High Speed Buffers? HS2 in London (Part 1)


Although not a London specific scheme, High Speed 2 will have an enormous impact on London. In part 1 we take a brief look at the scheme as whole to provide some background information. We briefly describe which topics will eventually be covered. We also cover the first of these – the reasons for the choice of route.

A brief HS2 resumé

High Speed 2, as regular readers must know, is the Government-sponsored scheme for a new London-Midlands-North express railway. It is intended to add capacity and shorten journey times on the main north-south intercity corridors. It has been around as a politically supported concept since 2008-09, although the 2006 Eddington Report dismissed a high speed line as poor value for money and said the government should instead concentrate on improving existing road and rail networks. Recession and post-recession arguments about capacity and stimulus for economic growth turned that policy corner.

Successive governments, Labour in 2009-10, Coalition in 2010-15 and now Conservative, have backed the proposition – one of few matters to secure and maintain all-party support. The government’s designated project company, HS2 Ltd, has developed detailed proposals and undertaken widescale consultation, for a scheme which now embraces about 335 miles consisting of:

  • Phase 1 trunk line (130 miles) between London, Birmingham and Handsacre, near Lichfield on the West Coast Main Line (WCML)
  • Recently-defined Phase 2a onwards to Crewe (around 40 miles)
  • The bulk of Phase 2, Crewe to Manchester and from the West Midlands to the East Midlands and Yorkshire (approximately another 165 miles including through spurs to NW and NE England)

This is a large ambition, and was to have included more elements in earlier versions with a Heathrow spur and an HS2-HS1 link.

The preparatory work led to a HS2 Phase 1 Hybrid Bill being lodged in Parliament in November 2013 to seek powers for construction and operation. There was also a paving Act – the High Speed Rail (Preparation) Act 2013 – to allow early start on preliminary elements. The main Bill has just concluded its Commons stages and has entered the House of Lords. During the Commons a major part of the proceedings was a Select Committee, whose work began in May 2014, and continued into February 2016. Meetings extended over 160 days of hearings with nearly 1,600 petitioners. Appointment to such a Select Committee has sometimes been compared to a Soviet posting to Siberia.

What we are covering

It is high time for those at LR Towers to sharpen our pencils since the scheme comes well into London Reconnections territory. We will identify the issues involved and the controversy surrounding them, so far as the proposals impact on the London area. We aren’t going to enter into the broader case for and against what, if authorised, will be new national intercity high speed tracks through the countryside and some city regions. We shall however look at various elements of the scheme, notably:

  • Purposes of HS2
  • Selected route in the London area
  • Demand and capacity case as it affects the London commuting area
  • Particulars at Old Oak and at Euston
  • Different options proposed by other parties
  • What have been the main petitioning points raised in Commons Select Committee

Purposes of HS2 – National economic growth objectives

Not to be forgotten, though it can easily be in the large cost envelope of the whole project (£42.6bn for Phases 1 and 2, plus £7.5bn for trains, at 2nd Quarter 2011 prices) [the 2015 Spending Review has now inflated numbers pro-rata], is that HS2 is fundamentally intended to be an instrument on a national scale for place-shaping and economic growth. It has the potential for large-scale economic impacts in the Midlands and the north as well as London. No-one can pin down the actual outcomes with accuracy, but there is a belief in a trajectory. A summary position can be described as significant capacity released on existing lines, in turn enabling that economic expansion, and while we are at it, let’s make the journey times shorter with other connectivity and economic gains. The original LGV (Ligne de Grande Vitesse) between Paris and Lyon had similar origins. The phrase ‘High Speed’ can, unfortunately, imply a different underlying policy priority.

