What is the minimum spacing or clearance for O scale Track?

[SleeperN06]

I think I might have asked this a few years ago but I forgot and can’t find it.

I’m running 042 MTH around 036 Fast Track and I’m short of space so I need to get them as close to each other as I can. I will be adding to the outside of my layout so that I don’t disturb what I have already.

I originally was just going to add 4” all the way around but after I started I realized that I didn’t think this out to well. For one thing I not only miscalculated the space between the track, but I didn’t include any outside clearance.

So what will I need to add to the outside?

[lionelsoni]

The minimum spacing is the spacing where the trains do not touch each other.

But, seriously, that's about the only hard and fast rule.  For straight track, I get away with 2 7/8 inches (on centers).  The width of a prototype train is 10 feet 8 inches, which becomes 2 2/3 inches in 1/48 scale.  Since toy trains are often under scale and virtually never wider than scale, that spacing is pretty safe.

Curves are a different matter.  How far trains move from the center of the track depends not only on the track curvature but also the geometry of the individual car or locomotive.  There is no simple answer.  There is however a pretty good trick for getting tracks closer together or closer to a straight boundary like a wall.  That is the spiral curve.  You use a little bit of very gently curved track to ease the train away from the other track or the wall, then switch to a sharper curve for the rest of the turn.  (It's also prototypical.) 

[Andrew Falconer]

4" between the Center Rails on straight sections.

6" between the Center Rails on Curved sections.

Andrew

[SleeperN06]

Thanks this give me a better idea of what I need.

I remember a few years ago I had a curve at the end of a bridge and my steamers were clipping it.  So I guess I’ll have go with 6” to keep anything on the inside track from clipping whatever is on the outside track coming out of the curves, just to be on the safe side.

[runtime]

As Bob Nelson said, it's the overhang on curves that matters,

If you are considering 6" center to center, that may be overkill. What I did for a recent layout expansion was to lay the track provisionally, then try my greatest overhanging unit on the inside (A Budd Unit in my case)with something large and appropriate on the outside to determine minimum spacing requirements on the curves. In the past, on straights, I've used 3 3/8" center to center,which I think is a close as I would like, but is too close for 031 curves approaching the outer straight from the inside, as I belatedly found out.

runtime

[11th Street]

Depends upon the length (overhangs) of your rolling stock.

Instead of calculating and polling opinions just put your longest cars on your turns & see what catches what... That's the way we used to do it in the 1950's.

[phillyreading]

One to watch out for is large steam engines, like a 4-6-6-4 or 2-10-2, the rear roof of the cab may catch or hit a lot of your rolling stock on corners. Also watch the steps on tenders(MTH has wide steps on some tenders) with steam engines as these may not clear track side accessories all the time.

Lee F.

[SleeperN06]

Thanks for the pointers. I’m still trying to add the other track and its taking up a little more room that I have. I figure that if I can use hinges to fold up one side so that I can get items through the door, I might be able to get it to work.

I’m using MTH RealTrax and was wondering if can cut the track so that it can be easily separated and folded. Would there be problems or things that I need to be concerned about?

[phillyreading]

I worked on a layout that used a folding or hinged area to get access to a doorway. The biggest problem was track alignment(I used tubular track) and supplying power to the area, as you will need to keep all wires out of the way as well. For under the platform wiring I used screw eyes to hold the wires in place, installed the screw eyes first than ran the wires through them. Unsure how to attach power to Realtrax other then adding a power terminal section to the area you want to power.

I like to keep all my wires under the layout area when possible or hide the wires with some putty of matching color to the layout.

Lee F.

[SleeperN06]

Thanks for replying. I’m not worried so much about the wiring as I am about the track alignment. I’ve been soldering feeder drops onto the copper tabs underneath.

I wonder if it would be better to cut in the curve so that the gaps wouldn’t be directly across from each other. I don’t know because I’ve never done anything like this.