A tether is a cord, fixture, or flexible attachment that characteristically anchors something movable to something fixed; it also may be used to connect two movable objects, such as an item being
towed by its tow.
Applications for tethers include:
fall arrest system
Fall arrest is the form of fall protection which involves the safe stopping of a person already falling. It is one of several forms of fall protection, forms which also include fall guarding (general protection that prevents persons from enteri ...
s,
lanyards, balloons, kites,
airborne wind-power systems,
anchor
An anchor is a device, normally made of metal, used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ', which itself comes from the Greek ().
Anch ...
s, floating water power systems, towing,
animal constraint,
space walks,
power kiteing, and
anti-theft
Anti-theft systems protect valuables such as vehicles and personal property like wallets, phones, and jewelry. They are also used in retail settings to protect merchandise in the form of security tags and labels. Anti-theft systems include devices ...
devices.
Failure
Failure modes for tethers are considered in their design.
A cord or rope tether may reach its
breaking strength and fail. Outcomes can include an injury or fatal fall, and damage or loss of life to personnel or bystanders caused by backlash of the ruptured segments.
Failure-prevention may be designed into a tethering system. Some
safety harness
A safety harness is a form of Personal protective equipment, protective equipment designed to safeguard the user from injury or death from falling. The core item of a fall arrest system, the harness is usually fabricated from rope, Wire rope, bra ...
es are used in combination with a
shock-absorbing lanyard, which has break-away stitching designed into it to prevent material failure and regulate
deceleration, thereby preventing a serious
G-force
The g-force or gravitational force equivalent is a Specific force, mass-specific force (force per unit mass), expressed in Unit of measurement, units of standard gravity (symbol ''g'' or ''g''0, not to be confused with "g", the symbol for ...
injury to the user when the end of the rope is reached.
Designed-to-fail safety links are sometimes used to prevent excessive tension in a tether involved in towing objects, such as
sailplane
A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailplan ...
s.
A signal tether is a system in which a constant signal designates a positive condition, and its interruption, whether by discontinuation or jamming, conveys a failure. The signal may be electrically generated, or a physical device such as flying a flag.
See also
*
Umbilical cable
*
Safety lanyard
References
External links
* by TechSander.com
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Hardware (mechanical)