Alternate universe: Would HS2 be built?

[najaB]

Another 'alternate universe' question - with apologies in advance if it's been asked previously.

If Network Rail, ATOC and the FOCs had been sat around a table and told they could have £30B (or £50B as it is now) to modernise the railway, do you think they would have come up with HS2? If not, how do you think they would have spent the money? (And no nonsense about spending 50p on the railway and pocketing the rest! )

I'm not anti-HS2, just curious if it's a diktat from the top or something that 'the railway industry' would have come up with themselves.

 

[swt_passenger]

Yes. As this quote from the original HS2 report in 2010 recalls, NR already had a new lines programme underway that had reported in 2009.

... In August 2009 Network Rail reported the findings of the first part of its New Lines Programme, which had begun in 2008 to look at some of the long term options for addressing capacity-constrained rail routes. The resultant Strategic Business Case pointed to a positive case for a new high speed line along the west coast
of Britain, serving Birmingham, Manchester, Liverpool and Warrington, Preston, Glasgow and Edinburgh. Network Rail is currently concluding its strategic work on new high speed lines to address capacity constraints on the East Coast Main Line and the Midland Main Line.

So yes, the railway industry had already thought of this. Funnily enough, I think we've already had this discussion before, probably 3 or 4 years ago.

 

[WatcherZero]

Well you sit down and you say whats the most pressing capacity problem..... Southern WCML.

How do you fix it? You could improve it but we have the bad experience of the WCML modernisation, building a new line is both cheaper and more bang for the buck.

Where should it go? London-Birmingham with capacity enhancements elsewhere.

Conclusion: They would have independently come up with HS2 phase 1, however its unlikely they would have suggested the eastern Y branch as there is not a great speed advantage over the ECML due to the dog leg via Birmingham, so likely they would have proposed upgrading ECML which is more practicable than the WCML.

 

[Holly]

There can be little doubt that a new Southern WCML relief line is needed.

It's perhaps not so obvious that it is worth the extra cost of making it HS over a slower speed is justified. However, now lots of money has been spent on HS design work the question is settled.

 

[Muzer]

I understand and don't at all disagree that the Southern WCML has a capacity problem. But out of interest, why is it generally seen as the most pressing capacity problem? To name a random example, the Brighton Main Line also has a capacity problem, yet there appears to be little serious consideration at the moment for BML2 (that's not to say this scheme is perfect and everyone needs to support it, I'm just using it as an example of a seemingly equally congested line not really having any alternatives seriously considered). Is it just the fact that the WCML provides some of the most important connections for businesses?

@Holly: I think one reason for making it high speed is to encourage people to use it. You don't really want a situation where the high speed line is running empty and everyone is still on the WCML because it has more stations/it's cheaper/etc. (ideally I think many people would agree that you don't want HS2 to be any more expensive than the remaining intercity WCML services, but I'm still concerned that this might not happen the way it should).

 

[NotATrainspott]

I understand and don't at all disagree that the Southern WCML has a capacity problem. But out of interest, why is it generally seen as the most pressing capacity problem? To name a random example, the Brighton Main Line also has a capacity problem, yet there appears to be little serious consideration at the moment for BML2 (that's not to say this scheme is perfect and everyone needs to support it, I'm just using it as an example of a seemingly equally congested line not really having any alternatives seriously considered). Is it just the fact that the WCML provides some of the most important connections for businesses?

The largest area connected to London by the BML is, oddly enough, Brighton. Most of the traffic on the line is London commuter traffic, and if the line is full and cannot take any more passengers most of the people who would move to the catchment area to commute could plausibly move anywhere else around the M25 to wherever has capacity. The WCML, MML and ECML may not carry as many commuters into London but they do connect the largest population centres of the UK together - Greater London, the West Midlands, Greater Manchester, Merseyside, South Yorkshire, West Yorkshire, Tyne and Wear and the Central Belt of Scotland. If the BML goes belly-up, it makes a lot of commuters get rather upset. If the WCML/MML/ECML go belly-up, it cuts off the north of Great Britain from the south.

 

[SpacePhoenix]

How many routes could have been converted to handle double-decker trains running on overhead for that £50B?

