Scottish Electrification: Stock

[CBlue]

Class 600 is the designation for the Hydrogen class 321 project.

Now it’s been classified people will suggest it for everything including replacing all electric fleets (including similar units that they are being converted from) it would now seem.

Of course, there's never a rationale for this beyond "I'd find it interesting"....

There was a thread on here a short while ago that got filled with all sorts of wonderfully silly (and somewhat tongue-in-cheek) suggestions....

An overhead electric Intercity fleet of 5 and perhaps 7 car trains that don’t need to be walked through - 80Xs look fine for this and they don’t even need to be bi-mode. These would be on Inter7City services. Being 140mph capable to enable future line improvements would be good, though it may not be used for a fair bit of time.

Personally I'd like to see more Stadlers in use than 80x on the intercity services around Scotland, especially when you consider that 125mph capability is overkill on the current alignments.....


140mph however is pure pie-in-the-sky with what signalling and infrastructure improvements are required against time saved by the speed increase (a matter of minutes)

And a hydrogen -and- battery fitted unit? What's the point of having both?

 

[HST43257]

And a hydrogen -and- battery fitted unit? What's the point of having both?

Honestly more about which type starts to get going first in terms of being safe and efficient etc.

 

[HST43257]

140mph however is pure pie-in-the-sky with what signalling and infrastructure improvements are required against time saved by the speed increase (a matter of minutes)

It’s just a thought, given that the Intercity stock would stick around for a good 40 or 50 years. Upgrades of some sort, at least to 125mph, would be good I think.

 

[Mollman]

Apologies if I am late to this but wasn’t the East Kilbride Elecrification already part of CP6 and that was where, the now cancelled, additional 10 385 were being bought for.?

By time new scotrail franchise takes over and new rolling stock ordered/leased, that line will already be complete and waiting......for how long

The additional 385 are technically not cancelled as they were never ordered but optional extra units based on Abellio operating the full length of the franchise. I assume (though could be wrong) that this was based on the logic that if (as is happening now) the optional franchise extension was not taken up the winner of the new franchise would order new stock not longer after the time Abellio would order the extra units had it got the extension.

 

[gingertom]

The additional 385 are technically not cancelled as they were never ordered but optional extra units based on Abellio operating the full length of the franchise. I assume (though could be wrong) that this was based on the logic that if (as is happening now) the optional franchise extension was not taken up the winner of the new franchise would order new stock not longer after the time Abellio would order the extra units had it got the extension.

As the break clause in the franchise was exercised the option for the 10 extra class 385s expired as the 2 were linked. Strange scenario really, as whoever is running the railway now and in the future is going to need those units once those extra wires go up.

 

[NotATrainspott]

I don't think Hitachi are in any rush to close down the 385 production line. The business value of being able to deliver a proven, reliable fleet with the option of a Hyperdrive-sourced battery is pretty huge. Just as the 385 fleet was designed for the EGIP spec, the people at Hitachi will be eyeing up the likelihood of a battery electric Class 170 replacement for Fife and other places. From a marketing perspective alone, having Hitachi branded trains run over the world-famous Forth Bridge under battery power each day will do quite a lot.

 

[GRALISTAIR]

I don't think Hitachi are in any rush to close down the 385 production line. The business value of being able to deliver a proven, reliable fleet with the option of a Hyperdrive-sourced battery is pretty huge. Just as the 385 fleet was designed for the EGIP spec, the people at Hitachi will be eyeing up the likelihood of a battery electric Class 170 replacement for Fife and other places. From a marketing perspective alone, having Hitachi branded trains run over the world-famous Forth Bridge under battery power each day will do quite a lot.

And that is what I called excellent short, medium and long term thinking. Kudos to Hitachi.

 

[Class 170101]

As the break clause in the franchise was exercised the option for the 10 extra class 385s expired as the 2 were linked. Strange scenario really, as whoever is running the railway now and in the future is going to need those units once those extra wires go up.

