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Information about Fail Safe

A fail-safe or fail-secure describes a device which, if (or when) it fails, fails in a way that will cause no harm or at least a minimum of harm to other devices or danger to personnel. Examples include:
  • Luggage carts in airports in which the hand-brake must be held down at all times. If it is released, the cart will stop. See dead man's switch.
  • Air brakes on railway trains and trucks. The brakes are held in the 'off' position by air pressure created in the brake system. Should a brake line split, or a carriage become de-coupled, the air pressure will be lost and the brakes applied. It is impossible for the train to be driven with a leak in the brake system.
  • Avionics using redundant systems to perform the same computation with voting logic to determine the "safe" result.
  • Motorized gates - In case of power outage the gate can be pushed open by hand with no crank or key required. However, as this would allow virtually anyone to go through the gate, a fail-secure design is used: In a power outage, the gate can only be opened by a hand crank that is usually kept in a safe area.
  • An operation which ensures that a failure of equipment, process, or system does not propagate beyond the immediate environs of the failing entity.
  • The automatic protection of programs and/or processing systems when a hardware or software failure is detected in a computer system. See fail-safe (computer).
  • A control operation or function that prevents improper system functioning or catastrophic degradation in the event of circuit malfunction or operator error; for example, the failsafe track circuit used to control railway block signals.
  • A system that has been structured such that it cannot fail (or that the probability of such failure is extremely low) to accomplish its assigned mission, regardless of environmental factors; for example, the hardening of a nuclear missile bunker, or the dispersion of nuclear bombers to multiple secret locations.
  • A precautionary secondary mechanism that achieves the same task as the primary mechanism; for example, the activation of grenades when the primary detonator is destroyed, or the release of lethal gas when a device that activates explosives is destroyed.
  • Aircraft landing on an aircraft carrier increase the throttle to full power at touchdown. If the arresting wires fail to capture the plane, it safely takes off again.[1]
  • During the Apollo program of Moon landings, the spacecraft was put on a free return trajectory – if the engines failed at lunar orbit insertion, the craft would safely coast back to Earth.
  • The iron pallet ballast on the Bathyscaphe is dropped to allow the submarine to ascend. The ballast is held in place by electromagnets. If electrical power fails the ballast is released, and the submarine then ascends to safety.
Fail-safe (foolproof) devices are also known as Poka-Yoke devices. Poka-yoke, a Japanese term, was coined by Shigeo Shingo, a quality guru.

See also

References

1. ^ Harris, Tom. How Aircraft Carriers Work. HowStuffWorks, Inc. Retrieved on 2007-10-20.
Failure modes are characterizations of the ways a product or process can fail.

Rather than the simple description of symptoms that many product users or process participants might use, the term failure mode refers to a rather complete description, including the
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Luggage is any number of bags, cases and containers which hold a traveller's articles during transit. The modern traveller can be expected to have packages containing clothing, toiletries, small possessions, trip necessities, and on the return-trip, souvenirs.
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For other uses, see CART (disambiguation).


A cart is a vehicle or device, using two wheels and normally one horse, designed for transport. A dray or wagon is a heavy transport vehicle with four wheels and normally at least two horses.
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Episode no. Season 3
Episode 13
Guest stars James LeGros as Ben Conklin, Kristin Lehman as Katya Rubanoff, Donnelly Rhodes as Gen. James Eiger, Yee Jee Tso as Hong
Written by B.
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Air brake may refer to the following contexts:
  • Air brake (aircraft), in aeronautics, a type of flight control system used on aircraft to reduce speed
  • Air brake (rail), a type of brake operated by compressed air and used on locomotives and railroad cars

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train is a series of rail vehicles that move along guides to transport freight or passengers from one place to another. The guideway (permanent way) usually consists of conventional rail tracks, but might also be monorail or maglev.
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Avionics is a portmanteau which literally means aviation electronics. In essence it comprises all electronic systems designed for use on an aircraft. At a basic level this comprises communications, navigation and the display and management of multiple systems.
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Redundancy in engineering is the duplication of critical s of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe.
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Operation may refer to:
  • Scientific Operation.
  • Surgery operation.
  • An operation or operator in mathematics. See unary operation, binary operation, arity.

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System (from Latin systēma, in turn from Greek σύστημα systēma) is a set of entities, real or abstract, where each entity interacts with, or is related to, at least one other
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Hardware is a general term that refers to the physical artifacts of a technology.It may also mean the physical components of a computer system.

Hardware historically meant the metal parts and fittings that were used to make wooden products stronger, more functional, longer
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Computer software is a general term used to describe a collection of computer programs, procedures and documentation that perform some task on a computer system. [1]
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computer is a machine which manipulates data according to a list of instructions.

Computers take numerous physical forms. The first devices that resemble modern computers date to the mid-20th century (around 1940 - 1941), although the computer concept and various machines
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The automatic protection of programs and/or processing systems when a hardware or software failure is detected in a computer system.

External links

  • Implementation and evaluation of failsafe computer-controlled systems

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In telecommunication, a control operation (control function) is an operation that affects the recording, processing, transmission, or interpretation of data.
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Catastrophe, from the Greek Καταστροφή (katastrephein), literally means "to turn" (strephein) "downwards" (kata-).
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Degradation may refer to;
  • Biodegradation, the process by which organic substances are broken down by living organisms
  • Chemical decomposition, the degradation of chemical compounds
  • Degradation (song), by the Violent Femmes

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An electronic circuit is an electrical circuit that also contains active electronic devices such as transistors or vacuum tubes. They can display highly complex behaviors, even though they are governed by the same laws as simple electrical circuits.
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A track circuit is a simple electrical device used to detect the presence or absence of a train on a railroad track, used to inform signallers and control relevant signals.
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Railway signalling is a system used to control railway traffic safely, essentially to prevent trains from colliding. Being guided by fixed rails, trains are uniquely susceptible to collision; furthermore, trains cannot stop quickly, and frequently operate at speeds that do not
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Nuclear weapons delivery is the technology and systems used to place a nuclear weapon at the position of detonation, on or near its intended target. Several methods have been developed to carry out this task.
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bunker is a defensive military fortification. Bunkers are mostly below ground, compared to blockhouses which are mostly above ground. They were used extensively in World War I and World War II.
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bomber is a military aircraft designed to attack ground targets, primarily by dropping bombs.

Classifications of bombers

Strategic bombers are primarily designed for long-range strike missions with bombs against strategic targets such as supply bases, bridges, factories,
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aircraft carrier is a warship designed to deploy and in most cases recover aircraft, acting as a sea-going airbase. Aircraft carriers thus allow a naval force to project air power great distances without having to depend on local bases for staging aircraft operations.
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Apollo program was a human spaceflight program undertaken by NASA during the years 1961 – 1975 with the goal of conducting manned moon landing missions. John F. Kennedy announced this goal in 1961, and it was accomplished on July 20 1969 by Neil Armstrong and Buzz Aldrin
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bathyscape, bathyscaphe, or bathyscaph is a free-diving self-propelled deep-sea diving submersible, consisting of a crew cabin similar to a bathysphere suspended below a float (rather than from a surface cable, as in the classic bathysphere design)
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Foolproof means designed to function despite human error.

Foolproof may also refer to:
  • Foolproof, a 2003 Canadian heist film

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Poka-yoke (ポカヨケ - pronounced "POH-kah YOH-keh"|
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This article contains Japanese text.
Without proper ,
you may see question marks, boxes, or other symbols instead of kanji or kana.

Japanese
日本語
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