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, since one train can carry more than 100 trailers at once. [1] The trailers will be moved by truck from their origin to an intermodal facility, where they will then be loaded onto a train, typically by a rubber tired gantry crane, for the bulk of their journey. Alternatively, trailers may be driven onto the flatcars via ramps by a terminal tractor. Near the destination, the trailers are unloaded at another facility and brought to their final destination by a tractor unit. [2]
Modern TOFC service was first introduced in North America in the 1950s, although the practice of carrying another mode of transport on flatcars was first recorded in 1843 when canal boats were moved by a portage railway between several cities in Pennsylvania. [1] [2]
TOFC is distinct from containerization. While both are examples of intermodal transport, trailer on flatcar is the loading of entire trailers onto railroad cars, while in containerization, the container is detached from the trailer chassis for railroad transport.
Besides the need for facilities to handle loading and unloading with road (preferably highway) access, trailer on flatcar operations impose certain height clearance requirements. In North America, including Mexico, this is mostly a non-issue as double-stack rail transport imposes much more demanding clearance requirements, [3] but regions with more constrained loading gauges may impose limits on this type of transport or make it impossible altogether. However, height clearance requirements tend to be slightly lower than for rolling highway transportation where entire trucks are loaded onto rail vehicles. The trailers themselves also need to meet certain minimum requirements to be able to be moved via crane, which is the most cost- and time-efficient way of loading and unloading them onto the train. [4] [5] To allow trailer on flatcar transport involving maximum height trailers, Switzerland is upgrading existing lines feeding into the "Gotthard Axis" of the New Railway Link through the Alps to a so-called "4-m corridor" named for the 4 meters (13 ft) maximum height of the trailers as specified in road transport regulations. [6] As upgrading the loading gauge of an existing railway can be very expensive, especially when tunnels and bridges follow in close succession like on the right Pegnitz Valley line, [7] [8] increasingly newly built lines are built to the most generous standards deemed feasible, even if the need for such generous clearances seems remote at the time of construction. For example, the Betuweroute in the Netherlands an important freight link from the Dutch seaports to the Blue Banana had all bridges and tunnels built to standards allowing double stack rail transport in the future by simply raising the overhead wire. [9] [10]
Containerization is a system of intermodal freight transport using intermodal containers. Containerization, also referred as container stuffing or container loading, is the process of unitization of cargoes in exports. Containerization is the predominant form of unitization of export cargoes, as opposed to other systems such as the barge system or palletization. The containers have standardized dimensions. They can be loaded and unloaded, stacked, transported efficiently over long distances, and transferred from one mode of transport to another—container ships, rail transport flatcars, and semi-trailer trucks—without being opened. The handling system is mechanized so that all handling is done with cranes and special forklift trucks. All containers are numbered and tracked using computerized systems.
An intermodal container, often called a shipping container or ISO Container, is a large standardized container designed and built for intermodal freight transport, meaning these containers can be used across different modes of transport – from ship to rail to truck – without unloading and reloading their cargo. Intermodal containers are primarily used to store and transport materials and products efficiently and securely in the global containerized intermodal freight transport system, but smaller numbers are in regional use as well. These containers are known under a number of names. Based on size alone, up to 95% of intermodal containers comply with ISO standards, and can officially be called ISO containers. Many other names are simply: container, cargo or freight container, shipping, sea or ocean container, container van or sea van, sea can or C can, or MILVAN, SEAVAN, or RO/RO. The also used term CONEX (Box) is a technically incorrect carry-over usage of the name of an important predecessor of the international ISO containers, namely the much smaller prior steel CONEX boxes used by the U.S. Army.
A railroad car, railcar, railway wagon, railway carriage, railway truck, railwagon, railcarriage or railtruck, also called a train car, train wagon, train carriage or train truck, is a vehicle used for the carrying of cargo or passengers on a rail transport network. Such cars, when coupled together and hauled by one or more locomotives, form a train. Alternatively, some passenger cars are self-propelled in which case they may be either single railcars or make up multiple units.
Piggyback transportation refers to the transportation of goods where one transportation unit is carried on the back of something else. It is a specialised form of intermodal transportation and combined transport.
A boxcar is the North American (AAR) term for a railroad car that is enclosed and generally used to carry freight. The boxcar, while not the simplest freight car design, is considered one of the most versatile since it can carry most loads. Boxcars have side sliding doors of varying size and operation, and some include end doors and adjustable bulkheads to load very large items.
Intermodal freight transport involves the transportation of freight in an intermodal container or vehicle, using multiple modes of transportation, without any handling of the freight itself when changing modes. The method reduces cargo handling, and so improves security, reduces damage and loss, and allows freight to be transported faster. Reduced costs over road trucking is the key benefit for inter-continental use. This may be offset by reduced timings for road transport over shorter distances.
A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and keep clear of platforms, trackside buildings and structures. Classification systems vary between different countries, and gauges may vary across a network, even if the track gauge is uniform.
