Design for a universal Battery EMU for the GB rail network

[Nottingham59]

What should be specification be for a national fleet of Battery EMU's to decarbonise the GB rail network?

It seems to me there is a need for Battery EMU's now, which can be deployed the many routes where there are currently diesels running under the wires. As electrification progresses, this fleet would be cascaded across the network, as new electrification projects open up new routes for battery trains, and the pure EMU's are brought in on those routes where infill electrification has filled in the gaps.

This need to cascade means that a single national design of BEMU would be much better than many different models of BEMU ordered for specific lines which would then form an inflexible collection of micro fleets, not be easily moved elsewhere.

This is one possible national BEMU specification:

• 100 miles guaranteed range off the wires
• Four-car (4x25m) units, with end-corridor connection, like class 350's, to allow longer trains up to 12-car. Reconfigurable into 3 and 5 car versions (or 2 and 6 car if necessary, depending on platform lengths)
• Top speed 110mph, which I think is the fastest allowed with connecting doors, and without losing space in leading cars.
• OHLE (of course, for traction and recharging batteries under the wires)
• Provision to recharge at remote termini using plug-in 350kW CCS superchargers, as used for rapid charging of EV cars

Parts that I'm not sure about. Any ideas or thoughts on these?

• Carriage doors at 1/3-2/3 spacing for speed of access?
• Convertible to 750V DC third rail supply?
• Recharging at the platform, rather than having to go off to a depot to refuel? Might need charging cables on swing gantries rather than having cables trailing across the platform.
• Is 100 miles off the wires right? Would 50 mile range be enough?
• Should BEMU's have a range-extender diesel engine to give them effectively unlimited range? HVO fuel would be low-carbon, and a 100kW car engine would be enough to top up batteries.
• Dual voltage OHLE to allow recharging at 1500V DC via the pantograph at termini without high-voltage grid connection.
• Is a 4-car base too long? Would a 3-car standard be better? Would allow reconfiguration into 2 and 4-car units.
• Would BEMUs need megawatt recharge capability, as in the emerging CharIn MCS standard for trucks?

Any thoughts or comments welcome.

 

[Basil Jet]

Since batteries are heavy, would it be possible for the battery to be modular, with the battery range being easily changed in the depot according to which line the train would be operating on, rather than have every train carrying around 100 miles of range even if it only needs 10 for its present diagram.

 

[D365]

That’s a fair enough baseline for the specification of a modern battery multiple unit.

 

[JamesT]

Since batteries are heavy, would it be possible for the battery to be modular, with the battery range being easily changed in the depot according to which line the train would be operating on, rather than have every train carrying around 100 miles of range even if it only needs 10 for its present diagram.

Making batteries modular makes them even heavier as you add packaging round the battery. (See the trend of portable devices to not have user-removable batteries).
Does carrying around more weight make much difference if the train has the performance needed? It would make diagramming more complex if you had trains with different capacities. Would you have to renumber into different subclasses each time to avoid putting a low capacity unit onto a diagram that needs more?

 

[Domh245]

I'm not convinced that there's a need to standardise the "above-floor" elements like body length and door positioning - different TOCs and different rotues have different needs, there's no point trying to force a compromise onto everything! A Battery train is fundamentally an EMU with a different power source, so really it's just a question of standardising the batteries so that they can be fitted to some off-the-shelf EMUs, and as with Bi-Modal diesel units they can be easily removed and transfered around leaving regular EMUs once there's sufficient electrification in place.

I'm also not sure about the idea of having plug-in charging - given the general move to keeping staff off the track I don't know why you'd design something requiring staff to move a fairly hefty* plug at track level (you're certainly not putting it on the platforms). For dedicated recharging sections, just use established railway infrastructure for supplying electricity (at high power!) to rail vehicles.

*Without knowing what sort of battery capacity would be considered typical, 350kW seems like a fairly low power that'd require a long charge period or limited recharging each time, so you'd want a higher powered connector with the consequent thicker cables, cooling, & connectors entailed

 

[CarrotPie]

Four-car (4x25m) units, with end-corridor connection, like class 350's, to allow longer trains up to 12-car.

