess your views on all these matters will become apparent at the end of your deliberations rather than on an interim basis throughout. I also want to speak, and the Community Association also wants to speak, on the assumption that you may decide that the appropriate route is the central alignment, and there are some very important things that the Committee could achieve for us if it is to be the central alignment. I would like to turn to those now.

2211. Our concerns, or the things about which you can do something, particularly relate to nuisance from noise and vibration. The construction noise will be prolonged and quite severe for some people, and obviously it goes without saying that the people of Covent Garden should not be subject to that if a better alignment would provide overall more long‑term benefits to the community, but I am not really going to say much about construction noise in the context of if it goes on central alignment, but there obviously will be serious construction noise nuisance for many people.

2212. I do note, and the Community Association is very pleased to note, that there is no proposal to use the Phoenix Garden for any part of the construction operations. Pheonix Gardens is the remaining community open‑space in Covent Garden, and I actually commend to the Committee, any time they are in the Charing Cross Road, Shaftesbury Avenue area, a visit to the Pheonix Garden. It is a truly delightful place, and we are very lucky that a group of women who live nearby fought to protect that from the problems with which it was associated a few years ago; and now a committee has been established and a lot of work has been done by them to maintain that as the haven that it is.

2213. I want to talk about noise from operations, because that is something that really does cause us serious concern. The first thing to note, and it is very important, is that the tunnel will be very close to the surface in Covent Garden. On the whole most of the tunnels of the board underground lines in London are quite deep, but in Covent Garden the tunnel will be very close to the surface. For example, in Neal's Yard it will be no more than 15 metres below the surface. It will only be 20 metres down to the running line. That is very different from almost anything else that there is at the moment in London, and it is actually much higher in the Covent Garden area than it will be elsewhere.

2214. The fact that the tunnel is so close to the surface does justify a different approach in Covent Garden to the approach that is taken elsewhere, because the risks in terms of noise and vibration are inevitably much greater when the tunnel is close to the surface; and I must apologise, in my Petition and that of the Community Association I think we suggested that the tunnel was only 25 metres from the surface. We were wrong. Unfortunately, that was not correct in the response document by the Promoters, but I did go and see them on Friday and ask certain questions, and, both from what they said and from my examination of various of the drawings, it is apparent that in the Neal's Yard area the top of the tunnel is 15 metres from the surface and the running lines are about 20 metres from the surface. That is a very important point of context. The second point of context is this. Noise from underground trains is very unsettling. It comes into your house through the walls and is then re‑radiated through the walls; so it is not like noise in the street ‑ you can close your window or you can install double‑glazing or triple‑glazing, you can draw the curtains, and so on ‑ it is something that actually comes in; it is there in side your house and it is very unsettling. I can remember I used at one stage to spend a lot of time in West London and I remember in one place there that at night you could hear the trains going underneath, or two trains going underneath, and it was a very strange feeling to have the noise from a train not coming through the windows but actually through the building. This is really very much related to something that you will have to grapple with, and that is the weight you attach to the various quantitative measurement of noise. There is no doubt that Mr Taylor, who has been a specialist adviser, or one of the specialist advisers on noise, is a leading man in the field, but all that he can do is tell you what he predicts on his computer model the noise measurements are going to be. He cannot tell you the tone of the noise or the quality of the noise. Noises of the same, as it were, energy level can be very different in terms of their effect, their terms of quality and how you experience them, and so the energy levels, which is effectively what you have in the various documents that set out the noise level in terms of decibels, DbA, is only part of the picture and needs to be qualified by an appreciation of the difference between noise that comes in, say, through the windows and through the street and noise that is actually coming up through your building and being radiated into your room. There are a variety of ways in which noise energy levels are measured, and the noise indexes (LAeq, the average energy level, or the LAmax, the maximum, the greatest noise that you get on single events), but one has to be cautious about all of those because various standards have been suggested by the World Health Organisation, for example, for maximum noise levels but, on the whole, the assumption is that those maximum noise levels will be relatively few events in number. Obviously with trains the maximum noise level is quite frequent. Here we have got 24 trains an hour; so the maximum noise level is not just Concorde flying over once a night, as it were, that maximum noise level is going to be something that people experience on quite a regular basis.

2215. A minor point but one nonetheless which is worth making: the way in which noise has been predicted and measured here is in the LAmax test, that is LAmax slow, but there is another way of measuring maximum noise, and that is LAmax F for fast ‑ it depends how you set your instruments ‑ but if you set your instruments to LAmax S you will get a reading that is one or two decibels lower than you would if you set it to LAmax F. In other words, the index that has been chosen, the measure that has been chosen, gives you a slightly lower reading than you would get if you chose a different one. That is not the largest point in the case, but it is something to bear in mind, that an index has been chosen, a measure has been chosen that is slightly lower and gives you slightly lower readings than you would have got if you had chosen another one.

2216. Crossrail say that they can ensure that neighbouring buildings do not experience noise levels in excess of 25 decibels L Max, because they say that wherever buildings need to have a noise level that does not exceed 25 DbA LAmax, they will do that because there are certain buildings that they say should only have a noise level of 25 ‑ theatres, for example, they say should only have noise levels of 25 ‑ and they say they will achieve that; so there is no doubt that they can achieve noise levels as low as 25 decibels. It is not a case where we, the Petitioners, are saying that the noise levels should be lower and they are saying you cannot do that. If you want to have a railway you have to have noise levels in houses of 40 decibels. This is not that situation. They can achieve lower noise levels than they are proposing to seek to achieve. The difference, of course, between 25 decibels and 40 decibels is a more than doubling in the noise, because the decibel scale is a logarithmic scale, and so it is a rather greater difference than you might otherwise suppose.

 

2217. The first condition that we seek, and in a sense it is not a matter of concern to us as to how it is achieved, but we do want the reassurance of a prohibition on the matters in respect of which we seek undertakings or legally enforceable obligations, is in relation to freight trains. It only takes a moment's reflection to realise that freight trains are likely to be noisier than passenger trains. The nature of freight trains makes them noisier than passenger trains. If freight trains are introduced, it is likely to be at night because that is an obvious time to run freight trains, and a lot of freight on British Rail does run at night. It has not been assessed. Nowhere in the Environmental Statement do we see what the noise associated with freight would be and, indeed, there is an information paper on freight which at paragraph 4.1 says that they are not envisaging running freight, indeed the whole route has not been designed for freight, it is not something that they are planning to do.

2218. However, although I have asked for an undertaking that there should be no freight, the Promoter refuses to give it. I shall come on to the submissions I make about the Environmental Assessment Directive, but the submission I make is that it would be quite unlawful for Parliament to authorise Crossrail without a prohibition on freight because it has not been assessed and the Environmental Assessment Directive requires that the environmental effects should be assessed and, as I shall explain in a little while, European Community law requires that a precautionary approach is taken.

2219. So that is the first point and it ought not to be a very difficult thing for the Promoter to give because it is not something that could possibly have formed part of their commercial assessment because they say that it is not designed for freight. It is disappointing that that undertaking has not been given, but you can imagine the serious effects that the running of freight trains through the tunnels at night would have on our community.

2220. The second undertaking that we would seek is that there should be no trains other than maintenance trains during the core night hours. On the Underground at the moment, as you know, the service winds down late in the evening and then during the core night hours, between 1 o'clock and 6 o'clock, there are just maintenance trains, and of course one accepts that maintenance has to take place at times when the service is not otherwise operating and one recognises that.

2221. It seems to us that the standard that has been taken by the Promoter, which is set out in their response to our petitions - it is in information paper D1 on groundbourne noise and vibration, which is appended to our information papers - is that the level of noise that is acceptable for residential buildings, 40 dBA, and it is table 1, page 2. I think somebody needs to turn over to page 2. Thank you very much. You will see that for residential buildings the maximum noise level is 40 decibels, exactly the same as for offices, where for theatres it is 25 for concert halls it is 25, for studios it is 30, and so on. There is a world of difference between what you need in your office and what you need in your home - a world of difference. One inevitably accepts that at work, in here for example, there are going to be noises and one has different expectations, and different standards should apply, but at home one needs a higher standard. Really what this is saying is that the standard people can expect in their bedrooms at night is no higher than the standard that they could expect in their offices during the day, and that is wrong as a matter of principle. People ought to be able to expect in their bedrooms at night to have a better standard than they would have in their offices in the day. They are also saying that somebody in the theatre is entitled to a higher standard than somebody in bed at night; that cannot be right. So we would suggest that the Promoter should be expected to achieve a standard - and I am always a great one for being modest in my suggestions - of 30 decibels in houses.

2222. Now the next point is in relation to the method of track construction and there are various methods by which tracks can be laid, and one is called floating slab. We think that in Covent Garden, where the line is as high as it is, there should be a requirement that it should be floating slab. It is wrong to ask us to rely on standards because effectively what the Promoter is doing is saying, "We are not going to tell you what we are going to do anywhere. We are simply going to invite Parliament to accept that we will work to a particular standard, the standard being 40 decibels in residences and so on, and we will decide as we are carrying out the project what is required in particular areas." One does not have to be a cynic to see the problems of that approach from the point of view of the people who live in Covent Garden because how are we going to engage with the Promoter effectively to ensure that we get what they are saying they are going to give us, even if it were right in principle? It is a very dodgy way of proceeding, simply to say that we will meet these standards and it does not, for reasons I shall come on to, comply with the Environmental Assessment Directive. Obviously the undertaking should be "floating slab or better" because one accepts that as technology changes it may be that different and superior track methods may be available, so one recognises that it should be floating slab or better.

2223. I remember in opening Mr Elvin said, "Do not just keep imposing burdens on us because the accumulation of expense will be very considerable," but if Crossrail is going to bring the benefits that the Promoter says it is going to bring - and of course that is not a matter, in a sense, for this Committee at the moment, that is a matter, I think, for the whole House - but if Crossrail is going to bring the benefits the Promoter says it is, then it is right that it should pay to ensure an adequate level of protection for the people who live in Covent Garden and who will have to experience the ill-effects of Crossrail on a day-by-day night-by-night basis for the whole of the rest of their existence. It is not something over which people will have any control. It is something that will continue forever. There are those of us like myself choose to live where we choose to live, and I see no reason why we should be driven out, but there are also many people in Covent Garden who do not really have a choice of where to live. The people in social housing do not really have the choice to move away if things do not work out, they are stuck there effectively.

2224. One of the odd things about the refusal of the Promoter to offer an undertaking to use floating slab track is if you look in the Environmental Statement, Volume 2, at paragraph 8.7.156 the Promoter says that they will be using floating slab track in our area, so we are not asking for something that they are saying will not be necessary. We are asking them for an undertaking that they do what they say they are going to do. I imagine that anybody looking at the Environmental Statement will say, "Oh great, there is going to be floating slab track in Covent Garden." I nearly thought, "Half of what I want I do not need to bother to turn up to ask for," but I thought I had better just check and ask for an undertaking, and I was a bit taken aback to be told that although the Environmental Statement says that we are going to have floating slab track that in fact the undertaking was not forthcoming.

2225. I was very grateful to the negotiating team whom I visited on Friday of last week for giving me a document which is not in the Environmental Statement and not in the public library and not therefore available to the generality of the public, and I shall come on this later, a document entitled "Crossrail Technical Report: Assessment of Noise and Vibration Impacts, Volume 8". I would like to go through with you, if I may, and the drawing entitled "Groundbourne Noise Contours Route Window C5: Tottenham Court Road Station". I do not know whether somebody could put that up on screen because I could illustrate the sensitivity of the uses in Covent Garden. Covent Garden runs for these purposes, broadly speaking, from Charing Cross Road to Kingsway.

2226. MS LIEVEN: We do have copies of this document because I was going to refer to it later. Would it be helpful for the Committee to have hard copies of it now? It is a bit easier to read, I suspect. (Same handed) It is much easier to follow with this. Can I ask whether the Committee's copies are colour copies?

2227. MR TAYLOR: Yes, they are.

2228. MR McCRACKEN: If you look more or less in the centre of the plan you can see Tottenham Court Road and you see Charing Cross Road running north-south. Picking up the westbound tunnel you have got these contours, the green is 25 LAmax and then the blue is 30 LAmax. So if you take the area of Charing Cross Road the way this works, as I understand it, is you have got 25 as the outer green and then the next contour line presumably is 26, then 27 and 28, and so on. So as you move closer to the centre of the tunnel the noise level is increasing. I think that is the way this is intended to work.

2229. The westbound tunnel, looking at that first of all, first of all goes underneath the Phoenix Garden. If you just orientate yourself, Shaftsbury Avenue is not marked but Shaftsbury Avenue, if I can hold up mine, is the road that is run diagonally across the page like that (Indicating), and between Charing Cross Road and Shaftsbury Avenue the westbound route is running underneath amongst other things the Phoenix Garden and then it goes across Shaftsbury Avenue. I should say there is a cinema just to the side of the route, there is a chapel to the side of route, and then it goes underneath the Covent Garden Hotel. That has in its basement, which is ten metres deep, a screening room which is used almost every evening of the week for the showing of rushes or the showing of films and so on. It is a very fashionable hotel which is important to London as a world city in the media industry.

2230. I should add at this point that the assumption on which these noise contours are drawn is that basements are no more than two metres deep. So that is the assumption, but the Covent Garden screening room is at a depth of ten metres. It then goes through Neal's Yard probably the heart of Neal's Yard, which is the therapy rooms and medication centre run amongst others by the internationally renowned Anya Saunders, and they have activities in the basement as well as high level. Those are the kind of activities where you can imagine quietness is actually quite important if you are practising or teaching meditation and offering therapy. That is really something that you need tranquillity for.

2231. It then goes across under Neal Street and then it goes across Endell Street and Endell Street is interesting because on the south side of Endell Street, more or less where the contour of 30 LAmax is shown, is the hospital which is no longer a hospital but is now a set of recording studios and a place which is reckoned to be important in the music industry. To the north of that is the Covent Garden Medical Centre which is the general practice for the area where all sorts of sensitive activities take place. Then the route swings under Drury Lane and starts to swing north and it goes by St Joseph's Roman Catholic School, underneath the alms houses, which are occupied by old people, and underneath the Dragon Hall, which is a new community hall, and then it joins the eastbound route, and when we reach New Oxford Street we have come to the end of the area that is of concern to the Covent Garden Community Association because our concern is from the area of Charing Cross Road to New Oxford Street. We simply say nothing about the area beyond that, either one way or the other.

