Categories
Business Case Ecology Route Alignments

OxCam Arc, Local Plan Update and the EWR Central Section

 

Growing up on the Cam in 2021

I hope that you all had a good break. Since our last blog post in June we have been able to read some of the responses to the EWR consultation; read the new OxCam Arc consultation and looked at the proposed update to the Greater Cambridge Local Plan. A disconnect between EWR Co.’s preferred railway alignment and the housing plan is continuing to emerge and we will illustrate this in this blog post.

If you want to make your voice heard about the OxCam Arc (of which EWR is a part) one thing you can do is to have a look at the 5 minute questionnaire put together by a group called StopTheArc – it asks some of the  fundamental questions not in the  official MHCLG consultation. They were kind enough to ask Cambridge Approaches to review it before publishing.

Still No Published Business Case

One of the things we do on this Cambridge Approaches blog is to ask questions about the business case for the central section of the EWR.

We know from EWR Co.’s Preferred Route Option Report published in January 2020 that the estimated total cost was £5.6Bn (having risen from £1.9Bn a year earlier) and, since we understand that this will be funded by the taxpayer, it’s not unreasonable for us to ask for the business case. For comparison, would the EWR Co. management team get very far in raising £5.6Bn on Dragon’s Den if, after working on their project since 2018, they still won’t share a business case with the people that they want to fund it? Put another way, they are taking us for granted.

For the record, the public line on the lack of business case from EWR Co. in response to our Freedom of Information request at the start of 2021, was that public servants need a safe space and that it is not normal for a business case to be published at this stage. People are sufficiently disturbed by the proposals so that they received 190,000 responses to the 2021 consultation, but it’s too early to publish the case for the project.  Really?

This questioning of the business case was followed by Anthony Browne MP asking about the effect of COVID on travel patterns which will likely permanently reduce passenger numbers by 40% as people have learnt to work from home. EWR Co.’s recent video from EWR Co on the 23rd August 2021 talks about this problem (see 3:07 into the video) without any convincing resolution. Covid-19 will pass, but the technology that allows people to work from home is here to stay and employee expectations have now changed. 

As EWR Co point out (video 2:36), the hope is that people will move into the area to live and work and set up businesses so it might be that this influx of people will to some extent counteract the others working from home. Indeed, the NIC report “Partnering for Prosperity” set out a target of 1.1 million additional jobs in the area by 2050 corresponding to about 2 million more people and 1 million more homes. We assume that the focus of this growth is intended to be along the EWR around the initial stations and any new ones that are added over the lifetime of the railway. (If not what is the point of the railway exactly?) The  impact of this on existing residents will be higher than that of the railway alone.

The second EWR consultation ended in June 2021 and we still have a lot of unanswered questions.  Looking at the consultation responses from bodies like the South Cambridgeshire District Council and the Cambridgeshire County Council, we were not the only ones with outstanding questions. You can read the Cambridge Approaches consultation response here and some others here.

In the Cambridgeshire County Council 2021 EWR consultation response we find the following: 

GrowthThe East West Rail Central Section should support growth and enable sustainable transport patterns to be realised from that growth. The detailed alignment of the Central Section should be considered alongside the consideration of appropriate locations for growth in the Ox-Cam Arc, and the appropriate scale of that growth. The strategy for station provision on the Central Section must be informed by the consideration of appropriate locations for growth. 

This is an appeal for the route alignment of the EWR central section and its station locations to follow a co-ordinated housing plan.

South Cambridgeshire District Councils 2021 EWR consultation response says: 

Significant further work is still needed to understand the localised impacts of the scheme, the options for mitigation, their effectiveness and implementation including the sequencing with wider strategic infrastructure and development. 

Again, they are concerned that the railway is not aligned with the housing and economic plan for the area.

So, some of the outstanding questions centre on how the route relates to other plans for the area e.g. for economic growth, housing and local transport. Unfortunately for all concerned, the EWR Co. management team are not in a good place to answer these questions because they are being pushed by the Department for Transport to get the route defined in advance of key decisions by other bodies.  This heightens the risk that EWR will not choose the right approach which will be to the detriment of its business case, local residents and potential users of the service.

Train Wreck in St. Neots

EWR Co.‘s Simon Blanchflower post consultation press release celebrated the scale of response:

The number of responses we’ve received, the breadth of information and level of detail they contain demonstrates the value of consulting with local people at an early stage, and the huge level of public interest in East West Rail.

But a strong response should not be taken as meaning respondents are in favour of what is being proposed.

A good example this and of the railway alignment not taking account of the housing plan can be found in the St. Neots Town Council Response to the EWR consultation which is, broadly, that they are furious.

We are surprised that EWR has aligned its preferred routes in close proximity to one of the largest housing developments in the East of England. None of the five corridors considered in the first phase of the consultation included this land, and the late inclusion has come as a shock to residents, housing developers and St Neots Town Council.

St Neots Town Council is opposed to the construction of these viaducts and asks EWR to urgently reconsider plans to align these routes with the eastern edge of our town.

EWR are proposing 12m high viaducts through St. Neots East reminiscent of the Great Wall they have proposed between Cambourne and Hauxton. There is also no station at St. Neots, maybe that is because of the Tempsford development, but since we don’t even have a vision for the OxCam Arc Spatial framework who knows? More to the point how do EWR Co. know?

Greater Cambridge Shared Planning (GCSP) Local Plan

On the 31st August 2021 an update to the local plan was published.  It is currently under consideration by councillors and will not open to public consultation until later in the year (November?). The updated plan will run to 2041 (previously it ran from 2011-2031). 

Figure 1 shows an overview map of the developments proposed.

Figure 1 Local Plan Update – Overview

Note that no new housing development is proposed around Cambridge South Station, despite this being one of the repeated justifications for the southern approach to Cambridge for the EWR. This diminishes both the justification for the EWR southern approach route and the business case for the central section of the railway. In contrast, significant new development around the northern route proposed by CBRR is confirmed and developments in Northstowe and Waterbeach are to be accelerated together with new brown field developments to the north and east of Cambridge.

The Mythical Houses Around Cambridge South Station

The myth of significant housing growth around Cambridge South Station has been discussed in a recent letter from a local resident to local District Councillors as follows:

“…the county council’s 2019 response to EWR Co (repeated in the third bullet of paragraph 2.3 of the covering note to the draft response) said ” The ability of EWR services to … provide for the very significant planned economic and housing growth in the south of the city including at the Cambridge Biomedical Campus”.  This was an odd statement in 2019, given that the county council is not the planning authority, and it was, at the time, not evident from the Local Plan what housing development the county council had in mind in saying this.  It appears even odder now, given the variety of housing development options under consideration by Greater Cambridge Shared Planning (“GCSP”)  – see their November 2020 development strategy options assessments and the emergence of the North East Cambridge Action Plan.  

In 2019, the constituent authorities of what is now GCSP made clear a new local plan was coming and that they would be looking at all reasonable development strategies and SCDC at least has repeated this point in its response to this consultation.  Notwithstanding this, what the county council said in 2019 appears to be understood as fact not just by EWR Co, but also by EWR Consortium.  

Among the papers for the EWR Consortium 9 June meeting (not, in fact, discussed) is this one under the heading “realising the potential of EWR” which says (emphasis added):

Cambridge South: Cambridge South [station] will be located near to Addenbrooke’s Hospital and Cambridge Biomedical Campus – key employers and site for new homes in the south of Cambridge. Planned to open in 2025, the station will be on the Cambridge line and West Anglia Main Line, and should also sit on the East West Main Line once it opens a few years later.”

It goes on to say that “The Cambridgeshire and Peterborough Combined Authority is working on the Outline Business Case…”.  It is not entirely clear what this outline business case is for and could be a historic priority of the former Mayor because the next paragraph of the document mentions the CAM.

It is possible that all these statements can be traced back to what the county council said in its 2019 response which may have served to lead others to believe that there were likely developments in the south of Cambridge.  It seems important for both EWR Co and EWR Consortium to understand the true position and the county council should take responsibility for doing this.”

Now would be a good time for EWR Co and EWR Consortium to review the evidence for the southern approach and the whole business case in the light of this new local plan since the local authorities are planning no new houses around either EWR station on the southern approach in Cambridgeshire all the way out to 2041. Do MHCLG people know better that the local experts about how best to develop Cambridge?

Conflicting Plans at Highfields Caldecote

One of the consequences of the EWR route being fixed in advance of related housing plans are conflicts emerging when the housing plans do come out. The detailed costing information that came out with the last consultation indicates that the preferred route had been established in outline all the way back in mid-2019. Such conflicts can no doubt be resolved by adjustments to the railway route or knocking down houses, but they are also symptomatic of the lack of co-ordination between EWR Co. and the other planning authorities. 

Here is another example of the issue. EWR Co’s preferred route goes through a station north of Cambourne and crosses the A428 with a long, skewed bridge just north of Highfields Caldecote (see blue route in Figure 2).

Figure 2 EWR Co Preferred Route Crossing the A428

However, the updated local plan has housing across the proposed route of the railway (See Figure 3).

Figure 3 GCSP Local Plan for the Same Area

Rate of Housing growth

The GCSP planners are estimating that to meet the demands of the local economy (i.e. the number of new jobs they foresee over the period) we need to add 1,771 houses per year over the next 20 years leading to a total of 48,794 houses from 2011 to 2041. This is a lot less than the 271,000 houses in the National Infrastructure Commission report (NIC Report) for this end of the EWR central section up to 2050.

It has been acknowledged that the case for the EWR central section depends on housing growth. For example, this is stated in the recent EWR video referred to earlier. In fact, it depends on the transformational housing growth put forward by the NIC report. However, if this level of growth is not going to come from the local plan where could it come from?

OxCam Arc Consultation

The Ministry of Housing Communities and Local Government (MHCLG) recently launched a consultation to help them shape the vision for the OxCam Arc. In section 5.8 of this document there is a rather hard-hitting paragraph:

“5.8 In parallel to the development of the Spatial Framework, the government is also exploring options to speed up new housing and infrastructure development in the Arc to help meet its ambitions, where evidence supports it. This includes examining (and where appropriate, developing) the case for new and/or expanded settlements in the Arc, including options informed by possible East West Rail stations between Bedford and Cambridge and growth options at Cambridge itself. The government will undertake additional Arc consultations on any specific proposals for such options as appropriate. The Spatial Framework will guide the future growth of the Arc to 2050, including on the question of new housing and infrastructure and will, as part of its development, take into consideration any significant new housing and infrastructure coming forward to meet the Arc’s ambition.”

They are reserving the right to add housing developments around EWR stations including at Cambridge itself. One assumes that, coming from central government, they would not be small developments. As pointed out by the county council it would be better for the transport infrastructure to fit around the housing plan rather than vice versa. Similar problems occur with the sites for schools and hospitals if the funding and hence the location is controlled by central government.

The housing plan proposed by GCSP considers environmental aspects by choosing dense developments often on brown field sites close in to Cambridge itself. If instead the plan is to be driven by the siting of EWR stations then these benefits will be lost. 

Water Supplies

I was looking at the flow of water in the Cam this morning on Stourbridge Common near to Cambridge North Station. Viewed from a footbridge, there were various pieces of vegetation and sticks on the surface, but none of them were moving at all. A recent episode of BBC Radio 4’s Costing the Earth explains why this is happening. The chalk aquifers that feed the rivers having accumulated water over a very long time are now running dry because so much water has been abstracted by the water companies to serve new houses. There is also a waste water capacity problem which leads to overflow events into the rivers. Plans to fix these problems are being studied, but are not expected to be in operation until the 2030s.

GCSP commissioned a study from Stantec on the Water Supply in late 2020 which states: 

For water supply, over-abstraction of the Chalk aquifer is having a detrimental impact on environmental conditions, particularly during dry years that may become more frequent due to the impacts of climate change. None of the growth scenarios considered here offer the opportunity to mitigate these existing detrimental impacts. Even without any growth, significant environmental improvements are unlikely to be achievable until major new water supply infrastructure is operational, which is unlikely to occur before the mid-2030s. Therefore, this analysis has focussed on a “no additional detriment” neutral position. To prevent any increase in abstraction and its associated detrimental environmental impacts, mitigation measures will be necessary. All stakeholders agree this should include ambitious targets for water efficiency in new development. 

If there is already a problem that won’t be fixed for 15 years why are we planning to accelerate growth in the area now?

There are also significant problems with waste water and flood risk downstream in The Fens. The campaign group Friends of the Cam has a lot more on these issues.

Discussion

In summary, the business case for the EWR central section depends on the housing growth around stations. In South Cambridgeshire the updated local plan to 2041 has accelerated housing growth in Northstowe and Waterbeach new town while Cambourne, Eddington, North East Cambridge and East Cambridge have new developments. This is not at all consistent with EWR Co.s preferred route into Cambridge south.

The level of housing growth has been objectively assessed by the planning officers to meet the needs of the area although it is not clear how the water infrastructure will cope with any more growth. It is also not clear how anyone would objectively assess housing needs – it really depends what assumptions are made. Do we want this to be a high growth area if so why? Are we trying provide more homes for London commuters? Are we trying to encourage migration into the area from other parts of the UK and abroad? Which parts of the economy are we trying to stimulate? For more in depth discussion of why the OxCam Arc is not a good idea see this article. If you would like a say try filling in this 5 minute survey.

Will MHCLG add further housing via development corporations as indicated in their consultation? Well, speaking to Eversden Parish Council recently, Bridget Smith (Leader of South Cambs. District Council) reported the housing Minister, Chris Pincher as saying that there would not be houses in addition to those that the local authorities are planning for. It would be nice to see this in writing.

We conclude that either:

(A)There is no business case for the EWR extending to Cambridge on the southern approach because it will not enable much housing growth OR

(B) Central Government need to push through large housing developments around the proposed route of EWR over and above the needs of the local economy to service additional fast economic growth in the OxCam Arc not recognised by the local planners and to serve more London commuters.

Option A is a waste of public money, option B looks like being even less popular than the railway itself and does nothing for those parts of the county that need levelling up investment.

OxCam Arc Consultations

Given the above situation, one might expect that an MHCLG consultation about the OxCam Arc vision might set out some indicative scale of development around EWR stations. It is instead phrased around prioritising various features of the plan without really setting out the core proposition. See this brief BBC South News report for some detail on the controversy around this consultation. Perhaps MHCLG are taking it a step as a time, but they are so far behind EWR Co. that their spatial framework may not be able to influence the route of EWR. MHCLG’s consultation suggests development is to be set around EWR stations no matter how poor those sites are in planning terms.

We encourage you to respond to the MHCLG consultation by October 12th. The Stop The Arc Group have some great ideas about what you might like to say here, but please also use this post to relate your response to the EWR Central Section.

The Stop The Arc Group have produced a 5 minute survey about the OxCam Arc which asks people some of the more fundamental questions about the Arc. Cambridge Approaches had some minor involvement in the development of the survey and support it. 

Please do fill in the 5-minute survey here.

One of the early results of the 5 minute survey after 1500 responses is that over 90% of people would vote against the OxCam Arc if there was a referendum.

Categories
Route Alignments

Northern approach – avoiding 4-tracking north of Cambridge

Introduction

The article below has been written by an anonymous Cambridgeshire contributor who has a keen passion for, and knowledge of, railways. The previous article on this subject showed that the general capacity of the existing twin track between Cambridge Station and Milton Junction was sufficient to take the existing traffic, planned growth and EWR trains without the need for 4-tracking.

In discussions and correspondence with EWR Co, it was clear that they have carried out their assessment based on the current timetable. They claim that this showed that 4-tracking of this section of the track would be required. Our previous article suggested that this was unnecessary as the current timetable would change over the next 10 years before EWR became operational.

However, to address EWR Co’s specific concerns, we have looked at the issues that they raise with the timetable and show that, with a minor revision, even on this basis there is no need to 4-track this track.

Summary

EWR Co’s argued need for 4-tracking in the north of Cambridge in a ‘northern approach’ scenario – which underpins their decision to discount that option in the latest consultation – is based on concerns about interfacing with current operations. EWR Co have not published their full analysis, but state that they cannot fit EWR trains at regular 15 minute intervals alongside the existing timetable. While that statement appears to be technically true (in the most tenuous sense), the analysis presents here suggests that without context, it is likely highly misleading – and 4-tracking is certainly not the only solution. The issue is not too many trains, but a few quirky ‘symmetry breaking’ inefficiencies in the current timetable (particularly the fast/slow Liverpool Street trains). The immediate EWR issue can be solved by slipping a single hourly train by a single minute, and even if we are to future-proof to include the reasonable-worst-case scenario (including a variety of other future trains beyond EWR), only very minor tweaks to the existing are needed to make it work. Once Cambridge to Liverpool Street services are expanded to four an hour (expected in a similar timeframe to EWR’s construction), the asymmetry issues will have resolved themselves anyway – so it is illogical to let such quirks control EWR’s design decisions.

