I want to run 54 radius on the inner and outer loop so will need a straight piece on the outer loop and they will connect with back to back switches. How much width will I need to make this work?
Original Post
It will vary a bit based on the turnouts you use, but connecting with realtrax O-54 switches (with no track between the switches) the width was just over 6'. Add a few inches, if you want to use those switches on the front and back, add a few more inches because the inner and outer loop don't match easily in realtrax, with switches on both sides.
If you post the track type, switch type and whether you want switches on both sides, might get a better Idea. It also looks to me, like you might be able to use a wider radius on the outer curve, or mixed radii.
All that rambling, you are probably at 6' plus and 7' should be plenty, unless you want trackside scenery.
