Some People Did Know Everything

Article by Rich Donnell, Editor-in-Chief, Timber Processing, August 2016 

As this issue’s article on the Swanson Group upgrade of its sawmill in Roseburg, Ore. makes quick mention of, there’s a lot of history at that site, which was the Sun Studs operation prior to its purchase by Swanson in 2001. Some rather testy lawsuits evolved from there in the 1980s over patent infringements, breach of contract and misappropriation of trade secrets.

Some of the technology at question was a method and apparatus for processing logs to obtain an optimum amount of wood products of predetermined quality from each log, including the steps of positioning each log along a reference axis, electronically scanning the log to determine its dimensions with respect to the reference axis, computing the center axis of the largest surface of a preselected shape that could be superimposed within the measured dimensions, and repositioning the log with the center axis parallel to an index line such as the cutting line of a predetermined processing equipment.

Okay, so I found the patent, as filed in 1970 and granted in 1974 to inventors Howard Mason and Fred Sohn, the latter of which was the owner of Sun Studs. Actually the technology was applicable in both the plywood mill and the stud mill that Sun Studs operated. Interestingly, the machinery that Swanson Group started up this year as depicted in our article has some resemblance of that earlier technology.

I started writing about this industry in late 1983, and that’s when such groundbreaking technology was coming on like gangbusters. Of course what drove it for the most part was the decrease in average log diameter, and the reduction in available timber supply on federal lands. Getting the most from the least became modus operandi in sawmills forevermore.

Mason’s inventions certainly left an impression, and so did the work of David Lewis and Hiram Hallock, both with the USDA Forest Service. About the same time as Mason’s work, Hallock was conceiving the idea of best opening face and both men jointly developed it through computer sawing simulation programs.

Their definition of BOF: “The BOF program finds the sawline placement resulting in the maximum yield for any specific log when sawn by a given set of actual or hypothetical sawing conditions. Thus, by specifying all of the sawing conditions and using the BOF program on a given range of log diameters, lengths and tapers, the best breakdown pattern can be determined for each situation.”

In one of their papers in 1976, Lewis and Hallock listed the eight breakdown patterns: live split-taper; live full-taper; cant split-taper-split-taper; cant full-taper-split-taper; cant split-taper-full-taper fixed fence; cant full-taper-full-taper fixed fence; cant split-taper-full-taper variable fence; and cant full-taper-full-taper variable fence. They made it easy for the rest of us.