HS2 infrastructure discussion... NOT whether the line should be built or not...

[RichW1]

I still think it should be 4 tracks until north of Birmingham

This has to be the single most important part of the whole thing imho. If this is not the case (and I don't think it will be) it'll be hugely short sighted. No-one can tell me that with 2 tracks it will handle all future high speed traffic from Leeds, Manchester, Birmingham, Derby, Notts etc etc as well as potential Scottish traffic. It's going to take over WCML and Midland as well as one ECML destination. It will not happen and we'll be having overcrowding before we know it.

I am not booking seats either unless I know I'm travelling. I have plenty of days where I want to go and visit somewhere and if I have to book like an airline I'm sticking to the classic network slow though it is.

 

[Striker]

It's going to take over WCML and Midland as well as one ECML destination. It will not happen and we'll be having overcrowding before we know it.

No it's not.

 

[Rhydgaled]

I think it should be built on the Great Central route as a 202mph line (possibly as far as Rugby and then turn off for Birmingham), with 3-tracks if possible and room to expand to 4 if need be. The 3rd track would allow a Javelin type 140-150mph service (possiblly run from a seperate terminus to the main HS service) to run on the line serving smaller stations that the HS trains wouldn't stop at. I think the site they have in Birmingham would be ok for a through station and would want this, but it depends what kind of gradient HS trains can manage to plunge into the tunnel afterwards.

In London I would have a triangle, allowing HS1 trains to run into Euston. Euston (again depending on the gradients) should also be a through station, with a tunnel to Heathrow (terminus for most trains that aren't classic compatible) and a line from there to Reading. This would allow a future HS3 to extend that line west from Reading to Bath, Wells and Taunton with a 140mph upgrade for the existing line from Taunton to Exeter.

3tph each way is enough for contenental passenger services from Birmigham/Manchester I think, but what about Berne guage freight? The existing links at the end of HS1 already would allow through trains to Birmingham (which by the way would be within the magic 4hrs to Brussels (with stops at Straford (for London) and Lille (change for Paris)) and therefore should be introduced ASAP in my opinion, no need to wait for HS2). Likewise similar sub 4-hour journeys would be posible to Bristol Parkway (could be extended to Temple Meads via Parkway) right now if only the line was electrified and such a service should be introduced as soon as the wires are up. I think the NOL Eurostar sets are the best train for those jobs. I'd only expect 2 or 3 trains per day on each of those routes (Bristol & Birmingham) without HS2 and HS3, but think it'd still be worth doing. I'm routing the NOL trains to Brussels rather than Paris because of the better connections to other European destonations than a service to Paris

 

[Chris125]

You cant build it on the GCR alignment without effectively starting from scratch - the alignment is too twisty, every embankment would need major rebuilding, every cutting widened, every tunnel rebored. You would probably knock down more houses and get more complaints while following a route optimised for minimal gradients rather than high speed - it just doesnt make sense.

Remember that the HS2 report includes many different options, including using existing railway formations, and why they werent persued.

Chris

 

[Rhydgaled]

Remember that the HS2 report includes many different options, including using existing railway formations, and why they werent persued.

That's a rather large document, I'll try to find time to look through more of it but if you happen to know where abouts they discuss this particular issue could you let me know?

You cant build it on the GCR alignment without effectively starting from scratch - the alignment is too twisty, every embankment would need major rebuilding, every cutting widened, every tunnel rebored. You would probably knock down more houses and get more complaints while following a route optimised for minimal gradients rather than high speed - it just doesnt make sense.

Using a route designed for minimal gradients makes alot of sense to me, helps reduce power consumpsion.

Yes the Great Central has a lot of curves, but I think I have found out the radius required for 202mph running. I've put a circle with this radius into Google Earth and compared it to all the corners. The HS2 line as I would propose it would join the GCR route around Quainton (about where the offical proposal does on the google earth file I have downloaded of it). This is also about where the Javelin style service would depart from the HS line to run to a different London station. The line would need to deviate at Brackley (one place a Javelin station might be put), staying East of the A43, as the original route looks blocked. There would be a further deviation due to route blockages just west of a small place called Moreton Pinkney and a longer one east of Woodford Halse / Hinton (the other sizable-looking place that could have a Javelin station). After these diversions are made no curve is tighter than 200mph all the way to Rugby. Fitting sufficent lines through Rugby might be difficult, but perhaps HS2 to Birmigham should leave the GCR before then anyway to rejoin the HS2 Ltd route (although I think serving Rugby would be useful, and allow the possible Leeds extension to use more of the GCR). Of course I've no idea if having curves of that radius in opposite directions close to each other would impact the linespeeds, but otherwise it's do-able. The GCR was supposedly built to a generous loading guage anyway, whether this is Berne guage standard or not is another thing I don't know.

