Hs2 Route Engineering

High Speed 2 Lim

ited High Speed 2 R

oute Engineering Report

High Speed 2 Limited High Speed 2Route Engineering Report

February 2011

High Speed 2 Limited High Speed 2 Route Engineering Report

Contents Page

1 Introduction 1 1.1 The Purpose of this Report 1 1.2 Overview of the Route 1 1.3 The Layout and Content of this Report 3

2 The Engineering “Footprint” and Indicative Land Requirements 4 2.1 Design Speed and Geometric Standards 4 2.2 The Width of the Railway 4 2.3 Tunnels 5 2.4 “Green Tunnels” 6 2.5 Geotechnical Assumptions 7 2.6 Structures Assumptions 8 2.7 Environmental Mitigation 10 2.8 Other Land Requirements 10 2.9 Infrastructure Maintenance Depot 11 2.10 Train Types, and the Train Maintenance Depot 11 2.11 Power Supply 12 2.12 Construction 12 2.13 The “Accuracy” of the Alignments 12 2.14 The Route Description 12

3 Euston Station 13 3.1 General Description 13 3.2 The Footprint of the Station 14 3.3 Platform Arrangements 16 3.4 HS2 Track Arrangements 18 3.5 Classic Track Alignment 20 3.6 Concourse Level 20 3.7 General Site Development 22 3.8 Constructability 23 3.9 Existing Train Services During Construction 23 3.10 Platform Use during Construction 23 3.11 Underground Facilities at Euston 24

4 Euston to Old Oak Common 26 4.1 Overview 26 4.2 The Horizontal Alignment 26 4.3 The Vertical Alignment 28 4.4 Intervention Shafts 30 4.5 Construction 33


5 The HS2 to HS1 Connection 34 5.1 Overview of the Connection 34 5.2 Alignment 34 5.3 Intervention Shafts 38 5.4 Surface Access Requirements at the HS1-HS2 Link Portals 38

6 Old Oak Common Station (West London Interchange) 39 6.1 Introduction 39 6.2 Track and Platform Arrangements on HS2 40 6.3 Platform Arrangements for the HS1 to HS2 Link 40 6.4 Platform Arrangements – GWML and Crossrail 41 6.5 Concourse 41 6.6 Crossrail Depot 42 6.7 Effects on Existing Old Oak Depot 42 6.8 Construction 42

7 Old Oak Common to the Ruislip Area 43 7.1 The Principles of On-Line Widening 43 7.2 The Connection to Heathrow 43 7.3 Old Oak Common to Acton 44 7.4 Acton Portal to Hanger Lane 46 7.5 Park Royal Footbridge, Coronation Road and Piccadilly Line 46 7.6 Hanger Lane Gyratory 46 7.7 Hanger Lane to Northolt 48 7.8 Northolt Area 50 7.9 South Ruislip 50 7.10 West Ruislip/Ickenham Road 52 7.11 West Ruislip to M25 54

8 The Chilterns: M25 to Wendover 56 8.1 The M25 to Amersham Tunnel 56 8.2 Amersham to Little Missenden 59 8.3 Little Missenden Tunnel 61 8.4 The 400kph Route 61 8.5 Little Missenden to the South Heath Area 61 8.6 South Heath to Wendover 63 8.7 Wendover 63

9 Wendover to Quainton 65 9.1 Stoke Mandeville 65 9.2 Aylesbury (Southcourt Area) 67 9.3 Hartwell Area 67 9.4 Aylesbury to Waddesdon 69 9.5 Waddesdon to Quainton 71


10 The Great Central Corridor: Quainton to Brackley 73 10.1 Quainton to Calvert 73 10.2 The Infrastructure Maintenance Depot 75 10.3 Calvert to Twyford 77 10.4 Twyford to Newton Purcell 79

11 Mixbury/Brackley to Lower Boddington 81 11.1 Mixbury – the End of the Great Central Corridor 81 11.2 Turweston, Brackley and Radstone 83 11.3 Radstone to Greatworth 85 11.4 Thorpe Mandeville to Edgcote 87 11.5 Chipping Warden to Lower Boddington 89

12 Wormleighton to Burton Green 91 12.1 The Wormleighton Area 91 12.2 Ladbroke 93 12.3 Southam, and Long Itchington Wood Tunnel 95 12.4 Offchurch and Cubbington 97 12.5 The National Agricultural Centre, Stoneleigh 99 12.6 Stoneleigh to Burton Green 101

13 The West Midlands 103 13.1 Burton Green 103 13.2 Berkswell to the NEC Area 105 13.3 Birmingham Interchange Station 107 13.4 The NEC/Birmingham Business Park Area 110

14 The Coleshill/Water Orton Delta Junction 111 14.1 Birmingham Interchange Station to Coleshill 111 14.2 Overall Layout 111 14.3 East Link (Main Line) 113 14.4 South Link 113 14.5 North Link 113

15 Delta Junction to Lichfield 114 15.1 Curdworth to the Belfry 114 15.2 Middleton 116 15.3 Hints 118 15.4 Whittington 120 15.5 North of Lichfield and Fradley 122 15.6 WCML Connection 124


16 The Link to Central Birmingham 126 16.1 Water Orton to A452 Chester Road 126 16.2 A452 Chester Road 126 16.3 M6 Crossing 128 16.4 A4040 Bromford Lane and Heartlands Spine Road 128 16.5 The Rolling Stock Maintenance Depot 130 16.6 Aston Church Road to Curzon Street Station 131

17 Birmingham Curzon Street Station 133 17.1 General Arrangement 133 17.2 Alignment 133 17.3 Concourse 133 17.4 Platform Level 134 17.5 Construction 134 17.6 Phasing 134

18 Glossary of Terms 135

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Introduction

1.1 The Purpose of this Report This report describes the Government’s proposed route for a high speed rail line between London and the West Midlands. It has been prepared on the advice of High Speed Two Limited.

It describes, in non-technical language wherever possible, the layout and main features of the route. It does not describe all the various route alternatives that have been considered since the start of route development work. This historical work has been presented to the public in a series of documents placed on the DfT website:

http://www.dft.gov.uk/pgr/rail/pi/highspeedrail/hs2ltd/

There are also other sources of information concerning the scheme on High Speed Two Limited’s website:

http://www.hs2.org.uk/

This report describes a scheme whose detailed drawings are on the DfT website referred to above. There are figures/drawings in this report, but they are at a smaller scale and they show considerably less detail. If full information is needed, the reader should visit the DfT website.

1.2 Overview of the Route The route would run from an expanded London Euston station to a new station in central Birmingham and it would also connect to the West Coast Main Line (WCML) near Lichfield. The route would:

●● lie in tunnel between Euston and the Old Oak Common area, where a new station would be constructed. This station would provide interchange with Crossrail and Great Western Main Line, including Heathrow;

●● provide a link to the existing High Speed 1 railway line;

●● run from Old Oak Common to West Ruislip along the existing rail corridor;

●● pass through the Chilterns, incorporating tunnels;

●● pass to the south-west of Aylesbury and east of Brackley, before passing between Kenilworth and Coventry;

●● pass east of Birmingham, with a new station near Birmingham International;

●● continue north to pass east of Birmingham, and would join the West Coast Main Line (WCML) north of Lichfield;

●● have a triangular junction in the Coleshill/Water Orton area, with a spur towards central Birmingham, and a north-facing chord for services northwards;

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http://www.hs2.org.uk

http://www.dft.gov.uk/pgr/rail/pi/highspeedrail/hs2ltd


●● have a new station in Birmingham near Curzon Street, with direct access to Moor Street Queensway, and with access to New Street Station and the City Centre.

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1.3 The Layout and Content of this Report This report is laid out as follows:

●● Chapter 1, this chapter, is introductory;

●● Chapter 2 does several things. It:

|● describes some of the engineering assumptions used to develop the route;

|● uses some photographs of High Speed 1 to show what typical engineering features could look like;

|● sets out how wide, and how deep or high, the railway would be in relation to existing features and ground levels;

●● Chapter 3 describes the proposals at Euston Station;

●● Chapter 4 describes the route between Euston and Old Oak Common;

●● Chapter 5 describes the proposals for a connection from HS2 to HS1;

●● Chapter 6 describes the proposals at Old Oak Common Station (West London Interchange);

●● Chapter 7 describes the alignment along the existing railway corridor between Old Oak Common and West Ruislip, including the allowance made in the design for potential connections to Heathrow Airport;

●● Chapters 8 to 15 then describe the more rural section of the route between the M25 near Chalfont St. Peter through to the connection into the existing West Coast Main Line north of Lichfield. This chapter also describes where the infrastructure maintenance depot is proposed;

●● Chapter 16 describes the connection from this route towards central Birmingham, and includes a description of where a rolling stock depot is proposed;

●● Chapter 17 describes the proposed station at Birmingham Curzon Street;

●● Chapter 18 is a Glossary of Terms.

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2


The Engineering “Footprint” and Indicative Land Requirements

2.1 Design Speed and Geometric Standards The design was based on a requirement to achieve 400kph running when practicable and reasonable. In most of the urban areas, the planned speeds are typically 200kph – 250kph.

The speed of 400kph required a minimum radius of about 8,200m with 150mm applied cant (the amount by which the higher rail is raised above the lower on curves) and a cant deficiency of 80mm. Vertical crest curves were designed to give acceptable human parameters, and, at 400kph, a curve radius of 56,000m was used.

2.2 The Width of the Railway For the majority of its length, the new route would be a twin-track railway.

The separation between the centre lines of the pair of tracks would be 5.0m where 400kph running was required. On the “outside” of the tracks would be provision for Overhead Line Equipment (supplying power to the trains), access road, drainage, and fencing. Therefore, on level ground, with no embankments or cuttings, the fences typically would be 22m apart.

Image of an ordinary section of high speed railway in a shallow cutting.

© Copyright Oast House Archive and licensed for reuse under this Creative Commons Licence.

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For cuttings and embankments, it was assumed that the side slope of the earthworks would be 1:2 (1 vertical to 2 horizontal). Therefore, for, say, an 8m deep cutting or an 8m high embankment, there would be a side slope width of 16m on one side, and 16m on the other side. Adding this to the “no earthworks” dimension of about 20m to 25m would therefore give a total fence-to-fence dimension of about 52m to 57m. This is a conservative design assumption. In practice it may be possible to use steeper slopes to reduce the fence-to-fence dimensions. Where tracks enter tunnels in two separate tunnel bores, the distance between tracks would be about 20m instead of the usual 5m.

2.3 Tunnels The range of tunnel configurations used was as follows:

●● Twin Bored, Single Track Tunnels (with cross passages where required);

●● Single Bore, Twin Track Tunnel (with or without central dividing wall).

The tunnelling methods considered were:

●● Tunnel Boring Machine (TBM) driven tunnels with the machine type dependent on ground conditions;

●● Mined tunnels, i.e. tunnel driven without a shield, generally utilising Sprayed Concrete Lining (SCL) for initial ground support.

The minimum tunnel size was determined by the size of the train, and all the ancillary equipment such as the electrification system, emergency walkways, drains etc. This minimum for a single-track, single-bore tunnel is 7.25m internal diameter. Aerodynamically, this tunnel size would allow speeds up to 250kph. Above 250kph, aerodynamic, rather than physical envelope considerations, determined the required tunnel size (the faster you travel, the larger the tunnel).

Tunnel sizes were calculated from the specific length and desired speed. In some cases, the tunnel would not be circular, but would be a flattened ellipse. Whether a circle or flattened ellipse, the “height” of the tunnel was determined, then it was assumed that the tunnel would be an equal distance below ground at the portal. Thus, for a tunnel of size “D”, the track level would be 2D below ground at the portal and deeper thereafter. In a twin-tunnel arrangement, the tunnels would be connected by cross-passages at 250m intervals.

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Image of typical twin-track tunnel and assembly area.

