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High Speed Two Limited High Speed 2 Automated People Mover (APM) Euston Station to St Pancras International Further Investigation Final Report

Ove Arup & Partners Ltd 13 Fitzroy Street London W1T 4BQ United Kingdom

High Speed Two Limited

High Speed 2 Automated People Mover (APM) Euston Station to St. Pancras International Further Investigation

Contents Page

1

2

Introduction

1

1.1 1.2 1.3 1.4 1.5 1.6

1 1 2 7 7 8

The December 2009 Report Further Work on the Route Summary of Previous Options Summary of Previous Cost Estimates Selected Options – Elevated APM Selected Options – Sub-surface APM

Elevated APM

9

2.1 2.2

9 9

Introduction Existing Conditions along the Route

3

St Pancras Terminus Station

11

4

Euston Terminus Station

16

5

Architectural Statement

19

5.1 5.2 6

Example of an Integrated Station Within a Larger Building 19 Example of Station Adjacent to Historical Buildings 20

Options 1B and 6B – Sub-surface Options Along Phoenix Road and Polygon Road 22 6.1 6.2 6.3 6.4 6.5 6.6

General Description The Tunnel Euston Station St Pancras Station Phoenix Road, Option 1B Polygon Road, Option 6B

Appendices Appendix A Drawings Appendix B Ground Investigation

22 22 23 23 24 24



1

Introduction

1.1

The December 2009 Report

In December 2009, Arup prepared a report to High Speed Two Limited (HS2 Limited) titled ‘Route Engineering Studies Final Report’. That report presented the findings of a route engineering and alignment study for a potential new high-speed rail line from London to the West Midlands. It described the processes for generating a large number of route options, and the ‘sifting’ process by which they were reduced to a preferred route and two close alternatives. In the process of the sifting, it was decided that some routes or route sections would not be carried forward. 1.2

Further Work on the Route

HS2 Limited presented its findings to the Secretary of State for Transport and a number of questions were raised, both about the preferred route and its alternatives, as well as about some of those ‘parked’ routes. More work was therefore commissioned by HS2 Limited. This work included the investigation of a people mover between Euston and St Pancras as an alternative to a rail connection from HS2 to HS1. The following additional investigations related to the people mover were instructed by HS2 Limited and are covered in this report: •

Investigation of underground utilities and tunnels along the line of the people mover;

•

Illustration of the people mover and its guideway structure superimposed against the North and South façade elevations along Phoenix Road; and

•

Development of the people mover interface with the existing St Pancras Station on Midland Road.


1.3


Summary of Previous Options

The following 8 options were previously considered: Option 1A

Option 1B

Elevated APM

Below-ground APM

This would comprise an elevated APM east-west along Phoenix Road. At Eversholt Street the guideway would traverse south to a ‘station’ at high level parallel to the classic platforms at Euston. At Midland Road the guideway would also turn south to a station parallel to the Midland platforms at St Pancras.

This option would be identical in plan to option 1A except the entire system would be sub-surface. The ‘station’ at Euston would be at the same level as the main line platforms with access to the concourse above via escalators. The station at St Pancras would be at a similar level to the Thameslink Station. Access would be via a walkway above the station (below road level) and crossing the Thameslink box similar to the Thameslink platforms access to the low level concourse area.



Option 2A

Option 2B

Elevated APM

Elevated Travelator

This option would be similar to option 1A except for the Euston Station zone where having crossed Eversholt Street the APM would slope down in to Euston Station at 6% to an internal APM station at concourse level. This would provide optimum access for both rail passengers and for the occupants of any future commercial development above.

This option would comprise a system of travelators following the same route as option 2A. Travelators of either 200m or 300m in length, laid end to end, would provide a ‘pedestrian’ route along Phoenix Road. At Euston this would culminate in a ‘lobby’ at high level alongside Eversholt Street, accessed by escalator from the ground level concourse. At St Pancras an additional travelator, about 60m long, would carry passengers from Phoenix Road south to the high level Midland Main Line concourse area.



Option 3 Elevated APM on a loop The loop option goes along Phoenix Road, Midland Road, Euston Road and Eversholt Street The route would align with the extreme ends of the two stations and therefore would not offer good travel distances for passengers. A single track loop is considered along the route and the this option can only support an elevated system as the Metropolitan and Circle lines are sited in shallow tunnel beneath Euston Road. There could be issues with broken down trains on the loop and the disruptions this may cause on the route.



