Double-Decker Trains

[rogerfarnworth]

It was announced on 22nd October 2025 that the lines through the Channel Tunnel would see double-decker trains by 2031. An order was placed for their construction and delivery in October 2025.

This article takes a look at the history of double-deck trains and carriages.

The featured image for this article shows what one of these trains would look like in Eurostar’s grey livery. The fully electric fleet of trains will be named Eurostar Celestia, which comes from the Latin word caelestis, meaning ‘heavenly’. The colour of the train has not yet been decided, but the current colour of Eurostar trains is grey, dark blue and yellow. Each train would be 200m long. Currently two are run together making an entire service 400m long. Double-decker trains don’t have twice as many seats as a single-deckers though, just because there needs to be room for interior steps, but there would be a fifth more seats. This means an increase from just under 900 seats on the current service to just over a thousand.

Double-Decker Trains

It was announced on 22nd October 2025 that the lines through the Channel Tunnel would see double-decker trains by 2031. An order was placed for their construction and delivery in October 2025. [6] …

rogerfarnworth.com

 

[Loonatic]

This sounds like a good idea. What are the downsides of double decker trains? The ones I can think of is fitting on track and higher roll over risk

 

[AlterEgo]

Bottlenecking at doors and longer dwelling times which eats into capacity. Poor accessibility for people with luggage if the stock requires steps to access every seat. Low ceilings.

 

[rogerfarnworth]

Disabled access can be an issue. Space for luggage can too be difficult. The increase in capacity is not particularly high. Loading gauge across the UK is tight, less of a problem on HS1 and the Tunnel (I believe).

 

[Rescars]

By definition, any double-decker requires access to both decks, which normally involves steps or stairs, typically accessed from each vestibule. Steps or stairs take up a significant amount of space which could otherwise be devoted to seating. There have been some instances where staircases have been placed on separate vehicles (e.g. Listowel and Ballybunion), but surely not for access to an upper deck.

 

[swt_passenger]

This sounds like a good idea. What are the downsides of double decker trains? The ones I can think of is fitting on track and higher roll over risk

Double decker trains are to all intents and purposes impossible within the normal loading gauge seen on the main British rail network. (Network Rail infrastructure.) The largest gauge is W12, and it’s designed for the corners of ‘hi-cube’ containers on normal wagons. It does absolutely nothing to improve the possibility of double deck passenger carriages.

 

[zwk500]

Disabled access can be an issue. Space for luggage can too be difficult. The increase in capacity is not particularly high. Loading gauge across the UK is tight, less of a problem on HS1 and the Tunnel (I believe).

No problem at all on HS1 and the Tunnel, they're built to UIC GB gauge or bigger.

(Technical Pedanty: HS1 is UIC GC from the Eurotunnel boundary to St Pancras via the 'main line', the route via Ashford is cleared for UIC GB+, Ashford International platforms 3/4 are UIC GB only. The Channel Tunnel is a special gauge larger than any UIC gauge for the double-decker car wagons).

== Doublepost prevention - post automatically merged: 18 Jun 2026 ==

Double decker trains are to all intents and purposes impossible within the normal loading gauge seen on the main British rail network. (Network Rail infrastructure.) The largest gauge is W12, and it’s designed for the corners of ‘hi-cube’ containers on normal wagons. It does absolutely nothing to improve the possibility of double deck passenger carriages.

There is a good comparison of the loading gauges on this Rail Engineer article: https://www.railengineer.co.uk/the-future-role-of-rail-a-strategic-freight-network/

[Image comparison of UIC GB+/GC gauges against normal UK Network Rail loading gauges]

 

[Taunton]

By definition, any double-decker requires access to both decks, which normally involves steps or stairs, typically accessed from each vestibule. Steps or stairs take up a significant amount of space which could otherwise be devoted to seating. There have been some instances where staircases have been placed on separate vehicles (e.g. Listowel and Ballybunion), but surely not for access to an upper deck.

The USA Amtrak Superliners, or more their 1950s Santa Fe 'Hi-Level' predecessors which originally set the style, are pretty ingenious in this, with just a single low level central entrance and vestibule, and one set of stairs up to the main upper deck, which is fully seated or sleeping berths end to end, and with the gangway connections at that upper level. On the lower level there are smaller seating saloons or roomettes either side, between the bogies, which handles the accessible requirements, along with the washrooms, and over the bogies in the limited headroom space is the air-con plant, baggage store, etc. In the diner the kitchen is at the lower level and the full length dining saloon above is served by dumbwaiters.

You wouldn't get away with this in the UK mainly because of the platform height which prevents entrance at a low level - it's as much a reason as a limited structure gauge why they cannot be used in the NE corridor, which has such platforms. The upper level gangways are also interesting to negotiate (or not) on uneven tracks!

