Double-Deck trains in UK

[NCT]

Maybe, but I understand the order book is pretty full for TGV-Ms, so if Eurostar don't take up the option for a couple of years, it could be a long wait to see HS1 from the top deck

I suspect production will be queued such that the 373 replacements will be after 2031 - so quite a while to wait.

 

[YorksLad12]

There is some scepticism that this order will lead to double deck trains through the Tunnel - Eurostar need to replace the Thalys sets, and 30 is only really enough to do that. Jon Worth has the figures plus some extra detail about concerns about Tunnel evacuation rules: https://jonworth.eu/eurostar-ordering-just-30-alstom-trains-pragmatism-and-a-lack-of-ambition/

The question really is, was HS1 built to allow proper double-height trains? I'm guessing so (hence the order) but the last double-decked trains were really 1.5 height, not double.

 

[zwk500]

I'm really glad to hear the UK is getting double decker trains on it's only Continental gauge line- it should be a great experience going on HS1 on the top deck of a train.
Who knows if the second best prospect for British double deck trains- HS2- will ever see them, although I hope it does if the Manchester branch ever gets finished.

The issue is whether HS2 is being built to a suitable platform profile, which IIRC it isn't.

(presunably third best is some sort of gauge clearance in Kent, allowing some of the HS1 domestic trains to be double decker.)

Height and platforms will be the issue with this. To get a sufficiently wide lower deck the platforms would be far too far back from a standard UK gauge train.

The question really is, was HS1 built to allow proper double-height trains? I'm guessing so (hence the order) but the last double-decked trains were really 1.5 height, not double.

Yes. It's build to full UIC-GC clearance expect for the bit through Ashford (Cleared to UIC-GB+) and any domestic platforms (built to UK profile). HS1 could only run Double-deck trains between the international platforms though, unless somebody designs one with a lower deck of reduced width for St Pancras - Ashford shuttles.

For reference, here is a UK-Gauge Class 373 at St Pancras, note the difference in height from the carriage floor and the extra step needed between the carriage body and the platform.

https://www.elle.fr/People/La-vie-des-people/News/La-reine-Elizabeth-II-debarque-en-France-avec-Kate-Middleton-et-le-prince-William-2710772

[image showing class 373 at St Pancras with HM the queen walking toward the camera along the platform]

 

[quantinghome]

The question really is, was HS1 built to allow proper double-height trains? I'm guessing so (hence the order) but the last double-decked trains were really 1.5 height, not double.

Yes, the trains they have ordered are Avelia Horizons which are the new generation double deckers also being built for SNCF.

 

[LLivery]

There is some scepticism that this order will lead to double deck trains through the Tunnel - Eurostar need to replace the Thalys sets, and 30 is only really enough to do that. Jon Worth has the figures plus some extra detail about concerns about Tunnel evacuation rules: https://jonworth.eu/eurostar-ordering-just-30-alstom-trains-pragmatism-and-a-lack-of-ambition/

Jon Worth was questioning whether it'd be possible to even use them on HS1 not long ago.

Eurostar plan to maintain the fleet at Temple Mills. I'd imagine they've done their homework enough to know whether they can base an entire fleet at a depot or not.

 

[zwk500]

Eurostar plan to maintain the fleet at Temple Mills. I'd imagine they've done their homework enough to know whether they can base an entire fleet at a depot or not.

See this thread:

Proposed new Channel Tunnel services discussion

If you were doing touristy things in Kent, you are probably driving there. There's a small market in people who don't want to drive on the other side of the road but might go to Canterbury Cathedral or Dover Castle, but this is going to be pretty low level. Or you take a coach tour. Canterbury...

www.railforums.co.uk

 

[JamesT]

The issue is whether HS2 is being built to a suitable platform profile, which IIRC it isn't.

Although you couldn't just take the Alstom double deckers and use them on HS2 as it would have 1100mm platforms instead of the 550mm or 760mm ones in Europe, I don't see it's necessarily a barrier to having double deck trains on HS2. If your entrance was at 1100mm then you'll have shorter stairs to the top deck and longer ones to the bottom. The accessible carriage probably remains as single-deck to avoid massive ramps internally.
The larger barrier would be with the cutbacks to HS2, there won't be enough captive services to make it worth ordering a microfleet of European gauge trains.