Belief or non-belief in an economic trajectory generates considerable light and heat between project promoters and doubters. As shown in the article The Queen vs DfT, the Department for Transport rules out use of wider economic gains (Gross Value Added or similar) for transport business case development, even though GVA is widely endorsed by local authorities including the GLA and TfL, and by the new National Infrastructure Commission. So HS2 has an inbuilt hindrance – or paradox – of a scheme intended to achieve place-shaping, but where those changes can only be modelled indirectly through the nominal economic impacts of changes in journey time and related parallel transport side-effects, these being considered a proxy for the real changes in the economy. It’s all rather perverse!

The topic has been underscored by the ‘Northern Powerhouse’ Chair of Transport for the North Partnership, ex-CBI leader John Cridland, who stated (on 22nd February, the same day as the HS2 Select Committee’s 2nd Report) that ambitious infrastructure should be on the agenda regardless of any business case shortfall:

I’m not claiming there is perfect science here… But I am convinced that after decades of under-investment, it’s now time to close that investment gap – and it will lead to better travelling experiences and economic growth… Transport economics can’t always prove this: sometimes, like the Victorian engineers, you have to take a leap of faith.

It is not clear how the billions of pounds of expenditure on a Northern leap of faith would go down well anywhere else in the UK, except as a ‘me too’ pork-barrel argument where economic assessments and value for money were temporarily suspended as a methodology throughout Britain. To take valuation matters a little further, the Government argues that in the case of any HS3, or conflation of HS3 and Trans-Pennine upgrade and electrification, economic impacts of what will be a combination of capacity and ‘isochrone geography’ will be beneficial two-way across Northern England – with the ‘Northern Powerhouse’ effect advantaging the cities east and west of the Pennines.

Logically, any equivalent effects will also arise two-way with HS2, although that isn’t talked about too much, and more political emphasis is given to benefits in the Midlands and the north. But surely the ‘London Powerhouse’ gains too, and with its strong centre of economic gravity you can work out some of the possible implications?

Purposes of HS2 – strategic changes to rail capacity in London and the Home Counties

There is a symmetry about the HS2 Phase 2 Yorkshire branch that matches with Phase 1. They are both about removing the fastest intercity services from the existing lines from London that serve the north of England – the West Coast, Midland and East Coast – until they reach the Midlands and the southern part of northern England. There, through trains would rejoin the classic network, while ‘captive’ services linking the main conurbation capitals (London, Birmingham, Manchester, Leeds) would serve new termini built specially for those trains.

Inter City Services to the North Post HS2

Rerouteing the intercity services basically provides additional commuting capacity for the Home Counties and shires to/from London on the existing lines. Outer suburban and longer-distance ‘intershire’ commuting is where a big change in demand is already arising, and is forecast to grow much more in the period to 2043, according to Network Rail’s long term planning forecasts and more recent documentation. The commuting aspects are discussed later in more detail. There is also at least a 50% growth in freight train movements expected on the West Coast Main Line (WCML) – largely inter-modal freight – and growth in regional passenger travel in the Midlands and northern England.

Whether HS2 is the best way of tackling London’s future needs on these lines, plus new economic growth, will not be discussed. Others have argued for maximum capacity increases to the existing WCML and its train fleets, the Great Central main line to be reopened somehow for freight if not for passengers, 4-tracking Welwyn Viaduct for the East Coast Main Line (ECML), and other interventions. The simple fact is that it is the longer distance intercity flows which are planned to be rerouted via HS2, so with two hits opening up more train slots on three existing main lines. The DfT has published technical reports in November 2015 which argue that further WCML upgrades would be wholly inadequate for that corridor’s foreseen future demand.

There is much general acceptance that trying to expand the existing WCML into a 6-track railway from its present 4 (and 8 tracks rather than 6 south of Watford) would be a very difficult task, bringing with it all the risks that were the downfall of the West Coast Route Modernisation’s financial and project management in the late 1990s and 2000s, and contributed to the death of Railtrack. A £2bn scheme became £9bn, which is about half of the works cost for HS2 Phase 1, while the collateral service impacts during years of reconstruction became part of standard railway folklore.

