Laying Switches on Curves

OK - I've created a series of screeshots for building curved turnouts. It goes on quite a while, so I hope it's not bad forum etiquette to post the 20 or so pictures. Hopefully, some folks might find the techniques I've been using to create smoothly curved trackwork to be helpful.

[FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]Let's suppose we're starting with a lopsided curve like this:[/FONT]
[FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]BuildCurvedTurnout_01.jpg
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[FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]And what we want is a smooth curve connected by a curved turnout to a new passing track, like this:[/FONT]
[FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]BuildCurvedTurnout_02.jpg

[/FONT]

To build curves with Fixed Track pieces means the angle between the straight tracks needs to be something achievable with curved Fixed Track sections. I use the Fixed Track assets created by bekaember available on the DLS. bekaember has made a wide and sufficient variety of curved and straight sections available. I have downloaded them all, and use them extensively (e.g., bekaember <kuid2:102376:65515:1> Fixed Track str l= 200m). For most radii, curved sections are available in 15, 10, 5 and 3 degree varieties, which I have found to be sufficient for my purposes. But, if your turn simply has to be 17.2 degrees, this technique cannot help you. In this example, the original turn was 30 degrees.
I am only able to build decent curved turnouts from curves that are decent to start with. So, I would begin by replacing the misshapen curve with a proper one. To do this, I would first add a couple spline points on the existing straight tracks, and splice away a portion leading into and away from the misshapen curve. With the portions of straight track deleted, the misshapen curve reverts to being a section of straight track:
BuildCurvedTurnout_03.jpg


Next, I would add sections of straight Fixed Track to extend the snipped-off straight portions at least through a point of intersection, and select a radius of curvature to work with:
BuildCurvedTurnout_04.jpg

I use the Fixed Track assets created by bekaember available on the DLS. bekaember has provided us with a wide and sufficient variety of curved and straight sections (e.g., bekaember <kuid2:102376:65515:1> Fixed Track str l= 200m). I have downloaded all of them, and use them extensively.
For this example, I chose to use a 325m radius (for no particular reason). The above screenshot shows a section of 10-degree 325 meter radius track (10d 325m) connected to the left-hand straight track extension. This connection sets the curved section to the correct angle, and I used the resulting orientation to place the three sections of 10d 325m that will form the needed 30d turn (shown below the other trackwork).
Next, I would "drag" my 30d turn into position. To ensure the final curve has no detectable kinks when driving (I don't like seeing rolling stock "wiggle" at the junctures between track sections), this step needs to be done as accurately as I am able to do it. I will sometimes move underlaying track sections to an alternate layer to make "grabbing" the piece I need to align "easier" (i.e., "possible"):
BuildCurvedTurnout_05.jpg

This close-up shows the desired alignment precision when dragging curves into place. The red arrow is at the end of the right-most 10d 325m section. To the right of the red arrow are the rails from the underlying straight section. The rails of the two sections are aligned at the tip of the red arrow. To achieve this, I first get one end of my curve aligned, and then "nudge" it closer to the correct position by sliding it bit by bit until the other end is also aligned. I zoom in and out to switch between the two ends to check my progress after each "nudge". All of this is done when viewing from directly overhead.
BuildCurvedTurnout_06.jpg

After the curve is positioned, the sectional straight track can be replaced with procedural track. First, I attach short straight sections to the pieces to be removed to mark their end points, and then I delete the longer sections. This screenshot shows the right-hand straight section having been "marked", and the left-hand straight section already having been deleted (leaving it's "marker" behind):
BuildCurvedTurnout_07.jpg


And this shot shows the original straight procedural tracks having been dragged and connected to their corresponding "markers":
BuildCurvedTurnout_08.jpg

Next, I mark the points where the curve joins the straight tracks. I will insert spline points at the marks, and trim away the excess straight track (and delete any remaining "markers"), before replacing the curved sections with procedural track. Any object that has a short, thin, straight post can be used as an end-point marker. I use <kuid2:87907:23317:2> Speed Limit 50 UK. Placing these markers also needs to be done as precisely as I am able to do it. They go right at the very tip of the sectional track red arrows. This screenshot is at a little bit of an angle so you can see the sign. I always view from directly overhead when placing the marker signs:
BuildCurvedTurnout_09.jpg

With the marker signs placed, I can delete the 10d 325m sections that intersect the straight tracks, and insert spline points at the marker signs:
BuildCurvedTurnout_10.jpg

By the way, straight procedural track will sometimes bend when attaching or deleting sections of track. I periodically check to make sure my straight track has remained straight, and if not I use the straighten tool to restore it.

