Longer trains on WCML - How much capacity would they have added, compared to HS2?

[Nottingham59]

In an Alternative Universe, how much capacity could have been added by running longer trains on the WCML, instead of building HS2?

To get the most capacity out of HS2 Phase One, it will be necessary to build 420m platforms at Crewe and Preston and Carlise, to allow more HS2 services to run double units through the bottlenecks of Colwich Junction and just six platforms at Euston. How much more would it have cost to extend platforms at the other main stations on the West Coast Mainline?

This thread is about long-distance trains, not London commuter services. And I'm not saying that this should have been the choice way back in 2009 when HS2 started. But with the benefit of hindsight, I'm exploring whether longer trains could have run on the WCML, and see if those lessons might apply to other routes like ECML and GWML. Any comments or (constructive) criticism welcome.

== == == == ==

For what it's worth, these are my thoughts about how we could have maximised the capacity of the WCML by running longer trains. I'd standardise on a train length of 520m (being 20x26m), so that a split train could reach all stations currently served by an 11-car Pendolino (265m). A 400m HS2 train has 1100 seats (2.75Pax/metre), so these 520m trains should be able to carry 1430 passengers, well over twice the 607 capacity of a Pendolino.

PHASE ONE

• Euston Extend P16 to 530m and build another three (P17, 18, 19) to the West of the current station, connected to the WCML fast lines, with a mezzanine departure lounge above the tracks to separate departing passengers from arrivals. This would use less space than has already been cleared for HS2. Four 530m platforms have the same passenger-carrying capacity as five HS2 platforms (420m), or nine Pendolino platforms. Estimated cost: £1bn for the station extension and railway, and £1-2bn for the land, because it's London. I'd not bother with oversite development. I've not costed changes to handle the increased pedestrian flows to and from the street and the tube, but from the cost for HS2 Euston I'd guess £1-2bn.
  
  
• Milton Keynes, Rugby, Crewe, Warrington BQ, Preston, Lancaster, Carlisle, Wilmslow, Stoke-on-Trent, Coventry, Birmingham International There seems to be space at each of these to extend two or four existing platforms to 530m, relatively easily. Most could be done within existing railway land: Carlisle would require some demolition. Coventry would need P1 extending to the East, P4 extending to the West, plus new bay platforms. Stations north of Crewe will need extending anyway to get the most out of HS2 phase one. Estimated cost: £50m per platform island.
  
  
• Birmingham Extending New Street would be impractical, so I would build a new seven-platform station at Curzon St, like HS2, but with classic platforms able to take trains from the rest of the network. Connections to the line from Water Orton and viaducts to join the WCML just west of Adderley Park station, along the line shown in this map.
  
  
  Cost £500m for the new station (same as HS2) and £1bn for the connecting viaducts.
  
  
• Manchester Mainline Manchester could be served by splitting at Crewe or Stoke, but Piccadilly really needs longer platforms. Extend P1 to 520m, and build two new platforms (P0 and P-1) on the existing railway structure that used to carry the goods lines, with platform P-1 cantilevered out over Sheffield St. Cost £250m.
  Previously discussed here:
  

  How to add 400m platforms to Manchester Piccadilly

  If HS2 Phase 2B is not going to be built, then capacity to Manchester will be severely limited by the number of trains that can get through Colwich Juntion and Stafford. The only way to increase capacity to Manchester is to run longer trains. This is how I would add 3 x 400m platforms at...

  www.railforums.co.uk
  
  
• Manchester Suburban To avoid conflicts with trains from Glossop and Rose Hill Marple, I'd convert those routes to Metrolink tram-train and connect them into the main Metrolink network with a new viaduct across the River Medlock from the Ancoats viaduct to join the metrolink tracks to the East of Piccadilly station. I've not costed this, but should be possible for well under £1bn.
  
  (Alternatively, build new suburban platforms (P-2, P-3) to the east of Piccadilly, encroaching on the HS2 station site, and serve them with a new 1.5km twin-track viaduct to Ardwick, to make eight tracks out of Piccadilly in total. Cost £250m for the suburban platforms and land, and £300m for the new viaduct.)
  
  
• Stockport It would be straightforward but not cheap to extend Stockport platforms northwards, on a high-level structure well above existing street level. Merging onto the main Stockport Viaduct would compromise that heritage landmark, so it may be better to construct a new twin-track bridge alongside the existing, and merge onto the mainline to the north of the river. Cost £500m (same as Curzon St) to rebuild the station, and £500m for a second bridge across the river.
  
