Talk:Overhead line

Name

Where should this be moved to? overhead line? overhead lines? overhead power transmission? --Robert Merkel

Comparison with streetcar/tram style lines could be interesting

I'm curious about what differences there might have been with old equipment used for streetcars. A lot of those vehicles had straight collection arms (instead of pantographs) with pulley-style wheels on the ends. Managing a transition between breaks would seem to be more difficult, and speed would seem to be an issue (although I know such systems ran at up to 100 km/h in the early 20th century in my region of the U.S.—possibly not over breaks, but certainly in between them). —User:Mulad (talk) 14:06, Sep 29, 2004 (UTC)

History

I removed this:

The use of overhead cables conducting electricity, invented by Granville T. Woods in 1888, amongst several other improvements by Woods, led to the development of electrified railways, the first of which was operated at Coney Island from 1892.

What? By 1888 Sprague's Richmond installation was already running. An amateur named John C. Henry used overhead copper cable to power his experimental car in 1884. And overhead wire was neither the first development, nor the critical one, in developing electric railways.

Woods' invention

For those curious, Woods' invention was not of the use of overhead wire for powering electric railways, but of an improved wire carriage (or "troller" or "traveller" designed to ride on top of a wire. These had previously been in use by other inventors, but Woods' invention was of an improved type with three wheels on a single wire and flanges, all apparently to address the problem that trollers had in falling off the wire. He did not submit a model, so I don't know that his design was ever tested.

The upshot is, that once sprung trolley poles were successfully deployed, all trollers became obsolete. -- Cecropia | explains it all ® 18:07, 25 Feb 2005 (UTC)

I am still new in this electrical knowledge, but somehow can someone tell me the differences between LRT and trams?

LRT and Trams.

I am still new in this electrical knowledge. But can someone tell me the differences between LRT and Trams?

Power Grids

please somebody help me out ....regarding what is proper functioning of power grids in india/US?

Ring Main Units Working

could somebody explain me about the ring main units working and about the construction of Ring main units... Ajay Bhargove, NDPL

Merged

• Overhead line, Overhead catenary, and Overhead cable are very similar (but not the same). These three articles should be reshuffled/reorganized/merged ito some sensible configuration. --Smack (talk) 17:29, 27 August 2005 (UTC)

Agreed

Its a little confusing to have three seperate articles about similar subjects. Why not have one article with three seperate sections? Piercetp 06:45, 25 May 2006 (UTC)

Merged

Merged as requested. SilkTork 22:09, 29 May 2006 (UTC)

Both Diagrams?

Do we really need both of these diagrams? They seem both the same to me. I am removing the first one, if you disagree, please revert without warning on my talk. I won't dispute this.martianlostinspace 14:06, 21 December 2006 (UTC)

Germany

It seems there are mixed up together "supply-lines" and the otherwise built "traction current lines". There are for example no "four lines on the lowest crossbar" of a "traction current line". The supply current lines have 110 kV power, the traction current lines is transformed down to 15 kV power. I live in Germany and I have never seen "eight conductor cables" on "traction supply lines". Regular are two lines for 110 kV supply and one line for direct supply of the traction line. The other bzw. feedback-"wire" then is the earth. Better kill the whole section "Germany"- it`s mostly wrong! 62.109.75.136 08:28, 1 February 2007 (UTC)

Why is 16.7 Hz used in Germany?LorenzoB 18:37, 7 April 2007 (UTC)

The reason for the frequency is apparently a Legacy from before the days of Power Electronics. One can allegedly practically operate a DC motor directly from this frequency but not 50 Hz.

86.18.84.41 20:48, 10 April 2007 (UTC)

Exactly correct. In the US, we got by with 25 Hz for the same reason. The basic problem is the inductive reactance of the traction motors.

Atlant 22:31, 10 April 2007 (UTC)

Im not sure if this is the correct place, but...