The essence of the scheme is that HS2 Phase 1 provides WCML tracks 5 and 6, and is intended to open in December 2026. Any early extension to Crewe, perhaps in 2027, would virtually complete the HS2 impact on the WCML – irrespective of any later authorisation of links towards Manchester and/or Liverpool. HS2 forecasting should take into account this non-linear impact on demand and capacity requirements from what at first sight appears to be a ‘modest’ Phase 2a. The construction timescales foreseen in March 2014 in Sir David Higgins’ HS2 Plus report, for HS2 Phase 1 including the London area, are set out below.

HS2 timescales

HS2 route in the Home Counties

Before the HS2 Phase 1 Bill was submitted to Parliament in November 2013, there was wide ranging optioneering about the preferred route to approach the London urban area. Whichever way you pointed, you were going to meet the Chilterns, which in practice extend in an arc all the way from south of the Goring Gap (Great Western Main Line) to east of the Luton Gap (Midland Main Line). This was bound to incur strong objections, and was likely to involve a commitment to tunnelling on some scale.

The route finally selected sought to take advantage of the underused and relatively straight railway corridor within NW London, the former Great Western & Great Central (GW&GC) Joint Line – also known as the New North Main Line (NNML) – which opened in the 1900s as – appropriately enough – the Edwardian high speed railway between London and the west and east Midlands. The first part of this line was opened in the London area in 1904. The last section, from Ashendon in Buckinghamshire to Aynho near Banbury, opened in 1910.

Routes into LondonHS2 route and other main line rail corridors in West and NW London

The GW&GC corridor informed the eventual choice of the HS route through the Chilterns, which follows much of the Misbourne Valley, shunned on the Denham-Amersham section by previous generations of railway builders. Amersham itself was only reached by the 1892 Metropolitan Railway extension from Chalfont to Aylesbury, which in reality was another railway encouraged by its forceful Chairman into paying for part of the 1890s Great Central extension to London. He also chaired the Great Central, South Eastern, Channel Tunnel and Nord Railways, and wanted to create a Manchester-Paris Main Line. The GCR was built to a smallish continental-sized loading gauge. History is now repeating itself.

Colne ValleyHS2 shown diverging from the New North Main Line over the Colne Valley

In the Home Counties, therefore, HS2 is planned after its London tunnel to diverge from the GW&GC corridor east of Denham, cross the Colne Valley with a brief glimpse of light, then back into a long tunnel to near Amersham, then with much cut-and-cover ‘green tunnel’ and deep cuttings for environmental protection reasons towards Wendover. In the Vale of Aylesbury and beyond, HS2 would parallel the Met and GC to near Brackley in Northants, physically using the GC alignment north of Calvert, then follow a new route past Daventry to the West Midlands. However, no commuter stations are planned on this section of line, which is a cause of mixed opinions in the commuter territory served. HS2 Ltd is clear why this is, the railway is intended for intercity flows, and line capacity would be lost by trains slowing and accelerating to serve intermediate stops. This view has prevailed so far during the passage of the HS2 Phase 1 Bill.

Choices within London

The GW&GC corridor points within London towards Old Oak Common (OOC), which is where the Great Western Main Line is met. OOC provides the opportunity for a direct interchange with the GW and with Crossrail 1, the latter being important to allow a one-stop interchange for the City and Canary Wharf, which helps to relieve passenger flows at Euston, as well as providing access to Heathrow Airport. Access to Heathrow Airport will be discussed in part 2.

