Was 4-track Crossrail considered?

[edwin_m]

To get a 40% increase in space is well worth it, and not future-proofing the new tunnels is criminal.

According to post #22 the tunnels are in fact big enough. But perhaps you'd like to suggest how this could be exploited, given that double deck trains are too wide to pass normal British platforms and standard British trains couldn't stop at platforms that were moved back to allow for double-deck trains.

 

[AM9]

Dwell times are not significantly longer. The passengers, unless stupidity is a contagious disease transmitted by season tickets, will learn how to use them properly as they have done in other places with double-deck commuter trains like Sydney, Paris, Germany, commuter lines near New York City and southern California to name a few.

To get a 40% increase in space is well worth it, and not future-proofing the new tunnels is criminal.

Please note that I said "for all their additional cost and incovenience...". I agree that on networks where the infrastructure has a loading gauge that universally can accommodate double deck stock, the decision may be a little easier. The fact is that in the UK, the whole route, i.e. from Reading to Shenfield, Abbey Wood, and now maybe including the WCML to Tring would need to be rebuilt to at least GB+. In addition, the standard platform height in the UK is 900mm which means either that double deck stock would need three floor levels with very limited accessible space between end doors over the bogies or the trains would need their own platforms where they shared running with the national system. All this would make project much more costly, - probably leading to its abandonment. And all for a modest increase in capacity per train.
As far as dwells are concerned, both Thameslink and Crossrail should be capable of frequencies as much as 30 tph. At that level, there is an optimum ratio of train capacity vs access routes (doors) that gives the necessary performance. If trains capacity was increased by having both upper and lower saloons, the door capacity would need to be increased accordingly.
The highest rates of passenger loading and decanting is probably achieved on the Indian commuter networks. Here trains are wide very long and single deck, (not accounting for those travelling on the roof). I've travelled in double deck trains in NYC, The Netherlands, Italy and Paris. In every case, the ingress and egress of passengers is far slower than any of the high density services operated by single level stock.
Crossrail is effectively an extended metro service, just like the London Underground Metropolitan line into Buckinghamshire. Like the Met and Thameslink, Crossrail's trains will have wide open vestibules between coaches to allow rapid distribution along the train. Linear distribution along the train is impossible on multi-level stock as it would involve the use of stairs, either up or down to each of the main seating areas, - on a moving train, all slowing the movement of passengers to a crawl.
Clearly capacity per train length can be increased by double decks, its benefit is very dependent on the number of stops and service frequency. We mustn't confuse individual train capacity with route capacity.

 

[macka]

The MI 09 units on RER A are double decker, have 3 pairs of doors per carriage and are only 10 cm wider than most UK units.

The problems here are the platforms and the restrictive loading gauge. The shape of the train tapers from the floor down to the wheels, and the platform overhangs creating some space between the platform and the wheels. That's handy if you get stuck down there, but not if you want a double decker train as they need to be the same width all the way down to the bottom to create space for the lower deck.

If Crossrail obtain a dedicated set of converted platforms and ensure there is enough clearance throughout the whole route, they would be able to use double decker units. But until then there's no point in adapting the tunnels - the fact that it can be done is enough.

 

[NotATrainspott]

Any capacity gain from double-deckers would be lost when it would no longer be possible to run 30tph in future. With platform edge doors and zero gap, there will be no impediment to passengers entering or leaving the three doors per carriage and thus sub-2m dwell times in the peaks are more than feasible. With stairs, that becomes almost impossible, as no other double-deck stock is used at such a high frequency. As the frequency would have to drop, the extra seats and standing positions of the double deck stock would become pointless as overall capacity would stay the same or drop.

If double-deck stock were a good idea for metro use, we would see it being used in the various brand new metro lines in Chinese cities. Double decks are suitable for some level of 'RER-style' service through a city from suburb to suburb, but not one that runs at metro frequency through the core.

 

[starrymarkb]

SNCF have their Spacium units which are similar to the units planned for Crossrail for suburban routes around Paris. They considered Double deck and have room for it but the throughput of a single deck was higher.

Not sure if it'll continue for RER orders.

 

[HSTEd]

SNCF might be ordering single deck stock.

But RATP is ordering double deck stock to replace single deck stock for use on its RER lines.

Talgo has now also announced stock that is available with two full length gangways (one on each deck) which would allow drastically improved passenger throughput.

 

[DownSouth]

Please note that I said "for all their additional cost and incovenience...". I agree that on networks where the infrastructure has a loading gauge that universally can accommodate double deck stock, the decision may be a little easier. The fact is that in the UK, the whole route, i.e. from Reading to Shenfield, Abbey Wood, and now maybe including the WCML to Tring would need to be rebuilt to at least GB+.

So you build the bigger tunnels now, to avoid the conversation in 20 years' time being "Reading to Shenfield ... and the Crossrail tunnels would need rebuilding."

That's why you do it for future-proofing, not to see the full benefits tomorrow.

In addition, the standard platform height in the UK is 900mm which means either that double deck stock would need three floor levels with very limited accessible space between end doors over the bogies or the trains would need their own platforms where they shared running with the national system.