Rugby would be difficult, the HS station would probablly need to be on the bridge across the existing lines and there would not be much room, and then there would be a tight curve to follow the M6 to Birmingham. Leeds bound, the GCR seems to become the M1, so the line would follow alongside (maybe taking a few short-cuts to avoid slow curves) but then it's time to slow to stop at Leicester. Nottingham is the major obstical on the Leeds route, with the GCR and M1 being very helpful elsewhere.

The reduction in max speed to 202mph I'd propose would also reduce power consumpsion (and even then some of the straightes bits would allow late trains to go a little faster to catch up).

 

[Waddon]

I can't agree on the 4 track option right now... to be honest, the whole scheme could still get cancelled, its more important that the route gets built as a basic railway without worrying about what may or may not be needed 30 or 40 years down the line and adding extras onto a hugely expensive cost, yes it will be more expensive to quadruple it later, but traffic demand for that is not going to exist until further northward extensions are built, and thats so far in the future that we can't possibly predict what the demand for the railway will be... can you really imagine the demand for non-stop travel to Birmingham only will need more capacity than that line can provide?

 

[jon0844]

Is the land they're going to acquire going to be wide enough to allow for adding two tracks later? Given new motorways are built with wide bridges to allow cheaper expansion later, I'd hope HS2 does too.

If they do, it will be relatively easy (albeit expensive) to add the new tracks, wires and signalling later than having to purchase land and build new bridges. The only thing I can imagine they might have a problem with is the tunneled sections. Maybe the tunnels should be built with room for more tracks too.

 

[WatcherZero]

No, their only purchasing the land to allow for two track not four track.

 

[Nym]

Jonmorris0844, they'll have ownership of the land needed for the tunnel portals, but all tunnels will be single bore..

 

[starlightEXPRESS]

It's interesting seeing the debate about four tracking. The SNCF boss Guillame Peppy has acknowledged that not building the Paris-Lyon line as four track from the outset was a mistake (see http://www.americainfra.com/article/Up-to-Speed/ ). That line is 400 km or around 250 miles, which is almost double the London-Birmingham distance.

AIUI, the Paris-Lyon line is a relatively special case, because of the mix of services with different stopping patterns that use the line. (Including Javelin-type services to Dijon and Geneva which branch off at different points.) Given that HS2 will be non-stop from Old Oak/Heathrow Hub to Birmingham Int, it's not really a fair comparison.

 

[jon0844]

No, their only purchasing the land to allow for two track not four track.

Then, along with the tunnels, I think we can safely say that it will not be made four track for ages - if ever.

Indeed for all the work involved, it might be better to seek to build another high-speed line somewhere else.

 

[Nym]

if the turnout speeds are good enogh, we'll run out of platform space at Euston before track capcaity, if eveything is running nicely you can get 20tph down a single track in one direction, 24tph at a push, and since HS2 is going to have 10 or 12 platforms at Euston, you'll run out of platforms first, with 20min occupancy and 5mins either side, you'd be full with 24tph...

When it gets bad enough to need more than 24tph into Euston, we'd be looking at HS3/4 up the East Coast via Cambridge or Pbro, that would take pressure off HS2 at that time, with only 2 or 3 tph having to proceed from Euston to the E Midlands Stops, terminating at Leeds, West Yorks Parkway (where it would meet HS3/4) or somwhere similar.

Then we're looking for a station on some empty land in Central London again, Shorditch High St facing out to Stratford anyone?

 

[jon0844]

Another line completely would sound like a better option, although the time we consider building it will be when the railway is (again) at breaking point! I doubt I'll be around then.

The only problem with trying such a service frequency is probably going to be demonstrated by Crossrail and the central core of Thameslink; when anything goes wrong, it's going to be a nightmare.

TL will be worse as there are different services and calling patterns, so you don't just get the next train like a delayed tube train. Perhaps HS2 won't be quite as bad, and people will just wait for the next one (or a train can easily be cancelled) but it could go pear shaped very quickly if a broken down train forces a single track to be used bi-directionally for any period of time.

 

[The Planner]

The only problem with trying such a service frequency is probably going to be demonstrated by Crossrail and the central core of Thameslink; when anything goes wrong, it's going to be a nightmare.

Doubt it, they will just cape or cancel services until it recovers like most lines do now.

 

[jon0844]

Yes, but through the core on TL, it's going to be a nightmare because people want different trains. At least at, say, Euston, there's a lot more scope for crowd control and taking trains out.

I am sure HS2 will cope far better, but if it ever became that popular then cancelling loads of services is always going to be messy.

 

[Nym]

Well, supposedly in the HS2 Side of Euston, there are only going to be TWO (EU and Classic Compatable) diferent kind of units, so if there is a delay on an arriving unit, send a diferent one out and rotate the units round until you're recovered.