 

[LLivery]

See this thread:

Proposed new Channel Tunnel services discussion

If you were doing touristy things in Kent, you are probably driving there. There's a small market in people who don't want to drive on the other side of the road but might go to Canterbury Cathedral or Dover Castle, but this is going to be pretty low level. Or you take a coach tour. Canterbury...

www.railforums.co.uk

While I do feel a bit of scepticism myself, it would be quite a way to pee off a regulator by doing something so brazenly dodgy.

Edit: But it's one thing to say 'we'll maintain the entire fleet there' and not be able to do that in full, it's another not being able to get ANY there in the first place.

 

[zwk500]

Although you couldn't just take the Alstom double deckers and use them on HS2 as it would have 1100mm platforms instead of the 550mm or 760mm ones in Europe, I don't see it's necessarily a barrier to having double deck trains on HS2. If your entrance was at 1100mm then you'll have shorter stairs to the top deck and longer ones to the bottom. The accessible carriage probably remains as single-deck to avoid massive ramps internally.
The larger barrier would be with the cutbacks to HS2, there won't be enough captive services to make it worth ordering a microfleet of European gauge trains.

The issue is whether the platforms are sufficiently far from the rail. If they're the standard UK distance from the rail, the lower deck will be very narrow. It would be possible to design such a train (using a 1+1 or 2+1 lower deck layout), but a bespoke minidesign for London-Birmingham-Manchester shuttles would have questionable economic case.

== Doublepost prevention - post automatically merged: 22 Oct 2025 ==

While I do feel a bit of scepticism myself, it would be quite a way to pee off a regulator by doing something so brazenly dodgy.

Edit: But it's one thing to say 'we'll maintain the entire fleet there' and not be able to do that in full, it's another not being able to get ANY there in the first place.

I don't know fully what's in E*'s mind, but it would be very possible to say 'well we're planning to base them there _eventually_'

 

[Bletchleyite]

Although you couldn't just take the Alstom double deckers and use them on HS2 as it would have 1100mm platforms instead of the 550mm or 760mm ones in Europe, I don't see it's necessarily a barrier to having double deck trains on HS2. If your entrance was at 1100mm then you'll have shorter stairs to the top deck and longer ones to the bottom. The accessible carriage probably remains as single-deck to avoid massive ramps internally.
The larger barrier would be with the cutbacks to HS2, there won't be enough captive services to make it worth ordering a microfleet of European gauge trains.

HS2 absolutely could use double deckers provided they were designed for 1100mm platforms as you say. Problem is that you could only use them for captive services on the "Aston-Acton" - it'll be a long time, if ever, before they are suitable for other services, and I'm not convinced the demand on that route can't just be met by 400m formations of the single deck classic compatible stock, while a micro fleet would be a pain.

 

[JamesT]

The issue is whether the platforms are sufficiently far from the rail. If they're the standard UK distance from the rail, the lower deck will be very narrow. It would be possible to design such a train (using a 1+1 or 2+1 lower deck layout), but a bespoke minidesign for London-Birmingham-Manchester shuttles would have questionable economic case.

The newly built HS2 platforms are supposed to be at European width. Part of the plan was that there could be a second rolling stock order of 'standard' European trains to run services solely on HS2 and this would be cheaper than the trains that have to fit on the legacy UK network.

 

[YorksLad12]

The BBC News Online story says:

They will be 4.33metres high, just 16cm higher than the E320 models currently in use.

Is that good or bad? If they'd said that a London bus was about 4.4m tall, that might have helped... I suppose one good thing about this is that it should release class 374/e320 stock to be used on the Ashford-Lille shuttle we talked about in the other thread

(Actually, amazed that no-one has yet asked what the class number will be...)

 

[43096]

Maybe, but I understand the order book is pretty full for TGV-Ms, so if Eurostar don't take up the option for a couple of years, it could be a long wait to see HS1 from the top deck

The full TGV-M order book is for SNCF. Eurostar is a SNCF business and these trains are from the overall SNCF contract - so SNCF Group will decide what takes priority.

 

[NCT]

Double decker trains are only exciting to a child that's never been on one. In the case of 'this child' - in his early thirties - it took just one journey on a TGV duplex go to from 'ZOMG so excite!' to 'hmm this doesn't quite work'.