Same as Sydney, where the City Loop operates in a very similar manner to Thameslink and Crossrail with inbound trains turning into outbound trains as they go through. All using British-style high platforms and double-deck trains correspondingly set up for mid-level entry.

All this would make project much more costly, - probably leading to its abandonment. And all for a modest increase in capacity per train.

So you base it on an off-the-shelf design from Sydney where they have over 50 years of experience with mid-level entry (for British-style high platforms) double-deck EMUs. They have nice wide doors, and plenty of space at mid-level between the platform doors and inter-carriage doors for standing passengers, passengers with wheelchairs, bicycles and a couple of toilets per set.

Mid-level entry DD EMUs are not prohibitively expensive or specialised work either, the Downer-Hitachi joint venture outsourced the carbody construction for the newest Waratah fleet to Changchun Railway Vehicles.

And all for a modest increase in capacity per train.

Rubbish.

The newest Waratah eight car EMUs (200 metres long) have a seated capacity of 896 plus 16 wheelchair spaces.

That's only a handful of seats off being double the 458 seats on an eight car Class 350 consist which is the same length. Build them to the same full length as the Crossrail EMUs and the doubled capacity would more than account for the marginal increase in dwell time.

 

[edwin_m]

So you build the bigger tunnels now, to avoid the conversation in 20 years' time being "Reading to Shenfield ... and the Crossrail tunnels would need rebuilding."

That's why you do it for future-proofing, not to see the full benefits tomorrow.

Same as Sydney, where the City Loop operates in a very similar manner to Thameslink and Crossrail with inbound trains turning into outbound trains as they go through. All using British-style high platforms and double-deck trains correspondingly set up for mid-level entry.

So you base it on an off-the-shelf design from Sydney where they have over 50 years of experience with mid-level entry (for British-style high platforms) double-deck EMUs. They have nice wide doors, and plenty of space at mid-level between the platform doors and inter-carriage doors for standing passengers, passengers with wheelchairs, bicycles and a couple of toilets per set.

Five seconds on Google Images confirms that the Sydney double deck EMUs are flat-sided, therefore unless the trains are really narrow the local platforms must be set back further than British ones. As I have already posted British platforms are too close to the track for any sensible double deck design to operate - as others have pointed out this means British stock has to curve inwards at platform level.

I and others have also posted that the Crossrail tunnels are high enough for double deck stock if that was ever needed.

 

[NotATrainspott]

So you build the bigger tunnels now, to avoid the conversation in 20 years' time being "Reading to Shenfield ... and the Crossrail tunnels would need rebuilding."

That's why you do it for future-proofing, not to see the full benefits tomorrow.

Same as Sydney, where the City Loop operates in a very similar manner to Thameslink and Crossrail with inbound trains turning into outbound trains as they go through. All using British-style high platforms and double-deck trains correspondingly set up for mid-level entry.

So you base it on an off-the-shelf design from Sydney where they have over 50 years of experience with mid-level entry (for British-style high platforms) double-deck EMUs. They have nice wide doors, and plenty of space at mid-level between the platform doors and inter-carriage doors for standing passengers, passengers with wheelchairs, bicycles and a couple of toilets per set.

Mid-level entry DD EMUs are not prohibitively expensive or specialised work either, the Downer-Hitachi joint venture outsourced the carbody construction for the newest Waratah fleet to Changchun Railway Vehicles.

Rubbish.

The newest Waratah eight car EMUs (200 metres long) have a seated capacity of 896 plus 16 wheelchair spaces.

That's only a handful of seats off being double the 458 seats on an eight car Class 350 consist which is the same length. Build them to the same full length as the Crossrail EMUs and the doubled capacity would more than account for the marginal increase in dwell time.

It is the opinion of Network Rail and the Department for Transport that no attempt should be made about getting suburban train lines prepared for double-deck stock because the cost of doing so would be so enormous and the benefits so comparatively small. For the price of double-deck clearing most of the Southern lines in London you could build several express bypass tunnels that would allow the existing tracks to be significantly better utilised by trains that need to, increasing capacity by entire 12-car trainloads an hour while requiring spectacularly little disruption and improving both frequency and speed for both types of services. Any new high speed lines are built to UIC GC gauge so it would be more than possible to run double-deck stock on them in future if the need arises.

 

[Abpj17]

Thameslink isn’t a fair comparison. The snarl up in the core is because the trains don’t seem to be maintained to an amazing standard and because of the change from one power source to another. The faults invariably happen when the switch take place - which is in the core. Neither should be a factor for Crossrail.

 

[AM9]

Thameslink isn’t a fair comparison. The snarl up in the core is because the trains don’t seem to be maintained to an amazing standard and because of the change from one power source to another. The faults invariably happen when the switch take place - which is in the core. Neither should be a factor for Crossrail.

It is hoped that by the time the full TL & GN service runs in 2018, that the new 700s together with the upgraded changeover kit will make failures a lot less frequent. That assumes that pantographs don't get raised at the wrong time!