A rail industry consultant has answered every question you have about HS2

Independent rail planning consultant William Barter has now published his answers to a list of frequently asked questions about the route and its implications.

What is HS2 in a nutshell?

HS2 will be a newly-built railway starting from London, and running as Phase 1 to Birmingham as well as to a new junction with the existing West Coast Main Line (WCML) at Handsacre, near Lichfield. Phase 2A will extend this railway to meet the WCML at Crewe, whilst Phase 2B will add extensions to Manchester, plus a new WCML junction near Wigan, and to Leeds and to a junction with the East Coast Main Line (ECML) south of York. Being new, it can also be built for high speed. Trains will run at up to 360kph (225mph) although to provide robustness in operation it is not expected that they will have to exceed 330kph to keep to the timetable.

Could HS2 for Leeds be scrapped to save money from the scheme?Newly built? So I’ll have to change trains where the new railway stops?

Not at all! The HS2 trains will include a fleet of what are known as 'Conventional Compatible' units. These can run off the HS2 infrastructure and onto the existing railway, as the track gauge (distance between the rails) doesn’t change, and these trains are designed to fit under existing tunnels and bridges. So a through train now from, say London to Liverpool or London to Newcastle, will remain a through train, just using the new railway and running faster for part of the journey. This would not be possible if the new railway were to be Maglev or a similar new technology.

Where trains use the new railway all the way, say from London to Birmingham and eventually to Manchester and Leeds, they could use what are known as 'Captive' trains, that is, units that are built to the full size currently used in Europe, and thus potentially seating more passengers or offering greater space to each.

Is it all worth it, just to shave 10 minutes off the London - Birmingham journey time?

Well it’s a bit more than 10 minutes! In fact the journey time between Euston and the new Curzon Street Station will be 35 minutes less than the normal time between Euston and Birmingham New Street. And a saving of around half an hour will also apply to journeys to Manchester, Glasgow and Liverpool, even in Phase 1. Phase 2A then saves another 10 minutes or so to those places, whilst Phase 2B offers further journey time savings, not just between London and the north east and north west, but also on Birmingham - Manchester and Birmingham - Leeds, both of which reduce dramatically.

Aren’t the trains we have quick enough?

They are indeed pretty good to and from London, but to and from Birmingham they are much slower now due to speed constraints, frequent stops and sharing the track with local trains. And the speed of the London trains comes at the expense of local, commuter and freight services, which simply can’t be accommodated on the same tracks as fast through trains.

Why not?

Railway capacity is maximised when all trains on a line are running at the same speed, like a metro. If you mix fast and slower trains on the same lines, capacity is lost as fast trains draw ahead of slower ones, creating a gap that can’t be filled. This also affects reliability. The timetable will be planned to put fast trains before slower ones, but the problem then is that if a fast long-distance train is delayed early on in its journey, it will end up following the slower train and becoming even later.

Judith Blake: The Yorkshire case for HS2 and Northern Powerhouse RailSo how does HS2 help?

To start with, it’s a new pair of tracks, capable of carrying 18 trains per hour out of London. That’s additional trains and thus additional capacity, until they run onto existing tracks at Crewe in Phase 2A and near Wigan and York in Phase 2B. So south of those junctions, the fast through trains are largely removed from the existing lines, and can be replaced by trains that stop at more stations. So the intermediate stations such as Milton Keynes, Rugby and Watford will have more frequent services, and their trains won’t be so crowded as the long distance passengers will be on HS2.

Is that why people say that the rationale for HS2 has changed from speed to capacity?

If they do, they’re wrong! The reason for building any new infrastructure is capacity. But speed is the opportunity that follows from building new infrastructure, and if we’re going to do that it’s sensible to build it for the best possible speeds. Then the existing lines can focus on what they are good at - commuter, local, inte-rurban and freight services, all of which play second fiddle to fast through trains now.

Why not build new freight or commuter lines then?

The existing lines have the network of junctions and feeder lines that freight trains need, and their stations are in urban areas that have grown up around them. A new freight line would need that network of junctions to be recreated, adding cost and land take. A new commuter line could hardly have stations conveniently in urban and residential areas, as it would be practically impossible to route the line into them. Either would cost nearly as much as HS2, but as they would serve only one purpose would have a fraction of the benefits, whilst HS2 addresses all these needs as well as providing long-distance capacity directly.

