W12 Freight and Double-Deck passenger

[Dennyboy]

Am I correct in perceiving that the electrified network (OHLE not 3rd rail) comprises surplus headroom beyond safe-arcing-distance? Further to this I would ask something. That is (1) were all the Diesel-only routes gauge-cleared would (2) W12 Container Freight and minimally taller passenger-stock be admitted to UK rail without unavailability of diversionary routes? I do appreciate that the 30% capacity-increase incurred by 'double-decking' would need to be offset by 50% extra door-provision to avoid compromising Dwell Times at stations. Additionally, 'interdecking' could even be achieved within current Structure/Loading constraints eg upper 3-abreast seating with two side passageways/aisles.

 

[Bald Rick]

Double deck doesnt fit in W12. By a long way!

 

[eldomtom2]

Double deck doesnt fit in W12. By a long way!

What's the maximum height and width of rolling stock for W12?

 

[edwin_m]

Any of the British loading gauges is much narrower at and below platform level than on the Continent, so it would be extremely difficult to fit the lower deck of DD stock (and moving the platforms further from the track would make the station unusable by conventional stock). British Rail did some feasibility work back in the 70s or 80s but it wouldn't have looked anything like what other countries use.

 

[Bald Rick]

What's the maximum height and width of rolling stock for W12?

bith are not much higher or wider than W6 gauge, the extra is the top corners for the boxes.

 

[Dennyboy]

What's the maximum height and width of rolling

bith are not much higher or wider than W6 gauge, the extra is the top corners for the boxes.

Taking 3' 6"+ above track-level (720--960mm & POSS' the former alluding to step-framed wagons), W12 containers measure at 9' 6" height & width.

 

[swt_passenger]

What's the maximum height and width of rolling stock for W12?

W12 adds a relatively small extra width, the height is the same as W10. W12 is not the answer to using bigger passenger stock, and doesn’t on its own make electrification any easier.

 

[Nottingham59]

This diagram shows the relative sizes of W6-12 and UIC loading gauges

 

[eldomtom2]

This diagram shows the relative sizes of W6-12 and UIC loading gauges
View attachment 167966

Is that diagram right in showing that the loading gauge is pretty much the same width below platform level?

 

[Nottingham59]

Is that diagram right in showing that the loading gauge is pretty much the same width below platform level?

Straight from the horse's mouth:

https://www.networkrail.co.uk/wp-content/uploads/2022/02/Network-Rail-freight-map-intermodal-sector-with-gauge-clearance.pdf

 

[edwin_m]

Is that diagram right in showing that the loading gauge is pretty much the same width below platform level?

Yes, as I posted above all the gauges have to be compatible with the standard platform dimensions.

 

[eldomtom2]

Straight from the horse's mouth:

https://www.networkrail.co.uk/wp-content/uploads/2022/02/Network-Rail-freight-map-intermodal-sector-with-gauge-clearance.pdf

Yes, as I posted above all the gauges have to be compatible with the standard platform dimensions.

Then you might be able to squeeze something in. In Japan, the first class double-decker coaches of the E233 series used in Tokyo are roughly 20m long, 2.95m wide, and 4.05m tall - that's only 10-20cm wider and taller than a Class 755. The key question, I think, is if there's enough room below platform level.
But the key thing to remember is that this would be maximising seated capacity, not total capacity - if you're expecting people to have to stand you'd want a single-decker design, which would maximise the total passenger capacity. This is why with the Japanese example I gave double-decker coaches are only used for first class.

 

[Trainbike46]

Then you might be able to squeeze something in. In Japan, the first class double-decker coaches of the E233 series used in Tokyo are roughly 20m long, 2.95m wide, and 4.05m tall - that's only 10-20cm wider and taller than a Class 755. The key question, I think, is if there's enough room below platform level.
But the key thing to remember is that this would be maximising seated capacity, not total capacity - if you're expecting people to have to stand you'd want a single-decker design, which would maximise the total passenger capacity. This is why with the Japanese example I gave double-decker coaches are only used for first class.

In that design, the passenger space will be less than 2m tall. I don't think that's acceptable in the UK, given how many people are well over 6 ft.

 

[Indigo Soup]

In that design, the passenger space will be less than 2m tall. I don't think that's acceptable in the UK, given how many people are well over 6 ft.

If you want the passenger space to be at platform level of 0.915m - which you probably do for various practical reasons - then the dimension stack leads you to unworkable results.

Assume that a deck spacing of 1.8 metres is acceptable. It'd require most passengers to duck - remember dynamic clearance for walking, plus the structure for the deck above - so this is definitely a lower bound. That puts the top of the train at 3.6m above platform level.

Total height of the train is then 4.515m above rail level. Not only is this substantially higher than any UK loading gauge, it's also higher than UIC GA and GB gauges.

The UK's high platforms and low loading gauge make double deck stock totally impractical. Even the Amtrak Superliners aren't high enough to allow it, though some of the bigger US stock (and Russian gauge) might be adequate.

 

[mike57]

Looking at the complexities of making changes to allow double deck passenger stock in the UK, I think there are a lot of other options which could/would be explored to provide increased capacity before attempting to introduce double deckers.

The Southern Region tried a sort of half way house with the 4DD stock, and this never got beyond the prototype stage.