© Copyright Kenneth Yarham and licensed for reuse under this Creative Commons Licence.

It was assumed that tunnels longer than 2km are likely to be driven by TBM rather than mined with SCL support. It was also assumed that, for tunnels shorter than 2km, there would be no need for a dividing wall in single twin-track tunnels. The train stopping distance is likely to mean that trains would run through, rather than stop in, tunnels of this length in case of an emergency. This assumption was based on North Downs tunnel on HS1.

In general terms, tunnels under London were required to offer 225kph capability, those through the Chilterns to offer 320kph, and those in “open country” to offer 400kph. Care was taken to ensure that the horizontal and vertical alignments in tunnel locations would not preclude 400kph running should suitable train technologies be developed. The specific solutions are described in the route descriptions.

Most tunnels would need some provision of buildings on the surface, above the line of the tunnel, for ventilation, escape, emergency intervention etc. These areas would need to be accessible to the emergency services. The report notes where these facilities are suggested.

2.4 “Green Tunnels” In some locations, a degree of environmental mitigation is proposed by placing the route in “green tunnels”. These could be formed by enclosing the railway (where it would otherwise be in cutting) in a box type of structure, with its lid covered by restored surface features such as footpaths or woodland. It could alternatively be elevated “over the railway” with the rail at original ground level and a mounded area provided over the roof element of the structure.

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© Copyright Rail Link Engineering.

The roof of the tunnel would therefore be about 9m above track level.

2.5 Geotechnical Assumptions The geological materials between central London and the West Midlands consist of a wide variety of sedimentary strata, overlain in many places by superficial deposits of glacial and fluvial origin.

The youngest materials are mainly clays which overlie the Upper Cretaceous Chalk Group. This largely comprises a weak pure limestone and forms the higher ground of the Chiltern Hills.

North-west of the Chiltern Hills, there is a broad flat vale underlain by various clays, broken up by a series of hills in the Aylesbury area.

To the north west of the clay vale, the HS2 route would traverse undulating topography underlain in turn by limestone, clay, mudstone and sandstone. In Warwickshire, the route would locally cross mudstones and sandstones.

There were no significant geotechnical issues associated with this route, so a common side slope of 1:2 was used (as described earlier). It is possible that more detailed desk-based and later, intrusive geotechnical investigations, might alter this 1:2 assumption – either steeper or slacker slopes may be needed.

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2.6 Structures Assumptions At this stage of design, vertical clearance has been provided where HS2 would cross, or be crossed by, roads and other obstacles. For short bridges, such as those used to carry the railway over local roads, or roads over the railway, bridges would be straightforward, as in the image below.

Image of typical bridge carrying the railway over a side road.

© Copyright David Anstiss and licensed for reuse under this Creative Commons Licence.

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For the larger, longer or higher structures, a “viaduct” form of structure would be used, as shown in the computer-generated image below.

Computer visualisation of typical viaduct.

There should be later opportunities to achieve construction speeds and economies due to standardisation and investment in special equipment, typically with whole spans being lifted in one to create viaducts. While it would not be necessary for all viaducts to have the same span lengths, it is likely that construction equipment would be passed from site to site, and the size of this equipment would be driven by the largest span.

No decision has been taken on whether the major structures would be constructed in steel or concrete, but it is likely that the usual cost advantage of steel would be lost on a very large project, and the basic material costs for concrete solutions are likely to benefit from repetitive construction in an enclosed, on-site, pre-casting facility.

It is anticipated that the major structures would be built with decks cast on site as full span concrete units. For the highest viaducts, continuous, push-launched concrete structures may be used. In either case, the construction would take place in safe working conditions within a factory-like environment on site.

The initial designs therefore assumed a structure rising 1,200mm above the underside of the track envelope, giving an overall structural depth below rail level of about 3.5m. It was assumed that the viaducts would have ballasted track, continuous rails and spans of up to 50m. It is also likely that structures would be built in pre-cast concrete with one half-joint per span.

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2.7 Environmental Mitigation The present drawings show the engineering footprint of the scheme.

For a major project, such as the proposed scheme, environmental mitigation including significant earthworks, planting areas, balancing ponds and replacement facilities will be required. The present drawings are not intended to show these areas or the land required for their provision. These matters will be addressed as the design of the scheme is developed.

Example of a “Balancing Pond” in which rainfall run-off from the railway is stored before controlled release into a receiving watercourse. These areas are often used to provide for habitats lost elsewhere on the scheme.

2.8 Other Land Requirements The basic fence-to-fence dimension of the railway described earlier would be sufficient only to contain the ordinary engineering side slopes. In addition to this footprint, other areas of land would be needed for things such as:

●● Side road diversions;

●● Environmental measures (flattening earthworks slopes, for example);

●● Construction working space requirements;

●● Access to properties and severed land;

●● Land needed for utilities diversions (gas, water, electricity etc).

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These requirements have not yet been fully designed, and the plans accompanying this report should therefore be regarded as a minimum requirement. This is because this stage of design was focussed more on the principles of the scheme (particularly in terms of its horizontal and vertical alignments) rather than a fully detailed proposal showing the totality of land that would ultimately be required.

2.9 Infrastructure Maintenance Depot A depot from which maintenance of the infrastructure of the route would be carried out is proposed in the Calvert area. This depot is described in the appropriate geographical section.

2.10 Train Types, and the Train Maintenance Depot A depot will be needed for maintaining the proposed new trains. These trains would be a mixture of what has become known as:

●● “Classic Compatible” or “Hybrid” trains. These can be used on both the proposed high speed and existing UK railway lines;

●● “Dedicated” or “GC Gauge” trains. These can run only on high speed lines

It is worth describing what this means before the depot is described.

If the route were to go ahead, some trains, such as those from Euston to Manchester, would run on HS2 from Euston to Lichfield, but would then need to run on existing Network Rail routes north thereof. These trains would need to be capable of achieving the design speeds of the new route. If they were physically large in cross-section, they would not fit under bridges on the existing routes. If they were too long, they would not fit into many platforms along the route. Of course, all these problems could be overcome by altering the existing infrastructure, but this would be disproportionately expensive. It is therefore proposed to build a number of trains that would be able to run over both HS2 and existing lines. These trains would be known as “classic compatible” or “hybrid”.

Some trains from Euston would however run to the proposed Birmingham terminus at Curzon Street, and would run entirely on the new HS2 infrastructure. These trains could be as long and as wide/high as desired to meet passenger loading predictions. It is envisaged that these trains would be “GC Gauge” which is a technical term describing the physical dimensions of the trains. These dedicated trains are envisaged as being 400m in length, capable of 400kph, and are physically “large”. These trains would be “dedicated” trains. If and when the high speed network expands, for example to Manchester, more “GC” trains could be built to serve the Euston to Manchester business, and the “classic” trains deployed elsewhere if running over existing routes is needed.

At night, some trains would need to be stabled at various locations on the initial network. A dedicated rolling stock maintenance facility is proposed in the Washwood Heath area of Birmingham. This depot is described in the appropriate geographical section.

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2.11 Power Supply The new route would require electrical power supplies, and feeder stations would be needed. A feeder station would take power from the National Grid and transform its voltage down before feeding it to the Overhead Line Equipment and hence to the trains. These feeder stations would be situated at intervals along the route.

Each feeder station would require a secure enclosure, within which high-voltage electrical equipment would be placed. The enclosure would be about 100m x 100m.

2.12 Construction On the open-country route elements, it was assumed a 10m construction width would be required beyond the permanent earthworks for site compounds, storage of contractor’s materials, laying-out areas for track components and units, and working space around major structures etc.

It is likely that major construction compounds will be provided at about 15-20km intervals along the route. Detailed locations cannot be provided at this stage, as much will depend on the contracting strategy that would develop through detailed design. Proposed tunnel entrances will need their own dedicated compounds located at the tunnel mouth.

2.13 The “Accuracy” of the Alignments The route alignments were designed on a computer using an alignment programme “InRail” and were then drawn on Ordnance Survey mapping. The design was based on a combination of source documents;

●● the HS2 Project Specification Version 2 (HS2-HS2-020SP-RW-0001);

●● European Standards, the TSI 2002/732/EC (Technical Specification for Interoperability relating to the infrastructure sub-system);

●● Network Rail Standard, NR/SP/TRK/0049 (Track Design Handbook);

●● practices adopted on HS1 and French systems.

The level of the ground was determined from the OS mapping, using a Digital Terrain Model (DTM) and Digital Surface Model (DSM).

It is possible to place a scale rule on the drawings to determine the position of the route in relation to observable features. It would be reasonable to assume that the “accuracy” would be in the order of 2-3m.

2.14 The Route Description The next series of chapters now describe the proposed route, starting from Euston Station covering a link to HS1 and up to a WCML connection at Lichfield, followed by a description of a link to central Birmingham.

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3


Euston Station

3.1 General Description Euston Station would be the London terminus for HS2.

The existing station footprint would be extended to the west and south to create room for the additional and longer platforms. The tracks would be lowered such that the platform roof would be at existing ground level, providing a level surface at street level. Improved London Underground facilities would be included.

There would be a total of 24 platforms as follows:

●● 10 high speed platform faces on the westerly side of the station;

●● 2 Hybrid platform faces situated between, and accessible from, the westerly HS side and WCML easterly side;

●● 12 WCML Classic platform faces on the easterly side.

Construction of the station would take approximately 8 years. During construction, planning would ensure that there is minimum impact on existing classic services.

Computer-generated external image of a potential station appearance

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3.2 The Footprint of the Station Due to the required platform length, the new platform level would extend southwards to the northern edge of Euston Square Gardens and would necessitate demolition of the existing office blocks immediately south of Euston Station. The Grade II* Listed Building at the south-west corner of the site would be retained.

A new concourse for HS2 and Classic services would be provided above the platform level and a new LUL concourse provided below platform level. The classic HS2 platform level would be lower so that the new concourse would be at approximately existing ground level and would provide permeability for pedestrian and vehicular movements.

The total reconstruction of the station would enable optimisation of platform and throat to maximise facilities for both HS2 and Classic services. However, it would be necessary to extend the footprint of the station across Melton Street to Cobourg Street on the west side to enable the development of a high speed throat, and to create track access to the wide high speed platforms, given their increased length.

The Grade II* Listed Building on the corner of Melton Street and Euston Road would be retained. It would be necessary to demolish four housing blocks along the west side of the site and to take part of St. James’s Gardens.

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3.3 Platform Arrangements For the 10 high speed platforms, the track layout to the north would connect only to the HS2 alignment towards Old Oak Common. These platforms would therefore be used only by “GC” trains on self-contained HS2 services, or those “north of Lichfield” hybrid HS2 trains needing to operate on the existing network. These platforms would be located on the west side of the station to enable provision of both platform length (415m) and a high speed throat (100kph to 85kph in the track fan). The 10 HS2 platforms (5 island platforms) would be 12m wide, reducing to a minimum of 9m over the last 70m at the country end.

For the 12 classic platforms to the east side, the track layout would only connect to the existing WCML towards Camden and Primrose Hill Tunnels. These platforms could only be used by domestic, standard UK sized trains.

For the 2 hybrid platforms, the track layout would connect to both the HS2 alignment towards Old Oak Common and the existing WCML towards Camden and Primrose Hill. These platforms would be 415m long and while they could not cater for “GC” trains, they would cater for classic compatible HS2 trains, as well as conventional UK size trains, including the existing sleeper services.

The hybrid platforms would add operational flexibility and robustness for service recovery from delays for both HS2 and classic services. They would also provide the only means of transferring trains between the HS2 and Classic networks at the London end of HS2. The connection would provide the opportunity for the late evening southbound HS2 hybrid trains to arrive from HS2, but go to the Willesden/ Wembley area for overnight stabling and maintenance (and vice-versa at the start-up of service in the morning). This Wembley facility would not be available for “GC” HS2 trains. The ‘hybrid’ platforms would be 12m wide with a similar taper to 9m. Where platforms would be curved, a minimum curvature of 1,000m would be used.

