Double-decker trains could hit Britain’s railways to ease overcrowding

[edwin_m]

Some places can handle 348.48m long trains (3xclass 221). What sort of % extra power would an 11 car double decker pull (if one existed in the UK, compared with a 11 car single decker?

Would probably be proportional to the extra weight. I haven't time to check now, but I think DD stock tends to use lighter materials so may not be much heavier than SD stock.

 

[Yew]

Because they were crap.

A clever idea that doesn't really work in the real world.

Im not convinced, I think the arguments of 'longer loading times' dont stand up, as at the time every compartment had a door in the southern region, whereas these days, we typically only have 2 doors per side. Of course, fitting that many plug doors would be expensive, but not impossibly so.

I do however think, that we cannot fit powered DD's in our loading guage, they would have to be trailer cars within an EMU rake also containing single deck coaches with all axles powered..

 

[jopsuk]

The older dutch DD stock, the DD-AR, features motor coaches with a single passenger deck that is higher than a normal single deck coach, but lower than the "full" DD coaches.

 

[dgl]

I suppose it would also for a British version require Jacobs bogies. Then at least all (or a fair proportion of the power stuff could be kept in the vestibules.

 

[Bletchleyite]

I suppose it would also for a British version require Jacobs bogies. Then at least all (or a fair proportion of the power stuff could be kept in the vestibules.

Short articulated vehicles might be a good way of gaining the extra width required, particularly below floor level for the DD bit.

Another option might be something like the Stadler GTW (possibly only built by Stadler if the design is patented), with small power cars carrying the bogies between full-length double-decker passenger modules.

Neil

 

[GrimsbyPacer]

I suppose it would also for a British version require Jacobs bogies. Then at least all (or a fair proportion of the power stuff could be kept in the vestibules.

That's a good idea to increase double deck space too.

 

[DynamicSpirit]

Im not convinced, I think the arguments of 'longer loading times' dont stand up, as at the time every compartment had a door in the southern region, whereas these days, we typically only have 2 doors per side. Of course, fitting that many plug doors would be expensive, but not impossibly so.

I think the only-2-doors-per-side thing isn't so much because of cost as because of safety: More doors would make the carriage structurally weaker and therefore less able to withstand a crash. For that reason, going back to the old thing where carriages had lots of doors along their length is unlikely to be possible.

 

[starrymarkb]

Short articulated vehicles might be a good way of gaining the extra width required, particularly below floor level for the DD bit.

Another option might be something like the Stadler GTW (possibly only built by Stadler if the design is patented), with small power cars carrying the bogies between full-length double-decker passenger modules.

Neil

The French are going down that route with the Regio 2N.

It's a mix of single deck electric power cars and double deck trailers. Though one of the double deck driving vehicles has a diesel generator in the upper deck for operating on non wired lines.

 

[Bletchleyite]

That's a really weird-looking thing, but something like that could well provide an answer.

Neil

 

[DownSouth]

It does look as though it's a solution optimised for French low platforms though.

A high-platform EMU for use in Britain would not need those bizarre power cars, or the Jacobs Bogies. No leadership or innovation would be needed, you'd boldly follow where others have gone before and take advantage of the 50 years of experience with the Sydney Trains double deck EMUs that have all the equipment under the floors and over the ceilings in the end sections of each car.

Yes, the Sydney Trains EMUs are 1500V DC units and so space would need to be found for a 25kV transformer, but this would not be hard to find though and is not enough of a reason to rule it out. You would reduce the number of Australian-spec heavy duty air conditioning units by one or more (and use ducting to evenly distribute the air from the remaining units to provide a UK-spec air conditioning system) and fit the transformer in the freed space.

 

[starrymarkb]

It does look as though it's a solution optimised for French low platforms though.

A high-platform EMU for use in Britain would not need those bizarre power cars, or the Jacobs Bogies. No leadership or innovation would be needed, you'd boldly follow where others have gone before and take advantage of the 50 years of experience with the Sydney Trains double deck EMUs that have all the equipment under the floors and over the ceilings in the end sections of each car.

