Discontinous electrification to permit battery trains on existing routes

[Nottingham59]

Splitting from https://www.railforums.co.uk/threads/is-electrifying-windermere-worth-it.231413/ I was struck to realise that with battery trains you only need to electrify from Bicester Station to Winslow station to electify the whole of East-West Rail.

BEMUs like the Stadler Flirt AKKU need 20mins to recharge, and this gives them 80km/50m guaranteed range. At 100mph, this means 30miles of OHLE, but much less than this if the recharging section included station stops (where you would have to have special wide conductors to cope with the localised heating).

Where else could a short length of OHLE allow existing diesel services to be electrified?

 

[MarkyT]

Splitting from https://www.railforums.co.uk/threads/is-electrifying-windermere-worth-it.231413/ I was struck to realise that with battery trains you only need to electrify from Bicester Station to Winslow station to electify the whole of East-West Rail.

BEMUs like the Stadler Flirt AKKU need 20mins to recharge, and this gives them 80km/50m guaranteed range. At 100mph, this means 30miles of OHLE, but much less than this if the recharging section included station stops (where you would have to have special wide conductors to cope with the localised heating).

Where else could a short length of OHLE allow existing diesel services to be electrified?

It's quite likely the Oxford area will be electrified by the time EWR is complete. Milton Keynes trains will be under the wires once they join the WCML and the Bedford and Cambridge areas are also electrified. This line should definitely be electrified througout, and the time to do it with least cost and disruption is during ongoing construction. Discontinuous techniques have their niches I'm sure, but more likely at peripheries of the network and on branches, not on a major interegional cross country link in the middle of England.

 

[snowball]

Discontinuous electrification as a means to eventul continuous electrification seems to be official policy in Scotland, as stated in this post from last summer (post #18 in the linked thread):

Scotrail future plans for network enhancements

This video has some information about ScotRail's future plans for the network in Scotland

www.railforums.co.uk

 

[Nottingham59]

electrified througout

In an ideal world Yes. But electrifying the full length of would cost three times as much as just Bicester to Winslow. Which approach do you think the Treasury will pay for?

== Doublepost prevention - post automatically merged: 22 May 2022 ==

Discontinuous electrification as a means to eventul continuous electrification seems to be official policy in Scotland,

Yes. In the map at 29:00 on that video, they show the places that would be electified by 2035, and the gaps in between that would not. In this thread, I was trying to work out what a similar programme of discontinuous electrification in England might look like.

My ideas so far

• Cheltenham station to Gloucester station. Would allow batterification of the XC Cardiff - Nottingham service. Extending north along the mainline to around Ashchurch would enable BEMUs to be used on the Cross Country route from Bristol TM to Newcastle.

 

[MarkyT]

In an ideal world Yes. But electrifying the full length of would cost three times as much as just Bicester to Winslow. Which approach do you think the Treasury will pay for?

Clearly, the discontinuous battery approach would be better than diesel throughout or inefficient potentially dodgily sourced hydrogen. It also wouldn't preclude further wiring extensions.

 

[61653 HTAFC]

Gaps in electrification should really be reserved solely for particularly difficult structures, such as the bridge/ticket hall at Wigan Wallgate.
With discontinuous electrification in open countryside, where are the savings? If it's just fewer masts required it's a bit of a false economy, as the various different wired sections still need a grid supply point and/or a high voltage cable linking them. The masts and wires aren't the expensive part.

Likewise batteries themselves have their uses, but are a pretty inefficient way of supplying power to your trains if there aren't other constraints preventing full electrification.

 

[Nottingham59]

With discontinuous electrification in open countryside, where are the savings?

The savings come from the fact that you electrify only in the open countryside. If you need, say, a 10-mile stretch somewhere along the line from A to B, then you choose the 10-mile stretch in open countryside with no overbridges. Or two 5-mile streches. The beauty of discontinuous is that it avoids having to rebuild bridges and other structures which are the most expensive element of any electrification scheme.

the various different wired sections still need a grid supply point

Yes, agreed: as you would need grid supply for any full electrification scheme.