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3.4 HS2 Track Arrangements Coming from Old Oak Common, the route would emerge from a new tunnel portal immediately south of Park Road to the west of the existing tracks. A vertically separated junction would then be formed between Mornington Street Bridge and Granby Terrace Bridge to provide two pairs of tracks into the station.

The west pair would serve the 4 platforms along the western edge. Due to space constraints, the Up (to London) and Down (from London) tracks would briefly share a sloping alignment immediately north of the track fan to enable provision of a diamond crossover, essential for operational requirements.

The east pair would serve the eastern 6 high speed platforms, together with 2 ‘hybrid’ platforms. It was assumed that the hybrid platforms would essentially serve Classic services and, therefore, a flat crossover of the HS2 and Classic fans would be acceptable.

All the track arrangements will continue to be reviewed as part of scheme development.

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The HS2 lines would need to be lower than the present track levels at Hampstead Road Bridge by approximately 1.5m and the bridge would require complete reconstruction for its entire length. The track lowering would require the new western retaining walls to be higher than the existing.

The track fans would start north of Hampstead Road Bridge. Their complexity and the requirement to link with adjacent Classic track fans would require all fans to

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be in a common flat plane. From a station planning perspective and to facilitate throat design, the track level would continue beneath Hampstead Road Bridge horizontally through the station. This would provide a track level of 16.5m above Ordnance Datum (OD). Current track levels at Hampstead Road Bridge are at approximately 18.5mOD and at the station 20mOD.

The tracks would extend approximately 100m further south than those of the existing station which, allowing for buffer stops (25m), would take the platform deck to the northern edge of Euston Square Gardens.

3.5 Classic Track Alignment The Classic platforms would be located on the east side of the station. The platforms could be accommodated on the outside of the reversed curves, still minimising their curvature (minimum radius 1,000m).

The Classic station would be served by 4 tracks from Camden Junction, passing under Park Road in tunnel. Minor track modifications in the Camden Junction area would enable the approach tracks to be paired (Up, Down, Up, Down) before reaching the two track fans beneath Hampstead Road Bridge.

South of Primrose Hill tunnels, the existing 4 WCML tracks would form a Slow line pair to the east at Camden Bank, with a Fast line pair to the west. The existing dive-under, which carries the Slow lines under the Up Fast, would remain, though would not have a particular use in normal operation. The existing underpass for northbound services from the presently low-numbered platforms would be lost to the new HS2 lines. The platforms would be split into 6 (3 islands) for the east-west fan and 6 (3 islands) plus 2 (1 island) ‘hybrid’ platforms for the west fan.

As noted, the vertical track alignment would descend at approximately 1.5% from Park Road to Hampstead Road Bridge (the start of the fans) and would then run horizontally through the station to buffer stops adjacent to Euston Square Gardens. The ‘hybrid’ platform would also be served from the east-west HS2 track via flat crossings.

The horizontal throat and station alignment at the same level as HS2 would facilitate the design of the fans and the interaction of HS2 and Classic lines for the ‘hybrid’ platforms.

The lowered alignments would require excavation of the throat by approximately 1.5m north of Hampstead Road, increasing to 3m down the length of the station. Civil works to existing retaining walls to the north would be augmented by new retaining walls along the station edge (Eversholt Street).

3.6 Concourse Level Euston Station currently handles a maximum flow of about 7,000 passengers per hour across the concourse to the Underground at peak periods. The introduction of HS2 services may involve an additional 10,000 passengers per hour needing to access the Underground. This would increase the pressure on concourse space for both Rail and Underground users by a factor greater than 2.0. It is anticipated the Old Oak Common Interchange would reduce pressure on the Victoria Line.

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Computer-generated image of the concourse level

The proposed concourse would be located above the platform deck level and would be integrated with the podium circulation of any future ‘air-rights’ development. The space would be open plan in the continental style, providing generally unconstrained public access. The track level would be 16.5mOD with concourse level above at approximately 24mOD, which would be compatible with the Euston Road level of 23.5mOD and Cobourg Street level of 25mOD. Thus the concourse would be effectively at ground level providing a high degree of permeability in all directions.

Gated bridge areas would provide access, via 6 banks of 2 escalators, lifts and stairs, to both HS2 and Classic platforms below. The escalators could be arranged in pairs (i.e. both up) for full length trains, or opposed (i.e. one up, one down) for half length formations. The escalators would clear the platforms in between 2 and 3 minutes.

Access to platforms for servicing has yet to be developed. It is anticipated that servicing would be from the north of the station to avoid conflict with passengers, possibly utilising the BT Depot Site (north-east corner) to access bridges or underpasses and ramps to platforms at their country end.

The design intent was to create a spacious, active, environment for public, residents and passengers alike, whilst retaining a clear identity and focus for the HS2 station. The concourse would be perforated to provide natural light through to platform level and enhance the overall volume of the station.

Access to the concourse would be from Euston Road (and Euston Square Underground Station) to the south, Cobourg Street to the west (possibly incorporating taxi provisions) and Eversholt Street to the east (with provision for

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buses, taxis and possible future trams). There would also be a facility to the north of the concourse level to provide a transverse route for buses and taxis. This would be developed at a future design stage.

The existing concourse space beneath the existing rail concourse would be taken by the platform level extension, necessitating its reconstruction. The new concourse, to be provided below railway track level, would extend from the existing footprint, both north and west, to provide 2 additional escalators to each of the Northern and Victoria lines, effectively doubling the platform access.

A zone would be reserved between Classic and HS2 platforms to provide vertical circulation for the new rail concourse above track level to the new LUL concourse below track level. This would be by escalator, lift and stairs. It is anticipated that interchange between the two concourse levels would be achieved locally to the points of access to HS2 and Classic platforms to minimise pedestrian movements and resulting conflicts. This central zone would also facilitate replacement vent shafts to the Underground lines.

3.7 General Site Development It is anticipated that the site would be developed by others as part of an integrated scheme. No master planning or urban planning was carried out as part of this study. Any development would respect the sight lines from Primrose Hill to St

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Paul’s Cathedral, which would limit the central zone of the site to approximately 50mOD (i.e. medium rise). The demolition of the westernmost office block would improve this sight line. However, the extension of the station footprint and throat to the west would displace four residential blocks owned by LB Camden and would significantly reduce St. James’s Gardens. The issues raised by these engineering requirements lie outside the scope of this report.

3.8 Constructability Euston station would be constructed in phases to enable retention of existing classic services throughout.Anumber of alternative sequences are being considered to reflect differing disruption and completion requirements. In all cases, the construction would start from the west taking in the site extension to Coburg Street, and then Platforms 14-18.

Services would then be temporary diverted from the low-numbered platforms into the newly constructed HS2 platforms, which would then support all the fast WCML services. At this stage, minor track modifications north of Park Road would segregate the fast and slow services and the final 4-line approach to the Classic Station would be completed.

The construction of the low-numbered platforms would then be followed by the middle zone of the station which currently serves the Slow WCML tracks.

Upon completion, the fast and slow services would be diverted back into their final platform allocations, and the HS2 platforms reconfigured for GC gauge.

3.9 Existing Train Services During Construction The construction phasing options would attempt to maximise the retention of existing classic services. Generally, the greater the Classic Service level to be retained, the more complex the construction process, overall construction programme, and disruption to passengers.

The current proposal would retain 14 classic platforms until HS2 was operational.

3.10 Platform Use during Construction During construction, the new high speed platforms would be occupied on a temporary basis by Classic Services.

It is proposed that the new HS2 platforms and deck above be constructed to facilitate transfer from Classic to GC gauge by building the structural envelope to the greatest required dimension. The dimension from deck to platform level would be set by the Classic gauge requirements and from centreline of track to platform edge by HS2 gauge requirements. Provision to raise the track level for HS2 could be through re-ballasting, and for the platform to Classic gauge conversion by replacement of the platform copings which would “bridge the gap” and at each change of platforms for the WCML station.

The horizontal alignment through the station and immediate throat would essentially then be unchanged between the two systems.

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3.11 Underground Facilities at Euston

3.11.1 LUL Lines Euston Underground station is served by the Victoria line and both branches of Northern line (City Branch and Charing Cross Branch) and it also directly connects to the Euston main line station concourse.

Passengers arriving by train wishing to access the Northern Line or Victoria Line platforms take the escalators located at the front of the station concourse area and descend to Underground Concourse level. At this level, passengers can purchase tickets and pass through the gates to continue their journey via two sets of escalators to an intermediate level.

From this level, two further sets of escalators provide access to and from platforms of the Victoria Line and the Northern Line City Branch.

Access to the Northern Line Charing Cross Platforms is also from this intermediate level and sets of stairs located at the end of the platforms.

3.11.2 Interchange Between Platforms Interchanges between the northbound and southbound Victoria and Northern City Line platforms are made via a passageway at the lower level. To access the Northern Line Charing Cross Branch from these platforms, passengers need to use the escalators to reach the intermediate level and then use the stairs to access both northbound and southbound platforms.

3.11.3 Current Station Arrangements Access to the underground is not step free. There are both up and down escalators as well as stairs.

Euston Station Underground Concourse area is relatively crowded and does not provide a free movement of passengers arriving or leaving the station. Passengers are frequently held in the main station concourse to relieve overcrowding in the Underground station.

There are no direct connections from street level to underground station and Euston Main Line station concourse is the only access point.

The HS2 proposal for the underground station would improve the station accessibility and would provide larger public concourse area for passengers as well as staff facilities and services.

3.11.4 Construction Phasing It would be essential to maintain LUL access throughout construction. This would require progressive staged construction and associated temporary ticketing facilities.

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The increase in passenger demand would impact on the construction staging:

●● Stage 1. A new concourse area would be constructed under the HS2 platforms linking the new part of the station via temporary walkways to the existing intermediate level. The new concourse area would provide 2 additional escalators to Northern Line platforms (Charing Cross Branch).

●● Stage 2. The east side of the concourse underground would be developed with 2 sets of additional escalators connecting the new concourse to Victoria and Northern line platforms (City Line) and one set of escalators for Northern line platforms (Charing Cross Branch).

●● Stage 3. The east and west concourses would be linked together in the centre creating one continuous public space.

The completed concourse would provide access and circulation from both the new station (High Speed 2) and from the new entrances at the front of the station, on Coburg Street and on Eversholt Street.

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4


Euston to Old Oak Common

4.1 Overview

From a portal immediately south of Park Road, the route would be in tunnel to Old Oak Common. The route would consist of twin 7.25m internal diameter tunnels, connected by cross-passages at 250m intervals.

It is assumed that all trains would stop at Old Oak Common.

4.2 The Horizontal Alignment The tunnels would head initially in a north-west direction on a 1,300m curve to pass to the north of Primrose Hill. This curve would limit the maximum speed to 180kph. The tunnels would pass below the existing WCML lines and the existing Primrose Hill Tunnels about 300m west of the tunnel portals.

The route would turn due west, then south-west, re-crossing below the WCML under South Hampstead Station. The alignment would then continue broadly parallel to the WCML. From the LUL Queens Park Station, the route would continue in tunnel beneath Kensal Green Cemetery, before entering Old Oak Common station.

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4.3 The Vertical Alignment The vertical alignment would be typically:

●● 27m below ground between Park Street and Primrose Hill;

●● 50m below South Hampstead;

●● 32m below ground under Queens Park;

●● 24m under Kensal Green Cemetery;

●● 16m below ground at the Old Oak Common Station location.

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4.4 Intervention Shafts Intermediate shafts would be needed to serve a number of separate or combined functions, inter alia:

●● tunnel ventilation;

●● draught/pressure relief;

●● emergency intervention access to the tunnels from surface; and

●● emergency passenger evacuation.

