Merge pull request #933 from peternewell/diesel-mechanic-bug

Fix AI DM crashing

Author: peternewell

Source/Orts.Simulation/Simulation/RollingStocks/MSTSLocomotive.cs

@@ -2015,9 +2015,6 @@ public override void Update(float elapsedClockSeconds)
 
             // Pass Gearbox commands
 
-
-
-
             // Note - at the moment there is only one GearBox Controller created, but a gearbox for each diesel engine is created. 
             // This code keeps all gearboxes in the locomotive aligned with the first engine and gearbox.
             if (gearloco != null && gearloco.DieselTransmissionType == MSTSDieselLocomotive.DieselTransmissionTypes.Mechanic && GearBoxController.CurrentNotch != previousChangedGearBoxNotch)
@@ -2156,8 +2153,13 @@ public override void Update(float elapsedClockSeconds)
                                     if (de.State != DieselEngineState.Running)
                                         de.Initialize();
                                 }
+
+                                // if train is a geared locomotive then set it to automatic operation as AI driver can't operate manual gearboxes
                                 if (de.GearBox != null)
                                     de.GearBox.GearBoxOperation = GearBoxOperation.Automatic;
+
+                                // Set gear to "low gear" at start.
+                                de.GearBox.currentGearIndex = de.GearBox.NumOfGears - 1;
                             }
                         }
                     }