An autorack, also known as an auto carrier, is a specialized piece of railroad rolling stock used to transport automobiles and light trucks. Autoracks are used to transport new vehicles from factories to automotive distributors, and to transport passengers' vehicles in car shuttles and motorail services, such as Amtrak's Auto Train route.
A flatcar (US) is a piece of rolling stock that consists of an open, flat deck mounted on a pair of trucks (US) or bogies (UK), one at each end containing four or six wheels. Occasionally, flat cars designed to carry extra heavy or extra large loads are mounted on a pair of bogies under each end. The deck of the car can be wood or steel, and the sides of the deck can include pockets for stakes or tie-down points to secure loads. Flatcars designed for carrying machinery have sliding chain assemblies recessed in the deck.
A container crane is a type of large dockside gantry crane found at container terminals for loading and unloading intermodal containers from container ships.
A RoadRailer is a trailer or semi-trailer that can be hauled on roads by a tractor unit and then by way of a fifth wheel coupling, operate in a unit train on railway lines. The RoadRailer system allows trailers to be pulled by locomotives without the use of flatcars, instead attaching trailers directly to bogies.
TTX Company is a provider of railcars and related freight car management services to the North American rail industry. TTX's pool of railcars—over 168,000 cars and intermodal well cars—supports shippers in several industries where flatcars, boxcars and gondolas are required.
Rail freight transport is the use of railroads and trains to transport cargo as opposed to human passengers.
Less-than-truckload shipping or less than load (LTL) is the transportation of an amount of freight sized between individual parcels and full truckloads. Parcel carriers handle small packages and freight that can be broken down into units less than approximately 150 pounds (68 kg). Full truckload carriers move entire semi-trailers. Semi-trailers are typically between 26 and 53 feet and require a substantial amount of freight to make such transportation economical. The term LTL can refer to the freight itself, or to the carrier that transports the such freight.
A well car, also known as a double-stack car, is a type of railroad car specially designed to carry intermodal containers used in intermodal freight transport. The "well" is a depressed section that sits close to the rails between the wheel trucks of the car, allowing a container to be carried lower than on a traditional flatcar. This makes it possible to carry a stack of two containers per unit on railway lines wherever the structure gauge assures sufficient clearance. The top container is secured to the bottom container either by a bulkhead built into the car — possible when bottom and top containers are the same dimensions, or through the use of inter-box connectors (IBC). Four IBCs are needed per well car. In the terminal there are four steps: unlock and lift off the top containers of an inbound train, remove the bottom containers, insert outbound bottom containers, lock assembly after top containers emplaced. Generally this is done car-by-car unless multiple crane apparatus are employed.
In rail transportation, a rolling highway or rolling road is a form of combined transport involving the conveying of road trucks by rail, referred to as Ro-La trains. The concept is a form of piggyback transportation.
Open wagons form a large group of railway goods wagons designed primarily for the transportation of bulk goods that are not moisture-retentive and can usually be tipped, dumped or shovelled. The International Union of Railways (UIC) distinguishes between ordinary wagons and special wagons (F/6). Open wagons often form a significant part of a railway company's goods wagon fleet; for example, forming just under 40% of the Deutsche Bahn's total goods wagon stock in Germany.
Double-stack rail transport is a form of intermodal freight transport in which railroad cars carry two layers of intermodal containers. Invented in the United States in 1984, it is now being used for nearly seventy percent of United States intermodal shipments. Using double stack technology, a freight train of a given length can carry roughly twice as many containers, sharply reducing transport costs per container. On United States railroads special well cars are used for double-stack shipment to reduce the needed vertical clearance and to lower the center of gravity of a loaded car. In addition, the well car design reduces damage in transit and provides greater cargo security by cradling the lower containers so their doors cannot be opened. A succession of larger container sizes have been introduced to further increase shipping productivity in the United States.
A pocket wagon is a freight wagon that has been specially designed for the transport of truck semi-trailers. This wagon belongs to the group of flat wagons in special design with bogies and is used in combined transport (CT). The name of these freight wagons comes from the fact that between the narrow longitudinal girders on the outside and also lengthways between the bogies, the so-called pockets are located, in which the wheels of the semi-trailers are particularly low. For flexible use in CT, pocket wagons have hinged latches with ISO spigots on the solebar, so that containers and swap bodies up to 45 ft can be accommodated. As a flat wagon, it bears the UIC generic letter S and, since it is intended for the transport of road vehicles on one level, the code letter d. Since it is also possible to transport containers in a pocket wagon, it bears the UIC generic mark Sdgs. In this context, the code letter g stands for "containers up to 60 feet" and the lower case s for the permitted speed of up to 100 km/h (62 mph). The wagons have a yellow triangle with a black P on the long side. The first pocket wagons were built in Germany as early as 1972 and further developed according to requirements.