A foot pedal acting as a dead man's switch in aA dead man's switch (for other names, see ) is a switch that is designed to be activated or deactivated if the operator becomes incapacitated, such as through, or being bodily removed from control. Originally applied to switches on a vehicle or machine, it has since come to be used to describe other intangible uses like in computer software.These switches are usually used as a form of where they stop a machine with no operator from a potentially dangerous action or incapacitate a device as a result of accident, malfunction, or misuse. They are common in such applications in, and many devices. On some machines, these switches merely bring the machines back to a safe state, such as reducing the throttle to idle or applying brakes while leaving the machines still running and ready to resume normal operation once control is reestablished.Dead man's switches are not always used to stop machines and prevent harm. These switches can also be used as a. A spring-operated switch can also be used to complete a circuit when it is no longer held down. This means that a dead man's switch may be used to activate a harmful device, such as a.
Apr 19, 2020 Canada's Worst Mass Shooting Leaves at Least 18 Dead. 2:47 PM PDT 4/19/2020 by the Associated Press. A 51-year-old man on Sunday went on a. The doctor postulated the soul was material and therefore had mass, ergo a measurable drop in the weight of the deceased would be noted at the moment this essence parted ways with the physical.
The user holds down a switch of some sort in their hand which arms the device. The device will activate when the switch is released, so that if the user is knocked out or killed while holding the switch, the bomb will detonate. The is an application of this concept in the field of nuclear weapons. A more extreme version is Russia's program, which allows for automatic launch of nuclear missiles should a number of conditions be met, even if all Russian leadership were to be killed.A similar concept is the handwritten from the to the commanding officers of the four British. They contain orders on what action to take if the British government were destroyed in a nuclear attack. After a prime minister leaves office the letters are destroyed unopened.This concept has been employed with computer data, where sensitive information has been previously encrypted and released to the public, and the 'switch' is the release of the decryption key, as with.
Contents.Background Interest in dead-man's controls increased with the introduction of (streetcars in North America) and especially electrified trains. The first widespread use came with the introduction of the mass-produced, though dead-man equipment was fairly rare on US until the successful, which had a left-foot-operated dead-man's pedal in conjunction with the right-foot-operated and power pedals. This layout has continued to be used on some modern trams around the world. In conventional trains, there was always a second person with the engineer, the fireman, who could almost always bring the train to a stop if necessary. For many decades this practice continued on electric and diesel, 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 system in the early 20th century.
The on the 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.The status and operation of both vigilance and dead-man's switch may be recorded on the train's (commonly known as a black box).Types Handle Many dead man's switches are mounted in the control handle of a vehicle or machine and engage if the operator ever loses their grip.Vehicles Handle switches are still used on modern trams and trains. Or electrically linked dead-man's controls involve relatively simple modifications of the controller handle, the device that regulates traction power. If pressure is not maintained on the controller, the train's emergency brakes are applied. Typically, the controller handle is a horizontal bar, rotated to apply the required power for the train.
Attached to the bottom of the handle is a rod that when pushed down contacts a or switch inside the control housing. The handle springs up if pressure is removed, releasing the rod's contact with the internal switch, instantly cutting power and applying the brakes.Though there are ways that this type of dead-man's control could conceivably fail, they have proven highly reliable. On some earlier equipment, pressure was not maintained on the entire controller, but on a large button protruding from the controller handle. This button also had to be pressed continuously, typically with the palm of the hand so that the button was flush with the top of the handle. Another method used, particularly with some lever-type controllers, which are rotated rather than pushed or pulled, requires that the handle on the lever be turned through 90 degrees and held in that position while the train is in operation. Some dead-man's controls require the motorman to hold it in the mid-position rather than apply full pressure (see ).In modern trains, for example, the dead man's switch is incorporated into the train's speed control. On the car, the train operator must continually hold the lever in place in order for the train to move.Machinery Handle-mounted dead man's switches are also used on many hand-held tools and lawn equipment, typically those that rotate or have blades such as saws, drills and lawn mowers.
On saws for example, they incorporate a squeeze throttle trigger into the handle. If the user loses grip of the saw, the springs in the throttle trigger will push it back out to the off or idle setting, stopping the blade from spinning. Some tools go further and have a trigger guard built into the handle, similar to.