 

[JamieL]

Double decker trains are to all intents and purposes impossible within the normal loading gauge seen on the main British rail network. (Network Rail infrastructure.) The largest gauge is W12, and it’s designed for the corners of ‘hi-cube’ containers on normal wagons. It does absolutely nothing to improve the possibility of double deck passenger carriages.

Didn't the UK used to have some double decker trains?

 

[zwk500]

Didn't the UK used to have some double decker trains?

No, the 4DD were *not* double decker. They were interleaved seating bays.

 

[JamieL]

interleaved seating bays

Indeed - but still effectively a double decker:

 

[Rescars]

Indeed - but still effectively a double decker:

.....with stairs in every compartment!

 

[swt_passenger]

No, the 4DD were *not* double decker. They were interleaved seating bays.

Pretty much a failure in any case. Weren’t boarding times extremely slow.

 

[zwk500]

Indeed - but still effectively a double decker:

No, in no sense was it a double decker. Passengers could not move independently on 2 levels.

 

[Peter Mugridge]

Pretty much a failure in any case. Weren’t boarding times extremely slow.

There's a story that Bulleid knew it wouldn't work but higher powers were insistent on having a double decker built, so he went ahead anyway and made absolutely certain that when it was in use it would be clear to everyone why it wouldn't work.

It's a nice story, but I don't know how much truth there is in it.

 

[biglads]

Pretty much a failure in any case. Weren’t boarding times extremely slow.

Yes, station dwell times were a problem for this stock, however they did run Charing Cross - Dartford services for many years. It was really a bodge job to see if they could avoid the expense of lengthening platforms from 8 to 10 cars to deal with higher usage and they quickly figured that the platform lengthening was needed. I have memories of a unit slowly rotting away at Hoo Junction from the early 80's. I'm not sure if that provided the motor car(?) that is still in existence.

 

[norbitonflyer]

Yes, station dwell times were a problem for this stock, however they did run Charing Cross - Dartford services for many years.

No point in scrapping them before their time, even if they were non-standard and sub-optimal. They were however outlasted by most of the post-war SUBs

== Doublepost prevention - post automatically merged: 20 Jun 2026 ==

The USA Amtrak Superliners, or more their 1950s Santa Fe 'Hi-Level' predecessors which originally set the style, are pretty ingenious in this, with just a single low level central entrance and vestibule, and one set of stairs up to the main upper deck, ............., and with the gangway connections at that upper level. On the lower level there are smaller seating saloons or roomettes either side, between the bogies, which handles the accessible requirements. In the diner the kitchen is at the lower level and the full length dining saloon above is served by dumbwaiters.

How was the diner made accessible, or was room/at seat service provided as an alternative?

== Doublepost prevention - post automatically merged: 20 Jun 2026 ==

No problem at all on HS1 and the Tunnel, they're built to UIC GB gauge or bigger.

(Technical Pedanty: HS1 is UIC GC from the Eurotunnel boundary to St Pancras via the 'main line', the route via Ashford is cleared for UIC GB+, Ashford International platforms 3/4 are UIC GB only. The Channel Tunnel is a special gauge larger than any UIC gauge for the double-decker car wagons).

== Doublepost prevention - post automatically merged: 18 Jun 2026 ==


[Image comparison of UIC GB+/GC gauges against normal UK Network Rail loading gauges]

A common muisconception/source of confusion is that "GB" and "GC" gauges are nothing to do with the typical UK loading gauge and the (rather more generous) loading guage used by the Great Central Railway The G stands for "Gabarit" (french for "gauge") and the letters are just letters (there is also a GA)

 

[Taunton]

How was the diner made accessible, or was room/at seat service provided as an alternative?

Indeed, there was/is specific waiter service to the lower level seats/roomettes in the adjacent vehicles when occupied by accessible passengers. Broadly, such passengers were booked into the immediately adjacent vehicles, the diner commonly being positioned mid-train between the coaches and the sleepers.

 

[zwk500]

A common muisconception/source of confusion is that "GB" and "GC" gauges are nothing to do with the typical UK loading gauge and the (rather more generous) loading guage used by the Great Central Railway The G stands for "Gabarit" (french for "gauge") and the letters are just letters (there is also a GA)

Yes, hence why I have made a habit of including UIC in front of them

 

[DelW]

The USA Amtrak Superliners, or more their 1950s Santa Fe 'Hi-Level' predecessors which originally set the style, are pretty ingenious in this, with just a single low level central entrance and vestibule, and one set of stairs up to the main upper deck, which is fully seated or sleeping berths end to end, and with the gangway connections at that upper level. On the lower level there are smaller seating saloons or roomettes either side, between the bogies, which handles the accessible requirements, along with the washrooms, and over the bogies in the limited headroom space is the air-con plant, baggage store, etc. In the diner the kitchen is at the lower level and the full length dining saloon above is served by dumbwaiters.

