Railway electrification voltages in Europe - a visualization

[Edwin_m]

18 minutes ago, 009 micro modeller said:

Actually on the subject of DC overhead electrification, in a modern context I’m sure I saw an article a few years ago that suggested the electrification of some branch lines (the sort of self-contained ones that don’t require inter-running with other lines, but are unlikely ever to justify proper main line electrification) with 750V DC overhead wires (so the same as modern trams, but I don’t think the article was suggesting light rail conversion as such). Frustratingly I can’t find the article now, or remember where it was. It would have probably been just before the interest in bi-modes and before battery power became a practical solution.

That may be true considering the branch in isolation but doesn't make much sense in the context of a wider network.  The main line probably has more traffic and therefore a better case for electrification than the branch, so is likely to have been electrified first with 25kV, which makes it much easier to do the branch at the same voltage.  Train maintenance also needs to be considered - the branch train would need to be dual voltage to get to the depot via the main line, unless it was hauled "dead" or serviced at a mini-depot on the branch.  

[Suzie]

The only advantage using low voltage DC overhead has nowadays is that you don't need the transformer/rectifier on the train. This is an adavantage on a closed tram system where you have a lot of trams and can save a lot of space/weight/money not fitting all those rectifiers and transformers to the trams and just provide a few at substations, but no advantage on a proper railway with just a few trains where the 25KV feed can be taken directly from the main line feed and standard AC trains can be used with no need to provide any substations (the Braintree branch is a good example of how to get an electrified branch line on the cheap!)

[009 micro modeller]

20 minutes ago, Edwin_m said:

That may be true considering the branch in isolation but doesn't make much sense in the context of a wider network.  The main line probably has more traffic and therefore a better case for electrification than the branch, so is likely to have been electrified first with 25kV, which makes it much easier to do the branch at the same voltage.  Train maintenance also needs to be considered - the branch train would need to be dual voltage to get to the depot via the main line, unless it was hauled "dead" or serviced at a mini-depot on the branch.  

Yes, I’m not sure where the article was now. The only context in which it might have made sense is where the surrounding network is 750V DC but you specifically want to avoid extending the third rail.

[Edwin_m]

1 hour ago, Suzie said:

The only advantage using low voltage DC overhead has nowadays is that you don't need the transformer/rectifier on the train. This is an adavantage on a closed tram system where you have a lot of trams and can save a lot of space/weight/money not fitting all those rectifiers and transformers to the trams and just provide a few at substations, but no advantage on a proper railway with just a few trains where the 25KV feed can be taken directly from the main line feed and standard AC trains can be used with no need to provide any substations (the Braintree branch is a good example of how to get an electrified branch line on the cheap!)

Generally agreed, but worth noting that safety concerns with live wires in the street are another reason why trams use 750V or less.  Incidentally some recent Metro projects have used 1500Vdc third rail.  

[phil-b259]

2 hours ago, 009 micro modeller said:

Another interesting ‘what-if’ is if the ex-GC lines, including into Marylebone, had been electrified at 1500V DC. Would we have ended up with a mixed network, or would it have still all been converted to AC eventually like the ex-GE lines? Would the GC main line still have closed? On a more specific level, would there have been any conflict with the Met/GC joint line, which was already partly electrified with four rail DC?

 

As an aside, does anyone know why third rail was chosen for the original Tyneside suburban electrification, given that other NER electrification in the region used DC overhead (which ironically is now used anyway by the Metro)?

 

Actually on the subject of DC overhead electrification, in a modern context I’m sure I saw an article a few years ago that suggested the electrification of some branch lines (the sort of self-contained ones that don’t require inter-running with other lines, but are unlikely ever to justify proper main line electrification) with 750V DC overhead wires (so the same as modern trams, but I don’t think the article was suggesting light rail conversion as such). Frustratingly I can’t find the article now, or remember where it was. It would have probably been just before the interest in bi-modes and before battery power became a practical solution.

Depending on length, a far more cost effective solution is battery powered trains plus short lengths of OLE at either end to charge them.

 

The Windermere branch would be a prime example here - a battery unit charges up via the 25KV in Oxenholme station then proceeds to Windermere on battery power. If it needs a boost then a short length of AC OLE could be fitted (probably wouldn’t need to be 25KV as modern electronics which can cope with multiple voltages are easy to design these days) to provide a boost for the return trip.

[Vecchio]

As a modeller of continental trains I find system changes quite interesting and they also add an extra into the operations. Had a Austrian - Italian border layout, so you have to change motive power or use multisystem locomotives. And even if the overhead voltage source is the same - as for instance between Austria and Switzerland - the profile isn't. You can drive all UIC stock in both countries, but the overhead system needs a more narrow pantographs in Switzerland. Makes again a playing field on a border station. 

