Exploiting the safeguarded route for Crossrail 2 to also carry Crossrail 3

[Nottingham59]

Another crayon question for you. The safeguarded route for Crossrail 2 is shown on this map:

ArcGIS Web Application

cr2.maps.arcgis.com

Looking at the section in central London (Clapham Junction-Victoria-Euston), could this corridor be built as 4-track railway? Either as two big tunnels, each carrying two tracks, like the Barcelona metro, or one pair of tunnels below the CR2 pair? Would there be space to do that?

If so, then in addition to Crossrail 2, this route could connect the WCML slows to the slow lines from East Croydon to Victoria, giving a Crossrail 3 from Watford Junction to South London, and relieving both Euston and Victoria, which are the two biggest London termini that haven't had the Crossrail treatment yet.

How many platforms at Euston would that release?

 

[Sad Sprinter]

I don't think there are many services at Euston that can be Crossrailed. Part from the DC routes which wouldn't save much space. If you really wanted to Crossrail the West Coast I think you can just do that with the Lizzie.

Others will be around to probably tell you there's not enough space on the CR2 alignment to add in another pair of tracks. Finding a path for Crossrail 3 will be difficult at best and I'm not sure where it can go given there's so much spaced used up under London already. My natural inclination would say it should serve the South Eastern lines, or "Kent Link" if you've just stepped out of a time machine from 1989, but there's no space in SE London where you can put a portal and no suitable route in North West London you can Crossrail.

 

[PTR 444]

but there's no space in SE London where you can put a portal and no suitable route in North West London you can Crossrail.

What about the Chiltern suburban services?

 

[Basil Jet]

Another crayon question for you. The safeguarded route for Crossrail 2 is shown on this map:

ArcGIS Web Application

cr2.maps.arcgis.com

Looking at the section in central London (Clapham Junction-Victoria-Euston), could this corridor be built as 4-track railway? Either as two big tunnels, each carrying two tracks, like the Barcelona metro, or one pair of tunnels below the CR2 pair? Would there be space to do that?

If so, then in addition to Crossrail 2, this route could connect the WCML slows to the slow lines from East Croydon to Victoria, giving a Crossrail 3 from Watford Junction to South London, and relieving both Euston and Victoria, which are the two biggest London termini that haven't had the Crossrail treatment yet.

How many platforms at Euston would that release?

When the Chelsea Hackney Line was planned to be tube gauge, it was planned to have platforms at Piccadilly Circus. When the plan was changed to be mainline gauge, the platforms at Piccadilly Circus were removed from the plan specifically because there was not enough room for platform tunnels around a mainline gauge tunnel. So I think it is impossible that there could be room for a stacked pair of pairs, or for 4 side by side.

 

[SynthD]

The problem would then become passenger throughput at each station, especially emergency exit. I don’t think there should be more than two crossrails (including thameslink as XR0) at any one station.

Chiltern is two track only, so no. DC lines would only work if you removed shared running with the Bakerloo.

 

[HSTEd]

The problem would then become passenger throughput at each station, especially emergency exit. I don’t think there should be more than two crossrails (including thameslink as XR0) at any one station.

The Chatelet Les Halles complex supports two and a half RER lines and five metro lines. With the RER A achieving passenger densities far beyond Crossrail or Thameslink.

WIth sufficient engineering I think there is no limit to how much you would force through.

Chiltern is two track only, so no. DC lines would only work if you removed shared running with the Bakerloo.

Why would two-track matter?
Thameslink goes to Cambridge and Brighton, why can't you take over the entire Chiltern Main Line?

 

[The Planner]

I dont understand the goal of releasing platforms at Euston. What are you going to use them for if the slow lines are still being used on the approach for CR3?

 

[SynthD]

The Chatelet Les Halles complex supports two and a half RER lines and five metro lines. With the RER A achieving passenger densities far beyond Crossrail or Thameslink.

WIth sufficient engineering I think there is no limit to how much you would force through.

Why would two-track matter?
Thameslink goes to Cambridge and Brighton, why can't you take over the entire Chiltern Main Line?

The safeguarded route includes the sites that will be redeveloped as stations, as extra exits to the existing station. Did each RER add capacity to Halles or was it designed with the present in mind?

Thameslink stays on the slows on both those lines.

 

[HSTEd]

The safeguarded route includes the sites that will be redeveloped as stations, as extra exits to the existing station. Did each RER add capacity to Halles or was it designed with the present in mind?

The RER section was built as a single project, however the Metro stations obviously existed before that.

Thameslink stays on the slows on both those lines.

Yes, but those lines both have major longer-distance traffic functionality.
On the Chiltern there isn't really a destination beyond Birmingham, and even there through traffic will be deemphasised compared to HS2 etc.

Could just hand the entire service over, lock stock and barrel.