Now I can trim away the unneeded straight sections, and use procedural track to connect the remaining straight sections to the remaining 10d 325m curved section:
BuildCurvedTurnout_11.jpg

And, at last, I can delete the remaining 10d 325m curved section, and replace it with procdural track:
BuildCurvedTurnout_12.jpg

Finally, I have a decent curve to work with in building a curved turnout to connect a new passing siding. Nothing to it!

This next screenshot has a bit to talk about:
BuildCurvedTurnout_13.jpg

Above, I've placed a section of straight track on the right-hand side of the curve and parallel to the exisiting straight track. This section will become the new passing siding. I did not use any particular spacing for the parallel track.
Then, by trial and error, I identified 225m as the radius that brings a curved turnout closest to the new passing siding track. To build this curved turnout, I will have to increase the spacing of my passing siding a bit, so it will align with the right end of the curved turnout track. Using techniques described earlier, it will be necessary to ensure that the left end of the curved turnout sections precisely align with the existing curved procedural track connection, as shown. The curved turnout is formed of two 10d 225m curve sections.

In this screenshot, the parallel spacing of the straight sectional track for the new passing siding has been increased a bit to provide the needed alignment with the right end of the curved turnout. Also, I have replaced the straight sectional track with procedural track (by connecting 5m straight sectional track "markers" to each end, deleting the long passing siding section, connecting the "markers" with procedural track, and then deleting the "markers"). Also, I have added a "Speed Limit 50 UK" marker sign at the point where the right end of the curved turnout will join the passing siding:
BuildCurvedTurnout_14.jpg


Here, I have deleted the left hand 10d 225m section of the curved turnout, and replaced it with procedural track, forming a "real" juction at the left terminus of the curved turnout, as indicated by the presence of a turnout lever:
BuildCurvedTurnout_15.jpg

And here, I have inserted a spline point at the marker sign on the passing siding track, and trimmed off the unneeded bit, and I have deleted the remaining 10d 225m section. This deletion has caused my junction to go faulty, as indicated by the red circle. But, this faultiness will resolve itself when the missing piece of procedural track is added.
BuildCurvedTurnout_16.jpg


OK! The last piece of procedural track has been connected. This is the completed turnout from overhead:
BuildCurvedTurnout_17.jpg

And this is what is looks like from ground level:
BuildCurvedTurnout_18.jpg

In general, I have gotten good results from using sectional track to design my trackwork, and then replacing it with procedural track. Here's a couple screen shots of the "Peerless Cement" plant under construction on my "Susquehanna Valley Railroad" with sectional tracks positioned:
TrackworkInProgress_01.jpg

TrackworkInProgress_02.jpg

And here's "Peerless Cement" with procedural tracks in place:
TrackworkInProgress_03.jpg

TrackworkInProgress_04.jpg

I like good looking, logical puzzle Track work, and you sir, have what it takes.....!

Very impressive, with exceptionally well documented Templates and tutorial exemplars for us to learn how you design complex slip and or Curve Switch assignments..........


I think back in time, I heard something of this type of Fixed Track Work mentioned, or it was something similar by another Author......It escapes for the moment.

Switches on Curves, which is perilous more often than not with kinking issues, suggestive of the particular Track behavior we have all faced.......Be that what it is, I still try to make it work, but nothing near as good as your examples show........

Industrial scene you created looks very professional.........

What a great presentation! Thanks for this; it will be very helpful.

regards,

Blabsky

You're very welcome, Blabsky! I do hope it will be helpful to you. And thanks, Blue, for the positive feedback!

... thankz a lot, GoofusClam57 ... very clear and helpful tutorial ... i will certainly document it in pdf form as a reference .. my analog brains cannot hold it together, but my digital assistant will .. maybe an item for the wiki .. ? ..
most respect
daveric