Railroads are designed to handle heavy loads, but not every load breaks the scales. Wood chips are one of the least-dense loads commonly carried by rail. Because of their relatively light weight, the chips can be hauled in large volume in very big cars.
Wood chips are used in a variety of products, from paper to construction material. The lumber industry is a model for raw material utilization. These chips are often the “left over” byproduct from milling operations. Rather than waste the material, it is collected, sold and shipped to other processing plants.
For the railroads, transporting the chips has always presented a challenge. How do you maximize the payload so that you can earn a profit while keeping the cars within the limits allowed by interchange rules?
Over the years, many railroads have created wood chip cars by converting older equipment. The cars have come from hoppers, gondolas, even boxcars. In almost every case, part of the process includes raising the sides of the car to the tallest height possible. Purpose-built wood chip hoppers and gondolas can also be found.
Many processing plants have large rotary dumpers, similar to those found for emptying coal and ore, which simply turn the entire car upside down to empty the load. In other cases, the hopper doors on the bottom of the car are used to empty the wood chips into a pit from which a conveyor delivers them to storage piles. Some boxcar conversions retained their doors so they could be unloaded by hand from the sides of the car.
In recent years, with a great rise in the amount of waste hauled by rail, some of these large cars have found new uses in bulk trash and scrap hauling service. Only certain types of refuge can be hauled in these cars. Compressed and heavy bales would overload their capacity very quickly. Like the wood chips, some of this scrap is recycled into other products.
There are several industries you could model which would take in these cars. Many, like paper and lumber mills, tend to be large complexes that will require many other types of rail cars as well. Or you could just add a few to the consist of your trains as they pass through your railroad on their way.
Creating an extended height conversion car could be done relatively easily by starting with one of our conventional hoppers or gondolas. Extended sides can be made from styrene plastic or basswood, available at most hobby shops. Don’t worry about being to precise – most of the prototype conversions were clearly after-market changes as well.
Loading your cars is easy – just sweep the sawdust off of the workbench or workshop floor after your next project. A car or two of wood chips is a great break from the many coal loads you’re already carrying.