Track Elevation

That's 4/72 = 5.55%.

I believe so. A friend and I built an 8.5% grade on which a Bachman shay doubled with a brass 4 truck shay will handle 6 cars. I don't recall what the Bachman will do by itself. We arrived at this grade by putting about 6 ft of track on a board and elevating one end. At

10% (our original target grade) a weighted brass shay would just pull itself up the grade. When the power was off it slid slowly down the grade. At 9.5% any vibration would cause the engine to slide downgrade. At 8.5% the 4 truck shay would handle 4 cars. NS track and plated wheels (whatever was stock on brass imports).

If you start down our 8.5% grade with too many cars, you'll reach the bottom whether you run the engine or not ;-)

Grades in excess of 9% were common especially off the main line. Cass Scenic RR in WV (which was Mower Lumber Co in the '50s) has such a grade on an S curve which works out to the equivalent of about 11% on straight track. Also another grade entering Bald Knob is about 13%. A grade of 5% would be very prototypical. Also, normal practice was to have the engine at the down hill end of the train.

Even if you don't have a power supply, set up 36 inches of tangent track on a board with 2 inches of elevation at one end. Put your Climax or Shay at the top of the grade and give it a light push with your finger and see if it slides down the grade. If it doesn't, increase the grade until it does, this will give you the absolute maximum that your grade can be. Try the same experiment with two or three cars in front of the loco. As Fred wrote, when the loco is under power and working, vibrations set up will cause slipping at shallower grades, but the above experiments will give you a bit of an idea as to your limits. Bill.

doubled with a brass 4

itself. We arrived at

end. At 10% (our original

When the power was off

engine to slide downgrade.

(whatever was stock on

bottom whether you run the

Scenic RR in WV (which was

out to the equivalent of

about 13%. A grade of 5%

at the down hill end of

Just curious, when the shay slid down the grade was the drivetrain (i.e. wheels, gearing and motor) (A) turning or (B) was the shay sliding with the wheels not truning at all. If (A) then that must be one slick and smooth mechanism.

Cheers, Bill S.

Fred and Bill,

Thanks So Much!!!

I will try the slide test to determine a maximum grade for four cars and the engine. This is great. It opens the door for some fun ideas that I had been toying with to create a RR scenario that would make perfect use of our Bachmann Shay. An interchange between the main line and this mountain dweller will generate all types of interesting car exchanges.

Matt

doubled with a brass 4

itself. We arrived at

10% (our original

the power was off

A locomotive with all wheels powered, like a Shay, will barely climb a grade equal to its adhesion. Adhesion for prototype locos is roughly 25% and for models (nickel-silver wheels and rail) around 21%, so a model Shay should be able to climb a 21% grade. If the rails and wheels are not absolutely clean, it can be a lot less. Even denatured alcohol and lacquer thinner (not recommended for cleaning track and wheels!) leave enough residue to drastically reduce adhesion, even though they are quite volatile and evaporate quickly. Forget-it if you use Goo Gone or Wahl clipper oil. Of course, the prototypes can sand the rail and that can increase adhesion above 25%.

I have a 7.1% grade on an outdoor G gauge layout and I routinely pull 10 cars up it with my Bachmann Shay. Sometimes I clean the tree sap off the rails with denatured alcohol or lacquer thinner (I take my chances), then the Shay can barely pull itself up the grade. A few hours later it is back to normal (I guess the residual traces of solvent evaporate).

Paul Welsh

Might someone have an idea as to how you could accelerate the evaporation process?

I don't anticipate exceeding a 5% grade in my planning, but your 'residue' concerns do change the numbers enough so that I am curious if there are other methods of cleaning track that people have used.

Paul,

That's why I find it hard to believe an HO shay would "slide down" a 10% grade under any conditions.

Cheers, Bill S.

I think just running the train gets rid of the residue.

Anyhow, it's not an issue with a 5% grade. On a 5% grade, a train much longer than 5 to 10 loaded log cars isn't prototypical. So you needn't worry. It's more important to have consistently weighted cars and well-laid track. You can go with up to 50% lighter than NMRA's recommended weighting _if_ you have well-laid track. (If you mix loaded (heavy) and empty (light) cars, always put the lighter cars at the end of the train, to reduce the risk of "string-lining" on curves.)

Anybody know how Aero-Car's rail-cleaner affects adhesion? (I don't have a grade on my shelf layout.)

HTH

Since you don't have a power supply, if you are in HO, just touch the terminals of a 9 volt battery to the end of the track and the train will run.

The engine slide without the wheels turning.

I think I got the attributes right.

The track for the test that I described in an earlier post was Atlas code 100 straight from the box so it probably had mold release residue on the rails. The Shay had no wear on the wheels and had not been tuned up but ran pretty well anyway. The owner is pretty strict about proper and very careful lubrication so I suspect that the wheels were free of any oil residue. However, we did not clean the wheels or the track IIRC. It's been about 6 years since we did the experiment.

The owner banned Goo Gone and Whal clipper oil from the RR eons ago.

It did in fact slide slowly down grade with the power off. Maybe the last vibrations as the motor stopped pushed it from the static to dynamic friction coefficient. The wheels were probably sliding before the motor stopped so it never did have static friction in play.

Assuming 10%, seee below.

Assuming the code 100 track was a piece 3' long (i.e. 36") then the grade to be

10% would have to be an incline 3.6" higher at one end from the other.

Cheers, Bill S.

straight from the

on the wheels and

about proper and

residue. However, we

did the experiment.

I'm not surprised that the loco slid down a 10% grade. It is surprising how large an adhesion loss can be caused by a little contamination.

You are probably right that the residual production oils on the new track caused the big loss in adhesion. When I did some adhesion tests on my HO locos (typical values around 21%), I first cleaned the rails and loco wheels with denatured alcohol, then polished the rails with a Bright Boy, then cleaned the Bright Boy dust off with a cotton swab.

For routine track cleaning, I use a Masonite board car--no solvents or oils. I clean the loco wheels with denatured alcohol.

Paul Welsh