A dead-man's vigilance device (also called the Driver Vigilance Device or DVD for short) is a

railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

safety device that operates in the case of incapacitation of the driver. It is a hybrid between a

dead-man's switch A dead man's switch (see alternative names) is a switch that is designed to be activated or deactivated if the human operator becomes incapacitated, such as through death, loss of consciousness, or being bodily removed from control. Originally ...

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 A train event recorder – also called On-Train Monitoring Recorder (OTMR), On-Train Data Recorder (OTDR), Event Recorder System (ERS), Event Recorder Unit (ERU), or simply Event Recorder (ER) – is a device that records data about the operatio ...

. This enables more sophisticated monitoring of the driver's alertness. The vigilance control cycle time can then be speed dependent, varying inversely to train speed in order to reduce the distance the train may travel before a non-response is detected and acted upon.

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 The Hinton train collision was a rail transport accident that occurred in Canada on 8 February 1986. Twenty-three people were killed in a collision between a Canadian National Railway freight train and a Via Rail passenger train called the '' S ...

(1986) *

Violet Town rail accident The Violet Town rail accident, also known as the Southern Aurora disaster, was a railway accident that occurred on 7 February 1969 following the incapacitation of the Railroad engineer, driver of one of the trains, near the McDiarmids Road crossi ...

(1969) *

Waterfall rail accident The Waterfall rail accident was a train accident that occurred on 31 January 2003 near Waterfall, New South Wales, Australia. The train derailed, killing seven people aboard, including the train driver. The accident is famously remembered by ...

(2003)

References

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External links

FRA Regulations
Locomotive parts Railway safety Safety equipment