PC Sandpatch Service Q249 Not Enough Power To Climb The Mountain

Discussion in 'Technical Reports' started by Rudolf, Feb 11, 2021.

  1. Rudolf

    Rudolf Well-Known Member

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    After a discussion on service Q249 from Cumberland to Rockwood, which appeared not to be working, I decided to try it for myself. See this thread for the post before:

    https://steamcommunity.com/app/1282590/discussions/0/3108016336250622719/

    The train has a total weight of 4600 ton I used two SD40-2 engines in the service and summer cloudy as weather conditions. I noticed till Hyndman that I could increase speed with full throttle up to 41 mph max. Then, at a 0.6% grade speed dropped gradually till a bit over 30 mph
    When the 1.4% climb starts, speed dropped further till 12mph. At that point I decided it is useless to continue the service, later you will face even steeper grades.

    So, I consider this as a bug, unless Matt shows in a stream what to do to complete it. I did not try t find other engines in the yard to complete this run. Below you see the speed profile, most with full throttle.

    20210211084035_1.jpg
     
  2. solicitr

    solicitr Well-Known Member

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    Don't run it with SD40s, use AC4400CWs. That's 8800 horsepower vice 6000- nearly 50% more. (and it's 3-phase AC, which gives better tractive force).
     
  3. Rudolf

    Rudolf Well-Known Member

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    I will gie it a try, but it is in the SD40-2 timetable, which means it is intended to work.
     
  4. breblimator

    breblimator Well-Known Member

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    This is not only SPG issue. MSB, RRO... Weather conditions/grade % vs insufficient HPPT * ratio * Horse Power Per Ton
     
  5. Richard CZE

    Richard CZE Well-Known Member

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    I would need another locomotive for MSB. Otherwise, the hill cannot be climbed in the rain. The third locomotive should be parked at the station. If necessary, I could connect it to my train.
     
  6. breblimator

    breblimator Well-Known Member

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    With the release of TSW2, the physics (including locomotives parameters) was slightly changed. According to the information that can be found in the official materials from DTG (Preserved Collection FAQ?), These changes also apply to preserved routes and trains. Services and cargo weight remained unchanged, adhesive physics added, etc. Some services today are not feasible with some locomotives in severe weather conditions. From Cumberland side climb with HPPT below 2 ~ 2.5, in rain... can be hard :)
    It is a pity, in the menu we cannot select a pair of locomotives for a specific task. In one scenario for RRO there is a pair of 185s from the head of the train if I remember correctly.
     
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  7. solicitr

    solicitr Well-Known Member

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    As Breblimator pointed out, it probably did work, when it was developed for TSW1 ("CSX Heavy Haul" was the first route released), but TSW2's more detailed physics, especially adhesion, may make it impossible with an underpowered consist. IRL, I doubt CSX would attempt the Grade with such a marginal hp/wt ratio: they would either use bigger locos, or triple-head.

    If you want to go nuts, you could try this: uncouple your SD40s from the train, run around the switch yard and add a third or third and fourth loco, then pick the train up again. Mind you, you can't get out and go hijack another loco on foot, or you'll end the scenario.
     
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