Distance Between Straight Tracks

On strictly straight rail, such as yard tracks, you can go down to 3 1/2" center to center without a clearance problem. The only time there will be a problem is with custom cars with "wide" loads.

I'm not the expert here but one thing to consider is the movement of cars side to side as they run by each other.  Variations in the track, joins, etc, can make cars sway.  If two trains are passing each other, and you have a low spot on both inside rails, each car would only have 1/4" of movement at the top before they touch.  If you have some tall cars, this could be a concern.  I do like you plan of 20' of 3 tracks side by side, could make for some very interesting runbys!

 

Best wishes.

Paul,  we have a Lionel N&W Class A that has an air tank or similar that juts out from the left side beneath the cab that occasionally would catch on scenery and bridges. I can't get to it to measure the actual width at this place on the locomotive but I would recommend erring to the positive when laying out your track!

 

 

How's the layout coming?  I'll wager the folks here would like to see some photos...

4 1/4" to  4 1/2" center to center seems to be acceptable standards even on the curves. 3 1/2" center to center acceptable yard standards.  You might note that the Atlas track system has the pre-made curves set to 4 1/2".

O27, O36, O45, O54, O63, O72.....

In response to Ironhorseman,

 

This is what makes the forum so valuable.

 

I never thought to think about slight wobble.  Your right, if each car wobbled just over 1/4", they would hit.

 

Something else I just thought about.  What if I want to place signals between the tracks.  I'll need a little extra room for them (of course, depending on the size of the signal).

 

Thanks to all for making me think all this out.  I think I'll go at least 4" from center to center.

 

I think I'll test out placing two tracks with 4" spacing and place a couple different signals I have between them to see if I will be able to keep the 4".  Heck, I may have to go wider if I want to have signals between tracks.  Of course, if I want to have the three tracks as close as possible, I can forego any signals during that 20' run, just to have three engines run as close as possible without hitting each other.

 

I guess I should just screw down three 20' long sections of track and test that area to see if it will work at 3 1/2" or 4".

 

Thanks to all for your input.

 

Corvettte

To Laidoffsick,

 

Do you have any cars wider than 3" ?

 

Does any body know if there is a place to go that gives dimensions for cars ?

A typical freight car is about 10 1/2 feet wide. If you're talking about mainlines at higher speeds, a 4-inch spacing is better to allow for minor derailments and the occasional pair of passing steam locomotive with oversized cylinders. In yards, where speed is low, 3 1/2 inches works fine. It allows for 1:1 fingers to get around 1:48 rolling stock.

 

An O scale (2-rail) modular group I socialize with runs at 4 1/2" mainline spacing even through their minimum curve radius is 72" (O-144) and [so far] they haven't had any problems with articulated steam hitting anything. 

The widest O gauge cars I know of are the wrecking cranes that have the hand wheel sticking out one side.  The widest that a railroad car was supposed to be is 12 foot, 8 inches, which would be just under 3 1/4" In O scale.  There were some plug door boxcars where the upper tracks and door roller assemblies got a little wider than, 12' 8", but it was up in the air where it did not interfer with anybody.  There were non interchange cars that got wider.  The steps on the Saltair (Salt Lake Garfield and Western) open bench cars are out at 14 feet (3 1/2" in O scale).  The tightest yard I ever saw was on the BC Hydro under the Queen Victoria bridge. I wanted to read a builder's plate on a small locomotive and I had to crawl between the cars and just stick may head up to read the plate when I got to the locomotive.  I believe that the tracks were on 14 foot centers. 

David Johnston got me to thinking more with his post.

 

So I did some reconfiguring.  I went back and remeasured my two Schnabel Flatcars.

They were not 3" wide, but 2 7/8".

 

So, if I leave 3 3/4" between center-to-center, that will leave me 7/8" between those cars.  I think that should be enough.

 

Furthermore, I doubt if I will ever have two trains running side by side with each one having one Schnabel on each one exactly side-by-side.  More than likely I'll run the two Schnabels one after the other on the same train.

 

One interesting thing I learned while playing out this exercise.  I was amazed that after measuring almost all the cars and engines I have, nothing came even close to those two 2 7/8" cars.

 

Thanks again to all for making me rethink this.

 

Corvettte (Paul)

Quite an interesting and useful discussion.  Paul, I think you've arrived at a sensible conclusion, and would like to see a shot of three engines steaming down your enviably long straightaway.

4¼" ...

 

do i win?

If you think a Coors Light Silver Bullet might ever visit your layout, know that it's a bit wider than typical scale width. I don't know by how much, but I understand the "snowmobile wheel" on the side runs into DZ-1000 switch machines.

 

---PCJ