GW ATP

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GW ATP ( Automatic Train Protection ) is an automatic train protection system used in the United Kingdom on the Great Western (GW) routes between London ( Paddington ), Bristol Temple Meads , Bristol Parkway and Newbury. It is based on similar hardware as the Belgian TBL system, but there are some technical and operational differences. The system consists of a trackside balise on each signal and an on-board unit.

The system is only relevant for trains that travel at speeds of more than 160 km / h. The system offers the following core functions:

  • Fully automatic train protection for trains that are equipped accordingly and run on appropriately equipped infrastructure
  • Monitoring of the maximum vehicle speed and anti-roll device for trains that are equipped accordingly and run on unequipped infrastructure

Data from the route are transmitted through balises on the signals. If necessary, infill loops are used to improve operational performance.

Main features

Data transmission to the trains:

Tensile properties such as B. basic brake types, maximum speed are set via a preprogrammed parameter plug that is plugged into the vehicle unit. Changes to the train configuration and brake availability can be set by the driver at the start of the journey.

The driver is shown:

  • Maximum safe speed
  • Target speed
  • Expected status of the next signal in the direction of travel
  • Presence of an emergency speed limit
  • Fault indicators
  • Roll away
  • Intervention activation
  • Shunting operation
  • Stop signal crossing mode
  • Driving over stop signals
  • Driving over substitute signals (permitted travel on an occupied route)

Acoustic is reported:

  • Short warning tone every time the visual display changes
  • Continuous warning tone when the safe speed is exceeded, when there is an emergency speed limit, when crossing a signal indicating a stop, when the vehicle is rolling away or when a system fault is detected

The driver's cab is equipped with the following controls:

  • Buttons and indicators
  • Confirmation button to regain control after system intervention
  • Activation button for shunting operation
  • Button for crossing signals indicating stop with permission
  • Disconnector

Be monitored:

  • Maximum safe speed (line speed and fixed speed limits)
  • Temporary speed limits
  • Breakpoint
  • Dynamic braking profile
  • Direction of movement (including roll-away monitoring)

The system triggers full service braking when:

  • Exceeding the displayed maximum safe speed by a specified value if the driver does not react to the warning tone
  • Presence of an emergency speed limit
  • Occurrence of a recoverable system fault, e.g. B. Absence of expected data from a trackside balise.

The ATP system initiates emergency braking in the following cases:

  • The train passes a signal, so that a dangerous situation arises (the train is brought to a stop, then the driver can continue driving under partial supervision for 3 minutes or until it passes the next balise at a maximum of 32 km / h)
  • Rolling away (i.e. when moving more than 10 m or more than 8 km / h in a direction that deviates from the location and direction given by the main control)
  • Occurrence of an unrecoverable system fault

With regard to ETCS , GW ATP is managed as a Class B system (Class B system).