BrakeControllers

Aim - this section describes some common brake control positions, and how they can be modeled within the Open Rails ENG file.

The BrakeControllers are used to model the valve positions on typical train or locomotive (engine) brake controllers.

For more information on the types of control valves used by each brake system refer to here.

Index

Introduction

A-6-ET (Engine and Tender) Brake Control

A-7-EL Brake Control

26-L Brake Control

24-RL Brake Control

Useful Links


Introduction

Over the years various brake systems have been developed. To control these brake systems various brake control valves were used to allow the locomotive driver to control the operation of the brakes. Older brakes tended to use air valves, whereas more modern systems have electrical (electronic) switches. The control valves or switches had multiple positions which allowed the driver to release or apply the brake under different scenarios. For more information on the types of control valves used by each brake system refer to here.

Open Rails attempts to emmulate the operation of these valves or switches by providing a number of brake control tokens which can be defined in the ENG file. Each of these tokens may have a different function associated with them, and therefore the user should use the relevant tokens for the brake control being modelled. The order of the tokens when defined in the ENG file should be maintaind in the same sequence as the tokens are designed to operate. Out of sequence tokens may create incorrect brake control operations.

This page shows the brake control token that are thought to be used currently by Open Rails to define each of the relevant brake controller types. This is currently a work in progress, so any relevant feedback is welcomed through the contact page.

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A-6-ET (Engine and Tender) Brake Control

This type of brake system was typically fitted to steam locomotives and their tenders.

Automatic Brake Valve Controller () (Train Brake)
Brake Valve Position State OR BrakeContoller Type
Release Brake releases. TrainBrakesControllerReleaseStart
Running Maintains pressure in train brake pipe as set by Equalising Reservoir pressure. TrainBrakesControllerRunningStart
Lap (or Neutral) Causes a minimum service pressure reduction (typically 6-8 psi) when moved from the running to the Lap position, then allows brake pipe pressure to decrease due to train pipe leakage. TrainBrakesControllerHoldLappedStart
Service Produces a gradual reduction in train brake pipe pressure. TrainBrakesControllerFullServiceStart
Emergency Emergency application of brakes. TrainBrakesControllerEmergencyStart
Independent Brake Valve Controller () (Engine Brake)
Brake Valve Position

State

OR BrakeContoller Type
Release Releases locomotive brake regardless of train brake setting. EngineBrakesControllerFullQuickReleaseStart
Running Allows the train brake to control the engine brake. This is the normal brake position when the train is running. EngineBrakesControllerRunningStart
Lap (or Neutral) Holds the brake pressure at the pressure set by other positions. EngineBrakesControllerHoldLappedStart
Slow Application Allows a slow application of the brake. EngineBrakesControllerFullServiceStart
Fast Application Allows a fast application of the brake. EngineBrakesControllerEmergencyStart

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A-7-EL Brake Control

This brake system was very similar to the A-6 described above, but was designed for diesel or electric locomotives. It could support removal of brake handles to allow changing ends on the locomotive, regenerative (dynamic) braking could be added if required, and the main air hoses, such as the main reservoir were interconnected between locomotive to more easily support multiple heading.

Automatic Brake Valve Controller () (Train Brake)
Brake Valve Position State OR BrakeContoller Type
Release Brake releases. TrainBrakesControllerReleaseStart
Running Maintains pressure in train brake pipe as set by Equalising Reservoir pressure. TrainBrakesControllerRunningStart
Lap (or Neutral) Causes a minimum service pressure reduction (approx 6-8 psi) when moved from the running to the Lap position, then allows brake pipe pressure to decrease due to train pipe leakage. TrainBrakesControllerHoldLappedStart
Service Produces a gradual reduction in train brake pipe pressure. TrainBrakesControllerFullServiceStart
Emergency Emergency application of brakes. TrainBrakesControllerEmergencyStart
Independent Brake Valve Controller () (Engine Brake)
Brake Valve Position

