My idea for Double Decker stock

[southern442]

Whilst this idea is purely theoretical, I believe that this could be one of the ways of solving the capacity problem in suburban areas.

The stock that would be required would have to theoretically have coaches of <23m in length, so that 10-car formations could operate. They would have to have a top speed between 70-110MPH, and would have to be able to operate in some instances where both traction currents would be needed. Obviously they would have to be not too high at the top, and therefore underside equipment would have to be moved to either the bogies or the ends of trains to allow space for the bottom deck. Seats would therefore have to be 2+2 bottom, 2+3 top with 2+2 or 2+1 in first class, which would take up a small compartment in the bottom deck of the first carriage. Vestibules would need to be at the end of carriages with a pair of wide sliding doors. They would also need to be compatible with the current platform heights (thus ruling out ex-french stock) but that would give lower deck passengers a limited view of stations. This would even out at around 125 seats per carriage, therefore including first class it would be around 500-600 seats per single unit depending on the formation.

They could be tested on the LTS line as it is a classic example of a suburban trunk route. This would also be an opportunity to trial the units and to hear passenger feedback. They could then move on to the North Kent Line and the ECML suburban routes after extensive testing on these lines, and eventually go on to SE, GA, and SWT services, and then on to the B'ham city lines and Southern. Note thameslink being omitted from this plan as it is receiving new stock already and the tunnels may not be able to take these units.

Please let me know what you think, suggest a flaw in the plan or say it won't work, I don't care . I just think this is a viable solution to the suburban capacity issues and would be an ideal compliment or replacement for the mark 3 stock and networkers.

 

[Manchester77]

The UK loading gauge is one of the most restrictive in Europe. It would probably cost more to modify the OHLE, bridges, signal gantries, tunnels etc (or in other words the infrastructure) than it would to build double decker stock. If say you did do the LTS, think of everything that would have to be modified, the OHLE would probably need to be raised (which may cause issues in places like Fenchurch street with offices on top. )

Southern tried double deckered stock (withdrawn in 1971), despite being split level, they showed the concept increased station dwell times.

To conclude its not a viable solution since as I said above the Uk network is designed roughly to the C3 gauge not the wider berne gauge which is more allowing. Look at how the 373s had to be designed to fit on the Kent classic lines!

 

[Haydn1971]

One big obstacle.... Track clearance !

Double deck rolling stock wouldn't fit under existing bridges and tunnels

 

[starrymarkb]

Biggest issue is the UK platforms, our platforms encrouch on the space underneath a standard floor, (continental stock is pretty much straight down to rail level) this means at best you could get 2+1 on the lower deck.

Heights are relatively easy in comparison as single deck stock isn't fussed by the greater clearance. But it wouldn't be possible to mix UK and Continental platforms without fitting UK size stock with a gangplank/steps at each doorway.

 

[cj_1985]

Best bet for double deck stock operating in this country in the 21st century is restricted to HS2 and possibly HS1


Edit:
Details of the 4DD units - http://en.wikipedia.org/wiki/4DD

 

[southern442]

The UK loading gauge is one of the most restrictive in Europe. It would probably cost more to modify the OHLE, bridges, signal gantries, tunnels etc (or in other words the infrastructure) than it would to build double decker stock. If say you did do the LTS, think of everything that would have to be modified, the OHLE would probably need to be raised (which may cause issues in places like Fenchurch street with offices on top. )

Southern tried double deckered stock (withdrawn in 1971), despite being split level, they showed the concept increased station dwell times.

To conclude its not a viable solution since as I said above the Uk network is designed roughly to the C3 gauge not the wider berne gauge which is more allowing. Look at how the 373s had to be designed to fit on the Kent classic lines!

That is a good point and it is the biggest danger in the plan. Now, alot of double deck stock is not any taller than regular stock. The reason for this is because the lower deck is placed where the underside equipment would normally be. It would be a tight squeeze but there would be lots of seats available as it would be in the 2+3 layout. The question of when it's full and standing is a difficult one, as the decks would be around 1.9m tall, and obviously you couldn't direct tall people to the vestibules!

As for the loading, there would be two pairs of large double doors each side, whilst on the 4DD stock, they were all compartments, so it took longer for people to find a seat.
--- old post above --- --- new post below ---

Biggest issue is the UK platforms, our platforms encrouch on the space underneath a standard floor, (continental stock is pretty much straight down to rail level) this means at best you could get 2+1 on the lower deck.

Heights are relatively easy in comparison as single deck stock isn't fussed by the greater clearance. But it wouldn't be possible to mix UK and Continental platforms without fitting UK size stock with a gangplank/steps at each doorway.

The doorways would be at standard height and on top of the bogies, with steps leading down into the lower deck.

 

[HSTEd]

Yes, but the platforms step out in a way which they don't in Europe.

Attempting to run a continental piece of rolling stock into a British platform will result in the sides of the bottom metre of the coach ripped out.