1.      Introduction

(I suggest you grab a cuppa and get comfortable before you continue, as this is quite a long and technical post)

I should start by saying that I’m not a campaigner and am not necessarily pushing for any particular outcome. Having seen the significant campaigning efforts of Cambridge Approaches, CBRR and others, however, I thought it would be interesting to delve into the ‘north vs south’ arguments from an objective viewpoint, to try and determine whether or not the proposed northern approach is actually a viable alternative. A few months of late-night analysis later, and yes, I do think there are – potentially – some aspects which may have been overlooked. I am not an industry expert and am of course willing to be stand corrected if I have missed something important, but am keen to open the discussion so that we maximise our chances of building the best railway possible. Although EWR Co have published many pages of technical documents describing the consequences of 4-tracking, they have unfortunately still not provided a robust technical justification for why they think it is necessary – instead simply claiming that they have “looked at it and concluded that it’s the only solution”. This makes it very difficult to peer review their work and assess the validity of their argument, so some guesswork is required in attempting to re-trace their steps. I’ve tried to present everything as clearly and transparently as I can in this document, so people can see the arguments for themselves.

If, as EWR Co claim, the only way to add four hourly EWR trains through Cambridge North is to add a second pair of tracks through the north of Cambridge, then the associated destruction of nearby properties and other infrastructure costs are very significant (as the infamous “appendix F” goes to great lengths to illustrate). These consequences feature front-and-centre in EWR Co’s justification for discounting a northern approach, and I suspect finding a way to avoid 4-tracking is at the core of the northern approach’s viability.

If my analysis has missed some vital other reason why 4-tracking really is the only solution, then the proposed southern approach certainly has its relative merits. However, there is still a possibility that as even more Cambridge-London trains are added, sending EWR trains into Cambridge from the south might mean it isn’t long before the track from Shelford to Harston needs 4-tracking, alongside grade separation of the Shelford junction, both of which would also be highly disruptive.

2.      Mapping the new railway

In the vector diagram below, every line corresponds to a single hourly train in each direction at present (except for the orange freight line, which is just indicative of routes).

Hourly services in each direction: existing (pre-pandemic)

The next diagram is a best guess at how EWR Co’s proposed ‘southern approach’ might look. This analysis is based on an assumed 4 trains an hour, which would be in line with the busiest UK inter-city services running today. I’ve included the potential Wisbech line (either running from Cambridge or splitting from existing trains at Ely), added second hourly trains to both Norwich and Ipswich, and extended a second hourly London train from Ely to King’s Lynn. This gives us a reasonable upper bound for the next few decades to the north and east. I’ve not added potential extra trains south of Cambridge, such as the mooted services to Maidstone or Haverhill, or additional London services (at least three of which are included in Network Rail’s 2030/40 scenarios). There is still some uncertainty about how EWR would be timetabled: I’ve taken the ‘best case’ scenario where Norwich keeps its direct Stansted service, but otherwise 3 of 4 EWR trains continue to Norwich (1/h) and Ipswich (2/h). EWR, then, serves Cambridge South and Central stations with every train; Cambridge North only sees a single hourly EWR service.

Hourly services in each direction: southern approach

Next, we have a potential ‘northern approach’. The same extra services are assumed as above, but EWR now arrives via a junction at Milton rather than Harston. There’s an optional station at Northstowe (and space still for one at Harston too), and 4-tracking may only need to go as far as Cambridge South. In this scenario, the ‘base case’ is that EWR trains all serve all three Cambridge stations, terminating at Cambridge South. There are options, such as linking with existing London (if electrified), Stansted and/or a reopened Haverhill line, or reversing at Cambridge in order to continue towards Norwich/Ipswich. It is a requirement that EWR’s design does not preclude the latter as an option, though it is probably not the most beneficial solution. Freight mostly avoids Cambridge via a new chord south of Ely. This would, admittedly, be expensive to construct (as it would include a new bridge over the Cam), but could remove freight from the single-track Newmarket route, reducing the need to dual quite as much of it.

Hourly services in each direction: northern approach

3.      Improving existing layouts

It is clear from the northern approach diagram that the section through the north of Cambridge is quite busy – so at first glance the argument for 4-tracking seems reasonable. But can it be avoided? The first step is to see what can be done, with only modest adjustments, to increase efficiency in that section. South of Cambridge (central) station we will have 4 tracks, a grade-separated Milton junction confers no additional capacity constraints, so the solution hinges on just the three miles of twin tracks between Cambridge’s central and north stations.

Two hourly Liverpool Street trains terminate at Cambridge North (except for 2/day to each of Ely and King’s Lynn). When they head back south, they block the northbound track until they reach the switch point south of the river. However, this can easily be avoided by moving the terminus platform from the west to the centre. Although it should not be necessary, the through-platforms could be doubled up: There’s space for the western one within the existing footprint, while a 5th on the eastern side will probably take a sliver of land from neighbouring properties. In the very worst-case scenario, if no extra land is available, then there is space further north to stagger northbound and southbound platforms. If, as has been suggested, the two Liverpool Street trains will in future need to continue to Ely, then a terminus here is not required, and either 2 or 4 platforms would suffice.

Cambridge North station – diagrammatic track layout
Cambridge North station – looking north

Cambridge Central is a large and complex station, currently having four terminus and four through-platforms (the latter all serving trains in both directions). The terminus platforms are all on the western side, so reversing trains again obstruct oncoming traffic as they switch tracks. According to Network Rail’s 2019 report, a southern approach would see a new island pair of through-platforms to the east, and 3-tracking to the Coldham’s Lane junction, as shown on the right in the figure below.

Diagrammatic track layout at Cambridge station – existing and Network Rail’s southern approach

There are many possible iterations for upgrading the station in a northern approach scenario. The first obvious step is to swap Ipswich/Newmarket trains onto a new eastern platform. Without the need to weave Newmarket-bound trains across from the eastern side of the Shelford junction as they approach from Oxford, it should be possible to separate them entirely from other services via 3rd track to the east towards the Coldham’s Lane junction. Ipswich trains currently only dwell at Cambridge for about five minutes, so even with two or more such services an hour, a single platform and single track under Coldham’s Lane bridge should be sufficient, assuming most freight is diverted via a new spur near Ely.

It may make sense to tidy the central portion of the station into a pair of northbound and a pair of southbound platforms. In a similar approach to Cambridge North mentioned above, it might also be possible to allocate a terminus-priority platform in the middle (the current platform 7) which could eliminate at-grade crossings on the section we’re interested in. This platform could be extended to the south, to also provide a central terminus for trains from London. If the latter option is chosen, platforms 5 and 6 might even become redundant: paved over, they’d make the ideal location for a second station entrance, providing a much shorter route from cycle parking to the platform bridge, and additional income from renting out retail space.

Cambridge station diagrammatic track layout – two options

It is worth noting that Cambridge central station is more constrained to the south than the north: the Hills Road bridge is just 100 metres beyond the end of platform 1 (and only four tracks wide), and the post office building & car park limits space to the southeast. At present, there is space for the existing platform island to be extended further south – though if the new eastern platform island were connected to the south, this option may become less viable. In a northern approach scenario, there is much better balance in the number of trains heading north vs south in and out of Cambridge, which should reduce the pressure on platform space and time from terminating services.

Cambridge station looking north – existing platforms

For completeness, we should mention Cambridge South. In the southern approach proposal, it has four platforms – two pairs serving ~14/h in each direction (plus any future London services). In a northern approach scenario it may serve slightly fewer trains, but some might terminate at the station. It should be possible for a single platform to cope with as little as 3 minutes between trains (see Tottenham Hale’s southbound platform 1, for example), but in the worst-case scenario a 5th platform may be required here, offering a central terminus and two through-platforms in each direction. Although there would be some opposition to encroachment on Hobson’s Park, the additional land and cost would be very modest (just the width of a single-track path, as the current proposed station design already has the requisite platform island). If few EWR trains terminate here (instead continuing south to a combination of Haverhill, London, Stansted or elsewhere), the chance of needing a 5th platform is reduced, but 4-tracking may instead need to continue to the Shelford junction – as is the case for a southern approach scenario.

Cambridge South station diagrammatic – four options

With a little effort, then, it should be possible (if needed) to entirely eliminate at-grade crossings on the busy section we’re interested in, between Cambridge and Cambridge North. We therefore have a simple scenario of twin tracks, around a dozen trains per hour, and no clashes or constraints linking the two directions. Fewer freight trains should need to use this route (with as many as possible moved to EWR and an Ely chord), so trains should follow very similar acceleration profiles on this short, slow section of track. Nonetheless, we will still aim to ensure one oversized hourly slot remains for freight just in case (because getting as much freight off of the road and onto rail is very much to be encouraged).

If we look at the existing timetables, we see that the minimum gap between trains leaving Cambridge to the north is 3 minutes (xx:00 and xx:03 Cross-Country and Great Northern respectively). A 3-minute headway is also what’s stated in EWR’s requirements [Appendix B 5.7.2 of the latest EWR Co consultation docs] – so we can safely assume this is our minimum acceptable gap. Indeed, it only takes about 3 minutes between leaving one station and arriving at the other, so even spaced this close together, we should never have two trains between the two stations at the same time.  

I should note that the Cross-Country train does not currently stop at Cambridge North station – so despite many examples to the contrary, such as Tottenham Hale mentioned above, EWR Co may still conclude in the worst-case scenario that Cambridge North requires expansion to twin platforms in each direction. This is an expense not required with a southern approach, but that’s only because in a southern approach few (if any) EWR trains actually serve Cambridge North.

4.      Symmetry and inefficiency – the spectre of 4-tracking

In an idealised world without external constraints, 3-minute headings should allow for a theoretical maximum of 20 ‘slots’ per hour (up to 15 of which can be used if we are to stick within the 0.75 resilience requirement). With this in mind, EWR Co’s argument that even the 6 current + 4 EWR trains cannot be accommodated without quadrupling the tracks has led to much head-scratching. So, what is going on; how is the real world so far from ideal that we can’t even manage what is – without even considering future signalling upgrades – just ~50% theoretical capacity?

Although EWR Co have still not published their actual analysis (only the consequences thereof), I recently managed to speak to EWR Co’s Paul Sparrow via their live chat events, and obtained slightly more insight into their analysis:

“We have used some operations specialists to conduct the assessment using rail operations modelling systems in order to ascertain where we could get our 4 trains per hour onto the existing twin track WAML using our regular 15 min clockface service pattern. These results demonstrated that the white space, the space between trains, does not exist to allow us to get 4 trains an hour every 15 mins.” (Paul Sparrow, 29th May 2021)

This snippet of information, although still quite cryptic, is perhaps just enough for us to solve the mystery. The issue, I now suspect, is actually quite simple – and it’s all down to symmetry. Despite computational advances, building railway timetables is still ultimately mathematically driven by repeating patterns: it’s what the Swiss call ‘taktfahrplan’, or clock-face scheduling. Most train lines interact with several others along the length of their routes, and weaving all of these interconnected requirements together without clashes is much easier if everyone is dancing to the same beat. Although modern timetables may look quite random, they are essentially still just perturbations on an underlying regular symmetry.

We can illustrate this with a simplified example. Consider a railway line serving four locations: Appletown and Bananaville each need four trains an hour; Carrotbridge and Donutland need two apiece. Treating C&D as a single set, we can schedule these 12 trains at 5-minute intervals, with a pattern repeating every 15 minutes (left clock-face below). However, what if Carrotbridge decide they need their pair of hourly trains spaced 20 minutes apart? We start with Appletown’s regular trains, but once we’ve added Carrotbridge’s symmetry-breaking requirements, there’s no space left for Bananaville to have a train every 15 minutes. We can squeeze in the pair of Donutland trains, but the remaining slots are unhelpfully distributed – poor Bananaville!

This scenario is conceptually very closely related to the issue we have at hand. Carrotbridge in this case is represented by the Greater Anglia trains to Liverpool Street – and Bananaville is Oxford!

The two hourly trains from Cambridge North to Liverpool Street arrive in London at regular half-hour intervals. However, one of them is slightly ‘fast’ and the other ‘slow’: the difference is a modest ~10 minutes (~1h10 vs ~1h20). In order to make this work, 30 minutes after the slow train has left Cambridge North, the fast train…sits there for another 10 minutes, and then departs. By stopping at fewer stations on route, by the time it reaches London it has caught back up again to the 30-minute periodicity. On the return leg back north, the fast train arrives back 10 minutes earlier than its slow train equivalent would have done, and so it ends up sitting at Cambridge North…for yet another 10 minutes.

The other trains all tend to run at roughly regular half-hourly slots, into which it would normally be quite easy to add an EWR train every 15 minutes, because their symmetries are in sync. The Liverpool Street train’s timings, however, makes this simple task so much more difficult. As we will see, there are a few other minor quirks in the existing timetables too, all of which can be dealt with quite easily.

5.      Building more efficient timetables

Let us consider how this would work in terms of timetables. We’ve removed all at-grade crossings from the section, and Newmarket-bound trains have been moved onto a separate track. This should make our task relatively straightforward, as we have a single stretch of dual track between Cambridge Central and Cambridge North, with one train simply following the one in front. This is the most constrained section, so if it can be shown to work then everything else should fall into place.

We can start with the current timetable, and then see how the new services might look added in the ‘white space’. In this example, a normal weekday between 1pm and 2pm has been used – the differences from hour to hour are quite minor, so a proof-of-principle assessment needn’t replicate the analysis for every hour of every day. Instead of showing you lots of graphs and lists of timetables, I’ll stick with the ‘clock-face’ diagrams from the Appletown example above.

In the clock-face diagrams below, each service is represented by a 3-minute block, during which no other trains may depart. In the current timetable, we can see the two closest trains’ blocks adjacent to one another at xx:00 and xx03 on the northbound chart, and vast swathes of free ‘white space’ in both directions. These really aren’t very busy lines at the moment, with a train on each track between the stations just 30% of the time! But as you can see, the pairs of trains to Liverpool Street and (in the southbound direction) King’s Cross are not nicely symmetrical, with the Norwich train sitting where one might expect the second Liverpool Street train to be.

Now, if we attempt to add four hourly EWR trains to the existing timetable, it might look something like the figure below. At first glance all seems fine, but on closer inspection one of the four EWR trains has been slipped by a single minute from its ideal 15-minute-interval service, in order to avoid overlapping with an existing train’s 3-minute window. Although you might think this a very minor issue – arising from an existing timetable quirk which will long since have changed by the time EWR is built – as far as I can tell (going by Paul Sparrow’s above quote), it is precisely this which has led EWR Co to claim that the only solution is to build two more tracks through the north of Cambridge!

Nonetheless, sticking for now with the nearly symmetrical EWR trains added alongside the existing timetable, what other services might we need to make room for in the next few decades, to ensure our design is future-proof? A second Norwich train is an obvious one: Northbound it can fit exactly 30 minutes away from the existing train; southbound we have to offset it by a couple of minutes from its ideal position (one bit of broken symmetry forcing another one). After this, there is still space for another half-hourly service (e.g. trains to Wisbech) – and we’re still within the 75% resilience threshold stated in EWR’s requirements [Appendix B 5.7.2]. In both directions, there’s an oversized gap left in the hourly timetable for even a very slow freight train to get through, although this should be avoidable in most instances as freight could travel via Soham or Newmarket instead. We could even (not shown) double up the Birmingham service (which some hope could be extended to Leeds in future), by simply moving the northbound freight slot to ~xx.45.

The figure above illustrates how a northern approach – and a bunch of potential other future services – could work, without any changes to the existing timetable, without any signalling upgrades, and within the documented requirements of headways (3 minutes) and resilience (25% unused wiggle-room), without resorting to knocking down any buildings to build more tracks. However, what if we absolutely must have a symmetrically perfect-to-the-minute EWR service? Or, indeed, what if we would just like to tidy up the existing inefficient broken symmetries, and thus optimise the potential capacity through Cambridge’s only traffic-jam-avoiding cross-city travel corridor?

Northbound, the solution is incredibly simple. The fast train from Liverpool Street (which is about to sit at Cambridge North for more than half an hour) can just wait for a single minute at Cambridge station. That’s it.

Southbound, we have slightly more work to do. First, we align the time for which the King’s Cross trains dwell at Cambridge. I suspect the reason for this asymmetry in the current timetable comes from train-splitting, but with platforms at Ely and Waterbeach due to be extended, Network Rail themselves expect that procedure to be phased out in the coming years. Next, we have the fast Liverpool Street train (which leaves 10 minutes later than symmetry would like), and the existing Norwich train (which is then in the way). A neat, symmetry-restoring solution (as shown in the diagram below) is to push the Norwich train back by two minutes, and have the fast Liverpool Street train depart Cambridge North 10 minutes early, and dwell at Cambridge for 10 minutes (where it will be overtaken by the Norwich train, and then continue to Cambridge South roughly alongside the EWR service on the quad tracks). This would only be needed until two more (slow) trains between Cambridge Central and Liverpool Street are added, at which point both Cambridge North to Liverpool Street trains can become fast services.