4-car units that run as 12-cars (Electrostars, Desiros etc) are 4x20m, making 80m in total or 240m for a 12-car train. This was the norm until the recent IET and Aventra age, where commuter EMUs and 80x are now 5x25m, making 120m (so length of a 6-car Electrostar) or 240m for a 10-car train (same as a 12-car Electrostar). Having 100m units coupled in trios would fit only on platforms designed for 15-car trains, which are few and far between, even on mainlines.

 

[skyhigh]

Provision to recharge at remote termini using plug-in 350kW CCS superchargers, as used for rapid charging of EV cars

Definitely not this. CCS is a perfectly good standard to use for cars and buses, but would be way too undersized for the charging needs of a 12 car unit that could do 110mph. A 333 at full whack is 1,400kW in comparison. Charging at 350kW would take an age.

 

[RobShipway]

What should be specification be for a national fleet of Battery EMU's to decarbonise the GB rail network?

It seems to me there is a need for Battery EMU's now, which can be deployed the many routes where there are currently diesels running under the wires. As electrification progresses, this fleet would be cascaded across the network, as new electrification projects open up new routes for battery trains, and the pure EMU's are brought in on those routes where infill electrification has filled in the gaps.

This need to cascade means that a single national design of BEMU would be much better than many different models of BEMU ordered for specific lines which would then form an inflexible collection of micro fleets, not be easily moved elsewhere.

This is one possible national BEMU specification:

• 100 miles guaranteed range off the wires
• Four-car (4x25m) units, with end-corridor connection, like class 350's, to allow longer trains up to 12-car. Reconfigurable into 3 and 5 car versions (or 2 and 6 car if necessary, depending on platform lengths)
• Top speed 110mph, which I think is the fastest allowed with connecting doors, and without losing space in leading cars.
• OHLE (of course, for traction and recharging batteries under the wires)
• Provision to recharge at remote termini using plug-in 350kW CCS superchargers, as used for rapid charging of EV cars

Parts that I'm not sure about. Any ideas or thoughts on these?

• Carriage doors at 1/3-2/3 spacing for speed of access?
• Convertible to 750V DC third rail supply?
• Recharging at the platform, rather than having to go off to a depot to refuel? Might need charging cables on swing gantries rather than having cables trailing across the platform.
• Is 100 miles off the wires right? Would 50 mile range be enough?
• Should BEMU's have a range-extender diesel engine to give them effectively unlimited range? HVO fuel would be low-carbon, and a 100kW car engine would be enough to top up batteries.
• Dual voltage OHLE to allow recharging at 1500V DC via the pantograph at termini without high-voltage grid connection.
• Is a 4-car base too long? Would a 3-car standard be better? Would allow reconfiguration into 2 and 4-car units.
• Would BEMUs need megawatt recharge capability, as in the emerging CharIn MCS standard for trucks?

Any thoughts or comments welcome.

As with the class 730 units, I would have two types of units available within the same fleet as follows:

/0 units specification:

• 100 miles guaranteed range off the wires
• Three car units, with end-corridor connection, like class 350's, to allow longer trains
• OHLE for traction and recharging of batteries
• Fitted with third rail shoes for traction and where they can be used to recharge batteries
• Have the ability to recharge at platforms away from electrified routes, but be able to recharge the batteries from 25KV pantograph and Third Rail shoes.
• Doors at 1/3 - 2/3 spacing for speed of access, but are level with majority of platforms to allow for disability access.
• Speed limited to 90mph.
• 2 + 3 seating

/1 specification extra or different to /0

• 200 miles guaranteed range off the wires
• 110mph top speed on OHLE (100mph on 3rd rail/battery)
• Operate as 5 to 9/10 car units in similar way to class 345/701
• 2 + 2 seating
• Include space for catering trolley?

I don't think that a range extender diesel engine should be used, as I do not believe that HVO fuel is as low in Carbon Emissions as is being quoted. Yes, it maybe low in GHG emissions (GreenHouse Gas Emissions), which is low Carbon Dioxide, low Methane and low Nitrous Oxide. But it would be better for the world not to be omitting these at all for the power of the train.

 

[2192]

What should be specification be for a national fleet of Battery EMU's to decarbonise the GB rail network?

