Union Pacific Piggyback Operations
This page was last updated on July 25, 2025.
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Union Pacific Piggyback Operations
Trailer On Flat Car (TOFC)
November 8, 1953
"In the west, the Union Pacific first tried the operation last June, with its own trucks. It now hauls "piggy-back" between Los Angeles, Salt Lake City, Portland, Pocatello, Spokane and Boise. John Turrentine, UP general agent in Lincoln, thinks the operation "holds a lot of promise - we're sold on it" at the Lincoln office. Turrentine says "so far it has made tremendous strides" in the west, and he predicts expansion into the Midwest in the not too distant future." (Lincoln Sunday Journal and Star, November 8, 1953)
June 26, 1955
"Lincoln (AP) - The state Railway commission Wednesday will give hearing to the Union Pacific railroad’s request for permission to establish "piggy back" railroad service in Nebraska. The commission spokesman said the Union Pacific's application is the first such in Nebraska. It asks permission to haul fresh meats, butter and other food and packing house products from Omaha to Kearney. The empty trailers would be hauled back by flatcar to Omaha. Letters protesting the move have been filed by trucking firms." (Scottsbluff Star Herald, June 26, 1955)
Mark Amfahr wrote in July 2025, "UP first used the trailers in highway service only, operating between company freight houses and pick-up and delivery locations. The freight was moved via boxcar between freight houses. The first UP TOFC service with those trailers that I'm aware of was between Southern Idaho and Northern Utah and the Los Angeles basin starting in 1953. From 1953 to 1957 TOFC service spread quickly across the system such that there are many photos of UP trailers on flatcars in 1955-59 and later."
As early as 1948, UP was using trailers to move supplies for its Dining Car and Hotel (DC&H) Department between the main warehouse in Omaha, and several commissaries across the system. Union Pacific operated large Dining Car and Hotel commissaries to store and distribute food and supplies to all of its passenger trains at several major locations. These commissaries were located in: Omaha; Denver; Los Angeles, Portland and Ogden.
The commissary in Ogden was particularly notable, as it housed the only laundry facility operated by the railroad for the entire system, handling a massive volume of linen and cotton items for dining cars, hotels, restaurants, crew clubs, and even the Sun Valley Resort. The Ogden commissary building was eventually closed and demolished in 1970.
These DC&H trailers may have also been used to supply UP's Bridges and Buildings, and Roadway Maintenance crews at their various remote locations across the system.
Union Pacific began offering trailer-on-flat-car service in 1954. UP was among those that started experimenting with TOFC fairly early. Union Pacific flatcars outfitted exclusively for handling trailers first appeared in the Official Railway Equipment Register of January 1954. The 43'-3" flats first appeared in the 1956 equipment register. You could also see Trailer Train cars in interchange service anytime after 1955, although UP didn't join Trailer Train until 1960.
UP's start of TOFC service followed some railroads that explored trailer-on-flatcar (TOFC) service as early as the 1920s. But ICC regulations limited the practice to short lines, short distances, and service within a single state (known as intra-state service). An Interstate Commerce Commission ruling in 1954 clarified the legality of trailers being moved on rail cars (known as intermodal), opening the doors to railroads nationwide. Quick to jump on the bandwagon after the 1954 ICC ruling were the Atchison, Topeka & Santa Fe; Baltimore & Ohio; Chicago & North Western; Great Northern; New York Central; Nickel Plate; Pennsylvania; and Wabash, among others. A year later, in 1955, Norfolk & Western, Pennsylvania, and Rail-Trailer Corp. combined forces to form Trailer Train.
On Union Pacific, the entire F-50-10 class of flat cars in the 53000-53084 series were converted from 56000-series cars in July 1953, November 1953 through June 1954, and in November 1958. The entire F-50-10 class had been built as 56000-series cars in September to December 1939. In the 1967 period, as more and more newer 87-foot double-trailer flat cars were entering service, the remaining single-trailer F-50-10 50-foot cars were renumbered back to their original 5600-series number.
