Logging grades.

Discussion in 'Logging, Mining and Industrial Railroads' started by KentBy, Feb 1, 2008.

  1. KentBy

    KentBy GN, NP, SP&S

    Hello, I new to this forum. I am working at setting up / planning my layout which will include logging. I bought a Rivarossi Heisler with two trucks. It is very nice looking and runs very slow and smooth.
    I was testing it last night to see how it will pull on a grade and was some what disappointed. At 4% it will only pull itself. At 3% I could pull two 40' box cars (I don't have any logging cars yet). At 2% I was up to 4 cars.

    The cars used to test were around 3 oz each and the Heisler is about 8 oz. It is a small model so I don't think that there will be any room to add weight to keep it from spinning the wheels.

    What would be the log loads on the prototype operation? How many cars?

    I plan on modeling an Oregon logging operation.

    Also forgot to mention that I would be using HO and that my testing was done on a 4x8 sheet of plywood with the section track (18" radius) just layed out on top.

    Kent Byerley
    Canby, Oregon
  2. Triplex

    Triplex Active Member

    That is disappointing. A Heisler should be able to get something up 7-8%.
  3. NIevo

    NIevo Member

    That is really low. Lots of logging lines were 4%+ grades that they used those on. What model is it?
  4. Jim Krause

    Jim Krause Active Member

    I don't know of any correlation between a models grade climbing ability and that of its prototype but 4 percent wouldn't have been a problem for a two truck Heisler. Did the wheels slip or did it just stall? If its wheel slip then added weight or modifying the loco to use traction tires would be your best bet.
  5. KentBy

    KentBy GN, NP, SP&S

    A little more info on my Rivarossi Heisler

    It is new and only use about 1 hour.

    The track is a basic oval on a 8x4 sheet of plywood with 1 inch of foam board laid on top. The track is snap track with 18 inch radius and is just laid down on top of the foam board. I know none of this is optimal, but this was just a quick test to see what kind of grade that I could get away with.

    I placed various amounts of boards under the one end of the foam board to give various amounts of grade. I placed my digital level at about the half way point of the top curve (18") which seemed to be the highest grade. The Heisler weights 8.2 oz. The cars that I used weighed about 3 oz.

    The hardest (failure to pull) point is always the mid point of the top curve.

    At 4.6 degrees:
    the engine only worked OK.
    with one car there was some spinning.
    with two cars it would just spin.

    At 4.0 degrees:
    with one car worked OK.
    with two cars there was some spinning.
    with three cars it would just spin.

    At 3.1 degrees:
    with two cars worked OK.
    with three cars there was some spinning.
    with four cars it would just spin.

    At 2.3 degrees:
    with three cars worked OK.
    with four cars spins a little.
    with five cars spins a lot.
    with six cars it would just spin.

    At 1.5 degrees:
    with five cars worked OK.
    with seven cars spins a little.
    with eight cars spins a lot.
    with nine cars it would just spin.

    I don't think that there is much room inside to increase the weight by much.

    SO.... Here are my questions:

    Is anyone else using this engine and seeing better grade performance?
    I am also considering buying the Bachmann three truck Shay. Does anyone else use this engine and know what grade performance that I could expect? How much does it weight?

  6. NIevo

    NIevo Member

    Wow, that is really light. Have you tried taking it apart to see if there are some empty cavities anywhere that you might be able to pour some weight in? I know I've seen pourable weights advertised before.
  7. pgandw

    pgandw Active Member


    I'd say you are getting pretty good performance as is. Let's equate your angles to %grades for a fair comparison.

    4.6 degrees = 8.05% grade
    4.0 degrees = 6.99% grade
    3.1 degrees = 5.42%
    2.3 degrees = 4.02%
    1.5 degrees = 2.62%

    Very few model locomotives can haul more than 1 car up an 8% grade - and there are plenty that can't even do one.

    3-5 cars is about normal maximum for a 5% grade without adding weight or other modifications. So 2 at 5.42% is not unreasonable.

    The only unmodified HO "geared" steam locomotives I have seen do significantly better are the Roundhouse "Climax" and the Keystone Shay. And that is because both are much heavier than the Rivarossi.

    The Roundhouse Climax is out of production, and is extremely noisy to boot. It is geared very, very low like the Roundhouse Shay and Box Cab diesel. It has a huge metal frame which makes the shell less than realistic. Most folks end up cutting the frame down to make a better looking Climax. But this reduces the pulling power some.

    The Keystone Shay is a kit - and not a simple one - for which the motorizing portion is also out of production. All the Keystone parts are cast from pewter-type metal which makes it quite heavy for its size.

    I own an early production Rivarossi Heisler (from the '70s). It's gearing is too high, it's mostly plastic (which makes it light), and its scale proportions are as big as any Heisler ever made. It doesn't fit in with my era or other locomotives so will eventually be sold. Otherwise, I would look at remotoring/regearing and adding weight for better performance on my planned 4% grades.

    By the way, the Bachmann Shay is also a model of a large Shay, bigger than most logging railroads used. But it is also the only non-brass RTR geared lokey in current production, and reportedly usually runs pretty well.

    Finally, smooth vertical transitions are critical for maintaining traction, keeping flanges between the rails, and preventing accidental uncouplings. The shortest vertical transition I have seen recommended for HO short cars and locomotives (I won't bore you with the math) is an 8ft radius vertical curve. This is only 5 inches long because we are using a short arc to go from 0 to 3 degrees. But anything less will likely cause the inside wheels on a truck to lose their grip somewhat.

    my thoughts, your choices
  8. NIevo

    NIevo Member

    Wow, good catch, I didn't even realize he was using degree's, I assumed he was talking about the grade percent. For the locomotive weight I would say it is doing well.
  9. Triplex

    Triplex Active Member

    Okay, now that performance doesn't look so bad.
  10. sumpter250

    sumpter250 multiscale modelbuilder

    The Bachmann HO 80 ton three truck shay, is based on Cass Scenic Railway #5, which I believe, was owned by the Mower Lumber Company (which became Cass Scenic).
    The model weighs approximately 14 ounces. I have not tested its pulling ability on grades, but I'm sure it will pull, at least, slightly better than the Rivarossi Heisler.
  11. KentBy

    KentBy GN, NP, SP&S

    Thanks, Fred.

