Talk:Railway signalling

message: This seems rather a UK-centered and europe-centered view of signalling practise.  I'm thinking about how it might be better done to reflect international variety.  In the meantime, I'll probably be making some tuning changes ... --Morven 03:39, 21 Sep 2003 (UTC)
thread_title:  UK-centered and Europe-centered view 

message: This article is still a bit of a mish-mash of different and sometimes duplicating information (always a problem when you have multiple authors), I'll have to think of a way to make the flow of the article better and to make more sense G-Man 11:53, 26 Sep 2003 (UTC)
replies: text: Definitely -- the page is, however, still in a state of flux, and thus a bit of chaos is inevitable.  As it gets more complete, it should also get more coherent. --Morven 18:08, 26 Sep 2003 (UTC)
thread_title:  mish-mash of different information 

message: Something seems to have gone awry here, as there are 2 unconnected articles with differing spellings on the same topic.  Railway signalling and railway signaling.  Surely the railway signaling should redirect to Railway signalling, and the content be merged. John 15:00, 30 May 2004 (UTC)
replies: text: Note to John just below above, he is exactly right in what he says. I have altered the article to correct it regarding UK signalling and have also included a note about 4 aspect sequences for fast lines. I am employed in the industry and have designed such systems so I know I am correct.  --Ellendee 21:28, 22 Jun 2005 (UTC)
thread_title:  Unconnected Articles 

message: Also, I cannot agree with the section on colour lights in Britain.  I have read that the lights are positioned so that the red is nearest the drivers eye level, not always red at the bottom, as suggested.  Can someone confirm?  (I have not changed this.) John 15:00, 30 May 2004 (UTC)
replies: text: The red light is positioned in order to satisfy the 'fail safe' principle.  In conditions of driving snow, snow can build up on the shades and obscure the signal above.  Since the red aspect is the lowest aspect, there is no shade below it for snow to build up on and thus the indication should always be visible.  Having said that, there are situations in which the rule is violated.  For example where a two aspect signal (red/green) is co-located with a two aspect repeater (yellow/green) in the same signal head.  In this situation, the main signal is usually the higher signal (for sighting reasons) and the shade for the green aspect of the repeater is immediately below it. 20.133.0.14 12:22, 21 August 2007 (UTC)
thread_title:  Position of Red Light in Britain 

message: I have moved single-'l' to double-'l', and double-'l' to Railway signalling/Temp, and also with the Talk page (Talk:Railway signalling/Temp). Eventually (that is, when the functionality is available), we might want to merge the histories, too, which is why I didn't just delete the pages.
James F. (talk) 22:42, 7 Jul 2004 (UTC)
thread_title:  Page move 

message: I don't know if it's just a terminology thing, but some of the information in this article is more properly known as safeworking.  The first two sections of the article are Timetable operation and Timetable and train order, which are both safeworking systems that have no signals.  I believe that we should either rename this article, or start a separate Safeworking article and move some of the information there.  Philip J. Rayment 02:54, 12 Oct 2004 (UTC)
replies: text: It seems that it is a matter of terminology.  I now discover that safeworking is an Australian word, and its use seems to be limited almost entirely to Australia. Philip J. Rayment 14:25, 15 Oct 2004 (UTC)
thread_title:  Safeworking 

message: "uniquely susceptible to collision because" this seems a bit of a weird construct, you could easily argue that not being able to turn into each other is a unique way of avoiding crashes. In a non track guided vehicle you generally have to observe in all directions on a track it's forward and back.--Son of Paddy's Ego 12:02, 30 September 2005 (UTC)
thread_title:   uniquely susceptible to collision because 

