Why is HS2 treated so differently by some Enthusiasts?

[Voglitz]

Would probably need the GC & GW joint quadrifying so you were not following the Chiltern all stations Birmingham to London stopper all the way from Ashendon to South Ruislip.

Or alternatively, just run the fast train(s) in front of the slow one.

Presumably there would then have to be a new line in a tunnel from there to a terminal station in central London. Would probably cost as much or more than a new line for that section but only be half as good.

Presumably, the New North Main Line would mean there wouldn't have to be a new line in a tunnel to a terminal station in central London.

Another problem is that the demand for travel is towards Birmingham and the GC turns right at Rugby.

For HS2 the demand for travel is towards Manchester so the line has to turn hard right at Tatton.

 

[NotATrainspott]

Or alternatively, just run the fast train(s) in front of the slow one.

Clearly NR/DfT should employ you for saving them £50bn with that stroke of genius.

Presumably, the New North Main Line would mean there wouldn't have to be a new line in a tunnel to a terminal station in central London.

Originally this was the plan for HS2. However, they've decided to put it in tunnel instead, because the cost of rebuilding the Hanger Lane gyratory and satisfying the residents along the NNML was too high. Plain line tunnels are cheap and easy to build now with modern TBM technology. You don't need to have much of an obstacle in the way of a surface route to make it worthwhile to build a tunnel.

Stations are a totally different kettle of fish. Even your ideas of a 4tph 10-car Class 80x service from Birmingham along the Chiltern line would be hard to accommodate at Paddington.

 

[najaB]

I am sure driverless cars WILL increase rail use as the roads clog up with cars being driven safely at the correct speed and distance apart, as opposed to the present mayhem where safety is sacrificed with cars doing 80-90mph a few feet apart just to increase capacity.

That might have been tongue in cheek, but in case it wasn't increasing the capacity of the existing road network is probably the biggest advantage of autonomous road vehicles. Presuming that they have some kind of short-range wireless communications setup they would be able to drive much closer together than humans can manage, much more safely since the reaction time would be milliseconds.

 

[Voglitz]

Originally this was the plan for HS2. However, they've decided to put it in tunnel instead, because the cost of rebuilding the Hanger Lane gyratory and satisfying the residents along the NNML was too high.

Too high for a HS2-type operation with 'Continental' size trains. Otherwise, not too high.

Plain line tunnels are cheap and easy to build now with modern TBM technology. You don't need to have much of an obstacle in the way of a surface route to make it worthwhile to build a tunnel.

If 'Continental' size plain line tunnels are cheap and easy to build now with modern TBM technology, one might well ask, why are new metro lines around the world built with small diameter tunnels?

Stations are a totally different kettle of fish. Even your ideas of a 4tph 10-car Class 80x service from Birmingham along the Chiltern line would be hard to accommodate at Paddington.

Not really. The Atkins interventions report conceded that it was possible to run a frequent service.

 

[najaB]

If 'Continental' size plain line tunnels are cheap and easy to build now with modern TBM technology, one might well ask, why are new metro lines around the world built with small diameter tunnels?

Why would they dig bigger tunnels than they need? :?

 

[Trog]

Or alternatively, just run the fast train(s) in front of the slow one.

If you did that how long until it catches up with the one in front. :roll:

Presumably, the New North Main Line would mean there wouldn't have to be a new line in a tunnel to a terminal station in central London.

Right so we are going to run the new service into Paddington via a low speed connection into the GWML reliefs to be shared with Cross-rail.

For HS2 the demand for travel is towards Manchester so the line has to turn hard right at Tatton.

No Birmingham that is why it goes there first.

 

[The Ham]

This is true. We are not party to private discussions within the DfT, treasury or indeed around the cabinet table. There is simply no way for us to tell whether investment in the rest of the railway will be squeezed in favour of HS2.

We only have the Governments word for it (and even that doesn't bind successor governments throughout the construction phase).

Given that the funding for Crossrail has squeezed the funding to the rest of the network to the level we currently have and HS2 on a year by year basis is expected to be broadly the same as Crossrail then we can expect the current level of squeezed funding to continue for some time to come.

As such we may only have enough funding for another few billion pounds worth of investment during CP6.

