KENILWORTH, BURTON GREEN, BERKSWELL AND
BALSALL COMMON TUNNEL PROPOSAL:
MITIGATION ARGUMENT
COMPILED BY BURTON GREEN ACTION GROUP
MARCH 2012
1
TUNNEL MITIGATION KENILWORTH, BURTON GREEN, BERKSWELL
& BALSALL COMMON
The proposed London to Birmingham High Speed Rail 2 link once
completed will, in its present guise, leave a scar up to 100m wide and tens
of metres deep across the Warwickshire countryside on its way to
Birmingham and beyond: During construction that width could possibly
more than double to encompass the haulage roads and other service,
construction and assembly areas necessary for the construction of the
track: Its potential for blight and damage to the countryside is immense –
no matter what form the final construction takes.
The environs of Kenilworth, Burton Green, Berkswell and Balsall Common
will be particularly badly affected suffering both constructional and
operational blight for many years to come. Construction blight alone with
its attendant noise, visual and physical disruptions, dirt, mud and huge
traffic disruptions, diversions, possible physical damage to homes and
road surfaces [and with no chance of redress for any of these before
2027 at the earliest], is daunting enough. Many businesses will suffer
continuing blight and the threat to people’s livelihoods is very real,
whether they be landlord or tenant, employer or employee, land owner or
tenant farmer.
In the environs of Kenilworth the route as planned will cause irreparable
damage to ancient woodlands, businesses, farmlands and dwellings.
Burton Green, a village of totalling some 400 dwellings and outlying farms,
will be bisected by the line and will suffer extensive blight during both
the construction and operational phases. The local school will be badly
affected by operational blight, as will many houses all within 100m of the
proposed track: Additionally, as many as 20 dwellings. 6 Alms houses and
the village Hall could face compulsory purchase and or demolition to make
way for the track. The whole village, and its environs, will suffer months
of traffic diversions, construction traffic pollution and dirt, and general
disruptions during the construction phase. There will also be the total
loss of woodland, farmland, and recreational amenities, footpaths and
bridal ways. Severely affected are farms adjacent to the Greenway, they
are faced with land loss, loss of revenue severe financial hardship and
loss of home and livelihood.
2
Similarly Berkswell and neighbouring Balsall Common will suffer extremes
of blight disproportional to any supposed benefit of the line. In Berkswell
alone 33 listed buildings will suffer severe blight, SINC’s and SSSIs,
essential recreational amenities, footpaths and bridal ways and leisure
sites along with several farms will be destroyed or blighted and
businesses and homes will also be badly affected by both constructional
and/or operational blight. Many of the business will not survive and this
will almost certainly affect the employment prospects in the area.
The proposal therefore is that where the line passes through our local
environs the viability of it going via a tunnel as opposed to the proposed
mixture of deep cuttings – both open and closed – should be considered
by HS2 as an alternative to the present scheme and in so doing obviate or
at least relieve much of the blight that it will cause.
Many factors have to be considered before this proposal is promulgated,
and the following questions and their answers must be explored to the
fullest extent if we are to formulate a convincing argument on which to
base our mitigation.
Suggested questions are:
1. Is a tunnel a feasible option?
2. Why do we want a tunnel – what is the need?
3. What are the impacts, on both the land and the affected
communities, of having a tunnel, versus the impacts of the current
proposals?
4. What is the most advantageous route and is it practical?
5. How much will this cost?
[1] FEASIBILITY
i.
High Speed Rail 2’s own 2010 survey document1 Optimisation
of Route 3 would suggest that it is.
ii.
3 tunnel options were looked at by ARUP– two were
discounted but a 7km option starting 1.5kM to the east of
Burton Green, [approx CP 144+00], and finishing at a point
1.5kM to the North of Berkswell [approx CP 150+00] was
said to be a realistic option which met the 400kph design
speed requirements.
1
High Speed Rail Two – Optimisation of Route 3: ARUP 2010 p.9
3
iii.
iv.
v.
vi.
Philip Hammond however, ignored this option and failed to
mention the 7km tunnel at all in a subsequent letter to
Caroline Spelman MP and dismissed the whole idea.
The ARUP report went on to say that2 “that there is no clear
engineering answer in this area but ALL options would meet
the 400kph design speed requirement. More detailed
exploration of the mitigation design opportunities in the
Burton Green area is needed.
