Add supply reservoir simulation

Author: SteelFill

Source/Documentation/Manual/physics.rst

@@ -2361,9 +2361,6 @@ be about 1 minute for every 12 cars. If the *Brake Pipe Charging Rate*
 will be disabled and will also disable some but not all of the other new
 brake features.
 
-Brake system charging time depends on the train length as it should, but
-at the moment there is no modeling of main reservoirs and compressors.
-
 For EP brakes, two variants are available:
 
 - If ``Wagon(ORTSEPBrakeControlsBrakePipe`` is set to 0 (default situation),
@@ -3071,6 +3068,9 @@ MaxAuxilaryChargingRate and EmergencyResChargingRate.
    single: ORTSBrakePipeTimeFactor
    single: ORTSEPBrakeControlsBrakePipe
    single: ORTSCompressorIsMuControlled
+   single: Supply_Reservoir
+   single: ORTSSupplyResCapacity
+   single: ORTSSupplyResChargingRate
 
 - ``Wagon(BrakePipeVolume`` -- Volume of car's brake pipe in cubic feet
   (default .5).
@@ -3105,7 +3105,9 @@ MaxAuxilaryChargingRate and EmergencyResChargingRate.
   during release. Remains active until aux res has recharged.
 - ``Wagon(ORTSMainResPipeAuxResCharging`` -- Boolean value that indicates,
   for twin pipe systems, if the main reservoir pipe is used for charging the auxiliary
-  reservoirs. If set to false, the main reservoir pipe will not be used
+  reservoirs. Alternately, if equipped with a supply reservoir, the supply reservoir
+  will charge from the main reservoir pipe instead. If set to false, the main reservoir
+  pipe will not be used (default: true).
   by the brake system.
 - ``Wagon(ORTSEPBrakeControlsBrakePipe`` -- Set to 1 for UIC EP brake: brake pipe
   pressure is electrically controlled at every fitted car.
@@ -3177,6 +3179,16 @@ MaxAuxilaryChargingRate and EmergencyResChargingRate.
 - ``Wagon(ORTSCylinderSpringPressure`` -- Below the specified pressure, no
   brake force will be developed, simulating the pressure required to
   overcome the brake cylinder return spring (default 0).
+- ``BrakeEquipmentType(Supply_Reservoir`` -- Adds a supply reservoir to the
+  loco or wagon, which will constantly charge to the brake pipe pressure
+  or MR pipe (if equipped) pressure. If a supply reservoir is equipped,
+  supply res air will be used to pressurize the brake cylinders thru the relay
+  valve. This allows for a small, fast charging auxiliary reservoir to
+  be used with large brake cylinders.
+- ``Wagon(ORTSSupplyResCapacity`` -- Volume of the supply reservoir. Larger
+  volumes relative to the brake cylinder volume allow for more brake applications.
+- ``Wagon(ORTSSupplyResChargingRate`` -- The rate at which the pressure of the
+  supply reservoir will increase when charging from the brake pipe or MR pipe.
 - ``Engine(ORTSMainResChargingRate`` -- Rate of main reservoir pressure change
   in psi per second when the compressor is on (default .4).
 - ``Engine(ORTSEngineBrakeReleaseRate`` -- Rate of engine brake pressure

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

@@ -338,7 +338,8 @@ public bool LargeEjectorSoundOn
             { BrakeSystemComponent.EmergencyReservoir, PressureUnit.None },
             { BrakeSystemComponent.MainPipe, PressureUnit.None },
             { BrakeSystemComponent.BrakePipe, PressureUnit.None },
-            { BrakeSystemComponent.BrakeCylinder, PressureUnit.None }
+            { BrakeSystemComponent.BrakeCylinder, PressureUnit.None },
+            { BrakeSystemComponent.SupplyReservoir, PressureUnit.None }
         };
 
         protected float OdometerResetPositionM = 0;
@@ -732,6 +733,7 @@ protected void GetPressureUnit()
                     BrakeSystemPressureUnits[BrakeSystemComponent.MainPipe] = BrakeSystemPressureUnits[BrakeSystemComponent.MainReservoir]; // Main Pipe is supplied by Main Reservoir
                     BrakeSystemPressureUnits[BrakeSystemComponent.AuxiliaryReservoir] = BrakeSystemPressureUnits[BrakeSystemComponent.BrakePipe]; // Auxiliary Reservoir is supplied by Brake Pipe (in single pipe brakes)
                     BrakeSystemPressureUnits[BrakeSystemComponent.EmergencyReservoir] = BrakeSystemPressureUnits[BrakeSystemComponent.BrakePipe]; // Emergency Reservoir is supplied by Brake Pipe
+                    BrakeSystemPressureUnits[BrakeSystemComponent.SupplyReservoir] = BrakeSystemPressureUnits[BrakeSystemComponent.BrakePipe]; // Supply Reservoir is supplied by Brake Pipe and MR Pipe
 
                     foreach (BrakeSystemComponent component in BrakeSystemPressureUnits.Keys.ToList())
                     {

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

@@ -276,6 +276,11 @@ public enum BrakeValveType
         /// </summary>
         public bool AuxiliaryReservoirPresent;
 
+        /// <summary>
+        /// Indicates whether an additional supply reservoir is present on the wagon or not.
+        /// </summary>
+        public bool SupplyReservoirPresent;
+
         /// <summary>
         /// Active locomotive for a control trailer
         /// </summary>
@@ -1292,6 +1297,9 @@ public virtual void Parse(string lowercasetoken, STFReader stf)
                             case "manual_brake": ManualBrakePresent = true; break;
                             case "retainer_3_position": RetainerPositions = 3; break;
                             case "retainer_4_position": RetainerPositions = 4; break;
+                            case "supply_reservoir":
+                                SupplyReservoirPresent = true;
+                                break;
                         }
                     }
                     break;
@@ -1641,6 +1649,7 @@ public virtual void Copy(MSTSWagon copy)
             HandBrakePresent = copy.HandBrakePresent;
             ManualBrakePresent = copy.ManualBrakePresent;
             AuxiliaryReservoirPresent = copy.AuxiliaryReservoirPresent;
+            SupplyReservoirPresent = copy.SupplyReservoirPresent;
             RetainerPositions = copy.RetainerPositions;
             InteriorShapeFileName = copy.InteriorShapeFileName;
             InteriorSoundFileName = copy.InteriorSoundFileName;

Source/Orts.Simulation/Simulation/RollingStocks/SubSystems/Brakes/BrakeSystem.cs

@@ -29,7 +29,8 @@ public enum BrakeSystemComponent
         EmergencyReservoir,
         MainPipe,
         BrakePipe,
-        BrakeCylinder
+        BrakeCylinder,
+        SupplyReservoir
     }
 
     public abstract class BrakeSystem