Disable braking wheel skid for rack railway stock

Author: peternewell

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

@@ -1595,6 +1595,11 @@ public override void Initialize()
                     Trace.TraceInformation("LocomotiveRailDriveType set to Default value of {0}", LocomotiveRailDriveType);
             }
 
+            if (LocomotiveRailDriveType == LocomotiveRailDriveTypes.Rack)
+            {
+                CogWheelFitted = true;
+            }
+
             SteamHeatPressureToTemperaturePSItoF = SteamTable.SteamHeatPressureToTemperatureInterpolatorPSItoF();
             SteamDensityPSItoLBpFT3 = SteamTable.SteamDensityInterpolatorPSItoLBpFT3();
             SteamHeatPSItoBTUpLB = SteamTable.SteamHeatInterpolatorPSItoBTUpLB();
@@ -1603,7 +1608,7 @@ public override void Initialize()
             if (WaterScoopFillElevationM == 0)
             {
                 WaterScoopFillElevationM = 2.7432f; // Set to default of 9 ft
-            } 
+            }
 
             if (WaterScoopDepthM == 0)
             {
@@ -1616,7 +1621,7 @@ public override void Initialize()
             }
 
             // Check if current sander has been set
-            if (CurrentTrackSandBoxCapacityM3 == 0 )
+            if (CurrentTrackSandBoxCapacityM3 == 0)
             {
                 CurrentTrackSandBoxCapacityM3 = MaxTrackSandBoxCapacityM3;
             }
@@ -1626,7 +1631,7 @@ public override void Initialize()
             {
                 if (MSTSLocoNumDrvWheels != 0 && MSTSLocoNumDrvWheels < 7)
                 {
-                    LocoNumDrvAxles = (int) MSTSLocoNumDrvWheels;
+                    LocoNumDrvAxles = (int)MSTSLocoNumDrvWheels;
                 }
                 else
                 {
@@ -1717,7 +1722,7 @@ public override void Initialize()
                     BrakePipeDischargeTimeFactor = 1.5f; // Air brakes
                 }
             }
-            
+
             // Initialise the resistance of the vacuum pump
             if (VacuumPumpResistanceN == 0)
             {

Source/Orts.Simulation/Simulation/RollingStocks/MSTSWagon.cs

@@ -101,7 +101,6 @@ public enum WindowState
         public bool IsDavisFriction = true; // Default to new Davis type friction
         public bool IsBelowMergeSpeed = true; // set indicator for low speed operation as per given speed
 
-
         public bool GenericItem1;
         public bool GenericItem2;
 
@@ -1549,8 +1548,10 @@ public virtual void Parse(string lowercasetoken, STFReader stf)
                     Couplers[CouplerCountLocation].Rigid = false;
                     Couplers[CouplerCountLocation].Rigid = stf.ReadBoolBlock(true);
                     break;
-               
 
+                case "wagon(ortscogwheel":
+                    CogWheelFitted = stf.ReadBoolBlock(false);
+                    break;
 
                 case "wagon(adheasion":
                     stf.MustMatch("(");
@@ -1756,6 +1757,7 @@ public virtual void Copy(MSTSWagon copy)
             Curtius_KnifflerB = copy.Curtius_KnifflerB;
             Curtius_KnifflerC = copy.Curtius_KnifflerC;
             AdhesionK = copy.AdhesionK;
+            CogWheelFitted = copy.CogWheelFitted;
             AxleInertiaKgm2 = copy.AxleInertiaKgm2;
             SlipWarningThresholdPercent = copy.SlipWarningThresholdPercent;
             Lights = copy.Lights;

Source/Orts.Simulation/Simulation/RollingStocks/TrainCar.cs

@@ -597,6 +597,8 @@ public Direction Direction
         public float BrakeShoeForceN;
         public float FrictionBrakeBlendingMaxForceN; // This is the maximum force for the friction barke when it is blended with the dynamic brake
 
+        public bool CogWheelFitted = false;
+
         // Sum of all the forces acting on a Traincar in the direction of driving.
         // MotiveForceN and GravityForceN act to accelerate the train. The others act to brake the train.
         public float TotalForceN; // 
@@ -1099,7 +1101,8 @@ public virtual void UpdateBrakeSlideCalculation()
         {
 
             // Only apply slide, and advanced brake friction, if advanced adhesion is selected, simplecontrolphysics is not set, and it is a Player train
-            if (Simulator.UseAdvancedAdhesion && !Simulator.Settings.SimpleControlPhysics && IsPlayerTrain)
+            // Rack stock with cog wheel fitted will not skid
+            if (Simulator.UseAdvancedAdhesion && !Simulator.Settings.SimpleControlPhysics && IsPlayerTrain && !CogWheelFitted)
             {
 
                 // ************  Check if diesel or electric - assumed already be cover by advanced adhesion model *********