And in many cases there will already be a grid supply available.

• In my EWR example,above, I'd use the HS2 supply at Calvert.
• For Cheltenham-Gloucester, I'd use the 400kV substation which is about 500m away from the railway in Gloucester. (See https://openinframap.org/#14.7/51.87689/-2.25256 for details)
• For Nottingham-Norwich, I think you only need to electrify Ely - Thetford, which can be fed from the WA mainline at Ely.
• For Birmingham-Stansted, I think you only need to do Syston-Melton, which can be fed from the proposed MML supply. BEMUs would be able to use existing OHLE at Birmingham, Leicester, Peterborough, Ely-Stansted. So we decarbonise a 100-mile service with just a few miles of new masts.

As routes like MML and Huddersfield get electrified, there are many opportunities now opening up to batterify other routes that cross them, with minimal extra investment. That's what I'm trying to explore in this thread.

 

[A0]

It's quite likely the Oxford area will be electrified by the time EWR is complete. Milton Keynes trains will be under the wires once they join the WCML and the Bedford and Cambridge areas are also electrified. This line should definitely be electrified througout, and the time to do it with least cost and disruption is during ongoing construction. Discontinuous techniques have their niches I'm sure, but more likely at peripheries of the network and on branches, not on a major interegional cross country link in the middle of England.

It's been pointed out on here (several times in fact) the reason EWR isn't being wired as part of its construction is because of the works needed in the Oxford area and when that's wired, it will be possible to do EWR as well.

 

[zwk500]

Discontinuous electrification is likely to be of most benefit for things like Crosscountry Brimingham-Stanstead and EMR Liverpool-Norwich trains, where the train intersects numerous main lines that deserve electrification but e.g. Melton Mowbray would struggle to justify OLE. I can also see cases where a majority of train terminate at a location but some continue on for being a limited electrification scheme.

To only electrify part of a plain line route (such as only doing the middle third of Oxford-Bletchley) would seem to be a false economy to me.

 

[Nottingham59]

the Oxford area and when that's wired, it will be possible to do EWR as well.

If Oxford were wired, then you wouldn't have to electrify EWR at all. It's only 33 miles from Oxford North junction to Bletchley, well within the 50-mile range of modern BEMU's.

Melton Mowbray would struggle to justify OLE.

I advocated wiring out to Melton as I don't think there would be enough time under the wires between Wigston and Syston for a BEMU to recharge fully. Obviously, if we had BEMUs that could recharge in less than the 20 minutes of the Flirt AKKU, then the MML wiring through Leicester would be enough.

To only electrify part of a plain line route (such as only doing the middle third of Oxford-Bletchley) would seem to be a false economy to me.

I'm just pointing out that you can electrify a route for a third of the infrastructure cost of wiring the whole route. Less than a third if you choose the recharge section wisely to avoid overbridges, complex junctions and big stations.

And if you later decide to wire the whole route, then you could cascade the BEMUs to other places.

For instance, Paddington-Oxford services could be run with battery trains today. It's only 13 miles from Didcot to Oxford. (Though you would want some sort of shore supply at Oxford to service BEMUs stabled there overnight.)

And when you put the wires up at Oxford, cascade those battery trains to the EWR Oxford-MK service, or elsewhere.

 

[Dai Corner]

Extensive use of discontinuous electrification is being made in the Cardiff Valleys (South Wales Metro) scheme.

 

[Magdalia]

Discontinuous electrification is likely to be of most benefit for things like Crosscountry Birmingham-Stansted and EMR Liverpool-Norwich trains, where the train intersects numerous main lines that deserve electrification but e.g. Melton Mowbray would struggle to justify OLE. I can also see cases where a majority of train terminate at a location but some continue on for being a limited electrification scheme.

