Does anybody know what my grade would be at 3&3/4 inches high by 6 foot long in HO scale?
a little over 5%
The percentage equals rise divided by run times 100.
Steve S
Your grade would be 5.28169 percent
The formulea is rise (in inches) divided by run (in inches) then multiply by 100.
5 percent is very steep. I have a mine branch at 4 % and only pull 3 cars plus a caboose up or down it.
This seem too steep for mainline running.
Dave
What type of grade you trying to depict? I would think something that steep is more like a roller coster. In all seriousness, aiming for a grade of 3% or less reduces the chances of issues.
Thats fine and dandy if you got the space, but I am working with a 4x8 with a 4x4 side.
Doug
Getting an over/under to work well is a big challenge on a small layout. I suggest that you mount a length of track on a board and test grades with the locos/cars you want to run before committing to a design.
My rule is 2" rise in 8ft of run gives me a just less than 2% grade. I don’t exceed this for my preferred operations. I.E. longer trains and grades on curves.
I have a 3½% grade ending up in a 30” radius and that’s pushing the envelope. I also have a 3½% helix with a 32” radius. My heaviest six wheel truck locomotives (2½ pounds) will pull 30 cars easily but unweighted or stock out of the box locomotives (Proto SD-9/six wheel trucks) wheel slip occures at 13 cars on my 3½% grade.
You would need 107” of track to gain 3¾” at 3½%. A curve in the grade will add friction to the dawbar decreasing the amount of cars towed to wheel slip.
Sorry if we popped your balloon but it’s physics. You might try lowering the crossover track a bit to drop your amount of rise needed, in other words a double grade, upper and lower track.
NMRA clearance in HO is 3”. A ½” rise equals .69% at 72”
Mel
Actually a little over 2% - 2.083% But not enough over to impair your operation.