The Norwich train, in ensuring regular hourly cycles, has a few minutes of wiggle-room to play with, but in a worst-case scenario it might miss its Stansted spot – in which case its lost slot could be taken up by an EWR train instead. A slightly less neat, but probably still workable and arguably less disruptive, solution (not shown) would have the existing Norwich train unaffected, the fast Liverpool Street train leaving just a minute or two earlier than it currently does, and the second Norwich train 32 minutes after (or 28 before) the existing one. These solutions involve very minor tweaks to the existing timetables, none of which should have any further knock-on effects on other services.

The above is, I would argue, a reasonable worst-case scenario for the 2040s, and is still acceptable within EWR Co’s given requirements. However, I suspect reality will be less constrained, as there are a variety of possible options which would each reduce the number of trains travelling through the busy corridor.

I would be slightly surprised if EWR needed four hourly trains, at least for the first decade or two. Even the busiest UK intercity services such as London to Bristol only have that many – as does Cambridge to King’s Cross (if we ignore the two slow trains which offer no utility for intercity passengers). EWR only serves relatively small towns and cities, and long-distance trips across the country which really aren’t that popular (and are mostly already quite doable via London, especially once Crossrail is operational). Half-hourly 8-carriage trains would have the same capacity as the proposed four hourly 4-carriage ones, and as EWR doesn’t really serve busy commuter routes east of Bletchley (where it’s expected that another 2/h will run from Oxford to the Milton Keynes  branch anyway), I suspect few would be very upset by a slightly less frequent service. Other than for a few select local routes (such as Cambridge and Bedford residents hopping on the train to Bletchley’s IKEA), EWR provides (at best) a modest improvement rather than a genuine transport revolution. Let’s just hope the trains have enough luggage space for flat-pack bookcases!

Next, it’s worth noting that Wisbech and King’s Lynn are a similar distance from Ely. The fast King’s Cross train, which currently splits at Cambridge (with only the front section continuing further north) could instead continue as one further north beyond the new Milton junction (where the track is less congested). It could then split in half at Ely (or the new Waterbeach station), with the front continuing to King’s Lynn, and the back departing for Wisbech three minutes later.

We could go further still. There are actually two routes from Norwich to Cambridge, of similar length. The route currently operating heads via Ely, but there’s another route via Diss and Bury St Edmunds. A direct train using the latter would either need to reverse in Stowmarket, or use a yet-to-be-built spur just north thereof. If a second Norwich train took this route, it would provide direct connections between Cambridge and Diss; Norwich and Bury St Edmunds. Moreover, while a large fraction of trips to Cambridge on the Norwich train involve people travelling the whole length of the line (with small numbers using intermediate stations such as Thetford), most Cambridge arrivals on the train from Ipswich come from Newmarket or Bury St Edmunds. Therefore, instead of having two Norwich trains via Thetford and two Ipswich ones via Bury, sending the second Norwich train via Bury may actually better serve passenger demand – as well as easing Ely’s congestion problems.

As a final potential tweak, it’s worth thinking about how to make best use of the station at Stansted Airport. Airports are the one location where direct trains are hugely advantageous, as swapping trains at intermediate stations is much more difficult if you have heavy luggage in tow (or are jetlagged!). However, the long single-track tunnel under the runway severely restricts how many trains can reach the airport. From Cambridge, two hourly trains make the journey – one from Norwich (Greater Anglia, class 755 diesel/electric hybrid trains) and one from Birmingham (Cross-Country, class 170 diesels). Could we use the advent of “Great British Railways” to shuffle rolling stock around, and thus find a way for these two trains to join together (at Ely or Waterbeach) and travel as one to Stansted? GA has a whole bunch of class 755s on local routes, a few of which could perhaps be swapped for CC’s class 170s – and I see no reason why the resulting 755 pair couldn’t couple together. This would then free up a Stansted slot, which (in a northern approach scenario) could enable an hourly direct EWR train from Oxford to Stansted!

If we put all of the above together in an optimistic scenario for the 2040s, we actually find ourselves with just a single extra train each hour compared with the current timetable (and even that is offset by an expected reduction in freight traffic, given a new spur south of Ely). I appreciate that at least some of the suggested optimisations might prove unworkable, but nonetheless it reinforces how many different options there are for ensuring there is absolutely no need to four-track through the north of Cambridge in a northern approach!

6.      Has this solved the problem?

The above examples show that there doesn’t appear to be any fundamental issue with scheduling all the trains we might possibly need in a way which avoids the need for 4-tracking. None of the tweaks suggested should cause any knock-on effects, so could be achieved while keeping all other timetables intact. Passengers boarding at Cambridge North towards Liverpool Street may see their southbound journey time increased by a few minutes – but I suspect that is an acceptable price to pay, given that a northern approach (unlike a southern one) would bring a regular EWR service to Cambridge North.

However, it is worth stressing that by 2030 (when EWR is expected to begin operation), the current franchises will be long gone: The current Greater Anglia franchise ends in 2025, and Great British Railways is about to completely shake up the way franchises work in the UK anyway. As such, so long as the *principle* of operation is sound, it’s not really worth worrying in fine detail what the precise timetables will look like at this stage – because they’ll all have changed by the time the line is built in any case.

It is, of course, worth noting that even in a southern approach scenario, the frequency of trains will increase – and symmetry-breaking carbuncles, which massively reduce line capacity, will need to be phased out regardless. The Liverpool Street asymmetry will probably be eliminated entirely within a few years anyway, as we expect to require a new pair of WAML trains which terminate at Cambridge Central. With four hourly trains in total, the Cambridge North pair will almost certainly both be designated as similarly ‘fast’, At which point the whole asymmetry issue disappears!

When designing new, it is always better to start as cleanly as possible, rather than adding yet more mess on top of existing inefficiencies. As the existing quirks can be easily tidied up – and will probably need to be resolved soon anyway – it would be wholly irrational to base major infrastructure design decisions around them. Nonetheless, given EWR Co’s claimed arguments, I thought it useful to illustrate how I think 4-tracking can be avoided both in principle, and in practice around the current timetable.

I haven’t considered in detail the extra services to London which Network Rail’s forecasts indicate will be needed by 2040. Most of these won’t pass north of Cambridge Central, so will not affect a northern approach. Looking at NR’s worst-case 2043 scenario, the only extra services needed north of Cambridge are one or two more Ely-KX trains (which could be the Wisbech trains, already factored into my model) and extending the two existing Liverpool Street trains beyond Cambridge North to terminate at Ely (which would remove the need for a 5th platform at Cambridge North, but add no further constraint issues so long as the junction at Milton is grade-separated). On the other hand, they will add further pressure to a southern approach, which even with 4-tracking may find the south Cambridge corridor eventually becomes problematically congested – risking platform capacity issues at Cambridge Central from so many terminating trains, and perhaps a need to rebuild Shelford junction as grade-separated.

7.      Concluding remarks

EWR’s Paul Sparrow has stated that the existing timetable doesn’t “allow us to get 4 [EWR] trains an hour every 15 mins” for a northern approach. The analysis presented here appears to confirm that this is technically a correct statement, but – unless I am very much mistaken – only in the same kind of way that I can say I was Time Magazine’s Person of the Year in 2006: It’s only *just* correct, and likely very misleading for them to have used it to draw the conclusions they have.

EWR Co claim that the only solution to the above, in a ‘northern approach’ scenario, is to 4-track north of Cambridge station. I disagree. The immediate EWR issue can be solved by slipping a single hourly train by a single minute, and even if we are to future-proof to include the reasonable-worst-case scenario (including a variety of other future trains beyond EWR), only very minor tweaks to the existing timetable – which will almost certainly disappear soon anyway – are needed to make it work.

If my analysis turns out to be sound, then I do not understand why EWR Co decided that 4-tracking (with dozens of demolitions, new bridges etc) is considered a lesser evil. I accept that there may be additional complications of which we are not aware, and which render the proposals in this document unworkable – but if that is the case, then they absolutely must be able to explain to the public why this is the case, and cannot continue to simply state “our modelling says it is not possible” without offering a technical justification.

If the timetabling issue can be resolved and 4-tracking rendered unnecessary, the question of a northern vs southern approach becomes much more balanced. I will leave it to others to expound the pros and cons of each option, but advantages such as keeping more freight out of Cambridge, EWR regularly serving Cambridge North (and potentially also London and/or Stansted), the option of a station at Northstowe (offering direct links to Cambourne, Oxford and Addenbrookes), an easier way to get the Haverhill line back up and running (without it adding even more N-v-S imbalance to the numbers of trains running through the Cambridge corridor), and simplifying the process of electrification between Oxford and Cambridge by decoupling from the Eastern section (not due for upgrade until 2040-50)…are all worth thinking about very seriously indeed.

Categories
Ecology

20th June Tour of the EWR Proposed Route

Will the EWR trains be friendlier to wildlife than this HS2 one? Find out from Kevin Hand on the 20th June.

On 20 June Kevin Hand will be doing a leisurely bike ride to some of the key wildlife sites mentioned in his Wildlife Impact Report for Cambridge Approaches and talking about the impact on them of the planned EWR Southern route and associated developments.

All welcome to come along for a chat at any point!
1030-1100 Nine Wells (Threatened)
1100 depart, cycle through Hobson’s Park (Threatened)
then via Trumpington Meadows to the Granta at Hauxton Mill (Threatened)
1200 Harston church, walk to the site of the huge viaduct over the River Rhee (Threatened)
Lunch break here.
1.30 Haslingfield church, walk to Haslingfield chalk quarry nature reserve and planned site of the Great Wall (Threatened) The orchids should be in bloom!
3pm Social gathering, Hare and Hounds, Harlton, in view of the southern route.
4pm Kevin will return to Cambridge via Toft village (Threatened) and Hardwick Wood (Threatened) finishing around 6pm

Categories
news

Bite-Sized EWR Videos

We have put together some short videos which summarise our campaign messages. Don’t forget to respond to the EWR Co. consultation which closes on June 9th 2021. Just say no to question 1!

1 – The South.
2 – Environment
3 – Freight
4 – Business Case
5 – The North

Categories
Route Alignments

Do EWR Cambridge Approaches Need 4-Tracking?

Why do we need to know about 4-tracking?

EWR Co’s decision to prioritise a southern approach into Cambridge primarily hinges on their assertion that a northern approach will require to be 4-tracked from the Milton junction with the existing West Anglia Main Line (WAML) into Cambridge. They also say that the existing Shepreth Branch Line between Hauxton Junction and Shepreth Junction (SBR) does not need to be 4-tracked but accept that this assessment needs further testing in later design stages.

Fig 1 – Northern and southern approaches into Cambridge with EWR Co’s 4-tracking proposals

It is vital that these matters are properly assessed now. To implement 4-tracking on either of these sections of existing lines would be extremely expensive. Major existing bridges would need to be modified or rebuilt and other infrastructure modified. If it is not resolved now, detailed design work would proceed based on a potentially faulty premise with the risk of locking the project into a solution that will lose valuable benefits of the alternative route.

To test EWR Co’s assessment, we have carried out our own evaluation of both their claims. We start by looking at the likely number of trains on the sections of the lines in question. We estimate the total number of trains likely to use the line including current traffic and probable growth for both passengers and freight. We discuss the likelihood of each of the scenarios occurring in practice and compare these rail traffic estimates with the capacity of the lines.

Summary

We found that EWR Co’s conclusion about the 4-tracking of the northern approach section NA2 is incorrect and that, for our estimate of the reasonable worst-case scenario, it does not need additional tracks. In fact, even with just traditional signalling there is likely to be sufficient capacity. With digital signalling, which is already specified by EWR Co, we expect there to be over-capacity.

Likewise, the southern approach section of the SBR line can probably take the reasonable worst-case passenger rail traffic estimate (which are based on Network Rail’s figures up to 2044). However, interfacing with the Thameslink services will impose severe restrictions on possible growth in traffic in excess of the figures shown due to anticipated expansion after 2044 as a result of the Ox-Cam Arc plans. The SBR line would not be able to accommodate EWR’s 6 trains per hour that are specified in the Project Wide Output Specification. The freight services estimated by Network Rail may not be able to be fully catered for because of limitations on the Newmarket line.

If EWR Co are wrong in their assertion that the SBR line does not need to be 4-tracked, the construction work that would be required exceeds the theoretical (but unrealistic) case for 4-tracking part of the northern approach.

Rail Traffic

The reasonable worst-case rail traffic scenarios for the northern and southern approaches to Cambridge are shown in Table 1. For the northern approach, we have considered the likely rail traffic on the critical section between Milton junction and Coldham’s Lane. All Newmarket trains would use platform 8 at Cambridge station enabling those services to avoid crossing movements between Cambridge Station and Coldham’s Lane. There is sufficient space in that length to increase the number of tracks should this be required.  

Table 1 – Reasonable worst-case rail traffic scenarios (trains per hour (tph) in each direction) for each approach into Cambridge

The assumptions and data sources used in compiling Table 1 are discussed below.  

  • We have not assumed any long-term change in the pre-pandemic forecasts for growth and and ‘existing’ services due to impact of COVID, even though this is likely to reduce the amount of rail traffic in the short and perhaps the medium term.
  • For consistency and independence, we have used Network Rail’s 2019 Cambridgeshire Corridor Study [Ref. 1] for assessing passenger and freight growth forecasts on the existing network for the two approaches. This will allow a fair operational comparison to be made between the approaches. We have resisted the temptation to consider in this assessment the beneficial effects (for a northern route) of an alternative future route via Newmarket for Norwich trains which has been suggested for many years, or the possibility of March trains splitting/joining other services at Ely. Combined, these could potentially reduce demand on the northern approach by 3tph. Nor have we considered the impact of a potential new Thameslink service between Cambridge and Maidstone East which may increase demand on the southern approach. Lastly, we consider that, if the Ox-Cam Arc proceeds as planned, there would be demand for even more Kings Cross services than mentioned in the Cambridgeshire Corridor Study with a timescale to 2044 only.
  • Future demand for freight on EWR is taken from a scenario suggested by Network Rail in the EWR Co’s Technical Report 3.10.7.
  • For a northern approach, EWR freight would be diverted northwards onto the WAML from Milton via a new grade-separated junction and then onto the main Felixstowe to Nuneaton freight line via a new chord just south of Ely. Any residual freight needing to pass through Cambridge would be planned out of peak hours.

Capacity

Basic ‘open-track’ Assessment

In addition to the basic number of trains per hour that could use an open railway line, the capacity is affected by a number of other factors, including timetabling, any crossing movements between tracks, whether the section of track is between junctions or between stations and the mixture of freight and passenger services. We start by looking at the open-line capacity and then go on to consider these other issues.

(i) Traditional signalling

Traditional signalling systems would allow for about 15 trains per hour with no other compounding factors. This is based on international standards (International Union of Railways or UIC which is the international rail transport industry organisation); a headway (the time between trains) of 3 minutes, as convention and a minimum required by EWR Co (Technical Report Appendix B 5.7.2); and a resilience ‘safety factor’ of 0.75 (UIC Code 406 for mixed traffic lines). The reasonable worst-case scenarios for both the northern and southern approaches as shown in Table 1 appears to be within the capacity of the existing twin track based on open track conditions and traditional signalling.

(ii) Digital Signalling

However, digital signalling will be used by EWR [Ref. 2] One of the benefits of digital signalling is the additional capacity that it provides. UIC have shown that on main railway lines, the capacity increase of ETCS level 2 (with ‘block’ lengths of 400m) over ETCS level 1 could be about 37% [Ref. 3]. This is supported by a statement by Network Rail quoting capacity increases ‘of up to 40%’ [Ref. 4]. These figures should be used with care, but they demonstrate that there would be a real and significant increase in capacity. Even using a capacity increase of half of these amounts, the number of trains per hour able to be accommodated could be increased to 18 by digital signalling without the need for 4-tracking,again without any complicating location-specific issues.

Importantly, digital signalling will also allow bi-directional running on tracks. This can provide significant flexibility, especially at stations, for reversing trains.

Other Factors in Capacity Assessment

There are several factors that could reduce actual capacity on a line, including whether clock-face timetabling is used (which is it on EWR) and the number of crossing of main lines radiating from London. Below we only consider those issues that are different between approaches.