2232. As I say, the assumptions behind this drawing are the basements are no more than two metres deep, and that was something I was told at the negotiating meeting by the negotiators on Friday and also something that Mr Taylor was good enough to confirm to me. That assumption is not right but in a sense it does not matter because they are saying at paragraph 8.7.156 of the Environmental Statement that they are proposing floating track beds in the Covent Garden area.

2233. I want briefly to say something about the environmental assessment procedures that have been followed. The authorisation, whether it be by Parliament or by any other body for a development project such as this, is invalid if the requirements of the Directive have not been met. There is a duty upon all emanations of the state, courts and the like, to seek to nullify the unlawful consequences of any such invalid authorisation. That applies to a legislative approval such as this just as much as it applies to approval by a planning authority, either the national planning authority, the Secretary of State, or a local planning authority, the local authority. That is a principle established by the case of Luxembourg v Linster, see C287/98, particularly paragraphs 49 to 54. Where that procedure applies, the Promoter has got to produce an Environmental Statement that sets out the data necessary to identify and assess the main effects which the project is likely to have. That is not only so that the decision-makers, yourselves in a sense, have that information but also, sir, the public who wish to participate in the discussion have that information themselves when they are participating in that discussion. The source of that is Schedule 4, part 2, paragraph 3 of the 1999 Regulation, which I think applies to these proceedings by virtue of Order 27A of the Standing Orders, or Article 5(3) of the Directive.

2234. In interpreting that requirement to give people the data to identify and assess the main effects, the Precautionary Principle applies because the Precautionary Principle is part of the European Treaty now. The European Court of Justice have held that it is necessary in interpreting environmental protection legislation to interpret it in a precautionary way so as to apply the precautionary approach. There is much authority for that but one case which establishes that is the Pally Granite (?) case C9/OO, at paragraph 23. An Environmental Statement has not only got to give you the data necessary to identify and assess the main effects, it has also got to describe the measures that are going to be used to prevent, reduce or offset adverse effects. It has got to describe the measures that are going to taken. That includes the mitigation measures such as, for example, are we going to use floating track bed or not. That is something the Environmental Statement has got to tell you.

2235. The English Court of Appeal have held that the assessment has to take place before the project is authorised in principle and that the authorisation has got to impose conditions that require that the Promoter should do the things that he says he is going to do. In other words, they cannot just leave it at large. They have got to impose conditions to require the Promoter to do the things he said he is going to do, and authority for that is Smith, 2003, England and Wales Court of Appeal civil cases, 262, and the paragraphs that are particularly relevant to that are paragraphs 25, 27 and 33.

2236. So my submission is that you and Parliament have to ensure that the Promoter is legally obliged to do the things that he has said he is going to do. And it is rather worrying that the Promoter is refusing to give an undertaking to do the things that he has said in his Environmental Statement that he is going to do.

2237. I want very briefly just to summarise some key deficiencies in the environmental assessment process here. First, data that is obviously necessary to assess the environmental effects of this project is data relating to the noise that will be experienced by the properties that will be affected, so one obviously needs to know the information that is included in this document here, but this information was not in the Environmental Statement, nor did the Environmental Statement make any reference in its introduction to the existence of this document. So the only way that one is able to get hold of this information is by being persistent. Now, I happen to be a lawyer and it just happens that environmental assessment is something that I have spent a lot of time on and I happen to spend a lot of time on planning inquiries and so on and to be reasonably capable of working out what there might be, and I went to see the Promoter and specifically asked for this information, but there is no way that this information could be said to have been made available in the way in which the Environmental Assessment Directive requires that this information should be made available. Indeed, in the Barclay case, which is 2001-02 AC 603, the House of Lords held - and it was a case that Mr Elvin and I were both involved in - that it was no good requiring people affected by a project to go on a paper chase to find the information. In that case Mr Elvin for the Government argued that provided the information was in the public domain it did not matter that it was not part of a systemic assembly of information, but the House of Lords said, no, it is important that people are not required to go on a paper chase to find the information. This is a classic instance of information not being readily available as it should have been in the Environmental Statement and something that only a persistent and, in terms of these procedures, a relatively knowledgeable participant is able to get hold of.

2238. The second point is that throughout there is a theme on the part of the Promoter that they simply want to have a standard to keep to. They want really at the end of the day simply to be told: "You must meet the standard of 40 in residences and how you do it is up to you but that is the standard you have got to meet." That is not what the Directive requires you to do. It requires you to know what is going to be done not simply to be told what standard is to be applied but to know what is going to be done. Couple that with the ruling of the Court of Appeal in Smith that you need to condition an authorisation so that the Promoter of the project does what he is saying he is going to do, and add that to 8.7.156 where floating track bed is said to be what is going to happen. That is something that should be a requirement.

2239. The third point - and I have already made it but I will make it just for the sake of completeness in relation to the Environmental Statement - the effects of freight traffic have not been assessed and therefore any authorisation must prohibit freight traffic. I will not weary you with the details of the next point, but quite a number of the plans that I have looked at are really quite misleading as to where the tunnels are going to be. For example, one of the plans I looked at in the Environmental Statement showed the tunnel as being, where I live, on the far side of me on Neal Street. I think I understand how that came to pass because I think probably what was being shown was something like a line that represented the midway point between the western and eastern tunnels. Okay, I could work that out but I very nearly went away when I looked at that and said to myself, "So far as I personally am concerned - leave aside the Community Association - I do not really have to worry about this," but happily I was pretty convinced that that could not be right and checked it out further, but I think that people will have been potentially quite misled by that.

2240. I think you will have inevitably a transcript of what I have said and I will not seek to summarise what I have said, other than to invite you not only in relation to the matter of principle but also in relation to the matters of detailed protection, to protect not only myself but, more importantly, the community of Covent Garden from the problems that we foresee, and to ensure, both by appropriate standards but also by specific measures, that we do not suffer what we fear we might.

2241. CHAIRMAN: You have no witnesses?

2242. MR McCRACKEN: No, I am my own witness, as it were.

2243. CHAIRMAN: Ms Lieven?

2244. MS LIEVEN: Sir, I have got a very few questions for Mr McCracken but before I ask them could I just explain our position and seek guidance on one point from you, sir. We have set out a petition response document to Mr McCracken that deals with all his issues. It is a relatively short document and I was simply going to seek to rely on that. I am not going to cross-examine him on issues that arise in that. They will arise in many other petitions and therefore would be very repetitious to go through with each petitioner. There are various points in the petition response document that I would like to highlight to the Committee. I do not know whether the Committee was intending - and it sounds a bit formalistic in such a short part of the hearing - to allow me to make a very brief closing just to highlight those paragraphs or whether it would be better to do it now. I am entirely in the Committee's hands.

2245. CHAIRMAN: The object of this is that you make a case and then of course you would be allowed to make a statement and I would imagine you would incorporate that in either part of that and that would be very useful?

2246. MS LIEVEN: In that case what I will do is ask Mr McCracken a very few specific questions and then I will make a short closing by reference to the petition response document, which of course Mr McCracken has had for a few weeks.

2247. Sir, I should make two other points before I ask the questions. One is on the Environmental Statement I think the Committee made clear on the first day that it certainly did not want us to be producing evidence on that, as it were. If necessary, at the end of the Committee hearings we will produce a further note on the legal position on the Environmental Statement but I am certainly not going to be entering into an esoteric cross-examination on law with Mr McCracken about what he says or otherwise. I suspect that would not help the Committee very much. I could suspect wrong but I do not think it would not.

2248. CHAIRMAN: I do not think it would.

2249. MS LIEVEN: I am very grateful, sir. On noise, you will have a presentation on noise this afternoon and on the issue of groundborne noise specifically, that is noise from the trains passing to and fro, that is a matter that the London Borough of Camden are raising and are the lead borough on, so I am not going to cross-examine Mr McCracken on that because that will be dealt with next week by the London Borough of Camden and by our dealing with them. I hope that is acceptable.

2250. CHAIRMAN: It is certainly acceptable to us. I would add Mr McCracken quite rightly, as far as he is concerned, raised the matter of noise here and if you do not wish to cross-examine him on that but to leave it to a later witness, that is fine.

2251. MS LIEVEN: Yes. So, Mr McCracken, that leaves very few issues that I do want to raise with you. You have raised a concern about the technical report not being accessible. You may not be appear of this but the technical reports are all on the Internet on the Crossrail site. Were you aware of that?

2252. MR McCRACKEN: I do not regard the availability of documents on the Internet as beginning to satisfy the requirements of the Environmental Assessment Directive, which is intended to enable ordinary people, who may not own computers or have the most up-to-date programmes or be able to use them, to access them. I could add to that in that I do have a computer and I do use the Internet and I communicated with the negotiating team. They sent through two documents to me which I could not open because my programme was in some way incompatible with theirs. So while I accept that these may be available on the Internet, I do not think that begins to satisfy the requirements of the Environmental Assessment Directive. I should add these documents were not available in the library although I was told that they were available in the library. The negotiating team said, "These are available in the library." I went back to the library because I did not think that I had seen them there and they were not there in the library.

2253. MS LIEVEN: Just for clarification; is that the local library you are talking about?

2254. MR McCRACKEN: Yes, I am talking about Westminster Reference Library.

2255. MS LIEVEN: Obviously, sir, we can take that up and check out the true position and make sure the right documents are in the library.

2256. MR McCRACKEN: Forgive me but that is the true position. I have told you what the true position is. If there is to be any suggestion that what I have said is not true I would want an opportunity to come back.

2257. CHAIRMAN: Mr McCracken, can I just come back on that. I think the Promoter has said they are going to check that out and report back to the Committee but we have got to give them the credit for doing that for the Committee. That is not to question yourself. It may be that maybe a member of staff at the library mislaid them or does not know about them, it could be any set circumstances, but I do not think the Promoter or their representatives are implying that you are telling untruths to the Committee.

2258. MS LIEVEN: Absolutely not, sir, thank you. The next point, Mr McCracken, if we can just go back to the noise contour map just as a convenient map. In terms of the part of Covent Garden lying between Shaftsbury Avenue and Kingsway, the heart of Covent Garden (and I appreciate your definition was Charing Cross Road to Kingsway) but just to take the heart of it, Shaftsbury Avenue to Kingsway, there is no Crossrail construction activity within that area other than passage of tunnel boring machines cutting the tunnel. That is right as a matter of fact, is it not?

2259. MR McCRACKEN: I am quite happy to accept that.

2260. MS LIEVEN: Thank you. And so far as groundborne noise is concerned, just looking at your individual position for a moment, Mr Fry helpfully has put a cross on where I think you live, just off Seven Dials; is that right?

2261. MR McCRACKEN: Yes, broadly speaking, that is right. It rather exaggerates the size of my flat but ---

2262. MS LIEVEN: Even as a very successful barrister I was not suggesting that you live in the entirety of that plot in Covent Garden! What we can see from that noise contour map is that on the noise assessment that we have carried out, where you live is actually outside the 25 LAmax contour, so the groundborne noise on your flat is assessed to be less than 25 LAmax, is it not.

2263. MR McCRACKEN: Actually that is not quite right because that is on the assumption that the basements are no more than two metres deep, but actually the building in which I live, which is quite a large complex, has a basement which is more than two metres. I just do not know really what it would be if one did the assessment with the basement at the depth that the basement actually is.

2264. MS LIEVEN: We can ask Mr Taylor this afternoon to try and get across to the Committee how noisy 25 LAmax is so I am not going to try and go through that with you. What floor of that building do you live on?

2265. MR McCRACKEN: I live on the third and fourth floor, I think, let me work it out. Yes, the third and fourth floor.

2266. MS LIEVEN: I do not know whether you are aware of this but I am instructed that one would expect attenuation from groundborne noise of about 2 dB per floor. Does that accord with your understanding?

2267. MR McCRACKEN: I do not have any particular understanding of what the attenuation would be, but I do know that noise travels through the walls of that building from the basement to my flat and I have certainly experienced in other parts of London railway noise that has gone right up to - when I experienced rail noise in West London - the top of the building, and it did not seem to me that there was all that much attenuation between the bottom and top.

2268. MS LIEVEN: Can you just tell me where in West London that was? I am not asking for the address.

2269. MR McCRACKEN: That was Kempsford Gardens, which is between Earl's Court Exhibition Centre and Earl's Court Station.

2270. MS LIEVEN: That is what I suspected, Mr McCracken. The noise that you would have been hearing there would be the noise from the Circle and Districts Lines that run in cut and cover tunnels just underneath the pavement. One hears it all across West London, Notting Hill Gate ---

2271. MR McCRACKEN: I am not sure about that because one only heard the noise in the middle of the night. One did not hear it during the time when the Circle Line was running normally. I think it is more likely to have been one of those little-used lines in that part of London which probably had occasional trains running late at night. The reason I do not think it can have been the Circle Line is because if it had it would have been something that I would have heard throughout the day. It was something you only heard at night on a regular basis. You heard it once or twice at night almost every night but you did not hear it, generally speaking, through the day.

2272. MS LIEVEN: It would almost certainly have been a track-cleaning machine that would have gone up and down at night, but the important point is that it was going on not deep level Tube lines but would have been going either on the surface line that goes to Olympia or the sub-surface lines at Circle Line level?

2273. MR McCRACKEN: I do not know the precise differences of alignment. What I do know is that the tunnel in Neal's Yard is very close to the ground and it is a lot closer to the ground than the generality of Underground lines in the centre of London.

2274. MS LIEVEN: Just one final point, reverting back to the area of Covent Garden as a whole rather than necessarily your particular spot, when you talked us through it, you referred to a number of locations where there were cinemas, theatres, recording studios ---

2275. MR McCRACKEN: Doctors' surgeries ---

2276. MS LIEVEN: --- Places of worship ---

2277. MR McCRACKEN: --- And charity rooms and so on.

2278. MS LIEVEN: Given the location of those uses in proximity to the route going through Covent Garden, the higher standards that are referred to in D10, standards of either 25 LAmax or 30, depending on precise use, will apply across Covent Garden, will they not?

2279. MR McCRACKEN: If you give the undertaking that I have asked, and that you have refused to give, they will apply. If you do not give that undertaking - and you have so far refused to give that undertaking - then I am by no means convinced that actually we will get it.