It is proposed that the course of action considered above
be taken by DfT and further that the tunnel option could in
fact be enhanced and lengthened in order to reduce the
blight/impacts still further.
It is appreciated that there are several cost centres that
will impact on the final cost these being: length of tunnel,
construction type, additional infrastructure requirements,
topography and condition of soil, water tables, flood plain
crossing and fault lines.
[2] PROPOSED BENEFITS TO THE COMMUNITY OF A TUNNEL:
Basically, a tunnel - once in operation - would effectively:i.
Reduce the disruption to village and urban areas, and lessen the
impact of the trains on people’s lives, visually, environmentally and
physically[through noise, light and visual impact reduction etc]
ii.
It would lessen the land take of important agricultural land,
greenbelt and amenity/recreational land along the route.
iii.
Would reduce the amount of Treasury monies required for
compensation, noise mitigation measures, compulsory purchases
and extra land take for trackside infrastructure [fencing, secure
areas etc.]
iv. Environmentally it will lessen the impact on vital natural habitats
and breeding grounds.
v. Hopefully it will lessen the environmental impacts both during the
construction phase as well as its operational phases.
vi. Would lessen the engineering requirements by obviating the need
for major infrastructure construction, [deep cuttings, retaining
walls, overhead bridges, road diversions both temporary and
permanent and pathway/right o`f way restorations.
2
Ibid ARUP report p.9
4
vii.
viii.
ix.
x.
Would hopefully reduce antagonism to line from local population.
There would be less disruption to village/town social and work
patterns [particularly important to local schools]. Would enable
better traffic management and lessen road disruption to busy
commuter routes, and could lessen risk to children – particularly
primary school ages.
Would lessen the risk/destruction to/of ancient and other
woodlands.
Reduce construction noise and pollution nuisance during
construction and more importantly once in operation.
[3.] DETAILED OVERVIEW OF IMPACTS? ADVANTAGES:
3.1. STONELEIGH – KENILWORTH
[Separate report being carried out]
3.2. KENILWORTH – BURTON GREEN
Chainage Point [CP] 142+500 – 142+800 [Note: CP 142 =500 – 142+650
proposed new HS2 culvert].
Reduced agricultural land take initially – however dependant upon start
point of tunnel[possibly at 142+700 between the 60 and 70m contour
lines] extra land take [1.214 – 2.023 hectares approx.(3-5 acres)] will
be required for lay apart/construction area at entrance area. Reduced
operational visual impact along route as overland power cables,
gantries etc and security fencing requirement will be lessened.
Reduced operational noise impact as noise from pantograph pick-up is
obviated. However construction will cause aggravated
road/construction nuisance particularly on A429 and houses in
Crackley Crescent and new build houses on edge of Gibbet Hill
development. A tunnel entrance here could possibly increase the
“startle effect/noise” of trains emerging from the tunnel without
some mitigation measures being taken.
CP 142+800 – 144+00
Agricultural land take reduced – again less operational visual and noise
impact on area. Woodland destruction in part of Birches Wood and
Roughknowles Wood could be obviated. Tunnel could also dispense with
possible compulsory acquisition of all or part of Birches Wood Farm.
Also obviates need to divert Crackley Wood Road over HS2 [CP
143+800 – 144+00] saves footpath diversion [CP 142+900] and Bridle
paths [143+700]
5
CP 144+00 – 144+500
Tunnel reduces operational noise and visual impacts on dwellings
[Gooseberry Hall, Meadow Bank & Mellow Dew and others]: saves
further agricultural land and Lark Wood.
CP 144+500 – 145+100
Saves partial destruction of Broadwells Wood, thus maintaining vital
habitats and ancient woodland flora and fauna:
Tunnelling reduces operational noise and visual impact on
approximately 35 dwellings and commercial properties [Red Lane
Chicken farm and Le Van static mobile homes], on Red Lane.
CP 145+100 – 146+00
Greatly reduced operational noise and visual impact and
construction/operational blight on a further 16 dwellings along Red
Lane and Bockendon Grange farm and the Moat: further reduction of
agricultural land take.
