CORVALLIS - It might seem like sacrilege to Casey Jones - but if they can make automobiles almost completely out of plastic, it's probably only reasonable to suppose they can make railroad cars out of cloth.
Mechanical engineers and students at Oregon State University have done just that, developing and patenting a new type of coated Kevlar fabric that can form the bed for a railroad coal car.
It appears the process could save many millions of dollars.
This material uses the high strength of Kevlar fibers to support the weight of the coal, and a polyurethane polymer and ceramic to protect the fibers from acid, abrasion and solar ultraviolet light corrosion.
The result will be a lighter coal car, trains that can carry more coal with fewer cars, and major savings on tracking equipment, fuel and labor.
"Steel has been the conventional material for this use, but for the same volume it's three times as heavy as aluminum and five times as heavy as Kevlar," said Ernest Wolff, an associate professor of mechanical engineering. "Our solution used the lightest material available."
Computerized mathematical techniques helped determine strength requirements, and multiple tests identified the necessary coatings to protect the fabric. Four graduate students developed their masters' degrees around this work, and six OSU undergraduate engineering students also collaborated.
The next step, Wolff said, will be actual field tests.
"Panels of the most promising coatings are currently being prepared and will be placed in a frame welded to the steel floor of a coal car," he said, "for a six-month test with full loads of coal."
Following that, a complete railcar floor will be tested.
This work is jointly sponsored by Gunderson Inc., a Portland, Ore., firm, and the Oregon Metals Initiative, a collaborative effort of higher education and the Oregon metals industry. Two patents received for the coatings process are jointly held by OSU and Gunderson, Inc.
If this approach gains widespread use, it may create new jobs in fabric weaving, polymer formulation and composite manufacture, researchers say.
Some estimates suggest the new system could save up to $100,000 per railroad car over its 20-year useful lifetime.
And approaches such as this - using polymer, fibers and composite manufacturing in lieu of metals - may also have future applications in other transportation, machinery, sporting goods and construction products, the scientists say.