Select Committee on the Crossrail Bill Minutes of Evidence


Examination of Witnesses (Questions 4900 - 4919)

  4900. MR ELVIN: That is why I wanted to deal with that.

   (Mr Berryman) It can be done in that way but, in this instance, the proposal is to excavate it from the surface. Mr Thornely-Taylor mentioned that the spoil would be going by conveyor to Paddington. In fact this is past the midpoint of the tunnel. The conveyor will be going out to a wharf on the River Lea and the spoil will be going away by barge from this particular area.

  4901. LORD YOUNG OF NORWOOD GREEN: So some goes that way and some goes the other way.

   (Mr Berryman) That is correct, my Lord.

  4902. Does the stuff which comes out of the shaft go into a skip or the back of a lorry?

   (Mr Berryman) It will go into the back of a lorry.

  4903. It goes straight into a lorry.

   (Mr Berryman) Yes.

  4904. In that way you do not get overfill, everything is sheeted.

   (Mr Berryman) That is correct.

  4905. MR ELVIN: How dry is the material likely to be that is coming out of the shaft?

   (Mr Berryman) It is likely to be very dry. London Clay, when it is excavated from the ground, is like rock. When you hear the description "London Clay" you may think of the kind of clay you get in your garden,. It is not like that. It is a very solid, hard material. You can certainly hit someone over the head with it and do them serious damage.

  4906. BARONESS FOOKES: It is not like Plasticine.

   (Mr Berryman) It is not like Plasticine.

  4907. LORD YOUNG OF NORWOOD GREEN: After the topsoil, you are into this compacted clay.

   (Mr Berryman) Frankly, my Lord, I doubt if there is any topsoil at Hanbury Street. There will be a level of what we call "made ground" which is where debris from previous buildings and so on has been levelled out in the Middle Ages or whatever and then we will be quickly into London Clay at this point.

  4908. BARONESS FOOKES: If it is rock-like, Mr Berryman, does that mean there is less dust or debris? I am thinking of possible air pollution.

   (Mr Berryman) When it is being broken, Lady Fookes, there is inevitably some dust being generated.

  4909. But that is underneath.

   (Mr Berryman) That is below ground.

  4910. And when it comes up ... ?

   (Mr Berryman) When it comes up, it is not usually dusty at all. It is usually pretty cohesive, and it sticks together, as I said, like rock.

  4911. MR ELVIN: The procedures in the Construction Code can provide for dust suppression techniques, including the use of spray and sheeting and other means to control any dust emissions, if indeed it is crumbling or fragmenting.

   (Mr Berryman) That is correct.

  4912. MR ELVIN: Unless the Committee have any further questions on this issue, I was going to move to the final question of why is a ventilation or intervention shaft needed at all. I do not know whether the Committee has any further questions on the routing of the construction site.

  4913. CHAIRMAN: No, you go ahead.

  4914. MR ELVIN: Finally, Mr Berryman, why do we need a shaft in Hanbury Street? We removed the need for a greater shaft when it became unnecessary to launch a tunnel boring machine from here as a result of the revised tunnelling strategy and the conveyor to Pedley Street was similarly removed from the project. Why do we still need a shaft there?

   (Mr Berryman) I do have some notes but I will do it from memory. The reason for a shaft is two-fold: firstly, for ventilation of the tunnels and, secondly, for intervention by the emergency service. The ventilation aspect of it has really two aspects: first of all, in the event of a fire for the purposes of smoke extraction, and, secondly, in the case of congested running or overheating of the trains it can be used to pump fresh air along the tunnels. The ventilation of the intermediate shafts, of which Hanbury Street is one, does not normally run. It normally runs at the station but does not normally run at intermediate shafts. It is only in the event of an emergency and what I described as perturbed running that it would be operated here. The intervention shafts are basically designed to allow the fire brigade to run down the stairs to get to an incident that is happening underground. The need for these is set out in what are known as the ROGS Regulations (the Railway and Other Guided Transport Systems Regulations) which call for intervention points at one kilometre centres. That is the rule that we have followed all the way through. We have not been able to quite get to one kilometre centres: some of the spacings are slightly more and some are slightly less but that is the reason for introducing them.

  4915. CHAIRMAN: Are these regulations British ones or do they come from Europe as well?

   (Mr Berryman) I was just about to mention the European dimension, my Lord Chairman. There is a set of regulations called the Interoperability Directives which include some documents called TSIs (technical specifications) and these also have the same specification of a one kilometre centre for intervention shafts. All of these regulations do have a get-out clause, and that is if you can demonstrate that there is a satisfactory way of dealing with incidents without these shafts. That is a matter on which the fire brigade and Her Majesty's Railway Inspectorate adjudicate.

  4916. MR ELVIN: We have given an undertaking, have we not, Mr Berryman, to the London Borough of Tower Hamlets in relation to the shaft to continue to work with the regulators on the need for the shaft?

   (Mr Berryman) We have been doing that. It would be very advantageous if we could get rid of this shaft and the other ventilation shafts. They have not caused so much difficulty for us as this one has but none of them is very easy to locate. We have been putting together a case for modifying the design and modifying the intervention by the fire brigade so the shafts are no longer needed. We have satisfied ourselves internally that the ventilation can be dealt with without this shaft. We have not yet satisfied the fire brigade. We are still in discussion with them and are likely to be for some time. There is also the matter, even when we have convinced them, that we will have to go to Europe to get a derogation from the Interoperability Directive. It is unlikely that will be turned down if the Fire Brigade here have agreed to it but it is still a process that has to be gone through.

  4917. CHAIRMAN: The Government will apply for it.

   (Mr Berryman) The Government applies for it, my Lord, yes.

  4918. MR ELVIN: So there still remains the possibility that the shaft could be done away with altogether but that is dependent on these processes being carried out and accepted?

   (Mr Berryman) It is, and it will be some time in the future before that is likely to be resolved. These processes unfortunately do take quite a long time and once you get Europe involved it seems to take even longer somehow.

  4919. BARONESS FOOKES: As far as the Fire Service are concerned, is there a likelihood that they will agree? Perhaps I should not ask you to speculate.

   (Mr Berryman) I am sorry, my Lady. I did not catch the last thing you said.



 
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