 

[Bald Rick]

I can only assume by "No. 4" you mean Leeds, which is far from being the country's 4th largest population centre, including its straggly bits being an entire city of just 700,000 or so people.

As I say, there are people in Liverpool (or as you call it "Merseyside") who would dearly love to be able to ask you a lot of questions.

Metropolitan areas, not cities.

https://en.m.wikipedia.org/wiki/List_of_metropolitan_areas_in_the_United_Kingdom

As I said earlier, there's nothing to stop a future branch to Liverpool. Although I'd be interested to hear what your view of the additional time saving would be of such a branch right into central Liverpool, given that the trains would need to continue to serve Crewe. And what the good folk of Runcorn would think.

 

[Voglitz]

Why would they dig bigger tunnels than they need? :?

If it's cheap and easy to build bigger tunnels with modern TBM technology, why wouldn't they? The tube lines of the capacity-challenged London Underground would be able to carry larger volumes, if they had been built to take bigger trains.

If you did that how long until it catches up with the one in front.

I think this eventuality was considered in the layout of tracks at stations on the Bicester cutoff.

Right so we are going to run the new service into Paddington via a low speed connection into the GWML reliefs to be shared with Cross-rail.

That is feasible. The platforms would not be shared with Cross-rail.

No Birmingham that is why it goes there first.

I don't see much difference, feasibility-wise, between a HS2 Tatton kink, and a non-HS2 Rugby kink, or somesuch.

 

[najaB]

If it's cheap and easy to build bigger tunnels with modern TBM technology, why wouldn't they? The tube lines of the capacity-challenged London Underground would be able to carry larger volumes, if they had been built to take bigger trains.

But only on completely new, self-contained underground lines. Like the Elizabeth Line - which, interestingly, has been built to take full-sized trains.

 

[Voglitz]

But only on completely new, self-contained underground lines. Like the Elizabeth Line - which, interestingly, has been built to take full-sized trains.

Not full-size, as in 'Continental-size'.

Tunneling tends to be expensive and the more earth there is to be removed, the higher the bill. Hence the small diameter tunnels of the Métro de Rennes, etc.

 

[najaB]

Not full-size, as in 'Continental-size'.

Again, the Elizabeth Line has to interface with the existing UK-gauge railway so there was no point making the tunnels any bigger than they are. Though, that said, the tunnels are 6.2m diameter but didn't *need* to be.

Tunneling tends to be expensive and the more earth there is to be removed, the higher the bill. Hence the small diameter tunnels of the Métro de Rennes, etc.

Exactly. Which is why they don't dig the tunnels wider than they need to be. But your point was:

If it's cheap and easy to build bigger tunnels with modern TBM technology, why wouldn't they? The tube lines of the capacity-challenged London Underground would be able to carry larger volumes, if they had been built to take bigger trains.

Which doesn't actually make any sense given that modern TBMs didn't exist in the 1800s when much of the tube network was built.

 

[NotATrainspott]

If 'Continental' size plain line tunnels are cheap and easy to build now with modern TBM technology, one might well ask, why are new metro lines around the world built with small diameter tunnels?

What do you mean by small diameter tunnels? Do you know what you mean? Tube-sized tunnels were built in London and Glasgow and basically nowhere else.

Metro systems don't have double deck trains, because dwell times and standing capacity are far more important than the number of seats. The only way you would have double-deck trains is if they were properly double-deck, with two independent flat decks with level boarding from full-length platforms. That doesn't exist anywhere in the world because it's not actually a good idea, rather than because the TBM technology isn't there. Barcelona Metro lines 9 and 10 have sections where they used a truly enormous TBM, large enough for the tracks to be in two levels and for station platforms to fit within the same bore. If you did have such high capacity requirements that true double-deck trains would be needed, then a far more efficient and useful way to do it is to have two effectively parallel lines; either have them serve slightly different sets of stations, or have one act as an express line for the other. That means serving more people and doing a better job of actually moving people around, rather than just willy-waving about stupidly tall trains just to fill up a TBM tunnel.

 

[NotATrainspott]

Not full-size, as in 'Continental-size'.

