Searchlight Simulations Bnsf Sd40-2 Power Bug

Discussion in 'Technical Reports' started by diesel power, Apr 12, 2024.

  1. diesel power

    diesel power Member

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    Hi! i have a big problem with the SS bnsf sd40-2 bundle. The locomotives do not deliver consistent power at a given notch. for example when i first introduce the throttle at a given notch , waiting for the train to accelerate to a given speed , then back to idle, engage the brakes , coming to a stop , and after again release the brakes , and advancing at the same notch, to start accelerating again from the stop to that same speed , the train may accelerate much quicker or much slower than before (like it is following a different tractive effort / power curve each time). does anyone know or imagine what can be done to resolve the problem?



    i' m also trying to put the links of the videos here but after i press''save changes'' , the links disappear



    Thanks in advance , Paris
     
    Last edited: Apr 13, 2024
  2. OldAlaskaGuy

    OldAlaskaGuy Well-Known Member

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    Do you have the latest patch v1.0.0.5 installed? Have you read the manual on how this locomotive reacts? Here is the link to the manual and the latest patch. https://www.store.searchlight-simulations.com/products/jrsd40-bnsf-bundle
    Remember during braking the cars have a tendency to run in reducing the slack between cars. There is an average of 3 inches of slack in between each car and this adds up on the train increasing the weight being pulled. When starting there is less of a load so the locomotive will accelerate faster. Acceleration is not linear. As more torque is generated the rate of acceleration will increase and will be easier to overcome the weight of the train. If the cars are stretched out then the full load of the train is on the locomotive and it will accelerate more slowly. Also involved is the grade or track curvature. These all come into play in the physics model. You can test this by finding a straight, level piece of track. Place your train. Using the #3 camera slowly move your loco forward until the last car begins to move then notch up. When testing you must be consistent or you will get skewed results.
     
  3. diesel power

    diesel power Member

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    Thank you! of course, the test was done on a straight flat level track and after all the cars were moving (measured times of 10-15 mph at the same notch multiple times). for some reason i cant post the video. But , I finally found when the locomotive does this. It is when you don't let a notch reach its full loading and you jump in the next notch. In order for a notch to deliver all its power you must let the previous notch to load fully. or jump straight to the intended notch. So for example, if you start up with notch 2 and wait till it fully loads , and after that you jump to notch 6 ,the loco delivers always all the power for notch 6. but if you jump to notch 6 before notch 2 fully loads you will experience less power than intended at notch 6 .

    Other than that , its a great dlc locomotive by any other means.
     
    Last edited: Apr 26, 2024
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  4. Spikee1975

    Spikee1975 Guest

    Notch up slowly, wait for the amps to stabilize, then notch up further.
     
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  5. 21c164fightercommand

    21c164fightercommand Well-Known Member

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    obviously only with freight cars that have the proper amount of slack in the coupler's blueprints
     
  6. Spikee1975

    Spikee1975 Guest

    All fixed on my end, first thing I check for after installing new stuff :D Can't pull 20,000 tons from a standstill without using slack slowly adding the weight. A lot of RSC and DTG locos and cars are totally wrong and rigid, resulting in those consist splits as forces can't travel.
     
    Last edited by a moderator: Apr 26, 2024

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