Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Minimum area for HO return loop

8338 views
5 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    March 2012
  • 52 posts
Minimum area for HO return loop
Posted by RealGomer on Saturday, September 2, 2017 2:43 PM

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.

Tags: return , size
  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Saturday, September 2, 2017 2:48 PM

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.

.

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.

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Saturday, September 2, 2017 7:30 PM

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

  • Member since
    March 2012
  • 52 posts
Posted by RealGomer on Saturday, September 2, 2017 8:27 PM
I'm confused. Where is the S curve coming into play?
  • Member since
    September 2003
  • From: California - moved to North Carolina 2018
  • 4,422 posts
Posted by DSchmitt on Saturday, September 2, 2017 9:51 PM

 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.

  • Member since
    March 2012
  • 52 posts
Posted by RealGomer on Sunday, September 3, 2017 9:32 PM

4x4 is what I was hoping to accomplish. Thanks!

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!