 

[WatcherZero]

Saw an article in a Scottish paper today demanding high speed rail to Inverness and Aberdeen and that Westminster pay for it O.o

 

[dalmahoyhill]

It was incredibly short sited to close the great central in the 60s but nostalgia shouldnt blind us to its use a modern rail line. sorry I just don't buy the "open it as a alternative to HS2 argument for many reasons".

Using the existing line out of london doesn't deal with the congestion issue at all, it is still heavily used for commuting traffic

The alignment, although fast for its time, is not straight enough, 200mph needs about 4500m radiii. 250mph is approx 7000m. the great central must be about 1500max, enough for <150mph running. i could check it on CAD but i dont have the time.

i think you are underestimating the cost of reopening it. a lot of the line has been built on, a lot of structures like viaducts need rebuilding. I think extensive earthworks would be required even on the existing track bed to make it suitable. all the sub base and ballast would need replacing.

costs like electrification, adding power supplies and signalling, which are significant, would be the same.

The alignment is fine if HS2 was designed to mimic the midland main line but HS2 is designed to relieve the WCML. adjoining back at rugby doesn't do much for WCML congestion. it doesn't do anything to relieve the congestion at new street.

it would still probably get the same amount of local opposition as a new line.

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i think the idea about future 4 tracking is to protect a corridor of land along HS2 from future development. either by putting it as a statute in the parliamentary bill or acquiring the land now.

 

[Nym]

Just put authority on the land that says it can't be developed beyond green space, or buy it...

 

[coral reef]

Yes the Great Central has a lot of curves, but I think I have found out the radius required for 202mph running. I've put a circle with this radius into Google Earth and compared it to all the corners.

I also tried this a few years ago and did not find that the GCR alignment was suitable for such speeds. The corners that do exist would still need straightening out, I was working on an assumed 300km/h route at the time which I found necessitating the realignment of about a third of the route length. Any faster and the rebuild quickly went beyond half the route.

 

[Nym]

Change of topic slightly, just looked at the HS2 - HS1 connection map, looks like the're going to 4 track and re-guage the NLL from Primrose Hill to the St Pancras Junctions.

Now, the sensible thing to do would be to have this as much 4 track as possible, ie. from Camden Road to St Pancras Junctions. To EU Guage, problem I'm seeing is EU Hight OHL is higher than standard UK Guage ones, would there be any problems in just increasing the hight for the NLL or reducing it for the EU Guage ones? I know that E* can run at both heights, and we'd want to keep it all compatable to all standard EU Stock, so would we need new pantos for the NLL stock?

EDIT: Just to throw somthing else into the mix, HSx from Birmingham to Bristol...

Theres space for 4 tracking from Temple Meads and space in the car park for 4 platforms, in Birmingham it could follow the route in roughly via the Longbridge alignment, would be a lot of widening to do, but it should fit. Then from Lifford Junction on the passenger line with no stations, to St Andrews Jcn area where it would form another Delta Junction, one part using the viaduct that HS2 is being built on to cross the NR lines to create a non conflicting junction near Saltley, add another part of the delta that can access the southern portion of platforms at Curzon street, thus creating a second 'delta juncton' in Birmingham round the Grand Junction area, wonder what the journey time to Bristol would be reduced to, if it's less than an hour, would make nice inroads for a better XC serice, and at a guess there would already be a line from Bristol Parkway into Bristol from London Via Swinton by the time this happens, any problems with using this route out of Birmingham to the south?

 

[Rhydgaled]

I also tried this a few years ago and did not find that the GCR alignment was suitable for such speeds. The corners that do exist would still need straightening out, I was working on an assumed 300km/h route at the time which I found necessitating the realignment of about a third of the route length. Any faster and the rebuild quickly went beyond half the route.

I was setting up some circles for slower speeds and it appears that one or both of my sources of curve radii are incorrect. I need a good, trustworthy, source, can anyone here provide one? Similarly I'd like to know the max gradients, particularlly immediatlly outside stations.

200mph needs about 4500m radiii.

That's 2.79617037 miles, I was working with a figure of 1½-miles providded by LE Greys in another topic. In that topic I was also asking for the reletive costs of various construction methods. I'd still like to know the answers, in terms of cost per mile probablly.

 

[dalmahoyhill]

i dont work in the rail sector but i believe that the radii is possibly parabolic and not circular but for drawing on maps it wouldnt make any difference. any advice from anyone who works in the industry would be welcome.

wikipedia has a equation for working in outhttp://en.wikipedia.org/wiki/Minimum_railway_curve_radius
also depends on cant and all that. every country has its own standard, i believe germany has higher radii for the same speeds as the french tgv network.

Hs2 give 7200m for 400km/hr and 1800 for 200kmhr.

of course you can always build it with local speed restrictions although this somewhat defeat the purpose.

does anyone know the fastest set of points in existing eg for diverging lines ie HS2 and HS3? I know colton junction is 125mph.