BEMUs and on-route charging

[D821]

I've been following Merseytravel's proposals to run some of their new Class 777 EMUs with batteries to serve a new station at Headbolt Lane, Kirby and possibly Wrexham.
Is it worth having 3rd rails at stations on non-electrified sections of route or does the the short dwell time not make it worth while?
I was assuming that terminus stations in similar stations would have a 3rd rail. A train sat there for 10 minutes could use a lot of electricity if it had HVAC systems running, etc.

 

[javelin]

David Powell discusses it in this talk;

Transport Committee - Thursday 15 July 2021, 2:00pm - Start video at 0:15:51 - Liverpool City Region Combined Authority Webcasting

Transport Committee - Thursday 15 July 2021, 2:00pm - Start video at 0:15:51 - Liverpool City Region Combined Authority Webcasting

liverpoolcityregion-ca.public-i.tv

For the longer routes like Wrexham you'll probably need charging at a couple of intermediate stations, though he says this would be for about a minute, versus present dwell times of ~30 seconds.

 

[D821]

David Powell discusses it in this talk;

Transport Committee - Thursday 15 July 2021, 2:00pm - Start video at 0:15:51 - Liverpool City Region Combined Authority Webcasting

Transport Committee - Thursday 15 July 2021, 2:00pm - Start video at 0:15:51 - Liverpool City Region Combined Authority Webcasting

liverpoolcityregion-ca.public-i.tv

For the longer routes like Wrexham you'll probably need charging at a couple of intermediate stations, though he says this would be for about a minute, versus present dwell times of ~30 seconds.

Thank you, I'll take a look at that this evening.

 

[Ken H]

I thought about this idea for the Uckfield line. Run BEMUs which would charge from London Bridge to Hurst Green, then on battery down to Uckfield. Some charging facilities at Uckfield would help keep the batteries charged. Even a short extension of the 3rd rail south of Hurst Green as far as can be done without any expensive lineside gear would help.

 

[D365]

RSSB are not convinced about the safety of new third rail installations at station platforms. Even if the power supply is ”interlocked”.

 

[D821]

RSSB are not convinced about the safety of new third rail installations at station platforms. Even if the power supply is ”interlocked”.

Stations have 3rd rail supplies running through them now, why don't they like the idea?

 

[D365]

Stations have 3rd rail supplies running through them now, why don't they like the idea?

My key word being new. The current policy is that all third rail installations have to be treated as live at all times, even if a supply interlock system is implemented.

Existing systems have grandfather rights and very stringent safety protocols for all rail staff.

 

[D821]

My key word being new. The current policy is that all third rail installations have to be treated as live at all times, even if a supply interlock system is implemented.

Existing systems have grandfather rights and very stringent safety protocols for all rail in

Interesting, I wasn't aware of that.

 

[wobman]

Some of the proposed new routes are pie in the sky ideas by politicians, they are to get votes. The 777 have no toilets so some of the journeys proposed are over 1 hour, how do they combat that issue ?
The route from Bidston to Wrexham would need high infasructure investment, as 3rd would have to layed in areas so high spec fencing and closing of barrow crossings throughout the route would need resolving.

The Wrexham to Bidston line after shotton would kill the batteries with the gradients and numerous stops, the line has 15 stops in each direction aswell including the Welsh side.

Then merseyrail propose an extension from Chester to Crewe aswell, that would cause issues at Chester with conflicting moves from P7 across to the main line towards Crewe then what if the batteries run out and that causes delays to the London services.

Why don't merseyrail concentrate on getting the 777's in service first and aim for realistic extension of services from Ellesmere port to helsby and routes like this.

 

[alf]

RSSB are not convinced about the safety of new third rail installations at station platforms. Even if the power supply is ”interlocked”.

Have RSSB specifically mentioned new interlocked third rail at station platforms ?

Or have you deduced this from their statement some time ago about new third rail & the criteria that must be applied to approve it.

I have tried to follow the RSSB position & I have missed any view about third rail in stations for BEMU charging.

 

[D365]

Have RSSB specifically mentioned new interlocked third rail at station platforms ?

Or have you deduced this from their statement some time ago about new third rail & the criteria that must be applied to approve it.

I have tried to follow the RSSB position & I have missed any view about third rail in stations for BEMU charging.

Your second sentence is - based on conversations that I have had with relevant stakeholders - the conclusion that I came to.

 

[Bald Rick]

RSSB are not convinced about the safety of new third rail installations at station platforms. Even if the power supply is ”interlocked”.

RSSB don’t need to be convinced. The ORR do.

