Rail freight transport


Rail freight transport is the use of railways and trains to transport cargo, as opposed to passengers.
A freight train, cargo train, or goods train is a group of freight cars or goods wagons hauled by one or more locomotives on a railway, transporting cargo all or some of the way between the shipper and the intended destination as part of the logistics chain. Trains may haul bulk material, intermodal containers, general freight or specialized freight in purpose-designed cars. Rail freight practices and economics vary by country and region.
When considered in terms of ton-miles or tonne-kilometers hauled, energy efficiency can be greater with rail transportation than with other means. Maximum economies are typically realized with bulk commodities, especially when hauled over long distances. Moving goods by rail often involves transshipment costs, particularly when the shipper or receiver lack direct rail access. These costs may exceed that of operating the train itself, a factor that practices such as containerization, trailer-on-flatcar or rolling highway aim to minimize.

Overview

Traditionally, large shippers built factories and warehouses near rail lines and had a section of track on their property called a siding where goods were loaded onto or unloaded from rail cars. Other shippers had their goods hauled by wagon or truck to or from a goods station. Smaller locomotives transferred the rail cars from the sidings and goods stations to a classification yard, where each car was coupled to one of several long-distance trains being assembled there, depending on that car's destination. When long enough, or based on a schedule, each long-distance train was then dispatched to another classification yard. At the next classification yard, cars are resorted. Those that are destined for stations served by that yard are assigned to local trains for delivery. Others are reassembled into trains heading to classification yards closer to their final destination. A single car might be reclassified or switched in several yards before reaching its final destination, a process that made rail freight slow and increased costs. Because, of this, freight rail operators have continually tried to reduce these costs by reducing or eliminating switching in classification yards through techniques such as unit trains and containerization, and in some countries these have completely replaced mixed freight trains. In many countries, railroads have been built to haul one commodity, such as coal or ore, from an inland point to a port.
Rail freight uses many types of goods wagon or freight car. These include box cars or covered wagons for general merchandise, flat cars or flat wagons for heavy or bulky loads, well wagons or "low loader" wagons for transporting road vehicles; there are refrigerator vans for transporting food, simple types of open-topped wagons for transporting bulk material, such as minerals and coal, and tankers for transporting liquids and gases. Most coal and aggregates are moved in hopper wagons or gondolas or open wagons that can be filled and discharged rapidly, to enable efficient handling of the materials.
Rail transport is very energy-efficient, and much more environmentally friendly than road transport. Compared to road transport which employs the use of trucks, rail transportation ensures that goods that could otherwise be transported on a number of trucks are transported in a single shipment. This saves a lot as far as cost connected to the transportation are concerned. Rail freight transport also has very low external costs. Therefore, many governments have been stimulating the switch of freight from trucks onto trains, because of the environmental benefits that it would bring. Railway transport and inland navigation are similarly environmentally friendly modes of transportation, and both form major parts of the 2019 European Green Deal.
In Europe, many manufacturing towns developed before the railway. Many factories did not have direct rail access. This meant that freight had to be shipped through a goods station, sent by train and unloaded at another goods station for onward delivery to another factory. When lorries replaced horses it was often economical and faster to make one movement by road. In the United States, particularly in the West and Midwest, towns developed with railway and factories often had a direct rail connection. Despite the closure of many minor lines carload shipping from one company to another by rail remains common.
Railroads were early users of automatic data processing equipment, starting at the turn of the twentieth century with punched cards and unit record equipment. Many rail systems have turned to computerized scheduling and optimization for trains which has reduced costs and helped add more train traffic to the rails.
Freight railroads' relationship with other modes of transportation varies widely. There is almost no interaction with airfreight, close cooperation with ocean-going freight and a mostly competitive relationship with long distance trucking and barge transport. Many businesses ship their products by rail if they are shipped long distance because it can be cheaper to ship in large quantities by rail than by truck; however barge shipping remains a viable competitor where water transport is available.
Freight trains are sometimes illegally boarded by individuals who do not have the money or the desire to travel legally, a practice referred to as "hopping". Most hoppers sneak into train yards and stow away in boxcars. Bolder hoppers will catch a train "on the fly", that is, as it is moving, leading to occasional fatalities, some of which go unrecorded. The act of leaving a town or area, by hopping a freight train is sometimes referred to as "catching-out", as in catching a train out of town.