2280. MS LIEVEN: Mr McCracken, that is not quite right, is it? What we have said in the Information Paper D10 on groundborne noise - and perhaps it is important that the Committee puts this up, paragraph 2.9 - this is the undertaking we have given to Parliament: "The nominated undertaker will be required to design the permanent track support system so that the level of groundborne noise near the centre of any noise-sensitive room is predicted in all reasonably foreseeable circumstances not to exceed the levels in Table 1." If one flashes back to Table 1 we can see the kind of uses you have been referring to in Covent Garden, those 25dB for theatres and 30dB for studios. So 2.9 is an undertaking to Parliament that in all the reasonably foreseeable circumstances those standards will be met. It is not an undertaking to you individually, but it is an undertaking to Parliament that can be enforced through the parliamentary mechanism, is it not?

2281. MR McCRACKEN: It is an undertaking that relates to standards, it is not an undertaking to do a particular thing in a particular area, and I do not agree with the standards. I do not think it is right that residences should be expected to have no better standard of protection than offices, because what you are saying is that the level of noise it is reasonable to expect in an office during the day is the same as the level of noise it is reasonable to expect in your bedroom at night, and I just do not think that is right.

2282. MS LIEVEN: Two points on that, Mr McCracken. So far as the residents of Covent Garden are concerned they are very unlikely to care what the form of the track is; what they will care about is the level of noise that emanates from the railway. They will not want an undertaking as to whether it is floating slab track or some utterly different kind of track; what they will be concerned about is to ensure that the noise does not go above the criteria.

2283. MR McCRACKEN: I do not agree with you, for this reason. We, as the residents of Covent Garden, have experienced over the years quite a number of problems. The more you rely on or have to rely upon environmental health officers or other experts getting involved and taking an interest in what you want to achieve ---

2284. CHAIRMAN: Before we proceed, could one of our colleagues ask Mr McCracken a question because he has to leave, he is number two on Prime Minister's questions.

2285. KELVIN HOPKINS: Thank you, Chairman. Presumably there is a simple formula relating to the depth of tunnel to the ground noise level and I wonder how much deeper the track would have to be to bring the noise levels down to a level acceptable to you; that is one question. Assuming that maximum use is made of all quiet track technology, floating slab and plastic fittings and all of that - we are not talking about jointed track, concreted to the ground and covering the surface, which is obviously very noisy - given that, could you not find a way forward or are you just simply insisting that the strategy is that the tunnels are made slightly lower and maximum is use made of the technology?

2286. MR McCRACKEN: I do not think in practice that the tunnels can be lower because what we have always been given to understand is that because of the configuration of existing tunnels at Tottenham Court Road this tunnel cannot go lower. I have always understood - perhaps wrongly - that it would have been lower had it been possible to do so. That is what I have always understood; I suspect Ms Lieven is going to give you a better answer than that. Of course we would be very pleased if the tunnel were lower and that would be an enormous boon, but we have always understood that the depth of the tunnel reflects the constraints of the existing power works underneath the surface in the vicinity of Tottenham Court Road. So while we would be very happy to have it deeper I have a feeling that the answer you will get from the engineers will be, "We would like to do that but we just cannot do it because of the way things are at Tottenham Court Road." But certainly we would be very pleased to have it lower.

2287. KELVIN HOPKINS: What about the use of quiet track technology if every effort is made to minimise the track noise in that area?

2288. MR McCRACKEN: That is why we are asking for the undertaking for a floating track bed. You are quite right, this is not an all or nothing situation where either it goes on the northern alignment or we have lives of misery forever thereafter. It is not that situation, there are obviously gradations and so on, and what we want is a floating track bed. We are very concerned. If we are getting, which is what we are getting at the moment, an undertaking to achieve a standard, there are so many hurdles towards the practical realisation of that standard. Ms Lieven asked a very good question, she said what the people of Covent Garden want is a level of noise, not a floating track bed. But our experience is when we are given, for example, conditions imposed on a bar, that the noise level should not exceed a certain level then that is not much use to us because we do not walk around with noise meters in our hands; the Camden environmental health officers cannot be dragged out at night. So from our point of view something that you can readily see, such as doors closed, double-glazing, no amplified music and so on, something that you can measure and see is so much more practical and feasible than something that is just based upon a standard that requires the intervention and involvement of a whole series of experts. So a floating track bed, coupled with the standard as well is something that we definitely do want and would make a difference to us, but if we are simply given a standard, whatever that standard is, there is a long way between being told about the standard and being able to measure whether it is being met and enforce it.

2289. KELVIN HOPKINS: Many thanks to you. I am sorry to interrupt your cross-examination.

2290. MS LIEVEN: Not at all, sir, I was at the end of the cross-examination. Perhaps I can put in my two-pennyworth about answering Mr Hopkins' question, if I may, in case you are not here in the next few minutes when I close? Mr McCracken is right in terms of the vertical alignment with the track. With very small sensitivities it is effectively impossible to start moving the track up and down because there are so many other constraints up and down the route, and the last thing we want is a roller coaster ride of passengers going up and down at various locations. So I am afraid one has to assume that the track cannot just be lowered in order to solve any particular noise problem. I will ask Mr Taylor this afternoon to answer the question as to how much it would need to be lowered, but in practice that is very, very unlikely to be a practicable solution.

2291. So far as the second part of your question is concerned, our position is that the way forward on this is to establish what is the appropriate level of noise for any receptor, including residents, and then for the Promoter to ensure that that level of noise will be met. So at different locations there will be different solutions assumed, but also in the noise assessment of which we have seen the contours we have assumed floating slab track through Covent Garden because of these various sensitive receptors - not through the entirety of Covent Garden but through ... I am sorry, that is wrong. In the Environmental Statement we have referred to the view - and I need to be very careful about how I phrase this - that for some 632 metres eastbound twin-bore tunnel between Argyle Street, Endell Street, Smart's Place and Barbican, and 879 metres westbound through some other locations, there is likely to have to be floating slab track at the present time. But it might be that by the time Crossrail is built there are even better ways of doing it. We do not want to be tied to a particular construction methodology; we want to be tied to achieving a standard in the most efficient and effective way we can. To answer Mr McCracken's point, what we say is that it is very easy to enforce a standard like that; you go out with a noise meter and check in the appropriate manner. So there is not this great enforceability problem over setting a standard and then ensuring that the nominated undertaker keeps to that standard. That is the way we believe - and obviously we will hear much more about this over the coming months - it is appropriate to deal with groundborne noise rather than tying us down at this stage to a particular engineering solution at particular points. Can I also say - and, again, you will hear a lot more about this later - that that is the way it has been dealt with on other similar projects, such as the Jubilee Line extension, where very similar arguments were raised and the Committee had to consider very similar issues. We will come back to this, but that is to establish our position at the moment.

2292. CHAIRMAN: Once again, we apologise for this interruption, but he has to be down there because he is not only number two but he has to get a seat. Before we move on, Mr Hollobone wants to ask a short question.

2293. MR HOLLOBONE: Can I just confirm in this LAmax index on decibels that it is actually a logarithmic scale and not a linear scale?

2294. MR McCRACKEN: As I understand it, it is logarithmic, yes.

2295. MR HOLLOBONE: Therefore 40 decibels is massively bigger than 25 decibels?

2296. MR McCRACKEN: As I understand it, yes.

2297. MS LIEVEN: Sir, I have no further questions.

2298. MR McCRACKEN: I wonder, sir, if I could re-examine myself because if I had been a witness I would have been re-examined? If I could just respond to a couple of points? So far as any possibility of confusion on the part of the librarian, if there was confusion on the part of the librarian - and I am pretty sure there was not because I asked for everything on two occasions and on two occasions I was given everything they had on Crossrail - that would just illustrate that they had not done what they were advised to do under the Directive, which was to have a systematic assembly, which is properly referenced. That is the first point.

2299. CHAIRMAN: There was no suggestion that a librarian was to blame, it is just that in everyday circumstances anything can happen on requests.

2300. MR McCRACKEN: I understand that and that is one of the reasons why I asked for everything because I am conscious that it is easy to make mistakes, so I did ask on two occasions, I am pretty sure. In any event, the key point is that the Environmental Statement describes itself and in its introduction says what it is, and it is a massive thing, including lots of very impressing looking figures on noise, which just do not happen to be the relevant figures on noise, the noise to which people are going to be subjected. This document here is not amongst the ones that were included in the index - unless there is a different one in the Westminster Library from here - and if you look through the Environment Statement it says what it contains, and it does not say it contains that.

2301. CHAIRMAN: Be assured, Mr McCracken, that we will pursue with the Promoters why this thing could not either be found or was not available, or was available.

2302. MR McCRACKEN: I want to be quite clear on one matter. We want floating slabs or better. We are not saying that it has to be stuck at floating slab because we do recognise that technology can change. But it does not follow that because technology can change and improve that we should not have at least the floating slab technology. That is quite important because I think what the Promoters will try to do is to say, "We might do something better so the Covent Garden people will be better off with our standard," rather than which what we would like to have which is a higher standard and a requirement it should be floating slabs or better.

2303. The final point about it being said that it is very easy to enforce, all you have to do is measure the noise. We do not have meters and we cannot get the Camden noise people out, so it is not easy actually; it is difficult. Thank you very much.

2304. MS LIEVEN: Sir, all I am going to do is refer you to various information papers and key parts. The first of Mr McCracken's points is that the correct route should be in the northern alignment rather than the Crossrail alignment between Paddington and Farringdon to conjoin Farringdon, as I understand it. Sir, in your pack for Mr McCracken, at the back of the Petition Response document there was an information paper, A1, which deals with the development of the Crossrail route. If I could just ask the Committee to focus on paragraph 4.3 of that document? What comes out of the document is that we did assess the northern alignment on the same principles as we assessed the Crossrail route, and this document refers to the RAM alignment - the Members of the Committee may pick up that that is the Residents of Mayfair alignment; they are also promoting the northern alignment and we will come back in more detail to it with them. What 4.3 says is: "In comparison with the safeguarded route" - that is the one that is being promoted to this Committee - "the CLRL assessment has shown that the RAM alignment would: attract few passengers; have lower passenger benefits; have higher costs; give less improvement to accessibility in the key areas of the West End; necessitate more property demolition; and affect more areas of archaeological importance." I am not going to seek to prove each of those at this point but we have assessed it and there is an unequivocal response that it is simply less good in transport terms, principally - if I can summarise the whole thing in one sentence - because it goes to the wrong place. It is getting people through the West End and the City that Crossrail is seeking to do and relieve the congestion on the Central Line, and running along Marylebone Road simply does not do that.

2305. The second issue is groundborne noise and the next document in the Committee's pack is Information Paper D10, which is on groundborne noise and vibration. Mr Taylor will deal with this in more detail this afternoon but on the second page of D10 there is a table there setting out the noise criteria, and if I can say to the Committee there are two points that come out of D10. One is that these criteria were applied on the Jubilee Line extension after consideration by a Parliamentary Committee and they have been applied on other infrastructure schemes in London as well; so they are very, very well precedented. It is our case - and one can assume it is Parliament's case from the previous acceptance - and Mr Taylor will explain why it is right that those criteria are wholly acceptable.

2306. So far as what we are undertaking I will ask the Committee again to note paragraph 2.9, but I am not going to be tedious and read it again because I read it to you a minute ago. That is the undertaking and it is in perfectly clear terms, and for the reasons I explored with Mr Hopkins it is our view that the correct way forward is to have an undertaking in respect of standards rather than an undertaking in respect of engineering solutions. Certainly, in my submission, that gives just as much protection, if indeed not more, to residents than would an engineering solution, and one of the dangers is that if you give an engineering solution and then there is something wrong with it you have lots of arguments about what is wrong and why there is noise coming out, whereas if you have a simple standard then whatever is right or wrong about the engineering solution if the standard is not met it needs to be sorted out. So in many ways it is a preferable way forward to that chosen by Mr McCracken. We will come back to this issue in more detail, both with Mr Taylor this afternoon but also with Camden's Petition next week, so I am not going to say any more about that now.

2307. Then there were two specific points on which Mr McCracken wanted undertakings, if the Committee remembers, of freight and night time use of the railway. At the present time there is no intention by the Promoters that either should take place. As far as freight is concerned the Information Paper on freight makes it clear that the tunnel and the track are not to be designed to take freight trains. This is a railway with 120-year life - and it is probably a theme the Committee will get very bored with - and 120 years is a long time to predict what is going to happen and we do not want to be tied by an undertaking to say that freight will never be taken on Crossrail in any circumstances when the future is the future and, by its nature, not possible to be entirely predictable. Similarly on night time use of the railway. The current intention, clearly stated, is that Crossrail will be used for ordinary operation for the same hours as the Underground is. But, again, 120 years or 50 years, whatever, is a difficult time to predict and we do not want to be straight jacketed by an undertaking at this stage that says forever more it will never be used at night by passengers. So that is why we are not prepared to give the undertakings on those two points. If the Committee is concerned about either of them either now or at a later stage in the proceedings we can obviously produce a note that deals with them in more detail. I suspect that Mr McCracken's response will be, "That may be all very good well and good sense but it does not comply with European environmental law." I will restrain myself from making a submission on that but, again, if the Committee has any concerns much the most appropriate way to deal with that is by detailed note that sets out the legal position. So if there are any concerns we will deal with that in that way. That is short, sir, but I hope it pulls together the principle points.

2308. CHAIRMAN: Mr Hollobone has one more question

2309. MR HOLLOBONE: Ms Lieven, looking at D10, groundborne noise and vibration, I do not profess to be an expert on noise but I cannot see anywhere in that note the decibel scale is logarithmic. To the average lay reader, if you saw a figure of 40 decibels and 20 decibels you would assume that 40 decibels is twice as much, but it is not twice as much; I do not know what the actual figure is, but it is way more than double.

2310. MS LIEVEN: You are entirely right and Mr Taylor will tell you how much more it is this afternoon. The Information Paper, I think it would be fair to say, assumed a certain level of knowledge, and it may be that in terms of informing the public we should have set out more of a basic position in the Information Paper. I think it is almost certainly in the Environmental Statement. It is difficult with a project like this. There was so much information and it is difficult to know how to target a particular document at the right audience. So we will have a think about whether or not we should be putting out - and indeed we may have done it - more basic information about noise in a format that members of the public who do not realise about logarithmic scales are more likely to understand. But perhaps we can come back to you on that, sir? Mr Mould reminds me that Mr Taylor is giving evidence this afternoon and will deal with this, and if there is a Committee concern perhaps we can think of ways to take it forward and explain it to other people.