Only when the user presses in the trigger guard first will it then release its lock on the trigger and allow the trigger to be pressed in. Typically, trigger guards can only be pressed in while the user has a firm grip of the handle.Every walk-behind mower sold in the US since 1982 has a dead man's switch called an 'operator-presence control', which by law must stop the blades within 3 seconds after the user lets go of the controls. Attached across their handle is a mechanical lever connected by a flexible cable to the kill switch on the engine. While mowing, the operator must always squeeze the lever against the handle. If the operator ever loses grip of the handle the engine will die, stopping the blades from spinning and if equipped, any drive wheels from turning. This switch configuration also acts as the main kill switch for the engine. When the operator wants to stop the engine, they intentionally release the dead man's switch.Touch sensor On some vehicles, including the diesel-electric railway locomotives in Canada, and on vehiclesthe tram's speed controller is fitted with a capacitive touch sensor to detect the driver's hand.
If the hand is removed for more than a short period of time, the are activated. Gloves, if worn, have to be finger-less for the touch sensor to operate. A back up dead-man's switch button is provided on the side of the controller for use in the case of a failed touch sensor or if it is too cold to remove gloves.Pedal A pedal can be used instead of a handle.
While some pedal switches must simply be held down in order for the machine to function (this system is often found on amusement rides, where the operator is likely to remain in a standing position for a lengthy period of time while the ride is in motion), this method has some shortcomings. In the, south of Sydney, Australia, in 2003, it appeared that the driver slumped on his seat, keeping the pedal depressed when he died suddenly of a heart attack. This also happened to a passenger train in the 1970s, but the problem was noticed by other crew members and the train safely halted. There are some solutions to this issue that are now used in modern pedal systems.
The pedal can have a vigilance function built in, where drivers must release and re-press the pedal in response to an audible signal. This prevents it from being defeated by the above circumstances and is a standard feature on most British DSD systems.Some types of locomotive are fitted with a three-position pedal, which must normally be kept in the mid-position. This also lessens the likelihood of accidentally defeating it, although it may still be possible to deliberately do so.
Adding a vigilance function to this type of pedal results in a very safe system. However, isolation devices are still provided in case of equipment failure, so a deliberate override is still possible. These isolation devices usually have tamper-evident seals fitted for that reason.Seat switches The dead man's switch can also be located beneath the seat of a vehicle or machine and engages if the operator is not in the seat holding the switch down. On modern tractors, the switch will cut the engine while the transmission is engaged or the is spinning. On riding lawn mowers, the switch is often more extreme where the switch will cut the engine even if the mower is parked and the blades aren't spinning.
Seat switches can also be used to keep small children from even starting the vehicle since they wouldn't weigh enough to completely hold down a switch adjusted to an adolescent's or adult's weight.Key switches On recreational vehicles such as boats, and snowmobiles, and on the control panel of many, the user or operator has a cord or lanyard attached to his or her wrist or life jacket, that is in turn attached to a mounted on the dead man's switch. Should the rider fall off the vehicle or the operator at least move away from the controls, the cord will be pulled out of the dead man's switch, turning off the engine or setting the throttle position to 'idle'. On powered boats in particular this cord is often called a 'kill cord' (for powered boats use around the wrist is not recommended). If the helmsman goes overboard or is forced away from the controls, the engine cuts out. This prevents the boat from continuing under power but out of control, risking injury to anyone in or out of the water including passengers who may have fallen out or may still be in the boat, and collision damage to any property in the path of this out of control boat. It is a common and dangerous practice to defeat the kill cord by fixing it to part of the boat instead of the operator; for convenience.
This has been the cause of accidents, some of which were fatal, and/or that have caused limb loss.Some luggage carts at airports and exercise have this feature. In the case of treadmills, the dead man's switch usually consists of an external magnet attached to a cord that clips to the user. If the user falls or walks away without turning off the treadmill, the switch cuts power to the treadmill belt.Altimeter switches developed a dead man's switch for its nuclear bombers, known as (SWESS), that ensured the nuclear payload detonated in the event of the crew becoming incapacitated through enemy action. The purpose of this device, unlike other examples mentioned above, was rather than. Once armed, the system would detonate the onboard nuclear weapons if the aircraft dropped below a predetermined level, typically due to being shot down.Vigilance control. See also:The main safety failing with the basic dead man's system is the possibility of the operating device being held permanently in position, either deliberately or accidentally. Vigilance control was developed to detect this condition by requiring that the dead man's device be released momentarily and re-applied at timed intervals.
There has also been a proposal to introduce a similar system to automotive. A hybrid between a dead man's switch and a vigilance control device is a.Software versions of dead man's switches are generally only used by people with technical expertise, and can serve several purposes, such as sending a notification to friends or deleting and data. The 'non-event' triggering these can be almost anything, such as failing to for 7 consecutive days, not responding to an automated e-mail, a -enabled telephone not moving for a period of time, or merely failing to type a code within a few minutes of a computer's.
