Why can't future train orders be for double deck trains?

[Bald Rick]

maybe no tunnels, but it does have over bridges, at least in Southend

And the small matter of an over-site development on the end of Fenchurch Street platforms. It's hard to tell if it'd be high enough from pictures though.

And the even ‘smaller’ matter of OLE wire height and gantries all the way!

 

[ChiefPlanner]

Sigh - people who used to go on overseas holidays and come home with "my idea for solving" commuter issues Remember the commuter crush ?

The Bullied 4DD's were a disaster for all sorts of reasons -even in Austerity Britain. 10 car EPB's were the answer. Networkers or so even better.

You could run UIC type DD's on HS1 and a few modest add on's to make it work. If there was demand.

Trust me , a well ploughed field - not much to add really - .......

== Doublepost prevention - post automatically merged: 9 Jun 2021 ==

And the even ‘smaller’ matter of OLE wire height and gantries all the way!

And a few overbridges for key and domestic routes to least Upminster and say Grays..........Been looked at before , despite new revelations en route to Damascus or the new railway Jerusalem....

 

[stuu]

And the even ‘smaller’ matter of OLE wire height and gantries all the way!

This is all completely theoretical and not going to happen, but isn't standard OLE at 5100mm, in which case something like MI09 could run comfortably (ignoring all the bridges and lower down constraints... and yes I know that is a massive if with far more issues)

 

[NoRoute]

"Granted, the European rail networks have more space to play with, but if you took some inspiration from airplane designers..."

1. Airplane designers are not used to bridges and tunnels, so don't have a headroom restriction.
2. At the time HS2 rolling stock was being discussed, a european firm produced a double deck design and Modern Railways printed a cross sectional drawing, but in the end the order was for stock capable of running on the whole of the network, not just HS2.
3. I went on a 4DD as a child from London Bridge to Charing Cross and back off peak and found it quite claustrophobic. IN rush hurs it would have been slow to load/unload. The tiny windows were no good for engine spotting.

Airplane design is under much greater financial pressure than the railways to use space and weight efficiently because of the very high fuel and operating costs of flying an aircraft, they direct huge effort to make planes as light as possible and to maximise seats in the space available to make them financially viable to operate. If you wanted to look to an industry that was expert in efficient use of space, you would look to airplane design rather than the railways.

I've never travelled on a 4DD but I have travelled on double deck trains in Europe and in peak times. They were modern, well designed, comfortable and the extra seating capacity ensured most people got a seat making it a pleasure to travel on them. It is a shame UK passengers cannot benefit from this innovation.

It would be totally unacceptable (and frankly unnecessary) to have such a closed layout on modern rolling stock.

But such a layout, with walkways and reduced head height in seating areas, is what you find on every passenger airplane and millions of people quite happily travel long distances on passenger aircraft in such arrangements, so to suggest it is "totally unacceptable", is clearly incorrect because people do accept it. Indeed many people even chose to travel with the bare minimum of space in order to get cheap tickets, opting for budget airlines with the minimum seating space. The railways seem rather stuck in a time warp with fixed and incorrect beliefs and assumptions of what people will and won't accept which don't reflect reality. People will accept a lot of different things if they see benefits in other areas.

All that stuff below the sole bar such as transformers, traction converters, batteries, switchgear, toilet tanks etc etc all has to go elsewhere in the train if it can’t go between the bogies....

The double deck trains I've travelled on were all hauled by a locomotive without drive equipment under the carriages so that wasn't an issue, I'm sure there may be disadvantages but the advantages must outweigh them otherwise rail networks around the world wouldn't chose to buy and operate them.

Disability Discrimination Act (and successors).

"Slips, trips and falls".

Deutsche Bahn, operating under European health and safety legislation, can safely operate double deck trains so my starting point would be to assume they could also be operated here and that the stairs are not an insurmountable hazard. I don't believe we in the UK are any more unsteady on our feet.

 

[JonathanH]

But such a layout, with walkways and reduced head height in seating areas, is what you find on every passenger airplane and millions of people quite happily travel long distances on passenger aircraft in such arrangements, so to suggest it is "totally unacceptable", is clearly incorrect because people do accept it.

Nothing to do with cramming people in - it is to do with passenger safety - open layouts mean that passengers can see each other and there aren't hiding places where assaults, murders and other horrific acts could take place (or more to the point could be seen as a consequence of the layout).

We may be at slight cross purposes because I think you are proposing a train with a sunken gangway whereas I am describing a train with a layout a bit closer to the 4DD with the seats designed in such a way that the view down the train is obscured. I'm not convinced that there is space for a sunken gangway approach and to have seats below it.