How come that when i cross a railway line, by means of a level crossing/one of those little paths that you use to cross the line with the STOP LOOK LISTEN sign in the UK, i dont get electrocuted? ACBestMy ContributionsAutograph Book 15:50, 21 June 2007 (UTC)

Back home, in Kent, the third rail has a dead section through the the level crossing (being foot path of cars, etc). This creates a gap, but normally Train are either a) long enough (think of a set of EMUs) to have more than one pick up show to collect the juice, and/or b) the train is going quick enough to cope with the loss of power (think of loco hauled trains). On OLE there is no gap, but a height limit to stop the high vehicles from electrocuting themselves. Hope that helps. Pickle 16:12, 28 June 2007 (UTC)

The conductor rails stop either side of the crossing, but are connected by cables to provide continuity for the electric current. Normally, there would also be "cow-boards" either side of the crossing to prevent people from trespassing. Canterberry 18:37, 28 June 2007 (UTC)

In the case of lines fed by an overhead wire (For example, throughout most of East Anglia), the overhead wire is the equivalent of the "Live" wire in a standard three pin plug, with the rails providing the "Neutral" connection. In the UK, the neutral connection is tied to earth (so the voltage between the ground and the rails is zero, and you don't get electrocuted). It's a different story if you were to look at the voltage across the overhead wire and the rails/ground, however... -- Ratarsed 13:05, 2 July 2007 (UTC)

Cost and Benefits

For heavy rail systems currently using diesels, I'm curious what the costs and benefits are of switching to overhead lines, both on tracks that don't yet have the overhead lines (is there some benefit to the proposed MBTA Indigo Line's use of DMUs, rather than putting in overhead lines and using EMUs?), and on tracks that have overhead lines but use diesels anyway (such as the MBTA train to Providence, which normally operates along the same track where Amtrak trains use the overhead lines). JNW2 14:54, 5 September 2007 (UTC)

It gets very complicated and contentious. Some people point to how is the user charged for the electricity they use. There are a lot of capital costs in building electrification (be it OLE or third rail) that put people off, especially for new lines. Also diesels (locos and especially DMUs) have made a lot of technical advances that make them more attractive. There are then system wide issues, so some operators may not like having to support tow types of fleets when they perceive fleet wide standardisation as preferable. Hope that gives you some pointers. Pickle 19:06, 5 September 2007 (UTC)

Height and other mechanical standards

It would be interesting to know the distance between the wire and the ground, and if there are different standards (including trams). Dvortex 14:55, 14 September 2007 (UTC)

I *think* they are built to the height gauge of the rail network concerned, and then the gap for the pantograph. I know the Channel Tunnel has higher wires than normal lines and the CTRL as the shuttle stock is higher (to take ro-ro trucks) - thus eurostars's pantograph has to go higher. Pickle 15:42, 14 September 2007 (UTC)

In the UK, on heavy rail (gauge just under 4 m) the height can vary between 4.14 m and 5.94 m, with a nominal height between 4.7 m and 4.9 m. CTRL uses a 'European' gauge so the minimum height is more like 5 m.Azmo247 22:04, 13 November 2007 (UTC)

Section Added

I added the section: Technical Advances Lowers Running Costs Waterspaces (talk) 13:25, 3 April 2009 (UTC)

Overhead lines compared to power transmission lines

Just wondered if anybody had any input on this

Wikipedia:Reference_desk/Science#Power_lines_compared_to_Overhead_cables_on_train_lines

Any help would be appreciated. Thanks GregB1968 (talk) 17:00, 2 April 2010 (UTC)

"Westinghouse catenary" or "Caténaire inclinée"

Skewed overhead lines on an Amtrak line

Skewed overhead lines typical of the former Compagnie du Midi at the Loubaresse (in French) train station in France

Strolling around the wikipedia articles about trains I found the remarkable "Westinghouse" or "inclinée" (in French) style overhead wiring. It is falling out of use by now because it is quite hard to construct and the tensioning cannot easily be changed after the wires are being constructed. It is not mentioned in the English article, but it is referred to in the French one. I found an image (on the right) showing that it is still in use in the US too.

It might be mentioned, I do however have little information about it. I do know it does not need weights to keep the line under tension and might be interesting for historic reasons. In France this system is only maintained when of historic of cultural relevance, other lines are being rebuilt to the standard French overhead support system. Does anyone know what the American policy towards the Westinghouse catenary is?

