Imaginary Locomotives

[Satan's Goldfish]

I think the solution it keeps coming back around to is to make the seating of the lower deck 'benches' along each side and standing room in the middle. 3+2 seating can go in the upper deck, and 2+2 for access clearance above the bogies.

 

If speed of entry/exit is an issue, what would the difference in height be between platform and lower deck? there's the option then to have 3 sets of doors per side: 1 at one end that leads to both upper, lower and above bogie decks, and 2 at the other end with 1 leading to lower deck, and the other leading to bogie and upper deck. The extra set of doors for the lower deck would just take up the space the stairs do anyway (but then there's the problem of this only working on one side of the train if the stair arrangement pictured above is used).

[Mr_Tilt]

Didn't the APT have steps? Correct me if I'm wrong. They're pointless now.

 

The APT-P Trailer cars had fold-down steps which moved before the doors opened, but the gap wasn't all that huge, and it was easy to get in and out without using the steps.

 

The APT-E only had steps under the cab doors, and they were fully retractable into the under-belly, when they bothered to do as they were designed, that is. The Joint Module entrance doors had no steps at all. 

[FPH 603]

I think the solution it keeps coming back around to is to make the seating of the lower deck 'benches' along each side and standing room in the middle. 3+2 seating can go in the upper deck, and 2+2 for access clearance above the bogies.

If speed of entry/exit is an issue, what would the difference in height be between platform and lower deck? there's the option then to have 3 sets of doors per side: 1 at one end that leads to both upper, lower and above bogie decks, and 2 at the other end with 1 leading to lower deck, and the other leading to bogie and upper deck. The extra set of doors for the lower deck would just take up the space the stairs do anyway (but then there's the problem of this only working on one side of the train if the stair arrangement pictured above is used).

And I was being told that 3+2 wouldn't work and that I'd have to use 2+1 seating! If you look at the picture above the lower deck windows sit at platform height, meaning the lower deck would be just low enough to have decent height.

[Regularity]

I think that if this was a truly viable solution for British railways, we would have seen it implemented by now.

You are discovering all the reasons why it hasn’t happened.

[Corbs]

I think that if this was a truly viable solution for British railways, we would have seen it implemented by now.

You are discovering all the reasons why it hasn’t happened.

That's kind of true of everything on this thread though.

[JimC]

I think that if this was a truly viable solution for British railways, we would have seen it implemented by now.

You are discovering all the reasons why it hasn’t happened.

That's probably true for the majority of our imaginary locomotives, except that few of them are being analysed to this level of detail.

 

The chances of us being able to solve problems the full time engineers have found insuperable are not great, but we can have fun trying and educate ourselves at the same time.

[Regularity]

That's kind of true of everything on this thread though.

I was aware of that, but most of these are fun what-ifs with an historical focus. Currently we seem to be focused on solving a major, current, problem: lack of capacity on the commuter lines due to physical restrictions (platform length, loading gauge)

[Suzie]

The problem of extra capacity has been solved in the past by other means that have now run out. We have had track quadrupling (separating fast from slow), electrification (faster acceleration and braking), longer platforms (longer trains), door to every compartment (6-wide seating), losing first class and luggage space (more seating), Less seating (more standing), motors under the coaches (no separate loco), 4-aspect signalling (closer trains), moving block signalling (even closer trains), better track (faster trains)..... Most of these have been done as a lower cost or easier to do than double decking but the time has come when there is no more that can be done in this vein, and customers are rightly expecting better accommodation so the time of the double decker is nigh if it can be done. Carefully thought out trains and a bit of re-gauging of structures (that needs to be done for freight flows anyway in most cases) may see a 50% increase in accommodation that can be used flexibly depending on flow - perhaps more standing room on Shepperton to Waterloo, more luggage space on Heathrow Connect, Bicycle racks on Cambridge to Kings Cross, extra rows of very hard seats on Liverpool Street outer suburbans, 2+1 seating in standard class on Northern...

[DavidB-AU]

If speed of entry/exit is an issue, what would the difference in height be between platform and lower deck? there's the option then to have 3 sets of doors per side: 1 at one end that leads to both upper, lower and above bogie decks, and 2 at the other end with 1 leading to lower deck, and the other leading to bogie and upper deck.

