Derailing when running downhill

[rabidcirquefan]

Hi all, I'm encountering a problem that's making it difficult to run some of my favorite train sim routes. When running downhill down a long incline, like on the Ffestioniog or Bernina railways, sometimes when I take a tight curve, the engine will follow the curve without issue, but then the first 1-2 cars in my consist will suddenly almost come to a violent halt, buckle and bang around, and often cause my train to derail without warning. Even while drifting downhill, if I'm following the train in external view, I frequently catch the first car 'jumping' up and down on its bogies as it follows the engine around.

I never had this problem until the last two weeks or so. My last few downhill runs on both these routes (Blaenau-Porthmadog / St. Moritz-Tirano) have all been prematurely terminated because of a surprise derailment when taking a downhill curve at the posted speed limit, or even 2-3mph below.

I don't have this problem at all when going *uphill* on either route, despite traversing the same tight curves at speed. And what's more curious, on the Ffestiniog, I don't have the problem at all if I'm running downhill with a double fairlie, but if I'm driving Linda or Blanche, one of the many sharp turns in the route will ultimately end up throwing me off the track.

Further details:
-On the Ffestiniog's case, I seem to derail on a down train anywhere from above the Ddualt spiral to Rhiw Goch
---Rolling stock: Blanche (tender first), 7 Ffestiniog coaches
-On the Bernina route southbound, I've derailed between the Brusio spiral and Campocologno
---Rolling stock: Abe 4/4 III and 6 coaches, or Allegra and 5 coaches

[749006]

Do you have the train brakes on going downhill or just the loco?
There is quite a bit of inertia going downhill

Peter

[rabidcirquefan]

Hi Peter, I use the train brakes.

[749006]

Maybe the speeds shown in the game are too high for the track curvature?

I believe the Heidi-Express from SimTrain has similar problems at a number of locations

Peter