Talk:Railway electrification

AC vs DC for mainlines

"Modern electrification systems take AC energy from a power grid which is delivered to a locomotive and converted to a DC voltage to be used by traction motors. These motors may either be DC motors which directly use the DC or they may be 3-phase AC motors which require further conversion of the DC to 3-phase AC (using power electronics). Thus both systems are faced with the same task: converting and transporting high-voltage AC from the power grid to low-voltage DC in the locomotive."

Why is an AC motor system faced with the problem of converting high voltage AC to low voltage DC? Surely it has to convert that mains AC into "3-phase AC". It is certainly not obvious to the lay person that this has to be via DC.

London's Central line trains are being converted to AC motors, but as DC is supplied to the track it will have to be converted 'on train' but it does not staand to reason that mains AC has to be converted to AC for motors via DC. — Preceding unsigned comment added by 92.232.34.78 (talk) 09:57, 4 November 2017 (UTC)

Clarification required

In Railway electrification#Overhead systems we read "Short pioneered "use of a conduit system of concealed feed". Can someone be more specific and tell us exactly what system Short pioneered? Peter Horn User talk 22:07, 4 November 2017 (UTC)

@Elektrik Fanne: Any idea? Peter Horn User talk 01:35, 5 November 2017 (UTC)

power supply system from generation to railway traction system

Please tell us how power supply provided to railway traction system by generating Grid sub-station. what type of substations or auxiliary substation are required to supply power to traction system and railway station? in case if u will found about the railway system you can explain about the metro station. — Preceding unsigned comment added by 122.176.188.166 (talk) 07:23, 14 February 2018 (UTC)

World electrification

Using the numbers from Template:Infobox rail network

Suggestion for expanding the World electrification-section. Many pages use the Template:Infobox rail network which has the attributes length and ellength (sometimes also el1length, el2length, and el3length). How about using this info (see example of graph presenting the data)?

• Data: https://gist.github.com/jsekamane/a1b50dd5bd439df175868a9c915d766a
• Script: https://gist.github.com/jsekamane/e0176568a04e0bfa4ccdb154308257a8

--Jsekamane (talk) 15:02, 11 March 2019 (UTC)

Deleted sections

What was the reason, and purpose, for deleting the following sections and thereby loosing the info. Would it not have been more useful to have dug up the appropriate references and/or corrected some statements? The following link forth rail now is useless.

Fourth rail

London Underground track at Ealing Common on the District line, showing the third and fourth rails beside and between the running rails

The London Underground in England is one of the few networks that uses a four-rail system. The additional rail carries the electrical return that, on third rail and overhead networks, is provided by the running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420 V DC, and a top-contact fourth rail is located centrally between the running rails at −210 V DC, which combine to provide a traction voltage of 630 V DC. The same system was used for Milan's earliest underground line, Milan Metro's line 1, whose more recent lines use an overhead catenary or a third rail.

The key advantage of the four-rail system is that neither running rail carries any current. This scheme was introduced because of the problems of return currents, intended to be carried by the earthed (grounded) running rail, flowing through the iron tunnel linings instead. This can cause electrolytic damage and even arcing if the tunnel segments are not electrically bonded together. The problem was exacerbated because the return current also had a tendency to flow through nearby iron pipes forming the water and gas mains. Some of these, particularly Victorian mains that predated London's underground railways, were not constructed to carry currents and had no adequate electrical bonding between pipe segments. The four-rail system solves the problem. Although the supply has an artificially created earth point, this connection is derived by using resistors which ensures that stray earth currents are kept to manageable levels. Power-only rails can be mounted on strongly insulating ceramic chairs to minimise current leak, but this is not possible for running rails which have to be seated on stronger metal chairs to carry the weight of trains. However, elastomeric rubber pads placed between the rails and chairs can now solve part of the problem by insulating the running rails from the current return should there be a leakage through the running rails.

On tracks that London Underground share with National Rail third-rail stock (the Bakerloo and District lines both have such sections), the centre rail is connected to the running rails, allowing both types of train to operate, at a compromise voltage of 660 V. Underground trains pass from one section to the other at speed; lineside electrical connections and resistances separate the two types of supply. These routes were originally solely electrified on the four-rail system by the LNWR before National Rail trains were rewired to their standard three-rail system to simplify rolling stock use.

