I’m working on a 2.25’x4’ N-scale layout. It features a double-track mainline with a crossover on the front and back straight-away. There are also a few sidings which use Atlas N Code 55 #5 turnouts.
I was originally going to use #5’s for the crossovers due to the small amount of space. I noticed that I have room to use #7 or even #10 turnouts on the crossovers.
Any thougths on this? Most track plans I’ve seen would probably tend to use #7’s on the mainline and #5 for sidings. I guess I’m wondering if the #10’s will look disproportionately long compared to the #5’s for sidings - or if they’ll simply underscore that the track is mainline.
Are more gradual turnouts always better if there’s room?
Looking at the local prototype (UP/LA&SL) the local industrial trackage uses #7 and #8 frogs. The mainline turnouts meant to be operated over at somewhat higher speeds appear to be about #16.
If you have room for #10 crossovers, go for it. Not only will it look more prototypical, but your rolling stock will find the S-curve easier.
When you successfully back a 12 car streamliner smoothly through the crossover without going on the ground you will know that the #10’s are the right choice for a mainline crossover or entrance to A/D tracks and passenger yards. You can use #8’s fpr freight yards and #6 for industrial tracks. John
Since we’re talking about a relatively small layout (and probbaly an oval), the entire circumference of the loop is only about 1600 scale feet long. Since a twelve-car streamliner plus power would encircle about three-quarters of the layout, it’s unlikley that backing such consist through the crossovers would be a concern.
I guess this is a case of “to each his own”, but on such a compact layout overall, there is precious little plain straight track – with an 11" minimum radius and double track main, only about 2 feet along each long edge. A crossover made with Atlas #10s will be roughly 30% longer than a crossover made with #7s, using up much of the minimal straight track.
On a larger layout, the decision to use #10s vs. #7s (there are no #6s or #8s in Atlas C55) would be more straightforward. In terms of appearance, in my view the #10s will overwhelm the rest of this layout, (but that’s just my view).
As John Armstrong pointed out, there is such a thing as using too large a radius or too large a turnout number for a given space.
This will be freight traffic. Mostly 4-axle diesels moving 50’ boxcars, tank cars, covered hoppers, gondolas, and some lumber. The three main features are a small yard as a switching puzzle, an industrial area to switch, and an interchange track to pick-up and set-out strings of cars. So no auto-racks or auto-parts boxcars.
Yeah, while it’s appealing to have #10 crossovers it’d probably look silly to terminate a #10 crossover with a 11.25" radius curve.
From Armstrong’s Track Planning for Realistic Operation (which just about every model railroader should own, IMHO), 11 inch radius in N scale corresponds with about a #4.5 frog. In Atlas C55, #5 is as low as you can go …