CP 146+00 -147+200
Tunnelling would save the construction of a new temporary road link
between Hodgetts Lane and Hob Lane: would cancel the need for
construction of new road bridge over HS2 at Cromwell Lane, and thus
also reduce lengthy traffic disruption on busy commuter routes along
Hob, Cromwell and Hodgetts Lanes during the construction phase: This
would also lessen the accident risk to children attending BG primary
school during this time.
Tunnelling would stop majority of noise and visual impact on Burton
Green village, particularly in the area of the school. Noise is known to
have a negative impact on children’s learning abilities and their health.
[See studies by: AR.McKenzie et al3; Bertollinni4; European Airports5
and Evans. GW6:]
This is an important factor given the proposed operational speeds,
[360kmph], frequency of trains [14tph] and operating schedule [18
3
AR Mckenzie,AJ Bullimore,IH Flindell The effects of wind speed and direction on
ambient and background noise levels in the suburban environment Inst of Acoustics Vol
24 pr3 2002
4
Roberto Bertollinni, World Health Organisation Study – Health and the Environment
5
Environmental Studies at Munich, Schipol and Arlanda [Sweden] Airports.
6
Professor GW Evans of Cornell University has found that children lack puzzle solving
skills [learned helplessness] when placed in a noisy environment whilst learning.
6
hours per day]. It is also necessary to factor in the proposed
maintenance hours, these being between 0001 – 0500 Monday to
Saturday and 0001 – 0530 Sunday, which compounds the noise effect
on young children.
Further, tunnelling would save the possible compulsory purchase
and/or destruction of 8 dwelling houses and 6 Alms Houses in
Cromwell Lane and 12 dwellings in Hodgetts Lane and the loss of the
village hall in Hodgetts Lane, and would greatly reduce the severe
operational and construction blights on the other dwelling houses in
Hodgetts Lane and adjacent properties in Cromwell Lane, all of whom
are well within 75m – 100m of the proposed route.
Tunnelling would also save destruction of the Greenway its woodland
mixture of Oak, Birch, Hornbeam and other timbers, flora, fauna and
natural habitats, all of which will be destroyed and not replaced under
the present scheme, thus losing a vital community amenity. It would
also stop the partial destruction of areas of woodland in Black Waste
and Little Poors woods and adjacent paddock land [146+100 &
146+700]
The need for a new 1020m retaining structure is done away with [CP
146+700 – 147+720] thus reducing construction blight issues from
Hodgetts Lane and Waste Lane areas. Will also ease severe traffic
disruptions through construction and spoil removal operations in this
area.
Proposed “green tunnel” [CP 146+180 – 146+700] construction done
away with, therefore much reduced blight both operational and
constructional, on all dwellings along Hodgetts Lane and adjacent
dwellings on Cromwell Lane, also saves re-routing of public footpaths
across the Greenway.
Little Beanit Farm, Oddnaull End and Crabmill farms and up to 10
other dwellings saved from blight and /or compulsory
purchase/possible destruction. All face loss of important revenue
producing land or amenities.
Obviates need for new road bridge crossing HS2 at Waste lane,
therefore stops lengthy traffic diversions and disruptions on busy
commuter route along Waste Lane during construction phase.
Would also cancel the need for WCML overhead crossing by HS2 with
all its attendant delays, diversions and disruptions
3.3. BURTON GREEN – BERKSWELL - MIDDLE BICKENHILL
CP 147+200 – 147+700
7
Tunnelling will reduce damage to flora and fauna in Beanit Spinney
[SINC] and public footpaths, both across and through nature
conservation area and Greenway.
It will reduce noise and health issues to houses along Waste lane to
east and west of route: Reduce the severe financial impact and loss of
livelihood on Little Beanit farm and severe operational and
constructional blight on Crabmill Farm, (listed building), and Little
Beanit and Oddnaull End Farms.
CP 147+700
Public footpaths saved and therefore no requirement for reinstatement/diversion.
CP 148+200
Severe operational noise and visual blights to dwelling within 200m of
line [Beechwood Farm] would be obviated and reduce land take of
valuable agricultural/stock land.
CP 148+300
Noise blight to 6 listed buildings 550m to east of line at Carol Green
obviated, thus reducing future noise mitigation costs.
CP 148+500
Operational and constructional blight, visual and noise affecting
building to east of line obviated, again reducing noise mitigation costs.
