The message to Network Rail was clear: “Over ambitious claims for improvements in capacity must be met with scepticism, and Network Rail should be very cautious about how it uses the 40% claim.”

So say MPs in the latest report of the House of Commons Transport Select Committee. The claim comes from Network Rail’s Digital Railway publicity and is based on its study of the South West Main Line from Waterloo. It reckons that a combination of ERTMS Level 3 signalling and automatic train operation (ATO) could permit 34 trains an hour between Waterloo and Woking, up from 28 today.

ERTMS (often also known as ETCS) Level 3 signalling is not available. It is not developed to the stage where it could be installed any time soon. While NR Chief Executive Mark Carne told MPs that NR did not claim the 40% was universal, the company’s Digital Railway publicity does not contain this caveat. It talks about unlocking “up to 40% more capacity from the existing urban network” by delivering ETCS, traffic management and ATO.

The publicity claims that ETCS comes with cost benefits because it removes “track circuits which fail often and are expensive to maintain”. It’s true that with Level 3 there are no track circuits (or other detection systems fixed to the track such as axle counters). But Level 3 does not exist.

Network Rail has produced publicity brochures to convince the railway and government to buy a product that cannot be bought. ERTMS Level 3 might well be developed to a stage where it can be installed at some point in the future but no-one appears to know when.

In the meantime, Level 2 is at a stage where it can be installed. It provides in-cab signalling, removing the need for lineside ‘lights on sticks’. It uses fixed-blocks with only one train allowed in a block of line at any one time. This is a principle established by the Victorians. To have more capacity you need more blocks, shorter blocks. This needs more track circuits. In conventional signalling it would need more signals too but this need is removed with in-cab signalling.

The back of NR’s brochure contains an infographic that explains the benefits that Digital Railway will bring to the lines from Waterloo – “Up to 11 extra trains per hour” – but it’s worth reading the Wessex Route Study from which these claims are drawn. Here, NR says: “In terms of ETCS and modern signalling operation no specific work has been carried out as part of this Route Study.” That casts doubt on the thoroughness of NR’s claims.

NR’s brochures and claims have not convinced the Transport Committee: “Rather than claims of up to 40% we expect to see a more sophisticated assessment of the likely capacity gains that look at different investment scenarios and their associated costs, benefits and risks. It is important that the Department for Transport and Network Rail make a realistic assessment of how much extra capacity each system within the Digital Railway programme can deliver to meet growing demand.”

The MPs recommend: “Projections based on ETCS Level 3 should only be considered valid when the Level 3 specification is ready for deployment, and Network Rail should avoid using such projections, or the promise of a ‘moving block’ signalling system, in its publicity until such technology is ready to be deployed.”

They are right because the railway has been here before. Railtrack planned its West Coast Route Modernisation in the late-1990s on the basis of moving block Level 3 signalling that would give a 140mph railway. It sold this claim to government and the newly privatised West Coast operator, Virgin Trains, procured 140mph trains. Railtrack’s plan collapsed. It was forced to revert to conventional signalling and trains today run at only 125mph. The theory of Level 3 signalling could be explained as convincingly in the 1990s as it can today. But it didn’t exist then and it still doesn’t exist today.

Network Rail’s had a few collapsed plans along its Digital Railway road. It published an ETCS roll-out plan that assigned dates to different lines then ditched it because Chief Executive Mark Carne wanted it all done by 2029. This proved impossible and NR changed the date to 50 years hence. NR was left without a coherent plan. Earlier this year, it announced that the lines from Norwich to Great Yarmouth and Lowestoft would have ETCS in use by December 2018. A few months later, NR ditched this plan.

NR issued a European procurement notice for a train management system in 2009 and cancelled this project in 2015. It promised an outline business case for Digital Railway by September but now says it will be the end of the year.

Yet there is more to digital railways than signalling. Much of it surrounds the collection, analysis and use of data. Go to Euston station and you’ll see the departures board displays icons that show how many seats are reserved in each Virgin Trains coach. The next stage would be for counting equipment on each coach to feed information to allow similar information to be displayed at each station along a train’s route. It could be displayed on passengers’ smartphones.

The same could be done for commuter trains with counting equipment providing live information about loading levels. A passenger would know where to stand on the platform to board the coach with the most space.

If staff in control offices know which trains are busy and which are not, they can make decisions in the best interests of more passengers. In recovering from an incident, controllers would know which busy trains should not be terminated short of their destination and which quiet ones perhaps could be.

GPS data can monitor train performance in real-time which can be fed into the timetabling process so that planners have a better idea of how long in practice it takes for a train to pass from A to B. They can see more easily where a dwell time of 30 seconds is sufficient at one station but not at another. The result should be more accurate timetables that can be consistently delivered.

In many ways, this is the real digital railway. It’s not one that NR’s publicity talks about. It’s one that the passenger operators pursue for the benefit of their customers. It’s the one the railway should concentrate on. Not least because NR is running out of money.

This article first appeared in RAIL 813, published November 9 2016.

By Philip Haigh

Freelance railway writer, former deputy editor at RAIL magazine - news, views and analysis of today's railway.