State

OR BrakeContoller Type
Release Releases locomotive brake regardless of train brake setting. EngineBrakesControllerFullQuickReleaseStart
Running Allows the train brake to control the engine brake. This is the normal brake position when the train is running. EngineBrakesControllerRunningStart
Lap (or Neutral) Holds the brake pressure at the pressure set by other positions. EngineBrakesControllerHoldLappedStart
Slow Application Allows a slow application of the brake. EngineBrakesControllerFullServiceStart
Fast Application Allows a fast application of the brake. EngineBrakesControllerEmergencyStart

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26-L Brake Control

Note - The following brake control valve settings are currently proposed only, and have not been tested. Feedback upon their sutability and effectiveness is welcomed through the contact page.

Automatic Brake Valve Controller () (Train Brake)

Brake Valve Position

State

OR BrakeContoller Type

Release

This position is used for charging the air brake system and to release the automatic brakes. The brake handle should be left in this position when running and no application is required. When in this position, the brake valve will maintain brake pipe pressure to the maximum setting of the brake regulating valve (i.e dependin upon the sytem typiucally 70 or 90 psi).

TrainBrakesControllerReleaseStart

Minimum Reduction

With the handle moved to this position, a 6-8 psi brake pipe reduction is made and minimum braking effort is obtained. This position is used to make initial applications to adjust train slack and set the brakes up for further heavier applications. As far as operation of the equipment is concerned, the brake valve should not be returned directly back to release from this position, since a release after such a light application can result in stuck brakes.

TrainBrakesControllerMinimalReductionStart

Full Service

Full braking effect applied - The farther the handle is moved into the service zone, from Minimum Reduction to Full Service, the greater will be the brake pipe pressure reduction (which is controlled by the equalizing reservoir). The handle is moved to such that it reduces the equalizing reservoir to the desired amount and then stopped. The valve will then "lap" itself stopping the reduction at that point. The brake pipe pressure will then reduce a like amount and the maintaining feature will then maintain that reduced pressure allowing air to flow into the brake pipe to compensate for leakage, if necessary. If a release is desired, the handle should be moved all the way to the left to release position.

TrainBrakesControllerFullServiceStart

Suppression

This position gives a full service application and suppresses a penalty application and recovers PC (power knockout) action, resulting from a penalty application. If the cause of the penalty has been corrected and a full service reduction has been made, the brakes can then be released without coming to a stop. This position will not suppress or recover an emergency application or recover PC action resulting from an emergency and no attempt should be made to use it for that purpose.

TrainBrakesControllerSuppressionStart

Handle Off

This is the position in which the handle must be placed on trailing units of a multiple-unit locomotive or on locomotives being towed 'dead' in a train. If the handle is placed in this position with the brake valve cut in, the brake pipe will reduce to zero at a service rate. As per air brake rules, a 20 lb. reduction should be made and brake valve cut out before moving handle to this position when conditioning units for trail.

TrainBrakesControllerNeutralHandleOffStart

Emergency

It is the position that can be used to make a 'desired' emergency brake application. This position must be used to reset either a 'desired' or 'undesired' brake application.

TrainBrakesControllerEmergencyStart

Independent Brake Valve Controller () (Engine Brake)

Brake Valve Position

State

OR BrakeContoller Type

Release / Full Application

Between release and full application is the application zone. Movement of the handle from left to right causes increasing applications. Brake can be graduated off; that is, movement from right to left will give decreasing brake cylinder pressures.

EngineBrakesControllerFullQuickReleaseStart

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24-RL Brake Control

Note - The following brake control valve settings are currently proposed only, and have not been tested. Feedback upon their sutability and effectiveness is welcomed through the contact page.

Automatic Brake Valve Controller () (Train Brake)

Brake Valve Position

State

OR BrakeContoller Type

Release

In this position feed valve air is supplied to brake pipe and will charge the brake pipe to the maximum setting of the feed valve. Brakes will release. The RELEASE position charges the brake pipe at the same rate as the RUNNING position.