The choke point isn't the doors, it's the stairs. Comeng did a lot of work on passenger flows in their bid for the Tangara in the 1980s (although Goninan eventually won the tender).

 

 

This was the Comeng bid, with a capacity of 165 seats in the driving motor and 174 seats in the trailer.

 

 

Cheers

David

Edited February 15, 2018 by DavidB-AU

[Tiptonian]

At the risk of missing the obvious, what is wrong with 2+2 seating in the 8'8" wide lower deck? Buses and coaches are only 8'4 1/2" (2.55m). The only reason I can see for resistance to this type of unit is the complexity (and hence, cost) of the structure involved, there being very little room for an underframe. The main strength for the double deck section would have to be the mid-deck sides. Interesting, expensive, but certainly not insurmountable.

[Coryton]

That's probably true for the majority of our imaginary locomotives, except that few of them are being analysed to this level of detail.

 

The chances of us being able to solve problems the full time engineers have found insuperable are not great, but we can have fun trying and educate ourselves at the same time.

 

Exactly - if nothing else, it's interesting seeing why double decker trains haven't been done (yet).

 

I'm still surprised that the width below platform height is such an issue - there isn't a huge difference between the height above and height below...and while they weren't exactly the world's greatest trains, people travelled on 141s which were bus width.

[FPH 603]

The choke point isn't the doors, it's the stairs. Comeng did a lot of work on passenger flows in their bid for the Tangara in the 1980s (although Goninan eventually won the tender).

 

https://www.youtube.com/watch?v=otTJfKcmF-s

This was the Comeng bid, with a capacity of 165 seats in the driving motor and 174 seats in the trailer.

 

Cheers

David

Looking at that I've not only realised how the stairs are the real problem, but also that the reason I turned down the Tangara design was due to the front shape. I will redesign this to be a cross between the Comeng and my modified Goninan fronts.

[Mr_Tilt]

...and while they weren't exactly the world's greatest trains, people travelled on 141s which were bus width.

 

Maybe because they had to? Nothing better being on offer, sad to say. 

[PhilJ W]

At the risk of missing the obvious, what is wrong with 2+2 seating in the 8'8" wide lower deck? Buses and coaches are only 8'4 1/2" (2.55m). The only reason I can see for resistance to this type of unit is the complexity (and hence, cost) of the structure involved, there being very little room for an underframe. The main strength for the double deck section would have to be the mid-deck sides. Interesting, expensive, but certainly not insurmountable.

Going to bus technology again you could eliminate the underframe altogether as in the Routemaster bus.

[runs as required]

Looking at that I've not only realised how the stairs are the real problem, but also that the reason I turned down the Tangara design was due to the front shape. I will redesign this to be a cross between the Comeng and my modified Goninan fronts.

Strange how our popular Imaginary Locos thread seems to have settled into a 5 month repetitive recycling of the same ideas .

Anyone yet trawled back to page 45 (September 2017 -, 67 pages back !) when the successor to Bulleids 4DD was being pondered?

Someone had flown the Talgo principle and I enjoyed a few late nights fiddling with this version

Acting on the axiom that a double decker is a train designed by a committee ( ) I’ve put this together from what was posted earlier in this thread.

xpdd2.jpg

As you can see the prototype XPDD is to be built in the land of the Prince Bishops by Hitachi using Talgo patents as part of the forthcoming trans-Pennine electrification project.

 

It also borrows the Swiss principle of having the compliant disabled access (power) cars top and tailing the non powered Talgo units.

talgo dd.jpg

Just to recap: Talgo offers a greater overall cross section for double deck seating including full access between short articulated units (with reduced 'throw over') providing access at mezzanine vestibules every pair of double deckers in the XPDD prototype.

Livery is my grandson's favourite dating from GNER journeys up from Kings+ way back in his primary school days.

dh

and the ultimate in dd141 misery - fancy Liverpool to Great Yarmouth in this anyone?