The GC entry to Central London, which is quite curvaceous and graded, leaves the NNML at South Ruislip towards Neasden, and is used fully by Chiltern Line services. The NNML southwards is hardly used these days. OOC was therefore the logical next location along the corridor, along with the original ambition of surface running on the London side of South Ruislip. Several options and complications then arise:

  • Design criteria for HS2 and effect along the NNML route
  • Choice of access to Heathrow Airport
  • Choice of access to a London terminus
  • Any access within London, other than via a London terminus

HS2 design criteria and effect on NNML route

The HS2 line design specification is for up to 400 km/h (about 250 mph), and for ‘captive’ inter-conurbation trains (London, Birmingham, Manchester, Leeds) to be a ‘GC’ European loading gauge dimension. A build of ‘classic-compatible’ trains will also be required for intercity trains running onto the existing network. More detailed information from HS2 Ltd is that the trains’ intended maximum speed on a day-to-day basis will be limited to 360 km/h, with the timetable scheduled at 320-330 km/h (about 200 mph), which is now a European HS norm. The 360 km/h upper limit gives a margin to recover from perturbations. A freedom of information response reveals that the main tunnel design on HS2 will be single track bores: 7.55m diameter for line speeds up to 230km/h, and 8.8m diameter for speeds up to 360km/h, and for tunnels over 1 km long the provision of evacuation facilities which includes a safe area. Typically ‘porous portals’ are required for line speeds of 230km/h and above because of the piston effect.

There is a debate to be had about the merits within the UK of large-gauge ‘captive’ trains, which will not be double-deck (too much delay with boarding and alighting at intermediate stops, apparently). A high-density 3+2 seat formation is being considered by HS2 Ltd for the ‘captive’ shuttles to maximise passenger capacity while maintaining some degree of comfort. This because there is a significant HS2 Ltd worry about potential passenger demand vs line capacity. However it might be advisable for HS2 to check out the views of, for example, Portsmouth Line users, about the ambience of their 3+2 Desiro 450 journeys on 50+ minute services, compared to the previous 2+2 seating on Desiro 444s. It would be a bit downbeat to travel at 200 mph in an inner suburban seating environment undesirable even for today’s scale of obesity, even if many of HS2’s passengers were commuters.

Width matters

Any ‘GC’ trains would be only marginally wider than UK-size carriages, four inches at best. The standard 26m-long UIC passenger coach has to be no more than 2,825mm wide. The late Gordon Hafter, London Underground’s rolling stock engineer, noted that “for the imperially minded that is 9ft 3ins, which is (surprise) exactly the overall width over door handles on a BR Mk 1 coach”. He observed that “It is only at the bogies, where there is no throwover, and generally below platform level, where the BR gauge is even narrower, that coaches built to UIC gauge can be noticeably wider, which is why the Trans-Manche Supertrains [the first Eurostar design] have had to have their bogies radically redesigned from those used on the TGV-A trains, although the car-bodies are literally but a few millimetres smaller, at 2,814mm according to the published drawings.”

HS2 Ltd believes that a standard off-the-shelf European train could be cheaper than a product modified for the UK loading gauge, although many such trains would be needed for ‘classic-compatible services’. The proportions foreseen by HS2 Ltd are 16 ‘captive’ and 45 ‘classic compatible’ trains for Phase 1 (61 in total), and 70 ‘captive’ and 95 ‘classic-compatible’ for a full Phase 2 (165 in total, with 104 additional).

Several manufacturers, based on direct discussions, consider that ‘classic compatible’ 360km/h trains can be achieved, though 400 km/h is likely to be a challenging design because of the energy and power demands at that speed, requiring larger equipment – but which is not currently required by HS2. So why would a 360km/h ‘captive’ build make any procurement sense or value for money, least of all with Phase 1 or Phase 2a when the vast majority of trains will need to be ‘classic compatible’?

The greatest impacts of design speed and train sizes are on the railway infrastructure. Under European regulations, whether or not it is an HS line, new non-metro lines must be built to a European loading gauge, subject to derogation in reasonable and proportional cases such as the new chord at Bicester. For example, the reopened Borders Line is GC gauge with some lesser derogations in place (eg UK platform heights and platform gap from the rail), and was generally built to the latest engineering and passenger access standards. Smaller loading gauge trains may use European-gauge lines, subject to addressing matters such as the relationship between the trains and strictly specified ‘GC’ platform clearances and heights. These regulations were complied with on the first generation Eurostar and Regional Eurostar trains (an example of a ‘classic-compatible’ design) though what was achieved was not necessarily a ‘step-free’ solution.