In the interim Renatus Class 321s displaced from GA might be able to stand in until new trains are built.

 

[gingertom]

In the interim Renatus Class 321s displaced from GA might be able to stand in until new trains are built.

or perhaps the 365s will make a another short comeback?

Does anyone in-the-know know what the differences are between Hitachi's AT200/385 and the metro AT100, and whether these latter units would be more suited to the Cathcart Circle etc?

 

[Philip Phlopp]

or perhaps the 365s will make a another short comeback?

Does anyone in-the-know know what the differences are between Hitachi's AT200/385 and the metro AT100, and whether these latter units would be more suited to the Cathcart Circle etc?

The AT family are all derived from the same basic structure. The AT100 is designed for metro operations, with suggested interior layouts featuring longitudinal and transverse seating and can have three sets of doors per side (so it's basically like the CrossRail stock). The AT200 is designed for longer distance commuter routes, and would be equivalent to the 100mph/110mph Electrostar family or those dreadful CAF Class 331 units, with two sets of doors at 1/3rd intervals, and the AT300 family is obviously the faster end door stock - 125mph/140mph/155mph capable units, can come in 20m, 23m and 26m lengths and in electric or bi-mode versions. I suppose, in terms of other stock, they're most like those catastrophically unreliable CAF Class 397 units in terms of speed and layout, Hitachi of course managed to make their rolling stock be reliable(ish).

 

[Philip Phlopp]

In the interim Renatus Class 321s displaced from GA might be able to stand in until new trains are built.

They're non standard to the current pool of Class 320 units (both the original units, and the ex Class 321 conversions).

 

[gingertom]

The AT family are all derived from the same basic structure. The AT100 is designed for metro operations, with suggested interior layouts featuring longitudinal and transverse seating and can have three sets of doors per side (so it's basically like the CrossRail stock). The AT200 is designed for longer distance commuter routes, and would be equivalent to the 100mph/110mph Electrostar family or those dreadful CAF Class 331 units, with two sets of doors at 1/3rd intervals, and the AT300 family is obviously the faster end door stock - 125mph/140mph/155mph capable units, can come in 20m, 23m and 26m lengths and in electric or bi-mode versions. I suppose, in terms of other stock, they're most like those catastrophically unreliable CAF Class 397 units in terms of speed and layout, Hitachi of course managed to make their rolling stock be reliable(ish).

I was meaning more about the running gear rather than the seating layout. I gather from other threads that the 385s aren't happy on the Cathcart routes, traction motor temperature issues.

 

[Philip Phlopp]

I was meaning more about the running gear rather than the seating layout. I gather from other threads that the 385s aren't happy on the Cathcart routes, traction motor temperature issues.

The running gear is essentially shared across all three iterations of the family.

 

[Clansman]

I was meaning more about the running gear rather than the seating layout. I gather from other threads that the 385s aren't happy on the Cathcart routes, traction motor temperature issues.

As expected with 100mph EMUs designed for faster and longer running. Pretty much the consequence of previous rolling stock strategies of bit part solutions for Glasgow over the years. Though to be fair, whatever displaces them, will most certainly be a gain when there's x amount of 385s available for use on core routes in future. So perhaps not so consequential (just realised I've essentially tied up my own argument aloud!).

They're non standard to the current pool of Class 320 units (both the original units, and the ex Class 321 conversions).

Agreed. If anything if ScotRail were desperate for more 321s, it's more in their interests to go non Renatus for that very reason. At the stage that the fleet's at, it's all about the basics of short term capacity and operational flexibility over going for something far more complex for the sake of it's potential lifespan/superior interior and traction fittings.

 

[43096]

Agreed. If anything if ScotRail were desperate for more 321s, it's more in their interests to go non Renatus for that very reason. At the stage that the fleet's at, it's all about the basics of short term capacity and operational flexibility over going for something far more complex for the sake of it's potential lifespan/superior interior and traction fittings.