(a) The Thameslink Effect and Slow Trains

Capacity reduction can arise when other train services use the section of track and the times of those services are not possible to change. This occurs for the southern approach where Thameslink services use the track. This leads to tight and sensitive interfaces with those services. The result is that the existing 6 passenger services are almost immutable because they form part of the complex Thameslink network and the East Coast Main Line traffic. The complexity of Thameslink can clearly be seen in the map[5] below, especially all the strands of services coming together in central London where it is planned to have 24tph crossing the Thames (which, incidentally, would not be possible without the capacity-enhancing benefits of digital signalling). EWR Co are very likely to be faced with predetermined ‘paths’ (planned slots for trains) at the Cambridge end of the route that do not mesh with their required paths elsewhere. This poses a serious risk to the effective capacity of this line, the outcome of which can only be resolved when timetabling of services is attempted. This is not the case for the northern approach.

If that were not sufficiently restrictive to the timetable, this line also has a slow service calling at all stations without a ‘loop’ or overtaking section for faster trains before they reach the East Coast Main Line near Hitchin. This means that timetabling for fast trains needs to allow for these slow trains, which will lead to greater gaps between trains. There are minimal such restrictions for a northern approach.

Fig 2 – Thameslink services – note number of lines passing through central London

(b) Crossing Movements and Junctions

Crossing movements required across other tracks and junctions can also reduce the capacity of a line. In the case where junctions are flat (‘at-grade’), one train joining another line could have to wait if another train were using the section of track the first one wanted to use. ‘Grade-separated junctions’ involving ramps and bridges over lines significantly reduce this delay. The southern approach into Cambridge has two junctions (Hauxton and Shepreth Branch junctions) compared to just one for the northern approach.

The northern approach allows trains that are temporarily blocked by other trains to wait for a short time at Cambridge North station. This would allow following trains to also wait at Cambridge North (obviously on another platform) and so minimise any concertina-type delay. On the southern approach, conversely, delayed trains would have to wait in line between junctions, magnifying the impact of such a delay.

(c) Freight

Operationally, slower freight and more speedy passenger services do not mix well. Freight on a northern approach (via a new northbound chord at Milton onto the WAML and then onto the Felixstowe to Nuneaton line via another new chord south of Ely), means that freight would have no impact on EWR operations in the busy section between Milton junction and Coldham’s Lane junction. Conversely, freight and passenger traffic on a southern approach intermingle, potentially resulting in less overall capacity. If the line were eventually used for even slower moving, heavy-haul freight, such as building materials, this would only exacerbate the situation.

For a southern approach, the Cambridgeshire Corridor Study estimates that the Newmarket line, even with the anticipated dualling between Coldhams Lane junction and Teversham, could accommodate 1tph for freight during off-peak hours. Network Rail estimate the freight demand could be 1.3tph during an 18-hour window (i.e. including peak and peak hours), assuming the scenario suggested by Network Rail in the Technical Report 3.10.7. This implies that there could be insufficient capacity on a southern approach for the anticipated freight.

Another operational disadvantage of a southern approach is that because freight needs to pass through Cambridge and Cambridge South stations, the problem of platform provision in both locations would be exacerbated.

What Do EWR Co. Say?

Northern Approach

EWR Co have stated (Appendix F, 2.2.4) that the results of their analysis of a northern approach showed that there would be several conflicting movements between EWR and other services including:

  • Trains towards Ely and eastbound EWR services conflicting where EWR services join the WAML; and
  • Conflicts on various platforms at Cambridge station.

We find the first point hard to understand as there could be a grade-separated junction at Milton specifically to overcome this issue. We find their conclusion that the only remaining option is ‘to add two extra tracks to the WAML, making it a four-track railway between the new Milton junction and Cambridge station’ (Appendix F 2.2.10) curious when they could much less onerously provide a grade-separated junction at Milton than the 4-tracking option. Confusingly, they then state in Appendix F 2.2.12 that ‘a grade-separated junction is required where the EWR route joins the WAML…’.

The second point would be overcome by the construction of two more platforms at Cambridge station which EWR Co already confirm would have to be done (App F section 2.2.10). Interestingly, they fail to mention that the southern approach also needs two new platforms at Cambridge station (Technical Report 11.1.5 ). Indeed, as we will see later, there is more pressure on Cambridge station platforms from a southern approach because a freight service will need to pass through. CamBedRailRoad documents[1] provide a solution without the need for additional platforms at Cambridge.

Southern Approach

EWR Co state (Technical Report 11.4.1): ‘…it is most likely  that the SBR can remain as a twin track railway as there is sufficient existing capacity to be able to add the EWR services required to achieve the Project Objectives and leave spare capacity for an increase in services in the future.’ (Our underlining). So they have not confirmed this vital point before choosing a southerly route.

They go on to state: ‘The working assumption for the operational timetable will be assessed further in the next design phase to confirm that it is correct. The focus will be on timetable and performance modelling of the SBR to ensure that both the EWR and GTR services can run as required with suitable resilience to allow for delay, disruption, and updates to service patterns.’

They appear to acknowledge from the last statement that there could be a problem of interfacing with existing services but without being explicit about it. The Sponsor’s Requirements (App A, 5.3 and 5.4) oblige them, as far as practical, ‘to be resilient to any periods of poor performance on the wider network’ and to ‘isolate the wider network from any periods of poor performance on the Railway [EWR]’.

We consider that such a fundamental point as this should be resolved at this stage or, if it really cannot be resolved now, to base decisions on a risk-based approach (i.e. they should analyse the chances of success and the costs of each scenario) in making the choice between a northern or southern approach.

EWR Co mention that two more platforms are required at Cambridge station for a southern approach. This it is not necessarily just a case of removing some sidings to add an extra pair of platforms at the east of Cambridge station: the Royal Mail building really isn’t that far away, and may need to be removed or reduced to allow space for the extra switching tracks, particularly if another pair of side-by-side platforms are needed. Additionally, there is a very short distance between the platforms at Cambridge station and Hill’s Road bridge, in which space all the different platform tracks need to condense down to just four tracks. Indeed, that itself could become quite a bottleneck for a southern approach, as each of the various trains from London and Oxford terminating at Cambridge need to reverse & switch on their way back out.

Other Issues With Approaches

Although the above sections attempt to show whether the two approaches need to be 4-tracked, there are other arguments that need to be considered in the choice of route from a railway operations and cost viewpoint.

1. Symmetry

EWR Co state (Consultation Document page 52) that trains using a northern approach would need to terminate at Cambridge South station. Similarly, a southern approach would need to terminate at Cambridge North station since this area is also an important employment hub.

If EWR Co persist in their conviction that a northern approach would need to be 4-tracked south of Milton, a southern approach would also need to be 4-tracked to Cambridge North as it would carry at least the same amount of rail traffic. This means that, according to EWR Co’s logic, 4-tracking on this section would be needed whichever approach were adopted.

We fully understand some of the severe practical difficulties in providing this. But this underscores our assertion that the northern approach, by providing relatively easy access to all three stations in Cambridge, serves Cambridge’s employment needs better than does a southern approach.

2. Risk and Impact on Infrastructure

We have already referred to the risk of EWR Co being wrong in their future assessment of whether the Shepreth Branch line would need 4-tracking between Hauxton and Shepreth Branch junctions. If they were wrong, the structures that would require to be constructed or modified specifically for 4-tracking are:

  • M11 crossing
  • River Cam crossing
  • Widened cutting E between Cam and A1301

The first two items are major construction works in their own right.

This list is in addition to those that are required even if 4-tracking is not required, including:

  • Hauxton grade-separated junction,
  • Harston level crossing changes,
  • A1368 bridge rebuild,
  • Hauxton Road level crossing changes,
  • A1301 (rebuilt bridge likely if grade-separated junction at Shepreth Branch junction)
  • Shepreth Branch grade-separated junction.

Clearly none of these 9 structures would require to be constructed if a northern approach were adopted.

Compare this to the two structures (the level crossing near Milton and the A14 crossing) that EWR Co state would be required if 4-tracking were required for a northern approach (which we, as detailed above, strongly refute). The other structures requiring modification (Fen Road, river Cam crossing, Newmarket Road and Mill Road) would need to be carried out anyway as a southern approach needs to terminate in Cambridge North station (see point 1 above). But all these works are less than those required for a southern approach.

This discrepancy in construction works between the approaches demonstrates EWR Co’s apparently sanguine approach to risk-based decision making.

3. Reversing Move at Cambridge

EWR Co have made much of the fact that a reversing move (i.e. the driver changing ends of the train) would be needed in Cambridge for onward eastbound traffic.

Two points are worth highlighting here. Firstly, it is not much of a penalty at all. A train approaching Cambridge from a southern approach would need to stop in the station for approximately 3 minutes before proceeding. For a train from a northern approach, the maximum time for the driver to change ends is about 5 minutes – a difference of some 2 minutes!

The second point is that onward eastbound passenger services are excluded from EWR Co’s remit. Although they need take such provision into account (the Sponsor’s Requirements 1.6 state that ‘Consideration should be given to the provision of or integration with services beyond the Oxford Cambridge sections…’), using this weak argument against a northern approach highlights their lack of strong arguments. It is especially rich when, in response to our queries about the problems that a southern approach would cause with freight east of Cambridge, EWR Co claim that it is not within their scope.

Conclusions

  1. The northern approach would not need to be 4-tracked between Milton junction and Cambridge station for the predicted maximum amount of rail traffic including future expansion of services to Wisbech and Norwich. As a result of digital signalling, it could also cater for EWR Co’s aspiration of 6tph. EWR Co have appeared to ignore a grade-separated junction at Milton in their analysis of 4-tracking of this section.
  2. It is not certain whether the southern approach between Hauxton and Shepreth Branch junctions (SBR line) can take any growth in passenger rail traffic beyond EWR’s 4tph until further timetabling work has been carried out by EWR Co. This is because of the severe constraints imposed by Thameslink and other services using the line. It would certainly not be able to provide capacity for the 6tph EWR services stated in the PWOS. This lack of flexibility to provide for growth is contrary to the Sponsor’s Requirements.
  3. If EWR Co’s future assessment of the SBR line shows that they do require to 4-track it, the construction works required is likely to exceed the theoretical additional works required for 4-tracking the northern approach (as stated in conclusion 1, they are not actually required).
  4. EWR Co have not been transparent about the adverse impact of freight using a southern approach on railway operations.

References

[1] Network Rail Cambridgeshire Corridor Study 2019.
[2] Programme-Wide Output Specification (Technical Report Appendix B 5.20.2) is ‘at least’ European Train Control System (ETCS) Level 2. The current signalling system in the general Cambridge area on existing track (i.e. in addition to the EWR track) is being upgraded to provide a platform ready for digital technologies and is planned to be complete by 2025, five years before the currently planned EWR completion date.
[3] ‘Influence of ETCS on line capacity – generic study’, UIC, Fig 24
[4] https://www.networkrail.co.uk/running-the-railway/railway-upgrade-plan/digital-railway/
[5] By Mvpo666 – Own work, CC BY-SA 4.0,
[6] CBRR Northern Approach Into Cambridge.

Categories
Ecology

Wildlife and Landscape Impacts of EWR’s Preferred Southern Route into Cambridge versus CBRR’s Northern Route

A Report for Cambridge Approaches

Chapel Hill, Haslingfield. By Euan Dunn

Summary

East West Rail are planning to link Oxford and Cambridge by rail as part of the huge Ox Cam Arc development of new towns and villages.

A Consultation on the final route is open until 9 June.

This new Report for Cambridge Approaches covers the wildlife and environmental impact of the two routes into Cambridge from Cambourne: the Southern Route, which EWR seem to have already decided on, and the Northern Fenland Route, which includes Northstowe and seems to be favoured by a majority of those affected by these proposals. The report shows the Southern route has much greater impact on wildlife and landscape.

Figure 2. Source: Making Meaningful Connections. EWR Co. 2021 Consultation Document.

The Northern route is supported over the Southern one by every organisation involved in wildlife and landscape protection in the area, including the Bedfordshire, Cambridgeshire and Northamptonshire Wildlife Trust (BCNWT), the Woodland Trust, Cambridge Past Present and Future (CPPF) and the Countryside Restoration Trust. The government body charged with protecting nature, Natural England, has said “We are concerned at the apparent lack of an environmental justification for the discounting of route options to the North of Cambridge.

It is important to note that the Consultation only asks people to consider the Southern route, not the Northern one. The route is only shown as a thin line on a map; it does not include the inevitable access roads, waste dumps, machinery parks and other infrastructure that will be needed nearby. It does not include impacts such as air pollution, noise and light pollution, toxic contamination, or changes to water quality and quantity.

Crucially it does not include any of the impact of the massive housing developments planned for the future. A stated aim of the Ox Cam Arc megaproject, of which this is a part, is to locate new development next to new transport infrastructure. One proposal, which has been put on hold for now at least, is for 25,000 homes (1), 5 times the size of Cambourne, in the Barrington area. Many other proposed new towns will follow, completely changing the character of the area and its villages.  1 million new homes are proposed within the Ox Cam Arc area by 2050 (one third of the total proposed for the whole of the UK). 

East West Rail is already being dubbed Cambridgeshires own HS2.

If the project does go ahead, the environmental impact of the Southern Route will be much greater, and will have negative impacts on:

  • Cambridgeshire’s internationally important chalk streams, with their populations of Brown Trout, Water Vole and Otter, and the River Cam itself, already severely under pressure from water extraction for other new developments. There are only 200 chalk streams in the world and five will be affected by the Southern route:
  • The River Cam at Hauxton
  • The Rhee or Cam at Harston
  • The Riddy at Hauxton
  • Coldhams Brook
  • Hobson’s Brook which flows from the Nine Wells Local Nature Reserve into the city and beside the Botanic Garden, and was the first source of fresh drinking water for the people of Cambridge.
  • The West Cambridgeshire Hundreds Living Landscape, where the BCNWT is linking ancient woodlands like Hardwick Wood that have survived for hundreds of years. The proposed route will form a barrier for wildlife, and for people from Cambridge and its many new developments, no longer able to walk and cycle from the city to explore these areas or the associated Cambridge Boulder Clay & Woodland Priority Area identified as part of the Cambridge Nature Network by BCNWT and CPPF. 
  • Our chalk hills and grasslands, one of the UK’s Priority Habitats, and in particular Haslingfield Chalk Pit and its associated landscape, which has thousands of orchids, including the nationally rare Man Orchid, and is widely valued and used by local communities.
  • The Bourn Brook, a site internationally famous for its success in restoring rare water vole populations and reducing introduced American mink, and the work of the Countryside Restoration Trust at Westfield Farm, where over 20 years of research work have resulted in growing populations of rare farmland birds and plants.
  • Many species of rare and endangered wildlife, including Barn Owls, Lapwings, Otters, Water Voles, Badgers and Bats. As just one example, the globally rare Barbastelle bat has a maternity colony centred on the Wimpole Hall estate and the Eversden Woods. This area has been awarded one of the UK’s highest levels of protection, a Special Area for Conservation. Feeding flights for the breeding mothers will be blocked, and bats may be killed, during the construction and operation of the Southern route. Many more less mobile mammals and birds will be greatly affected too. Mitigation for the Barbastelles suggested by EWR includes methods that have been shown not to work elsewhere, such as nest boxes and bridges(2).
  • Elms are a rare tree in the British landscape, and recent research has found 35 species in Cambridgeshire(3), many growing in woods and hedges that will be destroyed, including one found nowhere else in the world, Ulmus cantabrigiensis, the Cambridge elm. Rare black poplars are also to be found along the southern route.
  • As well as the Special Area for Conservation at Wimpole, the Southern route will destroy or damage 2 Sites of Special Scientific Interest (SSSIs), at least 11 County Wildlife Sites and 3 City Wildlife Sites, vitally important green spaces for the growing population of Cambridge.

The Northern route is much less damaging to wildlife and landscapes, as it would cross the area already affected by the A14 upgrade, and a small part of agricultural fenland. It would not need to cross the River Cam. It should not affect any SSSIs, one or possibly 2 County Wildlife Sites, and no City Wildlife Sites.

However, both routes are likely to damage Coldhams Common and Coldhams Brook with its associated chalk stream network, a key recreational and wildlife site for the people of Cambridge. A large loop will need to be built here to allow freight trains to wait for a path through Cambridge; there has been little discussion about this major impact.

The rest of the Report gives more details on the impacts.

The author is

Kevin Hand MSc MCIEEM  
Independent Ecologist
Vice President, Cambridge Natural History Society
Course Director, ACE Foundation and Stapleford Granary

References

  1. Brackley, P. (2020). Why Thakeham’s plans for 25,000 homes in South Cambridgeshire will still be considered for the Local Plan.  https://www.cambridgeindependent.co.uk/news/why-thakeham-s-plans-for-25-000-homes-in-south-cambridgeshire-will-still-be-considered-for-the-local-plan-9144678/
  2. Sutherland, W.J. & Wordley, C.F.R. (2017). Evidence complacency hampers conservation. Nature Ecology & Evolution 1, 1215–1216.

