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| Aileen Cho |
If the inventions presented at Grand Central Terminal the week of May 21 ever make it into commercial markets, they will surely improve people's lives in various ways both big and small.
Perhaps you're a kidney failure patient who will benefit from Dr. David L. Cull's device to regulate blood flow when connected to a dialysis machine. Or perhaps you are disabled, and need a wheelchair like that of Randall Kwapis, that will carry you easily over rough terrain. From automatic candle extinguishers to a new and better kind of pet nail clipper, the 25 semi-finalist inventions featured at the History Channel's first annual Modern Marvels Invent Now Challenge -- chosen from 4,200 nationwide submissions -- ranged from the clever to the life-supporting.
But what is more life-supporting in an everyday sense than the works of civil engineering? Completely unbiased, of course, I set about looking for the engineering inventions.
Here was Dr. Henry Liu, a frail-looking professor of engineering with a booming voice. He is in Phase 2 of a National Science Foundation project to create bricks made from fly ash, water and an air-bubble agent that creates bricks of up to 5,000 psi. They are comparable in strength to ordinary clay bricks. "More bricks, less landfill," he says of fly ash bricks. He performed 50 freeze-thaw cycles to prove the bricks' durability and is confident that further tests will prove rainfall won¹t release pollutants from the bricks.
Then there was David Ward, the inventor of StrawJet. It's a farm implement that processes straw from just about any type of field plant (hemp is best) into a mat. These mats, created right there in the field, become composite building panels with binders made from pulp, clay and cement. Rather like fiber-reinforced polymers gone rural.
With these panels, farmers can sell off the straw from their crops, and emerging cities in places like China can build affordable housing very quickly. "In China, a study determined it will build twice as many houses in the next 20 years as exist now in the United States," Ward told me. "They don't have enough trees, cement, etc." But they do have plenty of wheat, rice and hemp straw.
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| Engineer Denney Pate, still in love with bridges. (Photo courtesy of Figg Engineering)
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And then there was W. Denney Pate, once a young boy sketching bridges in school. He fell in love with bridges very early on and never thought twice about what he'd be doing with his life.
There was his cable-cradle system, where a continuous stay is carried from a cable-stayed bridge deck through the pylon and back. No anchorages in the pylon. No interaction among the cable strands. With the space saved, contractors in Maumee, Ohio, and Penobscot, Maine, have room to build soaring glass observatories within the structures of the bridges and maintain an elegant, slim design. Pate estimates the savings in maintenance of these bridges will reach $4 million over those with conventional anchorages. "You can take any individual strand out, inspect it and replace it, without taking out the whole cable," he says. "It can be done inside the bridge, invisible to the public."
Each cable strand passes through its own stainless steel sleeve within the cradle and is also sheathed in stainless steel. In Maine, the 1,161-ft main span also will include the first-ever use of pressurized inert gas to create a protective environment for the cable stays, with nitrogen to flow through the system.
The Maumee River Bridge would have been the first new major structure to sport the system, but unrelated worksite accidents involving collapsing gantry cranes and alleged OSHA violations have delayed that $200 million project by about a year. It will be the Penobscot Bridge, with a soaring 420-ft pylon and granite-themed façade, due to open this year. The theme, reflecting the area¹s Fort Knox tourist site, came about due to "charettes" or community workshops presenting residents with design choices. Linda Figg, president of Figg Engineers, Tallahassee, won an ENR newsmaker award in 1999 for creating the charette process. Pate's cable system, she says, "is the answer for 150-year lifespans for cable-stayed bridges."
Pate, who with Figg Engineers has been involved in some of the nation¹s most notable bridges, didn't tell Linda Figg at first the real purpose for entering the Modern Marvels contest. But it was this: If the system won the $25,000 grand prize, the money would go directly into the American Society of Civil Engineer's memorial scholarship fund, named in honor of Linda¹s father, Eugene Figg, who died in 2002.
"After Dad died, the company employees got together behind my back to create the fund using $50,000 of their own money," Linda Figg recalls. "A year later, they presented it to me."
Three students have each been awarded $3,000 to help them as they complete their studies in bridge engineering. They are required to write essays explaining why they are passionate about bridges. Reads one: "Ever since I was eight years old, when I first crossed a drawbridge in Florida, bridges have fascinated me," wrote Samantha J. Hockerman, the 2004 winner. "That was when the dreaming started."
Those words could have easily been Pate's. It¹s that kind of passion that leads to these kind of inventions.
The winner turned out to be Ward, with his straw harvesting machine that builds composite panels. But long after the prize money is gone, those bridges, the cradle system and those budding bridge engineers will still be here‹improving people¹s lives in ways both big and small.