But I’ve read that existing trains from Euston are only 43% full on average, why do we need to do anything?

That figure is an average over the day, including first thing in the morning and last thing at night, but demand for rail travel is heavily peaked. The peaks are when the value of a rail journey to the individual and to the country is greatest, so we shouldn’t just suppress demand by pricing or by compulsory reservations. The figure also refers only to long-distance trains, but commuter trains from Euston are not only amongst the most crowded in the country now, but also serve an area of massive housing growth so are just going to get busier and busier.

And it’s not just the number of seats on a train that matters, it’s the number of trains on the track. Links between intermediate stations on the West Coast Main Line are poor, because we simply can’t put enough trains on the tracks to serve them as they deserve, all the while the tracks are dominated by fast through trains.

The Yorkshire buildings and communities set to be demolished to make way for HS2Aren’t there other ways of creating capacity? Longer trains? Double deck trains?

Double deck trains are higher than single deck trains, naturally, but we being the pioneers in building railways went with a more restrictive structure gauge - that’s bridges and tunnels - than is now common in Europe and across the world. To take double deck trains, nearly every bridge and tunnel would have to be rebuilt, and on the line out of Euston just south of Rugby that means tunnels at Primrose Hill, Watford, Northchurch, Leighton Buzzard, Weedon and Kilsby. Imagine the disruption to services from opening all those out. It wouldn’t even add much seating capacity. Double deck doesn’t mean twice the capacity, as you have to allow for staircases that take up a lot of space. Estimates are that double deck trains would have only about 25 per cent more seats than conventional trains in practice. Train lengths are set by platform lengths, and at Euston some platforms used by commuter trains would be extremely difficult to extend without a major rebuild of the whole station and probably extra land take.

At Liverpool the platform length is limited by the tunnel just outside the station, and at Glasgow by the Clyde Bridge almost on the platform ends now. And neither of those address the issue of the number of trains that need to run, to link the full range of origins and destinations, and improve connectivity. Putting more seats on a passenger train doesn’t help to run more freight trains. Don’t forget that another advantage of building a new line is that you can build it for longer trains, and HS2 will be able to run trains up to 400 metres long, more than half as long again as the longest we run now.

Fair enough, but aren’t things worse in the north? Why not start building HS2 from the north and work southwards?

There certainly are crowding and capacity problems around cities such as Leeds and Manchester. But unlike the route out of Euston, there is still scope to address these issues with new rolling stock and longer trains, and indeed this is happening right now. But at the south end of the West Coast Main Line, the problem is one of putting enough trains on the track to meet all demands. The trains that already run are with few exceptions at the maximum practicable length. And to lengthen those that aren’t, serious work on platform extensions, for instance at Euston and on the route to Birmingham, would be involved. What that means is that if the northern sections of HS2 were built without the south end of the route, no extra trains to or from London could be run - they could start from Leeds or Manchester, but no paths into Euston would be available. Even to run to Birmingham would mean building the new Curzon Street Station and its approach junctions - which would take a cost out of Phase 1 of HS2 and make the case for completing it even stronger.

If trains using the new northern sections of HS2 were to be existing trains diverted, they would bypass locations such as Stockport and Stoke on Trent, without the ability to run extra conventional services that arises from Phase 1. And not least, if the Phase 1 route into Euston were now to be delayed, it would leave the area of the route through Buckinghamshire, Northamptonshire and Warwickshire blighted instead of getting on and finishing the job. In fact, for fear of route changes during the delay, the blight would spread well beyond the immediate planned route.

What if HS2 doesn’t happen? What would you do?

Various people have proposed packages of enhancements to existing lines, but none offer anything like the capacity that HS2 would. If commuter growth were to continue as expected, it would just be a fight for capacity between local and long-distance trains. It might be necessary to cut the London - Birmingham/Manchester trains back from three per hour to two per hour so as to run more commuter trains, whilst long-distance trains would be slowed so as to make extra stops to add connectivity.

What about the Great Central? I’ve been told that its trackbed is just lying unused all the way from London to Birmingham

It certainly isn’t! At the London end it is still in use as a commuter line to Marylebone, and could take no more trains due to limited platform capacity there. Paddington would not make an alternative terminus, as the lines into it will be heavily used by Crossrail trains when that opens in full. The Great Central never ran to Birmingham anyway, nor did it have a junction with the West Coast Main Line to allow trains from it to reach Manchester, Liverpool or Glasgow (its own route to Manchester was very roundabout, which is why it closed). It would hardly be less disruptive than building HS2 to re-open it. Much of the trackbed has become a Site of Special Scientific Interest, and bridges that have been taken out could not just be replaced but would have to be rebuilt to modern standards for width and headroom, which would mean increasing the height of the line and thus the width of embankments.