It was assumed that, to minimise their, each shaft would contain a number of combined functions namely:

●● emergency intervention access points and fire-protected stairs and lifts as appropriate;

●● provision for mechanical ventilation to assist in controlling smoke and hot gases in an emergency; and

●● provision for pressure relief/natural draught relief.

The proposed shafts would be located at:

Chainage (distance from Euston buffer stops (km))

Location Current land use

2+560 Adelaide Road Green area along railway embankment

3+885 Alexandra Place Commercial building/retail

5+800 Salusbury Road Car park/commercial buildings near existing railway

This report has yet to describe the proposed HS1 to HS2 link, but this link would be in tunnel, and would broadly parallel the Euston to Old Oak Common Tunnel, sharing its shaft provisions.

It was assumed that intermediate shafts would not be used for passenger evacuation in the event of an emergency. In this scenario, passengers would evacuate from the incident tunnel, via the cross-passages, to the non-incident tunnel which would act as a place of safety. They would then exit the tunnels via the portals (depending on the location of the incident) or via a dedicated relief or rescue train. All these emergency arrangements would be subject to future discussions with the emergency authorities and the HMRI/HSE.

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The shafts would contain mechanical and electrical equipment, and would require some form of structure at the surface. This structure is known as a “headhouse”. This headhouse would typically be a 2-storey building, and an image of a typical such headhouse is shown below.

Each headhouse would require a secure access from a public highway, and a typical urban arrangement is shown below.

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At the Adelaide Road Shaft location, there would be an additional requirement to provide an escape staircase, and the ventilation arrangements would be slightly more complicated because the HS1-HS2 Link tunnel, which would be higher than the Euston tunnels. This shaft would be taller or wider than proposed previously, but, as the structure would be located close to the bottom of a railway cutting, it is not anticipated that any more of the structure would be visible from street level.

4.5 Construction It is envisaged that the tunnels would be constructed from Old Oak Common towards Euston, such that the spoil (earth from tunnelling) would be brought to the Old Oak Common end for removal.

This tunnelling would not be able to begin until the Old Oak Common station box was substantially complete, and before completion of the station works. It is envisaged that two Tunnel Boring Machines (TBMs) would be used, with a slight lag between the two drives, with cutter-head refurbishment being carried out at the intermediate shafts. These tunnels would be driven through soft ground, generally competent (consistent and suitable for tunnelling) London Clay.

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5


The HS2 to HS1 Connection

5.1 Overview of the Connection It is proposed to construct a single-track rail connection between the existing HS1 line and the proposed HS2 line.

This connection is described here, but in order that the reader can understand what is proposed, it is necessary to briefly describe the layout at Old Oak Common Station.

At Old Oak Common, there would be a station constructed in a sub-surface concrete box. At the eastern end of the box, three tunnels would emerge. The northernmost tunnel would lead towards Euston, while the southernmost tunnel would carry trains from Euston. The HS1 link would be the central tunnel.

5.2 Alignment The HS1 link would lead from the Old Oak Common area towards the Chalk Farm area. It would be a single-track, GC-gauge link from Old Oak Common to the North London Line (NLL) at Camden Junction. A maximum speed of 160kph is proposed in the new tunnel, but existing linespeeds would be retained on the North London Line.

The route would begin at Old Oak Common in a single-track tunnel, approximately 15m below ground level between the HS2 Up and Down Line tunnels. It would be the same diameter as the HS2 tunnels (7.25m), and would initially lie between the Euston lines.

Between Old Oak Common and the shaft at Alexandra Place, the 3 tunnels would share a common alignment that would allow sharing of intervention shafts. Between the shafts at Alexandra Place and Adelaide Road, the HS1 link would begin to rise such that it would cross over the Euston-bound tunnel and then run to its north, while beginning its rise to the surface. The alignment of the tunnels would still be such that they can all be serviced by the intervention shaft at Adelaide Road.

The portal of the HS1 link tunnel would emerge on existing railway land near the disused Primrose Hill Station. This arrangement assumes that the existing “Up Empty-Stock line” tunnel, which is disused, would be abandoned.

From Camden Junction, the link would utilise the southern line across the Camden Viaduct through Camden Market. The proposed scheme would modify the existing Camden Road Station platform arrangement with the re-establishment of the northern platforms for NLL service.

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The line speed through Camden would be limited to approximately 60kph. The existing connection between HS1 at St Pancras Tunnel Portal and the north London Line corridor would be re-used. This connection was developed primarily for Eurostar access to the temporary maintenance facilities at North Pole and is now little used.

Whilst the new viaduct at the North London Line was designed for twin GC gauge operation, the remaining NLL connection was not enhanced and is standard W10 gauge. Full GC gauge provision is required, which is substantially larger than W10 gauge in both width and height. However, since running speeds would be severely constrained, the enhanced clearances associated with high speed operations have not been adopted.

The modifications on the North London Line corridor would be:

●● Reconstruction of Camden Lock and Camden Road bridges;

●● Modifications to south side of Randolph Street, Baynes Street and St Pancras Way bridges;

●● Widening of bridges at Kentish Town Road, Camden West Junction and at supermarket access;

●● Modifications to platforms and track layout at Camden Road Station;

●● Remodelling of Camden West Junction may be required; and

●● Installation of new turn-outs to connect to existing HS1 tracks.

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5.3 Intervention Shafts The inclusion of the HS1-HS2 Link tunnel does not alter the general assumptions for shaft provision and functionality on the Euston to Old Oak common tunnels, but Chapter 4 above described the changes necessary to incorporate the HS1-HS2 link.

5.4 Surface Access Requirements at the HS1-HS2 Link Portals

The portals and shafts would form part of the life safety and emergency intervention strategy and the portals would be one of the primary emergency access routes to the tunnels. The facilities at the portals are likely to be:

●● Hard standing provision for 2 x police vehicles, 4 x ambulances and 6 x fire appliances;

●● Emergency services Forward Incident Control Post (FICP);

●● Muster Area;

●● Walkway to Tunnel Portal.

It is assumed that the required permanent access area would be approximately 750-1000m².

The Primrose Hill portal would be located between two existing rail corridors and access for construction as well as emergency intervention in the permanent case will need detailed planning as the design of the scheme is developed.

During construction, sufficient space will be required for the TBM and, for this reason, it is likely that the permanent access area would be significantly reduced in size from the site needed for a lay-down area during construction.

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6


Old Oak Common Station (West London Interchange)

6.1 Introduction There would be a station at Old Oak Common, aligned approximately east-west.

It would occupy the site of the existing First Great Western Depot (which should become redundant in about 2020 after the introduction of new rolling stock) and Heathrow Express Depot (which would require displacement).

The station would provide interchange with Crossrail, by means of platforms to be constructed on the Great Western Main Line (GWML) at this location.

The station would be formed in an open cut box (similar to that at Stratford International Station) approximately 1000m long, 60m wide and 15m deep. Four piled walls would be constructed from ground level, and then excavation would take place to create the void for the platforms and tracks. The wall at the easterly end of the structure would receive 3 tunnel bores; the western end would have 2.

Image of Stratford International Station showing typical layout and size of cut-and-cover box for Old Oak Common.

Construction of a significant part of this box would be required before tunnelling could begin towards Euston on the main HS2 alignment and towards Primrose Hill on the HS1 to HS2 connection.

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6.2 Track and Platform Arrangements on HS2 As presently conceived, there would be 3 platforms, arranged as follows:

●● Anortherly island platform (two platform faces) serving HS2 trains heading to Euston;

●● A central island platform (2 platform faces) serving trains to and from the HS1 to HS2 connection, but also possibly accessible for trains to and from Euston and the Midlands;

●● A southerly island platform (2 platform faces) serving trains from Euston to the Midlands.

There would be no “non-stop” through lines.

6.3 Platform Arrangements for the HS1 to HS2 Link The international aspects of the HS1 to HS2 connection have implications on platform design and access control arrangements on the central platform. There would be options for this platform usage:

●● The central platform could be a terminal “Europe” platform. Passengers would alight from the HS2 train from the North, and would pass through immigration/security controls as they moved to the “Europe” platform. There would be no connections to HS2 at the west end of the station box.

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●● Train service frequency on the HS2 to HS1 link would be governed by the turn-round/layover times in the platforms, and the time occupancy of the single-track HS2 to HS1 connection.

●● A Through-running Platform to the HS2-HS1 link. There would be a connection to HS2 at the west end of the station box, so trains could run directly from the North through Old Oak Common and on to HS1. This would require an enlargement of the station box to the west to accommodate the required connections. Train service frequency on the HS2 to HS1 link would no longer be governed by the turn-round/layover times in the platform, but only by the time occupancy of the single-track HS2 to HS1 connection. Security and immigration issues would have to be addressed, either at the passengers’ originating stations, or on the train during the journey.

6.4 Platform Arrangements – GWML and Crossrail Old Oak Common Station would provide interchange with the Great Western Main Line.

Two island platforms (four platform faces) would be provided on the GWML Fast Lines, to permit successive trains to call without cumulative delay. The GWML Up Relief Line and the Down GWML Relief Line would have a platform face. There would also be an east-facing bay platform, with two platform faces and turnback facilities for Crossrail.

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6.5 Concourse The station would initially function largely as an interchange as there would only be modest local passenger demand, but this might change if redevelopment of the area was envisaged and implemented. Concourse facilities would be provided immediately above HS2 at approximately 6m below ground. This would link directly beneath the GWML and Crossrail at the same level. Both GWML and Crossrail platforms would be served by two banks of two escalators per platform, together with lifts and stairs. Additional segregated space for international traffic could be provided.

6.6 Crossrail Depot Crossrail propose to site their new maintenance facility and stabling (up to 35 tracks) immediately north of the proposed HS2 Old Oak Common Station. The new HS2 station would replace the existing GWML depot.

The proposed Crossrail depot does not have full grade-separation with the Relief Lines, but this would need to be reviewed if Crossrail were to be extended to Reading (14tph) and there were to be a turnback at Old Oak Common.

6.7 Effects on Existing Old Oak Depot The new HS2 station would replace the existing GWML depot which would have, by this time, become largely redundant. The relocation of facilities to the North Pole Depot leaves only Heathrow Express services using the old depot. This facility would require relocation.

6.8 Construction The station would be formed in an open cut box. The concourse would be sited at -1 level above the tracks (at level -2) with links to the ground level new GWML Station and Crossrail Station beneath the existing GWML tracks (at level 0). If emergency or full operational crossovers were required at both ends of the station, the box might need to be enlarged. The box would be sited to avoid conflict with the Crossrail Depot access line.

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7


Old Oak Common to the Ruislip Area

7.1 The Principles of On-Line Widening Between Old Oak Common and South Ruislip, the existing Network Rail tracks would be lifted, and the new HS2 line would generally adopt its position. The new lines would run alongside, and to the north of, the LUL Central Line. Speeds would be limited to 250kph, although the alignment could permit higher speeds.

The route would lie as close to the LUL lines consistent with 250kph rail standards. The cross-section would be accommodated by one or more of the following techniques along the section of route:

●● Placing the HS2 lines on the former Network Rail alignment without any effect on existing cutting or embankment slopes;

●● The use of retaining walls to contain the scheme without the need to acquire adjacent land;

●● Purchase of adjacent land where the width is too restrictive. In most cases, land acquisition would be less than 10m.

Wherever possible, existing bridges over the railway would be retained and the open spans would be used to accommodate one or both tracks, by lowering the track bed if necessary to achieve the GC gauge headroom. Where the bridge carries the railway over an obstruction, it would be widened and/or strengthened as necessary.

At each structure, a position of the HS2 centre-line was determined based on accommodating the GC Gauge. Clearly, where structures are in close succession, the centre line position might be such that a flowing 250kph alignment joining one structure to the next could not be achieved, perhaps passing satisfactorily passing through one structure, but not its neighbour. Between structures, the aim was to achieve, as far as possible given property constraints, a 250kph cross-section.