CP 148+600
Two public footpath diversions/re-instatements avoided.
CP 148+700 – 149+700
Tunnelling at this area would save major disruption to traffic flows
during construction of WCML Cross over [148+800] it would
immediately remove severe operational and construction phase blights
to Truggist Hill Farm which would be bisected by WCML and HS2 with
HS2 being on elevated track at this point, and so would obviate need
for compulsory purchase and or mitigation costs. Further, it would
remove noise blight and visual impact/blight at residential dwellings,
commercial properties [Carstin’s car dealership, the Railway Inn and
the new Medical Centre], and listed buildings [Ram Hall grade2* and
the Brick Layers Public House] in Station Road, Sunnyside Road,
Spencer’s Lane and the Riddings Hill estate. It would also obviate
8
severe blight to houses within 10m of line o the east along Truggist
Lane, and so would obviate possible compulsory purchase orders on
several properties and future mitigation costs on many others.
It would also save an important leisure amenity [fishing ponds at
149+000 -149+500]
CP 149+900
Severe blight, operational and constructional noise and visual affecting
two listed buildings at Lavender Hill farm with further severe impact
on commercial enterprise and leisure activity/amenities, [all within
500m] at Lavender Hall farm, and two dwelling houses, both within
100m of line would be obviated, thus saving on probable compulsory
purchase and or later mitigation costs.
CP 150+00 – 150+600
Severe Noise and visual operational blight/impact on Berkswell Village
Conservation area [22 listed properties all within 100m of route], also
noise and visual blight /impact on dwellings and commercial
undertakings on A452 including car salesrooms, antique dealership,
public house/hotel and farm shops, would all be obviated by tunnelling
and there is also the attendant saving of treasury costs in possible
compulsory purchases, future mitigation costs.
150+500 Construction costs savings by not closing Park Lane and
therefore no diversions, traffic closures etc.
The loss of amenities [clay shooting facility] and public footpath
closure and re-instatement and all attendant costs would also be
obviated.
Severe blight, visual and noise at all stages of construction and
operation to property in Park Lane would be obviated, this being within
100m would in all probability save compulsory purchase and or future
mitigation costs.
CP 150+700
Destruction of flora and fauna, possible loss of heronry and woodland
[SINC] could be avoided
CP 150+800
Severe noise and visual blight on multi-occupancy dwelling and B&B
business at Berkswell Hall would be obviated – thus saving on future
mitigation costs.
9
CP 151+400
Severe noise and visual impacts on Mercote Farm [already dissected
by A452] again future costs of noise mitigation obviated
CP 151+800
Impact of track route on 16 Acre Wood [SINC] flora and fauna and
SSSI [all within 50m] could be ameliorated.
CP 151+900 – 153+200
Noise blight to farm property, [Park Farm], destruction of public
footpaths, severe blight to Marsh Farm and severe noise and
operational blight to Harebrook Farm plus major road
works/construction and diversions to A452 all obviated or
ameliorated.
[4] TUNNEL ROUTE
In putting forth an argument for a tunnelled option it should be noted
that certain assumptions concerning the theoretical design and
construction have necessarily been made as to the physical
parameters/dimensions of the tunnel. These are to enforce the argument
only and it is fully realised that in the event of a tunnel option being
accepted such constraints/parameters are subject to change. It is also
accepted that for these proposals to have substance, the land owners
affected by them would have to agree to the initial land take – at the
portal entrances etc. and also for use of suitable sites for waste disposal.
There would also need to be local agreement to the proposals.
The assumptions are:
 That the proposed tunnel route will follow the preferred route 3
options as shown on HS2/ARUP documents7 wherever possible.
 That the tunnel will be constructed using suitable TBMs of the
closed type suitable for the terrain, being either an Earth Pressure
Balanced TBM or Slurry TBM.
 Meets the operational design speed criteria for a train speed of
400kmph. Will include forced ventilation and smoke control
measures, wider evacuation route walkways, emergency lighting and
PA systems etc.
