4x4 is what I was hoping to accomplish. Thanks!
4X4 by Donald Schmitt, on Flickr
4X4-1 by Donald Schmitt, on Flickr
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
a circular loop of radius R require 2R in each direction. 21" radius should fit within a 24" space with appropriate space between the track and layout edge
but a reverse loop requires at least another length of R for the curve joining the loop and mainline (or 2nd mainline track). in other words, a reverse loop with a nasty s-curve (as seeyou mentioned) requires at least 3R x 3R space, 63" in the long direction.
greg - Philadelphia & Reading / Reading
4 foot by 4 foot will only work if you are content with 22 inch radius curves and a nasty "S" curve in the middle. Even then, there will be an additonal "exit" required from the 4 by 4. A nominal total of 4 by 6 is really the effective minimum even with tight radius curves.
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Reverse loops absolutely devour space, and almost always require an access hatch or something in the middle for maintenance/cleaning chores.
There was an old article by John Armstrong in Model Railroader titled "Doodling by the Squares" that really did a good job of showing how much space is required for a reverse loop using different minimum radius curves. The other frightening fact in that article is how much length is required for a #6 yard throat.
-Kevin
Living the dream.
After sitting in cigar boxes and whatnot for 30+ years, I plan to create (hopefully) an L-shaped layout with return loops at each end. My thought is to make the straight section on an L-girder framework that's two feet deep. My question is this.
Would using 4'x4' panels at each end and the corner be large enough for a loop return? Hopefully I can use 21" radius track. I hope to run parallel tracks along the straight sections.