  
• Glasgow Straightforward to extend P1 and P2 across the river Clyde. As discussed here:
  

  400m platforms at Glasgow Central?

  [Crayon alert!] Could space be found for 400m long platforms at Glasgow Central? When HS2 phase 1 starts, the fastest route from London to Edinburgh will be via HS2 phase 1 and Carlisle. So I'm expecting England-Scotland passenger traffic via Carlisle to grow strongly over the next twenty...

  www.railforums.co.uk
  
  
• Liverpool, Edinburgh I don't think 530m platforms can be fitted in here, so serve these and other intermediate stations on the WCML with trains splitting at Crewe or Carlisle.

If six of the current Avanti paths out of Euston (607 seats) were replaced with 1430-seat trains, then the long-distance passenger capacity would increase by 5000 Pax/h, costing less than £10bn to build at current prices.

HS2 is being built with six platforms at Euston. It will carry five 400m trains (3tph to Birmingham and 2tph splitting at Crewe) plus five 200m to elsewhere, giving an uplift of 8,250 Pax/hour. This will cost around £40bn at 2019 prices, so £50bn at current prices. It seems to me that running longer trains on WCML would been a far cheaper way to add capacity than building a whole new line. What do you think?

PHASE TWO
The longer platforms added in Phase One would increase capacity without using any more paths on the WCML. But they would also add station capacity in Central Birmingham and Central Manchester. To exploit this, I'd propose a Phase Two which added limited new lines to bypass specific bottlenecks as cheaply as possible

• Colwich bypass New 5km twin-track line from Hixon diverting the line from Stoke to a grade-separated junction near Rugeley. By eliminating crossing moves, this would also increase the capacity of the route through Shugborough Tunnel. Cost £1bn with short tunnel under Coley Lane hill.
  
  
• Water Orton to Lichfield Follwing the route of HS2, but merging onto the WCML at Huddlesford east of Lichfield. There is no need to go round Lichfield to join the mainline at Handsacre. This section would allow Birmingham-Scotland and Birmingham-Manchester flows to avoid the slow route through Wolverhampton, and enable Euston-Curzon St-Manchester paths to fill the 520m trains all the way north. 20km of new line: Cost £2.5bn.
  
  
• Water Orton to Bedworth Merging onto the WCML east of Bedworth. 20km of new line: cost £2.5bn, as shown here:
  
  
• Delta junction As HS2, but connecting onto the Water Orton - Birmingham line. There is no need for six tracks between Water Orton and the city centre. Cost £1bn.
  
  
• Birmingham Interchange. Four-platform Park and Ride station with big car park, situated off the M42 somewhere near Water Orton. Cost £500m.

Total cost of Phase = £7.5bn, showing how expensive new lines are compared to merely lengthening platforms on existing tracks.

 

[A S Leib]

Milton Keynes, Rugby, Crewe, Warrington BQ, Preston, Lancaster, Carlisle, Wilmslow, Stoke-on-Trent, Coventry, Birmingham International

You'd presumably want to try to extend platforms at Watford Junction as well; railwaydata.co.uk lists platform 9 (southbound slow) as 222 metres and the other three main WCML ones as 253 m.

Wolverhampton, Wigan North Western, Macclesfield and possibly Chester (unless it has dividing services shared with Liverpool?) as well.

 

[Bletchleyite]

530m is probably a bit excessive. Perhaps just over 300m, which would give you 13 coach Pendolinos?

 

[Nottingham59]

You'd presumably want to try to extend platforms at Watford Junction as well; railwaydata.co.uk lists platform 9 (southbound slow) as 222 metres and the other three main WCML ones as 253 m.

Wolverhampton, Wigan North Western, Macclesfield and possibly Chester (unless it has dividing services shared with Liverpool?) as well.

I had imagined that Watford Junction would be served by the remaining Pendolino services, but it does look like there's space to extend the mainline platforms towards the south, with minimal demolition possibly required in Trinity Hall Close.

530m is probably a bit excessive. Perhaps just over 300m, which would give you 13 coach Pendolinos?

Yes, but that would only give a marginal capacity uplift at the cost of the same level of disruption. And they're going to have to build 400m platforms at Crewe and Preston anyway.