The TGV Duplex model only really works with platform heights no greater than 550mm. Eurostar operates principally in 760mm land (Britain, Belgium, Netherland and Germany) and there'll be a lot of fun going down from the platform (while avoiding banging your head) only to go all the way back up with all your luggage (the majority of the passenger accommodation is on the upper deck).

Overhead luggage racks on these are next to useless. Anything from a chunky backpack upwards will have to go to into the standing luggage racks, whereas on a single deck train cabin-sized suitcases and rucksacks go in the rack no problem leaving only the largest suitcases needing to go in the standing racks.

The Avelia Horizon will be compliant in the Netherlands - active suspension will raise the floor of the accessible carriage to bring the step down from the platform to within standards. For the majority of passengers however the annoyances still remain.

The accessibility problems with Alstom’s new TGV-M train – with implications for future Channel Tunnel operators

There is no way to sweeten this: my original conclusion that Alstom's Avelia Horizon (known as TGV-M with SNCF) is not legal at higher station platforms outside France was incorrect. Because transparency and correcting my errors matters to me, you can read the original blog entry in full here -...

crossborderrail.trainsforeurope.eu

The central point: the Avelia Horizon train is not ideal from an accessibility point of view, but is legal.

 

[zwk500]

The newly built HS2 platforms are supposed to be at European width. Part of the plan was that there could be a second rolling stock order of 'standard' European trains to run services solely on HS2 and this would be cheaper than the trains that have to fit on the legacy UK network.

So are gap fillers planned for the platforms or the trains for non-captive rolling stocK?

 

[NCT]

So are gap fillers planned for the platforms or the trains for non-captive rolling stocK?

Classic compatible trains will have extendable steps just like the Class 373.

 

[Zomboid]

They make reasonable sense once you get to American proportions. Though I'm not sure they necessarily get everything possible out of the concept, running trains of 2-3 bilevels. (Though they are the standard commuter rail stock over there so I guess it's off the shelf for those purposes, rather than a bespoke single level design).

 

[Sorcerer]

Even capacity gains as modest as 20% would effectively add an extra coach per 5. Now, what's wrong with that?

By itself there isn't anything wrong with it in the context of Eurostar's order where long dwell times are the norm. But for most services the extra capacity in every train is offset by the increased dwell times along with extra weight that would reduce acceleration which would mean you'd inevitably end up with increased gaps in the timetable which reduce overall route capacity. Double-decker trains have their niche with services like Eurostar like we've seen today, but in most cases they aren't a huge net gain relative to the expenditure and passenger experience.

 

[NCT]

Even the extra capacity could be debated. From my very rough guesstimates, a 16-car fixed formation (i.e. without 2 driving cars in the middle) ETR1000 without executive seats would seat about 950. A double Avelia Horizon with honest luggage rack provision and door widths would also seat about 950. There might a a couple of dozens of seats in it.

 

[birchesgreen]

(Actually, amazed that no-one has yet asked what the class number will be...)

An interesting question. Logically next in the sequence would be 375 but that is already used of course.

Maybe an 8xx class number.

 

[Sorcerer]

Maybe an 8xx class number.

If recent trends are anything to go by, then I'd wager on the new stock being TOPS designated as the Class 873.

 

[30907]

Though if these trains are to replace the Thalys sets, why would they be maintained at Temple Mills?

I am not the only one, apparently, with a suspicious mind that thinks this is a blocking move.

It might just be that the existing depots cannot be adapted and there is nowhere suitable near Paris, Lille or Brussels, but.....

 

[MarkyT]

Although you couldn't just take the Alstom double deckers and use them on HS2 as it would have 1100mm platforms instead of the 550mm or 760mm ones in Europe, I don't see it's necessarily a barrier to having double deck trains on HS2. If your entrance was at 1100mm then you'll have shorter stairs to the top deck and longer ones to the bottom. The accessible carriage probably remains as single-deck to avoid massive ramps internally.
The larger barrier would be with the cutbacks to HS2, there won't be enough captive services to make it worth ordering a microfleet of European gauge trains.

