Third rail is old fashioned and should be done away with

[AM9]

Oh please, the "unauthorised access" argument outside of urban areas is meaningless worry-gutzing.

The M6 runs through open countryside and is forbidden to trespassing. Doubtless people do trespass there, why is the railway any different.

The M6 has nothing to do with a discussion on the type of electrification on a railway.

 

[yorksrob]

The M6 has nothing to do with a discussion on the type of electrification on a railway.

It has everything to do with the calculations around risk and trespass.

 

[AM9]

It has everything to do with the calculations around risk and trespass.

Not in this thyread, If you want to start another thread, feel free.

 

[yorksrob]

Not in this thyread, If you want to start another thread, feel free.

Talking about "threads" is a cop-out.

You know as well as I do that railway passengers have to endure the costs of a far more stringent safety regime than motorists.

By saying such calculations are off-topic, you are endorsing the double standard between the safety of rail and road transport.

 

[stuu]

Oh please, the "unauthorised access" argument outside of urban areas is meaningless worry-gutzing.

The M6 runs through open countryside and is forbidden to trespassing. Doubtless people do trespass there, why is the railway any different.

Not many level crossings on the M6

 

[yorksrob]

Not many level crossings on the M6

Not many level crossings on the Brighton mainline either.

 

[mr_jrt]

The problem is, if you start whittling away the third rail system, the remainder becomes an even smaller fleet of less universal trains. The priority ought to be increasing the proportion of electrified route.

It's only a problem if you see the eventual removal of the third rail as a negative. Eventually you will reach a tipping point where converting the rump becomes economically viable. Then at long last, it's all gone. Regardless, the smaller pool are in fact going to end up being dual voltage units, so they would in fact end up being more universal What will end are DC-only units, and once those are gone then piecemeal conversion becomes marginally more acceptable. Even more so if they end up having small batteries as well to ease the "temporary" overlaps.

 

[zwk500]

Oh please, the "unauthorised access" argument outside of urban areas is meaningless worry-gutzing.

The M6 runs through open countryside and is forbidden to trespassing. Doubtless people do trespass there, why is the railway any different.

The M6 isn't electrically live.

 

[yorksrob]

The M6 isn't electrically live.

So what.

It's clearly dangerous, otherwise people would still be picknicking on the hard shoulder.

== Doublepost prevention - post automatically merged: 31 Dec 2023 ==

It's only a problem if you see the eventual removal of the third rail as a negative. Eventually you will reach a tipping point where converting the rump becomes economically viable. Then at long last, it's all gone. Regardless, the smaller pool are in fact going to end up being dual voltage units, so they would in fact end up being more universal What will end are DC-only units, and once those are gone then piecemeal conversion becomes marginally more acceptable. Even more so if they end up having small batteries as well to ease the "temporary" overlaps.

It's still a lot of expense when we've got so much route to electrify first time around.

 

[zwk500]

So what.

It's clearly dangerous, otherwise people would still be picknicking on the hard shoulder.

The nature of the risk is fundamentally different.

 

[yorksrob]

The nature of the risk is fundamentally different.

It's a risk we've managed with for long enough.

 

[Meerkat]

The M6 doesn’t go through the middle of towns and cities, and only the moving vehicles are dangerous, not the infrastructure itself.
Its also busier - only the very foolhardy would take a short cut across the M6 and you can’t sneak on to do graffiti or whatever.
Vehicles on the M6 can swerve or brake, and its much easier and quicker for the police to get to the scene.
So basically the M6 is in no way comparable to an electrified area

 

[WAO]

It's not really the comparative risk that matters but the inherited risk.

We didn't choose to have air pollution; our predecessors did unintentionally, etc.

Some inherited risks we choose to have eliminated, some only mitigated, depending on the costs and benefits that we judge.

We could choose to eliminate 3rd rail dc (I don't object - Merseyrail is a practical option) however mitigation is chosen as the absolute risks are actually quite low and the costs high.(The aviation industry/safety regulators give a human life a cash value).