I chose a length that would maximise the capacity into intermediate stations that already handle 265m Pendos. And the standard in Europe is now 400m. 520m is not all that much longer.

 

[The Planner]

How much do you lose from not running trains when this is being built?

 

[Nottingham59]

How much do you lose from not running trains when this is being built?

Most of the work at Euston and Manchester and Birmingham would be to the side, away from working tracks, so the disruption would be for short periods as the new platform approach tracks were connected into the live railway.

I would expect that extending platforms on the WCML would cause the same order of disruption to the working railway as building eight new platforms on the Great Western at Old Oak Common. How much will that lose?

 

[Grimsby town]

• Stockport It would be straightforward but not cheap to extend Stockport platforms northwards, on a high-level structure well above existing street level. Merging onto the main Stockport Viaduct would compromise that heritage landmark, so it may be better to construct a new twin-track bridge alongside the existing, and merge onto the mainline to the north of the river. Cost £500m (same as Curzon St) to rebuild the station, and £500m for a second bridge across the river.

I'd be a bit worried what was considered complex if extending Stockport is straightforward. I'm not sure how a new twin track bridge would work for London services given the tracks are paired by direction. It'd either involve flyovers or rebuild stations to pair tracks by use.

A big problem I'd forsee is what happens once people are off trains. If the extension occurs in one direction then you could theoretically be asking people to walk hundreds of metres to get to an exit. That's going to be a particular issue if you suffer a mobility impairment. HS2 stations generally include multiple entrances to mitigate this.

You're likely to need new entrances anyway. Most stations aren't built to deal with potentially 100s of people getting off at once. Wilmslow is a good example for a station which struggles with the current loadings due to its narrow underpasses. Passenger flow at stations is really important (see Euston and Piccadilly 13/14 where there are huge issues) and a lot of crowd/pedestrian modelling is involved in building modern rail stations. Its not as simple as just extending platforms unfortunately.

 

[The Ham]

There's two things which HS2 does which this wouldn't:

Extra capacity at somewhere like Manchester and Birmingham where the released platform capacity from removing the long distance services.


I've also said in the past that HS2 with 16 coaches would (when servicing Manchester) require the same number of coaches as the current train lengths due to the time saving from HS2.

If you want me explain again, let me know.

However, it does explain why something like HS2 could be better than just making trains longer as per this thread.

 

[Nottingham59]

I'm not sure how a new twin track bridge would work for London services given the tracks are paired by direction. It'd either involve flyovers or rebuild stations to pair tracks by use.

One potential layout would be to put the Down Fast and Down Slow onto a new viaduct across the Mersey, to the West of the existing, and extend the single island between P2 and P4 between them as shown in blue here. All the lines on the old viaduct would be southbound. (Note that this is not a fully worked out proposal: it's just to illustrate one possibility. You could do the equivalent to the East of old viaduct instead.)


The Down Slow would then need a new short platform on the line that is currently the Down Goods.

Alternatively, send the longest trains to Piccadilly via the Styal line, and avoid Stockport altogether.

 

[The Planner]

Most of the work at Euston and Manchester and Birmingham would be to the side, away from working tracks, so the disruption would be for short periods as the new platform approach tracks were connected into the live railway.

I would expect that extending platforms on the WCML would cause the same order of disruption to the working railway as building eight new platforms on the Great Western at Old Oak Common. How much will that lose?

You are extending platforms on a live railway at Euston and northwards. You are not doing that with all lines open. OOC is one station, not the WCML where are you are proposing several. Its taking two weeks to replace a bridge at Penrith.

 

[Nottingham59]

Extra capacity at somewhere like Manchester and Birmingham where the released platform capacity from removing the long distance services.

Phase One of this scheme releases capacity at both New Street, by switching most London traffic to Curzon St, and at Manchester by adding more platforms on the East side of the station, and by diverting the Glossop lines onto Metrolink. But agree that neither would add paths into or out of the city centre.

Phase Two would add many more paths into and out of the centre of Birmingham, for a relatively short length of new lines around Water Orton.

And I do understand that higher speed lines needs less rolling stock to delivder the same quantum of passenger kilometres per day. But this is a relatively minor effect compared to the cost of building new lines.

