What kind of steam engines (0-6-0, 2-6-0, 2-6-0, 4-4-0, etc) can take a 15" curve, or and 18" curve. There are certain spots, actually, quite a few, that will require a 15 inch curve. Advice?
There are 3 limiting factors here:
- Rigid Wheelbase - the above engines should not be a problem
- Engine/Tender connection - this may be an issue with short draw bars.
- Pulling cars around curves - Will the cars and engine/tender bind against each other in the curve?
I have a Mantua ‘General’ 4-4-0 that has no problem on 18" radius curves with 40’ cars behind it. It looks pretty foolish, and the pulling power really goes down when it goes through that tight of a curve.
Jim
If you’re in N scale, pretty much anything will take 15" radius. In HO, 15" is “Very Sharp” and suitable only for shorter equipment - and may require talgo rather than body-mounted couplers. Unfortunately about the smallest minimum radius manufacturers shoot for is 18" radius, so it may come down to a matter of trial and error to see what cars and engines can actually sneak around a 15" radius curve.
As far as advice: In the long run, you’d probably be better off redesigning the layout with larger radius curves, even if it means you can’t do all the things you want to do on the layout.
I might be able to get 18ers in there, and what about 24s? I might be able to have most of the curves this way, but a redesign will be necessary.
Which scale are we talking about now? On30? Sn42? HO? HOn3?
In standard gauge HO, just about all those mentioned will make a 15" radius. You may have to check the tender drawbar length to avoid shorting. Same is true for HOn3.
Sn42 will be dependent on the mechanism.
Most On30 is built for 18" radius curves. Whether they will make 15" radius curves is an unknown to me, and probably depends on the individual model. You will probably have to do some testing and possibly even some modifications to make the 15" radius with the larger engines.
Fred W
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AS 15"r and 18"r curves are basic minimum standards for HO scale, I am going out on a limb here to assume you are in HO scale.
The steamers mentioned will handle both 15" and 18" curves. I have a very small HO scale layout with a 15" oval and an 18" oval. I am going to expand it so as to eliminate the 15" R oval, though. I don’t like it and while the locos will run on it, if you ever want anything bigger, they won’t like it much either.
I would avoid a 15" curve at all costs if you can. Stick with a minimum of 18"r curves and you’ll be happier. I wish I had designed it with two 18"r ovals to begin with. I, and my locos, would be much happier.
National Model Railroad Association Recommended Practices, RP11 Curvature and Rolling Stock
It is not necessarily the type of locomotive but also how it is manufactured. I have some brass 0-6-0s that won’t go around 18" very well because there is absolutely no side to side play in the axles. On the other hand I’ve got some eight couples that will probably make a 15" radius with no problem because the axles slop back and forth and/or they have blind center drivers.
As another poster pointed out I have 4-4-0 (AHM - Rivarossi brand) that go around a 15" radius curves with no problems but they look really pretty silly.
IHC makes a really cool Mogul that would seem to be a good candidate to try.