I am just designing my layout to be and have a limited amt. of space to do it in and want to know what is the minimum radis I can use for a double track Helix for N scale Thanks for you suggestions…
David
That depends on the kind of equipment you will run. If you want to be able to run any size wheelbase, I suggest a 15" radius as an absolute minimum. If you are only going to run short (50’ or shorter) cars and four axle locomotives, you can probably get away with a 12" radius. Grades for a helix can be expected to be in the range of 1.5% to 2.5% which can have a significant reduction in pulling power when coupled with tight radi.
Runfastcc
Thank you for your response I have approx room for a 15 inch radis any ideas hoe to construct is there plans i can get from some where???
David Hanlin
This was something that I faced on my last layout. I found the 15" a tad tight, and ended up going 17". Using advice from NRMA members, I finally made it the shape of an upside down twisted cone - this gave me opportunity to scenic the bottom levels, making the benchwork, and consequently the run, longer. I wonder whether double tracking a helix in N is such a good idea as the space between level is usually a little over 1", how do you get at the inside track if the worst happens? Just a thought, you might be a neater track ganger than me!!
Good Luck
David Stokes