User talk:Luuluu MuuMuu

This is my second edit, and so far things appear to be fine. I was warned by friends to stay clear of Wikipedia, due to hostility from established users and from Administrators watching every edit to for 'vandalism' as they call it. Luuluu MuuMuu (talk) 11:05, 10 March 2014 (UTC)

March 2014
Hello, I'm Skr15081997. I wanted to let you know that I undid one or more of your recent contributions to Railroad electrification in the United States because it did not appear constructive. If you would like to experiment, please use the sandbox. If you think I made a mistake, or if you have any questions, you can leave me a message on my talk page. Skr15081997 (talk) 09:38, 28 March 2014 (UTC)

Talkback
Skr15081997 (talk) 16:22, 28 March 2014 (UTC)

I am finished with Wikipedia!
As per my second edit, I was warned by friends to stay clear of Wikipedia, due to hostility from established users and from Administrators watching every edit to for 'vandalism' as they call it.

It took just five edits before the heavy fist came downn. I did what I was supposed to ... read about the policies, and the five pillars.

Where did it get me --> NOWHERE!!

I should have heeded the warnings. - Luuluu MuuMuu (talk) 16:57, 28 March 2014 (UTC)
 * I think your 'friends' have exagerated somewhat. The admins are not watching every edit for vandalism.  They rely on reports from other users for that, and even they only get excited when there is persistent vandalism.  I note that you were critisised above for what seems to me a perfectly reasonable edit, though you had removed a 'needed tag'.  Was this because you changed the meaning of the sentence and thought that the bit you removed was being challenged?  Anyway, I note that no one has restored the tag.


 * I also grant that there are a few problem editors about, but that is inevitable in a project this size, but I will let you find then on your own! –  Live Rail    &lt; Talk &gt;  17:24, 28 April 2014 (UTC)

Original research and synthesis
Thank you for your interest in Railway electrification system. I note that you are a relatively new editor to Wikipedia, but you already seem to have a grasp of many of its policies (or is this a fresh start account?). You were, of course, perfectly entitled to challenge my addition to that article as it was, at the first insertion, unsourced. Wikipedia etiquette normally requires a claim that you are challenging to be flagged with a tag (unless the claim is patent nonsense). I note that someone did precisely that. If the required reference is not forcoming after a reasonable period, then the claim can be deleted with impunity, though a prefereable strategy is to find and provide a suitable reference yourself.

As for your claim of original research, this is not the case here.

Real original research, is if I grabbed a length of rail and measured it's resistance for DC and AC, and used those results to support the claim in the article. This is strictly not allowed. Though I could use someone else measuring said resistances if they were published with an authoritative backing.

The problem you complained of is a variation of original research called synthesis where one or more references are 'interpreted' to advance a position not directly covered by those references.

But that is not the case here. The statement, "... the dimensions of of a third rail are physically very large compared with the skin depth that the AC current penetrates ...", is directly supported by the supplied reference because it supports the current depth of AC at around 0.3 mm in steel. No conductor rail (or any rail) is anywhere close to approaching that small size. This then supports the claim that,"This effect makes the resistance per unit length unacceptably high compared with the use of DC", because the skin depth area is less than one hundredth of the rail cross section area (this can be established through established geometrical calculations - which are easily citeable from any half decent book on geometry). Resistance per unit length is inversely proportional to cross section area (a well established and easily citeble phenomenon - see next para, though I note it's not cited at Electrical resistance where it seems to have been accepted as it is well established princple). "The use of AC is not feasible because ...", is a direct and obvious logical conclusion. It is no coincidence there is no AC three rail system anywhere in the world. To use AC, you have to go to overhead wire high voltage distribution where the cross section of the contact wire is smaller than the skin depth of copper (around 10 mm or so).

Not everything has to be precisely cited on Wikipedia (see WP:BLUE). Statements that are generally acceptable by concensus can stand uncited as long as they are citeable (that's policy though some believe that even citeable is unnecessary). I note that two other users seem to be perfectly happy with the claims and the citation used to support it. One has even pointed out that this is a well understood phenomenon, which is why there is no shortage of citeable material to support it - but then following a claim with a few hundred references is just overguilding the lilly. – Live Rail    &lt; Talk &gt;  17:04, 28 April 2014 (UTC)


 * [Moved from 's talk page]
 * Thank you for you kind message.


