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Thread: Not getting full engine power?

  1. #1

    Default Not getting full engine power?

    Im running the current unstable version U2019.10/26-0321 of Monongame, and several versions before it have the a bug or issue. When im running trains I notice the locomotives are only loading to 75% give or take when in full throttle. I go back to older versions of Open Rails mono and engines will load to 100% with the variance in load from random changes. Is there some option im missing in the newest version causing this to happen? Thanks in advance.

  2. #2

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    There were some changes as described in this thread - http://www.elvastower.com/forums/ind...e-performance/

  3. #3

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    Well thats lovely. Only have 1000+ locos to add that parameter to its engine file lol. Oh well, ill just backdate my open rails for now. Thanks for the link.

  4. #4

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    The changes shouldn't reduce the power to the rail which was the MaxPower value.

    Is this not the case in your instance?

    If so, can you provide some more detail, or better still an example of a piece of rolling stock?

    Thanks

  5. #5
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    On another railfan forum, there was a discussion going on over how CN seems to be plugged up on it's prairie main lines. One person who worked for CN stated that CN prefers to dispatch it's monster trains with 0.4 hp/ton if AC traction is involved, and 0.6 hp/ton if the train has DC traction engines. The discussion centered on whether CN could untangle their situation if they just powered up their trains a bit more allowing more of them to successfully make their destination terminal within h.o.s. resulting in less siding storage and less dog-catching.

    This got me to thinking about testing Open Rails physics on a similar prairie-type route (no heavy grades). First thing I did was create a typical 7500 ton freight train. My test train was 82 cars. There were 30 car pairs of both loads and empties, and any additional non-paired cars were weighted more towards loads than empties. This produced a test consist of about 46 loads and 36 empties. All cars have ORTS physics and friction values. I powered this test consist with different locomotive pairs on different runs to evaluate their performances. I also tested with the newer open rails physics changes in the current unstable build and compared it with an older build from August, prior to the changes.

    I ran the test train on the Ruel Sub from Gogama to Makwa siding. There are some long straight stretches, and a few tight S-curves. Max uphill grade are two 0.4% steps separated by some flat or downhill running. Speed limits were ignored in attempt to evaluate raw pulling power. Every run the throttle went to notch 8 and never came .


    Test run 1, August 8 build. A pair of GP40s. 0.8 HP/ton. F5 Hud shows ~2820 hp at max speed, 94% efficiency (which is a bit high for GP40s)

    On the pull at 8:01
    Max speed ever attained is 40.2 mph.
    Passing the mp83 detector 40.0 mph at 8:09:15
    Passing west switch Makwa mp 37.6 mph at 8:15:45


  6. #6
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    Test run 2, October 26 build. A pair of GP40s. 0.8 HP/ton. F5 Hud shows ~2280 hp at max speed, 75% efficiency (which is a bit low for GP40s)

    On the pull at 8:01
    Max speed ever attained is 38.1 mph.
    Passing the mp 83 detector 37.7 mph at 8:09:15
    Passing west switch Makwa mp 79 34.0 mph at 8:16:45


  7. #7
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    Test run 3, October 26 build. A pair of GP40s with trailing unit deliberately taken off-line (representing engine failure). 0.4 HP/ton. F5 Hud shows ~2240 hp at max speed, 74% efficiency.

    Unable to move the train with a single GP40. Needed to re-fire the trailing unit for a minute and a half to get a roll on the train, then shut it down after 5 mph speed attained. Once train was underway, the lone GP40 handled the train well. Needle would often red-zone briefly when under 19 mph.

    On the pull (finally) at 8:02:45
    Max speed ever attained is 28.2 mph.
    Passing the mp 83 detector 25.4 mph at 8:12:45
    Passing west switch Makwa mp 79 15.7 mph at 8:25:30 (the second of two 0.4% grade steps is just before the siding)


  8. #8
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    Test run 4, October 26 build. A pair of SD40s with trailing unit deliberately taken off-line (representing engine failure). 0.4 HP/ton. F5 Hud shows ~2220 hp at max speed, 73% efficiency.

    Able to get a roll on the train with the 2 additional traction motors that the SD40 has available over the GP40.

    On the pull (finally) at 8:01:30
    Max speed ever attained is 28.7 mph.
    Passing the mp 83 detector 26.3 mph at 8:12:15
    Passing west switch Makwa mp 79 15.2 mph at 8:25:00


  9. #9
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    Another test that I tried was to mimic the consists of some trains that were notoriously involved in accidents, since the ICC and NTSB covers their composition and makeup so well in their accident reports.

    On March 12, 1972, PC suffered a head-on collision on the Buffalo-Harrisburg mainline involving a 104 car, 9,800 ton coal train and a 103 car freight train that was headed for the D&H's connection south of Wilkes Barre at Buttonwood yard. Both trains were powered by two 4-axle locomotives. Lead units were GP9 7095 on the coal train, and GP38 7828 on the freight. One other unit destroyed in the wreck was GP40 3176. The fourth unit was not identified, except that it was a 4-axle unit.

    https://ntsb.gov/investigations/Acci...s/RAR7303.aspx

    https://www.pennlive.com/life/2019/1...hiroshima.html

    Assuming the destroyed GP40 was on the coal train, and very few alternative options for a higher HP unit than a GP40 existed at the time, that would have resulted in a 4,750 hp locomotive set powering the 9,800 ton coal train. According to the NTSB report, the coal train was able to reach 35 mph at various points prior to the collision. The coal train originated in Clearfield PA and essentially followed a route along the river all the way to Harrisburg and it's destination. It had been stopped and re-crewed across the river from Williamsport PA and staffed by a new crew out of Newberry Yard that had been taxied over the bridge (by way of a local hotel bar) to the train.

    Since the coal train was made up of a mixture of 100 ton and 70 ton hopper cars common in the early 1970s, I used the CN ballast cars to mimic the mixture of hoppers. These CN ballast cars were set for 105 tons each, so I created a consist of 104 cars and substituted a fixed number of ballast empties for loads to get the resulting train weight down to 9,800 tons (the empties are placeholders for the 70 ton loads which I don't have). What is different from my earlier test consist is now the presence of (104 cars x 4 axles per car) worth of roller bearings that must be started by a lesser HP power set.

    Upon startup, I was able to get the power set to remove the slack from the train. I also was able to get the caboose to move ever so briefly from 'whiplash'. But the maximum HP produced by the engines before the stall was only about 150 hp, which did move the train forward about one car length before the stall set in. The second attempt to start went nowhere as the slack had already been removed from the consist. In the end I could not recreate the operation of the accident train.



  10. #10
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    This was what Conbuilder shows. 9842 US tons and 105 wagons (104 revenue + caboose)



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