An example of a software-based dead man's switch is one which starts when the computer boots up and can encrypt or delete user-specified data if an unauthorized user should ever gain access to the protected computer. Google's Inactive Account Manager allows the account holder to nominate someone else to access their services if not used for an extended period (the default is three months). An example of a software-based dead man's switch is deadswitch.eu.
Newer solutions available to the public utilize the growing market of mobile devices and instead of sending an automated e-mail, they will send a push notification directly to the mobile device and can alert family and/or friends in a much more convenient way.Spacecraft Many spacecraft use a form of dead man's switch to guard against command system failures. A timer is established that is normally reset by the receipt of any valid command (including one whose sole function is to reset the timer.) If the timer expires, the spacecraft enters a 'command loss' algorithm that cycles through a predefined sequence of hardware and/or software modes (such as the selection of a backup command receiver) until a valid command is received. The spacecraft may also enter a to protect itself while waiting for further commands.While having some similarities to a dead man's switch, this type of device (a command loss timer) is not actually a dead man's switch, because it aims to recover from a hardware failure rather than the absence of human operators. It is generally called a, and is also used extensively in nuclear power control systems. System components on a spacecraft that put it into a safe mode or cause it to execute default behaviors when no command is received within a predefined time window can be considered a dead man's switch, but hardware or software that attempts to receive a command from human operators through an alternate channel is an auto-recovering or adaptive communications system, not a dead man's switch. Recovered from a command receiver failure with a command loss timer.
See also:In most trains, a basic level of protection is provided by a 'Deadman's handle' or pedal. If the driver is taken ill and releases this, the power will be shut off and an will be initiated to stop the train.More recent safety standards do not consider this to be adequate, as the driver may slump over the deadman's handle and continue to hold it down even though they are not capable of controlling the train. Modern trains overcome this risk with the addition of a vigilance system to the deadman's system. A buzzer or bell sounds every minute or so in order to alert the motorman or engineer. If they do not respond by moving a controller, or releasing and then re-applying the deadman's handle, the system will automatically initiate an emergency brake application. Most major rail systems in the world use this equipment, both in their freight and passenger operations.
It is also used on the and other New York City Subway cars while under operation. In the US, older locomotives produced before 1995 do not carry this feature, but given the modular nature of the system it is not uncommon to find them retrofitted.Aircraft use vigilance control to minimize; descending to lower altitude if the pilot is unresponsive.In 2019, the became the first avionics suite capable of automatically diverting an aircraft to the nearest airport and landing it in the event a pilot fails to interact with the aircraft's controls or respond to system prompts. Brais, Rouco (April 13, 2019). RT. Newman, Andy (May 7, 2010). The New York Times.
Retrieved May 7, 2010. Retrieved 2013-11-15. Archived from on 2013-01-17. Retrieved 2013-05-07. Morris, Steven (6 May 2013).
Retrieved 2013-11-15. Sagan, Scott Douglas (1995). Princeton University Press. Retrieved 2008-11-16.
Retrieved 2019-07-05. Schneiders IT. Retrieved 2019-10-12. Allen, J.; Nance, H. Retrieved 4 March 2009. (PDF). Retrieved 2017-08-17.
Bertorelli, Paul (13 April 2015). Aviation Publishing Group. Retrieved 15 April 2015.External links. (PDF).
Published 2:10 PM EST Feb 20, 2020
HANAU, Germany – A 43-year-old German man who posted a manifesto calling for the 'complete extermination' of many 'races or cultures in our midst' shot and killed nine people of foreign background, most of them Turkish, in an attack on a hookah bar and other sites in a Frankfurt suburb, authorities said Thursday.
He was later found dead at his home along with his mother. Authorities said they were treating the rampage as an act of domestic terrorism.
The gunman first attacked the hookah bar and a neighboring cafe in Hanau at about 10 p.m. Wednesday, killing several people, then traveled about 1½ miles and opened fire again, first on a car and then a sports bar, claiming more victims.
The bloodshed came amid growing concerns about far-right violence in Germany and stepped-up efforts from authorities to crack down on it, including last week's detention of a dozen men on suspicion they were planning attacks against politicians and minorities.
Chancellor Angela Merkel said the shootings exposed the 'poison' of racism in Germany, and she pledged to stand up against those who seek to divide the country.
'There is much to indicate that the perpetrator acted out of far-right extremist, racist motives,' she said. 'Out of hatred for people with other origins, other faiths or a different appearance.'
