N Scale Gradiants

[Anonymous]

I want to build a layout in N scale (possibly HO9 narrow gauge, not decided which yet, which mimics a zig-zag railroad I've seen in Australia and climbs up a mountainside. Can anyone advise the maximum gradiant N scale locos will climb pulling only a couple/three of short wheelbase cars or wagons.

[Anonymous]

Hello mackenziebs,

The answer depends in part on the weight and type of locomotive doing the work, the weight of the cars, whether the rolling stock is equipped with free-rolling or low-friction wheelsets, and the minimum radius you'll choose (I recommend no tighter than 9.75" for N scale).

The tractive effort (pulling power) of the locomotives you select will be the chief determining factor. Build a test track using flextrack on a straight, warp-free board. Determine the gradients using the formula "rise divided by the run." A 1 percent grade rises 1" over 100", a 2 percent grade 2" in 100", 3 percent 3" over 100", and so on. Start with a 1 percent grade and test the pulling ability of the locomotive with the typical number of cars a train will pull. Increase the gradient by 1 percent increments until the locomotive stalls. Subtract a percent or two to account for friction imposed by curves. You'll have a rough idea of the maximum gradident you can use.

As a rule of thumb, I wouldn't expect to exceed 8 percent grades even with short trains. An exception would be if I were powering trains with a Shay or other geared locomotive; then I'd consider grades up to 10 percent. Most model railroads, aside from logging railroads, don't exceed 4 percent.

Hope this helps,

Paul Schmidt
Contributing Editor
Trains.com

[Anonymous]

QUOTE: Originally posted by mackenziebs

I want to build a layout in N scale (possibly HO9 narrow gauge, not decided which yet, which mimics a zig-zag railroad I've seen in Australia and climbs up a mountainside. Can anyone advise the maximum gradiant N scale locos will climb pulling only a couple/three of short wheelbase cars or wagons.

[Anonymous]

Mackenziebs, did you go forward with the zig-zag? I think it would be very interesting, both to do and to watch as a model in action. Marvin.