The Kent Route Study (Part 2): Crossrail to Gravesend


Much has been written about Crossrail in recent years. One topic that has largely slipped through the net, however, is the revival of the originally planned route from Abbey Wood to Ebbsfleet. This was to be part of Crossrail, with the new line’s trains running on existing tracks beyond Abbey Wood. A combination of the need for a more affordable scheme and a fear of ‘performance pollution’, however, led to this aspect of the scheme being dropped. That is, it seems, until this current Kent Route Study.

Over time, plans to extend Crossrail to Ebbsfleet has generally (and naturally) brought with it the idea of extending the proposal one station further – from Ebbsfleet to Gravesend. In recent years Gravesend station has been modified to include a 12-car terminating platform. Given that Ebbsfleet has not become the heavily-used international station originally envisaged, the idea of additionally capturing Gravesend commuter traffic would appear to make a lot of sense. It also fits in with a depot strategy of locating a depot at Hoo – just beyond Gravesend.

Possibly more important than an additional station was the emerging idea of running any future Crossrail extension on segregated track from Abbey Wood to Dartford. This would take advantage of a wide strip of railway-owned land – the same wide strip that enabled Crossrail to go from Plumstead to Abbey Wood with minimal property acquisition. The segregated track would overcome many of the original objections to the idea of extending beyond Abbey Wood.

Another significant change to the original plans, as passed by Parliament, was a redesign of Abbey Wood station to keep the existing and new Crossrail tracks entirely separate. The original scheme had cross-platform interchange achieved by putting the Crossrail platforms in the middle.

This change at Abbey Wood was made partly to avoid engineering works on one railway affecting the other and it did make the track layout slightly easier to build. There was also the claim that it would simplify any extensions, as the spare available land was mostly to the north which would minimise disruption to the existing line. Not mentioned was the fact that the revised layout effectively killed off any possibility of Crossrail continuing on beyond Abbey Wood using existing tracks.

Failure to go beyond Abbey Wood in the original scheme

There were several operational reasons why the original proposals to continue beyond Abbey Wood were unattractive. These were almost entirely related to the idea of running beyond Abbey Wood on existing tracks.

If it was assumed that alternate Crossrail trains went beyond Abbey Wood, then this originally meant that 6tph peak and 3tph or 4tph off-peak would have to share tracks with Southeastern trains. In peak hours, at least, to achieve this without introducing delays would have been a tall order.

A further concern at the time was the need for trains to be able to run on 25kV AC overhead or 750V DC third rail. Since those days, for technical reasons, dual voltage trains are much less of an issue and indeed the current Crossrail trains (class 345) are specified with the ability to be modified to accept third rail power if required. Also, at the time, there was fear of problems if a train was unable to switch voltage for any reason. Whilst this has generally proven to be reliable, concern has not entirely disappeared, although it is not the great fear it once was. Reassuringly, it is something a Thameslink train does nowadays on every trip through the centre of London and a failure (at least for this reason) is very rare indeed.

The operational (not political) Dartford problem

On top of the previous problems, there must have been quite an issue with Dartford station in the original Crossrail scheme. Dartford station has two narrow island platforms and is not really ideal for reversing trains. There is a need to keep two tracks as through tracks for trains to and from Gravesend and beyond, leaving two tracks available to terminate trains. Dartford is the logical terminus of the three Dartford loop lines from London Bridge and with the current London Bridge metro timetable it cannot handle the desired traffic – even in the off-peak.

One unusual feature of the London Bridge metro timetable is the “rounder” trains. These typically start from Cannon St and go outbound on one Dartford loop line and then – by means of suitable spur lines – return on another loop line back to Cannon St. As we discussed several years ago when talking about the Circle line, operationally, running services in a circle is not ideal. Operating “rounders” is not as bad but potentially shares some of the problems. One either has to add a lot of padding to the running times or have a service on which it is next to impossible to recover time – except at the London terminal station. Nevertheless, these services, out of necessity, feature a lot in the current Southeastern timetable.

It is hard to see how services can be significantly improved through Dartford without addressing the issue of the station. Given its already less-than-adequate status, any proposal requiring the station to handle more trains, be they through trains or terminating trains, really needs an appropriate solution to increase Dartford station capacity.

Why bother to extend Crossrail at all?

Given the initial rejection of extending Crossrail beyond Abbey Wood, one has to ask why it is being reconsidered now. Even more specifically, why reconsider it when any necessary improvement of services to Ebbsfleet to cater for the proposed garden city can be provided by HS1?

The answer appears to lie in serving the inner corridor. To quote from the Route Study:

5.12.8. The corridor from Bexley Riverside to North Kent has been identified as an area to support growth and regeneration, providing up to 55,000 new homes and 50,000 new jobs. To help fully unlock this potential, improvements to the transport network are required with enhancements to rail services and infrastructure seen as a key enabler.

The puzzle is that this seems to entirely contradict other parts of the Route Study, which were emphatic that Crossrail to Abbey Wood on its own would lead to a reduction of demand on trains to London Bridge on the North Kent line. It also stated that this would mean that no additional capacity would be required for this line.

The one page in the Route Study dedicated to the proposal to extend Crossrail beyond Abbey Wood seems not to be thought out in great detail. Even the map provided is a TfL map, which also includes other irrelevant TfL proposals – TfL proposals that are highly optimistic given the current funding situation.

