Select Committee on the Crossrail Bill Minutes of Evidence


Examination of Witnesses (Questions 12260 - 12279)

  12260. MS LIEVEN: Yes, my Lord, we have still got noise and the wall issue. I do not know if that is the end of the Association's evidence.

  12261. CHAIRMAN: Is that all your evidence?

  12262. LADY BRIGHT: Our main concern is that we get some more information, which we will get from the Promoter's team on precisely what the framework is, whether Network Rail is, for example, bound by the noise code and everything else, so clearly fundamental information like that.

  12263. CHAIRMAN: What are you talking about, the wall?

  12264. LADY BRIGHT: Not on the wall. Do you want me just to focus on the wall at this point?

  12265. CHAIRMAN: I just want to know what you are talking about, what topic.

  12266. LADY BRIGHT: I have done what I can on going through the headings of the items that we are concerned about. I have asked for information from the Promoter on how to deal with this overlap between Network Rail and Crossrail and I cannot really make a proposition as to exactly what we are asking for if I do not know what the information is. Would it be better to go straight to their evidence?

  12267. CHAIRMAN: Have you got any more witnesses?

  12268. LADY BRIGHT: No.

  12269. CHAIRMAN: If you have not then the next thing to do is to invite Ms Lieven to call Mr Thornely-Taylor on the noise and Mr Berryman on walls.

  12270. MS LIEVEN: Certainly, my Lord. I was going to call Mr Berryman first to explain the engineering and then Mr Thornely-Taylor to explain the consequences of the engineering.

MR KEITH BERRYMAN, recalled Examined by MS LIEVEN

  12271. MS LIEVEN: My Lords, there are two issues which are outstanding: one is the noise from the trains going into the batching plant and the other is the noise barrier issue. Let us start with the noise source, which is the noise from the trains going into the batching plant and the works that Crossrail are doing in this location. Mr Berryman, can we turn to the site plan, which I think is 027, and can you just start off by explaining on that in broad terms what is happening in this location and then we will come to look in detail at where the EWS trains are going to go?

  (Mr Berryman) Could I have the next one, please? I have got the wrong numbers on my exhibits. That is 028.[12] The works in this area consist of the tunnel portal and a ventilation shaft just here (indicating). The tunnel portal is where the tracks emerge into fresh air; in other words, there is air above them and at that point the tracks will be about seven metres or so below ground level. The section between what we call the tunnel portal, which is where the trains emerge into the air, and the tunnel eye, which is down here (indicating) --- The tunnel eye is where the actual tunnelling starts because to tunnel you have to have a certain amount of ground over the top of the tunnel otherwise the tunnel falls in; it does not work. We have to construct a section of that in cut and cover where we dig a big hole out and then we put a concrete slab over the top of it and the trains will come up through there and emerge into daylight here (indicating). Could we have number 027?[13] They will arise up from that portal to a point about here where they will be at ground level. They will be in an eight metre deep trench down here somewhere rising up to being at ground level at this point (indicating).

  12272. Just stopping there, in respect of Lady Bright's house, which is just over here, what is the effect of the fact that the train is dropping down in towards the portal?

   (Mr Berryman) That will provide to some extent a shielding of the noise. Most of the noise generated by trains—Mr Thornely-Taylor is an expert on this but I know a little bit about it—is at the rear wheel rail interface or from the electrical plant which is underneath the train. The noise tends to come from a lower point on these kinds of electrical multiple units. As the trains go down into that trench a lot of the noise will be shielded. This is in contrast to the diesel trains which are used for freight and for the high speed train where the noise is generated near the top of the vehicle.

  12273. CHAIRMAN: It is the exhaust stops, is it not?

   (Mr Berryman) It is the exhaust noise, yes.

  12274. MS LIEVEN: Lady Bright made some mention of constraints for the construction of Crossrail going along these tracks past Westbourne Park. Can you just explain what is going on there?

