BIG BOY: ON THE ROAD TO RESTORATION
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Trains Big Boy
Railroading Glossary
The following glossary is arranged alphabetically with each term catalogued by first letter. Select a letter below to begin.
A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z
UMLER
Universal Machine Language Equipment Register. Computerized database of information on every railroad car in service.
Union station
A station that united all the railroads serving a city in a single facility, consolidating the various railroads' station facilities under one roof.
Unit
Commonly, a single machine (usually a diesel-electric), characterized by a single frame and a coupler at each end; technically, the smallest indivisible portion of a locomotive, which is made up of one or more units coupled together and under the control of a single engineer.
Unit reduction
The principle of reducing the number of locomotives required for a given job by increasing horsepower per unit or effective adhesion. For example, replacing three 3000 h.p. SD40-2s with two 3800 h.p. SD60s. The SD60 has 800 more horsepower than the SD40-2 and a sophisticated wheel-slip control system.
Unit train
A train carrying a single bulk commodity, such as coal or grain, from one shipper to one consignee without any switching or classification en route.
Upper-quadrant semaphore
Signals whose blade extend upward from the lightbox to show "clear".
US&S
Abbreviation for Union Switch & Signal.
USRA
United States Railroad Administration, the federal agency that took over operation of almost all U. S. railroads during World War I; or the United States Railway Association, a U.S. government corporation formed about 1973 to develop a plan to save the bankrupt Penn Central.
UTU
United Transportation Union. Labor union headquartered in Cleveland, Ohio representing railroad, bus, and mass transit workers in the United States and Canada. Railroad industry personnel represented include conductors, brakemen, switchmen, ground service personnel, locomotive engineers, hostlers, and yardmasters. Formed in 1969 from the merger of four previously separate railroad unions.
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