I have started putting pencil to paper to get ideas down for my new layout and am at this stage specifically started dealing with track layout now that I have a reasonable idea of my best benchwork configuration.
I have been doing much reading (online and the various Kambalch books) and have come across some contradictory recommendations that I can’t seem to reconcile.
Reading various postings on the issue of minimum radius curves I came to the decision to aim for 15" wherever possible, with a minimum of 11" if I am in a tight squeeze. However further reading has suggested that if I ever have ambitions to run some of the larger steam locomotives they will struggle on even the 15" curves let alone the 11". Those stating this say their experience suggests curves of at least 18".
Now, this is where a contradiction sets in. When designing my benchwork configuration my reading made some very good, common sense, suggestions that no point on the benchwork should be more than 2 foot away from its given edge, so that you don’t have to climb on the scenery to reach a far track. But an 18" radius curve means a 36" diameter area + another 6" to allow a 3" clearance on either side, meaning that a turn-back of 180 degrees requires a 42" deep section of bench, thats 3 and a half feet. I don’t know about anyone else, but I don’t have 3.5 foot arms and I don’t want cut-outs and other bodges.
How do you all reconcile the issue of not having benchwork too deep with the need to maintain good radius curves around turn-back sections of track (180 degree curves)?
(Please note, my benchwork is an around the room layout with a spur in the middle, it is not an island configuration.)
AS you are learning, layout planning is trade offs and compromises.
The smallest radius on the mainline determines what you can operate. If you use 11" in one place then the only reason for bigger curves elsewhere is appearance. Keep in mind that mainline, branchline, sidings, yards, etc can each have a different minimum.
Personally I would opt for the largest radius I could fit that also allows for the other track arrangements I want. If you keep turnouts up front, then you shouldn’t need to use a duckunder/hatch very often.
Yes, it almost sounds as if you have two scales mixed up there. I don’t know of an HO mainline layout with 11" curves, so I’m guessing you are referring to N scale. So, when you go on to mention that suggestions are that you should use 18", now we’re into HO. Can you clear this up for us?
What you must do is draw a track system that meets your needs, and then draw a suitably framework around it. That means drawing the benchwork secondly, and then going back when you find problems with the reach or with other aspects, and compromising to the extent necessary to get a happy marriage between space, trackplan, and bench. Don’t be afraid to draw diagonal lines and to have to cut them in order to get it all to fit. Most of us have odd shaped benchwork in places so that we can reach things. Just be sure to keep your faster moving trains away from the edge of the layout, particularly on curves. 4" would be the minimum, unless you provide a sturdy barrier of trees or something right at the edge.
Start with a yard, or with staging, and work your way along with a bench style that offers you operational ability and maintenance. It may require a couple of peninsulas. It is rarely a linear process in layout design. You come up with a general idea, map it out, begin to scale it, and then find that your idealized grade to a logging camp or a mine just won’t fit in the run you had considered. So, you go back, change a curve or tangent somewhere, maybe ease the bench edge if necessary, and then measure how much additional length you have for you vertical easements and the grade proper. At some point you will have it. Move on to the rest of the layout.
You would be quite safe with anything 12" and above. I use 12" as the minimum as I run mainly six axle diesels and long cars (autoracks and passenger).
Happy modelling!
Cheers,
Thanks for this information, how do you go (if you do) with some of the larger steam locomotives around your 12" curves?
12" would work well, as it would permit me to have parallel tracks in some other places as well whilst maintaining a 3" gap between track centre lines around curves (15" outer track and 12" inner track).
I dont model N but anything 12" to 15" radius in N scale will totally be very nice on the railroad because N is smaller and does not require as much. It would be somewhat like trying to make a 32" radius curve in HO and to build that requires 6 feet or a touch more room space.
There is a certain amount of reach everyone is able to have and if you keep the switches within that reach (24"-30" for me at 6 foot) you should be fine.