You are extending platforms on a live railway at Euston and northwards. You are not doing that with all lines open. OOC is one station, not the WCML where are you are proposing several. Its taking two weeks to replace a bridge at Penrith.

Yes, you'd have to take platform 16 at Euston completely out of use, before extending the island between P16 and P17 alongside the existing tracks, plus a new island for P18 and P19. But because you're building that island on the land currently reserved for HS2 it wouldn't interact with the live railway at all until the weekend when you'd connect them in to Tracks E and D somewhere beyond Granby Terrace.

How long will it take for HS2 Ltd to extend the platforms at Crewe? Is it not possible to design a platform segment that can be simply lowered into place onto a precisely located narrow base in a single overnight possession?

 

[Stossgebet]

Remember also, that at the beginning of construction. HS2 was to create capacity for the MML and ECML too. So any such changes made to the WCML for longer trains, would need to be done for the other two mainlines north as well. I wonder how much it would cost to add more/longer platforms at St Pancras for the MML services in this alternative scenario. Or could the above include new and upgraded track and stations from Water Orton to Derby and on up to Doncaster/Leeds to benefit the routes chopped off HS2, and served from Euston?

Remember also, that at the beginning of construction. HS2 was to create capacity for the MML and ECML too. So any such changes made to the WCML for longer trains, would need to be done for the other two mainlines north as well. I wonder how much it would cost to add more/longer platforms at St Pancras for the MML services in this alternative scenario. Or could the above include new and upgraded track and stations from Water Orton to Derby and on up to Doncaster/Leeds to benefit the routes chopped off HS2, and served from Euston?

 

[Grimsby town]

One potential layout would be to put the Down Fast and Down Slow onto a new viaduct across the Mersey, to the West of the existing, and extend the single island between P2 and P4 between them as shown in blue here. All the lines on the old viaduct would be southbound. (Note that this is not a fully worked out proposal: it's just to illustrate one possibility. You could do the equivalent to the East of old viaduct instead.)

View attachment 172613
The Down Slow would then need a new short platform on the line that is currently the Down Goods.

Alternatively, send the longest trains to Piccadilly via the Styal line, and avoid Stockport altogether.

Stockport are pretty attached to their viaduct so I doubt any changes would be allowed. You'd be making interchanges quite a bit more difficult. You'd probably need some sort of access from the platforms to street level for evacuation purposes.

 

[The Ham]

Phase One of this scheme releases capacity at both New Street, by switching most London traffic to Curzon St, and at Manchester by adding more platforms on the East side of the station, and by diverting the Glossop lines onto Metrolink. But agree that neither would add paths into or out of the city centre.

Phase Two would add many more paths into and out of the centre of Birmingham, for a relatively short length of new lines around Water Orton.

And I do understand that higher speed lines needs less rolling stock to delivder the same quantum of passenger kilometres per day. But this is a relatively minor effect compared to the cost of building new lines.

However, the point is that if you are looking at ways of increasing capacity by just lengthening long distance trains that's all you get and not the other benefits.

Also the cost of rolling stock is far more than just the coaches, you've got to store and maintain them.

A 5 hour round trip for a train of 500m (20 coaches of 25m) would require 300 coaches to ruin a 3tph service.

Reduce that to a 3 hour round trip and for the saver length (500m) train would only need 180 coaches.

If each coach costs £200,000 a year to lease over 40 years that's almost £1.0bn in leasing costs alone, before you have to build 3km of extra storage capacity (and before anyone suggests that it could be stored in platforms, that is also true for either option).

(Note I'm excluding inflation, so assuming everything is 2024 prices, to make it straightforward).

Whilst £1bn isn't very much compared with HS2, it's one small part of the picture (not least it's only for the London to Manchester services) repeat again for other destinations.and the beanie would also increased. It's also only for 40 years, when HS2 could last for over 120 years.

 

[Nottingham59]

Stockport are pretty attached to their viaduct so I doubt any changes would be allowed. You'd be making interchanges quite a bit more difficult. You'd probably need some sort of access from the platforms to street level for evacuation purposes.

Yes probably true. But they're also quite attached to their 3tph express service to London.

What makes this interesting it that this is a live issue. When HS2 Phase One opens to Handsacre, we're going to have two or three HS2 trains per hour heading to Piccadilly. At the moment they will be 200m long with fewer seats than an 11-car Pendolino. There will be extreme pressure to lengthen these HS2 trains to 400m, or find more paths.