   (Mr Berryman) During the construction of the tunnels the excavated material from the tunnels will be brought out from underground by a conveyer and it will be delivered to a point here (indicating), more or less where the artists' studios are at the present time and from there it will be loaded onto trains and the furthest those freight trains will come down is approximately here, very close to the footbridge that we spent a little time talking about. There will not be any of those kind of freight trains going down here. What there will be will be small, narrow gauge trains which are used for the delivery of concrete segments and other materials into the tunnel and there will be about three or four of those a day, they will be fairly slow moving as compared with ordinary trains, so they generate correspondingly less noise in that respect.

  12275. CHAIRMAN: What are they powered by? Are they diesel?

   (Mr Berryman) Yes. They will be going down into that trench --- Sometimes they are powered by battery. On the Jubilee Line we used entirely battery power, so it can be done with batteries. We have not specified what the builder must use.

  12276. BARONESS FOOKES: Will that be quieter?

   (Mr Berryman) Batteries would be quieter. The diesel trains are not like big mainline locomotives; they are relatively small units. The tendency is to go to more electric and battery power simply because of the regulations about nitrous oxide in the air and it is very difficult to control that in tunnelling. It could go either way. In either case I would not have thought it would be particularly noisy.

  12277. MS LIEVEN: Let us move on to the batching plant trains. I am going to leave it to you to explain by reference to the exhibits what is happening in respect to these trains.
  (Mr Berryman) Unless your Lordships want, I do not think a full explanation of the train operations in this area would be a very useful use of your time. I am happy to do that if you want, but I think perhaps a brief resume would be more sensible. Could I have number 010 up, please?[14] Number 10 is an aerial photograph of the site. I think it is worth mentioning whilst this one is still up that this is the site of the existing batching plant. Where it says "Proposed discharge hopper" is the existing site of the artists' studios. You can see a line here where it says "End of headshunt in new proposals" and that is the furthest point at which diesel locomotives will be able to go in the new arrangements and you can see down here "End of headshunts in the existing situation". The current freight trains which are delivering to the batching plant come down the mainline, turn into the sidings and go right down to here and then they manoeuvre and bring the train back into short sections to be unloaded here. What will happen in the new arrangements is that the furthest point that the locos will come to is here (indicating). They will not be able to go beyond there because the corridor is not wide enough. We have devised, together with colleagues from the operating side, the method of working with this and established that this does work quite satisfactorily. People who live down this road here will no longer have the diesel trains going backwards and forwards in front of them. As has been mentioned earlier, some of these trains run at night. They are not particularly frequent. We believe there are only about three a week. At least they will be gone.

  12278. Let us move on to the issue of the noise barrier, please. Can you just explain what work we have done in respect of the height of the noise barrier that would be required and the difficulties of providing that?
  (Mr Berryman) Could I have number 024, please?[15] The wall which currently exists on this road is a brick wall built probably in Edwardian times. We have had our structural engineers do some calculations—

  12279. Can I just stop you for a moment so we understand what we are looking at? On this plan the yellow is the existing wall, is that right?

   (Mr Berryman) That is correct, the yellow is the existing wall. This is the road here with the residences on the other side (indicating). The railway is cutting down here and the wall is partly a brick retaining wall and then partly the wall which you can see from Westbourne Park, which I think most members of the Committee saw when we went down on the visit. We have done an analysis of that in accordance with BS5628, which is the appropriate British Standard, which shows that it has a safety factor at present of about 1.4; in other words, the stresses induced in the wall are greater than the loads which one experiences by a factor of about 1.4. The wall is not going to fall over. We did some calculations of the impact of extending the wall just by sticking something on the top which is four metres high and we came there to a figure that the wall would be overloaded by a factor of eight; in other words, the stresses induced in the wall would be eight times the permissible stresses.



12   Crossrail Ref: P79, Royal Oak Portal-Crossrail proposals (WESTCC-56_04-028) Back

13   Crossrail Ref: P79, Westbourne Park-Crossrail proposals (WESTCC-56_04-027) Back

14   Crossrail Ref: P79, Proposed positions of Tarmac Topmix discharge hopper, existing and new headshunts (WESTCC-40_04-010) Back

15   Crossrail Ref: P79, Schematic details for an Acoustic Wall (Provisional) (WESTCC-40_04-024) Back


 
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