 * Unfortunately I have read your analysis on the talk page, and I see many flaws in your "analysis". Prepare yourself for some serious feedback. -Luuluu MuuMuu (talk) 23:44, 28 April 2014 (UTC)


 * Please confine the discussion to the talk page where it started. You are on my watchlist so I will be alerted to any response that you make.
 * Please take the time to read WP:HOUND ... it could save you from being blocked from editing.


 * I am aware of the policy that you cite and it is clear that you are not. It is normal practice to put a talk page where a comment is left on one's watchlist (that is what they are for).  That way, I am alerted if you respond to my post.  Watching a talkpage is not watching your edits.  If you were not a relatively new editor, your post could be construed as WP:WIKILAWYERING.  And if you wish to discuss policy: it is not acceptable to insert comments inside somebody else's, and you failed to sign it with four tildes. –  Live Rail    &lt; Talk &gt;  16:28, 30 April 2014 (UTC)


 * If you believe there are flaws, then you are effectively saying that you believe an AC three rail system to be possible. Since my referenced claim seems to have been accepted by others, I await your evidence that AC three systems are practical with considerable interest.  My employer and every other builder of 'metro' light rail systems may also be very interested because they all currently believe it to be impractical (even with non ferrous rails).  It is, of course, quite possible but only if the substations are ridiculously close together (<20 metres). –  Live Rail    &lt; Talk &gt;  10:55, 29 April 2014 (UTC)
 * Your reaction reveals to me that you feel insecure in your position. The fact that a few other Wikipedians agree with you does not make you correct. As for your employer, if they are looking at this page, then if I were you, I would be worrying about my professional reputation. What is flawed about your argument is the skin depth, and how it affects the flow of AC current.  But lets not get ahead of ourselves, this discussion needs time to brew.Luuluu MuuMuu (talk) 17:28, 29 April 2014 (UTC)
 * It is clear from your comments above that you clearly do not understand the subject that you are attempting to discuss. What effect do you think that skin effect has and why do you think electrical engineers consider it important?  If you are not conversant with a subject, it would be better for the project if you did not attempt to contribute to those areas but stick to what you do know.


 * Skin effect is a complicated subject and I will attempt to put it as simply as possible (and let's stick to our conductor rail). A DC current is distributed throughout the entire cross section of the rail.  An AC current at 50 Hz flows only very near the surface of a steel rail.  There is a maximum wall thickness of a tube of exterior dimensions equal to the solid rail where the resistance to DC current is practically the same per unit length as to the AC current of the specified frequency.  As the wall thickness is made smaller, the resistance to AC and DC increases more or less together.  However, as the wall thickness increases, the resistance to DC falls with the inverse of the increasing cross sectional area.  However, because the AC current does not migrate much beyond the skin depth, the decrease of resistance to AC becomes less and less as the wall thickness increases (and the cross sectional area increases).  The skin depth that calculations using the resistivity and relative permeability of the conducting material give you (and tables and graphs depict) represents the depth at which the current density has fallen to 1/e of the current density at the surface (about 0.37).  This figure conveniently gives the wall thickness of the tube that has the same resistance to AC as the solid conductor would at the same frequency (to be pedantic: not exactly but the error is negligible).


 * The skin depth for steel is less than 0.3 mm (exact value depends on the composition of the steel - but let's stick with that figure). This means that for 50 Hz AC operation, the solid rail can, at least electrically, be replaced with a tubular rail with a wall thickness of 0.3 mm and it will have the same resistance as the solid rail.  My calculator tells me that the AC resistance of the tube (and hence the solid rail) is a little more than 150 times greater than the DC resistance of the solid rail. DieSwartzPunkt (talk) 15:13, 30 April 2014 (UTC)


 * It would appear that it is your position that is insecure as you have to resort to insulting comments. As far as I am aware, I have treated your comments and views with the respect that they deserve.  If you are not prepared to do likewise then expect an editing block, or at the very least a refusal to discuss the subject further.


 * That said: I am inclined to 's view that you are not fully cognizant of the subject. Read what he has said, it is a reasonable description of the problem.  A fuller discussion can be found in the article at Skin effect.  For your and 's information, the grade of steel currently used on UK railways has a skin depth of 0.16 millimetres.  This applies to both the conductor rail and the return running rail.


