Model Forum / General / Railroads / June 2006

Some thoughts...

First, grade is independent of scale.  A rise of say 1/4" per foot is the
same grade in O scale as it is in N scale.

Next, this sounds like a cliche, but it all depends... A curved grade pulls
harder than a straight one, so you sould have to account for that.  Your
train length and locomotives would be a good determining factor as well.
How high do you "need" to go?  If you are doing a cross-over, I'd guess
something around 2" would be enough clearance.

I'd set up a piece of track on an inclined board and do some test runs.  The
1/4" per foot I mentioned before would be about 2%; a half inch per foot
would be around 4%.  I would think that anything much steeper than that
would look "toy-like" UNLESS you were modeling a rustic lumbering line.  In
that case, steeper grades would usually be the norm.  Like I said, it all
depends.

One other thing that you want to consider when creating your grades...
transition.  When I built my layout, I didn't account for this and had some
real troubles.  Here's what happens... if you don't allow for transitions,
your locomotive is moving along then the front end suddenly kicks up onto
the grade.  This causes the back end to drop and if the couplers of your
locomotive stick out some distance, they can drop far enough to cause the
car to uncouple.  The same thing in reverse happens at the top of the
untransitioned grade.  The locomotive tops the hill and the rear end pops
up, again, possibly enough for the cars to come uncoupled.  So make sure
that your inclines are flowed into and out of smoothly.  If at all possible,
try not to have a track joint at either the beginning or the end of the
incline.  Flex track comes in real handy here.

If you are having trouble understanding the transition I'm talking about,
think of it in terms of driving your car onto an incline... if the incline
starts abruptly, the front of your car goes up and the back end drops down,
sometimes dragging.  That is about the best I can describe it w/o being able
to attach a drawing.

So get out those cars & locomotives and see what works well for you.  Good
luck!

dlm

First, in any scale, grade is rise/run x 100, which gives you the
"percent grade." thus, 1% means 1 foot in 100 feet, or 1/4" in 100 x
1/4", which is 24.5", or about 1/8th of inch per foot.

Second, in any scale, including full size, grade affects how much the
loco can haul, and the effect is drastic. Real railroads try to keep
grades around 1% or less if possible, but even a 1% grade will reduce
the hauling capacity of a loco by 30 to 50%. That's right: _half_ as
much as on the level.

As for N-scale: if the locos have traction tires, you can easily go to
about four percent (ie, 1/2" per foot) and even more. If they don't have
traction tires, stay at 2% or less if possible (about 1/4" per foot.)
You need about 1-1/2" clearance from railhead to overhead obstruction.

Dan Merkel's answer also has good advice.

HTH&HF

When I built my small 2x4 N-scale layout, I bought some foam risers and
inclines from Woodland Scenics and experimented with the inclines.

On a 2x4 layout, the loco would barely pull itself up a one inch incline in
that short of a distance. It couldn't maintain traction and would spin the
wheels all the way up.To make matters worse, when it started down the
incline, it was like watching a roller coaster.

I finally decided that half an inch was as good as it was going to get. The
loco pulls it nicely and it doesn't have the roller coaster effect. It isn't
much, but it at least gives variety to the terrain.