 

[edwin_m]

How many routes could have been converted to handle double-decker trains running on overhead for that £50B?

Fewer than you might expect. Conversion to the loading gauge required for double deck would involve shutting the line for a significant period and probably cost more than a new route.

 

[Haydn1971]

How many routes could have been converted to handle double-decker trains running on overhead for that £50B?

I'm currently loosely involved in a new bridge over part of the Crewe-Macclesfield line, the cost prediction is currently in the range of £10-12m for a single carriageway structure over four tracks. The new structure is being developed with a minimum clearance for a variety of reasons, but pushing to accommodate double deck would perhaps push the cost to £15m. Very loosely assuming 2 overhead structures per km - less in rural, more in urban, averaging some single carriageway, some dual, some motorway, some pedestrian - gives 500 structures to replace along something like the midland main line

Cost of new overhead power - was according to a DeltaRail report in 2010 - about £215k per single line km - assuming all feeder stations could be reused.

Using a basis of 250km between London and Sheffield, 2 line for half, 4 line for the other half, then another 100km for stations, parallel track, sidings etc. gives 1600km of track wiring.

On that very simplistic basis, raising the OHL would be about £420m for Midland Main Line with 22% optimism bias. Structures would cost an eye watering £9.1Bn with 22% optimism bias. Rolling stock could be another £1-2Bn for the route, plus modifications to signals, other track changes for improved points, revised station facilities for passenger growth and replacing the roofs on some stations to accommodate the taller trains.

Very roughly - your looking at about £15Bn just to do the Midland Main Line. Or about £50-60Bn to do the three main lines to Manchester, Leeds & York, probably in excess of £100Bn to go to Scotland. That's not even considering the cost of disruptions.

 

[edwin_m]

Worse than that. The track spacing would have to increase to accommodate European gauge. This would involve acquiring a strip of land over the entire route, then replacing every structure, and at least half the signals, OLE poles etc. Which would indeed cost about as much as a new route - a bit less for land costs but more for disruption and for modifying existing stuff instead of building new.

Even if it could be made to work with reduced clearances to leave the track in place, all platforms would have to be rebuilt further from the track, probably with some sort of temporary extension to allow UK standard stock to continue to run until there was a "big bang" changeover to the new stock.

 

[Haydn1971]

Ouch, good point Edwin ! Although my number of structures "guess" could be well off the mark, the more I go over the project with head math the more I'm assured that HS2 is the right way to invest for the future. And yes, I'm sure there will be some losers, but more people will benefit than not.

 

[najaB]

I thought that would be the case, thanks all. The press likes to make it seem that this is a pet project of the Government - it's nice to know that 'the industry' came up with the idea first.

 

[HSTEd]

Even if it could be made to work with reduced clearances to leave the track in place, all platforms would have to be rebuilt further from the track, probably with some sort of temporary extension to allow UK standard stock to continue to run until there was a "big bang" changeover to the new stock.

Actually there would be no need to rebuild platforms.
Who said it was going to be a European loading gauge?

You could just build a new British double deck loading gauge that is like our current one but a lot taller. More like American double deck trains for example. The trains are still wide enough for staircases - and since we can chose our gauge from the beginning to allow double deck operation we can make it tall enough to allow a corridor on both decks.

 

[najaB]

You could just build a new British double deck loading gauge that is like our current one but a lot taller. More like American double deck trains for example. The trains are still wide enough for staircases - and since we can chose our gauge from the beginning to allow double deck operation we can make it tall enough to allow a corridor on both decks.

Would such a vehicle design increase overturning risk?

 

[HSTEd]

Would such a vehicle design increase overturning risk?

Marginally, but not enough to matter.
Standard gauge trains in America are considered to be sufficiently stable for use on far worse tracks than those in Britain at heights approaching 20 feet above the railhead. (Indeed for freight use the trains get up to 20'2" above the railhead).
Although I would chose a height of 5.595m [18'5"] as that is the maximum train height that can go through the Chunnel and it would be useful to maintain that capability for the future.

 

[Haydn1971]

You could just build a new British double deck loading gauge that is like our current one but a lot taller.

Sticky one that - if your building a new line you'd want level carriage access wouldn't you ?

