Coke is a product created by baking coal, not unlike the process of making charcoal from wood. Baking removes impurities, and burns cleaner than bituminous coal. Because of this, coke is ideal for use in furnaces and stoves. It has also been used in specialty industries like malting. By volume however, the number one user of coke is the iron and steel industry. While it can occur naturally, most coke used today is man-made.
The baking process also reduces weight. Coke is considerably more porous and lighter than coal. This has had an impact on the freight cars designed to haul it.
Because of its clean-burning, “smokeless” qualities, coke has been a popular fuel for some smaller consumers. For those who did not want to buy coke by the carload, railroads developed smaller shipping containers which could be loaded into gondolas, similar to other early containers for traditional less-than-carload freight. The cars would be spotted on a customer siding such as a fuel company or even a team track. Individual containers would be unloaded and transported by truck directly to the consumer.
These shipments conveniently sub-divided the load, but were not very efficient from the railroads’ perspective. The loads were labor intensive and the cars had a very high car-weight to load-weight ratio. Many of the customers for this fuel would switch to natural gas or electric heat in the 1950s. Remaining customers were generally more efficiently served by truck.
For large users like steel mills, coke could be purchased not by the container but by the trainload. Many blast furnaces had coke ovens located adjacent, eliminating the need for rail transport. Since the number of mills and coking facilities has diminished since the 1970s, coke is increasingly produced off site. A single coke plant may supply several furnaces.
Coke is often transported in hopper cars, or large rotary-dump gondolas like coal. Because coke is lighter, coke will fill a conventional hopper’s capacity before reaching its weight limit. Consequently, coke service cars are often built taller than coal cars. In addition to new cars, railroads often rebuild older coal hoppers with extended sides. CSX has recently gone in the other direction and shortened some large hoppers designed for even lighter wood chips.
Modeling a complete coke plant would occupy more space than most of us have for our entire layouts. You can model the shipments however. Lionel’s coke-container gondolas are all you need for smaller, local shipments. Delivery to a malting plant or fuel supply depot would also make much easier modeling projects.
For larger coke trains and cars, conventional hoppers and rotary gondolas will work well. Our 100 ton hoppers would be a great starting point. You could also add extensions to car sides like the prototype if you have an interest in customizing your models. Coke, especially when reduced to O Scale, looks very similar to coal, so you can use the same loads.