Tunneling tends to be expensive and the more earth there is to be removed, the higher the bill. Hence the small diameter tunnels of the Métro de Rennes, etc.

http://www.metro-rennes-metropole.fr/accueil/les_travaux/methodes_de_construction/tunnel_profond

9.44m diameter TBMs are not 'small diameter'. That's larger than the majority of single-bore tunnels on HS2. Modern safety requirements mean that you have to have a walkway on both sides, for passenger evacuations and for maintenance crews, at which point the tunnel diameter necessarily is much larger than the train. The Northern Line Extension tunnels will have a 5.2m diameter as a result, when the Kennington loop tunnels they'll connect to are only 3.6m as a consequence. That's only one metre smaller than the 6.2m Crossrail tunnels, despite the 1995 Stock trains having a small proportion of the cross-section of the 345s. The Merseyrail Loop Line tunnels have a diameter of 4.7m despite taking full-size rolling stock.

 

[MarkyT]

Not full-size, as in 'Continental-size'.

Tunneling tends to be expensive and the more earth there is to be removed, the higher the bill. Hence the small diameter tunnels of the Métro de Rennes, etc.

Cross sectional area is a particular issue in the very densest old city centre areas mainly because there's usually a lot of preexisting underground infrastructure to weave around. There's simply more freedom of movement with a smaller tunnel and that might be vital to achieving a desirably smooth and speedy alignment, even finding a viable route at all. Extraction and disposal of material is also more of an issue in urban areas.

For Crossrail, 'full continental' gauge wasn't worth the extra trouble, particularly seeing as the new route joins conventional classic loading gauge routes at either end. Future bi-level trains are ruled out also due to loading time constraints in the core so a smaller tunnel was the logical compromise.

In Rennes, vehicles are rubber tyred people mover derivatives and are significantly narrower than even UK classic trains, more like trams. They can also turn and climb in a more agile manner than rail vehicles, even trams, so I expect the tunnels on their new line B under construction will be particularly sinuous.

 

[MarkyT]

9.44m diameter TBMs are not 'small diameter'. That's larger than the majority of single-bore tunnels on HS2.

That tunnel diameter will carry both tracks side by side in Rennes.

 

[fowler9]

Certainly for this rail enthusiast the reason I am not that interested in HS2 is because I don't agree with funneling more business to London and the South East. Nothing personal against anyone who lives or works there but that is what it is doing. We don't need to get more people to London, we need to change the way we live.

Increasing slots on the track is not going to free up capacity, it is going to increase demand.

 

[najaB]

Certainly for this rail enthusiast the reason I am not that interested in HS2 is because I don't agree with funneling more business to London and the South East.

It may well have the opposite effect - when the North is that much 'closer' to London businesses may move out of The Smoke since the cost of doing business (rent, wages, etc.) is so much less.

 

[Voglitz]

What do you mean by small diameter tunnels? Do you know what you mean? Tube-sized tunnels were built in London and Glasgow and basically nowhere else.

What do you mean by 'tube-size'?

In Europe at least, most urban metro systems do not have tunnels built to the dimensions of the national railway network.

Which doesn't actually make any sense given that modern TBMs didn't exist in the 1800s when much of the tube network was built.

In no sense has technology made tunneling "cheap and easy". If plain line full size tunnels were cheap and easy to build with modern TBM technology, why would new railways, like the Copenhagen metro, etc be built with small tunnels.

That tunnel diameter will carry both tracks side by side in Rennes.

General French practice is to carry both tracks - for diminutive trains - in one tunnel. This is another way of recognising that tunneling tends to be expensive, and the more earth there is to be removed, the higher the bill.

 

[NotATrainspott]

What do you mean by 'tube-size'?

In Europe at least, most urban metro systems do not have tunnels built to the dimensions of the national railway network.

In no sense has technology made tunneling "cheap and easy". If plain line full size tunnels were cheap and easy to build with modern TBM technology, why would new railways, like the Copenhagen metro, etc be built with small tunnels.

General French practice is to carry both tracks - for diminutive trains - in one tunnel. This is another way of recognising that tunneling tends to be expensive, and the more earth there is to be removed, the higher the bill.

Tube size is, well, tube-sized. 3.5m diameter with the trains taking up basically all of it. Basically every network after that has used proper-sized tunnels with square-profile trains. Square-profile trains require slightly larger circular tunnels.