The second example is that of bat gantries (pictured), designed to reduce bat mortality on roads. Gantries, which are meant to guide bats to fly high enough over roads to avoid traffic mortality, were used in the UK for nine years without being tested, at a total cost of around £1 million. When studies were eventually undertaken, they found the gantries to be ineffective yet gantries continue to be constructed. Again, this is not due to a lack of available evidence, nor even to awareness of existing evidence; the gantry studies were widely reported in the national press, in relevant conferences and on television.”

3. Wildlife Trust BCN (2019). Here and Nowhere Else. https://www.wildlifebcn.org/blog/wildlife-trust-bcn/here-and-nowhere-else.

Figure 1. The Cam at River Farm with permission from Doug Thompson.

Main Report

1. Chalk Streams

There are only around 200 chalk streams left in the world and 85% of them are in southern England.

The unique characteristics of chalk streams, with their pure cool water, support a wide range of flora and fauna, from plants such as Water-crowfoot, Lesser Water Parsnip and Water Starwort, to a diverse collection of invertebrates and fish including the iconic Brown Trout. A chalk stream teeming with life is also attractive to Water Voles, Kingfisher and Otter. The unique and diverse ecology of chalk streams makes them a globally rare, and globally important, habitat. It could be argued that chalk streams are our local equivalent of rainforests.

The chalk streams affected by the SOUTHERN ROUTE are detailed in the recent Greater Cambridge Chalk Streams Project Report produced for Cambridge City Council and Cambridge Water by Ruth Hawksley at the BCN Wildlife Trust and Rob Mungovan of the Wild Trout Trust(1)

Five chalk stream sites will be affected by the SOUTHERN ROUTE, namely:

  • The River Cam at Hauxton, which has Otter, Brown Trout and Brook Lamprey, a rarely seen and ancient fish which lives most of its life without eyes or mouth.
  • The Rhee or Cam at Harston, also with Otter and Brown Trout.
  • The Riddy at Hauxton.
  • Coldhams Brook, which has Water Voles and Otter, both unusual in an urban environment. 
  • Hobson’s Brook which flows from the Nine Wells Local Nature Reserve (LNR) into the city and beside the Botanic Garden, and was the first source of fresh drinking water for the people of Cambridge. Nine Wells LNR is a County Wildlife Site (CWS), and was formerly a Site of Special Scientific Interest (SSSI). It is also part of the Gog Magog Countryside Project connecting it with Wandlebury. 

Brown Trout are just starting to return to the area as water quality slowly improves. Otters are a protected species under the Wildlife and Countryside Act 1981, also returning after an absence of many years. Water Voles are also protected under the Wildlife and Countryside Act 1981. They are one of our fastest declining mammals, but are also present in good numbers. Both are found in all 5 of the chalk streams that will be affected.

Figure 3. Rhee southern crossing point by Kevin Hand.

Beside the Rhee, at the SOUTHERN ROUTE crossing point, is a complex of wet meadows and wet willow woodland, probably the rarest UK woodland type. Both are Priority Habitats. This area would qualify as a CWS on its own merits. The author noted breeding evidence of Cetti’s Warbler here, probably a new county record, and singing Grasshopper Warbler. The woodland and associated mature willows have potential as a breeding site for the endangered Lesser Spotted Woodpecker.

The national Chalk Stream Alliance is fighting to protect the remaining streams. Locally the Cam Valley Forum (https://camvalleyforum.uk) is working to combat threats such as this kind of development. On 21 June 2021 the Friends of the River Cam are launching the Rights of the River Cam.

The NORTHERN ROUTE does not affect any chalk streams, and does not affect the River Cam, except in that both routes can impact Coldhams Brook and Coldhams Common by building a loop of track there so that large freight trains can turn around. This could be avoided if a loop is built outside Ely instead.

All the streams and river sections listed are going to be affected by the SOUTHERN ROUTE. Particular damage can be done during the building works by things such as increased sediment load, pollution and the disruption of hydrology. Noise and light pollution disturbing breeding birds and mammals would also be a particular issue.

Otters are fully protected under the Wildlife and Countryside Act 1981. They are highly secretive when breeding, and cover a wide area, often up to over 35km of riverbanks, so laws protecting them could easily be broken. All nesting birds are protected, again under the Wildlife and Countryside Act 1981, so no work could be done during the breeding season, from at least March-July, without breaking the law. No licences are available to destroy or disturb birds’ nests. Special species, like Kingfisher and the wetland warblers present such as Sedge, Reed and Cetti’s, have nests that are particularly hard to find.

Figure 4. Swans, with permission from Doug Thompson

2. Hardwick Wood and the West Cambridgeshire Hundreds Living Landscape

(A) Hardwick Wood

This is an ancient ash and field maple woodland, with nationally rare Oxlips (Primula elatior), and is managed by the Bedfordshire, Cambridgeshire and Northamptonshire Wildlife Trust (BCNWT) as a nature reserve. Recent changes to the National Planning Policy Framework for England planning laws state that “ancient woodland should not be affected by any development”. It is also a Site of Special Scientific Interest (SSSI), often referred to as the Crown Jewels of nature sites in Britain, and specifically protected by planning laws.

Hardwick Wood has the sinuous outline of medieval woods and is surrounded by a substantial wood bank, well preserved on the south and east sides. After ceasing in the early 20th century, coppicing was reinstated in 1979. This traditional practice lets in more light to the benefit of flowers and insects. As the coppice grows it provides safe nesting sites for woodland songbirds such as willow warbler, marsh tit and blackcap. The large amount of dead wood is a boon for the woodpeckers that can be heard drumming in spring. The Mere Way runs along the western boundary, the banks of the adjoining ditch providing a haven for cowslips and the rare crested cow-wheat, usually found on the margins of ancient woodlands and in clearings and rides. As twilight descends, the hoots of owls can be heard and bats patrol the woodland edges in their search for food.”

 Sourcehttps://www.wildlifebcn.org/nature-reserves/hardwick-wood

(B) Impact

The SOUTHERN ROUTE does not cut directly through the Wood, but goes close enough to have a significant impact on it, especially during the construction phase. It will also cut through wildlife corridors associated with the Wood, reducing its wildlife value. As there is no indication where associated works will be, it may be that access roads, waste dumps, spoil pits etc have further impacts upon the Wood and its associated habitats. As such, it will impact on the West Cambridgeshire Hundreds project.

(C) The West Cambridgeshire Hundreds

These are a collection of wildlife-rich ancient woodlands in an area defined for over 1000 years by the old Anglo-Saxon regional divisions known as the Cambridgeshire Hundreds. It’s thought the word ‘hundred’ came from an area of land that could supply 100 warriors in times of war.

This is a joint project between the BCN Wildlife Trust, local landowners, the Farming and Wildlife Advisory Group East, the National Trust, Natural England, the Forestry Commission and the Woodland Trust. The Scheme area extends to 20,000 Ha.

The SOUTHERN ROUTE may also impact two nearby County Wildlife Sites (CWS). CWSs are areas of land in Cambridgeshire important for their wildlife, selected by the combined expertise of the BCN Wildlife Trust, Farming and Wildlife Advisory Group, Natural England, Environment Agency, local authorities and the Cambridgeshire and Peterborough Environmental Records Centre (CPERC).

  • Jason Farm Grassland CWS is just north-west of Hardwick Wood. This site is notified because it has 0.05ha of the National Vegetation Classification (NVC) community MG5 Crested Dog’s-tail (Cynosurus cristatus)) – Black Knapweed (Centaurea nigra)  grassland. 
  • Frogs Hall Drift CWS is south of Hardwick Wood and supports frequent numbers of at least eight neutral grassland indicator species and populations of Nationally Scarce vascular plant species (Sulphur Clover (Trifolium ochroleucon); Yellow Pea (Lathyrus aphaca); Slender Tare (Vicia parviflora); Purple Fescue (Vulpia ambigua ssp. Ciliata – taken from CPERC records)).

The author found breeding evidence of Corn Bunting (Emberiza calandra), Skylark (Alauda arvensis), Yellowhammer (Emberiza citronella) and Linnet (Linaria cannabina) in the area. All are classified as Red under the Birds of Conservation Concern 4: the Red List for Birds, and are Priority Species under the UK Post-2010 Biodiversity Framework.

Figure 5. Linnet (Linaria cannabina), with permission from Douglas Thompson.
(D) Cambridge Nature Network

BCNWT, working with Cambridge City Council and others, have identified the landscape west of Cambridge as having significant potential to connect Cambridge to the West Cambridgeshire Hundreds, for the benefit of wildlife and people. 

The EWR favoured Southern route from Cambourne to Cambridge fundamentally compromises this goal of creating landscape scale connections … in this part of Cambridgeshire in providing a pleasant and largely undeveloped green lung accessible to the people of Cambridge.” 

Source: https://www.wildlifebcn.org/news/east-west-rail-consultation

The proposed route will in effect form a barrier for some wildlife and most definitely for people between the West Cambridgeshire Hundreds and the Cambridge Boulder Clay & Woodland Priority Area identified as part of the Cambridge Nature Network. The barrier will also separate the people of Cambridge from the West Cambridgeshire Hundreds, in that attractive non-motorised travel routes will be severely degraded or even cut off.

Source: Martin Baker, Conservation Manager, BCNWT

3. Chalk Hills and Grassland

Cambridgeshire’s ridge of chalk hills, running here from Wimpole to the valley of the Cam at Haslingfield, are a highly visual highlight of the county’s landscape. They were formed in the Cretaceous period between about 90 and 99 million years ago, mostly from the remains of marine algae and various animals that sank to the bottom of a warm, deep sea. Rain filters through them to feed the chalk streams, and their aquifers supply much of our drinking water. Chalk grassland is only found in north-west Europe, and a significant proportion of this is in the southern counties of England. Chalk grassland has declined by an estimated 75-80%since the Second World War.

The SOUTHERN ROUTE from Cambourne to Harston contains a huge embankment, viaduct and cutting complex dubbed the Great Wall of Cambridge, which will transform the landscape. This route will cut through the chalk hills from Harlton to Harston, and will include a deep cutting through the historic Chapel Hill, the famous ridge that stands above the village of Barrington. Once changed, this landscape can never be restored.

Figure 6. Elm Woodland on Chapel Hill by Kevin Hand.

The chalk soils form another Priority Habitat under the UK Biodiversity Action Plan and the Natural Environment and Rural Communities Act. The roadside verges at Chapel Hill are rich in chalk flowers, and should qualify as a County Wildlife Site. 

Nearby Haslingfield Pit is a CWS, notified because of the thousands of rare orchids that grow there, in particular the Man Orchid, listed as Nationally Scarce. Other orchids include Common Twayblade, Bee Orchid and Common Spotted Orchid. They are counted annually by local volunteers led by Clive Blower. In 2017 the totals were:

  • Man Orchid (Orchis anthropophora) – 75
  • Bee Orchid (Orphrys apifera) – 12
  • Common Twayblade (Neottia ovata) – 606
  • Common Spotted Orchid (Dactylorhiza fuchsia) – 1515

Haslingfield Pit is widely used for recreation and relaxation by locals and visitors. It has the potential to expand into neighbouring areas, including the field margins nearby, which also potentially hold rare chalk flowers.

Figure 7. Common Spotted Orchids in Haslingfield Pit June 2020, with permission from Angela Thompson.
Figure 8. Bee Orchids in Haslingfield Pit June 2020, with permission from Angela Thompson.
Figure 9. Broom Rape in Haslingfield Pit June 2020, with permission from Douglas Thompson.

Also likely to be affected by the SOUTHERN ROUTE is the nearby Barrington Chalk Pit SSSI. This is a ‘Geological Conservation Review’ site, and is noted as the last remaining exposure of the famous Cretaceous ‘Cambridge Greensand’. The site has great stratigraphical importance for studies of the Upper Cretaceous of eastern England. 

The area is also noted for its wildlife interest, with protected species such as Peregrine Falcon (Falco peregrinus) and Raven (Corvus corax) nesting nearby, and many rare elms growing in the hedges.

4. Bourn Brook, the Countryside Restoration Trust land at Westfield Farm, Comberton, and nearby County Wildlife Sites

(A) Bourn Brook

Bourn Brook is part of the same network as the chalk streams that flow into the Cam, but is classified as a clay stream as it runs mainly beneath the chalk hills, all the way into the outskirts of Cambridge at Byron’s Pool, Grantchester. The SOUTHERN ROUTE will cross it south of Toft, with a huge potential impact on its wildlife and ecology.

Bourn Brook is internationally famous for its Water Vole conservation work, led by Dr Vince Lea and the Countryside Restoration Trust (CRT). Their project to eradicate introduced American Mink, Bourn Free, has been widely publicised and admired for its ground-breaking success. As a result, Water Vole numbers have increased such that every available habitat along the Brook is now occupied, with a similar increase in water birds and particularly Otters. Otters are rarely seen so their numbers are estimated by the number of spraints (droppings marking territory), which increased from 11 in 2011 to 90 in 2017. The project is described in detail in an article by Dr Lea(2) in British Wildlife in December 2020. Water Voles can, in theory, be moved elsewhere from a site that is threatened with destruction, when Natural England give developers a licence to do this, except that all suitable habitat nearby is already occupied. Otters cannot be subjected to licensed removal, and there is no mitigation possible for the thriving populations living here.

Otter and Water Vole conservation is just part of the work of the Countryside Restoration Trust, whose Westfield Farm at Comberton will be cut in half by the SOUTHERN ROUTE. The CRT statement on this gives an excellent overview of the impacts on the wildlife of the area, and we quote extensively from it here.

“ The latest preferred route option is potentially disastrous for nature and wildlife habitats in the Cambridge area.

  The rail link’s proposed route will directly and negatively impact wildlife habitats and species numbers and divide habitat corridors throughout the area. The route could destroy 27 years of endeavour to increase national declining species on CRT land at Westfield Farm in Comberton.

  We have been approached to have environmental studies on our land at Westfield Farm, Comberton, in 2021. The East-West Railway project has recently released an interactive map showing the route in a blue-grey proposed area (and layers of land designation can be highlighted).

  Westfield lies south-west of Comberton, and despite being listed as a ‘Priority Habitat’ (by Natural England) and a Greenbelt area (by The Ministry of Housing, Communities and Local Government’s formerly the Department for Communities and Local Government) which is specially designated area of countryside protected from most forms of development, the route dissects through the land.

  The concern is that this devastates CRT land and other habitats, reserves, and local homes. We join other organisations suggestions that the railway line should follow the A428 and not obliterate the precious rural countryside to the west of Cambridgeshire.

Sourcehttps://www.countrysiderestorationtrust.com/oxford-cambridge-arc

(B) Westfield Wildlife 

Again, quoting extensively from the CRT statement, and using their images, we note the extensive number of species that will be impacted by this development.

We are extremely concerned about the impact the East-West Railway project will have on the habitats of protected, rare and farmland species. These include many BAP species identified as being the most threatened and requiring conservation action under the UK Biodiversity Action Plan (UK BAP).

  • Birds
  • Yellowhammer (in the top 1% of sites nationally 2019)
  • Grey partridge (in top 1% of sites nationally 2019)
  • Corn Bunting (numbers in the top 10% of sites nationally 2019)
  • Skylarks (numbers in the top 10% of sites nationally 2019)
  • Linnet
  • Song Thrush
  • Barn Owl 
  • Kingfisher
  • Starlings
  • Hobby (rare migratory falcon – spotted 2020)
  • Lapwings (winter visitor)
  • Golden Plover (winter visitor)

Large numbers of Brown Hares on-site, with double-figure counts regularly seen. Brown Hares are listed as a Priority Species under the UK Post-2010 Biodiversity Framework.

   At least one Badger sett with activity in other areas suggesting possibly a secondary sett developing. It is against the law, under the Protection of Badgers Act 1992, in England and Wales to disturb a badger and intentionally or recklessly damage or destroy a badger sett or obstruct access to it.

Figure 10. Badger, with permission from Douglas Thompson.

   Bats are not systematically recorded but are seenPipistrelles particularly. Also, there are recorded sightings of the Barbastelle bat.

   In 2020 we undertook our first Harvest Mouse nest exploration on Westfield and found a nest, demonstrating that this species is present on site.

Figure 11: Water Vole. Source: https://www.countrysiderestorationtrust.com/oxford-cambridge-arc
(C)  Bourn Brook through Westfield, reptiles, butterflies and plants

Again, we quote extensively from the CRT statement on the biodiversity present. 

The Bourn Brook’s riparian habitat that runs through Westfield is regularly monitored and maintained to create habitats for declining species and remove invasive species.

  Water Voles have colonised the site following work on the Bourn Brook to remove the invasive American Mink. Through a collaborative project, started in 2011, called the Bourn Free project, the local numbers of Water Vole has risen on other parts of the Bourn Brook that flows through Lark Rise Farm, CRT land in Barton.

