Manual Interlocking

Discussion in 'FAQs' started by platypus1217, Jun 27, 2008.

  1. platypus1217

    platypus1217 Member

    I am thinking about rearranging my the yard on my layout. I doing so I end up a crossover, where the two turnouts are related, so that it if one gets changed, the other should get changed. I would like to have it so one switch controls both turnouts.

    This is in N scale and I am using Caboose Ind. 206S ground throws to control my turnouts right now. I was thinking about doing this using bicycle break cable or some other wire in sheath type of contraption to link both turnouts together.

    I was concerned about the tensioning on this. In theory the throw bars move the same amount so when one is fully closed the other should be, but I am skeptical if I am precise enough to make this translate into reality. The one solution that came to mind was using small rods, similar to the ones on Tortoise switch machines. The switch would have a slightly longer throw then required, and then these rods would flex slightly to take up the extra tension and insure that both sets of points were firmly closed.

    Anyway it is all in my head at this point and I would like to know if any of you have done some thing similar or have any suggestions on how to set it up.


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  2. steamhead

    steamhead Active Member

    Platypus...I don't think a manual ground throw is going to cut it....You'd be better off using electrical switch machines and operate both turnouts off a single set of push buttons, so that they are both aligned at the same time. Invariably mechanical linkages need some built in "play" in order to be operable, and the tolerances required for what you are attempting to do won't allow for hardly any "play".
    I have several points on my yard where two turnouts need to be aligned at the same time, and one where three need to be thrown at the same time. I use electrical switch machines and they work great..!!!
  3. MasonJar

    MasonJar It's not rocket surgery

    I think this is doable with mechanical/choke cable control. A couple of things to bear in mind:

    The points move in the opposite direction to "open" or "close" the crossover. Therefore, at some point, a push will have to translated into a pull that occurs at the same time.

    Allowing the rod or cable to flex slightly in order to keep the points open or closed is fine, but what about the opposite direction? That implies a "stretch", which will not happen. Instead put a "Z" bend into the wire. That way it can compress in one direction, and provide tension in the other.

    Perhaps you should try to sketch out what the required movements will be, and build even a paper/cardstock model to see if you can get it to work.

  4. nolatron

    nolatron Member

    Use a humpyard throw. It has linkages for controlling two turnouts on one cable.

    Or as mentioned, go to powered turnouts and use a single toggle switch to control both turnouts.

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