 

[NoRoute]

Nothing to do with cramming people in - it is to do with passenger safety - open layouts mean that passengers can see each other and there aren't hiding places where assaults, murders and other horrific acts could take place.

But double deck trains have open layouts, they have long, continuous seating areas on each deck. They have spacious areas around the doors which have open stair cases upto and down to the decks, so any disturbance can be heard. They have CCTV.

These trains are in service today, go to some European countries and this is the train which pulls up at the station, so while there may be unfamiliarity with the idea in the UK, it clearly works and whatever risks people in the UK might perceive, in practice they are evidently either not a problem or are manageable.

 

[JonathanH]

But double deck trains have open layouts, they have long, continuous seating areas on each deck. They have spacious areas around the doors which have open stair cases upto and down to the decks, so any disturbance can be heard. They have CCTV.

These trains are in service today, go to some European countries and this is the train which pulls up at the station, so while there may be unfamiliarity with the idea in the UK, it clearly works and whatever risks people in the UK might perceive, in practice they are evidently either not a problem or are manageable.

Yes, they would be fine, but they don't fit in our loading gauge as people keep on pointing out. To fit two layers of seats in our loading gauge means significant compromises because there is only room for 1.5 levels, not 2, ie one person's legs need to be at the same level as the body of the person below. That requires a somewhat complex interior which works with compartment stock, eg the 4DD but not with an open layout.

 

[RobShipway]

There's me thinking that this thread would be short with people saying that running double deck trains would be impossible on the UK rail networks.

But double deck trains have open layouts, they have long, continuous seating areas on each deck. They have spacious areas around the doors which have open stair cases upto and down to the decks, so any disturbance can be heard. They have CCTV.

These trains are in service today, go to some European countries and this is the train which pulls up at the station, so while there may be unfamiliarity with the idea in the UK, it clearly works and whatever risks people in the UK might perceive, in practice they are evidently either not a problem or are manageable.

Many comments have been provided within this thread as to why double deck trains cannot exist, one and probably the most important is the narrow gauge that the UK trains run on. Unlike double deck trains, where you have 2+2 seats within either the downstairs or upstairs, you would not be able to do that on UK rails. In fact you would be lucky even in standard class to get 2+1 seating in the double deck coaches with all the equipment that would in normal coaches be under the train, would need to be under the seat giving the passengers less legroom and luggage space.

You have to also remember that when the likes of double deck trains that ceased operation back in the early 1970's (4DD), the average height of most brits was about 5 foot 5 inches. I would say that is now more likely that the average height is over 6ft, so to do what you suggest a 6ft plus person would have to be travelling with his stomach on his legs due to the fact that you would only have 1.5 levels.

Yes, they would be fine, but they don't fit in our loading gauge as people keep on pointing out. To fit two layers of seats in our loading gauge means significant compromises because there is only room for 1.5 levels, not 2, ie one person's legs need to be at the same level as the body of the person below. That requires a somewhat complex interior which works with compartment stock, eg the 4DD but not with an open layout.

I have to agree with this comment 100%. The only way I can see double deck trains running is if you rebuild the lines that the trains would be travelling on, so you would have to do as was done with the OHLE going through Severn Tunnel by lowering the track, but for double deck trains you would have to lower the track to a lot deeper level.

By the time you have finished paying for the cost of replaying the line that the double track trains would be travelling on, you could have spent that money either making existing trains longer or buying no longer trains. yes, for these longer trains you may have to extend platforms, but it would be very likely that you would have to do the same with double deck trains anyway.

You also have to remember that back in the late 19th and early 20th century a good part of Europe had the same gauge of track line that we did here in the UK. Many of those countries have long since rebuilt the lines, as they found that it limited the type of trains that could be run on those tracks for their needs.

 

[D365]

There's me thinking that this thread would be short with people saying that running double deck trains would be impossible on the UK rail networks.

It’s not a short thread because you, and others, suggest it could happen. When it absolutely won’t.

Nothing is impossible when you throw enough money at it

 

[zwk500]

But such a layout, with walkways and reduced head height in seating areas, is what you find on every passenger airplane and millions of people quite happily travel long distances on passenger aircraft in such arrangements, so to suggest it is "totally unacceptable", is clearly incorrect because people do accept it.

The difference on planes being that everybody boards at the same time and then only 1 or 2 people will be stood up at any time. Whereas on a train with people still finding seats from the last stop the possibility of being thrown into the footwell as you're going over pointwork is very real, and in your suggestion would be a sharp edge at head height.

