Examination of Witnesses (Questions 9420
- 9439)
9420. Sir, with your permission I shall be calling
three witnesses who will each give short evidence. Mr Owen Whalley,
who is Head of Major Project Development at Tower Hamlets. He
will provide a short overview of the Council's case. Next is Dr
Keith Bowers, who is the Associate Director of Arup, which I have
mentioned already. He will deal with aspects of the GOMMMS analysis
at Hanbury Street. Finally, we have Stephen Turner, who is a noise
consultant. He will also give short evidence about aspects of
that GOMMMS analysis.
9421. With your permission, I propose to ask
all three to introduce themselves at the beginning and deal with
the Hanbury Street issue first. I suggest a convenient course
would be for all three of them to give their evidence in chief
before any cross-examination so that the Council's case is clear
before questioning.
9422. Sir, can I finally make good promise to
read onto the record the form of words which the parties have
agreed to this morning to deal with local labour and business
promotion issues.
9423. That form of words is that the Promoter
will continue discussions with the London Borough of Tower Hamlets
and the London Borough of Newham on local labour and business
opportunity provisions using terms agreed for the Docklands Light
Railway and the East London Line Agreements as the basis for discussion.
9424. Sir, I will now call Mr Whalley, Dr Bowers
and Mr Turner.
Mr Owen Whalley, Dr Keith Bowers
and Mr Stephen Turner, Sworn
Examined by Mr Drabble
9425. Mr Whalley, can I ask you to introduce
yourself formally. I think in the proof you have in front of you,
you set out your position and your qualifications. Perhaps you
can tell the Committee what that is.
(Mr Whalley) I am Owen, Colin
Whalley. I am the Head of Major Project Development within the
Directorate of Development and Renewal at the London Borough of
Tower Hamlets. I am presenting this evidence on behalf of the
Borough. I hold a degree in Town and Country Planning, and I am
a member of the Royal Town Planning Institute. I have been working
in town planning for some 28 years, with my experience being based
exclusively in inner city London. I have worked across a wide
range of town planning issues, including development control,
forward planning and policy formulation, as well as project implementation.
I have worked on behalf of Tower Hamlets on the Docklands Light
Railway (Lewisham) Act, both in its passage through Parliament
and subsequently on its implementation. I have led the Council's
team, which responded on behalf of the borough to the Docklands
Light Railway, through Three Car Enhancement Transport and Works
Act Order, and I am currently liaising with the Transport for
London East London Line Extension Team.
9426. Dr Bowers, can you again introduce yourself?
You are an Associate Director of Arup. You have been advising
the London Borough of Tower Hamlets on geological and engineering
matters and are presenting your evidence on behalf of the borough.
(Dr Bowers) My name is Keith, Henry Bowers,
as described.
9427. You have various qualifications in geology,
but I do not think we need to read them. You have got a PhD, amongst
other things, for work on sprayed concrete tunnelling.
9428. Chairman: That is very helpful!
9429. Mr Drabble: Can you give us a flavour
of your experience in tunnelling issues in London.
(Dr Bowers) I have been working in tunnel design,
construction and also transport tunnel operations for about 17
years. In that time I have worked for both Government and industry
at different times. I am currently the tunnel design manager for
London Underground's King's Cross Station upgrade and immediately
prior to that for a period of some five years. I was a principal
engineer on the Channel Tunnel rail-link, working on the project's
tunnels through London and the Thameslink 2000 tunnels.
9430. Mr Turner, you are Stephen Turner and
you are the Director of Acoustics with Bureau Veritas, again presenting
evidence on behalf of the borough.
(Mr Turner) That is correct, yes.
9431. Once again, you have got various qualifications
from the field of your expertise, namely noise. Amongst other
things, you Vice-President and a fellow of the Institute of Acoustics
and Chairman of the working party established by that institute
and the Institute of Environmental Management which is developing
guidelines on noise impact assessment.
(Mr Turner) That is correct, yes.
9432. Can you give a flavour to the Committee
of your experience with construction projects of this sort?
(Mr Turner) I have worked on many environmental
noise projects, including the effects of noise from rail transport
and construction sites. In particular, I have worked on many projects
in the London Borough of Tower Hamlets, including the Docklands
Highways and Canary Wharf. I have also been providing technical
advice to the noise and nuisance team at the Department for Environment,
Food and Rural Affairs since 1999 on a wide range of environmental
noise issues. I was commissioned by London Borough Tower Hamlets
and some other clients regarding the impact of Crossrail since
January 2005.