They’d be best going for the 321/9s and 322s in that case, being the only non-Renatus PRM modified sets.

 

[snookertam]

I was meaning more about the running gear rather than the seating layout. I gather from other threads that the 385s aren't happy on the Cathcart routes, traction motor temperature issues.

Most unit diagrams On the Cathcart routes have long (25 minute plus) lay over times at one point. Only ones that don’t are the Glasgow Central -Newton via Queens Park workings. Even at that, I’d have thought any issue would be a more longer term wear and tear one, as opposed to a day-to-day performance risk. No class of electric unit has ever been banned from the line for this reason.

 

[snookertam]

As expected with 100mph EMUs designed for faster and longer running. Pretty much the consequence of previous rolling stock strategies of bit part solutions for Glasgow over the years. Though to be fair, whatever displaces them, will most certainly be a gain when there's x amount of 385s available for use on core routes in future. So perhaps not so consequential (just realised I've essentially tied up my own argument aloud!).


Agreed. If anything if ScotRail were desperate for more 321s, it's more in their interests to go non Renatus for that very reason. At the stage that the fleet's at, it's all about the basics of short term capacity and operational flexibility over going for something far more complex for the sake of it's potential lifespan/superior interior and traction fittings.

It would make sense for when East Kilbride and Barrhead are electrified to get more 321 to 320 conversions to create a more standardised fleet to work interchangeably with the Cathcart routes.

equally they could go all in and seek a new build unit for around this time, replacing the 318s and 320s but I think they’ll wait until around 2030 for that. More conversions could be a decent stop gap between electrification and the need to replace.

 

[ABB125]

I would suggest the following (with the caveat that I am totally unfamiliar with Glasgow suburban services!):

• Fleet of "metro" commuter trains for use around Glasgow, specifically built for frequent stops. If we're sticking with Hitachi, AT100 units, possibly with a 75/90 mph design speed (depends on which lines they would operate). To replace class 318/320
• More class 385s for "outer suburban" services, possibly replacing class 334s. Used on Fife circle stuff amongst other things
• Longer distance services (seven cities) operated with a new fleet of AT300 derivatives (probably 26m coaches to match the LNER ones, but not necessarily)

 

[gingertom]

I would suggest the following (with the caveat that I am totally unfamiliar with Glasgow suburban services!):

• Fleet of "metro" commuter trains for use around Glasgow, specifically built for frequent stops. If we're sticking with Hitachi, AT100 units, possibly with a 75/90 mph design speed (depends on which lines they would operate). To replace class 318/320
• More class 385s for "outer suburban" services, possibly replacing class 334s. Used on Fife circle stuff amongst other things
• Longer distance services (seven cities) operated with a new fleet of AT300 derivatives (probably 26m coaches to match the LNER ones, but not necessarily)

sounds like a sensible, workable plan. I do think that any new train fleet(s) would be acquired by competitive tendering. Hitachi is the obvious choice but I'm sure Siemens, Bombardier, Caf, Stadler, etc, each have suitable products, would all be after a big slice of the pie. Don't forget Talgo: they are after bigger fish for setting up a factory at Longannet but an order to cover Scotrail's EMU requirements for the next 40 years is going to be some size- such an undertaking would create many Scottish jobs and could swing the decision their way. Ticks an awful lot of boxes.

 

[NotATrainspott]

And a hydrogen -and- battery fitted unit? What's the point of having both?

Hydrogen fuel cell vehicles need to have batteries because the fuel cells can't deliver enough for peak power requirements. It's one of the many drawbacks of hydrogen as a vehicle propulsion technology. You need many more components than a pure battery solution, which increases costs and reduces reliability and efficiency.

I think one of the requirements for the scenic train design is that it'll be capable of 100mph, at least under AC electric power. That will make sure it won't ever have a problem fitting into the rest of the railway network - e.g. if you want to run some summer WHL services to Edinburgh in an E&G path.