There's me thinking that this thread would be short with people saying that running double deck trains would be impossible on the UK rail networks.

Tbf, they did!

You have to also remember that when the likes of double deck trains that ceased operation back in the early 1970's (4DD), the average height of most brits was about 5 foot 5 inches. I would say that is now more likely that the average height is over 6ft, so to do what you suggest a 6ft plus person would have to be travelling with his stomach on his legs due to the fact that you would only have 1.5 levels.

The average height is not more than 6ft (even for men only), however there are a greater number of people who are 6ft or more.

You also have to remember that back in the late 19th and early 20th century a good part of Europe had the same gauge of track line that we did here in the UK. Many of those countries have long since rebuilt the lines, as they found that it limited the type of trains that could be run on those tracks for their needs.

? Everywhere that built it's lines to standard gauge is still standard gauge, and most places that didn't haven't changed.

I think you're talking about loading/structure gauge (2 separate but related concepts). GB has been continually rebuilding it's lines for better structure gauge, that's what the W10/12 clearance programme is. It's just that GB doesn't need DD trains, when longer trains are achievable.

 

[RobShipway]

I think you're talking about loading/structure gauge (2 separate but related concepts). GB has been continually rebuilding it's lines for better structure gauge, that's what the W10/12 clearance programme is. It's just that GB doesn't need DD trains, when longer trains are achievable.

yes, I am talking about loading gauge sorry.

For the record, I am not suggesting that it could happen. Just asking why that it cannot happen and I had the answer to that question within the first page of this thread, hence why I did not comment further.

 

[CBlue]

But such a layout, with walkways and reduced head height in seating areas, is what you find on every passenger airplane and millions of people quite happily travel long distances on passenger aircraft in such arrangements, so to suggest it is "totally unacceptable", is clearly incorrect because people do accept it. Indeed many people even chose to travel with the bare minimum of space in order to get cheap tickets, opting for budget airlines with the minimum seating space. The railways seem rather stuck in a time warp with fixed and incorrect beliefs and assumptions of what people will and won't accept which don't reflect reality. People will accept a lot of different things if they see benefits in other areas.

A few big differences here:

Firstly budget air fares are often seen as cheap, rail fares are not.

Lots of air travel abroad often doesn't have a practical alternative unless you want to spent several days travelling by car or train, hence people put up with the cramped conditions. Give domestic train passengers that sort of arrangement and they'll go and buy cars if they don't already have them.

Aircraft also don't have the same level of passenger circulation, their journies being point to point with no crowds of passengers boarding and alighting at the same time - so dwell times are far less of an issue compared to trains

 

[Peter Mugridge]

All that stuff below the sole bar such as transformers, traction converters, batteries, switchgear, toilet tanks etc etc all has to go elsewhere in the train if it can’t go between the bogies. The bogies can’t go further apart, so in a typical length suburban coach the theoretical lower floor volume is very small anyway, and it’s so narrow because of the lower structure gauge 2+1 would be a push. As they said in the report, with 2+2 seating, an increase in seating capacity of only about 8% was achievable. You can get that on a typical current 12 car train by using fixed formation rather than 3 x 4 car. So double decker ends up being a costly way of making a trivial improvement.

Looking at the French Z20500 class ( which is my favourite double decker ) the electrical equipment is concentrated at the ends of the driving vehicles, just behind the cabs and also a smaller section at the inner end. They're also extremely good at packing seats in on this design without making it feel cramped; 110 seats in the driving cars alone and 204 seats in the trailers. ( They also give good thrash on a long fast section! )

There's a number of photos on the Wikipedia page for the class:

SNCF Class Z 20500 - Wikipedia

en.wikipedia.org

 

[swt_passenger]

Looking at the French Z20500 class ( which is my favourite double decker ) the electrical equipment is concentrated at the ends of the driving vehicles, just behind the cabs and also a smaller section at the inner end. They're also extremely good at packing seats in on this design without making it feel cramped; 110 seats in the driving cars alone and 204 seats in the trailers. ( They also give good thrash on a long fast section! )

There's a number of photos on the Wikipedia page for the class:

SNCF Class Z 20500 - Wikipedia

en.wikipedia.org

Yes, and just look at how wide they are at low level. That’s impossible in GB.

 

[Peter Mugridge]

Yes, and just look at how wide they are at low level. That’s impossible in GB.

I'm not disputing that; I was answering about the principle of them.

