Should the third rail ban be lifted?

[martin butler]

Value for money, has to be whatever gives the best return, the best availability figures, the best traction usage cost per mile,
At the moment there is no one design of unit that can operate over 3rd rail, and Overhead with battery provision for non electrified stretches of route,

Only when such a unit is introduced can any such cost be accurately worked out, In an ideal situation, any depot manager would want one type of unit, that can operate every diagram that depot has to cover and for it to be able to work in multiple with the rest of their fleet.

 

[N1]

At the moment there is no one design of unit that can operate over 3rd rail, and Overhead with battery provision for non electrified stretches of route,

Not for 3rd rail, but Skoda are building BEMUs to operate under 25kV AC and 1.5kV DC overhead for Czech Railways, to be introduced next year. In the UK, Class 777s are capable of conversion to 25kV in future if required, so pretty much there.

 

[35B]

Value for money, has to be whatever gives the best return, the best availability figures, the best traction usage cost per mile,

Value for money is a difficult test, and depends on what is being measured.

At the moment there is no one design of unit that can operate over 3rd rail, and Overhead with battery provision for non electrified stretches of route,

There are dual voltage units, and there are BEMUs. The tech is much less of an issue than why anyone would build such a thing.

Only when such a unit is introduced can any such cost be accurately worked out, In an ideal situation, any depot manager would want one type of unit, that can operate every diagram that depot has to cover and for it to be able to work in multiple with the rest of their fleet.

There's a minor problem here - no one will build such a unit without a business case underpinning it. Which is why such cases are based on estimates and assumptions - necessarily so given that a train should last 30-40 years.

 

[JamesT]

Value for money, has to be whatever gives the best return, the best availability figures, the best traction usage cost per mile,
At the moment there is no one design of unit that can operate over 3rd rail, and Overhead with battery provision for non electrified stretches of route,

Only when such a unit is introduced can any such cost be accurately worked out, In an ideal situation, any depot manager would want one type of unit, that can operate every diagram that depot has to cover and for it to be able to work in multiple with the rest of their fleet.

That sounds like making perfect the enemy of good. Battery/third rail, battery/overhead, and third rail/overhead are all proven designs of unit. One that can do all three is not much of a leap.
But does it actually matter if you can't do all three? Routes are almost invariably going to be predominantly one type of electrification with an extension onto another or unelectrified. As long as the running on the electrified section is long enough to charge, what does it matter if you're running on battery with the other type?
The manufacturers will give their prices for rolling stock, and the bean counters will decide if it's worth it. Or if it's actually cheaper to have two types and enough spares that you don't need to care about substituting one for the other.

In the UK, Class 777s are capable of conversion to 25kV in future if required, so pretty much there.

The class 777s have a space that is either used for the transformer for OLE variants, or the batteries for BEMU ones. So you can't do both within the constraints of that rolling stock. But this doesn't mean that a different design couldn't handle it.

 

[Bald Rick]

I understand that all can be estimated. My point is that a decision may be taken despite not being the cheapest because the alternative, difficult to quantify, factors weigh heavy enough to outweigh a pure cost calculation.

Anyone taking a decison that results in something being more expensive and less safe can expect a trip to stand in front of a judge in the event of an incident that results in injury or worse caused by the element that is less safe than it could have been had the cheaper option been taken.

 

[35B]

Anyone taking a decison that results in something being more expensive and less safe can expect a trip to stand in front of a judge in the event of an incident that results in injury or worse caused by the element that is less safe than it could have been had the cheaper option been taken.

I specifically stated value for money as a criteria, which is not the same as cheaper. Much would depend on the precise factors, and how they had been considered; I think it unlikely but not impossible that a nonfinancial factor would be determinative in a close run decision.

 

[NCT]

If it's a close run decision between 'conventional' 3rd rail and a battery based solution, then I suspect the safety consideration would swing the decision towards battery.

 

[35B]

If it's a close run decision between 'conventional' 3rd rail and a battery based solution, then I suspect the safety consideration would swing the decision towards battery.

It might.

