Examination of Witnesses (Questions 1540
- 1559)
1540. Mr Binley: Can you remind us again
of how many people are employed in that building?
(Mr Chapman) I am afraid I have no idea.
1541. Mr Binley: Maybe you can find out
and let us know.
1542. Mr Laurence: In the UBS building,
yes. You have mentioned the proposed option one ticket hall shown
on your figure three there, Mr Chapman, as being situated almost
exactly under Blomfield Street, is that right?
(Mr Chapman) That is correct.
1543. You have mentioned that. Have you prepared
a table which is before the Committee, table 2, which sets out
to identify some objectives relevant to your thinking about that
ticket hall? [10]10
(Mr Chapman) Yes. Table 2 shows the basic design
criteria that we used for the ticket hall.
1544. For the record its heading is functional
capacity required from the new eastern ticket hall serving Crossrail
Liverpool Street Station.
(Mr Chapman) The numbers are derived from the
14,500 people who are exiting Crossrail. I cannot remember the
exact numbers, I think it is about two or three thousand people
who are entering and factored up by the 35 per cent factor that
has been discussed so far. The 25,000 people is intended to be
the SDG predicted capacity plus 35 per cent.
1545. Is there anything in table 2 that you
would want particularly to draw to the Committee's attention?
(Mr Chapman) I think they have had enough numbers
for today.
1546. Very good. I asked Mr Bennett to put up
on the screen a moment ago figure 3, I wonder if you would be
good enough to put up also figure 4, which is the other figure
relevant to the Ove Arup option 1 scheme that you want to draw
attention to.
(Mr Chapman) Can I just make one or two more
points on figure 3 please?
1547. Please do. If you go back to figure 3.
(Mr Chapman) There has been discussion about
three or four escalators, I imagine that is something which either
the Committee will direct or which will be agreed in time between
the two sides. I would just like to make the point that the number
of escalators from platform level to this point here which is
point J is a separate issue, I believe, to the ticket hall issue
because there will be predictions about the number of people who
will go from Crossrail to street and at some stage there will
be an agreement or a direction as to what the right number should
be. There are two elements, one is bringing them from the platform
to street, and that is a function of escalators, the second is
how you process them and get them out of the station which is
a ticket hall issue. The Arup scheme, if the direction is that
flows are sufficiently low to accommodate three escalators' worth
of people then that could be three or four escalators, but I think
there are two separate questions and it is worthwhile just disaggregating
them from the Committee's mind if that is acceptable.
1548. Would you be happy, Mr Chapman, if Mr
Bennett puts up figure 4 now?[11]11
(Mr Chapman) Yes.
1549. For the record, what that is is a figure
headed "Suggested Alternative Lay-Out Section along Eldon
Street with Crossrail scheme dashed".
(Mr Chapman) That is correct.
1550. What do we get from this figure?
(Mr Chapman) This basically is a section, as
you have said, along Blomfield Street, which takes you from platform
level up to street level. At the right hand side of the figure
we have the canopy which is the street level manifestation of
the station. It is a bit like the new station at King's Cross
or the various stations on the Paris Underground where you have
a direct discharge to street not through a building, as people
more commonly expect on the London Underground. It feeds down
under Blomfield Street to a ticket hall facility that we saw on
figure 3 and then comes from that level downwards by two flights
of escalators down to platform level. We have had some initial
discussions with the Promoter about these issues. They are concerned,
as are we, about the proximity of the escalator to the Metropolitan
Line because we are tunnelling underneath an existing London Underground
line. That is causing a lot of attention.
1551. Take that slowly, if you would, because
potentially it is of considerable importance, if not to the Committee's
deliberations at this stage, to its potential future deliberations
as to which is the best option if the Petitioners satisfy the
Committee on their demand case. Say something more about the suggested
disadvantage of your option 1 please?
(Mr Chapman) The main disadvantage of option
1 is that Crossrail—this is probably easier having seen
the model—took the passageway between the Post Office Railway
and the Metropolitan line as a flat passageway with a reasonable
clearance below the Metropolitan Line, about seven metres.
1552. Crossrail was able to do that because
the CLRL scheme does not require that you get to shallow level
until you get somewhere about half way along Liverpool Street
whereas your scheme requires that you get to shallow level rather
sooner, does it not?
(Mr Chapman) That is absolutely correct, Mr
Laurence.
1553. No problem then with the CLRL Promoters'
scheme. What do you say about the problem that has been floated
in relation to your scheme on this particular point?