As to Height, a TGV Duplex is 4.32m tall, whilst a Class 377 is 3.78m tall.
That 54cm makes a HUGE difference.

 

[swt_passenger]

Whilst this idea is purely theoretical, I believe that this could be one of the ways of solving the capacity problem in suburban areas.

It wasn't according to the quite detailed report done for DfT a few years ago:

In conclusion the benefits from the double deck solution on the existing network do not offset the relatively low volume of additional capacity generated, the significant disruption required to adapt the routes and the resulting long term inflexibility of operation.

http://webarchive.nationalarchives....railwhitepapersupportingdocs/provevalddtrains

I recommend you read it then get back to us.

 

[southern442]

Yes, but the platforms step out in a way which they don't in Europe.

Attempting to run a continental piece of rolling stock into a British platform will result in the sides of the bottom metre of the coach ripped out.


As to Height, a TGV Duplex is 4.32m tall, whilst a Class 377 is 3.78m tall.
That 54cm makes a HUGE difference.

I ruled out continental rolling stock if you read my post again. I will edit the plan to show 2+2 on the lower and 2+3 on higher.

By making each deck 1.9m tall (which is a HUGE squeeze I know) the overall train height shouldn't be more than 3.83m tall. This height would be the absolute maximum.

 

[Eagle]

The reason for this is because the lower deck is placed where the underside equipment would normally be.

So... where are you planning to put the underside equipment then?

 

[southern442]

I recommend you read it then get back to us.

I have just read it, and it uncovers more problems such as curve radius. As much as it is a squeeze, the 1.9m height could be fairly acceptable, as long as the majority of passengers have a seat, which wouldn't be too hard considering a 10 coach formation would have the capacity of a 15 car train.

As for the traction equipment, the leading and tail coaches could be 22m rather than 20m, the extra length housing the traction equipment between the drivers cab and the vestibule, like in European stock.
--- old post above --- --- new post below ---

So... where are you planning to put the underside equipment then?

see above

 

[Eagle]

As for the traction equipment, the leading and tail coaches could be 22m rather than 20m, the extra length housing the traction equipment between the drivers cab and the vestibule, like in European stock.

If you're going that far you might as well just make it a loco-hauled service.

 

[455driver]

I ruled out continental rolling stock if you read my post again. I will edit the plan to show 2+2 on the lower and 2+3 on higher.

By making each deck 1.9m tall (which is a HUGE squeeze I know) the overall train height shouldn't be more than 3.83m tall. This height would be the absolute maximum.

So the roof, upper floor, lower floor and rail clearance will only be 3cms in total!
What are you going to make them of which will be as strong as steel but with the thickness of a sheet of tissue paper?
With the deck height of 1.9m (6ft 3in in English) where is the lighting/air conditioning and wiring going to go?

The reason double deckers work abroad is because thewy have more height and width to play with, we dont!

 

[Eagle]

Also each deck would be quite a bit less than 1.9 metres if the whole thing was 3.83 m tall, unless the lower deck extends all the way to the ground and the floor between the two decks was very thin.

 

[southern442]

If you're going that far you might as well just make it a loco-hauled service.

I don't mean the whole coach, just a small section of the front and rear coaches, like on the Paris RER. It shouldn't be that hard to put all of the extra equipment in a different place. I don't know much about this sort of thing so I'm not aware of the full list of underside equipment, and what can't be replaced, but I think some of it doesn't have to be mounted on the underside.

 

[455driver]

That is a good point and it is the biggest danger in the plan. Now, alot of double deck stock is not any taller than regular stock. The reason for this is because the lower deck is placed where the underside equipment would normally be. It would be a tight squeeze but there would be lots of seats available as it would be in the 2+3 layout..

In the opening post you say they will me 23m long and the only stock that long with 3+2 seating is the 165/166s because they run on the ex broad gauge routes out of Paddington (plus certain other specific routes) and they wont fit on the vast majority of the network without very expensive route clearance.

In your post above you are now saying the inner coaches would be 20m long and the end coaches are going to be 22m so they can house the traction equipment, which is it 20 or 23m?

20m would seriously reduce the available double deck sections (and so available passenger capacity) compared to 23m long coaches.

Make your mind up.

 

[southern442]

So the roof, upper floor, lower floor and rail clearance will only be 3cms in total!
What are you going to make them of which will be as strong as steel but with the thickness of a sheet of tissue paper?
With the deck height of 1.9m (6ft 3in in English) where is the lighting/air conditioning and wiring going to go?

The reason double deckers work abroad is because thewy have more height and width to play with, we dont!

You are right, but if you see my later posts, you can see that my point was is that the size of each deck doesn't matter that much. Maybe 1.85m would be easier (although much more of a squeeze!).
--- old post above --- --- new post below ---

In the opening post you say they will me 23m long and the only stock that long with 3+2 seating is the 165/166s because they run on the ex broad gauge routes out of Paddington (plus certain other specific routes) and they wont fit on the vast majority of the network without very expensive route clearance.

