I am planning to build a sectional/modular HO scale railroad - starting with 2 "end of the line modules". each 2' x 4'. Luckily - I think - I started asking questions - because once I understood the geometry of turnouts, I am surprised how much that size constrains the track plan - at least if you stick to any of the modular standards I have seen. For example, assuming 48" minimum radius, and a minimum of #6 turnouts, a through siding with a train station pretty much won't fit in 4 feet. If the standard calls for 6" of straight track before the points at each end, and a #6 turnout is about 11" long, that's 34" the end of a the diverging route of the turn out - and a 9.5 degree arc of 48" radius (to bring the siding back to parallel - about 8" long. So we haven't even gotten to the straight track in front of the station, and we are at 50". Unless I am misunderstanding something pretty fundamental, it seems like on a 2' x 4' module there is mostly room for one - non through - siding.
That makes sense - I am thinking of modeling an LRV using the Piko-American NTCD Sprinter, which is about 18". If my math is correct, I should be able to use a #10 turnout and get a 22 inch commuter station.