 * There is another good example of the skin effect often clearly visible. Next time you are out for a walk in the country, have a look up at overhead electrical pylons.  Some of the larger ones are strung with multiple cables for each phase.  Now: why would that be?  Clue: it is not for the aesthetic appearance.  It is because the skin effect limits a copper conductor to about 0.66 inch at 50 Hz.  Any larger and the resistance does not significantly decrease (and hence current carrying capability does not increase).  Further the wires have to be supported such as to be apart from each other otherwise one cable will affect the resistance of its neighbour.  –  Live Rail    &lt; Talk &gt;  16:20, 30 April 2014 (UTC)

The flaw in both of your arguments is blindingly obvious. First, do you know what the running rails of a railway are made from? I think you will find that they are made from steel. Second, if your argument is true, then what applies to the power circuit (i.e. the third rail) must also apply to the return circuit (i.e. the running rails). So how does the current from a train get back to the substation on an AC railway??

Second, it would be perfectly feasible to design power system (not unlike the fourth rail system of London Underground), which uses aluminum rails with a thin layer of steel as the contact surface for the collector shoe of the train to run along (wear rather than electrical conductivity). If you care do do the maths, the skin depth is more or less equal to copper, so substation spacing would be as per today. You might be interested to know that many railway power systems actually use aluminum rails (e.g. Dockland Light Railway). Brecknell-Willis have supplied kilometer upn kilometer of the stuff. - Luuluu MuuMuu (talk) 17:23, 30 April 2014 (UTC)

So there are my two arguments for which I oppose your suggestion that an AC conductor rail system is no feasible.
 * Your three arguments (including the point about AC railways) are non runners. Your first point supports the assertion that an AC third rail system is not feasible and in any case was addressed in my last post.  The second point is not applicable.  Your third point has overlooked your first point.


 * [1] The return circuit for a third rail system is one of the running rails which, as you note, is made from steel (it is only one running rail, the other is isolated so that it can be used for signalling track circuits). It's resistance also increases for AC current just as any steel rail does - which is what I have been saying.  Did you not notice that I said above, "This applies to both the conductor rail and the return running rail ".  The combined increase renders the AC three rail system infeasible.  Any increase in the resistance at all would necessitate the sub stations having to be closer together which would be an unacceptable increase in capital cost amortised over the length of a railway.  Incidentally for the grade of steel that we use for rails, the resistance is closer to 1000 times greater for 50 Hz AC than it is for DC.  The AC resistance of the running rail is such that even for overhead (copper) wire systems where relatively low voltages are used, AC operation is still infeasible and consequently no low voltage overhead wire AC system exists anywhere. (low voltage systems exist up to 3000 volts but only in DC).


 * [2] Now: you asked how the current returns on a AC railway. There are two parts to this.  The first part is that AC systems use high voltages.  The only 50 Hz system in use is 25 kV.  It seems to have become a sort of world 'standard' though the Americas; Korea; Western Japan (and Pakistan I believe) use 60 Hz.  As the voltage rises, the current falls, and the resistance of the return running rail becomes less of an issue - but it does remain an issue.  The second part of the answer, is that the return current does not have to rely on the running rail alone.  All AC overhead wire systems have one or two copper return conductors slung along the side of the catenary support structure.  This is periodically connected to the return running rail, so the return current only has to flow through a relatively short length of rail.  If you have a look at the picture shown, you can clearly see the return conductor slung along the outside of the support poles.


 * [3] As for the use of aluminium conductor rails, the skin effect is around 12 millimetres or so (we can safely neglect the steel running surface). You haven't done all the maths.  The rail size is still very large compared with that skin depth and the resistance of the aluminium rail is still around 40 times larger to 50 Hz AC than it is to DC.  However, this apparant advantage of using aluminium is shot down completely by your very first argument.  The return running rail is still made out of steel and still has a substantially higher resistance to AC than it does to DC.  Many light and 'metro' type railway systems do use aluminium conductor rails these days, but none of them uses AC - not even new build systems.  London Underground (LUL) are introducing aluminium conductor rails for the third and fourth rails, but LUL remains a DC system.  AC would still not be feasible because the AC resistance of a pair of aluminium rails would still require the substations to be 50 odd metres apart.  –  Live Rail    &lt; Talk &gt;  13:55, 1 May 2014 (UTC)

