AWS Overview
There is an Advanced Warning System (AWS) implementation included with Trainz for use with BR locomotive cabs.
AWS is an in-cab safety system used throughout the United Kingdom from the British Railways era to the present day. It is also used in parts of Australia and Hong Kong. It is used to ensure driver vigilance to signalling aspects, and requires the driver to acknowledge a restrictive signal aspect. If the driver fails to acknowledge the restrictive signal aspect, the system will stop the train.
AWS is used in conjunction with conventional lineside signalling, and can be found with both semaphore and colour light signalling.
As a signal is approached, a device in the track activates the AWS equipment in the cab. If the signal is clear (green), a confirmation sound (a bell or ping sound) is played. If the signal is not green, a warning sound (horn or buzzer) is played, and the driver must press a button to acknowledge the warning. If the button is pressed, the warning stops playing, and reminder display shows a yellow 'sunflower' pattern to remind the driver he has acknowledged a warning. If the button is NOT pressed within a short timeout period, the AWS will apply the emergency brake and stop the train.
For semaphore signalling, AWS ramps are generally only fitted on approach to distant (Yellow/Green) signals only. For colour light signalling, AWS is typically fitted to all signals. AWS can also be fitted on approach to severe speed restrictions.
It is possible to isolate (turn off) the AWS system for a specific train using the Isolation Switch. This will completely disable the system.