were handling new automobiles in this way, including the CB&Q, C&NW, CRIP, D&H, D&RGW, ERIE/EL, GN, KCS, L&N, MILW, MKT, MP/TP, NP, SL-SF, SP, SSW, WAB and UP. The New York Central, which used the Flexi-Van system of transporting only the highway trailer body without the wheel assembly, developed a Flexi-Van automobile carrier rack. Seeking a more efficient method, in February 1959 the Saint Louis-San Francisco Railroad (SL-SF, or Frisco) designed and built a prototype bi-level rack mounted on flat car SL-SF 95844. Satisfied that the basic concept was sound, the railroad contracted with Pullman-Standard to design and construct a full-size tri-level prototype. The result that rolled out of the Pullman plant on January 29, 1960, was SLSF 3000, an tri-level car capable of carrying 12 automobiles. When testing proved the car satisfactory the Frisco ordered 130 production cars, SL-SF 3001–3130, delivered by Pullman that August and September. In 1960, the Frisco was not the only railroad experimenting with racks mounted on flat cars to carry automobiles. In January the Atchison, Topeka and Santa Fe Railway (ATSF) constructed a prototype trilevel rack mounted on flat ATSF 90082. Santa Fe's first production auto racks were trilevel Auto-Veyor units supplied by Dana-Spicer and Whitehead & Kales later in the year, both mounted on General American-built G85 cars. The Southern Pacific actually took delivery of the first Whitehead & Kales Auto-Pack tri-level racks in April, mounting them on General American-built Clejan and G85 cars. The slightly longer racks could carry 12 full size or 18 compact autos per car. Several other railroads quickly ordered their own auto racks from Dana and W&K or from American Car & Foundry, Darby Corporation, Evans Products, Paragon Bridge & Steel, or Thrall Car Manufacturing. The Santa Fe and Frisco also built some of their autoracks in their own car shops. Curiously, in 1961 a German-built three-unit, articulated bilevel autorack was imported into the United States to demonstrate the German design to U.S. railroads. North American Car Corporation handled promotion of the car, which was marked NIFX 1200. The car rode on four single-axle trucks and was tested by the B&O, but no sales resulted. Starting in this early period, most autoracks were mounted on flat cars leased from a leasing company, such as Trailer Train (see below), North American Car (NIFX marks), Merchants Despatch (MDAX marks), American Refrigerator Transit (MPFX marks), or Pullman's Transport Leasing Division (TLCX