It seems to me there is a need for Battery EMU's now, which can be deployed the many routes where there are currently diesels running under the wires. As electrification progresses, this fleet would be cascaded across the network, as new electrification projects open up new routes for battery trains, and the pure EMU's are brought in on those routes where infill electrification has filled in the gaps.

This need to cascade means that a single national design of BEMU would be much better than many different models of BEMU ordered for specific lines which would then form an inflexible collection of micro fleets, not be easily moved elsewhere.

This is one possible national BEMU specification:

• 100 miles guaranteed range off the wires
• Four-car (4x25m) units, with end-corridor connection, like class 350's, to allow longer trains up to 12-car. Reconfigurable into 3 and 5 car versions (or 2 and 6 car if necessary, depending on platform lengths)
• Top speed 110mph, which I think is the fastest allowed with connecting doors, and without losing space in leading cars.
• OHLE (of course, for traction and recharging batteries under the wires)
• Provision to recharge at remote termini using plug-in 350kW CCS superchargers, as used for rapid charging of EV cars

Parts that I'm not sure about. Any ideas or thoughts on these?

• Carriage doors at 1/3-2/3 spacing for speed of access?
• Convertible to 750V DC third rail supply?
• Recharging at the platform, rather than having to go off to a depot to refuel? Might need charging cables on swing gantries rather than having cables trailing across the platform.
• Is 100 miles off the wires right? Would 50 mile range be enough?
• Should BEMU's have a range-extender diesel engine to give them effectively unlimited range? HVO fuel would be low-carbon, and a 100kW car engine would be enough to top up batteries.
• Dual voltage OHLE to allow recharging at 1500V DC via the pantograph at termini without high-voltage grid connection.
• Is a 4-car base too long? Would a 3-car standard be better? Would allow reconfiguration into 2 and 4-car units.
• Would BEMUs need megawatt recharge capability, as in the emerging CharIn MCS standard for trucks?

Any thoughts or comments welcome.

Most of these specifications would be not needed for the Greenford - West Ealing shuttle, and so would make the trains unaffordable for the duty. However they can recharge at the platform, and probably have 1/3-2/3 doors.

 

[Snow1964]

I think a 100m long unit would be too long, yes they may be used where there are some wiring gaps, but they are going to be more useful on branches from wired mainline.

Having said that, in past was often seen as ok to wire a branch as a long siding (contact wire energised one end), with basic low speed catenary. Think Marks Tey, Romford-Upminster, St Albans branch etc. And This allows flexibility of using EMUs without batteries.

It is not that helpful needing non-standard unit types and might be cheaper if got to fit batteries to lots of units as they are a common pool

 

[Nottingham59]

CCS is a perfectly good standard to use for cars and buses, but would be way too undersized for the charging needs of a 12 car unit that could do 110mph.

I wasn't suggesting CCS as the main charging mechanism. I was thinking more about shorter units at risk of getting stranded at places like Scarborough or Skegness at the end of branch lines. A CCS connection (or better still an MCS connection if that becomes a standard) would allow provision for emergency top-ups at odd places using the sort of kit that will become commonplace in station car parks without all the infrastructure of OHLE and SFCs just in case a unit ends up there without enough charge to get back onto the wires.

But if you don't build that sort of top-up capability into the specification, then it's really expensive and may be impossible to retrofit it afterwards.

 

[Energy]

I wasn't suggesting CCS as the main charging mechanism. I was thinking more about shorter units at risk of getting stranded at places like Scarborough or Skegness at the end of branch lines. A CCS connection (or better still an MCS connection if that becomes a standard) would allow provision for emergency top-ups at odd places using the sort of kit that will become commonplace in station car parks without all the infrastructure of OHLE and SFCs just in case a unit ends up there without enough charge to get back onto the wires.

But if you don't build that sort of top-up capability into the specification, then it's really expensive and may be impossible to retrofit it afterwards.

CCS cables aren't that long, especially at 350kw. You can't just plug it into the car park. The largest portable CCS charger (made by kempower) is 40kw.

The easiest way to rescue a unit out of juice is to send another (diesel or a battery unit with sufficient range to get back) to rescue it.

 

[Nicks]

The trouble with a single new battery fleet is that, as with some of the first generation dmus, it is quite possible that this whole fleet could turn out to be duds and have a short life before scrapping as the technology is progressing fairly fast and things tend to improve with time and experience.

