Helix/Radius Advice

[wmcbride]

I am thinking seriously about re-doing things and that might involve adding a second level involving something I swore I would never do again on an N scale layout: have anything but a flat grade. However, since there are so many pioneering experts who charge ahead with skill and vision (see the BC Rail Ft Nelson Subdivision and RSN48's nolix for example), I figured maybe I could do kind of the same.

My longest cars would be Trainworx and Bluford 86' autoparts cars, Red Caboose centerbeams, and some Kato and Centralia passenger cars.

The space I have for the helix is exactly 36 inches. I know Ashlin Designs has a double-track helix that fits that dimension with 16.5" and 15" track radii on a 2% grade and 15-inch level separation. I would probably be running trains of 15-20 cars but perhaps even longer stack trains using Kato and Deluxe intermodal cars.

I know the larger the radius the better but do you think the 15" and 16.5" radii would be sufficient to do what I want to do?

Thanks for any input.

[basementcalling]

Go 17 inches so you have an inch on the outside just in case of a derailment, though helix issues tend to be inside the curve. The larger the radius the better.

Make sure it's the best laid track on the layout.

[rsn48]

I don't see Tim Horton replying so I'll send you to his layout with the link below, hit on construction, then on the helix which will take you to his construction and measurements of his helix.  I know his works well.

http://www.bcrdawsonsub.ca/

[wmcbride]

Thank you both.

I had looked at Tim Horton's site earlier but I appreciate being referred to it again. His is beautiful work like all you Canadians do in N!

[SD452XR]

I went with 22 and 24 inch radius. 3 inch climb per revolution. I have a 2.17 and 2.38 percent grade. (Inside track vs outside track). My helix has 14 revolutions. My layout also has three decks.

Steve

[nkalanaga]

I'd hesitate to run the long cars on 15 inch radius curves, but then, I haven't tried it.  They will run in 16.5 inch, but as Peter said, make sure the track is (almost) perfect.

You might have better luck than I have on such curves, as most of my long cars have have 1025 couplers.  The 1015s on must of today's models have more side swing.

I wouldn't try mixing body and truck mounted couplers!