It is ridiculous that 3rd rail mitigation consists merely of freezing its existing boundaries, without improving fencing, access procedures, protective clothing etc. Filling in the small gaps in third rail in the South would not increase overall risk significantly; failure to improve other matters over the whole dc network does.

HNY!

WAO

 

[A0]

I will inform the majority of Metro systems around the world, including many new ones.

If OHLE was such a straightforward conversion from 3rd rail, there would have been plenty of such examples by now. In fact there are hardly any. Even the North London Line issues that caused its conversion there were not 3rd rail ones, which had worked fine along there for the previous 60 years, but the installation of 25kV alongside by those who didn't understand electrical engineering fundamentals.

AIUI the conversion was in part to allow electric haulage of freight along the North London Line, which wasn't possible with 3rd rail.

I suspect @Bald Rick or @ChiefPlanner may be able to contribute on the rationale behind converting the NLL to OHLE.

 

[HSTEd]

AIUI the conversion was in part to allow electric haulage of freight along the North London Line, which wasn't possible with 3rd rail.

I suspect @Bald Rick or @ChiefPlanner may be able to contribute on the rationale behind converting the NLL to OHLE.

My understanding, which is inherently limited, it wasn't actually a conversion originally.
The line was dual electrified for a short period but it proved unworkable, so the third rail was removed to allow the 25kV operation to continue.

The original project had been conceived of as being cheaper than buying a dual voltage electric locomotive, which wouldn't happen until the Class 92.
Obviously if they had had a realistic understanding of the project at the start they probably would have opted for the locomotive.

 

[BrianW]

The thread title is perhaps a little 'limiting'-

Third rail is old fashioned and should be done away with​

I can't see that 'fashion' should be an issue; nor that something (as with someone) should be 'done away with'- tho the language does draw the eye
So what is the issue?

Is third rail unsafe, or expensive to maintain, or unsatisfactory in some other regard? AIUI, the ORR does not support its use where it is currently not in place, citing safety concerns, principally for trackworkers and trespassers. That is a logical policy.

To 'do away with' existing third rail provision (and associated infrastructure, rolling stock etc) will incur costs and inconveniences- analysis and decisions will need to be made as to costs and benefits.

Technology provides possible ways ahead, and 'climate change' also provides impetus, eg to decarbonisation. So extension of, and in this case conversion to 'standard' 25kV OH may makes sense. Electro-diesels and Bi-modes also show that not every metre of every track needs to be electrified.

Could Clapham Junction be travelled through without wires? Could a train arrive and depart Waterloo or Victoria, or Weymouth or Brighton with a 'quick-charge' in between?

Could the third rail be allowed to 'wither on the vine'?

 

[mr_jrt]

The "doing away with" bit to me isn't a problem as such. Infrastructure has a finite lifespan. Equipment with useful life still in it can be recovered and used in areas further down the conversion pipeline as that equipment itself wears out. Rolling stock will all be dual voltage compatible, we just have to make sure there's an active source for the transformers to fit if we don't want them fitted from new. The remaining DC-only stock will all long be razorblades by time any conversion project happens.

I would imagine that if we went through a phase of every unit having a battery or being a bimode of some sort then it would make the process somewhat simpler as you could avoid building all the complex temporary dual-electrified overlaps as you progressed inwards towards the London termini. You would almost certainly still want the overhead in place long-term, though, but it would indeed give you a lot of flexibility in installing it.

That said, doing the actual conversion without them isn't impossible. On horribly complex areas like the London termini approaches, it's not novel science - we already have complex London termini approaches with overhead. You could do the design work, rebuild any bridges, install the masts, the gantries, and possibly even the put the wires in, all in advance of a big bang switchover. You just have to leave any electrical interactions with the track until the inevitable switchover blockade. And hope nothing goes wrong!

