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Thread: ORTS Standard Engine Files - Version 2

  1. #1
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    Default ORTS Standard Engine Files - Version 2

    Just uploaded Version 2 of the Standard Engine files...these are meant to replace the include files found in "orts_standard_engines.zip". Took about 6 months longer than I expected, kept finding and receiving new sources of information.
    Here are the changes in version two:
    1. Expanded Comments Section
    2. Diesel Consumption tab expanded for some engines
    3. Throttle Rpm tab more accurate
    4. Diesel Torque Tab Expanded and corrected
    5. Units of Measure added where appropriate
    6. ORTS brake parameters expanded
    7. ORTS Max Tractive Curves refined for more prototypical curve form.
    8. 71 additional engine files added

    Found good data about diesel consumption here:
    http://www.gatx.com/wps/wcm/connect/...S&CVID=kBD-GwT

    Also took some effort, searching, and asking those who know about accurate rpm settings. Hopefully the Throttle RPM tab is now more accurate for most engines. ( lots of careful reading of manuals )

    In the course of reworking the files I kept finding more locomotives that interested me, so I kept adding new ones -- finally ended up adding 71 additional engine files...some are just different weights ( every road seemed to have their specific weight requirements ). Other new additions are not in the version one files. ( grand total 247 standard engine files )

    Most importantly version two gave me a chance to refine the ORTS Max Traction curves. I was never really satisfied with the curves for version one. I realized how I could "shape" the curves to a more prototypical curve form after I had found and examined five good traction curves from as many different diesel locomotives. Certainly it would be preferable to have actual curves for all 247...but that is just not possible. So knowing what the prototypical curve shape looks like allows one to produce a reasonable set of working curves for any locomotive, especially if you also have accurate values for Starting Tractive effort and Continuous Tractive effort.

    See the curves illustrations below...the plotted curve is from a British Railways Performance and Efficiency Test report for a 3300hp Co-Co "Deltic" diesel electric locomotive. ( thanks to Peter Newell for a copy of the report )
    Compare the test curve with similiar data points on the calculated curve set from the spreadsheet I am using.
    Test curves at 50mph = 20,000lbs
    OR curves at 50mph = 19,700lbs

    Test curves at 40mph = 25,000lbs
    OR curves at 40mph = 24,500lbs
    Similiar comparisons can be found at other points along both curves.
    I have seen very accurate calculated curves ( for example from Joe Realmuto ) - but I am not at that level of mathematical skill or knowledge of diesel locomotive physics to be able to construct such curves. Best I can do at this point.
    ORTS Calculated Curves bandicam 2020-03-11 18-06-12-429.jpg
    Test Report Curves bandicam 2020-03-11 18-03-01-411.jpg
    Cheers, R. Steele [Gerry] It's my railroad and I'll do what I want! Historically accurate attitude of US Railroad Barons.


  2. #2
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    Many thanks, Gerry
    Cheers
    Derek

  3. #3
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    yes thank you this is interesting - with tractive force does it decrease with speed like this always regardless of how gradually one increases speed? - i am guessing the answer might be in the manual, hopefully in laymans terms

  4. #4
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    First question: yes, it does always decrease with speed over the speed of maximum tractive effort.

    second question: It won't be in the manual.

    The diesel engine puts out a maximum value of power.

    Very simply

    Power is generated when a force is applied at a set speed. Power= force x speed

    If you double the force, you double the power.
    Cheers
    Derek

  5. #5
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    This is what I have been waiting for!! Thank you very, very, very much!!!
    Borislav
    https://www.trainsim.com/vbts/signaturepics/sigpic100353_2.gif

  6. #6
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    Have a question for you, Gerry. I wonder if the files in ver. 2 have Trainsimulations CN GP40-2LW series locomotives? I don't know if you have that route, CN Ruel Subdivision in your Open Rails program. Just asking to see if you work on these locomotives above.

    Thank you,

    John

  7. #7
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    Regarding cn bala's question more generally ... If I have the time and am supplied with ( or can find ) accurate data I will try to work up OR Standard Engine files on request --- provided --- I have the time, and the request is reasonable...both items are my decision.
    Just PM me, or use email found in Boilerplate.doc supplied with download.

    For those interested in trying their hands at understanding traction effort and what goes into curves expressing traction effort, here's a paper to read ( or wade through --- as the case may be --- I don't mind wading or swimming in deep waters myself, from time-to-time. )
    https://www.researchgate.net/publica...ing_Locomotive

    Also has information on Curtius Kniffler and other assorted mind bending data.
    head-spinning.jpg
    Last edited by R. Steele; 03-14-2020 at 08:19 PM.
    Cheers, R. Steele [Gerry] It's my railroad and I'll do what I want! Historically accurate attitude of US Railroad Barons.


  8. #8
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    Downloaded and installed!

  9. #9
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    Gerry, just getting around to applying these. Many thanks for your time and effort spent putting this together for the community.
    Neil

    Here at home, in the railroad mayhem capital of the world.

  10. #10
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    Gerry, I second everyone's kudos on your work. What an amazing task you've taken on, one all of us can benefit from.

    Uncle E
    Whatever's cold in my fridge is the Official Beer of Open Rails.

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