Skeptics shook their heads at the first double-stack cars, introduced in the 1970s. Heavy and expensive to operate, the first double-stack designs couldn't succeed in America's worst energy crisis in history-so why pursue them in an era of cheap oil?
Don Orris knew better. Simple math said specially-engineered rail cars carrying two tiers of containers instead of one would significantly reduce the locomotive power, track capacity and train crews required to move a comparable payload by conventional intermodal trains. Orris, head of the intermodal department of venerable freight carrier APL, told his team to make that math work.
Together they designed and implemented what APL termed an “articulated stackcar, of five individual platforms joined by fixed rigid connectors.” For every six trailers carried by a typical train car, stackcars bore ten containers, nearly a one hundred percent improvement. Without the trailer frame and chassis, stackcars dropped weight and increased fuel-efficiency, reducing the number of locomotives and crews needed for each load.
And, to add a final benefit, the new system all but eliminated slack action, swaying, and vibration.
When Orris invited reporters to witness the new double-stack network in action, he dubbed the exercise Stacktrain's “Smooth Move” test journey. To demonstrate that his team's design dramatically reduced in-transit damage, “he had us load up a container with a dinner table set with crystal, china and silverware, and rail it across North America,” says Tom Shurstad, then an APL colleague. “Everything arrived intact, and Don made his point.”


The commercial Stacktrain system launched in 1984, nearly three decades after the first containership between Port Newark and Houston launched the age of containerization. At last containers could transfer directly from ship to train or train to truck. “One of the boldest and most productive applications of containerization imaginable,” Shurstad says, “[double-stack rail technology] changed the entire intermodal freight distribution industry in North America forever.”
New container trains broke cost, capacity, security, and service barriers. In two decades, the double-stack market grew more than 100-fold. By the start of 2006, stackcars accounted for approximately 70 percent of all intermodal shipments.
“For freight intermediaries-the intermodal marketing companies, ocean carriers, and other third parties that market end-to-end transportation services to businesses that ship product worldwide-introduction of double-stack revolutionized their business,” says Shurstad.
In 1999, $1.7 billion third-party logistics and freight transportation provider Pacer Stacktrain acquired APL's still-dominant double-stack system. Today, the firm manages the largest intermodal rail network in North America.
“Much of the growth of Pacer Stacktrain's volumes -and the growth experienced by other providers-has resulted from conversion of freight from long-haul trucks,” Shurstad says. “We expect to see this growth continue, reflecting both modal conversions and growth of the total intermodal market.” He cites the movement of general merchandise between the United States and Mexico as “a particular focus area for future growth.”
Innovation and expansion “designed to keep freight flowing” continues into the new millennium. Next in Pacer Stacktrain's product pipeline is a wholesale door-to-door service, integrating rail and trucking in one operating unit. “This service looks and feels like an over-the-road, door-to-door truck product,” Shurstad summarizes. “It will significantly simplify the current intermodal transaction and improve the reliability of intermodal service by reducing the number of hand-offs between multiple participants.” wt