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
Hand brake
Device on a car or locomotive that allows the brakes to be applied or released manually.
Harvey, Fred (1835-1901)
An Englishman who established a chain of restaurants and hotels along the route of the Atchison, Topeka & Santa Fe Railway and later also operated Santa Fe's dining car service.
Movement of one railroad's traffic by a second road between specific points under the terms of a contract. The hauling road exercises no control over the traffic, is not shown in the route for the traffic, and does not get a division of the revenue.
Haulage rights
An arrangement where one railroad (the road receiving haulage rights) may negotiate rates or contracts with customers located on another railroad's line (the road granting haulage rights). The railroad receiving haulage rights supplies the cars. The railroad granting the haulage rights is responsible for the actual movement of cars on its trackage, providing switching services, track, train crews, dispatching, and sometimes locomotives, but does not receive any portion of the revenue.
Head-end cars
Mail, baggage, and express cars, so called because they were usually positioned just behind the locomotives of the passenger trains they moved in.
Head-end power (HEP)
Electric power supplied from the prime mover of the locomotive, an auxiliary generator on the locomotive, or a car equipped with generators, used for heating, lighting, and cooling passenger cars. Replaced steam heat and generators on passenger car axles.
Passenger cars of heavier construction, and generally earlier vintage, than streamlined "lightweight" designs.
Type of geared steam locomotive built by the Heisler Locomotive Works featuring two cylinders arranged in a V under the boiler driving a central longitudinal shaft gear to the outer axle of each truck. Side rods connected the outer and inner axles.
A locomotive added to a train for a portion of its run to provide extra power to climb a grade. Called a "pusher" if added to the rear of the train.
Helper district
A segment of railroad with steep grades that require the regular use of extra locomotives on heavy trains.
See Head-end power.
High iron
Slang term for a main line or main track. Iron was once the standard material for rails. Main line rail was heavier-and thus higher-than rail found on branch lines or short lines, and was also supported by deeper layers of rock ballast that raised the rails further above the surrounding landscape than lesser lines.
High-adhesion truck
Any locomotive truck designed to improve wheel-to-rail contact, usually by minimizing weight transfer between axles caused by varying combinations of forces acting on the truck.
The signal to go, proceed, depart, or pick up to full speed. Given by a crew member to the engineer using hand signals, lantern, or radio. First used in the days when old-time ball signals were hoisted high to show "clear".
High-rail vehicle
Motor vehicle with flanged wheels that can be extended for operation on tracks, or retracted for operation on roadways.
Hill Lines
The original components of Burlington Northern, which were once controlled by James J. Hill. They were: Chicago, Burlington & Quincy, Great Northern, Northern Pacific, Spokane, Portland & Seattle.
Slang term for locomotive engineer.
Holding company
A company that owns other companies for purposes of control.
Home signal
Lineside signal that governs the entrance to an interlocking.
Hood unit
A diesel locomotive with a long hood covering the engine, a short hood enclosing some auxiliary gear, and a cab near one end of the frame (as opposed to the streamlined, full-width body cab unit).
Freight car with inclined floors and bottom-opening doors that facilitate rapid unloading. Used to carry bulk commodities such as coal. Covered hoppers have roofs.
Horsepower hour
When locomotives began to be leased on a performance-use basis rather than on time alone, a new measurement was devised, the horsepower hour, recorded by on-board microprocessors. For example, a 3900-horsepower LMX Dash 8-39B operating for an hour at full power runs up a charge of 3900 horsepower hours.
An employee who operates locomotives in and around enginehouses.
Hot box
An overheated wheel bearing, which if left undetected, can burn off and cause a derailment. (Friction created between moving metal parts generates heat and eventually will melt a 6-inch diameter steel axle.)
Hot box detector (HBD)
Heat sensor placed along railroad tracks to monitor temperatures of the wheel bearings in passing trains and warn of overheated bearings.
A fast, high priority freight train.
Hours of service law
A federal law that limits train crew members to no more than 12 hours on duty. (Nickname: hog law.)
House track
A siding track running near a station where passengers or freight are loaded or unloaded.
Hump yard
Classification yards where strings of freight cars are slowly pushed over a hump, or small hill. When they reach the crest of the hump, the cars are uncoupled according to which track they are destined for. As the cars roll down the hump toward the "bowl" of the yard, remotely-controlled switches direct them onto the proper tracks.
The destructive tendency of a truck to nose from side to side even though the train may be moving on straight track.
Hydra-Cushion freight cars
Cars whose underframes are equipped with hydraulic devices that absorb forces in order to cushion the load from damage.
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