# Railway buffs; does this track configuration exist anywhere in the world? **URL:** \ **Category:** Factual Questions\ **Created:** [March 14, 2013, 8:03am UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902 "2013-03-14T08:03:39Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 14, 2013, 8:03am UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/1 "2013-03-14T08:03:39Z")
On the train to work this morning, my train stopped at a station that is adjacent to a rail yard, comprising many parallel sections of track. It struck me that the distance between the rails of adjacent tracks was very similar to the gauge of the tracks themselves, and I wondered if there are ever any cases where rail yards are constructed as just a large number of parallel rails, all at the same spacing. Obviously, the sleepers/ties would have to be interleaved to achieve this, and a more complex arrangement of points/switches too, and on the face of it, it seems like there would be really good reasons not to want to do this (the train on track 9 is liable to collide with the train on track 9.5, for example). But still, I wonder if anyone has ever tried it, for some weird reason or other (maybe more efficient packing of carriages with overhanging loads?). Are there any rail yards or similar which have no distinct and separate tracks, just an evenly-spaced grid of rails? ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [March 14, 2013, 10:08am UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/2 "2013-03-14T10:08:23Z")
It would be highly unlikely, because the loading gauge – specifically, the width allowed for rolling stock – would be greater than twice the spacing between tracks. Therefore, if a carriage or loco occupies a pair of tracks, the next tracks on each side could not be used, because of the likelihood of a collision, so you would waste every third track. ---
**Author:** ![VunderBob](https://avatars.discourse-cdn.com/v4/letter/v/839c29/32.png) [@VunderBob](https://boards.straightdope.com/u/VunderBob)\ **Post date:** [March 14, 2013, 10:45am UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/3 "2013-03-14T10:45:18Z")
The closest arrangement I’ve seen to this is on a funicular, where most of the way there were 3 rails, with the center one shared between the tracks. At the midpoint of the ride, the tracks separated into the more common 2 rail configuration to allow the cars to pass. I don’t remember the name of the funicular, but it was located in Chattanooga, TN. (ETA: Lookout Mountain Incline) Your idea would be a nightmare to implement, for all the reasons you’ve already listed. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 14, 2013, 11:36am UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/4 "2013-03-14T11:36:46Z")
> [@Giles](#): > > It would be highly unlikely, because the loading gauge – specifically, the width allowed for rolling stock – would be greater than twice the spacing between tracks. Not sure what you mean here - are you talking about existing spacing? (because what I saw this morning isn’t like that). > [@](#): > > Therefore, if a carriage or loco occupies a pair of tracks, the next tracks on each side could not be used, because of the likelihood of a collision, so you would waste every third track. I acknowledged this limitation in my OP - it certainly introduces new problems, but I’m not sure if that completely negates every possible reason why someone might try it. ---
**Author:** ![Peremensoe](https://avatars.discourse-cdn.com/v4/letter/p/ce7236/32.png) [@Peremensoe](https://boards.straightdope.com/u/Peremensoe)\ **Post date:** [March 14, 2013, 11:44am UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/5 "2013-03-14T11:44:10Z")
> [@VunderBob](#): > > The closest arrangement I’ve seen to this is on a funicular, where most of the way there were 3 rails, with the center one shared between the tracks. At the midpoint of the ride, the tracks separated into the more common 2 rail configuration to allow the cars to pass. What’s the point of having the three rails at all? It only allows one-way traffic anyway. Just run the cars on the same _two_ rails, opening up into four (two tracks) at the necessary spot. ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [March 14, 2013, 12:09pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/6 "2013-03-14T12:09:40Z")
> [@Mangetout](#): > > Not sure what you mean here - are you talking about existing spacing? (because what I saw this morning isn’t like that). No. For, example if you have lines like this: A B C D E F with lines each separated by standard gauge (1.435 metres), and with a loading gauge allowing rolling stock to be (say) 3 metres wide (which is pretty narrow), then if a train sits on lines A and B, it would be in danger of hitting a train running on lines C and D – the closest lines that could be used would be lines D and E, so line C is wasted. ---
