I’m working on my first layout, so I apologize in advance if this is a stupid question that has been solved hundreds of times before.
Here’s what I’m trying to do: Imagine the track is a perfect circle of 22" radius curved track (not what I’m doing, but that’s not what’s important right now). I want a turnout embedded in the circle, with the curved part of the turnout continuing around the circle and matching the 22" radius, and the straight part of the turnout going off at a tangent to the circle.
Is there a ready made product that matches this description?
Is this a foolish thing to do–derailments likely, very hard to build, whatever?
Is this something that will make for an “odd” operating environment, meaning “what the heck would he want to do that for?!”
Would a real RR ever do this?
Here’s what I’m really doing / planning: the tangent would lead off of an oval layout, along a wall to a shelf setup for staging.
Maybe look at the curved turnouts. But the curved turnouts curve the branch so you might have to curve the track to get it to go stright. Below is a picture of one that might work.
Any switch will do what you want, you just need to find a size (4, 6, 8) whose divergent route most closely matches a 22 inch radius curve. While there are standards, they aren’t exact. I’m thinking about 4.5 but you need to check with each manufacturer.
No it won’t. He specified a perfect curve. All north american standard turnouts have a flat spot in them, which requires two points of radius to properly align them. Peco code 100 turnouts are built to European standards and have a curved departure track, these will work in this environment. However, I think even a “small” Peco has a much larger radius than 22", so it is good 22" was just for example.
If you want to maintain the ‘perfect’ curve you might be handlaying. On the other hand, using either a curved turnout or a regular turnout using the straight leg as the diverging track could well get you what you want, close enough. Messing around with XTrkCad or another program might get you a feel for what the different options would look like.
This is one of the biggest reasons that I hand-lay all my specialwork. I lay out my trackwork full size (testing with temporarily-installed flex track) and build it as it was drawn. No searching for suitable commercial products, no compromises and no hassles. On top of that, a hand-laid turnout costs less in $$, and doesn’t take that much more time than careful installation of a commercial product.
Want a single tangent departing from a curve (with a proper easement between?) No problem. Want a six-track yard fanning out from a curved lead, all tracks curving the same way? Happens that I just built one, and am getting started on another (this one with seven tracks.) No big thing.
Peco small, medium and large are 24, 36 and 60 inch radii respectively with the diverging (in your application) track tangent to the curve and they make a curved double radius switch having an inside radius of 30’ and the outer route a 60" radius curve.
Finding something to fit the exact curvature you specified may be the problem. You may want to see if you can fudge things a bit to make a commercial product work, if you don’t want to handlay.
Keep in mind that two things are easy to do with manufactured turnouts that might help you make something fit. You can cut the ties in order to shift the curvature of the diverging routes some, although not a lot. Simply cut the plastic tie strip from underneath near the end of the dirverging end. Carefully work things around to get what you need. I actually had to “straighten” these some near the ends in my case.
With curved turnouts, you can also cut the outside, diverging curved route shorter, nearer the frog. Then take off straight from there. This might help for what you’re asking about, once you find something that is close to waht you need.
The HO Walthers/Shinohara code 83 curved turnouts I’ve used have given me very reliable service in several different radii, even after being hacked a bit.
To answer question #4, real railroads try to avoid using the diverging track of a turnout as part of a mainline curve. They would more likely put the turnout on a straight section of mainline at the end of the curve, even if this creates an S-curve. However, there are exceptions to every rule and I believe I saw one in one of the magazines last year. I’ve found that on a model railroad, using the diverging track of a turnout for a mainline curve is the lesser of two evils as opposed to creating an S-curve. The light weight of our cars make them more susceptible to derailments so I prefer to avoid S-curves whenever possible. Also, using the diverging route of a turnout on a mainline curve can be a great space saver, something that is much more critical on a model railroad than on the prototype.