  Westfield was the site where the first live-sighting of a wild, native Polecat was made in Cambridgeshire when one entered one of our mink traps and was released back into the wild following photographs as a record of the sighting.

  Grass snakes are seen in most years, including one record in 2020. These reptiles are listed as a Priority Species under the UK Post-2010 Biodiversity Framework.

  Great Crested Newts have been recorded on a few occasions. Great Crested Newts are listed as a Priority Species under the UK Post-2010 Biodiversity Framework.

  There is a regular survey of butterflies on the site, with nearly 20 years of data fed into the national butterfly monitoring scheme. This long-running data set would be threatened if a railway line crosses the site.
   While most species recorded are common and widespread, we have a good assemblage of species, including Small Coppers, Marbled Whites and Purple Hairstreaks.

   In recent years, the Biodiversity Action Plan Species White-letter Hairstreak has been recorded with photographic evidence.

Many rare and scarce arable weeds have been recorded on Westfield.

An example of some of the arable weeds include:

  • Shepherd’s Needle
  • Sharp-leaved Fluellens
  • Night-flowering Catchfly

Restored hay-meadows now have naturally colonised by Pyramidal Orchids recorded among other species.”

Sourcehttps://www.countrysiderestorationtrust.com/oxford-cambridge-arc

 (D)  Other County Wildlife Sites

Near to Westfield Farm are another two County Wildlife Sites that will be impacted:

  • The Radio Telescope area west of A603 

This supports over 0.05ha of the NVC community CG3 Upright Brome grassland.

  • Lords Bridge Observatory 

Situated east of the A603, this supports frequent numbers of at least 3 strong neutral grassland indicator species. Additionally it supports a population of the Nationally Scarce vascular plant species Slender Tare (Vicia parviflora). It is a large site at 34 ha.

The sides of A603 here are Protected Road Verges for similarly valuable neutral and calcareous grassland.

5. Endangered Wildlife, including Barbastelle bats

Many species of endangered and protected wildlife will be killed by the SOUTHERN ROUTE. Most of these are listed under their sites mentioned above.

In addition the route includes good populations of Water Vole, Otter, Brown Hare, Badgers and Bats. The last two are dealt with in more detail below. Rare species such as Marsh Harrier, Red Kite, Raven and Peregrine Falcon breed along the route: their locations are not publicised. Barn Owls nest in many places along the route, as do Grey Partridges, Skylarks, Yellow Wagtail, Lapwing, Yellowhammers, Bullfinch, Dunnock, Reed Bunting, Song Thrushand Linnets, all Red List farmland bird species of conservation concern. There are good populations of Whitethroat, Blackcap and Chiffchaff, and smaller numbers of Willow Warbler, Lesser Whitethroat, Sedge Warbler and Reed Warbler, as well as many other scarce bird species that use the many hedges and woodland strips along the route.

All birds and their nests have protection under the Wildlife and Countryside Act, with no Natural England licences available to exempt developers from the unlimited fines available for nest disturbance or destruction. This means all work should stop whenever birds are nesting, roughly half the year, adding considerably to the time needed to complete the project. 

The NORTHERN ROUTE also has nesting birds, but overall the numbers are likely to be less, with fewer species of special importance, particularly as much of the land is urban, suburban, already developed, or intensively managed farmland with few hedges and woods. Badgers do occur in reasonable numbers in the Dry Drayton area, but much less so on the drained fen farmland. Bats are likely to show a similar distribution, but more work should be done to confirm this. Otters are likely to be absent from the route, and Water Voles extremely scarce.

(A) Bats

All bat species are scarce and endangered, with some being our rarest animals. All are protected under the Wildlife and Countryside Act 1981, along with their roosts in trees and buildings. As with all the other wildlife recorded, it is likely that bat numbers affected are much greater along the SOUTHERN ROUTE. Many will roost in mature trees that will be felled, particularly Noctule, Long Eared and the two Pipistrelle species, with others roosting in woods, and for the last three species, some of the houses that will be destroyed.

The UK is a signatory to the Agreement on the Conservation of Bats in Europe, set up under the Bonn Convention. The Fundamental Obligations of Article III of this Agreement require the protection of all bats and their habitats, including the identification and protection from damage or disturbance of important feeding areas for bats. 

It is worth noting that bat roosts are notoriously hard to find. Many developers employ ecologists who will survey for bat roosts. This involves waiting beside potential roost trees at dusk or dawn, with audio bat detectors, in the hope of seeing or hearing the very fast emergence of the bats, which takes a matter of seconds. It is easily missed. With so many trees to look at it is highly unlikely that all bat roosts will be found before tree felling begins.

 (B) Barbastelles (Barbastella barbastellus)

Of particular importance, South Cambridgeshire is home to a large breeding colony of one of our rarest bats, the Barbastelle. The Wimpole Estate and Eversden Woods are protected for this reason with one of the highest UK designations, a Special Area of Conservation (SAC) https://sac.jncc.gov.uk/site/UK0030331

Figure 12. Barbastelle Bat

 Although the works associated with the SOUTHERN ROUTE will hopefully not destroy this area directly, Barbastelles feed at traditional sites some distance away in rural landscapes with deciduous woodland, wet meadows and water bodies. Barbastelles tolerate only minimal disturbance within 2 km of their roost. They can forage up to 20km from their roosts but more typically venture around 6-8km. They commute to foraging sites along linear landscape features, such as woodland edges and hedgerows, similar to the hedgerows that act as wildlife corridors. They have also been known to cross open areas such as arable fields to reach foraging grounds.

In 2008, a proposal for 8 wind turbines on land at Merry’s Farm, Great Eversden, was put to the landowner but not carried out because Natural England stated that “Separate to any Environmental Impact Assessment undertaken there will also need to be an Appropriate Assessment for the proposal under the Habitats Regulations. For the proposals to pass this assessment it will have to be conclusively shown that there will be no impacts on the integrity of the site (i.e. on the barbastelles for which the site is designated) arising from the development. If there is any
uncertainty about such impacts, then the proposal is unlikely to pass the assessment
.” 

In addition “given the international importance of the site and the acknowledged deficiencies in current scientific knowledge, we would also expect to see more innovative methods of survey employed to detect activity at turbine height (e.g. using remote systems or radar). In order to provide a robust evidence base to meet the requirements of an AppropriateAssessment, we would suggest that at least 3 years worth of survey data would be required.”

Source: This information has been shared with CA by Jane Rolph of Merry’s Farm.

The same level of compliance must be needed for the railway and its ‘Great Wall’ viaduct and all other associated works. Three years of intensive survey would significantly delay the project and increase the costs, and the results may well mean this route is rejected.

Disruption to the foraging routes and flight lines could have a potentially significant impact on the Barbastelle bats foraging habits, particularly impacting on the breeding females, putting at risk the maternity colony and, thus, ultimately the species. The species is very sensitive to disturbance, including disturbance to roost sites and access to food resources, which may be why it is such a rare bat. The Barbastelle is on the International Union for Conservation of Nature’s Red List of Threatened Species, where it is classified as ‘near threatened’ with extinction (IUCN Red List 2020).

Much radio tracking work has been done on the areas the breeding bats use when feeding their young, and many of these lie directly along the planned works. Other areas are the other side of the route, and there is good evidence that bats cannot cross these kind of large transport routes, and risk death if they try. The gantries proposed by EWR have been shown not to work see Sutherland & Wordley, 2017(3).  

Damant & Vine (2006)(4) stated the following:

“After another hour or two these bats would make excursions to the east, towards Cambridge. The favoured route for some bats was the old railway line with the radio telescope dishes; this also had tall neglected hedges either side and semi-natural grassland (another good source of micro-lepidoptera). Other routes were along Bourn brook and other tall hedges. The small villages of Toft, Kingston, Comberton, Barton and Harlton were also favoured. In 2003 one bat used Harlton quite frequently, including the old chalk quarry with its secondary growth of woodland and the tall hedges in and around the area.

The Barton area was extensively used by a single bat which sometimes flew to Barton, back to the maternity roost woodland and back to Barton in one night. It is very probable that these trackways are used because of the natural grassland margins, their quietness and also the fact that they may actually accumulate wind blown invertebrates from the surrounding arable land. Simon Damant has witnessed this in another trackway used by Pipistrelles where a short section had a tall hedge in a predominantly open landscape a long way from buildings and woodland.

To some extent the Wimpole population follows this basic assumption in that they do use Bourn Brook and go into Grantchester where the River Cam joins the River Rhee, almost certainly relying on the adjacent meadows to the waterways for a rich source of food. The small River Rhee catchment and Bourn Brook seem to be the main areas for foraging, though villages to the east are also frequented. However, in a much modified human landscape the bats would seem to have also adapted to using the more unkempt wider and taller boundary hedgerows with woodland copses for their flight lines and foraging in south west Cambridgeshire. They have also used the disused railway lines which have developed a secondary tree growth and tall hedgerows with semi natural grasslands. It is important to note that southwest Cambridgeshire is well wooded compared with much of the rest of the county but even here woodland is sparse and not particularly well linked by good tall and wide hedgerows.

… Therefore absolutely any woodland loss within a radius of 10-15km could be of great significance for the viability of the population of Barbastelles at Wimpole.

It is recommended by the Conservation of Habitats and Species Regulations 2017 that large infrastructure projects that could impact an SAC, whatever the distance, should undertake a Habitats Regulation Assessment. This has not been done, for either route. The Habitats Directive includes protection of the habitat, including the flight and foraging lines upon which the bats rely to successfully breed and rear young. Natural England have stated: For this reason, Natural England would advise that an Evidence Plan should be agreed with the relevant statutory bodies in order to inform EWR Co.’s approach to complying with the Habitats and Wild Birds Directives.

Source: Natural England response to the non-statutory consultation 2019, page 254.

Much has already been written about the impacts of the SOUTHERN ROUTE on the Barbastelles of Wimpole and Eversden. There is an excellent article by Angela Thompson, Chris Vine, Pippa Keynes and William Harrold on the Cambridge Approaches website. Sourcehttps://cambridgeapproaches.org/barbastelle-bats-are-they-important-when-considering-ewr-route/

This draws on the work of the Cambridgeshire Bat Group in radio tracking barbastelles from the SAC maternity colony (Vine 2002)(5). This showed their flight and foraging lines include the Bourn Brook corridor and the River Rhee/Cam, as well as the two CWS sites at Lords Bridge and the Radio Telescope line.

Note that this work would need to be brought up to date by EWR before they could make any suggestions of mitigation, tunnels or gantries, even though these have been shown not to work.

(C) Badgers (Meles meles)

Badgers are abundant along the Southern Chalk Hills route. The Cambridgeshire Mammal Group are aware of at least 20-30 family groups that will be impacted, and note that many more families are unrecorded. These families can have over 30 members. The average is 5- 8 adults per family, plus young, so an estimated 150 badgers at least could be affected, perhaps over 500. 

Many fewer badgers will be affected by the NORTHERN ROUTE, with few badgers in the fens themselves. 

Badgers are protected from death and destruction of their homes under the Protection of Badgers Act, 1992 and the Wildlife and Countryside Act, 1981. However developers are often able to appeal to Natural England, the government body involved in protecting nature, and NE will give them licences, not to kill badgers directly, but to block them from their homes, known as setts. This is done by covering the setts with thick mesh, and putting one-way gates on the remaining sett entrances, so they can leave but not return. As badgers spend the daytime hiding underground in their setts, there is little information on how they survive when they cannot access them. Anecdotal evidence suggests many badgers are killed by cars as they attempt to find new places to live. Because they are highly territorial, they will not be tolerated by other badgers living nearby, and may have to travel long distances, presumably hiding out above ground each day as they go, until they find an unoccupied area with enough food and a place to dig a new sett. Developers are supposed to provide some artificial setts for them nearby, but rarely enough for the number of badgers displaced, and in practice distressed badgers often reject the man-made setts. 

Along the 100 miles of the HS2 route currently under construction, just 4 man-made setts appear to have been provided so far, with many hundreds of badgers evicted.

(D) Polecat (Mustela putorius)

The native British Polecat is only now returning to Cambridgeshire, with some of the first sightings in areas along the SOUTHERN ROUTE. This rare and secretive mammal was persecuted to extinction in England in the past, and is supported in its natural reintroduction by the national Mammal Society and many other conservation groups.

(E) Elms 

Elms are a rare tree in the British landscape, decimated by Dutch elm disease in the 1970s and beyond. Recent research by Brian Eversham, CEO of BCNWT, has found 35 species in Cambridgeshire, many growing in woods and hedges that will be destroyed, including one found nowhere else in the world, Ulmus cantabrigiensis or the Cambridge elm.

Running along the summit of Chapel Hill, Barrington, is a particularly impressive mixed elm woodland with many mature trees. Many other mature elms are found in hedges and woodlands along the route, along with smaller hedgerow trees, which have the potential to grow into large trees.

(F) Oaks

There are many other mature trees along the route, most of which would qualify for Tree Preservation Orders. Of particular note are the many ancient oaks, many of which mark field and parish boundaries.

The hedges between Barrington and Harston have recently seen the planting of 300 oaks by community volunteers as part of the national Save the Oaks campaign (www.savetheoaks.org). The trees were planted in memory of those who died during the Covid pandemic. 

(G) Black Poplars (Populus nigra)

Black poplars have been reported along the SOUTHERN ROUTE, particularly in the Radio Telescope area. These are one of Britain’s rarest trees, with an estimated population of around 600.

6. Coldhams Common and the City Wildlife Sites

(A) Coldhams Common

Coldhams Common is protected as a County Wildlife Site, and is widely used by the people of Cambridge, including those from areas with less direct access to green spaces, such as Abbey and Romsey. Many enjoy access to the outdoor sports facilities here, and there are large areas used for healthy walking and exercise. A new community farm, CoFarm, has recently been set up by volunteers to grow and provide fresh organic food for those who are in need. The Friends of Coldham Common group represent local communities who use and value the area.

Coldhams Common has a rich wildlife biodiversity, particularly for an urban area. Amongst the breeding birds are many warblers, which migrate here annually from Africa, including Chiffchaff, Blackcap, the scarce Lesser Whitethroat and Goldcrest. The city’s resident Peregrine Falcons hunt over here, and other rare birds like Osprey and Hobby have been sometimes noted. 

The area likely to be affected, by both routes, is where the Coldhams Brook (described above under Chalk Streams) runs through the Common, near the Abbey football ground. Here, large freight trains will need a loop of new track built to allow them to wait for a path through Cambridge. Few details have yet been provided by EWR about this. It could have a large impact on that part of the Common, and on the ecosystem and hydrology of Coldhams Brook.

(B) Other Cambridge Wildlife Sites
Source: Cambridgeshire Green Infrastructure Strategy; Cambridgeshire Horizons (2011)

One other CWS (shown in blue above) is likely to be highly affected, and almost certainly destroyed, by the SOUTHERN ROUTE. This is the triangle of woodland beside the existing railway and guided busway, north of Long Road, known as Long Road Triangle CWS. The site qualifies as a County Wildlife Site because of the presence of a Nationally Scarce vascular plant species, Spreading Hedge Parsley (Torilis arvensis), but it is also an important piece of scarce undisturbed woodland in the city. The SOUTHERN ROUTE will require expansion of the existing railway line, destroying this site and its neighbour, below.

Long Road Triangle is given extra value because it joins a City Wildlife Site (CiWS), Long Road Plantation, just south of Long Road. CiWS are designated by the same body as the County Wildlife Sites, and are important urban wildlife refuges. Long Road Plantation qualifies because it is a woodland of over 1ha and has five or more characteristic woodland plant species.

Moving further south along the existing line, which will be widened, the next City Wildlife Site under threat is Hobsons Brook. This has a higher status as a Chalk stream (see above)together with its adjacent habitat. There is a very high risk it will become contaminated by sediment and debris during the building work.

Nine Wells was a geological SSSI, and is a main source for the Hobsons Brook chalk stream. Adjacent to it is Red Cross Lane Drain (TL465547), a CiWS that supports several neutral grassland indicator species in good numbers. Both sites are likely to be highly damaged by the expansion of the adjacent railway line.

Since these sites were designated a new area of high wildlife and public value has developed at Hobsons Park. It has a large amount of wildlife of interest, and is much used by the people of the city. In just one recent visit the author noted breeding evidence of Reed and Sedge warblers, Corn and Reed bunting, Yellow Wagtail, Skylark in large numbers, Meadow Pipit, and a large Black Headed Gull colony, with Common Terns also likely to breed. Hobsons Brook runs through the site. Expansion of the railway and associated works are likely to have a high impact on this important site.

7. Northern Route Wildlife Sites

The only SSSI near to the NORTHERN ROUTE is Madingley Wood, just over 2 km away, but separated from the route by the A428 dual carriageway. Because of this it is unlikely to be impacted by the route works

There is a Roadside Verge CWS south of Knapwell near the A428 crossing that supports populations of Nationally Scarce vascular plant species including Sulphur Clover (Trifolium ochroleucon) and Crested Cow-wheat (Melampyrum cristatum). This site could be damaged or destroyed.