Having travelled on double deck TGVs in France the other issue is dwell times. French TGV services tend to have much longer gaps between stops than the UK. A crowd of travellers from two decks all exiting with luggage via the end doors and then a similar crowd boarding. Dwell times of 5 mins+ seem to be common. If the next stop is 90mins or more, which is common on routes like Paris Lyon and south impact is small, unlike the UK where some inter city services are stopping every 15-20 mins, add 5 mins per stop here and impact on journey time would be significant.

Commuter services in and around Paris also use double deckers, but these have 3 sets of very wide double doors per carriage, and a large standing/circulating area with no seating at the doors. These work pretty well but as others have said its not just the height thats the issue, they are flat sided to almost rail level, which would foul platforms in the UK.

Given the distruption and cost of regauging routes to cope you would be looking at an almost complete rebuild, and that just couldn't be justified.

 

[Trainbike46]

If you want the passenger space to be at platform level of 0.915m - which you probably do for various practical reasons - then the dimension stack leads you to unworkable results.

In many places with double deckers the lower floor is (partially) below platform level

Assume that a deck spacing of 1.8 metres is acceptable. It'd require most passengers to duck - remember dynamic clearance for walking, plus the structure for the deck above - so this is definitely a lower bound. That puts the top of the train at 3.6m above platform level.

If you were to instead assume an absolute minimum height of 2m for passengers, 20 cm between railhead and the top of the floor passengers are standing on, and 5 cm each for the floor thickness of the next floor up, and for the roof, you end up with a total height of ~4300 mm. This fits in the UIC Gauges (the lowest is 4280 mm), but not in the UK loading gauges of 4 m tall.

Assuming most passengers would have to duck is utterly unacceptable, so not worth considering.

 

[edwin_m]

In many places with double deckers the lower floor is (partially) below platform level

Yes, but that is where width is most restricted in the UK, so the lower deck becomes extremely difficult and likely impossible.

 

[Snow1964]

Is that diagram right in showing that the loading gauge is pretty much the same width below platform level?

The Wagon W6a gauge is straight sided (I think it is 2500mm wide)

Coaching stock (C1) can be bow sided, from memory it is about 2900mm at about 850mm up from floor height which was about where the protruding door handles used to be (someone will probably know the exact measurements which might have been imperial based).

The roofs profile curves are drawn from a radius in centre about 3.5m above rail height. There are plots of it somewhere, and not all companies built their bridge and tunnel arches to standard dimensions. The Cx and Wx were standardised limits that in theory any vehicle built to, will fit on any route upto the number shown. Although these days box ticking tends to mean each type is separately assessed.

Just in case you are wondering W6a is the third rail electrified route version of W6, ie a wagon to W6a can be used on third rail lines, but a W6 wagon can't

 

[MarkyT]

But the key thing to remember is that this would be maximising seated capacity, not total capacity - if you're expecting people to have to stand you'd want a single-decker design, which would maximise the total passenger capacity. This is why with the Japanese example I gave double-decker coaches are only used for first class.

The DD 'green car' 1st class vehicles are clearly less dense than other accommodation on the same train. DD allows that lower density to be squeezed in at a similar capacity per train length unit compared to the standard cars. That means the doors are dealing with a similar number of passengers and don't introduce any or much additional delay.

 

[eldomtom2]

Even the Amtrak Superliners aren't high enough to allow it, though some of the bigger US stock (and Russian gauge) might be adequate.

The Amtrak Superliners are double-decker; I think you're confusing them with the Viewliners used on trains that travel on the Northeast Corridor, which are indeed single-deck. However double-decker commuter stock is used by MARC, NJ Transit, and the MBTA for their NEC services; these coaches are about half a metre less tall than Superliners.

In that design, the passenger space will be less than 2m tall. I don't think that's acceptable in the UK, given how many people are well over 6 ft.

The average height in Japan is just 3cm less than the average height in the UK.

 

[Indigo Soup]

The Amtrak Superliners are double-decker; I think you're confusing them with the Viewliners used on trains that travel on the Northeast Corridor, which are indeed single-deck. However double-decker commuter stock is used by MARC, NJ Transit, and the MBTA for their NEC services; these coaches are about half a metre less tall than Superliners.

No, I mean the Superliners. Their lower deck is below the level of either UK platforms (915mm) or US 'high' platforms (1220mm), as well as below bogie level. They get away with it by having the lower deck between the bogies, and having access between coaches on the upper deck only.

 

[Trainbike46]

The average height in Japan is just 3cm less than the average height in the UK.

I can't comment on what is and isn't acceptable in Japan. I'm just saying that a height from floor to ceiling of less than 2 metres would be unacceptable in the UK, given the reasonably large number of people well over 6 foot.
I'd also add that a small difference in average height can mean a very big difference in numbers at a given height, especially if the given height is near the extremes of the distribution

 

[Dennyboy]

In many places with double deckers the lower floor is (partially) below platform level

If you were to instead assume an absolute minimum height of 2m for passengers, 20 cm between railhead and the top of the floor passengers are standing on, and 5 cm each for the floor thickness of the next floor up, and for the roof, you end up with a total height of ~4300 mm. This fits in the UIC Gauges (the lowest is 4280 mm), but not in the UK loading gauges of 4 m tall.

Assuming most passengers would have to duck is utterly unacceptable, so not worth considering.

There'd still be scope to interlace the decks lest the need for 2-fold 2m headroom. 3-abreast upstairs with 2 side-aisles need not compromise the lower-deck's Standing Capacity much. OK, ramped access to lower deck via end-doors, coupled with stepped access from a central door, need not sufficiently reduce Standing Capacity to offset 30% gains in Seating Capacity.