Platforms at Piccadilly could be lengthened to 400m relatively easily. What's going to happen at Stockport? My guess is that Stockport will get 2tph 400m HS2 passing through without stopping, and 1tph WCML Pendolino calling at Stockport. And if the HS2 Phase Two tunnel ever gets built, Stockport loses its express London service completely.

 

[Bletchleyite]

Platforms at Piccadilly could be lengthened to 400m relatively easily. What's going to happen at Stockport? My guess is that Stockport will get 2tph 400m HS2 passing through without stopping, and 1tph WCML Pendolino calling at Stockport. And if the HS2 Phase Two tunnel ever gets built, Stockport loses its express London service completely.

Though to be fair most people who use Stockport don't live in Stockport and walk to the station, it is basically a South Manchester and North Cheshire Parkway, and if HS2 2B is built Manchester Airport station takes over that role.

(It is true that the two main losers from HS2 are Coventry and Stockport, though).

 

[Bevan Price]

Though to be fair most people who use Stockport don't live in Stockport and walk to the station, it is basically a South Manchester and North Cheshire Parkway, and if HS2 2B is built Manchester Airport station takes over that role.

(It is true that the two main losers from HS2 are Coventry and Stockport, though).

Stoke on Trent, Wolverhampton, Milton Keynes and Liverpool are also likely to be losers to some extent. The time taken to split / combine trains at Crewe - probably around 10 minutes - will partially cancel benefits of higher speed running on HS2.

A simpler (and chesper) way - for a lesser boost in WCML capacity would have been to make all Pendolinos 11 coaches - with only 2 first class coaches. (11 coaches is the maximum that could fit into Liverpool Lime Street)

 

[Nottingham59]

Though to be fair most people who use Stockport don't live in Stockport and walk to the station, it is basically a South Manchester and North Cheshire Parkway, and if HS2 2B is built Manchester Airport station takes over that role.

Which is even more reason to make Wilmslow the main station for London from South Manchester. There seems to be plenty or undeveloped woodland to the north of the river Bollin to extend platforms northwards and add car parks and station access.



Far far cheaper than digging a 15km tunnel under Manchester and a four platform underground station at Manchester Airport.

 

[Stossgebet]

HS2 is an expansion of capacity across the industry. Just extending existing trains on existing tracks, may increase seats on a few services, but actually reduces capacity across the industry (longer trains take longer to clear block sections/junctions/speed restrictions ect.

 

[Nottingham59]

A big problem I'd forsee is what happens once people are off trains. If the extension occurs in one direction then you could theoretically be asking people to walk hundreds of metres to get to an exit. That's going to be a particular issue if you suffer a mobility impairment. HS2 stations generally include multiple entrances to mitigate this.

Yes. In the Stockport example above and at Glasgow and Wilmslow, I could see scope for a secondary station entrance on the other side of the river, where it would be much easier to build very large car parks.

You're likely to need new entrances anyway. Most stations aren't built to deal with potentially 100s of people getting off at once. Wilmslow is a good example for a station which struggles with the current loadings due to its narrow underpasses.

So build wider underpasses. Or am I missing something?

 

[Bletchleyite]

Milton Keynes

Isn't a loser. Indeed may gain one train per hour (an extra classic line Birmingham) plus improved locals.

 

[Harpo]

Building platform extensions sounds simple but the existing ones have fiendishly complex pointwork and junctions laid right across the end of them, with the signalling arranged to match.

It ain’t going to be quick nor as cheap as bricks

 

[Nottingham59]

HS2 is an expansion of capacity across the industry.

At vast cost.

As far as I can see, the bits of HS2 that actually deliver increased capacity are:

1. More and longer platforms in the centres of our biggest cities (London, Birmingham, Manchester, Leeds)
2. More tracks from those city centres to the edge of the conurbation
3. Grade separation at critical junctions on the network

Just building those bits that deliver 1, 2, and 3 above would have provided most of the capacity uplift from HS2 at a small fraction of the eventual cost. This proposal addresses (1). Short segments of new line could have provided (2) and (3).

All the rest of HS2 including its unnecessary cuttings and green tunnels and novel viaduct design and 400kph design speed just add to the cost without adding capacity.