    It has been awhile sense the last time I use Trig. I forgot how to use it in the real (or model) world.wall1

  12. sumpter250

    sumpter250 multiscale modelbuilder

    :mrgreen: :mrgreen: :mrgreen:

    Yeah, I'll bet it was one of those " I'll never use this again" moments. :mrgreen: :mrgreen: :mrgreen:
  13. MasonJar

    MasonJar It's not rocket surgery

    A potential compounding factor (math pun not intended ;)) is that you are running a grade on a relatively tight (18" radius) curve. The added friction on the wheels going around the curve will also reduce your performance as compared with a straight track on a grade.

  14. KentBy

    KentBy GN, NP, SP&S

    Is there a formula for grade == curve?

    I am still trying to work out a track plan and had been think about 15" radius curves. I would reduce the grade before entering the curve. I have some 15" section track, so I will be doing some testing with my Heisler.

    Also I will be doing some testing on how to make a engine turn-around at the top of my logging site, or should I just run the engine backwards on the return trip?

    My current plan is to run the loaded log train around a wood trestle that goes by the mill and pond. After the log dump off the end of the trestle the train would pass behind scenery into the top of the logging operation (out of side of someone standing at the mill.
    I would have to disconnect from the cars and then back the engine down around the trestle into a wye for the turn around. Back again around the trestle to pick up the empty cars (hidden in the logging area) and then again round the trestle and then down the tracks before making the grade up to the logging area.
    I know this would be a lot easier to understand if I posted a picture, but I don't have one yet.

    Boy, I guess I should work on a sketch and then re-post this.

  15. pgandw

    pgandw Active Member

    There was a theory by John Allen that stated the effective increase in grade caused by curve = 30/r, where r = curve radius. This would mean a 15" radius curve is the same as a 2% grade by itself, and would add 2% to any grade that the curve was on.

    I have no idea what experiments, if any, the formula was based on. Since Allen proposed the formula trucks have gotten a lot more free-rolling. Personally, I believe there should be a real increase in effective grade at the radius at which wheels have to slide instead of roll to compensate for the extra distance traveled. The standard RP25 wheel tread taper of 3 degrees can compensate for curves to radii somewhere in the 20"-30" range, depending on how far up the flange fillet you allow. Curves sharper than that require the wheels to "slide" as they go around the curve, driving up friction significantly.

    just my thoughts
  16. KentBy

    KentBy GN, NP, SP&S

    Well now that I understand more about measuring.

    I have retested my Heisler and converted to max percent grade without spinning the wheels.

    Tested on straight track
    Engine with zero cars.... 11.4
    with one car....... 8.0
    with two cars..... 5.9
    with three cars... 4.9
    with four cars..... 4.0
    with five cars..... 3.3
    with six cars...... 2.1
    with seven cars.. 2.1
    with eight cars... 2.1

    Tested on 18" curve track
    Engine with two cars..... 7.5
    with four cars.... 5.1
    with six cars...... 3.0
    with seven cars.. 3.0
    with eight cars... 3.0

    Tested on 15" curve track
    Engine with two cars........ 6.6
    with six cars......... 2.6
    with seven cars..... 2.6

    With this testing I think that I can use 1 to 2 percent grade on curves and 2 to 3 percent on straight section.

    I put the conversion for degrees to percent grade into excel to figure all this numbers out. Then I got to looking at my level and it has a button to convert to percent grade on it. :oops:

  17. pgandw

    pgandw Active Member

    Results really look pretty good. Interesting that it does better on curves than on straight. Must be the extra friction the wheels are able to generate rubbing against the rail sides. I'm guessing that the track gauge on your straight track is the wide end of the NMRA tolerances. I wonder if straight track closer to the narrow end of the tolerances (ME flex track) would increase traction slightly. An experiment I'll have to try soon.

    Thanks for the report.
  18. NIevo

    NIevo Member

    I think the testing for the curves was done on level track? Otherwise I think he would have listed the grade for the curved test.
  19. KentBy

    KentBy GN, NP, SP&S

    Ok, here is my test setup.

    On a 4x8 sheet of 1/2 plywood with 1/2 inch of foam on top. I setup an oval of sectional track with straight on the side and curved across the top and bottom. The first piece of curve track is 18" and all the other curves are 15".

    I just check the track with my gauge and the 18" curve has some tight spots in it, but the straight and 15" pieces look OK.

    Now for my testing I put blocks of wood under one end of the plywood and started out really high. Ran the test and measured the angles.
    Keep in mind that the angle on the curved sections were measured with the level being parallel to the ends to that section and the thickness of the wood under the end is not guaranteed to be perfectly level, but the angle that I measured was at the place in the track that the engine was at. Another thing to keep in mind is that when the engine enters the curved track the cars are still in the straight track. I don't know how to judge that.

    Another thing to keep in mind is that my blocks don't represent all possible angle. I didn't publish the numbers I got from "slips a little", "Slips some", "slips a lot" and "spins/stalled".

    I have those numbers if you want to see them, but I thought that the only important one is the one without spinning the wheels.

  20. Triplex

    Triplex Active Member

    Geared engines could run equally fast (er... slow) in either direction. You don't need to turn it.

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