One vehicle to rule them all?

[35B]

Looking at the five or so tenders/prospective tenders amounting to ~2,000 vehicles, largely to replace Sprinters, Networkers, and Networker Turbos, isn't there a case for procuring a single common vehicle?

A lightweight aluminium car, electric final drive, electric/battery-electric/diesel-electric (changeable) underbody rafts, 20- and 23- meter variants, level boarding, heck let's go wild and say doors at thirds and end-door variants.

Award the job to a single manufacturer to build 200-300 cars a year, at a significant discount for a decade-plus contract. When that job is done it'll be time to replace the Turbo and Electrostars. When that job is done it'll be time to replace the Aventras and Desiros. When that job is done...

...what is current will have changed, and what looks like a good deal now will feel like locking in obsolescence then.

Its a great idea, if the right train is chosen and the right deal struck. But a couple of examples should give pause for thought:
1. BR Type 1 diesel. BR stopped production of the EE Type 1 and replaced it with the Claytons, ordering over 100 off the drawing board. This was a better design for crews but didn't work in practice and BR went back to EE for another 100 of the original design
2. IEP. Hitachi got themselves a monopoly position for inter city trains by winning a DfT competition, then renegotiating it to something that could work, and (with their business partners in "Alliance Rail") locked in a significantly higher cost per seat for 27 years for a train that has known design flaws, is uncomfortable to travel in, and delivers poor reliability.
3. Bombardier Aventra EMUs. A relatively standard design, purchased in the way you suggest. The SWR units have taken the best part of 5 years longer to get into service than planned, while the GA units are poorly configured (at best)

 

[pokemonsuper9]

. I seem to recall that on the Liz on some platforms the middle doors are out of us

Specifically at Paddington High Level, where the curve is indeed quite sharp towards the country end of the station.

 

[signed]

Biggest issue with one load at one or two manufacturers is that you’ll end up with new outdated stock by year 5. Not counting the inevitable massive scale unreliability of such an order as every new stock has been. @35B with the examples that have happen.

Get a basic inter-operablity spec, and order batches with a few year separation from separate manufacturers stock that can work together as multiple sets.

Much better plan and allows for the incremental or major improvements and still keep the option of running those units together.

 

[Bletchleyite]

3. Bombardier Aventra EMUs. A relatively standard design, purchased in the way you suggest. The SWR units have taken the best part of 5 years longer to get into service than planned, while the GA units are poorly configured (at best)

Yet the 730s went into service reasonably promptly (so far as new rolling stock goes) and seem to be reasonably popular.

 

[35B]

Yet the 730s went into service reasonably promptly (so far as new rolling stock goes) and seem to be reasonably popular.

True Which suggests that, for that platform at least, the issues are around the customisation for purpose.

Which reinforces my view that proposing such a model for procurement requires a whole lot of things also to be true if it is to work, each of which undermines the basic credibility of the model

 

[61653 HTAFC]

I personally think they're a bit rubbish compared to their European counterparts (of which I'm a huge fan) and that they haven't scaled down well at all* - I find them cramped and clumsily laid out. I would love to see what Siemens and Alstom could offer, I think it could potentially be a lot better. Something like a 3 car 24m Aventra with a low floor dip between the bogies of the centre vehicle could to me be a very good compromise indeed (the diesel version being able to have a larger engine under each end vehicle, say 750hp, but none under the middle one). It's going to be hard to do that meaningfully in a 20m unit, though - I think 20m unit land might be better off doing the work to be able to get longer distance services to 24m units (as is already the case on SWR), while for low speed innersuburbans a unit that is low floor throughout with smaller wheels for a lower top speed like the near-perfect London Underground S-stock would be worth considering.

The other downside is that the FLIRT design puts a lot of stuff above the floor that doesn't need to go there in a hybrid unit with only some vehicles low floor, which wastes platform length. It's like that because it's designed for European style *really* low platforms, but if you just want to get down from 1100mm to 960mm you don't need those compromises, you can still put stuff underneath - you're only making the floor about 15cm lower which is hardly anything.

That might I suppose get you two or even three separate tenders.

* Most notably the Class 777 is in my view absolute junk from start to finish, a hugely expensive load of scrap, and I loved the idea until I set foot on one, but while the Anglian and Welsh units are doubtless an upgrade on rotting old 15x I just think they are not particularly good designs of new unit, with the multiple levels of floor inside with awkward ramps, odd window sizes, "escape windows" and cramped seating (with limited scope to alter the layout) really not doing them any favours. Yes, on Greater Anglia the Class 720 is worse, but to be honest that would be worse than an open flat wagon pulled by a diesel shunter - and the actual unit isn't bad, just the seating - the 730 is pretty OK.

The 777s may be a Stadler product, but they aren't FLIRTs... so using them as a stick to beat UK FLIRTs with is a bit harsh.

There was always going to be compromises when it came to building a FLIRT suitable for the GB network, and I think you're being a bit picky in your complaints. Internal ramps or steps aren't ideal, but the alternative is to just have a uniform floor height throughout, which means you have to continue the current practice of using ramps which have to be placed by a member of staff. I suppose GA could have just ordered yet more CAF Civities, which from an accessibility standpoint offer no improvement over the Turbostars that were being built two decades earlier. Don't let the perfect be the enemy of the good.

 

[Bletchleyite]

The 777s may be a Stadler product, but they aren't FLIRTs... so using them as a stick to beat UK FLIRTs with is a bit harsh.