7.2 The Connection to Heathrow

It is necessary, when describing the route between Acton and West Ruislip, to introduce the concept of proposed connections to the Heathrow area.

These connections would consist of “stub ends” allowing later construction of the Heathrow link. In some cases, the stub ends could require substantial engineering provision, and it is clear where the subsequent alignment towards Heathrow would be. In other cases, only minimal stub provision is envisaged, affording later designers more freedom in alignment design.

The Heathrow provisions would consist of:

●● A junction in the Northolt area, with a south-facing connection;

●● A junction in the West Ruislip area with a south-facing connection;

●● A junction in the Denham area with a north-facing connection.

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Between them, these three junctions would allow Heathrow to be served either as a spur off a triangular delta junction in the Denham/West Ruislip area, or as a loop connecting the Denham junction to a South Ruislip junction. These junctions are described in the relevant route section.

7.3 Old Oak Common to Acton At the western end of the Old Oak Common Station box, the route would be in twin 7.25m tunnels, separated resulting from the central HS1 to HS2 platform. The tunnels would swing round to head north-west, on a radius capable of initially 225kph, then 250kph.

The tunnels would rise to a portal immediately to the east of Park Royal Road. The track level at the tunnel portal would be approximately 14m below ground level. This area is currently in use as an aggregate storage yard, and would provide sufficient space to allow the construction of the portal structure.

It is envisaged that the tunnel towards Acton would, like the Euston to Old Oak Common tunnel, be carried out from the Old Oak Common end as existing rail infrastructure could be utilised for removing excavated material and transporting in tunnel lining segments.

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7.4 Acton Portal to Hanger Lane At the Acton Portal, the horizontal alignments of the Up and Down lines would be separated by about 15m, as they emerge from the twin running tunnels.

Between the Acton Portal and Park Royal, the railway would rise between retaining walls to minimise the land requirement. North of Park Royal Road, these separated alignments would begin to converge towards each other. Construction of the retained cut would involve severance of Park Royal Road during construction, but would allow a replacement structure of span arrangements to match the proposed HS2 alignments and the existing LUL track positions. The road would be closed for a prolonged period.

7.5 Park Royal Footbridge, Coronation Road and Piccadilly Line

These 3 bridges follow each other in rapid succession.

Park Royal footbridge has a span over the LUL lines and a span over the Network Rail alignments which would become HS2. It is possible to accommodate HS2 horizontally and vertically with no alterations to the structure or ground levels.

Coronation Road is a single span structure, high above the LUL and Network Rail tracks. HS2 could be accommodated horizontally and vertically.

The LUL Piccadilly Line would lie over the proposed route. The bridge can neither (realistically) be moved, nor slewed on to a replacement structure, nor raised. The span is of sufficient width to accommodate HS2 laterally, but the track bed level would need to be lowered to achieve GC gauge. Subject to design development, a solution could be achieved by the use of dwarf retaining walls set “inside” the abutment and intermediate pier.

7.6 Hanger Lane Gyratory At the A40 Hanger Lane Gyratory system, the A40 runs east-west in an underpass, with Hanger Lane LUL station in the complex. The gyratory is a very heavily trafficked junction and includes two overbridges: one with five lanes and the other with eight lanes.

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The East Bridge has 2 brick arches carrying the LUL tracks, widely separated by the LUL island platform. There is then a “middle” span through which the Network Rail lines run, and a more northerly span with no railway infrastructure under it. The whole structure carries 8 lanes of highway traffic, but is split longitudinally, having been extended (widened) in the past. The West Bridge is a single span structure over all of the LUL and Network Rail lines. It appears to be wide enough and high enough to accommodate HS2 with, perhaps, a marginal lowering of the formation. The difficulty that arises is that it is not possible to devise a horizontal alignment for 250kph that retains both bridges.

The preferred option is therefore the on-line replacement of the East Bridge, retaining the road alignments. Comprehensive traffic management regime would be required so as to keep disruption to traffic to reasonable minimum. It is envisaged that the existing LUL station and lines would remain in their present positions during and after the completion of the HS2 works.

7.7 Hanger Lane to Northolt There are a number of bridges carrying the railway over roads, canals, other railways and footpath subways. Based on a high-level visual survey and subject to design development and detailed survey, it is assumed that all could be widened, extended or strengthened to accommodate HS2.

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7.8 Northolt Area In the Northolt area, there is a succession of 3 bridges over the planned route of HS2. All three must be considered together. These bridges are:

●● A public footpath connecting to Carr Road. This could be rebuilt on line with a temporary closure, or replaced off-line retaining the link. It could be raised to create the necessary headroom.

●● Mandeville Road (at Northolt LUL Station). The span through which the Network Rail tracks pass is sufficiently wide to accommodate HS2. The headroom is such that some lowering of the formation would be required. This appears to be readily achievable.

●● Eastcote Lane. As at Mandeville Road, the span through which the Network Rail tracks pass is sufficiently wide to accommodate 2 x GC trains. The headroom is such that some lowering of the formation would be required. This appears to be achievable by the construction of dwarf retaining walls set inside the abutment/piers.

In this area, there would be provision for a Heathrow link. North of the Grand Union Canal, the HS2 lines would include London-facing junctions, with a 4-track route north thereof. The outer pair of lines would descend between retaining walls to form the Heathrow connection, while the inner pair of lines would be the HS2 through route. Near Willow Tree Primary School, the outer pair of lines would pass under the LUL line, heading in a south-westerly direction.

7.9 South Ruislip At South Ruislip, Chiltern Railways is constructing “Evergreen 3” which will involve:

●● Doubling the present single line from Northolt Junction towards Neasden to a double-track, 160kph alignment;

●● Retention of the Down single-track as a bi-directional loop;

●● Platform works at South Ruislip station;

●● Modifications to the Northolt Junction to Old Oak West Junction line;

●● Modifications to the connections to the West London Waste Terminal.

Between South Ruislip and West Ruislip, the new HS2 lines would run wholly to the north of the Chiltern lines. In order to do so, they would need to cross the Chiltern alignments. It is proposed to build a “half up/half down” viaduct. The proposed Chiltern lines would be re-aligned to the south and elevated on viaduct about 3m to 4m height. This viaduct would be built clear of the proposed lines and station. HS2 would be lowered about 3m to 4m below ground to create the overall headroom needed and would pass below Chiltern. During construction, the Chiltern services and station would be unaffected.

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7.10 West Ruislip/Ickenham Road Ickenham Road and the station footbridge have a single span over the Chiltern lines (Down Main, Up Main, Up Platform loop). The Down platform has historically been pulled forward over the space formerly occupied by the Down Loop.

It is proposed to align the new HS2 lines not only to the north of the existing lines, but also to the north of the Up platform. This would leave the station unaffected, but would require one of the following two options;

●● Construction of a “thrust box” (concrete rectangular tube cross-section structure) under Ickenham Road. The new HS2 lines would pass through this box about 1.5m lower than the Chiltern Line’s levels in order to leave Ickenham Road at its present level.

●● Reconstruction of the Ickenham Road bridge to provide a multi-span bridge over Chiltern and HS2, probably by re-building the bridge in two longitudinal halves, and restricting traffic to half the current carriageway width during construction.

In both cases, the Chiltern lines and platforms would remain in their present positions, served as they are now. HS2 would be separated by some margin from the Chiltern tracks, passing to the north of and behind the Up platform buildings.

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7.11 West Ruislip to M25 The line speed would rise to 300kph at West Ruislip.

West of West Ruislip Station, the Chiltern Line turns slightly south. The HS lines would also turn to the south, but then the two rail corridors would start to diverge. The route would cross over the River Pinn and Breakspear Road on a new bridge and pass into a 1km long cutting. At this point, the new cutting for the HS corridor would be adjacent to the cutting for the Chiltern Line corridor. The cutting would have a maximum depth of 17m, comparable to the adjacent Chiltern Line cutting.

West of West Ruislip, there would be a Heathrow link. The route would include a London-facing junction, with a 4-track route west thereof. The outer pair of lines would descend into tunnel to form the Heathrow connection, while the inner pair of lines would be the HS2 through route.

The HS alignment would then cross the River Colne and its valley on a viaduct. The 3.6km long viaduct would be a maximum of 16m high due to the shallow nature of the valley; the design was based on a constant gradient over the whole length of the structure. Although the line’s geometry could allow 360kph from the Colne Valley to the M25 and then the Amersham Tunnel portal, this speed would not be usable given the 320kph speed of the tunnel itself. The viaduct would cross three flooded gravel pits, the River Colne, the Grand Union Canal and two roads including the A412 North Orbital Road. The design assumes that it would be possible to locate piers in the flooded gravel pits.

The viaduct would end immediately to the north of Northmoor Hill Wood with the alignment then continuing in a series of embankments and cuttings towards the M25. The topography of the land in this location results in the M25 being at the top of a slope. The HS2 alignment would therefore continue at a very shallow gradient and enter a tunnel portal immediately to the east of the M25. The gradient of the hillside would necessitate a 480m long approach to the tunnel portal which could either be formed as a cutting or a retained structure.

Just east of the M25 area, there would be Birmingham-facing connections to a Heathrow link. Here, the provision would be the space required to accommodate future turnouts from the main HS2 alignment.

Amersham Tunnel’s southern portal would be just south of the M25.

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8


The Chilterns: M25 to Wendover

8.1 The M25 to Amersham Tunnel The M25 to Amersham Tunnel would run from the M25 to a point north-west of Amersham Old Town.

Because of its length, the tunnel would consist of twin 8.7m internal diameter bores, connected by cross-passages at 250m intervals, allowing speeds of 320kph. The length of the tunnels would be approximately 9.6km.

The tunnel would be between 22m and 52m below ground, typically at least 33m from track level to the ground. The tunnel(s) would run under fields to the north of Chalfont St Peter and then pass under Chalfont St. Giles. The route would then pass under the River Misbourne valley towards Amersham and pass beneath residential properties at the southern side of Amersham. The alignment would run to the north of Amersham Old Town before emerging at the tunnel portal near Old Amersham Farm.

At two locations, the route would pass below the River Misbourne, at a depth of at least 24m. Detailed investigations would be required into the nature of the geology in the valley bottom at these locations. The presence of buried river valleys and saturated gravels or fines may require the tunnel(s) to be constructed deeper or special mitigation measures implemented.

Four intervention shafts are likely to be needed. The shafts would generally be adjacent to existing roads to facilitate both construction and long-term access. Local road construction might be required to provide suitable access. Space would also be required around the shaft to accommodate maintenance vehicles and emergency services vehicles. These could be required to access the tunnels for both routine and emergency maintenance access, during training exercises and in case of tunnel evacuation.

This would be a long tunnel under residential areas, and would probably use TBM construction techniques. The two ends of the tunnel would be in relatively empty areas in terms of construction site, but proximity to the motorway could be advantageous. The proximity of the south end of the tunnel to the Chiltern line offers the opportunity to investigate the use of rail transport for spoil disposal, but it is likely that export by road transport will be also be needed along the M25.

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8.2 Amersham to Little Missenden After emerging from Amersham Tunnel’s northern portal, the route would be in a partially retained cutting to the Little Missenden Tunnel. The cutting would run parallel and to the north of the A413 dual carriageway.

This area comprises a series of transverse valleys running down to the main valley. The route would cross these, resulting in significant variations in the depths of cuttings. The cutting would be about 2.4km in length, and between 12m and 26m deep. At this depth, none of the railway would be visible in a level view, and all the overhead electrification apparatus etc would also not be visible.

The whole length of the cutting would be a mixture of partial open and partial retained cutting. This means that, upwards from track level, there would initially be retaining walls, propped at the high level, but the upper slopes would be normal earthworks side-slopes.

Example of “Partial Retained Cut” where the upper slope is a cutting, and the lower part is a retaining wall.

© Copyright David Anstiss and licensed for reuse under this Creative Commons Licence.

