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    Fizzix!

    Playing with a GE44 tonner pulling 30 mixed cars up a 4% grade at half power, started wondering if all the MSTS guys were right about Trainz physics. Apparently not in general;



    Dunno how accurate the geeps and hoppers are, but it's close to what I remember from Plainsman's MSTS physics - rule of thumb for 3% grade, one engine for every six loaded cars. This test I used a 20mph running start at the bottom of the 3% grade for all three. The 2 geeps with 18 loaded hoppers dropped to zero and started sliding back about half a mile up, the 2 geeps with the empties slowed to 5mph near the summit but made it all the way, so it does indeed account for the loads. With the extra Alco RS11 adding muscle the loaded train slowed to a minimum of 2mph, but did groan all the way up.

    Again no clue about accuracy - I've been told the mass in each car is kilograms, by the time I convert to pounds and then tons while adding a French postage stamp and paying the European Union tax on metric math, take three aspirins and it comes out around 150 tons which don't seem right. Anyway it feels right, now to try it with that supercharged 44 tonner and see where that goes.
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    #2
    Jim,
    As quick sanity check is Train Forces Calculator by AAK: http://www.alkrug.vcn.com/rrfacts/RRForcesCalc.html

    Just plug in the values and see what the speed should be.
    Chris
    "True rail fans have two favorite railroads. The B&O and one other."

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      #3
      More fizzix

      Someone over at the Auran forum talking about steam locos coasting to a stop on a downgrade, decided to test that with the C-41 engine spec. (Posting here because of the silly restriction they have over there about image size in pixels rather than file size in kilobytes, never understood why a 640x480 uncompressed jpeg at 500kB is kinder for limited bandwidth users than a 1024x768 compressed jpeg at 100kB, but it's easier to see small numbers in the larger images.)

      This is a 3.42% downgrade, a bit extreme but the idea is to see if the drag from shutting the regulator and setting the cutoff to zero will stop it on the downgrade.



      Get her rolling about 5mph, she does want to quit when I shut the regulator, so I gotta feed more steam until it hits the top of the grade.



      Shut everything down and gravity takes over, just like real life.



      Tops out about 33 at the bottom of the grade, dunno if it's a good idea to run a coal fired steamer in the subway but it might clear some of the rats out.



      Second subway station, still coasting, dropped to 28 mph.



      This is all level but with some curves, down to 23 mph after a mile or so.



      Finally runs out of Isaac Newton on the upgrade coming into Wilson yard. Whatever problems the other steam loco specs have, it appears Prowler got the C-41 specs right.
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