Atlas O track tie spacing- 3R v. 2R

@BenLMaggi posted:

I was curious though: does anyone have a piece of "Scale" Atlas O 2-rail track and could they take a picture of it next to a piece of Atlas 3-rail track, and/or a piece of Lionel Fastrack? I wonder if the tie dimensions and spacing on the scale 2-rail track are the same as on Atlas or Lionel 3-rail track, and if it is just the presence of the third rail that is making it look wonky to me.

Thanks!

I can't really answer your question about 2-rail Atlas O, but here is what I can say:

Atlas O 3-rail track has a tie spacing of 15/32" between the centers of the ties. That is equal to 22.5 inches at full scale. Typical tie spacing on a railroad is between 20 inches and 24 inches.

Atlas O ties are 3/16" wide, 1/4" high, and 2-1/4" in length. This translates to 9" wide, 12" high and 9 feet in length at full scale. Standard railroad ties are 9 inches wide by 7 inches high by 8.5 feet long. Atlas O track was deliberately made with ties that are too high so that the top of the rail matches the height of (if I remember correctly) classic Lionel O gauge tubular track.

Atlas O solid nickel-silver rail is code 225 - and the rail height is 0.225". That translates to 10.8 inches in height. As an example, New York Central Standard Rail (127 pounds/yard) had a rail height of 7 inches. Atlas O 3-rail rail height is larger than scale to accommodate 3-rail wheel flanges, which are oversized to prevent derailments. I measured the rail height of a piece of Atlas O 3-rail track as 0.219 inches - equivalent to about 10.5 inches at full scale. I guess that's why 3-rail track is called "high-rail."

I've built 2 layouts (both still in operation) using Atlas O 3-rail track for the past 26 years. Looks fine to me and has been very durable.

I'm pretty sure that Atlas O 2-rail track has dimensions that are closer to scale - including the height of the ties and rail.

MELGAR

Here you go.... The tie spacing looks the same.  The 3R ties are a bit thicker.

Thanks for the comments and pictures. I guess the track without the middle rail would look good to my eyes but with the third rail it just appears too busy and crammed in.

IMO it's primarily the oversized rail itself that creates the 'crowded' appearance. The center rail only compounds it. Several of us some years ago experimented with assembling a more visually pleasing 3 rail system for out layouts or display dioramas.   I had a nice layout using MTH Scaletrax which to me was the best available commercially but the odd tie spacing gradually wore on me and I caved in and acquired Atlas 3 rail. The smaller MTH rail size looked very prototypical and the thin center 'blade' was non-intrusive in the manner that Lionel's Super O was.  

Ron H. here came up with using Atlas 2 rail and attached N gauge rail to the base for the electrical pickup. The result was very good and as with ScaleTrax, the smaller rail gave our locomotives a more massive appearance.

On real RRs the tie spacing varies by use.   I have a book of reprinted standard drawings for the PRR.    They list 3 tie spacing I think.   There is one for mainline, one for secondary, and third for sidngs - each progressively farther apart.   The standards if I remember correctly are in "ties per 100 feet".   

So the busier and faster the route, the more ties they use.

Now how do we work that into our modeling?

@prrjim posted:

On real RRs the tie spacing varies by use.   I have a book of reprinted standard drawings for the PRR.    They list 3 tie spacing I think.   There is one for mainline, one for secondary, and third for sidngs - each progressively farther apart.   The standards if I remember correctly are in "ties per 100 feet".  

So the busier and faster the route, the more ties they use.

Now how do we work that into our modeling?

On my HO scale layout, I cut the plastic web between the ties on my flextrack and respaced the ties out for sidings, which meant that I had to actually remove some. At the same time, I also slanted some of the ties for an irregular look.