Trains And Locomotives Wiki

EndOfTrainDevice\EOTD\FRED On Freight Wagons Rear Coupler

HeadOfTrainDevice\HOTD\WILMA In Lead Lokomotive Cab

An EndOfTrainDevice\EOTD, AlsoKnownAs FlashingRearEndDevice\FRED orSense&BrakingUnit\S&BU, is a wireless transceiver\controller mounted on a trains rear coupler, replacing the legacy caboose\brakevan & brakeman. The use of EOTDs originated in the US on the FloridaEastCoast\FECx railway in 1969, which began the transition of NorthAmerican Class1 railroads away from the traditional caboose on the end of freight trains. EOTDs have since come to be used worldwide: Australia, Africa, Britain, China, Europe, Japan,...


Beginning in the early 1970's, railroads began modernizing their equipment by reducing the amount of manpower needed to operate on a daily basis. In an attempt to revitalize the concept of active train crews, railroads opted to reduce labor costs, relieving overworked crew members, reducing caboose maintenance, while further replacing brakemen duties on the rear of a train by simply having an electronic device do all of the  aforementioned work in favor of hiring more crews or overworking understaffed crews. Once FREDs took effect and began phasing out the caboose, many duties of overworked crews were ultimately relieved, and the worry of having understaffed crews was over; for many "rookie" employees initially opted out of becoming a brakeman or rear-end crew member as a result of the stress-induced workload of existing members.

By 1990, most cabooses owned and operated by railroads for general use on the road were retired. However, some were saved for local and/or yard duties to be used as a "shunting platform", "shoving platform", or "buffer car", while others were converted for transporting MOW crews or track gangs for track repair and construction. Since then, FREDs are typically found and assigned to every active train as required by the FRA (Federal Railroad Administration). Non-active or mobile trains (such as strings of rollingstock or a consist of locomotives) are not required to have said device (or flag) mounted unless they are parked momentarily during switching operations.

Design and Use

HOTD & EOTD Diagram

End of train devices are often used send data and/or status reports (such as the status of the brakes) to the front of the locomotive through telemetry; essentially serving as rear-end crewmembers contacting front-end members via radio. Furthermore, FREDs with known features are commonly referred to as "smart" devices, which send said signals to the front leading locomotive of the train via a head-of-train device (HTD) or a "Wilma" (a nod to the fictional cartoon couple from the Flintstones), while simple devices (such as flags or generic blinking lights) are known as "dumb" FREDs. "Average intelligence" FRED devices are also used, and include a brake pipe pressure gauge. 

Most modern, microprocessor-equipped or integrated locomotives utilize the modern telemetric FREDs, for the status report signals are transmitted to and from the device, and are further are sent and received to the crew of the locomotive. Said status reports such as air pressure, brake pressure, speed, and defects are typically relayed between the rear of the train and the lead locomotive. Many earlier locomotives have since been retrofitted with radios capable of transmitting and displaying signals relayed from FRED's rather than relying on integrated desktop computer monitors.