Improvements to loco brakes, compressor synchronization, train brake release, and train brake sounds to improve compatibility with DPU

Author: SteelFill

Source/Orts.Simulation/Simulation/Physics/Train.cs

@@ -4312,10 +4312,10 @@ public List<TrainCar> DetermineLocomotiveGroup(TrainCar loco)
                 // If locomotive is a steam locomotive, check for tenders only
                 if (first >= 0 && loco is MSTSSteamLocomotive)
                 {
-                    if (first > 0 && Cars[first - 1].WagonType == TrainCar.WagonTypes.Tender)
-                        first--;
-                    if (last < Cars.Count - 1 && Cars[last + 1].WagonType == TrainCar.WagonTypes.Tender)
+                    if (last < Cars.Count - 1 && !loco.Flipped && Cars[last + 1].WagonType == TrainCar.WagonTypes.Tender)
                         last++;
+                    else if (first > 0 && loco.Flipped && Cars[first - 1].WagonType == TrainCar.WagonTypes.Tender)
+                        first--;
                 }
                 else // Other locomotive types
                 {
@@ -4351,9 +4351,8 @@ public TrainCar DetermineDPLeadLocomotive(TrainCar locoCar)
         {
             if (Cars.Contains(locoCar) && locoCar is MSTSLocomotive loco)
                 foreach (TrainCar dpLead in DPLeadUnits)
-                    if (dpLead is MSTSLocomotive dpLeadLoco)
-                        if (dpLeadLoco.DPUnitID == loco.DPUnitID)
-                            return dpLead;
+                    if (dpLead is MSTSLocomotive dpLeadLoco && dpLeadLoco.DPUnitID == loco.DPUnitID)
+                        return dpLead;
 
             return null;
         }

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

@@ -1644,7 +1644,8 @@ public override void Initialize()
                 // for airtwinpipe system, make sure that a value is set for it
                 if (MaximumMainReservoirPipePressurePSI == 0)
                 {
-                    MaximumMainReservoirPipePressurePSI = MaxMainResPressurePSI;
+                    // Add 5 psi to account for main res overcharging that might happen
+                    MaximumMainReservoirPipePressurePSI = MaxMainResPressurePSI + 5.0f;
                     if (Simulator.Settings.VerboseConfigurationMessages)
                     {
                         Trace.TraceInformation("AirBrakeMaxMainResPipePressure not set in ENG file, set to default pressure of {0}.", FormatStrings.FormatPressure(MaximumMainReservoirPipePressurePSI, PressureUnit.PSI, MainPressureUnit, true));
@@ -2694,31 +2695,37 @@ protected virtual void UpdateCompressor(float elapsedClockSeconds)
                 }
             }
 