 The tunnel construction will be of the Twin bore single track
variation with cross passages and a third central maintenance and
7
HS2-ARUP-00-DR-RW-05023 issue 3 and others:
10





emergency tunnel, primarily base on HS2’s own criteria as laid down
in the advisory note HS2 Tunnel Form 22/07/2010
It is also assumed that the main track tunnels will be in the order
of 10.8m diameter [finished diameter approximately 8.4m] with the
third tunnel being in the order of 5m dia.
It is further assumed that there will be a minimum of 5
ventilation/pressure relief shafts at approx 1.5km intervals, and
that cross passage shafts will be every 250m8 [4m dia shafts.].
There will be a lay apart/construction working area at either end
of the tunnel and that these will cover between 1.2 – 2.2 hectares
each.
That the spoil removed will be a mixture of sandstone and red mud.
[As per HS2 document Optimisation of Route 3].
All Chainage points are directly referenced from and attributable
to ARUP/HS2/DfT documents in particular ARUP-00-DR-RW05022[issue 4] - HS2-ARUP-00-DR-RW-05023[issue 3] HS2ARUP-00-DR-RW-05024[issue3]
From the outset it is appreciated that tunnelling is an expensive and time
consuming option in every phase, from initial survey, through design onto
construction and throughout its operational life. It is further appreciated
that as design track speed is designated as 400kmph that this will in all
probability exacerbate design, development and construction costs still
further; however, with industry sources predict tunnelling costs falling in
real terms by up to 4%p.a.9 it is expected that in 10 years time the cost
will be significantly lower than the projected costs as shown in the ARUP
document on the preferred route optimisation.10
The proposal is that a tunnel could be constructed between points
CP152+400 [drg. no. HS2 –ARUP-00-DR-RW-05024] and CP142+600/700
[HS2-ARUP-00-DR-RW-04223.] and following the preferred route as
designated by DfT.
At point CP152+300/400 the line is planned as starting in a cutting, at
this point given a 1 degree deflection downward [max allowable gradient in
tunnel for electric train], it is thought possible that a tunnel portal at the
8
In line with design features as laid down in HS2 Ltd: High Speed 2: Route Engineering
Report February 2011
9
AA Information Paper: Developing Britain’s Transport System: Going underground –
Tunnels: What role in town and country.
10
HS2 ARUP document: High Speed Two Ltd: High Speed 2: Optimisation of Route 3
11
required 2D depth could be started at or about CP151+500 then carrying
on the down gradient to the 60m contour at or about CP 150+428 This line
could then be maintained on the 60m contour to give the required portal
at 2D depth at or about the point CP 144+000/100 and continue in cutting
[possibly covered] to emerge as per original route at CP 142+700 to form
the Culvert structure over Crackley Brook Flood Plain.
It is thought that if the tunnel was started at the northern end then this
would have the advantage of reducing the traffic density/impact on the
minor roads at the eastern end as the A452 dual carriageway is adjacent
the line of route at this point. Obviously whatever route is chosen traffic
disruptions to what are already heavily used commuter and through
traffic routes will be a major consideration. A further positive is that it
may be possible, [with land owners agreement] that spoil could be used, at
least in some part, as landfill at the gravel extraction site and possibly in
ground works in any proposed infrastructure construction along the line
to the Interchange area. Further, it is thought that a cut and cover
tunnel preferably at both ends, but particularly at the northern end
would protect/preserve ancient woodlands at 16 acre wood. [Design
concepts similar to that of the Boxley Tunnel.].
It is realised that the proposal is very simply put – however, it is fully
understood that there are massive problems to overcome should a tunnel
be considered. Briefly these are:
[a] Cost:
As previously mentioned every aspect of the survey, planning, design,
construction and operation of such a tunnel would be more expensive.
Obviously the proposed length of the tunnel is also a factor in this: a
long tunnel has to be designed with additional safety features, such
as ventilation systems, etc. Also given the uncertain nature of
construction difficulties it is also more difficult to control/predict
construction costs during the tunnelling operation. As an example the
tunnelling costs of the Channel Tunnel was 80% over budget. All these
factors have been recognised in our proposals.
[b] Construction Difficulties: Traffic disruptions:
The major problem would be the amount of “spoil” or arisings. A twin
bored tunnel of this magnitude would generate approximately 3830
cubic metres of spoil per day11per shaft. This would require 380+
wagon trips12 per day to remove it; obviously this would lead to
11
12
Based on cut size of 10.08m with 4cm/min advance rate, on a 2x10hour shift pattern:
Assuming 10m3load per truck.