9433. Mr Whalley, can we start with your proof.
First of all, I think you are going to tell us what the scope
of your evidence is and what you are intending to cover.[4]
9434. Chairman: For the record, Mr Drabble,
can we read in that this is document A110.
(Mr Whalley) My evidence focuses
on the impact of the proposal on the borough as a whole. In light
of the discussions which have occurred over recent hours, I want
to cover two main things. One is the strategic importance of Crossrail
to the borough, and secondly the remaining concerns and objections
which the borough have. Here I want to deal with the mitigation
on the construction impact on the borough and finally a map summary
of matters we have agreed. In giving my evidence I will draw attention,
as appropriate, to the Council's response to the Promoter's formal
response. Looking at the context first, strategically the Council
strongly supports Crossrail because of the economic and transport
benefits it will bring to the borough. This is different from
the situation in 1990 when the Council also Petitioned against
the then Crossrail Bill. That was because the 1990 proposals did
not include stations at Whitechapel or the Isle of Dogs, which
meant that the borough would suffer the construction impacts but
receive none of the long-term benefits. Before coming to the detail
of my evidence, I think it is important for the Select Committee
to have a broader understanding of the character of Tower Hamlets.[5]
In many people's minds when Tower Hamlets is mentioned they will
either think of Canary Wharf and the Isle of Dogs with its multi-national
corporations occupying some of the tallest office blocks in London,
or perhaps luxury residential apartments overlooking the river.
In other words, there is a perception that Tower Hamlets is seen
as a fairly prosperous area. While in some respects this is true,
the borough also manifests great diversity, not just culturally
but also economically. In national terms, the borough has one
of the highest levels of deprivation in the country. Locally,
70 per cent of the wards in the borough, including many of those
through which Crossrail will run, are among the one per cent most
deprived wards in England. Unemployment is 9 per cent compared
with the inner London average of 6 per cent. Unemployment levels
amongst black and minority ethnic communities are three times
higher than in the white community. According to the 2001 Census,
unemployment amongst black and ethnic minority communities was
22 per cent compared with 7.2 per cent amongst white communities.
These unemployment levels exist, notwithstanding the fact that
there are over 150,000 jobs in the borough. With regard to business
structure, the pace of growth in the borough has not been confined
to the increase in large companies. There are now estimated to
be some 10,500 businesses in the borough. Encouraging small and
medium-sized enterprises to take advantage of large-scale investment
is a key priority of the Council. In terms of the project as a
whole, the Council welcomes the many changes that have been made
to the project since the Bill was first published. These changes
show positive benefits that can arise from pro-active negotiation
and discussion. Clearly the Promoter's acceptance for the Council's
end-to-end tunnelling strategy has been the most significant change.
The Council also welcomes the other important revisions to the
Bill which were anticipated, including the revised proposals for
the Eleanor Street travellers' site, changes to the Whitechapel
Station and the positive negotiations that are now taking place
on hours of working, noise and re-housing policy. The promoter's
formal response to the Council's Petition has also provided helpful
clarification and assurances on a number of issues raised in the
original Petition. I can now turn to the remaining objections
and concerns that the borough has. As Mr Drabble said in his introductory
remarks, the Council's original position included 35 specific
objections to various aspects of the Crossrail proposal. The most
important being the Crossrail tunnelling strategy which originally
proposed the tunnel site in Spitalfields. Since the Bill was first
published in February 2005, through a process of negotiation and
discussion, we have resolved all but two of our original objections.
These relate to the location of the intervention shafts in Spitalfields
and finally the issue which Mr Drabble has outlined with regard
to Whitechapel Station. Perhaps I can deal with each of these
in turn. Can we have slide 4, please.[6]
Firstly, I would like to strongly welcome the acceptance by the
Promoter of the Council's case for the end-to-end tunnelling strategy.