**Author:** ![VunderBob](https://avatars.discourse-cdn.com/v4/letter/v/839c29/32.png) [@VunderBob](https://boards.straightdope.com/u/VunderBob)\ **Post date:** [March 14, 2013, 12:21pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/7 "2013-03-14T12:21:50Z")
> [@Peremensoe](#): > > What’s the point of having the three rails at all? It only allows one-way traffic anyway. Just run the cars on the same _two_ rails, opening up into four (two tracks) at the necessary spot. [That is also done.](http://en.wikipedia.org/wiki/File:Funicular_layouts.svg) As far as Lookout Mountain is concerned, I don’t know why 3 rail was picked. I wasn’t in the engineering meeting that day. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 14, 2013, 1:16pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/8 "2013-03-14T13:16:52Z")
> [@Giles](#): > > No. For, example if you have lines like this: > > A B C D E F > > with lines each separated by standard gauge (1.435 metres), and with a loading gauge allowing rolling stock to be (say) 3 metres wide (which is pretty narrow), then if a train sits on lines A and B, it would be in danger of hitting a train running on lines C and D – the closest lines that could be used would be lines D and E, so line C is wasted. I’m still not getting you. In many real-life situations, I’m fairly sure I’ve seen examples where the distance between two adjacent tracks was smaller than the gauge. [Here’s](https://maps.google.co.uk/maps?q=fratton+station&hl=en&ll=50.796372,-1.073049&spn=0.000313,0.0006&sll=50.977862,-1.346359&sspn=0.001248,0.002401&t=h&gl=uk&hnear=Fratton&z=21) a (not very clear) aerial view of the exact track I was looking at this morning - the beige coloured bits bottom left are boarded walkways between tracks. The distance between tracks here is maybe 6 inches wider than the gauge. ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [March 14, 2013, 1:40pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/9 "2013-03-14T13:40:14Z")
Yes, but that’s probably about as close as the tracks can be together without risking trains hitting each other. If you want tracks any closer, you’d need to build narrower trains. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [March 14, 2013, 1:42pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/10 "2013-03-14T13:42:16Z")
> [@Peremensoe](#): > > What’s the point of having the three rails at all? It only allows one-way traffic anyway. Just run the cars on the same _two_ rails, opening up into four (two tracks) at the necessary spot. In the case of a funicular, which I assume is liable to be damaged by rockslides and stuff, it would mean you can continue to run the train even if one of the outside rails is damaged. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 14, 2013, 1:48pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/11 "2013-03-14T13:48:24Z")
> [@Giles](#): > > Yes, but that’s probably about as close as the tracks can be together without risking trains hitting each other. If you want tracks any closer, you’d need to build narrower trains. The distance between rail and platform edge is less than half the gauge - the train you see in that picture would work on tracks separated by a distance equivalent to the gauge. And remember, I’m talking about the context of a rail yard, not operational through track where trains can be expected to pass one another at speed. ---
**Author:** ![VunderBob](https://avatars.discourse-cdn.com/v4/letter/v/839c29/32.png) [@VunderBob](https://boards.straightdope.com/u/VunderBob)\ **Post date:** [March 14, 2013, 2:19pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/12 "2013-03-14T14:19:28Z")
> [@Mangetout](#): > > The distance between rail and platform edge is less than half the gauge - the train you see in that picture would work on tracks separated by a distance equivalent to the gauge. > > And remember, I’m talking about the context of a rail yard, not operational through track where trains can be expected to pass one another at speed. In a rail yard, it is imperative to have room between the tracks both for clearance of wide or shifted loads, as well as access for personnel and vehicles to perform duties such as train makeup, car accounting, and maintenance. Murphy’s Law rules in a rail yard. The close clearances cited just above are for passenger equipment, which in North American practice generally has a smaller cross-sectional dimension than freight equipment. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [March 14, 2013, 2:21pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/13 "2013-03-14T14:21:54Z")
The only thing I have seen that loosely fits this description is the use of three rails instead of two where the track is enabled to handle both wider and narrower railcars. But, I forget where I might have seen this and who explained this to me. ---
**Author:** ![VunderBob](https://avatars.discourse-cdn.com/v4/letter/v/839c29/32.png) [@VunderBob](https://boards.straightdope.com/u/VunderBob)\ **Post date:** [March 14, 2013, 2:27pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/14 "2013-03-14T14:27:19Z")
> [@Jinx](#): > > The only thing I have seen that loosely fits this description is the use of three rails instead of two where the track is enabled to handle both wider and narrower railcars. But, I forget where I might have seen this and who explained this to me. Known as mixed or dual gauge. This was common in Denver, CO for example, where the narrow gauge branches and lines met with their standard gauge interchange partners. Also existed in many other locales. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [March 14, 2013, 2:27pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/15 "2013-03-14T14:27:55Z")
