Thoughts on discontinuous electrification?

[Rhydgaled]

Send out a pilotman and reverse them out.

The other gain from batteries is that you can use regenerative braking all the time, not just when something is ready to take it. It's also much simpler to stick it in a battery than into the OHLE. Merseyrail seem to have established that it more than offsets the extra weight and cost of traction-capable batteries, though admittedly third rail uses much shorter sections than 25kV OHLE.

mods note - split from here.

Merseyrail does however illustrate one of the issues with having batteries for traction (rather than just for 'hotel power' which is almost certainly worth having) - once the train is capable of moving itself without wires/3rd-rail it opens the door to discontinuous (and just plain absent) electrification of routes which really should be fully electrified (such as the MML and the 'joint line' diversionary route for the ECML via Lincoln). This isn't such a big problem on 100mph stock since the secondary routes they are intended to work will be further down the electrification priority list and the only alternative to some form of multi-mode unit is the absolutely abhorrent choice of a straight DMU, but LNER's new trains will be a 125mph fleet...

 

[Bletchleyite]

Merseyrail does however illustrate one of the issues with having batteries for traction (rather than just for 'hotel power' which is almost certainly worth having) - once the train is capable of moving itself without wires/3rd-rail it opens the door to discontinuous (and just plain absent) electrification of routes which really should be fully electrified (such as the MML and the 'joint line' diversionary route for the ECML via Lincoln). This isn't such a big problem on 100mph stock since the secondary routes they are intended to work will be further down the electrification priority list and the only alternative to some form of multi-mode unit is the absolutely abhorrent choice of a straight DMU, but LNER's new trains will be a 125mph fleet...

125mph on the wires, 90mph on diesel. The UK is full of routes where that would be quite useful. Barrow and Windermere are the famous ones, not that LNER would ever go near either.

Yes, Windermere should be wired, but the case for Barrow is poor.

 

[zwk500]

125mph on the wires, 90mph on diesel. The UK is full of routes where that would be quite useful. Barrow and Windermere are the famous ones, not that LNER would ever go near either.

Yes, Windermere should be wired, but the case for Barrow is poor.

LNER could make plenty of use of that capability on their own network - Harrogate, Sunderland, Middlesbrough, Hull, Cleethorpes etc.

 

[Bletchleyite]

LNER could make plenty of use of that capability on their own network - Harrogate, Sunderland, Middlesbrough, Hull, Cleethorpes etc.

Indeed it could, and they do with the 80x. Plus diversions, plus emergency recovery. It's a very, very useful feature to have.

 

[zwk500]

Merseyrail does however illustrate one of the issues with having batteries for traction (rather than just for 'hotel power' which is almost certainly worth having) - once the train is capable of moving itself without wires/3rd-rail it opens the door to discontinuous (and just plain absent) electrification of routes which really should be fully electrified (such as the MML and the 'joint line' diversionary route for the ECML via Lincoln).

I don't see discontinuous electrification as a problem, but rather as a pragmatic strategy to getting emissions down. Why pay for full OLE when it's not needed for many sections? The MML should be OLE on the core route (via Leicester and Derby, with the branch to Nottingham included), but batteries are fine for diverts via Manton or the Erewash Valley. The GNGE join similarly - the ordinary service doesn't justify OLE, so freight and diverts won't either. Batteries are the better option there.

Indeed it could, and they do with the 80x. Plus diversions, plus emergency recovery. It's a very, very useful feature to have.

Agreed.

 

[D365]

I don't see discontinuous electrification as a problem, but rather as a pragmatic strategy to getting emissions down. Why pay for full OLE when it's not needed for many sections? The MML should be OLE on the core route (via Leicester and Derby, with the branch to Nottingham included), but batteries are fine for diverts via Manton or the Erewash Valley. The GNGE join similarly - the ordinary service doesn't justify OLE, so freight and diverts won't either. Batteries are the better option there.

My understanding of the ”discontinuous electrification” moniker is that it infers a fully electrified route with what amounts to longer neutral sections - bridges, tunnels etc. Not unnelectrified secondary routes.

 

[Bletchleyite]

My understanding of the ”discontinuous electrification” moniker is that it infers a fully electrified route with what amounts to longer neutral sections - bridges, tunnels etc. Not unnelectrified secondary routes.

It does, and it can save a fortune.

 

[Rhydgaled]

Yes, Windermere should be wired, but the case for Barrow is poor.

I don't see discontinuous electrification as a problem, but rather as a pragmatic strategy to getting emissions down. Why pay for full OLE when it's not needed for many sections? The MML should be OLE on the core route (via Leicester and Derby, with the branch to Nottingham included), but batteries are fine for diverts via Manton or the Erewash Valley. The GNGE join similarly - the ordinary service doesn't justify OLE, so freight and diverts won't either. Batteries are the better option there.

