The Pennsylvania Railroad was a pioneer in the development of trailer on flat car (TOFC) service and was the principal partner in the formation of Trailer Train Corporation.
F30D Flat Cars
When the Pennsy inaugurated service on July 12, 1954, it was on modified class F30D flat cars. The class of 250 cars was built in 1951 and 115 were converted for trailer service.
The modifications for piggyback service included the installation of metal bridge plates for circus-type loading, four tall stakes to prevent trailer loss in the advent of tie-down failure, two perforated side rails to guide the trailer when loading and a compartment built into the center of the floor for storage of the tie-down equipment.
![]() |
![]() |
Each F30D could carry one trailer.
The F30D class flatcar has been produced by Rapido. The car may be kitbashed from a Bowser F30A flatcar. Decals are available from Microscale.
Rapido F30D
F39 Flat Cars
In December 1954, Bethlehem Steel began delivery of 200 specially-built 75' flat cars capable of carrying two trailer each.They were numbered in the series 470400 - 470599. The F39A was dimensionally identical to the F39.
The F39 class flatcar has been imported in brass by Overland and also produced in plastic by Walthers. Decals are available from Mount Vernon Shops.
Walthers F39
F39A Flat Cars
After the full order of F39 cars were delivered, the PRR Holidaysburg shops built 250 of their own, classed F39A, in the 470600-470749 and 470800-470899 series.
The F39A class flatcar has been produced in plastic by Walthers. Decals are available from Mount Vernon Shops.
Walthers F39A
F39B Flat Cars
The PRR Holidaysburg shops also built 50 more flats, classed F39B, in the 470750-470799 series. The F39B cars can be distinguished from the F39A by their all-wood deck and prefabricated side sills.
This brought the Pennsy fleet to 110 50' cars and 500 75' cars.
Trailer Train Corporation
Trailer Train Corporation was incorporated in 1956. All 500 of the 75' cars were acquired by the new company and "TTX" was painted over "PENNSYLVANIA" on the cars. TTX also purchased 20 F30A flats from the Wabash and an additional 10 F39B from the Hollidaysburg shops in the 470900-470909 series.
F39C Flat Cars
TTX also had the Holidaysburg shops build 300 new F39C cars, in the 470930-471229 series.
This brought the TTX fleet to 830 cars.
With the introduction of 35' trailers and expectation of 40' trailers, TTX began to design 85' cars. To keep up with traffic until the new cars could be designed and produced, TTX bought 86 of the Pennsy's 110 F30D TrucTrain cars.
Modification of the ex-PRR F30D flats included removing the side rails, replacing them with rub rails made of steel angle-iron; removing all four side stakes and installing high-speed rollerbearing trucks. Bridge plates were removed and replaced with heavier versions and some cars received a long, thin metal panel along each side of the car to carry the new number and reporting marks. These flat cars then became TTX 475001-475086.
The most important modification to these cars, however, was the installation of the new American Car & Foundry retractable trailer hitch. Introduced in 1956, the new Model A hitch was designed to eliminate the need for all the mechanical stanchions and tie-down chains then in use.
To keep up with the increased demand for equipment, Trailer Train also purchased 200 additional class F30A, 50'-long flat cars from the PRR and began to modify them for piggyback use.
F85A Flat Cars
TTX contracted with American Car & Foundry (ACF) and Pullman Standard (PS) to each build 200 of the new 85' cars.
By 1959, the Trailer Train Company began to receive its first batch of 85'- long piggyback flats. The cars, built by ACF (classified F85A), were characterized by a structural channel side sill and wood decking. The Pullman Standard cars came with fabricated side sills and an all-steel deck. Both cars came equipped with two fold-down-type trailer hitches, roller-bearing trucks and a cushioned draft gear.
F39G Flat Cars
Meanwhile, Trailer Train continued to modify its 200 ex-PRR F30A flat cars, turning them into TTX F30G piggyback flats. These cars were numbered TTX 475087-475286. With the arrival of the new equipment, many of the older 75' flats were converted to other uses. Only 609 of the cars ever received hitches.
Paint
Pennsy flat cars were painted "Freight Car Color".
TTX flats were red through the 1950s.
TTX flats changed to yellow in the 1960s.