I've been contemplating redoing a prominent corner of my layout where I have a dual mainline featuring 22" and 24" radius' to include superelevation. My reasoning is to make it appear more prototypical. And although I know having such sharp radius' isn't very prototypical of itself, the radius' are roughly covering a 90-100 degree curve in my "L" shaped layout design. I'm more or less looking to emulate the picture in my avator.
Some of the questions I'm concerned with involve (1) since both mainline tracks are on the same flat plane currently, would superelevating each independently not achieve the prototypical appearance I'm looking for? In other words, should the dual-mainline be superelevated together as opposed to treating each track seperately. Something I wouldn't be able to do really. (2) my mainlines consist of cork roadbed and track glued to 1/2" plywood, using Elmers white glue. How difficult will it be for me to implement superelevation on track already glued down? (3) Being that the radius' are tight, will superelevating these curves introduce operating problems for me with my rolling stock?
Thanks to the community in advance of answering my previous questions. This is such a great resource for us model railroaders to share information like this!
To start with the last part, superelevation actually somewhat decreases the sharpness of the effect of the curve, so if anything it would make equipment run better thru the curves.
If you haven't ballasted the track yet, it shouldn't be hard to raise the outside ties with shims - lengths of wood or plastic - to create superelevation. You'll want to paint the shims to a similar color as the cork so they don't peek thru the later ballasting.
I think on a doubletrack line normally each track would be superelevated independently, rather than the whole area being superelevated. Otherwise water running off of the outside track would be running into the other track. Doing both separately allows for drainage of each track on it's own.
FWIW I haven't used cork for 35 years. An advantage of a product like upsom-board "Ribbonrail" which I used to use is the roadbed is pre-formed into curves. You can lay the track on top of the roadbed pieces, and then attach strips of wood or plastic under the roadbed to create the superelevation. My new layout uses Kato Unitrack, and I glue plastic strips under the outside edge of the ballast sections to create the superelevation.
Real main lines usually super elevate the outer rail of each line, with the inner rails at nearly the same level (or height). That is, each pair of rails (each line) is superelevated independently of the others.
Once your track and roadbed are glued to the subroadbed, you'll have to beak some glue joints to superelevate.
I suggest you try breaking the track free of the roadbed along the outer ends of the ties, and superelevating 1/32" with shims. Any higher and you may have trouble with cars tipping in toward the center (and possibly rolling off altogether, particularly the forward cars in heavy trains).
If you are running passenger cars or long freight cars, there will be more trouble than with shorter cars. The trucks have to be free to pivot up toward the car ends, as the car is running inside a cone.
Currently I am superelevating 1/16" around my 72" curves, and that height of outer rail causes trouble, with some cars leaning inboard too much. I have used the same setup in the past without problems, and could haul very long, heavy trains up hill without the train toppling. But, extra care was required to "tune" the cars to behave properly.
Nothing looks better than a train leaning into a curve, though, and the effort is worth it, in my opinion. But then, who would use a 72" minimum radius in HO?
The two tracks would be superelevated independently, and, depending on how you've attached the plywood subroadbed to the layout, this could be accomplished very easily. There was a discussion on this HERE. One of my replies to the original question outlines my method of adding superelevation, which requires the use of vertical risers between the layout framework and the subroadbed. While mine are mostly quite long, they could be as short as what would be required only to raise the outer rail. All of my superelevation was done with the cork and track in place, too, as I used a train placed on the various curves to determine when it "looked right".
I also have a section of double tracked line on a curve, but made the mistake of using a common subroadbed, resulting in an unprototypical superelevation. Trains still look good going through the curve, though, and no one seems to notice my faux pas.
Wayne
Robt. Livingston If you are running passenger cars or long freight cars, there will be more trouble than with shorter cars. The trucks have to be free to pivot up toward the car ends, as the car is running inside a cone.
I may run into this situation with my 89' auto racks. Perhaps if I use 1/32" shimms as you suggest, that will suggest enough of the effect for what I want. Also I need to consider that my curved area is on an incline (from -1/2" to level). This may cause trouble as well.
Thanks all for your input!!! All useful information