-            // Turn compressor on and off
-            if (MainResPressurePSI < CompressorRestartPressurePSI && LocomotivePowerSupply.AuxiliaryPowerSupplyState == PowerSupplyState.PowerOn && !CompressorIsOn)
+            // Determine compressor synchronization
+            bool syncCompressor = false;
+
+            // Compressor synchronization is ignored if 5 psi above the high setpoint
+            if (MainResPressurePSI < MaxMainResPressurePSI + 5.0f && LocomotivePowerSupply.AuxiliaryPowerSupplyState == PowerSupplyState.PowerOn)
             {
-                SignalEvent(Event.CompressorOn);
                 foreach (List<TrainCar> locoGroup in Train.LocoGroups)
                 {
-                    // Synchronize compressor between coupled locomotives
-                    if (locoGroup.Contains(this as TrainCar))
+                    // Only synchronize in a group of locomotives directly connected
+                    // or synchronize between any two locomotives with MU controlled mode
+                    foreach (TrainCar locoCar in locoGroup)
                     {
-                        foreach (TrainCar locoCar in locoGroup)
-                            if (locoCar is MSTSLocomotive loco && loco.LocomotivePowerSupply.AuxiliaryPowerSupplyOn && !loco.CompressorIsOn)
-                                loco.SignalEvent(Event.CompressorOn);
-                    }
-                    else if (CompressorIsMUControlled) // Synchronize compressor between remote groups if configured to do so
-                    {
-                        foreach (TrainCar remoteLocoCar in locoGroup)
-                            if (remoteLocoCar is MSTSLocomotive remoteLoco && remoteLoco.LocomotivePowerSupply.AuxiliaryPowerSupplyOn && !remoteLoco.CompressorIsOn && remoteLoco.CompressorIsMUControlled)
-                                remoteLoco.SignalEvent(Event.CompressorOn);
+                        if (locoCar is MSTSLocomotive loco)
+                            syncCompressor |= (locoGroup.Contains(this as TrainCar) || CompressorIsMUControlled && loco.CompressorIsMUControlled)
+                                && loco.CompressorIsOn && loco.MainResPressurePSI < loco.MaxMainResPressurePSI;
+
+                        // No need to check repeatedly if we already know to sync compressors
+                        if (syncCompressor)
+                            break;
                     }
+                    if (syncCompressor)
+                        break;
                 }
             }
-            else if ((MainResPressurePSI >= MaxMainResPressurePSI || LocomotivePowerSupply.AuxiliaryPowerSupplyState != PowerSupplyState.PowerOn) && CompressorIsOn)
-            {
+
+            if ((MainResPressurePSI < CompressorRestartPressurePSI || (syncCompressor && MainResPressurePSI < MaxMainResPressurePSI))
+                && LocomotivePowerSupply.AuxiliaryPowerSupplyState == PowerSupplyState.PowerOn && !CompressorIsOn)
+                SignalEvent(Event.CompressorOn);
+            else if (((MainResPressurePSI >= MaxMainResPressurePSI && !syncCompressor)
+                || LocomotivePowerSupply.AuxiliaryPowerSupplyState != PowerSupplyState.PowerOn) && CompressorIsOn)
                 SignalEvent(Event.CompressorOff);
-            }
 
             if (CompressorIsOn)
                 MainResPressurePSI += elapsedClockSeconds * reservoirChargingRate;

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

@@ -291,6 +291,11 @@ public enum BrakeValveType
         /// </summary>
         public MSTSSteamLocomotive AuxTendersSteamLocomotive { get; private set; }
 
+        /// <summary>
+        /// Tender attached to this steam locomotive
+        /// </summary>
+        public TrainCar AttachedTender { get; private set; }
+
         /// <summary>
         /// Steam locomotive has a tender coupled to it
         /// </summary>
@@ -3651,6 +3656,7 @@ public void ConfirmSteamLocomotiveTender()
                 {
                     SteamLocomotiveTender = Train.Cars[0] as MSTSSteamLocomotive;
                     SteamLocomotiveTender.HasTenderCoupled = false;
+                    SteamLocomotiveTender.AttachedTender = null;
                 }
 
                 var tenderIndex = 0;
@@ -3664,18 +3670,21 @@ public void ConfirmSteamLocomotiveTender()
                 {
                     SteamLocomotiveTender = Train.Cars[tenderIndex] as MSTSSteamLocomotive;
                     SteamLocomotiveTender.HasTenderCoupled = true;
+                    SteamLocomotiveTender.AttachedTender = Train.Cars[tenderIndex + 1];
                 }
 
                 else if (tenderIndex > 0 && Train.Cars[tenderIndex - 1].WagonType == WagonTypes.Tender) // Assuming the tender is "in front" of the locomotive, ie it is running in reverse
                 {
                     // TO BE CHECKED - What happens if multiple locomotives are coupled together in reverse?
                     SteamLocomotiveTender = Train.Cars[tenderIndex] as MSTSSteamLocomotive;
                     SteamLocomotiveTender.HasTenderCoupled = true;
+                    SteamLocomotiveTender.AttachedTender = Train.Cars[tenderIndex - 1];
                 }
                 else // Assuming that locomotive is a tank locomotive, and no tender is coupled
                 {
                     SteamLocomotiveTender = Train.Cars[tenderIndex] as MSTSSteamLocomotive;
                     SteamLocomotiveTender.HasTenderCoupled = false;
+                    SteamLocomotiveTender.AttachedTender = null;
                 }
             }
         }