What could be quite useful would be if the scenic stock were capable of taking on 'seven cities' duties if required. In my mind the scenic train stock would end up being split between the Glasgow and Inverness hubs, and it might be a good idea for them to run some Glasgow-Inverness runs to shuttle back and forth for maintenance.

The Stadler low-floor design would appear to be quite suitable for scenic duties since it reduces stepping distances at the rural platforms. Stadler have made a name for themselves by building specialised rolling stock for specific purposes, and a good sized run of Flirt derivatives with larger windows wouldn't be much of a challenge.

 

[gingertom]

Hydrogen fuel cell vehicles need to have batteries because the fuel cells can't deliver enough for peak power requirements. It's one of the many drawbacks of hydrogen as a vehicle propulsion technology. You need many more components than a pure battery solution, which increases costs and reduces reliability and efficiency.

I think one of the requirements for the scenic train design is that it'll be capable of 100mph, at least under AC electric power. That will make sure it won't ever have a problem fitting into the rest of the railway network - e.g. if you want to run some summer WHL services to Edinburgh in an E&G path.

What could be quite useful would be if the scenic stock were capable of taking on 'seven cities' duties if required. In my mind the scenic train stock would end up being split between the Glasgow and Inverness hubs, and it might be a good idea for them to run some Glasgow-Inverness runs to shuttle back and forth for maintenance.

The Stadler low-floor design would appear to be quite suitable for scenic duties since it reduces stepping distances at the rural platforms. Stadler have made a name for themselves by building specialised rolling stock for specific purposes, and a good sized run of Flirt derivatives with larger windows wouldn't be much of a challenge.

there's an article on how the hydrogen fuel cell operates in another thread. Basically there's 2 things: the fuel cells aren't sized to produce the train's total PEAK energy requirement, and a fuel cell can only give full output or no output, there's no inbetween. So when starting off and accelerating, the fuel cells give their all and the batteries make up the shortfall. When cruising, decelerating and (regenerative) braking the cells produce more energy than needed, so the batteries get charged. When the batteries approach full charge, the cells are shut off.

Stadler's Flirt power module has 4 rafts, I'd suggest for WHL etc 3 sets of batteries and one emergency diesel. I wouldn't like to think it is out of gauge and foul any of the tunnels.

 

[Philip Phlopp]

there's an article on how the hydrogen fuel cell operates in another thread. Basically there's 2 things: the fuel cells aren't sized to produce the train's total PEAK energy requirement, and a fuel cell can only give full output or no output, there's no inbetween. So when starting off and accelerating, the fuel cells give their all and the batteries make up the shortfall. When cruising, decelerating and (regenerative) braking the cells produce more energy than needed, so the batteries get charged. When the batteries approach full charge, the cells are shut off.

Stadler's Flirt power module has 4 rafts, I'd suggest for WHL etc 3 sets of batteries and one emergency diesel. I wouldn't like to think it is out of gauge and foul any of the tunnels.

Just wire the whole lot, it'll be cheaper than this bespoke nonsense in the long term.

 

[gingertom]

Just wire the whole lot, it'll be cheaper than this bespoke nonsense in the long term.

agreed.

The bespoke nonsense decarbonises whilst electrification progresses.

 

[NotATrainspott]

Batteries won't be bespoke, thankfully. The same battery tech will be used across the world, leading to huge economies of scale. Diesel trains do have *some* economies of scale with other road use, but the engines are a very different scale to the ones you see in normal vehicle applications. Battery trains will end up using the same sort of battery cells as anything from a car to a Powerwall-style battery in your house to your battery vacuum cleaner.

 

[Clansman]

I would suggest the following (with the caveat that I am totally unfamiliar with Glasgow suburban services!):

• Fleet of "metro" commuter trains for use around Glasgow, specifically built for frequent stops. If we're sticking with Hitachi, AT100 units, possibly with a 75/90 mph design speed (depends on which lines they would operate). To replace class 318/320
• More class 385s for "outer suburban" services, possibly replacing class 334s. Used on Fife circle stuff amongst other things

You're pretty much bang on. Though the outstanding 334s that are not on Airdrie to Bathgate are still needed and rotated on all routes alongside the 318/320s through Central and Queen Street Low Level.