As a result of this major change in strategy, the Council accepts
that the adverse construction impacts of a Spitalfields shaft
will now be significantly less than was the case when it was proposed
as a tunnelling site. Nevertheless, the even more limited construction
impacts of an intervention and ventilation shaft will still cause
concerns in such a very congested and built up area. Slide five
please.[7]
Ideally, the Council would prefer there to be
no intervention shaft anywhere in the Spitalfields area. I and
the Council's consultants consider that both engineering, technology
and railway safety regulations are developing all the time, and
that there remains a prospect that with working with the Promoter's
engineers it may be possible to obviate the need for any such
shaft. The Council accepts that the requirements of an adequate
safety and ventilation strategy are predominant, but it does not
accept that it is inevitable that any such strategy—which
will inevitably have to be kept under review as the project progresses—will
require the construction of ventilation shafts at the currently
proposed intervals when the railway is built.
The Council has sought and obtained assurances
from the Promoter that it will carry out this work which the Council
hopes will achieve the objective of avoiding any form of intervention
shaft in Spitalfields area. If once this further work has been
completed it still proves necessary to construct a shaft in Spitalfields,
the Council has requested that the Promoter should investigate
further the possibility of reducing the scale of the shaft in
Spitalfields, for example, by not providing forced ventilation
equipment at that site. The exact function of the shaft may affect
the site requirements, so the Council considers that no final
decision on the location of the shaft in Spitalfields should be
made before this work is completed. The Council has received undertakings
that the Promoter will carry out these further investigations.
Slide six, please.[8]
I now turn to the issue of the site location of the intervention
shaft in the Spitalfields area. Following the announcement by
the Secretary of State for Transport on 30 March that the Crossrail
tunnelling strategy would be revised to avoid launching tunnel
boring machines from this part of Tower Hamlets, it is understood
that Crossrail have been revising the works required in this area.
Chairman, if you see the two sites outlined in red, the lower
of the two is the Hanbury Street shaft area and the rectangular
site is the Woodseer Street option.
9435. Before we move on, have you any comment
on the relationship between the Hanbury Street site and residential
property as compared with Woodseer Street?
(Mr Whalley) I think, Mr Drabble,
if we move to the next slide, I can show that perhaps more helpfully.[9]
Again this is effectively the same slide, but with the land uses
and you can see that the brown areas are housing and, as you can
see, the southern site, Hanbury Street, there is housing to the
west and housing to the south-east. What you do not see on this
slide is this area in Princelet Street which is commercial premises
on the ground floor with residential accommodation above, so the
rear windows of those flats would look over the Hanbury Street
worksite. It is clear that the scale of the construction works
required would be reduced from the original proposals. Furthermore,
it is understood that were the Hanbury Street location to be kept
for the shaft, there would no longer be the need to demolish Britannia
House and Britannia House is the building there, which was in
the original proposal as part of the worksite. The use of the
Woodseer Street site located north of Woodseer Street and close
to its junction with Spital Street has been a suggested alternative
for the shaft location in this area for some time, even before
the tunnelling strategy was revised. Now with this revised proposal,
the Council is keen to see that this alternative is explored thoroughly
to ensure that the chosen option provides the optimum solution.
On 16 May this year Crossrail provided an initial comparative
assessment between using Hanbury Street or Woodseer Street. For
the latter, there were two options concerning route alignment,
either avoiding the Bishops Square development, which is Woodseer
Option 1, or passing under it or close to it, which is Woodseer
Option 2. The Council accept that the Woodseer Option 1 is not
appropriate, so I am going to concentrate on the Hanbury Street
and Woodseer 2 Options. Further documents were subsequently received
from Crossrail on 1 June and these describe in more detail the
type of works that would be involved and also provided further
information regarding the comparative study. The comparative process
adopted by Crossrail is known as the "Guidance on the methodology
for multi-modal studies", otherwise known as "GOMMMS".
This will be discussed in more detail by my colleagues Dr Bowers
and Mr Turner. The Council's general concern about this process
is that it has given too much weight to geological and engineering
issues and insufficient weight to the site-specific impacts. In
particular, no detailed assessment has been undertaken of the
noise and vibration impacts of the two options. The Council's
general conclusion is that it is possible that, with more detailed
information, the GOMMMS analysis could give rise to a different
outcome. Without this information, the Council considers that
the case for Hanbury Street over Woodseer Street is not proven
and that a decision should be deferred until sufficient evidence
has indeed been provided. Thank you, Chairman.
9436. You are handing over now to Dr Bowers.
The slide which has just come up is more within Dr Bowers' province,
I think, than yours.[10]
Dr Bowers, could you first of all tell us very shortly what the
scope of your evidence is going to be?
