One of the interesting aspects of Le Mars is all the split-point derails:
My original plan was to model these by cutting down a standard Walthers turnout and removing the frog. Unfortunately, the Walthers turnouts diverge too quickly, so a little more work will be needed. Since I don’t have on-the-ground measurements, I am relying on estimates from photographs.
Measuring the Prototype
From aerial views, the derails in Le Mars are 25′ or 30′ long:
At the end of the derail, the diverging route is approximately 0.16 to 0.18 of the track gauge:
Fortunately, Walthers provides printable templates for their Code 83 track. Using the #6 template, the above measurements were annotated. At the 25′ point, the rails have diverged 40% of the track gauge, more than double that on the prototype.
My next thought was to modify the Walthers turnout by liberating the diverging rails from the ties and moving them closer, using a PCB tie or two at the end to hold everything in the new place.
Good experiment, but the results were less than satisfying. It took a lot of carving of the molded on tie plates and the diverging point rail has a bend in it that doesn’t quite work well with the smaller diverging angle. Plus – I should have realized this before starting – the ties have a molded-on strip that went under (and was hidden by) the original diverging rail but is now exposed. Doh! Anyway, live and learn.
The next logical question would be, why not use the Walthers #10 turnout? Unfortunately, the #8 and #10 turnouts only diverge marginally less than the #6 at the 25′ to 30′ distance. So this approach is not going to work well either.
The next option is to look at the Fast Tracks system and build the split-point derail from scratch. Again, Fast Tracks provides templates for their turnouts. As it turns out (no pun intended), the #8 is an almost perfect fit for the prototype geometry.
Now, to invest in some Fast Tracks hardware…