12
massive road disruptions, traffic flow problems and would increase
the impact of the detritus of construction on the community as a
whole.
For those people living in close proximity the noise and mess would be
horrendous and it would go on for at least 12 months – probably
longer. There is then the further problem of how to dispose of the
spoil: Obviously special haulage roads would have to be constructed to
take the arisings away from the excavation site to the nearest public
roadway/access. This again would impinge on the land-take amounts
and would initially take as much if not more land than the cutting
option, although it is assumed that restoration works would be
undertaken on completion. Further, any public roads would suffer
disproportionate surface damage owing to the constant payloads being
imposed upon them.
There are also safety factors to be considered and the very real
threat of increased traffic accidents with this level of vehicular
traffic.
Also construction times would be increased, therefore nuisance
impacts would go on for a greater period of time. There is also the
problem of workers construction camps, these will require extra land
initially and access roads in to them and basic services, again all of
which will require land and make further loading upon the public roads
etc.
However again it should be noted that spoil logistics will be a major
factor irrespective of which method of construction is used. The
large cuttings proposed will necessitate the removal and disposal of
many thousands of cubic metres of spoil and the transport/road
difficulties will be of much the same order. [Taken over the length of
the tunnel[8km] approximately 5.4 km would be in cuttings under the
present plan – these cuttings are up to 15m deep in places and using
HS2 2:1 formula and taking an average cutting height of 6m that
alone would generate approximately 1.1 million cubic metres of spoil.].
[c] Construction Noise and Vibration [Tunnelling]:
In addition to the noise, dirt, traffic and spoil disposal issues, there
are other construction issues with the operation of the TBMs and
tunnelling in general. These mainly concern settlement, noise and
vibration from tunnelling itself – there will also be an issue from
ground noise once the line becomes operational.
13
Ground borne noise, that is noise that is perceived aurally that
differs from noise in general is said to arrive within a given space as a
result of propagation as vibration at an acoustical frequency13
transmitted through the ground or a structure; large scale tunnelling
/ construction work can result in the generation of such noise, and
therefore is a factor that must be addressed at all phases of the
project. There is another factor with ground borne noise in that
because of its transmission characteristics, it has the ability to be
heard without passing directly through air – through a bed frame and
pillow for example, and therefore will cause higher levels of
disruption than normal ambient [air carried] noise of the same level.
There are guidelines14 for such levels, though it must be appreciated
that there is no mandatory legislation covering this area. However
underground railways generally adopt the LAmax.S noise parameter,
using this as a guide the threshold level for buildings not currently
affected by ground borne noise is accepted as 35dB LAmax.S
However, the vibration issue would presumably be dealt with within a
similar document to the 200815 CrossRail Information Report on
ground noise and vibration. [Noise level measurement, cause and
effect are too complex to be dealt with within this document, but the
ramifications are acknowledged]. It should be noted that there have
been other areas where local councils, area authorities and suchlike
have developed plans16 and laid down levels that railway constructors
have had to abide to during construction and operation and it is hoped
13
Human response bandwidth frequency is said to be between 18-18000Hz
approximately.
14
BS 6472 Guide to evaluation of human exposure to Vibration within a building: Part 1
Vibration Sources other than Blasting 2008.
[14 cont.] BS 7385: Evaluation and measurement for vibration in buildings: Part 1 Guide
for measurement and evaluation of their effects on buildings 1990 and Part 2 [BS 7385]
Guide for damage levels from groundborne vibrations 1993.
BS 5228: Code of Practice for noise and vibration control on construction and open
sites Part 1: Noise 2009 & Part 2 Vibration 2009. ISO 14837 Harmful Effects of
vibration
15
CrossRail Information Report: D10: Groundborne Noise and Vibration (version 4
03.04.08] Construction and Operational Criteria.
16
Waverley Railway[Scotland]Bill; Environmental Statement: Sept 2003: Delta Rail
document ES-2007-059 Issue 1:
LDF Building on Success: Noise: Supplementary Planning Document – Adopted May 2009
Local Development Framework: Royal Borough of Kensington.