TfL proposal for extending Crossrail

The scheme for extending Crossrail as described in the Route Study seems rather ambitious.

5.12.10. A solution for a segregated alignment has been identified which runs to the north of the existing North Kent lines. Fourtracking of the railway has been proposed in order to overcome identified technical and operational concerns with performance, capacity and integration between rolling stock and railway systems.

This would seem to suggest four-track all the way in order to keep the Crossrail lines segregated, but this seems to be way beyond what is necessary. It is also not what it is understood to have been safeguarded, which was four-track to just beyond Dartford. One really has to question why it is now thought necessary to build an extra two tracks beyond Dartford. Perhaps the Network Rail team have simply misunderstood what the safeguarding proposed. Otherwise one wonders what sort of services is intended to be provided that justifies separating the two railways. Especially as issues like rolling-stock performance and signalling differences may have simply gone away by the time such a four-track railway were built.

If such an extension to Crossrail were to happen then the plan is for a new depot at Hoo as mentioned earlier. On the basis that Route Studies, for some reason, don’t include depot costs, we presume this cost is excluded.

On the basis of the comments about housing in the area and the map provided, it appears that extra platforms are planned at Belvedere, Erith and Slade Green stations. Initially, it seemed there was no intention to replicate these stations on Crossrail, but instead to run fast from Abbey Wood to Dartford. Indeed, it seems a bit strange to have what is effectively four all-stations lines rather than a pair of fast tracks and a pair of slow tracks.

Whilst Belvedere and Erith might be justified on housing development grounds, it is harder to imagine that a case could be made for Slade Green. There are proposals at Slade Green for a nearby freight terminal, but modern purpose-built freight terminals tend not to generate a lot of jobs at the terminal itself.

One could understand the desire to serve Greenhithe (for Bluewater) and Swanscombe (for the proposed London Paramount Entertainment Resort) but it is much harder to believe that any Crossrail train will ever serve Stone Crossing station. If Stone Crossing were to become part of Crossrail then, based on current figures, it would easily become the least used station on the line. Indeed it would probably become the least used station served by TfL-run trains – even beating Emerson Park.

Timescale and Cost

The cost of extending Crossrail to Gravesend is given as £1.5bn (excluding optimism bias and any land acquisition costs). The Timescale given is 10 years to design and build, which suggests that this is going to be no quick-fix solution.

What is hard to see is how it would be financed as TfL is not exactly flush with money at present. One could imagine the organisation being very happy to piggy-back on a scheme paid for by someone else to extend Crossrail to Kent though. TfL would perhaps consider funding work at Belvedere and Erith (and, maybe, Slade Green). At the absolute most, TfL might provide money to extend tracks to Dartford and, in addition to stations in London, provide some money in lieu of terminating facilities in Dartford. A specific concern of TfL and the Mayor would be to avoid anything that risks diverting money from Crossrail 2 which strategically is far more important.

Alternatively, funding could come from Kent County Council – except that this is probably a great deal of money for them. One could understand their reluctance to provide money just so people can commute to London, and also to provide council tax money to promote access to a new garden city (a government objective) or an entertainment park (a scheme proposed by a commercial company).

This does, however, highlight a third possible funding source – the government, as part of the Ebbsfleet Garden City scheme. The trouble with that is that whilst this scheme is technically something proposed by the current government, it is from its pre-Brexit iteration. As a Cameron / Osborne policy in a May / Hammond world the future for it is less certain. There is also the aforementioned high-speed elephant in the room, and indeed the Route Study also looks at providing longer trains on HS1 to cater for this demand.

For the long term future

It is clear that the Route Study is not expecting anything to happen anytime soon on this proposal. To quote the final paragraph on the relevant page:

5.12.12. The proposal is being promoted by local and strategic authorities through which the extension would pass. A Strategic Outline Business Case is currently being developed and outputs will also be fed into the Thames Estuary 2050 Growth Commission which has been tasked with developing a delivery plan for North Kent, South Essex and East London up to 2050.

The problem is that whilst it is possible that Kent might be ready to wait until around 2050, London needs something sooner to help with housing growth in the Belvedere and Erith area. The Mayor could, conceivably, extend Crossrail by a couple of stations, but railway solutions focusing on local issues tend not to be a good idea in the grand scheme of things.

What is the point of this extension?

At the end of the day, the biggest problem with the Crossrail extension scheme is that it is far from obvious what it is actually for. The extension is unlikely to solve any capacity problems. There is little that would be achieved in this area that could not be achieved by passengers changing at Abbey Wood where necessary. If the aim is to attract more housing to the Erith area then why bother to continue to Dartford? If the purpose is to make journeys more pleasant and faster into central London from those major stations further out (Dartford and Gravesend), then why does the current scheme appear to stop at every intermediate station? Similarly, if the objective is related to either the proposed Ebbsfleet Garden City or the London Entertainment Resort then why bother with intermediate stations at all?

The British solution – further investigation

The good news is that according to the Route Study:

[W]ork to understand the technical viability, value-for-money and potential to support growth is currently underway

This does seem very sensible and necessary. It is hard to believe there won’t be benefits from extending Crossrail beyond Abbey Wood. It’s just very hard to clearly establish what the benefits would be and whether they would be worth the cost. It is also far from clear which stations the trains should call at and exactly how much segregated track would be required. Only once this has been established can one really start to even think of funding and in recent years it has been clear that funding is generally the greatest challenge of all.

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Written by Pedantic of Purley