SYSTEM OVERVIEW

Following the decision to refurbish the existing train set for Stansted Express, running between Stansted Airport and London Liverpool Street, ADtranz were awarded the contract for 46 units. The audio communications refurbishment was awarded to GAI-Tronics to interface with the existing PA system, and to offer Driver to Guard (Crew) Communications, PA Facility, and Digitised Speech Messaging.

SYSTEM FUNCTIONALITY

The requirement from ADTranz was to provide replacement transmitter points for Stansted Express, utilising the existing train wiring and retaining original receiver amplifier units.

The new system provides for broadcast of up to 100 digitised PA messages in 5 languages - English, French, German, Italian and Spanish.
Messages are selected via a unit mounted keypad whereby the operator selects the appropriate language and message according to the incoming flights, i.e. if a flight is from Milan, then the announcements would be broadcast in English and Italian.

The unit also has a remote stalk microphone and handset enabling PA voice messaging via a footswitch operation from the driver/guard to the train set and crew to crew communication.

Digitised speech messaging is held on 'flash' memory, which is programmable on site with the use of a laptop computer.
The units are designed to occupy the same space envelope as the original units to simplify change over.

SYSTEM DIAGRAM



Illustration shows a typical simplified GAI-Tronics crew communications system incorporating all standard equipment.  Variations of the above are available