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Grade

Started by fhenn, April 11, 2014, 07:52:06 AM

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fhenn

I have got track on order, and several bags of crush rocks standing by. The spot I want to place the track has about a three inch drop over six feet. Will this grade be too much, or do I need to build it up. Thank You

Joe Satnik

Dear fhenn,

Well, here's the math:

6ft x 12"/ft =72"

3" drop/72" ~= 0.042 = 4.2%

Sounds a little steep.

I'll let others more knowledgeable comment.

Hope this helps. 

Sincerely,

Joe Satnik
If your loco is too heavy to lift, you'd better be able to ride in, on or behind it.

armorsmith

I would prefer to have a bit more information before I make any judgment. Here are a few questions to help evaluate your question.

1. Are you planning on running long trains with mainline diesels (AristoCraft or USA Trains)? Or are you going to run short trains with steam power or small box cab diesels (Bachmann or Hartland)?

2. Are you going to run a switching operation or just watch them go 'round in circles?

3. Track power or battery?  Possibly steam?

Off the cuff I would agree with Joe, that is a considerable grade.  Most of us try to keep grades at 2% or less. Some do run more, but the steeper the grades the shorter the trains you engines will be able to pull and the faster they will wear out.

Happy railroading!

Bob C.

fhenn

At this time I am going to use the Bachmann steam sets, and use track power. At first I will do the circle thing with one siding (back in) and one pull through siding.

Chuck N

How many cars are you planning to pull?  A stream engine will handle a 4.2 % grade.  By itself.  The cars being pulled dictate what you can pull.

Chuck

fhenn

No more than five including the tender

Chuck N

#6
That should work, but it will also depend on any curves and diameter of them on the grade.  Ball bearing wheels will help.  You may have to experiment.  There really are no hard and fast rules.  

You haven't said what type of engine you will be running.  Different style engines have a wide range of tractive effort.

Chuck

Ps. I have measured the tractive effort of some of my engines, on level straight track.  It ranges from about 25% (LGB Mogul) of the engine weight to about 40% (USAt F3A).  Any grades will reduce it.

tac

IMO, unless you are running a Shay, that is going to be a killer grade.  Rod locos hate grades much above 2-3%.  On the straight, many will manage a shorter than usual consist, on a bend, but with the added resistance of the curve, figure on no more than 2%.

tac
Ottawa Valley GRS

Loco Bill Canelos

Glad to see you have construction under way!!  The grade business can be tricky as the other responses have shown.  

Grades are bad just like the real railroaders found out.  If you have to have a grade keep it as low as possible(my personal rule of thumb is 3% MAXIMUM).   I have always regretted going over 2%.

The only thing worse than heavy grades are heavy grades on curves.  Almost always causes trouble for steam engines.  Diesels with 4 wheel trucks(and no traction tires) do much better on grades and curved grades.

You will regret it even more if you end up in a situation where you have to back your train up a 4% curved grade with truck  mounted couplers.

I know this because I am 74 years old and have been model railroading for 67+ years now and have made every mistake in the book.  I did better when I got older because I started believing what the other guys were trying to tell me.  

Remember to have fun and if you do not like your steep grades, all is not lost because you can in most cases redo them.

Bill
Loco Bill,  Roundhouse Foreman
Colorado & Kansas Railway-Missouri Western Railway
Official Historian; Bachmann Large Scale
Colorado RR Museum-Brakeman-Engineer-Motorman-Trainman
There are no dumb or stupid questions, just questions!

fhenn

Thanks for the help, and fine advice , gentlemen. I am going to build up the area in question, lay out the track, and run the equipment. If all works fine I will pull the track up and lay in the roadbed. The Loco's that I will be running are the Bachmann 460's tho I do have an old LGB set from the early 80's that I bought at the York meet

Chastity

Fairly step for electric, for live steam hope you hsve
oven mitts.  Even at 2.3. % live steam with a heavy train is a breath holder.

Dave

Thought I might put my two bobs worth in here. I have a 3% grade on an 8 ft curve and my Annie will pull 3 coaches and a box car up, on a good day. You could add 1/2lb of lead ballast to to the Loco and get extra traction but that only loads up the drive gears which are not keen on that sort of extra effort. I have a 5% grade on my Logging track and the Shay and Climax pull 5 to 6 log cars up with little trouble. The 10 wheeler struggles to get up that sort of grade with 3 pieces of rolling stock.
  My newest creation,a Garrett, will pull 14 cars up a 3% grade, but at a price. The Garrett is over 3ft long and Heavy.
    Ive only been into Railroading for 50 years+ and have lots more to learn, but I would recommend that you keep your grades as gentle as possible.
              Cheers
                  Dave

Kevin Strong

As a long-standing "generally accepted practice" for large scale, it's recommended to keep grades under 4%. That seems to be the point between "pulls without trouble," and "won't pull its own shadow" in terms of locomotives. On my dad's railroad, most of the grades are 4%, and we run 6 - 8 car trains all day long on that with a variety of "typical" large scale locomotives, both on my dad's roster and those belonging to his regular operating crew. As others have written already, if you're running tight curves, or want to run long "modern" trains, then you'll want to keep your grades even less.

That having been said, grades do the same thing to model trains that they do to the real ones. You've got to keep your hand on the throttle when running up and down grades, or the train will stop going up and/or speed up terribly going down. If you're building a railroad where you're going to want to just sit back and watch your trains run around the garden, then you're going to want to minimize your grades no matter what kind of trains you run. That keeps the speeds even as it runs around the garden without any input from you as they do.

The other thing to consider with steeper grades is that some locomotives don't like running down them with a heavy load behind them. It introduces "surging" where the weight of the train works against the worm gear on the locomotive, causing it to run very unevenly as it descends the grade. While not much of an issue on the 4% grades on my dad's railroad, he's got a long section of 5%+ where it does become a factor. If that is an issue on your trains (and it depends on how the gears are designed in the locomotive), then the solution is oddly the same as going up--shorten the train so there's not so much weight pushing the locomotive down. (Or, figure out a way to introduce some drag on the train; working brakes or similar.)

One last thought--you hear a lot of folks talk about the difference between "geared" steamers and "rod" steamers. That's a distinction that holds true only in the prototype world. In the model world (in terms of electrically-powered models), they're all geared locomotives. The difference between how one locomotive does on grades vs another has nothing to do with the prototype being modeled, but how the drive that goes between the electric motor and the axles is designed. The higher the gear ratio, the better the loco will be able to handle changes in grades. High gear ratios give you power at the expense of speed. Low gear ratios give you speed at the expense of power. In large scale, a locomotive with a low ratio like 15:1 ratio (for every 15 turns of the motor, the axle turns once) will be more susceptible to changes in grades than a locomotive with a 30:1 ratio. It's very plausible to have a model of a "rod" locomotive outpull a model of a "geared" locomotive because of how the gears are designed. (Note: in the automotive and biking world, "Low gear" refers to those gears with high gear ratios, while "High gear" refers to those gears with low gear ratios.)

Later,

K