From this video:

Here's the standard door lobby with steps down to the lower seating area and stairway to the left to the upper level. Note there is no through gangway at the lower level. The toilet and stairwell block access at the door end and there is a blank bulkhead at the opposite end of the lower saloon.

Note how the level walkway well of the upper deck drops between the entrance doors along the centre line of the car, with the steps to lower saloon descending clear of it. The entrance height is a little higher than the French 550mm standard platform height, sufficient to be compliant with EU maximum vertical step requirements at 760mm platfrom while not achieving easy level boarding anywhere, except on the special accessible coach, which as NCT explains, has active suspension, which can also change the door height to more perfectly match 550mm platforms for unassisted wheelchair use and a turntable lift in the lobby to access the lower deck.

So another new train design kicking the level boarding can down the line for another generation, though I can see its a difficult area of design with operators wanting to be able to run all over Europe with its varying platform heights. While their new Avril design has other issues and problems, at least Talgo defined the gold standard on this matter with fully level 760mm boarding at all passenger doors and a level train floor throughout. That potentially limits the range of their trains, though the company also claim to be able to create similar 550mm variants, with their special split axle running gear allowing a low walkway to pass between the wheels. It seems very difficult to design a train with level boarding that can do both standard platform heights effectively and legally. Stadler has managed the best compromise so far in their 'Smile' with multiple doors at each height throughout, at a cost of internal ramps and of course is only a single deck train.

I considered the Eurostar/Thalys service group and all its routes and stations would be good candidates to become a fully 760mm platform railway in the shift to LB, seeing as Belgium, North Germany, the Netherlands, and UK international platfroms on HS1 already follow that standard.

 

[Bletchleyite]

To be fair, there's usually a height difference between the platform and the door on level boarding stock. The Merseyrail units for instance are designed for a 915mm platform height but have a 960mm entrance, so what you get is about a 2.25cm step up onto the automatic step then about another 2.25cm step into the train. This is generally OK for a wheelchair to manage. The latter isn't avoidable as you can't have a step completely flush with the train floor - the only way to have perfectly same-level access is not to have a moving step, but then you potentially have a gap on curved platforms as per the London Underground S-stock.

 

[MarkyT]

To be fair, there's usually a height difference between the platform and the door on level boarding stock. The Merseyrail units for instance are designed for a 915mm platform height but have a 960mm entrance, so what you get is about a 2.25cm step up onto the automatic step then about another 2.25cm step into the train. This is generally OK for a wheelchair to manage. The latter isn't avoidable as you can't have a step completely flush with the train floor - the only way to have perfectly same-level access is not to have a moving step, but then you potentially have a gap on curved platforms as per the London Underground S-stock.

On TGV-M from a 550mm platform, it will be a 67mm step up in total to the train floor of 617mm, so a little more, but the important matter for legal international operation is the drop from a 760mm platform is under 160mm, in this case at 143mm. I guess the additional 17mm covers for normal wheel diameter and suspension variations.

 

[YorksLad12]

If recent trends are anything to go by, then I'd wager on the new stock being TOPS designated as the Class 873.

I was thinking 875, as we've had 373 and 374. The proposed Northern fleet does something similar; the last two digits progress sequentially.

Mind you, having seen @MarkyT's video, I hope it fails the safety case. In this day and age we should be able to line seats up with windows.

 

[ShadowKnight]

An interesting question. Logically next in the sequence would be 375 but that is already used of course.

Maybe an 8xx class number.

Could go backwards to 372/371?

 

[MotCO]

Could go backwards to 372/371?

Do Eurostars have 'dual-numbering'? i.e. a British and a French or Belgium numbering system? If so, presumably they need a numbering sequence which is spare in all countries.

 

[zwk500]

Do Eurostars have 'dual-numbering'? i.e. a British and a French or Belgium numbering system? If so, presumably they need a numbering sequence which is spare in all countries.

Eurostars (like all British rolling stock) have a UIC Vehicle Number for international running. I don't know how strictly the different national class numbers need to align with the UIC number.

 

[MotCO]

Eurostars (like all British rolling stock) have a UIC Vehicle Number for international running. I don't know how strictly the different national class numbers need to align with the UIC number.

Is the UIC number displayed? Do the French and Belgian railway authorities recognise the 373 and 374 designations which are displayed?