(Dr Bowers) My evidence focuses
on the issues arising from the GOMMMS analysis that has just been
described and I shall concentrate only on the comparison between
the base case, the Hybrid Bill scheme, and the Woodseer Street
Option 2. As we have already heard, we accept that Option 1 is
not appropriate. The GOMMMS analysis finds in favour of Hanbury
Street. However, our consideration with the scoring information
presented to us shows that this conclusion is substantially attributable
to two factors. These factors are both areas where the Borough
does not feel it has received sufficient information to be fully
satisfied that the conclusions are robust. What I shall do is
highlight the additional information that will be needed for the
Borough to be satisfied that the analysis is robust.
9437. First of all, I think you are going to
deal with the Bishops Square issue. Is that right?
(Dr Bowers) Certainly. I should say that the
two areas of concern are essentially Bishops Square and ground
conditions and I shall address Bishops Square first. Bishops Square
is a large building development on piles. In the Hybrid Bill scheme
the building is just offset from the Hybrid Bill scheme tunnels
and the lower pair of lines on that slide represent the Hybrid
Bill alignment and it clears the footprint of Bishops Square.
In the Option 2 alignment, which is also shown on the image here,
the two tunnels are displaced a little to the north and it can
be seen immediately that one of the tunnels passes under the footprint
of the Bishops Square building. The Option 2 alignment was developed
following requests from the Borough to demonstrate possible alignments
that pass through the Woodseer Street site and to establish what
issues, if any, they gave rise to. This was an iterative process
and in fact a number of variations were considered before we got
to this stage. The important point is that the Option 2 alignment
is not the only alignment which passes through the Woodseer Street
shaft; others are possible. As it is apparent that moving a tunnel
under Bishops Square is a significant concern to the Promoter,
my suggestion would be that it would be appropriate to further
consider additional iterations on this alignment and, in particular,
I would suggest that there is a fairly small amendment to Option
2 which would move the tunnel away from Bishops Square. Such an
alignment would be achieved at this end, which is Whitechapel
Station, and you will see that in Option 2 we swing a little to
the north as we come out of Whitechapel Station. That horizontal
curvature there is not down to the minimum desirable radius. It
would be possible for that curve to be a little tighter to take
the railway a little further to the north. In doing that, the
angle of attack, if you like, at Woodseer Street shaft would be
slightly different and, therefore, the route down between Woodseer
Street and Liverpool Street would be slightly different with a
different and, we believe, improved relationship with Bishops
Square. That is an iteration we would like to see. Even in the
event that such a change of alignment will not be possible, it
does not actually follow that the arrangement under Bishops Square
is not achievable. If we go to the next slide, this is a figure
we received on 5 June and it illustrates the arrangement with
the Option 2 tunnel under Bishops Square.[11]
It is a cross-section. We have the lower part of the building
shown, the foundations of the building, which are an extensive
array of piles illustrated here, and the running tunnels in Option
2 are shown. Clearly this tunnel is away from the building and
the other one comes under the foundations. It is apparent, however,
from an inspection of this figure that there are several metres'
clearance available between any of the foundations and the tunnel.
The desire of Cross London Rail Links to minimise the interface
between the two in terms of both settlement and noise is entirely
understandable. Nonetheless, this arrangement is such that both
construction and noise mitigation would clearly be possible using
well-established tunnelling and railway noise mitigation technologies.
This arrangement is well within the bounds of past construction
experience on other tunnelling schemes. I will now turn to the
second recurrent theme in the GOMMMS analysis, recurrent in the
sense that it influences heavily the scoring in favour of Hanbury
Street. This is the significance of the ground conditions. Cross
London Rail Links have argued that the Woodseer Street alignment
needs to be relatively deep to minimise the risk of meeting foundations
or being in close proximity to foundations. This in turn leads
to the shaft bottom being located in the top of the Lambeth group
strata rather than slightly higher just into the London clay,
as would be the case at Hanbury Street, and perhaps I can just
draw your attention in the figure to the geological section on
the side. It is London clay, then Lambeth group underneath and
we are talking about works in this interface area between the
two. This movement of the shaft slightly deeper into the Lambeth
group is presented as a problem in terms of ground movement, constructability
and safety, but the issues are not explained in detail. I agree
that in general the risk of difficulty with the ground conditions
and most particularly groundwater increases as excavations drop
into the Lambeth group. However, it is not a simple transition
as it is also a function of local geological variation. There
have been experiences of problems with groundwater pressure from
the London clay being encountered in shafts several metres above
the base of the London clay, so water pressures which exist in
this area have had an influence on construction up in this area.