Yes, the Sydney Trains EMUs are 1500V DC units and so space would need to be found for a 25kV transformer, but this would not be hard to find though and is not enough of a reason to rule it out. You would reduce the number of Australian-spec heavy duty air conditioning units by one or more (and use ducting to evenly distribute the air from the remaining units to provide a UK-spec air conditioning system) and fit the transformer in the freed space.

Sydney has an extra 30cm of width to play with right down to the rail head. The UK doesn't hence why we are pondering how to overcome the width issue, shorter cars would help hence Jacobs Bogies

 

[DownSouth]

Sydney has an extra 30cm of width to play with right down to the rail head. The UK doesn't hence why we are pondering how to overcome the width issue, shorter cars would help hence Jacobs Bogies

Of course.

It goes almost without saying that a rebuilt loading gauge would be needed for any proper double deck solution (i.e. pay no attention to the Southern Region attempt) mostly for the height where you'd need about 600mm.

Jacobs Bogies will not help when it comes to curvature if you're sticking to the current infrastructure profile, because the distance between bogie centres (and therefore the required clearance on the inside of curves) would be roughly the same as they are with conventional bogies - I'd point you to the difficulties involved with the former use of Eurostar's TGV-TMST sets on the ECML.

Stations are the hardest parts of the puzzle, not curves.

As I've pointed out earlier in the thread, rebuilding the loading gauge would be a huge undertaking to do as a single project. Therefore the ideal way to achieve it would be to include some element of future-proofing every time a bridge, tunnel, station or any other infrastructure element is rebuilt as part of routine renewal works. This is how, without a major shutdown for the purpose, the Adelaide-Melbourne line has managed to go from taking 1200 metre trains to taking 1800 metre trains, widened the gauge to take well cars, and another ten years should have it in the position that one final push to sort out a handful of short tunnels would open it up to double-stack container trains.

 

[NotATrainspott]

Of course.

It goes almost without saying that a rebuilt loading gauge would be needed for any proper double deck solution (i.e. pay no attention to the Southern Region attempt) mostly for the height where you'd need about 600mm.

Jacobs Bogies will not help when it comes to curvature if you're sticking to the current infrastructure profile, because the distance between bogie centres (and therefore the required clearance on the inside of curves) would be roughly the same as they are with conventional bogies - I'd point you to the difficulties involved with the former use of Eurostar's TGV-TMST sets on the ECML.

Stations are the hardest parts of the puzzle, not curves.

As I've pointed out earlier in the thread, rebuilding the loading gauge would be a huge undertaking to do as a single project. Therefore the ideal way to achieve it would be to include some element of future-proofing every time a bridge, tunnel, station or any other infrastructure element is rebuilt as part of routine renewal works. This is how, without a major shutdown for the purpose, the Adelaide-Melbourne line has managed to go from taking 1200 metre trains to taking 1800 metre trains, widened the gauge to take well cars, and another ten years should have it in the position that one final push to sort out a handful of short tunnels would open it up to double-stack container trains.

An incremental approach is obviously the least-bad idea but the problem is that on the GB rail network, just so much of the existing infrastructure is so constrained that replacing everything may well be an exercise in futility. The most striking example is the HS1-HS2 link, where to gauge-clear a single track along the North London Line for a few kilometres would cost hundreds of millions of pounds as it would necessitate the replacement of basically every bridge along the route. Crucially, the UK loading gauge is not just constrained at platforms as bridge members and other crucial pieces of infrastructure are put in that area, so even on routes without any overhead wires or obstacles, massive reconstruction would still be necessary. Widening the UK gauge by only a few centimetres could cost millions where there is not unrestricted free land on one or both sides, as that widening could then make it impossible to fit two of the gauges through a cutting or along an existing embankment. Other countries like France have had massive gauge-enhancement programmes before but none have had to deal with the sheer scale of legacy issues the UK network causes. It might be possible to gauge-clear some parts of the legacy network, but these would only be parts far away from London where there is some real strategic need for a larger loading gauge (e.g. once HS2 to Scotland is complete, gauge-clearing the WCML north of Preston for piggy back lorries and continental-gauge freight would be theoretically possible given that there is plenty of free land and no real constraints like tunnels or bridges).