385s on these would be a struggle both for coping with metro style frequencies and maximising capacity as shown already, though one would assume that if ever there was a need and a 'doability' for peak express services to say Dumbarton and Helensburgh, that potentially the 385s could fill that niche for greater quality stock on suburban runs (which makes sense).

I guess that's the issue with the Glasgow network in that it is strikingly similar to Thameslink - metro style services in the core of it's route but also a regular commuter service for those staying up to an hour outside of the city centre. So a balance between high density seating, standing areas, and medium distance commuting style provisions should be struck - quite in a similar way to how the 345s have been designed, but with half tables and high density seating added to the mix.

It was quite clever on TS' part to order additional 385s for use on the ex 314 runs to get the latter fleet retired. In the next 10 years when the 318s/320s/334s get replacing, that's a fair few 385s getting displaced elsewhere either to top up existing services or provided new ones with adapted technology to say Fife and Tayside.

 

[Philip Phlopp]

Batteries won't be bespoke, thankfully. The same battery tech will be used across the world, leading to huge economies of scale. Diesel trains do have *some* economies of scale with other road use, but the engines are a very different scale to the ones you see in normal vehicle applications. Battery trains will end up using the same sort of battery cells as anything from a car to a Powerwall-style battery in your house to your battery vacuum cleaner.

That's not necessarily the case - the Bombardier IPEMU demonstrator train used lithium iron magnesium phosphate cells. There was a concern about the safety of lithium ion batteries, of the type Tesla and others use in cars, and there was also a concern about the duty cycle, depth of discharge and life expectancy of more conventional lithium ion batteries. The ability for the battery packs to harvest/store as much energy as possible from regenerative braking was a particular issue and that too played into the selection of batteries. The IPEMU team looked at several technologies and conducted bench testing on a molten sodium nickel salt battery pack before choosing the lithium iron magnesium phosphate cells.

The battery technologies the Bombardier IPEMU team investigated and used were readily available, off-the-shelf products, but they are still not the most inexpensive of products. Transport Scotland are still reporting a premium of 25% over the cost of a standard 25kV AC EMU which someone somewhere is going to have to pay for during procurement and then through the leasing arrangements.

Hydrogen trains are more extensive still, Alstom's Coradia iLint 2 carriage units for RMV in Germany are costing €500m for 27 x 2 carriage units with 25 years of maintenance and supply of hydrogen. There are additional subsidies and grant aid from the German federal government and the state authorities, but the headline cost is €9.2m per vehicle which compares somewhat unfavourably with the initial £7.5m per vehicle for the first tranche of IEP vehicles and £4.4m per vehicle for the second tranche, both of which include maintenance for 27.5 years. The Class 385 fleet with 10 years of maintenance work out around £2m per vehicle, for comparison, though that does make use of the IEP investment in Craigentinny to reduce the maintenance investment costs for the ScotRail contract. If you add the £20m of investment into Craigentinny to the Class 385 order, it only adds £100k per vehicle.

I don't know the precise number of independently powered vehicles ScotRail will ultimately need, but assuming maybe 150 vehicles being needed across the West Highland, Far North, Kyle and Stranraer lines, a standard EMU order with some maintenance included would be around £400m, battery units with some maintenance would be around £500m and hydrogen units with maintenance and refuelling infrastructure included could be getting on towards maybe £1bn (which which I'm working out at £6.5m per vehicle cost to try and bring maintenance costs more in line with existing EMU order maintenance agreements). That ultimately will mean someone (i.e the Scottish Government, ScotRail and the Scottish passengers) will be having to cover that additional £500m to £600m over a 25 to 30 year period (plus around 3.5% interest per annum to cover the borrowing costs involved with the rolling stock company).