9438. Kelvin Hopkins: Can you tell me
precisely what the Lambeth group strata means, what does it do?
(Dr Bowers) Certainly. In summary
terms, the London clay is a relatively homogenous clay material.
The Lambeth group is a geological term which actually covers quite
a number of different units and there is quite a lot of variability
across London, so local variability is a big issue. The group
is characterised by quite a range of different materials. There
are very stiff clays, there are clays quite similar to the London
clay in some places and elsewhere there are sands. The particular
engineering issue that commonly arises is where you have sands
and those sand bodies can contain water and the water can be under
pressure, so you can imagine that if you started to excavate through
the clay and you met water under pressure, you would have a new
set of construction issues to deal with. What I was just saying
is that there is experience of these water issues I have just
been mentioning, albeit based in the sands at this level affecting
construction a little above, hence I will suggest that locally
within these ground conditions there is not a step change in construction
risk as when you meet the line on the drawing. What there is is
a gradational change in risk and it tends to be an increase in
risk as you go deeper down. The Promoter has indicated that the
depth increment for Option 2 is around two metres compared with
the Hybrid Bill scheme. Given the inherent uncertainty of dealing
with the ground and this very small difference in depth, I would
anticipate that ultimately similar and fairly conventional mitigation
measures would be needed for the construction of this shaft. Whether
or not the bottom of the shaft was in the bottom of the London
clay or the top of the Lambeth group, the risks are broadly similar
and they have to be addressed. Therefore, it seems likely that
this issue in itself will not make a substantial difference to
the works that are necessary and it is, therefore, not clear that
it should be a major driver in the selection of the shaft site.
9439. Mr Drabble: Before you get to the
conclusion, can you just say a little bit more about the mitigation
measures that would be required either in the London clay or the
Lambeth group and give us an explanation of why you think a similar
strategy would be adopted in relation to both of those?
(Dr Bowers) There are a number of issues which
arise with excavating different types of material, should you
encounter them, and you may need slightly different equipment.
The water issue is, I believe, the dominant concern here because
it has an effect on the stability of the ground and the excavation.
The course of action to address that is fairly well established
as this is not an unusual problem and there are a good many excavations
through these materials. Clearly the first stage in mitigating
the risk is site investigation and exploratory bore holes to establish
what materials are there. Those will be of great assistance, but
will not remove all uncertainty. In the event that the ground
investigation or indeed the subsequent excavation does establish
that there are water-bearing bodies there and that the water is
under pressure, the usual solution would be to use bore holes
down into those water-bearing bodies as effectively wells. You
would be able to extract water, but in fact you would not need
to extract a great quantity of water, but through a relatively
small bore hole what you can do is extract sufficient water to
bleed off the excess pressure. Now, if that is done slowly over
a considerable period of time in a planned fashion, so effectively
advanced works prior to the main shaft sinking, it should be possible
very largely to mitigate the risks through that sort of process.
4 Committee Ref: A110, London Crossrail-London Borough
of Tower Hamlets (TOWHLB-21805B-003). Back
5
Committee Ref: A110, Remaining Objections and Concerns (TOWHLB-21805B-004). Back
6
Committee Ref: A110, Spitalfields Area (TOWHLB-21805B-005). Back
7
Committee Ref: A110, Crossrail-Impact of Proposed Worksites
in the Spitalfields Area (Aerial View) (TOWHLB-21805B-006). Back
8
Committee Ref: A110, Crossrail-Impact of Proposed Worksites
in the Spitalfields Area (TOWHLB-21805B-007). Back
9
Committee Ref: A110, Crossrail Central Tunnels-Woodseer Street
Shaft Alignment Option 2 (TOWHLB-21805B-008). Back
10
Committee Ref: A110, Bishops Square Development-Option 2 Section
A-A (TOWHLB-21805B-009). Back
11
Committee Ref: A110, Qualitative Comment on Noise and Vibration
(TOWHLB-21805B-010). Back
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