Along this length, a “green tunnel” is proposed where two public footpaths lead from the A413 towards High Spring Wood. The bridge would be at ground level, and would straddle between the retaining walls. The bridges would provide continuity of public crossings and environmental/planting mitigation. The roads along this length (such as Weedon Hill Road and Keepers Lane) would be maintained at their present level, again on bridges straddling between retaining walls.

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8.3 Little Missenden Tunnel Immediately south of the Chiltern Railway line, the route would enter Little Missenden Tunnel.

Because of its short length (1.26km), the tunnel would not require cross-passages, and would be a single bore, in the form of a flattened ellipse, with a width of about 15m and a height of about 10m. The tunnel would pass beneath the existing rail corridor and under a hill. The ground surface climbs to the north, and the tunnel vertical alignment would also climb to match it.

The western side of the hill (which is tunnelled through) is very steep resulting in the approach portal being only 100m long. The northern portal of the tunnel would be near Mantle’s Wood.

8.4 The 400kph Route From this northern portal, the line speed would rise to 400kph, a speed which would be continuously maintained over the next 114km to the vicinity of the National Exhibition Centre area near Birmingham. This constant speed would minimise the number of changes in the speed profile, avoiding the energy implications of successive braking and re-acceleration.

8.5 Little Missenden to the South Heath Area The route would then rise up the northern side of the valley, and then run along the relatively level top of the Chiltern Hills.

The route would run in continuous cutting to the South Heath area. The cutting would generally be sufficiently deep that none of the railway and its apparatus would be visible in a level view.

The route would pass below Hyde Lane about 16m below ground, before entering a green tunnel of 900m length from south of Chesham Road to north of Frith Hill. Both roads would remain on their present alignments, at their present levels, on the lid of the green tunnel. At Chesham Road, HS2 would be 17m below ground, and 8m at Frith Hill. The “green tunnel” would allow The Coppice to be restored after completion of the cutting works.

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8.6 South Heath to Wendover The route would continue in 10m cutting under Leather Lane, which would be bridged over the route at its existing level. For the majority of this length, the route would run parallel to a pylon line.

Northwards from Bowood Lane, the route would follow the hillside down towards Wendover. The alignment would cross a steep valley in the Wendover Dean area on a 450m viaduct in the vicinity of Durham Farm. The use of an elevated alignment would necessitate a series of underbridges for the roads which would be crossed between the top of the hill and the A413 London Road.

A 500m viaduct would be used to cross the A413, railway and adjacent road at the southern end of the Wendover Bypass.

8.7 Wendover The route would follow the alignment of the Wendover Bypass, to its west. The route would affect Bacombe Lane and Ellesborough Road, with loss of 6 residential properties on Ellesborough Road. The route would incorporate a green tunnel at Ellesborough Road, though it would not be possibly to wholly bury this structure below ground, and exposed parts would require landscaping measures. There is likely to be a substantial road diversion to pick up the severed part of Bacombe Lane and to ensure connectivity of Ellesborough Road towards Wendover. Pedestrian links would remain along the existing alignments.

The route would then continue to run to the south-west of the Wendover Bypass, generally on embankment between 3m and 5m high to the Nash Lee Road area. The route would pass over Nash Lee Road, which would have to be diverted and lowered, with a new terminal roundabout at the northern end of Wendover Bypass.

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9


Wendover to Quainton The route would now enter a much flatter and low-lying landscape north of Stoke Mandeville.

9.1 Stoke Mandeville Northwards from Nash Lee Road, the route would run north-westwards to pass to the west of both Stoke Mandeville and Aylesbury.

It would cross above the A4010 Risborough Road at a gap in property near Old Risborough Road, and this section would run on a 600m viaduct avoiding the flood plain. The route would pass under a diverted Marsh Lane.

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9.2 Aylesbury (Southcourt Area) The route would be at existing ground level at the point where it would cross the existing railway from Princes Risborough to Aylesbury, which would have to be re-aligned and raised to create sufficient vertical clearance for HS2.

The route would pass about 200m from the Southcourt area of Aylesbury, and would then be elevated on a 200m viaduct across part of a flood plain.

9.3 Hartwell Area The route would generally be on shallow embankment until the A418 Oxford Road, on which works would be required to allow it to cross over HS2. The exact alignment has not been determined, and temporary works may be needed.

The route would then pass through the edge of the grounds of Hartwell House and through Aylesbury Park Golf Club, and there would be a need to consider a re-configuration of the layout.

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9.4 Aylesbury to Waddesdon North of Aylesbury and Stone, the route would generally follow the existing terrain, subsequently being raised on a viaduct to cross the River Thame and its flood plain on a 1000m long viaduct.

At the A41, the HS2 alignment would be about ground level, and the road would be realigned to the north and raised to pass over the route. The route would then pass about 500m east of Waddesdon. The line would generally be at-grade except for a short section on viaduct/bridges over the River Ray and its flood plain.

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9.5 Waddesdon to Quainton At Quainton, the route would join the Great Central Railway corridor, joining it in the vicinity of the Buckinghamshire Railway Centre and Station Road, which would have to be realigned and diverted.

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10


The Great Central Corridor: Quainton to Brackley

From Quainton to Brackley, the alignment would follow the partly-used but largely-abandoned Great Central (GC) Railway corridor.

10.1 Quainton to Calvert The route would run at ground level for about 7km along the railway corridor.

Approaching Calvert, the route would lie to the immediate west of the used portion of the Great Central route, which serves the Waste Recycling Group’s land fill site. There would be some loss of woodland from Sheephouse Wood. The bridge carrying the local road over the existing railway infrastructure at Calvert would have to be replaced, off-line, in order to create lateral space and headroom for HS2.

The Great Central route would still be usable for access to the land fill facility, by means of a new vehicular bridge over HS2.

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10.2 The Infrastructure Maintenance Depot In the Calvert area, an HS2 infrastructure maintenance depot is proposed.

The depot would be alongside the East-West Rail route between Bicester, Claydon LNE Junction and Bletchley, near Steeple Claydon. Placing the depot here would allow maintenance trains and on-track plant (for example ballast trains) use the WCML at Bletchley to gain access to HS2. There would be a link connecting HS2 to East–West Rail.

The depot would consist of:

●● Office accommodation, workshops and internal storage;

●● Maintenance shed;

●● Rail plant fuelling points;

●● Area for materials and equipment;

●● Access roads and parking;

●● Security measures.

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Further work is needed to devise an optimum layout accommodating the existing lines, Claydon LNE Junction, the HS2 line, and the spur to the maintenance depot.

The local road network would be affected by the HS2 route and the diverted East – West route, and it would be necessary to accommodate significant road diversions in this area.

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10.3 Calvert to Twyford North of Calvert and the Calvert Jubilee Nature Reserve, the East-West Rail Line is used for domestic waste “bin liner” trains from the Oxford direction towards Waste Transfer facility by reversal. There are proposals to considerably improve East-West Rail in this area, to deliver a 160kph passenger railway. The proposed HS2 route, being at ground level, would sever East-West Rail, which is also at ground level. East-West Rail would therefore have to be raised about 8m above HS2.

The route would be on the Great Central alignment just to the north of Twyford, crossing the flood plain there.

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10.4 Twyford to Newton Purcell North of Twyford, at Chetwode, the curve required to sustain 400kph speeds is such that the Great Central corridor could no longer be directly followed. The route would take a smoother alignment to the east.

The route would regain the GC formation at Newton Purcell, crossing the A4421, which would have to be diverted to the north over a length of about 1.5km.

The route would then be on the GC alignment to Mixbury.

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11


Mixbury/Brackley to Lower Boddington

11.1 Mixbury – the End of the Great Central Corridor The route, approaching this area from the south, could no longer follow the alignment of the Great Central railway corridor through Brackley. The route would therefore deviate to the east of Mixbury, leaving the GC corridor from this point north.

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11.2 Turweston, Brackley and Radstone The route would pass to the east of Turweston.

There would be a viaduct over the River Great Ouse flood plain about 700m west of Westbury, and the route would then run to the east of Turweston, by here being in a deep (up to 19m) cutting. The route would then cross the flood plain on a viaduct, before crossing the A43 east of Brackley. The A43 would have to be diverted to the north to create the headroom required for HS2. The route would then pass about 200m south of Radstone, and north of Hall Farm.

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11.3 Radstone to Greatworth Over the 11km length from Radstone to Edgcote, the route would adopt a virtually straight alignment.

In doing so, it would pass about 300m north-east of Greatworth, affecting Greatworth Park. The B4525 would cross the route where it would be in a 9m cutting.

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11.4 Thorpe Mandeville to Edgcote The cutting would continue north to the Thorpe Mandeville area, on a gradient falling into the valley of the River Cherwell near Edgcote.

The route would pass just south of Lower Thorpe Farm, probably requiring a lowering of the existing lane in that area. The route would cross the River Cherwell near Blackgrounds, passing about 600m north-east of Edgcote House.

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11.5 Chipping Warden to Lower Boddington The route would run north out of the valley of the Cherwell to pass in a cutting north-west of Chipping Warden. The cutting would typically be between 8m and 15m deep, about 200m from the village. In order to mitigate the environmental effects of the route, it is proposed to place the route in a green tunnel of 1,000m in length. Because the route would in any event be in cutting, it would be possible to create a box structure to surround the railway, and to restore the surface features such as the A361, local roads and other accesses at their existing level.

The route would continue north in increasingly deep cutting. It would pass through the disused airfield and about 500m south-west of Aston-le-Walls. The depth of the cutting (up to 32m) was determined by the need to be at low level near Lower Boddington to keep environmental impacts as low as possible. The route would emerge from cutting at the relatively abrupt change in landform west of Valley View Farm, near the disused rail line. The route would then continue onto a shallow embankment (about 4m in height) over the flood plain.

The route would be virtually at ground level south of Lower Boddington, about 400m to its south.

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12


Wormleighton to Burton Green

12.1 The Wormleighton Area The route would head north-west, to avoid the steepening hillside running north towards Stoneton. The route would avoid the Fox Covert woodland and Berryhill plantation.

The alignment would pass about 800m east of Wormleighton in a cutting typically between 8m and 12m deep. It would then cross the Oxford Canal and a series of waterways and flood plains on embankments and bridges towards Ladbroke.

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12.2 Ladbroke The route would run more or less at ground level between Radbourne and Ladbroke, except for a very localised cutting up to 26m deep at Windmill Hill.

The route would then pass north-east of Ladbroke, just above ground level, at about 600m distance. The A423 would have to be diverted and raised to pass over HS2.

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12.3 Southam, and Long Itchington Wood Tunnel The route would pass about 100m from the southerly apex of the Southam Industrial estate, but more typically 600m from the nearest residential areas. The route would sever the B4451, which would have to be reconnected to the existing road network, possibly involving loss of some light industrial property.

The route would cross the River Itchen on a short (110m) viaduct, before passing into a deep cutting on the approach to Long Itchington Wood Tunnel. The route would pass below the A425, affecting Lower Farm. It will also pass closely to the south-western corner of the Dallas Burston Polo Grounds.

Near Ufton, the alignment would pass into a cutting up to 30m deep, before entering Long Itchington Wood Tunnel, needed to protect the SSSI. The tunnel would be 1,000m in length, covering the full extent of the SSSI. The tunnel would be twin-bore with the approximate internal diameter of each bore being 10.2m. The tunnel separation would be approximately 25m and there would be 2 cross-passages connecting the two bores over this length.

The route would emerge from tunnel near Wood Farm, in an 11m cutting.

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12.4 Offchurch and Cubbington Upon exiting the tunnel at Wood Farm, the alignment would pass over the Grand Union Canal on an embankment up to 7m in height, before entering a cutting (typically 18m to 23m deep) at the Fosse Way.

The route would lie about 700m east of Offchurch, emerging from cutting and remaining at ground level, at Ash Beds. The route would then remain at ground level before crossing the River Leam on a 9m embankment.

