If you pay any attention to railroading today you have likely noticed all types of railroad freight cars moving within any given train, from the standard hopper cars and boxcars, to the more specialized well-cars and spine cars (used for ship container and truck trailer transport). Have you ever wondered the history of these railroad cars and what brought about the different types and designs? The history of railroad cars moving lading (another term for freight) can be traced back to the earliest days of the industry using simple flatcar designs. As the years progressed designs became larger, heavier, and more sophisticated to handle larger loads and specific cargo. Today, a wide range of cars can be found in service replacing the ubiquitous boxcar, which railroads used to haul most types of non-liquid and aggregate freight during the 20th century thanks to its redundancy.
Well, believe it or not freight cars, also known as rolling stock, actually preceded America’s railroads themselves, first being used in quarries and coal mines as early as the 1820s. And, as perhaps might be expected, the very first car designs were simple planks on axles, or the standard flatcar and covered gondolas (a shorter version in height of a boxcar). These first examples were used to carry almost all types of merchandise the railroads handled accept coal and other bulk loads which used “jimmies,” or the predecessor of today’s common open-top hopper cars. As the railroads began to show their superior advantage to horses and canals in being able to haul large amounts of freight in any type of weather, it quickly became the preferred mode of transportation by the mid-19th century. As demand grew so did the need for more specialized car types and better construction of them.
Early railroad cars, as mentioned before, were simple things, usually with only one axle attached rigidly to each end of the car. As demand grew it quickly became clear that better designs were needed as these single axle, simple designed cars were very impractical when used to haul heavier and heavier loads (the single-axle cars would bend around curves and by the axles being rigidly mounted to the car’s frame, there was no cushion for the freight, which was often damaged by the time it arrived at its destination).
The two-truck car (two sets of trucks, or wheel housings that hold two axles each, with each car carrying eight total wheels), which is what you commonly see on today’s cars, were invented as early as the 1830s by the Baltimore & Ohio Railroad and by the later years of that decade were becoming quite popular with their ability to more evenly distribute weight (as well as handle heavier loads), provide better stability for the car, and offer improved cushioning for freight with springs mounted in-between each side of the truck assembly.
Following the two-truck concept, car technology began to improve and become larger for heavier and heavier loads as locomotive horsepower increased and more types of freight were being moved resulting in better designs needed, although serious research and development was often hindered by the railroad industry’s conservative views on such (while railroads have always been conservative and “archaic” in their views they have also has had their reasons, to some degree, being that railroading in its very nature has nearly the highest cost of capital of any industry and relies on economies of scale to be profitable).
For more information on different railroad car types please click on each link's below:
Unique/Custom Built Designs
In any event, the next major milestone in car development was the switch from wood to steel in construction, which began to appear in cars in the late 19th century, mostly in areas of structural integrity such as sills and trusses. Even though all-steel cars became favored by the early 20th century, those made of wood remained in use as late as the 1960s until their age forced them into retirement (today the Federal Railroad Administration [FRA] has set a 50-year “shelf life” standard for cars before they must be retired, with roughly ten years between major overhauls while in service).
While cars continue to advance and better designs will continually come about making them of higher quality and able to haul heavier loads, as has been the case since railroads were born (and some railroads have even fabricated their very own cars such as the Baltimore & Ohio and Pennsylvania Railroads) the basic designs will likely continue to fall into one of six categories; gondolas, hoppers, tank cars, well and spine cars, boxcars, and the common flatcar. So, look for these types of freight cars rumbling along on railroad tracks near you throughout the foreseeable future!