It is all about risk assessment. Clearly, the risk of a ‘third party’ unintentionally coming into contact with a bare conductor at ground level is significantly reduced if it is shielded and only live when there is a train on it. In my view this should be sufficient to demonstrate that the risk is mitigated as far as is reasonably practicable.


Back to the OP - for Merseyrail and Headbolt Lane - there would be no need. The power needed to get from Kirkby and back again is relatively small - easily covered by a battery the size of which you’d get in a small electric car. The 777 battery is very much larger. Getting all the way to Wrexham might be more of a issue.

 

[D365]

RSSB don’t need to be convinced. The ORR do.

It is all about risk assessment. Clearly, the risk of a ‘third party’ unintentionally coming into contact with a bare conductor at ground level is significantly reduced if it is shielded and only live when there is a train on it. In my view this should be sufficient to demonstrate that the risk is mitigated as far as is reasonably practicable.

Oops, you caught me there. I did mean the ORR, of course.

Anecdotal this is, but I am told it would be expected that ground staff would still need to be fully trained on third rail safety, even in that scenario.

 

[Bald Rick]

Anecdotal this is, but I am told it would be expected that ground staff would still need to be fully trained on third rail safety, even in that scenario.

Naturally. Fortunately, at both Kirby (and Uckfield), they already are

And even if they weren’t, a half day course for a couple of dozen people is hardly going to stretch the budget.

 

[D821]

RSSB don’t need to be convinced. The ORR do.

It is all about risk assessment. Clearly, the risk of a ‘third party’ unintentionally coming into contact with a bare conductor at ground level is significantly reduced if it is shielded and only live when there is a train on it. In my view this should be sufficient to demonstrate that the risk is mitigated as far as is reasonably practicable.


Back to the OP - for Merseyrail and Headbolt Lane - there would be no need. The power needed to get from Kirkby and back again is relatively small - easily covered by a battery the size of which you’d get in a small electric car. The 777 battery is very much larger. Getting all the way to Wrexham might be more of a issue.

Wrexham would be more of a challenge, definitely. Plus, if Merseyrail extend through Headbolt Lane and build a new station in Skem they might face similar problems.

 

[Bald Rick]

Plus, if Merseyrail extend through Headbolt Lane and build a new station in Skem they might face similar problems.

Skem won’t be an issue. Well within range.

Of course the answer for when a battery EMU doesn’t have range is relatively simple. A bigger battery.

 

[Woods]

I'm surprised that nobody has mentioned Vivarail!

Vivarail claim to have a battery fast-charging system which utilises sections of conductor rail in the four foot. There is a video about it on their website: https://vivarail.co.uk/vivarails-technology/#storage

It states that, "Vivarail has developed and patented this unique system which can recharge a battery train in only 10 minutes. The ability to recharge batteries this quickly is the gamechanger to enable operation on the network. Fast Charge is set to become the UK’s standard system for all types of battery train."

The system was demonstrated in 2019 at Long Marston, funded by Innovate UK: https://www.railway-technology.com/...charging-system-for-class-230-battery-trains/

Which suggests that, if it's set to become the UK's standard system for all types of battery train, then Network Rail and ORR might already have reviewed and given it the nod? Otherwise I don't suppose Vivarail would be pouring so much effort into it, let alone marketing it as a product. Presumably the 230s which are set to operate the Wrexham-Bidston line could, one day, be converted to battery-only units, if fast charge stations were to be installed at selected stations en route. At the moment they are diesel-battery hybrids. Maybe that is seen as an intermediate step on the road to 'full battery'.

Skem won’t be an issue. Well within range.

Of course the answer for when a battery EMU doesn’t have range is relatively simple. A bigger battery.

If only it was that simple! Trains are limited by axle load and the infrastructure (gauge) such that there is only a limited 'envelope' for installing batteries. It's the same problem with hydrogen trains - which need batteries AND hydrogen tanks AND not to mention all the additional electrical kit to manage the power that goes with them. And then of course, the more weight you add to a battery train, the shorter will be its range, so it's a bit of a vicious circle. That's just physics, captain! Not to mention the extra cost of batteries - they won't be cheap, and trains are built to a price.

 

[D365]

Of course the answer for when a battery EMU doesn’t have range is relatively simple. A bigger battery.

 

[Bald Rick]

If only it was that simple! Trains are limited by axle load and the infrastructure (gauge) such that there is only a limited 'envelope' for installing batteries.

Oh I agree. However that envelope is quite large. If you think about the weight and space taken up by Diesel engines, transmission, fuel, exhaust systems etc, and replace that with battery and electric transmission, there is a fair degree of leeway - at least in theory. It’s conceivable that you could have 20t of battery on a 4 car EMU, and that would be enough for 4-6 hours of duty cycle off the juice for a typical plain vanilla EMU. Of course there are challenges with charging, and battery charge cycles, but it is certainly in the realm of possibility.