 

[6Gman]

What services would these units be used on?

Without knowing that the parameters of charging capacity are a tad difficult to assess.

 

[Sm5]

Why an EMU ?

Why not a power pack.. aka a loco.
Weve come a long way since the 1980’s.. locos can run at the front, rear or in the middle of a train (aka class 755). Coupling / Uncouple is revolutionised from screw link days.

Its easier to replaced a depleted power supply by a loco change than take a whole rake of stock out of service for a charge.

With Battery were in effect going back to Steam age days… Steam was limited in range by water, typically 40-60 miles, or water troughs to replenish on the go…

Battery has the same limitations solved in similar way… ie charging points and ohle/3rd rail wires.. the problem is your not getting much charge in a 3 minute station stop.

A Battery loco / mk5’s seems more practical to me.. that in itself is your EMU set.

Of course 100 locos on 50 rakes of coaches will never be as profitable for consultants, manufacturers as 100 EMU rakes to do the same task.


Nothing stops the coaches being self propelled… think of the engine as being not much more than a big Duracell battery with driving cabs.. it could supply power to the stock too.

As Electric is much more flexible, you dont need 30 classes of engine, 1 would probably do it nationwide.. thats very standard and efficient, with a network of charging points.

 

[RobShipway]

Why an EMU ?

Why not a power pack.. aka a loco.
Weve come a long way since the 1980’s.. locos can run at the front, rear or in the middle of a train (aka class 755). Coupling / Uncouple is revolutionised from screw link days.

Its easier to replaced a depleted power supply by a loco change than take a whole rake of stock out of service for a charge.

With Battery were in effect going back to Steam age days… Steam was limited in range by water, typically 40-60 miles, or water troughs to replenish on the go…

Battery has the same limitations solved in similar way… ie charging points and ohle/3rd rail wires.. the problem is your not getting much charge in a 3 minute station stop.

A Battery loco / mk5’s seems more practical to me.. that in itself is your EMU set.

Of course 100 locos on 50 rakes of coaches will never be as profitable for consultants, manufacturers as 100 EMU rakes to do the same task.


Nothing stops the coaches being self propelled… think of the engine as being not much more than a big Duracell battery with driving cabs.. it could supply power to the stock too.

As Electric is much more flexible, you dont need 30 classes of engine, 1 would probably do it nationwide.. thats very standard and efficient, with a network of charging points.

I don't think anyone has said where the battery power is to be located whether it is underneath the carriages or in a separate unit within the train a.k.a class 755/756.

The point is, that it would not be bi-mode in the sense of being diesel electric and if you did take the diesel engine out of the power unit for class 755/756 then replaced it with batteries it would be a BEMU. Where currently, the class 755/756 units certainly are EDMU units. Which is still a form of EMU.

 

[Nottingham59]

different TOCs and different rotues have different needs

I'm assuming a rolling programme of electrification, so when a gap in the wires is filled the BEMU fleet would be cascaded from that route to another. Which is why I think we need a national standard for BEMUs, just like the HST was designed as a "go-anywhere" train.

What services would these units be used on?

That depends on the range off wires, which is why this is such a critical parameter. With today's electrification, a 100-miler could be used on Paddington-Oxford; Waterloo-Salisbury; Liverpool-Newcastle; St-Pancras-Nottingham; London-Uckfield; Edinburgh-Bournemouth; most un-electrified cross-city services in Leeds, Birmingham, Scotland's central belt; etc. etc. A 50-miler would be more limited.

When the MML is wired, you could cascade 100-milers to routes from Nottingham to all of Liverpool, Norwich, Cardiff, Crewe, Worksop, Matlock; Birmingham-Stansted; etc. And I expect many local services around Sheffield too.

Electrifying Bristol Parkway to Temple Meads, gives you Portsmouth-Cardiff; Paddington-Weston via Bath; etc.

And just a few electrification islands, like around Exeter, coupled with a recharging solution for remote termini like Penzance and Skegness, could allow you to electrify almost the whole network.

Most of these specifications would be not needed for the Greenford - West Ealing shuttle, and so would make the trains unaffordable for the duty.

