PC Riesa - Dresden Br 146.2 Strange Behavior

Discussion in 'Technical Reports' started by echeij, Sep 10, 2021.

  1. echeij

    echeij New Member

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    I have done a few services on Riesa - Dresden (I really like the route btw) and I noticed the following things on the BR 146.2 on Riesa Dresden:
    1. When using AFB and opening the doors, the brake pressure is set to 3.8 bar. If you set the brake lever to 'Running' before closing the doors, the brakes don't come off when you close the doors. In this situation, when the loco reaches 10 kN of force, the brakes release to 1.5 bar, but get stuck there. Is that intentional?
    2. When you close the doors while using AFB and then release the brakes and apply power, a short brake release sound is played on the dosto cars while the loco is ramping up power, as if the brakes are repeatedly released (although this is not the case as this only happens at 10 kN of tractive force). Is this accurate?
    3. When you release the brakes after closing the doors (also using AFB) and apply power, it takes about 10 seconds before the loco actually starts to produce any torque. This is a very long delay compared to other trains/locos. I would expect the torque to build up in at most 2 seconds after setting the throttle lever. The throtlle in general is quite unresponsive while driving, as is the regenerative braking.
    4. The door indicator on the MFD does not work, so you can't see if the doors are opened or closed in the cab.
    5. The destination display lets you only set manual destinations, but the automatic destination button does not work.
    I also noticed (on other locos as well) that when applying the brakes at speed, the brake cylinder pressure goes up, but then shortly thereafter goes down to zero as the electric brake engages. Does that mean that when you apply the train brakes at speed, you only get braking on the locomotive axles, meaning you won't brake at all if you have wheelslip in your loco? Or is the indicator wrong / do I misinterpret it?
     
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  2. Doyden

    Doyden Active Member

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    I've found exactly the same as your point 1. The pressure sticks between 1.3 and 1.6 with brakes set to running. I've found that as the pressure drops and then sticks, quickly applying release results in the pressure dropping further and then the train begins to move. Without going as far as release, the pressure will remain stuck even if you apply full power.
     
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  3. KoeleKoen

    KoeleKoen Well-Known Member

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    Your last part is like irl, your coaches will brake with their disc (or blocks) but your loco will release its brakes so it can brake dynamic with its engine, if it stops braking dynamically your brake pressure will rise again, the needles only show BP of loco
     
  4. echeij

    echeij New Member

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    Ah I see, well that clears that point up then, thanks!
     
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  5. pacificorca#1435

    pacificorca#1435 Active Member

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    So apart from the obvious bug where the brakes get stuck at 1.5 bar, I think the 10kN might actually be modelled incorrectly. Someone more knowledgeable on German trains told me that the 10kN figure is actually measured in real life across all axles but TSW displays just the power applied to one axle. So that means we should theoretically expect the brakes to release at about 2.5kN (2.5*4=10).
    That certainly makes sense to me, if you watch trains in real life they don't take 8 seconds to spool up their motors before actually releasing the brakes.
     
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  6. chieflongshin

    chieflongshin Well-Known Member

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    If Im Reading this correctly I know Matt said in stream it’s been modelled based on driver feedback to release at 10kn
     
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  7. echeij

    echeij New Member

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    That's an interesting point, allthough I don't think that would solve the issue completely. The main problem is that the traction system only starts generating torque 8 seconds after it got an input from the throttle lever for some reason. So what happens after releasing the brakes and applying the throttle is:
    • ~8 seconds nothing
    • ~2 seconds building up torque
    • Brakes release and loco starts accelerating
    I can't imagine what the traction system would be doing in those 8 seconds, allthough I would love to know what it does in that time if it is realistic behavior.
     
  8. echeij

    echeij New Member

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    It seems to me after some more driving that this time is the time necessary to release the brakes on the dosto coaches. So by releasing the brakes to 1A or 1B during a station stop, the brakes release quicker and the 146 starts moving sooner.
     

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