PC Incorrect Markings On Sggmrss Cars Brake Distributor Cutout Switch

Discussion in 'TSW Troubleshooting & Issues Discussion' started by tygerways#2596, Sep 12, 2022.

  1. tygerways#2596

    tygerways#2596 Well-Known Member

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    Even though the Sggmrss container carrying flatbed cars are marked correctly as to have 2 brake distributors (one for each verhicle in a pair) with a braked weight of up to 36 tons respectively up to 72 tons, the brake distributor cutout switches on both vehicles in a pair are marked as operating axles 5-6 with a braked weight of 36 up to tons, even on the "B" verhicle, that runs on axles 1-4.
    upload_2022-9-12_20-0-58.png

    Today I was able to take a picture of the correct marking on the "B" vehicle, stating to operate axels 1-4 with a brakes weight of 72 tons (I think it was an Sggrss car, but this should not make a difference):
    upload_2022-9-12_20-5-19.png

    Maybe cwf.green can say if this also limits the actual brake performance of those cars.
     
    Last edited: Sep 12, 2022
  2. cwf.green

    cwf.green Well-Known Member

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    The prints are wrong in the game but the physics is right :) It has two distributors and the correct number of brake cylinders (can't remember the number right now, I think it was 2 x 16 inch brake cylinders). The maximum simulated braked weight is 108t, not 32t + 36t (if I understood you correctly) so as in reality. I presume the 32 is a typo of 72.
     
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  3. tygerways#2596

    tygerways#2596 Well-Known Member

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    The 32 tons was a typo of 36 tons, since I was writing about the markings, that are both "36 t max", and should be "36 t max" on one respectively "72 t max" on the other, to get to the max braked weight of 108 tons. Thanks for the clarification!
     
  4. cwf.green

    cwf.green Well-Known Member

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    Each axle in the Sggmrss has the same brake force at tare and above 108t, i.e. the axles are identical (in Simugraph). The wagons are then tuned as tare, 108t and max gross weight to satisfy the corresponding braked weights according to UIC leaflet 544-1. Since one part has two bogies the brake force is automatically doubled. Technically this is not the same as saying that the braked weight is doubled, since braked weight is ultimately a function of stopping distance, but it's probably as accurate as you can get without doing brake tests on the real wagon in all the permutations of partial loading (empty+empty, empty+72t, 36t+empty and so on, that would be 9 tests) and I'm not sure this is even required IRL.

    One potential error is that I changed the proportional load brake adjustment from a pneumatic setup to mechanical (i.e. from a variable brake cylinder pressure to a variable brake rigging moment arm length). Afaik the mechanical setup is much more common on freight wagons in Europe but I could be wrong on this (or on the particular wagon). Unfortunately, as often seems to be the case for me, I got better data when I was already done :D
     
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  5. tygerways#2596

    tygerways#2596 Well-Known Member

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    Really great that you are managing and sharing all this information!

    At least the markings on the car classify it as having a Dako-brake (DK). If you go by Appendix C to the UIC Leaflet 541-04, this brake system should be pneumatic, not mechanical:
    upload_2022-9-13_0-27-20.png

    I am still trying to figure out why the 40 loaded Sggmrss train has such a weak brake performance.
     
    Last edited: Sep 12, 2022
  6. cwf.green

    cwf.green Well-Known Member

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    I'm not so much managing the information as just describing what I programmed. If you asked me about other vehicles that I didn't work on I probably couldn't tell you very much ;) Thanks for the table, that's really helpful! This is one of the things I meant by "usually the good information shows up when it's too late". I actually found an old handbook from Knorr that had tons of data on all the different brake cylinders and types of KE-valves. That's what made me second guess myself about the pneumatic vs mechanical implementation. You certainly confirmed that I was wrong :D

    To reciprocate, here is the link to the handbook if you haven't seen it already.

    Regarding the low brake force on the loaded Sggmrss train, do you mean the 38x train on KWG or is there a 40x train on DRA that I've forgotten about? I'll try to investigate.
    EDIT: Just checked my old thread, there is a 40x loaded Sggmrss train on DRA. Maybe you could compare it against the 38x-L train on KWG (if you have this route). The brake tuning is slightly different.
     
    Last edited: Sep 13, 2022
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  7. tygerways#2596

    tygerways#2596 Well-Known Member

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    Thank you very much!
    Yes, I meant the formation on DRA. I will check out the formation on KWG and compare!
     
    Last edited: Sep 13, 2022

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