Editing Dead man's switch (section)

==Background==
Interest in dead man's controls increased with the introduction of [[tram|electric trams]] (streetcars in North America) and especially electrified [[rapid transit]] trains. The first widespread use came with the introduction of the mass-produced [[Birney|Birney One-Man Safety (tram) Car]], though dead-man equipment was fairly rare on US [[streetcar]]s until the successful [[PCC streetcar]], which had a left-foot-operated dead man's pedal in conjunction with the right-foot-operated [[brake]] and power pedals. This layout has continued to be used on some modern trams around the world. In conventional [[steam railroad]] trains, there was always a second person with the engineer, the ''fireman'', who could almost always bring the train to a stop if necessary.<ref>{{Cite news|url=https://newspapers.library.in.gov/?a=d&d=IJ19030112&dliv=userclipping&cliparea=1.1%2C6200%2C3393%2C1124%2C1070&factor=4&e=-------en-20--1--txt-txIN-------|access-date=2020-06-06|date=1903-01-12|page=1 col. 6|work=Indianapolis Journal|volume=53|number=12|location=[[Indianapolis]]|title=HAND OF CORPSE AT THROTTLE. Engineer Killed at His Post, but the Train Ran On. |quote=<!-- Jan. 11. -->Passengers on an Incoming Knoxville & Ohio River Railroad train rode several miles this afternoon with the hand of a corpse at the throttle of the engine. The train left Buckeye, Tenn., on time and ran through to Careyville, the next station. When Engineer A. C. Young ran through the latter town Fireman Matlock knew something was wrong and stepped to the engineer's side of the engine. He found Young dead and immediately stopped the train. There is a wound on the left side of the engineer's head, and the supposition is that a piece of rock fell from the side of a high cut through the mountains and killed him instantly. '''The train ran perhaps eight miles after Young was killed.''' }}</ref> For many decades, two people were assigned to electric and diesel [[locomotive]]s as well, even though a single person could theoretically operate them.

With modern urban and suburban railway systems, the driver is typically alone in an enclosed cab. Automatic devices were already beginning to be deployed on newer installations of the [[New York City Subway]] system in the early 20th century. The [[Malbone Street Wreck]] on the [[Brooklyn Rapid Transit]] system in 1918, though not caused by driver incapacitation, did spur the need for universal deployment of such devices to halt trains in the event of the operator's disability. According to a Manhattan borough historian, there have been at least three instances where the dead man's switch was used successfully – in 1927, 1940, and 2010.<ref>{{cite news|url=http://cityroom.blogs.nytimes.com/2010/05/07/not-the-first-time-the-dead-man-switch-did-its-job/|title=Not the First Time the 'Dead-Man' Switch Did Its Job|last=Newman|first=Andy|date=May 7, 2010|work=The New York Times|access-date=May 7, 2010|archive-url=https://web.archive.org/web/20200518070458/https://cityroom.blogs.nytimes.com/2010/05/07/not-the-first-time-the-dead-man-switch-did-its-job/|archive-date=May 18, 2020}}</ref>

The status and operation of both vigilance and dead man's switch may be recorded on the train's [[event recorder]] (commonly known as a ''black box''). Modern locomotive practice is to incorporate the dead-man's and vigilance functions under the control of the [[alerter]] or the event recorder.<ref>{{cite web |url=https://www.wabtec.com/business-units/bach-simpson |title=Bach-Simpson |publisher=Wabtec |access-date=2023-11-22 |archive-date=2021-06-21 |archive-url=https://web.archive.org/web/20210621100445/https://www.wabtec.com/business-units/bach-simpson |url-status=dead }}</ref>