Congratulations!! You have just self-proven that even an AC railway that uses steel rails for the return circuit is not feasible, because the substations would need to be placed only a few hundred meters apart. It must be pure magic that on the high speed lines in Europe that the substations that feed in power (not the auto-transformer sites), are spaced around 50 miles (80 km) apart. Just how do these AC railways get away with returning hundreds of amps along steel rails back to the substation??? It seems almost impossible based on your statements ... which are now a matter of public record (is your company still watching?). - Luuluu MuuMuu (talk) 23:54, 1 May 2014 (UTC)


 * You clearly have a serious problem with understanding simple English. Either that or you do not fully read posts before raising points that have already been addressed.  I have highlighted the part above that you either didn't read or didn't understand.  I can't put it any simpler.  Most, if not all, high speed lines in Europe have two copper return conductors running along the side of the overhead wire support structure.  No railway that relies entirely on a (steel) running rail to return AC current to the substation exists anywhere (and this applies to 16.7 Hz systems as well).  –  Live Rail    &lt; Talk &gt;  12:04, 2 May 2014 (UTC)


 * I am think that you know a little but put two and two together and make five ... you know this term? An autotransformer system with a spacing of 10km will not have any connections to the return wires you mention except at the substations. Also, the system is being designed for allowing a transformer not being in service.  Hence, under worse case, the current could have to flow in rail for 10,000 meters. There is a grounded cable connection to the rail, but this is only required for interference to telecomm cables.


 * If you could translate this into English, I might stand a fighting chance of figuring out what you are on about. We seem to have strayed somewhat from low voltage conductor rail systems.  –  Live Rail    &lt; Talk &gt;  12:20, 4 May 2014 (UTC)


 * It has been determined that you are not worthy of further interaction, and are WP:TROLL. I am not here to provide you with education on matters to which you clearly are not comprehending. - Luuluu MuuMuu (talk) 00:23, 5 May 2014 (UTC)


 * Well, there's the pot calling the kettle black! You have been, more or less, consistently insulting.  You have demonstrated admirably above that it it is you that is incapable of comprehension.  You are clearly incapable of understanding the concepts being discussed.  That you do not understand it is enough reason for you to believe that it does not exist and ignore it.  It is you that is not worthy or qualified enough to discuss this matter or to contribute further to Wikipedia.  AFAIAC, this discussion is therefore at an end. –  Live Rail    &lt; Talk &gt;  14:10, 5 May 2014 (UTC)


 * Well I think I worked most of it out, but apart from the dodgy English, it added nothing to the discussion. But seeing as how you think you know everything: let's turn this around the other way.  Looking at the picture that LiveRail added above.  I'm sure you can see that heavy cable suspended along the right hand side of the overhead wire support structure.  It's a pretty big cable designed for carrying a thousand Amps or so.  It clearly does not carry the 25kV feed as the insulated supports are far too small.


 * So tell us: what do you think this cable is for? And while you are at it, tell us who granted railways exemption from the immutable laws of physics?


 * Even I (and I am not a railway engineer, just a regular electrical engineer) can work out that a 25kV AC railway is going to have a very hard job working with a return conductor that has an AC resistance of hundreds of ohms per kilometre (I don't know the exact value, but that is certainly in the right ball park). At 500 Amps (a TGV or Eurostar - just looked it up), that resistance is more than enough to prevent the system from working at all.  The maximum tolerable resistance in the whole distribution system is just 12 ohms (to give the specified minimum permanent voltage of 19kV). DieSwartzPunkt (talk) 11:12, 5 May 2014 (UTC)


 * 500 amps is a bit low. If you got that figure by dividing the 12.2 Megawatt rating by 25,000 volts, you missed the fact that that wattage is the output power, not the input.  8 ohms is the maximum allowable impedance in the entire distribution system (both the cables and rail have inductance though the reactance is smaller in comparison, it is not negligible).  Non high speed lines have more leeway.  –  Live Rail    &lt; Talk &gt;  14:10, 5 May 2014 (UTC)

WP:DENY is now in operation towards DieSwartzPunkt and his muppet  Live Rail    &lt; Talk &gt;. - Luuluu MuuMuu (talk) 23:51, 5 May 2014 (UTC)
 * As a note referring to someone as a muppet is considered a personal attack. Remember in the future to comment on contributions not contributors. Tivanir2 (talk) 17:52, 6 May 2014 (UTC)

There is currently a discussion at Administrators' noticeboard/Incidents regarding an issue with which you may have been involved. Thank you.