Just getting started, radius questions....

Discussion in 'Track Planning' started by 2680, Dec 31, 2006.

  1. 2680

    2680 Member

    i am just in the planning stages of my layout. i have an area 3' x 9' against a wall. there is absolutly no extra room to get more than 36" out from the wall. i will be doing ho. my question is what is everyone's experience with small radius? i will be doing a main loop around the outside which will have 15" radius. it will be a GP40 engine with some smaller tanks, hoppers, and caboose. have tested this with no problems. as for the inner track, i want to set up a coal mining track, but it will need to have 12" raduis to fit. i have a 0-6-0 steam engine and 3 atlas 2-bay hoppers (pretty short). anyone have any idea if this will run smooth? not concerned with speed, as it will run slow, just don't want to run into any problems once the track is laid.

    thanks! these forums are great!
  2. Jim Krause

    Jim Krause Active Member

    As you are probably aware, your max radius would be 18 inches and that will put you right at the edge of the benchwork. Not good. Are you using flex track or sectional track with a fixed radius? Looks like your going with the type of equipment that fits your space. Don't know how those 12 inch radius curves will work but if you have tried it out and find it acceptable, go for it.
  3. 2680

    2680 Member

    i will be using flex trac (first time). i have tried the 15" radius with some old atlas fixed track and it worked fine, but not sure of the 12". what is the problem with being on the edge of benchwork? derailments? what is a good distance to leave around the edge?

  4. Jim Krause

    Jim Krause Active Member

    Being on the edge of the benchwork makes for some nasty damage if your train derails. You can compensate for this by adding a fascia that's high enough to prevent the trip to the floor. The only problem there is that you are looking down into a pit. Possibly you could make the fascia from clear plexiglas?The distance from the edge is determined by clearance of your loco's and cars. Assuming that you were to use a fascia that is.
  5. BigJim

    BigJim Member

    If your 3' size is absolute (can't you have two little bulges and loop over 180 degrees?) I would not recommend trying to do a loop in 36" but if that is your only option then I would do the following:

    Place your track by the wall just over an inch from the wall. Consider that straight tracks can be 2" apart so the midpoint would be 1".

    Place the front track 2" from the edge with a 2.5" high clear edge to prevent long, and expensive, drops.

    This will give you 33" wide. Use a 16" radius for the outside with 1/2" to ease into the straight (Very important). Now place the second track about 2.25" from the first or 13.75" radius. I know 13.75" vs 12" doesn't sound like much difference but it may help.

    If you could have a 2.5" bulge at each end (they would be less than 18" wide at the ends) then you could add 1.25" to each radius and have a 15" on the inside loop.

    I understand that you may have a 36" constraint at each end but if you don't have enough room for a couple of 2.5" bulges then I don't understand how you will be able to stand in front of the layout to operate the trains.
  6. 2680

    2680 Member

    i guess i could do a bulge, but it is not ideal. this layout will be in a finished basement in a long narrow passthrough. it is 6' wide, and i want to maintain a 36" walkway as a minimum.
  7. Fluesheet

    Fluesheet Member

    I have no experience with a radius as small as 12". However, something that may make it more feasible would be to create easements into it. Easements are short sections (as short as 6", typically about a foot) of track that trasition from straight to your chosen radius. This will help "ease" the train into curves, and will make your trackwork more reliable than if you went from straight immediately to your end radius. Disadvantage is that they take up *slightly* more room than a simple curve..

    I'd suggest experimenting before commiting.
  8. Triplex

    Triplex Active Member

    I've heard of people doing just that on 6" radius in N, so it should be doable.
  9. cidchase

    cidchase Active Member

    36 inches is probably too wide to permit reaching the rear tracks without
    considerable difficulty, plus the good chance of damaging foreground scenery
    while you're reaching over. 30" is generally recommended as a minimum. Those
    MicroMark work-over platforms might help. I would say that if you want continuous
    loops, you don't have room for HO. :oops: If you can do point-to-point, you would
    have a lots better chance of fitting an HO or HOn layout in that space!

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