Hookah lounges, also known as shisha bars, are places where people gather to smoke flavored tobacco from Middle Eastern water pipes. Metin Kan, who knew many of the victims, said it was obvious why the gunman chose the neighborhood.
'Look, a hookah bar there, a gaming parlor there, a doner kebab place there – it's a place frequented by immigrants,' he said. 'Why this hatred of foreigners? We all get along here.'
People of Turkish background make up Germany's single largest minority. Turkey's ambassador said five of the people killed in the attack were Turkish citizens.
Germany's federal prosecutor, Peter Frank, said that all nine people killed were of foreign backgrounds and that six others were injured, one seriously.
Investigators said it appeared the gunman acted alone, but Frank said the 'goal of the investigation is to find out whether there were, or are, people who knew of, or supported' the attacks. He added that his office was looking into any contacts the killer may have had inside Germany and abroad.
Kadir Kose, who ran over from a cafe he runs nearby after hearing the first shots, said he was shocked at the extent of the violence. While fights or stabbings aren't unheard of, he said, 'this is a whole other level, something we hear about from America.'
Witnesses and surveillance videos of the getaway car led authorities quickly to the gunman's home, said Peter Beuth, interior minister for the state of Hesse. Both the attacker and his 72-year-old mother had gunshot wounds, and the weapon was found on him, Beuth said.
Frank identified the gunman only as Tobias R., in line with German privacy laws, and confirmed he had posted extremist videos and a manifesto with 'confused ideas and far-fetched conspiracy theories' on his website.
The man identified himself as Tobias Rathjen on the website, which has now been taken down, with a mailing address matching that where the bodies of the killer and his mother were found.
In the manifesto, Rathjen claimed to have approached police several times with conspiracy theories. But Beuth said it does not appear the gunman had a criminal record or was on the radar of Germany's domestic intelligence agency.
Among the documents posted to the man's website, which has since been taken down, was a 24-page, rambling manifesto in German detailing, among other things, fears that he has been under government surveillance for years. He blamed the surveillance for his inability to have a relationship with a woman. He also called for genocide.
'We now have ethnic groups, races or cultures in our midst that are destructive in every respect,' he wrote. He said he envisioned first a 'rough cleaning' and then a 'fine cleaning' that could halve the world's population.
He wrote: 'The following people must be completely exterminated: Morocco, Algeria, Tunisia, Libya, Egypt, Israel, Syria, Jordan, Lebanon, the complete Arabian Peninsula, Turkey, Iraq, Iran, Kazakhstan, Turkmenistan, Usbekistan, India, Pakistan, Afghanistan, Bangladesh, Vietnam, Laos, Cambodia and the Philippines.'
The attack was quickly condemned by many organizations, including the Central Council of Muslims, the Confederation of Kurdish Associations in Germany, and the Central Council of Jews.
'Everything will be done to investigate the circumstances of these terrible murders,' Merkel pledged, declaring: 'Racism is a poison. Hatred is a poison.'
'This poison exists in our society and its is responsible for far too many crimes,' she added, citing the killings committed by a far-right gang known as the NSU, the fatal shooting last year of a regional politician from her party, and a deadly attack on a synagogue in Halle in October.
Turkish President Recep Tayyip Erdogan called it a 'heinous attack' and expressed confidence that German authorities 'will exert all kinds of effort to shed light on all aspects of this attack.'
German police were examining a video the gunman may have posted online several days before the attack in which he detailed a conspiracy theory about child abuse in the United States, the German news agency dpa reported. The authenticity of the video couldn't immediately be verified, but the YouTube account was under the same name as the website containing the gunman's manifesto.
In the video, the speaker said he was delivering a 'personal message to all Americans' that 'your country is under control of invisible secret societies.' In a slow and deliberate voice in accented English, he said there are 'deep underground military bases' in which 'they abuse, torture and kill little children.'
He made no reference to the far-right fringe QAnon movement in the U.S., but the message was similar to the movement's central, baseless belief that President Donald Trump is waging a secret campaign against enemies in the 'deep state' and a child sex trafficking ring run by satanists and cannibals.
In his manifesto, he made one reference to Trump, writing: 'I doubt that Donald Trump knowingly implements my recommendations.' He suggested that 'mind control' might be at work.
On the website, Rathjen wrote that he was born in Hanau in 1977 and grew up in the city, later training with a bank and earning a business degree in 2007.
Geir Moulson in Berlin, Michael Probst and Christoph Noelting in Hanau, and Suzan Fraser in Ankara contributed to this report. Rising and Jordans reported from Berlin.
Published 2:10 PM EST Feb 20, 2020