The economic success of the railroads depended on freight shipped in full cars. The idea of putting truck trailers on flatcars was a method of moving less-than-carload shipments economically. This "intermodal" concept held the hope of competing with trucks which were taking more and more of this business from the railroads.
In the mid-thirties, the Chicago, the Great Western and then the New Haven railroads began piggy back service limited to their own railroad. By 1953, the CB&Q, the Eastern Illinois and the Southern Pacific railroads had joined the innovation. Most cars were surplus 50's flatcars equipped with new decks by the railroads. By 1955, an additional 25 railroads had begun some form of piggy back service. A significant legal battle between the truckers and the railroads resulted in a ruling permitting interstate piggy back service using either railroad or privately owned trailers. The stage was set for rapid expansion of intermodal services.
The G24 were 41'-6" gondolas designed by the United States Railroad Administration (USRA) and plans provided to the PRR in April 1919. They were composite cars with wood in the sides, end and floor. They featured straight sides with drop doors in the floor and rode on USRA 2D-F3 trucks. They had Carmer cut levers.
Starting in 1929, the Pennsy replaced the composite sides with drop bottoms to steel sides with solid bottoms. Some cars received steel ends. Though most cars were converted in this manner, the program was halted in 1930.
In later years it appears the Pennsy may have replaced many with 2D-F8 trucks.
In 1936, the Pennsylvania Railroad led in the U.S. railroads in extending the length of gondolas by the introduction of its 52'6" interior length G27 all steel mill gondola. From 1936 to 1939, the PRR built 4500 of this innovative design. The PRR was the largest steel hauler in the U.S. and the purchase of these new gons reflected that fact.
The following tables illustrate the various spotting features of EMD GP7 and GP9 units purchased by the Pennsylvania Railroad. The basis for these tables are from a Jim Williams presentation at the May 2000 annual meeting of the Pennsylvania Railroad Technical & Historical Society.
Twenty five F31 were built by Altoona Car Shops (470300-470324) in 1929 to carry containers for the Pennsy's new COFC service. They were constructed as 70-ton cars and designed to carry eight DD1 containers. With a length of 62'6", they were the longest in the PRR's general service fleet at the time.
The earliest reference to conversion of XL box cars to maintenance of way and crew cars (or camp cars as they were called by the Pennsylvania Railroad) is 1937. Blueprints were issued for standard sets of cars. One set entitled "four car unit for living quarters" included a riding car, two sleeping cars and a kitchen/dining car. Another entitled "four car unit wreck train" included a tool car, cable car, riding/locker car, and commissary car. A third showed wire train cars: a riding car with cupola and pantograph and a tool/material car. These were far from the only variations as photos reveal many others. The details, especially smoke jacks and vents were added from available supplies, resulting in standard cars on which almost nothing was standard. The Westerfield models are based on the blueprints in most cases as the plans reveal the position of internal details making the location of ventilators more precise.
By the 1920s, trucks were chipping away at railroad freight service. Long haul trucking was decades away from being practical, but the short haul impact was being felt. By 1921, the New York Central had introduced less-than-carload (LCL) container service. In 1928, the Pennsylvania Railroad created a subsidiary, Keystone Container Car Co., to own fleet of containers for its new "Keystone Service".
There were two categories of containers in service -- merchandise freight containers and bulk freight containers.
Between 1924 and 1934, the Pennsylvania Railroad purchased or built over 30,000 of the X29 class of box cars and an additional 5,000 of the auto car variant, the X28. The X29 -- a 40' 50-ton all-steel car -- became the most ubiquitous freight car of the late steam/transition era. These cars appeared in every corner of the US and Canada.
The G30 were 52'-6" 70-ton gondolas that were built not only for the Pennsy, but also for the N&W, NYC, CNJ, and ATSF. They had drop ends and were of composite design with wood floors and sides. New to the G22, however, were sleeves on the sides to allow replacement of the wood with steel after the war. The first cars went into service in April 1943.
So you've got a model railroad and you want to operate it. Before you can host an operating session, an operational strategy must be developed -- how do trains move? How do cars move? How do crews communicate? The scope of questions goes well beyond this article.
One of the methods for freight car movement is the use of "Car Cards and Waybills". This was popularized as the "McFall" system decades ago, and forms for manual creation are available from MicroMark. A number of software products are also available to generate waybills, including Albion's popular ShipIt program.