To only electrify part of a plain line route (such as only doing the middle third of Oxford-Bletchley) would seem to be a false economy to me.

This is an interesting idea.

Ely-Peterborough might be a good section for discontinuous electrification. The line has few overbridges and would provide a reasonably long section for bimode battery/electric units on both routes to recharge.

It would also create a fully electrified ECML diversion.

 

[HSTEd]

With static frequency converters there is no reason a 25kV overehad installation requires any greater power supply arrangements than an equivaelnt power consumption third rail scheme.

Indeed you could potentially provide a (low power) 25kV supply from an 11kV distribution feeder, just as BR did in the past for third rail.

In addition SFCs will allow multiple feeding points to cooperate to supply a train with large parts of the overhead line system operated in parallel, without risking overloading any feeder.

This makes "discontinuous" electrification somewhat less expensive, although compared to this new fangled insulation paint thing for bridges, I don't know how much it actually would save.

 

[A0]

This is an interesting idea.

Ely-Peterborough might be a good section for discontinuous electrification. The line has few overbridges and would provide a reasonably long section for bimode battery/electric units on both routes to recharge.

It would also create a fully electrified ECML diversion.

BIB - only IF the electrification is to the standard which can take high draw units. Wasn't there a point made previously about the Hitchin - Cambridge electrification being capable of handling the current draw of the suburban EMUs being sent up there but sending a 91 or now an 8xx would be more than its designed to take ? Same with the wiring to Ilkley back when GNER used to run a service from there.

 

[Magdalia]

BIB - only IF the electrification is to the standard which can take high draw units. Wasn't there a point made previously about the Hitchin - Cambridge electrification being capable of handling the current draw of the suburban EMUs being sent up there but sending a 91 or now an 8xx would be more than its designed to take ? Same with the wiring to Ilkley back when GNER used to run a service from there.

That was indeed the case for the original specifications when Royston-Cambridge and Cambridge-Kings Lynn were first electrified. There's never been a problem for Hitchin-Royston.

There's been a lot of upgrading work since, to allow 8 car and then 12 car EMU operation. Is the draw on a 9 car 8xx unit significantly greater than a 12 car class 387 or FLU class 700?

 

[MarkyT]

It's been pointed out on here (several times in fact) the reason EWR isn't being wired as part of its construction is because of the works needed in the Oxford area and when that's wired, it will be possible to do EWR as well.

Funny, I thought it was a Grayling-era Government decision to abandon previously planned wiring at a time it had become extraordinarily unpopular after the original GWML project failings. It's possible the department's 'detailed report' that informed that decision pointed out dependency nuance but I don't think it was ever claimed officially in the public domain. An all-electric EWR would require wires into the north bay platforms at least at Oxford main station, while the OPs suggestion could allow wires on EWR elsewhere to be provided and battery used into Oxford, even though eventually the wires would also exist in the Chiltern/EWR facilities at Oxford. I believe the enabling work for the electrification of the Oxford area is now largely complete, namely resignalling and track layout remodelling, so the question is why are authorities not now getting on with the wiring? It would provide tangible benefits in allowing local stopping services to convert to EMU and a significant number of DMUs to be released. Seems like a DfT decision is required, as with EWR.

 

[Nottingham59]

Extensive use of discontinuous electrification is being made in the Cardiff Valleys (South Wales Metro) scheme.

Interesting. Would that be short lengths of non-conducting contact wire to allow the wires go under bridges? I've not heard of any of traction batteries to enable long lengths without wires in the Valleys.

IF the electrification is to the standard which can take high draw units.

Yes, of course. If you only electrify one third of a route, then on average trains would take three times their usual current draw when they were recharging. And you would need very roubust contact wires at stations, as there would be high current draw there when trains were stationary.