 

[WAO]

Reputation - not sure how that comes into it, except when a 12 year old trespasser is killed by the conrail when a battery solution would have been cheaper…

Death could more likely (and certainly) be caused by being hit by a (battery?) train which is also difficult to anticipate.

Diesels are arguably safer in that you can hear them coming.

Trespass is the problem, not juice.

WAO

 

[JohnRegular]

That sounds like making perfect the enemy of good. Battery/third rail, battery/overhead, and third rail/overhead are all proven designs of unit. One that can do all three is not much of a leap.
But does it actually matter if you can't do all three? Routes are almost invariably going to be predominantly one type of electrification with an extension onto another or unelectrified. As long as the running on the electrified section is long enough to charge, what does it matter if you're running on battery with the other type?

Portsmouth - Cardiff says hello; notably with the route termini (the most important locations for charging) having different electrification systems. I don't know the numbers but plausibly that could make all the difference between being able to use BEMUs or requiring diesel engines.

Your point is taken of course, just that there is at least one exception (if/when Exeter gets wires then the West of England trains will be another).

 

[Bald Rick]

Trespass is the problem, not juice.

Not always, as we have seen.

== Doublepost prevention - post automatically merged: 17 Mar 2026 ==

I specifically stated value for money as a criteria, which is not the same as cheaper.

Agreed.

Nevertheless, value for money is cost vs beenfit, and the benefit of a battery train on any given currently not electrified line is to all intents and purposes the safe as a regular electric train, apart from the safety benefit. And that would be assessed and converted to a monetary value.

There are also benefits to battery trains on electrified lines (including safety benefits), and those would need to be valued and included in the VFM calculations.

 

[35B]

Agreed.

Nevertheless, value for money is cost vs beenfit, and the benefit of a battery train on any given currently not electrified line is to all intents and purposes the safe as a regular electric train, apart from the safety benefit. And that would be assessed and converted to a monetary value.

There are also benefits to battery trains on electrified lines (including safety benefits), and those would need to be valued and included in the VFM calculations.

Indeed they would, and I'd expect that. But at the margins, there is a question of legitimate judgment when selecting options. Having sat as a trustee and director in making major strategic decisions, the question becomes one of the process by which decisions are made, and the information available to inform those decisions.

 

[Bald Rick]

Having sat as a trustee and director in making major strategic decisions, the question becomes one of the process by which decisions are made, and the information available to inform those decision

Quite, which brings me back to my question in post #258. (It was a rhetorical question)

 

[Pigeon]

Mine would include where and how the batteries are produced, what their expected lifetime is, and how they will be disposed of at the end of it.

Oh, don't worry, that all happens in the future in places on the other side of the world, so we can pretend it doesn't exist.

Lithium batteries are essentially a laboratory curiosity that has been inappropriately released into the outside world because their advantages are obvious right now while their disadvantages can be ignored on the above principle or simply by outright denial, so instead of them being treated simply as an important step in the process of learning how to achieve similar performance from more commonplace and benign materials, the depressingly inevitable forces of greed have kicked in and now they are all over the place.

Apart from anything else there simply isn't enough of the stuff. I've just looked up how much "the reserves" are reckoned to be and I am astonished to find that it's only about 20 million tonnes. Compare that with the number of vehicles worldwide (both road and rail) that we are led to believe will be "going electric" and the daftness is immediately obvious.

Then there is the nature of the fire hazard, a point from which people are distracted by such means as misleading propaganda statements like "the best way of putting them out is water". Yeah, right. It still isn't a good way of putting them out. They react with water. It doesn't stop the energy release. All it can do is carry away heat if you can use enough of it to have a useful effect. As well as the shock hazard from a vehicle battery, throwing water on them produces hydrofluoric acid, which is very nasty stuff, so now you are dealing with a chemical spill as well. For the same reason the smoke from the fire is highly toxic and dangerous to inhale.

We probably have to accept that a battery of useful capacity and energy density will be potentially able to go up unsmotherably, but then a fire from a burst fuel tank is effectively unsmotherable and is quicker to spread. The distinctive feature of lithium batteries is that both the fumes and the residue are so very much nastier than those from a fire in anything else that trains are made of.

