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Fellow Trainsimmers,I hope you activity geniuses can shed some light on this dilemma (I'm still pretty activity-challenged myself).About 40 miles/three hours into an activity on my Canada Atlantic route, I'm derailing when passing through a trailing point switch. This is an "open-ended" activity that only has a very short path defined at the start (so I can drop off and pick up cars at will). No AI traffic at all.Visually, the switch looks fine. Wheels follow the tracks as they should. But two of the cars (at different spots in the consist) give a big jolt at that point, and within a second or so I get an Activity Ended -- Derailment notice.I know there are sometimes problems when running through trailing point switches and I assume this is one of them. What's weird is that I've created another open-ended activity starting about a half mile before that same trailing point switch with the IDENTICAL consist, and this one works fine -- no problems at all running through the switch.Why does one activity work and the other fail? -JF-
Sounds like a nodes problem. The infamous "Cutbank coupler curse" is one of those, too much distance between switch nodes, and the game recalculates the position at each node. If you start a half mile away it's no problem, but from 15 miles away the train really jerks.Couple of possible contributing factors;1. Damping ( 1e6N/m 1e6N/m ) in the coupler datablock, change that to Damping ( 1e6N/m/s 1e6N/m/s ) (should be "Newtons per meter per second", not just "Newtons per meter", that one error screws up a lot of things). 2. CouplingHasRigidConnection () - This is in the default MSTS 1.2 cement hopper, and probably made it into some repaints as well. Delete that line or comment it out, the rigid coupling causes the back of the car to really "crack the whip" going thru a trailing point switch.
Thanks, Jim.Couplers are OK.It must be this pesky nodes problem. The switch in question is only nine miles from the previous one, but that seems to be far enough to do it.I've created two new activities starting just the other side of the previous node: the first a short open-ended one and the other with a path that passes through the switch where the derail occurs.I see a jolt in both cases (much worse in the open-ended activity) but not enough to derail the same consist.There are a couple of whistle stops in that nine-mile stretch and I guess I can add a team track siding at one of them to solve the problem. But I suppose that also means removing and replacing all the interactive objects on the route (more than a hundred). Yikes.I guess the moral of the story is to test with a variety of activities while building a route. I've run "Explore Route" trains over that switch countless times so I just assumed it was OK. My next step will be to check every switch on the whole route with activities to see if there are other unpleasant surprises. -JF-
Well, don't go ballistic on this. If the track database was okay before you added signals and other track objects it will still be okay if you take an unsignalled section of straight track and add a couple switches.Save the "remove everything and rebuild the TDB" as a last resort, in most cases it's not necessary."much worse in the open-ended activity", Otto did a whole series of tests on the behavior of switches in activities versus explore route, and there are a few times when a trailing point switch set against you will automatically reset for you when you're off the path in an activity;1. When the switch is part of, or would connect to a switch that is part of, a wye (British "triangle"),2. When the switch is part of, or is the final switch in setting up the path for, a reverse loop ("balloon track") or circle.Other than those two situations a trailing point switch that's set for the straight track, and you approach from the curve (typical with a passing siding or runaround track), will normally remain set for the straight. Real switches are generally spring loaded so a train can come thru the switch with the points set the wrong way and not derail, with MSTS the lead truck runs thru the curve, then the trailing truck "snaps" or "whips" over to the straight track.http://www.train-sim.com/cgi/dcforum/dcboard.cgi?az=show_thread&om=5089&forum=DCForumID5That particular problem with the US2freightcement was eventually traced to that rigid coupling line that shouldn't have been there.So yeah, in an open ended activity when the player is off the path you will see the back end of each car give a jerk, but provided the couplers are set up in accordance with Plainsman's physics 4.5 or later (and are not rigid), that shouldn't cause broken couplers or derailments. FYI the standard Invisocar has a rigid coupler, so if coupled between two back-to-back engines will derail on tight curves, but only in the player train. I still haven't figured out why anyone would WANT Invisocar in the player train, but when people use it that's what happens.
Thanks, Jim.We'll see what happens when I add the new siding. Maybe if all the stars and planets happen to be aligned right it'll turn out OK.I have seen that problem of the wheels jumping when approaching on the curved part of the switch in an open-ended activity. Happens on some switches on my route, doesn't happen on others (strangely enough).But on the trailing-point switch in question here I'm approaching on the straight track and the switch is set properly. No jumping wheels -- just the big jerk.("The train stopped with a jerk and I got off." Was it Groucho Marx who originally said that?)The couplers are set up properly, but in the long activity the jolt is strong enough that it doesn't matter -- game over.Thanks again. -JF-