2311. Sir, there is one last thing I should have dealt with because I got passed a note. In respect of this issue of the background documents and the Internet, I am instructed that the newspaper notices that went out relating to Crossrail did tell people that all those background documents were on the Internet. The weight that one puts that is entirely on the Committee, but it was in those newspaper notices. Thank you very much, sir.

2312. CHAIRMAN: Mr McCracken, what do you want to say?

2313. MR McCRACKEN: I do not want to say very much at all because I think what I have said is going to be fresh in your mind and I hope that what I have said has been persuasive both on behalf of myself and of course on behalf of the other people for whom I am speaking today. Above all else, just listening to what Ms Lieven said, I am conscious that she said that it would be a bad idea to have an undertaking to avoid that happening because if things do not work out then there will be a big dispute about why it has not worked out. It is not a very reassuring basis for the Promoter of this scheme to be inviting you to refrain from requiring a series of undertakings that would protect us, and I pray that in aid as a very good reason for the Committee to require the various safeguards that we have suggested.

2314. So far as the statement, "We have no intention at the present time", one does not have to have been in politics or public life for more than a week to know that those are words that strike terror into the heart of anybody who does not want a thing in respect of which there is no intention. If circumstances change and if in the future it is in the public interest there should be night time working then it is perfectly possible to come back to Parliament and get authorisation at that stage, and that is what should happen. What has been assessed has been assessed on one basis and that is how things should be improved. I can only say on behalf of the community that we are very grateful to you who represent communities in other parts of the country for the time you are taking over this and rely upon you as our guardians.

2315. Can I ask for the clerk arrange for me to be given a copy of the notices when the relevant bits of additional material are being presented, for example Ms Lieven suggested her questions on noise would be put to Camden later on, so I wonder if the clerk could let me know the relevant bits of Hansard to look for?

2316. CHAIRMAN: We will do that and we will also send you a copy of your evidence session today.

2317. MR McCRACKEN: I would be very grateful to you for that.

2318. CHAIRMAN: We are very grateful to you for appearing; thank you very much. Ladies and gentlemen, we are going to suspend ourselves until 2.30.

 

After a short adjournment

 

2319. CHAIRMAN: Mr Elvin, just before you start can I indicate to you that the Whips - who do not get everything right - have indicated to me today that we may have a division between four and 4.15. If it is nearer to 4.15 we will cease today's proceedings. I just wanted to prepare you in case that happens. If it is at four or before four we will return until 4.30.

2320. MR ELVIN: It may well be we will be finished before then in any event. Sir, this afternoon the Committee has agreed to hear two presentations on noise and settlement issues, generic issues that the Committee will be hearing a good deal about in the coming weeks and indeed I was listening on the Internet this morning and I gather you had a foretaste of some of the issues from Mr McCracken in his presentation of the two Petitions this morning. I was proposing, unless the Committee has different wishes, to call Mr Taylor first to give the noise presentation and then Professor Mair second, to give the settlement presentation. It is effectively a PowerPoint presentation but I hope that the Committee has had hard copies of it as well.

2321. CHAIRMAN: A33. Before we start, as the clerk has reminded me, we have to swear in the witnesses, so we will take a moment or two to do that.

 

MR RUPERT TAYLOR, Sworn

Examined by MR ELVIN

 

2322. MR ELVIN: If the Committee will allow Mr Taylor to introduce himself and then I will ask him to give his presentation. I have asked him to touch on a number of the issues which the Committee asked questions on this morning, including issues relating reduction in noise by reducing depth of tunnel and matters such as that, and Mr Taylor will touch on that, and I am sure it will come up in the context of fully contested Petitions in due course, but I appreciate there were some issues arranged on it this morning. Mr Taylor, you are Rupert Taylor and you are a founder Member of the Institute of Acoustics and you are a Fellow of it.

(Mr Taylor) That is right.

2323. You are a Member of the Institute of Noise Control Engineering of the USA, a Member of the National Institute of Acoustics and Vibration.

(Mr Taylor) That is right.

2324. You have specialised exclusively in the subject of noise, vibration and acoustics for more than 41 years and you have been an independent consultant in these subjects for the last 37 years and head your own practice?

(Mr Taylor) I do, yes.

2325. You were Chairman of the Association of Noise Consultants from 2003 until last year and for ten years a Member of the Noise Advisory Council, chaired by the Secretary of State for the Environment; you were Chairman and Deputy Chairman of two of the Working Groups; you are a Member of the Scott Committee, which drafted the basis of the noise section in the Control of Pollution Act 1974; and your practice is currently under contract to Defra for a review of the use of noise abatement notices served under the Environmental Protection Act, for whom your practice recently completed a review of the existing codes of practice to minimise noise.

(Mr Taylor) That is right.

2326. You also head the consultancy division of Rupert Taylor Limited, and that specialises in the numerical modelling of the generation and propagation of vibration, and you have developed a computer package, known as Fine Wave, which is being used for the prediction of vibration, reradiated noise and groundborne noise extensively over the past 12 years and that has been used in many countries around the world.

(Mr Taylor) I have, yes.

2327. Could you also explain to the Committee your experience in terms of noise and vibration in the context of rail projects, please?

(Mr Taylor) A large part of my work has been on vibration from railways. The list of railways that I have worked on is quite long, in particular the Channel Tunnel Rail Link, when it was in Parliament I was an expert witness; the Jubilee Extension and the first version of Crossrail in the early 1990s. There have been many railway projects around the world that I am or have worked on - underground railways in Sweden and Australia, and I have done surveys on many systems in Hong Kong, Singapore, the United States, and I have done some work in China as well. There is a long list, which I will not go through, sir.

2328. Have you been involved in the design of infrastructure projects, that is to say giving noise and vibration advice in the context of designing infrastructure projects?

(Mr Taylor) Yes, I have. For the Jubilee Line Extension I was responsible for overseeing the technical design of the vibration isolation in the track support system, both the system-wide Brazilian base plate system and the floating slab track, which we heard about this morning.

2329. Finally, have you carried out research into the impact of rail infrastructure projects in terms of noise and vibration?

(Mr Taylor) That is right. When the Crossrail project was first promoted we commissioned a social survey and vibration measurement report to study in more detail people's reaction to groundborne noise that Mr McCracken was describing this morning.

2330. I am going to ask you at this point if you would, please, present your material to the Committee and if there are any matters which I would like you to raise additionally I will intervene at an appropriate point.

(Mr Taylor) As we can see from slide one I propose to outline the basics of noise vibration, first of all, and hopefully explain one or two things like, for example, the logarithmic scale, about which questions were asked this morning. Then I will explain what the standards are which are used for assessing noise and vibration, and finally I will explain the mitigation measurements that are used to achieve those standards wherever possible. So on slide two, I think everyone is familiar with the fact that noise is vibrating, and most people have heard that it is measured using the decibel scale. We hear a lot about a thing called a dBA and the capital A means that the basic physical scale that is used, and is the same as decibels that you find in amplifiers and electronic instruments, has been specially adapted to make the measuring instrument a bit like a human ear, which is remarkably insensitive to low frequency noise and very high frequency noise. It is called A-weighted and in many, many cases we are going to see units called either dBA or sometimes expressed as a level, with a capital L, and the A appearing as a subscript to show that it has been weighted to match human response. If we move to slide three, this is the point which arose this morning about the logarithmic nature of the scale. Basically what logarithmic means is that the scale measures proportional changes rather than absolute changes. We are much more familiar with figures that are financial or temperature scales which are linear in their approach. The decibel scale is very special in that it measures by how much something has increased, and since the most important thing is what sounds are like to the listener and we can begin by talking about loudness, which is obviously one of the most important features of it. As it shows on this slide the basic thing is that every 10dB increase sounds about like a doubling of loudness and, conversely, every 10dB decrease sounds about a halving of loudness, and that works all the way up the scale - 70 is about twice as loud as 60, just as 40 is about twice as loud as 30. It is only an approximation because the ear is very complex, but it is a good rule of thumb, and there is a series of further rules of thumb one can see if we turn to slide four. Using that scale a change of one decibel, if it occurs as an instant step in a sound level, is virtually imperceptible. The human ear is not as good at discriminating changes in loudness as you would think from the change in the amount of energy in the sound. Slide five is an important one, often referred to in reports and evidence, that if there is a 3dB change in a sound level it is just noticeable. I do not know whether the Committee will take up the opportunity to go to a room that we have identified which does have groundborne noise from trains in it, which, quite conveniently, fall in a range in the mid to upper 30s with the noisiest being almost spot on 40. If the Committee does want to do that we can arrange it and you will hear trains passing which differ by 1dB and by 3dB and you will be able to hear what this is actually wants, and I think you will agree with these broad statements that one is almost possible to detect and three is just noticeable. If we move to slide six it is common in all presentations like this to show - sometimes it is in the form of a thermometer, but this is a staircase - if you were to be in a room that was only about 20 dBA you would actually say it was silence. You can find places quieter than that - I believe the rim of the Grand Canyon on a still day is 14. Even 30 is very, very quiet. This room now, I would guess, when I stop talking is approaching 50, in the upper 40s. In an office it would be around about the 50 mark; inside a car, depending on the make in the 70s; 87 stereo music. That is actually a benign sound level; people with an IPod on are doing a great deal of more in their ears. 95 is a rather noisy factory, 115 would be quite close to a pneumatic drill, and you do not have to be on the runway, I think, to get 141 for an aeroplane, but it gives you some idea of where to pitch these numbers. Slide seven takes us on to one of the complications in measurement. We did hear from Mr McCracken this morning, mention of this scale called Leq. It is necessary to cope with the fact that although the dBA works quite well as a measure of loudness there are a lot of circumstances where noises do not stay steady, and of course passing trains are a very good example - there are relatively quiet periods and then the trains go by during which it is noisier. If you are not to express the noise environment as a complicated long series of numbers - for so much percentage of the time it is at this level, for so much percentage of the time it is at that level, which is how we used to do it in the early days - it is much easier to use an index, which sums the total amount of noise energy that is generated and enters the ears of the listener over the period of interest. It is called Equivalent Continuous Sound Level - Leq for short, and it may have an A after it, to signify its dBA. It is not an average sound level, it is an average of the amount of energy in the sound. And one of the things which I have not yet mentioned is when I said the ear was rather bad at discriminating changes in sounds, I was referring to the fact that was touched on by Mr Hollobone this morning, that the nature of the scale is such that the actual energy in sound increases at a much greater rate at which you would think the rate at which the loudness goes up. When I said that a 10dBA increase sounds like twice the loudness the actual amount of energy in there - which is of academic interest only, we do not hear it but for calculation purposes - we need to be aware that when there is a 10dB increase there is a ten-fold increase in energy. What the Leq scale does is to average the energy and not the levels. The significance of that comes up in slide eight.

2331. It was alleged by an advocate at a public inquiry that those of us using LAeq were being misleading because we were averaging a very peaky noise history. The advocate said if you were to measure the height of the Lake District in LAeq, it would be flat. That prompted me to go away and take a section through the Lake District, a nice walk through Wast Water, Grasmere, up Scafell and Bow Fell, and it is not unlike a timed series plot of sound levels. In fact, whereas the actual heights are on the left‑hand side, I have put decibels on the right‑hand side, and you can perfectly validly look at that as a timed series of sound levels. You can see the effect of the point that I have just been making. LAeq is an average of the energy of sound and not an average of the levels. If it were an average of the levels there might have been some force in the argument that we were falsely representing the height of the Lake District because it would be that line roughly across the middle called the arithmetic average, but it is not that, it is the high one with LAeq against it, and you can see from that it is strongly influenced by the peaks because of the huge amount of energy they have in it, even though the ear is not very good at detecting that. That was what lay behind Mr Hollobone's question about it being a logarithmic scale, but it remains the case that a ten dB change is a doubling of the loudness.

2332. If I move on slide to nine, I mentioned what happens with the ten dB change. This is extending that a little bit on to a three dB change. This is one of the important pegs on the scale, whether you double the energy in the sound by putting two sources side‑by‑side, for example, whether you double the number of sources or whether you double the duration of the sound event. If it is a train that is twice as long, if a 12‑car train goes by compared with a six‑car train, the LAeq caused is three dB greater, and likewise if twice as many trains go by the LAeq scale shows a value of three dB greater.

2333. On slide ten, the same is true when it is ten times instead of a doubling. Again anywhere on the scale, whether it is 60 to 70, or 50 to 60, it is always the same effect.

2334. The important thing is that these numbers actually have no intrinsic meaning. They do not tell us anything unless we can link them to research work that has set about discovering what people think about noise at various levels. That is what makes the numbers meaningful. All expert evidence, all technical reports, all Environmental Statements that report noise effects in decibels or in LAeq levels only mean something if somewhere along the line you can trace it back to a study that was done that showed what people thought of noise at what level.

2335. Just to give you one example of what we get from that kind of study, we move to slide 11. The studies consist of a mixture of people going out and measuring noise and more or less at the same time teams going out and conducting social surveys to discover what people think about the noise. It has become conventional to classify their responses in terms of their degree of annoyance, and for planning purposes clearly an important degree of annoyance is when people say they are "highly annoyed" and like most things in life people vary enormously in their responses. There are people who are completely unmoved by a very large amount of noise and there are people who are much disturbed by very low levels. What happens is ‑ and just before I continue you may have noticed we have got something new at the bottom called Lden, that is LAeq but as adapted by the European Environmental Noise Directive to cover the whole 24‑hour period by including evening and night with weightings for their extra sensitivity - for present purposes we can treat it as if it was natural LAeq, the principles are exactly the same.

2336. We can see, for example, if we take road traffic noise and we find that the LAeq was, say, 67 (which an awful lot of people experience outside their house faēade) and we look along the bottom scale to the 67 point to the grid lines to the right of the 65 point and run our eye up that grid line to the blue line in the middle, that intersects a line which has a label on it at the left of 20. That means that if the LAeq outside the house facade is 67 you can expect to find 20 per cent of the population who would say they were highly annoyed by that traffic noise.