(Color photos of UP Fruehauf and Trailmobile trailers, including two loaded on UP F-50-10 53008, are on the back cover of The Streamliner, Volume 18, Number 3, Summer 2004)
As a single example, UP F-50-10 flat car 53019 was converted to TOFC service in December 1953, from its previous number of UP 56794, and is shown in the UP Equipment Record as "test car Pullman-Standard Trailmobile." Pullman-Standard bought control of Trailmobile in 1951, keeping the company as a separate business unit, known as Pullman-Trailmobile, Trailmobile Inc. Division of Pullman, Inc., until 1989.
In 1954, 100 of the 5100-series 40-foot flat cars were converted to trailer service by renumbering them to the new 53500-series cars. As with the F-50-10 cars, in the same 1967 period, many of the single-trailer 53500-series were renumbered back to their original 5100-series cars as the longer double-trailer cars came into service.
Dick Harley wrote on July 25, 2025.
UP's first TOFC flat cars were 9 class F-50-10 (53-ft) cars modified and renumbered 53000-53008 in July 1953.
See: https://donstrack.smugmug.com/UtahRails/Union-Pacific-Equipment-Record/Flat-Cars/i-TkZrf7s/A
The first 40-ft TOFC flats were converted and renumbered class F-50-15 cars in September 1954.
See: https://donstrack.smugmug.com/UtahRails/Union-Pacific-Equipment-Record/Flat-Cars/i-BnQPDmk/A
For more UP flat car data, see: https://harley-trains.smugmug.com/UP-FRT-DATA/UP-Flat-Car-Data
Items for Railway Age magazine
(research by Jim Eager, courtesy of Mark Amfahr).
1953:
UP begins Less-than-Carload (LCL) and trailer-load Trailer-on-Flat-Car (TOFC) service between Los Angeles-Las Vegas in August; extended to Salt Lake City in November, mainly to handle steel from US Steel's Geneva Works that had been lost to trucks. The service used converted 53-foot flat cars.
1954:
UP expands TOFC service between Idaho, Nevada, Oregon and Wyoming stations in May-July; begins interline service with SP in October; tests an experimental flatcar-mounted bilevel autorack developed by Evans.
1955:
UP was among the railroads that tested the use of dry ice and mechanical cooling of trailers. The other railroads indlude ATSF, B&O, C&EI, CGW, LV-NKP and NP.
1955:
UP begins handling Armour & Co trailers between Omaha and Kearney, Nebraska.
1955:
UP begins interline service between Chicago-Denver via C&NW, and St. Louis-Denver via Wabash in July.
Trailer-On-Flat-Car
The following comes from Josephine Ayre. "History and Regulation of Trailer-on-Flatcar Movement." Presented at the 5th Annual Meeting of the Highway Research Board, Washington, D. C., January 17-21, 1966.
Piggyback, known as early as 1855 with wagons on trains, began its modern development with a container service in 1921 and trailer-on-flatcar in 1926. The container service had become popular until an ICC decision in 1931 (In the Matter of Container Service, 173 I.C.C.403) established a rate formula that was not attractive to shippers, so railroads abandoned the service.
Although several favorable ICC decisions in 1936 established the principle of a substituted service, it was not until the New Haven case in 1954 (Movement of Highway Trailers by Rail. 293 I.C.C. 93) that piggyback received sufficient impetus to develop extensively. The ICC decision in that case set forth seven principles which served as a green light for piggyback operations. After this landmark decision, piggyback carloadings rapidly surged upward. The number of railroads offering piggyback service doubled in the ten year period between 1955 and 1965, while carloadings multiplied six times.
Piggyback operations soon resolved themselves into five major plans, with some variations of Plan II. Plan I is a substituted service in which a motor carrier provides its line-haul service by moving its trailers ôn a railroad flatcar. Plan II is an all-rail door-to-door service in which the railroad provides both trailers and flatcars. Plan III is a ramp-to-ramp service to shippers who provide their own trailers. Plan IV is a shipper operation in which the shipper provides both trailer and flatcar. Plan V is a coordination of truck and rail facilities in a joint rate, through-route operation.
Railroads generally began with Plan II, then added Plan I, which was followed by Plan III and Plan IV when shippers and freight forwarders became sufficiently interested to provide their own equipment. Plan V represents, more than any other plan, a truly coordinated transportation as it provides for a motor-rail-motor movement over through routes on joint rates. All railroads in the United States offering piggyback service have Plan II in operation.
(Link to the above paper at HathiTrust)
(Link to ICC 1954 decision - 293 ICC 93; 20 pages)
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