 

[whhistle]

Why don't we just re-build the railways?
Take line by line, make it bigger loading gauge, ready for double-deck trains.

Yes, it would cost billions of pounds, but if we're serious about rail, serious about growth, there's no point in simply extending trains and platforms to be longer and longer; we're already running out of land space as it is.

 

[Haydn1971]

Why don't we just re-build the railways?.

Because it's easier to build a completely new line instead - thus why we are looking at HS2

 

[LLivery]

I've long thought the LTS would be a decent candidate for Double Decks. Its relatively short, no tunnels and a busy commuter line. There aren't huge amount of over-rail bridges and most of them aren't at stations/c2c served stations, so track could be lowered or the bridge rebuilt. Barking is due to be rebuilt, so the design could easily be done for taller trains. Upminster could do with a rebuild too. As for the other stations (Westcliff, Pitsea, Laindon and West Horndon) I'm sure a solution can be found.

Also the OHLE is old, so that needs replacing in the future anyway. The real major problem is the width. I think the NSW fleet the best double decks in my opinion and looks wise are far better than the European ones. What would be wrong with a 12 car train with 2+2 seating??

 

[D1009]

Double deck trains in the UK have only ever been considered for London commuter routes, and I contend that is where the only demand there will be for the foreseeable future. Unfortunately suburbs of large cities are where the infrastructure would cost the most to enhance because of the number of bridges and tunnels that there are compared to other places. I can't see that changing.

Our European neighbours had the foresight when they built their railways to use a much larger loading gauge, so double deck trains are not a problem to them.

 

[3141]

Im not convinced, I think the arguments of 'longer loading times' dont stand up, as at the time every compartment had a door in the southern region.

The upper deck compartments, which were actually only half a deck higher than the lower deck ones, used a lower deck door for entry and exit. So there would be almost twice as many people using that door as normal. People had to pass between the knees and feet of seated passengers as they made their way to the door, which made it difficult to move quickly.

I think the Southern Railway deserves credit for trying a novel (or "innovative", as the PR men say today) approach to trying to increase capacity AND the number of seats. Today we do it by decreasing the number of seats.

The SR DD trains were brilliant for the game of train hee.

 

[jopsuk]

Why don't we just re-build the railways?
Take line by line, make it bigger loading gauge, ready for double-deck trains.

Yes, it would cost billions of pounds, but if we're serious about rail, serious about growth, there's no point in simply extending trains and platforms to be longer and longer; we're already running out of land space as it is.

We could go vertical, easy enough.


But ideally we'd go full on UIC. GC+ as you might as well go for it. Now that would be harder. Could maybe do it for the LTS (c2c)?

Rebuild platforms- to be lower and further from the track. Ideally straighten the stations up too. But then put a temporary surface & extension to make them compatible with current stock.

Buy and build stock. Get it tested, run in elsewhere. Train the drivers and guards*. Ship it to a holding location connected to the line.

Then, long weekend closure. Remove all the temporary platforms. Run test trains through. Reopen. Pray that it all works!

You'd lose the diversion ability to Liverpool Street through Stratford- until the GE was also cleared.

The hard parts nationally come when you start trying to do lines where more complex services run. You could perhaps, for a while, have stations with both sorts of platforms- being careful not to run the wide trains through the "classic" platforms.

By the time you hit the west midlands or north west you'd end have very complex untangling issues!

*lets have guards

 

[D1009]

The upper deck compartments, which were actually only half a deck higher than the lower deck ones, used a lower deck door for entry and exit. So there would be almost twice as many people using that door as normal. People had to pass between the knees and feet of seated passengers as they made their way to the door, which made it difficult to move quickly.