Option 4

Option 5

Street Level-Walk

Elevated Walkway

The walking distance between Euston station and St Pancras is approximately 600m (6 minutes walk). This option would require an improvement to landscaping of Phoenix road and improvement of the streetscape to create an attractive walking pathway linking both stations together.

This option would be similar to Option 2B except instead of travelators people would be walking at high level and would be able to directly walk into both Euston and St Pancras station concourse areas.

A visual connection can be used to direct passengers through a comfortable and safe pedestrianised route.

Their journey would take approximately 6 minutes but it would be in an enclosed space.



Option 6 A

Option 6 B

Elevated APM along Polygon Road

Below ground APM along Polygon Road

(option revisited from initial studies)

(option revisited from initial studies)

This would comprise an elevated APM east-west along Polygon Road. At Eversholt Street the guideway would traverse south to a ‘station’ at high level on top of the Classic platforms at Euston. At Midland Road the guideway would turn south to a station parallel to the Midland platforms at St Pancras. Polygon Road aligns with the extreme ends of the two stations and therefore would not offer good travel distances for passengers. Polygon Road is not continuous for the full route and it would be necessary to partially demolish existing Camden Housing (Somerstown Site B, 1975) to create a complete corridor.

This would comprise a sub surface APM east-west along Polygon Road. At Eversholt Street the route would travel southwards to a station beneath the road. At Midland Road the route would turn southwards to a station alongside the Thameslink St Pancras Station partially beneath the vacant site behind the British Library. Polygon Road aligns with the extreme ends of the two stations and therefore would not offer optimum travel distances for passengers. Polygon Road is not continuous for the full east west leg of the route. It would be necessary to partially demolish existing Camden Housing (Somerstown Site B, 1975) to complete the corridor.


1.4


Summary of Previous Cost Estimates

Initial construction costs were developed for each of these options to include infrastructure, systems, cars and maintenance facilities as appropriate. Optimism Bias was not included at this stage:

Option 1A

Elevated APM

Option 1B

Below-ground APM £110million

Option 2A

Elevated APM

£73 million

Option 2B

Elevated Travelator

£60 million

Option 4

Street Level-Walk

£2.25 million

Option 5

Elevated Walkway

£56.4 million

1.5

£75 million

Selected Options – Elevated APM

HS2 Ltd selected two options for further investigation, option 2A and option 6A. These options would comprise an APM or monorail at high level above either Phoenix Road (2A) or Polygon Road (6A). In both cases at Eversholt Street the guideway would cross directly into the new Euston Station (at the east of Euston Station in Option 2A and north of Euston Station in Option 6B) and descend at 6% down to concourse level where interchange facilities would be sited. At Midland Road the guideway would turn south to a station parallel to the Midland Platforms at St Pancras. Interchange would be achieved at high level into the existing upper concourse in St Pancras Station. The disruption to the Midland Road pedestrian and vehicle traffic would be greater in Option 6 where the APM would travel a longer distance to the St Pancras connection point. Both stations would be multi-platformed to provide separation for embarking and disembarking passengers optimising turnaround times and would therefore have end loaded platforms. The system would be based on shuttle operation with two guideways carrying one APM each shuttling between stations. The guideways would typically be formed in reinforced concrete with concrete columns supported on piles at approximately 11m centres carrying precast beams. The guideway would incorporate noise mitigation measures such as low level baffles. A maintenance depot would be sited on the disused post office depot to the northeast of the Euston Station site.



The main attraction with these options is that the passengers at Euston would leave the HS2 concourse level to arrive at the most convenient location and level at St Pancras where they could disperse on to the different transport modes to continue their journeys. The journey from St Pancras Station would also have the additional advantage of having the HS1 arriving passengers connecting to the APM link via a platform level route without having to change levels. Overall these link options would bring the advantage and comfort of having access to different modes of transportation available within these two major stations without having to go outdoors within a well guided and seamless route with the added benefit of a safe and unobstructed journey. The opportunity to redevelop the street level along the route of the high level people mover would also be considered to be a positive impact of this APM link. The redevelopment ideas may include pedestrianising Phoenix Road and bringing in commercial investment opportunities to the area while improving the streetscape by necessary hardscaping, landscaping and lighting concepts. For the purpose of this study, the street elevations below were taken along Phoenix Road, those along Polygon Road would be of a similar nature. The study at the interchange with St Pancras Station would be common to both options. 1.6

Selected Options – Sub-surface APM

In addition, HS2 Limited has selected two sub-surface options, options 1B and 6B. In both cases, at Eversholt Street the APM station would be situated below street level adjacent to the classic Euston Station platforms. The guideway would travel north, turning east either along Phoenix Road (1B) or Polygon Road (6B). At Midland Road the guideway would turn south to a station situated partially below the road and partially below the north boundary of the British Library Site, adjacent to the Thameslink Station. These options would comprise an APM below either Phoenix Road or Polygon Road. Both options are described in Chapter 6.