Agreed. But you want to avoid having separate solutions for different lines. That's why we need a national standard or standards for BEMUs.

CCS cables aren't that long, especially at 350kw. You can't just plug it into the car park. The largest portable CCS charger (made by kempower) is 40kw.

The easiest way to rescue a unit out of juice is to send another (diesel or a battery unit with sufficient range to get back) to rescue it.

I had envisaged a CCS charger near the buffer stops, not long cables from the car park! But you're right. We need either a megawatt-capable plug in, like MCS, at remote termini like Skegness and Penzance; or a low-cost way to recharge via the pantograph without the expense of 25kV OHLE and static frequency converters. Maybe a dual-voltage pantograph would work, able to take 1500V DC like some trams have in Europe? With heavy-duty conductor bars overhead to take the localised current?

EDIT: If these BEMUs are giong to be compatible with third-rail electrification at a nominal 750V DC, then the easiest way to recharge at the platform would be dual-voltage pantograph able to take 750V DC from an thick overhead contact bar. Or a separate 750V DC pantograph if that were electrically simpler to do.

 

[BrianW]

I would have hoped that this exercise has already been done by now, ready for a programme of construction/ procurement relating to a planned programme of scrapping/ remodelling/ cascading relating to decarbonisation etc.

UK government publishes its Transport Decarbonisation Plan

The groundbreaking Transport Decarbonisation Plan includes the aim to create a net zero rail network by 2050.

www.globalrailwayreview.com

Give-or-take that technologies develop and change; economic balances change; political priorities change, etc ... travel patterns continue to reflect the general 'economic structure' of the country, up and down over time. Yes, looking back over time with the benefit of hindsight mistakes/ poor decisions were made, and 'standardisation' may mean that mistakes will be multiplied more.

Short of lengthening of some bay platforms, some services may be limited in train length; more track-doubling or more or longer passing bays; perhpas in the future ... perhaps.

Is hydrogen still in the running? The notion of power unit interchangeability/ modularity has intellectual appeal. I'm pictuuring tri-quad-quin-modes.

Like Truss or not, actually making decisions and delivering on them does have appeal too. Mind you, the idea of a five- or ten- year plan or rolling programme does sound a bit 'Commie'/ collectivist/ command economy.

250 pages of 'interim' 'guidance' was published over two yyears ago!: https://www.networkrail.co.uk/wp-co...-Strategy-Interim-Programme-Business-Case.pdf

Most of these specifications would be not needed for the Greenford - West Ealing shuttle, and so would make the trains unaffordable for the duty. However they can recharge at the platform, and probably have 1/3-2/3 doors.

'Back in the day' following on from the 'push-pull' was a 'pairing' of a Class 121(?) single-car, with a trailer unit that sat in a siding east of Ealing Broadway off-peak.
Not sure whether the economics of coupling/ uncoupling 'work' versus to/fro continual shuttle; sure though that calculations could be done.

 

[skyhigh]

I had envisaged a CCS charger near the buffer stops, not long cables from the car park! But you're right. We need either a megawatt-capable plug in, like MCS, at remote termini like Skegness and Penzance; or a low-cost way to recharge via the pantograph without the expense of 25kV OHLE and static frequency converters. Maybe a dual-voltage pantograph would work, able to take 1500V DC like some trams have in Europe? With heavy-duty conductor bars overhead to take the localised current?

EDIT: If these BEMUs are giong to be compatible with third-rail electrification at a nominal 750V DC, then the easiest way to recharge at the platform would be dual-voltage pantograph able to take 750V DC from an thick overhead contact bar. Or a separate 750V DC pantograph if that were electrically simpler to do.

I doubt a remote terminus would already have an existing supply powerful enough to supply a 350kW charger (without at least some supply upgrade works) so I'd suggest it would be worth upgrading properly for a supply big enough to charge at a decent speed via some form of overhead power as you suggest. That would also give more flexibility for a quick top-up during the day or a full overnight charge if required.

If you stuck with a 350kW charger it would probably be cheaper and faster just to rescue a dead unit with another charged unit.

 

[Nottingham59]

I doubt a remote terminus would already have an existing supply powerful enough to supply a 350kW charger (without at least some supply upgrade works) so I'd suggest it would be worth upgrading properly for a supply big enough to charge at a decent speed via some form of overhead power as you suggest. That would also give more flexibility for a quick top-up during the day or a full overnight charge if required.