The route would enter a cutting typically 16m to 20m deep through South Cubbington Wood in order to provide a degree of mitigation to the village, which would lie about 500m from the route. The cutting would gradually reduce in depth, until the route emerges at ground level at the A445, Leicester Lane, which would have to be raised to pass over HS2.

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12.5 The National Agricultural Centre, Stoneleigh The route would run at ground level from the A445 to the National Agricultural Centre (NAC).

The route would sever the B4113 just north of its junction with the road to Stareton and the NAC access junction, requiring both roads to be realigned and elevated over HS2. The route would then pass through the northern side of the NAC, and just south of Stare Bridge.

The alignment would cross the River Avon on the western perimeter of the NAC, and would then pass below the present alignment of the B4115, which would be raised.

The route would then pass in 10m cutting below the A46 Kenilworth Eastern Bypass about 1km south of the Stoneleigh junction. It is anticipated that a cut and cover or jacked tunnel would be constructed under the A46.

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12.6 Stoneleigh to Burton Green Dalehouse Lane would be severed and diverted up the valley slope, and the route would involve the permanent acquisition of Dalehouse Farm.

The route would cross Finham Brook and pass under the Leamington to Coventry railway. The route would be in cutting in this area.

The alignment would then sever the A429 at Crackley, which would need to be diverted. The route would then cross Crackley Brook and its flood plain, but the brook may have to be permanently realigned if sufficient vertical clearance could not be achieved locally.

The route would then rise in cuttings of 10m then 15m depth towards Burton Green.

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13


The West Midlands

13.1 Burton Green At Burton Green, the route would join the abandoned Kenilworth to Berkswell railway line, and would pass through a tightly constrained gap in residential property.

This gap arises because much of the development in the area is “ribbon development” alongside the historic road network. The route would use the existing railway cutting formation, widening and deepening it to contain the width and height of the new route. Because of the constrained circumstances, the route would include retaining walls at the tightest locations, and would also be enclosed in a “green tunnel” of 300m in length. A “lid” would be created on which Cromwell Lane would be reinstated following a temporary diversion from the Red Lane area to Hodgetts Lane.

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13.2 Berkswell to the NEC Area East of Berkswell Station, the alignment would diverge away from the existing disused railway corridor and would cross the Birmingham to Coventry Railway Line north of Balsall Common and Berkswell Station on a 50m bridge, 8m high. The alignment would pass alongside the lakes adjacent to the Station and would then broadly follow the A452 as far as Middle Bickenhill.

The route would then follow the descending ground levels (towards the River Blythe) and would cross the A452 near Marsh Lane, and major permanent and temporary works would be needed to maintain continuity of the A452, which would be lifted over the route.

The route would cross the River Blythe and adjoining tributaries on shallow embankments and viaducts, with local roads being diverted and raised.

As the route approaches the proposed station at Birmingham Interchange, the existing A45 would need to be raised by about 3m, with a new overbridge to enable HS2 to approach the station at-grade requiring extensive traffic management.

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13.3 Birmingham Interchange Station An interchange station would be provided near to the existing Birmingham International Station serving both the Airport and NEC.

13.3.1 Track Arrangements South of the station, HS2 would bifurcate to form a 4-track railway, and the outer pair of lines would then further split to create 4 platform lines (an Up Island and a Down Island); there would be 2 through lines. North of the station, there would, like in the south, be a 4-track railway, with the outer pair of lines further bifurcating to create a 2-track route towards central Birmingham (see section 16).

13.3.2 The Interchange Concept – Station Arrangement Situated east of the M42, near to NEC, Birmingham International Station and Birmingham Airport, it would be a parkway-style station, with major road access requirements and car parking provision. There would be inter-connected access between all these components.

Two island platforms (four platform edges) would be provided, as well as two through non-stop lines. The westerly island would serve trains towards central Birmingham, or those stopping services on the London to North-West axis. The southbound platform would be fed by trains from Birmingham or the North-west towards London. Each platform island would be accessed by two banks of two escalators. Escape bridges would also be provided to the extreme ends of the platforms.

The concourse, directly accessed from the multi-storey car park to the east, would be suspended above the platform level. The concourse would connect directly to a people-mover adjacent to the platform zone aligned approximately north-south. This would provide interchange with the NEC Halls, Birmingham International Station, and Birmingham International Airport.

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13.3.3 Highway Access Arrangements Based on passenger demand forecasts, potential highway traffic loadings have been estimated in order to determine the major alterations needed in this area. These are likely to be the following (subject to much more detailed traffic assessments):

●● a connection from the station itself to the local network (assumed to be off the A452);

●● Improvements and widening of the circulatory carriageway and bridges at M42 J6 (NEC Junction);

●● Modification of A45 between M42 J6 and the A45/A452 junction (Stonebridge);

●● A segregated left-turning lane, with signalisation and circulatory carriageway widening on A452 between Stonebridge and the Station Junction;

●● Widening of the circulatory carriageway and full signalisation at M6 J4 (Coleshill).

13.3.4 Car Parking The passenger demand figures were used to derive an indicative number of car parking spaces required at the Interchange.

A multi-storey car park is presently proposed, with a total of 7,000 spaces over 5 floors, in a building of approximate dimensions 200m x 200m.

13.3.5 Internal Circulatory Road System

Given the car park location, a layout was prepared for an internal roadway system, serving the car park, a short-stay/drop-off area, and provision for coaches, taxis etc.

13.3.6 A People Mover to the Airport The new station is close to the NEC and Birmingham Airport.

A people-mover is proposed to facilitate connectivity. This connection would be of high capacity (potentially significant numbers of users at major NEC exhibitions etc) and of high speed as the distances involved are lengthy. It was assumed that a maximum of 2,000 passengers per hour would be carried, in vehicular units of about 100 passengers at a frequency of 20 per hour.

A twin-track APM system was assumed, and an indicative alignment derived. Most of this alignment would be on high-level structure crossing the M42 and would connect into the NEC and Airport.

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13.3.7 River Diversion The proposed station would cross Hollywell Brook, and an initial study was undertaken into the extent and effects of a river diversion. It was established that an approximate 1,200m diversion would be required with a 50m bridge, 3m high, built to carry the high speed lines over the diversion adjacent to the A45. This diversion was not considered likely to adversely affect the hydrology in this area. The south end of the station would be built on fill.

It is at this point that the 400kph design speed ends, although it is resumed further north.

13.4 The NEC/Birmingham Business Park Area North of the proposed Birmingham Interchange Station, the route would cross the M42 at exactly the position of the roundabout serving the A452, A446, B4438, the Birmingham Business Park and the NEC. HS2 would be at the same level as the present roundabout, and the road network in the area would be substantially altered as a result of severing this junction.

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14


The Coleshill/Water Orton Delta Junction

14.1 Birmingham Interchange Station to Coleshill The route would then fringe the westerly edge of the Business Park, before crossing the M6 to the immediate east of the eastern fringe of Chelmsley Wood, requiring the diversion of Coleshill Heath Road. The route would just avoid the 270° loop from the M42 to the M6.

The route would then include a “Delta Junction” to the west of Coleshill.

14.2 Overall Layout The three sides of the “Delta Junction” are:

●● A 4-track HS2 line running approximately north-south (the ‘Main Line’);

●● A twin-track link towards Birmingham heading north-west, then west towards the Water Orton area (the south link), named the ‘Up and Down Birmingham’.

●● A twin-track link from the Water Orton area back to the HS2 main line (the north link), named the ‘Up and Down Spur’

All the apexes of the Delta would be grade-separated junctions. Towards Birmingham, HS2 would follow the existing railway inwards from Water Orton.

The junction would allow high speeds on the Main Line, with lesser speeds to and from Birmingham on the north and south links. The speeds on these links need to be reviewed and optimised for likely train service patterns, loadings and value of time.

Overall, the Delta junction would have to cross a complex pattern of motorways, other roads, existing railways, rivers and canals. The frequency of these features means that much of the Delta would be situated on high embankments or elevated structures. A number of local roads would also need to bridged, and possibly diverted, to accommodate the junction.

The Delta Junction was primarily located to provide the Main Line and South Links. It would also allow train services from Birmingham to the North-West by using the northerly part of HS2 and the WCML connection at Lichfield. It could, subject to alignment studies currently underway, provide for trains from both London and Birmingham towards the East Midlands, South Yorkshire, West Yorkshire and North-East England.

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14.3 East Link (Main Line) The East Link (Main Line) would pass through Coleshill Hall Farm and then over the River Cole, and M42 on viaduct. In this area, the route would be on a gentle 320kph curve.

The route would then straighten to pass in a 7m cutting to the immediate east of Gilson Hall. It would cross the A446 between its junctions with Gorsey Lane and Watton Lane and then pass the western extremity of the Coleshill Industrial estate. It would then cross the adjacent Birmingham to Nuneaton railway on a bridge.

The straight route here would allow the positioning of the points and crossings between routes, and would thus allow 400kph.

The Main Line would then incorporate a viaduct to cross the River Tame, the Sewage Works, the canalised river and the Birmingham to Derby railway, passing the western edge of the Hams Hall Distribution Park.

14.4 South Link The South link would provide a 230kph connection. As the East Link would be on viaduct, it is proposed that the Up Birmingham Line would pass under the Main Lines before converging to the south.

There would be bridges, each 100m long and 8m high, to carry the South Link east of Coleshill Manor, then over the M6/M42 links to join the North Link near Attleboro Farm. There would be a 230m viaduct, 8m high to carry the Up Birmingham over the North Links in a grade-separated junction.

14.5 North Link The North link would connect HS2 in the Water Orton railway corridor to the East Link. Speeds would be restricted to 200kph west of Water Orton due to presence of the M6 and Water Orton Primary School. In order to tie into the Main Line, speeds would be further restricted to 170kph due to a tight radius.

A 200m viaduct, 8m high, would be required to carry the Down link over the M42 before tying into the Main Line. A viaduct of 1,390m length, and of varying height, would be required to carry the Up Spur over the M42, the Main Line, flood plains and existing railways before tying in. The Main Line was located as close as possible to Hams Hall Distribution Park without affecting the operation of that location to maximise the radii and speed joining the Main Line.

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15


Delta Junction to Lichfield

15.1 Curdworth to the Belfry The route would return to ground level, and would affect Faraday Avenue (the main access to Hams Hall) probably requiring road works on the A446.

The route would then be in cutting up to 16m deep near Dunton Hall before crossing the M42 about 1km north of the Curdworth Junction (M42 J9).

The 4-track railway would converge back to a 2-track railway via 230kph turnouts south of the crossing with the M42. A 260m viaduct, 8m high, would then be required to enable the Main Line to pass over the M42 and the Birmingham and Fazeley Canal. Line speed through this region would be up to 400kph.

The route would pass virtually at ground level to the east of the Belfry Golf Course, Hunts Green and Middleton. Two structures of 120m and 265m, 3m and 5m high respectively, would be required to carry the route over the flood plains adjacent to Belfry Golf Course.

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15.2 Middleton The route would pass at ground level through the alignment of the A4091, and a permanent diversion would be required to lift the A4091 over the railway.

East of Middleton, speeds would be restricted to 350kph to enable the alignment to pass west of Hints and to avoid the area of higher ground and quarry north east of Hints.

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15.3 Hints The route would pass below Cranebrook Lane in a 16m cutting, and would then run largely at ground level to the west of Hints but with a 21m cutting at Roundhill Wood. The route would pass 300m west of Hints to avoid the area of higher ground and quarry to the north-east.

The route would cross Bourne Brook on a 170m bridge. A retaining wall would be required to prevent the railway embankment footprint infringing on the flood plain.

Near Bucks Head Farm are the “old” Watling Street and the “new” A5. It would appear to be possible to pass below both roads, though some localised raising or lowering might be needed, subject to survey.

