From the dawn of railroading, the boxcar was the vehicle of choice for transporting solid goods that needed protection from the elements. And one of the biggest bottlenecks in shipping was getting the cargo in and out of a boxcar's doors. Over the years, doors grew wider to speed things up, and other expedients were tried - like end doors on automobile cars and small "lumber doors" on the ends of Milwaukee Road boxcars. Perhaps the ultimate solution was this all-door boxcar, where the entire side consisted of four sliding doors that could be opened in pairs to provide a 25' wide doorway.
The idea for these cars was sketched on a napkin in 1962 by Flake Willis, president of the McCloud River Railroad, over lunch with a vice president of International Car Company. A California logging and lumber carrier, the McCloud was looking for a lumber-carrying vehicle with the protection of a boxcar and the ease of loading of a flatcar. (The Southern Railway had previously introduced an all-door concept with rollup side doors, but the idea had not caught on at the time.)
Delivered later the same year, the prototype all-door car proved successful enough that the McCloud River, now owned by U.S. Plywood, ordered 100 similar cars in 1967 from Thrall Car Manufacturing Co. and Southern Iron Works. This time the concept caught on, and "Thrall Door" cars were purchased by lumber carriers across the U.S. and Canada though the late 1960s and early 1970s.
The cars were assigned their own class designation, LU, by the Association of American Railroads (AAR). The LU designation was defined as "An enclosed car with roof, having a special metal beam of heavy design at top of each side to support a series of retractable overhead side doors and their appurtenances, or other types of doors, running substantially the length of car, which beams also support the roof details. Car may be equipped with special loading devices or racks for handling various commodities".
In the mid-1970s, however, new developments in packaging, which protected stacks of finished lumber with colorful, weather-tight wrapping, made the center-beam flatcar the new vehicle of choice for finished lumber shipments - due to superior ease of loading and unloading. As a result, the original fleet of McCloud/U.S. Plywood all-door cars soon found itself retired. Other carriers, however, continued to roster Thrall-Door cars for several decades. Sporadic railfan sightings into the early 2000s indicated that some all-door cars likely served out the maximum 40-year life in interchange service allowed by the AAR for cars built before 1974.
MTH Premier O Scale freight cars are the perfect complement to any manufacturer's scale proportioned O Gauge locomotives. Whether you prefer to purchase cars separately or assemble a unit train, MTH Premier Rolling Stock has the cars for you in a variety of car types and paint schemes.
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