Supplementary Planning Guidance to the London Borough of Havering’s Unitary
Development Plan: Noise Vibration Standards for Railways: July 1995
14
that such measures would be taken and enforced by the relevant
authorities here.
[d] Settlement
All tunnel construction using a TBM will cause settlement. Such
settlement is caused by the phenomenon of ground loss caused by
stress release of the surrounding ground, [actual degree of effect is
dependant upon soil type and condition in area], as a result of the
operation of the TBM itself, and may be referred to as “face-loss”.
Such face loss is quantifiable as a percentage of the theoretical
tunnel bore volume or percentile face loss; it is also said to be 3
dimensional. In TBM tunnels the area so affected is referred to as
the zone of influence, in such tunnels the zone is centred along the
centre-line of the tunnel. There are certain factors associated with
the prediction of damage and are too complex to be contained within
this document, however below are tables showing the accepted
Classifications of Building Damage that may be predicted.
Table 1 Classification of Building Damage
Damage
Degree of
Typical Damage
Category
Severity
0
negligible
Hairline cracks <<0.1mm in width
1
Very slight
Fine cracks up to 1mm wide
2
Slight
Cracks easily filled, redecoration probably
required. Crack widths up to 5mm
3
Moderate
Cracks can be patched by a mason. Repointing
and possible replacement of some brickwork.
Cracks 5-15mm wide
4
Severe
Extensive repair work involving crack
replacement. Crack widths 15-25mm
5
Very severe Major repairs required including partial or
complete rebuilding. Crack widths generally
greater than 25mm
Table 2 Damage Categories
Category of Damage
0
1
2
Normal Degree of Severity
Negligible
Very slight
Slight
15
Limiting Tensile Strain
0.000 – 0.050
0.050 – 0.075
0.075 – 0.150
3
4-5
Moderate
Severe to very severe
0.150 – 0.300
>> 0.300
[e] Water Tables: Flood Plains: Fault Lines
There are hazards that can occur during tunnelling operations when
crossing water tables, fault lines and other hazards which may or may
not be apparent when carrying out even in-depth surveys prior to
boring. Water is a major problem and due to the high water table
levels and presence of flood plains in this area this is thought to be an
area of severe concern. Even if the problems can be overcome during
construction there may be a need for anchoring measures to be put in
place as water presence can cause a buoyancy issues with both cut and
cover tunnels and bored lined tunnels: [Therefore additional impact on
cost and design].
It should be noted that there may also be issues with flooding of
the water plains – particularly from Balsall Common/Berkswell to
Middle Bickenhill being particularly problematic, as there are known
flooding problems in this section.
However, it should also be noted that even if the Railtrack is laid
down as per the current plan, the problems of water levels may still
prove problematic as it may require quite considerable extra
foundation works to stabilise the overland/overhead tracks as
currently proposed. [Note for each additional tonne of cement
required there will be an additional carbon cost, [Embodied CO2
(ECO2) – for Portland cement is on average 930kgCO2/tonne] but will
also have an impact on the carbon footprint by releasing carbon
[eCO2] throughout its life – so not very “green”!!
Again detailed study of the geography and topography of the area has
been based on HS2’s figures and it should be noted that as yet no
detailed land, geology, environmental, noise or vibration surveys have
been carried out specific to the line of approach by ARUP or DfT.
It should further be noted that noise and environmental surveys as
well as protection of habitats are a requirement under EU
legislation.17
17
EU Directive on Noise – Directive 2002/49/EC: June 2002 requires all Member
States to produce strategic noise maps for major infrastructure works.
EU Habitats Directive
EU Directive 2001/42/EC – June 2001: Environmental assessment procedures.
16
[f] OTHER ISSUES: [Pipelines – Gas and fuel oil.].
It should be noted that within the line of route between Crackley
Flood Plain [MAP HS2-ARP-00-DR-RW- 04223 refers] and Marsh
Farm [Map HS2-ARP-00-DR-RW-05024 refers] there are
underground high pressure oil and gas pipelines that both bisect the
line and in some parts run along its proposed route.