North of the A5, the alignment would allow 400kph.

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15.4 Whittington The route would then run in cuttings of typically 7m but up to 19m depth to pass 400m west of Whittington Barracks and Whittington Heath.

The route would then be elevated on a mixture of embankment, minor structures (short spans) and viaducts to pass over a flood plain, the disused canal and the West Coast Main Line about 400m west of Huddlesford Bridge.

The route would then aim for a gap in property north of Streethay, passing over the Lichfield City to Wichnor Junction line and the A38 on viaduct.

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15.5 North of Lichfield and Fradley The alignment would then face north to facilitate a potential high speed line connection towards Manchester, before crossing the Trent and Mersey Canal and turning north-west to rejoin the WCML south of Handsacre. Over this final connection, speeds would be restricted by horizontal geometry to 250kph.

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15.6 WCML Connection It is proposed that a grade-separated junction would be formed with the WCML north of Elmhurst and south of Handsacre.

Both HS2 and the WCML would be 200kph routes, and a junction would be formed to maintain WCML line speeds. The Up Trent Valley Slow and Up Trent Valley Fast would be diverted to the east at ground level, allowing HS2 to pass over. This would make a simple connection into WCML’s Fast lines in the centre of the 4-track formation. Crossovers would be provided as close to the junction as possible to afford operational flexibility and compatibility with the bi-directional signalling on the Trent Valley lines.

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16


The Link to Central Birmingham

The next sections describe the route between the Coleshill Delta Junction and central Birmingham.

16.1 Water Orton to A452 Chester Road Along this length, there would be a south-side widening to accommodate the proposed HS2 tracks. The River Tame runs in a canalised course on the railway’s southern boundary, and it would be diverted approximately 20m southwards parallel to the existing river.

16.2 A452 Chester Road The new route would pass under the A452 Chester Road.

To the north of the railway, the A452 rises in elevation to meet the A47 Fort Parkway at an at-grade junction known as “Spitfire Island”. To the south, it reduces to a single 4-lane carriageway and passes under the M6, before connecting to a roundabout carrying the east-facing slip roads from the M6 at the Castle Bromwich junction.

It is proposed to construct a new A452 bridge alongside the existing, and then by means of a series of staged demolitions and new construction, re-create a dual-carriageway A452 at a higher level than existing to allow the higher HS2 gauge to pass under the structures. This would allow the proposed south-side widening.

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16.3 M6 Crossing The M6 crosses the existing railway on an elevated viaduct and in doing so would cross over the HS2 route. It crosses the existing railway and the River Tame on a series of portal structures supported by lines of piers, which carry deck structures on which the M6 is aligned. The existing railway and river would therefore lie under what is effectively a tunnelled structure, at minimum clearance over the existing railway. There are east-west openings through the structure, the southernmost of which carries the River Tame.

It is proposed to realign the River Tame outside and south of the M6 structure, and to utilise the river opening to carry HS2. This would be acceptable in providing the required headroom for HS2 trains, provided that the HS2 tracks were about 1.5m lower than existing. Some structural work would be required to strengthen the piers against train derailment. Because of the proximity of the River Tame, these lowered tracks would have to be protected from flooding by constructing bunds along the full length of the diverted river channel. A benefit of the realignment would be that the river would become an open-air watercourse, rather than covered, with aquatic benefits. More investigation is needed on structural clearances.

16.4 A4040 Bromford Lane and Heartlands Spine Road

The Heartlands Roundabout forms the junction of Heartlands Parkway, A47 Fort Parkway and the A4040 Bromford Lane north and south of the junction. There are traffic signal controlled junctions immediately north and south of Heartlands Roundabout which provide access into adjacent industrial areas. The circulatory carriageway of Heartlands Roundabout passes under the M6 Motorway and over the existing railway. As a result, Heartlands Roundabout is very constrained by the surrounding infrastructure.

The proposed alignment of HS2 would be adjacent to the southern side of the existing railway lines. In order to provide the required railway headroom, the circulatory carriageway of Heartlands Roundabout would be raised, but this is constrained by the M6 Motorway at its northern end. It is therefore proposed to reconstruct the western part of the circulatory carriageway as a dual 2-lane carriageway with an amended vertical alignment to obtain the clearances required. This would require a gradient possibly in excess of 4%. This would not change the clearance under the M6 Motorway. There would be a replacement roundabout to the south of the M6, with a realigned Heartlands Parkway and Bromford Lane.

The proposals include acceptable highways alignments. The junction is likely to be reduced in capacity during the construction of HS2, and the proposals (including traffic capacity and management measures) will require detailed consideration in partnership with Birmingham City Council.

This locality is the site of the proposed rolling stock maintenance depot, and this is described in the next section.

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16.5 The Rolling Stock Maintenance Depot A site at Washwood Heath in Birmingham was identified for a train maintenance depot. The depot was developed in order to determine the size and footprint requirements. HS2 Ltd provided the calculation on the numbers of trains needing to be serviced or stabled overnight. Key assumptions were made about issues such as:

●● Operational sequence;

●● Speed of connections from the main lines;

●● Distances/spacing between tracks;

●● Stabling sidings to provide CET and cleaning facilities;

●● Standage requirements;

●● Wheel lathe provision;

●● Under frame cleaning facility;

●● Storage/offices facilities.

Depot costs were estimated to cover:

●● Depot signalling;

●● OHLE;

●● Points heating;

●● Permanent Way;

●● Telecoms;

●● Civils and Structures;

●● Fencing and security.

Between Bromford Lane and Aston Church Road, HS2 would lie on the southerly side of the existing line. This would sever existing siding connections to the south side premises, and sever the industrial link road bridge. The proposed Heartlands Roundabout could provide a highway connection to the depot. Rail access to the Classic network would be provided.

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16.6 Aston Church Road to Curzon Street Station The route would pass, at a slightly lower level than existing, under Aston Church Road and the Stechford to Aston line to its immediate north. There would be a realignment of Aston Church Road to create adequate headroom.

The route would run on the south side of the existing lines and would then cross the Grand Union Canal at existing rail levels. It would pass below the B4144, a road known as Saltley Viaduct. Due to the close proximity of the Canal, it would not be possible to lower the HS2 lines and the B4144 viaduct would possibly need to be demolished and replaced to create adequate headroom.

Between Saltley Viaduct and Curzon Street Station, the route would then be on an elevated structure. This elevated structure would start to the west of Saltley Viaduct. The viaduct structure would be parallel to the existing lines before crossing over Duddeston Road sidings.

In order to allow the new route to cross from the southerly side of the existing railway to its north, a box structure is proposed over the existing lines. This box would stop as soon as practical after the crossing and the route would then run towards Curzon Street Station on viaduct.

The viaduct would be located over Lawley Street depot and would then cross the existing Cross-City line near Northumberland Street and St James’ Place.

The box structure could be avoided by realigning the HS2 lines further south of existing railway lines. This may also provide an opportunity to increase the throat speed, which is subject to a further study.

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Birmingham Curzon Street Station The proposed station in central Birmingham is near Curzon Street.

17.1 General Arrangement The station would comprise three island platforms providing six platform edges. The platforms would serve 400m length trains and would be 10m wide, served by 3 banks of 2 escalators each distributing passengers to and from the high-level walkway at concourse level.

17.2 Alignment The horizontal alignments would be broadly parallel to the New Street to Coventry line with a set of 80kph turnouts in the throat area, allowing all trains to access all platforms. These turnouts would be situated on straight tracks extending some 1km east of the platforms.

The vertical alignment was dictated by both the junctions to the east, and road clearances, particularly above New Canal Road; the tracks terminate immediately west of Park Street causing its diversion. The proposed track level would be about 3-5m higher than existing rail levels.

17.3 Concourse The concourse would be located at high level above Park Street and would feed onto Moor Street Queensway and hence Moor Street Station. The concourse would also extend over the road to deliver passengers on the north side facilitating pedestrian access both to the Business District (Snow Hill) and to New Street via the Bull Ring Pedestrian Plaza.

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The concourse building would act as a shared area for both the arriving and departing passengers, providing a seamless and integrated passenger experience to and from the New Street Station and city centre direction. The concourse would contain passenger and staff facilities, and would offer retail opportunities.

The connectivity with New Street Station could be achieved by travelators connecting the Bull Ring plaza at high level to the new HS2 station entrance concourses, and possibly by trams at street level providing safe inter-station movement without pedestrians crossing major roads. Taxis and buses would use a drop-off zone beneath the extended concourse, taking advantage of earlier provisions made along Moor Street Queensway.

17.4 Platform Level The high-level concourse would provide direct connections to a high-level walkway running above the centre platform with three transverse bridges providing travelator and escalator access to the platforms (two banks of three escalators for each platform, enabling platform clearance in 3 minutes).

17.5 Construction The station platforms (415m long and 10m wide) would be constructed on a new viaduct adjacent to the existing brick viaducts. These viaducts would vary in height up to approximately 8m.

A haul road could be formed from the Saltley Roundabout approximately 800m from the concourse beneath the void and station deck. This could subsequently be adapted to provide additional access to the station and adjacent development.

17.6 Phasing The new Curzon Street Station would be integrated into the adjacent developments currently envisaged as commercial offices and educational facilities. It is anticipated that the opportunity to develop above the station (air rights) and potentially above adjacent New Street lines would provide connectivity between the north and south sides of the railway corridor.

Through arch access would enable the majority of roads to be retained from New Canal Road to the east but only pedestrian access across the rail corridor to the west of New Canal Road.

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18


Glossary of Terms Throughout this report, there has been reference to technical issues, or abbreviations/ acronyms. The following list contains most of those as a glossary of terms:

Chapter 1

●● High Speed Two Limited – the Company established by Government to develop proposals for a high speed line

●● High Speed Two – the actual high speed line itself

●● DfT – Department for Transport

●● HS1 – High Speed 1 – the Channel Tunnel Rail Link from St. Pancras to the Channel Tunnel

●● WCML – the West Coast Main Line

Chapter 2

●● OLE – Overhead Line Equipment (supplying power to the trains)

●● TBM – Tunnel-Boring-Machine-driven tunnel

●● SCL – Mined tunnels generally utilising a Sprayed Concrete Lining (SCL) for initial ground support

●● GC Gauge – a technical term describing the physical dimensions of the proposed trains

●● TSI – Document 2002/732/EC (Technical Specification for Interoperability relating to the infrastructure sub-system)

●● OS – Ordnance Survey

●● DTM – Digital Terrain Model

●● DSM – Digital Surface Model

●● Up – a term used to describe the individual track heading towards London

●● Down – a corresponding term to describe the track heading away from London

Chapter 3

●● OD – Ordnance Datum, i.e. height above sea level

●● LUL – London Underground limited

●● LB Camden – the London Borough of Camden

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Chapter 4

●● Chainage – distance in km from the start point of the route

●● HMRI – Her Majesty’s Railway Inspectorate

●● HSE – Health and Safety Executive

Chapter 5

●● NLL – the Network Rail route known as the North London Line

●● LOROL – London Overground Railway Operations Limited

●● FICP – Emergency services Forward Incident Control Post

Chapter 6

●● GWML – the Network Rail route known as the Great Western Main Line

●● Crossrail – a proposed new railway route running east-west through and under central London

Chapters 7 and 8

●● None

Chapter 9

●● GCR – the alignment of the former Great Central Railway

Chapters 10 and 11

●● None

Chapter 12

●● SSSI – Site of Special Scientific Interest (a designation for a site generally of bio-diversity interest)

●● NAC – the National Agricultural Centre near Stoneleigh in Warwickshire

●● NEC – the National Exhibition Centre near Birmingham

Chapter 13

●● APM – Advanced People Mover

Chapters 14 and 15

●● None

Chapter 16

●● CET – Controlled Emission Toilet

●● OHLE – Overhead Line Equipment

Chapter 17

●● None

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Documents

Hs2 Route Engineering