Flashing rear-end device
The flashing rear-end device, or "FRED," (also called an end-of-train device, ETD or EOT) is an electronic device mounted on the end of North American freight
trainsin lieu of a caboose.
Design and use
More than just a flashing red taillight, the FRED monitors functions such as brake line pressure and accidental separation of the train using a motion sensor, functions that would have been monitored by a crew in the caboose. The FRED transmits the data via a
telemetrylink to the Head-of-Train Device (HOT) in the locomotive, known colloquially among railroaders as a Wilma—the FRED is said to be "married to Wilma," a play on Fred Flintstone's wife from The Flintstonescartoon. In Canada, this device is known as an SBU (Sense and Braking Unit).
A typical HOT contains a number of indicator lights indicating telemetry status and rear-end movement as well as a digital readout of the brake pipe pressure transmitted by the FRED. It also contains a toggle switch used to place the train's brakes into emergency from the rear end. In modern locomotives, the HOT is built into the locomotive's computer system, and the data is displayed on the engineer's computer screen.
Railroads have strict government-approved air brake testing procedures for various circumstances when making up trains in a yard or switching out cars en route. After a cut is made between cars in a train and the train is rejoined, in addition to other tests, the crew must verify that the brakes apply and release on the rear car (to ensure that all of the brake hoses are connected and the angle cocks, or valves, are opened). In most cases, the engineer is able to use data from the FRED to verify that the air pressure reduces and increases at the rear of the train accordingly, indicating that brake pipe continuity exists throughout the train. This device is said to constitute a
Though the FRED greatly cuts labor costs as well as the costs of the purchase and upkeep of cabooses, railroad "purist" fans seem to agree that a train simply isn't complete without a caboose at the end. The Brotherhood of Conductors, and Brotherhood of Railroad Brakemen were also greatly affected by FRED seeing that this electronic Unit replaced 2 career jobs per Freight Train in Transit. Somewhat earning the nickname "fucking rear end detector." The widespread use of FREDs has made the caboose all but obsolete, but some roads still use cabooses where the train must be backed up, on short local runs, as rolling
railroad policestations and transportation for right-of-way maintenance crews.
The first FRED use is attributed to
Florida East Coast Railwayin 1973; soon other Class I railroads began using FREDs as well. Early models were little more than a brake line connection, battery and flashing tail light. As their use became more widespread through the 1980s, FREDs were equipped with radio transmitters to send brake pressure data to a receiver in the locomotive. In order to alleviate the cost of constant battery replacements, ambient light sensors were added so the flashing light on the FRED would illuminate only after dark. Later models include a small turbine-powered electrical generator using air pressure from the brake line to power the FRED's radio and sensors.
The one-way communication of brake data from the FRED to the locomotive evolved into two-way communication that enables the engineer to apply the brakes from both ends of the train simultaneously in an emergency. This is useful in the event that a blockage in the train's brake pipe is preventing all of the cars in the train from going into an emergency application. Such a situation could be dangerous, as stopping distance increases with fewer functional brakes. Dumping the brake pipe pressure from both the front and rear of the train ensures that the entire train applies its brakes in emergency. Other electronics within the FRED were also enhanced and many now include GPS receivers as well as the two-way radio communications.
Railfans and railway photographers sometimes use FREDs as early warning systems to indicate the approach of an impending train. FREDs in North America operate on the 452.9375/457.9375 MHz frequency pair with the exception of those operated by Norfolk Southern Railway, which uses AAR channel 67 (161.115 MHz). Railfans often program these frequencies into their scanners, which can provide a handy indicator of train activity (usually 2-5 miles, transmitting at 2 watts).
Wikimedia Foundation. 2010.
Look at other dictionaries:
Glossary of rail terminology — Rail transport Operations Track Maintenance High speed Gauge Stations … Wikipedia
Caboose — A caboose (North American railway terminology) or brake van or guard s van (British terminology) is a manned rail transport vehicle coupled at the end of a freight train. Although cabooses were once used on nearly every freight train in North… … Wikipedia
Begleitwagen — Caboose der Burlington Northern im Jahr 1993 Als Dienst oder Güterzugbegleitwagen, Bremserwagen oder, auf Englisch, Caboose, Brake Van und Guard s Van werden spezielle Eisenbahnwagen bezeichnet, welche (einzeln) einem Güterzug oder Dienstzug in… … Deutsch Wikipedia
Caboose — der Burlington Northern im Jahr 1993 Als Dienst oder Güterzugbegleitwagen, Bremserwagen oder, auf Englisch, Caboose, Brake Van und Guard s Van werden spezielle Eisenbahnwagen bezeichnet, welche (einzeln) einem Güterzug oder Dienstzug in der Regel … Deutsch Wikipedia
Dienstbegleitwagen — Caboose der Burlington Northern im Jahr 1993 Als Dienst oder Güterzugbegleitwagen, Bremserwagen oder, auf Englisch, Caboose, Brake Van und Guard s Van werden spezielle Eisenbahnwagen bezeichnet, welche (einzeln) einem Güterzug oder Dienstzug in… … Deutsch Wikipedia
Güterzug-Begleitwagen — Caboose der Burlington Northern im Jahr 1993 Als Dienst oder Güterzugbegleitwagen, Bremserwagen oder, auf Englisch, Caboose, Brake Van und Guard s Van werden spezielle Eisenbahnwagen bezeichnet, welche (einzeln) einem Güterzug oder Dienstzug in… … Deutsch Wikipedia
EOT — is an abbreviation for:* Embedded OpenType, a font file format * End of tape, a term in in magnetic tape data storage * End Of Train device, see Flashing rear end device, as used by the railroad industry * End of transmission character, a… … Wikipedia
FRED — may be: * Fred s Inc. (NASDAQ: FRED), a regional chain of discount stores based primarily in the southeastern United States * FRED (disk magazine) diskzine for the SAM Coupé * FRED (jeweller) * FRED (quartet), the 1999 International champion… … Wikipedia
Utah Railway — Infobox SG rail railroad name=Utah Railway marks=UTAH locale=Utah and Colorado start year=1912 end year=present old gauge= hq city=Provo, UtahThe Utah Railway reporting mark|UTAH is a class III railroad operating in Utah and Colorado.HistoryThe… … Wikipedia
Schienengüterverkehr — Als Schienengüterverkehr (SGV), auch Eisenbahngüterverkehr genannt, werden die Verkehrsleistungen der Eisenbahnverkehrsunternehmen im Güterverkehr bezeichnet. Inhaltsverzeichnis 1 Grundlagen 2 Geschichte 3 Bedeutung … Deutsch Wikipedia