Lets talk about brakes (again)!

Discussion of rolling-stock creation & re-painting.

Lets talk about brakes (again)!

Unread postby Brahiam » Thu Jul 13, 2017 1:30 pm

Hello there!

On the last days I decided to try to tune the brakes of the freight cars to a more real approach.
As an ex-engineer here in Brazil, I used to drive heavy and long trains, up to 8500 metric tons and a mile long, so I have some practical knowledge about how a train must behave altought some of you alreday know that.
So...
As many of you knows, TS has a problem to calculate the brake effort on loadable cars so I tested on a empty version and on a load version of a BNSF grain hopper.
Our train setup here is 1 AC4400 or SD70Ace +1 C30 or Dash9 + 85~90 loaded cars + 1 AC44 or 2 x C30 (locotrol).
1) On a downgrade of 1.8% you must use at least 12psi and 60~70% of dynamic brake to hold it at 30(18mph)~35(21mph)km/h.
2) You must be able to drag an empty train with 2 engines on a minimal reduction.
In order to do both things I changed some values as follows:



On the loaded car:

<MaxForcePercentOfVehicleWeight d:type="sFloat32" d:alt_encoding="0000000000805140" d:precision="string">14</MaxForcePercentOfVehicleWeight>

<GraduatedRelease d:type="cDeltaString">eTrue</GraduatedRelease>
<ProportionalBrake d:type="cDeltaString">eTrue</ProportionalBrake>
<MaxReleaseRate d:type="sFloat32" d:alt_encoding="000000000000F03F" d:precision="string">0.20</MaxReleaseRate>
<MaxApplicationRate d:type="sFloat32" d:alt_encoding="000000000000F03F" d:precision="string">0.5</MaxApplicationRate>
<MaxCylinderPressure d:type="sFloat32" d:alt_encoding="0000000000004940" d:precision="string">65</MaxCylinderPressure>
<PressureForMaxForce d:type="sFloat32" d:alt_encoding="0000000000004940" d:precision="string">26</PressureForMaxForce>
<MaxSystemPressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</MaxSystemPressure>
<MinSystemPressure d:type="sFloat32" d:alt_encoding="0000000000000000" d:precision="string">1</MinSystemPressure>
<Distributor>
<EngineSimulation-cBrakeDistributorBlueprint d:id="85983264">
<NormalFullReleasePressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</NormalFullReleasePressure>
<FullServicePressure d:type="sFloat32" d:alt_encoding="0000000000003A40" d:precision="string">26</FullServicePressure>
<TrainPipeControlRatio d:type="sFloat32" d:alt_encoding="0000000000000440" d:precision="string">2.5</TrainPipeControlRatio>
<MaxEmergencyResPressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</MaxEmergencyResPressure>
<MaxAuxResPressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</MaxAuxResPressure>
<EmergencyApplicationPressure d:type="sFloat32" d:alt_encoding="0000000000405040" d:precision="string">65</EmergencyApplicationPressure>
</EngineSimulation-cBrakeDistributorBlueprint>
</Distributor>

<RollingFrictionCoefficient d:type="sFloat32" d:alt_encoding="000000C07493583F" d:precision="string">0.002</RollingFrictionCoefficient>




On the empty car:

<RollingFrictionCoefficient d:type="sFloat32" d:alt_encoding="000000C07493583F" d:precision="string">0.002</RollingFrictionCoefficient>

<MaxForcePercentOfVehicleWeight d:type="sFloat32" d:alt_encoding="0000000000805140" d:precision="string">20</MaxForcePercentOfVehicleWeight>