2337. I could show other slides for different levels of annoyance, but I think it is simpler to concentrate on this one. The interesting thing about this is if it was not a road, if you were a round an airport and the LAeq level was precisely the same - 67 - 30 per cent of people would say they were highly annoyed. They find aircraft noise, energy for energy, more annoying than road noise. The most interesting thing, given that we are here promoting a railway bill, is that if it was not a road but it was a railway it would go the other way, and only ten per cent of the population at 67 would say that they were highly annoyed. It is charts like this that are used for the basis of planning and political decisions about where noise levels should be pitched, whether one is in government or planning an infrastructure scheme or something of that nature.

2338. I am going to move on now from noise to vibration and slide 12 is the first vibration slide. A slightly different approach is used for quantifying vibration. You can use a decibel scale but in this country we use something called Vibration Dose Value. It has peculiar units but it is a totalling of the amount of vibration, again after weighting it heavily in favour of the peaks. Rather like LAeq, VDV is strongly driven by the maximum levels of vibration more than any of the other characteristics of the vibration.

2339. Then we go to slide 13, vibration also affects buildings with no people in them and the concern there is quite different. It is not how people respond to the vibration, it is not how annoyed they are, it is whether any damage is done to the building. It takes very, very much more vibration than annoying people to have any effect on a building whatsoever. When vibration is being enough to cause any damage to a building, there would be an outcry from people living and working in it. For engineering reasons, the best measure of vibration affecting buildings is called Peak Particle Velocity. It is known as PPV and it is the maximum speed any surface gets up to as it is vibrating.

2340. Now, if we move on to slide 14, we will start discussing the standards that are used. They are slightly different according to the circumstances and type of noise. It has become quite well‑established in dealing with construction noise to use the index LAeq that I have described and to look at it in two lights. One is to see how it compares with what was there before the construction of the work started, known as the baseline noise level, to see how much the noise level is pushed up by the addition of the construction noise. Again, it is possible to arrange to visit a room right by a fairly meaty construction site and listen to what you get inside the room with the windows open and the windows closed and matters of that kind. It is also important to look at the LAeq level in its own right against what I call here trigger levels which have some significance in what we will come to in the next slide, slide 15.

2341. If the construction is taking place in an area where it is really very quiet to start with, where the baseline is very low, then we look at the left‑hand side of this chart and we see first of all a black curve which has a flat bottom to it at 65 and if the noise level outside somebody's facade goes above 65, it is considered significant because if they had the windows open they would probably think, "I had better shut that window because of the construction noise and open one at the back of the house", and things like that. They will have to do things to make the noise level in their house tolerable, but it is not so bad that they cannot do that. Once we get up to 75, we have reached a point where shutting a window and ventilating from the other side of the house and things like that is not available because the sound insulation of closed windows is not really enough, and that is the point at which the Crossrail noise insulation scheme starts to kick in. The red line is if it is ten dB noisier still, and you will remember that these ten dB steps are a doubling of loudness, so the red line is four times as loud as the black line on the left‑hand side. That is when using a fairly generous assumption one says that the noise insulation will not be enough to cause acceptable noise levels in the house and that is when the temporary re‑housing part of the Crossrail policy kicks in. The reason why we have got a graph here is because if it is an area that is already noisy, and there are lots of areas like that, then clearly you have to look and see what the influence of the pre-existing ambient is - and ambient is just a term covering all the noise that is going on from all sources ‑ and if the base line ambient is higher than 65, then there needs to be a secondary check which is whether the effect of the new construction noise worsens the noise environment by five dB, and that is one of the tests that determines eligibility for either noise insulation or temporary re‑housing.

2342. To move on to slide 16, this gives us the standards for construction vibration. I mentioned Vibration Dose Values, VDV, and it is rather curious units. They are there. It is very unusual for high vibration to occur except in particular circumstances close to construction activities. Those are the levels that have been used in environmental assessment.

2343. And on slide 17 we see the threshold of significant impacts for vibration when one is only concerned with possible damage to buildings, causing cracks and things like that due to vibration. At this point I should say that whenever anyone has done research work to try to establish the relationship between vibration and building damage it has always been very hard to find cases where there is any damage at all caused by vibration. What tends to happen is when there is something going on like construction work that may cause vibration that people can feel through their tactile sense, they start to worry and they start to look at all the plaster in their house, in every corner of very room, and I challenge anyone to go home and look at all the plaster in their house and not find hairline cracks due to ground heave, due to changes in the moisture content of the soil, and things like that. It is very rare for vibration to damage buildings.

2344. Slide 18 takes us to the standards for airborne noise, airborne meaning noise that comes straight from something like the train wheels through the air to the person listening. The three Db that I mentioned when I was describing the effect of the decibel scale is important here. I said it was the smallest change that was normally noticeable and in considering whether noise from the surface railway is significant or not, the band between the increase of three to five is considered a slight increase but the formal label of significance is applied when the change is more than six. If it is more than ten it is significant but it is described as a "substantial" increase.

2345. Slide 19 - there is and has been for a number of years a statutory scheme entitling people to noise insulation when some conditions are satisfied relating to airborne railway noise. The daytime LAeq trigger is 68 and night‑time it is 63 and there has to be a one dB increase caused by the railway, and that applies to all new railway developments as part of the noise insulation regulations.

2346. Slide 20, we were considering this morning the question of noise from underground railways and I think most people have experienced, even if they only visit London occasionally, the many places in London where you can hear the old Tube lines and trains passing underneath. Something between 50,000 and 60,000 people in London hear rumble from the old lines. By "old lines" I mean those constructed up to and including the first part of the Jubilee Line. And that kind of noise is measured in a slightly simpler way than the method used for both construction noise and airbourne noise from a surface railway. We use a measure called LNmax, which is the maximum sound level. It is the easiest of all the indices to understand. If one had a meter in front of one - and if we go to this demonstration room I mentioned we will have a noise meter there and we can see the levels as they change -all that LAmax is is the highest level that the meter indicates as it rises and falls as the train goes by as you hear the distant rumble of the train. The capital S after LAmax relates effectively to the damping of the meter. Some old meters used to have needles, like barometers, and you could see the needle moving about. When they were first designed there was both a slow and a fast characteristic, and when it was on fast the needle moved at that sort of speed, it moved rapidly, when it was on slow the needle was much more sluggish. There are uses for both weighting time constants. The advantage of LAmax S is that it is much more repeatable because of the damping of the exertions of the needle. I mentioned when I had finished introducing the decibel scale that all numbers, whether they be just dB or Laeq or LAmax only have meaning if they are linked to studies that have been carried out on the reaction of human beings to the noise, and all the information that we have about people's reaction to the rumble of a train passing underground is based on their reaction to noise levels in LAmax S. We did have quite a debate about this in the Channel Tunnel Rail Link Committee, because one of the local authorities was very anxious that we should use the fast setting instead of the slow setting, but the outcome was we did all agree, experts from both sides, that for a modern railway good quality track, the difference between fast and slow is only about one dB and we do not really need to spend time debating which is the better. I would say that slow is better because it is more repeatable and more easily predictable.

2347. Slide 21 shows us how we rate the noise from trains passing in tunnels underneath. The impact classification used in the Environmental Statement was labelled low if the LAmax S was in the range 35‑39, and then we get significant impact should it be over 40. In fact there is no prediction over 40, because this is one of the areas where mitigation measures are well and truly available to reduce the level of noise of a passing train underground.

2348. MR ELVIN: Can I stop you there, because the issue about 40 in terms of ground-borne noise I raised this morning. Can I ask you to explain very briefly to the Committee because the issue, I know, is coming up with other Petitioners, in particular Camden, which I think is next, but can you just give a thumbnail sketch of the use of 40 and what it is used for?

(Mr Taylor) Yes, we began to take steps to deal with ground borne noise when the Jubilee line extension was planned, and clearly, that being part of the London Underground network, the most sensible thing to do was to talk to the then scientific adviser for London Underground and find out what they had found when investigating complaints about noise from the old tube lines, and all their complaints in the late 1960s early 1970s, which encompasses the period when the Victoria line was opened and the Victoria line, like all railways that have been built throughout the last century, has rail directly rigidly fastened to wooden blocks set into concrete ‑ it has no vibration isolation, no resilience in its track support at all ‑ and the results that were provided by the scientific adviser showed that in all cases where complaints have been investigated the sound level due to the passage of a train was over 40 ‑ many of them were quite a lot over 40 ‑ none of them were below 40, and so that was an important piece of guidance when the design aim for the Jubilee line extension was set. In fact, what happened there and what will happen with Crossrail, is that a type of track form is selected which, so far as one can, achieves the 40 from end to end even through the pinch‑points, if I can call them that, where you come either close to the surface or closer to the foundations of the building, as a consequence of which the great majority of the alignment goes well below 40. What should not happen, and does not usually happen, is that you have half a dozen different track forms and you keep changing them to keep pumping under the 40 as you go from end to end. The designer picks the most practicable, best vibration isolating platform for the whole system based on the difficult cases with the results we are going to see in a minute when I show some more slides.

2349. MRS JAMES: I have a question, and it relates to the Victoria line. This morning we saw some evidence in the Promoter's response about sound levels in theatres and the recommended level of 25 dB. I have recently been to see Billy Elliot at the Victoria Palace and every 15 minutes, without fail, it rumbled through, and to say I was uncomfortable was not true but you were constantly aware of the sound. About what level would that be? Would that be an acceptable level in a home?

(Mr Taylor) No, that would have been well above 40. I have been going to a lot of theatres in the course of the studies I have been doing for Crossrail.

2350. MR ELVIN: It is a hard job, Mr Taylor.

(Mr Taylor) There had not been any plays on at the time. I have not been to the Victoria theatre, because, although future Crossrail lines may affect that area, line one does not, but some theatres do have very bad conditions; some of them have got worse, some of them have got slightly better. The first time Crossrail was promoted in one of the West End theatres you could actually feel through the soles of your feet vibration from a train going by. Those levels are well above the levels, certainly well, well above the levels we set for theatres, but they are well above levels for residential buildings, but it is useful to experience that because there is a huge change in the fundamental design of the track from the Victoria line, which, as I say, was rigidly fastened to wooden blocks set in concrete. From the Jubilee line extension onwards ‑ not the old Jubilee line but from Green Park south to Stratford ‑ all modern underground railways are installed such that the rails themselves are on resilient base plates, they are known as, which are quite soft, the rail deflects anything up to five millimetres as the train goes over it, and in circumstances where you need even lower noise levels ‑ recording studios and things like that ‑ the technique is to construct the track so that the rails are supported from a concrete slab which itself is mounted on rubber bearings; and there are several stretches like that on the Jubilee line extension. There are one or two stretches on some of the older railways. The extension of the Piccadilly line from Houndslow West to Heathrow was one of early floating slab cases, and way bank in the 1960s a floating slab was installed when the Circle, Metropolitan and Moorgate lines were realigned at the Barbican, which we will hear about later in the proceedings.

(Mr Taylor) The Jubilee line was constructed with 40 dB LAmax S as a design aim and it has worked the very well. I, in fact, set out on behalf of Crossrail after the Jubilee line opened to get some measurements to compare the measurements with the predictions and validation model, and it was intensely difficult to find anywhere that one could actually detect the passage of trains on the Jubilee line. It is, of course, also interesting that the District and Circle line was reconstructed through Westminster station and it runs through the basement of Portcullis House, and that is on a floating track slab, and, although it has got a bit noisier than it was when it opened, because it is about time the rails were reground, I am not aware of any part of Portcullis House where you can hear the District and Circle line, and it is running effectively through the building. When Crossrail came to be designed in the early 1990s, clearly the data from the scientific advisers to London Underground that I mentioned were beginning to get a bit long in the tooth and we set about getting more information and commissioned a social survey and vibration measurement survey. It was not as successful as it ought to have been rather a large number of people were happy to answer the questions in the social survey but were not too keen to on having the instruments in to measure the vibrations; so it is not as big a sample as we would have liked, but it very forcefully confirmed that, particularly if, as is the case with modern railways, there is no 'feelable' vibration ‑ what I was describing a moment ago about the Victoria theatre or West End theatres where you can feel the vibration through the soles of the feet. With modern railways that effect is completely absent no matter what the audible sound level is. When vibration is completely absent the results of the social survey showed a zero response from the public at 40 dB LAmax S That well and truly reinforced the (inaudible) policy, and it has carried through many railways ‑ Docklands Light Railway, its several extensions, and through to Crossrail, CTRL and it is well established, having been tested, in fact, twice in Parliament and in public inquiries with arguments from local authorities and others who felt it should be reduced to a lower number, and it has always come out unscathed from whatever tribunal it has been tested in.

2351. Finally, on that point, can I understand this? Is the 40 dB ground-borne noise a target that Crossrail seeks to achieve or is it something else?

(Mr Taylor) What it is not is just a numerical target. Mr McCracken was concerned that people would be going out with noise meters to see if it was 40 or not. That is not the way it works. It is a design standard that is used for selecting the basic track form of the system and for designing those lengths of the track which have to have special treatment ‑ I mentioned the floating track slab ‑ to meet the special requirements of things like recording studios, so where it bites is the moment that the permanent wave engineers set about designing the track. After the railway opens, if there should be some problem somewhere, somebody complained and it was found to be above 40, or whatever the appropriate limit was according to the use of the building, then somebody might well do some measurements and see if there was a problem which could be rectified and bring the noise level down, but it is fundamentally a design principle given to the engineers when they start designing the railway.

2352. From your analysis, what is the likelihood of 40 dB being reached on the design which is to be adopted for Crossrail?

(Mr Taylor) It is probably quite well illustrated on my next two slides. If you go to slide 22 first, which says that, if you do set the 40 limit for the permanent wave designers, you will end up with much better than 40 in large areas of the railway.

