>4% N Scale Grade=Asking For Trouble?

[southernman]

I have a coal mine I'm about to place 'high up in the Appalachians':)  BUT I am not very experienced with acceptable N scale grades.

 Am I asking for trouble going higher than a 4% grade?  If not, whats the max I can go & still be functional?  Keep in mind I am okay taking only 5-6 car trains up at a time, there will only be 1 destination beyond this point, a lumber mill.

 Thanks everybody

 Lee

[Midnight Railroader]

In my experience, grades are grades, no matter the scale. I don't think you'll be happy with the performance you get with more than a 4% incline.

[cuyama]

Depends on the loco, the cars, and if there are any curves (which add to the effective grade). Bear in mind that you need a vertical transition at each end as well (you can't go from level to 4% grade instantaneously). That may make the run shorter and the grade steeper than you have planned.

You could mock this up with a few pieces of flextrack and a 2X4 to see what the effects of various grades are on the equipment you will be using. Then you would know for sure.

Byron
Model RR Blog

[Jacktal]

4% is the maximum that you should not exceed in any situation.However,there are other factors involved too like the tractive power to start with.Some steam era locos are equipped with traction tires witch can definitely help.Try to avoid long curvy climbs,running short light trains,and you may get away with it.But 4% is steep indeed.

[tgindy]

Construct a "dry run" with some track, engines, rolling stock, and a powerpack -- see what happens.

While some logging railroads and interurban traction did go over a 2% grade -- it would be pushing it to exceed a 4% grade. In the prototype, even the famous Horseshoe Curve did not exceed a 2% grade.

http://www.northeast.railfan.net/horseshoe.html

[southernman]

Thanks everybody!

 I did indeed do a mock up, RESULTS:

 coming off a 3% grade, I can transition to a %6 grade (straight) with 4-5 light cars at a decent but restricted speed, half throttle, Atlas SD9 & even better on an Intermountain F7.

 If I go with this, am I going to be burning motors left & right?  Hey, its only steep going up:)  The down trip will equal out the stress on the engine:)  The wind will cool it down:)

Basically, I'm trying to save the aesthetic of the full 6.25 inches of a Walthers timber trestle, just love the look, and this 6% grade will put me there.  but I dont wanna sacrifice operation.

 Thanks again

 Lee

[Looshi]

Is there any way you can kitbash the trestle a bit to make it shorter? You might be able to shorten one end and put it on a smaller grade.

[dehusman]

southernman

Basically, I'm trying to save the aesthetic of the full 6.25 inches of a Walthers timber trestle, just love the look, and this 6% grade will put me there.  but I dont wanna sacrifice operation

Rather than go up, why not go down?

If you put in a valley you could keep the track flat and still have a full height trestle.  Too many times modelers think the table top is inviolate.

[wjstix]

I would agree with Dave. If you're going to use flat-top construction, you could look into using Woodland Scenic risers to create enough height to allow for your trestle. (They're designed for HO but will work fine with N too.) If nothing else you could use 4" risers in most area, and use their inclines to get up to the 6" on a more gradual grade like 2-3%.

Also, you can build a section of benchwork lower than the benchwork on either side to allow for the trestle.

 

[Mntneer]

 Depends on the loco.  I've got a 3% grade on my layout and a little 0-6-0 steamer struggles up it if it's hauling more than 3 cars, while the GP diesel has no trouble at all.

[CSX Robert]

tgindy

Construct a "dry run" with some track, engines, rolling stock, and a powerpack -- see what happens.

While some logging railroads and interurban traction did go over a 2% grade -- it would be pushing it to exceed a 4% grade. In the prototype, even the famous Horseshoe Curve did not exceed a 2% grade.

http://www.northeast.railfan.net/horseshoe.html

But Horseshoe Curve isn't famous for it's grade.  Saluda Grade in North Carolina is the steepest mainline, standard gauge, railroad grade in North America, although Norfolk Southern did cease operations on it in 2001.  It is a three mile climb with an average grade of 4.7%, and it actually has a peak grade of just over 5%..

[cacole]

 Scale doesn't really matter.  A greater than 4 percent grade is going to place severe restrictions on the type of locomotives you can run and how many cars they can pull or push up that grade.  A geared locomotive such as a Shay or Heisler can usually climb such a grade easier than something like a Consolidation or GP/SD diesel engine.

 

[pcarrell]

Midnight Railroader

In my experience, grades are grades, no matter the scale.

This is true enough, but in N scale it's a bit more of an issue because of the lighter weight of the loco's which further inhibits adhesion.

[southernman]

cacole

 Scale doesn't really matter.  A greater than 4 percent grade is going to place severe restrictions on the type of locomotives you can run and how many cars they can pull or push up that grade.  A geared locomotive such as a Shay or Heisler can usually climb such a grade easier than something like a Consolidation or GP/SD diesel engine.

 

This actually appeals to me, I enjoy the challenge of solving in operations, more to do is a good thing in my opinion.

[southernman]

dehusman

southernman

Basically, I'm trying to save the aesthetic of the full 6.25 inches of a Walthers timber trestle, just love the look, and this 6% grade will put me there.  but I dont wanna sacrifice operation

Rather than go up, why not go down?

If you put in a valley you could keep the track flat and still have a full height trestle.  Too many times modelers think the table top is inviolate.

I DO have 1.5-2" in foam depth to play with, so will plan tonight, small space available though, have some spurs emptying into this area for a small coal yard/processing facility & need to research such industries, especially areas whereby vehicles cross UNDER hoppers for unloading & transport, that would actually be a case for 'dropping' ground level anyway to accomodate the trestle.

[blownout cylinder]

I might suggest stick with 4%---Phil's point re; adhesion ----go with a cut in the benchwork so you can drop maybe 2% down and still have a 2% incline---the effect would be almost the same----if we're concerned more about aesthetics----but I would consider 4% to be max myself.

[tangerine-jack]

cuyama

Depends on the loco, the cars, and if there are any curves (which add to the effective grade). Bear in mind that you need a vertical transition at each end as well (you can't go from level to 4% grade instantaneously). That may make the run shorter and the grade steeper than you have planned.

You could mock this up with a few pieces of flextrack and a 2X4 to see what the effects of various grades are on the equipment you will be using. Then you would know for sure.

Byron
Model RR Blog

 

Yes, this is always overlooked on a model railroad.  It's called a "verticle easement curve" for those who want to know, and it's basicaly a square parabola where the values are based on the maximum gradient, the length of transition, and the minumum curve the equipment can handle (pretty much the point where the couplers will pop off).  Often the verticle easement is the cause of operational headaches, not the grade itself.

Use a 4% or greater gradient if you have a need to, simply adjust your operations to double head the grade, reduce the train length, or other such things.  IMHO it will add a pleasant and realistic challenge to the operation of the layout.