Spacing on parallel O-27 tracks

[thankey]

I want to build a switching shelf layout using O-27 track for my just gifted GM&O RS-3. How far apart must the parallel tracks be to allow two switches to connect the two lines? I guess that there needs to be a short curve track on each turnout and maybe even a short straight.

[spankybird]

Center to Center rail = 7 1/2 inches for back to back switches

and 4" center to center rail for main line running





This part of the layout is at 4" center to center


This part of the layout with the switches is 7 1/2" centers


tom

[lionelsoni]

If you are willing to cut the curved part of the switches down, you can make a 45-degree turnout into 30 degrees. This will allow the tracks to be about 3.35 inches on centers, which is so close that you will be limited by the size of the switch machines. For intact switches, tom is right, except that I make it to be a little closer, 7.32 inches. If you locate the crossover on a corner, so that the outside main line uses the straight path through one switch and the inside main the curved path through the other, which forms part of the corner for that main line, the spacing is exactly 6.25 inches.