2

Elevated APM

2.1

Introduction


This section of the report describes the elevated APM option in further detail, both visually and physically, along with studying the locality of the high level link route along two alternative roads and associated design solutions relating to impact on the environment.

Figure 1 | View of Phoenix Road route

2.2

Existing Conditions along the Route

Option 2A – along Phoenix Road: Phoenix Road holds a mixture of properties comprising mainly of residential buildings along with social and commercial buildings and businesses. The west end of the road houses St Aloysius Roman Catholic Church and the Maria Fidelis Convent School, with residential buildings along the road on either side ending on the eastern end with a mixture of residential buildings and small ground floor businesses including a pub. The road then moves on to the Brill Place towards St Pancras end with open green areas surrounding residential properties and the backyard of British Library on either side.



Phoenix Road carries 2-way traffic, the road width being about 6m, and the distance between buildings being about 12m. There are a couple of zones where the road is adjacent to green areas which have a more open and spacious feel to them. The two lane traffic would still be possible after the APM route is constructed. The introduction of a 6m high structure standing on columns at every 11m with a cross width of approximately 4.4m would have a visual impact, especially on the lower floors of the residential blocks. The mitigation measures to minimise the impact would be introduction of translucent side panels to the sides of the monorail structure which would follow the central line of Phoenix Road. The monorail option would also enable the design of the slimmest structure of the options which were previously evaluated. The pedestrianisation of Phoenix Road together with the introduction of the elevated APM structure would bring opportunities to redevelop the neighbourhood into a more lively and pedestrian friendly area while encouraging investment from well known business chains and small commercial businesses creating social gathering areas and a busier and safer neighbourhood. A well designed hardscaping and landscaping strategy would create a safe and habitable environment serving the residents as well as the school and religious facilities.

Option 6A – along Polygon Road: Polygon Road comprises of properties of which almost all are residential together with Children’s Centre Services ‘SureStart’, St.Mary and St.Pancras School, an open air children’s playground area and Edith Neville Primary School. The road continues in to a pedestrian only path and at the intersection with Purchase Street the grounds of Camden Housing (Somerstown Site B, 1975) marking the east end of the route before meeting with St Pancras/Midland Road. Polygon road is a narrower road in comparison to Phoenix Road with less busy vehicle traffic. There would be still availability for two lane traffic in the case of the high level APM route being introduced along the centreline of the road. There is more pedestrian movement than Phoenix Road due to the presence of a number of schools. Polygon Road aligns with the extreme ends of the two stations and therefore would not offer optimum travel distances for passengers. Similarly along Polygon Road, consideration should be given to the impacts of the elevated APM route on the existing structures and the likely changes it would introduce to the pedestrian and traffic movements. The route improvement works would follow the same pattern as Phoenix Road with proposed landscaping and hardscaping works and encouragement of the local and small businesses to be created around the neighbourhood.


3


St Pancras Terminus Station

At the Grade 1 listed St Pancras end, the destination point where the APM link would connect to the existing station would be the lobby/concourse zone on Midland Road. The APM station would be located along Midland Road parallel to St Pancras Station. The structural impacts on the Thameslink Box tunnels should be carefully studied. The favoured location with these considerations in mind would be one which would move the APM building slightly towards the British Library site removing the likely complications with Thameslink Box below and the road clearances of Midland Road. This would also increase the space in between the APM station and St Pancras Station, minimising the visual impact on the listed building. The architectural language of the APM station at St Pancras would positively contribute to this busy and prestigious site without causing major physical and visual conflicts. The APM structure would have a sleek and minimalistic approach with clean lines without a cluttered external shell. The APM station building would reflect the speed and practicality of its function and would connect to St Pancras building at the glazed west entrance zone with a glass box link which would be perceived as a part and continuation of the original structure.

