A retarder is a device used to augment or replace some of the functions of primary friction-based braking systems, usually on heavy vehicles. Retarders serve to slow vehicles, or maintain a steady speed while traveling down a hill, and help prevent the vehicle from "running away" by accelerating down the hill. They are not usually capable of bringing vehicles to a standstill, as their effectiveness diminishes as vehicle speed lowers. They are usually used as an additional "assistance" to slow vehicles, with the final braking done by a conventional friction braking system. As the friction brake will be used less, particularly at higher speeds, their service life is increased, and since in those vehicles the brakes are air-actuated helps to conserve air pressure too.
Friction-based braking systems are susceptible to "brake fade" when used extensively for continuous periods, which can be dangerous if braking performance drops below what is required to stop the vehicle – for instance if a truck or bus is descending a long decline. For this reason, such heavy vehicles are frequently fitted with a supplementary system that is not friction-based.
Retarders are not restricted to road motor vehicles, but may also be used in railway systems. The British prototype Advanced Passenger Train (APT) used hydraulic retarders to allow the high-speed train to stop in the same distance as standard lower speed trains, as a pure friction-based system was not viable.
Friction-based braking systems are susceptible to "brake fade" when used extensively for continuous periods, which can be dangerous if braking performance drops below what is required to stop the vehicle – for instance if a truck or bus is descending a long decline. For this reason, such heavy vehicles are frequently fitted with a supplementary system that is not friction-based.
Retarders are not restricted to road motor vehicles, but may also be used in railway systems. The British prototype Advanced Passenger Train (APT) used hydraulic retarders to allow the high-speed train to stop in the same distance as standard lower speed trains, as a pure friction-based system was not viable.
by Huvudpersson July 24, 2017
An insult meant for someone who would lay down their opinion as absolute fact despite being intellectually dishonest. Typically once their claim has been addressed, instead of engaging with the point, they will quickly blurt out something off the top of their head that usually will yet again be dishonest.
by Barrack Hussein Obamna December 7, 2022
someone or something that is more than just retarded, it is the extreme version or next level of retardation
person 1.
dude, i just lost a game of rock, paper, scissors to Helen Keller
person 2.
man, that is piss retarded!
dude, i just lost a game of rock, paper, scissors to Helen Keller
person 2.
man, that is piss retarded!
by proman7777 August 17, 2011
by amoseboolsd September 8, 2023
Holy retard that is retarded
by HOLY RETARD August 19, 2019
A group of two or more weebs is called a Retardation. they typically do not use deodorant and smell of death. avoid a Retardation at all costs.
by TheHelpfulFlareon February 15, 2022