A battery technology intended to replace the amount of energy transport/storage we perform at the moment using tanks of hydrocarbon fuel needs to use only materials which are of comparable abundance - so we have plenty enough to scatter them around the place with similar abandon - and cause no more than comparably unpleasant consequences when things go wrong. While it may be possible to devise a lithium-based chemistry that overcomes the second objection, it is still inherently incompatible with the first. Consequently we do not currently have a battery technology suitable for the kind of mass deployment that we so like to delude ourselves into thinking we do.

 

[JamesT]

Oh, don't worry, that all happens in the future in places on the other side of the world, so we can pretend it doesn't exist.

Lithium batteries are essentially a laboratory curiosity that has been inappropriately released into the outside world because their advantages are obvious right now while their disadvantages can be ignored on the above principle or simply by outright denial, so instead of them being treated simply as an important step in the process of learning how to achieve similar performance from more commonplace and benign materials, the depressingly inevitable forces of greed have kicked in and now they are all over the place.

Apart from anything else there simply isn't enough of the stuff. I've just looked up how much "the reserves" are reckoned to be and I am astonished to find that it's only about 20 million tonnes. Compare that with the number of vehicles worldwide (both road and rail) that we are led to believe will be "going electric" and the daftness is immediately obvious.

Then there is the nature of the fire hazard, a point from which people are distracted by such means as misleading propaganda statements like "the best way of putting them out is water". Yeah, right. It still isn't a good way of putting them out. They react with water. It doesn't stop the energy release. All it can do is carry away heat if you can use enough of it to have a useful effect. As well as the shock hazard from a vehicle battery, throwing water on them produces hydrofluoric acid, which is very nasty stuff, so now you are dealing with a chemical spill as well. For the same reason the smoke from the fire is highly toxic and dangerous to inhale.

We probably have to accept that a battery of useful capacity and energy density will be potentially able to go up unsmotherably, but then a fire from a burst fuel tank is effectively unsmotherable and is quicker to spread. The distinctive feature of lithium batteries is that both the fumes and the residue are so very much nastier than those from a fire in anything else that trains are made of.

A battery technology intended to replace the amount of energy transport/storage we perform at the moment using tanks of hydrocarbon fuel needs to use only materials which are of comparable abundance - so we have plenty enough to scatter them around the place with similar abandon - and cause no more than comparably unpleasant consequences when things go wrong. While it may be possible to devise a lithium-based chemistry that overcomes the second objection, it is still inherently incompatible with the first. Consequently we do not currently have a battery technology suitable for the kind of mass deployment that we so like to delude ourselves into thinking we do.

Oh dear. Lithium is a massively common element, there is no worries about it running out.
‘Reserves’ are merely deposits that have been identified as commercially exploitable. That is not the total amount of lithium in the world. In the same way that an increase in the price of oil led to exploring new fields such as the North Sea, if there was an increase in demand then more sources would be identified.
There is also another potential source in the world’s oceans. It’s estimated there could be billions of tons of lithium in seawater, if someone wants to extract it.

 

[Harpo]

Reading, Basingstoke and onwards to Exeter should be 25kv overhead wired, and linked into an extension of any GW scheme, to extend from Bristol to Exeter…..

……and logically west of Newbury, but last I heard the required feeder station at Westbury had an exceedingly large price tag.

And, of course, putting the wires up westwards to Exeter raises the inevitable question after St Davids - Then what?

 

[Bald Rick]

Apart from anything else there simply isn't enough of the stuff. I've just looked up how much "the reserves" are reckoned to be and I am astonished to find that it's only about 20 million tonnes. Compare that with the number of vehicles worldwide (both road and rail) that we are led to believe will be "going electric" and the daftness is immediately obvious.

Fortunately, the amount of Lithium in (say) an LFP battery is rather small. About 10 kilos for a typical EV battery.

 

[WTT Gremlin]

……and logically west of Newbury, but last I heard the required feeder station at Westbury had an exceedingly large price tag.

And, of course, putting the wires up westwards to Exeter raises the inevitable question after St Davids - Then what?

Newbury to the Mendip quarries could enable a very substantial increase in power on the front of the heaviest loads on the network (may involve moving some operational moves from Hanwell Bridge Loop to Wembley).