Here's a nightmare for you...

rloline pacer ev.jpg

Ladies and gentlemen - less than 12ft 6ins from rail level  The Loline Pacer !

dh

Edit typos

Edited February 15, 2018 by runs as required

[Coryton]

Maybe because they had to? Nothing better being on offer, sad to say. 

 

Well yes and I'm not saying they were popular, but my point is that "narrow" train bodies have been used in the UK. We can argue about whether I should add "successfully" to that sentence or not but they carried people for quite a few years and I'm finding it hard to see why the (slightly) reduced width at platform height and below should be the factor that rules out double decker trains in the UK.

[Corbs]

My plan for solving congestion on the underground was to have trains a mile long, moving at 15 mph. The trains are just flat wagons. Each platform has a travelator section formed of two parts. The one nearest the running line moves at 10mph, the other at 5mph. To get on the train, which does not stop at stations, you simply walk alongside it and step sideways on to the faster travelator and eventually on to the train. The platforms are in two halfs, one for entry and one for egress. Can't see how this can go wrong

Edited February 15, 2018 by Corbs

[Compound2632]

Replace the track with travelators. Much lower maintenance.

[TheQ]

There is a fairly well known science fiction book, that my brain can't remember the name of, has exactly that. Three travellators running alongside each other at increasing speeds away from the platform. What it also says is when someone falls over at the interface between speeds you get  multiple people pile ups...

[Flying Pig]

My plan for solving congestion on the underground was to have trains a mile long, moving at 15 mph. The trains are just flat wagons. Each platform has a travelator section formed of two parts. The one nearest the running line moves at 10mph, the other at 5mph. To get on the train, which does not stop at stations, you simply walk alongside it and step sideways on to the faster travelator and eventually on to the train. The platforms are in two halfs, one for entry and one for egress. Can't see how this can go wrong

Surely this only works on the Circle Line?

[MJI]

There is a fairly well known science fiction book, that my brain can't remember the name of, has exactly that. Three travellators running alongside each other at increasing speeds away from the platform. What it also says is when someone falls over at the interface between speeds you get  multiple people pile ups...

 

By Isaac Asimov set in a megacity / arcology

Edited February 15, 2018 by MJI

[Corbs]

Surely this only works on the Circle Line?

dog bone loops at the end of the other lines

[Satan's Goldfish]

Stepping away from DD ideas briefly, discussions on the HSTs being short-formed as they're replaced by IETs got me thinking. Instead of having a power car at each end (a 4 coach set would be more than happy with just 1 power car), have a class 442 'plastic pig' style cab at one end instead. Saves a bit of train length and the maintenance cost of a class 43 that isn't really required. It also creates the situation that sets can be combined ugly end to ugly end to create a longer unit when required, or for travelling at higher speeds along certain stretches before being divided to serve 2 locations.

 

I've put a TGS by each power car, 2x TSO, then FO/Micro Buffet for each inner cab. The buffer fitted HST power cars might make a little more sense here for situations where sets in the same orientation meet.

[Coryton]

By Isaac Asimov set in a megacity / arcology

 

The Caves of Steel and the Naked Sun.

 

But I think Heinlein was there first (on a grand scale - intercity transport) with "The Roads Must Roll" 

[Regularity]

Stepping away from DD ideas briefly, discussions on the HSTs being short-formed as they're replaced by IETs got me thinking. Instead of having a power car at each end (a 4 coach set would be more than happy with just 1 power car), have a class 442 'plastic pig' style cab at one end instead. Saves a bit of train length and the maintenance cost of a class 43 that isn't really required. It also creates the situation that sets can be combined ugly end to ugly end to create a longer unit when required, or for travelling at higher speeds along certain stretches before being divided to serve 2 locations.

I've put a TGS by each power car, 2x TSO, then FO/Micro Buffet for each inner cab. The buffer fitted HST power cars might make a little more sense here for situations where sets in the same orientation meet.

With a single power unit, they would be restricted to maybe 90/95mph, I think, but the bigger question is how do you get around the forthcoming legislative requirements for accessibility, which are driving the removal from service of Britain’s, and the world’s, best DMU?

They could have used mk3 DVTs with shortform HST sets to create some comfortable long distance/cross country trains, otherwise: power car, 3 x TSO, buffet/restaurant TF, DVT.