2353. Slide 23 is another of those contour maps ‑ we saw one this morning ‑ and the green contour, which is the biggest one there, is only 25 and even that vanishes in some places; so that is an example of what you get when your starting point is: "Tell the engineers we want no more than 40 wherever possible." So they choose a rail support system of very high resilience, very good vibration isolation performance, and they choose that for the whole railway even where you might not strictly have needed it. I remember having an argument during JLE design as to whether we should continue it under the Thames, because nobody was going to hear it there, but we did. There is vibration isolation even under the Thames; so it is a very important point. It is not uncommon to have people, either a Petitioner at a Parliament Bill or objector to a transport and works order saying 40 is too big a number, we need a smaller number, but it is always essential to read the words that go with the number. There are the railways in the world that use smaller numbers, but the words that go with the number are much less effective than the approach which Crossrail takes, which, I believe, is far and away the best approach, that you use it to the design standards from end to end and you do get a much better railway as a result.

2354. We will leave ground borne noise now and move on to slide 24. There are other kinds of noise, obviously, arising from a railway scheme of this kind. One of the important ones is fixed plant, and the biggest pieces of fixed plant are tunnel ventilation fans, which compared with the fans which most people come into contact with, are enormous. They, like all fans, generate noise and because it is one of the oldest sources of noise that has been addressed in the control of environmental noise, there has long been a British standard which is appropriate for assessing this kind of source. What I am talking about is continuous unbearable noise that occurs as long as the plant is running, and it might be running at night, but not always. This uses a much stricter method of assessment, largely because this kind of noise can be more annoying than other kinds, and, particularly if it occurs at night, one has to be very strict. We use the LAeq scale that I have already described, but except in the very rare cases where the noise could be described as completely characterless, by which I would mean the noise of a waterfall or something like that, it has no tones in it, no rattles or clinks or clanks or anything like that, we add a notional five, a sort of tax put on the LAeq for the fact that this kind of noise can be more annoying, and then we compare it not with the baseline LAeq, as is normally the case, but we compare it with something new, which I will have to explain, called LA90.

2355. When I was introducing the LAeq scale a few minutes ago I said when sound varies it is quite lot of the time relatively low and goes up as a plane goes by or as a car or a lorry goes by so that it would be very cumbersome to say it is this level for such and such a percentage of the time, that level for such and such a percentage of the time. I was in fact anticipating the fact that we do sometimes talk about noise climates ‑ the word that was used ‑ in terms of statistical percentile, and the LA90, strictly speaking, is the level conceded for 90 per cent of the time. It is actually the troughs in a rising and falling sound-scape, if you put it like that. If the peaks, the crests of the waves are the passing vehicles ‑ passing trains, passing aircraft ‑ LA90 represents the troughs, which are when there is no vehicle or aircraft passing and the moment is quiet, that is the LA90.

2356. In slide 25, you can see there is the LA90 right down near water level. I have taken the Lake District nomenclature off, but it is the same chart. The most important thing about British Standard 4142 is that we are comparing that orange line at the top with LAeq, with the tax on it, the five dB added, against the LA90, which is way below it. We are not the comparing like with like in a way and we are looking at what is always an index of higher value than the yardstick against which we test it, and on slide 26 here is the important part of the standard. It says that if the LAeq with its five dB tax on it, which we call the rating level, is about ten units greater than the background expressed in the LA90 you can expect complaints from people. If the difference is only five, and because of that tax on the LAeq that actually means the real physical LAeq is the same as the background LA90, the standard says it is marginal; and it also says that if it is ten more than ten dB below the LA90, which effectively means it is completely inaudible, then, not surprisingly, you can say confidently complaints are unlikely.

2357. MR ELVIN: We then move on to mitigation. I think we are going to have to ask you to skim through this fairly rapidly so that we can make sure, given the Committee's other commitments, we can manage to fit in Professor Mair as well. I would be grateful if you could take this relatively shortly, please.

(Mr Taylor) The ways of mitigating construction noise ‑ obviously the best thing to do is to find quieter methods of working, and, indeed, over the years quieter methods of working have come about ‑ selection of quiet plant, use of noise barriers, noise encoders for noisy machines, monitoring and management. I have already talked about noise insulation and temporary rehousing schemes. All of this is subject to the provisions of Control of Pollution Act, section 61, under which contractors will be required to seek consent and local authorities in granting that consent have the power to ensure that the best practicable means have been used to reduce the noise.

2358. Slide 28 is for vibration. Not so many opportunities, but again methods of working and, by monitoring and management, levels of received vibration are controlled, and in section 61 vibration is technically noise and subject to the same provisions that I have just outlined.

2359. Slide 39, the surface railway is mitigated with line‑side noise barriers, and I have already mentioned the noise insulation scheme.

2360. Slide 30 takes us to ground-borne noise and vibration, which I have described in some detail. There is no need to take time on that.

2361. Slide 31, the fixed plant. That is the type of source that is assessed using that BS 4142 method when you are comparing the LAeq with the LA90. Where there is enough space, and there are limits sometimes, noise attenuators, which are really great big silencers, are installed on the fans, in the vent shafts, and, where it is not a tunnel vent fan but it is an air‑conditioning plant at the station or something of that kind, there are well‑established acoustical engineering principles that are used to control noise. Was that quick enough, sir?

2362. MR ELVIN: Can I ask you one final question, Mr Taylor. It relates to a question that you were asked this morning about what you could achieve if the tunnel were dug deeper in terms of reducing noise?

(Mr Taylor) It is a very unfruitful approach to reducing noise. You would have to double the depth of the tunnel to get about a five dBA improvement, if you stay in the same kind of soil. It is actually not as simple as that, because in almost all cases if you significantly lowered the tunnel ‑ for example east to Tottenham Court Road that we were considering this morning ‑ the tunnel is in London clay, would be in London clay if it were constructed. Lowering the tunnel would take it down into another formation known as the Lambeth Group, which is a much more complex mixture of gravel and clay and changes both the characteristics of the tunnel as a source and its propagation mechanism, but it is a very inefficient way of reducing ground-borne noise to lower the tunnel.

2363. KELVIN HOPKINS: Could you roughly say the extent to which quiet‑rail technology does reduce noise? If one took a tube tunnel, for example under a building, and it was making quite a lot of noise, if you could bring technology in how significant would be the noise reduction in terms of decibels?

(Mr Taylor) The difference between an old line, and it may happen with re‑railing of existing tube lines ‑ the effect of putting in new resilient support rails would bring the ground borne noise levels down by about ten to 15 dBA LAmax, which is significantly better than halving the level. It would drop the number of people exposed to more than 40, which currently at the last count it was 56,000 people, down to a very small number, almost zero.

2364. What about building for worst case scenarios? For example, I travel by train every day and almost every train I travel on has wheel flaps which sound like a metal hammer on a rail, and that would make a significant difference to the noise you hear, but if you were to do a worst case scenario you would have to pay much more attention to noise reduction?

(Mr Taylor) That is a very important point. Part of the engineering procedure that I was touching on involves having a policy for controlling, not just the wheel roughness and the occurrence of wheel flaps but also rail roughness. I did briefly mention that the track through Westminster station has started to rumble a bit, and that is because the rail is in need of regrinding, a normal maintenance procedure, but certainly Crossrail, as JLE has, will have a procedure for monitoring and rectifying defects in the running surfaces of vehicles.

2365. I am not suggesting you put freight through the tunnel, but with modern trucks, we are not talking about Thomas the Tank Engine trucks, we are talking about modern technology, is there a significant difference in the noise between those and passenger trains?

(Mr Taylor) The critical thing is the weight of the axle that is below the primary spring. With modern trucks, as you call them, that may be is not as high as it was in old‑fashioned vehicles. It tends to be higher than passenger vehicles, and that has to be taken into account, but not more than possibly a 50 per cent increase, something like that.

2366. One other question about cost. Is there a significant cost increase in putting quiet rail technology in than just concrete‑layering or whatever?

(Mr Taylor) I do not think anyone would contemplate putting in track nowadays that did not have the fundamental resilient support, the resilient base‑plate that I mentioned, but where the cost comes in is moving to floating slab track. As a rule of thumb that doubles the cost of the track work, which the last time I had a costed figure, which was the Jubilee line extension, so it is a few years ago, was about a million pounds per track kilometre. It would be a substantially higher figure now.

2367. MR ELVIN: I wonder, Mr Hopkins, if I could also refer you to information paper D10, which has something in it about the maintenance regime which will be expected in relation to the track. In that case, can I thank Mr Taylor and I will call Professor Mair to deal with the settlements.

PROFESSOR ROBERT MAIR, sworn

Examined by MR ELVIN

2368. MR ELVIN: We are following the same procedure and you should be getting paper copies. While that is happening, Professor Mair, I will introduce you. You are Professor Robert Mair. You were appointed Professor of Geotechnical Engineering in Cambridge in 1998. You are Head of Civil and Environmental Engineering and since 2001 you have also been a Master of Jesus College?

(Professor Mair) That is correct.

2369. Your career has been in both academia and dealing with settlement geotechnical issues in the professional sector. You have also founded and run a consultancy dealing with such matters?

(Professor Mair) Yes, that is correct.

2370. You worked continuously in industry from the early 1970s to the late 1990s with a short break for academic work.

(Professor Mair) That is right.

2371. Your PhD was in tunnelling in soft ground, and your tunnelling expertise began with that in the early 70s and has continued through research and giving practical consultancy advice since that date?

(Professor Mair) Yes.

2372. Can you give some examples of the projects that you have been concerned with, with particular emphasis on rail projects?

(Professor Mair) I spent a lot of my time on the Jubilee line extension which, as everyone knows, was completed about ten years ago. As well as the Jubilee line extension I was involved with other projects in many countries, railway projects in Bologna, in Florence, in Rome, and a number of other countries, Singapore and Hong Kong as well.

2373. You were awarded the British Geotechnical Society's medal in 1980 for your work on tunnels, the Institute of Civil Engineers Geotechnical Research medal in 1990 and the gold medal in 2004, you have been a board member of the International Society of Soil Mechanics and Foundation Engineering and for the last ten years Chairman of its technical committee on underground construction in soft ground?

(Professor Mair) Yes, that is correct.

2374. And you are a Fellow of the Institute of Civil Engineers and a Fellow of the Royal Academy of Engineering?

(Professor Mair) Yes.

2375. That is, of course, the shortened version, but I think it does at least short justice to your evidence in the field, if you will forgive me for taking it that shortly. Professor Mair, can I then ask you to present your material? The Committee will need to rise shortly after four o'clock. Can you bear that in mind when you go through your material, please?

(Professor Mair) I will bear that in mind. I am going to describe the principal factors concerning ground settlements and its effects. Slide two gives an outline of the presentation. I will start with an overview about settlement, and I will then talk about ground investigation and geology and ground settlements due to tunnelling, and I will also describe, reasonably briefly, tunnelling methods, and then I will talk about settlement and building damage assessment and give some examples of building response to tunnelling.

2376. Slide three really addresses the principal point as to why settlement occurs. Crossrail will require excavation of large volumes of ground to form the tunnel shafts and deep boxed basements, and the ground around these excavations will require some form of structural support. In the case of tunnels and shafts, there will be linings and in the case of deep basements there will be walls. The excavation and installation of that support to the ground inevitably produces small controlled ground movements, and it is the ground movements that cause settlement of the ground surface and settlement of buildings.

2377. I should emphasise that the level of settlements that we will be talking about in this context generally are of the order of tens of millimetres. Ten millimetres is approximately half an inch, which is very much less than mining subsidence, which can often be of the order of metres. I just want to emphasise that point.

2378. Slide four leads on to the assessment of the effects of settlement, and that is really all about the assessment of the risk of damage to buildings. The Crossrail process is a development of the same process that has been used on the Jubilee line extension and on the Channel Tunnel rail link and, indeed, on many other projects worldwide. It is intentionally a conservative approach, and, if necessary, protected measures can be designed to protect buildings at risk.

2379. Slide five shows just one example of the level of detail which has been involved in the ground investigation and establishing the geology for a Crossrail project. You will see the blue dots are each representing bore holes. This is in the area of Liverpool Street station. To give you an idea of the scale, each of the squares on the plan there is representing 50 metres - so extensive coverage of the area with a lot of bore holes to establish with a great deal of confidence the geology of the whole project. This, of course, is just for Liverpool Street station.

2380. Slide six shows a geological section, a longitudinal section, through part of the project. What you are looking at here is Farringdon station on the left‑hand side of the picture and the right‑hand side going east, right along to the right‑hand side, to the Isle of Dogs station area. About seven kilometres we are looking at here from left to right. It is, of course, highly exaggerated scales vertically. The different colour strata there are the different main geological strata. For example, the London clay, the one in brown, is about 25 metres thick in that picture ‑ so this gives you just a feel for the geology ‑ and the white line, the pair of lines going all the way through the section there, are the actual Crossrail tunnel alignment.

2381. Slide seven then deals with the issue of settlement, and I should immediately emphasise that this is a highly exaggerated drawing, but it illustrates the point that when a tunnel has been driven or constructed at depth below the ground surface there is a settlement trough that will develop at the ground surface ahead of the advancing tunnel, and, as the tunnel passes beneath, there will be a transverse settlement trough. I will use a pointer to point on the screen at this point. This is a sort of transverse settlement. So by the time the tunnel has passed beneath the point you are left with a settlement trough of that sort of shape, a transverse settlement trough.

2382. If we go to slide eight, you will see that same transverse settlement trough, again a grossly exaggerated scale, you will see the tunnelling beneath and you will see the settlement trough which occurs at the ground surface. An important parameter we use in tunnelling is called the volume loss, which is the volume of the settlement trough. All of the settlement troughs added up, the volume of that trough, divided by the volume of the tunnel expressed as a percentage. It is a means of expressing how such settlement occurs during the tunnelling process.

2383. Slide nine then looks further at volume loss, and it also illustrates the effect of the depth of the tunnels. You see here two tunnels. The one shown in red is a tunnel at a depth of 20 metres ‑ you can see the scale on the right‑hand side showing that ‑ and the red settlement trough above that tunnel, again highly exaggerated scale, shows the sort of settlement that you would expect for that tunnel, one of 20 metres depth, showing a maximum settlement of about 15mm directly above the tunnel, whereas the deeper tunnel, which is the tunnel in black, which is at 30 metres depth, the settlement trough for that is wider and less settlement and only about 10mm above the tunnel. So in essence the deeper the tunnel goes the less is the maximum settlement above the tunnel, although the trough actually gets wider with a deeper tunnel. Slide ten illustrates the effect of diameter and here we are looking at two examples of a tunnel of 30 metres depth: one is a 4.5 metre damage tunnel, a typical tunnel in the existing London Underground system, and that produces a settlement of about 10mm maximum settlement, as you can see, above the tunnel, and the red tunnel is a six metre diameter tunnel and that produces a maximum settlement of 15mm. So in essence a bigger diameter tunnel produces a larger settlement, which is perhaps what we would all expect.