 

[Bald Rick]

Looking at the section in central London (Clapham Junction-Victoria-Euston), could this corridor be built as 4-track railway? Either as two big tunnels, each carrying two tracks, like the Barcelona metro, or one pair of tunnels below the CR2 pair? Would there be space to do that?

In a word, no.

1) the alignment of the tunnels is rather intricate, horizontally and vertically. Whilst the safeguarding allows for some tolerance and variation, it would not be sufficient for two much bigger tunnels, especially at the stations. Bigger tunnels would need bigger separation, often outside the safeguarded area.

2) having a doubled up ‘Crossrail’ means having stations round twice as large to deal with passenger throughout. This means twice as much vertical circulation (lifts and escalators), twice as big gate lines, more passageways, emergency access, ‘back of house’ etc. This could not be accommodated within the existing safeguarded area, and in most places could not be accommodated without much more demolition above. Euston itself would be a particular problem where there is only one place the station can go (and that doesn’t point towards the WCML). I’m not sure Tottenham Court Road would be able to cope either.

3) from a transport planning point of view, having two high capacity railways literally on top of each other across London would offer a poor spread connectivity for the London economy.

4) building it would take longer (it’s bigger and more concentrated) and it would place further pressure on the central London road network during construction. (This is a major consideration in planning big works like this).

 

[MPW]

I would also disagree with idea of doubling up for the above mentioned capacity reasons but also to provide greater connectivity. A theoretical CR3 would be best connecting to CR1 at a different station to its CR2 connection, creating a triangle connection to better distribute passengers.

It would require undoing some expensive infrastructure but I really feel the thameslink core should be used for local services, with long distance trains being rerouted to terminate north and south of river. For example the greenwich SE branch is surrounded by 'opportunity areas' and residents who live in SE London are more likely to travel to north/NW London (to visit family etc) than someone from Brighton, who is more likely travelling to Central London for work or theatre. The southern metro through forest Hill is also overcrowded with many preferring Canada water connection to LB schlepping to the tube. Thameslink would provide more direct connections and bigger trains than overground.

 

[Sad Sprinter]

I would also disagree with idea of doubling up for the above mentioned capacity reasons but also to provide greater connectivity. A theoretical CR3 would be best connecting to CR1 at a different station to its CR2 connection, creating a triangle connection to better distribute passengers.

It would require undoing some expensive infrastructure but I really feel the thameslink core should be used for local services, with long distance trains being rerouted to terminate north and south of river. For example the greenwich SE branch is surrounded by 'opportunity areas' and residents who live in SE London are more likely to travel to north/NW London (to visit family etc) than someone from Brighton, who is more likely travelling to Central London for work or theatre. The southern metro through forest Hill is also overcrowded with many preferring Canada water connection to LB schlepping to the tube. Thameslink would provide more direct connections and bigger trains than overground.

RAIL Magazine predicted this would happen in 2018

 

[MPW]

RAIL Magazine predicted this would happen in 2018

Can you share the article please?

 

[Nottingham59]

In a word, no.

1) the alignment of the tunnels is rather intricate, horizontally and vertically. Whilst the safeguarding allows for some tolerance and variation, it would not be sufficient for two much bigger tunnels, especially at the stations. Bigger tunnels would need bigger separation,

Thank you. That's very helpful. I knew there was little space down there, but didn't appreciate just how little.

I dont understand the goal of releasing platforms at Euston. What are you going to use them for if the slow lines are still being used on the approach for CR3?

The question was just idle curiosity on my part, wondering how HS2 could have been designed to be wasteful of space in Central London.

[Post HS2, the classic lines out of Euston are proposed to carry 25tph in the peak hour, on six tracks. Putting all of the Slow Line and all DC Line traffic (around 12tph) onto CR3 platforms below ground would have released around 8 platforms in the main shed. These could have been used by 200m HS2 trains without the need for a new HS2 station at Euston.]

 

[mike57]

The Chatelet Les Halles complex supports two and a half RER lines and five metro lines. With the RER A achieving passenger densities far beyond Crossrail or Thameslink.

We visited it last year while on holiday, and its a destination in its own right, with a multi-level shopping centre as well as the RER and Metro stations. The scale is however beyond anything which would be built in Central London. Because of its scale some of the interchanges are to put it bluntly a pain, but it is impressive.

I have attached a couple of pictures taken last year which give some isea of the scale of Chatlet-Les-Halles

 

[The Planner]

Thank you. That's very helpful. I knew there was little space down there, but didn't appreciate just how little.

The question was just idle curiosity on my part, wondering how HS2 could have been designed to be wasteful of space in Central London.

[Post HS2, the classic lines out of Euston are proposed to carry 25tph in the peak hour, on six tracks. Putting all of the Slow Line and all DC Line traffic (around 12tph) onto CR3 platforms below ground would have released around 8 platforms in the main shed. These could have been used by 200m HS2 trains without the need for a new HS2 station at Euston.]

No way it would be 8. The DC lines tend to just use P9.