diff --git a/src/Devices/AtcBombardier.cs b/src/Devices/AtcBombardier.cs
index f399635..f988743 100644
--- a/src/Devices/AtcBombardier.cs
+++ b/src/Devices/AtcBombardier.cs
@@ -58,25 +58,25 @@ namespace OpenbveFcmbTrainPlugin
         private TrackStates TrackState;
 
         /// <summary>The time needed by the ATC device to initialize, in seconds.</summary>
-        private readonly double InitializationTime;
+        private double InitializationTime;
 
         /// <summary>A counter to keep track of initialization time, in seconds.</summary>
         private double InitializationCounter;
 
         /// <summary>The blinking time for lamps, in milliseconds.</summary>
-        private readonly double BlinkTime;
+        private double BlinkTime;
 
         /// <summary>A counter to keep track of blink time, in milliseconds.</summary>
         private double BlinkCounter;
 
         /// <summary>The time after which YARD mode enters idle state and engages the service brake, in seconds.</summary>
-        private readonly double YardIdleTime;
+        private double YardIdleTime;
 
         /// <summary>A counter to keep track of YARD mode idle time, in seconds.</summary>
         private double YardIdleCounter;
 
         /// <summary>The maximum speed in YARD mode, in km/h.</summary>
-        private readonly double YardMaximumSpeed;
+        private double YardMaximumSpeed;
 
         /// <summary>Represents an ATC movement permission order.</summary>
         private class MovementPermission
diff --git a/src/Devices/AtcDimetronic.cs b/src/Devices/AtcDimetronic.cs
index ae59c1d..3f834f8 100644
--- a/src/Devices/AtcDimetronic.cs
+++ b/src/Devices/AtcDimetronic.cs
@@ -50,7 +50,7 @@ namespace OpenbveFcmbTrainPlugin
         private TrackStates TrackState;
 
         /// <summary>The maximum speed in YARD mode, in km/h.</summary>
-        private readonly double YardMaximumSpeed;
+        private double YardMaximumSpeed;
 
         /// <summary>Represents an ATC speed code.</summary>
         private class SpeedCode
diff --git a/src/Devices/Deadman.cs b/src/Devices/Deadman.cs
index 5800cda..13cb93a 100644
--- a/src/Devices/Deadman.cs
+++ b/src/Devices/Deadman.cs
@@ -24,10 +24,10 @@ namespace OpenbveFcmbTrainPlugin
         private double Counter;
 
         /// <summary>The delay time until the service brake is applied, in seconds.</summary>
-        private readonly double BrakeDelay = 5.0;
+        private double BrakeDelay = 5.0;
 
         /// <summary>Whether the train must be completely stopped to release the brakes.</summary>
-        private readonly bool FullReset;
+        private bool FullReset;
 
         /// <summary>Creates an instance of the Deadman device.</summary>
         /// <param name="brakeDelay">The delay before the brakes are applied, in seconds.</param>
diff --git a/src/Devices/DoorClosingSound.cs b/src/Devices/DoorClosingSound.cs
index eb13768..e3b5527 100644
--- a/src/Devices/DoorClosingSound.cs
+++ b/src/Devices/DoorClosingSound.cs
@@ -118,18 +118,11 @@ namespace OpenbveFcmbTrainPlugin
                         // Use departure time - door closing sound duration
                         AiTriggerDoorClosingSound |= CurrentTime.Seconds >= route.CurrentStation.DepartureTime - DoorClosingSoundDuration;
                     }
+                    // TODO: AI gets stuck if doors open between stations, check distance to stop point
                 }
                 else
                 {
-                    // The doors have been opened between stations
-                    if (route.CurrentStation.StopPosition - route.CurrentStation.BackwardTolerance > train.State.Location)
-                    {
-                        AiTriggerDoorClosingSound = true;
-                    }
-                    else
-                    {
-                        AiTriggerDoorClosingSound = false;
-                    }
+                    AiTriggerDoorClosingSound = false;
                 }
             }
             else
@@ -173,10 +166,6 @@ namespace OpenbveFcmbTrainPlugin
             {
                 DoorOpenTime = CurrentTime;
             }
-
-            // Set door closing counter to value higher than maximum where doors are allowed to close
-            // This effectively locks the doors when they open
-            DoorClosingSoundCounter = DoorClosingSoundDuration + DoorClosingSoundTimeout;
         }
 
         /// <summary>Is called when the device should perform the AI.</summary>