message: Minor criticism of the red/yellow/green explanation.  Green doesn't mean "full line speed" necessarily, it means that the next signal is not red.  Also yellow doesn't mean the next signal is red... often the next signal is yellow as well.  (In the ABS section of the Chicago 'L', the usual sequence is red, two yellows, then green; assuming the red isn't an interlocking home signal).  Anyway, I think the signal color rules are dependent on individual railways, so this could be difficult to integrate into the page.  (For example, yellow on the L means that the operator must not exceed 30/35MPH, so some signals around sharp corners are never green.)
Jrockway 04:45, 1 December 2005 (UTC)
thread_title:  red/yellow/green explanation 

message: There is significant overlap of content and subject matter in Railway signal and Railway signalling and I propose the content from Railway signal be merged to Railway signalling, which is a more appropriately-named article.
Please discuss at Talk:Railway signal#Proposed merge. — JonRoma 21:35, 4 February 2006 (UTC)
thread_title:  Proposed merge 

message: Found this article that appears to be completely isolated and unlinked - British absolute block signalling. Probably should be deleted and merged with this or linked much better with other rail signalling pages. Pickle 22:04, 7 May 2006 (UTC)
thread_title:  British absolute block signalling 

message: I added a cleanup tag to the article--after rereading the whole thing, I really think that it's a mishmash of a lot of good, but poorly organized, information. Based on the other comments in this talk page, I think everyone else agrees that it needs a bit of help in this area, so I hope I'm not offending anyone by tagging it. cluth 18:53, 17 August 2006 (UTC)
thread_title:  Cleanup tag 

message: I've completely reordered this article without actually editing (much) of the text. I believe it flows much more smoothly now and appears to be much less focused on the signals themselves (which is really the domain of the railway signal article) and more on the operation and history of signalling/safeworking/operation methods. Before, it looked like it was a bunch of separate articles pasted together, and it really didn't flow.
There is still a bit of overlap and/or material in this article that may belong in the signals article, but it's more clearly delineated now, I believe. I hope you agree.
Also, there is still a small bit of repetitiveness in this article and it could still use some cleaning up, so I'm leaving on the cleanup tag. cluth 05:07, 18 September 2006 (UTC)
thread_title:  Reorder 

message: Just trying to sort out serveral articles on signalmen, and would be greatful if someone who knows a little more about the subject could make a half decent stub of signalman (rail). Renski 15:53, 20 September 2006 (UTC)
thread_title: [[signalman]] and [[signalman (rail)]]

message: The article states "Although signals vary widely between countries, and even between railways within a given country, ..."
Then there are separate wiki pages for individual countries.
I would be interested in seeing a discussion of why different countries have created different systems, and what advantages each one is attributed to have.
I am sure some systems are created as responses to percieved deficiencies in earlier systems of neighbouring countries.
195.24.29.51 12:31, 16 August 2007 (UTC)
thread_title:  colour signals: international comparisons 

message: I don't think this article makes the difference between ATP and In-cab signalling clear, especially when it talks about ATP being used in fog. ATP is typically a lower safety-level device than in-cab signalling. It is designed to replace a second driver in protecting the train rather than allowing operation in the absence of visible track-side signalling. For example, an ATP system might be SIL2 and apply the emergency brakes when the train moves out of established parameters (speed, movement authority, etc). The driver must still be aware of track-side signals and drive the train correctly in order to avoid the emergency brake from applying. Noone should die if the ATP gets it wrong. The driver is still responsible for following the signals.
An In-cab signalling might be SIL4, and thus would allow the train to be operated in fog and on railways with different signalling conventions to what the driver is trained for. It can replace, rather than merely supplement the track-side signals. A malfunctioning in-cab signal could allow a train to be driven into danger, and there would be nothing the driver could do to anticipate that danger.  In the absence of a second driver in-cab signalling can provide train protection capabilities that less drastic braking solutions than ATP, due to its higher safety level.  —Preceding unsigned comment added by FuzzyBSc (talk • contribs) 06:09, 3 October 2007 (UTC)
thread_title:  In-cab signalling vs automatic train protection 

