Hump Yard

hump yard

[′həmp ‚yärd]
(civil engineering)
A switch yard in a railway system that has a hump or steep incline down which freight cars can coast to prescheduled locations. Also known as gravity yard.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Hump Yard


an engineering facility located at classification yards and some railroad freight stations for making up freight trains and marshaling railroad cars according to type and load. Such a facility makes it possible to increase the volume of switching.

A hump yard is an artificially elevated area within a classification yard where the force of gravity is used to move rail cars along a network of marshaling tracks. A typical example consists of an approach section, the top of the hump, and the release area, which branches out into dozens of marshaling tracks. The release section includes high-speed and intermediate slopes, a braking section, and a sloping switching area. A hump yard’s elevation is determined by calculation (usually it is 3.5–5 m) and must be sufficiently high to enable the rail cars to reach the observation point of the marshaling tracks. Accelerating devices are used at some hump yards.

The rolling stock to be marshaled is pushed by a locomotive to the top of the hump (the cars are uncoupled while they are in motion), where individual cars and groups of cars are separated and allowed to coast on to the release point, where they are diverted by switching devices onto marshaling tracks according to their type and load. After each car or group of cars has passed through a switch, the switch is reset for the next car. To maintain a predetermined distance between the cars that have rolled onto various tracks and thus eliminate the danger of one car overtaking another while within the release area, their velocity is regulated by two or three braking sections fitted with clamp-type car retarders or by weight-operated clamp-type retarders. High-volume hump yards are equipped with automatic centralized equipment and automatic speed controls. Signaling, radio communication, and other such techniques are widely used in hump yards. High-volume hump yards can process up to 6,000–7,000 railroad cars per day.


Savchenko, I. E., S. V. Zemblinov, and I. I. Strakovskii. Zhelez-nodorozhnye stantsii i uzly, 2nd ed. Moscow, 1967.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Bohlin, "Hump yard track allocation with temporary car storage," in Proceedings of the The 4th International Seminar on Railway Operations Modelling and Analysis, RailRome, 2011.
There was the possibility of incorporating parts of the students' problems into myself and vice versa-organizing classes as a kind of "washing machine," a hump yard of fragments.
Norfolk Southern is also seeking to reduce circuitous miles by at least 20 percent by utilizing capacity at regional yards and focusing less on creating density at hump yards.
Further, Union Pacific declared that it doesn't anticipate closing any hump yards and declined to change any financial targets, the analyst adds.
Harrison introduced the company to a new way of thinking about the CSX network, which led to major operational enhancements, including the conversion of certain hump yards to flat switching and strategic adjustments to other facilities," Foote wrote.
Other operational initiatives cited by Harrison since he took over at CSX in March include idling around 550 locomotives and 25,000 railcars and converting hump yards to flat-switching yards that he maintains are more efficient.
I had to admit that, over the past 15 years, the railroads greatly improved the rideability of their new articulated flat cars; they eliminated the 'hump yards' and reduced switching at the Mississippi River-a move that reduced damages.