Otherwise as a starter for ten:
Exeter to Plymouth... Truro (Penwithers Jn)... Penzance
Wigston South to Sileby... Nottingham/Derby... Sheffield via Dore and Beighton... to South Kirby Jn, Horbury Jn, and Retford
Birmingham to Kingsbury Jn/Whitacre Jn... Burton/Nuneaton... Derby & Sheet Stores/Wigston North

Oh no... this is starting to look like sections of a rolling programme...

PS. When do mainline sized feeder stations not have large price tags?

 

[martin butler]

……and logically west of Newbury, but last I heard the required feeder station at Westbury had an exceedingly large price tag.

And, of course, putting the wires up westwards to Exeter raises the inevitable question after St Davids - Then what?

That could be the changeover point from Electric to Deisel, or Battery for local services,

The important question though will be the rolling stock, ideally there should be one type of unit that's able to be configured as either straight EMU, collecting via 3rd rail, or overhead, but able to be battery fitted by the depot and to keep it affordable, it would have to be a very large order to be used across every region Again ideally by a british based manufacturer to attract jobs,

 

[35B]

That could be the changeover point from Electric to Deisel, or Battery for local services,

The important question though will be the rolling stock, ideally there should be one type of unit that's able to be configured as either straight EMU, collecting via 3rd rail, or overhead, but able to be battery fitted by the depot and to keep it affordable, it would have to be a very large order to be used across every region Again ideally by a british based manufacturer to attract jobs,

Excellent. A single design that maximises risk and ensures that when fleet replacement is required, you have the greatest possible need.

I’m no fan of micro fleets and differences for difference sake (CAF DMUs, I’m looking at you), but this is really a case of putting all the eggs in one basket.

 

[zwk500]

Excellent. A single design that maximises risk and ensures that when fleet replacement is required, you have the greatest possible need.

I’m no fan of micro fleets and differences for difference sake (CAF DMUs, I’m looking at you), but this is really a case of putting all the eggs in one basket.

So the best answer to you would be to have a fleet of 50/50 split pure EMUs and BEMUs, such that there is flexibility enough to resource BEMU services consistently but if there are battery issues the all-electrified service can continue?

You could even have both classes based on a common platform for efficiency of maintenance.

 

[35B]

So the best answer to you would be to have a fleet of 50/50 split pure EMUs and BEMUs, such that there is flexibility enough to resource BEMU services consistently but if there are battery issues the all-electrified service can continue?

You could even have both classes based on a common platform for efficiency of maintenance.

Only if the predetermined answer is battery.

My issue with @Martin butler’s idea is the insistence on a single common design, which is pure pie in the sky.

 

[WAO]

Looking at the figures for dc safety (#152) it is evident that there has been a marked safety improvement in recent years, except perhaps for suicides which are probably largely unavoidable. The presupposition against dc is based on a 2012 report, before these improvements took effect.

Comparing other safety fields in transport, roadside recovery drivers suffer 6 - 8 deaths per year and injuries in proportion to a workforce of perhaps 5000.

Clearly dc is a relatively safe workspace with proper practice.

Whether trying to make it child-safe (after fencing, signage, publicity etc) is rational, I question.

That's not to say batteries don't have their economic place.

WAO

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.phsbesafe.co.uk/news/importance-of-roadside-recovery-workers&ved=2ahUKEwiKl4vqmqmTAxWKW0EAHRHtMlEQFnoECBsQAQ&usg=AOvVaw2S-4OSjulvX-YPhKO1MOL3

 

[N1]

Looking at the figures for dc safety (#152) it is evident that there has been a marked safety improvement in recent years, except perhaps for suicides which are probably largely unavoidable. The presupposition against dc is based on a 2012 report, before these improvements took effect.

Comparing other safety fields in transport, roadside recovery drivers suffer 6 - 8 deaths per year and injuries in proportion to a workforce of perhaps 5000.

Clearly dc is a relatively safe workspace with proper practice.

Whether trying to make it child-safe (after fencing, signage, publicity etc) is rational, I question.

That's not to say batteries don't have their economic place.

