Railroading Merit Badge
Requirement 7d Study Guide
Explain the use and function of the EOTD (end-of-train device) or FRED (Flashing rear
end device) used on the last car of most trains.
The End-of-Train Device (EOTD) is a technological alternative to having a caboose on modern
freight trains today. To understand why it is important, you should also understand what role the
caboose played in years past.
The caboose was normally the last car on a train. It's primary
role was to help the safe operation of the train. It did this in
many ways;
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It was a safe place to be inside during bad weather.
There were red lights, to stop trains that might come
up behind them.
It was a place where the crew could smell, and look
for, smoke from hot axles.
The crew could also observe for shifted freight on
the train ahead.
The crew could also apply the brakes on the train,
if the engineer was unable.
The caboose often carried tools, and other safety
devices, to help the brakemen.
The caboose was often assigned to a single conductor, on
many railroads, and it would be switched onto the train that
the conductor would be in charge of that day. The brakemen
assigned to the train would stow their equipment in the
caboose.
As the railroads grew, larger locomotives allowed them to run longer trains, with the same number of crew. This
saved time and money, rather than running multiple trains. Unfortunately, being in the caboose at the back end of
very long trains (3/4 of a mile or longer), the crews could be thrown about the caboose, due to the slack action of the
couplers running in and out. Sometimes, this resulted in injuries, and time-off for the employees, or even a
disability. As a result of the injuries, the railroads looked a technoloigical replacement for the caboose.
The first attempt to replace the caboose, was to use the Flashing Rear-End Device (FRED). This was essentially a
battery box that could be fit to the coupler on the last car of the train. It had a red reflector, and a flashing red light,
and was supposed to replace the red light on a caboose. Without a caboose, the conductor and the brakeman would
now have to sit in the locomotive(s), and there was nobody at the rear of the train to watch for trouble.
Unfortunately, these devices replaced very little of the services that the caboose used to perform. A better solution
was needed.
The smarter big brother to FRED is the
End-of-Train Device (EOTD). This
device also fits in the rear coupler, has a
reflector, and a flashing light, but it also
connects to the air brake pipe, and it has
a 2-way radio to communicate with the
engineer! The EOTD has a Code
Number so it can only communicate
with the controller in the cab. The radio
allows the EOTD to tell the engineer the
brake pipe pressure at the rear of the
train, and it also allows the engineer, in
an emergency, to push a control button,
and set the air brakes from the end of
the train as well as the front of the train.
Trackside Defect Detectors can watch
for hot axle bearings, and some can
watch for something dragging from the
train.
Photo by David K. Z. Harris.