<GraduatedRelease d:type="cDeltaString">eTrue</GraduatedRelease>
<ProportionalBrake d:type="cDeltaString">eTrue</ProportionalBrake>
<MaxReleaseRate d:type="sFloat32" d:alt_encoding="000000000000F03F" d:precision="string">0.20</MaxReleaseRate>
<MaxApplicationRate d:type="sFloat32" d:alt_encoding="000000000000F03F" d:precision="string">0.5</MaxApplicationRate>
<MaxCylinderPressure d:type="sFloat32" d:alt_encoding="0000000000004940" d:precision="string">65</MaxCylinderPressure>
<PressureForMaxForce d:type="sFloat32" d:alt_encoding="0000000000004940" d:precision="string">26</PressureForMaxForce>
<MaxSystemPressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</MaxSystemPressure>
<MinSystemPressure d:type="sFloat32" d:alt_encoding="0000000000000000" d:precision="string">1</MinSystemPressure>
<Distributor>
<EngineSimulation-cBrakeDistributorBlueprint d:id="85983264">
<NormalFullReleasePressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</NormalFullReleasePressure>
<FullServicePressure d:type="sFloat32" d:alt_encoding="0000000000003A40" d:precision="string">26</FullServicePressure>
<TrainPipeControlRatio d:type="sFloat32" d:alt_encoding="0000000000000440" d:precision="string">2.5</TrainPipeControlRatio>
<MaxEmergencyResPressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</MaxEmergencyResPressure>
<MaxAuxResPressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</MaxAuxResPressure>
<EmergencyApplicationPressure d:type="sFloat32" d:alt_encoding="0000000000405040" d:precision="string">65</EmergencyApplicationPressure>
</EngineSimulation-cBrakeDistributorBlueprint>
</Distributor>

<DryFriction d:type="sFloat32" d:alt_encoding="000000000000E03F" d:precision="string">0.1</DryFriction>
<WetFriction d:type="sFloat32" d:alt_encoding="000000000000D03F" d:precision="string">0.1</WetFriction>
<SnowFriction d:type="sFloat32" d:alt_encoding="000000403333C33F" d:precision="string">0.1</SnowFriction>



On the engine I changed this:

<MaxForcePercentOfVehicleWeight d:type="sFloat32" d:alt_encoding="000000A09999B93F" d:precision="string">0.1</MaxForcePercentOfVehicleWeight>

<GraduatedRelease d:type="cDeltaString">eTrue</GraduatedRelease>
<ProportionalBrake d:type="cDeltaString">eTrue</ProportionalBrake>
<MaxReleaseRate d:type="sFloat32" d:alt_encoding="000000000000F03F" d:precision="string">0.20</MaxReleaseRate>
<MaxApplicationRate d:type="sFloat32" d:alt_encoding="000000000000F03F" d:precision="string">0.5</MaxApplicationRate>
<MaxCylinderPressure d:type="sFloat32" d:alt_encoding="0000000000004940" d:precision="string">65</MaxCylinderPressure>
<PressureForMaxForce d:type="sFloat32" d:alt_encoding="0000000000004940" d:precision="string">26</PressureForMaxForce>
<MaxSystemPressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</MaxSystemPressure>
<MinSystemPressure d:type="sFloat32" d:alt_encoding="0000000000000000" d:precision="string">1</MinSystemPressure>
<Distributor>
<EngineSimulation-cBrakeDistributorBlueprint d:id="85983264">
<NormalFullReleasePressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</NormalFullReleasePressure>
<FullServicePressure d:type="sFloat32" d:alt_encoding="0000000000003A40" d:precision="string">26</FullServicePressure>
<TrainPipeControlRatio d:type="sFloat32" d:alt_encoding="0000000000000440" d:precision="string">2.5</TrainPipeControlRatio>
<MaxEmergencyResPressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</MaxEmergencyResPressure>
<MaxAuxResPressure d:type="sFloat32" d:alt_encoding="0000000000805640" d:precision="string">90</MaxAuxResPressure>
<EmergencyApplicationPressure d:type="sFloat32" d:alt_encoding="0000000000405040" d:precision="string">65</EmergencyApplicationPressure>
</EngineSimulation-cBrakeDistributorBlueprint>
</Distributor>

<RollingFrictionCoefficient d:type="sFloat32" d:alt_encoding="00000040BF7D4D3F" d:precision="string">0.001</RollingFrictionCoefficient>
<DryFriction d:type="sFloat32" d:alt_encoding="000000606666EE3F" d:precision="string">1.2</DryFriction>
<WetFriction d:type="sFloat32" d:alt_encoding="000000403333E33F" d:precision="string">0.8</WetFriction>
<SnowFriction d:type="sFloat32" d:alt_encoding="000000000000E03F" d:precision="string">0.5</SnowFriction>

-------------------------------------------------------------------------------------------------------------------------------------------------------
Going downhill with those settings it is a bit tricky as a freight train takes around 15 minutes to full recharge 85 cars and you be able to use the brakes without reciclying it.
As english isn't my mother language, feel free to correct me.
Brahiam
 
Posts: 8
Joined: Fri Oct 04, 2013 10:48 pm
Location: Rio Claro, Sao Paulo, Brazil

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