> [@Peremensoe](#): > > What’s the point of having the three rails at all? It only allows one-way traffic anyway. Just run the cars on the same _two_ rails, opening up into four (two tracks) at the necessary spot. If you run 2 rails and open it up to 4 where opposing trains pass each other, you need a switch (points) to direct the cars to the correct side. If you use 3 or 4 rails all the way, there is no need for a mechanism. Although 4 rails interleaved (overlapped) would have the same advantage, and take up even less space. And indeed, the railway in question (Incline Railway at Lookout Mountain) [uses both the 3-rail and 4-rail configuraitons](http://www.city-data.com/picfilesc/picc10101.php). I’m not sure why. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [March 14, 2013, 2:32pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/16 "2013-03-14T14:32:44Z")
> [@Really\_Not\_All\_That\_Bright](#): > > In the case of a funicular, which I assume is liable to be damaged by rockslides and stuff, it would mean you can continue to run the train even if one of the outside rails is damaged. Not without a complete rebuilding of the switches–or building of a very complex switching arrangement originally. There are a lot of three rail funiculaires in Switzerland and I don’t know the reason why. I never heard of any of them closed by rock or mud slides. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 14, 2013, 2:47pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/17 "2013-03-14T14:47:20Z")
> [@VunderBob](#): > > In a rail yard, it is imperative to have room between the tracks both for clearance of wide or shifted loads, as well as access for personnel and vehicles to perform duties such as train makeup, car accounting, and maintenance. Murphy’s Law rules in a rail yard. > > The close clearances cited just above are for passenger equipment, which in North American practice generally has a smaller cross-sectional dimension than freight equipment. Size is actually mostly irrelevant - the uniform-spacing of rails would just permit finer control of the chosen spacing between any two loads. ---
**Author:** ![Floater](https://avatars.discourse-cdn.com/v4/letter/f/dc4da7/32.png) [@Floater](https://boards.straightdope.com/u/Floater)\ **Post date:** [March 14, 2013, 3:11pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/18 "2013-03-14T15:11:45Z")
> [@Mangetout](#): > > [Here’s](https://maps.google.co.uk/maps?q=fratton+station&hl=en&ll=50.796372,-1.073049&spn=0.000313,0.0006&sll=50.977862,-1.346359&sspn=0.001248,0.002401&t=h&gl=uk&hnear=Fratton&z=21) a (not very clear) aerial view of the exact track I was looking at this morning - the beige coloured bits bottom left are boarded walkways between tracks. The distance between tracks here is maybe 6 inches wider than the gauge. I wouldn’t call that a rail yard. To me it looks like a normal railway station with a number of tracks for various local and intercity trains coming and going to and from different directions and are not supposed to be in use all at the same time. ---
**Author:** ![AdamF](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/adamf/32/6246_2.png) [@AdamF](https://boards.straightdope.com/u/AdamF)\ **Post date:** [March 14, 2013, 4:00pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/19 "2013-03-14T16:00:05Z")
> [@Peremensoe](#): > > What’s the point of having the three rails at all? It only allows one-way traffic anyway. Just run the cars on the same _two_ rails, opening up into four (two tracks) at the necessary spot. The reason is that this is not a regular rail, but a funicular. Cars do not have an engine. Instead, each car is pulled up the slope by a steel cable. You can see the rail arrangement very well in this video: [https://www.youtube.com/watch?v=nBVNL470WOw](https://www.youtube.com/watch?v=nBVNL470WOw) 0:40 - 1:15 After leaving the lower station, there are only two rails with the ascending car’s cable running between them. 1:16 - 1:47 There are two sets of rails where the cars pass each other 1:48 - 2:55 There are now three sets of rails. Cable pulling the ascending car runs between the left and center rail. Cable slowing down the descending car runs between the center and right rail. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [March 14, 2013, 4:53pm UTC](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902/20 "2013-03-14T16:53:10Z")
> [@Floater](#): > > I wouldn’t call that a rail yard. To me it looks like a normal railway station with a number of tracks for various local and intercity trains coming and going to and from different directions and are not supposed to be in use all at the same time. Yes - that bit isn’t a yard - further to the northeast there’s a smallish area with train works and some goods train storage areas. No through traffic uses anything but the three tracks adjacent to the platforms (the blu/red train is at platform 3) [Next page](https://boards.straightdope.com/t/railway-buffs-does-this-track-configuration-exist-anywhere-in-the-world/652902.md?page=2)