Elvas Tower: Additional Train Forces - Elvas Tower

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Additional Train Forces

#1 User is offline   steamer_ctn 

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Posted 30 July 2018 - 12:00 AM

I am currently working on a blueprint to add additional train forces as follows:

i) Wind Resistance - the current method of adding car resistance typically is for "Still Air" conditions. However in real life it is rare that there is no wind/breeze blowing. Typcally a cross wind will push the train against the far rail, and thus increases the amount of resistance that it experiences. Naturally the harder the wind is blowing, and the faster the train is traveling, the higher the resistance that will be generated.

ii) Wagon Derailment/Overturning - under certain circumstances if the wind is strong enough, then the train can be derailed or overturned. There are various accident reports, and other information describing the impact of wind on railway operation.

iii) Buff/Drafting Forces - poor operation of the train by a driver can cause excessive buffing or drafting forces, which in some instances can cause train derailment, especially when traveling around curves, in particular in yards.

The calculation of these forces is quite complex, and often they are impacted by various dynamic variables, such as track condition (track twist, imperfections, etc), hunting of the train bogies, movement of the bogie suspension, movement through cuttings or across embankments, etc.

The models implemented will attempt to model some dynamic variables, such as wind gusts, etc, but it is not intended to attempt to represent all dynamic variables in the implementation.

These changes however may require drivers to pay closer attention to their driving skills.

Thanks

#2 User is offline   Genma Saotome 

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Posted 30 July 2018 - 08:05 AM

I saw a video of a tornado ripping apart a train from the rear end, moving towards the cab, that was taken from the cab. Quite a sight.

I look forward to what you can come up with for buff and draft forces; managing the node properly will add a huge challenge. Do you think this effort will be creating new parameters specific to the draft gear or just trying to make KUJU's parameters work as expected?

It's too bad KUJU didn't require the modeler to name coupler1 and coupler2 in his mesh... we could have had visual movement of the slack running in and out. Oh! You could add that! There are still a few people making new rolling stock models.

#3 User is offline   Mike B 

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Posted 30 July 2018 - 04:45 PM

Quote

Buff/Drafting Forces - poor operation of the train by a driver can cause excessive buffing or drafting forces, which in some instances can cause train derailment, especially when traveling around curves, in particular in yards.

iirc in Open Rails before 1.0 it was possible to see (in one of the debugging F5 displays) whether or not the train was bunched or stretched, and how many cars of each. At some point, that disappeared. Is the code still there just not being used or did it go away in a later refactoring?

#4 User is offline   steamer_ctn 

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Posted 30 July 2018 - 08:54 PM

View PostGenma Saotome, on 30 July 2018 - 08:05 AM, said:

we could have had visual movement of the slack running in and out. Oh! You could add that!
Yes that would be interesting to see, but I suspect that it is quite complex to code.

View PostMike B, on 30 July 2018 - 04:45 PM, said:

iirc in Open Rails before 1.0 it was possible to see (in one of the debugging F5 displays) whether or not the train was bunched or stretched, and how many cars of each. At some point, that disappeared. Is the code still there just not being used or did it go away in a later refactoring?
I don't recall that. The current coupler forces are supposed to represent tension and compression in the coupler (or so I believe).

Are you able to find an old version that had the feature?

Thanks

#5 User is offline   Hamza97 

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Posted 31 July 2018 - 02:49 AM

Yes... I also have seen that feature in older versions of OpenRails. It also had total slack (in meters) as well as the number of coupler`s experiencing slack and number of them experiencing buffing forces. And it worked too...

#6 User is offline   hroch 

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Posted 31 July 2018 - 04:56 AM

Hello,

Is that it?
Attached Image: couplers.jpg
Attached Image: couplers1.jpg
Attached Image: couplers2.jpg

#7 User is offline   jtr1962 

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Posted 31 July 2018 - 12:04 PM

I think adding train forces will enormously improve the realism of the sim. It will also mean a lot more calculations. As an aside, is OR currently compiled to use AVX instructions? That essentially doubles the speed of floating point calculations on any processor which supports the AVX instruction set. Most CPUs less than 5 years old support AVX.

#8 User is offline   Hamza97 

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Posted 31 July 2018 - 07:48 PM

Quote

Hello,

Is that it?


Yes... That is what I am talking about... :thumbup3:

#9 User is offline   steamer_ctn 

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Posted 02 August 2018 - 01:09 AM

View PostHamza97, on 31 July 2018 - 02:49 AM, said:

Yes... I also have seen that feature in older versions of OpenRails. It also had total slack (in meters) as well as the number of coupler`s experiencing slack and number of them experiencing buffing forces. And it worked too...

I have had a quick look at this, and it was removed as part of this blueprint.

Given that there was extensive discussion (see accompanying thread) I don't believe that it is appropriate to reinstall it into the main HUD.

However if there is sufficient support it could possibly be added back into the Advanced FORCES INFORMATION HUD?

I personally think that it would be preferable to include a symbol beside the coupler forces column to show whether the car is pushing or pulling.

Now comes the time for support for this proposal to be offered.

Thanks

#10 User is offline   Genma Saotome 

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Posted 02 August 2018 - 10:48 AM

I remember that display and I liked it a lot. By Advanced HUD display, do you mean f5 displays 2-last? If so I'd like to see it returned to active duty.

Is that effort to pump data into an html broadcast stalled or did I miss the rollout? It could be configured for that too.

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