Engineering:Dead-man's vigilance device
A dead-man's vigilance device (also called the driver vigilance device or DVD for short[1]) is a railroad safety device that operates in the case of incapacitation of the driver. It is a hybrid between a dead-man's switch and a vigilance control. The main safety failing with the basic dead-man's control system is the possibility of the operating device being permanently held in position, either deliberately or accidentally. The dead-man's vigilance device was developed to detect this condition by requiring that the dead-man's device be released momentarily and re-applied at timed intervals.
Modern practice
Modern locomotive practice is to incorporate the dead-man's and vigilance functions under the control of the alerter or the event recorder.[2]
Warning and braking
If the timer period is beginning to expire, a visual and audible warning is given. If the operator fails to acknowledge the warning, a penalty brake application results.
Accidents due to insufficient vigilance control
- 1987 Maryland train collision
- 2008 Chatsworth train collision
- Beresfield rail disaster (1997)
- Hinton train collision (1986)
- Violet Town rail accident (1969)
- Waterfall rail accident (2003)
References
External links
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