Passing siding/double track distance

[E-L man tom]

As Jim pointed out, 2" clearance on the main line from any track (siding included) for a minimum, and that, I believe, is NMRA minimum, with about 2 1/2" minimum on curves. This, however, will be a little dependent upon the minimum turn radius and the length of the longest loco or cars you're running. In the yards, you can get away with as little as 1 3/8" clearance (straightaway), but to be more comfortable, I'd go with 1 1/2" spacing. I do have two yard tracks that are at the 1 3/8" spacing but they are a bit close, that's only about 10 scale feet.

[BroadwayLion]

These platforms are more narrow than what I would like, but as you can see, I have used up all of the real estatte that I have.

ROAR

[mobilman44]

Hi,

As previously written, 2 inch centers is a typical distance for parallel tangent tracks.  However, I tend to be a bit wider - 2 1/4 inch - as it helps getting the "0-5-0" switcher in there when cars are on both tracks.  Either one, you can't go wrong.

[doctorwayne]

The distance between mine varies depending on what else happens to be in the same area.  These are about 31/2" apart:

...and about 3" here on the upper tracks, at left, and 2 3/4" for the runaround on the lower level:

These are 2 1/2" o/c:

In order to include everything I wanted in this area, the tracks are only 1 3/4" o/c, and even then, my 90' turntable is actually an 89'-er. 

There is room for a whistle post between the tracks, but that's about it.  The distance between the tracks increases through the curve in the distance, though, to about 3", so 85' passenger cars can pass comfortably. 

Wayne

[hon30critter]

Ask yourself if you need to get your fingers in there on a regular basis to insert/remove cars. If no, then go with the NMRA standards which are here:http://www.nmra.org/standards/sandrp/s-8.html You will have to scroll down a bit to get the HO specs.

Dave

[tomikawaTT]

Prototype track spacing is a variable, ranging from very close (10' 6") at some old inner city freight houses to 14 feet for mainlines in the crowded Northeast to 25 feet for new construction in the desert southwest and for lines multi-tracked to handle PRB coal units.  And then there are those lines in places with vertical scenery where the eastbound and westbound tracks may or may not be in the same county.

On my model railroad (HOj, 1/80 scale but slightly narrower than American HO) I have some hidden tracks spaced 45mm (1 3/4") and a couple of those 'maybe in the same prefecture' second tracks built later on a more favorable alignment.  The ordinary passing sidings are spaced 50mm, a smidge under two inches.  Curve radii get spread to 60mm spacing by playing with the spiral easements.

If I was running US prototype HO with Mallet locomotives, 85 foot passenger cars and outsize goods vans (as Whit Towers defined humonguboxes and TTX flats) I would still use the same spacings - but my minimum radius would go from 610mm (24 inches) to a meter or more.

Chuck (Modeling Central Japan in September, 1964)

[mlehman]

This measurement also depends on what the siding is used for. If it's a regular spot for trains to meet, yes, double track spacing width as Jim recommended is what you probably want if you have no other plans for it.

But sometimes there are sidings that are used for MOW equipment or storage, too, and they may be wider. Then there are industrial tracks, which in tight areas are much closer than you often think of a siding being, but still wider apart than double track standards.In cases like those, how you do the ballast and scenery, even structures and fences will tell a lot about why you might have wider spacing.

[jrbernier]

  The prototype spaces two parallel tracks anywhere from 13' to 25' on center.  Most HO parallel track is about 2"(14'6").  You will need more than 2" track centers for curves....

Jim

[hustle_muscle]

On my layout plan, I have a passing siding with the tracks parallel to each other. How far apart do the tracks need to be spaced? They are 3 inches apart on my plan, but after placing 2 straight sections 3 inches from each other (measured from the middle of the tracks), it looked a little far.