December 19, 2005 | General

Thin Wood Cuts Pay Off

BioCycle December 2005, Vol. 46, No. 12, p. 37
Company demonstrates an approach for the forest products industry that generates more lumber from pine beetle killed logs while reducing greenhouse gas emissions.
Jack Petree

HUNDREDS OF THOUSANDS of acres of forest have been decimated by bark beetle infestations in recent years. As a result, these dead and dying trees have played a significant role in fueling the devastating wild fires in Southern California. Many persons believe removal is critical to enhance forest health. Immense quantities of wood fiber are being removed from backyards, shopping centers and forests as governments and individuals struggle to cope with tree deaths caused by the beetle. There is little disagreement that fiber from trees eventually removed to fight beetle infestation should be utilized to its highest and best purpose.
In Chino, California – only 30 miles away from the most intense fire zones – one innovative company, Woodwurx Corporation, has learned to utilize advanced approaches to sawmilling to profitably produce lumber from pine beetle killed logs. According to owner Bill Oerding, the company is helping to reduce greenhouse gas emission to the atmosphere by sequestering carbon that would have otherwise been released through the rotting or burning process. Adding importance to Woodwurx’s initiative, the company is demonstrating that an approach can be utilized throughout the forest products industry to achieve higher yield and, as a result, reduce the number of acres harvested in healthy forests each year to supply the world’s demand for lumber. Utilizing beetle killed trees for their highest and best use is economically challenging because of the fiber itself. It is the nature of beetle killed trees that some of the logs are discolored and, the length of time a stem may stand, dead and disintegrating before removal, can have impacts, perceived and real, on the quality of the products that can be made from the trees.
However, while often marginal as a reliable resource for manufacture of higher end products, beetle killed pine is structurally sound and perfectly suitable for making lumber to be turned into pallets. Any effort to utilize large quantities of fiber to produce pallet material must overcome the economic challenge inherent in handling the material to provide an adequate return on investment.
Bill Oerding’s “secret” is the combining of a tightly managed production flow in his sawmill coupled with the use of very thin kerf blade technology of a kind not truly available in a production mill setting until quite recently.
Kerf is the thickness of the cut made when a saw blade slices through wood, or any other material. A thick kerf means more log goes into sawdust and less goes into lumber. More lumber produced when a log is milled means more carbon is sequestered in the lumber, and fewer trees are needed to produce a set amount of lumber.
The environmental advantages of thin kerf sawmilling are substantial and demonstrable. One Forest Service researcher, Stephen Bratkovich of the Northeastern Area State and Private Forestry Division has reported that typical sawmills in the United States operate at about 50 percent efficiency in terms of lumber recovery. A study in a pallet lumber mill in Missouri, Bratkovich continues, demonstrated almost 70 percent efficiency for a thin kerf mill with a .050″ blade cutting thin lumber. “The U.S. annual cut of timber for lumber products is equivalent to approximately 240 million trees,” Bratkovich writes. “We could save the equivalent of 69 million trees annually if our recovery efficiency improved from 50 percent to 70 percent in our primary processing.” Those trees, according to Bratkovich, would continue to absorb about 900,000 tons of carbon dioxide and produce about 650,000 tons of oxygen each year.
The economic advantages of thin kerf sawmilling to a lumber manufacturer are equally striking. Very thin kerf technology, in improving efficiency from 50 percent to 70 percent, delivers as much as 140 percent more lumber out of a log than some traditional sawmills are able to generate. That extra lumber, in addition to its environmental importance, allows profitability where profitability might otherwise be problematic.
At the Woodwurx plant, beetle impacted pine is delivered by harvesters contracted by California and other entities to remove the fiber from the forest. Logs are inspected for potential grade then cut to appropriate lengths and forwarded to the break down system. According to Oerding, “About 10 percent of the wood can be used for making higher grade products, but most of it is best used for pallet stock.”
Woodwurx’s breakdown system is a AWMV/Wood-Mizer Products thin kerf sawmill system consisting of a primary break down saw, a six head resaw system (seven boards can be produced at one pass) and a twin blade edger. The blades used on most of the equipment in the mill produce a cut (kerf) that is only one-tenth of an inch thick. While kerfs in that range have long been available on smaller sawmills, the thin blade technology necessary to operate a production mill like Woodwurx Corporation runs has only recently become available.
Logs are initially processed through an LT300 headrig (main breakdown saw) utilized to produce a steady stream of logs cut into a variety of slabs, blocks (cants) or lumber pieces sized to most efficiently process through downstream equipment. From the headrig, material moves on to a twin blade edger used to cut the boards down to widths required by the customer then on to a trimmer which cuts the lumber to appropriate lengths.