What I would caution with those numbers is there's a reasonable amount of guess work, and there's also no way to know how much cheaper hydrogen rolling stock will become between now and the time at which this fleet is ordered by Transport Scotland/ScotRail.

However, on current sums and all currently available data, I don't think Scotland can't afford to stop electrification at Girvan, Craigendoran, Inverness and Nairn.

 

[gingertom]

That's not necessarily the case - the Bombardier IPEMU demonstrator train used lithium iron magnesium phosphate cells. There was a concern about the safety of lithium ion batteries, of the type Tesla and others use in cars, and there was also a concern about the duty cycle, depth of discharge and life expectancy of more conventional lithium ion batteries. The ability for the battery packs to harvest/store as much energy as possible from regenerative braking was a particular issue and that too played into the selection of batteries. The IPEMU team looked at several technologies and conducted bench testing on a molten sodium nickel salt battery pack before choosing the lithium iron magnesium phosphate cells.

The battery technologies the Bombardier IPEMU team investigated and used were readily available, off-the-shelf products, but they are still not the most inexpensive of products. Transport Scotland are still reporting a premium of 25% over the cost of a standard 25kV AC EMU which someone somewhere is going to have to pay for during procurement and then through the leasing arrangements.

Hydrogen trains are more extensive still, Alstom's Coradia iLint 2 carriage units for RMV in Germany are costing €500m for 27 x 2 carriage units with 25 years of maintenance and supply of hydrogen. There are additional subsidies and grant aid from the German federal government and the state authorities, but the headline cost is €9.2m per vehicle which compares somewhat unfavourably with the initial £7.5m per vehicle for the first tranche of IEP vehicles and £4.4m per vehicle for the second tranche, both of which include maintenance for 27.5 years. The Class 385 fleet with 10 years of maintenance work out around £2m per vehicle, for comparison, though that does make use of the IEP investment in Craigentinny to reduce the maintenance investment costs for the ScotRail contract. If you add the £20m of investment into Craigentinny to the Class 385 order, it only adds £100k per vehicle.

I don't know the precise number of independently powered vehicles ScotRail will ultimately need, but assuming maybe 150 vehicles being needed across the West Highland, Far North, Kyle and Stranraer lines, a standard EMU order with some maintenance included would be around £400m, battery units with some maintenance would be around £500m and hydrogen units with maintenance and refuelling infrastructure included could be getting on towards maybe £1bn (which which I'm working out at £6.5m per vehicle cost to try and bring maintenance costs more in line with existing EMU order maintenance agreements). That ultimately will mean someone (i.e the Scottish Government, ScotRail and the Scottish passengers) will be having to cover that additional £500m to £600m over a 25 to 30 year period (plus around 3.5% interest per annum to cover the borrowing costs involved with the rolling stock company).

What I would caution with those numbers is there's a reasonable amount of guess work, and there's also no way to know how much cheaper hydrogen rolling stock will become between now and the time at which this fleet is ordered by Transport Scotland/ScotRail.

However, on current sums and all currently available data, I don't think Scotland can't afford to stop electrification at Girvan, Craigendoran, Inverness and Nairn.

Also to be factored in to the running costs is the track access charges: batteries aren't light so a unit with a significant numbers of them (7tonnes?) will cost more.

Would Tweedbank be considered low-hanging fruit and easy and quick to wire up? AIUI it was rebuilt with the appropriate clearances. Are there sufficient EMUs in the system to run the service? Those 10 extra 385s could have proved useful. If this was done it would then allow the diesels to cascade elsewhere.