It is mainly this lower part issue that prevents the use of such stock in the UK; the only slightly lower overall most excellent French single decker, the Z50000 class, would fit in the UK if it wasn't for the lower parts arguing with the platforms.

The LTS routes out of Fenchurch Street could probably be converted reasonably easily - the platform edges* could be rebuilt and then fitted with securely mounted temporary edging ( removed on "changeover weekend" ) and the bridge clearances amended ( no tunnels on the LTS ), but that would of course then result in a fleet of trains which couldn't ever work anywhere else in the UK...


*There's a fair step up into a Z20500 so the platform heights are probably already pretty close to what would be needed, so it's only the edges that would need doing.

 

[zwk500]

The LTS routes out of Fenchurch Street could probably be converted reasonably easily - the platform edges* could be rebuilt and then fitted with securely mounted temporary edging ( removed on "changeover weekend" ) and the bridge clearances amended ( no tunnels on the LTS ), but that would of course then result in a fleet of trains which couldn't ever work anywhere else in the UK...

*There's a fair step up into a Z20500 so the platform heights are probably already pretty close to what would be needed, so it's only the edges that would need doing.

This point was already covered - you'd need to amend every single OLE stanchion. Rebuilding the platform edges will need a total blockade of each platform line and the adjacent platform line for a period of at least 2 weeks, probably closer to 4. I doubt the resource would be available to rebuild every platform simultaneously.
UK Platforms are typically 915mm above rail level, with the train having a floor 1100mm above rail level. Stations with level boarding will be at 1100mm, give or take. France's standard platform height is 550mm above rail level. Judging from the position in relation to the bogies, those doors are at or around the 720mm mark (EU standard for Belgium/Netherlands/Germany). Shaving 200mm off every platform is not a light task.

 

[Alfie1014]

The other thing to bear in mind with the LTS is that the London end and through the borough of Southend the overhead clearances are substandard compared with today’s standards for 25kv. They were therefore designed for 6.25kv, however time and experience has shown that 25kv is safe and as such these sections were re-electrified in the 1980s. That said they are very tight especially along the section between Bromley by Bow and East Ham. So unless you were to rebuild all these bridges (about 8 from memory) many of which have buildings on them including East Ham, Upton Park and Plaistow Underground station buildings gaining any additional clearance is almost impossible. The disruption to the LTS and adjacent District line would be enormous and almost might make it more worthwhile to consider building a new cut off.

 

[Shoeburysam]

In the unlikely event anyone would do it, the Fenchurch St-Southend route would be the most appropriate as it has no tunnels and is (almost) self-contained, and busy enough to justify it. Won't happen though.

The design of UK platforms and structures below the floor level, especially girders for underbridges, are at least as big a problem as the roof height too

The route isn't wide enough, we have plenty of bridges, and Fenchurch st has a building on it. East ham tube station there is a sort of tunnel thanks to buildings over head.
You'd have to re electrify the entire route.

 

[mike57]

Japan have double decker trains on their classic lines, but how does their loading gauge compare with ours (yes I know track gauge is 3ft 6in)

 

[Shoeburysam]

Japan have double decker trains on their classic lines, but how does their loading gauge compare with ours (yes I know track gauge is 3ft 6in)

Do double decker trains fit on 4 ft 8 1/2 track? I have no idea. I would of thought the added height would require wider track for stability probably wrong though.

I regards to the LTS. There is a lot of low bridges on the line. You wouldn't get the double decker in or out of shoebury. Fenchurch st alone sits under a building. London side of barking is underneath other rail lines.

Then there is the OHLE, which would need completely replaced. Expensive considering that signalling is advancing and probably more of a concern. Add into that Fen St needs to be increases platform wise.

 

[Ianno87]

Do double decker trains fit on 4 ft 8 1/2 track? I have no idea. I would of thought the added height would require wider track for stability probably wrong though.

Loads of examples. TGV Duplex for one. "Stability" (and passenger comfort) is attained by keeping the centre of gravity low, and canting ("banking") the track on curves.

 

[Shoeburysam]

Loads of examples. TGV Duplex for one.

Fair enough, I have no idea I just thought you'd want it wider. Assuming they are significantly taller that is.

 

[Annetts key]

The fundamental problem is something called loading guage. This is, to put it simply, how much space a train is allowed to take up (how tall, how wide etc) without hitting anything (bridges, tunnels, platforms, etc)

Loading gauge - Wikipedia

en.m.wikipedia.org

The railways in Great Britain were generally built much earlier than most railways in Europe and for various reasons were built to much smaller loading guages. One reason is for example the difficulties of building large tunnels before tunneling technology developed to where it is today. The most extreme example of this is the tube lines in London.