 

[Meerkat]

The "doing away with" bit to me isn't a problem as such. Infrastructure has a finite lifespan. Equipment with useful life still in it can be recovered and used in areas further down the conversion pipeline as that equipment itself wears out. Rolling stock will all be dual voltage compatible, we just have to make sure there's an active source for the transformers to fit if we don't want them fitted from new. The remaining DC-only stock will all long be razorblades by time any conversion project happens.

I would imagine that if we went through a phase of every unit having a battery or being a bimode of some sort then it would make the process somewhat simpler as you could avoid building all the complex temporary dual-electrified overlaps as you progressed inwards towards the London termini. You would almost certainly still want the overhead in place long-term, though, but it would indeed give you a lot of flexibility in installing it.

That said, doing the actual conversion without them isn't impossible. On horribly complex areas like the London termini approaches, it's not novel science - we already have complex London termini approaches with overhead. You could do the design work, rebuild any bridges, install the masts, the gantries, and possibly even the put the wires in, all in advance of a big bang switchover. You just have to leave any electrical interactions with the track until the inevitable switchover blockade. And hope nothing goes wrong!

Putting overhead all the way into the southern London termini would be heroic! No real need for the inner suburban area is there?

 

[mr_jrt]

There is if you want to use the same AC-only trains as you do everywhere else. Dual voltage trains have more bits, more complexity, more to go wrong, and thus more cost. Why is it any more heroic than wiring up Euston? Or Liverpool Street? Or Paddington?

 

[mike57]

The cost of converting the 3rd rail network to 25kv would be astronomical and the disruption would last years. Whilst NEVER is a long time I cant see it being considered within anyone currently alive lifetime. While there are large sections of un-electrified main lines spending billions on conversion would be unacceptable. Even the conversion most talked about, SW mainline to Southampton would be questionable until all of MML, GWR and TPE together with Birmingham-Bristol, which isnt even on the radar are completed.

I would go further and say that there even some obvious short 3rd rail infills that are needed to eliminate diesel

Mixing AC and DC on the same tracks introduces new issues, and dual voltage EMUs are more complex and heavier because they also need a transformer, so some of the efficency increase in transmission is lost elsewhere.

Which raises the question of what could be done to improve the efficency of the current 3rd rail system. I am assuming that the majority of the losses are caused by resistive losses in the conductor rails, so as conductor rail is replaced could a lower resistance per unit length rail be developed and used?

To be honest looking at the problems facing the current UK rail network 3rd rail has to be way down the list of issues.

To answer the OPs question it is 'old fashioned' but the only realistic way of doing away with it would be to revert to diesel operation in much the same way as happened on Tyneside back in the day, and surely no one would suggest that.

 

[zwk500]

There is if you want to use the same AC-only trains as you do everywhere else. Dual voltage trains have more bits, more complexity, more to go wrong, and thus more cost. Why is it any more heroic than wiring up Euston? Or Liverpool Street? Or Paddington?

It's more complex to convert than to wire from a clean(ish) base. But not that much.
However the cost of conversion, especially the disruption, means the additional cost of.dual voltage trains would still make it hard to justify 100% conversion. A reduced inner area, vaguely m25 boundary, would.likey remain.

 

[Falcon1200]

Why is it any more heroic than wiring up Euston? Or Liverpool Street? Or Paddington?

The two areas that stand out to me are the multi-track approaches to London Bridge and Waterloo: Is there space between the lines for support structures or can a gantry span up to eight tracks? Either way, erecting overheads on those routes in particular would be an engineering and operational challenge!

 

[zwk500]

The two areas that stand out to me are the multi-track approaches to London Bridge and Waterloo: Is there space between the lines for support structures or can a gantry span up to eight tracks? Either way, erecting overheads on those routes in particular would be an engineering and operational challenge!

There are already signal gantries spanning those approaches, no reason OLE gantries.would be particularly more problematic.

 

[mr_jrt]

Mixing AC and DC on the same tracks introduces new issues, and dual voltage EMUs are more complex and heavier because they also need a transformer, so some of the efficency increase in transmission is lost elsewhere.