message: I think Signalhead's edit of 8 September 2008 is unnecessarily restrictive.  Double yellow signals do exist so they should be mentioned somewhere. Biscuittin (talk) 09:14, 9 September 2008 (UTC)
replies: text: OK, found it at British railway signals.  I think we need better cross-referencing though. Biscuittin (talk) 09:26, 9 September 2008 (UTC)
thread_title:  Double yellow 

message: I do not fully understand this topic and am not able to optimally place this image.  I suggest someone who has a better understanding of the topic do so.--TonyTheTiger (T/C/BIO/WP:CHICAGO/WP:FOUR)  04:54, 11 June 2010 (UTC)
thread_title:  Suggested image 

message: The norm of the 19"-rack has been developed for / with railway signalling says that article. Should possibly be mentioned here. --Helium4 (talk) 13:03, 11 February 2012 (UTC)
replies: text: That information is too detailed for this particular article in my opinion. I would also like to see a reference.–Signalhead < T > 13:47, 11 February 2012 (UTC)
replies: text:  I agree wholeheartedly with Helium4 above and disagree wholeheartedly with Signalhead above.  As a long-time user of the 19-inch (i.e., 450mm aperture) rack in the telecom & datacom industries, I have recently come across a thread of apparent history that indicates that the 19-inch rack in the railroad signaling industry predates (by decades) Western Electric's 23-inch rack in the telecom industry.  If true, then the most important aspect of this article is the contribution that railroad signaling has made to modern telecom & datacom technology:  the 19-inch rack, which is now eclipsing the 23-inch rack.  I came to this article specifically looking for this 19-inch rack information instead of the dreck that fills this article. —optikos (talk) 18:31, 15 July 2013 (UTC)
thread_title:  19-inch rack 

message: Several previous comments suggest that the page is a mish-mash, and I agree. We need to separate out the issue of signalling -- which I take top mean the procedure to give messages to control train movements to prevent collision, from a lot of the mechanics.
The contrast between UK and US + Australian practice is also very stark, and fundamentally different and conflicting assumptions are made.
I was also surprised not to see "Time interval working" described (as a historical method) and not much about single line operation.Afterbrunel (talk) 06:48, 22 September 2012 (UTC)
thread_title:  Mish mash 

message: The main problem with a coherent description of railway signalling is the following: Any literature on railway signalling from one of the three large "cultures" (Middle Europe, UK, and US) did and does not (or only very very very rarely) look into the other two cultures (and the same seems true of most people I know). Therefore, extracting the worldwide principles (which do exists; e.g., block signalling; distinction between train and shunting signalling; etc.etc.) always borders on "original research", which is not acceptable in WP.
Currently, I know of only one book that transgresses these divides, namely Jörn Pachl's "Railway Operation and Control". Maybe we should try to excerpt that book, or at least follow its principal concepts. There are a few mostly dormant and out-of-date web sites that tried at least to collect many signalling practices, but they can be a starting point at best. Another candidate might be Theeg, G.; Vlasenko, S., Railway Signalling & Interlocking - International Compendium, Eurailpress, 2009!).
Maybe we should despair - and create unconnected pages for lots of countries, probably only in their own language (Argentina only needs a Spanish page, for example)- and that's it.
But do we really want this?
--haraldmmueller 19:15, 7 September 2014 (UTC)
thread_title:  There is a fundamental problem with signalling concepts' descriptions 

message: This article could use a section on railroad hand signals. Turrit hugger (talk) 12:41, 21 September 2021 (UTC)
thread_title:  Hand signals 

message: There is nothing here or at railway signal about approach lighting. --User:Haraldmmueller 08:10, 28 May 2022 (UTC)
thread_title:  Mention approach lighting? 

message: I was looking at a magazine article today which mentioned how code lines running on poles like telegraph and telephone lines are rarely used any more. Instead most updated communications systems for railroad signals and other purposes have been buried. But I don't see anywhere on Wikipedia where "Code lines" could redirect. It may be the details belong in this article.— Vchimpanzee •  talk • contributions •  17:22, 17 November 2022 (UTC)
thread_title:  Code lines