noun: railroad acronym for "Flashing Rear End Device", the "black
box" attached to the rear of most freight trains in the US since the 1980'
s, replacing the caboose.
Officially known as an End of Train Device (EOT), this is attached to the rear coupler and
air brake line of the last car on the train. The device incorporates a pressure sensor and a radio to transmit brake line
air pressure back to the lead locomotive, and a flashing red light to serve as a warning marker to other trains at night.
Also referred to in less complimentary terms as a "
Fucking Rear End Device", due to the fact that early versions were
heavy, cumbersome to handle, and not known to be especially reliable.
"FRED is telling us we have no
air. Either we
broke the train in two (uncoupled cars or
broke a coupler knuckle, which would disconnect an air line) or somebody closed an angle cock (valve that supplies air pressure to individual car brakes)."