AIUI, all new DC trains are in fact dual voltage trains, but with a block of concrete to simulate the transformer (that can be replaced with a real tansformer, if you have a source for the parts) so the suspension et al. don't need to be redesigned. So there's no gains to be had, efficiency wise.

 

[RobShipway]

The two areas that stand out to me are the multi-track approaches to London Bridge and Waterloo: Is there space between the lines for support structures or can a gantry span up to eight tracks? Either way, erecting overheads on those routes in particular would be an engineering and operational challenge!

AIUI, all new DC trains are in fact dual voltage trains, but with a block of concrete to simulate the transformer (that can be replaced with a real tansformer, if you have a source for the parts) so the suspension et al. don't need to be redesigned. So there's no gains to be had, efficiency wise.

Whilst most trains since the late 1990's have been built in design as dual voltage trains, enabling transformers to be added, you are still going to be having a lot of interference for any great distance where you have OHLE in place and third rail. How are you going to overcome this issue?

 

[CarrotPie]

AIUI, all new DC trains are in fact dual voltage trains, but with a block of concrete to simulate the transformer (that can be replaced with a real tansformer, if you have a source for the parts) so the suspension et al. don't need to be redesigned. So there's no gains to be had, efficiency wise.

Is that why SWR Desiros are so heavy?

 

[Meerkat]

There is if you want to use the same AC-only trains as you do everywhere else. Dual voltage trains have more bits, more complexity, more to go wrong, and thus more cost. Why is it any more heroic than wiring up Euston? Or Liverpool Street? Or Paddington?

Waterloo has more platforms, so a wider, more complex throat.
Victoria rapidly becomes the Clapham Junction with 17 platforms, multiple junctions etc. I would imagine sequencing the Waterloo and Victoria lines conversion Through Clapham/Stewart’s Lane would be ‘interesting’.
Liverpool St and Euston weren’t conversions and were wired decades ago under very different H&S standards, and presumably significantly less intense service levels?

 

[Falcon1200]

There are already signal gantries spanning those approaches, no reason OLE gantries.would be particularly more problematic.

Good point, although OLE structures would need to be a lot more closely spaced than signal gantries.

 

[D365]

Whilst most trains since thee late 1990's have been built in design as dual voltage trains, enabling transformers to be added, you are still going to be having a lot of interference for any great distance where you have OHLE in place and third rail. How are you going to overcome this issue?

EMC isn't the issue - it's current return paths. And it’s a well understood issue.

 

[AM9]

Waterloo has more platforms, so a wider, more complex throat.
Victoria rapidly becomes the Clapham Junction with 17 platforms, multiple junctions etc. I would imagine sequencing the Waterloo and Victoria lines conversion Through Clapham/Stewart’s Lane would be ‘interesting’.
Liverpool St and Euston weren’t conversions and were wired decades ago under very different H&S standards, and presumably significantly less intense service levels?

Although I'm not advocating OLE all the way to the Southern Tremini, actually if you look closely at the 'difficult' sections of track that some have mentioned here, they aren't as bad as they at first seem. Take from Clapham Junction to Waterloo:
The eastern throat of Clapham Junction has a maximum of 17 tracks, - a truly large number. But they are not all separated by a normal '6 foot way'. There is a significant separation between the 4 Brighton line tracks and the remainder right back to platofrms 11 & 12. But from the true station throat where the lines from the platforms 5 & 6 close down, the remaining 13 tracks start peeling off, first the Lavender Hill junction route, then there is a wide strip east of the shed there leaving the lines where they can be split 4 & 9 (where the Brighton Lines revert to a 6 foot way before they swing south at Pouparts junction). So the length of more than 9 tracks at 6 foot is about 400m, (maybe 5 of 6 gantries).
Further east apart from a short section on the curve approaching Vauxhall station, the track seems to have at least one wider corridor suitable for erecting gantries to break the spans down.