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Pneumatic nets haven't gone down the tubes

Why is that? Try delivering bottles of pills over Ethernet, explains one hospital exec.

By , Network World
May 24, 2004 12:17 AM ET

Network World - Pneumatic nets haven't gone down the tubes

Why is that? Try delivering bottles of pills over Ethernet, explains one hospital exec.

User authentication, security and traffic prioritization are hot topics for Ken Moeller, as they are for so many in the network business. Then there's the felt that keeps wearing out.

The felt is on the outside of cylindrical carriers - usually plastic and 6 inches in diameter - that zip through networks of tubes in and even between offices, factories, hospitals and stores. As president of Pneumatic Tube Products in Haywood, Calif., Moeller builds pneumatic tube networks, which in a sense were among the original LANs and MANs.

While the heyday of pneumatic tubes was in the late 19th and early 20th centuries, they haven't entirely gone away despite the rise of the Internet and high-speed corporate nets.

At San Antonio Community Hospital, in Upland, Calif., paperwork and medications shoot through the building in less than a minute, according to Bob White, who runs the hospital's tube network. Without it, San Antonio probably would have to hire 15 people to handle the 1,200 to 1,800 transactions per day, he says. By contrast, the computer-controlled tube network is virtually cost-free apart from quarterly maintenance.

But hospitals aren't the only places using tubes. Facilities that deal with trucks still handle a lot of paper forms, because there are so many different computer systems in use among trucking companies that it's hard to to work with all of them, Moeller says. One lumber company in Northern California is interested in tubes because it says paper is the fastest way to deal with shipping.

"They need the paperwork now," he says. "The system we're going to put in for them is going to handle about 20 orders a minute."

Routing is now controlled by software - a Windows XP-based system, in Pneumatic Tube Products' case. Users enter a code for the destination at a terminal when they drop off the carrier, and the software controls a mechanical "transfer unit" that handles the carrier at points where different tubes meet.

History lesson

Over the years, depending on where they were and who built them, pneumatic tube networks might carry documents, special postcards, regular mail and telegrams hot off the long-haul copper.

The technology is based on a simple premise: Push air into a tube and it will take whatever's in the tube along with it. Reduce the air pressure and things will get sucked backward. Using that principle, a postal agency could solve a serious congestion problem on the largely unregulated network called city streets.

"Traffic was a mess in the big cities . . . and to have one of its mail wagons sitting in traffic for 20 minutes while two horses are fighting or someone doesn't want to give up the right of way, it's a waste of time," says Nancy Pope, a historian at the National Postal Museum, part of the Smithsonian Institution in Washington, D.C. Letters moved between post offices in U.S. cities at about 35 mph, she says.

By the early 20th century, Philadelphia, New York, Boston, Chicago and other U.S. cities had pneumatic networks, as did Paris, Berlin and London. But when business districts shifted around and post offices had to be moved, it proved difficult to reroute the underground tubes, Pope says. Then traffic became smoother when cars took over.

Few postal networks soldiered on after World War I, but the story wasn't over for private tubes. Almost every department store in the U.S. had tubes carrying cash and paperwork in the 1920s and 1930s, says Craig Swank, a marketing and communications director at Swisslog North America, one of only a few big companies left making tube networks.

As the networks grew, the technology got more complex. Routing was needed, first in the form of rooms full of human operators picking up a carrier from one tube, reading its destination address and dropping it off at another "station" to go into another tube. Starting in the 1950s, switching went electromechanical, with the address encoded using a dial or a set of magnetic bands on the outside of the carrier, Swank says.

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