Merge pull request #1132 from SteelFill/correct_questionable_leaks

Fixes For Correct Questionable Braking Parameters

Author: twpol

Source/Documentation/Manual/options.rst

@@ -863,21 +863,23 @@ are a problem for OR, which has a more sophisticated braking model. The
 problem usually is that the train brakes require a long time to release,
 and in some times do not release at all.
 
-.. index::
-   single: AirBrakesAirCompressorPowerRating
-
 The following checks and corrections are performed if the option is
-checked (only for single-pipe brake system):
+checked:
 
 - if the compressor restart pressure is smaller or very near to the max
   system pressure, the compressor restart pressure and if necessary the max
-  main reservoir pressure are increased;
+  main reservoir pressure are increased (single pipe air brakes only)
 - if the main reservoir volume is smaller than 0.3 m\ :sup:`3` and the
   engine mass is higher than 20 tons, the reservoir volume is raised to 0.78
-  m\ :sup:`3`;
-- the charging rate of the reservoir is derived from the .eng parameter
-  ``AirBrakesAirCompressorPowerRating`` (if this generates a value greater
-  than 0.5 psi/s) instead of using a default value.
+  m\ :sup:`3`
+- the maximum brake cylinder pressure will be reduced to the maximum pressure
+  possible from a full service train brake application if it was set above this
+  amount
+- any brake pipe leakage specified by ``TrainPipeLeakRate`` is limited to 2.5 psi/minute
+- the dynamic brake delay on electric locomotives is reduced to 2 seconds
+  if it was defined to be above 4 seconds
+- dynamic brake force left at the default value of 20kN will be increased to
+  half the locomotive's continuous force, or 150kN, whichever is lower
 
 For a full list of parameters, see :ref:`Developing ORTS Content - Parameters and Tokens<parameters_and_tokens>`
 

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

@@ -389,7 +389,7 @@ public float OdometerM
         public float CompressorRestartPressurePSI = 110;
         public float CompressorChargingRateM3pS = 0.075f;
         public bool CompressorIsMUControlled = false;
-        public float MainResChargingRatePSIpS = 0.4f;
+        public float MainResChargingRatePSIpS = -1.0f;
         public float EngineBrakeReleaseRatePSIpS = 12.5f;
         public float EngineBrakeApplyRatePSIpS = 12.5f;
         public float BrakePipeTimeFactorS = 0.0015f;
@@ -1869,21 +1869,6 @@ public override void Initialize()
                 }
             }
 
-            // Initialise Train Pipe Leak Rate
-            if (TrainBrakePipeLeakPSIorInHgpS == 0) // Check to see if TrainBrakePipeLeakPSIorInHgpS has been set in the ENG file.
-            {
-                // Set Default Train Brake Pipe Leak depending upon whether locomotive has Vacuum or air brakes - overwritten by ENG file setting.
-                // Default currently set to zero - means that by default function is off, and a value must be entered into the ENG file to get it to work
-                if ((BrakeSystem is VacuumSinglePipe))
-                {
-                    TrainBrakePipeLeakPSIorInHgpS = 0.0f; // Vacuum brakes
-                }
-                else
-                {
-                    TrainBrakePipeLeakPSIorInHgpS = 0.0f; // Air brakes
-                }
-            }
-
             if (DynamicBrakeEngineBrakeReplacement && DynamicBrakeEngineBrakeReplacementSpeed == 0)
             {
                 DynamicBrakeEngineBrakeReplacementSpeed = DynamicBrakeSpeed2MpS;
@@ -1990,16 +1975,18 @@ protected void CorrectBrakingParams()
                     // correct questionable MaxCylPressurePSI
                     BrakeSystem.CorrectMaxCylPressurePSI(this);
                 }
-                if (MainResChargingRatePSIpS <= 0)
-                {
-                    MainResChargingRatePSIpS = Math.Max(0.5f, (CompressorChargingRateM3pS * Bar.ToPSI(1)) / MainResVolumeM3);
-                }
+                // Limit brake pipe leak to 2.5 psi/min (~ 1 bar every 6 minutes) to prevent stuck brakes
+                if (TrainBrakePipeLeakPSIorInHgpS > 2.5f / 60f)
+                    TrainBrakePipeLeakPSIorInHgpS = 2.5f / 60f;
+            }
+            // No OR compressor speed defined, use MSTS compressor speed or 0.025 m^3/s (whichever is higher)
+            if (MainResChargingRatePSIpS < 0) 
+            {
+                MainResChargingRatePSIpS = Math.Max(0.025f, CompressorChargingRateM3pS) * OneAtmospherePSI / MainResVolumeM3;
             }
-            else if (MainResChargingRatePSIpS <= 0) MainResChargingRatePSIpS = 0.4f;
 
             // Corrections for dynamic braking parameters
 
-            if (this is MSTSElectricLocomotive && DynamicBrakeDelayS > 4) DynamicBrakeDelayS = 2; // Electric locomotives have short engaging delays
             if (DynamicBrakeSpeed2MpS > 0 && DynamicBrakeSpeed3MpS > 0 && DynamicBrakeSpeed2MpS > DynamicBrakeSpeed3MpS)
             {
                 // also exchanging DynamicBrakesMaximumEffectiveSpeed with DynamicBrakesFadingSpeed is a frequent error that upsets operation of
@@ -2010,8 +1997,11 @@ protected void CorrectBrakingParams()
             }
             if (Simulator.Settings.CorrectQuestionableBrakingParams)
             {
+                if (this is MSTSElectricLocomotive && DynamicBrakeDelayS > 4)
+                    DynamicBrakeDelayS = 2; // Electric locomotives have short engaging delays
+
                 if (MaxDynamicBrakeForceN > 0 && MaxContinuousForceN > 0 &&
-                (MaxDynamicBrakeForceN / MaxContinuousForceN < 0.3f && MaxDynamicBrakeForceN == 20000))
+                    (MaxDynamicBrakeForceN / MaxContinuousForceN < 0.3f && MaxDynamicBrakeForceN == 20000))
                     MaxDynamicBrakeForceN = Math.Min (MaxContinuousForceN * 0.5f, 150000); // 20000 is suggested as standard value in the MSTS documentation, but in general it is a too low value
             }
         }