Examination of Witnesses (Questions 20140
- 20159)
20140. You say that, but you are physically
altering the support of the building by altering the ground, by
altering the water levels, and you are carrying out works which
could have an effect on the banana wall on which the building
stands. Both those points are correct, are they not?
(Mr Berryman) I do not think
the Banana Wall actually provides any support to the building
but we are certainly not intending to affect the groundwater.
The whole purpose of using recharged wells, if we do do that,
is to ensure that the groundwater regime stays exactly as it is
now.
20141. I do not want to talk at cross purposes
but absent the mitigation measures, which may be groundwater wells
pumping more water in or taking other action in relation to the
water, there is likely to be an effect on the ground on which
the building stands, so absent some action in mitigation there
is likely to be an adverse impact on the building. Do you agree?
(Mr Berryman) Potentially,
yes. Having said that, our predictions are that the impacts, even
without mitigation, will be negligible. We only get into Stage
Two of the settlement analysis because the settlement is so low.
However, we have worked these ideas up just in case our predictions
prove to be too optimistic.
20142. You have explained why you think Smithfield
is different but, if at Smithfield you can cope with a statutory
market operator and building owner approving details there can
be no reason in principle why you could not cope in terms of the
construction process with a statutory market operator approving
the details at Billingsgate.
(Mr Berryman) No, that is
not the case, simply because you have really given it away in
your question. The statutory market operator, the local authority
and the building owner are all the same person. We only have to
get one approval because all of those are functions by one body.
At Billingsgate all of those functions are actually held by three
or four different bodies.
20143. But in many parts of this railway you
are going to have to get approval from different people. You do
not just say, "Because we have to get approval for one thing
from one person it is all too difficult and therefore we should
not have to get approval from anybody", which is what you
are saying.
(Mr Berryman) No, that is
not true. Generally speaking, the only people we get approval
from are local authorities where we need to get planning consents,
section 61 approvals and all that sort of thing, and that is fine
because that is one body which can make a judgment about what
is the best thing for the occupants of this borough. What you
are talking about here is getting approval from one body. If we
gave them the right of approval we would need to give it to all
the other people that I have already mentioned and that is an
entirely different situation from something where you have just
got one organisation which is responsible for approvals.
20144. But it may cause you difficulties if
you have to get approval, you say, and in terms of the actual
practicalities there is no physical impossibility of obtaining
approval from more than one person, is there?
(Mr Berryman) I often say
when I am sitting in this chair that nothing is impossible in
engineering but obtaining approval from more than one person for
the same thing probably verges close to that.
20145. You were just saying how reasonable the
City were in dealing with you. You cannot say that it is impossible,
can you?
(Mr Berryman) It is not
impossible, of course it is not impossible, but it is very difficult
and time-consuming. I am sure members of the Committee themselves
will have experienced trying to get approval from a number of
different approving bodies on matters for which they may need
to do so.
20146. You have explained how it is on a critical
path. Why can you not start developing these plans and obtaining
approvals at an early stage? You do not have to leave it till
later, do you? If you know that you have to obtain approval from
the City under the deed then you can start early. You can alter
your programme so that you get approval early and then there is
no reason why it should hold up the programme at all, is there?
(Mr Berryman) One of the
reasons for having two scenarios is to give the contractor, when
appointed, some flexibility as to how he actually does the work,
and I think that is probably obvious from the Environmental Statement,
and of course that does put a time constraint on things because
when the contractor is appointed he will want to start work as
soon as is reasonably possible. Of course, we can work up the
ideas further and we intend to do that and we need to consult
with the City Corporation. I think a statement has been read out
that we are quite happy to sign up to about consultation.
20147. It is not going to be effective consultation
if you are going to leave it to the nominated undertaker to decide
which of those scenarios, is it, because you cannot resolve the
issues early?
(Mr Berryman) It will not
be the nominated undertaker. It will be more likely the specialist
contractor who is appointed by the nominated undertaker, but we
can work towards getting solutions for the two scenarios, of course
we can, and we will do that. I do not think there is very much
between us. What we are talking about really is whether we have
a right of approval or whether we work together to collaboratively
work out a way of doing the job.