Simplicity and originality in the design of both the structure that would support the high level APM building and the capsule that surrounds the platforms would enable the creation of its own identity without detraction from the adjacent HS1 station. Careful use of clear and frosted glass in and around the passenger link and use of translucent external finishes around the platform areas would create a light and welcoming environment as well as giving the APM building a lighter and practical image.



The passengers entering and leaving the APM station would follow the glass link bridging over the Midland Road with a level and step free access and would join the concourse area of the Midland Main Line. No significant impact on the existing passenger flow and circulation zones is anticipated with the estimated 10,000 to 15,000 per day passenger figures of the APM link which would bring up to 150-200 passengers at a time. A platform level access of the arriving HS1 passengers to the APM link would prove to be efficient eliminating the need to change levels within the St Pancras station.



Figure 1 Proposed APM station layout at St Pancras



Figure 2 Proposed APM station side elevation at St Pancras end

Figure 3 Proposed APM station front elevation at St Pancras



Figure 4 Proposed APM sation cross section at St Pancras


4


Euston Terminus Station

Option 2A feeds the APM link to the inside of Euston Station and on to its proposed HS2 unpaid concourse area. Here the people mover would slope down once inside the station entering from the east face of the station. Similarly in Option 6A the APM would be arriving from Polygon Road direction and would turn south where it would start descending over and in line with the classic platforms approaching the station from north. In both options the APM links are proposed to terminate in a capsule/box structure similar to the one at the St Pancras end. The use of the similar box features at either end will enhance the APM link identity and make it recognisable within the station space.

Figure 5 Internal APM Station

Similar to the St Pancras arrangement, passengers at Euston wishing to use the APM link to reach St Pancras would get to the HS2 concourse area by moving up one level from both the HS2 platforms and the street level and two levels from the London Underground level via escalators and MIP lifts. The APM station box would again have similar finishes to those at St Pancras with the clean and uncluttered lines and surfaces. The use of translucent and light materials would, especially during night time, let the box to be lit up to help contribute to the wayfinding strategy. All the aspects and design considerations for APM station within Euston Station would apply to the Option 6 route. The Polygon Road route would approach Euston station from north and would follow the same principles as Option 2A Phoenix Road route.



For Option 2A, the APM entrance to the Euston Station would mark and be a part of the connection of the redeveloped station to the street level and will serve as a gate to the Eversholt Street and Phoenix Road streetscapes. The opportunity to regenerate the area along and around Phoenix Road will be even more attractive given the permeability of the APM route which eventually flows in to Euston Station on the west and St Pancras Station on the east.

Figure 6 Proposed APM entrance into the Euston Station



Figure 7 Proposed APM route along Phoenix Road

Figure 8 Image showing a people mover within a transport hub



5

Architectural Statement

5.1

Example of an Integrated Station Within a Larger Building

The Detroit Metro Airport which is the second largest hub for Delta Airlines, the world’s largest airline, has a people mover, the Express Tram, that gets passengers from one end of the mile-long (1.6 km) Concourse A to the other, arriving at three different boarding stations, ‘Terminal Station’ (in the centre), ‘North Station’ and ‘South Station’, in a little over three minutes. The passenger movements were improved by moving walkways and the introduction of the passenger mover significantly, and the integration of the high level transport mode in to the modern terminal building was achieved successfully by the use of the underside of the APM link as retail facilities which gives the high level structure a secondary function other than carrying the people mover. The modern technology associated with APM systems allow easy integration within new structures through the use of materials, lighting effects, minimalistic and unobtrusive engineering design solutions.

Figure 9 Detroit Metro


5.2


Example of Station Adjacent to Historical Buildings

The Venice People Mover is a public transit system in Venice connecting the Tronchetto island with Piazzale Roma. It started operating on April 19, 2010. The two vehicles of the system are pulled by a cable similar to a funicular. The whole 853m long journey takes 3 minutes. The people mover has successfully managed to bring a high-tech and modern design edge to the historical environment of Venice, standing out as a required means of transport with contemporary design whilst also integrating with the historic city fabric through its function, practicality and connectivity.

