My idea for Double Decker stock

[Bald Rick]

The Crossrail name came about sometime around 1990, which is when the earliest plans for the current Crossrail date from.

Well yes, that was from central London Rail study of the late 80s. Which didnt include a branch to Canary Wharf and Abbey Wood. But I have a map from the 30s somewhere showing a proposed Line from Paddington to Liv St with stations at Bond Sr, Tottenham Ct Road and so on.

 

[Manchester77]

Quite I seem to remember CrossRail was an option for what to build in the 50s, although they chose 'route C' aka. the Victoria Line!

 

[edwin_m]

Classic compatible - single deck.
Captive - double deck.

Evidence?

My understanding is that both train types are assumed to have the same capacity.

 

[Peter Mugridge]

Ironically enough I was flicking through a french railway magazine the other week, and they referred to Crossrail as 'le RER de Londres'

I like to refer to HS1 as the LGV Angleterre...

 

[Eagle]

I like to refer to HS1 as the LGV Angleterre...

Well from a French point of view it's the last 100 km of LGV Nord (with the Belgian HSL1 being a branch off it).

 

[Peter Mugridge]

That's exactly why I call it LGV Angleterre, after all there is the LGV Sud Est, LGV Atlantique, LGV Nord, the LGV Belge, etc, so why not...?

 

[Peter Sarf]

That's exactly why I call it LGV Angleterre, after all there is the LGV Sud Est, LGV Atlantique, LGV Nord, the LGV Belge, etc, so why not...?

No no no no you have got it all wrong.

Its HS1 Paris, HS1 Atlanique branch, HS1 Mediterranean branch etc etc.




Oh er oh perhaps its LGV never mind the nimbys.

 

[Eagle]

Nah, it's all HS2 (Foreign Spur).

 

[Peter Sarf]

Nah, it's all HS2 (Foreign Spur).

Ah yes, of course. All made to some quirky non-standard gauge that is too big for any rolling stock envisaged beyond the forseable future :roll:.

This Marstons Strong Pale Ale is damn nice.

 

[HSTEd]

I'm not aware of that. Unless you mean larger than LU gauge, which is obvious.

In fact if the Moorgate crash taught us anything, it's that tube tunnels should be as small a gauge as possible to fit the stock that's running.

Apparently it will fit double decker trains through the tunnel with some relatively minor work to move cables around in the tunnels.

Why the cables aren't in the larger gauge position to start with is another question.

 

[jopsuk]

In fact if the Moorgate crash taught us anything, it's that tube tunnels should be as small a gauge as possible to fit the stock that's running.

A Moorgate-type crash is obviously simply not possible in Crossrail, what with there being no end-walls in the tunnels.

 

[swt_passenger]

Apparently it will fit double decker trains through the tunnel with some relatively minor work to move cables around in the tunnels.

Why the cables aren't in the larger gauge position to start with is another question.

'Can fit' is almost certainly academic, I suggest it will never happen. But saying it removes a line of criticism.

Firstly they obviously don't ever intend to use double decker trains over a 35-40 year life of the initial stock. Even afterwards no-one will seriously expect the gauge will ever be altered outside the core section, for instance into Heathrow, or out to Shenfield, Maidenhead (or Reading). Lastly, the Victoria tunnel under the docks would have to be fully rebuilt or it would seriously prevent DD trains on the Kent leg.

 

[starrymarkb]

Isn't all new build infrastructure built to allow UIC gauge (at least in terms of height/width) so Crossrail's UIC tunnels would take double deck stock)

 

[HSTEd]

'Can fit' is almost certainly academic, I suggest it will never happen. But saying it removes a line of criticism.

Firstly they obviously don't ever intend to use double decker trains over a 35-40 year life of the initial stock. Even afterwards no-one will seriously expect the gauge will ever be altered outside the core section, for instance into Heathrow, or out to Shenfield, Maidenhead (or Reading). Lastly, the Victoria tunnel under the docks would have to be fully rebuilt or it would seriously prevent DD trains on the Kent leg.

Well that assumes that Crossrail's core tunnels will always connect to the wider system as they do now.
Increasing demand does not make it impossible to imagine further tunnel construction will take place in the future to fully segregate Crossrail from the wider network, certainly on the decade length timescale.