A 14 inch pressurised emergency fuel oil pipeline cuts the line in at
least 3 places [For details see BPA Fuel Pipelines maps attached in
Appendix A] before running adjacent to the Greenway from a point
north of Waste Lane [approx position on Odnaull End Farm land]
before crossing under the WCML prior to Berkswell Station between
it and Truggist Hill Farm: A cross country gas pipeline crosses the
proposed line of route and runs along it between CP’s 151:100 –
151:500 [approximately] Any construction work would have to be
carried out in accordance with the regulations governing construction
work in the vicinity of such pipelines.18
[5] COSTINGS:
ESTIMATE AND COMPARISON OF COSTS:
[a] TUNNEL PROPOSAL
TWIN BORE
TUNNEL[10m
dia]
TWIN TRACK
O/H LINE
CUTTING
BASE COST
£/m
LENGTH
COST/km
TOTAL
85685
1370
780
17.60
8kM
8kM
8kM
85685000
1370000
780,000
685,484,491
10,960,000
6,240,000
685,000
2,761,695
SIGNALLING
POWER
SUPPLY
COMMS
4,489,797
4,000,000
3,000,000
4,672,000
2,089,931
EARTHWORKS
STRUCTURES
ROADS
UTILITIES
18
Special Requirements for Safe Working in close proximity to high pressure pipelines –
Revision No 110 and legislation The Land Powers [Defence] Act 1958: The Pipelines Act
1962: Pipeline Safety Regulations 1996 and others.
17
1,500,000
20,000,000
ADDONS
ADMIN
COSTS
TOTAL
745,882,914
These costs do not include cost of TBM, transportation to site, land
purchase or any associated costs and cover the cost of the tunnel only.
No additional contingencies have been added for extra support works,
flood containment or restoration works.
Rates assumed as at q3 2009
[b] CURRENT PROPOSALS (as DfT January 2012)
Component
P/WAY [2 Track]
OHLE
CUTTING
SIGNALLING
POWER SUPPLY
COMMS
EARTHWORKS*
STRUCTURES**
ROADS***
UTILITIES
ADDONS
ADMIN COSTS
COMPENSATION
BRIDGES***
CUT & COVER
TUNNEL
Base Cost
£/m
1,370.0
780
17.60
Length km
Cost £/km
Total
8km
8km
1,370,000
780000
10,960,000
6,240,000.
31,469,203
685,000
2,761,695.
4,489,797.
3,774,000
43,000,000
4,672,000
2,089,931.
1,500,000
20,000,000
15,000,000
7,277,643
44,556,200
TOTAL
198,475,469
0.52KM
*1020 m Retaining wall at Waste Lane
**ELEVATED SECTIONS [includes replacing OHLE on main line –
currently at cross country height – to enable 8m height requirement at
Berkswell Station].
*** includes temporary road Hodgetts Lane to Hob Lane, and diversions
at Park Lane and Lavender Hall Lane, Crackley Lane and Truggist Lane.
**** Includes bridges and road works etc at Crackley Lane, Cromwell
Lane, Waste Lane and Lavender Hall Lane.
18
THESE COSTS DO NOT INCLUDE CONTRACTORS COSTS, DESIGN,
TESTING OR COMMISSIONING, CLIENT COSTS OR RISK OR ANY
LAND PURCHASE OR ASSOCIATED COSTS [other than compensation
under a government proposed scheme] AND COVER THE COST OF THE
LINE AS DESIGNED. NO ADDITIONAL CONTINGENCIES HAVE BEEN
ADDED FOR EXTRA SUPPORT WORKS, FLOOD CONTAINMENT OR
RESTORATION WORKS.
RATES ASSUMED AS AT Q3 2009
CONCLUSION
In conclusion, from all the above it can be seen that a tunnel of proposed
length 7-8km would be a major engineering undertaking and would be
considerably more costly than the present route proposition. However the
tunnel proposed is only 1 km greater in length than a similar tunnel
evaluated by DfT/ARUP/HS2 which was deemed a realistic proposition.
It is therefore proposed that although the engineering and cost factors
of a tunnel are more challenging than the cutting option, the benefits to
the community as a whole, the saving of livelihoods, desperately needed
farm and other usage land, warrant that the option be fully appraised in
order to hopefully gain government approval, and therefore extra
funding, for such a scheme. The proposal is technically very challenging
and it may be that in today’s financial climate unviable, but given
ministerial/political backing and will, it could be done.
19
APPENDIX A
20
21
22
See attached pdf documents for tunnel representation.
23