 

Of course it would make sense to have 25kV/50Hz in all European countries, first the investment for changeover is high and second the modeller would lose all his border games he can put in now 🙂.

[Geep7]

I'm pretty sure that much, if not all, of the (standard gauge) high speed lines in Spain are 25kV, whereas the rest of the broad gauge network is mostly 3kv DC. Obviously there are the odd patches of other stuff. I can't remember what the ex-FEVE lines are electrified at, for example.

Edited September 27, 2023 by Geep7

[RJS1977]

13 hours ago, 009 micro modeller said:

Another interesting ‘what-if’ is if the ex-GC lines, including into Marylebone, had been electrified at 1500V DC. Would we have ended up with a mixed network, or would it have still all been converted to AC eventually like the ex-GE lines? Would the GC main line still have closed? On a more specific level, would there have been any conflict with the Met/GC joint line, which was already partly electrified with four rail DC?

 

It's questionable whether the main line into Marylebone would ever have been electrified at 1500v DC - one of the reasons it's the last diesel-operated terminus in London is beacuse the tunnels under Lord's cricket ground preclude overhead wiring and can't be lowered because of the Regent's canal (which cuts through the site of the previous Lord's cricket ground near where the ex-GC line crosses the canal!). However 1500V DC does not require as much clearance as 25kV AC does, so it may have been possible.

I do not anticipate there to have been any issues with running 1500v DC overhead over the Metropolitan line, as both systems are DC, and I think it is only AC that causes interference problems.

 

The alternative of course would have been for the GCR to have dual-voltage locos converting from 1500v overhead to 750v 4th rail at Amersham (or possibly further north).

[Gordonwis]

15 hours ago, 009 micro modeller said:

 

Not sure about Greenland but the railways in Iceland aren’t electrified because they aren’t there. Although 100% of all the steam locos that have worked in Iceland (i.e. both of them) are preserved.
 

 

Yes, that was the point of my joke!

[RJS1977]

Iceland would seem to me to be a good place to make use of fireless locomotives - all that geothermal heat! Just charge the loco up from the nearest volcano....

[Stefan88]

Italy is another place that is not homogeneously 3kV DC, most of the newer high speed lines are 25kV AC (presumably because its easier and cheaper to run at 300km/h on 25kV AC than 3kV DC).

[pete_mcfarlane]

On 26/09/2023 at 15:56, phil-b259 said:

(In fact the UK was very much behind the times in the 1920s and 30s by not investing in electrification - had we been more enlightened then like France we could have ended up with a mix of 1.5KV DC and 25KVAC systems....)

Surely the situation in France in the 30s wasn't much different to here - with large scale electrification being confined to a a couple of the private railway companies (Midi and the Paris-Orleans). Not much different from the Southern going after large scale electrification on its own. 

[Gordonwis]

12 hours ago, RJS1977 said:

Iceland would seem to me to be a good place to make use of fireless locomotives - all that geothermal heat! Just charge the loco up from the nearest volcano....

 

Fireless engines just need hot steam, so connecting up to the nearest geyser would be the quickest way

[Gordonwis]

50 minutes ago, pete_mcfarlane said:

Surely the situation in France in the 30s wasn't much different to here - with large scale electrification being confined to a a couple of the private railway companies (Midi and the Paris-Orleans). Not much different from the Southern going after large scale electrification on its own. 

 

 

Not forgetting the Etat Paris - Le Mans

[phil-b259]

48 minutes ago, pete_mcfarlane said:

Surely the situation in France in the 30s wasn't much different to here - with large scale electrification being confined to a a couple of the private railway companies (Midi and the Paris-Orleans). Not much different from the Southern going after large scale electrification on its own. 

That may be so but the point is like the Southerns 3rd rail in network in the U.K., the size of the 1.5KV electrification already installed meant it was logical to expand that - even after 25KV had proven itself*
 

*Note that even after the decision had been made to go for 25KV for the WCML the Southern region still took 3rd rail to Bournemouth because it was the logical thing to do.

 

Had there been a sizeable chunk of main line 1.5KV electrification been in existence in the U.K. before WW2 (e.g. Leeds Doncaster /  - York Newcastle then the Woodhead scheme could simply have become a extension of that network (as was the case with in France during the 1950s with the Midi and Orlean systems)

[Edwin_m]

8 hours ago, Stefan88 said:

Italy is another place that is not homogeneously 3kV DC, most of the newer high speed lines are 25kV AC (presumably because its easier and cheaper to run at 300km/h on 25kV AC than 3kV DC).

The EU Technical Specifications for Interoperability require 25kV for high speed lines, although I believe exceptions can be made if there's a good reason.  This is aiming to minimise the need for multi-system trains and heading for a seamless network right across the continent, although that goal is decades or possibly centuries away.

