New pole requires lesslumber than model in use

by Bei Hu

In the eyes of Robert Erickson, professor emeritus at the College of Natural Resources, conservation isn’t just a good idea for the environment; it can make money, too.
Erickson retired from his position as a professor of wood physics and wood moisture relations in 1994, but still maintains an office in Kaufert Laboratory. He has been working since 1991 on the development of a new type of utility pole called hollow veneered pole.
Unlike conventional solid wood poles, the new pole is hollow in the middle and built by gluing and finger-jointing narrow strips of wood, then wrapping them with layers of veneer. “The idea is to create the same kind of integrity that the standing tree has out in the forests without the non-essential wood,” Erickson said.
The new design reduces the weight of the pole by half, while retaining 95 percent of the bending strength of a solid wood pole. More importantly, it uses about half the amount of lumber needed for producing a conventional wood pole. Wooden poles still command the greatest share of the pole market, but steel and fiberglass poles are also produced.
Erickson is also considering using waste wood as a possible raw material in producing the hollow veneered pole. He said the manufactured housing industry generates a considerable quantity of lumber, which is usually wasted or used as firewood. Leftover wood from housing could be used for the hollow veneered pole, he said, which means the veneer wood would be the only wood in the pole that would have to come directly from the forests.
Aside from conservation benefits, Erickson said he expects the hollow veneered pole to be priced at half or one-third that of a fiberglass pole and to compete price-wise with steel or conventional wood poles.
Decay poses a big threat to conventional wood poles, Erickson said. The drying process is still incomplete when the pole is put in service, leading to cracks in the wood. This hastens the onset of decay, which begins at the ground line and eventually eats away the wood at the heart of the lumber.
While wood preservatives are used to alleviate the problem, Erickson said they only penetrate the outer part of the pole, allowing the inside to rot. “My reasoning is, if you end up with a hollow pole, why not start with one?” Erickson said. With the hollow structure of his new design, the anti-decay solution can be pressured into the pole from both inside and out.
Meanwhile, Erickson is considering inserting a layer of synthetic fiber strong enough to resist the damages done by woodpeckers, which often constitutes a serious threat to unattended wood poles in out-of-the-way areas.
Erickson was a professor in the Department of Forest Products for 28 years. He said he came upon his idea after reviewing energy conservation proposals for the Washington-based Office of Energy-Related Inventions, a subsidiary of the Department of Energy. In the past two years, his project has received funding from Northern States Power Co. and the Alternative Agricultural Research and Commercialization Center of the U.S. Department of Agriculture.
The University recently granted exclusive licensing rights of the product to PoleTech, Inc., with which Erickson is working to commercialize the design. PoleTech wishes to “pick up a special niche in the utility pole business,” he said.