Frequent Broken Coupler!

[meeshu]

Running an activity for Cajon Pass V4.2 under Open Rails version 1.4.

Simple activity with just hauling 142 loaded coal cars with 12 locomotives "over the hill". No AI traffic.

While running the activity for a while, started getting slight skipping/stuttering of video. I thought this was due to slow loading of data from my HDD. This maybe the primary cause of the stuttering, but on saving the activity to continue later, I looked at the OR log (HUGE file of 16 MB!!!) and it contained literally hundreds if not thousands of entries related to broken coupler almost entirely for car 0-2, but some entries for car 0-3!?

Here is the zipped OR log.

Basically kept getting the message (for example)- "Information: Coupler on CarID 0 - 2 has broken due to excessive static coupler force -2495183" This number at the end varies.

The coupler break values for all the cars and locomotives have been edited to 5.4e7N values, which are technically unrealistic, but which should prevent coupler breaks. But despite this high value, continue to get coupler breakages!?

Hoppers are from this file - fepxcoal.zip available from the File Library here.

Locomotive placement is in 5-3-4 configuration. Five locomotives at the front, three in the middle of the consist, and four at the rear.

Why are coupler breakages still continuing despite high coupler break values within the hopper wag files?

[R. Steele]

A known bug ---- Please review this thread >>> http://www.elvastower.com/forums/ind...-static-force/ ( Elvas Tower 5-13-2020 ).

After adding ORTS carbody/derail parameters and reworking other data, I have not encountered this "static breaking" lately...I've been using monogame, so I have not run any heavy consists using Ver1.4. It's a quirky bug, hard to duplicate with test equipment.

I do not have that activity...is it available or can you provide me with a copy? I'll do some testing...PM if you so desire.

[meeshu]

Here is the custom activity -

Conrail Coal Run.zip


And here is the custom consist -

5_3_4_sd80_142_coal.zip


Note that I'm using Conrail SD80MACs for all of the locomotives. I believe the SD80MACs are available to download from the File Library here. You could substitute other locomotives, of course.

[R. Steele]

Got the act and con, will work on it tomorrow...let you know. Thanks, Gerry

Whoops, I forgot to ask about the path UP first run...don't have that, can make it up easy enough, start and end points?

[meeshu]

Start is from UP West Colton yard, end is literally the end of the line at ~ MP 380. Path is along UP line.

Here is the path file -

UP First Run.zip

[derekmorton]

Try the consist at 3-5-4, or 2-5-5 and see what happens.

[R. Steele]

Apologies, have not yet had time to start looking into this, life-chores intervened today...but I'd go with Derek's suggestions...especially 2-5-5 for the power---in my experience all the "static breaks" occur up front...more force there---moving some of the power back in the consist might help...I always place my "mid-train" a little less than 2/3 back from the head --- and maybe one locomotive less in the trailing.

Is there a rule-of-thumb for power placement in this type of long heavy trains??

[meeshu]

The coupler break values for all of the consist were set at 5.4e7N which, as mentioned before, is technically unrealistic. The realistic values should be much less and should be 2.22e6N.

With the break value set at 5.4e7N, this is 24 times the breaking strength of realistic value, and should prevent any coupler breakages occurring. The fact that couplers are breaking with this high strength value set at 5.4e7N, suggests there is some serious issue with Open Rails. And as mentioned earlier, it appears to be a "bug" in Open Rails.

I was aware that having a bit more power at the head end (five units) of the consist would create a bit more force at the head end of the consist, but with coupler strength set at 5.4e7N, there shouldn't have been issues with coupler breakages.

Regardless, I was considering rearranging the locomotive configuration to 4-4-4 and see if the breaking coupler issues still persist. I might test that configuration later on.

Power placement within a consist, I believe, depends on how curvy and steep the lines are.

I don't have a rule of thumb as such for power placement, but try to consider the forces within the consist and place locomotives at locations where I believe forces will be minimized to prevent coupler breakages and to prevent string lining occurring.

[geepster775]

You have twice as much tractive effort that any real world RR manager and their rule book would ever dispatch over that hill, as part of some fantasy test built around ancient MSTS physics.

I don't have a rule of thumb as such for power placement, but try to consider the forces within the consist and place locomotives at locations where I believe forces will be minimized to prevent coupler breakages and to prevent string lining occurring.

Garbage input

suggests there is some serious issue with Open Rails.

equals garbage output

[meeshu]

Thanks for constructive comment! NOT!

Try Open Rail physics which is more realistic than MSTS physics. Don't mix the two up.

[meeshu]

I have run a modified consist with the locomotives in a 4-4-4 configuration, and have successfully crossed over the hill at Cajon Pass without getting any broken coupler messages anywhere!

However! This is with the coupler break values set at the unrealistic 5.4e7N value. I'll try to run the same consist again but with realistic coupler values set to 2.22e6N instead. This could be interesting!

[R. Steele]

I've had an opportunity to try to duplicate the coupler breaks, static or otherwise, with no success so far...have not completed the whole run, but will keep going, it is challenging with this consist, although I gotta agree with geepster -- it probably is not based on a real train that went over the Cajon route...is it? But still, okay by me, interesting.

Here's a comparison of the specs.
meeshu original consist --- power 60,000HP --- loco mass = 2,286t --- car mass = 17,735.8t --- total mass = 20,021.8t --- loco-config = 5-3-4

my test consist --- power = 51,000HP --- loco mass = 1,551.94t --- car mass = 17,735.8t --- total mass = 19,287.74t --- loco-config = 3-3-3 -- using advanced adhesion/OR physics MG Ver118 --- I did add a caboose on the end, to hang out on rear platform...that's just mandatory in any consist for me.

[meeshu]

I forgot to mention that I think the broken couplers seemed to occur when resuming saved activities while climbing the hill. Otherwise there didn't seem to be any broken couplers if running activities without resuming saved activities.

Try saving an activity while climbing hard up the hill and then resuming it.

[R. Steele]

I forgot to mention that I think the broken couplers seemed to occur when resuming saved activities while climbing the hill. Otherwise there didn't seem to be any broken couplers if running activities without resuming saved activities.

Try saving an activity while climbing hard up the hill and then resuming it.

I understand ... and Yes, that's exactly what I've been doing. The first time I reported this...I was running an activity on the Roger's Pass route with loaded sulphur gons and helpers...could not resume a saved activity on a grade of about 1.8% to 2% or so...always got the "static coupler" break, even though while running the activity on the grade before the save there where no broken couplers.

So far so good, although --- like I posted --- have not completed the run...will post here when I complete it.

*Just a Note...watch the coupler force on the force information hud and if it is above 300klbf near the front of the train, you will probably experience coupler breaks.

[meeshu]

OK.

I have just resumed an activity with locomotives in a 4-4-4 configuration and with coupler break strength values set to a realistic value of 2.22e6N. No broken coupler issues were seen after resuming the activity and running the resumed activity for at least 5 minutes.