[Chen Melling]

On 27/09/2023 at 13:16, Edwin_m said:

Generally agreed, but worth noting that safety concerns with live wires in the street are another reason why trams use 750V or less.  Incidentally some recent Metro projects have used 1500Vdc third rail.  

 

I don't think street-running trams with 1500VDC overhead lines are so rare - certainly in Israel the new Red Line in the Tel Aviv area is one:
https://en.wikipedia.org/wiki/Red_Line_(Tel_Aviv_Light_Rail)

and I understand the the Haifa-Nazareth interurban line under construction is also planned to use this voltage:
https://en.wikipedia.org/wiki/Haifa–Nazareth_Light_Rail

 

[johnofwessex]

Interesting that the Belgium's & Dutch chose different systems both to each other and their neighbours

[Edwin_m]

15 hours ago, Chen Melling said:

 

I don't think street-running trams with 1500VDC overhead lines are so rare - certainly in Israel the new Red Line in the Tel Aviv area is one:
https://en.wikipedia.org/wiki/Red_Line_(Tel_Aviv_Light_Rail)

and I understand the the Haifa-Nazareth interurban line under construction is also planned to use this voltage:
https://en.wikipedia.org/wiki/Haifa–Nazareth_Light_Rail

 

Do these actually run in lanes with other traffic?  The Wikipedia talks about "street level" only.  

[Chen Melling]

6 hours ago, Edwin_m said:

Do these actually run in lanes with other traffic?  The Wikipedia talks about "street level" only.  

There are no shared lanes with other traffic, but there are countless level intersections with public roads (and foot and bicycle paths). Here's an example:

[Edwin_m]

3 hours ago, Chen Melling said:

There are no shared lanes with other traffic, but there are countless level intersections with public roads (and foot and bicycle paths). Here's an example:

Thanks for that.  So similar to modern tramways elsewhere, which are pretty universally 750V.  Possibly because European standards don't apply in Israel.  

[Chen Melling]

14 minutes ago, Edwin_m said:

Thanks for that.  So similar to modern tramways elsewhere, which are pretty universally 750V.  Possibly because European standards don't apply in Israel.  

This list:
https://en.wikipedia.org/wiki/List_of_tram_systems_by_gauge_and_electrification

suggests more voltage variation than you implied, though it seems 1500V DC is indeed very rare.

 

I know of no relevant pan-European standard, but such existed, it would probably would not be compulsory here. The Jerusalem system is 750 VDC.

[009 micro modeller]

21 minutes ago, Chen Melling said:

This list:
https://en.wikipedia.org/wiki/List_of_tram_systems_by_gauge_and_electrification

suggests more voltage variation than you implied, though it seems 1500V DC is indeed very rare.

Some of those are different because they’ve been developed from older systems and retain the historic voltage (so Blackpool, for instance, uses 600V increased from 550 rather than 750). Some of the US ones are probably higher because they are (or were originally) interurbans, so more like ‘proper’ railways (a bit like how Tyne & Wear in the UK is 1500V - it’s a light metro rather than a tram).

 

Not voltage-related but the number of old systems in the US on 3’ 6” gauge is interesting, as unlike 3’ that gauge doesn’t seem to have been used much over there for heavy rail.

[Edwin_m]

50 minutes ago, Chen Melling said:

This list:
https://en.wikipedia.org/wiki/List_of_tram_systems_by_gauge_and_electrification

suggests more voltage variation than you implied, though it seems 1500V DC is indeed very rare.

 

I know of no relevant pan-European standard, but such existed, it would probably would not be compulsory here. The Jerusalem system is 750 VDC.

Most European systems follow the German BOStrab to some degree although it's not mandatory to do so.  This doesn't appear to specify voltage but by implication does allow on-street voltages of up to 1500Vdc.  

 

The UK guidance references EN51063, which I can't access but may say something on maximum voltage.  

 

Thanks for clarification on Jerusalem.  I was actually involved in an unsuccessful bid for the extension a few years ago and was trying to remember the voltage.  

 

Edited October 15, 2023 by Edwin_m

[4700mm]

On 15/10/2023 at 21:20, Edwin_m said:

Most European systems follow the German BOStrab to some degree although it's not mandatory to do so.  This doesn't appear to specify voltage but by implication does allow on-street voltages of up to 1500Vdc.  

 

The UK guidance references EN51063, which I can't access but may say something on maximum voltage.  

 

Thanks for clarification on Jerusalem.  I was actually involved in an unsuccessful bid for the extension a few years ago and was trying to remember the voltage.  

 

 

 

I think that should be EN 50163 which gives the highest nominal DC voltage as 3kV with a note that says "Future d.c. traction systems for tramways and local railways should conform with system nominal voltage of 750V 1500V or 3000V.". I cannot see anything specific for street running.