2384. Slide 11, I will briefly describe some of the principal tunnelling methods which will be used on Crossrail and for which there is a great deal of experience already. The first one illustrated on slide 11 is the use of open face tunnel boring machines, TBMs, which is the abbreviation used for tunnel boring machine, and what you can see here is that the actual tunnelling machine is, in essence, a mechanical digger which you can see here, which is digging out the clay from within the protection of a cylindrical steel shield which protects the workers from any possible fall or instability of the ground about, and looking in this direction we are looking from within the tunnel looking towards the tunnel face. This face of the tunnel, the ground is being protected with breasting plates and you can see in the photograph below the same thing - this is taken from within the tunnelling machine looking forward - and you can see the exposed clay just down here. This part is exposed clay and this is called open face tunnelling because it is precisely that - the face of the ground that is being exposed is completely open; it is partially supported by its upper part but otherwise it is completely open. This open faced tunnelling has been widely used for tunnelling in London clay because London clay is such a strong, competent soil, and this technique will be used from Paddington to the Fisher Street shaft for the Crossrail project.

2385. Slide 12 shows a closed face TBM, and this is a picture of an eight metre diameter closed face tunnel machine emerging. This is one of the machines used for the Channel Tunnel Rail Link and this is a view of the closed face machine where, in essence, there is no open unsupported soil - it is completely supported at all times and that is why it is called a closed face machine. The technology used, specifically, is called an earth pressure balance machine. Slide 13 gives us bit more detail of an earth pressure balance machine and the points to take note of here are, first of all, right at the very front, number one here is the cutter head; that is the view we saw emerging in that previous slide. That is the cutter head, which is a big rotating wheel, cutting the soil. Point number three is the TBM skin, which is really the shield that I described earlier, the big cylindrical shield that supports the ground. Another important aspect of the machine is number five, the screw conveyor, and this allows the pressurised soil in here, which is under high pressure because the face has been supported with this high pressure, to come up the screw conveyor and then the pressure is dissipated and drops on to a conveyor belt and the spoil is taken away. The lining is a very important part of the tunnelling process and the actual linings are shown in grey here; they are erected continuously at the back of the machine and these linings support the ground permanently. The lining segments can be seen being brought into position here, to be erected inside the machine.

2386. The next slide, 14, shows a view from inside the tunnelling machine and here are the lining segments being brought along to the front of the machine and they will in due course be erected to support the soil. Slide 15 shows just that process. This is looking at the very back of the machine. You can see the exposed clay here, this is actually the exposed ground and this is a fully completed lining here and this segment has been erected and another one will very shortly be placed above here, completing the full circle of the tunnel lining.

2387. Slide 16 illustrates a quite different technique which is the use of sprayed concrete linings to support the ground. Sprayed concrete, as the words suggest, is the use of concrete that is actually sprayed in order to support the ground. So this is a very versatile technique. So the excavation can be made - this is no longer using a tunnelling machine, as I have been describing earlier - and if the ground is competent and strong enough, as is the case in the London area, then as soon as the excavation has been made concrete is sprayed on to the surface of the ground and that concrete goes hard very rapidly and it forms a very effective lining to support the ground. And here you can see how it can be used in a very sequential way; that the final tunnel to be constructed is shown here, but it can be built in parts, effectively. So the first bit of the excavation, which is shown on page 17, is when the top heading here, this part here is excavated only. So looking sideways along the tunnel that one metre of excavation just at the very top heading part is excavated. Then the next slide illustrates the next bit of the excavation where that part is done and the sprayed concrete is being applied all the time as this is done. Then the next slide shows the bottom part of the next metre of excavation being done for both the top heading and the bench, and the following slide will show the invert being excavated. Now there will be sprayed concrete all the way around, so this will be an egg-shaped first part of the tunnel, temporarily formed like this. Then a very similar procedure takes place, that the top heading has been excavated, as shown here, and then the next line will show the bench being excavated, and then the next slide will show the same thing happening for a further metre in both the top heading and bench. Then finally the invert will be excavated and all the time during that process the temporary central wall is demolished and you end up finally with the complete tunnel. That is quite a complicated sequence I have described, but it is in order to explain how the very large tunnels can now be constructed in competent ground, using this technology of sprayed concrete. There is considerable experience of it; it has been used extensively for the Jubilee Line Extension.

2388. Slide 26 shows the view of that very process I have described, the first left-hand part with the temporary wall, or the egg-shaped tunnel I described, and the right hand part is being constructed and that temporary wall will soon be demolished leaving the entire completed tunnel. This is a nine metre diameter tunnel constructed for the Jubilee Line Extension.

2389. Slide 27 summarises the principal advantages of sprayed concrete linings. It enables excavation of large tunnels in smaller parts, and those smaller parts are what I was demonstrating in the previous slides, taking out a piece of ground one at a time. It enables early application of support, which is important - the sooner the support is provided to the ground the better from the point of view of reducing movements. It enables construction of non-circular tunnels - that is a very important point - so that the tunnel no longer has to be circular, it can be perhaps more elliptical in shape rather than circular. It is very useful for construction of openings between tunnels. It allows rapid mobilisation of plant and equipment; it is a highly mechanised method and it has great programming and sequencing flexibility, and I should emphasise that it was used very extensively and very successfully on the Jubilee Line Extension, principally at Waterloo and London Bridge Stations and also it has been used on the Channel Tunnel Railway. There is considerable experience of its use.

2390. Slide 29 moves on to the process of assessment of settlement and there are essentially three stages of that. Stage one is based on simple criteria which themselves are based on settlement and slope values to eliminate buildings subjected to minimal effect. So this is a screening exercise. So stage one would be to look at the likely settlement caused by the product and to eliminate those buildings that are only going to be subjected to minimal, very small effects. Stage two is a conservative assessment of potential damage to buildings and that is based on distortions that might be caused by the "green field" displacement. I should explain that by green field we would mean the settlement that would take place due to the tunnelling project as if there was a green field above and no buildings; so, unaffected by the buildings. Then there is a third stage which may apply in certain cases where a much more detailed assessment is undertaken to determine the risk of potential structural damage and the design of protective measures if they are necessary. The considerable experience on the Jubilee Line Extension has confirmed that the results of the stage two process are conservative. A number of very safe assumptions go into that process and we know that they are conservative. Slide 29 then addresses the question of risk categories. These risk categories relate to the level of potential damage to buildings and this slide shows three categories listed under the left-hand column: damage risk category zero, risk category one and risk category two. The description of the typical damage associated with these risk categories is shown on the right-hand side. So when it is category zero, which is negligible, the typical damage associated with that negligible risk category means that there are only hairline cracks, which are very small indeed, less than about 0.1mm; in other words, barely visible to the eye. The next category, risk category one, very slight, is that there are fine cracks, usually just in the plaster and they might be up to about 1mm, which is something like where you can get a thumbnail into, just, depending on the thickness of your nails; a mm is still a very small amount. The category two is slight, where there are potentially wider cracks, but the point is they are very easily filled and probably would need some redecoration and the cracks would be visible and you would have to redecorate and repaint. The point of this slide is that all three of these categories are only of potential aesthetic significance.

2391. Slide 30 goes up to risk categories three, four and five, and these are of potential structural significance, so these are distinctly different from the previous three categories, and in these cases there may well have to be some action taken. For example, category three, which is known as moderate, the cracks may well require patching and there may have to be repainting and replacement of parts of the external brickwork of the building and doors and windows may be sticking and the crack widths are really significantly wider than the lower categories. Categories four and five, severe or very severe, there could be major structural damage. The important matter is that categories three, four and five, which are of potential structural significance, will not be allowed to occur on the Crossrail project, as they were not allowed to occur on the Jubilee Line Extension project. Slide 31 shows the stage one process I have described. What you see here is the Liverpool Street Station area, you see settlement contours, and the numbers there illustrate the estimated magnitude of the settlement. So where you see minus ten, for example, minus ten means that that is the contour of 10mm of settlement and in the more central part, immediately above the station, you will see some quite large numbers - in fact the largest is 100, which means potentially that there could be 100mm of settlement there. The point of this screening exercise is that outside the 10mm contour no other buildings are considered for the stage two process. So we only proceed to stage two inside the yellow shaded part; outside the yellow shaded part all buildings are eliminated.

2392. MR ELVIN: Professor Mair, the fact that something appears in the yellow zone does not mean that significant damage will occur but you go to the next stage in the assessment.

(Professor Mair) Indeed. So the next slide will now talk a little about the kinds of deformation of masonry structures and what is illustrated here is in terms of a brick wall. There are two brick walls shown here and what is important from the point of view of assessing potential damage is deferential settlement. If a brick wall settles completely uniformly then it will experience very little damage, but if it experiences differential movement or curvature then potentially cracking will occur. There are two types of deformation mode shown here: on the left-hand side you will see a wall experiencing sagging deformation, which I hope is self-explanatory. You will see that the bottom part is potentially experiencing rather more cracking than the top part. Conversely, on the right-hand side you see a wall that is experiencing hogging curvature, where the cracking is more severe on the upper part of the wall than the down part, and it is the case, and we know from experience, that buildings and walls are more susceptible to damage when they experience the hogging mode of deformation rather than the sagging mode, and that is largely because the cracking takes place up higher up in the building and is unrestrained, whereas in the sagging case the cracking is taking place near the bottom of the building, near the foundations and may well be restrained by the foundations. These two forms of deformation are shown again on the next slide, number 33, and I must emphasise again that this is highly exaggerated but you will see a tunnel down here and this is a settlement trough at the ground surface in a highly exaggerated form with a building being forced to follow that settlement trough. If the building follows that settlement trough this part of the building will be in sagging, and that is what that is showing, and this part of the building is in hogging. So we find it is very important to distinguish the sagging behaviour of the building from the hogging behaviour. Slide 34 goes through to the stage two assessment and the results of that. Again the Liverpool Street Station, you will see the yellow contours I showed you earlier.

2393. CHAIRMAN: I am sorry; we will have to adjourn the Committee. We will be back in 15 minutes.

 

The Committee suspended from 4.02 pm to 4.16 pm for a division in the House.

 

 

2394. CHAIRMAN: Mr Elvin?

2395. MR ELVIN: Professor Mair, you were just coming on to the assessment results of Liverpool Street because the Committee had seen the stage one elimination and this is the next stage.

(Professor Mair) Yes.

2396. MR ELVIN: If you could continue then, please?

(Professor Mair) Yes, this slide shows the same Liverpool Street Station area and you will recognise that outside the yellow contour, the grey area, that had been eliminated as part of the stage one process, and then inside the yellow area had all been considered at the stage two process, and that considers much more carefully the behaviour of each building as to whether it, for example, is subjected to sagging deformation or hogging deformation, as I described earlier, and then the level of strain is calculated in the building. The level of strain is very important because that links directly to the category of potential damage. So as a result of this stage two exercise many of the buildings are eliminated as experiencing damage no worse than "slight". So that what we are left with for consideration for proceeding to stage three is what is shown in the red hatched area on this slide. So only within the red hatched area are buildings that are potentially - and I should emphasis the word "potentially" - which may be subjected to damage categories of "moderate" and above. That is damage category three or above. So the stage three process takes those buildings within those red shaded areas and subjects them to an extremely detailed assessment process.

2397. We will come and show the Committee briefly at the end how the various assessments at each stage compare to what actually is found to occur when the work is actually carried out. You have produced a couple of graphs which we will come to at the end?

(Professor Mair) Correct, yes.

2398. Can you move to slide 35, Professor.

(Professor Mair) Slide 35 summarises the volume loss experience. You might recall the diagram shown on the bottom right part of the slide. The volume loss defines the magnitude of settlement in the settlement trough, and it is expressed as a percentage of the whole volume of the tunnel. This slide shows actual quantities of volume loss experienced on previous projects, and on using earth pressure balance machines, in the Channel Tunnel Rail Link, a project fairly recently completed, the volume losses were in the range of 0.5 to 1.0 per cent, and for the Jubilee Line Extension, when earth pressure balance machines were used, a very similar range was measured. So we have a lot of confidence in that range of volume losses using earth pressure balance machines. Using sprayed concrete lines, the SCL technique, for the Jubilee Line Extension, the range of volume loss was 1.0 to 1.5 per cent. Those are the actual measured and observed volume losses for previous major tunnelling projects. The Crossrail assessments is of what might happen to buildings, based on the following assumptions, a volume loss of 1.7 per cent for all of the running tunnels and a volume loss of 2.0 per cent for all of the stations, and you will see that those figures, 1.7 per cent and 2.0 per cent, are significantly higher than the figures that were actually seen and measured on the Channel Tunnel Rail Link and on the Jubilee Line Extension.

2399. Does that mean that the settlement assessments that have been assumed for the Crossrail assessment have therefore been based on conservative assumptions with regard to volume loss?

(Professor Mair) That is correct. Slide 36 summarises some general conclusions from the stage two settlement assessments that have been undertaken for the Crossrail project. The first is that for buildings that are affected by the running tunnels alone, that is all the tunnels between the stations, the potential damage category is almost entirely "negligible" to "slight", so very, very small levels of damage for all buildings affected by the running tunnels only. For buildings close to shaft sites the potential damage category is generally in the "slight" damage category, occasionally the "moderate" category. At stations, a large proportion of the buildings are in the "moderate" or "severe" potential damage categories. I should emphasise the word "potential". For that reason, stage three assessments will determine the need for protective measures. So the overall conclusion from the stage two assessments that have been done for the Crossrail project is that the buildings near stations require more attention than elsewhere.

2400. Slide 37 - when the stage three settlement assessment process is completed and a building is still identified as being potentially at risk there is a series of protective measures that can be taken, and these are summarised on this slide. Firstly, there are what we call at-source measures which really means that actions can be taken from within the tunnel itself or from within the deep excavation. In other words, particularly when sprayed concrete lining technology is used, there can be actions taken to minimise the ground movements taking place from within the tunnel. The second category of protective measures are ground treatment measures. These involve improving or changing the engineers' response of the ground by grouting. By "grouting" I mean injecting liquid cement into the ground, and I will be explaining that shortly. The third category are structural measures where you can increase the capacity of a building or a structure to resist or modify or accommodate movements. The kind of thing that is done is steel tie rods, for example, can be placed in certain masonry buildings to achieve that.