Also along the route is Beach Ditch and Engine Drain CWS south of Cottenham, designated for its wet ditch flora and fauna. Again this could be damaged or destroyed. 

Other impacts of the NORTHERN ROUTE are also much less, and are mentioned above.   

Kevin Hand MSc MCIEEM   May 2021
Independent Ecologist
Vice President, Cambridge Natural History Society
Course Director, ACE Foundation and Stapleford Granary

Acknowledgements

Many thanks to all at Cambridge Approaches, particularly Dr Anna Gannon, Dr William Harrold, Pippa Keynes, Dr Sharon Erzinclioglu and Angela Thompson; the Cambridge Bat Group; and the Cambridge and Peterborough Environmental Records Centre (CPERC).

References
  1. Hawkesley, R. & Mungovan, R. (2020). Greater Cambridge Chalk Streams Project Report. https://www.cambridge.gov.uk/media/9067/greater-cambridge-chalk-streams-project-report.pdf
  2. Lea, V. (2020) Is Mink control for ever? Prospects for eradication in East Anglia. British Wildlife 32(3):165-172.
  3. Sutherland, W.J. & Wordley, C.F.R. (2017). Evidence complacency hampers conservation. Nature Ecology & Evolution 1: 1215–1216.
  4. Damant, S. & Vine, C. (2006). The Barbastelle at Wimpole. Nature in Cambridgeshire 48: 60-64.
  5. Vine, C. (2002). A. study of Barbastelle bats at Wimpole, Cambridgeshire, July 2000 to August 2002. Report to Natural England. Available from Natural England on request or directly from the National Trust.
Categories
Route Alignments

In Search of a Low Impact Design for the Cambridge Approaches

Figure 1 San Jose, Silicon Valley. A vision of Cambridgeshire in 2050?

Introduction

The EWR Co. 2021 non-statutory consultation includes a policy statement[1] on noise and vibration in which we find the following statement. “Sometimes we will need to elevate the track, for instance when trains intersect with roads and cross land in a floodplain. However, where it’s practicable we will consider building the track low in the landscape. This can help reduce noise and has the benefit of reducing the impact on the landscape.” 

Although they recognise that it is good to build low in the landscape (and as we shall see, this is good for several more reasons than just noise and vibration), the circumstances where they elevate the railway occur frequently. This has resulted in proposals for the approaches to Cambridge, north or south, which can only be described as a desecration of the landscape in our precious green belt. Indeed, it is hard to overstate the hideous nature of the proposals that we have before us.

This post has been written with the guidance of experienced civil engineers and the hope is to help EWRCo. find a better solution. But it is also to explain to others what is possible and is achieved elsewhere in the world and so to set all our expectations a lot higher. CBRR have, as volunteers, looked at a low impact railway design for the northern approach, but have not done so for the southern approach.

But before we get into all that, we start with some important background.

Background: Number of Houses in Cambridgeshire to Double by 2050

The EWR project forms part of Whitehall’s OxCam ARC initiative as set out in their National Infrastructure Commission (NIC) report[2] and confirmed in the recent OxCam Spatial Framework 2021 from the Ministry of Housing, Communities and Local Government (MHCLG)[3]. The NIC report (p.28) envisages building 1 million homes in the Arc between now and 2050 and in particular 271,000 in an area approximating to Cambridgeshire. 

Since the area in the NIC report is not the same as the county of Cambridgeshire the percentage increase between the baseline date of 2014 and 2050 is harder to estimate from publicly available figures, however and Oxford Professor David Rogers has stated that it represents an 81% increase. The recent rate of housing growth will soon have to double to make that target by 2050. 

The average home in the UK generates over 50 tonnes of CO2 in construction and emits a further 2.7 tonnes per year[4].  That’s 26.7 million tonnes of CO2 between 2014 and 2050 for construction and a rate of emission of 0.73 million tonnes / year after 2050 excluding any further construction. We cannot go on like this.

The population of the UK is forecast to grow by 16% by 2050 with the addition of 3 million homes. Therefore, the 1 million homes in the Arc is one third of the number for the whole UK and is concentrated in just 4.7% of the UK’s land area. The NIC report refers to this  “transformational” growth, way beyond anything needed to serve existing residents. We will be transformed into an urban sprawl from Oxford to Cambridge – see Figure 1. Who does this benefit? Not local residents. I suggest that local politicians consider who they are elected to represent. We do not want this.

The OxCam Arc plan is for Cambridgeshire to grow much, much faster than the UK average. The OxCam Spatial Framework plans to create 1.1 million new jobs. We are talking about a lot of people moving into the area. Everyone should be interested in the environmental impact of this and we recommend watching the talk given to the Friends of the Cam recently by the Oxford Professor of Ecology David Rogers who provided many of the insights above.[5]

Our local environment and residents are in for some cruel and unusual punishment if the OxCam Arc goes ahead and EWR Co.’s project is a core part of it.

Yes, we need more houses and we need better transport for local commuters, but the plans for the OxCam Arc go way beyond that. Perhaps Whitehall have the scene in Figure 1 in mind for the whole OxCam Arc and Cambridge in particular. How long will even the green belt last?

Incidentally, how can anyone plan, propose, decide or even comment on the route of the railway when there is no plan for where these 271,000 additional houses are to be built?

Why talk about this in the context of a post about ‘low Impact design for railways’? Well, most of the Cambridge Approaches material is working on the premise that the EWR Central Section does have a sensible triple (profit, people, planet) bottom line case and, given that it will be built, we are looking at where might be the most sensible place for it to go based on available information. Put another way, we are addressing the proposition in front of us. However, we will just make two points.

  • If there is a business case for the Bedford to Cambridge section it will be predicated on this massive housing growth and EWR Co. are therefore in no position at all to take the any moral high ground on CO2 emissions.
  • To encourage all these people to want to work in the area the railway needs to be attractive as specified in the Sponsors Requirements[6]The Great Wall, huge grade separated junctions and lots of 4-tracking in Cambridge are an appalling start on this.


Railway Engineering Structures – A Survey of the Options for Low Impact Design

Table 1 Environmentally-adverse Impact of Structures (In order of decreasing overall impact).

Level crossings are no longer being built for safety reasons, so we are left with some of the more difficult choices in Table 1 above. EWR Co. have proposed a route involving long embankments, viaducts and rail-over-rail grade-separated junctions as part of the extensive 4-tracking as the new railway approaches Cambridge from the south or the north. As can be seen from Table 1, these are some of the structures with the most adverse impact from an environmental point of view. So why are EWR Co. proposing them?

EWR Co. have expressed concern about crossing flood plains and cite a recent landslide in Scotland as a reason to avoid them where possible. We assume that they are talking about the Stonehaven derailment in Aberdeenshire.[7] This occurred in severe weather near a river crossing in quite hilly terrain where the land slipped. Landslips are often triggered by inadequately maintained drains. The flood plains to the north and south of Cambridge are in flat terrain and there are no river crossings on the northern approach proposed by CBRR. So, we fail to see the relevance of this incident to the Cambridge approaches. It would perhaps be more relevant to the Cam-crossing south of Harston as EWR Co.’s proposed route emerges from Chapel Hill and crosses the river on a high viaduct and embankment.

Towards the bottom of Table 1 we see trench railways as a low impact solution. However, EWR Co. have concerns about these. We address their concerns in Table 2.

Table 2 EWR Co. Objections to Trench Railways*As expressed in the EWR Co. Clapham Green to the Eversdens Presentation 11/5/2021.

EWR Co.’s Analysis of the Northern Approach

EWR Co. flag that “A northern route would cross the newly upgraded A14 trunk road to the west of Girton, which at this location is an eight-lane dual carriageway. This would therefore require a substantial bridge structure. The prevailing low-lying land level mean that this structure would be a prominent feature in the surrounding landscape” see Technical Report Appendix F §1.1.4.

In §1.1.5 of the same report they go on to say: “An additional station could be provided at Northstowe, but the area is low-lying and forms part of a floodplain so the station and its approaches would necessarily be elevated. A junction with the existing West Anglian Main Line (WAML) would be located north of Milton and this too sits in a floodplain.”

As previously discussed they immediately assume that rail goes over road and flood plains need embankments. CBRR’s hugely experienced consulting engineers do not make any such assumptions.

CBRR’s Fen Crossing Proposal for the Northern Approach

In 2018, CBRR published some preliminary alignment notes for CBRR’s proposed route. After discussion with EWR Co. during 2018, CBRR revised their notes[8]. The route proposal included a Fen Crossing section involving a trench railway so that, where necessary, the railway can have low impact as set out in Table 1.

To quote from their notes. For Map 6 “The highest ground along the route is north of Bourn Airfield where it is about +70mOD, and the line will need a cutting to limit the height to +65m. East of the station it leaves the A421/A428 alignment and drops steadily while heading north east to the east of Dry Drayton and passing below the A14 near the Cambridge Crematorium. By crossing below the A14 the impact on the crematorium will be reduced.”

For Maps 7 & 8 we find the following notes: “North-east of the A14 the line passes to the south-east of Oakington, where a station is proposed to serve Oakington and Northstowe. It then has to cross the fens for about 9km before joining the Cambridge – Ely line. For the fen crossing it is proposed to once again lower the alignment to below existing ground level and contain the line in a structural trench with walls up to flood protection level. This allows it to pass below the Oakington – Girton road, the guided busway, B1049 north of Histon, Landbeach road, and the A10 north of Milton. The advantages of keeping the line low are the reduced visual impact, the ease of building over-bridges, and the avoidance of new embankments which would cause continuing settlement for years after construction.”

EWR Co. have clearly missed the option of rail under road and trench railways in their write up of the northern approach, but they do follow the same route as CBRR in their analysis of the northern approach[9].  They have also completely missed it for the southern approach. In terms of structures the only options they consider are embankments, viaducts and overbridges. They then conclude, correctly, that these have higher visual impact as we have said in Table 1.

It seems that EWR Co.’s analysis has missed an opportunity to reduce the environmental impact of the railway and this has led them to produce hideous proposals for approaches both northern and southern. One of their reasons to reject the northern approach is the hideous nature of their own design. This is completely invalid.

To get an initial impression of what the design of a trench railway would look like in context it is perhaps best to look at this fly-through of an Oakington / Northstowe Station as proposed by CBRR. 

Notice that right at the end of the video, it is practically impossible to see any evidence of the station. This fly-through has been created by a local game designer based on engineering drawings from CBRR.

Northstowe Station

EWR Co., misleadingly, describe the access to the proposed Northstowe station as follows: “The proposed station at Oakington for Northstowe is at the very southern end of the new town, south of Oakington village, nearly 5km away from the northern edge of Northstowe (roughly a one hour walk).” 

It is also worth seeing this in the context of Homes England’s plans for Northstowe when fully built out as we assume it would be when the EWR services would start in 2030 (see Figure 2).  We agree with EWR that the current settlement of Northstowe is some way from Oakington, but this rather misses the point that only 7% of the housing has currently been completed and that happens to be at the other end of the new town (Phase 1 in Figure 2). When fully built with phase 2 and phase 3, it will reach all the way to Oakington. We also point out that there are other ways to travel 5km than walking. Why don’t EWR Co. say this? 

Although the Sponsors requirements ask for a commuter railway and the EWR Co. traffic model says that 70% of journeys will be local, EWR Co. are proposing a solution which will serve very few people in the area at least initially. It’s for people that live in Cambourne and happen to work at the Biomedical Campus or central Cambridge. How many is that? There are other ways to meet that demand.

Figure 2 Homes England Phased Plan for Northstowe – CBRR’s Proposed Station is at the Oakington End

EWR Co. also point out that that Northstowe already has the guided busway and imply that it does not need any more public transport provision.

Note that the busway shown in Figure 2 has two stops. During a visit on the 11th May 2021 we found this sign (see Figure 3) at the Longstanton stop to the north of the plan in Figure 2 and repeated on the front of the buses. Passenger numbers are reduced due to the pandemic and some social distancing is required on the buses, but Stagecoach are using all their buses and there is a currently a capacity shortage. We understand from bus users that the Cambridge buses are already full before they get to the Longstanton stop and this has been the case for years.

Figure 3 Indications that the Busway is Overloaded May 2021

We then visited the Oakington stop at around 11am the first Cambridge-bound bus to arrive displayed a “bus full” sign and did not stop. Here is a video of it passing through. Also we could only find two car parking spaces at Oakington Station.

EWR Co. may have spoken to Cambridgeshire County Council about future plans for the busway, but they should realise that these plans are now the responsibility of the Mayor of the Peterborough and Cambridgeshire Combined Authority not of the County Council. Why don’t EWR Co. know this? Furthermore, the new Mayor has dropped the Cambridge Autonomous Metro. This means that the roadmap for the busway is in a state of flux.

What will the situation be like in 2050 if 271,000 more houses have been built in the Cambridgeshire area?

CBRR Trench Design

CBRR are proposing a particular design for their structural trench which makes it suitable for use in low lying areas in flood plains. Figure 4 shows a cross-section of this trench.

Figure 4 CBRR Trench Cross Section

The main features are as follows:

  • Trains run in a trench of neutral buoyancy so most of the time it neither tries to float or sink
  • Flood walls on either side
  • Inverted siphons to allow any flood waters to pass beneath the railway line
  • ‘Green’ crossings about every 500m for any roads, PROWs or agricultural access

Trench Railways around the world

Figure 5 Trench Railway on HS1 Near Dagenham

The designers of the CBRR proposal used a similar approach for the design of a section of the HS1 link near Dagenham which has since been implemented (see Figure 5)

Figure 6 San Gabriel Trench Railway

The technique is used for the San Gabriel railway near Los Angeles in a place where there is an earthquake risk and where it won a Californian design award in 2019 (see Figure 6). The currently proposed central section of East West Railway does not look like it is about to win a design award.

Figure 7 Brussels to Amsterdam High Speed Railway in South Holland

The high-speed line between Brussels and Amsterdam also uses the same idea (see Figure 7). See for example this stretch on the approaches to a tidal river called Dordrecht Kil. As with the CBRR approach, the railway goes underneath. Note the water in the ditches on either side of the line – this is a really low-lying area. Dutch engineers know a thing or two about working in flood plains. EWR Co. imply that the precious green belt approaches to Cambridge do not warrant such a low impact design. Perhaps in Holland the government values the environment more than EWR Co. appear to.

Comparison of a Trench and an Embankment

In our previous post relating to the embankments of EWR Co.’s proposed Great Wall, we described the likely dimensions of such structures.

It is perhaps worth comparing the scale of the two side by side to show their cross sections.

Figure 8 Comparison of an 70m wide embankment with a 10m wide trench

This is shown in Figure 8 above. The trench is narrow, reducing land-take and facilitating crossings. It is also deep enough to hide the 4m high trains and any overhead line equipment. The embankment is just the opposite, and may even be worse if it needs a noise barrier on top. 

We talked about land-take in our earlier post about farming, but these embankments would be much worse due to the direct land-take and the difficulty of getting across them. We have spoken a local farmer who told us that his family had worked and developed their farm for 5 generations, but if this happened, it would all be over.

Other farmers have been estimating the effective loss of farm land due to uneconomically sized and shaped plots left by cutting fields indiscriminately. The land that would fall directly under the embankments are a small part of the total lost. The ease of crossing trenches is really important to farming. 

Conclusion

We have set out a variety of railway structures and ranked them in order of their impact from high to low. EWR Co. have proposed using high impact techniques for both their southern and northern approaches through the Cambridge green belt as though there was no alternative and to hideous effect.

During the current consultation, EWR Co. have objected to the use of low impact railway designs at all on the grounds of CO2 emissions associated with their construction. They have not compared it with their own high impact proposals on those grounds. Nor have they even mentioned them in their analysis despite them having been published by CBRR for use where necessary and for all to see in 2018. 

Their comments seem to indicate a disrespect for the environment and for local residents. This is a shame on multiple levels, not least since we presume that one of the objectives of the OxCam Arc is to create an area will people will actually want to live. 

The fact that EWR Co. CEO Simon Blanchflower speaking on Radio Cambridgeshire recently said that he would not want the railway coming near the village where he lives, speaks volumes. It can be compared to the moment in 1992 when Gerald Ratner described one of his companies’ jewellery products as ‘crap’. This led to severe damage to Ratners’ business. But what will happen to the state-owned monopoly EWR Co.? How unpopular do their proposals have to be to have any effect?

We have presented some background to set the railway construction in the context of the OxCam Arc and its toxic assumption that a million homes will be constructed by 2050. This is so that the attempt by EWR Co. to take the moral high ground on climate change can be seen in context. If there is a case for the EWR, it is as part of the OxCam Arc with all that that entails.

