by jerryaayyyy March 8, 2009
Get the jumping retardmug. 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
Get the Retardermug. by Grandepapa November 7, 2022
Get the Retardmug. homie 1: yo sug happy birthday!
sug in question: it’s march 23rd…my birthdays in july?
homie 1: yea but it’s national retard day!
sug in question: it’s march 23rd…my birthdays in july?
homie 1: yea but it’s national retard day!
by abcdefjhijk May 22, 2024
Get the National retard daymug. by its ya boiiiiiiiiiiiiiiii February 21, 2022
Get the Retardmug. People who drive 10+ miles under the speed limit even though the speed sign is clearly shown.
People who text and drive.
Republican candidates after 1930.
People who have a perfectly functioning brain yet choose to be self entitled and ignorant.
People who text and drive.
Republican candidates after 1930.
People who have a perfectly functioning brain yet choose to be self entitled and ignorant.
Friend1: Why is the person in front of us not following the speed limit?They have plenty of room to go faster.
Friend2: Probably just some retard on their phone.
Friend2: Probably just some retard on their phone.
by givesnofucks26 June 16, 2023
Get the Retardmug. by lilleluderpik March 10, 2023
Get the Retardismmug.