A unit train, also called a block train or a trainload service, is a

train A train (from Old French , from Latin">-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ... , from Latin , "to pull, to draw") is a series of connected vehicles th ...

in which all

cars A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people rather than cargo. There are around one billio ...

(wagons) carry the same commodity and are shipped from the same origin to the same destination, without being split up or stored en route. They are distinct from

wagonload In rail freight transportation the terms wagonload or wagonload freight refer to trains made of single wagon consignments of freight. In the US and Canada the term carload refers to a single car of any kind, and manifest train refers to trains mad ...

trains, composed of differing numbers of cars for various customers. Unit trains enable railways to compete more effectively with road and internal waterway transport systems. Time and money are saved by avoiding the complexities and delays that would otherwise involve assembling and disassembling trains at

rail yard A rail yard, railway yard, railroad yard (US) or simply yard, is a series of Track (rail transport), tracks in a rail network for storing, sorting, or loading and unloading rail vehicles and locomotives. Yards have many tracks in parallel for k ...

s near the origin and destination. Unit trains are particularly efficient and economical for high-volume

commodities In economics, a commodity is an economic good, usually a resource, that specifically has full or substantial fungibility: that is, the market treats instances of the good as equivalent or nearly so with no regard to who produced them. Th ...

. Since they often carry only one commodity, cars are of all the same type; often identical. Some commodities (e.g., coal) can be loaded at the origin while the train moves slowly on a loop track. The procedure is reversed at the receiving end, and because there generally is not any commodity to be hauled in the opposite direction, the train returns empty. In the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

the Santa Fe is credited with operating the first true unit train, hauling coal from a mine near

Raton, New Mexico Raton ( ) is a city in and the county seat of Colfax County, New Mexico, Colfax County in northeastern New Mexico, United States. The city is located just south of Raton Pass. The city is also located about 6.5 miles south of the New Mexico–Col ...

to a steel mill at

Fontana, California Fontana is a city in San Bernardino County, California, United States. Founded by Azariel Blanchard Miller in 1913, it remained essentially rural until World War II, when entrepreneur Henry J. Kaiser built a large steel mill in the area. It ...

Use

Unit trains are typically used for the transportation of bulk goods. These can be solid substances such as: * Aggregate *

Coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

from

mines Mine, mines, miners or mining may refer to: Extraction or digging *Miner, a person engaged in mining or digging *Mining, extraction of mineral resources from the ground through a mine Grammar *Mine, a first-person English possessive pronoun Mi ...

power stations A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the electricity generation, generation of electric power. Power stations are generally connected to an electr ...

* Coke from

coking plant A coking factory or a coking plant is where coke and manufactured gas are synthesized from coal using a dry distillation process. The volatile components of the pyrolyzed coal, released by heating to a temperature of between 900°C and 1,400&nb ...

s to

steel mill A steel mill or steelworks is an industrial plant for the manufacture of steel. It may be an integrated steel works carrying out all steps of steelmaking from smelting iron ore to rolled product, but may also be a plant where steel semi-fini ...

s *

Iron ore Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the f ...

from mines to

ports Ports collections (or ports trees, or just ports) are the sets of makefiles and Patch (Unix), patches provided by the BSD-based operating systems, FreeBSD, NetBSD, and OpenBSD, as a simple method of installing software or creating binary packages. T ...

steel mills A steel mill or steelworks is an industrial plant for the manufacture of steel. It may be an integrated steel works carrying out all steps of steelmaking from smelting iron ore to rolled product, but may also be a plant where steel semi-finish ...

Ore Ore is natural rock or sediment that contains one or more valuable minerals, typically including metals, concentrated above background levels, and that is economically viable to mine and process. The grade of ore refers to the concentration ...

Phosphate Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...

from mines to fertilizer plants *

Potash Potash ( ) includes various mined and manufactured salts that contain potassium in water- soluble form.

Sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

(e.g., for

hydraulic fracturing Fracking (also known as hydraulic fracturing, fracing, hydrofracturing, or hydrofracking) is a well stimulation technique involving the fracturing of Formation (geology), formations in bedrock by a pressurized liquid. The process involves the ...