In your post above you are now saying the inner coaches would be 20m long and the end coaches are going to be 22m so they can house the traction equipment, which is it 20 or 23m?

20m would seriously reduce the available double deck sections (and so available passenger capacity) compared to 23m long coaches.

Make your mind up.

I said <23m, not 23m. Altering the plan slightly, your point about 20m coaches is a very valid one, so increasing the length to 21 or 22m would be a good option.

 

[Monty]

So in laymans terms a paper aeroplane will be more crashworthy.

Double deck trains won't happen in this country unless we see some serious money being put into rebuilding the network to the UIC loading gauge but I just don't see it happening, the electrification of the GWML is a missed opportunity IMO.

 

[Eagle]

Maybe 1.85m would be easier (although much more of a squeeze!).

Nope, I reckon you'd struggle to get 1.7 m height in there. (TGV Duplex decks are about 2 m and they're 0.6 m taller overall.)

1.7 m is 5 ft 7 in, by the way. Shorter than the average male.

 

[The Ham]

So in laymans terms a paper aeroplane will be more crashworthy.

Double deck trains won't happen in this country unless we see some serious money being put into rebuilding the network to the UIC loading gauge but I just don't see it happening, the electrification of the GWML is a missed opportunity IMO.

Depending on how crowded our network gets as (assuming HS2 is built) there maybe some good cases for converting conventional lines to cope with the larger loading gauges for stock which would otherwise require a new lne to travel a fairly short distance.

 

[Loki]

Once the time comes for new rolling stock each line should be examined on its own. If it comes down to just cutting platforms and there are no low tunnels/bridges it would be a terrible idea not to clear the line for DD stock.

Also double deckers are coming to UK on HS2. HS1 is cleared for dd as well and so is the heritage Nene Valley Railway (converted from W gauge to UIC). Basically anything that is at least UIC GA can do. Crossrail's new tunnels are also build to UIC GA but it needs changes to the old infrastructure.

 

[jopsuk]

the problem is that if we clear a line to UIC clearances, instantly the existing stock on the route would be unusable. For example, UIC GA/GB/GC stock can't enter the domestic platforms at Ashford, Ebsfleet, Stratford and St Pancras. For use with domestic stock during the Olympics, Stratford's International platforms had a wooden structure built on them that extended the platform up and out
--- old post above --- --- new post below ---
The problem is of course that very few of the busy lines are isolated in service. What could be done though is to do services spreading out from a terminal- so that express services retain their own platforms, passing non-stop through "metro" and "suburban" stations. The extremes of the widened sections would need both widened and "classic" platforms. The wide stock would not be able to divert via/into classic platforms.

But you'd still need to convert the platforms and then add Stratford-style extensions. You'd then need the new fleet to be fully built, run in and all staff trained. It would need to be delivered (by road) to a depot connected to the widened/height cleared lines.

Then, over a single blockade, you would need to withdraw the old stock, remove all the platform extensions and run some test trains just to check that the clearance works were done correctly.

Very high risk! Very expensive!

 

[Loki]

the problem is that if we clear a line to UIC clearances, instantly the existing stock on the route would be unusable. For example, UIC GA/GB/GC stock can't enter the domestic platforms at Ashford, Ebsfleet, Stratford and St Pancras. For use with domestic stock during the Olympics, Stratford's International platforms had a wooden structure built on them that extended the platform up and out

Fit extensions under the door on the existing stock. The difference is a few inches. UIC platforms are not necessarily lower.

W train on UIC platform:
http://www.flickr.com/photos/bow_legged/6824299930/sizes/l/

 

[jopsuk]

UK stock is already generally very high floor- higher, bizarrely, than the standard we've adopted for new platforms, even with new stock.

 

[6Gman]

So the roof, upper floor, lower floor and rail clearance will only be 3cms in total!
What are you going to make them of which will be as strong as steel but with the thickness of a sheet of tissue paper?

Kryptonite!

 

[The Planner]

Haven't there been threads about rolling stock designs for double decks that would fit our loading gauge before and they were looking for funding or suchlike? I may going mental though....

 

[6Gman]

Fit extensions under the door on the existing stock. The difference is a few inches.

Won't that be knocked off at conventional platforms?

 

[Loki]

Won't that be knocked off at conventional platforms?

Extensions could retract or platforms could:
http://en.wikipedia.org/wiki/Platform_gap_filler
Whichever is cheaper. But again we are talking about converting fairly self contained lines so you might need neither depending on the case.
It's a case by case basis in general however immediately dismissing any UIC conversions on any line is irrational.

 

[Yew]

Its a shame none of the bullied DD's are still in working condition. It would be interesting to see how people would react to to their interior by today's standards.

 

[Eagle]

Not a great comparison, being as they weren't actually double deck in the sense of this thread. They were split-level compartment stock.