Attached is a basic drawing of the layout I have planned which I am hoping will use mostly "off the shelf" track and turnouts. The layout area will be 20 x 50 and on a 5% grade from the fence (gray line across top of image) toward the bottom of the image and the curved brick retaining wall (red line). The large brown mass at the top of the image is my mountain which will have a water feature. The lattice structure at the bottom of the image is my trestle, and the partial structure above that will be an abandoned trestle and overgrown tracks leading to it. The yard tracks are on 8 inch centers. The faint gray line that is perpendicular to the ends of the yard spurs will be a retaining wall for the yard and also an abutment for the two (1 and a half ) trestles and will be made to look like it was done in several sections at different times during the history of the 'road, starting with an abutment for the abandoned trestle, expanded into a retaining wall for the yard and then into an abutment for the new trestle. The tunnel will be two rows of cinder blocks lined up 8 inches apart (4 inches from track centerline) and will be capped with 16 inch square by 2 inch thick cement pavers. ////////CAUTION!!\\\\\\\\ Stupid Questions Ahead!! \\\\\\\\CAUTION!!//////// I have spent the better part of 4 hours searching the internet today looking for something so simple that I should not have had to search in the first place. I have found several descriptions for the numeric system used to define turnouts. From what I understand, the number is the distance (in whatever units you choose) which must be traveled from the points to a point where the centerlines of the two tracks is exactly 1 unit apart. Example, in a "number six" (#6), six inches from the points, the centerlines of the two tracks will be 1 inch apart. Now here is my question: Is there a way to determine what turnout is compatible with a given radius of track? For example, if you have a 4 foot radius track and you want to split off a straight spur track on the outside of the curve, what number turnout would you use? Is there a turnout whose curved track exactly matches a section of standard curved track (from the same manufacturer at least, let's say Aristo since that seems to be what I will be using...)? What about the other common radii? My second question is, I have a "compound curve" which will be built up of 90° worth of 4 foot radius and then 90° of 8 foot radius. I need to build a "Y" using the 4 foot radius portion of this curve as one leg of the "Y" and 90° of 4foot radius for the other leg of the "Y". Look at the upper right corner of the drawing for the "Y". I would prefer not to have any straight segments in the middle of this curve, so is there a "Y" piece that I could use that would give me the (two) 4 foot radii legs and the 5 foot radius approach or is this a custom piece that would have to be built? Would I be better off to build a lopsided "Y" by using an appropriate standard turnout in place of the last segment of 8 foot radius? I hope my questions all made sense. Please let me know what you think of my track plan as well. 'nother longwinder by DC
Okay, I don't know large scale. The turnouts I know about are HO and N. But here goes... Numbered turnouts do not have a continuous radius on the diverging route and cannot be fitted into a continuous curve. For example, an HO #4 has a 15" minimum radius, but cannot fit in a 15" curve. There are also curved-frog turnouts, not as often discussed in modelling books. These are not the same as curved turnouts, where both routes curve the same way. These are turnouts whose curved route exactly matches some continuous curve. Atlas Snap-Switches in HO are 18" radius curved-frog turnouts. Most Peco (and, I believe, Fleischmann and other European brands') N turnouts are also curved-frog, and of different radii. So are Lionel and other 3-rail O turnouts. I suspect large scale turnouts are curved-frog, but I'm not sure.
