By the mid-1950s El Capitan had become the most consistent year-round moneymaker for the Santa Fe; it was so popular it was often unable to meet the demand for reservations. In an effort to boost capacity; Santa Fe turned to Budd with a bold proposal, which became Santa Fe's trademark Hi-Level coaches. While bilevel designs had been in service in local commuter operations for several years, this represented the first application of the double-deck design to a through long-distance train. The new equipment featured baggage storage and large restrooms on the lower level, while the upper levels were entirely devoted to seating. (Unlike today's Amtrak Superliners, there was no seating area on the lower level and the restrooms were not unisex. Handicapped passengers had to negotiate the stairs at least once coming and going, although once they were upstairs they were seated in a special reserved section adjacent to the lounge car, which had upper level restrooms available.) A nine-car train of the new equipment seated 496 passengers, up from 350 for the single-level train, while the diner could serve 80 passengers at a sitting with a much roomier downstairs kitchen for the crew to work in.

This timetable, from July of 1956, shows the transition from the old to the new. The new Hi-Level El Capitan entered service on July 8 of that year, and effective as of its introduction, El Capitan's extra-fare status (which had lapsed a couple of years previously) was restored.

Read the feature article from the July 9, 1956 issue of Railway Age (PDF format, 1.5 MB [new, smaller scan])

The new Hi-Level El Capitan was a smash hit with the traveling public. It was so popular, in fact, that a new problem arose: it was impractical to run second sections of the expensive new equipment, and a single-level second section would disappoint passengers who were expecting Santa Fe's latest and greatest. The solution, implemented in the 1960s after El Capitan was combined with the Super Chief in the schedule, was to add a section of single-level coaches (with separate diner and lounge) and market them as part of the Super Chief, with a reduced extra fare of $3.00, during the highest peak traffic periods of the summer. What train's name had more cachet than that of the Super Chief?—although the idea of any coach operating under that name would have been unthinkable twenty years previously. Desperate times—and, in the passenger train business, the entire decade of the 1960s was a desperate time—call for desperate measures.