Examination of Witnesses (Questions 2680
- 2699)
2680. Chairman: Can I ask that at some
point in the future, Mr Morton, you can get us a revised drawing
of this which rectifies the mistake?
(Mr Morton) Of course.
2681. Mr Honey: That is a matter I will
deal with in re-examination. For the avoidance of doubt, I will
make it clear that we do not think there is a mistake.
2682. Chairman: I am just referring to
the witness.
2683. Ms Lieven: It is quite important,
sir, that we know if there is a disagreement between counsel because
we need to work on the drawings that are correct.
2684. Chairman: The reason I referred
to it was because the witness gave evidence that it was a mistake.
Therefore, I wanted the new plan showing no mistakes to be put
in front of the Committee. If you have a different view on that,
you can perhaps make it clear in your rejoinder this afternoon.
We will return at 2.30.
After a short adjournment
2685. Ms Lieven: Sir, before I return
to cross-examining Mr Morton, the undertaking which I read out
this morning is being passed round. Mr Morton, could we go back
to your options and use your tab 7 as an aide memoir? All your
options involve a pile shaft, do they not?
(Mr Morton) No, the third option
could be the segment system. What I am saying is that the third
option could be exactly as shown on the drawing.
2686. The third option is the one that lops
three metres off the end of the building.
(Mr Morton) That is right.
2687. Let us take options 1 and 2 for a moment,
the piled options. I just want to run through with you various
problems associated with a site like this, a very constrained
site, with piling. First of all, piles themselves are thicker
than the segmented wall, are they not, so they take up more space?
(Mr Morton) Yes, 1.2 metres
diameter.
2688. Once you have put the piles in you then
have to line the shaft as well.
(Mr Morton) Yes, you do.
2689. So what that means is that the total diameter
of a shaft has to be bigger with your options than it does with
a segmented shaft.
(Mr Morton) That is exactly
right.
2690. Obviously that is a disadvantage on what
I think we can all agree is a highly constrained site.
(Mr Morton) It is certainly
a disadvantage, but if it were possible to move the shaft as I
have suggested then a particular amount of that would be taken
up in that way.
2691. That is option 1?
(Mr Morton) Yes.
2692. What it means by having a bigger shaft
is that you are taking up more of what little extra space you
gain.
(Mr Morton) That is true
enough, yes.
2693. In terms of the construction plant that
you need for piling, you need the crane, which you need for a
segmented shaft as well, but you also need a piling rig.
(Mr Morton) Yes.
2694. And you need to have on the site not just
all the piles but also the reinforcement cages.
(Mr Morton) Yes.
2695. And piles and the reinforcement cages
are pretty big bits of kit, something in the region of eight metres
long, I am instructed.
(Mr Morton) That sort of
order.
2696. So you have to find space for all those
sorts of things on the site. We will come to the space allowance
in a minute. The other issue with piling, if you pile this shaft
down 22 metres you then have to break through the piles at the
bottom to get into the adits, do you not?
(Mr Morton) Yes, you do
but that was taken account of in the Crossrail engineers' proposals
for a rectangular shaft, which they put into their report.
2697. It is not impossible but it will add time
to the construction programme because it is more difficult to
break through the piles than to go through and spray a concrete
lining system, is it not?
(Mr Morton) I do not think
that is necessarily true.
2698. You do not think it will add time?
(Mr Morton) I do not think
necessarily, no.
2699. Then can we deal with a specific issue
around piling on option 2, which is the one with the biscuit chunk
taken out. We talked this morning briefly about how that option,
because it had lost its circular structural stability, would require
propping; do you remember we agreed that? One point I should have
put to you and I did not, you suggested that the propping could
be provided by building the floors and the stairs as you go down?
(Mr Morton) That is possible, yes.
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