Bulk

Bulk cargo constitutes the majority of tonnage carried by most freight railroads. Bulk cargo is commodity cargo that is transported unpackaged in large quantities. These cargo are usually dropped or poured, with a spout or shovel bucket, as a liquid or solid, into a railroad car. Liquids, such as petroleum and chemicals, and compressed gases are carried by rail in tank cars.
File:Mack Point rail yard weigh station.jpg|thumb|Bulk freight car scales at the MMA Mack Point yard, Searsport, Maine Hopper cars are freight cars used to transport dry bulk commodities such as coal, ore, grain, track ballast, and the like. This type of car is distinguished from a gondola car or open wagon in that it has opening doors on the underside or on the sides to discharge its cargo. The development of the hopper car went along with the development of automated handling of such commodities, with automated loading and unloading facilities. There are two main types of hopper car: open and covered; Covered hopper cars are used for cargo that must be protected from the elements such as grain, sugar, and fertilizer. Open cars are used for commodities such as coal, which can get wet and dry out with less harmful effect. Hopper cars have been used by railways worldwide whenever automated cargo handling has been desired. Rotary car dumpers simply invert the car to unload it, and have become the preferred unloading technology, especially in North America; they permit the use of simpler, tougher, and more compact gondola cars instead of hoppers.

Heavy-duty ore traffic

The heaviest trains in the world carry bulk traffic such as iron ore and coal. Loads can be 130 tonnes per wagon and tens of thousands of tonnes per train. Daqin Railway transports more than 1 million tonnes of coal to the east sea shore of China every day and in 2009 is the busiest freight line in the world Such economies of scale drive down operating costs. Some freight trains can be over 7 km long.

Containerization

Containerization is a system of intermodal freight transport using standard shipping containers that can be loaded with cargo, sealed and placed onto container ships, railroad cars, and trucks. Containerization has revolutionized cargo shipping. approximately 90% of non-bulk cargo worldwide is moved by containers stacked on transport ships; 26% of all container transshipment is carried out in China., some 18 million total containers make over 200 million trips per year.
Use of the same basic sizes of containers across the globe has lessened the problems caused by incompatible rail gauge sizes in different countries by making transshipment between different gauge trains easier.
While typically containers travel for many hundreds or even thousands kilometers on the railway, Swiss experience shows that with properly coordinated logistics, it is possible to operate a viable intermodal cargo transportation system even within a country as small as Switzerland.

Double-stack containerization

Most flatcars cannot carry more than one standard container on top of another because of limited vertical clearance, even though they usually can carry the weight of two. Carrying half the possible weight is inefficient. However, if the rail line has been built with sufficient vertical clearance, a double-stack car can accept a container and still leave enough clearance for another container on top. Both China and India run electrified double-stack trains with overhead wiring.
In the United States, Southern Pacific Railroad with Malcom McLean came up with the idea of the first double-stack intermodal car in 1977. SP then designed the first car with ACF Industries that same year. At first it was slow to become an industry standard, then in 1984 American President Lines started working with the SP and that same year, the first all "double stack" train left Los Angeles, California for South Kearny, New Jersey, under the name of "Stacktrain" rail service. Along the way the train transferred from the SP to Conrail. It saved shippers money and now accounts for almost 70 percent of intermodal freight transport shipments in the United States, in part due to the generous vertical clearances used by U.S. railroads. These lines are diesel-operated with no overhead wiring.
Double stacking is also used in Australia between Adelaide, Parkes, Perth and Darwin. These are diesel-only lines with no overhead wiring. Saudi Arabian Railways use double-stack in its Riyadh-Dammam corridor. Double stacking is used in India for selected freight-only lines.