Last, the fiber is processed through a multihead resaw system with each blade prepositioned to produce lumber of the proper thickness. Large cants or small cants, slabs, or other pieces of lumber can be run through in mixed runs. A slab only large enough to produce two boards is cut in half, while larger cants able to produce as many as seven boards make use of all six blades available for slicing the wood. About 30,000 board feet of lumber are produced each day at Woodwurx. That amounts to more than 8.5 million board feet per year, all out of dead or nearly dead trees.
Waste at the edger, the trimmer and the resaw, is reduced to absolute minimums because close attention is paid to the sizing of the fiber run through those machines when the log is originally blocked out on the LT 300 headrig. Still, significant quantities of sawdust, small slabs with bark still attached, and pieces of wood are produced. That fiber, according to Oerding, is the resource a nearby firm, Recycled Wood Products, utilizes to produce mulch and other soil amendments. “Every single thing coming off our saw with any structural value at all is recovered and made into a product,” he declares. “Everything else is ground and used to create other products. Nothing goes to waste around here.”
While being every inch a business professional, Bill Oerding takes great pleasure in the environmental benefits he brings to the community as he goes about his work. “I feel good about this because when we first started up most of this fiber was just being ground up or landfilled,” he comments. “We’ve taken a problem and turned it into an opportunity. We’re creating jobs, making a good product at a good price, and we’re practicing waste avoidance. I think we’re serving the public well.”
Waste avoidance is at the top of the hierarchy of values sought by recycling advocates. At Woodwurx Corporation, more than 8 million board feet of production per year using the most advanced thin kerf technology available results in reduced forest harvest in healthy forests, immense quantities of carbon sequestered in long lived, and recyclable, products and improved forest health in ecosystems severely impacted by the western pine beetle.
FOR thousands of years, storms and floods have washed trees down to the Columbia River in Oregon. Over time, a whole forest’s worth of lumber has sunk to the river’s bottom. With the coming of settlement, thousands of logs harvested upriver, then rafted downstream, also sank and added to the unseen forest.
Today, Ross Bennett and his partners in Underwater Timber Salvage Corporation (UTSC) based in St. Helens, Oregon are working to complete the voyage those logs began. Utilizing state-of-the-art equipment, the company locates, recovers and processes the sunken “stems” then – using advanced, thin kerf, sawmill technology – converts them into unique and coveted specialty lumber products.
UTSC was founded in 1996 when Bennett purchased a 1950 vintage tug boat because, he says, “I simply loved the water and it was a good deal.”
In the course of operating his tug, Bennett heard stories about dangerous encounters between boats and submerged logs. His interest piqued, Bennett inquired of a physicist about the percentage of logs once transported on the river that may have sunk rather than reaching their intended destination. An estimate of five to seven percent surprised him but it turned out to be an estimate affirmed by old tug boat captains who had worked the river in the days of the log raft.
Interested, Bennett began “looking at the river bottom” employing sonar, revealing a river bed saturated with logs. He began to wonder, “Are they good for anything?” To find out, some sample logs were recovered and milled. The results, he says, were astounding. The logs were nearly as sound today as they were the day they sank years, or even centuries, ago.
Excited, Bennett decided to do something about his discovery. After much patient effort working with the Corps of Engineers, state departments of Fish and Wildlife, and the National Oceanic and Atmospheric Administration, UTSC was issued, in 2003, a permit to salvage logs in the Columbia River between the Canadian border and the river’s mouth.
To harvest logs, UTSC locates “stems” on the river bottom using a “side view-top sonar” equipped research vessel. Sections of the river are systematically mapped and the location of each log is electronically recorded with Global Positioning System coordinates. “Mapping logs,” he comments, “is a Herculean task and we have just begun to scratch the surface.”
All logs are removed from the river bottom, not just those with possibly high value. Species include Douglas Fir, Western Hemlock, Big Leaf Maple and Ponderosa Pine.
Once ashore, logs are cut to length, pressure washed and decked. Fresh cuts on log ends are treated with stain inhibitor to prevent “air exposure discoloration.”
To process its logs, UTSC selected an AWMV/Wood-Mizer LT300 very thin kerf sawmilling system for many of the same, environmentally sound reasons Woodwurx Corporation (see associated story) did. UTSC’s milling process is similar to the Woodwurx process as well although UTSC is more oriented to custom milling. “The logs in the river are often colored by minerals so the lumber in varying shades of grey, green and blue are coveted by customers who want a unique effect,” explains Bennett. Thin kerf sawmilling provides greater yield in very high value woods.
Boards are separated by color and species then sold in lots. One builder buys colored lumber for custom homes which include flooring, trim and cabinets, all with the same hue. Lumber from unique logs is also kept together, then sold as a unit for custom projects.
UTSC is completing the harvest of timber that, in some cases, began over 100 years ago. In the process, the company makes the river safer – lessening chances of toxic spill producing collisions between watercraft and logs. Further environmental benefit comes as the logs removed from the water are milled to produce valued products that, at once, sequester carbon for decades to come and, reduce harvest in still growing forests.

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