This is the text the French wikipedia has on it:

"La caténaire inclinée est un cas à part. Les bras de rappel n’existent pas : seuls la tension du fil de contact ainsi qu’un positionnement judicieux des points de fixation du fil porteur permettent au fil de contact de suivre l’axe de la voie. C’est dans les courbes que cette caténaire prend son aspect le plus insolite, car son axe est alors proche de l'horizontale, tandis que les autres caténaires restent verticales.

Elle est aussi connue sous le nom de caténaire Westinghouse, du nom de la firme qui a développé la technique aux États-Unis. En France elle est le plus souvent appelée caténaire « midi » car elle a été utilisé sur le réseau de la compagnie des Chemins de fer du Midi pour l'alimentation en 1 500 V continu."

My French is quite poor, but it roughly says:

"The inclined overhead system is a seperate case. There are no tensioning arms, only the tensioning of the contact wire and a careful placement of the fixation points to the carrier wire allow the wire to follow the axis of the track. It's in the curves this catenary shows its unusual aspect, because there the axis of the wires is near horizontal, while other systems remain vertical.

This type of wiring is also called Westinghouse overhead, named after the firm that developed the technique in the United States. In France it is usually called "caténaire Midi" because it was used in the network of the Compagnie du Midi for the electrification with 1500 V DC"

Can anyone (preferably a Francophone) check my translation, for it is of doubtful quality? Does anybody know a suitable source of information on this type op equipment, the French article doesn't cite any references.

NB: I found another picture showing the way it looks on straight tracks: Skewed overhead lines over straight tracks

82.139.114.136 (talk) 13:48, 1 August 2012 (UTC)

Problems with overhead equipment

'Overhead line equipment can be adversely affected by strong winds' [citation needed]:

I don't know if this article with an embedded video explaining and demonstrating the effect during stormy weather on the danish Great Belt Bridge is a citation in that sense?:

http://ing.dk/artikel/kamerasystem-skal-advare-lokofoerere-mod-svingende-koereledninger-paa-storebaelt-163994 — Preceding unsigned comment added by 200.63.47.32 (talk) 08:34, 17 January 2016 (UTC)

That would do as a source. I'll add it.

I'd like to note though that this is highly dependent on the type of overhead system. The only time I heard that my train slowed down because of swinging overhead wires was years ago, on the train from Harwich to London (UK) in 18 m/s wind. 10 hours before I was still in the Netherlands, in the train to Hook of Holland in ca. 23 m/s wind, and the trains were unaffected. The difference is that Dutch overhead wires are much heavier than British ones, because the Dutch ones have to handle more current due to a lower voltage. PiusImpavidus (talk) 14:41, 25 June 2016 (UTC)

What are they made of?

Steel? Copper? Aluminium? Titanium? Some alloy?

Usually copper, or some alloy with copper as main ingredient. PiusImpavidus (talk) 14:01, 25 June 2016 (UTC)

I added some info from the USSR in this under "types of wires".

How much energy are the overhead wires capable of transmitting, typically?

This detail is not included in the article, but it would be valuable to know the capacity of typical overhead conductors and the contacts used by trains. — Preceding unsigned comment added by 76.126.241.23 (talk) 05:02, 12 April 2017 (UTC)

How can a tram route cross a trolley bus route without short circuits listed at Redirects for discussion

An editor has asked for a discussion to address the redirect How can a tram route cross a trolley bus route without short circuits. Please participate in the redirect discussion if you wish to do so. Steel1943 (talk) 21:20, 10 July 2019 (UTC)

Surely it's answered in the "Contacts" section? SCHolar44 (talk) 23:14, 10 July 2019 (UTC)

That should have been "Crossings" section -- sorry! SCHolar44 (talk) 22:21, 11 July 2019 (UTC)

OLE Gantries

There is Headspan and Portal type of OLE, so should they be included? I Like The british Rail Class 483 (talk) 17:56, 25 March 2023 (UTC)

Ridged OLE

What should we refer it on this page? Since it gets referred to by different names in different sections, I suggest we agree on a name for all of them. I believe 'rigid OLE' or some version of it makes the most sense because it describes that it can not move in use and also is above the train. But third rail seems a bit off since it is not a third rail. I Like The british Rail Class 483 (talk) 16:29, 11 July 2023 (UTC)