Figure 10 Venice APM


Figure 11 Venice APM




6

Options 1B and 6B – Sub-surface Options Along Phoenix Road and Polygon Road

6.1

General Description

Two sub-surface schemes for the APM were selected by HS2 Limited as reserve options for further work. In each case the options comprise ‘stations’ beneath Eversholt Street at the Euston End and the Midland Road/ British Library site at St Pancras. The route would leave the Euston Station northwards along Eversholt Street, then would turn eastwards along either Phoenix Road (Option 1B) or Polygon Road (Option 6B) to Midland Road where it would turn south to the station at St Pancras. 6.2

The Tunnel

In both cases the APM would be located within a ‘cut-and-cover’ tunnel about 7.5m below road level. The ‘running’ tunnel would include running tracks, service access for the APM system, means of escape for passengers, together with a separate service corridor for diverted utilities. The total internal tunnel width would be of the order of 10m. It is anticipated that the tunnel would be constructed by piling the two side walls (sheet or contiguous), excavation to form a base slab and finally casting the roof slab to form the base for the reinstated road. The option of boring the tunnel has been excluded as the depth of tunnel (twice its diameter) would be substantial, therefore this scheme would offer no benefit above existing connections via Victoria and Northern lines. In addition the use of a tunnel boring machine (TBM) would require large launch pit and would necessitate further property acquisition and associated disruption. The minimum horizontal radius for the APM would be of the order of 50m dependant on system selected. Therefore, there would be additional site requirements at the road junctions with both Eversholt Street and Midland Road where the alignment turns through 90° which would entail demolition (see detailed discussion later). In both schemes there would be significant disruption to the community during construction. This would include: -

Road closures for temporary and permanent services diversions as well as for the tunnel construction works;

-

Loss of access to properties fronting the road or on adjacent culs-de-sac;

-

Noise and dust during construction works;

-

Potentially mitigating foundation works to existing structures to safeguard against damage during construction;

-

Severance of communities north and south of the road including residential, school, and communal facilities; and

-

Severance of utilities servicing properties.



It is highly likely that some occupants would require re-housing during the works. As previously noted, both the roads have significant buried utilities which would require diversions. At a local level, distribution to properties on either side of the road could, to some extent, be reinstated above the tunnel. However, for deeper services there would need to be collectors on both sides of the tunnel. In addition, the tunnel and its structure would effectively create an east-west barrier from the east side of Eversholt Street to the Thameslink Box under Midland Road to all deep buried services. This would necessitate major utilities diversions. 6.3

Euston Station

The new station would be located adjacent to the classic platforms (Platform 1) beneath Eversholt Street at approximately the same level as the classic station. The two APM tracks would be served by an island platform which would be connected by escalators to the main concourse above. Passengers from HS2 and classic services would traverse the mainline station at concourse level to the APM, with maximum walking distances of the order of 500m for HS2 passengers (from Platform 24) and 300m for classic passengers (from Platform 12). The clear width of the new station would need to be 17m allowing for escalator services to the central platform. The construction of the cut-and-cover tunnel box beneath Eversholt Street would be highly disruptive. The traffic flow on Eversholt Street is significant, which may make closures impossible and therefore require construction of the box in two halves. Bus services would require diversion. The properties along the west side of Eversholt Street would be in close proximity to this substantial construction site and would face disruption to access and use as local facilities. The buried utilities beneath Eversholt Street would also require diversion, possibly into a dedicated corridor between the APM and classic line stations. Clearance to the Northern line tunnels which would run beneath the station would require checking. 6.4

St Pancras Station

The station at St Pancras would be located partially below Midland Road and partially below the back of the British Library Site, immediately adjacent to the Thameslink Box and Midland Road mainline station entrance. The two APM tracks would also be served by an island platform with central escalators. Passengers would access the station from the lower Thameslink concourse area via a pedestrian walkway traversing above both the Thameslink platforms and the APM beneath road level. The track level for the APM would be approximately 10m below road level. The station box would also be of the order of 17m wide.



Whilst there are currently few properties in the immediate proximity of the site there would be disruption to traffic flows along Midland Road and access to St Pancras Station including buses and taxis from Midland Road during the box construction. It is understood that The UK Centre for Medical Research and Innovation (UKCMRI) have major development plans for the entire site South of Brill Place and Phoenix Road between Midland Road and Ossulton Street. The development comprises approximately six levels above ground and three levels of basement. Initial inspection of the plan and model suggest the front entrance of the development is set sufficiently back from Midland Road to enable a sub surface station to be located beneath its apron. This would require further investigation. Again, major utilities would need to be diverted, possibly into a dedicated corridor between the APM station and the Thameslink Box. This would be complicated by the passenger walkway beneath the road which bisects this corridor. 6.5

