Radius vs loco size

[Bob Trask]

I am planning a garden railroad to fit an existing garden plot. The limiting factor so far is the possibility of tight radius’ in two corners. Since I do not have rolling stock currently, I believe that the radius’ that I have to work with will limit what locomotive classes I could use.

  Is there a standard that specifies what locomotive class can effectively be used with a certain radius curve?

[two tone]

Hi Bob,   Some locos 0-4-0 and 2-6-0 will go around Radius 1 curves at a reduced speed but any thing bigger will need R3 curves.    If you are having a raised layout the bigger the curves the better its very costly if loco falls.         Bob it helps if you show your base as you can see im in the UK By doing that you may find there is some one close to you who can offer advice  Hope this helps

[piercedan]

LGB designed all their rolling stock to run on 2 foot radius/4 foot diameter.

I find that the 2 axle LGB engines do run on my 32inch diameter circle.

 

The larger engines do require larger circles and long power trucks like level track.  My worst engine is my Aristocraft RDC version 1.  But, I use this engine for making sure my track is oin great shape as if it does not derail, my track is nearly perfect for running anything.

I have run the SD45 (stock, no coupler mods) with passenger cars through 3 foot radius switches.  Spec says 4 foot radius minimum.  These engines will travel through 2 foot radius, but will derail the first trailing car as the coupler hangs over the outer rail.

[Narrowgauge]

For those of us Yanks that didn't cut our teeth on LGB, could you possibly reference the curvature and length in real world information in stead of LGB's secret code?

 

Thanks,  Bob C.

[vsmith]

R1 = 2' radius, 4' diameter

R2 = 2.5' radius, 5' diameter

R3 = 4' radius, 8' diameter

R5 = 6' radius, 12 diameter (I think ]

Basic rule of thumb:

2 axle engines (HLW Mack/Bachman Davenport) = 4' diameter OK

4 axle engines (Aristo GP9) = 5' diameter OK but recommend wider

6 axle engines (Aristo Dash-9) 8' diameter OK

Steam: (excluding LGB which are all 4' OK)

2 axle steamers (Bachmann Porter) = 4' diameter OK

3 axle steamers (Aristo Pacific/ Mikado/Connie/Bachmann K-27) = 8 foot diameter and larger

Generally if your planning to run large steamers like Mikados or the K-27 its best to plan on 10' diameter .

[kstrong]

Note that the "R" values Vic mentions are applicable to LGB track only. Other manufacturers also use "R" values, but they are not necessarily--and likely not--the same. Always check the actual radius/diameter of the track you're buying. Do not rely on labels and expect consistency between manufacturers.

I heartily agree with his "rule of thumb" for loco size vs. radius.

Later,

K

[g. gage]

In addition to the above posts I recommend using larger curves where practical, like twenty foot diameter. Trains look sooooo much better. Have fun Rob