I think the Southern Railway deserves credit for trying a novel (or "innovative", as the PR men say today) approach to trying to increase capacity AND the number of seats. Today we do it by decreasing the number of seats.

The SR DD trains were brilliant for the game of train hee.

Not exactly DDA compliant then

These were the days that a typical normal coach (4SUB or EPB) had 11 compartments seating 12 each, 6 a side, and in the peak with slam door stock many of the punters were off the train before it came to a stand.

 

[21C101]

Not exactly DDA compliant then

These were the days that a typical normal coach (4SUB or EPB) had 11 compartments seating 12 each, 6 a side, and in the peak with slam door stock many of the punters were off the train before it came to a stand.

I came a cropper at Beddington Lane when I was a kid playing jump off the train before it stops at as fast a speed as you dare. Grazed knees and hands all round.

Ah the days when there was a proper semaphore signalled branch line in south London.

 

[AM9]

I came a cropper at Beddington Lane when I was a kid playing jump off the train before it stops at as fast a speed as you dare. Grazed knees and hands all round.

Ah the days when there was a proper semaphore signalled branch line in south London.

It depended which side the platform was. If it was on the left side, the door would swing open against the coach side, if on the right, you had to make sure that with braking, it didn't swing forward and hit you.
With practice, it was like skipping of the rear platform of an RT, except it could be another passenger who ran into you rather than a cyclist!

Eeeh sliding doors, you were lucky!

 

[NotATrainspott]

We could go vertical, easy enough.


But ideally we'd go full on UIC. GC+ as you might as well go for it. Now that would be harder. Could maybe do it for the LTS (c2c)?

Rebuild platforms- to be lower and further from the track. Ideally straighten the stations up too. But then put a temporary surface & extension to make them compatible with current stock.

Buy and build stock. Get it tested, run in elsewhere. Train the drivers and guards*. Ship it to a holding location connected to the line.

Then, long weekend closure. Remove all the temporary platforms. Run test trains through. Reopen. Pray that it all works!

You'd lose the diversion ability to Liverpool Street through Stratford- until the GE was also cleared.

The hard parts nationally come when you start trying to do lines where more complex services run. You could perhaps, for a while, have stations with both sorts of platforms- being careful not to run the wide trains through the "classic" platforms.

By the time you hit the west midlands or north west you'd end have very complex untangling issues!

*lets have guards

The LTS lines are an ideal candidate to be Crossrail'ed at some point, therefore there won't be a case to do such a massive reconstruction of them.

Fundamentally, how much extra capacity could be gained by double-decking (remember that it inevitably cannot have dwell times as short as is possible for single-deck stock) compared to simply working on the route to extend every platform to its longest possible length, installing moving-block signalling and ensuring complete grade-separation? These steps require only targeted infrastructure changes, ensure the network is still fully compatible with the non-LTS lines and deliver higher frequencies to make journeys better and faster. If the problem is that there are not enough tracks in a specific section, build more tracks by building new bypass tunnels in a comparatively simple TBM job.

 

[Haydn1971]

Indeed, whilst double decking sounds a great idea, it's riddled with issues that just don't make the costs worth it - look at the step change that Northern Hub will bring, even more so, the step change that Crossrail brings, in that the core of the budget is invested at locations where the greatest bottleneck is - to clear routes into London even something like the GWML to Bristol would a much greater investment than say adding extra track at the London end (still costly) which would effectively achieve the same goal without decades of disruption. Building new lines at the larger gauge makes perfect sense as there is little extra cost, building replacement larger gauge bridges along a route that may never be cleared for DD is simply a waste of capital investment as it won't yield a return for potentially decades, maybe a even century.

I've worked on many study's of this kind, you have to rule things in to be able to rule them out - you get a single snapshot of options costed at the same time, analysed at the same time and you make a recommendation based upon the options reviewed at that time and run through to completion. Constantly going back to alternative ideas is wasteful, gives incomparable results and ultimately ends with nothing being moved forward.