(Mr Chapman) The main issue is that you have
to fit the escalators between two existing tunnels. The Metropolitan
Line is obviously the most important of those tunnels because
it is a fully functioning railway. There are a number of issues
with that: making sure the trains do not derail, which is obviously
fundamental to the safety of any railway, so any work that would
need to be done under the Metropolitan Line would need to be done
with great care. We have shown our drawings to the Promoters.
The Promoters engaged Mott MacDonald to look at them and make
comments on them. I believe Mott MacDonald show the distance on
the Metropolitan Line to the crown of our tunnels to be about
two metres. We had a number slightly bigger than that, we had
about four metres clearance between the two sets of tunnels. It
does not really matter the fact that we disagree slightly. The
Promoters' figures are based on more accurate information than
we have available to us because we do not have their information.
In principle, two metres to four metres, in either case it needs
to be done with extreme care. It is not something that any engineer
would dismiss lightly but in both cases it needs to be done incredibly
carefully.
1554. Mr Bennett is kindly zooming in on the
particular area that we are talking about. This is the bit that
interests me. What does an engineer say when he is told that it
is going to be difficult to create a bank of escalators under
an existing railway line, difficult if not impossible if you have
four banks of escalators rather than three? What do you say?
(Mr Chapman) I would say it is difficult but
not impossible. The reference to impossible came from Mott MacDonald's
report which we were given on 23 December. That was very helpful
in many regards. The information that was not available to Mott
MacDonald was Mr Weiss's agreement which we discussed with him
previously, that if needed his corporation would be prepared to
consider closing the Metropolitan Line for a short period of time
to allow this very critical piece of infrastructure to be built,
taking a long term view.
1555. You probably were not in the room when
Ms Lieven was cross-examining Mr Weiss about this. I was looking
for the reference but could not find it on day four. She put to
him that there would have to be a period, possibly running into
months, during which the Metropolitan Line would have to be closed
or at any event there would have to be speed restrictions while
the work was being done. He cited the example of the Waterloo
and City Line having to be closed for five months, from recollection.
(Mr Chapman) Ironically this morning I came
here via Green Park Station and on the barriers coming out there
was a weekend closure of the Metropolitan, Circle and City Line
between Baker Street and Liverpool Street, so it does happen.
1556. Mr Cameron reminds me that it was at paragraph
852 on day four when Ms Lieven was putting to Mr Weiss on instructions
that with your scheme, Mr Chapman, it would be very likely to
lead to a closure of the Metropolitan and Circle Lines for a period
of weeks, if not months, probably something in the region of two
to three months, and it was highly likely to lead to speed restrictions
on the Metropolitan and Circle Lines for a large number of weeks
thereafter, in the region of 14 weeks. It was in response to that
question that Mr Weiss said he would like to comment and did so
by reference to the proposed closure of the Waterloo and City
Line which he said would be closed for improvement for a period
of five months. What about whether it is precedented to do something
as tricky as this? Has it been done before?
(Mr Chapman) Yes. I travelled here yesterday
via Westminster Station. At Westminster, you have a major box,
a deep excavation for the Jubilee Line that goes underneath the
District Line. In that particular location the District Line was
temporarily closed. A bridge was built over the area and the entire
ground underneath was completely undermined. The District Line
now runs over the hole that was underneath. That was done as a
huge excavation, not by a tunnel. By reference to those figures,
I believe track level on the Metropolitan Line, using the Promoters'
figures is about +106.6 or about +6.6 metres ordnance datum to
the rest of the world. At that level there are two boreholes the
Promoters put down in the street which I was involved in doing
in 1992. They show the London clay level at about that level,
so we are tunnelling about two to three metres below the top of
the London clay. It is good tunnelling material to tunnel through
which helps stability.
1557. Mr Binley: Might I ask the percentage
difference between the prices of the two exercises?
(Mr Chapman) Do you mean option one to option
six?
1558. Yes.
(Mr Chapman) I do not have access to the Promoters'
figures. I believe a couple of days ago the Promoters' price option
one was mentioned to be 40 to 80 million. I had some pricing done
of the two options but at the moment I would caveat the figures
very, very heavily because there are a lot of unknowns, things
that nobody knows yet and things that we do not know yet that
the Promoters know. My guess for option one was about 52 million
and my guess for option six was about 70 million.
1559. Mr Binley: As a politician, I am
very aware of spending money.
10 Committee Ref: A20, Functional capacity required
from new eastern ticket hall (SCN-20060126-007). Back
11
Committee Ref: A20, Suggested Alternative Layout-Section along
Eldon Street with Crossrail Scheme (dashed) (LONDLB-EXH03-006). Back
| 