Tunnelling is cheap and easy compared to the alternatives when you're in a built-up area or are in an area of difficult geography. Of course tunnelling is more expensive than building a plain line in a flat field.

Oddly enough tunnels are only built big enough for the things that will be passing through them. Unless you have a reason to build them bigger, you will. Most metro trains don't need big tunnels because they're necessarily single deck, with the only real variation being in how wide they are and even then you won't find much wider than 3.5m because of diminishing returns.

This is the cross-section of the Barcelona L9/10 tunnels. TBM tunnelling is cheap and easy compared to the cost of digging out station caverns using spray concrete lining. On L9/10 the geology, number of stations and expected ridership levels all worked out to mean that having one whacking great TBM bore was cheaper than a traditional tunnel type. The stations consist of little more than simple shafts sunk into the ground alongside the tunnel, with access passages cut into the tunnel lining as appropriate. These decisions were made by engineers who looked at all of the options and worked out that this was the best one.

 

[The Ham]

Certainly for this rail enthusiast the reason I am not that interested in HS2 is because I don't agree with funneling more business to London and the South East. Nothing personal against anyone who lives or works there but that is what it is doing. We don't need to get more people to London, we need to change the way we live.

Increasing slots on the track is not going to free up capacity, it is going to increase demand.

What you have to remember is that most of the HS2 track will be north of Birmingham. As such given that there will be two arms of track merging into a single arm into London that there will be spare paths available, those spare paths could then be used by services not going towards London.

Even if such services don't exist there will be significant capacity enhancements for rail travel between HS2 stations (excluding London) that will be able to release capacity on the existing XC core that will mean that there will be increased demand over those routes.

As someone who works for a company based in the South East which is less than an hour from London, we find that we have the best of both worlds, the ability to find staff without them needing to pay the high train fares to get to London but also the ability to attend meetings in London without it taking up too much of the working day.

Post HS2 it likely that companies based in Manchester would find a similar level of benefits but with an even lower cost base. As such I would expect business to be spread more evenly than is the case at present.

 

[najaB]

In no sense has technology made tunneling "cheap and easy". If plain line full size tunnels were cheap and easy to build with modern TBM technology, why would new railways, like the Copenhagen metro, etc be built with small tunnels.

Again, why dig tunnels bigger than they need to be? The fact that you can do something doesn't mean that you must.

 

[D365]

Again, why dig tunnels bigger than they need to be? The fact that you can do something doesn't mean that you must.

The point that's being made is that tunnel cutting for HS2 won't need to be compromised as there is no longer a significant cost saving by reducing tunnel diameter.

 

[najaB]

The point that's being made is that tunnel cutting for HS2 won't need to be compromised as there is no longer a significant cost saving by reducing tunnel diameter.

That point is being made, but not by Voglitz. They seem to be arguing the opposite.

 

[Camden]

Metropolitan areas, not cities.

Thanks for the Wiki link, is that where HS2 got its data??...

West Yorkshire isn't a metropolitan city and only nominally a metropolitan county with lots of people scattered in towns here and about. As far as transport goes, the reading of Leeds as a standalone entity of only around 700,000 is a correct one. Unlike very large metropolitan Liverpool, with all the obvious HS2 related advantages that centricity of city and services bring and would have brought.

Although I'd be interested to hear what your view of the additional time saving would be of such a branch right into central Liverpool, given that the trains would need to continue to serve Crewe. And what the good folk of Runcorn would think.

Yes I suppose you might like me to muddy the waters of this conversation down to pros and cons of the project, rather than concentrating on the core issue. Given your involvement, I am sure you will be aware that "HS2 isn't just about speed".

As I said earlier, there's nothing to stop a future branch to Liverpool.

Except perhaps what stopped it last time?...

I say again, I think there are people in Liverpool who would like to put a lot of questions to you if you would be willing to meet with them?

 

[The Ham]

Yes I suppose you might like me to muddy the waters of this conversation down to pros and cons of the project, rather than concentrating on the core issue. Given your involvement, I am sure you will be aware that "HS2 isn't just about speed".

Except perhaps what stopped it last time?...