====

One further route for consideration:

• Electify Kidderminster-Dorridge; Bicester North-Princes Risborough; Wembley Stadium- Marylebone. I think this would enable BEMU's for the entire Chiltern network. The longest section off the wires would be 40 miles, well within the target 50mile range. (EDIT:you'd need a BEMU with third rail pick-up, or else install OHLE between Aylesbury and Wendover.)

 

[Taunton]

BEMUs like the Stadler Flirt AKKU need 20mins to recharge, and this gives them 80km/50m guaranteed range. At 100mph, this means 30miles of OHLE, but much less than this if the recharging section included station stops (where you would have to have special wide conductors to cope with the localised heating).

Where else could a short length of OHLE allow existing diesel services to be electrified?

I've encountered a range of battery applications over many years, from battery buses in the 1970s (there were several) to a Tesla, and the over-riding consistency is that battery sustainability just never achieves its specification, for whatever reason - over optimism, deterioration of the battery, utopian conditions only, plain lies by the sales team.

You only have to look at various RAIB reports about modern broken down trains (Kentish Town, Lewisham, etc) where the on board emergency batteries have failed long before their stipulated holdover times.

 

[MarkyT]

That was indeed the case for the original specifications when Royston-Cambridge and Cambridge-Kings Lynn were first electrified. There's never been a problem for Hitchin-Royston.

There's been a lot of upgrading work since, to allow 8 car and then 12 car EMU operation. Is the draw on a 9 car 8xx unit significantly greater than a 12 car class 387 or FLU class 700?

Royston was the limit of wiring in the original GN electrics scheme in the late 70s. Royston to Cambridge remained a DMU shuttle for a further decade.

 

[Nottingham59]

battery sustainability just never achieves its specification, for whatever reason - over optimism, deterioration of the battery, utopian conditions only, plain lies by the sales team.

That is always a risk. But the Stadler Flirt AKKU has gone a record distance of 225km on one charge, and the company only guarantees 80km, so that's a 200% safety margin. For details, see the link below:

the Stadler FLIRT Akku which has 80 kilometres guaranteed by the company, according to this: https://www.railtech.com/rolling-st...kku-sets-world-record-for-battery-only-range/

Personally, if I was specifying an order of BEMUs for the GB network, I'd want a small biodiesel engine running to act as a range extender for emergency use and diversionay routes. But specify the battery capacity to be able to cope with all expected normal loads.

The engine could be very small and efficient as it would be used to top up the battery rather than providing traction power directly. But that's just me suffering from range anxiety. The German's aren't worrying about it. See this thread: https://www.railforums.co.uk/thread...nger-service-in-germany-and-elsewhere.227375/

 

[Taunton]

Personally, if I was specifying an order of BEMUs for the GB network, I'd want a small biodiesel engine running to act as a range extender for emergency use and diversionay routes. But specify the battery capacity to be able to cope with all expected normal loads.

The engine could be very small and efficient as it would be used to top up the battery rather than providing traction power directly. But that's just me suffering from range anxiety.

This is like the Boris Buses in London, with a small engine and hybrid electric propulsion. One notices over time that the engines are running more and more.

 

[Dai Corner]

Interesting. Would that be short lengths of non-conducting contact wire to allow the wires go under bridges? I've not heard of any of traction batteries to enable long lengths without wires in the Valleys

The tricky bits like low bridges, Caerphilly Tunnel, Cardiff Queen Street and Central station. Also the Network Rail owned lines the Welsh Government don't want to pay them to electrify.

It's political as well as technical!

 

[snowball]

Interesting. Would that be short lengths of non-conducting contact wire to allow the wires go under bridges? I've not heard of any of traction batteries to enable long lengths without wires in the Valleys.

I think conducting and earthed rather than non-conducting?

 

[MattRat]

In an ideal world Yes. But electrifying the full length of would cost three times as much as just Bicester to Winslow. Which approach do you think the Treasury will pay for?

Neither. They'll buy diesel bi modes with more range.