20148. Mr Cameron: Thank you, Mr Berryman.
Re-examined by Ms Lieven
20149. Just a couple of points, Mr Berryman.
First of all, Mr Cameron placed a great deal of emphasis on the
fact that there are two alternative construction methodologies
here and that what that meant was that we did not know what the
detailed mitigation measures for Billingsgate would be, but is
there anything unique to the Isle of Dogs about not yet having
drawn up detailed measures for a particular building or is that
a situation which arises elsewhere?
(Mr Berryman) No, it is
a situation which arises all along the route. Generally speaking,
we have developed in principle methods of mitigation but the detailed
design of mitigation measures, obviously, is not done yet. I believe
some of it is just starting, as you would expect at this stage
of a design.
20150. The only other thing I wanted to check
with you is that he pressed the point that, absent mitigation
measures, there may be some impact on the building at Billingsgate.
Is it the case elsewhere on the route that, absent mitigation
measures, Crossrail might well have settlement impacts?
(Mr Berryman) Indeed it
is. This is by no means one of the—I was going to say worst
examples; that is perhaps the wrong expression to use—most
critical buildings on the route where mitigation measures will
be needed. I think some of the buildings around Soho Square, for
example, St Patrick's Church or the Huguenot church there, are
good examples of buildings where mitigation is absolutely essential
to prevent damage to the buildings.
20151. Ms Lieven: Thank you. That is
all.
Examined by The Committee
20152. Chairman: Just one question. Is
there any history of the dock having been empty before?
(Mr Berryman) It was obviously
empty when it was built. Sections of it have been empty but not
this particular bit. The Banana Wall is an interesting structure.
It is quite an old structure. It was built by a chap called William
Jessop in 1802 or thereabouts. It actually extends all around
the extensive range of docks which exist at what is now Canary
Wharf and Canary Wharf themselves have dewatered several of them
from time to time, although not this particular one, but there
is no reason to believe that this is any different from any of
the others which have been dewatered.
20153. Kelvin Hopkins: On this principle
of the Banana Wall, is it rather like the retaining walls of railway
passages where they slope upwards?
(Mr Berryman) Yes, it is
a similar sort of principle. The shape of the Banana Wall was
partly dictated by the kinds of vessel which used the docks when
they were built. In modern times the wharves have been extended
out over the dock, but when they were built ships would moor directly
against the dock and so the shape of that was conducive to that.
20154. But if the water level varied a lot they
would need to be built in this particular way to restrain the
earth behind, presumably? If they were just straight and the dock
stood empty there would be the possibility of them collapsing
inwards.
(Mr Berryman) That is right.
They are gravity walls and that is why they are that shape. As
I say, they stood pretty well for a long time. We have had a look
at the historical factors of safety when various things have been
done to the water levels in the docks.
20155. I am not suggesting that you do these
extra works now but, for example, you know where the long walls
fan out at St Pancras into the mainline?
(Mr Berryman) I know the
lines.
20156. So do I, and before they did the electrification
they pinned them in.
(Mr Berryman) Yes, with
ground anchors.
20157. That is right. Is that the same kind
of principle?
(Mr Berryman) That is an
idea that we have looked at for another part of the dock wall,
not the bit underneath the market; we do not think it would ever
be necessary there. There is another little bit—it is off
this plan; it is kind of there on this plan—where we may
have to go to ground levels, but, as you are aware, it is a well-established
method of stabilising these things. The complicating factor is
that the Banana Wall is Grade I listed even though you cannot
see it, touch it or experience it with any human senses.
20158. Chairman: In relation to that
answer you gave, if the soil structure is part of the foundations
what is the difference between that and at Havering where you
would not drill through a wall to get access?
(Mr Berryman) At Havering
the wall is a buttress wall.
20159. Is that not?
(Mr Berryman) No, it is
not. Havering is a series of arches laid out in a horizontal plane.
If you can imagine a railway viaduct rotated through 90 degrees
and laid on its side, it resists the earth pressure by the arch
action of the ends of the buttress and concentrates the forces
very specifically down into the nibs which form the front of the
buttresses. This is a different kind of wall. It is a gravity
wall. It is almost as Mr Hopkins described it, laying back on
the ground. You can see its shape on the cross-section and it
works in a different way. It is purely a gravity wall.
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