These smaller loading guages are not large enough for double decker trains to fit without serious design compromises that make them fairly impractical (there have been some examples in the past, where this can be seen). Therefore they cannot be used anywhere on the GB rail network, with the single exception of HS1 which was built to a European loading guage.

See also https://bathtrams.uk/structure-gauge-and-dynamic-kinematic-envelope/

The structure/loading gauge affects not only bridges and tunnels, but absolutely everything lineside including signals (all types), lineside signs, OHL, viaducts, cuttings, station canopies (some of which are listed buildings) and platform edges/faces.

Hence the cost of changing the infrastructure of existing lines would be hugely expensive. To give you an idea, you only have to look at the amount of work needed on the infrastructure for the GWML OHL scheme. As well as having to rebuild bridges or replace them, extensive work was required in the various tunnels (mostly lowering the track bed) and various stations to have alterations done to them, plus hundreds of signals had to be replaced (although most of these were to provide clearance to the OHL pantograph).

 

[DelW]

Do double decker trains fit on 4 ft 8 1/2 track? I have no idea. I would of thought the added height would require wider track for stability probably wrong though.

Stability isn't an issue - Amtrak Superliners and Surfliners are double deck and very spacious internally (both width and height), but run on standard gauge tracks.

Of course those tracks have had clearance increased to accommodate double stacked container trains - which are even taller and still run on standard gauge rails.

 

[WideRanger]

Japan have double decker trains on their classic lines, but how does their loading gauge compare with ours (yes I know track gauge is 3ft 6in)

The overall height and width of the standard Japanese loading gauge is similar to the UK. However, if you look at the pictures of the bi-level commuter trains, they stay wide pretty much all the way down to the track, which I understand would not work on the UK system because of clearances at the bottom half of the train.

 

[DB]

It's not a DVT it's more akin to a DBSO in our parlance as it is mostly passenger accommodation with just a cab on the end.

Or DTS (which I believe is the classification for the Mk5a driving trailers)?

 

[mike57]

The overall height and width of the standard Japanese loading gauge is similar to the UK. However, if you look at the pictures of the bi-level commuter trains, they stay wide pretty much all the way down to the track, which I understand would not work on the UK system because of clearances at the bottom half of the train.

Your comment got me looking into it, after a bit of googling I managed to find two images which I have managed to superimpose to the same scale, its not 100% accurate, but shows the problem we have in the UK, we cant go out or up.

Red is UK C1, Blue is pre 1987 Japanese 3'6", Grey is post 1987 Japanese, and green is Japanese 4'8" high speed. current Japanese loading gauge is bigger all round, earlier one (which still applies on some line as far as I can work out) is very similar to UK, except the bottom quarter, which as you say is a lot more generous

 

[WideRanger]

Your comment got me looking into it, after a bit of googling I managed to find two images which I have managed to superimpose to the same scale, its not 100% accurate, but shows the problem we have in the UK, we cant go out or up.

Red is UK C1, Blue is pre 1987 Japanese 3'6", Grey is post 1987 Japanese, and green is Japanese 4'8" high speed. current Japanese loading gauge is bigger all round, earlier one (which still applies on some line as far as I can work out) is very similar to UK, except the bottom quarter, which as you say is a lot more generous

View attachment 99676

Wow. That's rather fabulous work. Thanks!

 

[Falcon1200]

Airplane design is under much greater financial pressure than the railways to use space and weight efficiently because of the very high fuel and operating costs of flying an aircraft, they direct huge effort to make planes as light as possible and to maximise seats in the space available to make them financially viable to operate. If you wanted to look to an industry that was expert in efficient use of space, you would look to airplane design rather than the railways.

Being crammed into an airplane seat a couple of times a year in order to have a reasonably cheap holiday somewhere far away is a very different matter from being crammed into a similar seat on a train going to and from work, 5 days a week/47 (say) weeks a year ! I have never been on a train, in the UK or elsewhere, with seating as packed in as on a plane, and that includes transatlantic flights. So I am not convinced that plane design should be the model for trains.

 

[zwk500]

Your comment got me looking into it, after a bit of googling I managed to find two images which I have managed to superimpose to the same scale, its not 100% accurate, but shows the problem we have in the UK, we cant go out or up.

That's magnificent! I don't suppose there's any chance you've got one showing C1, W12 and UIC GB? Would be interesting to have a visual representation of what we'd need for something like the French or German DD trains on our network