Building platform extensions sounds simple but the existing ones have fiendishly complex pointwork and junctions laid right across the end of them, with the signalling arranged to match.

It ain’t going to be quick nor as cheap as bricks

I'm sure it's not going to be cheap. Do you think my estimate of £50M per platform island is adequate? It seems an awful lot of money to me.

But it's a issue that needs addressing. They're going to have to extend platforms at Crewe and at least one other station on the northern WCML, or HS2 phase one will fail.

It would be a really good idea for the industry to demonstrate how to do that cheaply and with minimal disruption to the live railway.

 

[Stossgebet]

Except that HS2 as it currently is, can still be built to its original scope (and beyond) in future. Adding piecemeal new tracks for the current WCML service, does nothing for the MML and ECML.

 

[Nottingham59]

Except that HS2 as it currently is, can still be built to its original scope (and beyond) in future. Adding piecemeal new tracks for the current WCML service, does nothing for the MML and ECML.

Not if HS2 Euston is built with only six platforms and can only support ten departures per hour, which is the current plan.

And you can bet that Lendlease will make sure that every square inch of spare space that might conceivably be used for more platforms in future will end up being developed for housing instead.

 

[Harpo]

Do you think my estimate of £50M per platform island is adequate?

The cost would be holistic rather than per platform. Push any one platform across an existing crossover or junction and it’s wholesale remodelling of one or both ends at most places.

It would be a really good idea for the industry to demonstrate how to do that cheaply and with minimal disruption to the live railway.

Maybe three choices?
- Weekends only closures over a huge timeframe,
- Big bang closure like Crewe remodelling (6 weeks wasn’t it?)
- Capacity/speed reductions lasting years, the way that motorways get altered.

 

[SynthD]

Is it not possible to design a platform segment that can be simply lowered into place onto a precisely located narrow base in a single overnight possession?

Yes, once they have had many possessions to clear the area, build that narrow base. These segments will be a small portion of a platform, requiring many nights to lower them all in. There is much optimism in other areas too. Hs2 had a lower budget once, some of the growth was in finding that some tasks are more difficult than previously thought.

I would have far fewer >300m platforms. Rugby and Crewe need them for splitting and joining. Birmingham and Manchester need them for terminating. Long platforms will need to be wide and covered in their entirety, to make it bearable. I would build extra tracks from Rugby northwards, which branch off towards Leicester for MML relief. Once the trains are split, they can go many ways from Crewe (not Wales) without needing platform works at the following stops.

 

[The Ham]

Though to be fair most people who use Stockport don't live in Stockport and walk to the station, it is basically a South Manchester and North Cheshire Parkway, and if HS2 2B is built Manchester Airport station takes over that role.

(It is true that the two main losers from HS2 are Coventry and Stockport, though).

In what way is Coventry going to be loosing out? Maybe slightly slower trains to London due to a few extra stops being added in. However for others from Coventry that then means that they can more easily get to more places.

Likewise Stockport, the reduction in direct services to London could be an issue for some people. However, having fewer passengers who are only passing through (for example 100 people on a train who are traveling between Manchester and London who no longer are on those services) means that there's more capacity for people travelling now locally.

By only thinking about travel to London it highlights how stuck in the thinking of so many people that everything has to make things better for London or be focused on London.

Stoke on Trent, Wolverhampton, Milton Keynes and Liverpool are also likely to be losers to some extent. The time taken to split / combine trains at Crewe - probably around 10 minutes - will partially cancel benefits of higher speed running on HS2.

A simpler (and chesper) way - for a lesser boost in WCML capacity would have been to make all Pendolinos 11 coaches - with only 2 first class coaches. (11 coaches is the maximum that could fit into Liverpool Lime Street)

Again, many of those places only lose out of you are only focusing on the to/from London travel aspects.

I don't know if it still exists, but there used to be a service at Guildford which split to serve Portsmouth and Haslemere, I'm fairly sure that the second service left the platform in under 8 minutes after the first.

However, it's not unreasonable to have 4 minutes to split a service (2 minutes for people to job/leave the train 1 minute for the split and a further 1 minutes for people to join/leave the train) with then the second train leaving 3 minutes after the first. If the train arrives late it's possible to split the train as soon as it arrives (say, 45 seconds - although I've seen it done faster than that) and then depart the first train fairly promptly after that (say 105 seconds) and so recover some time (using the above timings that's 90 second recovered).