Network Rail's TDNS came to different conclusions than both of you. Erewash valley, the 'joint line' via Lincoln and the line to Barrow were all identified as 'Core Electrification' (the rest of the Cumbrian Coast is also down for electrification but only narrowly) while batteries are proposed for Windermere. I suspect 'joint line' (and possibly Erewash) scores high because of the freight use of these lines and the lack of alternatives to diesel or electric locomotives for freight haulage.

My understanding of the ”discontinuous electrification” moniker is that it infers a fully electrified route with what amounts to longer neutral sections - bridges, tunnels etc. Not unnelectrified secondary routes.

It does, and it can save a fortune.

It could save a fortune on infrustructure costs, yes, but it puts additional costs (inc. environmental ones) onto rolling stock and operations. Increased power draw due to the weight of the batteries and all the impacts of battery manufacture.

 

[AlexNL]

Wiring throughout is obviously preferrable. That aside, using discontinuous electrification is what's made it possible for TfW to start electrifying the Valley routes in the first place. Otherwise they just wouldn't have had the money.

 

[Rhydgaled]

Wiring throughout is obviously preferrable. That aside, using discontinuous electrification is what's made it possible for TfW to start electrifying the Valley routes in the first place. Otherwise they just wouldn't have had the money.

Agreed subject to adding the qualification 'in the same timescale' at the end - given more time the money could be found (eg. the Welsh Government are hopefully going to abandon their trunk road investment programme - the current schemes are contractually committed so cannnot be stopped but in a few years time the money for the projects that were planned for implementation then would be available for other purposes).

 

[zwk500]

Network Rail's TDNS came to different conclusions than both of you.

The TDNS was about the best way to decarbonise. It did not provide even an outline business case for all schemes. Wiring windermere could be done fairly quickly and would save on fitting batteries to the fleet. Wiring the GNGE is obviously desirable in the long term especially as its the dominant freight route but it will take a long time and would need a wholesale replacement of the class 66 with electro diesels.

 

[GRALISTAIR]

Wiring throughout is obviously preferrable. That aside, using discontinuous electrification is what's made it possible for TfW to start electrifying the Valley routes in the first place. Otherwise they just wouldn't have had the money.

Agreed. Get stuuf done and infill bits can always happen later. I was dead against bimodes at first and now I realise they are useful for similar reasons.

 

[zwk500]

Agreed. Get stuuf done and infill bits can always happen later. I was dead against bimodes at first and now I realise they are useful for similar reasons.

This. A potential bimode life of 30-50 years gives scope for a lot of wiring to happen in the meantime. Only issue is making sure we don't waste time.

 

[Rhydgaled]

The TDNS was about the best way to decarbonise.

Kind of; obviously it wasn't just what was technically the best option (otherwise it would be electrification everywhere, except perhaps the odd seldom-used route where the carbon savings on the operations side are outweighed by the maintainance and construction of the electrification infrustructure). Still, surely the key thing should be getting the routes where electrification is clearly the best option (ie. those identified as 'core electrification' by the TDNS) done ASAP?

I was dead against bimodes at first and now I realise they are useful for similar reasons.

There are bi-modes and bi-modes. I can't remember what my original stance on regional bi-modes was, but I have always been dead against 125mph (and above) bi-modes because the routes they run should be way up the priority list for electrification. I will admit that even the class 80x/810 units have proved useful but, with enough diesel engines under the 80x/810 fleet to power around 200 such units, I think we have plenty of those now. I am however currently in favour of procurement of new lower-speed bi-modes (90-110mph), particularly regional express units (444 alikes) for the likes of Waterloo-Exeter. Indeed, since the publication of the TDNS I have been strongly of the view that no more single-mode units (other than straight EMUs) should ever be built for GB rail. Apparently, the 10 speculative hydrogen Aventras will be single-mode hydrogen-only units and, unless converting them to multi-mode is as simple as adding OLE compatability to a class 707 then I think this is a big mistake. Passive provision for OLE compatability has been a requirement on new third rail EMUs for many years, it's high time the same was applied to new trains for (currently) non-electrified routes.

This. A potential bimode life of 30-50 years gives scope for a lot of wiring to happen in the meantime. Only issue is making sure we don't waste time.

Yes, bi-modes appear pretty much essential to delivery of decarbonisation as recommended by the TDNS in a sensible timeframe. My go-to example of this is Wolverhampton-Shrewsbury, which is 'core electrification' but the case for wires would be weakened substantially if the units used on the Cambrian lines (where TDNS recommends hydrogen) lack OLE compatibility, unless you fancy angering the local user group by terminating their trains at Shrewsbury. Another angle on this is that having the busy part of a long route wired helps with the range issue - if you have a multi-mode train you can conserve battery-charge/hydrogen-stocks while under the wires rather than 'burning' it under the wires. So yes, bi-mode is a useful concept but can we have it more on regional units now please? InterCity has enough of 'em, get wiring.