 

[DarloRich]

Fundamentally, how much extra capacity could be gained by double-decking (remember that it inevitably cannot have dwell times as short as is possible for single-deck stock) compared to simply working on the route to extend every platform to its longest possible length, installing moving-block signalling and ensuring complete grade-separation? These steps require only targeted infrastructure changes, ensure the network is still fully compatible with the non-LTS lines and deliver higher frequencies to make journeys better and faster. If the problem is that there are not enough tracks in a specific section, build more tracks by building new bypass tunnels in a comparatively simple TBM job.

Exactly!

 

[Blamethrower]

Exactly!

Really?

Citing dwell times as a reason NOT to go with DD is moot.

Dwell times only exist to be as long as the operator wants them to be. As an easy comparison, go to Bletchley and observe the dwell time difference between a 377 and a 350.

Look at the dwell times of a pendolino, ridiculous!

It's all about providing a large enough vestibule area and large enough doors as is proven in Holland every single day. This CAN be done in the UK but it seems like every new train built has a longer dwell time due to "waiting for the train to come to a complete stop" and everyone has to listen to the siren indicating "doors opening".

You are effectively using stupid H&S initiatives to prove that DD's don't work and that is moot. We CAN (as proven by 377's and ViRMs) have a short dwell time at stations, we CAN build the stock to fit within our gauge, we CAN clear the routes for slightly larger trains.

It all depends on inclination and as British we love to bad mouth any idea because that would mean change, and we fear change. "We've always done it like this ergo...." mentality is a poison of this country.

A DD commuter service will EASILY have shorter dwell times because people can just get on and off, rather than trying to get in/out of tiny, overcrowded vestibules and 3+2 seating.

What people are assuming is that the DDs will be full from the moment they start, which they won't.

 

[Bald Rick]

Really?

Citing dwell times as a reason NOT to go with DD is moot.

You have to compare like with like.

A DD train with the same number and size of vestibules and door openings per metre length of coach will have longer dwell times than a single decker. That is on the assumption that it has more passengers on board.

What reduces dwell times is :

More doors
Wider doors
Quicker door opening / close procedure
Larger stand back area in the vestibules
Level access
Good PIS
Fewer passengers

All of these can be done regardless of how many decks the stock has. See the new Thameslink and Crossrail units.

 

[Greenback]

This idea surfaces and is discussed regularly. The consensus is always the same, it won;t work here given the constraints of the loading gauge. Unless there's a radical new idea that will solve this problem, and the associated ones of ingress, egress, dwell time, capacity, DDA compliance and so on, then nothing's really changed.

 

[Clip]

I've long thought the LTS would be a decent candidate for Double Decks. Its relatively short, no tunnels and a busy commuter line. There aren't huge amount of over-rail bridges and most of them aren't at stations/c2c served stations, so track could be lowered or the bridge rebuilt. Barking is due to be rebuilt, so the design could easily be done for taller trains. Upminster could do with a rebuild too. As for the other stations (Westcliff, Pitsea, Laindon and West Horndon) I'm sure a solution can be found.

Also the OHLE is old, so that needs replacing in the future anyway. The real major problem is the width. I think the NSW fleet the best double decks in my opinion and looks wise are far better than the European ones. What would be wrong with a 12 car train with 2+2 seating??

Erm, what about Fenchurch street? Im pretty sure you wouldn't be able to do much with it given the building on top of it. Cant lower it or you would have to lower the whole viaduct it runs in on and that would also mean having to redo the DLR too. That's gotta be pricey.

 

[swt_passenger]

...Rebuild platforms- to be lower and further from the track. Ideally straighten the stations up too. But then put a temporary surface & extension to make them compatible with current stock.

The platforms are easy compared to the bridges (oh, and not forgetting the tunnels). Visualise all those under and over bridges where the lines between Clapham Junction, Victoria and Waterloo meet and cross for instance. They are nearly all parallel multiple girder bridges, usually one track wide spans. All those girders that sit up between the tracks would need to be further apart for larger gauge trains. Now multiply that out over the whole southeast network...