Derail Confusion

wstevenson94 Apr 1, 2022

  1. wstevenson94

    wstevenson94 New Member

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    I have a 4x8 layout. One locomotive pulls the cars perfectly with no problems. Another locomotive pulls the same cars and there are many derailments from different cars at different locations. The coupler heights are identical on both locomotives and are not a problem on any of the cars. Any suggestions as what may cause this will be greatly appreciated.
     
  2. Hardcoaler

    Hardcoaler TrainBoard Member

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    Are the cars that derail always the first car behind the locomotive? If so, the locomotive's coupler may extend further out than the other, causing it to pull the first car behind it off the rails on curves.
     
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  3. wstevenson94

    wstevenson94 New Member

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    That does happen some of the time, but not all the time. Might be a good place to start. I am pretty new to this hobby so am I right in assuming that I may beed to replace the coupler with a shorter one? Thanks for the reply.
     
  4. Mr. Trainiac

    Mr. Trainiac TrainBoard Member

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    If anything, you will need to replace it with a longer coupler. A shorter coupler will reduce the ability to center over the tracks. The issue arises with longer locomotives because they swing out farther from the track centerline. That basically drags the first car off the tracks when the train goes around a curve. A longer-shank coupler will allow it to reach over, even when the pilot is hanging outside the curve.

    What types of locomotives are you running, and what are your minimum radii? Are your cars weighted to NMRA standards? Plastic or metal wheels? There are many variables at play here, so it can be hard to tell what the exact issue is.
     
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  5. Hardcoaler

    Hardcoaler TrainBoard Member

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    Ah, you're right! I got it backwards.
     
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  6. glenng6

    glenng6 TrainBoard Member

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    wstevenson94,

    Mr. Trainiac asked some very helpful questions. As he said there are many variables involved in derailing. We need information if we are going to be able to help with your issue. Is the loco that runs well, without derailments, shorter than the loco that is experiencing derailments? Exactly which locos are they and what type of couplers are installed? Glenn
     
  7. acptulsa

    acptulsa TrainBoard Member

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    No, not really. What you meant was the coupler box is farther from the truck pivot. A long wheelbase, six axle locomotive is more likely to pull the first car off than a shorter four axle engine because the coupler box hangs farther off the center line on a curve.

    You were right the first time.
     
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  8. wstevenson94

    wstevenson94 New Member

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    These are the 2 engines. I am thinking if may be a problem with the length. The shorter one gives no problems. I do have some 18 radius curves on the layout. Might be time to send the longer one to Ebay. :) IMG_3977.jpeg
     
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  9. acptulsa

    acptulsa TrainBoard Member

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    Try putting a car with body-mounted couplers behind the SD (the Southern engine) and see if you still have problems.
     
  10. Hardcoaler

    Hardcoaler TrainBoard Member

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    Thanks for clarifying my thinking. I puzzled over that very thing for quite a while.
     
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