 

[Loki]

'Can fit' is almost certainly academic, I suggest it will never happen. But saying it removes a line of criticism.

Firstly they obviously don't ever intend to use double decker trains over a 35-40 year life of the initial stock. Even afterwards no-one will seriously expect the gauge will ever be altered outside the core section, for instance into Heathrow, or out to Shenfield, Maidenhead (or Reading). Lastly, the Victoria tunnel under the docks would have to be fully rebuilt or it would seriously prevent DD trains on the Kent leg.

I doubt they drilled larger tunnels just to shut the critics.

 

[swt_passenger]

I doubt they drilled larger tunnels just to shut the critics.

The tunnels are sized to what you get if you allow for normal mainline stock with electrification, a circular cross section, a continuous emergency walkway and a maintenance walkway.

That just happens to allow for a certain type of DD stock to be squeezed in. But they are not actually full scale UIC GB+ or GC tunnels.

--- old post above --- --- new post below ---

Isn't all new build infrastructure built to allow UIC gauge (at least in terms of height/width) so Crossrail's UIC tunnels would take double deck stock)

New build infrastructure in GB is usually W12 with electrification clearances AFAIK. I doubt they'll 'overengineer' any bridges or tunnels unless it can be done at the same cost as not doing so.

 

[asylumxl]

I'm not aware of that. Unless you mean larger than LU gauge, which is obvious.

In fact if the Moorgate crash taught us anything, it's that tube tunnels should be as small a gauge as possible to fit the stock that's running.

Actually, if the King's Cross fire taught us anything, it's that tube tunnels should be larger than the stock to reduce pressure waves thus reducing the "piston" effect.

A nice side-effect of this is the reduction of the ear popping sensation when entering a tunnel. This is why the German high speed lines have considerably oversized tunnels.

 

[Bald Rick]

Isn't all new build infrastructure built to allow UIC gauge (at least in terms of height/width) so Crossrail's UIC tunnels would take double deck stock)

Nope. There's plenty of existing stock that won't be able to get down the new Canal Tunnels between the ECML and St Pancras. But then it wouldn't be able to fit through the rest of the TL core either.

 

[DXMachina]

Actually, if the King's Cross fire taught us anything, it's that tube tunnels should be larger than the stock to reduce pressure waves thus reducing the "piston" effect.

I recently saw a documentary about the KX Fire. It proved fairly conclusively that the piston effect would have had barely a fractional influence on the fire - the main cause of the conflagration on the escalator was a mix of accelerants already present and the design of the station, which purely by chance was absolutely optimal for feeding oxygen to fuel a fire at 600 centigrade in that stairwell.

 

[asylumxl]

I recently saw a documentary about the KX Fire. It proved fairly conclusively that the piston effect would have had barely a fractional influence on the fire - the main cause of the conflagration on the escalator was a mix of accelerants already present and the design of the station, which purely by chance was absolutely optimal for feeding oxygen to fuel a fire at 600 centigrade in that stairwell.

If it's the one I think it is, it is quite old now. But the piston effect does exist, even if it did not have a major effect on the fire in question.

Good practice is to use larger tunnels to reduce pressure waves, particualrly on high speed lines. Simples.

 

[DownSouth]

Good practice is to use larger tunnels to reduce pressure waves, particualrly on high speed lines. Simples.

Especially if used in conjunction with cross-passages between paired single track tunnels, allowing the piston effect to be reduced by spreading it out through cross-passages and being countered by the trains travelling in the opposite direction in the other tunnel.

Larger tunnels and cross-passages also allow for better fire containment and evacuation procedures, and a reduced reliance on vehicles having end doors where otherwise unnecessary.

 

[asylumxl]

Especially if used in conjunction with cross-passages between paired single track tunnels, allowing the piston effect to be reduced by spreading it out through cross-passages and being countered by the trains travelling in the opposite direction in the other tunnel.

Larger tunnels and cross-passages also allow for better fire containment and evacuation procedures, and a reduced reliance on vehicles having end doors where otherwise unnecessary.

Indeed. I believe the Channel Tunnel has cross passages in addition to it's several (rather large) ventilation shafts.

 

[jopsuk]

yes, the channel tunnel has cross passages that go over the service tunnel purely for pressure relief