WAO

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.phsbesafe.co.uk/news/importance-of-roadside-recovery-workers&ved=2ahUKEwiKl4vqmqmTAxWKW0EAHRHtMlEQFnoECBsQAQ&usg=AOvVaw2S-4OSjulvX-YPhKO1MOL3

Safety improvements are being delivered on 3rd rail (and OLE) under the Electrical Safety Delivery Programme by Network Rail. This is a programme of capital investment required by the ORR and agreed by Network Rail to bring exisitng electrical rail infrastructure into better compliance with Electricity at Work Regultions, and other legal requirements. It is focused on improving safety for Permanent Way maintenance and improving isolations. The ORR do not consider exisitng 3rd rail infrastructure in its current form safe, and require actual continuous improvements in safety from Network Rail.

 

[Bald Rick]

Looking at the figures for dc safety (#152) it is evident that there has been a marked safety improvement in recent years, except perhaps for suicides which are probably largely unavoidable. The presupposition against dc is based on a 2012 report, before these improvements took effect.

I don’t know how you reach that conclusion.

Workforce fatalties and injuries have reduced, largely because of the removal of red zone working and the improvements mentioned by the previous poster.

Public fatalities and injuries continue at broadly the same level.

For the third time, these statistics do not include suicides, which are not reported in the numbers obtained through the FOI. Please stop saying, or implying, that they do.

 

[martin butler]

Only if the predetermined answer is battery.

My issue with @Martin butler’s idea is the insistence on a single common design, which is pure pie in the sky.

Surely having one manufacturer and a larger order, with a lot of common interchange of parts, would lessen problems and enable a greater fleet to be built for the lowest cost per unit, which will be the main issue going forward, and with a life of say 40 years, costs will be the main consideration for any government wanting to reduce costs.

 

[JamesT]

Surely having one manufacturer and a larger order, with a lot of common interchange of parts, would lessen problems and enable a greater fleet to be built for the lowest cost per unit, which will be the main issue going forward, and with a life of say 40 years, costs will be the main consideration for any government wanting to reduce costs.

Or once said manufacturer knows they have a monopoly, they take the mickey for all following orders as they know they're the only game in town.

But this has very little to do with whether to deploy further third rail.

 

[martin butler]

Or once said manufacturer knows they have a monopoly, they take the mickey for all following orders as they know they're the only game in town.

But this has very little to do with whether to deploy further third rail.

To an extent, but if there is to be no further extensions of 3rd rail to close gaps, and the decision is to use battery power, then, new stock would be needed, especially if GBR plan to reduce diesel haulage for electric over a decided timeline.

 

[Stephen42]

Death could more likely (and certainly) be caused by being hit by a (battery?) train which is also difficult to anticipate.

I was interested in what the publicly available numbers suggested for this. In case it's useful for anyone else:

Between April 2018 and March 2025 the ORR railway safety dashboard has 187 non-workforce mainline fatalities for all Network Rail routes. The 2019 to May 2024 figure in the table quoted earlier for 3rd rail related was 31. Figures exclude suspected suicides for both.

That makes the third rail number a sixth of the total. The railway safety number is a year and half longer period so proportion will be higher. With 3rd being a small share of the network, if restricted to those routes it could plausibly be the majority of the deaths. The railway safety figure includes more than struck by train too, including platform-train interface and station accidents as well.

 

[35B]

Surely having one manufacturer and a larger order, with a lot of common interchange of parts, would lessen problems and enable a greater fleet to be built for the lowest cost per unit, which will be the main issue going forward, and with a life of say 40 years, costs will be the main consideration for any government wanting to reduce costs.

All true - but you are assuming (a) that economies of scale are unlimited, (b) the chosen option will be the best one and (c) one individual supplier would have capacity. As @JamesT observes, having exclusivity is unlikely to deliver value (see Hitachi for evidence). There is empirical evidence of this from the Mk1 extinction orders, where Bombardier (Electrostar 375/7) and Siemens (444/450) provided satisfactory responses at the scale required.

Going back to the role of batteries, technologies vary and so do their implementations. If this is to be done, then better by far that it's done by looking for the best fit for the job and not trying to meet a mythical "do everything" requirement.