That's true. The discussion here is really helping me to think through the practicalities of operating BEMUs on the GB network. I hope the people who are currently specifying the BEMUs for Scotland are reading this thread!

If you stuck with a 350kW charger it would probably be cheaper and faster just to rescue a dead unit with another charged unit.

Sure, but if you've got a dead unit at say Penzance, and the nearest OHLE is at Bodmin Lostwithiel 49 miles away, then even a fully charged 100-miler is not going to have the juice to drag it back to the wires. Same for Skegness and Holyhead and Scarborough. I can see lots of places where a simple and cheap CCS capability might be incredibly useful for emergencies, even if it's not used routinely for recharging.

 

[HSTEd]

I doubt a remote terminus would already have an existing supply powerful enough to supply a 350kW charger (without at least some supply upgrade works) so I'd suggest it would be worth upgrading properly for a supply big enough to charge at a decent speed via some form of overhead power as you suggest. That would also give more flexibility for a quick top-up during the day or a full overnight charge if required.

If you stuck with a 350kW charger it would probably be cheaper and faster just to rescue a dead unit with another charged unit.

350kW chargers can be supplied with 400V supplies, with the DNO handling all the high-voltage stuff.

Above that level, you start having to provide high-voltage supplies all the way to the sharp end, which makes things considerably more expensive.
And 350kW is hardly a slouch, that's approaching the motor output of an MLV!

EDIT:

At something like ~3kWh/vehicle-km you are looking at a range addition of nearly 120 vehicle-km per hour! Most rescue situations in the UK you would be ready to return to base before the rescue unit even arrives.
Additionally, the CCS charger current is controlled by the charger not by the train thanks to signaling in the specification.

So you could install CCS chargers with any current you want up to 350kW based on what supplies are available.

 

[Elecman]

350kW chargers can be supplied with 400V supplies, with the DNO handling all the high-voltage stuff.

Above that level, you start having to provide high-voltage supplies all the way to the sharp end, which makes things considerably more expensive.
And 350kW is hardly a slouch, that's approaching the motor output of an MLV!

EDIT:

At something like ~3kWh/vehicle-km you are looking at a range addition of nearly 120 vehicle-km per hour! Most rescue situations in the UK you would be ready to return to base before the rescue unit even arrives.
Additionally, the CCS charger current is controlled by the charger not by the train thanks to signaling in the specification.

So you could install CCS chargers with any current you want up to 350kW based on what supplies are available.

350kW is pushing the limits of an LV DNO supply as that translates to over 550 amps at 0.95 power factor most DNOs dont normally supply that level of current at lv most apply a limit of 400 amp at lv ( approx 260kW at 0.95 power factor.

 

[Nottingham59]

Having looked at https://railmap.azurewebsites.net/Public/ElectrificationMap , I'm coming round to the view that the network will need two distinct ranges for BEMUs: around 50 miles and around 120 miles.

50-MILE RANGE
The 50-miler could handle almost all of the cross-pennine and cross-country routes between existing wiring:

• between the WCML and the MML (e.g. BHM-LEI; BHM-DBY; SOT-DBY; HAZ-SHF; SYB-LDS; MCV-LDS; CAR-NCL) and
• between the MML and the ECML (LEI-PBO; NOT-GRA; NOT-NCT; SHF-RET; SHF-DON; SHF-LDS)
• plus suburban services around Liverpool, Leeds and Manchester
• Most of the termini on the Eastern Coast of England (SLB, SCA, WTB, HUL, CLE, SKE, GYM) are 40-50 miles from the nearest wires on the ECML or the GEML, though for these you would have to recharge at the coastal terminus, and also must wire the crossing lines for a few miles at places like Grantham, Newark, Retford Low-Level, Hambleton, etc.

EDIT: Other routes where the gap is a bit over 50 miles (CAR-NCL; YAE-BMV) could be served by short extensions of the wiring at each end. And short sections of OHLE on the Chiltern route (Moor St to Dorridge; Bicester to Princes Risborough; Oxford; Marylebone) would enable electrification of both East-West Rail and the entire Chiltern network.