There's three schools of thought for the UK;
1, Narrow lower deck to fit the platforms with a step down into it - not quite double deck capacity though.
2, Level access to the lower deck, would require platform and overhead structure work
3, Step up as now, but very high units that would require just overhead structure work.

 

[The Ham]

The other problem with just rebuilding the old lines is that you don't have any extra services, meaning that it would be a lot of work for at most 100% more capacity (although more likely closer to 50%).

 

[HSTEd]

It does help with TPE and the like though since you could put a completely different short-distance layout on the lower deck but a longer distance layout on the upper deck.
People aboard for 15 minutes probably wouldn't go upstairs unless downstairs was full.

 

[SpacePhoenix]

For any given section of 3rd rail track, can the masts be installed over weekends with full possessions? Obviously any structures that would need raising probably can't be done in a weekend

 

[NotATrainspott]

Actually there would be no need to rebuild platforms.
Who said it was going to be a European loading gauge?

You could just build a new British double deck loading gauge that is like our current one but a lot taller. More like American double deck trains for example. The trains are still wide enough for staircases - and since we can chose our gauge from the beginning to allow double deck operation we can make it tall enough to allow a corridor on both decks.

No, you would need to rebuild every platform along the line if you want any real capacity increase at all. Unlike other loading gauges around the world, the British one gets narrower below platform level, enough so that 2+2 seating is impossible. It's also the reason why British trains are so 'conventional' now compared to European alternatives, where it's now common to have the floor level at the lower platform height for accessibility purposes. Since 2+2 seating is impossible below platform height, the actual capacity uplift as a result of double deck stock, even allowing for increased height, would be marginal and absolutely not worth the effort. This was all analysed in detail by Network Rail and the clear conclusion from that effort was that there was no point even considering regauging lines to fit double deck stock. The HS1-HS2 link fiasco shows just how complicated it is to regauge busy rail lines running through high-value land.

 

[HSTEd]

No, you would need to rebuild every platform along the line if you want any real capacity increase at all. Unlike other loading gauges around the world, the British one gets narrower below platform level, enough so that 2+2 seating is impossible

The width of the gauge below platform level is completely irrelevant to whether you can have double decker trains or not, if there are no other constraints.
I am proposing double deck trains with the lower deck at exactly the same elevation as that of conventional trains. They can therefore be exactly the same width as conventional trains.

This was all analysed in detail by Network Rail and the clear conclusion from that effort was that there was no point even considering regauging lines to fit double deck stock.

The network rail study was based on a half baked conversion to GB+ or GC for TSI compatibility purposes, which is indeed pointless.
I am proposing a gauging effort that would require essentially no work to track layouts or below platform level equipment at all.
Once you concede a massive reconstruction for increased top room there is no need to stop at GC.
If you push to 5+ metres you can have a double deck train entirely above the platform level, eliminating the problems that render GB+ and GC impractical.
Especially considering there are great stretches of lines in urban terrain with no overbridges since they are already on viaducts - which have essentially unlimited headroom.
The only limitation is stability due to the tall vehicle, but this does not become a problem until 20 feet or so.
Which is far beyond what we need.

EDIT:
A TGV duplex is approximately 4.32m tall.
If we assume the structural floor of the bottom deck is in contact with the railhead (this is obviously a bad assumption but it is conservative) then the entire height of the train is required for two decks.
If we adopt the Channel Tunnel gauge height of 5.595m as our constraint (which makes sense for standardisation purposes as a starting point, even if we can't adopt the width, maxing the height now saves potential trouble later) then that means we have an addition of 1.275m of headroom, which means the bottom deck can now be ~1.3m off the railhead.

The Height of a Class 508 is roughly 3.58m, an estimate from a picture says roughly a third of this is below the platform floor. That means the floor is something like 1.2m above the railhead - if we assume the floor is the beginning of the full width section, it can be shown that if CT height is permitted you can have a double deck train without a reduced width lower deck.

(Note: An earlier analysis based on a Cl508 was replaced with one based on a TGV Duplex to remove problems with estimated structural height requirements).

 

[najaB]

I am proposing double deck trains with the lower deck at exactly the same elevation as that of conventional trains. They can therefore be exactly the same width as conventional trains.