 

[Woods]

Oh I agree. However that envelope is quite large. If you think about the weight and space taken up by Diesel engines, transmission, fuel, exhaust systems etc, and replace that with battery and electric transmission, there is a fair degree of leeway - at least in theory. It’s conceivable that you could have 20t of battery on a 4 car EMU, and that would be enough for 4-6 hours of duty cycle off the juice for a typical plain vanilla EMU. Of course there are challenges with charging, and battery charge cycles, but it is certainly in the realm of possibility.

I don't know the 777s, but I suspect that 20 tonnes of battery on a 4-car EMU is probably a bit on the optimistic side. Traction battery rafts of the type that Vivarail use are around 2 tonnes each, I think I heard this quoted in a talk once. And the rafts are quite big - around 2m long by 1m wide by 1m deep? Or thereabouts. 20 tonnes divided by 2 = 10 battery rafts, suspect that could be quite tricky to squeeze in, even on a 4-car unit. But I may be wrong. And I suppose that battery energy density is improving all the time.

 

[edwin_m]

I don't know the 777s, but I suspect that 20 tonnes of battery on a 4-car EMU is probably a bit on the optimistic side. Traction battery rafts of the type that Vivarail use are around 2 tonnes each, I think I heard this quoted in a talk once. And the rafts are quite big - around 2m long by 1m wide by 1m deep? Or thereabouts. 20 tonnes divided by 2 = 10 battery rafts, suspect that could be quite tricky to squeeze in, even on a 4-car unit. But I may be wrong. And I suppose that battery energy density is improving all the time.

The other potential issue is that the 777s have a lower floor than most other units.

 

[AM9]

... And then of course, the more weight you add to a battery train, the shorter will be its range, so it's a bit of a vicious circle. That's just physics, captain! Not to mention the extra cost of batteries - they won't be cheap, and trains are built to a price. ...

It's not quite true that increasing the weight of on-board batteries reduces range. On such a train, a large proportion of the energy is reclaimed during braking as long as the emergency brakes aren't used. Obviously not all of the energy cames back because of losses in the electronics, the motors and the batteries, but up to a certain size most of the extra capacity can be converted a larger range.

 

[Woods]

It's not quite true that increasing the weight of on-board batteries reduces range. On such a train, a large proportion of the energy is reclaimed during braking as long as the emergency brakes aren't used. Obviously not all of the energy cames back because of losses in the electronics, the motors and the batteries, but up to a certain size most of the extra capacity can be converted a larger range.

Unfortunately I don't think it's a very large proportion of energy which is reclaimed during braking. Think it's in the 5-10% range.

 

[Bald Rick]

I don't know the 777s, but I suspect that 20 tonnes of battery on a 4-car EMU is probably a bit on the optimistic side.

it probably is, but then the weight of engine, alternator, fuel, cooler group and exhaust under a typical DMU coach is typically 5t plus.

Unfortunately I don't think it's a very large proportion of energy which is reclaimed during braking. Think it's in the 5-10% range.

More than that even on long distance duty cycles. On metro operation with continuous acceleration / braking cycles it can be well over 30% of the whole cycle.

 

[Skie]

An alternative charging solution that is possible with the 777s is to provide 750v via overhead electrification.

 

[Woods]

More than that even on long distance duty cycles. On metro operation with continuous acceleration / braking cycles it can be well over 30% of the whole cycle.

Fair enough, I was not aware that it could be as much as that. Learn something every day!

 

[Ribbleman]

An alternative charging solution that is possible with the 777s is to provide 750v via overhead electrification.

David Powell has spoken about that being a possible solution for Liverpool-Wrexham operation. 3rd rail as far as Bidston, then battery power until the point is reached when a couple of miles of overhead would recharge the batteries whilst the unit remains on the move. I would think that the likelihood of that happening will depend upon how keen the WAG are to make through running to and from Liverpool possible.

 

[SynthD]

For the safety point, does it matter how likely a third party is to come onto the third rail? What if the third rail was only more than 100m away from stations, level crossings and pedestrian crossings?

 

[Bald Rick]

For the safety point, does it matter how likely a third party is to come onto the third rail?

yes it does matter, it is a factor in the risk assessment. Clearly it is more likely at stations, level crossings, and places with known trespass.

 

[AM9]

yes it does matter, it is a factor in the risk assessment. Clearly it is more likely at stations, level crossings, and places with known trespass.

It might be considered a higher risk as regular tresspassers might not know of the charging strips' presence if they weren't visible from platforms and crossings.