 

[NotATrainspott]

That's not necessarily the case - the Bombardier IPEMU demonstrator train used lithium iron magnesium phosphate cells. There was a concern about the safety of lithium ion batteries, of the type Tesla and others use in cars, and there was also a concern about the duty cycle, depth of discharge and life expectancy of more conventional lithium ion batteries. The ability for the battery packs to harvest/store as much energy as possible from regenerative braking was a particular issue and that too played into the selection of batteries. The IPEMU team looked at several technologies and conducted bench testing on a molten sodium nickel salt battery pack before choosing the lithium iron magnesium phosphate cells.

The battery technologies the Bombardier IPEMU team investigated and used were readily available, off-the-shelf products, but they are still not the most inexpensive of products. Transport Scotland are still reporting a premium of 25% over the cost of a standard 25kV AC EMU which someone somewhere is going to have to pay for during procurement and then through the leasing arrangements.

Hydrogen trains are more extensive still, Alstom's Coradia iLint 2 carriage units for RMV in Germany are costing €500m for 27 x 2 carriage units with 25 years of maintenance and supply of hydrogen. There are additional subsidies and grant aid from the German federal government and the state authorities, but the headline cost is €9.2m per vehicle which compares somewhat unfavourably with the initial £7.5m per vehicle for the first tranche of IEP vehicles and £4.4m per vehicle for the second tranche, both of which include maintenance for 27.5 years. The Class 385 fleet with 10 years of maintenance work out around £2m per vehicle, for comparison, though that does make use of the IEP investment in Craigentinny to reduce the maintenance investment costs for the ScotRail contract. If you add the £20m of investment into Craigentinny to the Class 385 order, it only adds £100k per vehicle.

I don't know the precise number of independently powered vehicles ScotRail will ultimately need, but assuming maybe 150 vehicles being needed across the West Highland, Far North, Kyle and Stranraer lines, a standard EMU order with some maintenance included would be around £400m, battery units with some maintenance would be around £500m and hydrogen units with maintenance and refuelling infrastructure included could be getting on towards maybe £1bn (which which I'm working out at £6.5m per vehicle cost to try and bring maintenance costs more in line with existing EMU order maintenance agreements). That ultimately will mean someone (i.e the Scottish Government, ScotRail and the Scottish passengers) will be having to cover that additional £500m to £600m over a 25 to 30 year period (plus around 3.5% interest per annum to cover the borrowing costs involved with the rolling stock company).

What I would caution with those numbers is there's a reasonable amount of guess work, and there's also no way to know how much cheaper hydrogen rolling stock will become between now and the time at which this fleet is ordered by Transport Scotland/ScotRail.

However, on current sums and all currently available data, I don't think Scotland can't afford to stop electrification at Girvan, Craigendoran, Inverness and Nairn.

I know there are different battery chemistries, but we're seeing a huge amount of innovation and investment in the space. This will cross-feed from one use-case to another in a way which just does not happen for other power sources. A team working on making laptop batteries better may well develop a chemistry that can be used in trains and other vehicles, and vice-versa. When you're planning for the next century's rail infrastructure, you need to look at the trends as well as the current state of things. Batteries are only going to get better, and the rate of progress will be far higher than it will be for hydrogen power.

I think the 'no electrification' green lines covered the concept of intermittent electrification for the purpose of vehicle charging alone. Discontinuous electrification seems to me to be more like the idea in South Wales where batteries will cover gaps in standard 25kV AC electrification. Battery charging infrastructure would be optimised for that use-case and not for normal traction power. You could have overhead fixed bar electrification at high voltage DC only above the platforms where trains are expected to wait for some time to recharge.

 

[Philip Phlopp]

Batteries are only going to get better, and the rate of progress will be far higher than it will be for hydrogen power.

You could have overhead fixed bar electrification at high voltage DC only above the platforms where trains are expected to wait for some time to recharge.

Batteries are improving, but there are fundamental limitations in terms of the chemistry and the underlying physics. Energy density is only doubling once every 10 to 12 years and that won't continue forever. Safety considerations, the duty cycle/depth and thermal management requirements will continue to dictate which battery chemistries are most suited to railway traction, and they may not be the battery technologies which are showing the greatest improvements over any particular period.

