COFC, or Container On Flat Car, conjures images of long strings of double-stacked containers racing across the continent. The shipment of containerized freight on flatcars goes back many years beyond the modern intermodal boom.
Early uses of containerized freight were often centered around LCL or Less than Car Load shipments. These smaller steel containers could be delivered by truck to a customer, loaded and then taken to a terminal. Here, the containers were grouped together and shipped to another hub where the process was reversed. The entire process was supposed to be more economical and convenient for the customer but was very labor-intensive and low return for the railroads. As roads improved, it was simply easier for both parties to let trucks carry the small load the whole way.
The COFC concept gained new ground in the 1960s and 1970s using larger vehicles. Again some railroads experimented with door-to-door container service with technologies like "Flexivan." These containers were loaded on special flatcars and trailers owned by the railroads. Many moved in passenger trains to afford the best-operating schedules.
An even greater market for COFC traffic has been international shipments. Shipping containers arrive and depart from seaports on the coast and can be loaded onto trucks or trains for shipment inland. Some containers may move all the way across the continent by train to be reloaded onto ships. This intermodal shipping can take days off a journey from Asia to Europe.
Other containers serve a domestic North American market. These tend to be larger than the boxes used for international shipments; up to 53 feet in length. When not on the train, these containers are carried on chassis to the customer like a conventional truck trailer.
Since the 1980s, many of these containers have traveled on "double-stack" trains to increase efficiency. These tall cars are restricted to lines that have the adequate vertical clearance for the twin containers. Often, COFC and TOFC (Trailer on Flatcar) intermodal cars can be seen on the same train.
The most recent and one of the fastest-growing COFC markets in North America are trash containers which haul municipal waste from large cities to rural landfills. Many of these containers move in solid "trash trains" and can cross several states. They are easy to spot, even with your eyes closed.
COFC equipment can take many forms. The most common today are flatcars, well cars, and spine cars. Traditional flatcars have a very limited capacity and high weight. Spine cars come in 3, and 5 unit articulated sets, reducing weight, coupler slack and friction. Well, cars come in many configurations and can carry stacks of two containers.
It is not uncommon to see all three cars in a single train. On lines with low clearances, well cars may still be used but only with one container. Modern intermodal trains may be solid blocks of international or domestic containers or a combination of both.
Earlier LCL containers also used flatcars (often the 40 or 50-foot standard lengths) or even gondolas. Coke, lime and other materials have also been transported in small containers as well.
International containers come in 20,40 and 45-foot lengths. Often the boxes are brightly colored with the company name or initials on the sides. Thousands of older containers now serve as stationary storage units.
Domestic containers come in 28, 48 and 53-foot lengths. These are the equivalent of the common trailer lengths on North American roads today. Many of these are owned by large trucking companies.
When stacked, whether on trains, ships or in port, containers are often held together by pins called IBC's, or Inter-Box Connectors. Some older well cars used bulkheads to secure the upper container. These increased car weight and limited the length of containers.
Modern container terminals can be extremely large and complex places. Large cranes pick up and reload containers. Stacks of containers await transfer. Trucks, yard tractors, and trains scurry about. Yards of empty chassis and rail cars are kept nearby. Such a facility would be a challenge to model in its entirety - especially a coastal port.
Inland facilities are often at least slightly smaller and usually include trailer and container operations. The essential elements are the same - a paved loading area, traveling cranes or lifts, and driving/parking spaces for the containers and trucks. A small office, scale and security lighting and fencing complete the scene.
Older LCL terminals were often smaller affairs near stations or team tracks. A small crane or ramp was often present to help load containers. Urban facilities could include multiple tracks and warehouse facilities.