I say again, I think there are people in Liverpool who would like to put a lot of questions to you if you would be willing to meet with them?

You are right HS2 isn't just about speed (although Liverpool benefits to some extent on those grounds with journey time savings, although they are not as big as they could have been with a new line all the way), it is also about capacity.

At present there is 1 fast service per hour whilst after HS2 opens it is expected that there will be two fast services per hour. However there will also still be the services from Crewe which for one service an hour currently take about 15 minutes longer than the fast services. Under HS2 these local services will still exist and so it would likely be possible to travel to Liverpool via Crewe in under 2 hours going via Crewe (even allowing 15 minutes to change trains). As such going this "slower" route would likely be only about 20 minutes slower than going direct (but depending on times could still be faster than waiting for the next direct HS2 service) but also would be about 15 minutes faster than the current fast service.

As such there is likely to be three trains an hour which would get you form London to Liverpool faster than the current direct train (up from 1), it could be that there is enough demand for the existing direct train to be retained, in which case it would be four trains an hour (that are as fast or only slightly slower than the current direct train, assuming a few extra stops on the existing direct train). 4 trains per hour with a journey time to London of less than 2:15 compared with 1 train per hour currently would, even if they were shorter than the current 9 coach 390's, provide significantly more seats per hour than the current timetable.

The current 11 coach 390s have 589 seats, even allowing just 350 seats per train on a frequency of 4tph would be 1,400 seats, or 2.4 times the number of seats. Chances are the two direct trains per hour would have about 550 seats each (1,100 vs 589) meaning that the other one or two services would only need a few hundred seats in total to make up the difference.

I'm sorry but whether you like it or not, Liverpool are getting faster trains (although not such a big saving as some other places which are on the HS2 lines) and more capacity (again, not such a big uplift in capacity as other places).

Personally I wouldn't be surprised if HS2 phase 1 gets filled up with trains meaning that it becomes viable to build a High Speed line which runs straighter up to Leeds which then allows more services to run to Liverpool and therefore increases the need for a High Speed line to Liverpool.

 

[D365]

That point is being made, but not by Voglitz. They seem to be arguing the opposite.

Sorry, I quoted your reply because I was consolidating the point that you had made.

 

[najaB]

Sorry, I quoted your reply because I was consolidating the point that you had made.

Ah, okay.

 

[Bald Rick]

Yes I suppose you might like me to muddy the waters of this conversation down to pros and cons of the project, rather than concentrating on the core issue. Given your involvement, I am sure you will be aware that "HS2 isn't just about speed".

I say again, I think there are people in Liverpool who would like to put a lot of questions to you if you would be willing to meet with them?

The pros and cons of the project isn't muddying the issue, it is the core issue. Without demonstrating that the 'pros' outweigh the 'cons', there isn't a project!

Quite right, HS2 isn't just about speed. It is more about capacity. Something the line between Crewe and Liverpool has plenty of to spare.

Whilst I would definitely be the wrong person to answer questions (not being the decision maker, nor being involved for the last decade), I'd be more than happy to answer them from the perspective of a transport planner.

Therefore, I will be on one of the London trains out of Lime Street that runs down HS2 in the first hour that Phase 2a opens to passenger service. Unfortunately we'll have around 40 minutes less time for questions than we do if we made the journey today. And rather than just one train to choose from, there will be two, so pick the right one.

 

[fowler9]

What you have to remember is that most of the HS2 track will be north of Birmingham. As such given that there will be two arms of track merging into a single arm into London that there will be spare paths available, those spare paths could then be used by services not going towards London.

Even if such services don't exist there will be significant capacity enhancements for rail travel between HS2 stations (excluding London) that will be able to release capacity on the existing XC core that will mean that there will be increased demand over those routes.

As someone who works for a company based in the South East which is less than an hour from London, we find that we have the best of both worlds, the ability to find staff without them needing to pay the high train fares to get to London but also the ability to attend meetings in London without it taking up too much of the working day.

Post HS2 it likely that companies based in Manchester would find a similar level of benefits but with an even lower cost base. As such I would expect business to be spread more evenly than is the case at present.

Yeah good points mate. I was just speaking from fear of a further brain drain being created. the opposite could happen and at the end of the day further capacity is needed. Much to ponder.