CBRR’s experienced engineers have shown how where necessary, low impact design techniques can be applied to the northern approach. Although not described in this article a lot more could be done with a southern approach to reduce the impact with trenches, tunnels and putting the railway under roads, railways and rivers. The CBRR design sets the standard that we want to see in the green belt of Cambridge.


[1] Our approach to Mitigating the Impact of Noise and Vibration in Local Communities, Section entitled Low-impact route alignment.

[2] “Partnering for Prosperity”, NIC Report 2018.

[3] Planning for Sustainable Growth in the Oxford Cambridge Arc: An introduction to the Oxford-Cambridge Arc Spatial FrameworkFebruary 2021

[4] What is the carbon footprint of a house?

[5] The Oxford-Cambridge Arc; An Environmental Catastrophe – Professor David  Rogers. 30 April 2021

[6] Making Meaningful Connections Technical Report Appendix A §1.2

[7] Stonehaven Derailment August 2020

[8] CBRR Preliminary Alignment Notes May 2018, revised Sept 2018

[9] Making Meaningful Connections, Technical Report Appendix F

Categories
Route Alignments

EWR’s ‘Comparison of Factual Data’ Tables

Background

EWR Co’s Appendix F to the Technical Report contains two tables comparing the northern approach into Cambridge with the southern approach using a variety of parameters. They include such factors as length of viaducts, impact on residential areas, number of bridges required and impacts on environmental sites such as SSSIs and scheduled monuments. Cambridge Approaches has carried out a similar exercise months before East West Rail and presented the conclusions to the press, to EWR and to the rail minister. The tables from EWR Co are in response to our work. Now that we have confirmation of the route and the results of EWR Co analysis we have updated our assessment as shown in this post to show what we believe is a fairer comparison between the routes.

EWR Co presented their comparison tables to local councillors on the opening day of the of the consultation with a table entitled “actual facts”. We are not sure if this is a reference to a belief that CA analysis is wrong or whether they mean that the rest of their consultation does not contain “actual facts”. Perhaps they can clarify.

Our results very clearly contradict EWR Co claims of an advantage for the southern route. In most cases the total reverse is true. For the few remaining counts, the result is broadly balanced. The main reasons for the difference in conclusions are what factors EWR Co have decided to measure, the assumptions they have made and how they have chosen to measure their figures.

Assumptions and Measurement Points

One important assumption that EWR Co have used to underpin their case is that the West Anglia Main Line (WAML) would require to be 4-tracked (increasing the 2 existing tracks to 4) from where a northern approach would join the WAML at Milton and Cambridge. We believe that this would not need be carried out and we will explain our thinking on this in another post. As a result, we have, for some items, provided two counts – one with the 4-tracking (for direct comparison with EWR Co’s own figures) and one without 4-tracking (which we believe is more realistic).

We have also, in some cases, used two measuring points to gain a more accurate assessment of the factors. EWR Co have consistently used only Cambridge station as the basis for comparison between approaches. This may be reasonable for passenger trains but for freight trains, Coldham’s Common is more appropriate since that is the point where freight trains from the two approaches diverge. A freight train is generally accepted to be noisier than an electrified passenger train and just because EWR Co. will not be operating the freight train themselves, it does not mean that the noise will not wake residents in the middle of the night. A map of the area is shown in Figure 1.

EWR Co have said that they have combined the two northern approach options (i.e. freight passing via a new chord just south of Ely and freight passing via a new chord on Coldham’s Common). They have, notably, omitted to mention any of the advantages of the former option in their comparison of factual data. In particular, there would be no impact of freight on Cambridge residents if our first option were adopted and much less overall. For clarity in comparison of numbers, we have used the Coldham’s Common chord option for measurements.


Figure 1 – Route options and measuring points

Results

Analysis

General factors

Operational length

EWR Co recognise that there is little difference (1.1km) between the track lengths of the two approaches for passenger trains measured to Cambridge station. However, the northern approach is over 3km shorter for freight using the Coldham’s Common chord.

Length of infrastructure

While the northern route passes through a greater length of flood zone, it plays this to its advantage by adoption of a trench solution which utilises the buoyancy effect in the waterlogged ground. This results in no viaducts and minimal embankments. It passes beneath roads and the guided busway and could be constructed while keeping the road traffic and guided buses operational. Oddly, when making the comparison, EWR Co have used a similar route to CBRR but, instead of using the CBRR trench construction methodology, they have taken an embankment solution and then proceeded to criticise it. The southern approach has a combined length of over 5km of embankment exceeding 8m in height. The trench approach has been presented on the CBRR website since 2018, so it is strange that EWR Co. do not even comment on it. Did they just miss it? Do they disagree with this widely used approach or are they just looking for reasons to justify a political decision made in favour of the southern approach and find this to be an inconvenient truth?

Impact on residents

This is one of the most important factors between a northern and southern approach, particularly in respect of noise. Night-time noise is clearly more problematic than day-time noise, so we believe that measures appropriate for freight services are more relevant than for passenger services. Although EWR Co have used a variety of assessments, including the length of railway in Cambridge wards, the most direct measure of this is the count of residential properties within 200m either side of the track. The length of track in Cambridge wards is not a very meaningful measurement because in some places the line passes through residential areas and in other places it does not. They have used Cambridge station as the basis for measurements: this is only appropriate for passenger services. We have also considered Coldham’s Common as a basis – see section above on ‘Assumptions and measuring points’. Our figures (which have been assessed by three separate people) are considerably less than those obtained by EWR. However, the absolute numbers are not critical for a comparison – it is the relative numbers between the northern and southern approach that matters. For passenger services the count is similar (slightly in favour of a southern approach) but the critical night-time freight measurement is massively in favour of a northern approach by a factor of over 8:1 (i.e. there are more than 8 times the number of residential properties within 200m of the track on a southern approach than a northern approach).

Roads and other crossings

The number of road and other crossings significantly impacts the overall construction cost of a railway. The greater the span of a bridge, the greater the cost so major road crossings affect the cost more than those for minor roads and farm-tracks. Assuming that 4-tracking will not be undertaken for whichever option is chosen, the overall result is in favour of a northern approach with slightly fewer A- and minor road crossings required. A more significant difference between the approaches is that because the northern approach would pass beneath existing roads, this would result in less temporary traffic disruption during construction and lower noise and visual impacts because of the trench technology.

Environmental factors

Measuring distances to environmental sites cannot reveal the whole picture of the impact of the railway on a site. This would partly depend on the wildlife or ecology that the site is trying to protect. For example, the railway following a southern approach can cause a lot of damage to the Wimpole and Eversden Woods SAC but this is not revealed by the measure EWR Co use to show the impact. Although we have compared the approaches using the same measures as EWR Co, they still need to be considered with some degree of caution.

SSSIs

There are 4 SSSIs within a 2km buffer of the southern approach but none on the northern approach. EWR Co have mistakenly measured the northern approach as having 1 within this distance. The one they counted was probably Madingley Woods which is about 2.3km from the northern route.

SACs

There are no Special Areas of Conservation (SACs) within any of the buffers used by EWR Co. This does not demonstrate the impact of the Southern Approach on the SAC at Wimpole and Eversden Wood in which a colony of Barbastelle bats roost. The bats forage for around 5-7km from the roosting site and would not be affected by the Northern route. See our previous post on this subject, the Wimpole/Eversdens SAC is one of only Barbastelle SACs in the UK and it is in great danger from EWR Co.’s cavalier assertions about mitigation techniques that have failed in the past and would fail here again

Scheduled monuments

The southern route impacts directly (within about 10m) on 3 scheduled monuments whereas there would be no direct impact with a northern approach. Even using a 2km buffer, the southern route fares worse.

Listed buildings

As for other environmental counts, EWR Co have measured two distances from listed buildings to assess the impact of each approach: 10m and 2km, and only using Cambridge station as the measuring point. We consider this to be misleading and have counted listed buildings within three different bands, 10m, 200m and 500m for both passenger trains and freight trains. While EWR Co’s assessment shows broadly similar impacts of both approaches (with a slight disadvantage for the northern route for grade 1 & 2* buildings), our more nuanced and thorough evaluation shows a clear and significant advantage for a northern route, even when considering passenger trains. As mentioned earlier, using Coldham’s Common as a basis for assessment is appropriate for freight trains which cause by far the bulk of noise and air pollution impact on all types of residential property. On this basis, our figures demonstrate that there are more than double the number of grade 1 and 2* properties within 500m of the track on a southern route than on a northern route. The difference is even more stark for grade 2 properties with over 4 times the number within 500m.

Priority habitats

EWR Co have counted the number of priority habitats within 10m and 2km of the alignments. This presentation fails to take account of the size of each habitat. To address this omission, we have considered the length of a 200m zone passing through each site[WH1] , as shown schematically below.


Figure 2 Measurement of priority habitats

Although imperfect, it is considered more accurate than EWR Co’s measure. EWR Co’s assessment results in broadly similar outcomes. However, our measure shows the southern route has about a 2.5 times greater impact than the northern route.

Wildlife Trust sites

There is an advantage of the northern route over a southern route (1 site compared to 2 sites within 2km of the routes) but, because the total numbers are low and the 2km distance is great, this is not a differentiating measure.

Local Nature reserves

Our figures are much lower than EWR Co’s figures for both alternatives so it is likely we have not been able to access all the data that EWR Co have used. But taking EWR Co’s numbers at face value, there is a nominal difference slightly in favour of a southern option (12 sites for a northern approach and 10 sites for a southern approach). Again, this is not a differentiating measure.

Residential properties

EWR Co include commercial as well as residential properties in their assessment, whereas we have considered only residential properties. As previously mentioned, they have also assumed that the West Anglia Main Line (Cambridge to Ely line) will be 4-tracked but without providing any supporting evidence. We dispute this assumption and consider that it could be left as a twin track line. Putting this argument to one side, we have looked in detail at EWR Co’s figures. We count 33 residential properties within 10m of the line that could be impacted by a northern approach with 4 tracks between Milton and Cambridge. This compares to 39 for a southern approach. EWR Co, on the other hand, count 40-85 residential and commercial properties close to the line for a northern route and just 5 for a southern route. We have measured to the boundary of a property. While we do not correlate these figures directly with the requirement for demolition, we consider that EWR Co have made some errors in their assessment. For example, there would be about 11 properties that would be directly impacted on just one site at Highfields Caldecote (the Linden development) on a southern approach.

Conclusions

The overwhelming message from our analysis is that on the vast majority of measures, the northern approach is superior to the southern approach, including embankments, residential impact, road crossings and environmental aspects. For the remaining factors, there is a broad similarity between approaches. The measure that EWR Co have ‘afforded particular weight in the back-check undertaken’, the impacts on residential properties, is broadly similar in our assessment even using the doubtful assumption that the northern route will need some 4-tracking.

Categories
Route Alignments

The Great Wall – Part 2

Figure 1 The Great Wall. Not easy to get across…

We made an initial assessment of the Great Wall in our previous post on the subject. We have now had time to look at the proposal in a bit more detail and this post presents more of our analysis.

Height Profile and Distribution

The structure we describe varies in height along its length and also switches between being an embankment, a viaduct and a cutting. EWR Co. are picking statistics about The Great Wall which may make it seem smaller than it actually is. For example, some of it is at ground level (not much, but some). As it is not one continuous type of structure, the length of each individual section of embankment, viaduct or cutting obviously has a limited length. But one thing is clear: the length of the entire structure from Cambourne North Station to Hauxton junction is 17.4km. As you enter a cutting from an embankment, yes there will be a point where the level difference between the track and the local ground level is zero.

We prefer to present the data in a form that makes it easier to understand.

Figure 2 EWR Co.’s Proposed Great Wall Section from Cambridge North Station to Hauxton Junction.

Figure 2 shows the height above local ground level in metres versus the distance along the track or “chainage” starting at EWRCo.’s proposed Cambourne North Station and ending at their proposed Hauxton Junction. The height is above 4m for 12 km out of the 17.4km from Cambourne north to Hauxton Junction. But the line is particularly high near houses in Highfields Caldecote, Little Eversden, Harlton, the two approaches to Haslingfield and wrapped around the south and east of Harston. 

Figure 3 Distribution of Embankment and Viaduct Heights

Figure 3 shows the distribution of heights of the structure above local ground level. Specifically, it shows the length of track above a threshold level. For example, looking at figure 3, there would be just over 6km above a height of 8m.

Leaving out any overhead line equipment, trains are around 4m high. So, with a 4m high embankment or viaduct, it would be possible to see the top of a train above the 8m rooftop of a 2-storey house. 

Embankment Cross Section

CBRR have produced a cross-section of what a 10-metre high embankment would look like (see Figure 4).

Figure 4 Cross Section of a 10m Twin Track Railway Embankment

The tracks are on a 10m wide platform. To reduce noise impact, we would expect acoustic barriers on either side of the track.  If we are lucky enough to get an electrified line then the Overhead Line Equipment (OLE) would be on top. Remember also that in most of this section the trains will be travelling at up to 100 mph.

Either side there would be slopes, usually at an incline of 1:3, making the width of a 10m high embankment 70m. These slopes would be too steep to be returned to farming. There would be security fences on either side of the embankment and culverts every so often to allow the passage of wildlife and people. 

Consider the school children making their way to Comberton Village College from The Eversdens. Will they divert and cycle down the busy A603? Will they pass through a 70m culvert on dark December afternoons? Will they get through the security fence and cross the tracks? There could be similar issues for young children from Newton to Harston primary school or from Harlton to Haslingfield primary school if there is no safe way to get across the Great Wall.

Much of the route will be on clay and a significant foundation will be necessary with piles beneath it to reduce settlement as shown in Figure 4. Consider the carbon emissions required to make these large structures and carry in the material to do so. The material from the destruction of Chapel and Money hills will not be enough.

Land Take

We have estimated that the total area of land required in this 17.4km section, taking viaducts to be just 10m wide and embankments and cuttings with 1:3 slopes. The width of the embankments can be calculated from their height profile and a 3m width allowance for security fences on either side. The result is an estimated 206.3 acres of land taken by this structure excluding any construction or maintenance roads on either side.

It would be interesting to get an estimate of the weight of material that would need to be transported to make these embankments.

As previously explained the farmland to the south of Cambridge is particularly important for food security when climate change induced sea level rises are considered. The author of that article has estimated that 44.5 acres of his land near Harlton will either be directly lost or become unfarmable – and that is just one farm. The effective land take is likely to be much-much higher than 206 acres. This is farmland that has been cultivated for generation after generation.

Before you reach the conclusion that it would be the same to the north – please consider the trench railway technology proposed by CBRR for the fen-crossing section of their proposal and their proposal is low in the landscape all the way from Cambourne North station into Cambridge.

Viaducts

We can get an idea of what a modern railway viaduct will look like from the recently constructed Hitchin Flyover (See figure 5). But bear in mind this is only 5m high and single track.

Figure 5 Hitchin Flyover in 2021. The Security Fences have been breached and Graffiti is everywhere.

Composite Photograph of Highfields Caldecote

Figure 6 Junction of West Drive and Highfields Road in 2021
Figure 7 Composite with EWR proposed Embankment. Railway underpass on Highfields Road to be confirmed by EWR Co.


An Impression of the Environmental Impact

This post has so far focussed on the facts about the proposed Great Wall. We shared something about how we feel about it here and here.

Local residents Anna and Tom have prepared a video entitled “Muted By Covid” which shows part of the section of the proposed route between Harlton and Haslingfield on the ground.

Categories
news

Webinar Programme Spring 2021 – Updated

Programme

Our evolving programme of webinars can be found on the Support Us page this website – scroll down to the bottom. Check back there since we will update the programme in due course. For people that missed webinars, many of them are recorded and made available on this website on the Support Us page and elsewhere on this site.

Fair Consultation on a Northern Approach Webinar

William Harrold and Sebastian Kindersley will hold a webinar for the Caldecote area (but all welcome)

at 7pm (BST) on the 4th of May 2021.

*** To register for this meeting click *** here.
*** NOW WITH CORRECTED LINK ***

It will be based on the presentation we gave to the rail minister on the 23rd February, but we have added new material relating to the current EWR Co. consultation

The last presentation on this subject was given to the Harston area on the 19th of April 2021

A recording of that webinar can be found here.

Cambridge to Newmarket Webinar

On the 16th March 2021 Steve Edmondson, William Armes and William Harrold from CA presented to people affected by the East West Railway on the Cambridge to Newmarket corridor. Our message was to alert people to the effect of the East West Railway both in Cambridge and to the east, especially the impact of freight traffic. We also pointed out that, with the route proposed by CBRR, then these problems can be significantly alleviated either at the time the railway is built or as a subsequent upgrade. This could be achieved for example with a rail chord to the south of Ely.

A recording of that webinar can be found here.