Fourth-rail trains occasionally operate on the National third-rail system. To do so, the centre-rail shoes are bonded to the wheels. This bonding must be removed before operating again on fourth-rail tracks, to avoid creating a short-circuit.

Linear motor

Main articles: Linear motor and linear induction motor

Five rail system

An S-series northbound train at Lawrence East station. Note the slab between the running rails.

In the case of Scarborough Line 3, the third and fourth rails are outside the track and the fifth rail is an aluminum slab between the running rails.

Peter Horn User talk 20:12, 28 March 2019 (UTC)

@Wtshymanski: @Andy Dingley: May be we should restore this material and other massive, unproductive and malicious deletions by User:TheVicarsCat. I went through the revision history of this article and noted all his deletions and "why". Peter Horn User talk 16:55, 31 March 2019 (UTC)

There would be many reasons for that, from WP:DENY onwards. Just watch out for new socks returning to it. Andy Dingley (talk) 18:11, 31 March 2019 (UTC)

@Andy Dingley: Please clarify. Do you mean many reasons for restoring and that new socks would again delete this? Peter Horn User talk 19:13, 31 March 2019 (UTC)

I'd support restoring it. But both of these two are shameless sockers, and will likely be back. Andy Dingley (talk) 19:24, 31 March 2019 (UTC)

Are you saying that User:Wtshymanski as well, and if not, who is the other one? In addition there are no doubt many other "sockers". Peter Horn User talk 19:38, 31 March 2019 (UTC)

I B Wright (talk · contribs) / Bhtpbank (talk · contribs) Andy Dingley (talk) 00:35, 1 April 2019 (UTC) / Thanks. Peter Horn User talk 03:53, 1 April 2019 (UTC)

(off topic) To be perfectly clear, I am not a sock puppet, and have never used sock puppets. --Wtshymanski (talk) 19:39, 1 April 2019 (UTC)

Double stack under wire

As can be seen by the edit history, I added a bit about Indian railways successfully running double stack container trains on electrified routes, which disproves the Anglo-American claim that such a thing is impossible. I think if the claim that electrification and double stacking are in conflict is germane for this article, an example of the conflict being resolved is germane, too. As a matter of fact, Indian Railways is not the only railway that double stacks under wire - similar successes have been achieved in China on standard gauge tracks. I furthermore added a bit about Switzerland being a country with 100% railway electrification which was reverted as unsourced. I'll find a source if it is deemed okay to include this statement with source. Hobbitschuster (talk) 11:23, 21 June 2020 (UTC)

I don't know why @Wtshymanski: reverted your contribution, as it was sourced. Do you have a source for double-rail stacking in China? NemesisAT (talk) 12:48, 21 June 2020 (UTC)

A quick search with a generic search engine yielded this Hobbitschuster (talk) 13:08, 22 June 2020 (UTC)

Thanks I did have a search but didn't come across that one. It's not clear though if that's two full size containers in that case.NemesisAT (talk) 14:20, 22 June 2020 (UTC)

I have reinstated the edit in question since the user who did the revert has not engaged on the talk page. They are free at any time to raise their concerns here... Hobbitschuster (talk) 13:37, 30 June 2020 (UTC)

The names of overhead line supports

What would one call the supports of overhead lines? gantry? Utility poles in case of trams? Peter Horn User talk 00:33, 19 September 2020 (UTC)

I found Traction current pylon. That solves half of the naming problem. Peter Horn User talk 17:36, 11 October 2020 (UTC)

What about Overhead catenary bridge? Peter Horn User talk 14:42, 12 October 2020 (UTC)

No "History" Section??

Very simply, I came to this page to see when Electrification of Railway lines began. And there is nothing, nothing AT ALL!

It is a very good break-out of the types of electrification, voltages, advantages and disadvantages, etc. However, unlike almost every other WIKI page in existence, which ALWAYS start with a section titled: "History", this page does not.

Over on the Diesel locomotive page, which starts with a "History" section, one gets the idea that locomotives went from Steam to Diesel, to Diesel-electric, and this process took a while. So except for subways inside cities, the arrival of wide-spread Railway electrification was (I assume) rather late in arriving.

Still, it would be nice to have a quick overview, with some DATES as to when and where things got started, and perhaps some sense of the percentages of electrification in different nations along with some dates as things moved along.

Well, this is my idea/gripe. I have no knowledge on this topic, or I would put it in myself.

All the best,

James 202.44.216.44 (talk) 19:08, 20 January 2022 (UTC)