Rivet Games, Please Don't Turn Arosa Linie Into An Arcade Game.

Discussion in 'TSW General Discussion' started by erg73, Mar 28, 2021.

  1. solicitr

    solicitr Well-Known Member

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    Exactly. The speed curve on a downhill should resemble, precisely, the teeth of a saw. Air brakes on, decelerate, off, accelerate, repeat. With enough interval between that the reservoirs can recharge.
     
  2. Oli R C

    Oli R C Member

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    It doesn't look like they're using that method on the Arosa cab ride videos. (either visually or audibly)
     
  3. solicitr

    solicitr Well-Known Member

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    No, they aren't. And as I said above, I have an inkling that what they're doing is a workaround because the wonky modeling doesn't allow proper braking procedure. I doubt the RhB has procedures which are precisely the reverse of every other railway in the world* that operates in mountains.

    *Well, except in the UK: apparently Britons regard dynamic brakes as a form of "conceiving the death of the Queen" or something.
     
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  4. grob-e

    grob-e Well-Known Member

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    Actually, it seems to be a problem with the missing cab car...

    'On the unilaterally inclined Chur - Arosa line, the cab cars, which are always lined up on the mountain side, can be used to guide the train both uphill and downhill. When the train is traveling downhill, the cab car running at the end of the train brakes the entire weight of the train electrically.'

    As we don't have a cab car in the rear, it can't help us braking the train...
     
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  5. Lamplight

    Lamplight Well-Known Member

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    5F97CD20-A286-4939-BF84-05CFA883BA21.jpeg
    It says: If the electric brakes alone can no longer hold the train ...
    Is it just me or does this officially confirm that you‘re supposed to only use the dynamic brakes as long as they‘re strong enough and not blended braking?
     
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  6. LucasLCC

    LucasLCC Well-Known Member

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    That was my reading of the translation too. Dynamics until they can't hold, and then use the sawtooth method as necessary.

    It certainly isn't advocating the Rivet method of using vacuum until they melt and burn.
     
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  7. solicitr

    solicitr Well-Known Member

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    No, I read "if electric brakes alone can no longer hold the train" as meaning that you then use dynamic and vacuum together, i.e. blended. Which is exactly how it's done everywhere else: dynamics stay on, all the way down, supplemented by friction brakes at intervals for just long enough to bleed off speed: "sawtooth."

    While dynamics alone on a steep grade will not hold speed, they will retard your acceleration, giving the air/vacuum brakes sufficient time to recharge between applications (otherwise you run out of air, which is Very Very Bad.)
     
    Last edited: Mar 29, 2021
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  8. roggek

    roggek Active Member

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    As far as I know, Jasper at Rivet said that "...20% vaccum brake and then regulate the speed with the dynamic brake..." is sufficient to take the train down from Arosa to Chur.
    My own experience says the opposite: 100% dynamic brake at the 6 % descents, then regulate the speed accordingly with the vaccuum brake with the "sawteeth" method

    I don't think there are any issues with the coaches physics, I think people are more too "enthusiastic" with the controls...
    The primary key on Arosa is small steps with both the speed and braking controls.
    It is the "slowest express train in the world..." after all...
     
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  9. Lamplight

    Lamplight Well-Known Member

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    That‘s what I meant. My reading was: You use the dynamics alone. If and only if they cannot hold the train alone, then you switch to blended braking via sawtooth.
     
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  10. Monder

    Monder Well-Known Member

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    This might also depend on the age of this article/manual. Let's say it's from the 60s... dynamic brakes have become a lot stronger since then and can more likely hold the train.
     
  11. solicitr

    solicitr Well-Known Member

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    Dynamic brakes of necessity cannot produce more braking force than the same motors and transformer can produce positive tractive force. While you are correct that an SD70ACe has much more powerful dynamic braking than, say, an F7, the Ge 4/4 II is still only a 4-axle, 2000 hp locomotive.
     
  12. grob-e

    grob-e Well-Known Member

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    As it says 'Stand 1. Januar 2020', which would mean 'Valid from January 1th, 2020' it is about15 month old, dynamic brakes haven't evolved that fast in the last 15 months...
     