777s may technically be the METRO product, but unlike other METRO products they are built using the FLIRT style body panels - compare the window surrounds and doors between these and the Newcastle units for example - they don't even look similar.

There was always going to be compromises when it came to building a FLIRT suitable for the GB network, and I think you're being a bit picky in your complaints. Internal ramps or steps aren't ideal, but the alternative is to just have a uniform floor height throughout, which means you have to continue the current practice of using ramps which have to be placed by a member of staff. I suppose GA could have just ordered yet more CAF Civities, which from an accessibility standpoint offer no improvement over the Turbostars that were being built two decades earlier. Don't let the perfect be the enemy of the good.

It would have been possible, given the low top speeds, to have done a uniform low floor on Merseyrail as per the S-stock.

But away from Merseyrail you probably can't. My preference there would be a drop between the bogies of one vehicle (ideally the centre vehicle or the centre two vehicles in the case of an even number) which would reduce the amount of this needed. I would also go for a clearly marked step with handrails rather than a ramp - it's the ramps that people seem to be easily tripping on.

I don't think I am being picky, though. I very much look forward to seeing another manufacturer's UK low floor unit design (e.g. Siemens are proposing one) and if it is better - I think it could well be if it's a dedicated UK design rather than a bodge of a UIC gauge unit into the UK gauge, the same approach having led to the cramped nature and tiny windows of the Pendolinos.

This Modern Railways article contains an artist's impression of Siemens' proposed product which is a 23m unit (probably actually nearer 24) with a drop between the bogies and doors at thirds in that dropped section - as it's designed specifically for the UK I think this may well be less of a compromise:

Establishing a secure connection ...

Siemens’ next generation Desiro Verve trains will come in EMU and battery EMU forms, with the train builder promising wide route availability and high levels of accessibility for passengers with restricted mobility.

Northern, TransPennine Express and Southeastern are seeking new trains, with longer term orders expected for Great Western Railway, Chiltern Railways and South Western Railway to replace their ageing ex-BR DMU fleets.

Desiro Verve vehicles will be 23 metres long and formed in three-to-five car sets (longer versions can be built if required), and Siemens says the trains will be able to run on all routes cleared for Class 158/159 DMUs and Mk 3 coaches. Initial versions will be offered as 25kV AC trains with battery options, but the manufacturer is considering a dual-voltage version capable of operating on 750V DC third-rail routes.

Maximum speed operating in straight electric mode is up to 110mph, and up to 100mph on battery. Siemens says experience gained with its Mireo Plus B battery units in Europe means it can guarantee a minimum range of 50 miles under all conditions for end-of-life batteries (lifespans are expected to be 20 years), with longer intervals likely for newer batteries. Just one change of battery is expected during the train’s predicted 35-year life. The batteries are based on those used on the Mireo Plus Bs, with the same Lithium titanate oxide chemistry which offers a longer cycle life and wider range of operating temperatures than lithium-ion batteries typically used in electric cars. Siemens can also offer discontinuous electrification using its Rail Charging Converter to convert power from domestic rather than high voltage supplies if desired.

Configurations
Traction power is said to be flexible depending on customer requirements, and unlike previous generation Desiros, power bogies can be located on intermediate vehicles historically running as trailers in older trains. Power bogies are based on those on the company’s Mireo fleets, while trailer bogies are those used on the Class 700/707/717 fleets operated by Govia Thameslink Railway and Southeastern. Unlike European Mireos, Desiro Verve will not be articulated.

While interior configurations are flexible, on vehicles with no PRM-compliant toilet, upwards of 70 seats per car are expected: doors will be in a 1/3 and 2/3 configuration.
Extendable electric footsteps at doorways to improve unassisted boarding are claimed to offer ‘industry-leading compliance’ with accessibility standards.

Drivers’ cabs are based on those used on the Mireo fleets, adapted for the UK loading gauge, with extensive commonality between the two designs.

Siemens plans to assemble Desiro Verve at its Goole plant, which is building the 2024 Stock trains for London Underground’s Piccadilly Line. Delivery of the first trains post-order for testing is expected within around 2.5 years. Significant pre-service testing will take place at Siemens’ Wildenrath facility.

Siemens Mobility UKI’s Head of Business Development – Rolling Stock Graeme Clark told Modern Railways he is confident Desiro Verve will win orders: “It’s an excellent product, with service-proven technology throughout,” he said.

CDAS options
Siemens’ Connected Driver Advisory System (CDAS) is being offered on Desiro Verve, and trials conducted on ScotRail Class 380 EMUs suggest its use can offer energy consumption savings of around 15% or more. While its main use is to help drivers regulate their trains to avoid stopping at red signals, on battery versions of the train, it can also be used to optimise the state of charge, suggesting coasting downhill to save energy, for example.


Siemens Mobility UKI’s Head of Sales – Rail Infrastructure, Rob Thomas, says the ongoing integration of passenger operators within DfTO offers scope for commercial models not considered viable with conventional franchising, such as offering CDAS as part of the trains’ long-term contract, with energy consumption savings over the lives of the train exceeding the cost of installation and operation.

CDAS can also be retrofitted on to any other train in the UK using the already installed GSM-R radio, and longer term potential is said to include real-time response to weather conditions, something Mr Thomas says is more feasible under an integrated railway. “The sort of whole system thinking we’re seeing on the railway now presents so many opportunities waiting to be unlocked: we are genuinely excited about the potential of CDAS to improve efficiency and safety across the network.”