Phoenix Road, Option 1B

The running tunnel would run down the centre of Phoenix Road to minimise structural impact during construction on properties on either side. There appears to be sufficient width for the overall construction (approximately 13m including structure) but access for piling tunnel walls is severely constrained (ideal site width greater than 23m to provide for rig clearance). At the intersection with Eversholt Street the alignment would curve, requiring additional land-take on the corner and probable demolition of St Aloysius Roman Catholic Church. Similarly at the intersection of Brill Place and Midland Road the curved alignment would impact on the proposed UKCMRI development. The width of the tunnel would take the entire road width for the majority of its length precluding access to properties during construction. It is unlikely these properties would be habitable during construction. Detailed construction programming has not been carried out, however, there will be of the order of 2km of tunnel wall to be piled, and therefore the structure would be unlikely to be completed in less than 2½ years. 6.6

Polygon Road, Option 6B

The running tunnel would be located centrally along Polygon Road and continue at its east end across the Camden Housing Estate to Midland Road. Polygon Road is marginally less wide than Phoenix Road and offers significantly greater spatial constraint. It is therefore possible that the full width tunnel (10m) would not fit at pinch points and that additional land would be required for example at Edith Neville Primary School. At the Eversholt Street end the curved alignment would require demolition of both the four storey bridge flats and the six storey flat block immediately south of Phoenix Road. At the east end, the alignment leaves the road and passes through the Camden Housing estate (Somerstown Site B). Demolitions would be required including



Coopers Lane Estate Community Hall, one two storey residential block, two four storey blocks, and the old arch wall along Midland Road, the remains of the original coal depot site. As with Phoenix Road, for much of the tunnel length the immediate proximity to adjacent housing and schools would preclude access during construction making then inaccessible and probably uninhabitable. The construction programme has not been studied in detail, but as there would be 2.7km of piled wall (longer that Option B) construction is unlikely to take less than 3 years.

Appendix A

Drawings


A1

Drawings


Appendix B

Ground Investigation


B1


Groundwise Search – Phoenix Road

Figure 12 Map of utilities along Phoenix Road and Eversholt Street - HS2-ARP03-DR-BL-30440 The drawing above illustrates a number of existing utilities along the proposed route of Phoenix Road and Brill Place. One of the most significant is a large Thames Water combined sewer, approximately 4m deep and, at its largest approximately 1.2x0.8m in size. It is likely this sewer runs down the centre of the road. In addition, there are a number of EDF-Energy High Voltage (HV) cables, running on both sides of the road. The number of ducts varies from 2no.–6no. along the length of the road to 9 no. at points of street intersections, and varying in depth from 0.5m to 2.0m. Low Voltage (LV) cables are also present. Along with the above mentioned utilities, the following are also present along Phoenix Road & Brill Place:•

2no. low pressure gas mains (NGG), at approximately 0.6 – 0.7m below ground;

•

4” potable water mains (Thames Water), at approximately 0.9m below ground;

•

Various communications ducts, which may include fibre optic cables (i.e. British Telecom, and Virgin Media), at approximately 0.25 – 0.6m below ground.

As well as the above discussed utilities, Eversholt Street also contains a 16” trunk potable water main (Thames Water), at approximately 1.1m below the ground, and contains additional HV cables belonging to SSE, likely to be at approximately 0.45 – 0.6m below ground. Similarly, in addition to those listed above Midland Road also contains a 16” trunk potable water main.



Note: Locations of existing infrastructure as shown on the sketch are indicative only. Exact locations and depths should be verified on site.



List of Utilities along Eversholt Street, Phoenix Road, Brill Place and Midland Road Utility Provider

Number of Ducts

Size Ducts/Pipes

Fujitsu

No info

No info

No info

NGG - Gas main

2

/

/

Thames Trunk Potable Water Mains

1 (Eversholt Street)

16"

1100mm

1 (Eversholt Street)

4"

900mm

2 (Phoenix Road)

4"

900mm

1 (Brill Place)

6"

900mm

1

1194x813 (Varies)

4-5 m

100mm

450mm

Thames Water Potable water mains

Thames Water Combined Sewer EDF-Energy (HV) EDF-Energy (LV)

Refer to drawing no HS2ARP-03-DR-BL30440

TfL-Signals

1

of

Depth

Colt Virgin Media Verizon Media Global Crossing Refer to drawing no HS2-ARP-03-DR-BL-30440 Fibre Net BT Cable and Wireless Abovenet