2401. But the next slide, slide 38, will illustrate the ground treatment measures that can be used, and I am going to describe now the principle of a technique known as compensation grouting. You will see that what this slide shows is a building on shallow foundations near the ground surface and a tunnel being constructed below that building. The settlement that might have occurred in the absence of any protective measures is shown in this dashed line here (Indicating) which in this particular example might be severe settlement if no protective measures were taken. There are different ways of doing compensation grouting, but typically a shaft would be excavated in the ground outside the building, some distance from the building, and from that shaft grouting tubes would be installed into the ground, drilled into the ground, and all this would take place long before any tunnelling. Then during the actual tunnel construction process, while the tunnel is being constructed, liquid cement (that is grout) is injected through those tubes in such a way as to achieve the building only experiencing slight settlement. So that constantly during the actual tunnel excavation grout is injected and it is a very effective means of protecting buildings.

2402. The next slide, slide 39, shows just a little bit detail as to how these grout tubes can be installed. I will not spend much time on this but just to show the commonest technique is from a shaft, as I explained earlier, but you can also do them from a much shallower excavation, a very shallow hole in the ground, and in some cases you can install these grout tubes directly from the ground surface below a building and, exceptionally, they can be installed from an existing tunnel like this, but the principle really is that there are many ways of installing these grout tubes in the ground.

2403. Slide 40 shows the actual process of compensation grouting going on in that you will see in the lower photograph a person in the shaft and he is actually inserting a grout tube into one of those drilled grout tubes that I described earlier, and that will enable grout to be injected, liquid cement to be injected between the tunnel and the overlying building to protect that building from any excessive settlement.

2404. MR ELVIN: I think you have got some photographs of a well-known example?

(Professor Mair) A well-known example now follows, slide 41. This technique was used with enormous success to protect the tilt of Big Ben for the Jubilee Line Extension during the construction of Westminster Station right opposite Big Ben, shown here, and also the Jubilee Line Extension tunnels that run along Bridge Street between Westminster Station and the Houses of Parliament. There was a significant risk of Big Ben tilting in a northerly direction towards the construction of the new station. So a shaft was constructed in Bridge Street. It is shown circled in yellow on the photograph here. And the left-hand photograph is a photograph taken at night-time of a drilling rig being lowered into that shaft, so that drilling rig goes right down into the bottom of the shaft and then grout tubes were installed horizontally for a distance of about 50 metres from that shaft right underneath the foundations of Big Ben. Then throughout the construction of Westminster Station and of the tunnels along Bridge Street, for a period of about 18 months, liquid cement periodically was injected through those grout tubes to control the tilt of Big Ben, and that was done by having very comprehensive instrumentation attached to the clock tower so that every small movement of Big Ben was measured and the grouting was done to protect that. This technology was used with great success not only for Big Ben but for other buildings on the Jubilee Line Extension project.

2405. What I would just like to do, Professor Mair, so that we do not take too much more time with the Committee, is to look at the conservative nature of the various stages in the assessment and you have got two examples. The first is the very attractive Elizabeth House which backs onto Waterloo International Rail Terminal, it runs parallel to it. The entrance to Waterloo is just down to the left, is it not?

(Professor Mair) That is correct, yes.

2406. If we can skip over two slides to slide 44, you have there a graph which deals with assessment prediction and observation. Can you just describe briefly what that demonstrates?

(Professor Mair) Yes, there were two major tunnels and a third enlargement tunnel built directly beneath this building, Elizabeth House, and what is shown on this slide 44 are, first of all, the green line represents the settlement profile of that building undertaken as part of the stage two assessment process. So this graph is plotting settlement on the left-hand axis and the distance of 100 metres represents the whole length of that building Elizabeth House. The green graph represents the stage two assessment which assessed that the building could be subjected to something like 53 millimetres maximum settlement. Then there can be a stage three prediction which is a more detailed process, as I explained earlier, and the stage three prediction process for that building predicted that the movement of the settlement of the building would be just a little bit less than 40 millimetres and that is shown in the red line. And then finally the tunnelling was actually undertaken and when all the tunneling had finished the observed movement of the building is shown in those purple squares. The purpose of this slide is to illustrate two things. Firstly, that the original assessment process (that is the green line) was conservative and it over-estimated the settlement of the building. It is known to over-estimate it because of the conservative nature of the calculations. The second purpose of the slide is to show that the actual observed movement of the building turned out to be in pretty good agreement with the prediction that would be undertaken using a stage three more detailed process.

2407. There is then another example, Neptune House in Southwark near Canada Water. If we skip over to slide 47, does the Committee there see not the same graph but does one draw similar conclusions, namely that the further down the assessment route one goes, the closer it is to what actually happens?

(Professor Mair) That is correct and, in particular, the stage two assessment process, that is the green line, again is very conservative and over-estimated very much what actually happened to the buildings during tunnelling.

2408. Professor Mair, if I could ask you to be so kind to go to your final slide and to conclude with that, please.

(Professor Mair) My final slide, slide 48, really summarises what I have been presenting about ground settlement and its effects. I think the first point is that there is considerable experience in the London area from the Jubilee Line Extension and the Channel Tunnel Rail Link, and for both those projects very little building damage was recorded. The second point is that the methodology that I have described for settlement assessment is proven to be very robust and conservative. The final point is that there are protective measures available and those have been well-proven and they are very effective. That completes my presentation.

2409. MR ELVIN: I do not know whether the Committee has any questions.

Examined by THE COMMITTEE

2410. KELVIN HOPKINS: I am very interested in what you say but the extent of deflection on the ground level is much greater than I would have expected. Some boring techniques cause much less settlement than others. What can you do underground? I would have thought, I forget the technique now, that frontal boring would perhaps be less of a problem than the sprayed cement system because of a less exposed surface, I do not know. That is one thing. We have been told that more deflection of the ground underneath a building could cause serious cracking of the building. I am just interested to know.

(Professor Mair) Well, the first point you make is that, yes, the principle of the earth pressure balance machines, which is the sort which I described, applies a positive high pressure to the face of the tunnel all the time during excavation so at no time is the face unsupported. That is shown in slide 12 here. Certainly it is extremely effective in reducing movements to small amounts. I think it would be fair to say that no technique at present really reduces settlement to zero, but this kind of technology which is very advanced and there is now considerable expertise with it, does reduce movements a lot, so you are right, face support certainly improves matters considerably. Your second point is to do with building damage and I am sorry ---

2411. Deflection is what I was talking about, an inch and a half in my terms, 3.5 centimetres in yours, and that seems a lot to me. I know that concrete, for example, is very porous in deflecting pressures. I want you to reassure me that buildings will not be affected.

(Professor Mair) I think the key point is that concrete structures, brick structures, or any masonry structures are very sensitive to differential movement, so that if the building uniformly goes down by 50 millimetres, or perhaps two inches in old units, it may not experience damage if it goes down relatively uniformly. That example, Elizabeth House, was a very long building. It is about a 100 metres long and it did in fact settle 40 millimetres at its maximum, but it was very gradual so the actual differential movement in terms of how much each part of the building was experiencing different amounts of settlement was very low, and therefore Elizabeth House suffered absolutely no damage at all despite having the maximum settlement of 40 millimetres. So the real nub of the issue is differential settlement. If it is relatively spread out then it is not damaging.

2412. MR ELVIN: Professor, is that why when you go down the various routes of the stages, stage three is the most rigorous individual assessment of the individual buildings and what stresses they are likely to be experiencing?

(Professor Mair) Correct, yes.

2413. CHAIRMAN: Could I just come back, Professor Mair, although it is not the same as coal-mining subsidence, it is a similar set of activities and it is across geological structures which are already fitted with a range of other tunnels and accesses for everything from sewerage through to electricals and Tube lines and everything else. Clearly, as you showed on grid 34, where you had the red grid inside the yellow box system, the areas of probable damage or potential damage, it is still, by and large, guesswork. It is qualified guesswork, yes, I agree with that, very qualified indeed, as we heard from your outline at the beginning but still it is guesswork. I represent a constituency that gets all kinds of settlement damage and long line settlement damage. They are not dissimilar in any regard. What I wanted to ask, and probably Mr Elvin will answer this, I suspect that we are going to get many petitioners who are going to raise this particular matter, and I think your help and advice on some of the stuff you have given today might be very helpful indeed. One thing I did want to raise, though, was in relation to other types of structures which maybe used after the tunneling or alongside it. Are there any skin-to-skin workings on the structures which are going nearer to the surface where you will see where tunnels come together or emerge together pre the station or after the station in areas where you have got a large expanse of tunnels together, and you may leave or build structured walls where the two joints come in because, as you know from your engineering, skin-to-skin working has been seen to be quite dangerous in relation to movement and settlement and subsidence. The second element of that is is it envisaged that within the structure there will be any hanging roof bolt structures which might go at sections like that? Hanging roof bolt systems sometimes become the foundation structure themselves. I just wondered if any of those had been envisaged or are you aware if that has been envisaged in the construction?

(Professor Mair) I think, perhaps taking some of your earlier points first, when you referred to slide 34 and you have referred to the red hatched area where buildings were proceeding to stage three, the more detailed assessment, you use the word "guesswork". I think ---

2414. Qualified guesswork!

(Professor Mair) With respect, I would say we know a lot more about it than having to guess. In terms of having a very good idea as to the level of movement the buildings could be subjected to. It is much more than guesswork. We have a much better handle on with all the experience of the Jubilee Line Extension and indeed the Channel Tunnel Rail Link. Your second point was about when tunnels are in very close proximity when coming out of stations when they were perhaps rather close.

2415. The reason for this is we paid a visit to Liverpool Street Station and we were taken down one of the platform lines at the station where we were shown a building which is almost certainly going to come down or is envisaged to come down which will form part of the new structure. I have got that in my mind and every time I see entrances and exits I see the possibility of other large buildings nearby the proposed demolition that may be affected simply by the demolition itself and structures that will be put in place. So as you can see from the whole plans of this, things come together and when they do they become bigger structures underground, and therefore they have a different effect that sometimes can go outside of these perimeters. As I said, I represent a constituency, it is different in that it is chalk and stone by and large rather than clay, but I know and I have learned from that that if a structure is somewhere between half a mile or a quarter of a mile away from the envisaged area, even though you have got a pillar of stone precisely for the protection of properties it may be because of another building being affected it can cause a settlement problem on a fault line somewhere else. That is why I am asking the question whether or not it has been taken into consideration.

(Professor Mair) I think it is fair to say that the conditions in London with the relatively soft soils we are talking about, soft in the sense of not being like stone or hard mining materials, and the effect of an excavation, for example, for Liverpool Street Station, as we are looking at here, a long way away from Liverpool Street Station, the chances of that are extremely remote. It is much more localised. When you are dealing with tunnel construction in soil, we have got a very much better understanding of the limits of how much the movement will affect other areas. I think in the context of unknown faults or something like that taking place, which can be a problem in other areas of the country, would not apply here. We can say that with confidence.

2416. You did accept in your earlier evidence things at a lower level can stop windows and doors opening and cause cracks down the walls inside buildings?

(Professor Mair) Yes, indeed.

2417. That is at the minor end of it but, as has been pointed out, at the major end of it, it does not have to be within the area, it can be outside of that. People see cracks in their walls and blame everything on everything, but what I am saying is that there can be occasions where because of the buildings, not just the excavation, the buildings which have to go at the cost of other buildings being taken out, it can have a causal effect on other things outside this grid.

(Professor Mair) It would be surprising if buildings outside the contours shown here were affected by the construction. I think that is the point I really want to say. We know enough about it that tunnelling at particular depths in the ground has an effect on a certain number of buildings at the ground surface and beyond those would have minimal effects. We know that with considerable confidence from all the measurements that have been made on previous projects.

2418. CHAIRMAN: Again, I am not trying to give a straight comparison, but in my area we had coal-mining subsidence which had effect outside of areas, and the explanation which was given in those days was that nothing could have occurred in terms of cause by coal-mining because coal-mining had ceased to be operational some six years prior. Actually it was not coal-mining but the collapse of the tunnels where the coal was got from which had a repetitive effect throughout the strata. The reason I am raising this is because without any shadow of a doubt we will have other petitioners before us who will say, "It is alright for this to be stated by Crossrail, but we have got other evidence that shows it may affect our properties." I wanted to ask Mr Elvin, if at some point we need Professor Mair to come back, you could create that possibility?

2419. MR ELVIN: Sir, the whole point of doing this exercise was simply to give the Committee an introduction to this issue, precisely because the chances of it coming up again are fairly strong, and the whole idea is that we present more detailed evidence as and when necessary, whether in oral form or on paper.

2420. CHAIRMAN: We are extremely grateful. I have found this to be very enlightening and very helpful.

2421. MR ELVIN: It was intended precisely to give you an introduction to the sorts of issues that are likely to arise without seeking to answer all the questions in site specific areas.

2422. SIR PETER SOULSBY: Just one point, you did say if anything happened outside it would be 'surprising", were the words you used. Having lived to the age I have, I have been surprised at how many times I have been surprised! I just wanted you to qualify that word for me in terms of degree because it is rather subjective and I would like to have a slightly more objective view of the word "surprising" in relation to the various sites that we will be dealing with. We have looked at Liverpool Street but there are other sites. This is the reason I think the Chairman is saying will Professor Mair be around because we will be delighted for the help. But if you could clarify "surprising", forgive me, but it did seem just a little loose.

(Professor Mair) I would be happy to clarify that. I said that if tunnel construction caused significant movement to a building outside the contours that would be surprising; I would say it is extremely unlikely.

2423. SIR PETER SOULSBY: I am slightly relieved by those words.

2424. CHAIRMAN: That is very helpful. Is there anything further on that?

2425. MR ELVIN: No sir, simply to say that there are more details on these issues also in one of the information papers, D12. Sir, can I thank you the Committee for sitting late. I am afraid our time estimates were a little out but I hope it has been helpful.

2426. CHAIRMAN: Can I say that the Committee will next meet for open public session next Tuesday at 10 am in this room. Thank you very much.

 

Adjourned until 10 am on Tuesday morning