Despite its sensational jet-age styling, the General Motors Aerotrain was a spectacular flop. Here’s the how and why.

In hindsight, it’s a surprise that the Aerotrain was such a complete failure. General Motors and its Electro-Motive Division had revolutionized the rail freight industry with their two-stroke diesel-electric locomotives. Surely GM could do the same for the passenger rail business, then reeling due to increasing competition from air travel, bus lines, and improved highways. That was the plan, anyway: The streamlined and ultra-modern GM Aerotrain would be light, fast, comfortable, and attractive to American travelers. Its light weight would provide both high speeds and low operating costs.

The Aerotrain’s locomotive (LWT12) was, underneath, Electro-Motive’s tried-and-true SW1200 four-axle switcher engine, regeared for 100+ mph travel, with its 567C V12 two-stroke diesel engine (6.804 CID) rated at 1200 hp. But the exterior was totally new, created by the rising star of the GM advanced automotive studio, Chuck Jordan, who would later become VP of GM design. The sleek design featured aerodynamic lines, a jet-age lamp pod in the front, and an elevated cabin with wrap-around windscreen for the crew.

Designed for lightness and comfort, the passenger cars were adaptations of the aluminum body for the 40-passenger highway bus produced by GM Truck & Coach. Riding on a two-axle carriage with air suspension, each car was 40 feet long and weighed 16 tons, compared to 65 tons for a conventional rail coach. Each car was air conditioned with airline-style seating and accommodations, while a tailfinned observation car would ride at the rear of each 10-car consist. The Aerotrain was “the lightweight with a heavyweight future,” GM proclaimed in national advertisements.

Three Aerotrains were built, including two demonstration units at a cost of $1 million each. The two demonstrators were leased or loaned to multiple railroads starting in early 1956, including the Pennsylvaia, the Atchison, Topeka & Santa Fe, and the Union Pacific. After 600,000 miles of total service, In every case the railroads made the same discovery: The Aerotrain was a flop.

The 1,200 horsepower of the Aerotrain’s engine was insufficient, requiring a helper locomotive to join in and assist in climbing grades. Meanwhile, the two-axle, bus-bodied passenger coaches were noisy and uncomfortable—riders complained of a bumpy, jarring ride, especially at higher speeds. For its intended purpose, high-speed intercity travel, the Aerotrain was a failure, and the defects were fatal. GM threw in the towel at the end of 1957 and sold off the two Aerotrains, at a loss, to the Chicago, Rock Island and Pacific Railroad for commuter service in the Chicago area, where they operated through 1966.

The two demonstrators have survived, one at the National Railroad Museum in Green Bay, Wisconsin, and one at the National Museum of Transportation in St. Louis. While the Aerotrain was a failure, the doomed project has enjoyed a few more moments in the sun. In 1957-58, when the Aerotrain still looked like the future, Disneyland operated two miniature versions with a 30-in gauge and Oldsmobile V8 power (below). The Oregon Zoo in Portland, Oregon operates a 5/8 scale Aerotrain replica it calls the Zooliner.