A unit train, also called a block train or a trainload service, is a train in which all cars (wagons) carry the same commodity and are shipped from the same origin to the same destination, without being split up or stored en route. This saves time and money, as well as the hassle, delays and confusion associated with assembling and disassembling trains at rail yards near the origin and destination. It also enables railways to compete more effectively with road and internal waterway transport systems, However, unit trains are economical only for high-volume customers. Since unit trains often carry only one commodity, cars are of all the same type, and sometimes the cars are all identical apart from possible variations in livery.
Unit trains are typically used for the transportation of bulk goods. These can be solid substances such as:
- Track ballast or gravel
- Iron ore from mines to ports or steel mills
- Coal from mines to power stations
- Coke from coking plants to steel mills
Bulk liquids are transported in unit trains made up of tank cars, such as:
- Crude oil from oil fields to refineries (can be 60,000 barrels (9,500 m3) of oil in a unit train of 100 tank cars)
- Mineral oil products from the refineries to the storage facilities
- Ethanol from ethanol plants to motor fuel blending facilities
- Molten sulfur (non-US:sulphur)
Food, such as:
Other examples include:
- Shipping containers, generally between a port and a truck depot.
- Waste (garbage), usually for recycling, often metals or paper
- "Unit train". Encyclopædia Britannica. 2014.
- Oliver Wyman. "The Mixed Train Concept: The Best of Both Worlds for European Rail Freight?". www.oliverwyman.com.
...trainload service (point to point, complete train for one customer) or wagonload service (single wagons for various customers, assembled into trains)
- McGurty, Janet; Adler, Lynn; Gregorio, David (2011-07-22). "Union Pacific sees rail oil shipments quadrupling". Reuters.
- Thompson, Stephen (September 2006). "Keep on Truckin’: Ethanol boom creates transportation challenges". United States Department of Agriculture.