You wouldn't get away with this in the UK mainly because of the platform height which prevents entrance at a low level - it's as much a reason as a limited structure gauge why they cannot be used in the NE corridor, which has such platforms. The upper level gangways are also interesting to negotiate (or not) on uneven tracks!

Amtrak decided earlier this year that the Superliners will be replaced by new single-level coaches. Reasons include:

• Difficulty providing disabled access in accordance with ADA requirements
• Preference for standardisation of equipment between eastern and western routes (most north-eastern routes cannot accommodate bi-levels)
• Failure of a 2015 procurement for new bi-levels when prototypes failed compression-load tests

(Source: Trains magazine, May 2026, p5)

 

[U-Bahnfreund]

It's funny to see UK people discuss potential downsides of double-decker trains, when double-decker buses are used everywhere. Basically the opposite of mainland Europe where almost noone uses double-decker buses in favour of longer (bendy) ones, whereas double-decker trains are used fairly often in almost every country

 

[TheWierdOne]

It's funny to see UK people discuss potential downsides of double-decker trains, when double-decker buses are used everywhere. Basically the opposite of mainland Europe where almost noone uses double-decker buses in favour of longer (bendy) ones, whereas double-decker trains are used fairly often in almost every country

That is actually in part also due to the same issue of confined infrastructure that railways in the UK have.

Double deckers can be shorter and have smaller turning circles than some high capacity single deckers, notably bendy buses. Given that enough British cities have a street layout that is restrictive enough to make this relevant, articulated buses became quite niche over here and double deckers or very high frequency, or both, became the default for increasing capacity on British bus routes. Even “regular” full-length single decks can be blocked from areas a double-deckers, with their shorter wheelbase and turning circle, are permitted.

 

[Rescars]

That is actually in part also due to the same issue of confined infrastructure that railways in the UK have.

Double deckers can be shorter and have smaller turning circles than some high capacity single deckers, notably bendy buses. Given that enough British cities have a street layout that is restrictive enough to make this relevant, articulated buses became quite niche over here and double deckers or very high frequency, or both, became the default for increasing capacity on British bus routes. Even “regular” full-length single decks can be blocked from areas a double-deckers, with their shorter wheelbase and turning circle, are permitted.

Until there is a low bridge in the way! Many years ago the road under Wallington station was hollowed out to accommodate double deckers. Even in recent times this dip can fill spectacularly fast during a downpour and catch out unsuspecting motorists who find themselves suddenly out of their depth.

 

[TRAX]

Double deckers can be shorter and have smaller turning circles than some high capacity single deckers, notably bendy buses.

Articulated buses can negotiate much tighter turns than rigid buses (10, 12, 13 m, etc.), because you only have to put the fairly short front section through and the trailer will follow (unlike semi-trucks).

 

[zwk500]

It's funny to see UK people discuss potential downsides of double-decker trains, when double-decker buses are used everywhere. Basically the opposite of mainland Europe where almost noone uses double-decker buses in favour of longer (bendy) ones, whereas double-decker trains are used fairly often in almost every country

If our infrastructure supported true double decker trains i am fairly confident the UK would have adopted them.

Their downsides are small enough that if you only need minor modifications it can be quite cost effective, but big enough that it's not worth rebuilding every bridge, tunnel and platform for them.

 

[Transilien]

Another reason less discussed about double decker trains in the UK is, before the 80s (in France) and even the 2010’s (in Germany) double decker trains were usually carriages hauled by locomotives. I think this was because older traction equipment took up too much space in a double decker train for a multiple unit to make sense, capacity wise (this is just speculation on my part). However, the UK has had a policy since at least the 60s that all new suburban stock should be multiple units. BR wouldn’t have wanted non-standard traction, with a lower acceleration hauling commuter trains in south London.

 

[yorksrob]

A door to every seating bay worked much better at shifting people quickly.

 

[52290]

Another reason less discussed about double decker trains in the UK is, before the 80s (in France) and even the 2010’s (in Germany) double decker trains were usually carriages hauled by locomotives. I think this was because older traction equipment took up too much space in a double decker train for a multiple unit to make sense, capacity wise (this is just speculation on my part). However, the UK has had a policy since at least the 60s that all new suburban stock should be multiple units. BR wouldn’t have wanted non-standard traction, with a lower acceleration hauling commuter trains in south London.

Indeed, my first journey on double decker stock was in 1973 from Magdeburg to Rostock hauled by a DR 01.5 Pacific.

 

[Rescars]

Seen near Basle today, a double decker set in traffic being propelled by a loco with an addition double deck driving trailer attached at the rear - with the cab facing the loco. The Swiss have a style all of their own!

 

[Beebman]

The Austrians their own style too - on the Friday before last I travelled from St. Pölten to Wien Westbahnhof on a coaching set (propelled by a Vectron loco) which had a double decker at either end bookending several single deck vehicles!