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Scheme description / Schemenbeschreibung

Position of trainBrakes in the XML-Tree / Position von trainBrakes im XML-Baum

Multiplicity / Anzahl


Semantics / Bedeutung

The element <trainBrakes> describes the type of vehicle brakes and their applciation as brake effort or deceleration. There is a distinction between normal brake operation and emergency brake application.

Das Element <trainBrakes> beschreibt die Bauart(en) und Wirkung, d.h die erzielbare Bremskraft bzw. -verzögerung, der Fahrzeugbremsen. Es wird dabei zwischen der normalen Betriebsbremsung und der Schnell-(Not-)bremsung unterschieden.

Attributes of trainBrakes / Attribute von trainBrakes

  • brakeType: This names the type of brake producing the brake effort. According to the way of controlling the brake application one of the following values should be selected:
  • none no brake at all
  • compressedAir (pneumatic) brake system using compressed air to press the brake shoes onto the wheels or brake discs.
  • vacuum brake system using vacuum in the control pipe. The brake shoes are pressed onto the wheels by means of athmospheric air pressure.
  • handBrake manually applied brake by turning a handle or a lever which operates a gear/rod assembly with brake shoes
  • parkingBrake mainly spring applied brake used to keep a parking vehicle stationary
  • cableBrake brake applied by a cable running along the train
    "Seilzugbremse", z. B. Bauart Heberlein
  • other:anything: Any value that does not fit any value from the previous enumeration list, fulfilling the constraint: at minimum two characters, whitespace is not allowed. Please, apply Dev:usingAny accordingly.
    brake applied by any other mechanism
  • airBrakeApplicationPosition: This is the setting for the air brake application defining the time span for activation. Possible values are:
  • N/A not applicable as brakeType is not compressedAir
  • G slow activation, typical for freight trains or Merchandises
  • P fast activation, typical for passenger trains with speed up to 120 km/h
  • R rapid activation, typical for passenger trains with higher speed
  • regularBrakeMass: This is the brake mass in metrical tons for normal brake operations of none-automatic brakes.
  • regularBrakePercentage (introduced with version 2.5): This is the brake percentage related to brake mass for normal brake operations of none-automatic brakes.
  • emergencyBrakeMass: This is the brake mass in metrical tons for emergency brake operations of none-automatic brakes. It differs from regular brake mass depending on auxiliary brakes.
  • emergencyBrakePercentage (introduced with version 2.5): This is the brake percentage related to brake mass for emergency brake operations, differs from regular brake percentage depending on auxiliary brakes.
  • maxDeceleration: This is the alternative specification of maximum possible momentary deceleration in metres per square second. Typically this value is achieved near standstill.
  • meanDeceleration: This is the alternative specification of effective mean deceleration of a whole brake operation in metres per square second.

Syntactic Constraints / Syntaktische Beschränkungen

  • regularBrakePercentage xs:integer, within the range of 6 and 225, brake percentage as value of braking performance in relation to vehicle weight, optional
  • emergencyBrakePercentage xs:integer, within the range of 6 and 225, brake percentage as value of braking performance in relation to vehicle weight, optional
  • maxDeceleration: xs:decimal, 3 fraction digits, acceleration value measured in m/s², optional
  • meanDeceleration: xs:decimal, 3 fraction digits, acceleration value measured in m/s², optional

Best practice & Examples / Empfohlene Anwendung & Beispiele

It may be assumed that there are defined the following two vehicles at <vehicles>:

An engine:

<vehicle id='veh_ME26' … bruttoWeight='122' … >
    <vehicleBrake brakeType='parkingBrake' regularBrakeMass='24'/>
    <vehicleBrake brakeType='compressedAir'
    <vehicleBrake brakeType='compressedAir'
    <vehicleBrake brakeType='compressedAir'
    <vehicleBrake brakeType='compressedAir'
      <auxiliaryBrakes brakeUse='both' E='true'/>

And a carriage:

<vehicle id='veh_DABpza785.2' … bruttoWeight='55.000' … >
    <vehicleBrake brakeType='parkingBrake' regularBrakeMass='5'/>
    <vehicleBrake brakeType='compressedAir'
    <vehicleBrake brakeType='compressedAir'
    <vehicleBrake brakeType='compressedAir'
      <auxiliaryBrakes brakeUse='both' ep='true'/>
    <vehicleBrake brakeType='compressedAir'
      <auxiliaryBrakes brakeUse='both' ep='true'/>
      <auxiliaryBrakes brakeUse='emergency' Mg='true'/>

A formation consisting of one engine id='veh_ME26' (operating in brake appli-cation R+E ) and four carriages id='veh_DABpza785.2' (operating in brake application R+Mg<ep>) would look like this:

<formation id='fmt_1' name='ME26+4xDABpza785.2' … >
    <vehicleRef orderNumber='1' vehicleRef='veh_ME26' vehicleCount='1'/>
    <vehicleRef orderNumber='2' vehicleRef='veh_ DABpza785.2' vehicleCount='4'/>
  <trainBrakes brakeType='compressedAir'
          <auxiliaryBrakes E='true' Mg='true' ep='true'/>

Due to the difference between emergency and regular brake mass of the carriage in brake application R+Mg (the magnetic brake being effective at emergency brake actions only), there is also a difference in the brake percentages of the train.
regular brake mass = 215 t + 4x 95 t
emergency brake mass = 215 t + 4x 127 t

Note: A formation can normally be "used" (by the timetable) fully loaded or empty or anywhere in-between. The brake switch (G/P/R) and the brake mass (where there is a full/empty switch or an automatic brake) depend on the load of the formation. Therefore, it is not common to write the <trainBrakes> element of a formation but rather to use the element <brakeUsage> of a train. The latter is recommended.

Notes / Anmerkungen

Ein Fahrzeug hat in der Regel mehrere Bremswirkungen, weil

  1. mehrere unabhängige Bremssysteme eingebaut sind und/oder
  2. ein Bremssystem mehrere "Betriebsarten" ("Bremsstellungen") haben kann.

Dabei wird es bei den meisten heutigen Eisenbahnfahrzeugen darauf hinauslaufen, dass mehrere Bremsstellungen aus dem Sammelsurium [G, P, R, P+Mg, R+Mg, P+E, R+E, P+H, R+H...] angegeben sind. Es kann aber auch Wagen geben (und die gibt es wirklich!), die mehrere Bremssystembauformen haben, also Druckluftbremse und Saugluftbremse oder Druckluftbremse und Seilbremse oder so. Je nachdem, was das Triebfahrzeug hat, ist dann entweder die eine oder die andere Bremsbauform benutzt. Außerdem hat jedes Fahrzeug noch eine Handbremse / Feststellbremse, die hier als eigene Bremsbauform zu betrachten ist und daher als eigene Instanz von <trainBrakes> angegeben werden soll.

Open issues / Offene Punkte/Pendenzen

Not yet described. / Noch nicht beschrieben.