Grandfather rights apply to existing main lines with smaller loading gauges, such as the bulk of the existing UK network. Otherwise there could be the logical nonsense of no through running back onto the ‘classic’ network. There would be little benefit from HS2 Phases 1 and 2a if infrastructure changes for through HS trains became prohibitively expensive and railway standards blocked through services to Manchester, Glasgow etc as long as those cities were excluded from the new HS lines. However, if an existing UK line were to be upgraded significantly, the new Technical Specifications for Interoperability (TSI) requirements might be expected to apply (again subject to derogation).

In the London area, in theory the NNML could be used by HS trains between Ruislip and Old Oak Common, with electrification, upgraded tracks and signalling, providing that only ‘classic-compatible’ trains were used and relevant TSIs adopted if required. The NNML used to be 4-track on part of the line through Ruislip shared with Chiltern. There would be a similar opportunity to share tracks on the approaches to Euston and other conurbation termini.

The adoption of a very high speed specification (faster than intended to be used at present) and European gauge ‘captive’ trains, forces a requirement for new line specification all the way to the buffers at London, Birmingham, Manchester and Leeds. Not cheap, with shades of a Brunellian broad gauge effect including ‘change of gauge’ impacts at major cities and on major corridors that might not see through HS trains even as UK economic and population growth improved the case for more through-running services.

It is acknowledged that many present intercity services are a city-centre to city-centre only offering, but they often call at towns and cities elsewhere en route, eg at major interchanges, whereas HS trains wouldn’t because of the route and service specification. Essentially, HS2 has adopted a Japanese stand-alone style of HS offer, rather than one of the other options such as the French HS radiating services structure or the integrated ‘neubaustrecke’ extra HS lines and junctions joining up with many existing networks and city centre stations, as preferred by Germany and Switzerland. The UK, of course, doesn’t have other European-gauge city centre approaches, except for HS1 to St Pancras International.

The 22nd Century population may yet applaud 400 km/h operability, just as we benefit from Brunel’s 19th Century foresight or wastefulness (take your choice). 21st Century Treasurers and financiers might prefer something less exciting and more affordable, incremental, and nearer in line with what much of Europe has already settled on. That could affect the final HS2 train order – maybe full dimension trains, eventually …? The Dutch had a saying in 1940 – we like you Germans but we don’t want all of you at once.

Adaptation of the NNML was originally proposed on the non-GC section south of South Ruislip to near OOC. However according to HS2 Ltd the net cost of tunnelling all the way wasn’t much different to an adapted and TSI’d NNML rebuilt to ‘GC’ dimensions, while the timescale for tunnel construction was acceptable. It also avoided many local environmental concerns about the noise and other impact of very high speed trains operating along a corridor no longer familiar with having an express railway on their doorstep (albeit the adjoining Central Line is a frequent service). The impact had been a significant petitioning point by the GLA and TfL irrespective of the fact that the debated section of railway now falls within and adjoining the parliamentary constituency of Uxbridge and South Ruislip (Boris Johnson MP since May 2015). Other NNML constituencies are Brent Central, Ealing Central & Acton, Ealing North, and Ruislip Northwood & Pinner.

So there is now the paradox of an under-used surface main line railway corridor in a congested London, the GW&GC Joint Line/NNML, which has influenced the location of HS2, yet on present plans will remain under-used with the new high speed railway in tunnel below it all the way to near Old Oak Common. The NNML is potentially also interrupted in some locations while HS2 tunnel ventilation and escape shaft works are undertaken. The involvement with the NNML of the proposed WCML-Crossrail 1 link is discussed later.

In part 2 we shall, amongst other things, look at access to Heathrow and the choice (or lack of choice) of a London terminal.

Written by Jonathan Roberts