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  13. FD1003

    FD1003 Well-Known Member

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    Thankfully the swiss document was available in italian as well.

    Just wanted to point out the sawtooth method is described in this document (German version) in a paragraph named:

    2.7.2 Use of the automatic brake using compressed air on standard gauge trains during descends.

    And Arosa uses vacuum brakes (I couldn't find anything that said to use the sawthoot method on the vacuum brakes part of the document), and is also a narrow gauge railroad, so I'm not sure that applies here.

    I will look at the other documents on that website and see if I find something else.

    Sadly I can't check the german document as I would have to rely on machine translation
     
    Last edited: Mar 29, 2021
  14. paladinman8

    paladinman8 New Member

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    I have to agree with you on the passenger side of things, seriously lacking in passengers and passenger movement, for example boarding and alighting the train.

    As for the stars, I did a night run In summer clear, at around 22:00 and found the night sky full of stars!
     
  15. Monder

    Monder Well-Known Member

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    Vacuum and air brakes are only different in the way of applying pressure, the brake shoes still go through the same pain and heat.
     
  16. Monder

    Monder Well-Known Member

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    Not necessarily, it also depends on how effectively you can get rid of the energy produced. If you can't cool it down, it can't go full force when braking. That's why Swiss locos have some serious cooling mechanism to be able to go full dynamic AND go for a long time.

    Compare a German E42 normally and what they looked like prepared for Switzerland
    [​IMG]
    [​IMG]
     
  17. FD1003

    FD1003 Well-Known Member

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    No doubt about that, just wanted to point out how that document seemed to be more focussed on standard gauge modern stock instead of being RhB specific, of course Switzerland is still Switzerland, but I think there is some RhB specific documentation we are missing.
     
  18. junior hornet

    junior hornet Well-Known Member

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    Totally agree, It has to be fun to play. Driving it for half an hour or so, only to have the train derail would be frustrating and not fun at all. Of course the physics should be improved, but maybe be a little more forgiving than in the real world i.e. if you are driving recklessly, you should derail but a little leeway wouldn’t go amiss to avoid me putting my foot through the telly.

    Having said that, I had great fun on TS2021 driving a Class 43 at 130mph through Rickmansworth station on the Metropolitan line and watching the carnage. But that time, I was doing it on purpose.
     
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  19. solicitr

    solicitr Well-Known Member

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    It means they can take advantage of the full 2000 hp- but it doesn't give them any more than they have.

    Besides, 6% is steep, but it only represents a threefold increase in gravity vector over a 2% grade- while on the other hand, the whole train weighs less than 150 tons: 300000 (.06) = 18000 lb or 9 tons of force to resist. That isn't really all that much (a smallish US freight train weighs 40 times that)
     
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  20. paul.pavlinovich

    paul.pavlinovich Well-Known Member

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    There are manual points at Arosa, but unfortunately there are red signals between you and them :). There might be a scenario or service where you can make it happen but I've not found one yet. Thinking about it while typing, there is a service that starts in Arosa yard I think. Maybe its possible to do it with that one. You know what I'm about to try now don't you :).
     
  21. paul.pavlinovich

    paul.pavlinovich Well-Known Member

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    Thanks, I'm glad they're going to keep it complex while curing the derailments. That's good news. Good to have you back and hope to see you on stream again soon (even though they will be at 5am for me after this Sunday - sigh... bloody daylight savings).

    Paul
     
  22. ASRGT

    ASRGT Well-Known Member

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    the way i have managed it has always been around 80 -100% dynamic brake depending on grade with minor uses of air brakes.
    I found that 95% dynamic is enough generally to hold the train at around 33 -35 km/h and using air brakes for reductions to 30 or coming to a stop at stations ect.

    Not sure this is correct in terms of real world usage however it does get me down every time.
    That said don't think i have once met the timetable, always end up about 5 - 10 mins late but hey better late than never :P
     
  23. paul.pavlinovich

    paul.pavlinovich Well-Known Member

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    What a really good manual, thanks. I just translated the whole thing and will have a read.

    Paul
     

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