B2


Groundwise Search – Polygon Road

Figure 13 Map of utilities along Polygon Road and connecting streets HS2-ARP03-DR-BL-30441 Sheet 1

Figure 14 Map of utilities along Polygon Road and connecting streets HS2-ARP03-DR-BL-30442 Sheet 2 Drawing above illustrates a number of existing utilities along the proposed route of Polygon Road and adjoining streets. One of the most significant is a large Thames Water combined sewer, approximately 4m deep and, at its largest approximately 1.2x0.8m in size. It is likely this sewer runs down the centre of the road. Furthermore, there are a number of connecting sewers (of similar dimension) from the adjoining streets. In addition, there are a number of EDF Low Voltage (LV) ducted cables on both sides of the road. Ducts vary from 2–4 in number along the length of the road. Depths vary between 0.5m to 2.0m. At the intersection with Ossulston Street, HV cables cross Polygon Road in a bank of 9 ducts. Along with the above mentioned utilities, the following are also present along Polygon Road:•

1no. low pressure gas main (NGG), at approximately 0.6 – 0.7m below ground;

•

6” potable water main (Thames Water), at approximately 0.9m below ground;

•

Various Communications ducts, which may include fibre optic cables (i.e. British Telecom, Virgin Media, Cable & Wireless, and Verizon Business), at approximately 0.25 – 0.6m below ground. Colt also crosses Polygon Road at Ossulston Street.

With reference to the aforementioned utilities in Eversholt Street (Section 6.1), communications ducts are also present, which may include fibre optic cables (i.e. Abovenet, and Global). Similarly, Midland Road also contains further communications ducts (i.e. Global).



Note: Locations of existing infrastructure as shown on the sketch are indicative only, exact locations and depths should be verified on site. List of Utilities along Polygon Road

Utility Provider

Number of Ducts

Size Ducts/Pipes

Fujitsu

No info

No info

No info

NGG - Gas main

1

/

/

Thames Water Potable Mains

1

6"

900mm

Thames Water Combined Sewer

1

1194x813 (Varies)

4-5 m

EDF Energy (HV) EDF Energy (LV)

of

Depth

Refer to drawing no HS2-ARP-03DR-BL-30441 and 30442

Colt (Ossulston St) Cable & Wireless Virgin Media

Refer to drawing no HS2-ARP-03-DR-BL-30441 and 30442

Verizon Business BT

B3

Potential Impact on Utilities

Due to the large number of utilities within both Phoenix Road and Polygon Road, identified by the (Groundwise) utilities search returns, it is likely that the utilities are located across the full width of both road corridors. It is also likely, therefore, that the installation of ground piles or the construction of a tunnel, would necessitate the diversion of a large number of these utilities. Prior to any works, subtronic surveys and trial excavations would be required to determine precise positions/depths of utilities and to establish available space to divert utilities into.


B3.1


Piled Solution

It is considered that the sewer would be the first utility to require diverting due to its size/depth/position and would probably require shallower utilities to be diverted first to release available space for it to be diverted into. Once diverted, piling in close proximity to the sewer would need to be outside an agreed exclusion zone and be subject to technical scrutiny and agreement by the responsible utility company. Other utilities e.g. gas and water mains, would also place similar constraints upon the piling works and phased/temporary diversions may be required. It is also considered that utility connections into adjacent properties and cross connections into roads could be coordinated between the pile locations and with the agreement of the relevant utility company, it may also be possible to ‘slew’ ducts/cables from one side of the pile line to the other. B3.2

Tunnel Solution

As with the piled solution, it is considered that the sewer would need to be the first utility to require diverting prior to the installation of the tunnel. It may be possible for the sewer to be diverted into a sewer constructed immediately adjacent to the tunnel, thereby potentially minimising disruption to other existing services. However, this would require a temporary sewer and/or pumping whilst this is being constructed. The position of the diverted sewer would require careful consideration to minimise the severance of cross connections and a new smaller sewer may also be required to receive flows from adjacent properties on the opposite side of the tunnel. Due to the overall width of the tunnel, compared with the piled solution, it is probable that more utilities would require diverting together with existing services requiring rationalisation to make further space available. Where utilities are required to cross the proposed tunnel alignment, should there be limited depth of cover to the roof slab, it may be possible to cast a ‘trough’ in the roof slab for utilities. This would need to be confirmed during later design stages.