) *

Steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

Taconite Taconite () is a variety of banded iron formation, an iron-bearing (over 15% iron) sedimentary rock, in which the iron minerals are interlayered with quartz, chert, or carbonate. The name ''taconyte'' was coined by Horace Vaughn Winchell (1865– ...

Track ballast Track ballast is the material which forms the trackbed upon which railroad ties (UK: sleepers) are laid. It is packed between, below, and around the ties. It is used to bear the compression load of the railroad ties, rails, and rolling stock; ...

gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

Bulk liquids are transported in unit trains made up of

tank car A tank car (International Union of Railways (UIC): tank wagon) or tanker is a type of railroad car (UIC: railway car) or rolling stock designed to transport liquid and gaseous commodity, commodities. History Timeline The following major event ...

s, such as: *

Crude oil Petroleum, also known as crude oil or simply oil, is a naturally occurring, yellowish-black liquid chemical mixture found in geological formations, consisting mainly of hydrocarbons. The term ''petroleum'' refers both to naturally occurring u ...

from oil fields to refineries (can be [] of oil in a unit train of 100 tank cars) * Ethanol from ethanol plants to motor fuel blending facilities * Molten sulfur (non-US:sulphur) Food, such as: *

Fruit juice Juice is a drink made from the extraction or pressing of the natural liquid contained in fruit and vegetables. It can also refer to liquids that are flavored with concentrate or other biological food sources, such as meat or seafood, such ...

Corn Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout Poaceae, grass that produces cereal grain. It was domesticated by indigenous peoples of Mexico, indigenous peoples in southern Mexico about 9,000 years ago ...

Mineral oil Mineral oil is any of various colorless, odorless, light mixtures of higher alkanes from a mineral source, particularly a distillate of petroleum, as distinct from usually edible vegetable oils. The name 'mineral oil' by itself is imprecise, ...

products from the

refineries A refinery is a production facility composed of a group of chemical engineering unit processes and unit operations refining certain materials or converting raw material into products of value. Types of refineries Different types of refineries a ...

to the storage facilities *

Refrigerated Refrigeration is any of various types of cooling of a space, substance, or system to lower and/or maintain its temperature below the ambient one (while the removed heat is ejected to a place of higher temperature).IIR International Dictionary of ...

food *

Wheat Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, whe ...

Other examples include: *

Automobiles A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, peopl ...

autorack An autorack, also known as an auto carrier (also Flat wagon#Car transporters, car transporter outside the US), is a specialized piece of railroad rolling stock used to transport automobiles and light trucks. Autoracks are used to transport new ...

s *

Intermodal container An intermodal container, often called a shipping container, or a freight container, (or simply "container") is a large metal crate designed and built for intermodal freight transport, meaning these containers can be used across different Mode ...

s, generally between a port and a truck depot *

Mail The mail or post is a system for physically transporting postcards, letter (message), letters, and parcel (package), parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid ...

* Military Equipment (weapons) *

TOFC Trailer on flatcar, also known as TOFC or piggyback, is the practice of carrying semi-trailers on railroad flatcars. TOFC allows for shippers to move truckloads long distances more cheaply than can be done by having each trailer towed by a truck, ...

(Trailer on

flat car A flatcar (US) (also flat car, or flatbed) is a piece of rolling stock that consists of an open, flat deck mounted on trucks (US) or bogies (UK) at each end. Occasionally, flat cars designed to carry extra heavy or extra large loads are mounted ...

) *

Waste Waste are unwanted or unusable materials. Waste is any substance discarded after primary use, or is worthless, defective and of no use. A by-product, by contrast is a joint product of relatively minor Value (economics), economic value. A wast ...

(garbage), usually for

recycling Recycling is the process of converting waste materials into new materials and objects. This concept often includes the recovery of energy from waste materials. The recyclability of a material depends on its ability to reacquire the propert ...

, often metals or paper

References

{{Reflist Rail transport operations Trains Rail freight transport

Use

See also

References