It's also unclear how improvements to battery packs will be incorporated into units when the battery pack is replaced at the end of its life, given in many circumstances, there will be no benefit to a lighter, more energy dense or higher capacity battery pack, given the way we want rolling electrification to infill gaps and reduce the amount of battery running, not the opposite.

DC rapid charging is unlikely to happen, the industry plans currently centre around 25kV AC on either conventional OLE or rigid overhead conductor, that can provide around 4MW before the pan head catches fire, but where that 4MW comes from is of course the major question. You don't have OLE to take that supply from a feeder plugged into, say, 400kV and get it to a train, if it's battery charging, it may well have to come from a more local grid connection and getting 4MW from the local grid is challenging in some of the places people are wanting battery trains to run to.

 

[NotATrainspott]

Batteries are improving, but there are fundamental limitations in terms of the chemistry and the underlying physics. Energy density is only doubling once every 10 to 12 years and that won't continue forever. Safety considerations, the duty cycle/depth and thermal management requirements will continue to dictate which battery chemistries are most suited to railway traction, and they may not be the battery technologies which are showing the greatest improvements over any particular period.

It's also unclear how improvements to battery packs will be incorporated into units when the battery pack is replaced at the end of its life, given in many circumstances, there will be no benefit to a lighter, more energy dense or higher capacity battery pack, given the way we want rolling electrification to infill gaps and reduce the amount of battery running, not the opposite.

DC rapid charging is unlikely to happen, the industry plans currently centre around 25kV AC on either conventional OLE or rigid overhead conductor, that can provide around 4MW before the pan head catches fire, but where that 4MW comes from is of course the major question. You don't have OLE to take that supply from a feeder plugged into, say, 400kV and get it to a train, if it's battery charging, it may well have to come from a more local grid connection and getting 4MW from the local grid is challenging in some of the places people are wanting battery trains to run to.

DC rapid charging appears to be inevitable for exactly those difficult cases you've identified. As soon as you need to have static batteries being trickle charged by the mains supply or local renewables, it becomes pointless to convert it back into 25kV AC for charging the train. 25kV AC will remain the optimum supply method, as it can provide enough power for simultaneous charging and traction power.

I don't believe the railway is going to be spared the sort of tidal wave of disruption that batteries are going to cause in the rest of the ground transportation industry. There are a great many leaders of traditional companies who thought the transition to zero-carbon vehicles would be slow and managed by the usual suspects. Their companies are now floundering, and their investors are demanding to know what their electrification plans are. The only job of a car company CEO now seems to be to come up with some sort of plan to catch up with Tesla and the Chinese, or your shareholders will kick you out the door.

On the railway I think we'll see frequent experiments with whatever state of the art battery technologies there are. Each one of these will shock more and more people. We might get to the point where some enterprising ROSCO realises that some modern DMUs might be able to have their diesel kit ripped out and replaced with a battery pack even without the expense of fitting 25kV AC, since the economics will be so strong even on totally unelectrified routes.

In the UK at least we have a fixed bound on the size of the railway electrification problem. If Transport Scotland come up with a spec for the WHL and other routes to have battery electric trains with rapid charging at key stations, then enhancements to battery capacity are unlikely to change anything. If a train only needs to go 60 miles on a charge, then the theoretical ability for it to go 200 miles with the same size and weight of a future, more energy-dense battery is largely irrelevant. Given that trains are often fitted with ballast weights to provide consistent suspension settings, it's not even clear that any weight savings could be achieved. Nonetheless, the next time the train fleet needs replacement, the new design would be able to have smaller and lighter batteries, leading to even more efficiency.

The main thing is that the roadmap for batteries is pretty comprehensively better than the roadmap for hydrogen. Install a very expensive hydrogen network for the WHL and then in 30 years, it'll look a little bit dumb. Electricity won't be going anywhere any time soon, so betting on electricity seems as sensible an option as you can get.