Imagine a national network of pipes, some as small as one foot in diameter and half a mile long, for transporting mail or machine parts between two buildings, and others as large as six feet in diameter and hundreds of miles long for intercity and interstate freight shipment. Sound far-fetched?
Not to Professor Henry Liu, director of the Capsule Pipeline Research Center (CPRC) at the University of Missouri in Columbia. Liu has spent more than 20 years researching pipeline technology systems in which close-fitting capsules carry freight through underground tubes between terminals.
As traffic congestion and pollution increase and fossil fuel supplies dry up, scientists are looking to innovative modes of transportation to transport freight more cost effectively and efficiently.
"This new pipeline technology can transport freight such as coal; solid waste, including hazardous waste; [and] agricultural products, as well as mail and parcels," Liu says.
Two Propulsion Systems
Liu is investigating two capsule propulsion systems to move freight: pneumatic systems propelled by air pressure, which use air from booster fans or pumps to move the wheeled capsules through underground tubes, and a slower hydraulic system.
Hydraulic systems would push freight at 6 to 10 feet (2-3m) per second, while pneumatic systems would run at much higher speeds - 20 to 50 feet (6-14m) per second, Liu says.
Freight pipelines would employ a communication system that uses microwaves, cables and satellites operated automatically by a computer at the pipeline company's headquarters, he says.
William Vandersteel, an inventor in Alpine, New Jersey, is working to improve the technology used in the pneumatic pipeline system. In Vandersteel's tube pipeline, called TubeExpress, goods are carried in free-wheeling vehicles (capsules) that are pumped through the pipelines by electrical power. The CPRC is studying the use of an electromagnetic propulsion system called a linear induction motor, like those used in roller coasters and high-speed trains, to move freight through the pipeline, according to Liu.
Using this system, an electromagnetic charge in induction coils set at intervals within the pipeline would propel the capsules forward. Moving the capsules directly instead of by pumping air would allow the system to operate without interruption or distance limitation.
Daryl Oster in Crystal River Florida has invented the Evacuated Tube Transport, which he claims could move goods from Miami to New York in 25 minutes and from New York to Hong Kong in three or four hours. Oster says his patented system, which works by eliminating friction, could be built aboveground as well as underground.
And while Oster's system - with its promise of speeds that surpass 2,000 miles per hour - may strain the imagination, there are already real freight pipelines either in existence or close to development.
In the Netherlands, the Dutch parliament is discussing a freight pipeline project that could link Schiphol Airport in Amsterdam to the flower market at Aalsmeer. And in Japan, an older pneumatic system, the Sumitomo Capsule Liner, carries limestone from a mine in Tochigi Prefecture to a plant 188 miles away, keeping heavy truck traffic off local roads.
But capsule pipelines aren't the only innovative transportation technology that could be used to move freight.
Francis Reynolds, an engineer and technical inventor in Bellevue, Wash., has developed what he calls a "dual-mode" system that would allow delivery vehicles to be used on streets as well as on "guideways."
Cargo-containing vehicles would travel on automatic guideways - which would use electricity to power the vehicles - built on a different level than the streets. The dual-mode vehicles would be battery electric or fuel cell electric for street use.
"Since we can't get rid of the [vehicles], let's make [vehicles] that aren't bad," Reynolds says. "They can travel in a normal manner on local streets, but most of the highway traffic will be done on guideways, where they can travel automatically at 60 mph (95 kph) in the city and 200 mph (315 kph) on the guideways between cities."
Reynolds says some dual-mode advocates propose supporting the vehicles on the guideways with pneumatic tires; others propose steel wheels on steel rails. But many advocates believe that maglev (magnetic levitation) guideways show the most promise, he says.
James Guadagno, a general partner at Cimarron Technology, has developed the Integrated Transportation System, a dual-mode system in which vehicles would be propelled by linear synchronous motors, which would allow vehicles to travel automatically on a guideway at a constant speed.
Though engineers and inventors are high on new transportation technologies to move freight, the US government, which is a necessary partner in the development of new transportation technology, doesn't share their enthusiasm.
In fact, the US Department of Transportation (DOT) says it isn't doing any research into any of these systems. The Federal Railroad Administration (FRA) is, however, exploring the use of maglev vehicles to transport people, says Arnold Kupferman, manager of the FRA's maglev program.
According to Kupferman, it would take an act of Congress for any federal agency to shift its focus to alternative modes of transportation.
John Fontanella, an analyst at AMR Research Inc. in Boston, says that's not likely to happen. The reason the government isn't on board with these new technologies is that none of these systems is economically viable, he says.
But Liu has a different explanation for the lack of government involvement. "A more possible reason for DOT neglect in freight pipeline research is the strong lobbying efforts by the trucking industry and the railroad industry," he says. "They do not want competition from pipelines."