X1670 behavior with single loco on hill

[Sid Penstone]

X1670 Strange behavior with single diesel loco starting on slope
Release 0.9 does not show this effect.
In explore mode, start ORTS with a SINGLE loco (no cars) on a slightly climbing hill. In X1670, the loco starts to roll back and the brakes (Engine or train ) cannot stop it.
If there are two locos (e.g. one flipped), everything is normal - the brakes easily hold the locos.
I have tried it with the default Dash9 and some other locos.
In default Marias pass - try "Glacier Park - Essex" - (there is only a short open length of track behind the loco).
In Surfliner 1 - try "Mirada - Mirada" path.

[Sid Penstone (penstone)]

More tests - in default Marias Pass "Glacier Park - Essex" path. Watch F4 monitor speed:
You may have to apply some forward power to move away from the buffer at the rear, then power to zero. When the locos start to coast back on the hill, apply the brakes. (The last part of this track is quite steep.)
Pair of GP38s, neither flipped - runs away in X1670, OK in 0.9 when brakes applied
Pair of GP38s, one flipped - OK in X1670 and 0.9 when brakes applied.
Apparently having a flipped loco changes the operation.
I realize that this is a very steep section of track, but I have observed the same brake problem elsewhere, e.g. La Mirada yard.

[Dennis A T (dennisat)]

I have also observed this effect. A single loco will not stand on a slope of 1/100, it very gradually creeps down the slope even on full brake.

[Matej Pacha (matej-pacha)]

It is caused by the advanced adhesion physics being overlapped when the train speed is nearly zero - to enable the train to stop correctly. Confirmed and in progress...

[Matej Pacha (matej-pacha)]

V1690

[Sid Penstone (penstone)]

Fixed! Thank you.