120-MILE RANGE
The 120-miler would be useful in the in the South-West and Scotland where there are longer distances between existing electrification.

• Exeter is 120-130 from the limits of wiring at Basingstoke and at Newbury, and also 120 miles from Penzance. So electrifying 10-15 miles each side of Exeter would allow BEMUs to run Penzance-Exeter-Waterloo and Penzance-Exeter-Paddington, effectively covering all of the South West.
• It could also do the eastern coastal routes mentioned above and back again, if you wanted to avoid recharging at the coastal terminus.
• Most of Wales
• And routes like Skipton-Carlise; the entire Chiltern Mainline (recharging at Moor St and Marylebone); and much of Scotland (though they have their own BEMU programme)

And of course, you can convert a 120-mile gap into two 50-mile gaps by wiring the 20 miles in the middle, if you needed that flexibility.

 

[Bevan Price]

I think that - in the near future - speeds of 110 mph would require far too much energy to get a decent range out of battery trains. They are much more likely to be suitable for secondary routes limited to around 60 mph. Whilst there is still scope to increase battery capacity a bit, the final limit is what energy can be extracted from "safe" electrochemical reactions -- and lithium is probably the most reactive metal that can be used safely in batteries.

 

[Nottingham59]

speeds of 110 mph would require far too much energy to get a decent range out of battery trains. They are much more likely to be suitable for secondary routes limited to around 60 mph.

Agreed, speeds on battery will be lower than the 110mph top speed of these units. But the only places where trains can reach 110mph are now electrified, so that would be on electric traction, rather than battery.

Looking at https://railmap.azurewebsites.net/Public/SpeedsMap , the only sections I can see over 100mph away from the wires are short sections of the Berks and Hants line and just south of Weston-Super-Mare. So maybe we'd need to wire Exeter-Taunton to compensate for the reduced range over these section?

EDIT: And Water Orton to Tamworth

 

[RobShipway]

Having looked at https://railmap.azurewebsites.net/Public/ElectrificationMap , I'm coming round to the view that the network will need two distinct ranges for BEMUs: around 50 miles and around 120 miles.

50-MILE RANGE
The 50-miler could handle almost all of the cross-pennine and cross-country routes between existing wiring:

• between the WCML and the MML (e.g. BHM-LEI; BHM-DBY; SOT-DBY; HAZ-SHF; SYB-LDS; MCV-LDS; CAR-NCL) and
• between the MML and the ECML (LEI-PBO; NOT-GRA; NOT-NCT; SHF-RET; SHF-DON; SHF-LDS)
• plus suburban services around Liverpool, Leeds and Manchester
• Most of the termini on the Eastern Coast of England (SLB, SCA, WTB, HUL, CLE, SKE, GYM) are 40-50 miles from the nearest wires on the ECML or the GEML, though for these you would have to recharge at the coastal terminus, and also must wire the crossing lines for a few miles at places like Grantham, Newark, Retford Low-Level, Hambleton, etc.

EDIT: Other routes where the gap is a bit over 50 miles (CAR-NCL; YAE-BMV) could be served by short extensions of the wiring at each end. And short sections of OHLE on the Chiltern route (Moor St to Dorridge; Bicester to Princes Risborough; Oxford; Marylebone) would enable electrification of both East-West Rail and the entire Chiltern network.

120-MILE RANGE
The 120-miler would be useful in the in the South-West and Scotland where there are longer distances between existing electrification.

• Exeter is 120-130 from the limits of wiring at Basingstoke and at Newbury, and also 120 miles from Penzance. So electrifying 10-15 miles each side of Exeter would allow BEMUs to run Penzance-Exeter-Waterloo and Penzance-Exeter-Paddington, effectively covering all of the South West.
• It could also do the eastern coastal routes mentioned above and back again, if you wanted to avoid recharging at the coastal terminus.
• Most of Wales
• And routes like Skipton-Carlise; the entire Chiltern Mainline (recharging at Moor St and Marylebone); and much of Scotland (though they have their own BEMU programme)

And of course, you can convert a 120-mile gap into two 50-mile gaps by wiring the 20 miles in the middle, if you needed that flexibility.