Contrary to what is often said, the Great Central was not built to the continental dimensions, so if this aspect of HS2 were to be replicated the conversion work would be much more extensive. And all for journey times that would be no better than now!

Why are there so few stations on HS2? And why aren’t they in city centres?

Well, the whole point of HS2 is to take trains that currently don’t stop at stations. There are few population centres between the major cities on the HS2 route, but the benefit to them is better services at the stations they already use (like Buckingham is served by Milton Keynes, for instance). Operationally, station stops use up capacity, so unless all trains were to stop at all stations like on metro lines, it would not be possible to run the planned number of trains. It works at Old Oak Common, because all trains would stop there to interchange with Crossrail, whilst at Birmingham Interchange trains take different routes after reaching the station so some can stop and some needn’t.

And HS2’s key stations are in city centres. At Euston, Manchester and Leeds the HS2 trains will use extensions of the existing city centre stations. At Birmingham, there will be a new city centre station adjacent to the existing Moor Street - there has to be a new station as New Street is full, working already at well beyond the capacity for trains and passengers for which it was designed. There are out of town stations planned as well - ‘parkways’ if you like to call them that, south of Birmingham, near Manchester Airport, and between Nottingham and Derby. These stations will serve markets that city centre stations don’t, and capture the rail travellers who are currently deterred by city centre traffic congestion and high charges for limited parking.

Then there is the Old Oak Common interchange station with Crossrail, which will serve journeys to the City and Docklands better than Euston. And of course don’t forget that of 33 stations that HS2 trains will serve, 25 of them are exactly the same stations as existing trains use, and are just as central to cities and towns as now.

If Old Oak Common is such a good interchange, why not use that as the terminus instead of tunnelling to Euston?

Good as it is, it serves flows on an east-west axis by connection with Crossrail. People wanting to go from or to places north and south of London are better served by Euston, and that’s about two-thirds of HS2 users. If Crossrail had to carry all these people to central London it would be overloaded, and any problem on Crossrail would effectively shut HS2 as well. And anyone with heavy luggage or mobility issues who might want to complete their journey, or to cross London to continue it, by taxi would have a much longer and more expensive ride than from Euston.

Didn’t you say earlier that HS2 could carry 18 trains per hour? Surely that’s too many for a high speed line?

Actually high speed is the least of the issues with that! It is easy to show by calculation and by simulation modelling that with modern digital signalling, the minimum possible interval between consecutive trains can be only just over 120 seconds (two minutes) even at 360kph. So for a train every three minutes, there’s nearly a minute of buffer to absorb small delays and irregularities. And with 18 trains per hour there are even a few minutes to spare in each hour. That minimum interval actually grows bigger in slow speed areas such as station approaches, but should never exceed 150 seconds.

That means that in a timetable with 18 trains per hour, only 75 per cent of the potential capacity is used, which is in accordance with International Union of Railways guidelines. And with all trains running at the same speed, this intensive usage is much less of a risk to reliability than on a conventional mixed traffic railway, especially as HS2 trains can use their full speed potential to recover from small delays and restore the interval between trains even if a late-runner has to push into the flow.

What about the fares, though? How high will they be? Who will be able to afford them?

Well, we don’t know what any rail fares will be in 10 years time, do we? That depends essentially on government policy. What we do know is that the HS2 business case assumes fares levels as now, not any sort of premium. Unlike HS1 where there are alternative conventional services for all locations, HS2 will be the only service (as the WCML is now) for many places, which is a reason why it should not have a premium fare. And of course with up to 1,100 seats on each train, as capacity (supply) will be vastly increased, there is less reason for suppressing demand through high fares, which is what we do now.

William Barter is an independent consultant in rail operations and planning. He specialises in capacity and performance assessments, train service feasibility analysis, investment and business case development and operations costing. He is a technical author who has written papers, articles, educational materials and edited franchise bid plans.

His clients include the Department for Transport and Transport for London. He lives in Northamptonshire. Twitter: @williambarter1