Probably worrying for nothing, but that seems like a lot of weight, up high on a comparatively narrow base.

 

[Haydn1971]

Probably worrying for nothing, but that seems like a lot of weight, up high on a comparatively narrow base.

It is an alternate universe... Gravity and force will be all different haha

 

[HSTEd]

Probably worrying for nothing, but that seems like a lot of weight, up high on a comparatively narrow base.

Double stack trains put 14 tonne containers that high up on a base of an exactly the same width (4'8.5").

5.595m is ~18'5".
Stack trains go up to 20'3" now.
They are also of comparable width (roughly ~10' for the passenger train compared to 8 for the top of the containers).

EDIT:
This monster DMU from America is 19'6" tall. Which is effectively six metres. (It was part of a very small run put together by the now defunct Colorado Railcar).

 

[najaB]

Double stack trains put 14 tonne containers that high up on a base of an exactly the same width (4'8.5").

But the base of the containers isn't 1.3m or so above the railhead, pretty sure they get them as low down as possible.

 

[AM9]

But the base of the containers isn't 1.3m or so above the railhead, pretty sure they get them as low down as possible.

Maybe they should be tilting, (as this is a fantasy thread).

 

[HSTEd]

But the base of the containers isn't 1.3m or so above the railhead, pretty sure they get them as low down as possible.

The base of the first container is low as possible.
The base of the second container is about the same height as the roof of a conventional train. And can potentially weigh as much as a whole rail vehicle (~30t).

 

[edwin_m]

I may have lost track here, but surely:

- if this is a new line, the platforms could be built to European dimensions
- if this is an upgraded existing line, replacing every bridge, tunnel and bit of OLE to give the greater height would be more difficult than replacing the platforms to give greater width?

 

[Haydn1971]

Double stack trains put 14 tonne containers that high up on a base of an exactly the same width (4'8.5").

5.595m is ~18'5".
Stack trains go up to 20'3" now.
They are also of comparable width (roughly ~10' for the passenger train compared to 8 for the top of the containers).

EDIT:
This monster DMU from America is 19'6" tall. Which is effectively six metres. (It was part of a very small run put together by the now defunct Colorado Railcar).

And at what speed do these run at ? Speed greatly increases sideward forces - going high will place a real strain on the suspension components and importantly the trackbed lifespan. Bit of a tip, don't get used to driving a roundabout in a sports car then jump into a SUV and try it at the same pace - you'll end up in the verge wrapped around a tree.

 

[HSTEd]

- if this is an upgraded existing line, replacing every bridge, tunnel and bit of OLE to give the greater height would be more difficult than replacing the platforms to give greater width?

GC or GB+ would still require all the overheads be replaced along with reconstruction of every overbridge, tunnel and other equipment.#
Modifications would be unlikely to do the job, you would be looking at total reconstructions - at which point, within sane limits, the amount of height gained does not have a huge effect on the price.
This way you avoid the additional reconstructions associated with european gauges, such as reconstruction of platforms and underbridges that may have structural components that would impinge on the European gauges.

Reconstructed platforms would also not be able to accept conventional trains - whereas this extended height gauge would.

And at what speed do these run at ? Speed greatly increases sideward forces - going high will place a real strain on the suspension components and importantly the trackbed lifespan. Bit of a tip, don't get used to driving a roundabout in a sports car then jump into a SUV and try it at the same pace - you'll end up in the verge wrapped around a tree.

Double stack trains, which are considerably more top heavy that this train are commonly run at 79mph in the US.
Indeed on certain parts of the American network (along parts of the route of the Southwest Chief for example) they have been recorded reaching ~85mph thanks to the automatic train protection gear deployed there.

Additionally 'Surfliner' cars which are 4.93m tall are considered suitable for 125mph.
This indicates that trains of around 5m tall are considered suitable for high speeds. 5.595m seems unlikely to provoke many additional concerns, considering European standard coaches are likely to be made largely of aluminium and be lighter than 70t American monsters.
The high floor height also means that heavy traction equipment can be mounted under the floor which will tend to hold down the centre of gravity to a great extent. (Certainly no need for roof mounted equipment).
Something you have to remember is that trains rarely take un-cambered corners at high speed. So there relative instability is not that important.