help with hump yard operation

Discussion in 'FAQs' started by Wolv33, Sep 20, 2002.

  1. Wolv33

    Wolv33 Member

    Hello everyone,

    I am faced with a dilemma that hopefully someone can help me with. I have a humpyard and want to simulate the actual master retarder process of slowing the cars down before they hit the secondary retarders, but still having enough momentum to make it to the classification yard.

    Does anyone have any ideas on how to do this?

    I looked into the idea of using Kadee electric magnets, but people have told me that the car's weight would probably not slow it down any.

    I also was interested in using the DelAire compression system for simulating track retarders, but even DelAire was less than helpful with the idea and process.

    Any help is greatly appreciated. Thanks in advance.
  2. Jim de Bree

    Jim de Bree Member

    Hey Wolv:

    I also replied to your post at There is an old Model Railroader Video Tour video tape that Allen Keller did before he left MR to start his own shop that goes into this in great detail. Although the tape is nearly 20 years old by now it probably still contains some helpful info. My recollection is that the tape demonstrated operation and also showed how it was constructed.

  3. Gary Pfeil

    Gary Pfeil Active Member

    I haven't seen one that worked well. The Model Railroad Society in Carlstadt NJ has (or had, been years since I was there) a hump yard using compressed air to retard the cars. It's a novelty type of thing to my way of thinking. Bear in mind that all cars have different rolling characteristics. And the mass or weight of the real railroad cars versus the friction they face doesn't scale to our models. This club had installed small pipes facing toward the hump on each track, and as the car rolled down, the air was turned on for that track. The result was often unpredictable, with some cars coming to a complete stop and actually rolling back uphill, then with the air turned off, resuming their downhill trek. sometimes the operator missed the car and it slammed into the other cars further down the track. Sometimes the car was a poor roller and once air was applied to slow it, it just stopped and stayed stopped, so the next car would slam into it before reaching the air jet. When it worked, maybe 50% of the time, it was pretty cool. I would think they kept a coupler repairman pretty busy! I had read of plans The Model Railroad Club of Union NJ had to build a hump yard more nearly level which would roll the cars down the modest grade by means of some tecnique of vibrating the track. Don't know if this was tried or how it worked out.

    Good luck! Gary
  4. Jim de Bree

    Jim de Bree Member


    i think that you are right. This was a novelty type item and it is my recollection that in the MR video the owner of the layout used standardized 40 ft box cars for the yard. However, at least on the video it seemed to work well.

  5. Wolv33

    Wolv33 Member

    Thanks guys. Your replies are much appreciated.

    I was thinking of just rolling the cars down the hump without any retarder control, but wasn't sure they would get damaged or not.

    I used a test track coupled with pier and trestle pieces to elevate the track, and all my cars that I tested made it into the classification track. However, I feel that a retarder control is still needed to avoid possible damage to couplers or worse.

    I will keep pluggin' at this dilemma though. Thanks again.
  6. cidchase

    cidchase Active Member

    Hey Wolv33,
    A metal wheel rolling thru a fixed magnetic field will be retarded in proportion to its speed. It happens because the rotation tries to generate an eddy current in the wheel. The mass of the wheel and the conductivity of the wheel material also changes this effect. Whether or not the force generated is enough to slow the car would have to be determined by experimentation. You would need to have magnetic poles on opposite sides of each track and down low enough for clearance under the car. Sort of like having two Kadee uncouplers, one straddling each track. Would definitely take some real fancy fiddlin'. The good point is that if you could make this work, it would be self-compensating for the velocity of the car. If you could make it work good enough, you could generate a magazine article:D :D :D
    Coin telephones use this effect to get slugs to roll past a magnet faster than the real coin, thus rejecting the slug. A least they did some years ago when I had the pleasure of working for Western Electric. Hope this isn't just a wild goose chase, but it may be workable. Well, you asked....
  7. Wolv33

    Wolv33 Member

    Thanks Cid.

    At this point, I am willing to try anything that works.
  8. Rusted

    Rusted Member

    Did you ever get any farther on this?
  9. rockislandmike

    rockislandmike Active Member

    I'm not sure Wolv hangs out here very often anymore, but I am in touch with him through other channels. He's still working on the problem, has a variety of ideas that he's not sure any of 'em will work effectively.
  10. tomfassett

    tomfassett Member

    His idea of "working on it" is to harrass me to figure it out... ;)
    The only thing I have been able to come up with is an opto sensor system feeding a "time to voltage" converter contolling an electromagnet. If it sounds complicated, that's because IT IS! That's why I haven't built it... :D I'll get to it when I retire (maybe--don't hold me to it...).

    Tom F
  11. RailRon

    RailRon Active Member

    In my former H0 model RR club we built a hump yard and tested also all the versions of retarders already described.

    Finally we used yet another system: We glued fairly stiff bristles from a brush between the rails. They reached up to the axles and slowed the passing cars down. The more bristles, the higher the braking effect. :cool:

    It took an awful lot of fiddling with bristle number and height to get satisfactory results.
    Further on, every car we used on the yard had to be the same weight and 'free-rollingness'.
    And third, these tracks were strictly forbidden terrain for locomotives. We learned the hard way: After adjusting one track fairly well, somebody drove the switcher down that very track to haul back the cars to the hump for another experiment. The loco started to act strangely and finally stood still. You guessed it - all the bristles were distributed between the gear wheels of the loco. :eek::mad:

    Result: After almost half a year of experiments we rebuilt the hump yard as a flat yard. :(

    Perhaps there really IS a good method to do it. Sorry to say, but this one doesn't work out either...

  12. eightyeightfan1

    eightyeightfan1 Now I'm AMP'd

    Amherst Model Railroad Scociety has an operating hump yard that they set up at teh West Springfield Mass show every year. They use air for retarding the cars. Its a blast to watch.Could stand there for hours.
  13. MCL_RDG

    MCL_RDG Member

    Here's a way to do it but... has caveats*- Read on. I thought of this on the spur of the moment. Seems someone suggested this previously- sorry but I think this warrants exploration other than a "didn't work". It will with enough tinkering.

    'Magine a steep enough* (modeled) hump- properly weighted cars*- and up from the bottom- between the tracks- OH Man! I think I might burst at the thought- hairs (paint brush type- light fibre) that look like weeds sprouting uP thru the tracks yet offer light resistance as they "wipe/tickle brush" the trucks/undercarriage. Depending on your skills and acceptance of the "BAM" (Move over Emeril- we {Blake and I} invented "BAM") might be able to contrive an acceptable result.

    Mind you- this is off the cuff, I call it the MMR/TBH. MMR-Tickle Brush Hump. Explain that to the YL*!

    With courtesy,

    Mark :rolleyes:
  14. 60103

    60103 Pooh Bah

    If I remember the article in Model railroader from decades ago (was it Cliff Robertson?), he was using air and determined that a fixed length of time for the air blast was enough -- the fast cars got more retarding and the slow ones less or none.
    Maybe you could mount the bristles on boards and raise and lower them.
    I was in a prototype hump yard and, although car weights were programmed in with the tracks, the tower man would occasionally add extra retardant when a car came down too fast.

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