It has always been the case that two types of BEMU would be required. One type for local services and another for more longer express type services as pointed out in my post last Sunday, which I have copied below:

As with the class 730 units, I would have two types of units available within the same fleet as follows:

/0 units specification:

• 100 miles guaranteed range off the wires
• Three car units, with end-corridor connection, like class 350's, to allow longer trains
• OHLE for traction and recharging of batteries
• Fitted with third rail shoes for traction and where they can be used to recharge batteries
• Have the ability to recharge at platforms away from electrified routes, but be able to recharge the batteries from 25KV pantograph and Third Rail shoes.
• Doors at 1/3 - 2/3 spacing for speed of access, but are level with majority of platforms to allow for disability access.
• Speed limited to 90mph.
• 2 + 3 seating

/1 specification extra or different to /0

• 200 miles guaranteed range off the wires
• 110mph top speed on OHLE (100mph on 3rd rail/battery)
• Operate as 5 to 9/10 car units in similar way to class 345/701
• 2 + 2 seating
• Include space for catering trolley?

I don't think that a range extender diesel engine should be used, as I do not believe that HVO fuel is as low in Carbon Emissions as is being quoted. Yes, it maybe low in GHG emissions (GreenHouse Gas Emissions), which is low Carbon Dioxide, low Methane and low Nitrous Oxide. But it would be better for the world not to be omitting these at all for the power of the train.

 

[Nottingham59]

One type for local services and another for more longer express type services

Yes, I saw that. I thought it was very interesting.

I did wonder what services would need 200 miles of range off the wires? Apart from the lines to Exeter, all of the high speed routes in this country are electrified, or only tens of miles away from electrification. So wouldn't the faster models be likely to require less range than slower models snaking their way around Wales or the Highlands?

What I did particularly like was the idea (post #2 by @Basil Jet) that the battery capacity should be adjustable to suit the routes that the BEMU was deployed on. So a specification that said "battery capacity adjustable as required to provide up to 200 miles range, as measrued on routes with low gradients" could be very useful.

Maybe the answer would be to have two models of centre carriage - one with batteries and one without - so that the range of the consist can be adjusted by simply swapping these around?

 

[RobShipway]

Yes, I saw that. I thought it was very interesting.

I did wonder what services would need 200 miles of range off the wires? Apart from the lines to Exeter, all of the high speed routes in this country are electrified, or only tens of miles away from electrification. So wouldn't the faster models be likely to require less range than slower models snaking their way around Wales or the Highlands?

What I did particularly like was the idea (post #2 by @Basil Jet) that the battery capacity should be adjustable to suit the routes that the BEMU was deployed on. So a specification that said "battery capacity adjustable as required to provide up to 200 miles range, as measrued on routes with low gradients" could be very useful.

Maybe the answer would be to have two models of centre carriage - one with batteries and one without - so that the range of the consist can be adjusted by simply swapping these around?

It really depends on what routes you are looking into and you also have to work on the basis, say for instance where it is 109 miles from Crewe to Holyhead, well the train will need to travel at least 300 miles on battery to do teh round trip from Holyhead to Crewe before being able to recharge using the OHLE down from Crewe to London.

 

[Bald Rick]

They’ll be no need for a plug in charger under any scenario. There is no point having another charging system on the train when you have one already on the roof. The cost of providing 2-3 span lengths of non tensioned OLE, and a link to the local supply, will be relatively small.

Since batteries are heavy, would it be possible for the battery to be modular, with the battery range being easily changed in the depot according to which line the train would be operating on, rather than have every train carrying around 100 miles of range even if it only needs 10 for its present diagram.

But compared to a train, batteries are not heavy. A 1 MWh Lithium Titanate (best suited to rail applications) battery weighs about 10 tonnes. That would give a 4 car unit at least 2 hours power - easily good for 100 miles. 10tonnes in a train weighing 150 is hardly worth worrying about. Especially when the equivalent engines, cooler groups, exhaust, and full fuel tanks would weigh more.

 

[popeter45]

expanding this idea a standardised spec for Multible units espically with conversion and interopribility in mind would go a long way
e.g. like the 4TC units you could serve unelectrified branches with BMU's that could couple up to EMU's once they reach the mainlines and are easy to convert to EMU's once said line is electrifed