diff --git a/lua/entities/gmod_subway_81-717_mvm/init.lua b/lua/entities/gmod_subway_81-717_mvm/init.lua
index 7863c4b..4310f9a 100644
--- a/lua/entities/gmod_subway_81-717_mvm/init.lua
+++ b/lua/entities/gmod_subway_81-717_mvm/init.lua
@@ -670,7 +670,7 @@ function ENT:Think()
     else
         self:SetPackedRatio("BLPressure", Pneumatic.BrakeLinePressure/16.0)
     end
-    self:SetPackedRatio("TLPressure", Pneumatic.TrainLinePressure/16.0)
+    self:SetPackedRatio("TLPressure", Pneumatic.AuxiliaryLinePressure/16.0)
     self:SetPackedRatio("BCPressure", Pneumatic.BrakeCylinderPressure/6.0)
     self:SetPackedRatio("EnginesVoltage", self.Electric.Aux750V/1000.0)
     self:SetPackedRatio("EnginesCurrent2",  0.5 + 0.5*(self.Electric.I13/500.0))
diff --git a/lua/entities/gmod_subway_base/cl_init.lua b/lua/entities/gmod_subway_base/cl_init.lua
index bc508eb..be41d96 100644
--- a/lua/entities/gmod_subway_base/cl_init.lua
+++ b/lua/entities/gmod_subway_base/cl_init.lua
@@ -1097,7 +1097,9 @@ function ENT:Think()
 
                 if i==1 then
                     local no1 = ntbl.loop and ntbl.loop==0
-                    local endt = (ntbl.loop and snd:GetTime() > ntbl.loop or snd:GetTime()/snd:GetLength() >= 0.8) or no1
+                    --Any use of endt local was commented out to avoid unexpected interruption of the horn sound being played during air pressure reduction
+                    --(seems like it doesn't affect other sounds but still need to be repeatedly tested)
+                    --local endt = (ntbl.loop and snd:GetTime() > ntbl.loop or snd:GetTime()/snd:GetLength() >= 0.8) or no1
                     if stbl.state and stbl.volume < v.volume and not no1 then
                         if snd:GetState() ~= GMOD_CHANNEL_PLAYING then
                             snd:Play()
@@ -1118,7 +1120,7 @@ function ENT:Think()
                         end
                         stbl.time = nil
                     end
-                    if stbl.state and endt then
+                    if stbl.state then --and endt then
                         stbl.state = false
                         if no1 then
                             stbl.time = true
diff --git a/lua/metrostroi/systems/sys_81_717_pneumatic.lua b/lua/metrostroi/systems/sys_81_717_pneumatic.lua
index 689a11d..3c6f475 100644
--- a/lua/metrostroi/systems/sys_81_717_pneumatic.lua
+++ b/lua/metrostroi/systems/sys_81_717_pneumatic.lua
@@ -36,6 +36,8 @@ function TRAIN_SYSTEM:Initialize(parameters)
     -- Pressure in trains brake line
     self.BrakeLinePressure = 0.0 -- atm
     self.EPKPressure = 0.0 -- atm
+    -- Pressure in train's auxiliary line
+	self.AuxiliaryLinePressure = 8.0 -- atm
     -- Pressure in brake cylinder
     self.BrakeCylinderPressure = 0.0 -- atm
     -- Pressure in the door line
@@ -155,7 +157,7 @@ end
 
 function TRAIN_SYSTEM:Outputs()
     return { "BrakeLinePressure", "BrakeCylinderPressure", "DriverValvePosition",
-             "ReservoirPressure", "TrainLinePressure", "DoorLinePressure", "WeightLoadRatio", "WorkingChamberPressure" }
+             "ReservoirPressure", "TrainLinePressure", "DoorLinePressure", "WeightLoadRatio", "WorkingChamberPressure", "AuxiliaryLinePressure" }
 end
 
 function TRAIN_SYSTEM:TriggerInput(name,value)
@@ -324,6 +326,7 @@ function TRAIN_SYSTEM:Think(dT)
     self.BrakeCylinderPressure_dPdT = 0.0
     self.ParkingBrakePressure_dPdT = 0.0
     self.WorkingChamberPressure_dPdT = 0.0
+	self.AuxiliaryLinePressure_dPdT = 0.0
 
     local rnd = math.random(1,10)
     local offs = 0.1
@@ -593,6 +596,10 @@ function TRAIN_SYSTEM:Think(dT)
     -- Simulate cross-feed between different wagons
     self:UpdatePressures(Train,dT)
 
+	-- Simulate air pressure drop while the horn is engaged
+    local horny = self.Train:GetNW2Bool("HornState",false)
+	self:equalizePressure(dT,"AuxiliaryLinePressure", horny and math.max(0,self.TrainLinePressure - 0.3) or self.TrainLinePressure, 22)	--was 12		
+	self.TrainLinePressure = self.TrainLinePressure - (horny and 0.012 or 0)
     ----------------------------------------------------------------------------
     -- Simulate compressor operation and train line depletion
     self.Compressor = Train.KK.Value * (Train.Electric.Aux750V > 550 and 1 or 0)