The extra capacity by lengthening the existing services to 11 coaches is limited, as the split in the fleet is 22*9 and 35*11.

Also, the 390's have (after refurbishment) two full first class coaches and a further part coach (end coach) of first class. Assuming that we're talking about splitting off 1/3 of a full coach so there's exactly 2 coaches worth of first class seating that change may add up to 10 seats (which when the refurbished sets have 607 seats isn't a significant uplift for quite a lot of extra cost, as you'd have to add in an extra door, which may well mean the loss of the extra row of seats is assumed that you could have squeezed in, which case the increase is only 6).

 

[MarkyT]

The cost would be holistic rather than per platform. Push any one platform across an existing crossover or junction and it’s wholesale remodelling of one or both ends at most places.

While ~400m is likely possible for some platforms at Crewe, Preston, Carlisle, any more than that would be very difficult. Junctions can't necessarily just move if they're constrained by tunnels, bridges or other trackside development. The OPs consideration of Stockport Viaduct is an example.

Another concern at through stations is signalling overlaps. Best practice is to provide a fully clear plain track overlap beyond the platform starting signal appropriate for the approach speed before any pointwork. On platform loops with a 40/50mph entry speed, about 100m should suffice as an emergency overrun before any conflicting movement could be encountered if the approaching train passes the signal at danger. If the platform is on a fast line then a default 220m overlap applies. Where a clear plain line overlap isn't provided, an approaching movement's overlap locking will penetrate the throat junction at the other end of the station, possibly preventing some other simultaneous movements until the train has arrived and timed out on the berth track. ETCS doesn't solve this fully either. While a no or very limited overlap scenario can be catered for, this comes at the cost of a more restricted approach speed envelope. Where a full overlap is provided, a speedier approach can be made, with the safety benefit of the overlap allowing a higher release speed. Colour light signalling has a similar trick with alternative warning class routes able to be selected by the signaller, at the cost of a delayed yellow at the entry signal.

 

[Grimsby town]

Yes probably true. But they're also quite attached to their 3tph express service to London.

What makes this interesting it that this is a live issue. When HS2 Phase One opens to Handsacre, we're going to have two or three HS2 trains per hour heading to Piccadilly. At the moment they will be 200m long with fewer seats than an 11-car Pendolino. There will be extreme pressure to lengthen these HS2 trains to 400m, or find more paths.

Platforms at Piccadilly could be lengthened to 400m relatively easily. What's going to happen at Stockport? My guess is that Stockport will get 2tph 400m HS2 passing through without stopping, and 1tph WCML Pendolino calling at Stockport. And if the HS2 Phase Two tunnel ever gets built, Stockport loses its express London service completely.

I don't think 400 metre platforms are going to be built at Piccadilly. Yes its cheaper but it's still likely to be a couple of £billion scheme. The problem is it provides very few of the benefits compared to Phase 2b. It'll provide the crowding reduction benefits on London trains but does nothing to:

• Release train paths on the classic line
• Improve Manchester to Liverpool or Manchester to Birmingham
• Provide speed benefits for London services
• Provide improved reliability

Which is even more reason to make Wilmslow the main station for London from South Manchester. There seems to be plenty or undeveloped woodland to the north of the river Bollin to extend platforms northwards and add car parks and station access.

View attachment 172623

Far far cheaper than digging a 15km tunnel under Manchester and a four platform underground station at Manchester Airport.

The problem with that alignment at Wilmslow is that you're building into viaducts. Building platforms raised 5 metres+ above the ground is going to be very expensive.

Yes. In the Stockport example above and at Glasgow and Wilmslow, I could see scope for a secondary station entrance on the other side of the river, where it would be much easier to build very large car parks.


So build wider underpasses. Or am I missing something?

Yes you could build a wider underpass but that would start to increase the cost significantly. You'd be looking at scheme more akin to the Oxford Station upgrade which is costing £160 million. As others have said you'll have to realign track and change signalling but you also have to make the station and surrounding onward travel infrastructure capable of handling additonal footfall. For reference extending platform 17 at Leeds with improved lifts is costed at £24 million. That's one short platform.

Even then you're likely still providing a station environment that's not anywhere near HS2s with its 6 metre wide platforms and significant onward transport infrastructure. This is why a project like this has never been considered?, the BCR would be awful.