Track spacing

[Lillen]

Hi,

 

I would like to know how much apart a double track railroad should be? What I'm interested in is from tie to tie.

 

Also, would the roadbed be the same lever trough out or should there be a dip in between?

 

Magnus

[HEdward]

Actually, the general method is to measure from the center between the rails as tie widths may vary.  I'm designing my double track section with 3" centers.  If you have tighter radius curves, you may need to widen that to accomodate longer locos or passenger cars. 

[selector]

Magnus, the gentleman above is absolutely correct.  While your engine and rolling stock centres sit within a very narrow variation from the centreline of the tracks, the tie ends, either side, are all over the place in some cases.  Perhaps not so much with Atlas and Model Power and Peco, but certainly for ME it will vary considerably.  Also, remember that the degree of curvature greatly impacts the necessity for spacing between adjacent and parallel tracks.  You would be much safer, and less likely to lose much time and effort, in adhering to the NMRA guidelines.  For curves with radii below 24", you would want something close to 3 full inches, and probably even more if you plan on using longer cars such as heavyweghts.  Steamer cab rear roof corners are really bad for swiping stuff nearby on curves much less than 30".

I am sorry, Magnus, but I don't think I understand your last question. 

-Crandell

[HEdward]

Gentleman?  I'm flattered!

As for the last question, I've been looking at alot of youtubes of real and model trains...ballast doesn't care about adjacent trackage.  So if you have fairly wide centers, your ballast will have a gulley between the tracks..

[DeadheadGreg]

you'll want some sort of little ditch, because the prototype needs somewhere for water to drain into. 

[MPRR]

You can have 2" spacing between centerlines on straight track. Just Broaden the spacing before you approach curve.

Mike

[ericboone]

Lillen,

    Here is a link to the NMRA S-8 standard that answers your question.

    I also made a spreadsheet to calculate minimum curved track spacing if you know the dimensions of your longest rolling stock and locomotives. 

    For true double track, most railroads did have a small drop in the level of the ballast between the two tracks.  Here is a link to a PRR profile.

Eric 

[John Busby]

Hi Lillen

My sugestion would be to get a couple of the Peco 6' way gauges use the flex track gauge for straight track and the set track gauge for curves that should give enough clearance for even the big 90' cars.

It is important to note that track spacing is measured from center to center not from the ends of the sleepers both on the real and model railways as that is the dimention quoted in publications and standards for both kinds of railway.

If I follow your second question you should have a dip between the tracks for drainage and you should also have a drain each side of the track.

regards John Busby

[dstarr]

Hi,

 

I would like to know how much apart a double track railroad should be? What I'm interested in is from tie to tie. 

Also, would the roadbed be the same lever trough out or should there be a dip in between? 

Magnus

I am using 2 1/4" from center line to center line for HO straight track.  For 22" curves I should be allowing 2 3/8" on the curves, but my measurement and tracklaying skills may not actually achieve the 1/8" difference between curves and straights.  I use the John Armstrong book (Track Planning for Realistic Operation) for details like this.  Or go to the NMRA website and down load Standard S-8 (TRack Centers). 

[Lillen]

Thanks for the advice guys.

 

I will be using 36" radius minimum so I guess the extra distance isn't to much to worry about then.

 

Magnus

[HEdward]

Lillen,

    Here is a link to the NMRA S-8 standard that answers your question.

    I also made a spreadsheet to calculate minimum curved track spacing if you know the dimensions of your longest rolling stock and locomotives. 

    For true double track, most railroads did have a small drop in the level of the ballast between the two tracks.  Here is a link to a PRR profile.

Eric 

Nice of the standards folks to footnote my planned 28" curves and 85' passenger cars.

I'll take a look at your spreadsheet instead.  Or I'll layout some track and roll some cars about on the floor!

[jrbernier]

  36"/38" radius curves will work fine for double track, except I would never run an articulated steamer on the inside track while meeting a passenger train with 'full length' passenger cars.  The 'hunting' of the articulated may/may not hit the passenger cars.  Intermodal 'Husky Stack' or enclosed tri-level auto racks will also be a concern on the outer track - a lot of overhang with those cars.  I would mock up some flex track curves and 'test' with all of your equipment before going from paper to the finished layout.

Jim

[wedudler]

The prototype has track spacing as narrow as 13' or 14' and up to even 20' I've heard. 14' is very common.

At one place my H0 track is 45mm apart. This is the example,tangent mainline.

 

For curves you need a much wider spacing. This depends on the car length. I've used Excel to calculate the track spacing for curves.

Wolfgang 

[HEdward]

Snce the space between the rails is fixed at 4'8.5", a shortcut to keeping the centerlines space right is to measure from the rail on one side to the rail on the same side of the second track.  Looking at more videos(the boys love watching trains on "TV" while on my lap.) I'll be keeping my centers at 2" on straight sections and by starting the curves on the inner track first, open the spacing to 3".  At 28" minimum, that makes my outter minimum 31".  I know many super realism guys would say that it's unrealisticly tight, but my space is my space.

When ballasting track, each track is handled seperately.  Therefore, a dip in the cross-sections profile between the tracks is a natural occurance.  Drainage?  Isn't that half the purpose of ballast to begin with?  Raising the track above ground level and the coarseness of the ballast provides the drainage.  On hillsides, drainage ditches are needed to keep the runoff from the hill from washing away the ground underneath.  A ditch on the high side and frequent drains to carry water past the track keeps everything working properly.  While we indoor modelers can get away with forgetting about drainage, those guys on the other part of this forum, Graden Railways, are experts.  At one point I was plotting(not planning, plotting, like a conspiracy I was going to take over the yard)a garden railroad of my own.  Young kids need the yard to play in.

Lastly, I am slightly envious of some of the superb photography and modeling skills such as seen in the images on this thread.  Good work folks.  Maybe if my layout ever gets going, I'll get to post something to inspire others as your pic inspire me. 

[D&RGWRR476]

One of Sperandeo's books recommends 2" spacing on straights and 2 3/8" on curves. I cut two wood blocks of these lengths to measure track centers quickly when planning and laying track.