TrainBrakesControllerReleaseStart

Running

In this position, the feed valve air is supplied to the brake pipe and will charge the brake pipe to the setting of the feed valve. The RUNNING position charges the brake pipe and is used for releasing the engine and train brakes. When the automatic brake is not being used, place the brake valve handle in this position.

TrainBrakesControllerRunningStart

First Service

In this position an intial minimum service reduction is made, and then reduction continues at a much slower rate. The service brake reduction is made in the SERVICE position and then the brake valve handle must be moved to the FIRST SERVICE position while the air is exhausting from the service exhaust port. Do not pause in the LAP position. The brake valve handle must not be moved from the FIRST SERVICE position to the RUNNING position or the LAP position then back to the FIRST SERVICE position. More than one service application can be made by moving the brake valve handle from the FIRST SERVICE position to the SERVICE position and then returned directly to the FIRST SERVICE position. The FIRST SERVICE function can be disabled if desired by the driver.

TrainBrakesControllerMinimalReductionStart

Lap

Brake pipe pressure will not be maintained against leakage when the brake valve handle is in this position. All operating ports are closed when in this position and the resulting brake pipe leakage will cause the engine and the train brakes to apply. This position is used primarily for:

  • Recovery from penalty brake application
  • Testing the amount of leakage in the brake pipe

TrainBrakesControllerGraduatedSelfLapLimitedStart

Service

This position allows the feed valve air supply to the brake pipe to be cut off. The equalizing reservoirs is exhausted to the atmosphere through the preliminary exhaust port, actuating the equalizing discharge valve to the exhaust brake pipe air with a corresponding amount (through the discharge valve and the rotary valve exhaust), at a service rate. In this position the equalizing reservoir pressure is reduced and brake pipe pressure reduced accordingly, at a service rate. This brake valve is not self-lapping in this position; that is, the reduction will not be limited by the valve. Equalizing reservoir pressure should be reduced the desired amount, and then handle should be moved to lap or pressure maintaining position, whichever is required.

TrainBrakesControllerContinuousServiceStart

Emergency

This position allows passages to be connected to provide a large, direct exhaust passage from the brake pipe to the atmosphere which produces an emergency rate of brake pipe reduction.

TrainBrakesControllerEmergencyStart

Independent Brake Valve Controller () (Engine Brake)

Brake Valve Position

State

OR BrakeContoller Type

Locking

Brake disabled, uses train brake.

EngineBrakesControllerNeutralhandleOffStart

Release / Full Application

Between release and full application is the application zone. Movement of the handle from left to right causes increasing applications. Brake can be graduated off; that is, movement from right to left will give decreasing brake cylinder pressures.

EngineBrakesControllerFullQuickReleaseStart

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Sample Coupler Code

Typically the lines shown in red text are the only ones that would need to be changed on individual wagons.

Comment ( ************************* Engine Controls ******************************* )

Brake_Train ( 0 1 0.01 0.25(
NumNotches ( 5
Notch( 0.0 0 TrainBrakesControllerReleaseStart )
Notch( 0.25 0 TrainBrakesControllerRunningStart )
Notch( 0.50 0 TrainBrakesControllerHoldStart )
Notch( 0.75 0 TrainBrakesControllerFullServiceStart )
Notch( 1.0 0 TrainBrakesControllerEmergencyStart )
)

Brake_Engine ( 0 1 0.01 0.25(
NumNotches ( 5
Notch( 0.0 0 EngineBrakesControllerReleaseStart )
Notch( 0.25 0 EngineBrakesControllerRunningStart )
Notch( 0.50 0 EngineBrakesControllerHoldStart )
Notch( 0.75 0 EngineBrakesControllerFullServiceStart )
Notch( 1.0 0 EngineBrakesControllerEmergencyStart )
)

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Useful Links

24-RL Locomotive Brake Equipment

26-L Locomotive Brake Equipment

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