Minimum center line distance in yards

The real railroads typically use 13 or 14 feet for track center spacing in yards.

• 14-foot centers translate to 3.5" in O scale.
• 13-foot centers translate to 3.25" in O scale.

2.5" track center distance is too close. That's only 10 feet in the real world.

You can find a nice calculator for these kinds of things here.

You need to use the Ross TR35 transition curves, not standard curves, to match the 3.5” spacing of the center tracks.

Thank you both.  This is very helpful.  When I looked at the diagram, it seemed too close and then I actually measured it at 2.5 inches and thought Uh Oh!

The problem with anything less than 3.5” is it’s difficult to get your fingers in there to place, remove and retail cars.

For my RR I use 15' which is 3 3/4".  I use #6 yard turnouts.

Not to steal the thread but a question for tom tee, why use #6 instead of #4?  The Ross site is a bit mysterious and the #6 is five inches longer than the #4.

Almost every locomotive can negotiate a #6 switch. Large steam locos have problems on #4 switches because the diverging route radius is too sharp.

You need to add a short straight section between the switch and the O-72 curve to get 3.5” C-C.  I use 3.5” in my classification yard and it is tight if you need to add cars.  I use Ross Regular swiches, not quite No 5 (O-100), and they work great with all my steamers. Some bigger steamers, and my Centipedes, do not like backing through my Ross double-slip switches which are No 4.

I made these to space the tracks 3-1/2" apart. I'm done with them no more yards for me.

So email me, and I can ship them to you. However, you must not ship them back to me but instead to someone else that needs them.

Alan

When you surgically shorten a #6 you can tighten up the throat.  Have you approached Ross about ladder track?

Alan nailed the primary reason so you will not have any limitations.  Additionally #6 just looks better.  A #4 sort kinda looks a bit too traction for me.

For long parallel alignment I use two tools for staging and other yards.  Shorn SS sheet metal and tempered Masonite.  Most any sheet metal shop will shear off a  band of metal for you.  Or you can rip some Masonite.

Alan's gauges are really neat, they could be handy for curved yards.

Something that will help you lay out steady curves would be to pre-bend all your curved flex track.  That is one way to avoid having angular or peaked rail end joints.  Depending on the type of rail bender you use there is always a degree of necessary cut off scrap to acquire even curves.

All track centerlines are drawn on the deck using tangent straight edges and transition templates.  All curved track is pre bent using a rail bender then one rail is advanced for staggered splicing.  On two rail track as shone, I stagger rail ends about 6" to 8".   Hard fixed rail like Micro Eng or GG all ends are trimmed back to exact curvature.    I use dozens of square spacers with a nail tacked in the center.  I will lay out one exact track then using a series of spacers I will add additional adjoining like here:

I use the squares for  the curve and strips of metal for the tangent track.   The above staging loop is 13' X 29'.  It can hold up to 18 medium trains.

If you look closely you will notice all curves have a  spiral easement.  I use a range of easement templates:

I also use Masonite gauge strips which are 1 1/4 wide and pre-drilled for the factory nail holes.  I drop them between the rails to hasten fastening the track down.  Your curve can not be too consistent and your tangent track cannot be  too straight.

Tom and Alan, Remarkable work and great ideas.  Tom, did you use the Armstrong book for figuring the spiral easements?

Essentially, yes.  I blend Armstrong and NMRA S-8 standards on multi track right a ways.  IF you follow their simple steps there will always be safe clearance margins. 

There are four math formulas for laying out a spiral easement but setting an easement of 1/2 your fixed radius centered at the theoretical start of your curve offset by a set X factor will be just fine for a model railroad.  The important thing is to make sure you bent stick is exactly sitting on 1/2 of your offset and your stick conforms to the right of way at both ends.

Using templates you merely set your desired clearance on the fixed arcs and all else finds it's place.

Maintaing separation at concentric Curves. Instead of the rectangular bases I'd make 2 oval shaped bases where the bases can rotate with marks indicating the radius on the inside and outside curves while still maintaining the proper separation with fixable movable sliders that can vary to maintain the separation.

A bit more complicated

The center legs on a Ross 4-way are spaced at 3.5 inches. That's plenty of space to get your fingers in when placing/removing equipment. Make sure you don't park anything too close to the turnout because the inter-track spacing goes away quickly near the switch.