Appropriate HO scale grade

[BR60103]

Redrider:
You shouldn't burn your engines out on a grade unless you've added so much weight that the wheels no longer slip. If your grade is too steep the trains should spin their wheels to a stop -- not good for wheels, but safe for the motors.
--David

[Sperandeo]

To add to what Paul said, a lot depends on the locomotives you want to use, and the cars. On my Cajon Pass layout at home, a three-unit Stewart FT diesel can pull more than 40 1940s-era 40 and 50-foot cars up 2 percent grades on 32"-radius curves.

(As a matter of fact that's too much for the way I want to operate the layout, so I'm taking the motors and gear trains out of two of every three units. That way I'll need steam helpers to get up the hill with a train of 22 40-foot cars, which is what my passing tracks are designed to hold).

If you want to run trains of bigger, more modern cars they will probably be heavier, and may take more power. Still, on our MR&T club layout two 6-axle SD diesels can take 30 modern-era cars up a 2 percent grade with 32"-radius curves, although three units have an easier time of it.

A lot depends on attitude as well. I like mountain railroading, so I think grades and the need for extra units or helpers just adds to the fun.

Good luck,

Andy

Andy Sperandeo
MODEL RAILROADER Magazine

[Anonymous]

Hello Redrider,

There are other factors beside train length that need to be plugged into the equation. What's your minimum radius? How many locomotives and what type would be available to pull a typical train? Will the cars be weighted to NMRA recommendations? What era, theme, and locale are you modeling? A train of 30 33-foot twin-bay hopper is going to weigh much less than the same number of 57-foot reefers.

I don't see any major difficulties arising from using a 3 percent ruling grade, although I'd aim for 2 to 2.5 percent just to be more prototypical. For a grade of more than 2 percent I would consider assigning a consist of three powered diesel locomotives (six axles would perform better than four) or a couple of hefty steamers, such as Mikados, Northerns, or Mountains -- or even bigger steam power, depending on the locale and era you are modeling.

A generous minimum radius (28 inches or more) would be preferable, with adequate transition curves. Also, the vertical curves leading into and out of the grades should be accommodating.

Hope this helps,

Paul Schmidt
Contributing Editor
Trains.com

[BentnoseWillie]

With 30 cars or more, say under 2% for mainlines. I have much steeper grades (5.5%), but only on a spur line, and only with trains of 10 cars or less (1 engine).

The wider radius is also wise, as trains of 30 or more cars will introduce some pretty strong coupler forces on sharper curves. You don't want to "stringline" 'em!

BentnoseWillie out -

[Anonymous]

Wow if you think that 30 cars is a modest consist, don't go any higher than 2%. You might want to go with a 1% or 1.5% grade. also make sure that you use a relatively wide minimun radius of say 30".

[Anonymous]

2 percent

[Anonymous]

To any and all...
What would be the maximum grade for an HO scale layout that would not burn my engines out while pulling a modest consist of say 30 cars?

Thanks.